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Data Model
A data model is an abstract model that organizes elements of data and standardizes how they relate to one another and to the properties of real-world entities. For instance, a data model may specify that the data element representing a car be composed of a number of other elements which, in turn, represent the color and size of the car and define its owner. The term data model can refer to two distinct but closely related concepts. Sometimes it refers to an abstract formalization of the objects and relationships found in a particular application domain: for example the customers, products, and orders found in a manufacturing organization. At other times it refers to the set of concepts used in defining such formalizations: for example concepts such as entities, attributes, relations, or tables. So the "data model" of a banking application may be defined using the entity-relationship "data model". This article uses the term in both senses. A data model explicitly determines th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abstract Model
A conceptual model is a representation of a system. It consists of concepts used to help people know, understand, or simulate a subject the model represents. In contrast, physical models are physical object such as a toy model that may be assembled and made to work like the object it represents. The term may refer to models that are formed after a conceptualization or generalization process. Conceptual models are often abstractions of things in the real world, whether physical or social. Semantic studies are relevant to various stages of concept formation. Semantics is basically about concepts, the meaning that thinking beings give to various elements of their experience. Overview Models of concepts and models that are conceptual The term ''conceptual model'' is normal. It could mean "a model of concept" or it could mean "a model that is conceptual." A distinction can be made between ''what models are'' and ''what models are made of''. With the exception of iconic models, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
4-2 ANSI-SPARC Three Level Architecture
A coxless four is a rowing boat used in the sport of competitive rowing. It is designed for four persons who propel the boat with sweep oars, without a coxswain. The crew consists of four rowers, each having one oar. There are two rowers on the stroke side (rower's right hand side) and two on the bow side (rower's lefthand side). There is no coxswain, but the rudder is controlled by one of the crew, normally with the rudder cable attached to the toe of one of their shoes which can pivot about the ball of the foot, moving the cable left or right. The steersman may row at bow, who has the best vision when looking over their shoulder, or on straighter courses stroke may steer, since they can point the stern of the boat at some landmark at the start of the course. The equivalent boat when it is steered by a coxswain is called a "coxed four". Racing boats (often called "shells") are long, narrow, and broadly semi-circular in cross-section with gradual tapers, causing little dr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CODASYL
CODASYL, the Conference/Committee on Data Systems Languages, was a consortium formed in 1959 to guide the development of a standard programming language that could be used on many computers. This effort led to the development of the programming language COBOL, the CODASYL Data Model, and other technical standards. CODASYL's members were individuals from industry and government involved in data processing activity. Its larger goal was to promote more effective data systems analysis, design, and implementation. The organization published specifications for various languages over the years, handing these over to official standards bodies ( ISO, ANSI, or their predecessors) for formal standardization. History CODASYL is remembered almost entirely for two activities: its work on the development of the COBOL language and its activities in standardizing database interfaces. It also worked on a wide range of other topics, including end-user form interfaces and operating system con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Hardware
Computer hardware includes the physical parts of a computer, such as the case, central processing unit (CPU), random access memory (RAM), monitor, mouse, keyboard, computer data storage, graphics card, sound card, speakers and motherboard. By contrast, software is the set of instructions that can be stored and run by hardware. Hardware is so-termed because it is " hard" or rigid with respect to changes, whereas software is "soft" because it is easy to change. Hardware is typically directed by the software to execute any command or instruction. A combination of hardware and software forms a usable computing system, although other systems exist with only hardware. Von Neumann architecture The template for all modern computers is the Von Neumann architecture, detailed in a 1945 paper by Hungarian mathematician John von Neumann. This describes a design architecture for an electronic digital computer with subdivisions of a processing unit consisting of an arithmetic log ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Systems Analyst
A systems analyst, also known as business technology analyst, is an information technology (IT) professional who specializes in analyzing, designing and implementing information systems. Systems analysts assess the suitability of information systems in terms of their intended outcomes and liaise with end users, software vendors and programmers in order to achieve these outcomes.Shelly, Gary B., Cashman, Thomas J., & Vermaat, Misty E. ''Discovering Computers 2008, Complete.'' Boston: Thomson Course Technology. ISBN 1 -4239-1205-5 A systems analyst is a person who uses analysis and design techniques to solve business problems using information technology. Systems analysts may serve as change agents who identify the organizational improvements needed, design systems to implement those changes, and train and motivate others to use the systems. Industry As of 2015, the sectors employing the greatest numbers of computer systems analysts were state government, insurance, computer sys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Processing
Data processing is the collection and manipulation of digital data to produce meaningful information. Data processing is a form of '' information processing'', which is the modification (processing) of information in any manner detectable by an observer.Data processing is distinct from '' word processing'', which is manipulation of text specifically rather than data generally. The term "Data Processing", or "DP" has also been used to refer to a department within an organization responsible for the operation of data processing programs. Data processing functions Data processing may involve various processes, including: * Validation – Ensuring that supplied data is correct and relevant. * Sorting – "arranging items in some sequence and/or in different sets." * Summarization(statistical) or (automatic) – reducing detailed data to its main points. * Aggregation – combining multiple pieces of data. * Analysis – the "collection, organization, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
:w:John Krogstie
John Krogstie (born 23 May 1967) is a Norwegian computer scientist, professor in information systems at the Norwegian University of Science and Technology (NTNU) in Trondheim, Norway, and an expert in the field of enterprise modelling. Biography John Krogstie received a MSc in 1991 and a PhD in 1995 both in information systems from the Norwegian University of Science and Technology. From 1991 to 2000 he was employed as a manager in Accenture. In 2000-2005 he was a senior researcher in SINTEF. He is a professor in information systems at NTNU in Trondheim, Norway. John Krogstie is the Norwegian representative for IFIP TC8 and was Chair (2010–2015) of IFIP WG 8.1 on information systems design and evaluation. Work Krogstie's research interests include information systems, conceptual modeling, mobile information systems, eGovernment and enterprise modelling. The SEQUAL framework The SEQUAL framework is a reference model for evaluating the quality of models, the semiot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Janis A
Janis may refer to: As a first name *Janis Amatuzio (born 1950), American forensic pathologist * Janis Antonovics (born 1942), Latvian-British-American biologist * Janis Babson (1950–1961), Canadian child, organ donation *Janis Carter (1913–1994), American actress *Jānis Daliņš (1904–1978), Latvian athlete * Janis Hughes (born 1958), British politician * Janis Ian (born 1951), American songwriter and folksinger *Janis Irwin (born 1984), Canadian politician * Janis Joplin (1943–1970), American singer and songwriter * Janis Kelly (volleyball) (born 1971), Canadian volleyball player *Janis Kelly (soprano), Scottish opera singer * Janis Paige (born 1922), American actress *Janis Rozentāls (1866–1916), Latvian painter *Janis Tanaka (born 1963), American bassist *Janis Winehouse, British pharmacist, mother of Amy Winehouse Fictional characters *Janis Gold, a fictional character on ''24'' *Janis Day, one of the two main characters in the comic strip '' Arlo and Janis'' *J ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Data Model
A physical data model (or database design) is a representation of a data design as implemented, or intended to be implemented, in a database management system. In the lifecycle of a project it typically derives from a logical data model, though it may be reverse-engineered from a given database implementation. A complete physical data model will include all the database artifacts required to create relationships between tables or to achieve performance goals, such as indexes, constraint definitions, linking tables, partitioned tables or clusters. Analysts can usually use a physical data model to calculate storage estimates; it may include specific storage allocation details for a given database system. seven main databases dominate the commercial marketplace: Informix, Oracle, Postgres, SQL Server, Sybase, IBM Db2 and MySQL. Other RDBMS systems tend either to be legacy databases or used within academia such as universities or further education colleges. Physical data m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Logical Data Model
A logical data model or logical schema is a data model of a specific problem domain expressed independently of a particular database management product or storage technology (physical data model) but in terms of data structures such as relational tables and columns, object-oriented classes, or XML tags. This is as opposed to a conceptual data model, which describes the semantics of an organization without reference to technology. Overview Logical data models represent the abstract structure of a domain of information. They are often diagrammatic in nature and are most typically used in business processes that seek to capture things of importance to an organization and how they relate to one another. Once validated and approved, the logical data model can become the basis of a physical data model and form the design of a database. Logical data models should be based on the structures identified in a preceding conceptual data model, since this describes the semantics of the informa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conceptual Schema
A conceptual schema is a high-level description of informational needs underlying the design of a database. It typically includes only the main concepts and the main relationships among them. Typically this is a first-cut model, with insufficient detail to build an actual database. This level describes the structure of the whole database for a group of users. The conceptual model is also known as the data model that can be used to describe the conceptual schema when a database system is implemented. It hides the internal details of physical storage and targets on describing entities, datatypes, relationships and constraints. Overview A conceptual schema or conceptual data model is a map of concepts and their relationships used for databases. This describes the semantics of an organization and represents a series of assertions about its nature. Specifically, it describes the things of significance to an organization (''entity classes''), about which it is inclined to collect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Data Model
A physical data model (or database design) is a representation of a data design as implemented, or intended to be implemented, in a database management system. In the lifecycle of a project it typically derives from a logical data model, though it may be reverse-engineered from a given database implementation. A complete physical data model will include all the database artifacts required to create relationships between tables or to achieve performance goals, such as indexes, constraint definitions, linking tables, partitioned tables or clusters. Analysts can usually use a physical data model to calculate storage estimates; it may include specific storage allocation details for a given database system. seven main databases dominate the commercial marketplace: Informix, Oracle, Postgres, SQL Server, Sybase, IBM Db2 and MySQL. Other RDBMS systems tend either to be legacy databases or used within academia such as universities or further education colleges. Physical data m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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