应急物流系统概述

1、应急物流系统研究概述1.研究背景目前我国正处于社会、经济高速发展的关键阶段，同时又处于突发性公共事件高发时期。据统计，我国每年因自然灾害、事故灾害和社会安全事件等突发公共事件造成的人员伤亡逾百万，经济损失高达6500亿元，约占我国GDP的6%。1976年唐山大地震，由于灾害发生的非常突然而且发生在人们熟睡的夜晚，给中国唐山人民带来了毁灭性的打击；1998年，在我国长江沿岸许多城市暴发了一场洪涝灾害，使许多沿岸人们失去了家园，也造成了非常巨大的财产损失。2003年，首先发生在我国广东省的一场非典型肺炎，给中国人名乃至全世界带来了长时间混乱的医疗物资市场秩序。2008年初，我国南方地区发生了一场冰

2、冻灾害，造成了我们交通运输系统的中断，给居民的出行、生存带来了极大的麻烦，造成很大的财产损失；不仅是冰冻灾害，而2008年5月12日，发生在中国四川汶川地区的8.0级特大地震，更造成四川数十万的同胞丧命，给许多灾区人们带来了灾难性损失。2013年4月20日，四川雅安发生7.0级地震，百余人死亡，上千人受伤，约200万受灾。在大自然的暴怒面前，人们显得束手无策，所有的力量都显得不堪一击，实践证明，一个有效的应急物资配送系统会大大降低各种自然灾害带给我们生命和财产的损失。因此我们非常重视应急预案的制定，在全国各地都储存着大量的应急物资，以备不时之需，希望在灾害发生后能够第一时间将应急物资配送到受灾

3、地区，使受灾地区及时地得到救援。突发公共事件一旦发生，若不能及时采取有效的应对措施，其后果不堪设想。应对突发公共事件是一项复杂的系统工程，是关乎人民群众生命安全和维持社会安定的重大问题。因此，如何科学地优化应急交通与物流系统，增强整个应急管理与应急系统的应急保障和应急反应能力，就成为提高突发公共事件预警防御系统稳定性、可靠性和时效性的关键。2.国内外研究现状统计表明有效的应急救援系统可将事故损失降低到无应急系统的6。显然，对于建立一个有效的应急物资配送系统非常的重要。国内外学者对应急物流方面做了很多的研究，这些研究成果给政府和相关决策部门在应对自然灾害方面带来了很大帮助。国外对于应急物资配送方

4、面研究较早，技术比较成熟，有下面一些代表性的研究成果：文献1中Rathi等用线性规划模型使应急物资配送过程中配送车辆的路线在网络中达到最优，由于线性规划模型是传统优化算法，使得在求解过程中容易陷入局部最优解，在求解应急物资配送问题是具有很大的局限性1。文献2中Equi L等在供应中心数量不变的情况下，研究了确定最优的旅行次数和完成各个旅行路线需要分配多少车辆2。文献3中Quentin Wodon和Saul S. Morris针对贫困国家或地区，建立了在自然灾害发生后应急物资配送问题的模型，就给出了实例3。文献4中Trevor Hale等针对应急物流供应节点的选择和各个供应节点应急物资储存量的多

5、少做了研究，最后建立了解决问题的定量模型4。文献5中作者针对有时间窗限制的车辆路径选择问题展开了研究，在有车辆数限制的情况，建立了解决问题的模型，研究成果能很好地解决传统的车辆路径选择问题5。文献6中Linet Ozdamar等综合考虑应急物资，运输应急物资和工具的车辆，建立模型，并设计了求解模型的算法6。总体来说，国外对于应急物资配送的研究比较深入，涉及到了模型中各种因素的变化，使用的算法也更先进。但是大部分研究都局限于理论研究，实用的算法也大多是传统的优化算法，而且一些研究成果和我国的国情不相符合，不能直接应用到中国的应急物资配送系统中。还有，大部分研究都是局限于确定环境下的，不确定环境下

6、的应急物资配送问题的研究成果几乎没有。我国自然灾害频发，是世界上自然灾害损失最为严重的少数国家之一。在我国，几乎每年都会发生不同种类的自然灾害，如地震、台风、水灾、旱灾、雪灾、泥石流、山体滑坡、风暴等。自然灾害表现出种类多、区域性特征明显、季节性和阶段性特征突出、灾害共生性和伴生性显著等特点。这些灾害严重威胁着受灾地区人们的生命和财产安全，影响我国的国民经济的增长和人民生活生活水平的提高，因此，我国非常重视应急预案的制定，希望在灾害发生后能够第一时间将救助物资送到灾区，尽量减小生命和财产损失，国内许多学者也对于应急物流配送方面做了许多研究，解决了我国的许多实际问题，下面是一些有代表性的研究成果

7、。在文献7中，刘春林主要研究的是多个物资输送点向灾区运送救灾物资的问题，其研究的前提条件是应对灾区的反应时间最短，再依据不间断应急的特征，确定目标函数则是应急点的个数最少，在这种条件下建立的模型有一定的实用性，而且其解决问题的精确程度也很高，因此这个模型具有一定的实用价值和参考意义。李大为将自适应变异算子和爬山算法加入到了遗传算法当中，是算法的实用性和适应性更好，更利于解决物资有效配送8。牛永量提出了更切合实际情况的三层次物流配送网络结构，针对其车辆选择的运输线路应用四叉树原理对服务区分区，采用两阶段启发式算法优化车辆行驶的线路，利用计算机编程实现算法的设计9。卢安文建立了多种运输方式的物流配

8、送模型，采用了0-1整数规划模型，其目标主要是以运输费用和运输目标。戴更新建立了多种模式的物资配送问题的模型，利用多处救灾物资的配送以及多种运输方式的模式，可以利用单种模式将其应用在多模式当中，对现实中的问题进行求解11。计雷在我国较早的提出物资运送的问题模型，其主要建立在物资运输途中其运输费用最小和运输所用的时间最少的多目标规划问题，但是还存在一些重要问题，其问题是没有建立相关的数学模型和相应的解决方法12。李全亮13利用分组匹配的亲和力算法解决带有时间窗的车辆路径问题的实际问题。李军14和樊建华15分别分析了多车场满载的VSP问题和车辆调度问题进行相应的建模和求解。作者傅克俊所建立的模型是

9、将所研究的对象分开，然后在进行相应的分析研究，将物资配送过程中的影响因素分为货物状态、车辆状态和道路状态，针对以上三种因素分开进行细化研究。对于应急救助物资配送方面的研究由于国外起步较早，研究成果也相对比国内多一些，技术也比较成熟。研究成果用于实际的应急物资配送问题中，给我们带来了很大的帮助，减少了许多生命和财产的损失。然而我国的学者对此问题的研究起步较晚，近年来才有相应的研究成果，并且大部分都是理论层面上应急物流的处理机制、应急物资的特点等。也有许多学者应急物流配送优化模型方面做了研究，并使用一些优化算法对模型进行求解。但是许多国外学者的研究和我国的实际国情不符合，不能直接应用到我国的应急物

10、资配送系统中。并且大部分文献只考虑了确定环境下的物流配送问题，本文将尝试研究在不确定环境下应急物资配送问题，但这些前期研究成果将为本文的研究提供有价值的参考。3.该研究领域存在的问题许多国内外学者在应急物资配送方面做了开创性研究，取得了很多成果，给政府和相关的决策部门带来了很多帮助，但都没有考虑运输时间、运输风险等的不确定性，没有考虑不确定环境下的应急物资配送优化问题。事实上，在实际应急物资配送路径进行优化的过程中，由于道路情况、司机的驾驶水平、不同时间段、以及天气等原因，各个路段的走行时间和路径风险往往很难给出一个确定量。因此，很有必要考虑不确定环境下的应急物资配送问题。对于含有不确定变量的

11、优化问题，一般不能用传统的优化算法进行解决。因此，本文将尝试建立随机环境下和模糊环境下的机会约束规划模型和相关机会规划模型，并结合模拟技术和遗传算法，设计混合智能算法求解该模型，并用两个实例来验证所建模型和算法的有效性。对于不确定环境中的规划问题，我们没办法用传统的一些算法来解决，因为我们不能直接比较两个不确定变量的大小，对于我们来说，比较不确定变量的大小通常是很困难的。在期望值模型被提出之后，Charnes和Cooper16于1959年提出了第二类随机规划，即机会约束规划。其显著特点是随机约束条件至少以一定的置性水平成立。机会约束模型采用的主要原则是允许所做的决策在一定程度上不满足约束条件，

12、但是我们事先给定一个置性水平，最后选择的决策使约束条件被满足的概率应不低于我们是事先给定的置信水平。在随机机会约束规划提出之后，Liu和Iwamura17提出了模糊机会约束规划。为了求解机会约束规划模型，我们事先给定了一个置信水平，以便将其转化为等价的确定性模型，然后可以用用传统的方法求解与其等价的确定性模型。然而，对于比较复杂的机会约束规划模型，有时我们很难讲机会约束转化成与其等价的确定性模型。为了极大化事件的机会函数，Liu18于1997年提出了随机相关机会规划。其主要思想是在不确定环境下，通过极大化随机事件成立的机会来给出最优决策。提出随机相关规划以后，Liu19又提出了模糊相关机会规划

13、，使得选择决策时，让事件满足的可能性、必要性或者可信性最大。对于确定性规划、期望值模型和机会约束规划中，将问题的模型建好以后，可行集也就确定了，这样经常会导致在实际的求解过程中找不到最有解。相关机会规划不同于前几种方法，其可行集为不确定环境下的，在求解实际的问题时，我们只要求尽可能的找到一个比较优的确定解。综上所述，国内外部分学者在应急物资运输与车辆调度等方面进行了开创性研究，取得了很多可喜的成果，但其研究成果都未将交通运输与物流系统作为一个整体展开应急方面的定量研究。现有研究都是对其分别进行优化，因而未能实现系统整体最优的目标。研究其综合优化问题，对于提高城市突发公共事件应急物流与交通运输系

14、统的稳定性、可靠性和时效性，实施科学有效的决策及救援等具有重要意义。4.本研究的理论与应用价值（1）在理论方面，目前我国应急物流研究总体上还属于研究初期，少量学者对其实现了从定性向定量研究的跨跃。本课题的研究有助于解决复杂的应急交通与物流系统中的众多关键问题，有助于丰富和发展应急管理理论。同时对于应急交通与物流系统的研究也有助于丰富物流系统设计理论及交通运输规划理论，进一步拓展对特种行业运输与物流技术的研究。（2）在应用方面，通过应急交通与物流系统的研究，可以帮助制定应急救援计划、建立临时的高效快速的物流与交通运输网络，确保突发事件应急处置的科学、快捷、安全、高效。另外，本课题通过深入研究应急

15、交通与物流系统，建立一系列的决策方法，可以帮助应急决策人员在突发事件环境中快速形成一系列的应急方案，可最大限度地降低突发事件对社会正常生产、生活秩序地冲击，减少由于物资供应不及时而造成的人员伤亡，同时最大限度的缩短决策者的决策时间，为救援赢得时间。5.研究目标（1）把应急交通运输系统与物流系统两个系统综合起来，整体研究“应急交通与物流系统”这一大系统的诸多关键问题，从根本上实现整体最优、集成最优。（2）运用复杂网络理论研究应急交通与物流网络复杂特性，特别是研究网络的脆弱性、可靠性，并进行网络蓄意攻击仿真，找到网络中的关键节点及边，为综合优化决策提供依据。（3）运用改进的元胞自动机理论研究应急交

16、通与物流系统中人流、车流的动态特性，包括疏散特性、拥堵特性等，为综合优化决策提供依据。（4）运用不确定规划理论与方法研究应急交通与物流系统中八个重点问题（临时救援路径的确定、受损的运输干线及设施的抢修安排、受灾人员的及时抢救与转移、救灾人员的及时调配与送达、应急物流设施的布局优化、应急救援物资的储备控制、应急救援物资的优化调度、各种运输方式的协作调运计划），分别建立确定环境下的优化方法和不确定环境下的优化方法。6.主要研究内容（1）应急交通与物流系统特点研究（拟运用复杂网络理论研究应急物流与交通运输网络复杂特性，特别是研究网络的脆弱性、可靠性，并进行网络蓄意攻击仿真，找到网络中的关键节点及边，

17、为后面的集成优化决策提供依据）。（2）应急交通与物流系统中网络流（车流、人流）特征研究（拟运用改进的元胞自动机理论研究应急物流与交通运输系统中人流、车流的动态特性，包括疏散特性、拥堵特性等，为后面的集成优化决策提供依据）。（3）研究应急交通与物流系统中八个重点问题，分别建立确定环境下的优化方法和不确定环境下的优化方法。7.研究思路和方法应急交通与物流系统具有动态性、实时性、多目标性、非线性以及不确定性等复杂特点。本研究提出应急交通与物流系统“综合优化”思路，对系统中各组分进行细致的解构分析，并在剖析多层次、多组分间互动关系的基础上，对此复杂系统进行整合研究。这一解构与整合分析体系将有助于研究众

18、多关键问题，有助于建立实用、高效的应急交通与物流决策支持系统。课题的研究遵循系统“解构与整合”思路，同时遵循“问题提出优化模型构建整体模型求解系统模拟仿真决策方案产生”这一技术路线。首先将应急问题解构为八个重点问题（如上文所述），针对这八个问题，相互协调，建立最优决策方法；然后将应急交通与物流作为一个整体，建立综合优化方法。在该课题的研究过程中，将用复杂网络理论对应急交通与物流网络的特性进行宏观分析，将用改进的元胞自动机理论对紧急情况下的人流、车流疏散特性进行微观仿真，力求做到宏观分析和微观分析相结合。同时，在国内外相关研究的基础上，从动态的、系统的和综合的视角，运用应急系统理论、现代物流理论

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25、 B. Dependent-chance programming: A class of stochastic programming. Computer & Mathematics with Applications, 1997, 34(12):89-104.19 Liu B. Dependent-chance programming in fuzzy environments. Fuzzy Sets and System, 2000,109(1): 97-106.Overview of Emergency Logistics System Study1. Research Backgrou

26、ndOur country is now in a critical phase of high development of both society and economy, and at the some time, its also in a period of high frequency of public emergencies. According to statistics, there are more than millions of casualties and 650 billion economic losses, accounting for 6% of GDP,

27、 caused by public emergencies, such as natural disasters, accidents, social security incidents and so on.The Tangshan earthquake in 1976 happened very suddenly at night when people were sleeping, which brought devastating blow to Tangshan people; the flood disaster happened in many cities along the

28、Yangtze River in 1998, making people along the coast lose their homes and also causing huge property losses. The first atypical pneumonia occurring in Guangdong province in 2003 brought long-time chaotic medical market order to not only Chinese people but also people around the world. At the beginni

29、ng of 2008, there was a freeze disaster in the southern China, which disrupted the transportation systems, bringing great trouble to peoples going out and living and causing great property losses. Besides freeze disaster, 8.0 magnitude earthquake on May12, 2008 caused hundreds of thousands of compat

30、riots in Sichuan lose their lives and brought catastrophic losses to many people in the disaster areas. The 7.0 magnitude earthquake in Yaan, Sichuan province on April 20, 2013 killed more than 100 people, injured thousands of people and affected about 2 million people.Faced with natures fury, peopl

31、e seem to be helpless and all their power seems vulnerable. But practice has proved that an effective emergency material distribution system will greatly reduce the losses of life and property caused by various natural disasters. So we place great emphasis on the formulation of contingency plan. We

32、have stored large amounts of contingency materials all over the country for a rainy day, hoping that we can distribute contingency materials to affected areas at the first time.When public emergencies occur, if there is no effective solution, their consequence will be unimaginable. Dealing with publ

33、ic emergencies is a complicated system engineering which relates to peoples life security and social stability. Therefore, it is key to improve stability, reliability and timeliness of public emergency early warning defense system that how to scientifically optimize emergency transportation and logi

34、stics system and how to enhance emergency security and emergency response ability of the whole emergency management and system.2. Research Status at Home and AbroadStatistics show that effective emergency rescue system can reduce the losses caused by accidents to 6% of non-emergency system. Obviousl

35、y, its very important to establish an effective emergency material distribution system. Scholars at home and abroad have made lots of research of emergency logistics, which give great help to the government and relevant decision-making department in responding to natural disasters.Study of emergency

36、 material distribution is earlier in the abroad, and the technology overseas is mature. Here are some representative research results:Rathi in reference 1 makes the route of distribution vehicle in the process of emergency material distribution achieve the optimal in the network with the linear prog

37、ramming model. But it is of great limitations for this traditional optimization solution makes the solving process easily fall into locally optimal solution. Equi L in reference 2 has studied how to determine the number of travel and the number of vehicles allocated to finish each itinerary. Quentin

38、 Wodon and Saul S. Morris in reference 3 have established emergency material distribution model after natural disasters for poor countries and regions. Instance 3 is just the case. Trevor Hale in reference 4 has established quantitative model 4 to solve the problem of how to select supply nodes of e

39、mergency logistics and how to determine the storage volume of emergency material in each supply nodes. Authors in reference 5 have researched on how to select vehicle routing under the condition of time limitation. They established the model to solve this problem under the limitation of the number o

40、f vehicles, which can well solve the problem 5. Linet Ozdamar in reference 6 established the model and the algorithm 6 of it, considering comprehensively of emergency material and vehicles transporting these material and tools.In general, foreign study of emergency material distribution relatively p

41、rofound which involves the changes of various factors in the model and the algorithm is also more advanced. But most of the researches are limited to theoretical research and practical algorithm is mostly in the form of traditional optimization algorithm. Besides, some research results dont coincide

42、 with our national conditions, which cannot be directly applied to emergency material distribution system in China. In addition, most studies are limited to determined environment, while researches on emergency material distribution under uncertain environment are rare. Natural disasters are frequen

43、t in our country, the losses of which are one of the most serious among the minorities around the world. There are different kinds of natural disasters happening almost every year in our country, such as earthquake, typhoon, flood, drought, snow storms, debris flow, landslide, storm, etc. Natural di

44、sasters show many characteristics, such as various kinds, obvious regional features, prominent seasonal and periodic type, and disaster symbiotic and so on. These disasters throw serious threats to peoples life and property safety in affected areas, and also impact the growth of national economy and

45、 the improvement of peoples living standards. Therefore, our country attaches great importance to the formulation of contingency plans, hoping that relief supplies can be delivered to disaster areas at the first time so as to reduce the losses of lives and property. Many domestic scholars has also m

46、ade a lot of research on emergency logistics distribution, which solves many practical problems in our country, here are some representative research results. In reference 7, Liu Chunlin mainly studies the problem of relief material delivered to disaster areas from multiple material delivery points.

47、 Its premise is the shortest response time to the disaster. Then based on the continuous characteristic of emergency, the objective function can be determined with the least emergency points. The model established under this condition owns certain practicability, and the accuracy to solve problems i

48、s high, therefore this model is of certain practical value and of reference significance. Li Dawei added self-adaptive mutation operator and hill climbing algorithm to genetic algorithm, making the algorithm more practical and adaptive, which is more conducive to solve the effective distribution of

49、emergency material 8. Niu Yongliang has put forward a three-level logistics distribution network structure which is more suitable to actual circumstances. As for the selection of transportation routines, it uses quadtree principle to part service areas and adopts two-phase heuristic algorithm to opt

50、imize the routes. It adopts computer programming to complete the design of the algorithm 9. Lu Anwen has established a logistics distribution model of multiple transportation ways. He has adapted the 0-1 integer programming model and the main goals are transportation costs and targets. Dai Gengxin h

51、as established material distribution model of multiple types. It can solve practical problems by applying single model to multiple models with the relief material distribution of many places and multiple transportations 11. Ji Lei is prior in putting forward the model of material distribution. His m

52、odel is mainly based on the minimal cost and time in the distribution process. But the model has many problems that it has no relevant mathematical model and corresponding solution 12. Li Quanliang 13 has solved the practical problem of routines with time window by the way of using grouping match, a

53、n affinity algorithm. Li Jun 14 and Fan Jianhua 15 respectively analyzed full-loaded VSP problems in multiple car yards and established model for scheduling problem of vehicles and solved it. The model established by the author Bo Kejun, separated the objects of study and then carried corresponding

54、analysis and research. It divided the influencing factors in the process of material distribution into the state of goods, vehicles and roads and it would conduct refining research on these three factors.The research results of emergency relief material distribution are relatively more and the techn

55、ology is more mature in foreign countries because of their earlier start. These research results have solved many practical problems which is of great help to us and also reduces the losses of lives and property. However, scholars in our country started later in the research. There are corresponding

56、 research results in recent years, but most of them are on theoretical level about handling mechanism of emergency logistics and the characteristics of emergency materials, etc. There are also many scholars doing research on optimization model of emergency logistics distribution and solving the mode

57、l by some optimization algorithm. But many researches by foreign scholars dont conform to our national conditions and cannot be directly applied to our country. Besides, most of documents are only limited to distribution under determined circumstances. The essay will try to study emergency material

58、distribution in uncertain environment. But the previous research results will provide valuable reference to the research in this paper.3. Problems Consisting in the Research Field Many scholars, at home and abroad, has done pioneering research on emergency material distribution and also made many significant achievements, which brings to the government and the relevant decision-making departments a lot of help. But they dont consider the uncertainty of transportation time and risk and so on, and they also dont consider optimization of emergency material distrib