01-04-2020-Oxford_English_for_Infomation_Technology (1171844), страница 4
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The software thenlooks for other patterns based on these rules orsends out an alarm when a trigger value is hit.Clustering divides data into groups based onsimilar features or limited data ranges. Clustersare used when data isn't labelled in a way that isfavourable to mining. For instance, an insurancecompany that wants to find instances of fraudwouldn't have its records labelled as fraudulentor not fraudulent.
But after analysing patternswithin clusters, the mining software can start tofigure out the rules that point to which claimsare likely to be false.Decision trees, like clusters, separate the datainto subsets and then analyse the subsets todivide them into further subsets, and so on (fora few more levels). The final subsets are thensmall enough that the mining process can findinteresting patterns and relationships within thedata.Once the data to be mined is identified, itshould be cleansed. Cleansing data frees it fromduplicate information and erroneous data.
Next,the data should be stored in a uniform formatwithin relevant categories or fields. Mining toolscan work with all types of data storage, fromlarge data warehouses to smaller desktopdatabases to flat files. Data warehouses and dataUNIT 3 Computer ApplicationsBYou must first havedata to mine.
Datastores include oneor severaldatabases or datawarehouses.23Re- read the text to find the1 Match the terms in Table A with thestatements in Table B.Table Aa Data miningb AlData must bestored in aconsistent formatand free from errorsand redundancies.c Cleansed datad Data warehouseTable BiStorage method of archiving largeamounts of data to make it easy to accessii Data free from duplicate and erroneousinformationiii A process of filtering through largeamounts of raw data for useful informationiv A computing tool that tries to operate in away similar to the human brainActual miningoccurs when data iscombed forpatterns and trends.Rules for patternsare noted.Someone mustanalyse miningresults for validityand relevance.2The mining resultscan then bereviewed andinterpreted, and aplan of actiondetermined.marts are storage methods that involve archivinglarge amounts of data in a way that makes it easyto access when necessary.When the process is complete, the miningsoftware generates a report.
An analyst goes overthe report to see if further work needs to bedone, such as refining parameters, using otherdata analysis tools to examine the data, or evenscrapping the data if it's unusable. If no furtherwork is required, the report proceeds to thedecision makers for appropriate action.The power of data mining is being used formany purposes, such as analysing SupremeCourt decisions, discovering patterns in healthcare, pulling stories about competitors fromnewswires, resolving bottlenecks in productionprocesses, and analysing sequences in the humangenetic makeup. There really is no limit to thetype of business or area of study where datamining can be beneficial.[Adapted from 'Data Mining for Golden Opportunities', SmartComputing Guide Series Volume 8 Issue 1, January 2000]Mark the following as True or False:a Data mining is a process of analysing knownpatterns in data.b Artificial intelligence is commonly used indata mining.c In data mining, patterns found while analysingdata are used for further analysing the data.d Data mining is used to detect false insuranceclaims.e Data mining is only useful for a limited rangeof problems.3 Complete the following description of thedata mining process using words from the text:Large amounts of data stored in dataare often used for data .The data isinformationfirstto removeand errors.
Theis then analysed usingAna tool such asanalysis report is then analysed by anwho decides if theneed to be refined,other datatools need to be used, or ifthe results need to be discarded because theyareThe analyst passes the finalresults to themakers who decide onaction.thePeripheralsSTARTERIdentify the peripherals in this computer application. Dividethem into input and output devices.Fig 1EPOS tillLink the inputs on the left and the outputs on the right withthe appropriate peripherals in the centre.InputFig 2Input and output devicesPeripheralsOutputStudy this description and answer these questions.LISTENING123How do digital cameras differ from conventional cameras?How do they work?What are their advantages and disadvantages compared toconventional cameras?HOW a digital camera worksDigital cameras store images on memorycards so pictures can be transferred easilyto a computer.A lens focuses the image on to a CCD unit orCharge-Coupled Device where the film wouldnormally be.So you can aim the camera accurately, thereis an optical viewfinder.So you can play back the images and decidewhich to keep and which to re-shoot, theimage is passed to a small LCD screen on theback of the camera.Fig 3Canon PowerShot, G1Listen to Part 1 of this discussion between A and B andcomplete this table of similarities and differences betweenconventional and digital cameras.
Tickor crossthe boxes.FeatureDigitalConventionallensviewfinderrequires chemical processingfilmtransfer images directly to PCcan delete unsatisfactory imagesListen to Part 2 of the dialogue to list the disadvantagesof digital cameras.26UNIT 4 PeripheralsNow listen to both parts again to find the answers tothese questions:12345678LANGUAGE WORKWhat does a CCD contain?What is a pixel?How can you view pictures before they are downloaded to a PC?When you have downloaded the images, what can you do withthem?Is special software required?Why is the resolution important?What does the capacity of a digital camera depend on?Why is it worth getting a rechargeable battery?Revision: Comparison and contrastStudy this comparison of digital andconventional cameras.FEATUREDIGITALCONVENTIONALComparing features which are similar:1 Both cameras have lenses.2 Like the conventional camera, the digitalcamera has a viewfinder.lensviewfinderrequires chemicalprocessingfilmtransfer imagesdirectly to PCcan deleteunsatisfactoryimagesNote how we can compare and contrastthese types of cameras.Contrasting features which are different:3 The conventional camera requires chemicalprocessing whereas the digital cameradoes not.4 The conventional camera uses film unlikethe digital camera.5 With a digital camera you can transferimages directly to a PC but with aconventional camera you need to use ascanner.6 With digital cameras you can deleteunsatisfactory images; however withconventional cameras you cannot.UNIT 4 Peripherals27Study this data about storage devices.
Then complete theblanks in the following sentences comparing and contrasting thedifferent types.DeviceRead/WriteSpeedMediaCapacityMediaRemovableCostFloppy diskRead and writeSlowVery lowYesLowFixed hard diskRead and writeFastVery highNoMediumRemovable hard diskRead and writeMedium to fastHighYesMediumCD-ROMRead onlyMediumHighYesLowCD-RRecordableSlowHighYesMediumCD-RWRead and writeMediumHighYesMediumCD-MORead and writeMediumHighYesHighDVD-ROMRead onlyMediumHighYesMediumDVD-RAMRead and writeMediumVery highYesHighMagnetic TapeRead and writeVery slowHighYesMedium1You can write to hard disks2Floppy disks have a3CD-ROMs and floppy disks are4DVD-RAM has a5CD-ROMs cannot be re-recordeddisks can be.6optical disks.capacityother devices.low priced.capacityother optical disks.some other opticalhard disks, you can read from and write to CD-MOdrives.78CD-ROMs, CD-Rs are recordable.Magnetic tape is much9other devices.DVD-RAM and fixed hard disks have very high mediacapacity.10Floppy disks are cheapDVD-RAM is expensive.28UNIT 4 PeripheralsWrite your own comparison of printer types.TypeSpeedTextQualityGraphicsCapabilityColour QualityCostDot-matrixSlow tomediumFair togoodLimitedFair if you add acolour optionLowInk-JetMedium tofastGood toexcellentGood toexcellentGood toVery GoodLow tohighLaserMedium tovery fastExcellentGood toexcellentGood in colourlaser printersMedium tohighThermal TransferMedium tofastExcellentGood toexcellentGood tosuperiorMedium tohighSolid InkMedium tofastExcellentGood toexcellentGoodMedium tohighElectro-staticSlow tofastFair togoodFair togoodFair to goodLow tohighStudy this list of needs.
Which type of peripheral would youadvise in each case?1 inputting printed graphics2building cars3controlling the screen cursor in a fast action game4making choices on a screen in a public information terminal5recording moving images6recording a book loan in a library7printing very high quality text and graphics8creating drawings9printing building plan drawings10recording sound11listening to music without disturbing others12storing programs and data13inputting a lot of text14backing up large quantities of dataUNIT 4 PeripheralsWRITING29Describe the EPOS till shown in Fig 1.
Explain the function ofeach peripheral using the structures studied in Unit 2.Check these websites for the latest digital cameras. Comparethe newest cameras with the one described in Fig 3. You will find itsspecifications on www. canon. com.FUJIFILMMINOLTAwww. minolta.
comwww. fujifilm. comPENTAXOLYMPUSOPtio330www. pentax. comwww. olympus. comItImage Communicationwww. samsungcamera. comwww. ricohcamera. comCanonImaging across networkswww. sony. comwww. canon. com30 UNIT 4 PeripheralsDFind the answers to these questions in thefollowing text.l What is Currie Munce's main aim?2 How quickly did the possible areal densityof hard disks increase in the 1990s?3 How long does Munce think magnetic45678910recording technology will continue to make.rapid advances in capacity?What problem does he predict for magneticstorage?What is the predicted limit for discrete bitmagnetic storage capacity?What storage technologies might replacecurrent magnetic systems?What is the advantage of holographicstorage being three-dimensional?What improvements are predicted due tothe fast access rates and transfer times ofholographic storage?What is predicted to be the most importanthigh capacity removable storage media inthe next 10 years?What method of software distribution islikely to replace optical disks?Thinking about writing your memoirs - puttingyour life story down on paper for all eternity?Why not skip the repetitive strain injury and justcapture your whole life on full-motion video,putting it all in a device the size of a sugar cube?It might not be as far off as you think.Currie Munce, director of IBM's Advanced HDDTechnology Storage Systems Division, has oneavowed goal: Build bigger storage.
RecentlyMunce and his fellow Ph. Ds restored Big Blue'slead in the disk space race with a new worldrecord for areal (bit) density: 35. 3 gigabits persquare inch - roughly three times as dense asany drive shipping at press time.During the 1990s, areal density doubled every 18months, keeping pace with the transistor densitygains predicted by Moore's Law. But increasinglydaunting technical challenges face those whowould push the storage envelope further.
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