基于辩论的多商品谈判模型研究*

旨在对一组商品的多agent谈判进行研究,这组商品具有共同的性质,能满足买方特定需求。通过分析一组商品的属性特征,将商品的属性分为主属性和非主属性,用辩论方法构建多商品谈判机制,提出基于辩论的多商品谈判模型,并通过原型系统实验验证了模型的正确性和有效性。提出的模型将一组商品的多agent谈判统一到一个过程中,有利于达成谈判协议,提高谈判效率。     

基于agent的两阶段式一对多谈判模型研究

提出了一种两阶段式一对多谈判模型。与多个一对一并行谈判模式相比,它可以更好地体现一对多谈判的特点,即加强了多个卖方之间的竞争关系和单个买方的主导地位,使得单个买方有机会获得更优报价,也使其他卖家不会因为采取了竞争力较小的策略而丧失谈判机会。模型中提出了暂时接受报价的概念,即令其等于买方接收到的第一阶段最后一轮最小报价或第二阶段每轮最小报价,并利用此值计算卖方下一轮的报价,从而利用上一轮最低报价压低下一轮报价,达到多方竞争的目的。     

基于辩论的多Agent商务谈判认知模型

针对在基于辩论的谈判中如何表示Agent的认知结构和决策机制的问题,提出一个应用于商务谈判的Agent的认知决策模型。该模型由卖方和买方Agent两部分构成,其中,Agent的认知结构用自我目标认知以及对对方的目标认知等集合来表示,Agent的决策用多目标优化模型来辅助进行。基于辩论的谈判实例验证了该模型的实用性。     

基于多Agent多对象多要素的智能谈判模型

多Agent的协作协商问题是当前MAS系统研究的重点和热点.现实世界中买卖谈判所涉及的领域和问题极其广泛,其中又以多对象多要素买卖谈判更为常见.文章通过对现实谈判中的复杂的谈判协商问题,提出了基于多Agent多对象多要素的智能谈判模型（M3INM）.该模型为谈判支持系统在多对象多要素环境下的应用提供一个参考.     

基于模糊的电子商务谈判模型及其仿真

主要是从模糊的角度来讨论谈判者对对方报价的接受度,采用隶属值来表示这个接受度.考虑了不同的谈判条款对谈判者的影响权重不同,采用组合的方法来考虑多条款谈判中的让步问题,建立并应用模型解决了一个电子商务谈判的实例,并且用Swarm仿真对此实例进行了仿真研究.结果表明,此模型比传统的谈判模型更加符合现实谈判.     

基于模糊多准则决策的谈判模型

针对目前谈判支持系统中谈判模型存在的难以准确获知谈判人的偏好，以及利用偏好构造其效用函数的问题，应用模糊数学的方法，将谈判人的偏好和对目标值的评价用梯形模糊数表示，由此提出一种基于模糊多准则决策方法求解谈判问题的模型。通过示例分析计算，表明该模型能帮助谈判各方达成一个满意解。     

基于MAS的电子商务谈判支持系统

随着Internet技术的发展,网上电子商务谈判方式正在兴起。为了提高谈判效率,并增加谈判的智能辅助机制,该文引入Agent技术,重点介绍了以多Agent系统为基础的谈判支持系统(NSS)设计框架。在此系统中,建立了一个结合多目标决策理论和基于偏好理论的决策模型。     

基于Agent的谈判模型研究

提出了一种基于Agent技术的谈判模型，应用模糊数学理论建立了谈判论据及谈判解接受度数学模型。采用约束放松的方法对谈判模型进行求解，得到了谈判Agent满意的谈判解。阐述了双边多属性谈判过程，设计并开发了Agent谈判系统原型，实例计算分析表明，该谈判模型是一种双赢的谈判模型。     

基于Agent的多问题并行遗传谈判模型

Agent谈判增加了电子商务系统的主动性,一个有效的谈判模型是系统实现的关键。分析了已有Agent谈判模型的特点,设计的基于Agent的多问题并行谈判模型解决了已有谈判模型中存在的谈判问题单一、非并行、不考虑对手收益和固定权重等问题。模型中产生谈判方案的算法的自适应性体现在问题权重、遗传参数和收益偏差的动态调整上,给出了问题实数编码和权重调整公式。最后,设计了一个面向三个问题的电子谈判实例,验证了谈判模型的可行性和有效性。     

基于遗传算法的关联议题并发谈判

基于遗传算法的并发谈判在电子商务应用中具有独特的优势,但已有的研究尚未考虑议题之间的相关性、动态权重的变化规则依赖于对手信息的获取,极大地限制了其使用价值.对此,提出议题分组的方法以解决议题的相关性问题,而议题权重的变化则采取从历史资源中发掘知识的方法进行动态调整.构建了基于遗传算法的关联性议题并发谈判模型,给出了模型的形式化描述、谈判算法设计和动态权重更新方案.通过对模型的实验和比较分析,证实了该方案能够更方便地满足用户谈判的多样性需求,解决谈判中议题关联性的问题,而且能够快速、有效地得出最优谈判结果.     

Managing commitments in multiple concurrent negotiations

Automated negotiation by software agents is a key enabling technology for agent mediated e-commerce. To this end, this paper considers an important class of such negotiations – namely those in which an agent engages in multiple concurrent bilateral negotiations for a good or service. In particular, we consider the situation in which a buyer agent is looking for a single service provider from a number of available ones in its environment. By bargaining simultaneously with these providers and interleaving partial agreements that it makes with them, a buyer can reach good deals in an efficient manner. However, a key problem in such encounters is managing commitments since an agent may want to make intermediate deals (so that it has a definite agreement) with other agents before it gets to finalize a deal at the end of the encounter. To do this effectively, however, the agents need to have a flexible model of commitments that they can reason about in order to determine when to commit and to decommit. This paper provides and evaluates such a commitment model and integrates it into a concurrent negotiation model.     

Managing commitments in multiple concurrent negotiations

Automated negotiation by software agents is a key enabling technology for agent mediated e-commerce. To this end, this paper considers an important class of such negotiations – namely those in which an agent engages in multiple concurrent bilateral negotiations for a good or service. In particular, we consider the situation in which a buyer agent is looking for a single service provider from a number of available ones in its environment. By bargaining simultaneously with these providers and interleaving partial agreements that it makes with them, a buyer can reach good deals in an efficient manner. However, a key problem in such encounters is managing commitments since an agent may want to make intermediate deals (so that it has a definite agreement) with other agents before it gets to finalize a deal at the end of the encounter. To do this effectively, however, the agents need to have a flexible model of commitments that they can reason about in order to determine when to commit and to decommit. This paper provides and evaluates such a commitment model and integrates it into a concurrent negotiation model.     

Reducing model checking commitments for agent communication to model checking ARCTL and GCTL*

Social commitments have been extensively and effectively used to represent and model business contracts among autonomous agents having competing objectives in a variety of areas (e.g., modeling business processes and commitment-based protocols). However, the formal verification of social commitments and their fulfillment is still an active research topic. This paper presents CTLC⁺ that modifies CTLC, a temporal logic of commitments for agent communication that extends computation tree logic (CTL) logic to allow reasoning about communicating commitments and their fulfillment. The verification technique is based on reducing the problem of model checking CTLC⁺ into the problem of model checking ARCTL (the combination of CTL with action formulae) and the problem of model checking GCTL^* (a generalized version of CTL^* with action formulae) in order to respectively use the extended NuSMV symbolic model checker and the CWB-NC automata-based model checker as a benchmark. We also prove that the reduction techniques are sound and the complexity of model checking CTLC⁺ for concurrent programs with respect to the size of the components of these programs and the length of the formula is PSPACE-complete. This matches the complexity of model checking CTL for concurrent programs as shown by Kupferman et al. We finally provide two case studies taken from business domain along with their respective implementations and experimental results to illustrate the effectiveness and efficiency of the proposed technique. The first one is about the NetBill protocol and the second one considers the Contract Net protocol.     

Extending UN/CEFACT’s modeling methodology by a UML profile for local choreographies

UN/CEFACT’s modeling methodology (UMM) is a UML profile for specifying global choreographies of inter-organizational e-business systems. As we outline in this paper, the practical use of UMM is limited to bi-lateral business collaborations, since it does not support nested business transactions. This means UMM does not support multi-party business collaborations. UN/CEFACT argues that UMM serves as model capturing the agreements and commitments between business partners. These agreements and commitments are always on a bi-lateral basis. However, a business partner in the middle of a supply chain must establish multiple agreements and commitments with multiple partners. It is the local choreography of a business partner that binds the various bi-lateral models leading to a multi-party choreography. Unfortunately, UN/CEFACT does not give any guidance on how to model the local choreographies. We close this gap by extending UMM by a UML profile for local choreographies.     

On the interaction between knowledge and social commitments in multi-agent systems

Both knowledge and social commitments have received considerable attention in Multi-Agent Systems (MASs), specially for multi-agent communication. Plenty of work has been carried out to define their semantics. However, the relationship between social commitments and knowledge has not been investigated yet. In this paper, we aim to explore such a relationship from the semantics and model checking perspectives with respect to CTLK logic (an extension of CTL logic with modality for reasoning about knowledge) and CTLC logic (an extension of CTL with modalities for reasoning about commitments and their fulfillments). To analyze this logical relationship, we simply combine the two logics in one new logic named CTLKC. The purpose of such a combination is not to advocate a new logic, but only to express and figure out some reasoning postulates merging both knowledge and commitments as they are currently defined in the literature. By so doing, we identify some paradoxes in the new logic showing that simply combining current versions of commitment and knowledge logics results in a logical language that violates some fundamental intuitions. Consequently, we propose CTLKC⁺, a new logic that fixes the identified paradoxes and allows us to reason about social commitments and knowledge simultaneously in a consistent manner. Furthermore, we address the problem of model checking CTLKC⁺ by reducing it to the problem of model checking GCTL^?, a generalized version of CTL^? with action formulae. By doing so, we directly benefit from CWB-NC, the model checker of GCTL^?. Using this reduction, we also prove that the computational complexity of model checking CTLKC⁺ is still PSPACE-complete for concurrent programs as the complexity of model checking CTLK and CTLC separately.     

基于证人不可区分的通用可复合安全并行可否认认证

针对并行可否认认证问题,在UC(universally composable)安全框架中,基于WI(witness indistinguishable)提出了一种新的研究思路和解决方法.根据可否认认证的安全目标,形式化地建立了UC安全的并行可否认认证模型.利用可验证平滑投影哈希函数和非承诺加密体制,构造了一类新的并行可否认认证协议结构,基于确定性复合剩余假设和确定性Diffie-Hellman假设,实现了一个具体的协议方案.在公共参考串模型中,利用UC框架解决并行协议仿真问题,与定时假设和公共目录方案相比,不需要限定攻击者能力.新方案具备前向可否认性,是自适应攻击者UC安全的.不同于CCA2加密体制结构或多陷门承诺结构的并行可否认认证,协议效率得到了改善.     

Constraint satisfaction as a tool for modeling and checking feasibility of multiagent commitments

Commitments are being used to specify interactions among autonomous agents in multiagent systems. Various formalizations of commitments have shown their strength in representing and reasoning on multiagent interactions. These formalizations mostly study commitment lifecycles, emphasizing fulfillment of a single commitment. However, when multiple commitments coexist, fulfillment of one commitment may have an effect on the lifecycle of other commitments. Since agents generally participate in more than one commitment at a time, it is important for an agent to determine whether it can honor its commitments. These commitments may be the existing commitments of the agent as well as any prospective commitments that the agent plans to participate in. To address this, we develop the concept of commitment feasibility, i.e., whether it is possible for an agent to fulfill a set of commitments all together. To achieve this we generalize the fulfillment of a single commitment to the feasibility of a set of commitments. We then develop a solid method to determine commitment feasibility. Our method is based on the transformation of feasibility into a constraint satisfaction problem and use of constraint satisfaction techniques to come up with a conclusion. We show soundness and completeness of our method and illustrate its applicability over realistic cases.     

基于多故障模型的并发测试生成方法

精简测试向量集是解决电路测试问题的一种行之有效的方法。针对故障电路,采用多故障模型方法可以简化有多个单故障的电路,且保持电路功能完整。论文在结构分析的基础上,利用多故障模型寻找故障集中的并发故障,建立并发关系图,并运用分团的思想对故障集中的并发故障进一步划分,以获得故障集的并发测试集。与传统的方法相比,并发测试生成将获得更加精简的测试向量集。     

一种新的并行Java程序的监护模型

提出了一种新的并行Java程序异常处理的监护模型。该模型针对并行Java程序异步信息传递方式进行异常处理。当并行Java程序的某个线程出现异常时,该线程的监护模块把检测到的异常情况的信息传递到其它线程的监护模块,每个线程根据当前事项与异常事项的向量时钟关系,对当前事项进行回滚或停止操作,以达到对并行Java程序的保护。过去一些并行程序的监护方案是在信息交换的基础上把并行程序结构化为许多原子行为,把多个并行异常当作单个异常进行处理,具有较大的局限性。提出的监护模型是从全局上对并行Java程序的异常情况进行处理,并指导每个线程根据自身情况作出相应反映。实验证明提出的新的并行Java程序监护模型具有较强的实际操作性,并能有效地保护并行Java程序。     

Model checking probabilistic social commitments for intelligent agent communication

Interaction among autonomous agents in Multi-Agent Systems (MASs) is a key aspect for agents to coordinate with one another. Social approaches, as opposed to the mental approaches, have recently received a considerable attention in the area of agent communication. They exploit observable social commitments to develop a verifiable formal semantics through which communication protocols can be specified. Developing and implementing algorithmic model checking for social commitments have been recently addressed. However, model checking social commitments in the presence of uncertainty is yet to be investigated.In this paper, we propose a model checking technique for verifying social commitments in uncertain settings. Social commitments are specified in a modal logical language called Probabilistic Computation Tree Logic of Commitments (PCTLC). The modal logic PCTLC extends PCTL, the probabilistic extension of CTL, with modalities for commitments and their fulfillments. The proposed verification method is a reduction-based model checking technique to the model checking of PCTL. The technique is based upon a set of reduction rules that translate PCTLC formulae to PCTL formulae to take benefit of existing model checkers such as PRISM. Proofs that confirm the soundness of the reduction technique are presented. We also present rules that transform our new version of interpreted systems into models of Markov Decision Processes (MDPs) to be suitable for the PRISM tool. We implemented our approach on top of the PRISM model checker and verified some given properties for the Oblivious Transfer Protocol from the cryptography domain. Our simulation demonstrates the effectiveness of our approach in verifying and model checking social commitments in the presence of uncertainty. We believe that the proposed formal verification technique will advance the literature of social commitments in such a way that not only representing social commitments in uncertain settings is doable, but also verifying them in such settings becomes achievable.