交通运输与物流专业英语(Unite-6)中英文

UnitSixAlternativeEvaluationandChoiceTextAFeasibilitydeterminationEverydecisioninvolvesatleasttwooptions.Eventhoughasingleproposalwaspresented,decisionmakershaveachoicebetweentheproposalanddoingnothing.Evaluationappraisesthepositiveimpactsandthenegativeimpactsofalternativeoptionsintermsofeitherasingleormultipledecisioncriteria.Determiningrelevantimpactstoparticulardecisionandspecifyingtheappropriatedecisioncriteriaarerelatedtothevaluesystemwithinwhichthechoiceistobemade.Inthecaseoftransportationdecisionsinthepublicsector,theoperatingvaluesystemisnotthatofanysingleindividualorsubgroupbutthatofthecommunityasawhole.Thereexistconflictingvaluesystemswithinsociety.Consequently,transportationdecisionalsoentailstheresolutionofconflicts.每一项抉择至少包含两个选项，即使是一个单一的提议，决策者也可以选择执行这个提议或什么也不做。不管是根据单一的还是多样化的决策标准，评估的目的在于评价每个选项的积极影响和消极影响。（人们）在做决定时，确立具体抉择的相关影响并详细说明合理的评判标准与其价值体系是相关联的。在公共部门的交通决策中，其价值体系代表的不仅是某一个人或小团体的利益，而是整个社区的价值体系。社会中常存在着相互冲突的价值体系，因此，交通决策也包含着解决（价值冲突）的问题。Twotypesofevaluationstudiesarecommonlyundertaken:pre-implementationstudies,whichfacilitatethechoiceofthebestcourseofactionfromamongseveralalternativeproposals,andpost-implementationstudies,whichassesstheperformanceofalreadyimplementedaction.Post-implementationstudiesareimportantfortworeasons.First,theyhelptodiscoverwhetherornottheimplementedalternativeperformswell,andsecond,theyhelptodeterminewhetherornotitcontinuestoperformproperlyovertime.Thisisespeciallyimportantinthecaseoftransportationsystems,whicharesubjecttochangingconditionsandalsotoevolvinggoalsandobjectives.Continuousmonitoringandperiodicperformanceevaluationcanhelpidentifyemergingproblemsandalsoprovideguidancetothedesignofpossibleimprovements.（交通决策中）通常存在着两种类型的评估调查：实施前调查，这有助于在几种备选方案中选出最佳方案；实施后调查，用于评估实施项目的各项性能指标。实施后调查非常重要，原因有二：第一，它有助于发现实施项目是否运行良好；第二，它有助于确定（实施项目）随着时间流逝仍然能良好运行。在易受条件、目标和目的改变影响的交通运输系统中，（实施后调查）显得尤为重要。持续的监测和周期性的性能评估有助于发现问题，为可能的改进设计提供帮助。Analternativemustbebothfeasibleandsuperiortoallothersinordertobeselectedforimplementation.Theprerequisitestotheadmissionofanalternativetothelistofacceptableoptionsincludetheconditionsoftechnologicalfeasibility,economicefficiency,andcost-effectiveness,andavailabilityoftheneededresources.Wepresentthefundamentalelementsofefficiencyandeffectivenessevaluationtechniques,alongwithbriefdescriptionoftheirconceptualfoundationsandtheirmajorstrengthsandweaknesses.用于实施的选择方案必须具有可行性且优于其他备选方案。（项目中）能够进入候选名单的方案必须包括：技术可行性条件、经济效率、成本效率以及资源可得性。我们举出了一些基础的与效率和有效性相关评估技术指标，简单地描述了它们的概念和各自的优缺点。FeasibilityTechnologicalfeasibilityreferstotheabilityofasystemtofunctionaccordingtothelawsofnatureandnottoitsdesirability:Aperpetual-motionmachinemaybehighlydesirablebuttechnologicallyimpossible.Engineersandothertechnologistsarequalifiedtodealwithquestionsrelatingtotechnology.Researchanddevelopmentareon-goingactivitiesthatoccasionallyleadtotechnologicalbreakthroughs.Thevastmajorityofpracticalapplications,however,involvetheuseofexistingtechnology.Eventhen,innovativeandcreativewaysofcombiningoff-the-shelftechnologyarecommon.Consequently,thequestionoftechnologicalfeasibilityisanaspectofevaluationthatcannotbeignored.技术可行性指的是在遵循自然规则的条件下系统能展现出的性能，它排除了不切实际的幻想，例如，人们都渴望（发明）永动机，但在技术上这是不可能做到的。工程师和技术人员的职责在于处理与技术相关的问题，持续不断的研发偶尔能够实现技术上的突破，然而在大量的实践应用中使用的仍然是现存的技术。尽管如此，将创新方法与现存技术相结合仍然普遍使用，因此，技术可行性问题是评估过程中不可忽视的一个方面EfficiencyEfficiencyisdefinedastheratioofthequantityproduced(output)totheresourcesrequiredforitsproduction(input).Physicalormachineefficiencyistheratiooftheenergydeliveredbyamachineoraprocesstotheenergysuppliedtoit.Althoughexpressedinthesameunitofmeasurement,theinputandtheoutputenergydifferinform,forexample,energyintheformofelectricityvis-à-visenergyintheformofworkdonebythesystem.Machineefficiencyisalwayslessthanunitybecauseoftheunavoidableenergylossesthatareincurredntheprocess.Thiswastecanbejustifiedonlywhentheusefulness,orutility,oftheoutputexceedsthatoftheinput.Whenboththenumeratorandthedenominatorareconvertedtothesamemeasureofeconomicvalue,theirratioisreferredtoastheeconomicefficiencyofthemachine,whichmustbegreaterthanunityifthemachineistobeeconomicallyfeasible.Theideaofeconomicefficiencyhasbeenextendedtotheevaluationofsystemstocontrasttheeconomicvalueoftheadvantages(orbenefits)thatarederivedfromthesystemtoitsdisadvantages(orcosts).效率指的是产出量（输出）与生产所需资源（输入）之比。机械效率指的是一台机器能量输出比率或做功功率。尽管（输出和输入）在同一测量单位上体现，但输出能量和输入能量在形式上截然不同，例如，一个系统中的能量以电力和做功的形式同时存在。在运行过程中由于不可避免的损失机械效率总是低于100%，而损失的能量只有在输出价值大于输入价值时才有评价的意义。当输出与输入转化为具有相同经济价值的等价物时，输出与输入的比率指的是机器的经济效率，只有当比率大于1时可以说这种机器在经济上具有可行性。经济效率的观点已经推广到系统评价中以对比其所创造的经济价值和成本EffectivenessEffectivenessisdefinedasthedegreetowhichanactionaccomplishestisstatedobjectives.Itdiffersfromefficiencyinthatitneednothavetoexplicitlyexpressallimpactsinthesamescaleofmeasurement.Forexample,theeffectivenessofaregionaltransportationsystemforelderlyandhandicappedpersonsmaybeexpressedastheproportionofeligibleusersthatlivewithintheserviceareaofthesystemorasthetotalnumberofpersonsserved,whereasitsoperationcostmaybeexpressedintermsofdollars.Cost-effectivenessevaluationistheattempttodeterminetheefficacyofaltern