The Leaves of a Tree
"How much do the leaves on a tree weigh?" How might one estimate the actual weight of the leaves (or for that matter any other parts of the tree)? How might one classify leaves? Build a mathematical model to describe and classify leaves. Consider and answer the following:
?Why do leaves have the various shapes that they have?
?Do the shapes “minimize” overlapping individual shadows that are cast, so as to maxi mize exposure? Does the distribution of leaves within the “volume” of the tree and its branches effect the shape?
?Speaking of profiles, is leaf shape (general characteristics) related to tree profile/branching structure?
?How would you estimate the leaf mass of a tree? Is there a correlation between the leaf mass and the size characteristics of the tree (height, mass, volume defined by the profile)?
In addition to your one page summary sheet prepare a one page letter to an editor of a scientific journal outlining your key findings.
Nowadays the heavy metal pollution is so common that people pay more and more attention to it. The aim of this paper is to calculate the maximum of methylmercury in human body during their lifetime and the maximum number of fish the average adult can safely eat per month. From City Officials research[1], we get information thatthemeanvalue of methylmercury in bass samples of the Neversink Reservoir is 1300 ug/kg and the average weight of bass people consume per month is 0.7 kg. According to the different consuming time in every month, we construct a discrete dynamical system model for the amount of methylmercury that will be bioaccumulated in the average adult body.In ideal conditions, we assume people consume bass at fixed term per month. Based on it, we construct fixed-ingestion model and wereach the conclusion that the maximum amount of methylmercury the average adult human will bioaccumulate in their lifetime is 3505 ug. As methylmercury ingestedis not only coming from bass but also from other food, hence, we make further revise to our model so that the model is closer to the actual situation. As a result, we figure out the maximum amount of methylmercury the average adult human will bioaccumulate in their lifetime is 3679 ug. As a matter of fact, although we assume people consume one fish per month, the consuming time has great randomness. Taking the randomness into consideration, we construct a random-ingestion model at the basis of the first model. Through computer simulations, we obtain the maximum of methylmercury in human body is 4261 ug. We also calculate the maximum amount is 4420 ug after random-ingestion model is revised.As
it is known to us, different countries and districts have different criterions for mercury toxicity. In our case, we adopt LD50 as the toxic criterions(LD50 is the dosage at which 50% of the humans exposed to a particular chemical will die. The LD50 for methylmercury is 50 mg/kg.). We speculate mercury toxicity has effect on the ability of eliminating mercury, therefore, we set upvariable-elimination model at the basis of the first model. According to the first model, the amount of methylmercury in human body is 50 ug/kg, far less than 50 mg/kg, so we reach the conclusion that the fish consumption restrictions put forward by the reservoir advisories can protect the average adult. If the amount of methylmercury ingested increases, the amount of bioaccumulation will go up correspondingly. If 50 mg/kg is the maximum amount of methylmercury in human body, we can obtain the maximum number of fish that people consume safely per month is 997.
Keywords: methylmercury discrete dynamical system model variable-elimination model
discrete uniform random distributionmodelrandom-ingestion model
Introduction
With the development of industry, the degree of environmental pollution is also increasing. Human activities are responsible for most of the mercury emitted into the environment. Mercury, a byproduct of coal, comes from acid rain from the smokestack emissions of old, coal-fired power plants in the Midwest and South. Its particles rise on the smokestack plumes and hitch a ride on prevailing winds, which often blow northeast. After colliding with the Catskill mountain range, the particles drop to the earth. Once in the ecosystem, micro-organisms in the soil and reservoir sediment break down the mercury and produce a very toxic chemical form known as methylmercury. It has great effect on human health.
Public officials are worried about the elevated levels of toxic mercury pollution in reservoirs providing drinking water to the New York City. They have asked for our assistance in analyzing the severity of the problem. As a result of the bioaccumulation
of methylmercury, if the reservoir is polluted, we can make sure that the amount of methylmercury in fish is also increasing. If each person adheres to the fish consumption restrictions as published in the Neversink Reservoir advisory and consumes no more than one fish per month, through analyzing, we construct a discrete dynamical system model of time for the amount of methylmercury that will bioaccumulate in the average adult person. Then we can obtain the maximum amount of methylmercury the average adult human will bioaccumulate in their lifetime. At the same time, we can also get the time that people have taken to achieve the maximum amount of methylmercury. As we know, different countries and districts have different criterions for the mercury toxicity. In our case, we adopt the criterion of KellerArmyCommunityHospital. If the maximum amount of methylmercury in human body is far less than the safe criterion, we can reach the conclusion that the reservoir is not polluted by mercury or the polluted degree is very low, otherwise we can say the reservoir is great polluted by mercury. Finally,the degree of pollution is determined by the amount of methylmercury in human body.
Problem One
discrete dynamical system model
The mean value of methylmercury in bass samples of the Neversink Reservoir is 1300 ug/kg and the average weight of bass is 0.7 kg. According to the subject, people consume no more than one fish per month. For the safety of people, we must consider the bioaccumulation of methylmercury under the worst condition that people absorb the maximum amount of methylmercury. Therefore, we assume that people consume one fish per month.
Assumptions
● The amount of methylmercury in fish is absorbed completely and instantly by
people.
● The elimination of mercury is proportional to the amount remaining.
● People absorb fixed amount of methylmercury at fixed term per month. ● We assume the half-life of methylmercury in human body is 69.3 days. Solutions
Let 1α denote the proportion of eliminating methylmercury per month, 1βdenote the accumulation proportion. As we know, methylmercury decays about 50 percent every 65 to 75 days, if no further methylmercury is ingested during that time. Consequently,
111,βα=-
69.3/3010.5.β=
Through calculating, we get
10.7408.β=
L et’s define the following variables ：
0ω denotes the amount of methylmercury at initial time,
n denotes the number of month,
n ω denotes the amount of methylmercury in human body at the moment people have just ingested the methylmercury in the month n ,
1x denotes the amount of methylmercury that people ingest per month and 113000.7910x ug ug =?=.
Moreover, we assume
0=0.ω
Though,
111,n n x ωωβ-=?+
we get
1011x ωωβ=?+
2201111x x ωωββ=?+?+
???
10111111n n n x x x ωωβββ-=?+?+???+?+
121111(1)n n n x ωβββ--=++???++?
1111
1.1n n x βωβ--=- With the remaining amount of methylmercury increasing, the elimination of methylmercury is also going up. We know the amount of ingested methylmercury per mouth is a constant. Therefore, with time going by, there will be a balance between absorption and elimination. We can obtain the steady-state value of remaining methylmercuryas n approaches infinity.
1*
1111111lim 3505.11n n n x x ug βωββ-→∞-===-- The value of n ω is shown by figure 1.
Figure 1. merthylmercury completely coming from fish and ingested at fixed term per month
If the difference of the remaining methylmercury between the month n and 1n - is less than five percent of the amount ofmethylmercury that people ingest per month, that is,
115%.n n x ωω--
Then we can get
11=3380ug.ω
At the same time, we can work out the time that people have taken to achieve 3380 ug is11 months.
From our model, we reach the conclusion that the maximum amount of methylmercury the average adult human will bioaccumulate in their lifetime is 3505 ug.
If people ingest methylmercury every half of a month, however, the sum of methylmercury ingested per month is constant, consequently,
11910405,0.86.2
x ug β=== As a result, we obtain the maximun amount of methylmercury in human body is 3270ug. When the difference is within 5 %, we get the time people have taken to achieve it is 11 months.
Similarly, if people ingest methylmercury per day, we get the maximum amount is 3050ug, and the time is 10 months.
Revising Model
As a matter of fact, the amount of methylmercury in human body is not completely coming from fish. According to the research of Hong Kong SAR Food and Environmental Hygiene Department [1], under normal condition, about 76 percent of
methylmercury comes from fish and 24 percent comes from other seafood. In order to make our model more and more in line with the actual situation, it is necessary for us to reviseit. The U.S. environmental Protection Agency (USEPA) set the safe monthly dose for methylmercury at 3 microgram per kilogram (ug/kg) of body weight.If we adopt USEPA criterion, we can calculate the amount of methylmercury that the average adult ingest from seafood is 50.4 ug per month.
Assumptions
● The amount of methylmercury in the seafood is absorbed completely and
instantly by people.
● The elimination of methylmercury is proportional to the amount remaining. ● People ingest fixed amount of methylmercury from other seafood every day. ● We assume the half-life of methylmercury in human body is 69.3 days. Solutions
Let 0ωdenote the amount of methylmercury at initial time,t denote the number of days,t ω denote the remaining amount on the day t , and 2x denote the amount of methylmercury that people ingest per day. Moreover, we assume
0=0.ω
In addition, we work out
2x =50.4/30=1.68 ug.
The proportion of remaining methylmercury each day is 2β, then
69.320.5.β=
Through calculating,we get
20.99.β=
Because of
1222
1,1t t x βωβ--=- we obtain steady-state value of methylmercury
1*
2222211lim 168.11t t t x x ug βωββ-→∞-===-- If the difference of remaining methylmercury between the day t and 1t - is less than five percent of the amount of methylmercury that people ingest every day, that is,
125%.t t x ωω--
We have
301= 160 ug.ω
So we can reach the conclusion that the maximum amount of methylmercury the average adult human will bioaccumulate from seafood is 160 ugand the time that people take to achieve the maximum is 301 days.
Let 1x denote the amount of methylmercury people ingest through bass at fixed term per month, so the amount of methylmercury an average adult accumulate on the day t is
1221221if t is a positive integer and not divisible by 30if t is a positive integer and divisible by 30.
t t t t x x x ωωβωωβ--=?+??=?++? The value of t ω is shown by figure 2.
Figure 2. merthylmercury coming from fish and other seafood and ingested at fixed term per day
The change of t ω reflects the change of the amount of methylmercury in human body. Through revising model, we can figure out the maximum amount of methylmercury the average adult human will bioaccumulate in their lifetime is 3679 ug.
Problem Two
Random-ingestion model
Although people consume one fish per month, the consuming time has great randomness. We speculate the randomness has effect on the bioaccumulation of methylmercury,therefore, we construct a new model.
Assumptions
The amount of methylmercury in fish is absorbed completely and instantly by
people.
● The elimination of methylmercury is proportional to the amount remaining. ● People consume one fish per month, but the consuming time has randomness. ● We assume the half-life of methylmercury in human body is 69.3 days.
Let 0L denote the amount of methylmercury at initial time, n L denote the amount of methylmercuryat the moment people have just ingestedmethylmercury in the month n , and x denote the amount of methylmercury that people absorb each time.
We assume
0=0.L
We have
910.x ug =
We define 1βthe proportion of remaining methylmercury every day.
Through
69.310.5,β=
we can get
10.99.β=
Let i obey discrete uniform random distribution with maximum 30 and minimum 1and n t denote the number of days between the day 1n i - of the month 1n - and the
day n i of the month n , then we have
-130-,n n n t i i =+
(1)1.n t n n L L x β-=?+
The value of n L is shown by figure 3.
Figure 3. merthylmercury completely coming from fish and ingested at random per month
Figure3 shows the amount of methylmercury in human body has a great changedue to the randomness of consuming time. Through the computer simulation, if we have numberless samples, n L will achieve the maximum value.
That is,
4261.n L ug =
Revising model
In order to make our model more accurate, we need to make further revise.We take methylmercury coming from other seafood into consideration. We know the amount of methylmercury that people ingest from other seafood every day is 1.68 ug.
In that situation, we have
1212.
30(-1)30(-1)n n n n n n L L x if n n i L L x x if n n i ββ=?+≠?+??=?++=?+? Through the computer simulation, we can geta set of data about n L shown by figure
4.
Figure 4. remaining merthylmercury coming from fish consumed at random per month and other
food consumed at fixed term per day
Though the revised model, we reach the conclusion that if we have numberless samples, n L will achieve the maximum value.
That is,
4420.n L ug =
Variable-eliminateion model
As a matter of fact, the state of human health can affect metabolice rate so that the ability of eliminating methylmercury is not constant. We have koown the amount of methylmercury in human body will affect human health. So we can draw the conclusion that the amount of methylmercury in human body will affect the abilitity of eliminating methylmercury.
Assumptions
● The amount of methylmercury in fish is absorbed completely and instantly by
people.
● the elimination of methylmercury isnot only proportional to the amount
remaining, but also affected by the change of human health which are caused by the amount of methylmercury.
● People absorb fixed amount of methylmercury at fixed term per month through
consuming bass.
● We assume the half-life of methylmercury in human body is 69.3 days.
● In condition that no further methylmercury is ingested during a period of time, we
let χ denote the eliminating proportion per month. We have known methylmercury decays about 50 percent every other day 5 to a turn 5 days, so we determine the half-life of methylmercury in human body is 69.3 days.Then we
have
69.3/301(1)0.5χ?-=.
By calculating,we get
χ=0.2592.
We adoptLD50 as the toxic criterions, then we get the maximum amount of methylmercury in human body is 63.510? ug.
L et’s define the following variables ：
0ω denotes the amount of methylmercury at initial time,
n denotes the number of month,
n ω denotes the amount of methylmercury in human body at the moment people
have just ingested the methylmercury in the month n ,
n χ denotes the ability of eliminating methylmercuryin the month n .
γ denotes the effect on human health caused by methylmercury toxicity.
1
161 3.510r n n ωχχ-????=?- ??? ??????
1(1)n n n ωωχ?-=?-+
Hence, we have 101(1)ωωχ?=?-+
20212(1)(1)(1)ωωχχ?χ?=?-?-+?-+
[]
01233(1)...(1)(1)(1)...(1)(1)...(1)...(1)1n n n n n ωωχχ?χχχχχχ=?--+?-?--+--++-+
We define the value of γ is 0.5, then we get the maximum amount of maximum in human body is
3567 ug, that is,
*=3567 ug n ω
Not taking the effect on the ability of eliminating maximum caused by methylmercury toxicity into account in model one,we obtain the maximum amount is 3510 ug. The difffference proves methylmercury toxicity has effect on eliminating methylmercury. We find out through calculating when r increases, the amount of
methylmercury go up correspondingly. The reason for it is that methylmercury toxicity rises as a result of r increasing. Correspondingly, the effect on human health will increase, which is in accordance with fact.
Problem Three
According to the first model revised, we can get the maximum amount of bioaccumulation methylmercury is 3679 ug. We assume the average weight of an adult is 70 kg and the amount of methylmercury in human body is 53 ug/kg,far less than 50 mg/kg. Therefore,according to our model,the fish consumption restrictions put forward by the reservoir advisories can protect the average adult from reaching the LD50(LD50 is the dosage at which 50% of the humans exposed to a particular chemical will die. The LD50 for methylmercury is 50 mg/kg).
We assume the lethal dosage of methylmercury is not gradually increasing. If the amount of methylmercury people ingests goes up rapidly, the bioaccumulation amount will reach to a higher value. Moreover, the value probably endangers human safety.Let LD50 be the maximum amount of methylmercury in human body, that is,
*n =50 mg/kg 70 kg=3500 mg.ω?
Let 1x denote the amount of methylmercury people ingest per month. According to the first model,
1*
1111111lim .11n n n x x βωββ-→∞-==-- We can figure out
1 x =907.
2 mg.
We know the mean value of methylmercury in bass samples is 1.3 mg/kg,hence,we can obtain the maximum amount of fish that people consume safely per month is
1max 698.1.3
x M kg =≈ The maximum number of fish is 698/0.7=997.
Conclusion
In problem one, the paper calculates the final steady-state value at the same time interval per month, per half a month and per day. Through comparing the results, we get the final bioaccumulation amount of methylmercury is less, when discrete time unit is smaller. It shows when the interval of consuming fish is smaller and the sum of methylmercury ingested is constant for a period of time, the possibility of poisoning is lower.
In problem two, we analyze the change of the amount of methylmercury under
the condition that consuming time is random. We find out the amount of methylmercury in human body is changing constantly in fixed range, when people have just consumed fish. Moreover, the maximum is 4261 ug, which is far bigger than 3505 ug. So we can reach the conclusion that people are more endangered when the consuming time is irregular.
In order to closer to the actual situation, we construct a model in which the half-life of methylmercury in human body is not constant. Through analyzing the data of computer simulation, the maximum amount of methylmercury will increase, that is, the risk of poisoning will be higher.
References
[1] Dr.D.N.Rahni, PHD. Airborne Mercury Contamination and the NeversinkReservoir.
https://www.doczj.com/doc/fe8492395.html,/dnabirahni/rahnidocs/Envsc/Airborne%20Mercury%20C ontamination%20and%20the%20Neversink%20Reservoir.doc
[2] Hu Dong Bai Ke. Bass.https://www.doczj.com/doc/fe8492395.html,/wiki%E9%B2%88%E9%B1%BC.
[3] Centre for Food Safety Food and Environmental Hygiene Department The
Government of the Hong Kong Special Administrative Region. Mercury in Fish and Food Safety.
https://www.doczj.com/doc/fe8492395.html,.hk/english/Programmme/programme_rafs/Programme_rafs_fc _01_19_mercury_in_fish.html.
破案模型 您的组织，ICM正在调查一个作案阴谋。调查者非常有信心，因为他们知道阴谋集团的几名成员，但他们希望在进行逮捕之前能找出其他成员和领导人。主谋者和所有可能涉嫌同谋的人都以复杂的关系为同一家公司在一个大办公室工作。这家公司一直快速增长，并在开发和销售适用于银行和信用卡公司的计算机软件方面打出了自己的名气。 ICM最近从一个82个工人的小集体那儿得知了一个消息，他们认为这个消息能将帮助他们在公司里找到目前身份尚不明确的同谋者和未知的领导人的最有可能的人选。由于信息流通涉及到所有的在该公司工作的工人，所以很可能在这次信息流通中有一些（或许很多）已经确定的传播者实际并不涉及阴谋。事实上，他们确定他们知道一些并不参与阴谋的人。 建模工作的目标是确定在这个复杂的办公室里谁是最有可能的同谋。 一个优先级列表是最理想的，因为ICM可以根据这个来调查，**，和/或询问最有可能的候选人。 一个划分非同谋者与同谋者的分割线也将是有益的，因为可以对每个组里的人进行清楚的分类。 如果能提名阴谋的领导人，那对于检察官办公室也是非常有帮助的。 在把当前情况下的数据给你的犯罪建模团队之前，你的上司给你以下情形（称为调查EZ），那是她几年前在另一座城市工作时的案例。她对她在简单案件的工作非常自豪，她说，这是一个非常小的，简单的例子，但它可以帮助你了解自己的任务。 她的数据如下： 她认为是同谋的十人分别为Anne#, Bob, Carol, Dave*, Ellen, Fred, George*, Harry, Inez, and Jaye#.（*表示之前已知的同谋，＃表示事先已知的非同谋者） 她对她的案件的28个消息记录按照她的分析依据主题进行了编号。Anne to Bob：你今天为什么迟到了？（1） Bob to Carol：这该死的Anne总是看着我。我并没有迟到。（1） Carol to Dave： Anne 和 Bob又再为Bob的迟到吵架了。（1） Dave to Ellen：我今天早上要见你。你什么时候能来？把预算文件顺便带过来。（2） Dave to Fred：我今天随时随地都可以去见你。让我知道什么时候比较
数学中国MCM/ICM参赛指南翻译（2014版） MCM:The Mathematical Contest in Modeling MCM：数学建模竞赛 ICM:The InterdisciplinaryContest in Modeling ICM：交叉学科建模竞赛ContestRules, Registration and Instructions 比赛规则，比赛注册方式和参赛指南 (All rules and instructions apply to both ICM and MCMcontests, except where otherwisenoted.)（所有MCM的说明和规则除特别说明以外都适用于 ICM） 每个MCM的参赛队需有一名所在单位的指导教师负责。 指导老师：请认真阅读这些说明，确保完成了所有相关的步骤。每位指导教师的责任包括确保每个参赛队正确注册并正确完成参加MCM/ ICM所要求的相关步骤。请在比赛前做一份《参赛指南》的拷贝，以便在竞赛时和结束后作为参考。 组委会很高兴宣布一个新的补充赛事（针对MCM/ICM 比赛的视频录制比赛）。点击这里阅读详情！ 1.竞赛前
A．注册 B．选好参赛队成员 2.竞赛开始之后 A．通过竞赛的网址查看题目 B．选题 C．参赛队准备解决方案 D．打印摘要和控制页面 3.竞赛结束之前 A.发送电子版论文。 4.竞赛结束的时候, A. 准备论文邮包 B．邮寄论文 5.竞赛结束之后 A. 确认论文收到 B．核实竞赛结果 C．发证书 D．颁奖 I. BEFORE THE CONTEST BEGINS:（竞赛前）A.注册 所有的参赛队必须在美国东部时间2014年2月6号（星期四）下午2点前完成注册。届时，注册系统将会自动关闭，不再接受新的注册。任何未在规定时间
2012年美赛B题 题目翻译： 到Big Long River（225英里）游玩的游客可以享受那里的风景和振奋人心的急流。远足者没法到达这条河，唯一去的办法是漂流过去。这需要几天的露营。河流旅行始于First Launch，在Final Exit结束，共225英里的顺流。旅客可以选择依靠船桨来前进的橡皮筏，它的速度是4英里每小时，或者选择8英里每小时的摩托船。旅行从开始到结束包括大约6到18个晚上的河中的露营。负责管理这条河的政府部门希望让每次旅行都能尽情享受野外经历，同时能尽量少的与河中其他的船只相遇。当前，每年经过Big Long河的游客有X组，这些漂流都在一个为期6个月时期内进行，一年中的其他月份非常冷，不会有漂流。在Big Long上有Y处露营地点，平均分布于河廊。随着漂流人数的增加，管理者被要求应该允许让更多的船只漂流。他们要决定如何来安排最优的方案：包括旅行时间（以在河上的夜晚数计算）、选择哪种船（摩托还是桨船），从而能够最好地利用河中的露营地。换句话说，Big Long River在漂流季节还能增加多少漂流旅行数？管理者希望你能给他们最好的建议，告诉他们如何决定河流的容纳量，记住任两组旅行队都不能同时占据河中的露营地。此外，在你的摘要表一页，准备一页给管理者的备忘录，用来描述你的关键发现。 沿着大朗河露营 摘要 我们开发了一个模型来安排沿大河的行程。我们的目标是为了优化乘船旅行的时间，从而使6个月的旅游旺季出游人数最大化。 我们模拟团体从营地到营地旅行的过程。根据给定的约束条件，我们的算法输出了每组沿河旅行最佳的日程安排。通过研究算法的长期反应，我们可以计算出旅行的最大数量，我们定义为河流的承载能力。 我们的算法适应于科罗多拉大峡谷的个案分析，该问题的性质与大长河问题有许多共同之处。 最后，我们考察当改变推进方法，旅程时间分布，河上的露营地数量时承载能力的变化的敏感性。 我们解决了使沿大朗河出游人数最大化的休闲旅行计划。从首次启动到最终结束（225英里），参与者需使用桨供电的橡胶筏或机动船在指定的参与者露营地游玩6到18个晚上。为了确保一个真实的荒野体验，一组在同一时间最多占据一个营地。这个约束限制了公园的6个月的旅游旺季期间可能的旅行数量。 我们模拟情景，然后把我们相似特性的研究结果进行比较，从而验证了我们的方法是否能得到令人满意的结果。 我们的模型是适用于针对有着不同长度的河流、不同数量的露营地、不同的行程持续时间、以及不同的船的速度的情况中，找到最佳的行程安排。
数学模型的组队非常重要，三个人的团队一定要有分工明确而且互有合作，三个人都有其各自的特长，这样在某方面的问题的处理上才会保持高效率。 三个人的分工可以分为这几个方面： 数学员：学习过很多数模相关的方法、知识，无论是对实际问题还是数学理论都有着比较敏感的思维能力，知道一个问题该怎样一步步经过化简而变为数学问题，而在数学上又有哪些相关的方法能够求解，他可以不能熟练地编程，但是要精通算法，能够一定程度上帮助程序员想算法，总之，数学员要做到的是能够把一个问题清晰地用数学关系定义，然后给出求解的方向； 程序员：负责实现数学员的想法，因为作为数学员，要完成大部分的模型建立工作，因此调试程序这类工作就必须交给程序员来分担了，一些程序细节程序员必须非常明白，需要出图，出数据的地方必须能够非常迅速地给出；ACM的参赛选手是个不错的选择，他们的程序调试能力能够节约大量的时间，提高在有限时间内工作的工作效率； 写手：在全文的写作中，数学员负责搭建模型的框架结构，程序员负责计算结果并与数学员讨论，进而形成模型部分的全部内容，而写手要做的。就是在此基础之上，将所有的图表，文字以一定的结构形式予以表达，注意写手时刻要从评委，也就是论文阅读者的角度考虑问题，在全文中形成一个完整地逻辑框架。同时要做好排版的工作，最终能够把数学员建立的模型和程序员算出的结果以最清晰的方式体现在论文中。一个好的写手能够清晰地分辨出模型中重要和次要的部分，这样对成文是有非常大的意义的。因为论文是评委能够唯一看到的成果，所以写手的水平直接决定了获奖的高低，重要性也不言而喻了。 三个人至少都能够擅长一方面的工作，同时相互之间也有交叉，这样，不至于在任何一个环节卡壳而没有人能够解决。因为每一项工作的工作量都比较庞大，因此，在准备的过程中就应该按照这个分工去准备而不要想着通吃。这样才真正达到了团队协作的效果。 比赛流程：对于比赛流程，在三天的国赛里，我们应该用这样一种安排方式：第一天：定题+资
PROBLEM B: Camping along the Big Long River 问题B：沿着大长河露营 Visitors to the Big Long River (225 miles) can enjoy scenic views and exciting white water rapids. 游客到大长河（225英里）可以享受风景和令人兴奋的白色水急流。 The river is inaccessible to hikers, so the only way to enjoy it is to take a river trip that requires 河是徒步旅行者无法进入的，所以唯一享受它的方法是采取河之旅，需要几天的露营several days of camping. River trips all start at First Launch and exit the river at Final Exit, 225 河旅行都开始在第一次启动和退出河在最后退出，225英里下游。 miles downstream. Passengers take either oar- powered rubber rafts, which travel on average 4 乘客乘橡皮艇桨驱动平均每小时4英里，或摩托艇，平均每小时8英里的速度行驶。 mph or motorized boats, which travel on average 8 mph. The trips range from 6 to 18 nights of 旅程从开始到完成6到18个晚上， camping on the river, start to finish.. The government agency responsible for managing this river 负责管理这条河的政府机关想要，以最少的接触与其他群体在河的小船，享受荒野之旅。wants every trip to enjoy a wilderness experience, with minimal contact with other groups of boats on the river. Currently, X trips travel down the Big Long River each year during a six month ×旅行每年在一六个月期间旅行下来，大长江（一年的其余太冷对于河旅行）。 period (the rest of the year it is too cold for river trips). There are Y camp sites on the Big Long 大长河上有Y个露营地，在整个河流廊分布相当均匀。 River, distributed fairly uniformly throughout the river corridor. Given the rise in popularity of river rafting, the park managers have been asked to allow more trips to travel down the river. They 鉴于流行起来的漂流，公园管理人员被要求允许更多的旅行来到河上来旅行。 want to determine how they might schedule an optimal mix of trips, of varying duration (measured in nights on the river) and propulsion (motor or oar) that will utilize the campsites in the best way 他们想确定他们如何可能安排的最佳组合，不同的时间（以夜河）和推进（电机或桨）将利用营地以可能的最佳方式。 possible. In other words, how many more boat trips could be added to the Big Long River’s 换句话说，如何使更多的游船可以被添加到大长河泛舟季节？ rafting season? The river managers have hired you to advise them on ways in which to develop the best schedule and on ways in which to determine the carrying capacity of the river, remembering 河流管理者雇你来指导他们如何在发展最好的安排和方法，确定承载力的河流， that no two sets of campers can occupy the same site at the same time. In addition to your one 记住，没有两支露营队可以在同一时间占据相同的露营地。 page summary sheet, prepare a one page memo to the managers of the river describing your key findings.除了你的一页表，准备了一一页的备忘录的管理人员的描述你的调查结果。 问题：露营沿大长河 游客到大长河（225英里）可以享受风景和令人兴奋的白色水急流。河是徒步旅行者无法进入的，所以唯一享受它的方法是采取河之旅，需要几天的露营。河旅行都开始在第一次启动和退出河在最后退出，225英里下游。乘客乘橡皮艇桨驱动，而旅行的平均每小时4英里或摩托艇，平均每小时8英里的速度行驶。车次范围从6到18个晚上露营的河流，开始完成。
眼看一年一度的美国高中生数学建模竞赛就要到来了，聪明机智的你准备好了吗？ 今年和码趣学院一起去参加吧！ 什么是HiMCM HiMCM(High School Mathematical Contest in Modeling)美国高中生数学建模竞赛，是美国数学及其应用联合会（COMAP）主办的活动，面向全球高中生开放。 竞赛始于1999年，大赛组委将现实生活中的各种问题作为赛题，通过比赛来考验学生的综合素质。
HiMCM不仅需要选手具备编程技巧，更强调数学，逻辑思维和论文写作能力。这项竞赛是借鉴了美国大学生数学建模竞赛的模式，结合中学生的特点进行设计的。 为什么要参加HiMCM 数学逻辑思维是众多学科的基础，在申请高中或大学专业的时候（如数学，经济学，计算机等），参加了优质的数学竞赛的经历都会大大提升申请者的学术背景。除了AMC这种书面数学竞赛，在某种程度上数学建模更能体现学生用数学知识解决各种问题的能力。
比赛形式 注意：HiMCM比赛可远程参加，无规定的比赛地点，无需提交纸质版论文。重要的是参赛者应注重解决方案的设计性，表述的清晰性。 1.参赛队伍在指定17天中，选择连续的36小时参加比赛。 2.比赛开始后，指导教师可登陆相应的网址查看赛题，从A题或B题中任选其一。 3.在选定的36小时之内，可以使用书本、计算机和网络，但不能和团队以外的任何人 员交流（包括本队指导老师） 比赛题目 1.比赛题目来自现实生活中的两个真实的问题，参赛队伍从两个选题中任选一个。比赛 题目为开放性的，没有唯一的解决方案。 2.赛事组委会的评审感兴趣的是参赛队伍解决问题的方法，所以不太完整的解决方案也 能提交。 3.参赛队伍必须将问题的解决方案整理成31页内的学术论文（包括一页摘要），学术 论文中可以用图表，数据等形式，支撑问题的解决方案 4.赛后，参赛队伍向COMPA递交学术论文，最终成果以英文报告的方式，通过电子 邮件上传。 表彰及奖励 参赛队伍的解决方案由COMPA组织专家评阅，最后评出： 特等奖（National Outstanding) 特等奖提名奖（National Finalist or Finalist） 一等奖（Meritorious)
PROBLEM A: The Ultimate Brownie Pan When baking in a rectangular pan heat is concentrated in the 4 corners and the product gets overcooked at the corners (and to a lesser extent at the edges). In a round pan the heat is distributed evenly over the entire outer edge and the product is not overcooked at the edges. However, since most ovens are rectangular in shape using round pans is not efficient with respect to using the space in an oven. Develop a model to show the distribution of heat across the outer edge of a pan for pans of different shapes - rectangular to circular and other shapes in between. Assume 1. A width to length ratio of W/L for the oven which is rectangular in shape. 2. Each pan must have an area of A. 3. Initially two racks in the oven, evenly spaced. Develop a model that can be used to select the best type of pan (shape) under the following conditions: 1. Maximize number of pans that can fit in the oven (N)
2.竞赛开始之后 A．通过竞赛的网址查看题目 B．选题 C．参赛队准备解决方案 D．打印摘要和控制页面 3.竞赛结束之前 A.发送电子版论文。 4.竞赛结束的时候, A. 准备论文邮包 B．邮寄论文 5.竞赛结束之后 A. 确认论文收到 B．核实竞赛结果 C．发证书 D．颁奖 1．您必须在在美国东部时间2014年2月6日（星期四）晚上8点大赛开始以前选择好您的参赛队的队员。一旦比赛开始，您将不能增加或是改变任何一个参赛队队员（但是如果参赛队员本人决定不参加比赛，您可以把他/她从队员名单中删除）。 2．每个参赛队最多都只能由3名学生组成。 3．一个学生最多只能参加一个参赛队。 4．在比赛时间段内，参赛队成员必须是在校学生，但可以不是全日制学生。参赛队成员和指导教师必须来自同一所学校。 2.竞赛开始之后 A.通过网站的得到赛题 ! 美国东部时间2014年2月6日（星期四）晚上8点竞赛开始时，可以通过竞赛网站得到题目。 1.赛题会于美国东部时间2014年2月6日（星期四）晚上8点公布：所有的参赛队员可以通过访问https://www.doczj.com/doc/fe8492395.html,/undergraduate/contests/mcm.得到赛题。无须任何密码，仅通过网页链接就可以得到赛题。 2、美国东部时间2014年2月6日晚7点50分，比赛题目也会同步发布于一下镜像网站：
https://www.doczj.com/doc/fe8492395.html,/mcm/index.html https://www.doczj.com/doc/fe8492395.html,/mcm/index.html https://www.doczj.com/doc/fe8492395.html,/mcm/index.html https://www.doczj.com/doc/fe8492395.html,/mcm/index.html B．选题 每个参赛队可以从三个题目中任选一个题目作答： MCM的参赛队可以选择赛题 A 或 B； MCM的参赛队只要提交两个问题之一的解决方案就可以。MCM参赛队不得选择赛题C。 ICM的参赛队可以选择赛题C。ICM参赛队除了赛题C别无其它选择，不能选择赛题A或者B。C．参赛队准备解决方案： 1. 参赛队可以利用任何非生命提供的数据和资料——包括计算机，软件，参考书目，网站，书籍等，但是所有引用的资料必须注明出处，如有参赛队未注明引用的内容的出处，将被取消参赛资格。 3.部分解决方案是可接受的。大赛不存在通过或是不通过的分数分界点，也不会有一个数字形式的分数。MCM /ICM的评判主要是依据参赛队的解决方法和步骤。 4.摘要 摘要是 MCM 参赛论文的一个非常重要的部分。在评卷过程中，摘要占据了相当大的比重，以至于有的时候获奖论文之所以能在众多论文中脱颖而出是因为其高质量的摘要。 好的摘要可以使读者通过摘要就能判断自己是否要通读论文的正文部分。如此一来，摘要就必须清楚的描述解决问题的方法，显著的表达论文中最重要的结论。摘要应该能够激发出读者阅读论文详细内容的兴趣。那些简单重复比赛题目和复制粘贴引言中的样板文件的摘要一般将被认为是没有竞争力的。 Besides the summary sheet as described each paper shouldcontain the following sections: 除了摘要页以外每篇论文还需要包括以下的一些部分： l Restatement and clarification of theproblem: State in your own words what youare going to do. 再次重述或者概括问题——用你自己的话重述你将要解决的问题。
IMPORTANT CHANGE TO CONTEST RULES FOR MCM/ICM 2012: Teams (Student or Advisor) are now required to submit an electronic copy (summary sheet and solution) of their solution paper by email to solutions@https://www.doczj.com/doc/fe8492395.html,. Your email MUST be received at COMAP by the submission deadline of 8:00 PM EST, February 13, 2012. Teams are free to choose between MCM Problem A, MCM Problem B or ICM Problem C. COMAP Mirror Site: For more in: https://www.doczj.com/doc/fe8492395.html,/undergraduate/contests/mcm/ MCM: The Mathematical Contest in Modeling ICM: The Interdisciplinary Contest in Modeling 2012 Contest Problems MCM PROBLEMS PROBLEM A: The Leaves of a Tree "How much do the leaves on a tree weigh?" How might one estimate the actual weight of the leaves (or for that matter any other parts of the tree)? How might one classify leaves? Build a mathematical model to describe and classify leaves. Consider and answer the following: ? Why do leaves have the various shapes that they have? ? Do the shapes “minimize” overlapping individual shadows that are cast, so as to maximize exposure? Does the distribution of leaves within the “volume” of the tree and its branches effect the shape? ? Speaking of profiles, is leaf shape (general characteristics) related to tree profile/branching structure?
如何准备美赛 数学模型：数学模型的功能大致有三种：评价、优化、预测。几乎所有模型都是围绕这三种功能来做的。比如，2012年美赛A题树叶分类属于评价模型，B题漂流露营安排则属于优化模型。 对于不同功能的模型有不同的方法，例如 评价模型方法有层次分析、模糊综合评价、熵值法等； 优化模型方法有启发式算法（模拟退火、遗传算法等）、仿真方法（蒙特卡洛、元胞自动机等）； 预测模型方法有灰色预测、神经网络、马尔科夫链等。 在数学中国、数学建模网站上有许多关于这些方法的相关介绍与文献。 软件与书籍： 软件一般三款足够：Matlab、SPSS、Lingo，学好一个即可。 书籍方面，推荐三本，一本入门，一本进级，一本参考，这三本足够： 《数学模型》姜启源谢金星叶俊高等教育出版社 《数学建模方法与分析》Mark M. Meerschaert 机械工业出版社 《数学建模算法与程序》司守奎国防工业出版社 入门的《数学模型》看一遍即可，对数学模型有一个初步的认识与把握，国赛前看完这本再练习几篇文章就差不多了。另外，关于入门，韩中庚的《数学建模方法及其应用》也是不错的，两本书选一本阅读即可。如果参加美赛的话，进级的《数学建模方法与分析》要仔细研究，这本书写的非常好，可以算是所有数模书籍中最好的了，没有之一，建议大家去买一本。这本书中开篇指出的最优化模型五步方法非常不错，后面的方法介绍的动态模型与概率模型也非常到位。参考书目《数学建模算法与程序》详细的介绍了多种建模方法，适合用来理解模型思想，参考自学。 分工合作：数模团队三个人，一般是分别负责建模、编程、写作。当然编程的可以建模，建模的也可以写作。这个要视具体情况来定，但这三样必须要有人擅长，这样才能保证团队最大发挥出潜能。 这三个人中负责建模的人是核心，要起主导作用，因为建模的人决定了整篇论文的思路与结构，尤其是模型的选择直接关系到了论文的结果与质量。 对于建模的人，首先要去大量的阅读文献，要见识尽可能多的模型，这样拿到一道题就能迅速反应到是哪一方面的模型，确定题目的整体思路。 其次是接口的制作，这是体现建模人水平的地方。所谓接口的制作就是把死的方法应用到具体问题上的过程，即用怎样的表达完成程序设计来实现模型。比如说遗传算法的方法步骤大家都知道，但是应用到具体问题上，编码、交换、变异等等怎么去做就是接口的制作。往往对于一道题目大家都能想到某种方法，可就是做不出来，这其实是因为接口不对导致的。做接口的技巧只能从不断地实践中习得，所以说建模的人任重道远。 另外，在平时训练时，团队讨论可以激烈一些，甚至可以吵架，但比赛时，一定要保持心平气和，不必激烈争论，大家各让3分，用最平和的方法讨论问题，往往能取得效果并且不耽误时间。经常有队伍在比赛期间发生不愉快，导致最后的失败，这是不应该发生的，毕竟大家为了一个共同的目标而奋斗，这种经历是很难得的。所以一定要协调好队员们之间的关系，这样才能保证正常发挥，顺利进行比赛。 美赛特点：一般人都认为美赛比国赛要难，这种难在思维上，美赛题目往往很新颖，一时间想不出用什么模型来解。这些题目发散性很强，需要查找大量文献来确定题目的真正意图，美赛更为注重思想，对结果的要求却不是很严格，如果你能做出一个很优秀的模型，也许结果并不理想也可能获得高奖。另外，美赛还难在它的实现，很多东西想到了，但实现起来非常困难，这需要较高的编程水平。 除了以上的差异，在实践过程中，美赛和国赛最大的区别有两点： 第一点区别当然是美赛要用英文写作，而且要阅读很多英文文献。对于文献阅读，可以安装有道词典，
2012 MCM Problems PROBLEM A:The Leaves of a Tree "How much do the leaves on a tree weigh?" How might one estimate the actual weight of the leaves (or for that matter any other parts of the tree)? How might one classify leaves? Build a mathematical mode l to describe and classify leaves. Consider and answer the following: ? Why do leaves have the various shapes that they have? ? Do the shapes “minimize” overlapping individual shadows that are cast, so as to maximize exposure? Does the distribution of leaves within the “volume” of the tree and its branches effect the shape? ? Speaking of profiles, is leaf shape (general characteristics) related to tree profile/branching structure? ? How would you estimate the leaf mass of a tree? Is there a correlation between the leaf mass and the size characteristics of the tree (height, mass, volume defined by the profile)? In addition to your one page summary sheet prepare a one page letter to an editor of a scientific journal outlining your key findings. “多少钱树的叶子有多重？”怎么可能估计的叶子（或树为此事的任何其他部分）的实际重量？会如何分类的叶子吗？建立了一个数学模型来描述和分类的叶子。考虑并回答下列问题：?为什么叶片有，他们有各种形状？?请勿形状的“最小化”个人投阴影重叠，以便最大限度地曝光吗？树叶树及其分支机构在“量”的分布效应的形状？说起型材，叶形（一般特征）有关的文件树/分支结构？你将如何估计树的叶质量？有叶的质量和树的大小特性（配置文件中定义的高度，质量，体积）之间的关系吗？除了你一个页面的汇总表，准备一页纸的信中列出您的主要结果的一个科学杂志的编辑. PROBLEM B:Camping along the Big Long River Visitors to the Big Long River (225 miles) can enjoy scenic views and exciting whi t e water rapids. The river is inaccessible to hikers, so the only way to enjoy i t is to take a river trip that requires several days of camping. River trips all start at First Launch and exi t the river at Final Exit, 225 miles downstream. Passengers take either oar- powered rubber rafts, which travel on average 4 mph or motorized boats, which travel on average 8 mph. The trips range from 6 to 18 nights of camping on the river, start to finish.. The government agency responsible for managing this river wants every trip to enjoy a wilderness experience, with minimal contact wi t h other groups of boats on the river. Currently, X trips travel down the Big Long River each year during a six month period (the rest of the year it is too cold for river trips). There are Y camp sites on the Big Long River, distributed fairly uniformly throughout the river corridor. Given the rise in popularity of river rafting, the park managers have been asked to allow more trips to travel down the river. They want to determine how they might schedule an optimal mix of trips, of varying duration (measured in nights on the river) and propulsion (motor or oar) that will utilize the campsites in the best way possible. In other words, how many more boat trips could be added to the Big Long River’s rafting season? The river managers have hired you to advise them on ways in which to develop the best schedule
2015年美国大学生数学建模竞赛赛题翻译 2015年美国大学生数学竞赛正在进行，比赛时间为北京时间：20１5年2月６日(星期五)上午9点—２月10日上午9点.竞赛以三人(本科生）为一组，在四天时间内,就指定的问题，完成该实际问题的数学建模的全过程,并就问题的重述、简化和假设及其合理性的论述、数学模型的建立和求解(及软件)、检验和改进、模型的优缺点及其可能的应用范围的自我评述等内容写出论文。 2０15 ＭＣM/ICM Ｐｒｏblems 总计4题，参赛者可从MＣM Pｒoｂlｅm A, MＣM Problem B，ICM Pｒoblem C oｒICM Ｐｒｏbｌem D等四道赛题中自由选择。 201５Contest Proｂｌems MCM ＰROBLEMS PROBLEM A: Erａdiｃating Ebｏla The wｏrｌｄmedical assoｃiatiｏn has ａnnounced that ｔheｉｒneｗmｅdiｃatioｎcouｌd stop Ｅbola anｄcｕｒｅｐａtｉents ｗhose dｉsease ｉs not aｄｖanced. Ｂuild a realistｉc, sensｉblｅ, ａnｄusefｕｌmodel thaｔｃｏnsiders not onlｙｔhｅsｐｒead of the dｉsease，ｔｈｅqｕaｎtｉｔy of ｔhｅmedｉcine needed，ｐｏｓsｉble ｆeasible delivｅｒy sysｔemｓ（seｎdiｎg ｔhe meｄiｃine to where iｔis neｅdｅｄ), （gｅｏgrａphiｃal）loｃatioｎs of ｄelｉvery，ｓｐeed of mａｎufacturing of tｈe ｖa ｃcine ｏｒｄruｇ, but also ａｎy oｔheｒcriticａl factors your ｔeam cｏnｓidｅrs ｎecessaｒｙas ｐarｔｏf thｅｍodel to ｏpｔimize thｅerａdicaｔioｎoｆEｂola，oｒａt lｅａｓt ｉts current sｔrain. Iｎadd ｉtion ｔo your ｍodｅling apprｏach fｏr thｅcontest, prepare ａ１—2 page ｎon-teｃｈnical ｌettｅr for ｔhe wｏrld ｍｅｄicaｌａｓsocｉation ｔｏuse ｉｎtheir announｃｅmｅｎt． 中文翻译： 问题一：根除埃博拉病毒 世界医学协会已经宣布他们的新药物能阻止埃博拉病毒并且可以治愈一些处于非晚期疾病患者。建立一个现实的,合理的并且有用的模型，该模型不仅考虑了疾病的蔓延,需要药物的量,可能可行的输送系统,输送的位置,疫苗或药物的生产速度，而且也要考虑其他重要的因素，诸如你的团队认为有必要作为模型的一部分来进行优化而使埃博拉病毒根除的一些因素，或者至少考虑当前的状态。除了你的用于比赛的建模方法外，为世界医学协会准备一份１-２页的非技术性的信,方便其在公告中使用。 PＲＯBLEＭB: Sｅａrchinｇfoｒａloｓt pｌａne Recａll the loｓｔMalａysian flight MH370．Build ａgeneriｃmaｔheｍatｉcaｌmｏｄel ｔｈat coｕld assist "seａrｃhers" ｉn plaｎninｇa useful seａrch ｆｏｒ a loｓt plaｎｅfeａred to hａｖe cｒａshed in ｏpｅn ｗatｅr sucｈas the Ａｔlantic, Paｃific，Iｎdian, Sｏuthｅrｎ，or Arcｔic Oceａn ｗｈil ｅｆlyinｇfrom PoinｔA to Poiｎt B. Ａｓsume thａt there are no sigｎals ｆroｍthe ｄowｎｅd pｌane。Your moｄel should recogｎiｚe thaｔｔherｅarｅmaｎy dｉfｆerｅnt ｔyｐes ｏf plaｎｅs ｆoｒｗ
最终的布朗尼蛋糕盘 Team #23686 February 5, 2013 摘要Summary/Abstract 为了解决布朗尼蛋糕最佳烤盘形状的选择问题，本文首先建立了烤盘热量分布模型，解决了烤盘形态转变过程中所有烤盘形状热量分布的问题。又建立了数量最优模型，解决了烤箱所能容纳最大烤盘数的问题。然后建立了热量分布最优模型，解决了烤盘平均热量分布最大问题。最后，我们建立了数量与热量最优模型，解决了选择最佳烤盘形状的问题。 模型一：为了解决烤盘形态转变过程中所有烤盘形状热量分布的问题，我们假设烤盘的任意一条边为半无限大平板，结合第三边界条件下非稳态导热公式，建立了不同形状烤盘的热量分布模型，模拟出不同形状烤盘热量分布图。最后得到结论：在烤盘由多边形趋于圆的过程中，烤焦的程度会越来越小。 模型二：为了解决烤箱所能容纳最大烤盘数的问题，本文建立了随烤箱长宽比变化下的数量最优模型。求解得到烤盘数目N 随着烤箱长宽比和烤盘边数n 变化的函数如下： A L W L W cont cont cont N 4n 2nsin 122 2??? ??????????? ????? ??+?--=π 模型三：本文定义平均热量分布H 为未超过某一温度时的非烤焦区域占烤盘边缘总区域的百分比。为了解决烤盘平均热量分布最大问题，本文建立了热量分布最优模型，求解得到平均热量分布随着烤箱长宽比和形状变化的函数如下： n sin n cos -n 2nsin 22n tan 1H ππδπδ π????? ? ? ????? ???- =A 结论是：当烤箱长宽比为定值时，正方形烤盘在烤箱中被容纳的最多，圆形 烤盘的平均热量分布最大。当烤盘边数为定值时，在长宽比为1:1的烤箱中被容纳的烤盘数量最多，平均热量分布H 最大。 模型四：通过对函数??? ??n ,L W N 和函数?? ? ??n ,L W H 作无量纲化处理，结合各自 的权重p 和()p -1，本文建立了数量和热量混合最优模型，得到烤盘边数n 随p
优化和评价的收费亭的数量 景区简介 由於公路出来的第一千九百三十，至今发展十分迅速在全世界逐渐成为骨架的运输系统，以其高速度，承载能力大，运输成本低，具有吸引力的旅游方便，减少交通堵塞。以下的快速传播的公路，相应的管理收费站设置支付和公路条件的改善公路和收费广场。 然而，随着越来越多的人口密度和产业基地，公路如花园州公园大道的经验严重交通挤塞收费广场在高峰时间。事实上，这是共同经历长时间的延误甚至在非赶这两小时收费广场。 在进入收费广场的车流量，球迷的较大的收费亭的数量，而当离开收费广场，川流不息的车辆需挤缩到的车道数的数量相等的车道收费广场前。因此，当交通繁忙时，拥堵现象发生在从收费广场。当交通非常拥挤，阻塞也会在进入收费广场因为所需要的时间为每个车辆付通行费。 因此，这是可取的，以尽量减少车辆烦恼限制数额收费广场引起的交通混乱。良好的设计，这些系统可以产生重大影响的有效利用的基础设施，并有助于提高居民的生活水平。通常，一个更大的收费亭的数量提供的数量比进入收费广场的道路。 事实上，高速公路收费广场和停车场出入口广场构成了一个独特的类型的运输系统，需要具体分析时，试图了解他们的工作和他们之间的互动与其他巷道组成部分。一方面，这些设施是一个最有效的手段收集用户收费或者停车服务或对道路，桥梁，隧道。另一方面，收费广场产生不利影响的吞吐量或设施的服务能力。收费广场的不利影响是特别明显时，通常是重交通。 其目标模式是保证收费广场可以处理交通流没有任何问题。车辆安全通行费广场也是一个重要的问题，如无障碍的收费广场。封锁交通流应尽量避免。 模型的目标是确定最优的收费亭的数量的基础上进行合理的优化准则。 主要原因是拥挤的