1、数学建模竞赛论文写作数学建模竞赛论文写作丁永生丁永生东华大学信息学院东华大学信息学院第1页近年来获奖情况近年来获奖情况20美国大学生数学模型竞赛,国际特等奖20全国大学生数学模型竞赛,上海赛区二等奖20美国大学生数学模型竞赛,国际一等奖20全国大学生数学模型竞赛,全国二等奖和上海赛区一等奖20全国大学生数学模型竞赛,上海赛区二等奖年全国大学生数学模型竞赛,上海赛区二等奖1999年全国大学生数学模型竞赛,上海赛区二等奖1998年全国大学生数学模型竞赛,全国一等奖和上海赛区一等奖第2页数模小组任务分工数模小组任务分工三个人侧重点不一样三个人侧重点不一样:建模:推导数学模型,数学能力建模:推导数学模
2、型,数学能力强强编程:计算机能力强编程:计算机能力强论文写作:写作能力强论文写作:写作能力强第3页竞赛时间安排竞赛时间安排第一天:第一天:早晨:确定题目,并查阅文件早晨:确定题目,并查阅文件下午:开始分析,建立初步模型下午:开始分析,建立初步模型晚上:编程,得到初步计算结果晚上:编程,得到初步计算结果12:00PM休息休息第二天:第二天:早晨:得到第一个模型合理结果早晨:得到第一个模型合理结果下午:开始写论文,并考虑对第一个模型下午:开始写论文,并考虑对第一个模型改进改进第4页竞赛时间安排竞赛时间安排第二天:第二天:晚上:得到第二个模型初步结果晚上:得到第二个模型初步结果12:00PM休息休息
3、第三天:第三天:早晨:得到第二个模型合理结果早晨:得到第二个模型合理结果下午:考虑对前二个模型深入优化,得到下午:考虑对前二个模型深入优化,得到第三个数学模型,或对前二个模型正确性第三个数学模型,或对前二个模型正确性进行验证进行验证晚上:得到最终结果,完成整篇论文晚上:得到最终结果,完成整篇论文第5页论文格式规范论文格式规范论文(答卷)用白色论文(答卷)用白色A4纸,上下左右各留纸,上下左右各留出出2.5cm页边距页边距第一页为确保书,详细格式按要求第一页为确保书,详细格式按要求第二页为空白页,用于论文编号第二页为空白页,用于论文编号论文题目和摘要写在第三页上论文题目和摘要写在第三页上第四页开
4、始是论文正文第四页开始是论文正文论文从第三页开始编写页码,页码必须位论文从第三页开始编写页码,页码必须位于每页页脚中部,从于每页页脚中部,从“1”开始连续编号开始连续编号论文不能有页眉,不能有任何可能显示答论文不能有页眉,不能有任何可能显示答案人身份标志案人身份标志第6页论文格式规范论文格式规范论文题目用论文题目用3号黑体字、一级标题用号黑体字、一级标题用4号黑号黑体字,并居中。论文中其它汉字一律采取体字,并居中。论文中其它汉字一律采取小小4号宋体字,行距用号宋体字,行距用1.5倍行距倍行距注意:摘要在整篇论文中评阅中占有主要注意:摘要在整篇论文中评阅中占有主要权重,请认真书写摘要权重,请认真
5、书写摘要引用他人结果或其它公开资料(包含网上引用他人结果或其它公开资料(包含网上查到资料)必须按照要求参考文件表述方查到资料)必须按照要求参考文件表述方式在正文引用处和参考文件中均明确列出。式在正文引用处和参考文件中均明确列出。正文引用处用正文引用处用“”标出,如标出,如13等。等。第7页论文格式规范论文格式规范参考文件按正文中引用次序列出,其中参考文件按正文中引用次序列出,其中书籍表述方式为:书籍表述方式为:编号编号作者,书名,出版地:出版社,出作者,书名,出版地:出版社,出版年版年期刊杂志论文表述方式为:期刊杂志论文表述方式为:编号编号作者,论文名,杂志名,卷期号:作者,论文名,杂志名,卷
6、期号:起止页码,出版年起止页码,出版年网上资源表述方式为:网上资源表述方式为:编号编号作者,资源标题,网址,访问时间作者,资源标题,网址,访问时间(年月日)(年月日)第8页论文学作及评卷标准论文学作及评卷标准论文组成部分论文组成部分:1.摘要摘要2.问题重述问题重述3.假设假设4.建模建模5.求解求解6.讨论优缺点讨论优缺点7.模型改进模型改进第9页论文评卷标准论文评卷标准1.假设合理性假设合理性2.建模创造性建模创造性3.结果正确性结果正确性4.文字清楚程度文字清楚程度第10页一定要写好。主要写三个方面:一定要写好。主要写三个方面:1.处理什么问题(一句话)处理什么问题(一句话)2.采取什么
7、方法(引发阅卷老师注采取什么方法(引发阅卷老师注意,不能太粗,也不能太细)意,不能太粗,也不能太细)3.得到什么结果(简明扼要、生动、得到什么结果(简明扼要、生动、公式要简单、必要时可采取小图公式要简单、必要时可采取小图表)表)(一)摘(一)摘 要要第11页正正文文10页左右,公式推导放在附录中页左右,公式推导放在附录中将原问题用数学语言表示出来将原问题用数学语言表示出来重点处理问题应着重说明,把阅重点处理问题应着重说明,把阅卷老师引导到自己思绪中,把他卷老师引导到自己思绪中,把他们看成不懂本问题读者。们看成不懂本问题读者。(二)问题重述(二)问题重述第12页最关键一步从假设开始。需要下很最关
8、键一步从假设开始。需要下很大功夫,简明扼要、准确清楚大功夫,简明扼要、准确清楚1)假设太多,阅卷老师记不住。要归)假设太多,阅卷老师记不住。要归结出一些主要假设,普通结出一些主要假设,普通35条,条,有些不是很主要假设在论文适当地有些不是很主要假设在论文适当地方提一下方提一下2)假设要数学化,重视逻辑性要求)假设要数学化,重视逻辑性要求3)设计好符号,使人看起来清楚)设计好符号,使人看起来清楚(三)假(三)假 设设第13页说明建模思绪说明建模思绪有些简单事情往往是最主要东西,一有些简单事情往往是最主要东西,一定要说清楚定要说清楚刚才开始原始想法,很主要刚才开始原始想法,很主要推导时,公式若很长
9、,可放在附录中推导时,公式若很长,可放在附录中普通要求设计普通要求设计23个模型(一个简单、个模型(一个简单、再对模型进行改进,得到第二个模型,再对模型进行改进,得到第二个模型,就会生动)就会生动)(四)建(四)建模模第14页(1)模型定性)模型定性线性或非线性线性或非线性连续、离散或混合连续、离散或混合时变或非时变时变或非时变(2)模型求解)模型求解利用现成软件利用现成软件自己解出来,实际意义更清楚自己解出来,实际意义更清楚(五)(五)模型求解模型求解第15页(六)模型优缺点及改进(六)模型优缺点及改进提出一些新思绪,使问题更准提出一些新思绪,使问题更准确、也使模型得到深入优化。确、也使模型
10、得到深入优化。勇于讨论学生,成绩会好。勇于讨论学生,成绩会好。第16页举例说明举例说明 设某生物种群在其适应环设某生物种群在其适应环境下生存,试预测该种群数境下生存,试预测该种群数量。量。第17页普通解法普通解法记记N(t)为为t 时刻该种群数量,设该时刻该种群数量,设该种群自然增加率为种群自然增加率为,则,则即即假定初试时刻种群数量为假定初试时刻种群数量为N0,则有则有于是:于是:第18页模型假设模型假设假设该环境下只有一个生物群体,或假设该环境下只有一个生物群体,或者其它生物群体不影响此生物群体生者其它生物群体不影响此生物群体生成成假定该种群自然增加率与时刻假定该种群自然增加率与时刻t和时
11、和时刻刻t时该种群数量无关,记为时该种群数量无关,记为因为种群数量很大,故可设种群个体因为种群数量很大,故可设种群个体N(t)是时间连续可微函数是时间连续可微函数假定初始时刻,种群数量为假定初始时刻,种群数量为N0第19页试验验证试验验证 美国战后人口增加美国战后人口增加 不一样时间段世界人口增加不一样时间段世界人口增加 深入改进深入改进 (1 1)变参数)变参数 (2 2)各种群共存)各种群共存 (3 3)随机模型)随机模型第20页飓风疏散问题建模飓风疏散问题建模StrategiesforEscapingaHurricanesWrath年美国竞赛B题第21页第22页AMonumentalTr
12、afficJamin1999TrafficslowedtoastandstillonInterstateI-26,whichistheprincipalroutegoinginlandfromCharlestontotherelativelysafehavenofColumbiainthecenterofthestate.Whatisnormallyaneasytwo-hourdrivetookupto18hourstocomplete.Manycarssimplyranoutofgasalongtheway.TrafficleavingColumbiagoingnorthwestwasmov
13、ingonlyveryslowly.第23页ReversaloftrafficonI-26,sothatbothsides,includingthecoastal-boundlanes,havetrafficheadedinlandfromCharlestontoColumbia.TrafficreversalonprincipalroadsleadinginlandfromMyrtleBeachandHiltonHeadisalsoplanned.ThePrincipalProposal第24页Charlestonhasapproximately500,000peopleMyrtleBeac
14、hhasabout200,000people,andanother250,000peoplearespreadoutalongtherestofthecoastalstripColumbia,anothermetroareaofaround500,000peoplePeopleinDifferentCities第25页Theinterstateshavetwolanesoftrafficineachdirectionexceptinthemetropolitanareaswheretheyhavethree.Columbiadoesnothavesufficienthotelspacetoac
15、commodatetheevacuees(includingsomecomingfromfarthernorthbyotherroutes),sosometrafficcontinuesoutboundonI-26towardsSpartanburg;onI-77northtoCharlotte;andonI-20easttoAtlanta.OthersFactors第26页Thequestionsthatneedtobeaddressed:1.Underwhatconditionsdoestheplanforturningthetwocoastal-boundlanesofI-26intot
16、wolanesofColumbia-boundtraffic,essentiallyturningtheentireI-26intoone-waytraffic,significantlyimproveevacuationtrafficflow?ConstructaModel第27页2.In1999,thesimultaneousevacuationofthestatesentirecoastalregionwasordered.Wouldtheevacuationtrafficflowimproveunderanalternativestrategythatstaggerstheevacua
17、tion,perhapscounty-by-countyoversometimeperiodconsistentwiththepatternofhowhurricanesaffectthecoast?ConstructaModel第28页3.SeveralsmallerhighwaysbesidesI-26extendinlandfromthecoast.Underwhatconditionswoulditimproveevacuationflowtoturnaroundtrafficonthese?4.Whateffectwouldithaveonevacuationflowtoestabl
18、ishmoretemporarysheltersinColumbia,toreducethetrafficleavingColumbia?ConstructaModel第29页5.In1999,manyfamiliesleavingthecoastbroughtalongtheirboats,campers,andmotorhomes.Manydrovealloftheircars.Underwhatconditionsshouldthereberestrictionsonvehicletypesornumbersofvehiclesbroughtinordertoguaranteetimel
19、yevacuation?ConstructaModel第30页6.Ithasbeensuggestedthatin1999someofthecoastalresidentsofGeorgiaandFlorida,whowerefleeingtheearlierpredictedlandfallsofHurricaneFloydtothesouth,cameupI-95andcompoundedthetrafficproblems.Howbiganimpactcantheyhaveontheevacuationtrafficflow?ConstructaModel第31页RequiresClea
20、rlyidentifywhatmeasuresofperformanceareusedtocomparestrategies.Prepareashortnewspaperarticle,nottoexceedtwopages,explainingtheresultsandconclusionsofyourstudytothepublic.第32页(1)Theinterstates(e.g.,I-26,I-77,I-20)havetwolanesoftrafficineachdirectionexceptinthemetropolitanareaswheretheyhavethree,which
21、meansthetrafficenteringametropolitan(suchasColumbia)canbesmoothlyseparateintotheroutesleavingitinmostcase.(2)ThenormaldrivetakestwohourstocompletefromCharlestontoColumbia.TheaveragedrivespeedforacarontheinterstateI-26,I-77,andI-20islimitedto60-80mph,whiletheoneforacaronprincipalroads(e.g.,US501)isli
22、mitedto50-70mph.Assumptions第33页(3)Charlestonhasapproximately500,000people,MyrtleBeachhasabout200,000people,andanother250,000peoplearewell-distributedalongtherestofthecoastalstrip.Also,weshouldconsidersomeevacueesfromthecoastlineofGeorgiaandFloridainQuestion6.Assumptions第34页(4)Columbiahasaround500,00
23、0people.And,accordingtoourroughsearchviaInternet,thetotalnumberofthehotelsandmotelsinColumbiaandbeyondColumbia,SC,isabout184,whichcanoccupyaround50,000people.Hence,Columbiadoesnothavesufficienthotelspacetoaccommodatetheevacuees(includingpeoplecomingfromfarthernorthbyotherroutes).So,sometrafficmustco
24、ntinueoutboundonI-26towardsSpartanburg;onI-77northtoCharlotte;andonI-20westtoAtlanta.Assumptions第35页(5)ThereareseveraltropicalcycloneguidancemodelsavailabletotheNHCandCPHCforecastersforthehurricaneseason.Thesemodelsrangeincomplexityfromsimplestatisticalmodelstothree-dimensionalprimitiveequationmodel
25、s.Accordingtotheirmodels,weassumethattheNationalHurricaneCenter(NHC)inMiami,Floridacanissue72hourtropicalcyclonetrackandintensityforecasts.Also,hurricanesarepossibleinthespecifiedareaoftheWATCH,usuallywithin36hours,andareexpectedinthespecifiedareaoftheWARNING,usuallywithin24hours.Assumptions第36页(6)E
26、vacueestravelingonI-26inthenormalwestboundlanesoftravelwillbeallowedtoexitatallinterchangesbetweenCharlestonandColumbia.Evacueestravelinginthereversedlanesoftravelwillbeallowedtoexitatmost,butnotall,interchanges.Assumptions第37页10109 96 65 54 43 32 21 11111T TS Sx x1 1x x2 2x x3 3x x4 4x x5 5x x7 7x
27、x6 6x x8 8x x9 9x x1010 x x1111x x1212x x1414x x1515x x13138 87 7x x1616SSupersourceSSupersource1(1(V V1 1)HiltonHead)HiltonHead2(2(V V2 2)Charleston)Charleston3(3(V V3 3)MyrtleBeach)MyrtleBeach4(4(V V4 4)Thecrossoverpoint)ThecrossoverpointbetweenI-95andI-26betweenI-95andI-265(5(V V5 5)Thecrossoverp
28、oint)ThecrossoverpointbetweenI-95andI-20betweenI-95andI-206(6(V V6 6)Columbia)Columbia7(7(V V7 7)HotelsinColumbia)HotelsinColumbia8(8(V V8 8)TemporarysheltersinColumbia)TemporarysheltersinColumbia9(9(V V9 9)Atlanta)Atlanta10(10(V V1010)Spartanburg)Spartanburg11(11(V V1111)Charlotte)CharlotteTSupersi
29、nkTSupersinkFig.1.Thetrafficnetworkofthemainroutesofevacuation.第38页TheMaximumFlowProblem TheobjectivefunctionforQuestions1to6exceptQuestion2:Theconstraintconditions:第39页TheMaximumFlowProblem TheobjectivefunctionforQuestions2:Theconstraintconditions:第40页EvacueesfromSources(HiltonHead,Charleston,andMy
30、rtleBeach)Weshouldfirstdealwiththe250,000peoplewelldistributingalongtherestofthecoastalstrip,anddividethemintothreesources.Thenwemustconsidertwocasesinouralgorithms:(1)Non-considerationofthesomeofthecoastalresidentsofGeorgiaandFloridacameupI-95;(2)ConsiderationofsomeofthecoastalresidentsofGeorgiaand
31、FloridacameupI-95.第41页TheFamousGoldenSectionMethod=500,000+125,000=625,000=200,000+I-95:I-26:US501:(case2)第42页TheImpactofTemporarySheltersTheflowofenteringColumbiaandthatofstayingatandoutgoingColumbiashouldbeequalto:-I-26westboundtraffictoColumbia-I-20westboundtraffictoColumbia-I-26westboundtrafficl
32、eavingColumbia-I-20westboundtrafficleavingColumbia-I-77northboundtrafficleavingColumbia-InhotelsandmotelsinColumbia-InestablishedtemporarysheltersinColumbia第43页ThePerformanceMeasureofTrafficFlow ThetrafficflowtobeanimportantperformancemeasureFlow=第44页SimulationResultsandModelTesting Fivedifferentstr
33、ategiesaccordingtoQuestions1to5consideringtwocases:(1)Non-considerationofthesomeofthecoastalresidentsofGeorgiaandFloridacameupI-95;(2)ConsiderationofsomeofthecoastalresidentsofGeorgiaandFloridacameupI-95,whichisQuestion6.第45页Q:Underwhatconditionsdoestheplanforturningthetwocoastal-boundlanesofI-26int
34、otwolanesofColumbia-boundtraffic,essentiallyturningtheentireI-26intoone-waytraffic,significantlyimproveevacuationtrafficflow?A:StrategyI第46页Q:SeveralsmallerhighwaysbesidesI-26extendinlandfromthecoast.Underwhatconditionswoulditimproveevacuationflowtoturnaroundtrafficonthese?A:StrategyII第47页StrategyII
35、I Q:WhateffectwouldithaveonevacuationflowtoestablishmoretemporarysheltersinColumbia,toreducethetrafficleavingColumbia?第48页StrategyIV Q:In1999,manyfamiliesleavingthecoastbroughtalongtheirboats,campers,andmotorhomes.Manydrovealloftheircars.Underwhatconditionsshouldthereberestrictionsonvehicletypesornu
36、mbersofvehiclesbroughtinordertoguaranteetimelyevacuation?第49页Table1.TheStrategiescomparisonleavingthecoasttoColumbia.PerformancePerformancemeasuresoftrafficmeasuresoftrafficflow(cars/hour)flow(cars/hour)StrategyIStrategyIStrategyIIStrategyIIStrategyIIIStrategyIIIStrategyIVStrategyIVTheTheFlowonFlowo
37、nI-26I-26Case1Case14327.54327.54496.84496.85048.85048.85770.15770.1Case2Case23854.43854.43823.13823.15049.55049.55770.85770.8TheTheFlowonFlowonUS501US501toI-20toI-20Case1Case119201920224022402240224025602560Case2Case219201920224022402240224025602560TheTheFlowonFlowonI-95I-95Case1Case1330.6330.6356.5
38、356.5385.7385.7440.8440.8Case2Case2945.6945.6992.9992.91193.71193.71364.21364.2第50页StrategyV Q:In1999,thesimultaneousevacuationofthestatesentirecoastalregionwasordered.Wouldtheevacuationtrafficflowimproveunderanalternativestrategythatstaggerstheevacuation,perhapscounty-by-countyoversometimeperiodcon
39、sistentwiththepatternofhowhurricanesaffectthecoast?第51页Table2.ThecomparisonofevacuatingtimesbetweenusingStrategyVcombinedwithStrategyItoIVandusingonlyStrategyItoIVStrategyStrategyI IIIIIIIIIIIIVIVCompletingCompletingsimultaneouslysimultaneouslyCase1Case1108.4571108.457172.216972.216966.964966.964961
40、.898461.8984Case2Case2121.7968121.796878.136678.136674.490574.490563.886263.8862EscapingEscapingcounty-by-county-by-countycountyCase1Case1105.4008105.400866.191666.191661.065761.065755.896255.8962Case2Case2112.3379112.337972.769072.769069.131969.131956.523356.5233第52页SensitivityAnalysis Twoimportant
41、impliedfactorstoaffecttheperformanceoftheentirenetwork:(1)TheaccommodationcapacityinColumbia,and(2)TheevacueesfromGeorgiaandFloridacameupI-95.第53页StrengthsandLimitationsDiscussionsandConclusions Others第54页Fig.2.ThetrafficflowonI-26changingwiththetimeperiodofpredictedlandfallofhurricane,resultingindi
42、fferentregionsofthestrategies(ItoIV)tobecarriedout.第55页Fig.3.Theminimumtotalrequiredtrafficflowchangingwiththetimeperiodofpredictedlandfallofhurricane,resultingindifferentregionsofthestrategies(ItoIV)tobecarriedout.第56页Fig.4.Thecomparisonofmaximumtrafficflowbyevacuatingcounty-by-county(StrategyVcomb
43、inedwithStrategiesItoIV)andinasimultaneousway(usingonlyStrategiesItoIV).第57页Fig.5.TheinfluenceofevacueesaccommodatedinColumbiaonthetrafficflowonI-26,resultingindifferentregionsofthestrategies(ItoIII)tobecarriedout.第58页Fig.6.TheimpactsofevacueesfromGeorgiaandFloridaonthetrafficflowonI-26,resultingindifferentregionsofthestrategies(ItoIV)tobecarriedout.第59页Fig.7.TheimpactsofevacueesfromGeorgiaandFloridaonthetrafficflowonI-95,resultingindifferentregionsofthestrategies(ItoIV)tobecarriedout.第60页Thanks!TheEnd第61页
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