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1.
基于Agent的Web网信息传播仿真模型   总被引:1,自引:0,他引:1  
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.  相似文献   

2.
1. Introduction As an important application field of the data clustering technologies (Jain and Murty et al. 1999), text clustering is unsupervised partitioning of a collection of textual documents into self-similar groups so that any item is more similar with another item in the same group thanwith an item outside the group. Such groups are called clusters, which are run-timely formed during the clustering process, instead of being pre-defined as in the case of text categorization, which comm…  相似文献   

3.
Formal systems engineering approaches to modeling misperceptions and attitudes are employed within the framework of the graph model for conflict resolution to systematically study the War of 1812 between the United States of America and Great Britain in order to provide enhanced insights into the causes of the war. More specifically, relational definitions for preferences, movements and stability concepts are defined for describing the attitudes and associated behavior of decision makers involved in a conflict. To capture misperceptions of decision makers in the War of 1812, attitudes are studied within the structure of a hypergame. Combining attitudes and misperceptions within the paradigm of the graph model furnishes the flexible analytical tool which demonstrates that misunderstanding of attitudes by Great Britain and the United States may have contributed to the outbreak of this nasty war.  相似文献   

4.
1. Introduction With the development of information technology and the increasing market competition, simultaneously reducing inventory costs of raw materials, work-in-process, and finished items in different stages has become a major focus for supply chain management. Industrial practice and academic research have shown that VMI (Vendor Managed Inventory) can improve supply chain performance by decreasing inventory levels and costs. VMI is a collaborative business initiative where the vend…  相似文献   

5.
The class of anisotropic meshes we conceived abandons the regular assumption. Some distinct properties of Carey's element are used to deal with the superconvergence for a class of two- dimensional second-order elliptic boundary value problems on anisotropic meshes. The optimal results are obtained and numerical examples are given to confirm our theoretical analysis.  相似文献   

6.
1. Introduction A supply chain is a network composed osuppliers, manufacturers, retailers, etc., whichcooperate to offer a kind of goods or servicesThese supply chain members cooperate andcompete with each other to maximize theiown profits. For example,…  相似文献   

7.
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.  相似文献   

8.
1. Introduction The services industry provides services notgoods (Hughes and Mitchell et al., 1993). Thisindustry is moving towards globalization(Kathawala and Abdou, 2003). In 1870 theservice sector employed slightly more than 20%of the U.S.…  相似文献   

9.
In this paper, we investigate optimal policies for an age-dependent n-dimensional competition system, which is controlled by fertility. By using Dubovitskii-Milyutin's general theory, the maximum principles are obtained for the problems with free terminal states, infinite horizon, and target sets, respectively.  相似文献   

10.
Based on system dynamics approach, SDMUWEIC model is developed in order to evaluatefuture dynamics of urban water infrastructure development in China. Firstly, this paper presents thebasic structure and characteristics of the model, focusing on water infrastructure‘s dynamicrelationships with population increase, economic development, water resources shortage and waterconservation practices. Secondly, model veracity and robustness tests based on behavior reproductionand uncertainty analyses are illustrated. Thirdly, based on the model, future pattems of China‘s urbanwater infrastructure investment requirements are simulated, and effectiveness of two different policyscenarios are evaluated. Finally, conclusion,; and policy implications are drawn, allowing insights intoChina‘s sustainable water infrastructure policies and managements.  相似文献   

11.
This paper considers the economic production quantity (EPQ) problem with backorder in which the setup cost, the holding cost and the backorder cost are characterized as fuzzy variables, respectively. Following expected value criterion and chance constrained criterion, a fuzzy expected value model (EVM) and a chance constrained programming (CCP) model are constructed. Then fuzzy simulations are employed to estimate the expected value of fuzzy variable and α-level minimal average cost. In order to solve the CCP model, a particle swarm optimization (PSO) algorithm based on the fuzzy simulation is designed. Finally, the effectiveness of PSO algorithm based on the fuzzy simulation is illustrated by a numerical example. This research is supported by the National Natural Science Foundation of China under Grant No. 70471049.  相似文献   

12.
已有演化元胞遗传算法中的演化规则多从元胞自动机中直接引入,未在状态演化中考虑个体间适应值的差异。根据密度制约关系提出一种新的演化元胞遗传算法来处理动态优化问题,在考虑个体适应值优劣与局部种群密度的前提下,通过密度制约与种内竞争实现个体在元胞空间内的生死演化,并建立种群规模增长模型控制元胞空间内存活个体规模。选取不同强度、复杂度的动态优化问题对算法性能进行验证,结果表明新算法具有良好的处理动态优化问题的能力。  相似文献   

13.
This paper employs a stochastic endogenous growth model with productive government expenditure in a small open economy to analyze the optimal fiscal policy. First, a stochastic model of a small open economy is constructed. Second, the equilibrium solutions of the representative agent's stochastic optimization problem are derived. Third, we obtain the equilibrium solutions of the central planner's stochastic optimization problem and the optimal government expenditure policy. Finally, the optimal tax policy is characterized.  相似文献   

14.
In order to tradeoff exploration/exploitation and inspired by cell genetic algorithm a cellshift crossover operator for evolutionary algorithm (EA) is proposed in this paper. The definition domain is divided into n-dimension cubic sub-domains (cell) and each individual locates at an ndimensional cube. Cell-shift crossover first exchanges the cell numbers of the crossover pair if they are in the different cells (exploration) and subsequently shift the first individual from its initial place to the other individual's cell place. If they are already in the same cell heuristic crossover (exploitation) is used. Cell-shift/heuristic crossover adaptively executes exploration/exploitation search with the vary of genetic diversity. The cell-shift EA has excellent performance in terms of efficiency and efficacy on ten usually used optimization benchmarks when comparing with the recent well-known FEP evolutionary algorithm.  相似文献   

15.
Extant studies of cooperative advertising mainly consider a single-manufacturer-single-retailer channel structure.This can provide limited insights,because a manufacturer,in real practices,usually deals with multiple retailers simultaneously.In order to examine the impact of the retailer’s multiplicity on channel members’ decisions and on total channel efficiencies,this paper develops a multiple-retailer model.In this model,the manufacturer and the retailers play a Stackelberg game to make the optimal advertising decisions.Based on the quantitative results,it is observed that:1) When there are multiple symmetric retailers,as the number of retailers scales up,the manufacturer’s national advertising investment contributes increasingly to add to channel members’ profits in equilibrium,but the total channel efficiency deteriorates quickly and converges down to a certain value;2) When there are multiple asymmetric retailers,the distribution channel suffers from the manufacturer’s uniform participation strategy due to the retailer’s free-riding,and benefits with the manufacturer’s retailer-specific participation strategy.This study derives equilibrium solutions in closed form for all games considered and measures explicitly the gains/losses of channel efficiencies under different game settings.  相似文献   

16.
A class of robust location estimators called weighted randomly trimmed means are introduced and not only their consistency and asymptotic normality are proved, but their influence functions, asymptotic variances and breakdown points are also derived. They possess the same breakdown points as the median, and some of them own higher asymptotic relative efficiencies at the heavy-tailed distributions than some other well-known location estimators; whereas the trimmed means, Winsorized means and Huber's M-estimator possess higher asymptotic relative efficiencies at the light-tailed distributions, in which Huber's M-estimator is the most robust.  相似文献   

17.
This paper analyses Chinese manufacturing performance from a multilateral perspective in 1980–2004. The PPPs, relative price levels, labor productivity and ULCs in multilateral comparison are used to explore Chinese manufacturing competitiveness. The PPPs are based on the benchmark year 1997. These results are compared to the previous estimates based on the 1987 benchmark. The findings are as follows: the PPPs derived by the different approaches in the base year 1997 in Chinese manufacturing are approximately 3.7 yuan/international $. Since the middle 1980s, China’s relative price level has been the lowest among all five countries and declined during the period of time. Its ULC has also been declining with some fluctuation. In the 1980s, there was “no catch-up rapid growth” in its labor productivity. However, after 1992, a beginning has been made with catch up distinctly, though from a very low level. This work was supported by the National Natural Science Foundation of China under Grant 70173029, 70571004 and 70531010. Ruoen Ren Professor of School of Economics & Management in Beihang University received Ph.D. in Economics in Renmin University of China in 1987. As one who enjoys the Government Special Allowance, he specializes in the study of international competitiveness, macroeconomics analysis, input-output table research, and credit risk management etc. His primary academic achievements are as follows: ICP in China, ICOP in China, KLEMS in China, Credit risk management in China commercial bank. In addition to his teaching and research at school, he is a chief economist in China Development Bank, a member in Science & Technical committee in Ministry of Education, and an executive director in China’s Input-output Association, etc. Haitao Zheng Doctorial candidate of School of Economics & Management in Beihang University, majors in the study on international competitiveness and insurance actuary. Meanwhile, he is an Associate of Society of Chinese Actuary.  相似文献   

18.
This paper argues that agent-based simulation can be used as a way for testing Kansei Engineering methods which deal with the human reaction from sensory to mental state, that is, sensitivity, sense, sensibility, feeling, esthetics, emotion affection and intuition. A new fuzzy linear quantification method is tested in an artificial world by agent-based modeling and simulations, and the performance of the fuzzy linear method is compared with that of a genetic algorithm. The simulations can expand people's imagination and enhance people's intuition that the new fuzzy linear quantification method is effective.  相似文献   

19.
The authors give an upper bound for the projective plane crossing number of a circular graph. Also, the authors prove the projective plane crossing numbers of circular graph C (8, 3) and C (9, 3) are 2 and 1, respectively.  相似文献   

20.
Traditional Chinese medicine (TCM) has a rich knowledge about human health and disease by its special way evolved along a very long history. As modern medicine is achieving much progress, arguments and disputes toward TCM never end. To avoid losing precious knowledge of living TCM masters, endeavors have been engaged to systematic collection of those knowledge of TCM masters, such as their growth experiences, effective practical cases toward diseases and typical therapeutic principles and methods. Knowledge mining methods have been expected to explore some useful or hidden patterns to unveil some mysteries of the TCM system. In the paper, some computerized methods are applied toward those collected materials about some living TCM masters in China mainland to show a different way of exposing essential ideas of those TCM masters by correspondence visualization which aims to help people understand TCM holistic views toward disease and body, and facilitate tacit knowledge transfer and sense-making of the essence of TCM. The work is one kind of qualitative meta-synthesis of TCM masters' knowledge.  相似文献   

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