基于Agent的Web网信息传播仿真模型

web网上的信息传播是社会复杂网络与信息复杂网络相互作用的结果。分析了web网和网民社会关系的结构特征,定义了信息价值时变函数,将网民基本行为归纳为读、写、评、传四类。基于多Agent建模方法建立web网信息传播仿真模型,用BA算法生成虚拟信息环境,采用WS模型刻画虚拟社会关系;定义了网民Agent的属性和行为规则,以及网民和网站的交互规则。设计了相关算法,实现了仿真模型,仿真结果表明该模型能够较好地模拟常态下的网络信息传播规律。

Abstract：

Information diffusion on the worldwide web results from the interactions between social network and information network.The structural characteristic of Worldwide Web and users＇ social network was analyzed,the time-dependent function of information value was defined,and users＇ basic behavior was classified into read,write,review and propagate.An agent-based model of information diffusion on the web was built,the virtual information environment was generated by BA algorithm,and the virtual social network was depicted with WS algorithm.The property of agents,the behavior rules of users,and the interaction rules between user and web site were described.All the related algorithms were designed and the simulation model was implemented.The results show that some information diffusion rules in normal situation can be reproduced.     

新一代交通仿真技术综述

简要回顾了国内外交通仿真技术的发展历程,总结了新世纪以来新一代交通仿真技术的主要特点。然后,比较分析了当前主流交通仿真模型的特性,并对交通仿真应用程序接口、硬件在环和软件在环交通仿真、在线交通仿真等面向智能交通系统应用的高级仿真技术进行了深入解析。最后,根据我国交通仿真研究和应用的现状,在符合我国交通特性的基础仿真模型研究、交通仿真系统的开发模式、在线仿真技术的开发方法等方面提出了改进建议。

Abstract：

The historical course of traffic simulation in China and abroad was briefly reviewed firstly,and some major features of the new generation traffic simulation technology since 21st century were summarized then. Afterwards,the simulation model characteristics of some prevailing traffic simulation models were comparably analyzed,and several advanced traffic simulation techniques for ITS applications were expatiated,including traffic simulation API,hardware-in-the-loop traffic simulation,software-in-the-loop traffic simulation,online traffic simulation. Finally,based on the state-of-the-practice of traffic simulation in China,some suggestions were given on fundamental simulation modeling fitting for Chinese traffic characteristics,development modes of traffic simulation system,development methodologies of online traffic simulation,etc.     

The Queuing Model of M/M/S/K ＋ M Based on the Impatience and Changeable Service Rate

The work flow of call center is a typical stochastic service system. This article exploites service rate, which is the most controllable artificial factor of call center, and integrates the abandoning rate of impatient customers, models a new-style call center＇s queuing model - the queuing model of M/M/S/K ＋ M based on the impatience and changeable service rate. Then, making use of the traffic forecast result coming from the time series, it models to figure out the numbers of agents per hour, and complete the agents＇ office-hour arrangements in the restriction of some system indexes. Finally, it optimizes the design method by the contrast and analysis of the changeable service rate model and the traditional regular service rate model.     

Modeling the congestion cost and vehicle emission within multimodal traffic network under the condition of equilibrium

Traditional system optimization models for traffic network focus on the treatment of congestion, which usually have an objective of minimizing the total travel time.However,the negative externality of congestion,such as environment pollution,is neglected in most cases.Such models fall short in taking Greenhouse Gas(GHG) emissions and its impact on climate change into consideration.In this paper,a social-cost based system optimization(SO) model is proposed for the multimodal traffic network considering both traffic congestion and corresponding vehicle emission.Firstly,a variation inequality model is developed to formulate the equilibrium problem for such network based on the analysis of travelers’ combined choices.Secondly,the computational models of traffic congestion and vehicle emission of whole multimodal network are proposed based on the equilibrium link-flows and the corresponding travel times.A bi-level programming model,in which the social-cost based SO model is treated as the upper-level problem and the combined equilibrium model is processed as the lower-level problem,is then presented with its solution algorithm.Finally,the proposed models are illustrated through a simple numerical example.The study results confirm and support the idea of giving the priority to the development of urban public transport,which is an effective way to achieve a sustainable urban transportation.     

Method of Generating Strategic Guidance Information for Driving Evacuation Flows to Approach Safety-Based System Optimal Dynamic Flows: Case Study of a Large Stadium

In previous evacuation flow planning, a system optimal dynamic traffic assignment(SODTA) did not consider the exogenous costs caused by potential traffic accidents. A traffic accident,which might occur as a result of traffic congestion, will impact an evacuation process because of accidentrelated delays experienced by the downstream vehicles. This paper establishes a safety-based SO-DTA linear programming model in which the generalized system cost incorporates both the travel time and the accident-related delay. The goal is to minimize the generalized system cost under the cell transmission setup. Furthermore, the authors provide strategic guidance information that considers both the objective of the decision maker and the route choice behavior of the evacuees. Mathematically,the authors propose an unconstrained non-linear programming model aimed at minimizing the gap between the safety-based flows and the stochastic real-world evacuation flows, to provide strategic travel time information to be published on variable message signs(VMS). In the case study, the authors found that the safety-based SO-DTA model can reduce congestion and improve the evacuation efficiency; the stochastic real-world evacuation flows, guided by strategic information, can approach the safety-based flows.     

Rebuilding of the Diamond Model Based on Evolutionary Economics and Demonstration of Industrial Clusters in China

The Industrial Clusters show more competitive advantage in the world obviously since 1970＇s, which attracts extensive attention from all over the world. As the most important researches of the New Economic Geography, Poter＇s diamond model generalizes the internal mechanism of clusters, but the model has not given the microcosmic status of the factors of the clusters, therefore, it is significant to go deeper into the diamond model and the dissertation wishes to do some researches deeply. Based on the actuality of research, this paper surveys Porter＇s diamond model from the Evolutionary Economics, and combines the research of the field with the instance in China, then puts forward the diamond model of twin-screw and implements the model into traditional industrial clusters in Zheiiang province. Detailed explaining is as follows. The main innovations of the dissertation are as follows： （1） having taken the points of biology into economics, and developing the Evolutionary Economics creatively; （2） having proved the diamond model, put forward a twin-screw microcosmic model for the first time, and tried to study the dynamic and solid relationships of each factor in the diamond model, which is the most important innovation of the dissertation.     

Algorithm Research on the Influence of Traffic Environmental Variation to City Radiation Scope Based on P.D.Converse Breaking Points Model

By analyzing and comparing the existing methods for the division of urban economic region, this paper supplemented and developed the breaking point theory. In this model, put forward for the first time using ＂the space-time distance＂ to replace ＂the space- linear distance＂ and ＂the city comprehensiveness quality- fuzzy comprehensive assessment Index＂ to ＂the urban population or GDP＇. Set up the algorithm of including ＂the space- time distance＂ and the city radiation scope changed with the changes of traffic conditions. Thus has realized ＂dynamically＂ tracing of the city radiation scope influenced by the traffic conditions. Taking Yichang city as an example, the paper analyzed the city function localization in the times of new traffic environments. Because China＇s cities are at the times of the traffic great changes, therefore, the method and the main conclusions of this paper have some methodology guiding sense to the majority cities of deffernt country to re-position.     

Research of improving the dynamic scheduling algorithm in the CAN bus control networks

Currently, the article analyzes the CAN bus＇s rule of priority＇s arbitration bit by bit without destroy. It elicits the conclusion that if static priority based on the affirmatory system model is used, the lower priority＇s messages will be delayed considerably more, even some data will be lost when the bus＇s bandwidth is widely used. The scheduling cannot be modified neither during the system when static priority is used. The dynamic priority promoting method and the math model of SQSA and SQMA are presented; it analyzes the model＇s rate of taking in and sending out in large quantities, the largest delay, the problems and solutions when using SQMA. In the end, it is confirmed that the method of improving dynamic priority has good performances on the network rate of taking in and sending out in large quantities, the average delay, and the rate of network usage by emulational experiments.     

Multi-agent aggregation behavior analysis: The dynamic communication topology*

The authors extend the Gazi＇s swarm model with local neighbor rules and the dynamic communication topology, and study its aggregation properties. Results of analysis show that all agents in the models aggregate and eventually form a cohesive cluster of finite size around the swarm center or the appointed point. Finally, simulations are provided to testify some of the results. Models in the paper are more applicable to the reality for the advantage that each agent only needs the partial information of the entire dynamic system when making motion decision.     

Virtual reality mobility model for wireless ad hoc networks

For wireless ad hoc networks simulation, node＇s mobility pattern and traffic pattern are two key elements. A new simulation model is presented based on the virtual reality collision detection algorithm in obstacle environment, and the model uses the path planning method to avoid obstacles and to compute the node＇s moving path. Obstacles also affect node＇s signal propagation. Considering these factors, this study implements the mobility model for wireless ad hoc networks. Simulation results show that the model has a significant impact on the performance of protocols.     

Cluster Analysis in the Target Countries of China＇s International Oil Investment

China＇s oil demand has been skyrocketed. In 2004 China became the world＇s second largest oil consumer and imported 122.7 million tons of crude oil, which accounted for 41.9% of China＇s crude oil consumption. International oil investment becomes an important channel for China to obtain oil resource. The cluster analysis in the target countries of China＇s international oil investment is studied here. An investment environment model incorporating 9 factors is established firstly, the order of these factors is ranked by their importance. Then the weight of such factors is determined by Analytic Hierarchy Process （AHP） and these countries are classified into 3 categories using cluster analysis. The results provide an important decision-making tool for China＇s international oil investment.     

基于Dymola的液压系统热力学模块化建模与仿真

以模块化建模方法为指导,提出了液压系统的热力学模块化建模方法。将液压元件工作机理分为容积型和阻尼型,建立容积型模块和阻尼型模块模型,由容积型模块和阻尼型模块单独或组合建立液压元件的模块化模型。采用Dymola对所建立的各元件模型进行仿真实现,建立了温度仿真模块库-ThermalHydraulic,可以实现面向液压原理图的可视化温度仿真。对模块库进行测试,验证了建模和仿真实现的可行性。

Abstract：

According to the modular modeling method,a thermal-hydraulic modular modeling method of hydraulic system was presented. Basic operating principles of all hydraulic components were divided into two types：volume and resistance. Volume model and resistance model were developed to represent the volume and resistance characteristic of hydraulic component. Component＇s modular model was established by signal or both of volume model and resistance model. Then,the hydraulic system temperature simulation modular library-Thermal Hydraulic was established by Dymola software,and the library could establish system model conveniently by visual modeling style based on hydraulic principle figure. At the last,the system test was made to evaluate the feasibility of modeling and simulation.     

An Empirical Research on the Evolution Model of Competitiveness Between Different Life Cycle Stages in Chinese Enterprises

The characteristic of enterprise competitiveness is different between different life cycle stages. In this paper we surveyed the enterprise competitiveness＇s differences in various stages of the life cycle and the evolution model of three aspects of enterprise com- petitiveness as resource, capability and dynamic capability by questionnaire survey. The result shows that there are significant differences between different life cycle stages of en- terprise competitiveness in China. The enterprise competitiveness is stronger and stronger during the periods from the enterprise＇s birth to maturity, while in the enterprise＇s recession period the competitiveness becomes much weaker. The competitiveness＇s constitutive features in each stage are as follows： in the enterprise＇s born stage the enterprise is lack of resources and its competition mainly relies on the ability; in the enterprise＇s growth stage the enterprise＇s resources become richer and are as important as enterprise＇s ability in the constitution of enterprise competitiveness; in the maturity stage the enterprise＇s people, money and material resources all become very rich but the role of capability in enterprise competitiveness begins to decrease; in the enterprise＇s recession stage the en- terprise resources begin to exhaust, and the enterprise＇s competitiveness returns to rely on capability, and in this period the enterprise＇s learning ability, innovation ability and dynamic mechanisms perform worst, which will affect the enterprise＇s revival and lead to the ultimate death of enterprise. These conclusions have great value for reference to the enterprise＇s competitive strategy making for different life cycle stages.     

具有中心车站的元胞自动机城市交通流模型

在Biham等人提出的二维元胞自动机交通流模型基础上,建立了具有中心车站的二维元胞自动机城市交通流模型,该模型考虑了对外交通对城市交通流的影响,推导出了这种二维CA交通流模型的演化方程.在计算机上模拟了在不同对外交通概率情况下的交通状况,得到了车辆在不同参数下交通流模型的基本演化图,进一步还模拟了城市长途车站数量对城市交通的影响.结果表明,较小的对外交通概率就会对城市交通状况产生较大的影响,适当增加中心车站的数量对城市交通状况有一定的改善.     

Fuzzy Neural Network-based Evaluation Model on Chinese Area＇s Macroscopical Credit

Traditional credit evaluation models failed to produce partial results due to their ignorance of the whole risks of credit environment. An excellent evaluating model on credit should take into account the credit environment impersonally and comprehensively. In this paper, a novel area＇s macroscopical credit evaluation model based on Fuzzy Neural Network is constructed. A set of scientific and reasonable evaluating indexes are extracted from feature space of macroscopical credit, then based on these indexes a Fuzzy Neural Network （FNN） model on credit evaluation is constructed and applied into the practical credit evaluation of some Chinese provinces randomly selected for the first time. Results show our model is both practical and capable.     

Tax Evasion: Models with Self-Audit

Different from traditional tax audit, supervision with self-audit is a combination of audit by the taxpayer himself and audit by the tax authority. This paper mainly studies a taxpayer＇s optimal policy of tax evasion under supervision with self-audit and its related properties, in order to deduce some effective suggestions and theoretical bases to restrain tax evasion. Assuming that only a certain proportion of evaded tax can be discovered when the audit is executed, the authors first formulate a static model with self-audit. This model is divided into two stages. At the first stage, taxpayers declare their taxes, then the tax authority chooses audit objects, based on a known probability, and announces the result; if the taxpayer is chosen, he will enter the second stage, during which he has a chance to pay the evaded tax and the corresponding late fees and then is audited by the tax authority. The authors show the existence and uniqueness of the optimal amount of tax evasion at the first stage and the optimal proportion to self-expose at the second stage. The authors also discuss the related properties of the interior solution, and do elasticity analyses on some parameters. Besides, the authors extend the static model into the corresponding two-period model, and study the existence and uniqueness of the solution of the extended model. Finally, under the assumption that tax evasion can only be discovered with a certain probability when the audit is executed, the authors formulate another static model with self-audit and investigate its properties.     

Novel sensor selection strategy for LPI based on an improved IMMPF tracking method

Sensor platforms with active sensing equipment such as radar may betray their existence, by emitting energy that will be intercepted by enemy surveillance sensors. The radar with less emission has more excellent performance of the low probability of intercept（LPI）. In order to reduce the emission times of the radar, a novel sensor selection strategy based on an improved interacting multiple model particle filter（IMMPF） tracking method is presented. Firstly the IMMPF tracking method is improved by increasing the weight of the particle which is close to the system state and updating the model probability of every particle. Then a sensor selection approach for LPI takes use of both the target＇s maneuverability and the state＇s uncertainty to decide the radar＇s radiation time. The radar will work only when the target＇s maneuverability and the state＇s uncertainty exceed the control capability of the passive sensors. Tracking accuracy and LPI performance are demonstrated in the Monte Carlo simulations.     

Solving multi-object radar cross section based on wide-angle parabolic equation method

1. INTRODUCTION The parabolic equation (PE) was first introduced to treat the problems of diffraction of radio waves around the earth by Leontovich and Fock[1,2]. It’s a full-wave technique based on splitting the wave equation into two parabolic equations: outgoing and incoming parabolic wave equation, which describes the forward and backward propagating fields. The solution is marched from plane to plane along some preferred direction (say, paraxial direction). This technique reduces t…     

考虑列车性能差异的城市轨道交通特性研究

参考实际地铁交通系统,根据移动自动闭塞的特点,建立了基于元胞自动机的轨道交通模型,并研究列车车长、加速度、最高速度对轨道交通流的影响。重点研究了性能不同的列车同时在同一条轨道上混合运行时的列车延迟现象。仿真结果表明列车车长差异会对列车流特性产生影响,延误后续列车运行;列车的加速度对列车流影响较小;列车最高速度不同时列车延迟现象严重,多数列车出现晚点现象。

Abstract：

A cellular automaton model based on real traffic system was proposed for subway railway moving block systems.With this model the subway traffic flow in the case that different trains with different performances,for instance train length,acceleration,deceleration and maximum speed run in the same track was analyzed.The analysis focused on trains’ delay time in that case.Simulation result shows that： differences in trains’ length affect the train flow,and delay the following trains;differences in acceleration have insignificant influences on the property of train flow;differences in maximum speed lead to trains’ longtime delay,most of the trains on the track are running late in this case.