多用户博客系统 外文翻译范文.docx

多用户博客系统 外文翻译范文.docx

《多用户博客系统 外文翻译范文.docx》由会员分享，可在线阅读，更多相关《多用户博客系统 外文翻译范文.docx（27页珍藏版）》请在冰豆网上搜索。

多用户博客系统外文翻译范文

外文文献资料

（外文文件名：

Defining,Modeling,andSolvingaRealUniversity

CourseTimetablingProblem）

Introduction

Aswithmanyreallifeproblems,theuniversitycoursetimetablingproblem

canbemessyandcomplicated.Solvingtheuniversitycoursetimetablingproblem

involvesmanypeoplecommunicatingtotrytoachieveatimetablethatmeetsaset

ofrequirementsandgoals.AsexplainedinChapter3,theliteratureonautomated

timetablingoftentakesagiventimetablingproblemandreducesittoa

mathematicaldefinition,whichcanthenbesolved.Inreality,thereisalotmoreto

arealworldtimetablingproblemthanwhatisrepresentedinsuchadefinition.The

timetablingprocessislongandconsistsofmanystagesbeforethatofactually

placingcoursesintotimeslots.ThefirststageofsolvingaprobleminORinvolves

adetailedstudyofthesystem,identifyingspecificproblems,systemconstraints,

andobjectivefunctions.

Thischapterlooks,indetail,atthetimetablingproblematthefacultyof

appliedscienceandengineeringattheUniversityofToronto（APSC）.Theprocess

describedistheonethattookplaceinordertocreatethetimetableforthe

2006-2007schoolyear.Thisprocessshowshowrealworldproblemsareactually

muchmorecomplicatedthanwhatappearsinamathematicalmodel.Aswell,a

detailedanalysisofagivenproblemisasteptowardscreatingaproblemdefinition.

Itallowsonetoidentifyalloftheprocessissues,constraints,restrictions,andgoals,

therebyprovidingabaseofinformationthatmaybeincludedinaproblem

definition.

TheundergraduateprogramatAPSCconsistsoffouryearsofstudy.There

are4000students,over1200ofwhicharefirstyears.Therearesevendepartments

andninedegreeprogramstotaling79POSts1.Thereare219facultymembers,12

buildings,and80labroomsthataremanagedinternally.Thefacultyusesa

softwareschedulingpackagethatispartoftheSyllabusPlussuiteofscheduling

products.InparticularthesoftwareCoursePlanner（CP）isusedtoschedule,

identifyissues,andsupportdecisions.CPisasoftwarepackagethatusesseveral

heuristicswhenscheduling.75%oftimetablesaredeliveredtotheindividual

studentconflict-free,basedonprogramstructure.Inthefollowingsections,we

describethegoalsthatthetimetabletriestoachieve,theconstraintsinvolved,and

thestrategy,theprocess,usedwhencreatingthetimetable.Wethenoutlinesome

problematicareasexistinginthecurrentprocessandhighlighttheareaswhereIT

couldbehelpful.IdentifyingareaswhereITcouldbehelpfulshouldmakethe

problemdefinitionproblemeasier.

Constraints

Inthetimetablingdomain,therearetwotypesofconstraints.Hardconstraints

areconstraintsthatcannotbeviolatedbecauseiftheywere,theschedulewouldbe

infeasible.Softconstraints,otherwiseknownaspreferences,aretheretomakethe

timetableasgoodaspossible.Fewersoftconstraintviolationsmeanthatthe

scheduleisbetter.Inaddition,intheUniversityofTorontoexample,thereare

certainsituationsthatarise,duetothenatureoftheprogram,thatseriously

constraintheschedule.Althoughtheseareconstraintsinaslightlydifferent

meaning,theywillbereferredtoasconstrainingfactorsandtheywillbelistedin

thissectionaswell.

Strategy

Thereisnowrittenprotocolthatisfollowedwhencreatingthetimetable.This

isbecauseeveryyearisuniqueanddifferentthanthepreviousone.Thereis,

however,ageneralstrategythatisused.Thebasicstepsthatmakeupthe

schedulingprocessarethesameeachyear.Firstisdataacquisition.Secondis

decidingontherolloverstrategy.Therolloverstrategyisdecidingwhatpartofthe

previousyear'sscheduleiskeptandrolledoverforthefollowingyear.Afterthe

rolloverstrategyisdetermined,eachyear'stimetableisscheduled,oneatatime,

startingwiththefirstyearprogramandfinishingoffwiththefourthyear.

Theschedulingprocessreallybeginsbeforethedataacquisitionstage,with

thecreationofthecurriculumandcalendar.However,thispartoftheprocessisnot

discussedhere.Inthefollowingsections,eachstepintheaboveschedulingprocess

willbelookedatinmoredetail.

ProblemsintheProcess

Therearemanyareasoftheprocesswherethereisaneedforimprovement.

Theseproblemsrangefromtechnicalissuessuchastherebeingtoomuchdata

beingenteredmanually,tocommunicationissues,topoliticalissueswithinthe

faculty.SomecanbenefitfromanITsolution,andsomecannot.

ITSolutions

Thereareseveralinstancesduringtheprocesswhereautomationwouldbe

helpful.Theobviousoneisthatofthecreationofthetimetable.Softwareis

currentlyused,butthatsoftwarerequiresalotofinteractionandinawayitis

merelyadatabasethatholdsdataandnotifiestheuserwhenconflictsexist,while

thetimetableisactuallycreatedmanually.TheCPsoftwarecanschedule

automatically,butfromexperience,thecreatedschedulesareoftenquitefarfrom

ideal.CPoftenhasalotofdifficultyfindingatimetablethatdoesn'tviolate

constraints.CPdoes,afterall,useheuristicstomakeitsschedulingdecisions,

whichmaynotbethebestoption.Usingmathematicalprogramming,amodel

couldbecreatedtosolvetheAPSCtimetablingproblem.Suchamodelmightnot

requireasmuchinteraction.Itwouldtakethedataandcreateatimetable,which

couldthenbemodifiedbytheuser.Thereareotherareas,earlierintheAPSC

processthatcouldalsobenefitfromautomation.Thedirectorofschedulinghas

identifiedtheseareasaswellastheproposedsolution.Onesuchareaisthestepof

verifyingtheCPandcalendardata.Thisiscurrentlyamanual,two-personprocess

involvingcross-checkingdatafromthreedifferentsources.Ifthesedatawere

connectedelectronically,alotoftimewouldbesaved.Also,duringthedata

acquisitionphase,dataiscollectedthroughspreadsheets.Theprocessinvolves

passingbackandforthinformationthatgetschangedslightlyeachtime.This

processiscurrentlydonemanually,creatingmanyopportunitiesfor

miscommunicationanderrors.Errorsincludefillingoutformsincorrectlyaswell

asmissinginformation.Athirdareawhereautomationwouldbehelpfulisthatof

updatingtheCPdataafterthespreadsheetsarecompleted.Thisisdonemanually.

Theproposedsolution,fromthedirectorofscheduling,istomaketheprocess

ofverifying,collecting,andupdatingdataelectronic.Adatabasecouldbecreated

fromwhichthecalendardatacouldbeuploadedelectronicallytoCP.Also,data

collectioncouldbedonethroughonlineforms,wheretherecouldbeinput

restrictionssothatthecounselorswouldnotbeallowedtofillouttheforms

incorrectlyandblankslotswouldnotbepermitted.Thedatafromtheseforms

couldthenbeuploadedelectronicallyintoCP.Suchasolutionwouldsavealotof

timeaswellaspreventmanyerrors.

AnotherareawhereanITsolutionwouldbeusefulisthatofthedisconnect

betweenthesystemsusedfortheschedule.Whenachangeismadetotheschedule,

threesystemsmustbeupdated:

CP,ROSI,andtheRoomReservationSystem

（RRS）.Often,therearedifferentpeopleupdatingthedifferentsystemsandifitis

notdonesimultaneously,someonemayworkononeofthesystemsassumingitis

uptodatewhenitisnot.Thiscancauseproblems.Itwouldbeusefultoconnect

thesystemssothatwhenoneisupdated,soaretheothers.

Non-ITSolutions

TherearetworeasonswhyanITsolutionmaynotbepossible:

thereisnoIT

solutionthatappliestothespecificproblem,ortheITsolutionthatappliesisnot

feasible.

Thebiggestissueexistinginthecurrenttimetablingprocessisthatof

communicationduringthedataacquisitionphase.Duringthisphase,the

counselorsaresupposedtogetalltherequirementsfromthefacultyinregardsto

theirschedulepreferencesandnecessities.Facultyaresupposedtosupplytheir

departmentswiththedeliveryofthecoursestheywillbeteaching.Deliveryrefers

tothenumberofsectionsthecourseshouldhaveandthenumberandlengthofall

meetingsofthecourse.Facultymembersarealsosupposedtosupplytheir

roomingrequirements.Itisverycommoninthecurrentprocessthatfaculty

membersdonotsupplymuchdataduringthedataacquisitionphase.Insuchcases,

itisassumedthattherearenostrictconstraintsandthatthedeliveryisthesameas

whatiswritteninthecalendar.Itisalsoverycommonforsuchfacultymembersto

cometotheschedulingofficewithdemandsorcomplaintsoncethescheduleis

completedanduploaded.Thesedemandsrangefromwantingdifferentroomsto

wantingtochangeaone-hourlabtobeathree-hourlab.

AlthoughitmaybepossibletohaveanITsolutionwherefacultymembers

likely

isitcounselor,thethroughgoingofinsteadonline,datatheirentercould

infeasibletoexpectuyinfromallthefacultymembers.Amorerealistic

solutionwouldbetodevelopawrittenpolicythatincludesadatebywhichthe

departmentsmusthavealltheirteachingassignmentsdone,adatebywhichthe

facultymembersmustsubmittheirschedulingdata,andwhatdatamustbe

included.Theschedulingofficewouldthenberequiredtoapproveanydeviations

fromthefacultymembers'requestsandtherewouldbenochangesmadeoncethe

scheduleisuploaded.Asimilarpolicywouldbeusefulinregardstothe

developmentofcurriculum.Thereshouldbenochangestocurriculummadepasta

certaindate.Implementingsuchastrictsetofruleswouldnotbeasimpletas