Learning in multi-agent systems: a case study of construction claims negotiation

The ability of agents to learn is of growing importance in multi-agent systems. It is considered essential to improve the quality of peer to peer negotiation in these systems. This paper reviews various aspects of agent learning, and presents the particular learning approach—Bayesian learning—adopted in the MASCOT system (multi-agent system for construction claims negotiation). The core objective of the MASCOT system is to facilitate construction claims negotiation among different project participants. Agent learning is an integral part of the negotiation mechanism. The paper demonstrates that the ability to learn greatly enhances agents' negotiation power, and speeds up the rate of convergence between agents. In this case, learning is essential for the success of peer to peer agent negotiation systems.     

基于加速模拟退火策略的Agent协商优化算法

网络的普及促进了电子商务的发展，而智能代理是电子商务的关键，如何实现智能代理的快速、高效协商是一个很重要的问题。本文在加速模拟退火策略的基础上，提出了一种Agent协商优化算法。理论分析和仿真实验都表明该算法是一个快速、有效的方法。     

基于移动Agent的自动协商应用

主要研究电子商务中的协商问题,为实现自动协商提供了一个可行的方向。通过分析目前电子商务的协商现状及所存在的问题,提出将移动Agent技术引入电子商务,为B2C电子商务中一对多的协商问题自动化指出了一个实现方向,并得出基于移动Agent的自动协商系统的建设目标及特点。这将对于实现电子商务协商的自动化,提供有力的理论支持及发展方向。     

基于移动Agent的电子商务模型研究

在分析电子商务中应用移动代理技术的原因和优势的基础上,设计并实现了一个基于移动代理的电子商务系统模型。描述了一种用以设计和开发电子商务系统的移动Agent技术的概要性实现框架。在电子商务中采用Agent技术的目的主要是为了解决用户在使用电子商务中遇到的相关问题,并且以较低的代价增强商家为用户提供商品和服务。移动代理技术的引入将进一步增强电子商务的吸引力及其服务的能力,有效地解决目前电子商务发展中出现的诸多问题,如资源发现、交易协商,以及交易自动化等。     

Reputation management and signature delegation: A distributed approach

In this paper, we present a novel protocol, called Distributed Signcryption with Verifiable Partial Signature (DiSigncryption) protocol, to allow an agent owner to securely distribute his signing capability among a set of trusted third party hosts (TTP-hosts) via a mobile agent. The protocol incorporates three schemes: a novel Distributed Reputation Management scheme, a modified version of the Distributed Signcryption method proposed in [23], and an extended version of the Agent-based Threshold Proxy Signcryption (ATPS) protocol proposed in [2]. The security properties of the proposed protocol are analyzed, and the protocol is compared with the most related work. Omaima Bamasak received her Ph.D. degree from the University of Manchester, UK, in 2006. Her research interests are in designing protocols using cryptography for the provision of security in distributed systems, mobile agent security, electronic/mobile commerce, reputation management, and non-repudiation and fairness protocols. Ning Zhang received her Ph.D. degree from the University of Kent at Canterbury in 1994, and is now a lecturer in the School of Computer Science at the University of Manchester. Her research interests are in computer security and applied cryptography, e.g., security and privacy in distributed systems, ubiquitous computing, and electronic commerce, with a focus on security protocol design, access control, and trust management.     

Agents in Electronic Commerce: Component Technologies for Automated Negotiation and Coalition Formation

Automated negotiation and coalition formation among self-interested agents are playing an increasingly important role in electronic commerce. Such agents cannot be coordinated by externally imposing their strategies. Instead the interaction protocols have to be designed so that each agent is motivated to follow the strategy that the protocol designer wants it to follow. This paper reviews six component technologies that we have developed for making such interactions less manipulable and more efficient in terms of the computational processes and the outcomes: 1. OCSM-contracts in marginal cost based contracting, 2. leveled commitment contracts, 3. anytime coalition structure generation with worst case guarantees, 4. trading off computation cost against optimization quality within each coalition, 5. distributing search among insincere agents, and 6. unenforced contract execution. Each of these technologies represents a different way of battling self-interest and combinatorial complexity simultaneously. This is a key battle when multi-agent systems move into large-scale open settings.     

Kailar逻辑的缺陷

近年来,电子商务协议的设计逐渐成为热点.可追究性是指电子商务协议迫使个人或组织对自己在电子交易中的行为负责的能力.缺乏可追究性,电子交易容易引起争议.因此,Rajashekar Kailar提出了一种用于分析电子商务协议中可追究性的形式化分析方法,简称Kailar逻辑.该文指出这一逻辑的缺陷：（1） 不能分析协议的公平性;(2) 对协议语句的解释及初始化假设是非形式化的,存在局限性;(3) 无法处理密文.     

DynamiCS: An Actor-Based Framework for Negotiating Mobile Agents

In this article, a framework to integrate negotiation capabilities—particularly, components implementing a negotiation strategy—into mobile agents is described. This approach is conceptually based on the notion of an actor system which decomposes an application component into autonomously executing subcomponents cooperating with each other. Technically, the framework is based on a plug-in mechanism enabling a dynamic composition of negotiating agents. Additionally, this contribution describes how interaction-oriented rule mechanisms can be deployed to control the behavior of strategy actors.     

基于Agent的电子谈判协议设计

Agent谈判和人类谈判一样,需要事先就谈判内容、程序、方案和礼节等事项达成协议,确保谈判的正常进行。该文设计了一个电子谈判协议,该协议包括发起谈判、终止谈判、并行谈判和身份认证4个子协议,为Agent谈判提供了一组规则框架。协议符合安全性和公平性原则,具有Pareto最优、Nash平衡和无欺诈特性。     

Negotiation among autonomous computational agents: principles,analysis and challenges

Automated negotiation systems with software agents representing individuals or organizations and capable of reaching agreements through negotiation are becoming increasingly important and pervasive. Examples, to mention a few, include the industrial trend toward agent-based supply chain management, the business trend toward virtual enterprises, and the pivotal role that electronic commerce is increasingly assuming in many organizations. Artificial intelligence (AI) researchers have paid a great deal of attention to automated negotiation over the past decade and a number of prominent models have been proposed in the literature. These models exhibit fairly different features, make use of a diverse range of concepts, and show performance characteristics that vary significantly depending on the negotiation context. As a consequence, assessing and relating individual research contributions is a difficult task. Currently, there is a need to build a framework to define and characterize the essential features that are necessary to conduct automated negotiation and to compare the usage of key concepts in different publications. Furthermore, the development of such a framework can be an important step to identify the core elements of autonomous negotiating agents, to provide a coherent set of concepts related to automated negotiation, to assess progress in the field, and to highlight new research directions. Accordingly, this paper introduces a generic framework for automated negotiation. It describes, in detail, the components of the framework, assesses the sophistication of the majority of work in the AI literature on these components, and discusses a number of prominent models of negotiation. This paper also highlights some of the major challenges for future automated negotiation research.     

公平的消息传输协议

公平性是电子交易走向实际应用所必须解决的课题.提出了一个在电子商务环境下消息传输协议,目的是为了保证在消息传输协议终止后,双方都能收到对方消息或都收不到.该协议基于乐观模型,使用了可转化签名和非交互式零知识证明等技术.协议在实现有效性、公平性和不可抵赖性要求的基础上,还实现了透明的可信第3方,且生成的最终抗抵赖证据是标准的GDH签名（gap diffie-hellman signature）,这使得该协议既高效,又非常容易融入现有交易系统.     

Verifying Compliance with Commitment Protocols

Interaction protocols are specific, often standard, constraints on the behaviors of autonomous agents in a multiagent system. Protocols are essential to the functioning of open systems, such as those that arise in most interesting web applications. A variety of common protocols in negotiation and electronic commerce are best treated as commitment protocols, which are defined, or at least analyzed, in terms of the creation, satisfaction, or manipulation of the commitments among the participating agents.When protocols are employed in open environments, such as the Internet, they must be executed by agents that behave more or less autonomously and whose internal designs are not known. In such settings, therefore, there is a risk that the participating agents may fail to comply with the given protocol. Without a rigorous means to verify compliance, the very idea of protocols for interoperation is subverted. We develop an approach for testing whether the behavior of an agent complies with a commitment protocol. Our approach requires the specification of commitment protocols in temporal logic, and involves a novel way of synthesizing and applying ideas from distributed computing and logics of program.     

Agent-Mediated Electronic Commerce

Electronic commerce has been one of the traditional arenas for agent technology. The complexity of these applications has been a challenge for researchers that have developed methodologies, products, and systems, having in mind the specificities of trade, the interaction particularities of commerce, the strict notion of commitment and contract, and the clearly shaped conventions and norms that structure the field. In this paper I survey some key areas for agent technology which, although general, are of special importance in electronic commerce, namely, solid development methodologies, negotiation technologies and trust-building mechanisms. I give examples of systems in which I have directly participated, although I also try to refer to the work of other AgentLink Special Interest Group members over the last few years.     

一种基于时间-效用的Agent社会承诺机制

在多Agent系统中,为了完成任务,Agent之间需要建立社会承诺。本文通过将T．Sandholm的分级承诺合同协议思想与时间-效用对协商的影响有机地结合起来,提出了一种基于时间-效用的Agent社会承诺机制,为电子商务环境下存在最大协商时间的一对多协商中的买卖双方Agent之间的社会承诺问题提供了有效的解决方案。文章分析了解除承诺的条件,提出了建立承诺、解除承诺和遵守承诺的规则,从而有效规避了协商中买方Agent与卖方Agent随意达成一致的行为,同时保证了买方Agent能够在最大协商时间内确定最佳交易卖方,从而提高了协商系统的效率和效用。     

Knowledgeable Cyberbrokers for electronic markets

Electronic commerce is just beginning to be realisable. A number of technological, sociological and economic developments will be required before a large-scale roll out of electronic commerce can be expected. An architectural framework should be defined and needs to incorporate the semantics of contracting and negotiation based on knowledge technology. Electronic commerce has recently increased the demand for personalisation capabilities dramatically. This would imply the use of user-adaptive agents. Because electronic commerce is intrinsically interactive with virtual catalogues, this framework should make such interaction possible. This framework is centred around the Cyber e-Broker concept based on knowledge-based agents. Electronic commerce involves parties that may belong to different domains or administrations with different ontologies. This framework should enable manipulation of such information and enable conversion between ontologies. The e-broker ensures the correct negotiation protocols, and enforces the constraints and contracts, but also interacts with the virtual catalogues.     

An ontology based approach to organize multi-agent assisted supply chain negotiations

Effective supply chain management (SCM) comprises activities involving the demand and supply of resources and services. Negotiation is an essential approach to solve conflicting transaction and scheduling problems among supply chain members. The multi-agent system (MAS) technology has provided the potential of automating supply chain negotiations to alleviate human interactions. Software agents are supposed to perform on behalf of their human owners only when equipped with sophisticated negotiation knowledge. To better organize the negotiation knowledge utilized by agents and facilitate agents’ adaptive negotiation decision making ability, an ontology-based approach is proposed in this paper. Firstly, the multi-agent assisted supply chain negotiation scheme is presented to configure the general design components of the negotiation system, covering the agent intelligence modules, the knowledge organization method and the negotiation protocol. Then, the ontology-based negotiation knowledge organization method is specified. The negotiation knowledge is separated into shared negotiation ontology and private negotiation ontology to ensure both the agent communicative interoperability and the privacy of strategic knowledge. Inference rules are defined on top of the private negotiation ontology to guide agents’ reasoning ability. Through this method, agents’ negotiation behaviors will be more adaptive to various negotiation environments utilizing corresponding negotiation knowledge.     

Kailar逻辑的缺陷及改进

近年来，电子商务协议的设计逐渐成为热点。Kailar提出了一种用于分析电子商务协议中可追究性的形式化分析方法，简称Kailar逻辑。指出这一逻辑的缺陷：在发生重放攻击时不能正确分析各方面的责任，在验证协议是否满足公平性原则时，具有一定的局限性。针对上述缺陷提出改进措施。     

A Negotiation Protocol for Dynamic Load Distribution Using Batch Task Assignments

Adynamic load distribution(LD) algorithm improves the performance of a distributed system by using current system load information to relocate application tasks among processing nodes, so that workload imbalance in the system can be smoothed out. In this paper, we propose aguarantee and reservation protocol(GR protocol) which can be used by dynamic LD algorithms. In contrast to the commonly usedsingle task assignments, GR protocol usesbatch task assignments, meaning that multiple tasks can be selected for remote execution during each single sender–receiver negotiation session. GR protocol is used to obtain a mutual agreement between a task sender and a receiver on an appropriate task batch size. GR protocol is based on avirtual workload modelwhich ensures coordinated even dispersements of tasks in the system. This model also avoidsprocessor thrashing, a situation when a receiver node is flooded with excessive remotely assigned tasks and thus becomes overloaded inadvertently.     

电子商务中洽谈技术的研究与分析

商务洽谈是电子商务活动中的关键行为。首先介绍了电子商务洽谈的概念和分类 ;然后从软件工程的角度描述了电子商务洽谈的生命周期 ;最后给出了电子商务洽谈的过程模型 ,并解释和分析了实现过程模型所需的框架———商务洽谈空间及其各参数的含义。     

Dealing with inconsistent secure messages by weighting majority

Messages transmitted between senders and receivers might be inconsistent owing to potential communication block, message lost and/or malicious attacks, in electronic commerce. And current formal methods for security protocol analysis show limitations in handling the incoherent secure messages that may be derived from different sources or at different moments. This results in increasing risk of e-commerce activities. This paper thus proposes a formal framework to deal with the inconsistency in secure messages by weighting majority. The freshness and dynamics properties of secure messages are considered and a reliability function is developed to measure the belief in secure messages. This helps us verify protocols in an intuitive way and guarantees correct verification results. The experimental results demonstrate our method is useful in secure protocol analysis.