Aim To study the implicit restriction mechanism for hidden action in multi stage dynamic game. Methods A reputation model for restriction on repeated principal agent relationship was established by using the theor...Aim To study the implicit restriction mechanism for hidden action in multi stage dynamic game. Methods A reputation model for restriction on repeated principal agent relationship was established by using the theory on principal agent problem in information economics and the method of game theory to study the implicit restriction mechanism for hidden action. Results and Conclusion It is proved that there exists implicit restriction mechanism for the multi stage principal agent relationship, some conditions for effective restriction are derived, the design methods of implicit restriction mechanism are presented.展开更多
The paper discusses the Internet trade trust problemby using KMRW reputation model in incompleteinformation limited repeated game,concluding thatin certain conditions,both Internet trade participatorswill give up shor...The paper discusses the Internet trade trust problemby using KMRW reputation model in incompleteinformation limited repeated game,concluding thatin certain conditions,both Internet trade participatorswill give up short-time revenue for maximizinglong-term revenue and accordingly employ the cooperationstrategy,and the times of cooperation isvulnerable to trade price and product utility.At last,the paper proposes several policies and suggestionssuch as forming Internet honesty culture,strengtheningInternet brand and figure and protecting Internetwell-known brands.展开更多
It is well known that the reputation is the basis of a seller to survive and gain trust from customers in a competitive business environment. But as the existence of information asymmetry between buyer and seller, the...It is well known that the reputation is the basis of a seller to survive and gain trust from customers in a competitive business environment. But as the existence of information asymmetry between buyer and seller, the moral hazard problem is the key obstacle that impedes the benefits of related shareholders and reduces the efficiency of total market. It is crucial to design a control mechanism to avoid the negative impact of moral hazard. This paper studies the principal and agent relationship between buyer and seller in C2C e-market;because of the influence of information asymmetry, many customers suffered from being cheated by sellers with defective products in practice. These frequent cases will deteriorate long term relationship between sellers and buyers. Here we focus on the analysis of the causes of moral risks and the effect of reputation on oral risk with repeated game theory. The purpose of this paper is to help both firms and customers effectively avoid morality risk and realize a win-win situation.展开更多
It is necessary to construct an effective trust model to build trust relationship between peers in peer-to-peer （P2P） network and enhance the security and reliability of P2P systems. The current trust models only fo...It is necessary to construct an effective trust model to build trust relationship between peers in peer-to-peer （P2P） network and enhance the security and reliability of P2P systems. The current trust models only focus on the consumers＇ evaluation to a transaction, which may be abused by malicious peers to exaggerate or slander the provider deliberately. In this paper, we propose a novel trust model based on mutual evaluation, called METrust, to suppress the peers＇ malicious behavior, such as dishonest evaluation and strategic attack. METrust considers the factors including mutual evaluation, similarity risk, time window, incentive, and punishment mechanism. The trust value is composed of the direct trust value and the recommendation trust value. In order to inhibit dishonest evaluation, both participants should give evaluation information based on peers＇ own experiences about the transaction while computing the direct trust value. In view of this, the mutual evaluation consistency factor and its time decay function are proposed. Besides, to reduce the risk of computing the recommendation trust based on the recommendations of friend peers, the similarity risk is introduced to measure the uncertainty of the similarity computing, while similarity is used to measure credibility. The experimental results show that METrust is effective, and it has advantages in the inhibition of the various malicious behaviors.展开更多
Based on the outstanding characteristics of Cloud Model on the process of transforming a qualitative concept to a set of quantitative numerical values, a formalized model of subjective trust is introduced by which we ...Based on the outstanding characteristics of Cloud Model on the process of transforming a qualitative concept to a set of quantitative numerical values, a formalized model of subjective trust is introduced by which we can transform between qualitative reputation and quantitative voting data. The present paper brings forward algorithms to compute direct trust and recommender trust. Further more, an effective similarity measuring method used to distinguish two users＇ reputation on knowledge level is also proposed. The given model properly settles the uncertainty and fuzziness properties of subjective trust which is always the weakness of traditional subjective trust model, and provides a step in the direction of proper understanding and definition of human trust.展开更多
This contribution deals with a generative approach for the analysis of textual data. Instead of creating heuristic rules forthe representation of documents and word counts, we employ a distribution able to model words...This contribution deals with a generative approach for the analysis of textual data. Instead of creating heuristic rules forthe representation of documents and word counts, we employ a distribution able to model words along texts considering different topics. In this regard, following Minka proposal (2003), we implement a Dirichlet Compound Multinomial (DCM) distribution, then we propose an extension called sbDCM that takes explicitly into account the different latent topics that compound the document. We follow two alternative approaches: on one hand the topics can be unknown, thus to be estimated on the basis of the data, on the other hand topics are determined in advance on the basis of a predefined ontological schema. The two possible approaches are assessed on the basis of real data.展开更多
Reputation systems represent soft security mechanisms that complement traditional information security mechanisms.They are now widely used in online e-commerce markets and communities in order to stimulate good behavi...Reputation systems represent soft security mechanisms that complement traditional information security mechanisms.They are now widely used in online e-commerce markets and communities in order to stimulate good behaviors as well as to restrain adverse behaviors.This paper analyzes the limitations of the conversational reputation models and proposes an incentive reputation model called the resilient reputation model(RRM)for the distributed reputation systems.The objective of this reputation model is not only to encourage the users to provide good services and,therefore,to maximize the probability of good transaction outcomes,but also to punish those adverse users who are trying to manipulate the application systems.The simulation results indicate that the proposed reputation model(RRM)could effectively resist against the common adverse behaviors,while protecting the profits of sincere users from being blemished by those adversaries.展开更多
文摘Aim To study the implicit restriction mechanism for hidden action in multi stage dynamic game. Methods A reputation model for restriction on repeated principal agent relationship was established by using the theory on principal agent problem in information economics and the method of game theory to study the implicit restriction mechanism for hidden action. Results and Conclusion It is proved that there exists implicit restriction mechanism for the multi stage principal agent relationship, some conditions for effective restriction are derived, the design methods of implicit restriction mechanism are presented.
文摘The paper discusses the Internet trade trust problemby using KMRW reputation model in incompleteinformation limited repeated game,concluding thatin certain conditions,both Internet trade participatorswill give up short-time revenue for maximizinglong-term revenue and accordingly employ the cooperationstrategy,and the times of cooperation isvulnerable to trade price and product utility.At last,the paper proposes several policies and suggestionssuch as forming Internet honesty culture,strengtheningInternet brand and figure and protecting Internetwell-known brands.
文摘It is well known that the reputation is the basis of a seller to survive and gain trust from customers in a competitive business environment. But as the existence of information asymmetry between buyer and seller, the moral hazard problem is the key obstacle that impedes the benefits of related shareholders and reduces the efficiency of total market. It is crucial to design a control mechanism to avoid the negative impact of moral hazard. This paper studies the principal and agent relationship between buyer and seller in C2C e-market;because of the influence of information asymmetry, many customers suffered from being cheated by sellers with defective products in practice. These frequent cases will deteriorate long term relationship between sellers and buyers. Here we focus on the analysis of the causes of moral risks and the effect of reputation on oral risk with repeated game theory. The purpose of this paper is to help both firms and customers effectively avoid morality risk and realize a win-win situation.
基金supported by National Natural Science Foundation of China (No.60873231)Research Fund for the Doctoral Program of Higher Education (No.20093223120001)+2 种基金Science and Technology Support Program of Jiangsu Province (No.BE2009158)Natural Science Fund of Higher Education of Jiangsu Province(No.09KJB520010)Special Fund for Fast Sharing of Science Paper in Net Era by CSTD (No.2009117)
文摘It is necessary to construct an effective trust model to build trust relationship between peers in peer-to-peer （P2P） network and enhance the security and reliability of P2P systems. The current trust models only focus on the consumers＇ evaluation to a transaction, which may be abused by malicious peers to exaggerate or slander the provider deliberately. In this paper, we propose a novel trust model based on mutual evaluation, called METrust, to suppress the peers＇ malicious behavior, such as dishonest evaluation and strategic attack. METrust considers the factors including mutual evaluation, similarity risk, time window, incentive, and punishment mechanism. The trust value is composed of the direct trust value and the recommendation trust value. In order to inhibit dishonest evaluation, both participants should give evaluation information based on peers＇ own experiences about the transaction while computing the direct trust value. In view of this, the mutual evaluation consistency factor and its time decay function are proposed. Besides, to reduce the risk of computing the recommendation trust based on the recommendations of friend peers, the similarity risk is introduced to measure the uncertainty of the similarity computing, while similarity is used to measure credibility. The experimental results show that METrust is effective, and it has advantages in the inhibition of the various malicious behaviors.
基金Supported bythe National Basic Research Programof China (973 Program) (G2004CB719401) National Natural Sci-ence Foundation of China (60496323 ,60375016)
文摘Based on the outstanding characteristics of Cloud Model on the process of transforming a qualitative concept to a set of quantitative numerical values, a formalized model of subjective trust is introduced by which we can transform between qualitative reputation and quantitative voting data. The present paper brings forward algorithms to compute direct trust and recommender trust. Further more, an effective similarity measuring method used to distinguish two users＇ reputation on knowledge level is also proposed. The given model properly settles the uncertainty and fuzziness properties of subjective trust which is always the weakness of traditional subjective trust model, and provides a step in the direction of proper understanding and definition of human trust.
文摘This contribution deals with a generative approach for the analysis of textual data. Instead of creating heuristic rules forthe representation of documents and word counts, we employ a distribution able to model words along texts considering different topics. In this regard, following Minka proposal (2003), we implement a Dirichlet Compound Multinomial (DCM) distribution, then we propose an extension called sbDCM that takes explicitly into account the different latent topics that compound the document. We follow two alternative approaches: on one hand the topics can be unknown, thus to be estimated on the basis of the data, on the other hand topics are determined in advance on the basis of a predefined ontological schema. The two possible approaches are assessed on the basis of real data.
基金the National Basic Research Program of China(973 Program)(Grant No.2003CB314800)the National Natural Science Foundation of China(Grant No.60203044)the 242 Program(Grant No.(242)2007A07)
文摘Reputation systems represent soft security mechanisms that complement traditional information security mechanisms.They are now widely used in online e-commerce markets and communities in order to stimulate good behaviors as well as to restrain adverse behaviors.This paper analyzes the limitations of the conversational reputation models and proposes an incentive reputation model called the resilient reputation model(RRM)for the distributed reputation systems.The objective of this reputation model is not only to encourage the users to provide good services and,therefore,to maximize the probability of good transaction outcomes,but also to punish those adverse users who are trying to manipulate the application systems.The simulation results indicate that the proposed reputation model(RRM)could effectively resist against the common adverse behaviors,while protecting the profits of sincere users from being blemished by those adversaries.
