Free Essay

Computer

In: Science

Submitted By sahilmaredia
Words 7438
Pages 30
Computer crime involves: Theft by computer (including identity theft and phis hing) Software piracy and intellectual property misuse Software sabotage (malw are- including worms, viruses, Trojan horses, e tc.) Hacking and electronic trespassing. The computer crime dossier Computer crime: any crime accomplished through knowledge or use of computer technology Businesses and government institutions lose billions of dollars every year to computer criminals The majority of crimes is committed by company insiders Typically covered up or not reported to authorities to avoid embarrassment According to a 2001 survey of over 500 companies and government agencies: 85% detected computer security breaches in the preceding 12 months Financial losses due to security breaches topped $377 million 70% reported that Internet connections were frequent points of attack Only 31% said that internal systems were frequent points of attack. Theft by computer Theft is the most common form of computer crime. Computers are used to steal Money Goods Information Computer resources One common type of computer theft today is the actual theft of computers, such as notebook and PDAs Notebook and PDAs are expensive Data stored on a computer can be more valuable Denial o f Service ( DOS) Attacks bombard servers and Web sites with so much bogus traffic that they are effectively shut down networks, denying service to legitimate customers and clients. Computer security Protecting computer systems and the information they contain against unwanted access, damage, modification, or destruction Two inherent characteristics A computer does exactly what it is programmed to do, including reveal sensitive information Can be reprogrammed Any computer can do only with it is programmed to do Cannot protect itself from malfunctions or deliberate attacks Physical access restrictions Identify people attempting to access computer equipment Usually using a number of tools and techniques. Depending on the security system, you might be granted access to a computer based on: Something you have A key, an ID card with a photo, or a smart card containing digitally encoded identification in a built-in memory chip Something you know A password, an ID number, a lock combination, or a piece of personal history, such as your mother’s maiden name Something you do Your signature or your typing speed and error patterns Something about you A voice print, fingerprint, retinal scan, facial feature scan, or other measurement of individual body characteristics; these measurements are collectively called biometrics. Passwords The most common tool for restricting access to a computer system Effective passwords are: Not real words Not names Changed frequently Kept secret A combination of letters and numbers Firewalls, encryption, and audits Firewalls A locked gate that opens only for information packets that can pass one or more security inspections Can be used for both corporations and individuals. Firewalls, encryption, and audits Encryption Encrypts a message by applying a secret numeric al code, called an encryption key The message is sent as an indecipherable garble of characters After it is received, it will be reconstructed with a matching key Audit-control software Monitor and record computer transactions as they happen so auditor can trace and identify suspicious computer activity after the fact To avoid the case that electromagnetic signals emanating from the computer hardware is “heard” so that some sensitive information is read. Backups and other precautions A power surge or failure can wipe out well protected data Uninterruptible power supply (UPS) Can protect computers from data loss during power failures Surge protectors Do not help during power failure Can shield electronic equipment from power spikes Backup Disasters cannot be avoided completely, so we need to back up data Have a routine for making regular backups Many systems are backed up at the end of each work day Storage technology, redundant array of independent enables to backup data at several hard disks simultaneously. Human security controls: law, management and ethics Computer security is human problem that cannot be solved by technology alone Manager must understand the practical, ethical, and legal issues surround security If manager do not defend against security threats, information cannot be secure The role of system administrator Play a key role in determining the security of a computer network so as to ensure that only legitimate users have access to the system Authentication mechanism Asking potential users to identify themselves—pass word management Guarantee that users have permission to perform particular actions. The role of system administrator Ensure that each user’s privileges are set correctly Updating operating system periodically with the latest patches Performing backups on a regular basis Back up data and keep data far from the computer system. Computer security measures can create problems of their own – a double-edged sword Overstating the importance of computer security Interfere with people getting their work done In the extreme, threaten individual human rights When security threatens privacy Active badges Best example that technology can simultaneously improve security and threaten privacy by: Identifying who enters a door or logs onto a machine Finding an employee’s current or earlier location Remembering: at the end of the day, an active-badge wearer can get a minute-by-minute printout listing exactly where and with he’s/she’s been. Justice on the electronic frontier Dozens of hackers have been arrested for unauthorized entry into computer systems and for the release of destructive viruses and worms In order to respond to the growing computer crime problem, new laws against electronic trespassing are created, for example: Canadian PIPED ACT (The Personal Information Protection and Electronic Documents Act) Each of these laws introduced new problems by threatening rights of citizens—problems that have to be solved by courts and by future lawmakers 20 Security and reliability. Bugs and breakdowns Software errors and hardware glitches are also important issues related to computer security Software bugs do more damage than viruses and computer burglars combined Facts about software engineering: It is impossible to eliminate all bugs Even programs that appear to work can contain dangerous bugs The bigger the system, the bigger the problem Computer breakdowns pose a risk to the public and the incidence rate doubles every two years A traffic system controlled by a computer system Hardw are problems are rare when compared with software failures. Computer at war Smart weapons Missiles that use computerized guidance systems to locate their targets In theory, they can greatly reduce the amount of civilian destruction in war They reduce the amount of time people have to make the decision An autonomous system A complex system tha t can assume almost complete responsibility for a task without human input.Layered Defenses Organization with large computer networks will need to resort to a layered defensive approach Place sophisticated pattern-recognition software and special hardware on the perimeter of the network Special-purpose hardware, called security p rocessors will allow every message to be encrypted The People Problem This is the weak link in the system For example, some people continue to spread viruses by opening attachments to e-mail from unknown sources. How Open? Will the onslaught of malware and spam place the openness of the Internet in peril? Either computer administrator or computer user cannot spend a lot of time to eliminate malicious software o r spam message. The electronic file cabinet: database basics Database anatomy Database classification Legacy databases Relational databases Object (object-oriented) databases Multidimensional Databases Data warehousing Data marts Multimedia databases Natural language database. Object-oriented databases Future database Will not store records in tables and hierarchies, but store objects Every object is an instance of a class The class specify the data contained in the object as well as the kinds of operations perhaps performed on the data Multimedia databases Can handle graphical and dynamic data along with text and numbers Catalog art, photographs, maps, video clips, sound files, etc Media files are not really stored in database Database is used as an index. Natural language database More artificial intelligence technology will be incorporated in future database Now, database and data-mining software can response to simple natural language queries Queries in English or other human languages. Natural language database More artificial intelligence technology will be incorporated in future database Now, database and data-mining software can response to simple natural language queries Queries in English or other human languages. Database anatomy Relational Database A collection of information stored in an organizational form in a computer Typically composed of one or more tables A table is a collection of related information For example A database of an address book can have two tables One for personal contacts and the other for business contacts. Relational Database A database table is a collection of records A record: A database of an address book, a record contains information about one person Each discrete chunk of information in a record is called a field For example, A record of an address book can contains fields for last name, first name, phone number, etc The type of information a field can hold is determined by its field type or data type Data can be viewed by the ways Form views: show one record at a time List views: display several records in lists. Relational Database What makes a database relational Information stored in one table will be related to that stored in another table, for example, student information If information in one table is changed, the other table will need to be changed too This can be done by a relational database program A relational database program Can allow tables to be related to each others so that changes in one table are reflected in other tables automatically Used by most of database management system. Database operations Browsing Browse through the records of the database as if you look through the data printed on a piece of paper Sort data Arrange records based on values in one or more fields Printing reports, labels, and form letters Database program can print a variety of printouts For example, print a report, which is an ordered list of selected records and fields. Database operations Complex queries: Structured Query Language (SQL) Used by most modern database-management programs Programmers and users do not need to learn new language Allows you to access a database Retrieve data from a database Insert new records in a database Delete records from a database Update records in a database There are many different versions of the SQL language, but they are similar each other. Special-purpose database programs Preprogrammed for specific data storage and retrieval purpose Directories and geographic information systems Using a specialized database named electronic street atlas to pinpoint the place you plan to go Geographic information systems can combine the name of a person or the name of a company with other data describing its location Can reveal valuable strategic information Pinpoint the best locations for branch office based on average incomes and other data. Special-purpose database programs Personal information managers One type of specialized database program Can automate some or all of the following functions: Address/phone book: displaying the records Appointment calendar: enter appointment and print it To-do list: enter and organize ongoing lists of things to do Miscellaneous notes: diary notes, personal notes Popular among people with busy schedules Specially work well on notebooks or PDAs. From file managers to database management systems A file manager a program enabling users to work with one file at a time Not a real database manager For example, personal information manager Database-management system A program or system of programs that can manipulate data in a large collection of files. The many faces of databases Large databases often contain hundreds of interrelated tables Users do not need to access every piece of information For example, a product A customer just needs to be shown the price and availability A clerk just needs to be given the power to complete transactions. Real-time computing Earliest file-management programs could do only batch processing Accumulate transactions and feed them into computer in large batches Cannot get feedback immediately Still being used for printing periodic bills, invoices, reports, etc or for making backup Now, interactive processing has replaced batch processing Users can interact with data through terminals, viewing and changing values online in real time Bank transactions, airline reservations, course registrations Usually run on powerful servers and accessed by users remotely. Downsizing and decentralizing Centralized database Popular in the pre-PC days Most databases are housed in mainframe computers Accessible only to information-processing personnel Client/Server Used by many business today Client programs in desktop computer, notebooks, or PDAs Requests are send to database servers via a network or the Internet Integrated data warehouses Used by some corporations to keep copies of all corporate data Unlike centralized database, users can access data directly. Downsizing and decentralizing Distributed databases Spread data across networks on several different computers Data mining The discovery and extraction of hidden predictive information from large databases Using statistical methods and artificial intelligence technology to locate trends and patterns in data that would have been overlooked by normal database queries For example, a grocery chain used data mining to discover difference between male and female shopping patterns based on the shopping history stored in its database Such patterns can help the grocery chain improve its services Practical data mining requires a lot of sophisticated techniques like neural networks or decision trees to a table of data. Databases and the web Internet technology is being used in internal networks-intranets Employees can access corporate database using the same web browsers and search engines XML - a data description language XML stands for E Xtensible Markup Language Serving as a query language to access database and as a web construction tool XML was designed to describe data and to focus on what data is. HTML was designed to display data and to focus on how data looks XML tags are not predefined. You must define your own tags. XML - a data description language XML is not a replacement for HTML. XML and HTML were designed with different goals. XML was only created to structure, store and to send information. XML - a data description language An XML file is just pure information wrapped in XML tags. Just like using a browser to view a HTML file, a piece of software is needed to be written to send, receive or display it. Web database strategies revolve around directories Directories can be used to store basic employee and customer information, along with access policies, identity proof, payment information, and security information Very useful in e-commerce. Databases and the web The web makes it possible for employees and customers alike to have instant access to database The possibility of data errors and the importance of eliminating those errors are increased Dirty data Records with spelling or punctuation mistakes, incorrect values, or obsolete values Most large database use data-check routines whenever data is entered Data scrubbing or data cleaning Process of going through a database and eliminating dirty data. No secrets: computers and privacy Databases provide us with conveniences, but we will have to pay with our privacy Privacy A common theme is the notion of access, where access means physical proximity to a person or knowledge about that person People need a certain amount of privacy, but information about people can have great value to a society Personal database: all about you Personal privacy can be taken away by abuse or misuse of database Privacy violations are due to various reasons, for example: Government surveillance, activities Innocent mistake Privacy violations are not new, but takes a new dimension in database. The privacy problem Data-mining techniques can be used to extract information about individuals or groups without their knowledge or consent Database information can be easily sold or used for purposes other than those for which it was collected Most of time, this kind of activity goes unnoticed by the public Big brother and big business Other information technologies amply the threat to personal privacy posed by database technologies Networks make it possible for personal data to be transmitted almost anywhere instantly. Big brother and big business Microsoft’s passport can optionally collect consume information in a database controlled by Microsoft Potential for abuse of this technology Workplace monitoring technology Managers can learn more than ever before about workers From work habits to screen email Surveillance cameras Can be helpful for locating criminals, but may also threaten the privacy of law-abiding citizens Surveillance satellites Permanent peepholes into our lives for anyone willing to pay. Big brother and big business Cell phone User’s location can be determined by law, however can be used for less noble purposes. Technological Factors Pixel Tiny dots of white, black, or color arranged in rows An image, words, and numbers are patterns of pixels created by software Software create these patterns automatically in response to commands Press e key, the software constructs a pattern appearing on the screen as an e Color depth Number of bits devoted to each pixel Resolution The density of the pixels, usually described in dots per inch, or dpi. Or, describe how many pixels can be included in each inch Also factors controlling image quality in monitor or printer Resolution for printer is higher Determining an artist’s ability to create realistic on-screen images. Painting software Enable you to “paint” pixels on the screen with a pointing device Accept input from a mouse, joystick, trackball, touch pad, or stylus Then translating the pointer movements into lines and patterns on-screen A typical painting program offers a palette of tools on-screen Some tools mimic real-world painting tools Some tools can do thing that is even difficult on paper or canvas Software Image-processing software Enables the photographer to manipulate digital photos and images Remove unwanted reflections, eliminated “red eye”, and brush away facial blemishes Also distort photos, apply special effects, and fabricate images Also combine photographs in composite scenes. Focus on computer graphics Bitmapped graphics Simple maps show how pixels on the screen should be represented Simplest bitmapped graphics A single bit of computer memory represent one pixel Value of one bit can be 0 or 1 , so each pixel can only display two colors, usually black & white If more memory is allocated to each pixel Each pixel will display more possible colors or shades The quality of a graphics will be high Gray-scale graphics Allow each pixel to appear as black, white or one of several shade of gray Focus on computer graphics Bitmapped graphics (continued) 8 bits for each pixel 256 different shades of gray to appear on screen More than the human eye can distinguish Realistic color graphics require more memory Require 24 or 32 bits of memory for each pixel. Drawing: object-oriented graphics Images and photographs need a lot of storage if they are saved as bitmaps Object-oriented graphics Draw software When drawing a graphics, Draw software calculates and remembers a mathematical formula for each line, shape, and other object on the graphics Shapes are stored as shape formula and text as text Its drawing tools are similar to those in bitmapped programs Can manipulate objects and edit text without affecting neighboring objects Objects drawn on screen are similar with those by a bitmapped program, but appearing smooth when printed out. Drawing: object-oriented graphics PostScript A standard page-description language Describing text fonts, illustrations, and other elements of the printed page Many professional drawing programs use PostScript to store images Is built into ROM in many laser printers and other high-end output devices Object-oriented drawing and bitmapped painting each offer advantages for certain application. Object-oriented drawing vs. bitmapped painting Bitmapped image-editing program Give unsurpassed control over textures, shading, and fine detail Used for create screen display Simulate natural paint media Embellish photographic images Object-oriented drawing Better choice for creating printed graphs, charts, and illustrations with clean lines and smooth shapes Some integrated programs contain both of them Choose right tool for each job For example, Coral Draw and AppleWork. 3-D modeling software With 3-D modeling software graphic, a 3-D object can be designed A 3-D model can be rotated, stretched, and combined with other model objects to create complex 3-D scenes A designer can Create or rotate a 3-D model of an object View it from a variety of angles Take two-dimensional “snapshots” of the best views for inclusion in final printouts 3-D modeling software With 3-D modeling software graphic, a 3-D object can be designed A 3-D model can be rotated, stretched, and combined with other model objects to create complex 3-D scenes A designer can Create or rotate a 3-D model of an object View it from a variety of angles Take two-dimensional “snapshots” of the best views for inclusion in final printouts. CAD/CAM Turning pictures into products Computer-aided design (CAD) Using computers to design products Using 3-dimensional graphics Allowing users to create 3-dimensional models with physical characteristics such as weight, volume, and center of gravity Models can be rotated and viewed from any angle The computer can evaluate the structural performance of any part of the model Computer-aided manufacturing (CAM) The numbers of a designed product are fed into a program controlling the manufacturing of parts. CIM Computer-integrated manufacturing Combination of CAD and CAM A major step toward a fully automated factory Presentation: graphics bring lectures to life Presentation-graphic software Example, Microsoft Powerpoint Most commonly used for creating and displaying a series of onscreen “slides” to serve as visual aids for presentations Display “slide shows” directly on computer monitors or LCD projectors Convert presentation into web pages automatically. CIM Computer-integrated manufacturing Combination of CAD and CAM A major step toward a fully automated factory Presentation: graphics bring lectures to life Presentation-graphic software Example, Microsoft Powerpoint Most commonly used for creating and displaying a series of onscreen “slides” to serve as visual aids for presentations Display “slide shows” directly on computer monitors or LCD projectors Convert presentation into web pages automatically. Animation: graphics in time More sophisticated animation Through the use of vector graphic Describe a collection of objects and how they change over time Most popular formats SWF: Shockwave Flash Format SVG: Scalable Vector Graphics Advantage Occupy less space Computer animation can be combined with live-action film Harry Porter, Spider-Man. Desktop video: computer, film, and TV Computer can be used to edit video, splice scenes, add transitions, create titles, etc if the video is in a digital form Analog and digital video Traditional television and video images are stored and broadcast as analog electronic waves A video digitizer Can convert analog video signals from a television broadcast or videotape into digital data Can import signals from televisions, videotapes, or other sources and display them on computer’ screen Can capture entire video sequences and convert them into digital “movies” that can be stored, edited, and played. Digital video cameras Capture and store all video footage as digital data Video production goes digital Today most video editing is done using nonlinear editing technology Video and audio clips are stored in digital form on a computer’s hard disk Clips can be organized, enhanced, and combined by onscreen tools and commands Much faster and easier than older editing techniques Can do thing that cannot be done without a computer. Video production goes digital Video editing software such as Adobe Premiere makes it easy to eliminate extraneous footage, combine clips from multiple takes, splice together scenes, create specific effects and other activities Some software can combine live action with computer animation Morphs are video clips in which one image metamorphoses into another Edited video clip can be output to a videotape, or DVD Dynamic media: beyond the printed page Data compression Digital movies can make heavy hardware demands A lot of disk spaces are needed Data compression software and hardware will be needed Squeeze data out of movies so that they can be stored in smaller spaces Often with a slight loss of image quality Can be classified into lossy compression and loseless compression Dynamic media: beyond the printed page The synthetic musician: computer and audio Digital audio basics Any sound can be recorded by an audio digitizer as a sample-a digital sound file Digitized sound data can be manipulated by software Change a sound’s volume and pitch Add special effects such as echoes Remove extraneous noises Rearrange musical passages Recorded sound can consume massive amounts of space on disk and in memory It will be needed to reduce the size of an audio file Dynamic media: beyond the printed page The synthetic musician: computer and audio Record computer sound at a lower sampling rate and bit depth Sampling rate The number of sound “snapshots” the recording equipment takes each second A higher sampling rate produces more realistic digital sounds Bit depth Number of bits per sample, usually 8 or 16 Similar with bit depth of digital photograph Dynamic media: beyond the printed page The synthetic musician: computer and audio Sound data compression can make a file even smaller A file can be squeezed to a fraction of their original CD file size Often with an imperceptible loss of quality. Samplers, Synthesizers, and Sequencers: Digital Audio and MIDI Multimedia computers can control a variety of electronic musical instruments and sound sources using MIDI MIDI: Musical Instrument Digital Interface MIDI commands can be interpreted by a variety of: Music synthesizers Electronic instruments synthesizing sounds using mathematical formulas Samplers Instruments digitizing or sampling audio sound, turn them into notes, and play them back at any pitch Dynamic media: beyond the printed page A piano-style keyboard sends MIDI signals to the computer, which interprets the MIDI commands using sequencing software Sequencing software turns a computer into a musical composing, recording, and editing machine Electronica—music designed from the ground up with digital technology Hypertext and hypermedia Hypertext Refers to information linked in non-sequential ways Can lead readers to other parts of the document or to other related documents Hypermedia Combines text, numbers, graphics, animation, sound effects, music, and other media in hyperlinked documents Useful for on-line help files The biggest hotbed of hypertext/hypermedia activity is the World Wide Web Hypertext links connect documents all over the Internet Hypertext and hypermedia Limitations of hypermedia documents Can be disorienting and leave readers wondering what they’ve missed You will not know where you are when surfing online Do not always have the links reader want Contain “lost” links sometimes, especially on the Web Do not encourage scribbled margin notes, highlighting, or turned page corners for marking key passages Hypermedia hardware More tiring when reading a computer screen Interactive multimedia: eye, ear, hand, and mind Interactive multimedia: what is it? Multimedia A combination of text, graphics, animation, video, music, voice, and sound effects that allows the user to take an active part in the experience Requirements: high-quality color monitors, fast processors, large memory, CD-ROM drives, speakers, and sound cards Multimedia Authoring: Making Mixed Media Multimedia-authoring software Used to create and edit multimedia documents Combining source documents-including graphics, text files, video clips and sounds-in an aesthetically pleasing format Interactive media: visions of the future One-way passive communication Television, radio, newspapers, magazines, and books pour information into people everyday With interactive multimedia software, the audience is a part of show People can control over the media by using interactive multimedia tools Inventing the Future: Shared Virtual Spaces Virtual reality combines virtual worlds with networking Places multiple participants in a virtual space People see representations of each other, sometimes called avatars Most avatars today are cartoonish, but they convey a sense of presence and emotion Tele-immersion Uses multiple cameras and high-speed networks to create a videoconferencing environment in which multiple remote users can interact with each other and with computer-generated objects Combines the display and interaction techniques of virtual reality with new vision technologies that allow participants to move around in shared virtual spaces, all the while maintaining their unique points of view. The Wordsmith’s Toolbox Word processing tools and techniques Working with a word processor involves several steps Entering text Typing Handwriting OCR (Optical Character Recognition) Speech Recognition (SR) Editing text Formatting the document Proofreading the document Saving the document on disk Printing the document (paper or electronic) 4 The Wordsmith’s Toolbox Word processing tools and techniques These steps cannot be mixed on early wordprocessing system Some mainframes and other timesharing machine are still using such rules now Most writer today can switch freely between editing and formatting All modern word processors have feature “what you see is what you get” 5 The Wordsmith’s Toolbox Text formatting commands Enable users to control the format of the document The way the words will look on the page Can control individual characters, paragraphs, and even the whole document Character formatting commands Select the font and size of the characters Changing the color of a character, put it in boldface or italics or underline it. Other formatting command Applying to paragraphs, control Margins Space between lines Indents, Tab stops Justification Alignment of a line 8 The Wordsmith’s Toolbox Some formatting commands Apply to entire documents Microsoft Word’s Page Setup Enable to control the margins applying throughout the document Other commands Enable to specify the content, size, and style of headers and footers Blocks appearing at the top and bottom of every page Displaying repetitive information, such as author names, page number 9 The Wordsmith’s Toolbox Advanced formatting features Define stylesheets containing customer styles for each of the common elements in a document Ex. Defining a style called “subhead” as a paragraph that is 12-point Helvetica font and then apply that style to every subhead in the document without reselecting this command for each new subhead Define alternate headers, footers, and margins Left- and right- facing pages can have different margins, headers, and footers Create document with multiple variable-width columns 10 The Wordsmith’s Toolbox Advanced formatting features Create, edit, and format multicolumn tables Incorporate graphics created with other applications Use automatic footnoting The program automatically places footnotes and endnotes where they belong on the page Use automatic hyphenation Divide long words falling at the ends of lines Use automatic formatting (autoformat) automatically apply for formatting to your text For example, to automatically number lists 11 The Wordsmith’s Toolbox Use automatic correction (autocorrect) Automatically catch and correct common typing errors For example, type Teh, it will change into The Generate tables of contents and indexes for books and other long works Attach hidden comments Can be seen without showing up in the final printed document Use coaching or help features Walk you through complex document formatting procedures Convert formatted documents to HTML Can be easily published on the Web A typical word processor might include A built-in outliner, spelling checker, and thesaurus Or, those features can be enhanced with stand-along programs. Spelling checkers Correct spelling is an important part of most written communication A word processor typically includes a built-in spelling checker Comparing the words in your document with words in a diskbased dictionary The spelling checker will suggest you correct word if a potential miss-spelling Cannot replace careful proofreading by alert human eyes Keep two potential problems in mind when using a spelling checker 15 The Wordsmith’s Toolbox Keep two potential problems in mind Dictionary limitations and errors No dictionary includes every word Can add a new word by yourself Errors of context A word appears in a dictionary does not guarantee that it is correctly spelled in the context of the sentence Grammar checker will be needed For example They wanted too know when you wood go to the park. 16 The Wordsmith’s Toolbox Grammar and style checkers Grammar-and-style-checking software can analyze each word in context, checking for Errors of context Common grammatical errors and stylistic foibles Can analyze prose complexity using measurements The length of sentence Paragraph length Such software is imperfect Misses many true errors Not substitute for practice, revision, editing, and a good English teacher 17 The Wordsmith’s Toolbox Form-letter generators Most word processor have mail merge capability Producing personalized form letters Many programs can incorporate custom paragraphs based on the recipient’s personal data Each letter look as if it were individually written Collaborative writing tools Group-software designed to be used by a workgroup Can keep track of a document’s history Make sure that all changes are incorporate into a single master document Microsoft word’s track changes option Record and display contributions from several writers and editors Can compare document versions and highlight difference 18 Emerging Word Tools Word-processing software has evolved rapidly and is not over Processing handwritten words Pen-based systems provide an alternative tool for entering text Handwriting recognition does not come easy Requiring sophisticated software interpreting pen movements as characters and words Handwriting is diverse, so it is hard to translate all of our scribbles into text For different system, different technologies are used 19 Emerging Word Tools Powerful pen-based systems For example, Tablet PC Use all the processing punch of modern notebook PC Advanced handwriting-recognition algorithms Simpler pen-based systems Palm OS Requiring users to print characters using a carefully defined system minimizing errors 20 Emerging Word Tools Processing words with speech By such software, user tells the computer what to do and how to do by talking into a microphone Speech-recognition software Looks for patterns in the sound waves Interprets sounds by locating familiar patterns Segmenting input sound patterns into words Separating commands from the text Passing those commands to the word-processing software Such software are still severely limited Due to the complexities of human speech 21 Emerging Word Tools Limitations of such software Need to be trained to recognize a particular person’s voice User has to speak slowly in a quiet environment and use a small and defined vocabulary Current research focuses on overcoming the following limitations Recognize words without being trained to an individual speaker Handle speech without limitations vocabulary Handle continuous speech Speech at normal speed Growing in popularity especially for people who cannot use keyboards 22 Emerging Word Tools Intelligent word processors Word processors should be able to anticipate the writer’s needs, acting as an electronic editor or coauthor Remind you that you have used the same word for many times Change an alternative from the list Continuously analyze your style Determine your writing habits and patterns, learns from its analysis Modifying your input so as to conforms the specific style Search on the Web for you to find relevant facts to support your argument 23 The Desktop Publishing Story What is desktop publishing Process of producing a publication includes several steps: Writing text Editing text Producing drawings, photographs, and other graphics to accompany the text Designing a basic format for the publication Typesetting text Arranging text and graphics on pages Typesetting and printing pages Binding pages into a finished publication 24 The Desktop Publishing Story What is desktop publishing In traditional publishing, many of steps required expensive equipment, highly trained specialists, and lots of time A desktop publishing system can accomplish these steps with small, easy to use, and affordable tools, including One or more Macs and PCs A scanner A high-resolution printer software 25 The Desktop Publishing Story What is desktop publishing Producing source documents The first step in publishing process Generally using standard word processors and graphic programs Using scanners with image-editing software Transfer photographs and hand-drawn image Page-layout software Such as QuarkXPress, Adobe PageMaker, or Adobe InDesign Combine the various source documents into a coherent, visually appealing publication 26 The Desktop Publishing Story Page-layout software (continued) Provide designers with control over virtually every element of the design The spacing between each pair of letter The spacing between lines of text Today’s word-processing programs include basic page-layout capabilities Most page-layout and word-processing programs include templates Professionally designed “empty” documents Desktop publishing becomes more complicated when color is introduced Printers and monitors use different types of color-mixing technology Publication displayed on screen is different from that printed 27 The Desktop Publishing Story Why desktop publishing Save money Publications can be produced in-house for a fraction of their former cost Save time Using a few time compared with using a traditional way Reduce the quantity of publication errors The real winner for desktop publishing is everyday people with something to say Individuals now have affordable publishing alternatives 28 Beyond the Printed Page Paperless publishing and the web Paperless electronic media cannot replace paper publishing Reading printed words on pages is easier on the eyes than reading from a screen Can be read and scribbled on almost anywhere, with or without electricity Digital media forms are likely to eclipse paper for many applications Email messages outnumber post office letter deliveries CD-ROM encyclopedias outsell briskly their paper counterparts 29 Beyond the Printed Page The Web offers publishing possibilities to millions of Internet users Programs can save documents in HTML format Microsoft Word, AppleWorks, and PageMaker Other programs offer capabilities for graphic, animation, and multimedia publishing Users can face such a wide audience by paying with a few dollars for using the Internet Challenges in Web publishing How to attract people to a site once it is online Copyright protection 30 Beyond the Printed Page Electronic books and digital paper Electronic books A handheld device containing stories or novels Not very successful The screens were hard to read Content for them was not easily accessible Books, periodicals and other software This situation is being changed Because of LCD technology, screens are brighter and easier to read Advances in font technologies from Microsoft and Adobe Reducing pixel “blockiness” 31 Beyond the Printed Page Other advances An open ebook standard is being developed by several companies Industry-wide standards will let ebook publishing be more practical In future, electronic paper (epaper) will be used A flexible, portable, and paper-like materials Dynamically display black-and –white text and image Contents can be erasable 32 The Spreadsheet: software for simulation and speculation Spreadsheet software Enables the users to take control of numbers, manipulating them ways that would be difficult or impossible otherwise Make short work of tasks involving repetitive calculations Budgeting, investment management, grade books Enable to reveal hidden relationships between numbers. All popular spreadsheet programs work share most of these features Lists Use these applications for tasks such as making and managing lists of grocery items, phone numbers, and other related information Automatic replication of values, labels, and formulas Most worksheets contain repetition, such as exam scores are calculated the same way for every student in the class Replication commands are extension of the basic copy-andpaste functions 37 The Spreadsheet: software for simulation and speculation Automatic recalculation Any time a change is entered into the spreadsheet, all data related to the change automatically updates Predefined functions Spreadsheet programs contains built-in functions instructing the computer to perform some predefined set of calculations Macros Custom-designed procedure storing keystrokes and commands so they can be played back automatically Formatting Most modern spreadsheets enable you to control typefaces, test styles, cell borders, etc or include pictures and other graphics 38 The Spreadsheet: software for simulation and speculation Templates and wizards Offer ready-to-use worksheets with labels and formulas already entered Validation Helping users check complex worksheets for consistency of entries and formula logic. Moreover, can also check spelling and grammar Linking When the values are changed in one spreadsheet, the data is automatically updated in all linked spreadsheets Database capabilities Search for information Sort the data by a specific criteria Merge the data with a word processor Generate reports 39 The Spreadsheet: software for simulation and speculation “What If?” Questions Spreadsheets allow you to change numbers and instantly see the effects of those changes “What if I enter this value?” Equation solvers Enables you to define an equation, enter your target value, and watch while the computer determines the necessary data values 40 The Spreadsheet: software for simulation and speculation Spreadsheet graphics: from digits to drawings Most spreadsheet programs can turn worksheet numbers into charts and graphs automatically Done by filling in a few blanks in a dialog box A variety of basic chart types are offered by most spreadsheet programs 41 The Spreadsheet: software for simulation and speculation Pie charts Relative proportions of the parts to a whole Line charts show trends or relationships over time Show relative distribution of one variable through another Bar charts Similar to line charts More appropriate when data falls into a few categories Scatter charts Used to discover a relationship between two variables 42 Statistical software beyond spreadsheets Money Managers General-purpose spreadsheets cannot work well for accounting Professionally designed accounting and financial-management software will be used Allows you to do electronically handle routine transactions such as: Writing checks Balancing accounts Creating budgets Online banking services Tax preparation Statistics and data analysis Statistical and data analysis software Collects and analyzes data that tests the strength of data relationships Can produce graphs showing how two or more variables relate to each other Can often uncover trends by browsing through two- and three-dimensional graphs of data, looking for unusual patterns in the dots and lines that appear on the screen 45 Statistical software beyond spreadsheets Scientific Visualization Scientific visualization software Uses shape, location in space, color, brightness, and motion to help us visualize data Visualization helps researchers See relationships that might have been obscure or even impossible to grasp without computer-aided visualization tools 46 Calculated risks: computer modeling and simulation Computer model Is an abstraction- a set of concepts and ideas designed to mimic some kind of system A well-designed model should behave like the system it imitates Examples: Games (chess boards, sports arenas, and mythological societies) Models of organisms, objects, and organizations Simulations of science lab activities Business, city, or nation management simulations 47 Calculated risks: computer modeling and simulation Computer simulations the rewards Widely used for research in various areas. There are many reasons Safety Some activities are so dangerous that they are not ethically possible without computer simulations For example, study the effects of a nuclear power plant meltdown on the surrounding environment. Economy Test the computer model firstly in a serials of simulations before a product is made 48 Calculated risks: computer modeling and simulation Projection A computer simulation can serve as a time machine for exploring one or more possible futures Visualization Visualization enables researchers and students to see and understand relationships that might go unnoticed Replication In the real world, it can be difficult or impossible to repeat a research project with slightly different conditions Thus can be done on a computer Input new values and running a new simulation 49 Calculated risks: computer modeling and simulation Computer simulations the risks GIGO (garbage in, garbage out ) Revisited The accuracy of a simulation depends on how closely its mathematical model corresponds to the system being simulated Some models suffer from faulty assumptions Some models contain hidden assumptions that may not even be obvious to their creators Some models go astray simply because of clerical or human errors Still, garbage in, garbage out is a basic rule of simulation 50 Calculated risks: computer modeling and simulation Making Reality Fit the Machine Some simulations are so complex that researchers need to simplify models and streamline calculations to get them to run on the best hardware available Sometimes this simplification of reality is deliberate; more often it’s unconscious Either way, information can be lost, and the loss may compromise the integrity of the simulation and call the results into question 51 Calculated risks: computer modeling and simulation The Illusion of Infallibility Risks can be magnified because people take computers seriously A computer simulation, whether generated by a PC spreadsheet or churned out by a supercomputer, can be an invaluable decision-making aid The risk is that the people who make decisions with computers will turn over too much of their decisionmaking power to the computer 52 Inventing the Future: Truly Intelligent Agents Agents are software programs designed to be managed rather than manipulated. Future user interfaces will be based on agents rather than on tools An intelligent software agent can: Ask questions as well as respond to commands Pay attention to its user’s work patterns Serve as a guide and a coach Take on its owner’s goals Use reasoning to fabricate goals of its own…...

Similar Documents

Free Essay

Computer

...Discovering Computers 2011 Chapter 4 DISCOVERING COMPUTERS 2011 CHAPTER FOUR: THE COMPONENTS OF THE SYSTEM UNIT PROBLEM SOLVING TIP SHEET Use this Tip Sheet as suggested starting points for the Problem Solving exercises. Problem Solving @ Home 1. Malfunctioning Speakers While working on a homework assignment, you decide to listen to one of your favorite music CDs through your computer speakers. The media player program on your computer automatically starts when you insert the CD. Although it looks like the CD is playing, no sound is coming from your speakers. What might be causing this? What is the first step that you will take to correct this problem? The sound might be muted or the volume turned down; adjust accordingly There may be a problem with your computer recognizing the sound card; check the drivers 2. Optical Disc Drive Stuck While using your computer, you attempt to open the optical disc drive to insert an installation disc for a program you wish to install. The drive, however, does not open when you press the eject button. The drive opened a few minutes prior, when you removed a music CD. What steps will you take to open the drive before calling technical support? Restart the computer. If the problem persists after restarting the computer, shut the computer down and insert the end of a paperclip into the small hole in the optical disc drive (if one exists) to open the drive manually. If necessary, check with technical support or your computer’s......

Words: 1370 - Pages: 6

Free Essay

Computer

...Accountability and Ethics Computer Addiction and Cyber Crime Nick Nykodym The University of Toledo Sonny Ariss The University of Toledo Katarina Kurtz The University of Toledo This research explores the relationship between computer addiction and cyber crime. There is evidence of computer addiction in medical settings, scholarly journals and legal proceedings. Reviewing the history of computer addiction has shown that computer addiction can be related to cyber crime. This paper will define computer addiction, show how various cyber crimes, especially those against businesses and organizations, can be motivated by computer addiction and propose further research on how managers can deal with cyber crime in a business, by recognizing addictive behaviors and computer addiction in their employees. HISTORY OF COMPUTER ADDICTION Computer addiction is an idea that has been in existence for years. Since the 1970s, avid computer programmers and hackers have been called “addicts” by both psychologists and the general public (Reed, 2002, p. 135). In 1976, Weizenbaum wrote about computer programmers who could sit and work at their computer terminals for twenty or thirty hours at a time. This behavior however, was viewed at the time as useful to technology and society. Computers, once seen as huge government machines that only very knowledgeable people could use, transformed into user-friendly tools that could be used by the everyday person. It became more common to see computers in......

Words: 3633 - Pages: 15

Premium Essay

Computers

...Computers types I, Computer: Definition A computer is a machine that can be programmed to manipulate symbols. Its principal characteristics are: § It responds to a specific set of instructions in a well-defined manner. § It can execute a prerecorded list of instructions (a program). § It can quickly store and retrieve large amounts of data. Therefore computers can perform complex and repetitive procedures quickly, precisely and reliably. Modern computers are electronic and digital. The actual machinery (wires, transistors, and circuits) is called hardware; the instructions and data are called software. All general-purpose computers require the following hardware components: § Central processing unit (CPU): The heart of the computer, this is the component that actually executes instructions organized in programs ("software") which tell the computer what to do. § Memory (fast, expensive, short-term memory): Enables a computer to store, at least temporarily, data, programs, and intermediate results. § Mass storage device (slower, cheaper, long-term memory): Allows a computer to permanently retain large amounts of data and programs between jobs. Common mass storage devices include disk drives and tape drives. § Input device: Usually a keyboard and mouse, the input device is the conduit through which data and instructions enter a computer. § Output device: A display screen, printer, or other device that lets you see what the computer has accomplished. In addition to these......

Words: 2089 - Pages: 9

Free Essay

Computer

...Computer and our life Importance of computer: Computer is an important machine in our life. Without computer our life is nothing. We need to use it in every sector of our life. What type of work sector that is we are using computer. It makes our job easier and simple. Computer creates a great opportunity for us. We are changing our life style quickly through computer. We are using it in education sector, medical sector, research and experimental job, designing, architectural designing, planning, public administration and etc. Computer changed our education system. We can learn through long distance education system. Now we do not need to go far from home to learn something. We can save our time and money by this. Without that we are able to get every service at home. Computer is also able to provide us another service. Now doctor can do operations through computer. It resumes risk for a patient. Doctors do not need to work more. Computer also helps us in research like educational, scientific, medical and etc. Really, computer is a great invention of human life. Computer and communication: ------------------------------------------------- Without helping in our work we can communicate through computer. Now-a-days computer is the powerful communication media. Generally it communicates through network and internet is the well known network system. We can talk, chat, mail through computer. We can keep contract with international community by internet. E-mail is a......

Words: 850 - Pages: 4

Premium Essay

Computer

...Title: Windows: How to manually remove a computer from the Princeton domain Synopsis: How to manually remove a computer from the Princeton domain Solution: Reasons why you should remove their Windows machine from the PRINCETON domain if you are leaving the University (for faculty, staff and all students): • Windows machines can only be joined to one domain at a time. After you leave Princeton, and you attempt to join your machine to another Windows domain, you would not be able to, unless the computer is first removed from the PRINCETON domain. Once joined to another domain other than Princeton, it becomes difficult to retrieve files or other information stored locally under your Princeton\netID domain account. • Once away from the Princeton network, your machine may at some point stop allowing you to log in with your PRINCETON windows credentials. This would additionally make it difficult to retrieve files or other information stored locally under your Princeton\netID domain account. • If you continue to attempt to log in to a domain profile and you one day forget your password, there is no way to reset that password (there is no local account associated with it). ________________________________________ Windows Manual Instructions The following is the process to manually remove your computer from the domain. Section One: Create a new user profile 1. Open the Start Menu and Right click Computer and Click Manage. 2. Expand Local Users and Groups......

Words: 1618 - Pages: 7

Premium Essay

Computers

...Computers in Our World Our world is constantly evolving. The only thing in life that is constant is change, and Computers are no different. Even though computers have only existed in the last seventy years, many believe computers have changed the world more than any other technological advance. Over the past seventy years, computers have made a quick evolution into our world with several major advancements. Just as with all things, however, there was a beginning to the computer generation. Computers were invented to solve “complex mathematical problems using calculators within a computer(De la Bedoyere,1). Computers now can do anything within a large box. A desktop computer has many external parts joined together. A computer consist of a mother board,the motherboard controls and processes what is typed and clicked and programs running. The middle of the motherboard consist of all the work being processed. Including work and data which is sent through the motherboard to the Central Processor unit (CPU). The computer has to hold memory also to save things within computers. The Ram is a major component in saving information but only works when the computer, is running. The reason a Ram is used is to save and store information,so that when it is being worked on it wont be erased. A Computer also has external and internal drives that can read information. When the computer came out for personal use, it made it better for communication possibilities(ceruzzi,6,7) 1939 was an......

Words: 1404 - Pages: 6

Premium Essay

Computer

...The History of Computers http://inventors.about.com/library/blcoindex.htm "Who invented the computer?" is not a question with a simple answer. The real answer is that many inventors contributed to the history of computers and that a computer is a complex piece of machinery made up of many parts, each of which can be considered a separate invention. This series covers many of the major milestones in computer history (but not all of them) with a concentration on the history of personal home computers. Ads Cars - Motor Traderwww.motortrader.com.myBuy and Sell New Cars, Used Cars You Can Find 15000+ Cars From Here! BGS Repair Servicewww.lelong2u.comRepair/Sales/Buy/Used-Projector,LCD Laptop,Server,PC,Printer and iMAC. Network Traffic Shapingwww.exinda.comVisibility of all Applications. Traffic Shaping for WAN & Web. Computer History Year/Enter | Computer History Inventors/Inventions | Computer History Description of Event | 1936 | Konrad Zuse - Z1 Computer | First freely programmable computer. | 1942 | John Atanasoff & Clifford Berry ABC Computer | Who was first in the computing biz is not always as easy as ABC. | 1944 | Howard Aiken & Grace Hopper Harvard Mark I Computer | The Harvard Mark 1 computer. | 1946 | John Presper Eckert & John W. Mauchly ENIAC 1 Computer | 20,000 vacuum tubes later... | 1948 | Frederic Williams & Tom Kilburn Manchester Baby Computer & The Williams Tube | Baby and the Williams Tube turn on the......

Words: 593 - Pages: 3

Premium Essay

Computer

...Introduction:- Computer is an electronic device which can take input from the user and process this input data and if need, store data or information on storage devices and give output on output devices. It follow the instructions us it is which we input. It takes input through Keyboard, mouse, etc and then it processes the input data and give output on display screen and store data if need. Desktop Computer:- Mostly called personal computer (PC), design to fit completely on a typical desk of office or home. It mainly comes with a monitor, a minitower or horizontal casing. Today, mostly Casing contains processor, hard disk in gigabytes, built-in modem, LAN port, USB ports and CD-ROM. Over the past few years. CPU processing speed has been increasing processing speed can be increase by adding capable RAM, capable BUS, high processor which have high processing cycle, hence more heat is also produced we use heat sinks and fans for the removal of heat from the computer as higher temperature can cause severe damage to the computer, fans are noisy and aren’t much effective so the new trend is liquid cooling. It’s just like a radiator installed for cooling, a liquid is circulated in the heat sink attached to the processor heat is transferred from the processor to the liquid is then transferred to the radiator the liquid is cooled down there and then again circulated to the heat sink. It’s less noisy as compared to fan as high speed processor clocked at higher speed need......

Words: 1247 - Pages: 5

Premium Essay

Computers

...A computer is a machine that manipulates data. The first devices that resemble modern computers date to the mid-20th century (1940†1945), although computer concept and various machines are similar to computers existed earlier. Early electronic computers were the size of a large room, consuming as much power as several hundred modern personal computers (PC).[1] Modern computers are based on tiny integrated circuits and are millions to billions of times more capable while occupying a fraction of the space.[2] Today, simple computers may be made small enough to fit into a wristwatch and be powered from a watch battery. Personal computers, in various forms, are icons of the Information Age and are what most people think of as "a computer"; however, the most common form of computer in use today is the embedded computer. Embedded computers are small devices that are used to control other devices—for example, they may be found in machines ranging from fighter aircraft to industrial robots, digital cameras, and children's toys. The ability to store and execute lists of instructions called programs makes computers extremely versatile and distinguishes them from calculators. The Church†Turing thesis is a mathematical statement of this versatility: any computer with a certain minimum capability is, in principle, capable of performing the same tasks that any other computer can perform. Therefore, computers with capability and complexity ranging from that of a personal digital......

Words: 256 - Pages: 2

Premium Essay

Computers

...The computer is one of the most brilliant gifts of science. This device was originally developed by Charles Babbage. Most countries have developed fast due to computerization. Writing a program is essential for a computer. Speed, accuracy, reliability, and integrity are the main characteristics of a computer. Many of the routine activities today at home and in business are done by computers. The computer has proved a friend and servant of science, technology and industry. Most offices, shops, factories and industries use computers. The Internet is a storehouse of information. The computer is a boon to all. Telecommunication and satellite imageries are computer based. Computers have made the world a global village today. The computer is one of the most brilliant gifts of science. It is an electronic device for storing and analyzing information fed into it, for calculating, or for controlling machinery automatically. Charles Babbage developed this device first in 1812 followed by George Boole in 1854, Howard and Aitten in 1937, Dr. John Nouchly and J. P. Eckert in 1946. These computers were named the first generation equipment. Today, wit the 'Artificial Intelligence' technology, we are using fifth generation computers. Each new generation of computers has been smaller, lighter, speedier and more powerful than the earlier ones. Now note-book sized computers like laptop are fairly common. Computers have been dominating technology since 1970s, and has now entered almost all......

Words: 1135 - Pages: 5

Premium Essay

Computer

...Structure and Functions of a Computer "Hardware: the parts of a computer that can be kicked." ~ Jeff Pesis After completing this chapter, you will be able to: 1. Explain the importance of computer literacy. 2. Define the term computer. 3. Identify the components of a computer. 4. Compare the uses of various types of: input devices, output devices, and storage devices. 5. Describe categories of computers and their uses. Structure and Functions of a Computer 1 1.0 Introduction A computer is an electronic machine designed for the storage and processing of data. The machinery is called hardware, and this highly sophisticated equipment needs equally sophisticated programs (called software) to become a working computer system. Modern society has come to depend very heavily on the use of computer systems. Banks, businesses, government departments, industries, shops, people at home and school all rely on computer to play a vital role in their daily activities. These activities are centered on information. In business, the computer system has been used a lot and replaced filing cabinets as means of storing information, and clerical workers as a means of processing it. By storing and processing information on a computer system, these businesses can function more quickly and efficiently, because information can be found and collated much faster. Discovery Learning: A computer was also called a data processor. Why? 1.1 Major Parts and Functions A Computer is an......

Words: 47755 - Pages: 192

Premium Essay

Computer

... THE HISTORY OF COMPUTER One of the earliest machines designed to assist people in calculations was the abacus which is still being used some 5000 years after its invention. In 1642 Blaise Pascal (a famous French mathematician) invented an adding machine based on mechanical gears in which numbers were represented by the cogs on the wheels. Englishman, Charles Babbage, invented in the 1830's a "Difference Engine" made out of brass and pewter rods and gears, and also designed a further device which he called an "Analytical Engine". His design contained the five key characteristics of modern computers:- 1. An input device 2. Storage for numbers waiting to be processed 3. A processor or number calculator 4. A unit to control the task and the sequence of its calculations 5. An output device Augusta Ada Byron (later Countess of Lovelace) was an associate of Babbage who has become known as the first computer programmer. An American, Herman Hollerith, developed (around 1890) the first electrically driven device. It utilised punched cards and metal rods which passed through the holes to close an electrical circuit and thus cause a counter to advance. This machine was able to complete the calculation of the 1890 U.S. census in 6 weeks compared with 7 1/2 years for the 1880 census which was manually counted. In 1936 Howard Aiken of Harvard University convinced Thomas Watson of IBM to invest $1 million in the development of an electromechanical version of Babbage's......

Words: 1597 - Pages: 7

Premium Essay

Computer

...CHAPTER 1 INTRODUCTION TO INFORMATION TECHNOLOGY 1.1 Introduction Modern civilization has become so complicated and sophisticated that to survive one has to be competitive. This compels people to keep themselves informed of all types of happening in the society. And this in turn entails the need for an infrastructure of information. This is the point where information technology or IT becomes most important, as it is the infrastructure that allows us to get information accurately and in time. Before we define information technology, it is important to understand the notion of Data, Information, Technology, and Knowledge. In everyday conversation, people use the terms data and information interchangeably. However, some computer professional make a distinction between the two terms. Data It is the words, numbers, letters, symbol, sound, video and graphics that describe people, events, things and ideas. It is raw facts about people, objects, and events that have little or no meaning. It is the raw material used to create useful information. It becomes information when you use it as the basis for initiating some action or for making a decision. Information It is defined as the words, numbers, letters, symbol, sound, video and graphics used as the basis for human action or decisions. It is data that have been processed and presented in a form suitable for human interpretation, often with the purpose of revealing trends or patterns that can be used in decision-making. It is data...

Words: 12773 - Pages: 52

Free Essay

Computer

...Computer The word'computer ' is an old word that has changed its meaning several times in the last few centuries.The Techencyclopedia(2003) defines computer as " a general purpose machine that processes data according to a set of instructions that are stored internally either temorarily or permanently" Computer history The trem history means past events.It indicates the gradual development of computers.Here we will discuss how this extraordinary machine has reached of it's apex. In the begining............................... The history of computers starts out about 2000 years ago, at the birth of the 'abacus' a wooden rack holding two horizontal wires with breads strung on them.Just like our present computer,abacus also considered a digit as a singal or codeo and processed the calculation. Blasie Pascal ists usually credited to building the first digital computer in 1942.It added numbers to help his father.In 1671,Gottofried Wilhelm Von Leibniz invented a computer that was built in 1694.It could add,and, after changing somethings around,multiply. Charles Babbage: A serious of very intersting developement in computer was started in Cambridge,England,by Charles Babbage, a mathmatics proffessor.In 1982,Babbge realized that many lng calculations,espically those need to make mathematical tabes ,were really a series of predictable actions that were constantly repated.From this he suspected that it......

Words: 995 - Pages: 4

Premium Essay

Computers

...The computers process information's that come in all shapes and sizes from any fields so accurately that, some people may call these "Informatics"— The Science of Informal ion Processing, i.e. the methods of recording, manipulating and retrieving information's. It may be from a mathematical equation to a company's work-force necessary to produce a payroll or from meteorological department to forecast tomorrow's weather or from space research to project a new space craft. The following characteristics that make the computers very popular for its multifarious uses may give the befitting reply. Speed First, the computers are regarded as high speed calculators. They can process voluminous data within a fraction of second which no human being could do earlier. If we want tomorrow's forecast today, meteorologists can use the computers for necessary calculations and analyses. The units of speed of a computer are the microsecond, the nano (10)-9 second and even the picot second. Storage As human brain can store the knowledge in memory and can able to recall it, the Central Processing Unit (CPU) of a computer can do the same job without any failure. But the internal memory of CPU is only large enough to retain a certain amount of information. So, to store each and every information inside the computer, an Auxiliary or Secondary Storage Device is being attached outside the memory of the CPU. Accuracy The computers are much popular due to their high speed along with......

Words: 343 - Pages: 2

Biotin 5mg (5000mcg) hair skin nails (90 tablets) [Lindens 3879] | Return To Sandakan | Descriptive Essay: A Beautiful Place