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UNIT: III. COMPUTER SOFTWAREThe term software refers to set of computer programs, proceduresand associated programs, documents describing the programs andhow they are used.A software package is a group of programs that solve a specificproblem or performs a specific type of job eg: a word processingpackage may contain programs for text editing, formatting, drawings,graphics,etc. hence,a multipurpose computer syatem has a severalsoftware package one each foe each type of job it can perform.

APPLICATION & SYSTEM SOFTWARESoftware refers to a collection of programmes & associated documents.There are two types of software:-

o System Software : It is a set of 1 or more programs, which controlsthe operation &/or extends the processing capability of acomputer system. It makes the operation of a computer systemmore effective & efficient. It helps hardware components worktogether & provide support for the development & execution ofapplication software (programs).Good system software enablesdevelopment & execution of application packages on a computersystem with less time & efforts. A computer without some kind ofsystem would be very ineffective & most likely impossible tooperate. Programs included in a system software package arecalled system programs & programmers who prepare system

software are referred as system programmer.

o Application Software : It is a set of 1 or more programs, whichsolves a specific problem, or does a specific task. Programsincluded in an application software package are called applicationprograms & programmers who prepare system software arereferred as application programmer.

1. PROGRAMMING LANGUAGES AND THEIRSOFTWARE

A programming language is an artificial language designed tocommunicate instructions to a machine, particularly a computer.Programming languages can be used to create programs that controlthe behavior of a machine and/or to express algorithms precisely.

o Object-Oriented Programming Languages:

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Known as the newest and most powerful paradigms, object-orientedprogramming requires the designer to specify the data structures aswell as the types of operations to be applied on those data structures.The pairing of data, and the operations that can be done on it is calledan object. A program made using this language is therefore made up of

a set of cooperating objects instead of an instructions list. The mostfamous object-oriented programming these days are C#, C , VisualBasic, Java, and Python.

o Structured Programming Languages:

An exceptional type of procedural programming, structuredprogramming provides programmers with additional tools to handle theproblems created by larger programs. When using this language,programmers are required to cut program structure into small pieces ofcode that can easily be understood. Instead of using global variables, it

employs variables that are local to every subroutine. Among the popularfeatures of structured programming is that it doesn't accept GOTOstatement which is usually associated with the top-down approach. Suchapproach starts with an opening overview of the system with minimaldetails about the various parts. To add these details, design iterationsare then included to complete the design. Commonly used structuredlanguages include C, Pascal, and ADA.

o Procedural Programming Languages:

Procedural Programming involves a list of operations the program

needs to complete to be able to attain the preferred state. It is asimple programming paradigm where every program comes with astarting phase, a list of tasks and operations, and an ending stage.Also called imperative programming, this approach comes withsmall sections of code that perform certain functions. Thesesections are made up of procedures, subroutines, or methods. Aprocedure is made up of a list of computations that should bedone. Procedural programming lets a part of the code to be usedagain without the need to make several copies. It achieves this bydividing programmatic tasks into small sections. Because of this,programmers are also capable of maintaining and understanding

program structure. Among the known procedural languages areBASIC and FORTRAN.

2. ASSEMBLERS, COMPILERS & INTERPRETERS

o Assemblers: For an assembly language, a computer programto translate between lower-level representations of

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computer programs. An assembler converts basic computerinstructions into a pattern of bits which can be easilyunderstood by the computer and the processor can use it toperform its basic operations.

o Compilers: A compiler is a computer program (or set ofprograms) that transforms source written in a programminglanguage (the source language) into another computerlanguage (the target language, often having a binary formknown as object code). The most common reason forwanting to transform source code is to createan executable program. The name "compiler" is primarilyused for programs that translate source code from a high-level programming language to a lower level language(e.g., assembly language or machine code). If the compiledprogram can run on a computer whose CPU or operating

system is different from the one on which the compiler runs,the compiler is known as a cross-compiler. A program thattranslates from a low level language to a higher level one isadecompiler. A program that translates between high-levellanguages is usually called a language translator, source tosource translator, orlanguage converter.A language rewriteris usually a program that translates theform of expressions without a change of language.

o Interpreters: An interpreter normally means a computerprogram that executes, i.e.performs, instructions written ina programming language. An interpretermay be a program

that either Executes the source code directly translates source code into some

efficient intermediate representation (code) andimmediately executes this

explicitly executes stored precompiled code madeby a compiler which is part of the interpreter system

OPERATING SYSTEMS

MeaningOperating system is a integrated set of programs that control theresources (cpu,i/o devices etc. ) of a computer system and provides itsusers with an interface or virtual machine that is easier to use than thebare machine. it has two main objectives :-1) make a computer system easier to use2) manage the resources of computer system.

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7. TYPES OF OPERATING SYSTEMS Batch Processing Operating System:In a batch processing

operating system interaction between the user and processor is

limited or there is no interaction at all during the execution ofwork. Data and programs that need to be processed are bundled

and collected as a batch and executed together.

Multi-Tasking Operating System:In this type of OS several

applications maybe simultaneously loaded and used in the

memory. While the processor handles only one application at a

particular time it is capable of switching between the applications

effectively to apparently simultaneously execute each application.

This type of operating system is seen everywhere today and is the

most common type of OS, the Windows operating system wouldbe an example.

Real-time Operating System:A real-time operating system

processes inputs simultaneously, fast enough to affect the next

input or process. Real-time systems are usually used to control

complex systems that require a lot of processing like machinery

and industrial systems.

Single User Operating System:A single user OS as the name

suggests is designed for one user to effectively use a computer ata time.

Multi-User Operating System:This type of OS allows multiple users

to simultaneously use the system, while here as well, the

processor splits its resources and handles one user at a time, the

speed and efficiency at which it does this makes it apparent that

users are simultaneously using the system, some network systems

utilize this kind of operating system.

Distributed Operating System:In a distributed system, software

and data maybe distributed around the system, programs and

files maybe stored on different storage devices which are located

in different geographical locations and maybe accessed from

different computer terminals.

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DBMSCOMPONENTS OF DATABASE SYSTEMA database system is composed of four components; Data Hardware

Software Users

1. Data - It is a very important component of the database system. Most

of the organizations generate, store and process 1arge amount of data.

The data acts a bridge between the machine parts i.e. hardware and

software and the users which directly access it or access it

through some application programs.

2. Hardware - The hardware consists of the secondary storage devices

such as magnetic disks (hard disk, zip disk, floppy disks), optical disks(CD-ROM), magnetic tapes etc. on which data is stored together with theInput/Output devices (mouse, keyboard, printers), processors, mainmemory etc. which are used for storing and retrieving the data in a fastand efficient manner. Since database can range from those of a singleuser with a desktop computer to those on mainframe computers withthousand of users, therefore proper care should be taken for choosingappropriate hardware devices for a required database.

3. Software - The Software part consists of DBMS which acts as a bridgebetween the user and the database or in other words, software that

interacts with the users, application programs, and database and filessystem of a particular storage media (hard disk, magnetic tapes etc.) toinsert, update, delete and retrieve data. For performing these operationssuch as insertion, deletion and updation we can either use the QueryLanguages like SQL, QUEL, Gupta SQL or application softwares such asVisual 3asic, Developer etc.

4. Users - Users are those persons who need the information from thedatabase to carry out their primary business responsibilities i.e.Personnel, Staff, Clerical, Managers, Executives etc. On the basis of thejob and requirements made by them they are provided access to the

database totally or partially.Database management system concepts

1) Data Definition Language (DDL) statements are used to define thedatabase structure or schema. A popular data manipulation language is

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that ofStructured Query Language (SQL), which is used to retrieve andmanipulate data in arelational database.Some examples:

o CREATE - to create objects in the databaseo ALTER - alters the structure of the database

o DROP - delete objects from the databaseo TRUNCATE - remove all records from a table, including all spaces

allocated for the records are removedo COMMENT - add comments to the data dictionaryo RENAME - rename an object

Syntax : The create table statement does exactly that:

CREATE TABLE ( ,... );

The data types that you will use most frequently are characterstrings, which might be called VARCHAR or CHAR for variable orfixed length strings; numeric types such as NUMBER orINTEGER, which will usually specify a precision; and DATE orrelated types. Data type syntax is variable from system tosystem; the only way to be sure is to consult the documentationfor your own software.

2) Data Manipulation Language (DML) statements are used formanaging data within schema objects. The DataManipulationLanguage (DML) is a subset of SQL programming language used toretrieve, insert and modify database information. These commands willbe used by all database users during the routine operation of thedatabase Some examples:

o SELECT - retrieve data from the a databaseo INSERT - insert data into a tableo UPDATE - updates existing data within a tableo

DELETE - deletes all records from a table, the space for therecords remaino MERGE - UPSERT operation (insert or update)o CALL - call a PL/SQL or Java subprogramo EXPLAIN PLAN - explain access path to datao LOCK TABLE - control concurrency

Syntax :

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1)The insert statement is used, obviously, to add new rows to atable.

INSERT INTO VALUES (, ... );

The comma-delimited list of values must match the table

structure exactly in the number of attributes and the data typeof each attribute. Character type values are always enclosed insingle quotes; number values are never in quotes; date valuesare often (but not always) in the format 'yyyy-mm-dd' (forexample, '2006-11-30').

Yes, you will need a separate INSERT statement for every row.

2) The update statement is used to change values that are alreadyin a table.

UPDATE

SET = WHERE ;The update expression can be a constant, any computed value,or even the result of a SELECT statement that returns a singlerow and a single column. If the WHERE clause is omitted, thenthe specified attribute is set to the same value in every row ofthe table (which is usually not what you want to do). You canalso set multiple attribute values at the same time with acomma-delimited list of attribute=expression pairs.

3) The delete statement does just that, for rows in a table.

DELETE FROM WHERE ;

If the WHERE clause is omitted, then every row of the table isdeleted (which again is usually not what you want to do)andagain, you will not get a do you really want to do this?message.

3) Data Control Language (DCL ) statements DCL is abbreviation of DataControl Language. It is used to create roles, permissions, and referential

integrity as well it is used to control access to database by securing it..Some examples:

o GRANT - gives user's access privileges to databaseo REVOKE - withdraw access privileges given with the GRANT

command

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9. TRADITIONAL FILE CONCEPTS ANDENVIORNMENT

The traditional file-oriented approach to information processing has foreach application a separate master file and its own set of personal files.COBOL language supported these file-oriented applications. It was usedfor developing applications such as of payroll, inventory, and financialaccounting. However, in general an organization needs flow ofinformation across these applications also and this requires sharing ofdata, which is very difficult to implement in the traditional file approach.In addition, a major limitation of file-based approach is that theprograms are dependent on the files and the files are dependent uponthe programs.These file-based approaches, which came into being asthe first commercial applications of computers, suffered from the

following significant disadvantages:

1. Data Redundancy: In a file system if an information is needed bytwo distinct applications, then it may be stored in two or morefiles. For example, the particulars of an employee may be storedin payroll and leave record applications separately. Some of thisinformation may be changing, such as the address, the pay drawn,etc. It is therefore quite possible that while the address in themaster file for one application has been updated the address inthe master file for second application may have not been.Sometimes, it may not be easy to find that in how many files the

repeating items such as the address has occurred. The solution,therefore, is to avoid this data redundancy by storing the addressat just one place physically, and making it accessible to allapplications.

2. Program/Data Dependency: In the traditional file orientedapproach if a data field (attribute) is to be added to a master file,all such programs that access the master file would have to bechanged to allow for this new field that would have been added tothe master record. This is referred to as data dependence.

3. Lack of Flexibility: Since the data and programs are strongcoupled in a traditional system, most information retrievalrequests would be limited to well anticipated and pre-determined.The system would normally be capable of producing scheduledrecords and queries that it has been programmed to create. In thefast moving and competent business environment of today, apart

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from such regularly scheduled records, there is a need forresponding to un-anticipatory queries and some kind ofinvestigative analysis that could not have been envisagedprofessionally.

11. ER MODELLING

An entity-relationship model (ERM) is an abstract and conceptualrepresentation ofdata. Entity-relationship modeling is a databasemodeling method, used to produce a type of conceptualschema or semantic data model of a system, often a relationaldatabase, and its requirements in atop-down fashion. Diagrams createdby this process are called entity-relationship diagrams, ERdiagrams, or ERDs. An entity may be defined as a thing which is

recognized as being capable of an independent existence and which canbe uniquely identified. An entity is an abstraction from the complexitiesof some domain. When we speak of an entity we normally speak of someaspect of the real world which can be distinguished from other aspectsof the real world. An entity may be a physical object such as a house ora car, an event such as a house sale or a car service, or a concept suchas a customer transaction or order. Although the term entity is the onemost commonly used, following Chen we should really distinguishbetween an entity and an entity-type. An entity-type is a category. Anentity, strictly speaking, is an instance of a given entity-type. Examples:a computer, an employee, a song, a mathematical theorem.A

relationship captures how two or more entities are related to oneanother. Relationships can be thought of as verbs, linking two or morenouns. Examples: an owns relationship between a company and acomputer, a supervises relationship between an employee and adepartment, aperforms relationship between an artist and a song,aproved relationship between a mathematician and a theorem.

: Two related entities

Entities and relationships can both have attributes. Examples:an employee entity might have a Social Security Number(SSN)attribute; theproved relationship may have a date attribute.Every entity(unless it is a weak entity) must have a minimal set of uniquelyidentifying attributes, which is called the entity's primary key.Entity-relationship diagrams don't show single entities or single instances ofrelations. Rather, they show entity sets and relationship sets. Example: a

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particular song is an entity. The collection of all songs in a database isan entity set. The eaten relationship between a child and her lunch is asingle relationship. The set of all such child-lunch relationships in adatabase is a relationship set. In other words, a relationship setcorresponds to a relation in mathematics, while a relationship

corresponds to a member of the relation.

: An entity with an attribute

: A relationship with an attribute

: Primary key

12. INTEGRITY CONSTRAINTS

Integrity constraints are used to ensure accuracy and consistency ofdata in a relational database. Data integrity is handled in a relationaldatabase through the concept ofreferential integrity. There are manytypes of integrity constraints that play a role in referential integrity.Codd initially defined two sets of constraints but, in his second version of

the relational model, he came up with five integrity constraints:Entity integrity

The entity integrity constraint states that no primary key value can benull. This is because the primary key value is used to identify individualtuples in a relation . Having null value for the primary key implies thatwe cannot identify some tuples.This also specifies that there may not beany duplicate entries in primary key column key row.

Referential Integrity

The referential integrity constraint is specified between two relationsand is used to maintain the consistency among tuple's in the two

relations. Informally, the referential integrity constraint states that atuple in one relation that refers to another relation must refer to anexisting tuple in that relation.It is a rule that maintains consistencyamong the rows of the two relations

Domain Integrity

The domain integrity states that every element from a relation shouldrespect the type and restrictions of its corresponding attribute. A type

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can have a variable length which needs to be respected. Restrictionscould be the range of values that the element can have, the defaultvalue if none is provided, and if the element can be NULL.

User Defined Integrity

e.g.: Age>=18 && Age


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a single column or a set of columns. No two distinct rows in a table canhave the same value (or combination of values) in those columns if NULLvalues are not used. Depending on its design, a table may havearbitrarily many unique keys but at most one primary key.

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UNIT IIIDATA COMMUNICATION & NETWORK

1. CONCEPT OF DATA COMMUNICATION

These basic concepts of data communications are:

1.1. Send and Receive Data

Send/write data: A program sends a value for a data point, andthe Data Hub records, or writes, the value for that point. This typeof communication is synchronous. The send and the write areessentially two parts of a single process, so we use the termspretty much interchangeably. You can write a value to the DataHub manually using the Data Browser.

A typical write command from a program using DDE protocolis DDEPoke.

Receive/read data: A program requests to receive the value of adata point. The Data Hub then responds by sending the currentvalue of the point. We call this reading the value from the CascadeData Hub. Again, we sometimes use the two termsinterchangeably, and again, this type of communicationis synchronous.

A typical read command from a program using DDE protocolis DDERequest.

'Automatic' Receive: It is possible to set up live data channels,

where a program receives updates on data points sent from theCascade Data Hub. How it works is the program sends an initialrequest to the Data Hub to register for all changes to a data point.The Data Hub immediately sends the current value of the point,and then again whenever it changes. The Data Hub can receivedata automatically in a similar way. This asynchronous type ofcommunication is sometimes referred to aspublish-subscribe.

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A DDEAdvise command sets up this type of connection, which iscalled an advice loop.

1.1.2. Client - Server

Exchanging data with the Cascade DataHub is done through a client-server mechanism, where the clientrequests a service, andthe serverprovides the service. Depending on the programs it interactswith, the DataHub is capable of acting as a client, as a server, or as bothsimultaneously.

The client-server relationship itself does not determine the direction ofdata flow. For example, a client may read data from the server, or itmight write data to the server. The data can flow either way; the clientmight initiate a read or a write, and the server would respond.

1.1.3. Synchronous and Asynchronous Communication

Every type of communication, natural or man made comes in two basicforms: synchronous or asynchronous.

Synchronous communication means that for each message, thesender expects to get a reply from the receiver, like a telephonecall. There is a back-and-forth exchange, so that each party knowsthat the other is receiving the message. If there is no response,you can be pretty sure that communication didn't occur.

Asynchronous communication means that a message gets sentbut the receiver is not expected to reply, like a radio broadcast ora newspaper.

Each of these communication types has its own value and purpose indata communications, and the Cascade Data Hub is capable of both. Thespecific circumstances and application will determine which form ofcommunication you end up using.

COMMUNICATION MEDIA

Computer networks can be classified according to the hardware andassociated software technology that is used to interconnect theindividual devices in the network, such as electrical cable (HomePNA, power line communication, Ghn), optical fiber, and radiowaves(wireless LAN).

A well-known familyof communication media is collectively knownas Ethernet. It is defined by IEEE 802 and utilizes various standards and

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media that enable communication between devices. Wireless LANtechnology is designed to connect devices without wiring. These devicesuse radio waves or infrared signals as a transmission medium.

Wired technologies

Twisted pairwireis the most widely used medium fortelecommunication. Twisted-pair cabling consist of copper wires

that are twisted into pairs. Ordinary telephone wires consist of twoinsulated copper wires twisted into pairs. Computer networkingcabling (wiredEthernetas defined byIEEE 802.3) consists of 4pairs of copper cabling that can be utilized for both voice and datatransmission. The use of two wires twisted together helps toreducecrosstalkandelectromagnetic induction. Thetransmission speed ranges from 2 million bits per second to 10billion bits per second. Twisted pair cabling comes in two formswhich are Unshielded Twisted Pair (UTP) and Shielded twisted-pair

(STP) which are rated in categories which are manufactured indifferent increments for various scenario.

Coaxial cableis widely used for cable television systems, officebuildings, and other work-sites for local area networks. The cablesconsist of copper or aluminum wire wrapped with insulating layertypically of a flexible material with a high dielectric constant, all ofwhich are surrounded by a conductive layer. The layers ofinsulation help minimize interference and distortion. Transmissionspeed range from 200 million to more than 500 million bits persecond.

ITU-T G.hn technology uses existinghome wiring(coaxial cable,phone lines andpower lines) to create a high-speed (up to 1Gigabit/s) local area network.

Optical fibercable consists of one or more filaments of glass fiberwrapped in protective layers that carries data by means of pulsesof light. It transmits light which can travel over extendeddistances. Fiber-optic cables are not affected by electromagneticradiation. Transmission speed may reach trillions of bits persecond. The transmission speed of fiber optics is hundreds oftimes faster than for coaxial cables and thousands of times fasterthan a twisted-pair wire.

Wireless technologies

Terrestrial microwave Terrestrial microwaves use Earth-basedtransmitter and receiver. The equipment looks similar to satellitedishes. Terrestrial microwaves use low-gigahertz range, whichlimits all communications to line-of-sight. Path between relaystations spaced approx, 48 km (30 mi) apart.

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Communications satellites The satellites use microwave radio as theirtelecommunications medium which are not deflected by theEarth's atmosphere. The satellites are stationed in space, typically35,400 km (22,000 mi) (for geosynchronous satellites) above theequator. These Earth-orbiting systems are capable of receiving

and relaying voice, data, and TV signals.Cellular and PCS systems Use several radio communications

technologies. The systems are divided to different geographicareas. Each area has a low-power transmitter or radio relayantenna device to relay calls from one area to the next area.

Wireless LANs Wireless local area network use a high-frequency radiotechnology similar to digital cellular and a low-frequency radiotechnology. Wireless LANs use spread spectrum technology toenable communication between multiple devices in a limited area.

Infrared communicationcan transmit signals between devices within

small distances of typically no more than 10 meters. In mostcases,line-of-sight propagationis used, which limits thephysical positioning of communicating devices.

A global area network(GAN) is a network used for supporting mobileacross an arbitrary number of wireless LANs, satellite coverageareas, etc. The key challenge in mobile communications ishanding off the user communications from one local coveragearea to the next. In IEEE Project 802, this involves a succession ofterrestrialwireless LANs

CONCEPT OF COMPUTER NETWORKS

A computer network, often simply referred to as a network, is acollection of hardware components and computers interconnected bycommunication channels that allow sharing of resources andinformation.

Networks may be classified according to a wide variety of characteristicssuch as the medium used to transport the data, communicationsprotocol used, scale, topology, and organizational scope.

INTRANET & EXTRANETS

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13(B) EXTRANETS

An extranet is a computer network that allows controlled access fromthe outside, for specific business or educational purposes. An extranetcan be viewed as an extension of a company's intranet that is extended

to users outside the company, usually partners, vendors, and suppliers.It has also been described as a "state of mind" in which the Internet isperceived as a way to do business with a selected set of othercompanies (business-to-business, B2B), in isolation from all otherInternet users. In contrast, business-to-consumer (B2C) models involveknown servers of one or more companies, communicating withpreviously unknown consumer users. An extranet is like a DMZ in that itprovides access to needed services for channel partners, withoutgranting access to an organization's entire network.

UNIT IV: FUNCTIONAL AND ENTERPRISE

SYSTEMS

1. DATA, INFORMATION & KNOWLEDGE CONCEPTS

The term data refers to qualitative or quantitative attributes ofa variable or set of variables. Data (plural of "datum") are typically theresults of measurements and can be the basis ofgraphs, images, orobservations of a set of variables. Data are often viewed as the lowest

level of abstraction from which information and then knowledge arederived. Raw data, i.e. unprocessed data, refers to a collectionof numbers, characters, images or other outputs from devices thatcollect information to convert physical quantities into symbols.

Information in its most restricted technical sense is a message(utterance or expression) or collection of messages that consists ofan orderedsequence ofsymbols, or it is the meaning that can beinterpreted from such a message or collection of messages. Informationcan be recorded or transmitted. It can be recorded as signs, or conveyedas signals by waves. Information is any kind of event that affectsthe state of a dynamic system. The concept has numerous othermeanings in different contexts.Knowledge is a familiarity with someone or something, which caninclude information, facts, descriptions, and/or skills acquiredthrough experience or education. It can refer to the theoretical orpractical understanding of a subject. It can be implicit (as with practicalskill or expertise) or explicit (as with the theoretical understanding of a

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subject); and it can be more or less formal or systematic.[1] In philosophy, the study of knowledge is called epistemology, and thephilosopher Plato famously defined knowledge as "justified true belief."There is however no single agreed upon definition of knowledge, andthere are numerous theories to explain it. Knowledge acquisition

involves complex cognitive processes: perception, learning,communication, association and reasoning; while knowledge is also saidto be related to the capacity ofacknowledgmentin human beings.

2. DECISION MAKING PROCESS

The figure given below suggests the steps in the decision-makingprocess:-

Identifying the Problem: Identification of the real problembefore a business enterprise is the first step in the process ofdecision-making. It is rightly said that a problem well-defined is aproblem half-solved. Information relevant to the problem shouldbe gathered so that critical analysis of the problem is possible.This is how the problem can be diagnosed. Clear distinction shouldbe made between the problem and the symptoms which maycloud the real issue. In brief, the manager should search the'critical factor' at work. It is the point at which the choice applies.Similarly, while diagnosing the real problem the manager shouldconsider causes and find out whether they are controllable oruncontrollable.

Analyzing the Problem: After defining the problem, the nextstep in the decision-making process is to analyze the problem indepth. This is necessary to classify the problem in order to knowwho must take the decision and who must be informed about thedecision taken.

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Uniqueness of the decision.: Collecting Relevant Data: Afterdefining the problem and analyzing its nature, the next step is toobtain the relevant information/ data about it. There is informationflood in the business world due to new developments in the fieldof information technology. All available information should be

utilized fully for analysis of the problem. This brings clarity to allaspects of the problem.

Developing Alternative Solutions: After the problem has beendefined, diagnosed on the basis of relevant information, themanager has to determine available alternative courses of actionthat could be used to solve the problem at hand. Only realisticalternatives should be considered. It is equally important to takeinto account time and cost constraints and psychological barriersthat will restrict that number of alternatives. If necessary, groupparticipation techniques may be used while developing alternativesolutions as depending on one solution is undesirable.

Selecting the Best Solution: After preparing alternativesolutions, the next step in the decision-making process is to selectan alternative that seems to be most rational for solving theproblem. The alternative thus selected must be communicated tothose who are likely to be affected by it. Acceptance of thedecision by group members is always desirable and useful for itseffective implementation.

Converting Decision into Action: After the selection of the bestdecision, the next step is to convert the selected decision into aneffective action. Without such action, the decision will remain

merely a declaration of good intentions. Here, the manager has toconvert 'his decision into 'their decision' through his leadership.For this, the subordinates should be taken in confidence and theyshould be convinced about the correctness of the decision.Thereafter, the manager has to take follow-up steps for theexecution of decision taken.

Ensuring Feedback: Feedback is the last step in the decision-making process. Here, the manager has to make built-inarrangements to ensure feedback for continuously testing actualdevelopments against the expectations. It is like checking theeffectiveness of follow-up measures. Feedback is possible in the

form of organised information, reports and personal observations.Feed back is necessary to decide whether the decision alreadytaken should be continued or be modified in the light of changedconditions.

3. PHYSICAL COMPONENTS OF INFORMATION SYSTEM

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An information system is a system that accepts data resources as input

and processes them into information products as output. This information

system model highlights the relationships among the components and

activities of information systems.

Information System Resources:(i) People Resources:

People are required for the operation of all information systems. Thesepeople resources include:

End users (also called users or clients) are people who use an

information system or the information it produces. They can be

accountants, salespersons, engineers, clerks, customers, or managers.

Most of us are information system end users.

IS Specialists are people who develop and operate information

systems. They include systems analysts, programmers, computer

operators, and other managerial technical, and clerical IS personnel.

Briefly, systems analysts design information systems based on the

information requirements of end uses, programmers prepare computer

programs based on the specifications of systems analysts, and

computer operators operate large computer systems.

(ii) Hardware Resources:

The concept ofHardware resources includes all physical devices andmaterials used in information processing. Specially, it includes notonly machines, such as computers and other equipment, but also alldata media, that is, all tangible objects on which data is recorded, fromsheets of paper to magnetic disks.

(iii) Software Resources:

The concept ofSoftware Resources includes all sets of information

processing instructions. This generic concept of software includes notonly the sets of operating instructions called programs, which directand control computer hardware, but also the sets of informationprocessing instructions needed by people, called procedures.It isimportant to understand that even information systems that dont usecomputers have a software resource component. This is true even forthe information systems of ancient times, or the manual and machine-

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supported information systems still used in the world today. They allrequire software resources in the form of information processinginstructions and procedures in order to properly capture, process, anddisseminate information to their users.iv) Data Resources:

Data is more than the raw material of information systems. The conceptof data resources has been broadened by managers and informationsystems professionals. They realize that data constitutes a valuableorganization resource. Thus, you should view data as data resourcesthat must be managed effectively to benefit all end users in anorganization.Data can take many forms, including traditional alphanumeric data,composed of numbers and alphabetical and other characters thatdescribe business transactions and other events and entities. Text data,consisting of sentences and paragraphs used in written communications;

image data, such as graphic shapes and figures; and audio data, thehuman voice and other sounds, are also important forms of data.The data resources of information systems are typically organized into:

Database that hold processed and organized data.

Knowledge bases that hold knowledge in variety of forms such as

facts, rules, and case examples about successful business practices.For example, data about sales transactions may be accumulated andstored in a sales database for subsequent processing that yields daily,weekly, and monthly sales analysis reports for management. Knowledgebases are used by knowledge management systems and expert systemsto share knowledge and give expert advice on specific subjects.

4. CLASSIFICATION OF INFORMATION SYSTEM

Transaction Processing System (TPS): Applications of information

systems that process business transaction data. Its use at

operational level and focuses on the data. An example is a

computer application for typing.

Management Information System (MIS):Applications ofinformation system that aims to provide information used in the

field of management (management-oriented reporting.) Examples

are computer applications for hospital services, pharmacy

purchasing, scheduling of production machinery and others.

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Decision Support System (DSS):Applications of information

systems that provide decision-oriented information and especially

in situations where decision-making. At the executive level often

called Executive Information System. For example a computer

application to determine the purchase of drug stocks at thehospital, the determination of sugar distribution system and

others.

Expert System (ES):Information system designed to produce a

decision by reproducing knowledge and expertise of the decision

maker and problem solver and then simulate it. For example

advanced applications of artificial neural networks, face

recognition and so forth.

Office automation system: Systems that support business

activities on a large scale. Examples ERP applications for the

company.

5. OVERVIEW OF SECURITY ISSUES IN INFORMATIONTECHNOLOGY

Information security means protecting information and informationsystems from unauthorized access, use, disclosure, disruption,modification, perusal, inspection, recording or destruction. The terms

information security, computer security and information assurance arefrequently incorrectly used interchangeably. These fields areinterrelated often and share the common goals of protectingthe confidentiality, integrity and availability of information; however,there are some subtle differences between them.These differences lieprimarily in the approach to the subject, the methodologies used, andthe areas of concentration. Information security is concerned with theconfidentiality, integrity and availability ofdata regardless of the formthe data may take: electronic, print, or other forms.Computer securitycan focus on ensuring the availability and correct operation ofacomputer system without concern for the information stored or

processed by thecomputer.Governments, military, corporations, financialinstitutions, hospitals, and privatebusinesses amass a great deal ofconfidential information about their employees, customers, products,research, and financial status. Most of this information is now collected,processed and stored on electronic computers and transmittedacrossnetworks to other computers.Should confidential information

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about a business' customers or finances or new product line fall into thehands of a competitor, such a breach of security could lead to lostbusiness, law suits or even bankruptcy of the business. Protectingconfidential information is a business requirement, and in many casesalso an ethical and legal requirement.For the individual, information

security has a significant effect on privacy, which is viewed verydifferently in different cultures.The field of information security hasgrown and evolved significantly in recent years. There are many ways ofgaining entry into the field as a career. It offers many areas forspecialization including: securing network(s) and allied infrastructure,securing applications and databases,security testing, informationsystems auditing, business continuity planning and digitalforensics science, etc.

6. EMERGING TRENDS OF INFORMATION TECHNOLOGY

Ten trends are identified consisting of aspects of: the difficulty of hiring

qualified labor in-country; establishment of strategy resides entirelywithin the IT management; security remains a serious concern; offshoresubcontractors sometimes place their employees within Icelandiccompanies; mid- and upper-level employees who can strategicallydevelop networks and systems are in strong demand; use of informationsystem (IS)/IT standards for information security is mostly voluntary;generally, the establishment of IS/IT strategy does not remain withboard of directors; virtually all Icelandic corporations engage in, or haveengaged in, outsourcing over the past five years (11 sub-trends areidentified); and the business school curricula is inadequate to the needsof Icelandic corporations with respect to IT demands.
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