最新脊髓损伤的评定（精品ｐｐｔ课件ppt.ppt

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1、脊髓损伤的评定（精品ＰＰＴ）内容◆解剖学复习◆概述◆临床表现◆功能评定损伤程度分级（ASIA）专项评定心理评定日常生活活动(ADL)能力预后预测脊柱解剖◆脊柱由24个椎骨、1个骶骨、1个尾骨借韧带、关节盘及椎间关节连接而成◆颈椎7块、胸椎12块、腰椎5块及尾椎3-5块。随着年龄的增长，5块骶椎融合成1块骶骨，尾椎也融合成1块TheNewsvendorModel报童模型“Toomuch”and“toolittle”costsCo=overagecostThecostoforderingonemoreunitthanwhatyouwouldha

2、veorderedhadyouknowndemand.Inotherwords,supposeyouhadleftoverinventory(i.e.,youoverordered).Coistheincreaseinprofityouwouldhaveenjoyedhadyouorderedonefewerunit.Cu=underagecostThecostoforderingonefewerunitthanwhatyouwouldhaveorderedhadyouknowndemand.Inotherwords,supposeyouhad

3、lostsales(i.e.,youunderordered).Cuistheincreaseinprofityouwouldhaveenjoyedhadyouorderedonemoreunit.BalancingtheriskandbenefitoforderingaunitOrderingonemoreunitincreasesthechanceofoverage…ExpectedlossontheQthunit=CoxF(Q)F(Q)=Distributionfunctionofdemand=Prob{Demand<=Q)…butthe

4、benefit/gainoforderingonemoreunitisthereductioninthechanceofunderage:ExpectedgainontheQthunit=Cux(1-F(Q))Asmoreunitsareordered,theexpectedbenefitfromorderingoneunitdecreaseswhiletheexpectedlossoforderingonemoreunitincreases.NewsvendorexpectedprofitmaximizingorderquantityToma

5、ximizeexpectedprofitorderQunitssothattheexpectedlossontheQthunitequalstheexpectedgainontheQthunit:Rearrangetermsintheaboveequation->TheratioCu/(Co+Cu)iscalledthecriticalratio.（临界比或关键比例）Hence,tomaximizeprofit,chooseQsuchthatwedon’thavelostsales(i.e.,demandisQorlower)withaprob

6、abilitythatequalsthecriticalratioTheNewsvendorModel:Performancemeasures绩效指标NewsvendormodelperformancemeasuresForanyorderquantitywewouldliketoevaluatethefollowingperformancemeasures:Expectedlostsales（期望销售损失）TheaveragenumberofunitsdemandexceedstheorderquantityExpectedsales（期

7、望销售）(comparedtoexpecteddemand)Theaveragenumberofunitssold.Expectedleftoverinventory（期望售后剩余库存）Theaveragenumberofunitsleftoverattheendoftheseason.ExpectedprofitExpectedfillrate（期望订单完成率）ThefractionofdemandthatissatisfiedimmediatelyIn-stockprobability（存货满足概率）Probabilityalldemand

8、issatisfiedStockoutprobability（缺货概率）ProbabilitysomedemandislostformulaExpec