Information

INFORMATION SYSTEM

2011-04-09T12:47:00.001-07:00

INFORMATION SYSTEMBasic Concepts SystemsSystem: a collection of elements that interact to achieve a goalparticular.According to Jerry FithGerald; system is a network of proceduresinterconnected, gathered together to perform an activity oraccomplish a particular goal.System Characteristics:• Have a component;A system consists of several components that interact with each other, working togetherto form a unity. The components of the system can be a subsystemor the parts of the system. Each system no matter however small, alwayscontaining the components or subsystems. Each subsystemhas the properties of the system to perform a particular function andaffect the overall system process. A system can have aa larger system called the supra system, for example a company canreferred to as a system and industry which is a larger system cancalled the supra system. If the industry is seen as a system, thencompanies can be called a subsystem. Similarly, if a company is deemedas a system, then the accounting system are subsystems.• Limit system (boundary);Boundary is an area that limits the system between a system with which systemother or with the environment outside. Boundary system allows a systemviewed as a whole. Boundary of a system indicates the scope (scope)of the system.• The environment outside the system (environment);Is anything outside the limits of the system that affect system operation.• Liaison system (interface);Is a media liaison between one subsystem with another subsystem.• Enter the system (input);Energy is fed into the system. Input can be inputmaintenance (maintenance inputs) and input signal (input signal). Maintenance inputis the energy that is inserted so that the system can operate. Signal inputis the energy that is processed to obtain the output. For example in the systemcomputer, the program is the maintanance inputs used to operatecomputer and data is input signal to be processed into information.• Output system (Output);Is the result of the energy processed by the system.• Processing systems (Process);Is part of that process the input to be output as desired.• Target system;If the system does not have a target, then the operating system will not be any good.2Classification System:• abstract system; system in the form of thoughts or ideas that are not apparentphysical (system of theology)Physical systems; an existing physical system (a computer system, accounting system,production systems, etc..)• Natural Systems; system that occurs through natural processes. (Solar system, outside the systemspace, etc. reproductive system.Man-made systems; system designed by humans.Man-made systems that involve human interaction with machines called humanmachinesystem (eg information systems)• System Specific (deterministic system); operate with existing behaviorcan be predicted. The interaction of the parts can be detected with certainty thatoutput of the system can be predicted (eg computer systems)Indeterminate system (probabilistic system); system that conditions the future can notpredictable because it contains elements of probability.• closed system (closed system); systems that are not related and are not affectedwith external systems. This system works automatically without interferinghand from the outside. Theoretically such systems exist, but in fact nothere is a system that is completely covered, there is only Relatively Closed system (inrelatively closed, not completely closed).Open system (open system); system-related and affected byouter environment.More specifically recognized also called the automated system, which is partof man-made systems and berineraksi with control by one or more computersas part of the system used in modern society.Automated system has several components, namely;
Hardware (CPU, disks, printers, tape).�� software (operating system, database system, communication control program,application program).�� Personnel (who operate the system, providing input, output consumedand perform activities that support manual systems).�� The data (which must be stored in the system during a certain period).�� Procedure (instructions and policies for operating systems.)Automated system is divided into several categories:♦ On-line systems. On-line system is a system that receives direct input on the areawhere inputs are recorded and produce output that can be the resultcomputing in the areas where they are needed. The area itself can be broken inscale, for example, hundreds of kilometers. Usually used for the reservation of air transport,railway reservations, banking, etc..♦ Real-time systems. Real-time system is a mechanism for controlling, recording data,processing is very fast so that the output can be received in timerelatively equal. The difference with on-line system is a unit of time usedreal-time, usually one-hundredth or thousandth of a second on-line while still dalahscale of seconds or even sometimes a few minutes. Another difference, on-line usually3only interact with the user, while real-time interacting directly withuser and the mapped environment.♦ Decision support system + strategic planning system. Systems that process transactionsorganization on a daily basis and help managers make decisions, evaluateand analyze organizational goals. Used for payroll system, the systemreservations, accounting systems and production systems. Normally shaped statistical package,marketing package, etc.. This system not only records and displays the data but alsomathematical functions, statistical analysis of data and display the information in the formgraphics (tables, charts) as a conventional report.♦ Knowledge-based system. Computer programs are made close to the capabilities andknowledge of an expert. Generally use hardware and softwarespecial software such as LISP and PROLOG.Systems based on the basic principle generally divided into:• The system is specialized, is a difficult system on environmental diterakpandifferent (eg systems biology; fish transferred to landline)• large system; is a system that most of its resources to function doDaily care (eg dinosaurs as a biological system spends mostof his life by eating and eating).• System as part of another system, the system is always a part of the systemlarger, and can be divided into smaller systems.• developing systems; although not applicable to all systems but almost allsystem is always evolving.Performer system consists of 7 groups:1. Users;In general, 3 is the type of user, ie operational, supervisory and executive.2. Management;Generally consist of 3 types of management, namely the user in charge of managementaddress use where a new system implemented, the management system involvedin the development of the system itself and the general management involved instrategic planning systems and decision support systems. Groupmanagement is usually involved with decisions relating to people, timeand money, for example;"The system must be capable of performing the functions x, y, z, but it must be developedwithin six months with the involvement of programmers from the department w, withcost of x ".3. Examiner;The size and complexity of the system that worked and the natural form of organization where the systemwas implemented to determine whether or not inspectors conclusions.Examination usually determine things based on standard measuresdeveloped at many similar companies.4. Analyzer systems;Its functions such as:- Archaeologist; namely that explore how the old system was running,how the system is run and all matters relating to the old system.4- Innovators; namely that helped develop and open the user insightfor other possibilities.- Mediators, namely the communication functions of all levels, among otherusers, managers, programmers, inspectors and other system actorsmay not have the attitude and views of the same.- The head of the project; analyzer system should be more experienced personnelfrom the programmer or designer. In addition, given the general system analyzerdetermined in advance in a job before the other work, iswhich is normal if a portion of the work in charge analyzer system.5. The designer of the system;The designer of the system receives the results of analyzer systems in the form that the user needsnot oriented to a particular technology, which is then transformed to designhigh-level architecture and can be formulated by the programmer.6. Programmer;Working in the shape of the design program that has been received from the designer.7. Operating personnel;Duty and responsibility at the center of the computer such as networking, securityhardware, software security, printing and backups. Actors maynot required when the system is running is not great and does not require classificationspecifically to run the system.The basic point in the development systemAnalyser system is part of a team that works to develop a systemhas high efficiency and meet the needs of end users. This developmentinfluenced by a number of things, namely:• Productivity, the current system is needed for more, better and faster.This requires more programmer and analyzer system quality,extra working conditions, the ability of users to float its own, languagebetter programming, better system maintenance (generally 50% to70% of resources are used for system maintenance), use of technical disciplinesoftware and automated systems development.• Reliability, time spent testing the system in general spend50% of total system development time.Within 30 years a number of systems used in different companiesexperienced an error and ironically is not easy to change it. If thereerrors, there are two ways you can do is to do source trackingerror and must find a way to correct these errors withreplace the program, eliminating a number of long statement or adda new statement.• Maintabilitas, nursing covers;- Modifications to fit the development of hardware systems to improveprocessing speed (which plays an important role in the operationsystem),- Modification of the system according to the development needs of the user. Between 50% to 80%work performed on most systems development undertaken torevision, modification, conversion, improvement and tracking error.5Basic Concept of Information:Information: data that has been processed into a form that has meaning for the recipient andcan be a fact, a value that is useful. So there is a data transformation processbecome an information == input - process - output.Data is the raw material for the information. Differences of information and data isrelative depending on the value of use for management that need. An informationfor certain management-level data for management can be a level above it, orvice versa.Representation of information: information figuratively, for example: binary representation.The quantity of information: the unit of measure information. Depending on the representation. For representationbinary unit: bit, byte, word, etc..Quality of information: the bias against error, because: error measurement andcollection, failure to follow procedures prmrosesan, lost or no dataprocessed, or recording error correction data, error history file / master, errorprocessing procedure non disabling the system.Age of information: when or how long an information has value / meaning forusers. There informasion condition (refer to the particular point in time) and operatinginformation (stating a change in a range of time).Information quality; depends on 3 things, that information must:• Accurate, meaningful information should be free from mistakes and not biased ormisleading. Accurate also means that information must clearly reflect masudnya.• Stay on time, means the information that came at the recipient should not be too late.• Relevant, means that information should be entitled benefits to the wearer. Relevanceinformation for each person differ from one another.Information Value; determined from two things, namely the benefits and costs to get it. Ainformation said to be worth more effective if its benefits compared to costsget it. Measuring the value of information is usually associated with cost analysiseffectiveness or cost benefit.Information Systems Definition:An integrated system that can provide useful information forusers.Or;An integrated system or human-machine system, to provide information forsupport the operation, management within an organization.These systems utilize hardware and computer software, manual procedures,management model and database.6From the above definition there are some keywords:1. Computer-based Systems and Human / Machine- Based computer: the designer must understand the knowledge of computer andinformation processing- Human Systems machines: there is interaction between humans and machines to manageas a tool to process information. There is a manual process that must be donehumans and there is an automated process by machine. Therefore we need aprocedure / manual system.2. Integrated database system- The use of databases together (sharing) in a data basemanagement system.3. Support Operations- Information that is processed and generated used to support the organization's operations.The term Information System= Management Information System= Information Processing System= Information Decision System= Information System.Everything refers to a computer-based information system designed tosupport the operation, management and decision-making functions of an organization.According to Robert A. Leitch; information system is a system in an organizationwhich bring together the needs of daily transaction processing, support operations, aremanagerial and strategic activities of an organization and provide a specific outside partywith the necessary reports.Physical Component Information System:1. Computer hardware: CPU, Storage, device Input / Output, Terminal forinteraction, data communication media2. Computer software: system software (operating system and utilitinya)common software applications (programming language), software applications (applicationaccounting etc.).3. Databases: storing data on computer storage media.4. Procedure: step-by-step use of system5. Personnel for operations management (SDM), includes:- Clerical personnel (for handling and processing transaction data and performinquiry = operator);- First level manager: to manage the data processing is supported with planning,scheduling, identification of situations out-of-control and decision making levelslower middle.- Staff specialist: used for the analysis for planning and reporting.- Management: for making periodic reports, requests khsus, special analysis,khsusus report, supporting the identification of problems and opportunities.Applications = program + operating procedures.7RELATIONS WITH MANAGEMENT INFORMATION SYSTEMIn part 1 already mentioned that one of the components of information systems ispersonnel as managers of information. Therefore, the relationship between information systemsvery closely with the managers. System information required depends on theneeds of managers.Management information system organized in a management structure. Thereforeshape / type of system the necessary information in accordance with the level of management.Top Level Management: strategic planning, policy and decision making.Medium Level management: for tactical planning.Lower level management: for planning and monitoring operationsOperator: for transaction processing and responding to requests.For the development of an information system necessary organizational management structurepersonnel.Strutktur basically:Director of Information SystemsSystems Development ManagerSystems AnalystProgrammerComputers and Operations managers.The variation of the management structure is very dependent on Managerial Efficiency vs. User Service.INFORMATION SYSTEM DESIGNThe design of information systems is the development of new systems from old systemsThere, where the problems occurred in the old system is expected to be resolved inthe new system.INFORMATION SYSTEM DEVELOPMENT LIFE CYCLE(SYSTEM DEVELOPMENT LIFE cycles - SDLC)Conceptually an information system development cycle is as follows:1. Systems Analysis: analyze and define problems and possible solutionsfor information systems and organizational processes.2. System Design: designing output, input, file structure, programs, procedures,hardware and software needed to support information systems3. Development and Testing System: build the necessary software tosupport systems and perform accurate testing. Perform installation and testingof the hardware and operating software4. System Implementation: switch from the old system to new system, conduct training andguidance as necessary.5. Operation and Maintenance: support the operation of information systems and make changesor additional facilities.6. System Evaluation: evaluate sejauih where the system has been built and how wellsystem has been operated.8The cycle takes place repeatedly. The cycle represents the classical modelof information systems development. New models, such as prototyping, spiral, 4GT andcombination of the classical model developed above.ANALYSIS SYSTEMThe reason for the importance of beginning the analysis of systems:1. Problem-solving: the old system was not functioning as required. For that analysisnecessary to fix the system so it can function as needed.2. New needs: the need for new in the organization or environment so thatrequired any modifications or additional information systems to supportorganization.3. Implementing new ideas or technologies.4. Improve overall system performance.Limitation of System Analysis:Activities conducted in the analysis system must be able to answer general questions, as follows:1. The new system is to be built? or2. The system is to be added or modified on the old system that alreadythere?To that must be answered in detail questions:1. What information is needed?2. By whom?3. When?4. Where?5. In what form?6. How do I get it?7. Where did it come from?8. How do I collect?Proposal conduct systems analysis; Contains:1. The definition is clear and consistent about the reasons for the analysis2. The definition limits the analysis to be performed3. Identify the facts that will be collected and studied during the analysis4. Identify sources where the facts can be obtained5. Description of objectives and constraints that may be in the analysis6. Projection of potential problems that will occur during the analysis7. Schedule tentative analysisThe sources of facts that can be learned for the analysis of the system:1. Existing system2. Other internal sources: people, documents, and the relationship between those organizations orthere are functions3. External Source: interface with other systems, seminars, vendors, journals, textbooks andinformation or other sciences which are outside the system9Analysis Framework:1. Analysis of levels of decision makers (management organization): analysisorganization, functions and information required and the information generated.2. Analysis of the flow of information: identifying what information is needed, whorequiring, where it comes from.3. Analysis of input and output.In this analysis techniques and tools used, ie: interview, questionaire, observation,sampling and document gathering, charting (organization, flow, dfd, ER, OO, etc.), decisiontables and metricsReport the results of the analysis:Report the results of the analysis must contain:1. Description of the reason and scope (limitations) analysis2. Description of existing systems and operations.3. Description of the purpose (objective) and the constraint system4. The description of the problems and potential problems not resolved5. A description of the assumptions taken by the system analyst during the analysis process6. The recommendations that the new system and the need for preliminary design7. Projection of resource requirements and costs are expected to include in the designnew systems or modify them. These projections include eligibility for the processnext.Categories aspects of feasibility:1. Technical feasibility: the feasibility of hardware and software.2. Economic feasibility: whether there are gains or losses, unusual operational efficiencyorganization.3. Feasibility surgery: associated with operating procedures and the people who runorganization4. Feasibility schedule: to use models such as PERT and schedulingGantt Chart. Whether or not feasible development schedule.The final result of the analysis system (decision):1. Stop the job, because the proposal is not feasible.2. Wait a moment, because there are still other considerations.3. Modification, management decided to modify prososal with other subsystems.4. Process with the terms, there eligibility requirements.5. Process unconditionally, all requirements are met. Submissions will be accepted and the process continues intooriginal design.System development cycle by J. F. Kelly;1. Research systemsa. Definition of the scope.b. Research Studies2. Analysis and design of the systema. Research Studiesb. Data collection and analysisc. Design systemd. Plan implementation103. Development systema. Developmentb. Testingc. Operationd. TreatmentSystem development cycle according to Martin L. and Thomas Harrel;1. Conception system2. Preliminary Analysisa. Pendefinisan preliminary issuesb. Investigationc. Preparation of the proposed system3. Design systema. Detailed Analysisb. Designing decisionc. Designing targetd. System design4. Programminga. Solving back designb. Develop an outline flowchartc. Writing instruction programd. Assembling programse. Preparing data for testf. Testingg. Checking resultsh. Diagnose faultsi. Repair programj. Starting the testing system5. Documentation6. Installation system7. Operating systemDESIGN SYSTEMThe analysis system used to answer the question what? While the design usedto answer the question how? The design concentrates on how the system is builtto meet the needs analysis phase.The elements of knowledge related to the design process:1. Organizational resources: based on 5 elements of the organization, namely: man, machines,material, money and methods.2. The information needs of users: information obtained from users during the phasesystems analysis.3. System requirements: results of the analysis system.4. Data processing methods, whether: manual, elektromechanical, puched card, orcomputer base.5. Operating data. There are some basic operations of data, ie: capture, classify, arrange, summarize,calculate, store, retrieve, reproduce and disseminate.6. Design tools, such as: dfd, DCD, dd, decision tables, etc..11The basic steps in the design process:1. Defining the purpose of the system (defining the system goal), not only based on informationusers, but also a study of abstraction and the overall characteristicssystem information needs.2. Building a conceptual model (develop a conceptual model), a pictureoverall system that describes the functional unit as the unit system.3. Applying kendala2 organization (applying organizational contraints). Applysystem constraints to obtain the most optimal system. Organizational elementsis a constraint, while the functions that must be optimized are:performance, reliability, cost, schedule instalation, maintenability, flexibility,grouwth potential, life expectancy. Models for optimal system can be describedas a model that contains: the need for system and organizational resourcesas input; weighting factor consists of the functions above optimal, and the total valueshould be optimized from the weight factor.4. Defining a data processing activities (defining data processing activities).This can be done by defining the approach of input-process-output. Fordetermine this requires an iterative process as follows:a. Mengidentifikasn most important output to support / achieve the goal system(System's goal)b. It lists the specific fields of information needed to provide these outputsc. Identify spesifikik data input required to build fieldrequired information.d. Describe the data processing operations are applied to process inputoutput should be required.e. Identify the input element to be input and stored partsduring the processing of inputs into outputs.f. Repeat steps ae continuously till all the required output is obtained.g. Build databases that will support the effectiveness of the system to meetsystem requirements, how data processing and data characteristics.h. Based on the constraints on system development, priority support, the estimatedcost of development; reduce the input, output and processing the extremei. Define the various control points to regulate the activities of data processingdetermine the general quality of data processing.j. Complete the input and output format is best for system design.5. Prepare a proposal system design. This proposal is necessary for the management whetherthe next process feasible to proceed or not. Things that need to be prepared inpreparation of this proposal are:a. Restate the reasons for the commencement of work the system includingpurpose / specific objective and related to user needs and designsystem.b. Setting up a simple model however, a comprehensive system that willproposed.c. Showing all available resources to implement andcare system.12d. Identify critical assumptions and issues that might not resolvedaffect the final system design.While the format of the design proposal is very berfariasi but contain thingsabove.Basic Principles of DesignThere are 2 basic principles of design, a.l:1. Design of monolithic systems. Emphasis on systems integration. Resource which can beintegrated to obtain an effective system, especially in cost.2. Modular system design. Emphasis on solving the functions that haveLow idependensi into modules (functional subsystem) so that separateallows us to concentrate on design per module. An information systemcan be broken down into seven functional subsystems, ie: data collection, data processing, fileupdates, data storage, data retrival, information reports and data processing controls.A general guideline in the design of a functional subsystem of a system of information:1. Sources of data should be collected only once as an input to information systems.2. Accuracy of data sources is highly dependent on the number of steps to his records, collectand prepare data for processing. The fewer steps the more accurate.3. Data generated from computer-based system should not be inserted again intosystem.4. Timing necessary to collect data must be smaller than the timinginformation will be needed.5. Keep the selection means the most optimal data collection6. Data collection did not have on-line, but depending on the needs of information.7. All data sources should be in the validation and edited immediately after the gather.8. Data that has been validated, should not be validated in further processing.9. Total control must be checked again before and after a processing activitygreat done.10. Data must be stored only in 1 place in the database unless there is a constraint system.11. All fields should have data entry and maintenance procedures.12. All data must be printed in a format that is meaningful for audit purposes.13. Transaction file must be at least maintained in a cycle of updates to the database.14. Backup and security procedures must be provided for all field data.15. Any non-sequential files need to have periodic reorganization procedures.16. All data fields must have the date of update / access to storage last.To analyze the system effectively, we need more than just a devicemodeling, which is the method. This method changed from time to time in accordance withtechnological developments. This cycle tends menglami significant change withdiscovery of a fourth-generation language fifth and last generation where the approachwith object-oriented paradigm and the compatibility between models.There are basically two methods of approach in building the system, the first of which is topdown.In this method the system derived from the global mapping is thenwill be reduced to a more descriptive. This method is analogous to the creationhome that starts from the most fundamental aspect that is the foundation down to the smallest
such as a faucet in the bathroom. The second method is bottom-up, where the systemmapped from the smallest unit so that the largest unit, such as automobile assembly. Inearly 1980_an becoming known techniques by using the concept of designing structuredparallel and cycle, for example between test programs and programming work can be doneparallel, and if there is something wrong when implementing the survey,analysis and redesign that replaces the classical method of designing that tends toserial.In principle, the design activities in a structured system covers:Survey; function to determine the needs of users, the errors inold system, set design goals, proposed automation systemfeasible and acceptable, and prepare a report containing a survey of allsomething, the points above.

Windows XP Hidden Tips

2011-04-08T03:09:00.000-07:00

1 – Total Uptime

It boasts how long your computer has been running.

Click Start, then run and then type ’systeminfo’.

The computer will produce a lot of useful info, including the uptime. If you want to keep these, type ’systeminfo > info.txt’. This creates a file called info.txt you can look at later with Notepad.

2 – Delete Files Immediately

You can delete files immediately, without having them move to the Recycle Bin first. Go to the Start menu, select Run… and type ‘gpedit.msc’; then select User Configuration, Administrative Templates, Windows Components, Windows Explorer and find the Do not move deleted files to the Recycle Bin setting. Set it. Poking around in gpedit will reveal a great many interface and system options, but take care — some may stop your computer behaving as you wish.

3 – Lock XP

You can lock your XP workstation with two clicks of the mouse. Create a new shortcut on your desktop using a right mouse click, and enter ‘rundll32.exe user32.dll,LockWorkStation’ in the location field. Give the shortcut a name you like. That’s it — just double click on it and your computer will be locked. And if that’s not easy enough, Windows key + L will do the same.

4. Remove System Software

XP hides some system software you might want to remove, such as Windows Messenger, but you can make it show everything. Using Notepad or Edit, edit the text file /windows/inf/sysoc.inf, search for the word ‘hide’ and remove it. You can then go to the Add or Remove Programs in the Control Panel, select Add/Remove Windows Components and there will be the software and you can now uninstall it.

5. Interesting New Commands

For those skilled in the art of DOS batch files, XP has a number of interesting new commands. These include ‘eventcreate’ and ‘eventtriggers’ for creating and watching system events, ‘typeperf’ for monitoring performance of various subsystems, and ’schtasks’ for handling scheduled tasks. As usual, typing the command name followed by /? will give a list of options.

Computer virus

2011-04-05T09:03:00.000-07:00

Who can forget the way the world was frozen with the threat of the "Millennium Bug"? While people around the globe should have been counting down to a phenomenal celebration, we were too busy preparing for certain doom and gloom beset by a computer virus. Of course, the clock struck twelve on January 1, 2000 and a new millennium quietly began, bug-free.

Those unfortunate enough to have had to deal with a computer virus knows all too well the damage that can be done. From taking on annoying quirks, to erasing files, to completely obliterating computers or entire systems, the powerful effect of a computer virus is nothing to sneeze at. Computer viruses pose real threats that can be minimal, or can cause worldwide destruction.

In computer security technology circles, the definition of a computer virus is a "self-replicating program that spreads by inserting copies of itself into other executable code or documents".

Related Coverage

A computer virus behaves in a manner similar to a biological virus, which spreads by inserting itself into living cells.

Extending the analogy, the insertion of a computer virus into a program is termed as an "infection" and the infected file (or executable code that is not part of a file) is called a "host". Viruses are one of several types of malicious software, also known as "malware". The term "virus" is often extended to refer to worms, Trojan horses and other sorts of malware. These are less common than they used to be, however, so the inclusion of these types of malware can be confusing to computer users. This confusion can have serious implications, as it can lead to a focus on preventing one genre of malware over another, potentially leaving computers vulnerable to future damage. The basic rule holds that computer viruses can only damage software, not hardware.

Viruses have targeted in the following types of hosts:

* Boot sectors of floppy disks; hard disk partitions.

* Master boot record of a hard disk.

* Binary executable files (.COM-files and .EXE-files in MS-DOS; portable executable files in Microsoft Windows; ELF files in Linux).

* General-purpose script files (batch files in MS-DOS and Microsoft Windows; shell script files on Unix-like platforms).

* Application-specific script files (Telix scripts).

* Documents containing macros (Microsoft Word documents).

A computer virus by nature is destructive, but others are created solely for the annoyance factor. Some viruses pester computer users with a delayed payload, also known as a "bomb". For example, a bomb virus might display a message on a specific day, or wait until it has infected a certain number of hosts. A time bomb occurs on a particular date or time, and a logic bomb occurs when the computer user takes an action that triggers the bomb. However, the predominant negative effect of viruses continues to be their uncontrolled self-reproduction, which wastes or overwhelms computer resources.

To hinder the continuous spread of computer viruses, programmers have created anti-virus software. However, a fast infector can infect every potential host file that it's able to access. This presents a special problem to anti-virus software. A virus scanner will perform a system-wide scan, accessing every potential host file on the computer. If the virus scanner fails to notice that a virus exists in the computer's memory, the virus can "piggy-back" on the virus scanner, and infect every file that is scanned. Fast infectors rely on their incredible spreading rate. To combat the problem, certain anti-virus software programs, like the well-known Spyware, are expanding to cover worms and other threats.

Like the potential devastation of the Millennium Bug in 2000, computer viruses continue to present a real threat to single users and corporate networks alike.

about the data base

2011-04-04T03:06:00.001-07:00

about the data base
Since there are courses Database, so I'm going ga would (should not!! Hehehehe) at least know the ins and outs of the Database. This is the beginning I started to investigate about the Database. Let us see the definition ..What the Data Base System Sih?The integration consists of a number of functional components that are interconnected and together aim to meet a particular process. Functional component or relation is usually shown with a key from each file that exists. In one file there are records of the same type, same size, same shape, which is a uniform set of entities. One record consists of fields that are interconnected shows that the field is in one sense a complete and recorded in one record.Hmmm .. from above there are several important points that we can take. Hayoo hell? Ask Why? (Halah.. So digress not clear). The following important points:

    * Is data oriented and not oriented programs.
    * Can be used by several application programs without the need to change its data base.
    * Can be developed with ease, both the volume and structure.
    * Able to meet the needs of new systems easily.
    * Can be used in different ways.
Do not be confused .. (O_O), grab a coffee .. sit .. medhang .. while reading this article ..Key Principles and purpose
but the point setting data. If the goal is:

    * Efficiency of storage space (Space)
Conducting a number of suppression of data redundancy (duplicate data).

    * Accuracy (Accuracy)
Performed coding or the formation of relationships among the data along with the application of rules / constraints (constraint) data type, data domain, the uniqueness of the data, which can be applied strictly in a database.

    * Availability (Availability)
Because the interests of a usage data, a database may have data that spread in many geographical locations. With the use of computer networking technologies that are disuatu location / branch, can also be accessed (that would be available / available) for locations and other branches.

    * Completeness (Completeness)
Complete absence of data we manage in a data base is relative (both to the needs of users as well as with respect to time).

    * Security (Security)
Determining a nobody (user) who may use the data base along with the objects therein and determine the types of operations are allowed by that user.

    * Togetherness User (Sharbility)
The user database is often not limited to one user only, or in a single location or by a system / application only. The database can be used by multiple users, for example by a number of departments within the company or by multiple systems such as payroll systems, inventory systems, system sales of goods, and so forth. To meet the goal should be managed by the system (application) that support multiuser environment.Database system is a combination of database and database management system (DBMS). The components of the database system include:

    * Hardware (Hardware) as a supporting data processing operations.
    * Operating System (Operating System) or software to manage databases.
    * Data Base (database) as the core of the system database.
    * Database Management System (DBMS).
    * Users (Users).
    * Other applications.
Device to maintain data abstraction known as the data model. The data model is a collection of concepts that can be used to draw the structure of the data.The structure of the database includes data type, relationship, and several conditions must be fulfilled database.There are some common definitions used in the database, namely:

    * Entity: Entity is a person, place, event or concept that information is recorded. In the field of Student Administration, for example, students, books, payment.

    * Attributes: Attributes are also called data elements, data fields or data items used to describe an entity and have certain values, such as attributes of an entity described by the employee, name, age, address, occupation.

    * Data Value (Value Data): Data Value is the actual data or information stored on each data element, or attribute. The attribute name of the employee indicates the place where information is stored employee name, the value of such data is Anjang, Arif, Suryo, and others which is the content of the employee's name.

    * File / Table: Collection of similar records that have the same length of elements, attributes the same, but different data values.

    * Record / tuple: A collection of elements related to each other informed about a complete entity. One record represents one data or information.
Data AbstractionThe main purpose of the database system is that users are able to compile an abstract view of data. Shadow of the data is no longer considering how one actual condition data entered into the database is stored in which sector, but involves a whole how this data can be abstracted on the conditions faced by everyday users. Real system, the technical how data is stored and maintained as if the hidden complexity and then expressed in the language and images are easily understood by the layman.There are three user groups in the level of abstraction when looking at a database, namely:

    * Physical Level: This level represents the lowest level of abstraction for describing how data is stored in real conditions.
    * Conceptual Level: This level describes what data is stored in a database and relationships between data from the entire database. Users do not care for the physical level of complexity in the structure again, drawing simply by using boxes, lines, and the relationship sufficiently.
    * Level Users view (View level): This level represents the highest level of abstraction that describes the data only partially viewed and used from the entire database, it is because some database users do not need all the contents of the database.
Anybody want to add style gan?