Software Engineering (SE) is the application of a systematic, disciplined, quantifiable approach to the development, operation, and maintenance of software, and the study of these approaches; that is, the application of engineering to software.It is the application of Engineering to software because it integrates significant mathematics, computer science and practices whose origins are in Engineering. It is also defined as a systematic approach to the analysis, design, assessment, implementation, test, maintenance and reengineering of software, that is, the application of engineering to software. The term software engineering first appeared in the 1968 NATO Software Engineering Conference, and was meant to provoke thought regarding the perceived "software crisis" at the time.
Software development, a much used and more generic term, does not necessarily subsume the engineering paradigm. Although it is questionable what impact it has had on actual software development over the last more than 40 years, the field's future looks bright according to Money Magazine and Salary.com, which rated "software engineer" as the best job in the United States in 2006
Friday, 2 December 2011
Visual Basic (VB)
Visual Basic (VB) is the third-generation event-driven programming language and integrated development environment (IDE) from Microsoft for its COM programming model. Visual Basic is designed to be relatively easy to learn and use.[1][2]
Visual Basic was derived from BASIC and enables the rapid application development (RAD) of graphical user interface (GUI) applications, access to databases using Data Access Objects, Remote Data Objects, or ActiveX Data Objects, and creation of ActiveX controls and objects. Scripting languages such as VBA and VBScript are syntactically similar to Visual Basic, but perform differently.[3]
A programmer can put together an application using the components provided with Visual Basic itself. Programs written in Visual Basic can also use the Windows API, but doing so requires external function declarations.
The final release was version 6 in 1998. Microsoft's extended support ended in March 2008 and the designated successor was Visual Basic .NET (now known simply as Visual Basic).
Visual Basic was derived from BASIC and enables the rapid application development (RAD) of graphical user interface (GUI) applications, access to databases using Data Access Objects, Remote Data Objects, or ActiveX Data Objects, and creation of ActiveX controls and objects. Scripting languages such as VBA and VBScript are syntactically similar to Visual Basic, but perform differently.[3]
A programmer can put together an application using the components provided with Visual Basic itself. Programs written in Visual Basic can also use the Windows API, but doing so requires external function declarations.
The final release was version 6 in 1998. Microsoft's extended support ended in March 2008 and the designated successor was Visual Basic .NET (now known simply as Visual Basic).
Characteristics Of Visual Basic (VB)
Visual Basic has the following traits which differ from C-derived languages:
Multiple assignment available in C language is not possible. A = B = C does not imply that the values of A, B and C are equal. The boolean result of "Is B = C?" is stored in A. The result stored in A would therefore be either false or true.
Boolean constant True has numeric value −1.[4] This is because the Boolean data type is stored as a 16-bit signed integer. In this construct −1 evaluates to 16 binary 1s (the Boolean value True), and 0 as 16 0s (the Boolean value False). This is apparent when performing a Not operation on a 16 bit signed integer value 0 which will return the integer value −1, in other words True = Not False. This inherent functionality becomes especially useful when performing logical operations on the individual bits of an integer such as And, Or, Xor and Not.[5] This definition of True is also consistent with BASIC since the early 1970s Microsoft BASIC implementation and is also related to the characteristics of CPU instructions at the time.
Logical and bitwise operators are unified. This is unlike some C-derived languages (such as Perl), which have separate logical and bitwise operators. This again is a traditional feature of BASIC.
Variable array base. Arrays are declared by specifying the upper and lower bounds in a way similar to Pascal and Fortran. It is also possible to use the Option Base statement to set the default lower bound. Use of the Option Base statement can lead to confusion when reading Visual Basic code and is best avoided by always explicitly specifying the lower bound of the array. This lower bound is not limited to 0 or 1, because it can also be set by declaration. In this way, both the lower and upper bounds are programmable. In more subscript-limited languages, the lower bound of the array is not variable. This uncommon trait does exist in Visual Basic .NET but not in VBScript.
OPTION BASE was introduced by ANSI, with the standard for ANSI Minimal BASIC in the late 1970s.
Relatively strong integration with the Windows operating system and the Component Object Model. The native types for strings and arrays are the dedicated COM types, BSTR and SAFEARRAY.
Banker's rounding as the default behavior when converting real numbers to integers with the Round function.[6] ? Round(2.5, 0) gives 2, ? Round(3.5, 0) gives 4.
Integers are automatically promoted to reals in expressions involving the normal division operator (/) so that division of one integer by another produces the intuitively correct result. There is a specific integer divide operator (\) which does truncate.
By default, if a variable has not been declared or if no type declaration character is specified, the variable is of type Variant. However this can be changed with Deftype statements such as DefInt, DefBool, DefVar, DefObj, DefStr. There are 12 Deftype statements in total offered by Visual Basic 6.0. The default type may be overridden for a specific declaration by using a special suffix character on the variable name (# for Double, ! for Single, & for Long, % for Integer, $ for String, and @ for Currency) or using the key phrase As (type). VB can also be set in a mode that only explicitly declared variables can be used with the command Option Explicit.
Multiple assignment available in C language is not possible. A = B = C does not imply that the values of A, B and C are equal. The boolean result of "Is B = C?" is stored in A. The result stored in A would therefore be either false or true.
Boolean constant True has numeric value −1.[4] This is because the Boolean data type is stored as a 16-bit signed integer. In this construct −1 evaluates to 16 binary 1s (the Boolean value True), and 0 as 16 0s (the Boolean value False). This is apparent when performing a Not operation on a 16 bit signed integer value 0 which will return the integer value −1, in other words True = Not False. This inherent functionality becomes especially useful when performing logical operations on the individual bits of an integer such as And, Or, Xor and Not.[5] This definition of True is also consistent with BASIC since the early 1970s Microsoft BASIC implementation and is also related to the characteristics of CPU instructions at the time.
Logical and bitwise operators are unified. This is unlike some C-derived languages (such as Perl), which have separate logical and bitwise operators. This again is a traditional feature of BASIC.
Variable array base. Arrays are declared by specifying the upper and lower bounds in a way similar to Pascal and Fortran. It is also possible to use the Option Base statement to set the default lower bound. Use of the Option Base statement can lead to confusion when reading Visual Basic code and is best avoided by always explicitly specifying the lower bound of the array. This lower bound is not limited to 0 or 1, because it can also be set by declaration. In this way, both the lower and upper bounds are programmable. In more subscript-limited languages, the lower bound of the array is not variable. This uncommon trait does exist in Visual Basic .NET but not in VBScript.
OPTION BASE was introduced by ANSI, with the standard for ANSI Minimal BASIC in the late 1970s.
Relatively strong integration with the Windows operating system and the Component Object Model. The native types for strings and arrays are the dedicated COM types, BSTR and SAFEARRAY.
Banker's rounding as the default behavior when converting real numbers to integers with the Round function.[6] ? Round(2.5, 0) gives 2, ? Round(3.5, 0) gives 4.
Integers are automatically promoted to reals in expressions involving the normal division operator (/) so that division of one integer by another produces the intuitively correct result. There is a specific integer divide operator (\) which does truncate.
By default, if a variable has not been declared or if no type declaration character is specified, the variable is of type Variant. However this can be changed with Deftype statements such as DefInt, DefBool, DefVar, DefObj, DefStr. There are 12 Deftype statements in total offered by Visual Basic 6.0. The default type may be overridden for a specific declaration by using a special suffix character on the variable name (# for Double, ! for Single, & for Long, % for Integer, $ for String, and @ for Currency) or using the key phrase As (type). VB can also be set in a mode that only explicitly declared variables can be used with the command Option Explicit.
Database storage
Main article: Computer data storage
Database storage is the container of the physical materialization of a database. It comprises the Internal (physical) level in the database architecture. It also contains all the information needed (e.g., metadata, "data about the data", and internal data structures) to reconstruct the Conceptual level and External level from the Internal level when needed. It is not part of the DBMS but rather manipulated by the DBMS (by its Storage engine; see above) to manage the database that resides in it. Though typically accessed by a DBMS through the underlying Operating system (and often utilizing the operating systems' File systems as intermediates for storage layout), storage properties and configuration setting are extremely important for the efficient operation of the DBMS, and thus are closely maintained by database administrators. A DBMS, while in operation, always has its database residing in several types of storage (e.g., memory and external storage). The database data and the additional needed information, possibly in very large amounts, are coded into bits. Data typically reside in the storage in structures that look completely different from the way the data look in the conceptual and external levels, but in ways that attempt to optimize (the best possible) these levels' reconstruction when needed by users and programs, as well as for computing additional types of needed information from the data (e.g., when querying the database).
In principle the database storage can be viewed as a linear address space, where every bit of data has its unique address in this address space. Practically only a very small percentage of addresses is kept as initial reference points (which also requires storage), and most of the database data is accessed by indirection using displacement calculations (distance in bits from the reference points) and data structures which define access paths (using pointers) to all needed data in effective manner, optimized for the needed data access operations.
Database storage is the container of the physical materialization of a database. It comprises the Internal (physical) level in the database architecture. It also contains all the information needed (e.g., metadata, "data about the data", and internal data structures) to reconstruct the Conceptual level and External level from the Internal level when needed. It is not part of the DBMS but rather manipulated by the DBMS (by its Storage engine; see above) to manage the database that resides in it. Though typically accessed by a DBMS through the underlying Operating system (and often utilizing the operating systems' File systems as intermediates for storage layout), storage properties and configuration setting are extremely important for the efficient operation of the DBMS, and thus are closely maintained by database administrators. A DBMS, while in operation, always has its database residing in several types of storage (e.g., memory and external storage). The database data and the additional needed information, possibly in very large amounts, are coded into bits. Data typically reside in the storage in structures that look completely different from the way the data look in the conceptual and external levels, but in ways that attempt to optimize (the best possible) these levels' reconstruction when needed by users and programs, as well as for computing additional types of needed information from the data (e.g., when querying the database).
In principle the database storage can be viewed as a linear address space, where every bit of data has its unique address in this address space. Practically only a very small percentage of addresses is kept as initial reference points (which also requires storage), and most of the database data is accessed by indirection using displacement calculations (distance in bits from the reference points) and data structures which define access paths (using pointers) to all needed data in effective manner, optimized for the needed data access operations.
Database security
Main article: Database security
Database security deals with all various aspects of protecting the database content, its owners, and its users. It ranges from protection from intentional unauthorized database uses to unintentional database accesses by unauthorized entities (e.g., a person or a computer program).
The following are major areas of database security (among many others).
Access control
Main article: Access control
Database access control deals with controlling who (a person or a certain computer program) is allowed to access what information in the database. The information may comprise specific database objects (e.g., record types, specific records, data structures), certain computations over certain objects (e.g., query types, or specific queries), or utilizing specific access paths to the former (e.g., using specific indexes or other data structures to access information).
Database access controls are set by special authorized (by the database owner) personnel that uses dedicated protected security DBMS interfaces.
Data security
Main articles: Data security and Encryption
The definition of data security varies and may overlap with other database security aspects. Broadly it deals with protecting specific chunks of data, both physically (i.e., from corruption, or destruction, or removal; e.g., see Physical security), or the interpretation of them, or parts of them to meaningful information (e.g., by looking at the strings of bits that they comprise, concluding specific valid credit-card numbers; e.g., see Data encryption).
Database audit
Main article: Database audit
Database audit primarily involves monitoring that no security breach, in all aspects, has happened. If security breach is discovered then all possible corrective actions are taken.
Database design
Main article: Database design
Database design is done before building it to meet needs of end-users within a given application/information-system that the database is intended to support. The database design defines the needed data and data structures that such a database comprises. A design is typically carried out according to the common three architectural levels of a database (see Database architecture above). First, the conceptual level is designed, which defines the over-all picture/view of the database, and reflects all the real-world elements (entities) the database intends to model, as well as the relationships among them. On top of it the external level, various views of the database, are designed according to (possibly completely different) needs of specific end-user types. More external views can be added later. External views requirements may modify the design of the conceptual level (i.e., add/remove entities and relationships), but usually a well designed conceptual level for an application well supports most of the needed external views. The conceptual view also determines the internal level (which primarily deals with data layout in storage) to a great extent. External views requirement may add supporting storage structures, like materialized views and indexes, for enhanced performance. Typically the internal layer is optimized for top performance, in an average way that takes into account performance requirements (possibly conflicting) of different external views according to their relative importance. While the conceptual and external levels design can usually be done independently of any DBMS (DBMS-independent design software packages exist, possibly with interfaces to some specific popular DBMSs), the internal level design highly relies on the capabilities and internal data structure of the specific DBMS utilized (see the Implementation section below).
A common way to carry out conceptual level design is to use the Entity-relationship model (ERM) (both the basic one, and with possible enhancement that it has gone over), since it provides a straightforward, intuitive perception of an application's elements and semantics. An alternative approach, which preceded the ERM, is using the Relational model and dependencies (mathematical relationships) among data to normalize the database, i.e., to define the ("optimal") relations (data record or tupple types) in the database. Though a large body of research exists for this method it is more complex, less intuitive, and not more effective than the ERM method. Thus normalization is less utilized in practice than the ERM method.
The ERM may be less subtle than normalization in several aspects, but it captures the main needed dependencies which are induced by keys/identifiers of entities and relationships. Also the ERM inherently includes the important inclusion dependencies (i.e., an entity instance that does not exist (has not been explicitly inserted) cannot appear in a relationship with other entities) which usually have been ignored in normalization.[13] In addition the ERM allows entity type generalization (the Is-a relationship) and implied property (attribute) inheritance (similarly to the that found in the Object model).
Another aspect of database design is its security. It involves both defining access control to database objects (e.g., Entities, Views) as well as defining security levels and methods for the data itself (See Database security above).
Database security deals with all various aspects of protecting the database content, its owners, and its users. It ranges from protection from intentional unauthorized database uses to unintentional database accesses by unauthorized entities (e.g., a person or a computer program).
The following are major areas of database security (among many others).
Access control
Main article: Access control
Database access control deals with controlling who (a person or a certain computer program) is allowed to access what information in the database. The information may comprise specific database objects (e.g., record types, specific records, data structures), certain computations over certain objects (e.g., query types, or specific queries), or utilizing specific access paths to the former (e.g., using specific indexes or other data structures to access information).
Database access controls are set by special authorized (by the database owner) personnel that uses dedicated protected security DBMS interfaces.
Data security
Main articles: Data security and Encryption
The definition of data security varies and may overlap with other database security aspects. Broadly it deals with protecting specific chunks of data, both physically (i.e., from corruption, or destruction, or removal; e.g., see Physical security), or the interpretation of them, or parts of them to meaningful information (e.g., by looking at the strings of bits that they comprise, concluding specific valid credit-card numbers; e.g., see Data encryption).
Database audit
Main article: Database audit
Database audit primarily involves monitoring that no security breach, in all aspects, has happened. If security breach is discovered then all possible corrective actions are taken.
Database design
Main article: Database design
Database design is done before building it to meet needs of end-users within a given application/information-system that the database is intended to support. The database design defines the needed data and data structures that such a database comprises. A design is typically carried out according to the common three architectural levels of a database (see Database architecture above). First, the conceptual level is designed, which defines the over-all picture/view of the database, and reflects all the real-world elements (entities) the database intends to model, as well as the relationships among them. On top of it the external level, various views of the database, are designed according to (possibly completely different) needs of specific end-user types. More external views can be added later. External views requirements may modify the design of the conceptual level (i.e., add/remove entities and relationships), but usually a well designed conceptual level for an application well supports most of the needed external views. The conceptual view also determines the internal level (which primarily deals with data layout in storage) to a great extent. External views requirement may add supporting storage structures, like materialized views and indexes, for enhanced performance. Typically the internal layer is optimized for top performance, in an average way that takes into account performance requirements (possibly conflicting) of different external views according to their relative importance. While the conceptual and external levels design can usually be done independently of any DBMS (DBMS-independent design software packages exist, possibly with interfaces to some specific popular DBMSs), the internal level design highly relies on the capabilities and internal data structure of the specific DBMS utilized (see the Implementation section below).
A common way to carry out conceptual level design is to use the Entity-relationship model (ERM) (both the basic one, and with possible enhancement that it has gone over), since it provides a straightforward, intuitive perception of an application's elements and semantics. An alternative approach, which preceded the ERM, is using the Relational model and dependencies (mathematical relationships) among data to normalize the database, i.e., to define the ("optimal") relations (data record or tupple types) in the database. Though a large body of research exists for this method it is more complex, less intuitive, and not more effective than the ERM method. Thus normalization is less utilized in practice than the ERM method.
The ERM may be less subtle than normalization in several aspects, but it captures the main needed dependencies which are induced by keys/identifiers of entities and relationships. Also the ERM inherently includes the important inclusion dependencies (i.e., an entity instance that does not exist (has not been explicitly inserted) cannot appear in a relationship with other entities) which usually have been ignored in normalization.[13] In addition the ERM allows entity type generalization (the Is-a relationship) and implied property (attribute) inheritance (similarly to the that found in the Object model).
Another aspect of database design is its security. It involves both defining access control to database objects (e.g., Entities, Views) as well as defining security levels and methods for the data itself (See Database security above).
Database languages
Main articles: Data definition language, Data manipulation language, and Query language
Database languages are dedicated programming languages, tailored and utilized to
define a database (i.e., its specific data types and the relationships among them),
manipulate its content (e.g., insert new data occurrences, and update or delete existing ones), and
query it (i.e., request information: compute and retrieve any information based on its data).
Database languages are data-model-specific, i.e., each language assumes and is based on a certain structure of the data (which typically differs among different data models). They typically have commands to instruct execution of the desired operations in the database. Each such command is equivalent to a complex expression (program) in a regular programming language, and thus programming in dedicated (database) languages simplifies the task of handling databases considerably. An expressions in a database language is automatically transformed (by a compiler or interpreter, as regular programming languages) to a proper computer program that runs while accessing the database and providing the needed results. The following are notable examples:
SQL for the Relational model
Main article: SQL
A major Relational model language supported by all the relational DBMSs and a standard.
SQL was one of the first commercial languages for the relational model. Despite not adhering to the relational model as described by Codd, it has become the most widely used database language.[10][11] Though often described as, and to a great extent is a declarative language, SQL also includes procedural elements. SQL became a standard of the American National Standards Institute (ANSI) in 1986, and of the International Organization for Standards (ISO) in 1987. Since then the standard has been enhanced several times with added features. However, issues of SQL code portability between major RDBMS products still exist due to lack of full compliance with, or different interpretations of the standard. Among the reasons mentioned are the large size, and incomplete specification of the standard, as well as vendor lock-in.
OQL for the Object model
Main article: OQL
An Object model language standard (by the Object Data Management Group) that has influenced the design of some of the newer query languages like JDOQL and EJB QL, though they cannot be considered as different flavors of OQL.
XQuery for the XML model
Main articles: XQuery and XML
XQuery is an XML based database language (also named XQL).
Database architecture
Database architecture (to be distinguished from DBMS architecture; see below) may be viewed, to some extent, as an extension of Data modeling. It is used to conveniently answer requirements of different end-users from a same database, as well as for other benefits. For example, a financial department of a company needs the payment details of all employees as part of the company's expenses, but not other many details about employees, that are the interest of the human resources department. Thus different departments need different views of the company's database, that both include the employees' payments, possibly in a different level of detail (and presented in different visual forms). To meet such requirement effectively database architecture consists of three levels: external, conceptual and internal. Clearly separating the three levels was a major feature of the relational database model implementations that dominate 21st century databases.[12]
The external level defines how each end-user type understands the organization of its respective relevant data in the database, i.e., the different needed end-user views. A single database can have any number of views at the external level.
The conceptual level unifies the various external views into a coherent whole, global view.[12] It provides the common-denominator of all the external views. It comprises all the end-user needed generic data, i.e., all the data from which any view may be derived/computed. It is provided in the simplest possible way of such generic data, and comprises the back-bone of the database. It is out of the scope of the various database end-users, and serves database application developers and defined by database administrators that build the database.
The Internal level (or Physical level) is as a matter of fact part of the database implementation inside a DBMS (see Implementation section below). It is concerned with cost, performance, scalability and other operational matters. It deals with storage layout of the conceptual level, provides supporting storage-structures like indexes, to enhance performance, and occasionally stores data of individual views (materialized views), computed from generic data, if performance justification exists for such redundancy. It balances all the external views' performance requirements, possibly conflicting, in attempt to optimize the overall database usage by all its end-uses according to the database goals and priorities.
All the three levels are maintained and updated according to changing needs by database administrators who often also participate in the database design.
The above three-level database architecture also relates to and being motivated by the concept of data independence which has been described for long time as a desired database property and was one of the major initial driving forces of the Relational model. In the context of the above architecture it means that changes made at a certain level do not affect definitions and software developed with higher level interfaces, and are being incorporated at the higher level automatically. For example, changes in the internal level do not affect application programs written using conceptual level interfaces, which saves substantial change work that would be needed otherwise.
In summary, the conceptual is a level of indirection between internal and external. On one hand it provides a common view of the database, independent of different external view structures, and on the other hand it is uncomplicated by details of how the data is stored or managed (internal level). In principle every level, and even every external view, can be presented by a different data model. In practice usually a given DBMS uses the same data model for both the external and the conceptual levels (e.g., relational model). The internal level, which is hidden inside the DBMS and depends on its implementation (see Implementation section below), requires a different level of detail and uses its own data structure types, typically different in nature from the structures of the external and conceptual levels which are exposed to DBMS users (e.g., the data models above): While the external and conceptual levels are focused on and serve DBMS users, the concern of the internal level is effective implementation details.
Database languages are dedicated programming languages, tailored and utilized to
define a database (i.e., its specific data types and the relationships among them),
manipulate its content (e.g., insert new data occurrences, and update or delete existing ones), and
query it (i.e., request information: compute and retrieve any information based on its data).
Database languages are data-model-specific, i.e., each language assumes and is based on a certain structure of the data (which typically differs among different data models). They typically have commands to instruct execution of the desired operations in the database. Each such command is equivalent to a complex expression (program) in a regular programming language, and thus programming in dedicated (database) languages simplifies the task of handling databases considerably. An expressions in a database language is automatically transformed (by a compiler or interpreter, as regular programming languages) to a proper computer program that runs while accessing the database and providing the needed results. The following are notable examples:
SQL for the Relational model
Main article: SQL
A major Relational model language supported by all the relational DBMSs and a standard.
SQL was one of the first commercial languages for the relational model. Despite not adhering to the relational model as described by Codd, it has become the most widely used database language.[10][11] Though often described as, and to a great extent is a declarative language, SQL also includes procedural elements. SQL became a standard of the American National Standards Institute (ANSI) in 1986, and of the International Organization for Standards (ISO) in 1987. Since then the standard has been enhanced several times with added features. However, issues of SQL code portability between major RDBMS products still exist due to lack of full compliance with, or different interpretations of the standard. Among the reasons mentioned are the large size, and incomplete specification of the standard, as well as vendor lock-in.
OQL for the Object model
Main article: OQL
An Object model language standard (by the Object Data Management Group) that has influenced the design of some of the newer query languages like JDOQL and EJB QL, though they cannot be considered as different flavors of OQL.
XQuery for the XML model
Main articles: XQuery and XML
XQuery is an XML based database language (also named XQL).
Database architecture
Database architecture (to be distinguished from DBMS architecture; see below) may be viewed, to some extent, as an extension of Data modeling. It is used to conveniently answer requirements of different end-users from a same database, as well as for other benefits. For example, a financial department of a company needs the payment details of all employees as part of the company's expenses, but not other many details about employees, that are the interest of the human resources department. Thus different departments need different views of the company's database, that both include the employees' payments, possibly in a different level of detail (and presented in different visual forms). To meet such requirement effectively database architecture consists of three levels: external, conceptual and internal. Clearly separating the three levels was a major feature of the relational database model implementations that dominate 21st century databases.[12]
The external level defines how each end-user type understands the organization of its respective relevant data in the database, i.e., the different needed end-user views. A single database can have any number of views at the external level.
The conceptual level unifies the various external views into a coherent whole, global view.[12] It provides the common-denominator of all the external views. It comprises all the end-user needed generic data, i.e., all the data from which any view may be derived/computed. It is provided in the simplest possible way of such generic data, and comprises the back-bone of the database. It is out of the scope of the various database end-users, and serves database application developers and defined by database administrators that build the database.
The Internal level (or Physical level) is as a matter of fact part of the database implementation inside a DBMS (see Implementation section below). It is concerned with cost, performance, scalability and other operational matters. It deals with storage layout of the conceptual level, provides supporting storage-structures like indexes, to enhance performance, and occasionally stores data of individual views (materialized views), computed from generic data, if performance justification exists for such redundancy. It balances all the external views' performance requirements, possibly conflicting, in attempt to optimize the overall database usage by all its end-uses according to the database goals and priorities.
All the three levels are maintained and updated according to changing needs by database administrators who often also participate in the database design.
The above three-level database architecture also relates to and being motivated by the concept of data independence which has been described for long time as a desired database property and was one of the major initial driving forces of the Relational model. In the context of the above architecture it means that changes made at a certain level do not affect definitions and software developed with higher level interfaces, and are being incorporated at the higher level automatically. For example, changes in the internal level do not affect application programs written using conceptual level interfaces, which saves substantial change work that would be needed otherwise.
In summary, the conceptual is a level of indirection between internal and external. On one hand it provides a common view of the database, independent of different external view structures, and on the other hand it is uncomplicated by details of how the data is stored or managed (internal level). In principle every level, and even every external view, can be presented by a different data model. In practice usually a given DBMS uses the same data model for both the external and the conceptual levels (e.g., relational model). The internal level, which is hidden inside the DBMS and depends on its implementation (see Implementation section below), requires a different level of detail and uses its own data structure types, typically different in nature from the structures of the external and conceptual levels which are exposed to DBMS users (e.g., the data models above): While the external and conceptual levels are focused on and serve DBMS users, the concern of the internal level is effective implementation details.
Database type examples
The following are examples of various database types. Some of them are not main-stream types, but most of them have received special attention (e.g., in research) due to end-user requirements. Some exist as specialized DBMS products, and some have their functionality types incorporated in existing general-purpose DBMSs.
Main article: Active database
An active database is a database that includes an event-driven architecture which can respond to conditions both inside and outside the database. Possible uses include security monitoring, alerting, statistics gathering and authorization.
Most modern relational databases include active database features in the form of database trigger.
Main article: Cloud database
A Cloud database is a database that relies on cloud technology. Both the database and most of its DBMS reside remotely, "in the cloud," while its applications are both developed by programmers and later maintained and utilized by (application's) end-users through a Web browser and Open APIs. More and more such database products are emerging, both of new vendors and by virtually all established database vendors.
Main article: Data warehouse
Data warehouses archive data from operational databases and often from external sources such as market research firms. Often operational data undergoes transformation on its way into the warehouse, getting summarized, anonymized, reclassified, etc. The warehouse becomes the central source of data for use by managers and other end-users who may not have access to operational data. For example, sales data might be aggregated to weekly totals and converted from internal product codes to use UPCs so that it can be compared with ACNielsen data. Some basic and essential components of data warehousing include retrieving, analyzing, and mining data, transforming,loading and managing data so as to make it available for further use.
Operations in a data warehouse are typically concerned with bulk data manipulation, and as such, it is unusual and inefficient to target individual rows for update, insert or delete. Bulk native loaders for input data and bulk SQL passes for aggregation are the norm.
Main article: Distributed database
The definition of a distributed database is broad, and may be utilized in different meanings. In general it typically refers to a modular DBMS architecture that allows distinct DBMS instances to cooperate as a single DBMS over processes, computers, and sites, while managing a single database distributed itself over multiple computers, and different sites.
Examples are databases of local work-groups and departments at regional offices, branch offices, manufacturing plants and other work sites. These databases can include both segments shared by multiple sites, and segments specific to one site and used only locally in that site.
Main article: Document-oriented database
Main article: Active database
An active database is a database that includes an event-driven architecture which can respond to conditions both inside and outside the database. Possible uses include security monitoring, alerting, statistics gathering and authorization.
Most modern relational databases include active database features in the form of database trigger.
Main article: Cloud database
A Cloud database is a database that relies on cloud technology. Both the database and most of its DBMS reside remotely, "in the cloud," while its applications are both developed by programmers and later maintained and utilized by (application's) end-users through a Web browser and Open APIs. More and more such database products are emerging, both of new vendors and by virtually all established database vendors.
Main article: Data warehouse
Data warehouses archive data from operational databases and often from external sources such as market research firms. Often operational data undergoes transformation on its way into the warehouse, getting summarized, anonymized, reclassified, etc. The warehouse becomes the central source of data for use by managers and other end-users who may not have access to operational data. For example, sales data might be aggregated to weekly totals and converted from internal product codes to use UPCs so that it can be compared with ACNielsen data. Some basic and essential components of data warehousing include retrieving, analyzing, and mining data, transforming,loading and managing data so as to make it available for further use.
Operations in a data warehouse are typically concerned with bulk data manipulation, and as such, it is unusual and inefficient to target individual rows for update, insert or delete. Bulk native loaders for input data and bulk SQL passes for aggregation are the norm.
Main article: Distributed database
The definition of a distributed database is broad, and may be utilized in different meanings. In general it typically refers to a modular DBMS architecture that allows distinct DBMS instances to cooperate as a single DBMS over processes, computers, and sites, while managing a single database distributed itself over multiple computers, and different sites.
Examples are databases of local work-groups and departments at regional offices, branch offices, manufacturing plants and other work sites. These databases can include both segments shared by multiple sites, and segments specific to one site and used only locally in that site.
Main article: Document-oriented database
General-purpose DBMS
A DBMS has evolved into a complex software system and its development typically requires thousands of person-years of development effort. Some general-purpose DBMSs, like Oracle, Microsoft SQL server, and IBM DB2, have been in on-going development and enhancement for thirty years or more. General-purpose DBMSs aim to satisfy as many applications as possible, which typically makes them even more complex than special-purpose databases. However, the fact that they can be used "off the shelf", as well as their amortized cost over many applications and instances, makes them an attractive alternative (Vs. one-time development) whenever they meet an application's requirements.
Though attractive in many cases, a general-purpose DBMS is not always the optimal solution: When certain applications are pervasive with many operating instances, each with many users, a general-purpose DBMS may introduce unnecessary overhead and too large "footprint" (too large amount of unnecessary, unutilized software code). Such applications usually justify dedicated development. Typical examples are email systems, though they need to possess certain DBMS properties: email systems are built in a way that optimizes email messages handling and managing, and do not need significant portions of a general-purpose DBMS functionality.
Though attractive in many cases, a general-purpose DBMS is not always the optimal solution: When certain applications are pervasive with many operating instances, each with many users, a general-purpose DBMS may introduce unnecessary overhead and too large "footprint" (too large amount of unnecessary, unutilized software code). Such applications usually justify dedicated development. Typical examples are email systems, though they need to possess certain DBMS properties: email systems are built in a way that optimizes email messages handling and managing, and do not need significant portions of a general-purpose DBMS functionality.
Database research
Database research has been an active and diverse area, with many specializations, carried out since the early days of dealing with the database concept in the 1960s. It has strong ties with database technology and DBMS products. Database research has taken place at research and development groups of companies (e.g., notably at IBM Research, who contributed technologies and ideas virtually to any DBMS existing today), research institutes, and Academia. Research has been done both through Theory and Prototypes. The interaction between research and database related product development has been very productive to the database area, and many related key concepts and technologies emerged from it. Notable are the Relational and the Entity-relationship models, the Atomic transaction concept and related Concurrency control techniques, Query languages and Query optimization methods, RAID, and more. Research has provided deep insight to virtually all aspects of databases, though not always has been pragmatic, effective (and cannot and should not always be: research is exploratory in nature, and not always leads to accepted or useful ideas). Ultimately market forces and real needs determine the selection of problem solutions and related technologies, also among those proposed by research. However, occasionally, not the best and most elegant solution wins (e.g., SQL). Along their history DBMSs and respective databases, to a great extent, have been the outcome of such research, while real product requirements and challenges triggered database research directions and sub-areas.
The database research area has several notable dedicated academic journals (e.g., ACM Transactions on Database Systems-TODS, Data and Knowledge Engineering-DKE, and more) and annual conferences (e.g., ACM SIGMOD, ACM PODS, VLDB, IEEE ICDE, and more), as well as an active and quite heterogeneous (subject-wise) research community all over the world
The database research area has several notable dedicated academic journals (e.g., ACM Transactions on Database Systems-TODS, Data and Knowledge Engineering-DKE, and more) and annual conferences (e.g., ACM SIGMOD, ACM PODS, VLDB, IEEE ICDE, and more), as well as an active and quite heterogeneous (subject-wise) research community all over the world
Evolution of database and DBMS technology
The introduction of the term database coincided with the availability of direct-access storage (disks and drums) from the mid-1960s onwards. The term represented a contrast with the tape-based systems of the past, allowing shared interactive use rather than daily batch processing.
In the earliest database systems, efficiency was perhaps the primary concern, but it was already recognized that there were other important objectives. One of the key aims was to make the data independent of the logic of application programs, so that the same data could be made available to different applications.
The first generation of database systems were navigational,[2] applications typically accessed data by following pointers from one record to another. The two main data models at this time were the hierarchical model, epitomized by IBM's IMS system, and the Codasyl model (Network model), implemented in a number of products such as IDMS.
The Relational model, first proposed in 1970 by Edgar F. Codd, departed from this tradition by insisting that applications should search for data by content, rather than by following links. This was considered necessary to allow the content of the database to evolve without constant rewriting of applications. Relational systems placed heavy demands on processing resources, and it was not until the mid 1980s that computing hardware became powerful enough to allow them to be widely deployed. By the early 1990s, however, relational systems were dominant for all large-scale data processing applications, and they remain dominant today (2011) except in niche areas. The dominant database language is the standard SQL for the Relational model, which has influenced database languages also for other data models.
Because the relational model emphasizes search rather than navigation, it does not make relationships between different entities explicit in the form of pointers, but represents them rather using primary keys and foreign keys. While this is a good basis for a query language, it is less well suited as a modeling language. For this reason a different model, the Entity-relationship model which emerged shortly later (1976), gained popularity for database design.
In the period since the 1970s database technology has kept pace with the increasing resources becoming available from the computing platform: notably the rapid increase in the capacity and speed (and reduction in price) of disk storage, and the increasing capacity of main memory. This has enabled ever larger databases and higher throughputs to be achieved.
The rigidity of the relational model, in which all data is held in tables with a fixed structure of rows and columns, has increasingly been seen as a limitation when handling information that is richer or more varied in structure than the traditional 'ledger-book' data of corporate information systems: for example, document databases, engineering databases, multimedia databases, or databases used in the molecular sciences. Various attempts have been made to address this problem, many of them gathering under banners such as post-relational or NoSQL. Two developments of note are the Object database and the XML database. The vendors of relational databases have fought off competition from these newer models by extending the capabilities of their own products to support a wider variety of data types.
In the earliest database systems, efficiency was perhaps the primary concern, but it was already recognized that there were other important objectives. One of the key aims was to make the data independent of the logic of application programs, so that the same data could be made available to different applications.
The first generation of database systems were navigational,[2] applications typically accessed data by following pointers from one record to another. The two main data models at this time were the hierarchical model, epitomized by IBM's IMS system, and the Codasyl model (Network model), implemented in a number of products such as IDMS.
The Relational model, first proposed in 1970 by Edgar F. Codd, departed from this tradition by insisting that applications should search for data by content, rather than by following links. This was considered necessary to allow the content of the database to evolve without constant rewriting of applications. Relational systems placed heavy demands on processing resources, and it was not until the mid 1980s that computing hardware became powerful enough to allow them to be widely deployed. By the early 1990s, however, relational systems were dominant for all large-scale data processing applications, and they remain dominant today (2011) except in niche areas. The dominant database language is the standard SQL for the Relational model, which has influenced database languages also for other data models.
Because the relational model emphasizes search rather than navigation, it does not make relationships between different entities explicit in the form of pointers, but represents them rather using primary keys and foreign keys. While this is a good basis for a query language, it is less well suited as a modeling language. For this reason a different model, the Entity-relationship model which emerged shortly later (1976), gained popularity for database design.
In the period since the 1970s database technology has kept pace with the increasing resources becoming available from the computing platform: notably the rapid increase in the capacity and speed (and reduction in price) of disk storage, and the increasing capacity of main memory. This has enabled ever larger databases and higher throughputs to be achieved.
The rigidity of the relational model, in which all data is held in tables with a fixed structure of rows and columns, has increasingly been seen as a limitation when handling information that is richer or more varied in structure than the traditional 'ledger-book' data of corporate information systems: for example, document databases, engineering databases, multimedia databases, or databases used in the molecular sciences. Various attempts have been made to address this problem, many of them gathering under banners such as post-relational or NoSQL. Two developments of note are the Object database and the XML database. The vendors of relational databases have fought off competition from these newer models by extending the capabilities of their own products to support a wider variety of data types.
The database concept
The database concept has evolved since the 1960s to ease increasing difficulties in designing, building, and maintaining complex information systems (typically with many concurrent end-users, and with a diverse large amount of data). It has evolved together with database management systems which enable the effective handling of databases. Though the terms database and DBMS define different entities, they are inseparable: a database's properties are determined by its supporting DBMS and vice-versa. The Oxford English dictionary cites[citation needed] a 1962 technical report as the first to use the term "data-base." With the progress in technology in the areas of processors, computer memory, computer storage. and computer networks, the sizes, capabilities, and performance of databases and their respective DBMSs have grown in orders of magnitudes. For decades it has been unlikely that a complex information system can be built effectively without a proper database supported by a DBMS. The utilization of databases is now spread to such a wide degree that virtually every technology and product relies on databases and DBMSs for its development and commercialization, or even may have such embedded in it. Also, organizations and companies, from small to large, heavily depend on databases for their operations.
No widely accepted exact definition exists for DBMS. However, a system needs to provide considerable functionality to qualify as a DBMS. Accordingly its supported data collection needs to meet respective usability requirements (broadly defined by the requirements below) to qualify as a database. Thus, a database and its supporting DBMS are defined here by a set of general requirements listed below. Virtually all existing mature DBMS products meet these requirements to a great extent, while less mature either meet them or converge to meet them.
No widely accepted exact definition exists for DBMS. However, a system needs to provide considerable functionality to qualify as a DBMS. Accordingly its supported data collection needs to meet respective usability requirements (broadly defined by the requirements below) to qualify as a database. Thus, a database and its supporting DBMS are defined here by a set of general requirements listed below. Virtually all existing mature DBMS products meet these requirements to a great extent, while less mature either meet them or converge to meet them.
Database
A database is an organized collection of data for one or more purposes, usually in digital form. The data are typically organized to model relevant aspects of reality (for example, the availability of rooms in hotels), in a way that supports processes requiring this information (for example, finding a hotel with vacancies). This definition is very general, and is independent of the technology used.
The term "database" may be narrowed to specify particular aspects of organized collection of data and may refer to the logical database, to physical database as data content in computer data storage or to many other database sub-definitions.
The term database is correctly applied to the data and their supporting data structures, and not to the database management system (referred to by the acronym DBMS). The database data collection with DBMS is called a database system.
The term database system implies that the data is managed to some level of quality (measured in terms of accuracy, availability, usability, and resilience) and this in turn often implies the use of a general-purpose database management system (DBMS).[1] A general-purpose DBMS is typically a complex software system that meets many usage requirements, and the databases that it maintains are often large and complex. The utilization of databases is now spread to such a wide degree that virtually every technology and product relies on databases and DBMSs for its development and commercialization, or even may have such embedded in it. Also, organizations and companies, from small to large, heavily depend on databases for their operations.
Well known DBMSs include Oracle, IBM DB2, Microsoft SQL Server, MS Access, PostgreSQL, MySQL, Lotus Domino, and SQLite. A database is not generally portable across different DBMS, but different DBMSs can inter-operate to some degree by using standards like SQL and ODBC to support together a single application. A DBMS also needs to provide effective run-time execution to properly support (e.g., in terms of performance, availability, and security) as many end-users as needed.
The design, construction, and maintenance of a complex database requires specialist skills: the staff performing these functions are referred to as database application programmers and database administrators. Their tasks are supported by tools provided either as part of the DBMS or as stand-alone software products. These tools include specialized database languages including data definition languages (DDL), data manipulation languages (DML), and query languages. These can be seen as special-purpose programming languages, tailored specifically to manipulate databases; sometimes they are provided as extensions of existing programming languages, with added database commands. Database languages are generally specific to one data model, and in many cases they are specific to one DBMS type. The most widely supported database language is SQL, which has been developed for the relational data model and combines the roles of both DDL, DML, and a query language.
A way to classify databases involves the type of their contents, for example: bibliographic, document-text, statistical, or multimedia objects. Another way is by their application area, for example: accounting, music compositions, movies, banking, manufacturing, or insurance.
The term "database" may be narrowed to specify particular aspects of organized collection of data and may refer to the logical database, to physical database as data content in computer data storage or to many other database sub-definitions.
The term database is correctly applied to the data and their supporting data structures, and not to the database management system (referred to by the acronym DBMS). The database data collection with DBMS is called a database system.
The term database system implies that the data is managed to some level of quality (measured in terms of accuracy, availability, usability, and resilience) and this in turn often implies the use of a general-purpose database management system (DBMS).[1] A general-purpose DBMS is typically a complex software system that meets many usage requirements, and the databases that it maintains are often large and complex. The utilization of databases is now spread to such a wide degree that virtually every technology and product relies on databases and DBMSs for its development and commercialization, or even may have such embedded in it. Also, organizations and companies, from small to large, heavily depend on databases for their operations.
Well known DBMSs include Oracle, IBM DB2, Microsoft SQL Server, MS Access, PostgreSQL, MySQL, Lotus Domino, and SQLite. A database is not generally portable across different DBMS, but different DBMSs can inter-operate to some degree by using standards like SQL and ODBC to support together a single application. A DBMS also needs to provide effective run-time execution to properly support (e.g., in terms of performance, availability, and security) as many end-users as needed.
The design, construction, and maintenance of a complex database requires specialist skills: the staff performing these functions are referred to as database application programmers and database administrators. Their tasks are supported by tools provided either as part of the DBMS or as stand-alone software products. These tools include specialized database languages including data definition languages (DDL), data manipulation languages (DML), and query languages. These can be seen as special-purpose programming languages, tailored specifically to manipulate databases; sometimes they are provided as extensions of existing programming languages, with added database commands. Database languages are generally specific to one data model, and in many cases they are specific to one DBMS type. The most widely supported database language is SQL, which has been developed for the relational data model and combines the roles of both DDL, DML, and a query language.
A way to classify databases involves the type of their contents, for example: bibliographic, document-text, statistical, or multimedia objects. Another way is by their application area, for example: accounting, music compositions, movies, banking, manufacturing, or insurance.
Monday, 25 July 2011
Sunday, 24 July 2011
Digital signal processing
Digital signal processing (DSP) is concerned with the representation of discrete time signals by a sequence of numbers or symbols and the processing of these signals. Digital signal processing and analog signal processing are subfields of signal processing. DSP includes subfields like: audio and speech signal processing, sonar and radar signal processing, sensor array processing, spectral estimation, statistical signal processing, digital image processing, signal processing for communications, control of systems, biomedical signal processing, seismic data processing, etc.
The goal of DSP is usually to measure, filter and/or compress continuous real-world analog signals. The first step is usually to convert the signal from an analog to a digital form, by sampling it using an analog-to-digital converter (ADC), which turns the analog signal into a stream of numbers. However, often, the required output signal is another analog output signal, which requires a digital-to-analog converter (DAC). Even if this process is more complex than analog processing and has a discrete value range, the application of computational power to digital signal processing allows for many advantages over analog processing in many applications, such as error detection and correction in transmission as well as data compression.
DSP algorithms have long been run on standard computers, on specialized processors called digital signal processors (DSPs), or on purpose-built hardware such as application-specific integrated circuit (ASICs). Today there are additional technologies used for digital signal processing including more powerful general purpose microprocessors, field-programmable gate arrays (FPGAs), digital signal controllers (mostly for industrial apps such as motor control), and stream processors, among others.
The goal of DSP is usually to measure, filter and/or compress continuous real-world analog signals. The first step is usually to convert the signal from an analog to a digital form, by sampling it using an analog-to-digital converter (ADC), which turns the analog signal into a stream of numbers. However, often, the required output signal is another analog output signal, which requires a digital-to-analog converter (DAC). Even if this process is more complex than analog processing and has a discrete value range, the application of computational power to digital signal processing allows for many advantages over analog processing in many applications, such as error detection and correction in transmission as well as data compression.
DSP algorithms have long been run on standard computers, on specialized processors called digital signal processors (DSPs), or on purpose-built hardware such as application-specific integrated circuit (ASICs). Today there are additional technologies used for digital signal processing including more powerful general purpose microprocessors, field-programmable gate arrays (FPGAs), digital signal controllers (mostly for industrial apps such as motor control), and stream processors, among others.
What is digital signal ?pp
A signal in which the original information is converted into a string of bits before being transmitted. A radio signal, for example, will be either on or off. Digital signals can be sent for long distances and suffer less interference than Analog signals. The communications industry worldwide is in the midst of a switch to digital signals.Sound storage in a compact disk is in digital form.
What is DBMS?
As one of the oldest components associated with computers, the database management system, or DBMS, is a computer software program that is designed as the means of managing all databases that are currently installed on a system hard drive or network. Different types of database management systems exist, with some of them designed for the oversight and proper control of databases that are configured for specific purposes. Here are some examples of the various incarnations of DBMS technology that are currently in use, and some of the basic elements that are part of DBMS software applications.
As the tool that is employed in the broad practice of managing databases, the DBMS is marketed in many forms. Some of the more popular examples of DBMS solutions include Microsoft Access, FileMaker, DB2, and Oracle. All these products provide for the creation of a series of rights or privileges that can be associated with a specific user. This means that it is possible to designate one or more database administrators who may control each function, as well as provide other users with various levels of administration rights. This flexibility makes the task of using DBMS methods to oversee a system something that can be centrally controlled, or allocated to several different people.
There are four essential elements that are found with just about every example of DBMS currently on the market. The first is the implementation of a modeling language that serves to define the language of each database that is hosted via the DBMS. There are several approaches currently in use, with hierarchical, network, relational, and object examples. Essentially, the modeling language ensures the ability of the databases to communicate with the DBMS and thus operate on the system.
Second, data structures also are administered by the DBMS. Examples of data that are organized by this function are individual profiles or records, files, fields and their definitions, and objects such as visual media. Data structures are what allows DBMS to interact with the data without causing and damage to the integrity of the data itself.
A third component of DBMS software is the data query language. This element is involved in maintaining the security of the database, by monitoring the use of login data, the assignment of access rights and privileges, and the definition of the criteria that must be employed to add data to the system. The data query language works with the data structures to make sure it is harder to input irrelevant data into any of the databases in use on the system.
Last, a mechanism that allows for transactions is an essential basic for any DBMS. This helps to allow multiple and concurrent access to the database by multiple users, prevents the manipulation of one record by two users at the same time, and preventing the creation of duplicate records.
As the tool that is employed in the broad practice of managing databases, the DBMS is marketed in many forms. Some of the more popular examples of DBMS solutions include Microsoft Access, FileMaker, DB2, and Oracle. All these products provide for the creation of a series of rights or privileges that can be associated with a specific user. This means that it is possible to designate one or more database administrators who may control each function, as well as provide other users with various levels of administration rights. This flexibility makes the task of using DBMS methods to oversee a system something that can be centrally controlled, or allocated to several different people.
There are four essential elements that are found with just about every example of DBMS currently on the market. The first is the implementation of a modeling language that serves to define the language of each database that is hosted via the DBMS. There are several approaches currently in use, with hierarchical, network, relational, and object examples. Essentially, the modeling language ensures the ability of the databases to communicate with the DBMS and thus operate on the system.
Second, data structures also are administered by the DBMS. Examples of data that are organized by this function are individual profiles or records, files, fields and their definitions, and objects such as visual media. Data structures are what allows DBMS to interact with the data without causing and damage to the integrity of the data itself.
A third component of DBMS software is the data query language. This element is involved in maintaining the security of the database, by monitoring the use of login data, the assignment of access rights and privileges, and the definition of the criteria that must be employed to add data to the system. The data query language works with the data structures to make sure it is harder to input irrelevant data into any of the databases in use on the system.
Last, a mechanism that allows for transactions is an essential basic for any DBMS. This helps to allow multiple and concurrent access to the database by multiple users, prevents the manipulation of one record by two users at the same time, and preventing the creation of duplicate records.
Saturday, 23 July 2011
Internal command
A command that is stored in the system memory and loaded from the command.com. Below are examples of internal commands in MS-DOS and the Windows command line currently listed in the Computer Hope database.Assoc
Atmadm
Break
Call
CD
Chdir
Cls
Color
Copy
Ctty
Date
Del
Dir
Drivparm
Echo
Endlocal
Erase
Exit For
Goto
If
LH
Loadhigh
Lock
Md
Mkdir
Move
Path
Pause
Popd
Prompt
Pushd Rd
Ren
Rename
Rmdir
Set
Setlocal
Shift
Start
Switches
Time
Title
Type Unlock
Ver
Verify
Vol
Atmadm
Break
Call
CD
Chdir
Cls
Color
Copy
Ctty
Date
Del
Dir
Drivparm
Echo
Endlocal
Erase
Exit For
Goto
If
LH
Loadhigh
Lock
Md
Mkdir
Move
Path
Pause
Popd
Prompt
Pushd Rd
Ren
Rename
Rmdir
Set
Setlocal
Shift
Start
Switches
Time
Title
Type Unlock
Ver
Verify
Vol
External command
A MS-DOS command that is not included in command.com. External commands are commonly external either because they require large requirements or are not commonly used commands. Below are examples of MS-DOS and Windows command line external commands currently listed in the Computer Hope database.Append
Arp
Assign
At
Attrib
Backup
Cacls
Chcp
Chkdsk
Chkntfs
Choice
Cipher
Comp
Compact
Convert
Debug
Defrag
Delpart
Deltree
Diskcomp
Diskcopy
Doskey
Dosshell
Dumpchk
Edit
Edlin
Expand
Extract
Fasthelp
Fc
Fdisk
Find
Forfiles
Format
FTP
Gpupdate
Graftabl
Help
Hostname
Ipconfig
Label
Loadfix
logoff
Mem
Mode
More
Msav
Msbackup
Mscdex
Mscdexnt
Mwbackup
Msd
Nbtstat Net
Netsh
Netstat
Nlsfunc
Nslookup
Pathping
Ping
Power
Print
Reg
Robocopy
Route
Runas
Scandisk
Scanreg
Setver
Sfc
Share
Shutdown
Smartdrv
Sort
Subst
Sys
Systeminfo Taskkill
Tasklist
Telnet
Tracert
Tree
Tskill
Undelete
Unformat
Xcopy
Many of the external commands are located in the Windows\system32 or Winnt\system32 directories. If you need to locate the external file in order to delete it, rename it or replace it, you can also find the file through MS-DOS.
Arp
Assign
At
Attrib
Backup
Cacls
Chcp
Chkdsk
Chkntfs
Choice
Cipher
Comp
Compact
Convert
Debug
Defrag
Delpart
Deltree
Diskcomp
Diskcopy
Doskey
Dosshell
Dumpchk
Edit
Edlin
Expand
Extract
Fasthelp
Fc
Fdisk
Find
Forfiles
Format
FTP
Gpupdate
Graftabl
Help
Hostname
Ipconfig
Label
Loadfix
logoff
Mem
Mode
More
Msav
Msbackup
Mscdex
Mscdexnt
Mwbackup
Msd
Nbtstat Net
Netsh
Netstat
Nlsfunc
Nslookup
Pathping
Ping
Power
Reg
Robocopy
Route
Runas
Scandisk
Scanreg
Setver
Sfc
Share
Shutdown
Smartdrv
Sort
Subst
Sys
Systeminfo Taskkill
Tasklist
Telnet
Tracert
Tree
Tskill
Undelete
Unformat
Xcopy
Many of the external commands are located in the Windows\system32 or Winnt\system32 directories. If you need to locate the external file in order to delete it, rename it or replace it, you can also find the file through MS-DOS.
Keyboard
One of the main input devices used on a computer, a PC's keyboard looks very similar to the keyboards of electric typewriters, with some additional keys. Below is a graphic of the Saitek Gamers' keyboard with indicators pointing to each of the major portions of the keyboard.
Finally, today most users use the QWERTY style keyboards
Finally, today most users use the QWERTY style keyboards
IP
Short for Internet Protocol, IP is an address of a computer or other network device on a network using IP or TCP/IP. For example, the number "166.70.10.23" is an example of such an address. These addresses are similar to an addresses used on a house and is what allows data to reach the appropriate destination on a network.
There are five classes of available IP ranges: Class A, Class B, Class C, Class D and Class E, while only A, B and C are commonly used. Each class allows for a range of valid IP addresses. Below is a listing of these addresses.Class Address Range Supports
Class A 1.0.0.1 to 126.255.255.254 Supports 16 million hosts on each of 127 networks.
Class B 128.1.0.1 to 191.255.255.254 Supports 65,000 hosts on each of 16,000 networks.
Class C 192.0.1.1 to 223.255.254.254 Supports 254 hosts on each of 2 million networks.
Class D 224.0.0.0 to 239.255.255.255 Reserved for multicast groups.
Class E 240.0.0.0 to 254.255.255.254 Reserved for future use, or Research and Development Purposes.
Ranges 127.x.x.x are reserved for loopback or localhost, for example, 127.0.0.1 is the common loopback address. Range 255.255.255.255 broadcasts to all hosts on the local network.
IP address breakdown
Every IP address is broke down into four sets of octets that break down into binary to represent the actual IP address. The below chart is an example of the IP 255.255.255.255. If you are new to binary, we highly recommend reading our binary and hexadecimal conversions section to get a better understanding of what we're doing in the below charts.IP: 255 255 255 255
Binary value: 11111111 11111111 11111111 11111111
Octet value: 8 8 8 8
If we were to break down the IP "166.70.10.23", you would get the below value. The below fist row is the IP address, the second row the binary values, and the third row the binary value calculated to equal the total of that section of the IP address.
166 70 10 23
10100110 01000110 00001010 00010111
128+32+4+2=166 64+4+2=70 8+2=10 16+4+2+1=23
Automatically assigned addresses
There are several IP addresses that are automatically assigned when you setup a home network. These default addresses are what allow your computer and other network devices to communicate and broadcast information over your network. Below is the most commonly assigned network addresses in a home network.
192.168.1.0 0 is the automatically assigned network address.
192.168.1.1 1 is the commonly used address used as the gateway.
192.168.1.2 2 is also a commonly used address used for a gateway.
192.168.1.3 - 254 Addresses beyond 3 are assigned to computers and devices on the network.
192.168.1.255 255 is automatically assigned on most networks as the broadcast address.
Getting an IP address
By default the router you use will assign each of your computers their own IP address, often using NAT to forward the data coming from those computers to outside networks such as the Internet. If you need to register an IP address that can be seen on the Internet, you must register through InterNIC or use a web host that can assign you addresses.
There are five classes of available IP ranges: Class A, Class B, Class C, Class D and Class E, while only A, B and C are commonly used. Each class allows for a range of valid IP addresses. Below is a listing of these addresses.Class Address Range Supports
Class A 1.0.0.1 to 126.255.255.254 Supports 16 million hosts on each of 127 networks.
Class B 128.1.0.1 to 191.255.255.254 Supports 65,000 hosts on each of 16,000 networks.
Class C 192.0.1.1 to 223.255.254.254 Supports 254 hosts on each of 2 million networks.
Class D 224.0.0.0 to 239.255.255.255 Reserved for multicast groups.
Class E 240.0.0.0 to 254.255.255.254 Reserved for future use, or Research and Development Purposes.
Ranges 127.x.x.x are reserved for loopback or localhost, for example, 127.0.0.1 is the common loopback address. Range 255.255.255.255 broadcasts to all hosts on the local network.
IP address breakdown
Every IP address is broke down into four sets of octets that break down into binary to represent the actual IP address. The below chart is an example of the IP 255.255.255.255. If you are new to binary, we highly recommend reading our binary and hexadecimal conversions section to get a better understanding of what we're doing in the below charts.IP: 255 255 255 255
Binary value: 11111111 11111111 11111111 11111111
Octet value: 8 8 8 8
If we were to break down the IP "166.70.10.23", you would get the below value. The below fist row is the IP address, the second row the binary values, and the third row the binary value calculated to equal the total of that section of the IP address.
166 70 10 23
10100110 01000110 00001010 00010111
128+32+4+2=166 64+4+2=70 8+2=10 16+4+2+1=23
Automatically assigned addresses
There are several IP addresses that are automatically assigned when you setup a home network. These default addresses are what allow your computer and other network devices to communicate and broadcast information over your network. Below is the most commonly assigned network addresses in a home network.
192.168.1.0 0 is the automatically assigned network address.
192.168.1.1 1 is the commonly used address used as the gateway.
192.168.1.2 2 is also a commonly used address used for a gateway.
192.168.1.3 - 254 Addresses beyond 3 are assigned to computers and devices on the network.
192.168.1.255 255 is automatically assigned on most networks as the broadcast address.
Getting an IP address
By default the router you use will assign each of your computers their own IP address, often using NAT to forward the data coming from those computers to outside networks such as the Internet. If you need to register an IP address that can be seen on the Internet, you must register through InterNIC or use a web host that can assign you addresses.
ASCII
Short for American Standard Code for Information Interexchange, ASCII is an industry standard, which assigns letters, numbers and other characters within the 256 slots available in the 8-bit code.
The ASCII table is divided in 3 sections:
Non printable, system codes between 0 and 31.
Lower ASCII, between 32 and 127. This part of the table (as shown below) originates from older, American systems, which worked on 7-bit character tables. Foreign letters, like and were not available then.
Higher ASCII, between 128 and 255. This part is programmable, in that you can exchange characters based on language you want to write in. Foreign letters are placed in this part and an example is shown below.
Standard aka Lower ASCII characters and codesDec Char Dec Char Dec Char Dec Char Dec Char Dec Char
33 ! 49 1 65 A 81 Q 97 a 113 q
34 " 50 2 66 B 82 R 98 b 114 r
35 # 51 3 67 C 83 S 99 c 115 s
36 $ 52 4 68 D 84 T 100 d 116 t
37 % 53 5 69 E 85 U 101 e 117 u
38 & 54 6 70 F 86 V 102 f 118 v
39 ' 55 7 71 G 87 W 103 g 119 w
40 ( 56 8 72 H 88 X 104 h 120 x
41 ) 57 9 73 I 89 Y 105 i 121 y
42 * 58 : 74 J 90 Z 106 j 122 z
43 + 59 ; 75 K 91 [ 107 k 123 {
44 , 60 < 76 L 92 \ 108 l 124 | 45 - 61 = 77 M 93 ] 109 m 125 } 46 . 62 > 78 N 94 ^ 110 n 126 ~
47 / 63 ? 79 O 95 _ 111 o 127 _
48 0 64 @ 80 P 96 ` 112 p
Extended ASCII uses eight instead of seven bits, which adds 128 additional characters. This gives extended ASCII the ability for extra characters, such as special symbols, foreign language letters, and drawing characters
The ASCII table is divided in 3 sections:
Non printable, system codes between 0 and 31.
Lower ASCII, between 32 and 127. This part of the table (as shown below) originates from older, American systems, which worked on 7-bit character tables. Foreign letters, like and were not available then.
Higher ASCII, between 128 and 255. This part is programmable, in that you can exchange characters based on language you want to write in. Foreign letters are placed in this part and an example is shown below.
Standard aka Lower ASCII characters and codesDec Char Dec Char Dec Char Dec Char Dec Char Dec Char
33 ! 49 1 65 A 81 Q 97 a 113 q
34 " 50 2 66 B 82 R 98 b 114 r
35 # 51 3 67 C 83 S 99 c 115 s
36 $ 52 4 68 D 84 T 100 d 116 t
37 % 53 5 69 E 85 U 101 e 117 u
38 & 54 6 70 F 86 V 102 f 118 v
39 ' 55 7 71 G 87 W 103 g 119 w
40 ( 56 8 72 H 88 X 104 h 120 x
41 ) 57 9 73 I 89 Y 105 i 121 y
42 * 58 : 74 J 90 Z 106 j 122 z
43 + 59 ; 75 K 91 [ 107 k 123 {
44 , 60 < 76 L 92 \ 108 l 124 | 45 - 61 = 77 M 93 ] 109 m 125 } 46 . 62 > 78 N 94 ^ 110 n 126 ~
47 / 63 ? 79 O 95 _ 111 o 127 _
48 0 64 @ 80 P 96 ` 112 p
Extended ASCII uses eight instead of seven bits, which adds 128 additional characters. This gives extended ASCII the ability for extra characters, such as special symbols, foreign language letters, and drawing characters
Microsoft Word shortcut keys
Below is a listing of all the major shortcut keys in Microsoft Word. See the computer shortcut page if you are looking for other shortcut keys used in other programs.
Shortcut Keys Description
Ctrl + 0 Adds or removes 6pts of spacing before a paragraph.
Ctrl + A Select all contents of the page.
Ctrl + B Bold highlighted selection.
Ctrl + C Copy selected text.
Ctrl + E Aligns the line or selected text to the center of the screen.
Ctrl + F Open find box.
Ctrl + I Italic highlighted selection.
Ctrl + J Aligns the selected text or line to justify the screen.
Ctrl + K Insert link.
Ctrl + L
Aligns the line or selected text to the left of the screen.
Ctrl + M Indent the paragraph.
Ctrl + P Open the print window.
Ctrl + R Aligns the line or selected text to the right of the screen.
Ctrl + T Create a hanging indent.
Ctrl + U Underline highlighted selection.
Ctrl + V Paste.
Ctrl + X Cut selected text.
Ctrl + Y Redo the last action performed.
Ctrl + Z Undo last action.
Ctrl + Shift + L Quickly create a bullet point.
Ctrl + Shift + F Change the font.
Ctrl + Shift + > Increase selected font +1pts up to 12pt and then increases font +2pts.
Ctrl + ] Increase selected font +1pts.
Ctrl + Shift + < Decrease selected font -1pts if 12pt or lower, if above 12 decreases font by +2pt. Ctrl + [ Decrease selected font -1pts. Ctrl + / + c Insert a cent sign (¢). Ctrl + ' + Insert a character with an accent (grave) mark, where is the character you want. For example, if you wanted an accented è you would use Ctrl + ' + e as your shortcut key. To reverse the accent mark use the opposite accent mark, often on the tilde key.
Ctrl + Shift + * View or hide non printing characters.
Ctrl + Moves one word to the left.
Ctrl + Moves one word to the right.
Ctrl + Moves to the beginning of the line or paragraph.
Ctrl + Moves to the end of the paragraph.
Ctrl + Del Deletes word to right of cursor.
Ctrl + Backspace Deletes word to left of cursor.
Ctrl + End Moves the cursor to the end of the document.
Ctrl + Home Moves the cursor to the beginning of the document.
Ctrl + Spacebar Reset highlighted text to the default font.
Ctrl + 1 Single-space lines.
Ctrl + 2 Double-space lines.
Ctrl + 5 1.5-line spacing.
Ctrl + Alt + 1 Changes text to heading 1.
Ctrl + Alt + 2 Changes text to heading 2.
Ctrl + Alt + 3 Changes text to heading 3.
Alt + Ctrl + F2 Open new document.
Ctrl + F1 Open the Task Pane.
Ctrl + F2 Display the print preview.
Ctrl + Shift + > Increases the highlighted text size by one.
Ctrl + Shift + < Decreases the highlighted text size by one.
Ctrl + Shift + F6 Opens to another open Microsoft Word document.
Ctrl + Shift + F12 Prints the document.
F1 Open Help.
F4 Repeat the last action performed (Word 2000+)
F5 Open the find, replace, and go to window in Microsoft Word.
F7 Spellcheck and grammar check selected text or document.
F12 Save as.
Shift + F3 Change the text in Microsoft Word from uppercase to lowercase or a capital letter at the beginning of every word.
Shift + F7 Runs a Thesaurus check on the word highlighted.
Shift + F12 Save.
Shift + Enter Create a soft break instead of a new paragraph.
Shift + Insert Paste.
Shift + Alt + D Insert the current date.
Shift + Alt + T Insert the current time.
In addition to the above shortcut keys users can also use their mouse as a method of quickly do something commonly performed. Below some are examples of mouse shortcuts.Mouse shortcuts Description
Click, hold, and drag Selects text from where you click and hold to the point you drag and let go.
Double-click If double-click a word, selects the complete word.
Double-click Double-clicking on the left, center, or right of a blank line will make the alignment of the text left, center, or right aligned.
Double-click Double-clicking anywhere after text on a line will set a tab stop.
Triple-click Selects the line or paragraph of the text the mouse triple-clicked.
Ctrl + Mouse wheel Zooms in and out of document.
Shortcut Keys Description
Ctrl + 0 Adds or removes 6pts of spacing before a paragraph.
Ctrl + A Select all contents of the page.
Ctrl + B Bold highlighted selection.
Ctrl + C Copy selected text.
Ctrl + E Aligns the line or selected text to the center of the screen.
Ctrl + F Open find box.
Ctrl + I Italic highlighted selection.
Ctrl + J Aligns the selected text or line to justify the screen.
Ctrl + K Insert link.
Ctrl + L
Aligns the line or selected text to the left of the screen.
Ctrl + M Indent the paragraph.
Ctrl + P Open the print window.
Ctrl + R Aligns the line or selected text to the right of the screen.
Ctrl + T Create a hanging indent.
Ctrl + U Underline highlighted selection.
Ctrl + V Paste.
Ctrl + X Cut selected text.
Ctrl + Y Redo the last action performed.
Ctrl + Z Undo last action.
Ctrl + Shift + L Quickly create a bullet point.
Ctrl + Shift + F Change the font.
Ctrl + Shift + > Increase selected font +1pts up to 12pt and then increases font +2pts.
Ctrl + ] Increase selected font +1pts.
Ctrl + Shift + < Decrease selected font -1pts if 12pt or lower, if above 12 decreases font by +2pt. Ctrl + [ Decrease selected font -1pts. Ctrl + / + c Insert a cent sign (¢). Ctrl + ' +
Ctrl + Shift + * View or hide non printing characters.
Ctrl +
Ctrl +
Ctrl +
Ctrl +
Ctrl + Del Deletes word to right of cursor.
Ctrl + Backspace Deletes word to left of cursor.
Ctrl + End Moves the cursor to the end of the document.
Ctrl + Home Moves the cursor to the beginning of the document.
Ctrl + Spacebar Reset highlighted text to the default font.
Ctrl + 1 Single-space lines.
Ctrl + 2 Double-space lines.
Ctrl + 5 1.5-line spacing.
Ctrl + Alt + 1 Changes text to heading 1.
Ctrl + Alt + 2 Changes text to heading 2.
Ctrl + Alt + 3 Changes text to heading 3.
Alt + Ctrl + F2 Open new document.
Ctrl + F1 Open the Task Pane.
Ctrl + F2 Display the print preview.
Ctrl + Shift + > Increases the highlighted text size by one.
Ctrl + Shift + < Decreases the highlighted text size by one.
Ctrl + Shift + F6 Opens to another open Microsoft Word document.
Ctrl + Shift + F12 Prints the document.
F1 Open Help.
F4 Repeat the last action performed (Word 2000+)
F5 Open the find, replace, and go to window in Microsoft Word.
F7 Spellcheck and grammar check selected text or document.
F12 Save as.
Shift + F3 Change the text in Microsoft Word from uppercase to lowercase or a capital letter at the beginning of every word.
Shift + F7 Runs a Thesaurus check on the word highlighted.
Shift + F12 Save.
Shift + Enter Create a soft break instead of a new paragraph.
Shift + Insert Paste.
Shift + Alt + D Insert the current date.
Shift + Alt + T Insert the current time.
In addition to the above shortcut keys users can also use their mouse as a method of quickly do something commonly performed. Below some are examples of mouse shortcuts.Mouse shortcuts Description
Click, hold, and drag Selects text from where you click and hold to the point you drag and let go.
Double-click If double-click a word, selects the complete word.
Double-click Double-clicking on the left, center, or right of a blank line will make the alignment of the text left, center, or right aligned.
Double-click Double-clicking anywhere after text on a line will set a tab stop.
Triple-click Selects the line or paragraph of the text the mouse triple-clicked.
Ctrl + Mouse wheel Zooms in and out of document.
How do I make a picture a link in my Webpage?
Use the A HREF link tag around the IMG image tag as shown below.
The above example would give you the below clickable image link.
The above example would give you the below clickable image link.
How do I make a link to another web page?
Specify the complete URL in the A HREF tag as shown below.
Visit ComputerHope
Replace our address with the address that you would like to link. Where it says "Visit ComputerHope" replace this what you want to name the link.
Visit ComputerHope
Replace our address with the address that you would like to link. Where it says "Visit ComputerHope" replace this what you want to name the link.
Friday, 22 July 2011
DOS
DOS, short for "Disk Operating System",[1] is an acronym for several closely related operating systems that dominated the IBM PC compatible market between 1981 and 1995, or until about 2000 if one includes the partially DOS-based Microsoft Windows versions 95, 98, and Millennium Edition.
Related systems include MS-DOS, PC-DOS, DR-DOS, FreeDOS, PTS-DOS, ROM-DOS, Caldera DOS, Novell DOS and several others.
In spite of the common usage, none of these systems were simply named "DOS" (a name given only to an unrelated IBM mainframe operating system in the 1960s). A number of unrelated, non-x86 microcomputer disk operating systems had "DOS" in their name, and are often referred to simply as "DOS" when discussing machines that use them (e.g. AmigaDOS, AMSDOS, ANDOS, Apple DOS, Atari DOS, Commodore DOS, CSI-DOS, ProDOS, and TRS-DOS). While providing many of the same operating system functions for their respective computer systems, programs running under any one of these operating systems would not run under others.
User interface
DOS systems utilize a command line interface. Programs are started by entering their filename at the command prompt. DOS systems include several programs as system utilities, and provides additional commands that don't correspond to programs (internal commands).
In an attempt to provide a more user-friendly environment, numerous software manufacturers wrote file management programs that provided users with menu- and/or icon-based interfaces. Microsoft Windows is a notable example, eventually resulting in Microsoft Windows 9x becoming a self-contained program loader, and replacing DOS as the most-used PC-compatible program loader. Text user interface programs included Norton Commander, Dos Navigator, Volkov Commander, Quarterdesk DESQview, and SideKick. Graphical user interface programs included Digital Research's Graphical Environment Manager (originally written for CP/M) and GEOS.
Eventually, the manufacturers of major DOS systems began to include their own environment managers. MS-DOS/IBM DOS 4 included DOS Shell;[36] DR-DOS 5, released the next year, included ViewMAX, based upon GEM.
Limitations
Several limitations plague the DOS architecture. The original 8088 microprocessor could only address 1 megabyte of physical RAM. With additional hardware devices being mapped into this range, the highest amount of available memory was 640 kilobytes, known as conventional memory. Due to DOS's structure, this was assumed to be the maximum, and DOS could not address more than this. An early workaround was expanded memory; later, extended memory was developed with the 80286. While these provided usable memory to applications, they still had to start in conventional memory, thereby using part of the existing 640 KB. With the 80386 microprocessor's redesigned protected mode, DOS extenders and the DOS Protected Mode Interface were able to provide additional memory to applications, as well as multitasking.
DOS also has an upper limit to the size of hard disk partitions. This has two causes. First, many DOS-type systems never had support for any file system newer than FAT16, which, by design, does not allow partitions larger than 2.1 gigabytes.[43] Additionally, DOS accesses the hard disk by calling Interrupt 13, which utilizes the cylinder-head-sector system of mapping the disk. Under this system, only 8 gigabytes are visible to the operating system.[44] Newer operating systems accomplished disk access via software means, e.g. 32-bit disk access.
Using FAT16 (and FAT12 for floppy disks) required use of the 8.3 filename. Filenames in DOS can not be longer than eight characters, and the filename extension cannot be longer than three. Win95's patented VFAT hack worked around this in a unique way.
Related systems include MS-DOS, PC-DOS, DR-DOS, FreeDOS, PTS-DOS, ROM-DOS, Caldera DOS, Novell DOS and several others.
In spite of the common usage, none of these systems were simply named "DOS" (a name given only to an unrelated IBM mainframe operating system in the 1960s). A number of unrelated, non-x86 microcomputer disk operating systems had "DOS" in their name, and are often referred to simply as "DOS" when discussing machines that use them (e.g. AmigaDOS, AMSDOS, ANDOS, Apple DOS, Atari DOS, Commodore DOS, CSI-DOS, ProDOS, and TRS-DOS). While providing many of the same operating system functions for their respective computer systems, programs running under any one of these operating systems would not run under others.
User interface
DOS systems utilize a command line interface. Programs are started by entering their filename at the command prompt. DOS systems include several programs as system utilities, and provides additional commands that don't correspond to programs (internal commands).
In an attempt to provide a more user-friendly environment, numerous software manufacturers wrote file management programs that provided users with menu- and/or icon-based interfaces. Microsoft Windows is a notable example, eventually resulting in Microsoft Windows 9x becoming a self-contained program loader, and replacing DOS as the most-used PC-compatible program loader. Text user interface programs included Norton Commander, Dos Navigator, Volkov Commander, Quarterdesk DESQview, and SideKick. Graphical user interface programs included Digital Research's Graphical Environment Manager (originally written for CP/M) and GEOS.
Eventually, the manufacturers of major DOS systems began to include their own environment managers. MS-DOS/IBM DOS 4 included DOS Shell;[36] DR-DOS 5, released the next year, included ViewMAX, based upon GEM.
Limitations
Several limitations plague the DOS architecture. The original 8088 microprocessor could only address 1 megabyte of physical RAM. With additional hardware devices being mapped into this range, the highest amount of available memory was 640 kilobytes, known as conventional memory. Due to DOS's structure, this was assumed to be the maximum, and DOS could not address more than this. An early workaround was expanded memory; later, extended memory was developed with the 80286. While these provided usable memory to applications, they still had to start in conventional memory, thereby using part of the existing 640 KB. With the 80386 microprocessor's redesigned protected mode, DOS extenders and the DOS Protected Mode Interface were able to provide additional memory to applications, as well as multitasking.
DOS also has an upper limit to the size of hard disk partitions. This has two causes. First, many DOS-type systems never had support for any file system newer than FAT16, which, by design, does not allow partitions larger than 2.1 gigabytes.[43] Additionally, DOS accesses the hard disk by calling Interrupt 13, which utilizes the cylinder-head-sector system of mapping the disk. Under this system, only 8 gigabytes are visible to the operating system.[44] Newer operating systems accomplished disk access via software means, e.g. 32-bit disk access.
Using FAT16 (and FAT12 for floppy disks) required use of the 8.3 filename. Filenames in DOS can not be longer than eight characters, and the filename extension cannot be longer than three. Win95's patented VFAT hack worked around this in a unique way.
What Is A Workstation ?
A workstation is a high-end microcomputer designed for technical or scientific applications. Intended primarily to be used by one person at a time, they are commonly connected to a local area network and run multi-user operating systems. The term workstation has also been used to refer to a mainframe computer terminal or a PC connected to a network.
Historically, workstations had offered higher performance than desktop computers, especially with respect to CPU and graphics, memory capacity and multitasking capability. They are optimized for the visualization and manipulation of different types of complex data such as 3D mechanical design, engineering simulation (e.g. computational fluid dynamics), animation and rendering of images, and mathematical plots. Consoles consist of a high resolution display, a keyboard and a mouse at a minimum, but also offer multiple displays, graphics tablets, 3D mice (devices for manipulating and navigating 3D objects and scenes), etc. Workstations are the first segment of the computer market to present advanced accessories and collaboration tools.
Presently, the workstation market is highly commoditized and is dominated by large PC vendors, such as Dell and HP, selling Microsoft Windows/Linux running on Intel Xeon/AMD Opteron. Alternative UNIX based platforms are provided by Apple Inc., Sun Microsystems, and SGI.
Historically, workstations had offered higher performance than desktop computers, especially with respect to CPU and graphics, memory capacity and multitasking capability. They are optimized for the visualization and manipulation of different types of complex data such as 3D mechanical design, engineering simulation (e.g. computational fluid dynamics), animation and rendering of images, and mathematical plots. Consoles consist of a high resolution display, a keyboard and a mouse at a minimum, but also offer multiple displays, graphics tablets, 3D mice (devices for manipulating and navigating 3D objects and scenes), etc. Workstations are the first segment of the computer market to present advanced accessories and collaboration tools.
Presently, the workstation market is highly commoditized and is dominated by large PC vendors, such as Dell and HP, selling Microsoft Windows/Linux running on Intel Xeon/AMD Opteron. Alternative UNIX based platforms are provided by Apple Inc., Sun Microsystems, and SGI.
MsgBox Function:
MsgBox Function:
Displays a dialog box containing a message, buttons, and optional icon to the user. The Action taken by the user is returned by the function as an integer value.
Syntax: MsgBox(prompt, buttons, title, helpfile, context)
Arguments:
* Prompt: The text of the message to display in the message box dialog.
* Buttons: The sum of the Button, Icon, Default Button, and Modality constant values.
* Title: The title displayed in the Title-bar of the message box dialog.
* Helpfile: An expression specifying the name of the help file to provide help functionality for the dialog.
* Context: An expression specifying a context ID within helpfile.
Displays a dialog box containing a message, buttons, and optional icon to the user. The Action taken by the user is returned by the function as an integer value.
Syntax: MsgBox(prompt, buttons, title, helpfile, context)
Arguments:
* Prompt: The text of the message to display in the message box dialog.
* Buttons: The sum of the Button, Icon, Default Button, and Modality constant values.
* Title: The title displayed in the Title-bar of the message box dialog.
* Helpfile: An expression specifying the name of the help file to provide help functionality for the dialog.
* Context: An expression specifying a context ID within helpfile.
InputBox Function
InputBox Function:
The InputBox function displays a dialog box containing a label, which prompts the user about the data you expect them to input, a text box for entering the data, an OK button, a Cancel button, and optionally, a Help button. When the user clicks OK, the function returns the contents of the text box.
Syntax: InputBox(prompt,title,default,xpos, ypos, helpfile, context)
Arguments:
* Prompt: The message in the dialog box.
* Title: The title-bar of the dialog box.
* Default: String to be displayed in the text box on loading.
* Xpos: The distance from the left side of the screen to the left side of the dialog.
* Ypos: The distance from the top of the screen to the top of the dialog box.
* Helpfile: The Help file to use if the user clicks the Help button on the dialog box.
* Context: The context number to use within the Help file specified in helpfile.
The InputBox function displays a dialog box containing a label, which prompts the user about the data you expect them to input, a text box for entering the data, an OK button, a Cancel button, and optionally, a Help button. When the user clicks OK, the function returns the contents of the text box.
Syntax: InputBox(prompt,title,default,xpos, ypos, helpfile, context)
Arguments:
* Prompt: The message in the dialog box.
* Title: The title-bar of the dialog box.
* Default: String to be displayed in the text box on loading.
* Xpos: The distance from the left side of the screen to the left side of the dialog.
* Ypos: The distance from the top of the screen to the top of the dialog box.
* Helpfile: The Help file to use if the user clicks the Help button on the dialog box.
* Context: The context number to use within the Help file specified in helpfile.
Displaying Help by Using the InputBox and MsgBox Functions
Both the InputBox and MsgBox functions provide optional helpfile and context arguments that can be used to display a Help topic when a user clicks the Help button or presses F1. To display a custom Help topic, you must specify both optional arguments. The helpfile argument is a string value that specifies the Help file that contains the topic you want to display. This argument can accept either a .chm or .hlp file. The context argument specifies the mapped context ID of the topic to display.
If you specify the helpfile and context arguments when you are using the InputBox function, a Help button will automatically be added to the dialog box created by the InputBox function. If you specify the helpfile and context arguments when you are using the MsgBox function, you must also specify the vbMsgBoxHelpButton built-in constant in the buttons argument in order to add a Help button to the dialog box created by the MsgBox function.
The following code fragment shows how to display a Help topic when you are using the InputBox function:
InputBox Prompt:="Enter data", _
HelpFile:=strAppPath & "\sample.chm", _
Context:="2001"
The following line of code shows how to display a Help topic when you are using the MsgBox function:
MsgBox Prompt:="You must enter a valid date.", _
Buttons:=vbMsgBoxHelpButton, _
HelpFile:=strAppPath & "\sample.chm", _
Context:="2002"
The InputBox and MsgBox functions allow you to display a Help topic contained in a compiled HTML Help file in all Office applications, including Word and Access. There is no need to use the HtmlHelp API to display a Help topic in a .chm file when you are using these functions in Word and Access.
If you specify the helpfile and context arguments when you are using the InputBox function, a Help button will automatically be added to the dialog box created by the InputBox function. If you specify the helpfile and context arguments when you are using the MsgBox function, you must also specify the vbMsgBoxHelpButton built-in constant in the buttons argument in order to add a Help button to the dialog box created by the MsgBox function.
The following code fragment shows how to display a Help topic when you are using the InputBox function:
InputBox Prompt:="Enter data", _
HelpFile:=strAppPath & "\sample.chm", _
Context:="2001"
The following line of code shows how to display a Help topic when you are using the MsgBox function:
MsgBox Prompt:="You must enter a valid date.", _
Buttons:=vbMsgBoxHelpButton, _
HelpFile:=strAppPath & "\sample.chm", _
Context:="2002"
The InputBox and MsgBox functions allow you to display a Help topic contained in a compiled HTML Help file in all Office applications, including Word and Access. There is no need to use the HtmlHelp API to display a Help topic in a .chm file when you are using these functions in Word and Access.
What Is USB?
Types of Universal Serial Bus (USB) devices and standards
Today just about every PC comes with Universal Serial Bus, or USB ports. In fact, many computers will even have additional USB ports located on the front of the tower, in additional to two standard USB ports at the back. In the late 1990s, a few computer manufacturers started including USB support in their new systems, but today USB has become a standard connection port for many devices such as keyboards, mice, joysticks and digital cameras to name but a few USB-enabled devices. USB is able to support and is supported by a large range of products.
Adding to the appeal of USB is that it is supported at the operating system level, and compared to alternative ports such as parallel or serial ports, USB is very user-friendly. When USB first started appearing in the marketplace, it was (and still is) referred to as a plug-and-play port because of its ease of use. Consumers without a lot of technical or hardware knowledge were able to easily connect USB devices to their computer. You no longer needed to turn the computer off to install the devices either. You simply plug them in and go. USB devices can also be used across multiple platforms. USB works on Windows and Mac, plus can be used with other operating systems, such as Linux, for example, with a reliable degree of success.
Before USB, connecting devices to your system was often a hassle. Modems and digital cameras were connected via the serial port which was quite slow, as only 1 bit is transmitted at a time through a serial port. While printers generally required a parallel printer port, which is able to receive more than one bit at a time — that is, it receives several bits in parallel. Most systems provided two serial ports and a parallel printer port. If you had several devices, unhooking one device and setting up the software and drivers to use another device could often be problematic for the user.
The introduction of USB ended many of the headaches associated with needing to use serial ports and parallel printer ports. USB offered consumers the option to connect up to 127 devices, either directly or through the use of a USB hub. It was much faster since USB supports data transfer rates of 12 Mbps for disk drives and other high-speed throughput and 1.5Mbps for devices that need less bandwidth. Additionally, consumers can literally plug almost any USB device into their computer, and Windows will detect it and automatically set-up the hardware settings for the device. Once that device has been installed you can remove it from your system and the next time you plug it in, Windows will automatically detect it.
Today just about every PC comes with Universal Serial Bus, or USB ports. In fact, many computers will even have additional USB ports located on the front of the tower, in additional to two standard USB ports at the back. In the late 1990s, a few computer manufacturers started including USB support in their new systems, but today USB has become a standard connection port for many devices such as keyboards, mice, joysticks and digital cameras to name but a few USB-enabled devices. USB is able to support and is supported by a large range of products.
Adding to the appeal of USB is that it is supported at the operating system level, and compared to alternative ports such as parallel or serial ports, USB is very user-friendly. When USB first started appearing in the marketplace, it was (and still is) referred to as a plug-and-play port because of its ease of use. Consumers without a lot of technical or hardware knowledge were able to easily connect USB devices to their computer. You no longer needed to turn the computer off to install the devices either. You simply plug them in and go. USB devices can also be used across multiple platforms. USB works on Windows and Mac, plus can be used with other operating systems, such as Linux, for example, with a reliable degree of success.
Before USB, connecting devices to your system was often a hassle. Modems and digital cameras were connected via the serial port which was quite slow, as only 1 bit is transmitted at a time through a serial port. While printers generally required a parallel printer port, which is able to receive more than one bit at a time — that is, it receives several bits in parallel. Most systems provided two serial ports and a parallel printer port. If you had several devices, unhooking one device and setting up the software and drivers to use another device could often be problematic for the user.
The introduction of USB ended many of the headaches associated with needing to use serial ports and parallel printer ports. USB offered consumers the option to connect up to 127 devices, either directly or through the use of a USB hub. It was much faster since USB supports data transfer rates of 12 Mbps for disk drives and other high-speed throughput and 1.5Mbps for devices that need less bandwidth. Additionally, consumers can literally plug almost any USB device into their computer, and Windows will detect it and automatically set-up the hardware settings for the device. Once that device has been installed you can remove it from your system and the next time you plug it in, Windows will automatically detect it.
Friday, 15 July 2011
Che guvera BiographyChe guvera Biography
*Ernesto (Che) Guevara was born
in Rosario in Argentine in 1928.
After studying medicine at the
University of Buenos Aires he
worked as a doctor. While in
Guatemala in 1954 he witnessed
the socialist government of
President Jacobo Arbenz
overthrown by an American
backed military coup. Disgusted
by what he saw, Guevara decided
to join the Cuban revolutionary,
Fidel Castro, in Mexico.
In 1956 Guevara, Castro and
eighty other men and women
arrived in Cuba in an attempt to
overthrow the government of
General Fulgencio Batista. This
group became known as the July
26 Movement. The plan was to
set up their base in the Sierra
Maestra mountains. On the way
to the mountains they were
attacked by government troops.
By the time they reached the
Sierra Maestra there were only
sixteen men left with twelve
weapons between them. For the
next few months Castro's
guerrilla army raided isolated
army garrisons and were
gradually able to build-up their
stock of weapons.
When the guerrillas took control
of territory they redistributed the
land amongst the peasants. In
return, the peasants helped the
guerrillas against Batista's
soldiers. In some cases the
peasants also joined Castro's
army, as did students from the
cities and occasionally Catholic
priests.
In an effort to find out
information about the rebels
people were pulled in for
questioning. Many innocent
people were tortured. Suspects,
including children, were publicly
executed and then left hanging
in the streets for several days as
a warning to others who were
considering joining the
revolutionaries. The behaviour of
Batista's forces increased
support for the guerrillas. In
1958 forty-five organizations
signed an open letter supporting
the July 26 Movement. National
bodies representing lawyers,
architects, dentists, accountants
and social workers were
amongst those who signed.
Castro, who had originally relied
on the support of the poor, was
now gaining the backing of the
influential middle classes.
General Fulgencio Batista
responded to this by sending
more troops to the Sierra
Maestra. He now had 10,000 men
hunting for Castro and his 300-
strong army. Although
outnumbered, Castro's guerrillas
were able to inflict defeat after
defeat on the government's
troops. In the summer of 1958
over a thousand of Batista's
soldiers were killed or wounded
and many more were captured.
Unlike Batista's soldiers, Castro's
troops had developed a
reputation for behaving well
towards prisoners. This
encouraged Batista's troops to
surrender to Castro when things
went badly in battle. Complete
military units began to join the
guerrillas.
The United States supplied
Batista with planes, ships and
tanks, but the advantage of using
the latest technology such as
napalm failed to win them victory
against the guerrillas. In March
1958, President Dwight
Eisenhower, disillusioned with
Batista's performance, suggested
he held elections. This he did, but
the people showed their
dissatisfaction with his
government by refusing to vote.
Over 75 per cent of the voters in
the capital Havana boycotted the
polls. In some areas, such as
Santiago, it was as high as 98
per cent.
Fidel Castro was now confident
he could beat Batista in a head-
on battle. Leaving the Sierra
Maestra mountains, Castro's
troops began to march on the
main towns. After consultations
with the United States
government, Batista decided to
flee the country. Senior Generals
left behind attempted to set up
another military government.
Castro's reaction was to call for a
general strike. The workers came
out on strike and the military
were forced to accept the
people's desire for change.
Castro marched into Havana on
January 9,1959, and became
Cuba's new leader.
In its first hundred days in office
Castro's government passed
several new laws. Rents were cut
by up to 50 per cent for low
wage earners; property owned
by Fulgencio Batista and his
ministers was confiscated; the
telephone company was
nationalized and the rates were
reduced by 50 per cent; land was
redistributed amongst the
peasants (including the land
owned by the Castro family);
separate facilities for blacks and
whites (swimming pools,
beaches, hotels, cemeteries etc.)
were abolished.
In 1960 Guevara visited China
and the Soviet Union. On his
return he wrote two books
Guerrilla Warfare and
Reminiscences of the Cuban
Revolutionary War . In these
books he argued that it was
possible to export Cuba's
revolution to other South
American countries. Guevara
served as Minister for Industries
(1961-65) but in April 1965 he
resigned and become a guerrilla
leader in Bolivia.
In 1967 David Morales recruited
Félix RodrÃguez to train and head
a team that would attempt to
catch Che Guevara. Guevara was
attempting to persuade the tin-
miners living in poverty to join
his revolutionary army. When
Guevara was captured, it was
Rodriguez who interrogated him
before he ordered his execution
in October, 1967. Rodriguez still
possesses Guevara’s Rolex watch
that he took as a trophy.
In their book, Ultimate Sacrifice,
published in 2006, Larmar
Waldron and Thom Hartmann
argued that in 1963 Guevara was
involved in a plot with Juan
Almeida Bosch to overthrow Fidel
Castro.
in Rosario in Argentine in 1928.
After studying medicine at the
University of Buenos Aires he
worked as a doctor. While in
Guatemala in 1954 he witnessed
the socialist government of
President Jacobo Arbenz
overthrown by an American
backed military coup. Disgusted
by what he saw, Guevara decided
to join the Cuban revolutionary,
Fidel Castro, in Mexico.
In 1956 Guevara, Castro and
eighty other men and women
arrived in Cuba in an attempt to
overthrow the government of
General Fulgencio Batista. This
group became known as the July
26 Movement. The plan was to
set up their base in the Sierra
Maestra mountains. On the way
to the mountains they were
attacked by government troops.
By the time they reached the
Sierra Maestra there were only
sixteen men left with twelve
weapons between them. For the
next few months Castro's
guerrilla army raided isolated
army garrisons and were
gradually able to build-up their
stock of weapons.
When the guerrillas took control
of territory they redistributed the
land amongst the peasants. In
return, the peasants helped the
guerrillas against Batista's
soldiers. In some cases the
peasants also joined Castro's
army, as did students from the
cities and occasionally Catholic
priests.
In an effort to find out
information about the rebels
people were pulled in for
questioning. Many innocent
people were tortured. Suspects,
including children, were publicly
executed and then left hanging
in the streets for several days as
a warning to others who were
considering joining the
revolutionaries. The behaviour of
Batista's forces increased
support for the guerrillas. In
1958 forty-five organizations
signed an open letter supporting
the July 26 Movement. National
bodies representing lawyers,
architects, dentists, accountants
and social workers were
amongst those who signed.
Castro, who had originally relied
on the support of the poor, was
now gaining the backing of the
influential middle classes.
General Fulgencio Batista
responded to this by sending
more troops to the Sierra
Maestra. He now had 10,000 men
hunting for Castro and his 300-
strong army. Although
outnumbered, Castro's guerrillas
were able to inflict defeat after
defeat on the government's
troops. In the summer of 1958
over a thousand of Batista's
soldiers were killed or wounded
and many more were captured.
Unlike Batista's soldiers, Castro's
troops had developed a
reputation for behaving well
towards prisoners. This
encouraged Batista's troops to
surrender to Castro when things
went badly in battle. Complete
military units began to join the
guerrillas.
The United States supplied
Batista with planes, ships and
tanks, but the advantage of using
the latest technology such as
napalm failed to win them victory
against the guerrillas. In March
1958, President Dwight
Eisenhower, disillusioned with
Batista's performance, suggested
he held elections. This he did, but
the people showed their
dissatisfaction with his
government by refusing to vote.
Over 75 per cent of the voters in
the capital Havana boycotted the
polls. In some areas, such as
Santiago, it was as high as 98
per cent.
Fidel Castro was now confident
he could beat Batista in a head-
on battle. Leaving the Sierra
Maestra mountains, Castro's
troops began to march on the
main towns. After consultations
with the United States
government, Batista decided to
flee the country. Senior Generals
left behind attempted to set up
another military government.
Castro's reaction was to call for a
general strike. The workers came
out on strike and the military
were forced to accept the
people's desire for change.
Castro marched into Havana on
January 9,1959, and became
Cuba's new leader.
In its first hundred days in office
Castro's government passed
several new laws. Rents were cut
by up to 50 per cent for low
wage earners; property owned
by Fulgencio Batista and his
ministers was confiscated; the
telephone company was
nationalized and the rates were
reduced by 50 per cent; land was
redistributed amongst the
peasants (including the land
owned by the Castro family);
separate facilities for blacks and
whites (swimming pools,
beaches, hotels, cemeteries etc.)
were abolished.
In 1960 Guevara visited China
and the Soviet Union. On his
return he wrote two books
Guerrilla Warfare and
Reminiscences of the Cuban
Revolutionary War . In these
books he argued that it was
possible to export Cuba's
revolution to other South
American countries. Guevara
served as Minister for Industries
(1961-65) but in April 1965 he
resigned and become a guerrilla
leader in Bolivia.
In 1967 David Morales recruited
Félix RodrÃguez to train and head
a team that would attempt to
catch Che Guevara. Guevara was
attempting to persuade the tin-
miners living in poverty to join
his revolutionary army. When
Guevara was captured, it was
Rodriguez who interrogated him
before he ordered his execution
in October, 1967. Rodriguez still
possesses Guevara’s Rolex watch
that he took as a trophy.
In their book, Ultimate Sacrifice,
published in 2006, Larmar
Waldron and Thom Hartmann
argued that in 1963 Guevara was
involved in a plot with Juan
Almeida Bosch to overthrow Fidel
Castro.
Tuesday, 12 July 2011
where was the god when he is created universe?
Great question, Erwin! To be
honest, when I first read it, I had
to stop and think for a while.
Such a concept baffles our
human logic.
Nevertheless, I came up with a
statement that might hint at an
answer: Just because nothing
existed doesn't mean "nowhere"
existed.
For instance, we call space
"space" because nothing is there.
But a rocket ship can still fly
through it. Just because nothing
is there doesn't mean there isn't
a space that can be inhabited.
The absence of matter is "space,"
and we could say that the
absence of space is "matter." So
before there was matter, I
suppose you could say there was
still space.
Admittedly, that's all just my
human logic at work, and I
wouldn't bank on it being
perfect. So let's turn to the Word
of God.
It is true that God made the
earth, and we know a few things
about where God was at the
moment of creation.
honest, when I first read it, I had
to stop and think for a while.
Such a concept baffles our
human logic.
Nevertheless, I came up with a
statement that might hint at an
answer: Just because nothing
existed doesn't mean "nowhere"
existed.
For instance, we call space
"space" because nothing is there.
But a rocket ship can still fly
through it. Just because nothing
is there doesn't mean there isn't
a space that can be inhabited.
The absence of matter is "space,"
and we could say that the
absence of space is "matter." So
before there was matter, I
suppose you could say there was
still space.
Admittedly, that's all just my
human logic at work, and I
wouldn't bank on it being
perfect. So let's turn to the Word
of God.
It is true that God made the
earth, and we know a few things
about where God was at the
moment of creation.
Tuesday, 21 June 2011
Is Management ART or SCIENCE?
Is Management ART or
SCIENCE
It’s an Art
The question of whether
management is an art or
science is quite old.
When viewed as an art,
management is
remarkable, but natural
expression of human
behavior. It is intuitive,
creative and flexible.
Managers are leaders
and artists who are able
to develop unique
alternatives and novel
ideas about their
organizations needs.
They are attuned to
people and events
around them and learn
to anticipate the
turbulent twists and
turns around them.
However, artistry in
management is neither
exact nor precise. Artists
interpret experience and
express it in forms that
can be felt, understood
and appreciated by
others. Art allows for
emotion, subtlety and
ambiguity. An artist
frames the world so that
others can see new
possibilities.
Science is extraordinary.
It is a method of doing
things. It is the
organized systematic
expertise that gathers
knowledge about the
world and condenses
the knowledge into
testable laws and
principles. When science
is done correctly, it can
advice us in all of our day
to day decisions and
actions.
Management is basically
an art which can be
made efficient by
scientific methods. The
artistic talents of the
manager can be
enriched by the usage of
scientific tools. However
as the famous quote “A
fool with a tool is still a
fool ”, the artist in any
manager definitely has
an edge. His creativity
and productivity can be
magnified by using the
correct scientific
methods.
The art of management
existed long before
automation. Without
doubt, the science has
made the management
easier. But focusing only
on the science may lead
to shift of focus of the
entire team and create
overheads. Success of
managers depends on
how effectively they can
use the scientific aid to
enhance their artistic
skills.
It’s a Science
Einstein said: “Intellect…
has…no personality, it
cannot lead, it can only
serve ”
From the original five
dimensions
(inconsistently referred
to throughout the book
as dimensions, domains
or abilities – the use of
the word "abilities" will
be utilized for this
review), the authors
have simplified these
into four:
1. Self-awareness
2. Self-management
3. Social awareness
4. Relationship
management
All four are closely
related and build on the
preceding ability, but it
begins with self-
awareness. Self-
awareness helps us
recognize emotions in
others. Good, resonant
leaders have the ability
to manage their own
emotions to do and say
the appropriate things at
the appropriate time.
Possessing a social
awareness – being
aware of how others feel
individually or in a group
– creates empathy,
which is crucial for
relationship
management.
The four abilities have
been defined into 18
competences. The
authors argue that these
competences are not
innate talents, but
learned abilities. From
the four abilities and the
18 competences, people
can identify their own
abilities and
competences. The
authors have found that
no leader has an across-
the-board set but, rather,
a critical mass of a
selection of abilities or
competences.
Management is a set of
activities (including
planning and decision
making, organizing,
leading, and controlling)
directed at an
organization's resources
(human, financial,
physical, and
information) with the
aim of achieving
organizational goals in
an efficient and effective
manner. A manager is
someone whose primary
responsibility is to carry
out the management
process within an
organization. The
effective practice of
management requires a
synthesis of science and
art; that is, a blend of
rational objectivity and
intuitive insight. Good
management is a
mixture of art and
science.
Management as an Art is
a practice that has been
followed for ages
(donkey ’s years!) by
many noble-beings
(were they called
managers in the early
era??) and has been
unremitting since
then...maybe the style
has changed but the
objective hasn't. Being
an art, its practice to
perfection was one of
the most essential
feature (sine-qua-non)
that everyone was
looking at. However, due
to efflux of time, many
realized that it wasn't
important to be perfect
BUT necessary to be
excellent. If you aren't
excellent, u better take a
jump!
Management as a
Science always had (and
continues to have) a
'Cause & Effect'
relationship that has
been practiced (did I say
preached?) for time
immemorial (well, still
being very well practiced
and preached in many
companies!) inorder to
enable people to
perform better
(hopefully!) and
understand the
quantification (many-a-
times distorted!) behind
their performance. I
guess, time has come for
us to realize the
importance of
management BOTH as an
art and science and to
appreciate its co-
existence within an
organization.
SCIENCE
It’s an Art
The question of whether
management is an art or
science is quite old.
When viewed as an art,
management is
remarkable, but natural
expression of human
behavior. It is intuitive,
creative and flexible.
Managers are leaders
and artists who are able
to develop unique
alternatives and novel
ideas about their
organizations needs.
They are attuned to
people and events
around them and learn
to anticipate the
turbulent twists and
turns around them.
However, artistry in
management is neither
exact nor precise. Artists
interpret experience and
express it in forms that
can be felt, understood
and appreciated by
others. Art allows for
emotion, subtlety and
ambiguity. An artist
frames the world so that
others can see new
possibilities.
Science is extraordinary.
It is a method of doing
things. It is the
organized systematic
expertise that gathers
knowledge about the
world and condenses
the knowledge into
testable laws and
principles. When science
is done correctly, it can
advice us in all of our day
to day decisions and
actions.
Management is basically
an art which can be
made efficient by
scientific methods. The
artistic talents of the
manager can be
enriched by the usage of
scientific tools. However
as the famous quote “A
fool with a tool is still a
fool ”, the artist in any
manager definitely has
an edge. His creativity
and productivity can be
magnified by using the
correct scientific
methods.
The art of management
existed long before
automation. Without
doubt, the science has
made the management
easier. But focusing only
on the science may lead
to shift of focus of the
entire team and create
overheads. Success of
managers depends on
how effectively they can
use the scientific aid to
enhance their artistic
skills.
It’s a Science
Einstein said: “Intellect…
has…no personality, it
cannot lead, it can only
serve ”
From the original five
dimensions
(inconsistently referred
to throughout the book
as dimensions, domains
or abilities – the use of
the word "abilities" will
be utilized for this
review), the authors
have simplified these
into four:
1. Self-awareness
2. Self-management
3. Social awareness
4. Relationship
management
All four are closely
related and build on the
preceding ability, but it
begins with self-
awareness. Self-
awareness helps us
recognize emotions in
others. Good, resonant
leaders have the ability
to manage their own
emotions to do and say
the appropriate things at
the appropriate time.
Possessing a social
awareness – being
aware of how others feel
individually or in a group
– creates empathy,
which is crucial for
relationship
management.
The four abilities have
been defined into 18
competences. The
authors argue that these
competences are not
innate talents, but
learned abilities. From
the four abilities and the
18 competences, people
can identify their own
abilities and
competences. The
authors have found that
no leader has an across-
the-board set but, rather,
a critical mass of a
selection of abilities or
competences.
Management is a set of
activities (including
planning and decision
making, organizing,
leading, and controlling)
directed at an
organization's resources
(human, financial,
physical, and
information) with the
aim of achieving
organizational goals in
an efficient and effective
manner. A manager is
someone whose primary
responsibility is to carry
out the management
process within an
organization. The
effective practice of
management requires a
synthesis of science and
art; that is, a blend of
rational objectivity and
intuitive insight. Good
management is a
mixture of art and
science.
Management as an Art is
a practice that has been
followed for ages
(donkey ’s years!) by
many noble-beings
(were they called
managers in the early
era??) and has been
unremitting since
then...maybe the style
has changed but the
objective hasn't. Being
an art, its practice to
perfection was one of
the most essential
feature (sine-qua-non)
that everyone was
looking at. However, due
to efflux of time, many
realized that it wasn't
important to be perfect
BUT necessary to be
excellent. If you aren't
excellent, u better take a
jump!
Management as a
Science always had (and
continues to have) a
'Cause & Effect'
relationship that has
been practiced (did I say
preached?) for time
immemorial (well, still
being very well practiced
and preached in many
companies!) inorder to
enable people to
perform better
(hopefully!) and
understand the
quantification (many-a-
times distorted!) behind
their performance. I
guess, time has come for
us to realize the
importance of
management BOTH as an
art and science and to
appreciate its co-
existence within an
organization.
Sunday, 19 June 2011
What is a rendering?
Rendering is when you take a
3d or 2d model or picture
and apply reflections, light,
effects, refreactions,
shadows, and ect.... basicly, it
makes a computer creation
look better or real.
3d or 2d model or picture
and apply reflections, light,
effects, refreactions,
shadows, and ect.... basicly, it
makes a computer creation
look better or real.
What is assembly language. Give its advantages over machine language?
Machine language is binary:
0010001111010111011011
1011. Humans can read this
code, but it is tedious and
painfully slow for most
humans to do so.
Assembly language is a
mnemonic language: it
translates directly into
machine code, but is easier
on the eyes. The above
machine language might
translate into a more
readable:
mov r1,3412
mov r2,2231
add r2,r1
push r2
"mov r1,3412" is far easier to
read than a string of 1s and
0s that the computer sees. Of
course, like any language, you
still have to understand the
code, and there is a lot more
documentation to work with
assembly as opposed to high
level languages.
The advantage is that
assembly is easier to read
and write for humans than
pure machine code.
0010001111010111011011
1011. Humans can read this
code, but it is tedious and
painfully slow for most
humans to do so.
Assembly language is a
mnemonic language: it
translates directly into
machine code, but is easier
on the eyes. The above
machine language might
translate into a more
readable:
mov r1,3412
mov r2,2231
add r2,r1
push r2
"mov r1,3412" is far easier to
read than a string of 1s and
0s that the computer sees. Of
course, like any language, you
still have to understand the
code, and there is a lot more
documentation to work with
assembly as opposed to high
level languages.
The advantage is that
assembly is easier to read
and write for humans than
pure machine code.
Why computer known as data processor?
A computer is an electronic
device which manipulates or
transforms data. it accepts
data, stores data, process
data according to a set of
instructions, and also retrieve
the data when required.
Hence it is known as a data
processor.
device which manipulates or
transforms data. it accepts
data, stores data, process
data according to a set of
instructions, and also retrieve
the data when required.
Hence it is known as a data
processor.
What are the advantages and disadvantages of machine language?
Advantage
The only advantage is that
program of machine
language run very fast
because no translation
program is required for the
CPU.
Disadvantages
1. It is very difficult to
program in machine
language. The
programmer has to
know details of
hardware to write
program.
2. The programmer has to
remember a lot of
codes to write a
program which results
in program errors.
3. It is difficult to debug
the program.
The only advantage is that
program of machine
language run very fast
because no translation
program is required for the
CPU.
Disadvantages
1. It is very difficult to
program in machine
language. The
programmer has to
know details of
hardware to write
program.
2. The programmer has to
remember a lot of
codes to write a
program which results
in program errors.
3. It is difficult to debug
the program.
What is multiprogramming and an example of multiprogramming?
Multiprogramming is a
feature of an OS which allows
running multiple programs
simutaneously on 1 CPU. So,
say, you may be typing in
word, listning to music while
in background IE is
downloading some file &
anti-virus program is
scanning. These all happen
simultaneously to you.
Actually programs dont run
simultaneously, but OS divides
time for each program
acccording to priorities.
When the chance of that
program comes it runs, after
the stipulated time is over,
next program runs & so on.
Since this process is so fast
that it appears programs are
running simultaneously.
MOst of recent OSes are
multiprogramming. For eg.
Windows XP, Liunux
feature of an OS which allows
running multiple programs
simutaneously on 1 CPU. So,
say, you may be typing in
word, listning to music while
in background IE is
downloading some file &
anti-virus program is
scanning. These all happen
simultaneously to you.
Actually programs dont run
simultaneously, but OS divides
time for each program
acccording to priorities.
When the chance of that
program comes it runs, after
the stipulated time is over,
next program runs & so on.
Since this process is so fast
that it appears programs are
running simultaneously.
MOst of recent OSes are
multiprogramming. For eg.
Windows XP, Liunux
What is the difference between computer science and information technology?
At the most basic level,
Computer Science is a "Hard"
Science, well grounded in
what is now known in the
field of Mathematics as
Information Theory.
Computer Science (as a field)
is concerned with developing
new ideas around the use
and design of computing
systems, and with the
mathematical concepts of
computation and
information.
Information Technology, on
the other hand, is a practical
Engineering discipline,
concerned with
implementing solutions to
practical problems using
current-day technology.
Computer Science is a "Hard"
Science, well grounded in
what is now known in the
field of Mathematics as
Information Theory.
Computer Science (as a field)
is concerned with developing
new ideas around the use
and design of computing
systems, and with the
mathematical concepts of
computation and
information.
Information Technology, on
the other hand, is a practical
Engineering discipline,
concerned with
implementing solutions to
practical problems using
current-day technology.
Saturday, 18 June 2011
What is a Dedicated Server?
A Dedicated Server is one that
only has a single website
running on it. Rather than a
shared server which has multiple
websites being served up.
only has a single website
running on it. Rather than a
shared server which has multiple
websites being served up.
What is Disk Space?
Disk Space - the total physical
amount of hard drive space a
host allows a user to have.
amount of hard drive space a
host allows a user to have.
What is Bandwidth?
Bandwidth in respect to hosting,
is the amount of information that
can be transferred from the
server to a Browser. Hosts usually
limit the amount of bandwidth a
user has available per month. As
an example, if you had a file on
your site that was 1mb and you
had 1Gb of bandwidth, users
could download the file 1000
total times.
is the amount of information that
can be transferred from the
server to a Browser. Hosts usually
limit the amount of bandwidth a
user has available per month. As
an example, if you had a file on
your site that was 1mb and you
had 1Gb of bandwidth, users
could download the file 1000
total times.
what is a CGI Service?
CGI stands for Common Gateway
Interface. CGI provides a method
to interface a computer program
with an HTML page. CGI programs
can be written to do many
different things, which includes:
counting visitors to your web
site; processing data obtained
from online forms; and creating
simple animations. If you want
any of these features it is
essential that your host includes
a CGI Service usually in the form
of a CGI-bin.
Interface. CGI provides a method
to interface a computer program
with an HTML page. CGI programs
can be written to do many
different things, which includes:
counting visitors to your web
site; processing data obtained
from online forms; and creating
simple animations. If you want
any of these features it is
essential that your host includes
a CGI Service usually in the form
of a CGI-bin.
What is WebMail?
WebMail - Provides the user an
interface on the Internet so they
can access their e-mail messages
from any computer.
interface on the Internet so they
can access their e-mail messages
from any computer.
What are POP and SMTP servers?
Post Office Protocol is the most
common protocol used to
retrieve e-mail from a mail server.
Most e-mail applications
(sometimes called an e-mail
client) use the POP protocol,
although some can use the
newer IMAP (Internet Message
Access Protocol). The newest
version, POP3, can be used with
or without SMTP (an e-mail
sending protocol, stands for
Simple Mail Transfer Protocol).
IMAP servers are similar to POP
servers, the only difference being
they save the e-mail so they can
be retrieved from multiple
locations or multiple users.
common protocol used to
retrieve e-mail from a mail server.
Most e-mail applications
(sometimes called an e-mail
client) use the POP protocol,
although some can use the
newer IMAP (Internet Message
Access Protocol). The newest
version, POP3, can be used with
or without SMTP (an e-mail
sending protocol, stands for
Simple Mail Transfer Protocol).
IMAP servers are similar to POP
servers, the only difference being
they save the e-mail so they can
be retrieved from multiple
locations or multiple users.
What is E-Mail?
As most people already know E-
mail stands for Electronic Mail
and is now an integral part of
business and personal
communication.
mail stands for Electronic Mail
and is now an integral part of
business and personal
communication.
What is Downloading?
Downloading - Is the transferring
of files from a remote computer
to your local computer.
of files from a remote computer
to your local computer.
What is Uploading?
Uploading - Is the transferring of
files from your local computer to
a remote computer, usually a
server.
files from your local computer to
a remote computer, usually a
server.
What does FTP stand for?
File Transfer Protocol - Allows the
transfer of one or more files
from one computer to another
across the Internet. Usually from
a personal computer to a Server
or vice versa. FTP is fully covered
here
transfer of one or more files
from one computer to another
across the Internet. Usually from
a personal computer to a Server
or vice versa. FTP is fully covered
here
What does DNS stand for?
Domain Name System - a system
of mapping names to IP
addresses. Because domain
names are alphabetic, they're
easier for humans to remember.
The Internet, however, is really
based on IP addresses. Every
time you use a domain name,
DNS translates the name into the
corresponding IP address. It is
similar to a phonebook for the
Internet.
of mapping names to IP
addresses. Because domain
names are alphabetic, they're
easier for humans to remember.
The Internet, however, is really
based on IP addresses. Every
time you use a domain name,
DNS translates the name into the
corresponding IP address. It is
similar to a phonebook for the
Internet.
What does URL Stand for?
Uniform Resource Locator - the
global address of documents and
other resources on the World
Wide Web. The first part of the
address indicates what protocol
to use, and the second part
specifies the IP address or the
domain name where the
resource is located. http://
www.coffeecup.com/ is the URL
for CoffeeCup Software.
global address of documents and
other resources on the World
Wide Web. The first part of the
address indicates what protocol
to use, and the second part
specifies the IP address or the
domain name where the
resource is located. http://
www.coffeecup.com/ is the URL
for CoffeeCup Software.
What is an IP Address?
Every computer connected to the
Internet must have a unique
address known as an IP (Internet
Protocol) address. The IP address
is a numeric address written as a
set of four numbers separated by
dots, for example
64.149.219.213. The address
provides a unique identification
of a computer and the network it
belongs to.
Internet must have a unique
address known as an IP (Internet
Protocol) address. The IP address
is a numeric address written as a
set of four numbers separated by
dots, for example
64.149.219.213. The address
provides a unique identification
of a computer and the network it
belongs to.
What is a Domain Name?
An addressing construct used for
identifying and locating
computers on the Internet.
Domain names provide a system
of easy-to-remember Internet
addresses, which can be
translated by the Domain Name
System (DNS) into the numeric
addresses (Internet Protocol (IP)
numbers) used by a network.
(india.com is a domain
name as is Google.com)
identifying and locating
computers on the Internet.
Domain names provide a system
of easy-to-remember Internet
addresses, which can be
translated by the Domain Name
System (DNS) into the numeric
addresses (Internet Protocol (IP)
numbers) used by a network.
(india.com is a domain
name as is Google.com)
What is HTTP?
HyperText Transfer Protocol - the
underlying protocol used by the
World Wide Web. HTTP defines
how messages are formatted
and transmitted, and what action
Web servers and browsers
should take in response to
various commands. For example,
when you enter a URL in your
browser, this actually sends an
HTTP command to the Web
server directing it to fetch and
transmit the requested Web
page.
underlying protocol used by the
World Wide Web. HTTP defines
how messages are formatted
and transmitted, and what action
Web servers and browsers
should take in response to
various commands. For example,
when you enter a URL in your
browser, this actually sends an
HTTP command to the Web
server directing it to fetch and
transmit the requested Web
page.
What is a Web Server?
Generally used in reference to the
computer hardware that
provides World Wide Web
services on the Internet, a Web
server includes the hardware,
operating system, server
software, TCP/IP protocols and
the Web site content. Web
servers process requests from
Browsers for web pages and
serves them up via HTTP.
computer hardware that
provides World Wide Web
services on the Internet, a Web
server includes the hardware,
operating system, server
software, TCP/IP protocols and
the Web site content. Web
servers process requests from
Browsers for web pages and
serves them up via HTTP.
What is Web Hosting?
Web Hosting or 'Hosting' is a
service provided by a vendor
which offers a physical location
for the storage of web pages
and files. Think of a Web Hosting
Company as a type of landlord,
they rent physical space on their
servers allowing webpages to be
viewed on the Internet.
service provided by a vendor
which offers a physical location
for the storage of web pages
and files. Think of a Web Hosting
Company as a type of landlord,
they rent physical space on their
servers allowing webpages to be
viewed on the Internet.
What are the differences between Meta Data and Data Dictionary?
Metadata is nothing but the data
about data if you take term of
informatica in that through
metadata only you will be
converting or solving the
problem. In the flow of
Informatica mapping real data
will first convert in to metadata
which is not actual data and then
it will be converted to again
metadata to data that is the way
how metadata works in
datawarehouse.
Data Dictionary is the tool where
you can find views tables
restrictions alias and etc data
base activities in perticular
datawarehouse.
about data if you take term of
informatica in that through
metadata only you will be
converting or solving the
problem. In the flow of
Informatica mapping real data
will first convert in to metadata
which is not actual data and then
it will be converted to again
metadata to data that is the way
how metadata works in
datawarehouse.
Data Dictionary is the tool where
you can find views tables
restrictions alias and etc data
base activities in perticular
datawarehouse.
How Do I Create My Own Website?
Creating your own website can
be useful for a number of
purposes. Whether it's to share
your expertise on a particular
topic, start an online business,
foster a community, or just
maintain an online journal of
your activities, having a website
will allow you to make your
content accessible from any
connected computer. It can also
theoretically allow you to have a
larger audience for your ideas
than you would ever have
otherwise. If you have useful
ideas or observations to share,
you may be able to share them
with as many as a few dozen
people throughout the day, if
you are lucky. With a website,
you can share them with
hundreds or even thousands.
Possibly the easiest way to
create your own website is to
use an online site creation tool.
These services often provide
intuitive interfaces for adding
text, images, links, and other
bits of content to a webpage.
Many of these tools have a
WYSIWYG web design platform,
which means "What You See is
What You Get" — what you
create in the design interface is
what your visitors will see.
If you want more options and
functionality on your website,
as well as your own dedicated
web address, you'll need to
create pages in HTML, register a
web domain, and get a hosting
server to upload your pages to.
Web domains can be registered
at any number of registrars —
Godaddy.com is a popular one.
Search for "hosting" or "cheap
hosting" to find many
thousands of available hosting
companies. As a general rule of
thumb, if you're paying more
than about $10 US dollars (USD)
per month for hosting for a
low-traffic website, you're
paying way too much. Many
companies offer space for even
less.
To create HTML, you can write it
from scratch in notepad, or use
a WYSIWYG software program.
HTML is not a programming
language per se, and as such is
much easier to use than true
programming languages. You
can learn basic HTML in less
than an hour and start using it
to create your very own web
pages.
After you create your pages,
they must be uploaded to your
server. You will receive a
username and password from
your host once you register
with them. You can use these in
an application called an FTP
program to connect your
computer with the server, then
send your completed pages
from computer to server. Once
uploaded, your website will be
visible on the World Wide Web
for all to enjoy. Within a few
days, pages with inbound links
will be indexed by major search
engines and begin to appear in
search results.
be useful for a number of
purposes. Whether it's to share
your expertise on a particular
topic, start an online business,
foster a community, or just
maintain an online journal of
your activities, having a website
will allow you to make your
content accessible from any
connected computer. It can also
theoretically allow you to have a
larger audience for your ideas
than you would ever have
otherwise. If you have useful
ideas or observations to share,
you may be able to share them
with as many as a few dozen
people throughout the day, if
you are lucky. With a website,
you can share them with
hundreds or even thousands.
Possibly the easiest way to
create your own website is to
use an online site creation tool.
These services often provide
intuitive interfaces for adding
text, images, links, and other
bits of content to a webpage.
Many of these tools have a
WYSIWYG web design platform,
which means "What You See is
What You Get" — what you
create in the design interface is
what your visitors will see.
If you want more options and
functionality on your website,
as well as your own dedicated
web address, you'll need to
create pages in HTML, register a
web domain, and get a hosting
server to upload your pages to.
Web domains can be registered
at any number of registrars —
Godaddy.com is a popular one.
Search for "hosting" or "cheap
hosting" to find many
thousands of available hosting
companies. As a general rule of
thumb, if you're paying more
than about $10 US dollars (USD)
per month for hosting for a
low-traffic website, you're
paying way too much. Many
companies offer space for even
less.
To create HTML, you can write it
from scratch in notepad, or use
a WYSIWYG software program.
HTML is not a programming
language per se, and as such is
much easier to use than true
programming languages. You
can learn basic HTML in less
than an hour and start using it
to create your very own web
pages.
After you create your pages,
they must be uploaded to your
server. You will receive a
username and password from
your host once you register
with them. You can use these in
an application called an FTP
program to connect your
computer with the server, then
send your completed pages
from computer to server. Once
uploaded, your website will be
visible on the World Wide Web
for all to enjoy. Within a few
days, pages with inbound links
will be indexed by major search
engines and begin to appear in
search results.
What Is Web Design?
Web design is used as a general
term to describe any of the
various tasks involved in
creating a web page. More
specifically, it refers to jobs
focused on building the front-
end of a web page.
The web consists of myriad
pages, presenting information
using different technologies
and linked together with
hyperlinks. There are two basic
aspects to any web page found
on the Internet.
The first is a
presentation that the user
interacts with, usually visually,
while the second is a back-end
that includes information for
non-human browsers.
The basic markup language
used to tell a browser how to
present information is called the
HyperText Markup Language
(HTML). A stricter version of
HTML is also widely used,
known as eXtensible HyperText
Markup Language ( XHTML).
Using HTML or XHTML, a web
designer is able to tell a
browser how a web page
should appear. In the last few
years there has been a push
towards separating the
underlying structure of a web-
page (using HTML) from the
visual presentation of the site
(using Cascading Style Sheets or
CSS). This approach has a
number of major benefits in
both the short and long term,
and is gathering popularity as
time progresses.
From a technical standpoint, the
act of web design can be quite
difficult. Unlike more traditional
print media, HTML has a number
of variable factors. To begin
with, not all browsers interpret
HTML according to the
standards created by the
standard-setting body — the
World Wide Web Consortium,
also known as W3. This means
that while one piece of web
design will appear as the
designer wishes it to in one
browser, it may appear
completely differently in
another. There are numerous
fixes and work-arounds to try
to circumvent browser-specific
bugs, but it is a tenuous
business at best.
Another major limiting factor of
web design is the plethora of
formats a site might be viewed
in. While graphic designers
know exactly how large the
piece of paper they are printing
on will be, a web designer must
account for different monitor
sizes, different display settings,
and even browsers for non-
sighted surfers! Combined,
these concerns often leave a
web designer struggling to
incorporate enough dynamism
to make a web page attractive
on a range of browser sizes,
while creating a layout static
enough to allow for the use of
images and other necessarily
fixed-size components.
In addition to XHTML and CSS,
web designers often use a
number of database driven
languages to allow for more
dynamism and interactivity on
their websites. While useful
with smaller sites, database
driven languages become a
virtual necessity on any site
presenting huge amounts of
data. Some of the most popular
languages for 'dynamic' web
design include ASP, PHP, and
ColdFusion. Macromedia's Flash
also allows for a different sort
of web design and is very
popular amongst many web
designers.
The possibilities for web design
are virtually limitless, although
at one point they were quite
constrained by the boundaries
of the browser itself. With the
advent and flexibility of Flash
and other embedded
technologies, these boundaries
have been all but removed,
allowing for a versatility and
dynamism that challenges the
imagination of anyone
interested in web design.
term to describe any of the
various tasks involved in
creating a web page. More
specifically, it refers to jobs
focused on building the front-
end of a web page.
The web consists of myriad
pages, presenting information
using different technologies
and linked together with
hyperlinks. There are two basic
aspects to any web page found
on the Internet.
The first is a
presentation that the user
interacts with, usually visually,
while the second is a back-end
that includes information for
non-human browsers.
The basic markup language
used to tell a browser how to
present information is called the
HyperText Markup Language
(HTML). A stricter version of
HTML is also widely used,
known as eXtensible HyperText
Markup Language ( XHTML).
Using HTML or XHTML, a web
designer is able to tell a
browser how a web page
should appear. In the last few
years there has been a push
towards separating the
underlying structure of a web-
page (using HTML) from the
visual presentation of the site
(using Cascading Style Sheets or
CSS). This approach has a
number of major benefits in
both the short and long term,
and is gathering popularity as
time progresses.
From a technical standpoint, the
act of web design can be quite
difficult. Unlike more traditional
print media, HTML has a number
of variable factors. To begin
with, not all browsers interpret
HTML according to the
standards created by the
standard-setting body — the
World Wide Web Consortium,
also known as W3. This means
that while one piece of web
design will appear as the
designer wishes it to in one
browser, it may appear
completely differently in
another. There are numerous
fixes and work-arounds to try
to circumvent browser-specific
bugs, but it is a tenuous
business at best.
Another major limiting factor of
web design is the plethora of
formats a site might be viewed
in. While graphic designers
know exactly how large the
piece of paper they are printing
on will be, a web designer must
account for different monitor
sizes, different display settings,
and even browsers for non-
sighted surfers! Combined,
these concerns often leave a
web designer struggling to
incorporate enough dynamism
to make a web page attractive
on a range of browser sizes,
while creating a layout static
enough to allow for the use of
images and other necessarily
fixed-size components.
In addition to XHTML and CSS,
web designers often use a
number of database driven
languages to allow for more
dynamism and interactivity on
their websites. While useful
with smaller sites, database
driven languages become a
virtual necessity on any site
presenting huge amounts of
data. Some of the most popular
languages for 'dynamic' web
design include ASP, PHP, and
ColdFusion. Macromedia's Flash
also allows for a different sort
of web design and is very
popular amongst many web
designers.
The possibilities for web design
are virtually limitless, although
at one point they were quite
constrained by the boundaries
of the browser itself. With the
advent and flexibility of Flash
and other embedded
technologies, these boundaries
have been all but removed,
allowing for a versatility and
dynamism that challenges the
imagination of anyone
interested in web design.
MANAGEMENT; Is a Art or Science?
Management
is everywhere - office, hospital,
school, curity, Finance, trust etc.,
Management is basically
Planning, Organizing,
Coordinating, Directing,
Assessing, Correcting, Motivating
and Achieving a set goal. It is
objective-oriented. We always
have a doubt whether it is an art
or science. It is the oldest of arts
and youngest of science, because
it is of dynamic nature.
Different Managements need
different approaches; for
example Business Management
and Personnel Management are
based on Common principles but
vary a lot in the approach.
Economists say Management is a
Factor of Production; Socialist
views it as a Group of People;
others say that is a process;
Mary
Parker says “ Management in its
true sense, a process by which
an organization realizes its
objectives in a planned manner”;
Management is all about great
ideas, people and achievements;
though there are many
definitions of Management no
single definition is universally
accepted, as it changes from
situation to situation, industry to
industry; it has got different
dimensions and hence cannot be
defined precisely as a Scientific
Theory or Law;
James A. F. says “
Management is the process of
Planning, Organizing Leading
and Controlling efforts of
organization members and of
using all other organizational
resources to achieve pre-
determined Organizational
goals”.
Dr. James Lundy’s views :
“Management is a task of
Planning, Coordinating,
Motivating and Controlling the
efforts of others towards specific
objectives”.
According to Henry
Fayol, “Management is to
forecast, plan, organize,
command, coordinate and
control".
Peter F Drucker defines
Management as “An Economic
Organ of industrial society”; E.F.L.
Breach says “Management is
concerned with seeing that the
job gets done, its tasks are
centered on planning and
guiding the operations that are
going on in the enterprise”;
According to George R Terry
“Management is a distinct
process consisting of planning,
organizing, actuating and
controlling performance to
accomplish the objectives by the
use of people and resources”.
Management is taking inputs,
transforming them into output-
either a good or service; the
effectiveness of this
transforming the input into
output depends on the
Management - especially when
the resources are scarce; It is a
group activity; motivating others
and getting the things done
within the stipulated time,
without compromising on the
quality of the result; it gives
shape and color to the great
ideas of the manager;
Management involves dealing
with people who have different
understanding, sensitivity,
knowledge, capability,
responsibility, maturity.
Science is a collection of
systematic knowledge, collection
of truths and Inferences after
continuous study and
experiments. The Relationship
between Variables and Limits are
defined and the Fundamental
Principles discovered.
Science has got three specific
characters :
1. It is a systematic and
organized knowledge and based
on scientific methods of
observation.
2. Inferences are arrived after
continuous observation and
experiemtns;
3. It has logical principles which
are well defined and are
Universally applicable without
any limitations.
Management Principles have also
evolved and it is changing day by
day according to the change in
the human behaviour; In science
keeping one factor as Variable
and all others as constants the
same experiment is repeated
many times in order to arrive at a
conclusion; but Management
involves human element and
hence all the factors are wildly
varying.
Art uses the known rules and
principles and uses the skill,
expertise, Wisdom, experience to
achieve the desired result. The
point is how to get the things
done in the desired manner to
get the desired result. New
methods can be adopted from
the past experiences and
incidents what to do and what
not to do; Effective Management
is extracting voluntary
cooperation from the staff. So it
is definitely an art and it can be
acquired only by practicing the
theoretical knowledge skillfully
and prudently.
Management has got two faces
like a coin; on one side it is art
and on the other it is science.
Management has got scientific
principles which constitute the
elements of Science and Skill and
Talent which are the attributes of
Art.
Management skills are acquired
by constant practice as in the
case of medicine, engineering
and accountancy; Mere
knowledge of concepts will not
fetch results; understanding
human behaviour, tactfulness,
vision, pragmatism, creativity,
compassion towards staff, team
spirit are all needed by a
Successful Manager for effective
management. The Science and
Art are not mutually exclusive but
complementary to each other.
Therefore Management is both a
science and an art.
is everywhere - office, hospital,
school, curity, Finance, trust etc.,
Management is basically
Planning, Organizing,
Coordinating, Directing,
Assessing, Correcting, Motivating
and Achieving a set goal. It is
objective-oriented. We always
have a doubt whether it is an art
or science. It is the oldest of arts
and youngest of science, because
it is of dynamic nature.
Different Managements need
different approaches; for
example Business Management
and Personnel Management are
based on Common principles but
vary a lot in the approach.
Economists say Management is a
Factor of Production; Socialist
views it as a Group of People;
others say that is a process;
Mary
Parker says “ Management in its
true sense, a process by which
an organization realizes its
objectives in a planned manner”;
Management is all about great
ideas, people and achievements;
though there are many
definitions of Management no
single definition is universally
accepted, as it changes from
situation to situation, industry to
industry; it has got different
dimensions and hence cannot be
defined precisely as a Scientific
Theory or Law;
James A. F. says “
Management is the process of
Planning, Organizing Leading
and Controlling efforts of
organization members and of
using all other organizational
resources to achieve pre-
determined Organizational
goals”.
Dr. James Lundy’s views :
“Management is a task of
Planning, Coordinating,
Motivating and Controlling the
efforts of others towards specific
objectives”.
According to Henry
Fayol, “Management is to
forecast, plan, organize,
command, coordinate and
control".
Peter F Drucker defines
Management as “An Economic
Organ of industrial society”; E.F.L.
Breach says “Management is
concerned with seeing that the
job gets done, its tasks are
centered on planning and
guiding the operations that are
going on in the enterprise”;
According to George R Terry
“Management is a distinct
process consisting of planning,
organizing, actuating and
controlling performance to
accomplish the objectives by the
use of people and resources”.
Management is taking inputs,
transforming them into output-
either a good or service; the
effectiveness of this
transforming the input into
output depends on the
Management - especially when
the resources are scarce; It is a
group activity; motivating others
and getting the things done
within the stipulated time,
without compromising on the
quality of the result; it gives
shape and color to the great
ideas of the manager;
Management involves dealing
with people who have different
understanding, sensitivity,
knowledge, capability,
responsibility, maturity.
Science is a collection of
systematic knowledge, collection
of truths and Inferences after
continuous study and
experiments. The Relationship
between Variables and Limits are
defined and the Fundamental
Principles discovered.
Science has got three specific
characters :
1. It is a systematic and
organized knowledge and based
on scientific methods of
observation.
2. Inferences are arrived after
continuous observation and
experiemtns;
3. It has logical principles which
are well defined and are
Universally applicable without
any limitations.
Management Principles have also
evolved and it is changing day by
day according to the change in
the human behaviour; In science
keeping one factor as Variable
and all others as constants the
same experiment is repeated
many times in order to arrive at a
conclusion; but Management
involves human element and
hence all the factors are wildly
varying.
Art uses the known rules and
principles and uses the skill,
expertise, Wisdom, experience to
achieve the desired result. The
point is how to get the things
done in the desired manner to
get the desired result. New
methods can be adopted from
the past experiences and
incidents what to do and what
not to do; Effective Management
is extracting voluntary
cooperation from the staff. So it
is definitely an art and it can be
acquired only by practicing the
theoretical knowledge skillfully
and prudently.
Management has got two faces
like a coin; on one side it is art
and on the other it is science.
Management has got scientific
principles which constitute the
elements of Science and Skill and
Talent which are the attributes of
Art.
Management skills are acquired
by constant practice as in the
case of medicine, engineering
and accountancy; Mere
knowledge of concepts will not
fetch results; understanding
human behaviour, tactfulness,
vision, pragmatism, creativity,
compassion towards staff, team
spirit are all needed by a
Successful Manager for effective
management. The Science and
Art are not mutually exclusive but
complementary to each other.
Therefore Management is both a
science and an art.
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