Train service timetabling in railway open markets by particle swarm optimisation

Railway timetabling is an important process in train service provision as it matches the transportation demand with the infrastructure capacity while customer satisfaction is also considered. It is a multi-objective optimisation problem, in which a feasible solution, rather than the optimal one, is usually taken in practice because of the time constraint. The quality of services may suffer as a result. In a railway open market, timetabling usually involves rounds of negotiations amongst a number of self-interested and independent stakeholders and hence additional objectives and constraints are imposed on the timetabling problem. While the requirements of all stakeholders are taken into consideration simultaneously, the computation demand is inevitably immense. Intelligent solution-searching techniques provide a possible solution. This paper attempts to employ a particle swarm optimisation (PSO) approach to devise a railway timetable in an open market. The suitability and performance of PSO are studied on a multi-agent-based railway open-market negotiation simulation platform.     

Design of Roles and Protocols for Electronic Negotiations

Support for negotiations in electronic markets is one of the primary issues in today's e-commerce research. Whereas most activities are focused on automation aspects, only few efforts address the design of electronic negotiations. However, for the efficiency of electronic negotiation processes and the success of resulting settlements, it is essential to achieve an a-priori agreement among the negotiating parties about issues such as the syntax and semantics of offer specifications, the sequence of actions, possible responses, or time constraints, because these factors might influence, for instance, the fairness of the electronic negotiation.This paper demonstrates how an explicit and specific design can capture the way electronic negotiations are organised. The organisation design meta-model presented is part of SILKROAD, a design and application framework for electronic negotiations. On the basis of this framework, organisations creating an electronic market or sellers intending to offer potential buyers the option to bargain, can generate, in a flexible and efficient way, customised electronic negotiation systems supporting the roles and protocols designed. Furthermore, the consequent application of this meta-model can lead to the discovery of common negotiation patterns, eventually resulting in a reference model for electronic negotiations.     

Multi-attribute negotiation mechanism for manufacturing service allocation in smart manufacturing

Smart manufacturing is undergoing rapid development along with many disruptive technologies, such as Internet of Things, cyber-physical system and cloud computing. A myriad of heterogeneous manufacturing services can be dynamically perceived, connected and interoperated to satisfy various customized demands. In smart manufacturing, the market equilibrium is variable over time due to changes in demand and supply. Thus, efficient manufacturing service allocation (MSA) is critical to implementation of smart manufacturing. This paper considers the MSA problem under market dynamics with maximization of utility of customers and service providers. Many conventional methods generally allocate manufacturing services to the customers by multi-objective optimization without considering the impact of interactions between customers and service providers. This paper presents a multi-attribute negotiation mechanism to address the MSA problem under time constraints relying on autonomous agents. The proposed negotiation mechanism is composed of two models: an atomic manufacturing service negotiation model and a composite manufacturing service coordination. The former model is based on automated negotiation to seek an atomic manufacturing service over multiple attributes for an individual subtask. The latter model incorporates the global distribution and surplus redistribution to coordinate and control multiple atomic manufacturing service negotiations for the whole manufacturing task. Numerical studies are employed to verify the effectiveness of the multi-attribute negotiation mechanism in solving the MSA problem. The results show that the proposed negotiation mechanism can address the MSA problem and surplus redistribution can effectively improve the success rate of negotiations.     

A self-protecting and self-healing framework for negotiating services and trust in autonomic communication systems

In a federation of heterogeneous nodes that organize themselves, the lack of a trusted third party does not allow establishing a priori trust relationships among strangers. Automated trust negotiation (TN) is a promising approach to establish sufficient trust among parties, allowing them to access sensitive data and services in open environments. Although the literature on TN is growing, two key issues have still to be addressed. The first one concerns a typical feature of real-life negotiations: we are usually willing to trade the disclosure of personal attributes in exchange for additional services and only in a particular order (according to our preferences). The second one concerns dependability. By their nature TN systems are used in unreliable contexts where it is important not only to protect negotiations against malicious attack (self-protection), but also against accidental failures (self-healing). In this paper we address these issues proposing a novel dependable negotiation framework where services, needed credentials, and behavioral constraints on the disclosure of privileges are bundled together.     

Ant colony system: a cooperative learning approach to the travelingsalesman problem

This paper introduces the ant colony system (ACS), a distributed algorithm that is applied to the traveling salesman problem (TSP). In the ACS, a set of cooperating agents called ants cooperate to find good solutions to TSPs. Ants cooperate using an indirect form of communication mediated by a pheromone they deposit on the edges of the TSP graph while building solutions. We study the ACS by running experiments to understand its operation. The results show that the ACS outperforms other nature-inspired algorithms such as simulated annealing and evolutionary computation, and we conclude comparing ACS-3-opt, a version of the ACS augmented with a local search procedure, to some of the best performing algorithms for symmetric and asymmetric TSPs     

E-negotiation versus face-to-face negotiation what has changed – if anything?

The focus of the present study is the relatively new and still controversial electronically mediated negotiation (hence denoted e-negotiation) as compared to the good old face-to-face negotiations. The main research question is the impact that the type of negotiation media (face-to-face versus e-negotiation) has on the features of the negotiation process (duration and tactics) and on its outcomes. It also examines the moderation effects of the sequence of the negotiation media, i.e., face-to-face negotiation, when carried out prior to, or after e-negotiation. For this purpose, 80 young students were exposed to the two types of negotiations, whilst various intervening variables were controlled by randomization. It was found that the negotiation media, as well as the negotiation sequence, barely affects the negotiation outcomes. Face-to-face negotiation was not different than e-negotiation, in terms of the final price, the number of installments for the balance and the sum of the advanced payment. However, both the negotiation media and the negotiation sequence significantly affected the main features of the negotiation process, in terms of time duration and the use of hard or soft tactics. These results are discussed and interpreted in terms of existing theories.     

基于遗传算法求解TSP问题的一种算法

TSP问题是一个经典的NP难度的组合优化问题，遗传算法是求解TSP问题的有效方法之一。利用交换启发交叉算子实现局部搜索加快算法的收敛速度和利用变换变异算子维持群体的多样性防止算法早熟收敛，给出了一种求解TSP问题的遗传算法。仿真实验结果表明了该算法的有效性和可行性。     

Towards a web services and intelligent agents-based negotiation system for B2B eCommerce

With the explosive growth of the number of transactions conducted via electronic channels, there is a pressing need for the development of intelligent support tools to improve the degree and sophistication of automation for eCommerce. With reference to the BBT business model, negotiation is one of key steps for B2B eCommerce. Nevertheless, classical negotiation models are ineffective for supporting multi-agent multi-issue negotiations often encountered in eBusiness environment. The first contribution of this paper is the exploitation of Web services and intelligent agent techniques for the design and development of a distributed service discovery and negotiation system to streamline B2B eCommerce. In addition, an effective and efficient integrative negotiation mechanism is developed to conduct multi-party multi-issue negotiations for B2B eCommerce. Finally, an empirical study is conducted to evaluate our intelligent agents-based negotiation mechanism and to compare the negotiation performance of our software agents with that of their human counterparts. Our research work opens the door to the development of the next generation of intelligent system solutions to support B2B eCommerce.     

Compromising Adjustment Strategy Based on TKI Conflict Mode for Multi‐Times Bilateral Closed Negotiations

Bilateral multi‐issue closed negotiation is an important class for real‐life negotiations. Usually, negotiation problems have constraints such as a complex and unknown opponent's utility in real time, or time discounting. In the class of negotiation with some constraints, the effective automated negotiation agents can adjust their behavior depending on the characteristics of their opponents and negotiation scenarios. Recently, the attention of this study has focused on the interleaving learning with negotiation strategies from the past negotiation sessions. By analyzing the past negotiation sessions, agents can estimate the opponent's utility function based on exchanging bids. In this article, we propose a negotiation strategy that estimates the opponent's strategies based on the past negotiation sessions. Our agent tries to compromise to the estimated maximum utility of the opponent by the end of the negotiation. In addition, our agent can adjust the speed of compromise by judging the opponent's Thomas–Kilmann conflict mode and search for the Pareto frontier using past negotiation sessions. In the experiments, we demonstrate that the proposed agent has better outcomes and greater search technique for the Pareto frontier than existing agents in the linear and nonlinear utility functions.     

A formal framework for connective stability of highly decentralized cooperative negotiations

Multiagent cooperative negotiation is a promising technique for modeling and controlling complex systems. Effective and flexible cooperative negotiations are especially useful for open complex systems characterized by high decentralization (which implies a low amount of exchanged information) and by dynamic connection and disconnection of agents. Applications include ad hoc network management, vehicle formation, and physiological model combination. To obtain an effective control action, the stability of the negotiation, namely the guarantee that an agreement will be eventually reached, is of paramount importance. However, the techniques usually employed for assessing the stability of a negotiation can be hardly applied in open scenarios. In this paper, whose nature is mainly theoretical, we make a first attempt towards engineering stable cooperative negotiations proposing a framework for their analysis and design. Specifically, we present a formal protocol for cooperative negotiations between a number of agents and we propose a criterion for negotiation stability based on the concept of connective stability. This is a form of stability that accounts for the effects of structural changes on the composition of a system and that appears very suitable for multiagent cooperative negotiations. To show its possible uses, we apply our framework for connective stability to some negotiations taken from literature.     

Ws-AC: A Fine Grained Access Control System for Web Services

The emerging Web service technology has enabled the development of Internet-based applications that integrate distributed and heterogeneous systems and processes which are owned by different organizations. However, while Web services are rapidly becoming a fundamental paradigm for the development of complex Web applications, several security issues still need to be addressed. Among the various open issues concerning security, an important issue is represented by the development of suitable access control models, able to restrict access to Web services to authorized users. In this paper we present an innovative access control model for Web services. The model is characterized by a number of key features, including identity attributes and service negotiation capabilities. We formally define the protocol for carrying on negotiations, by specifying the types of message to be exchanged and their contents, based on which requestor and provider can reach an agreement about security requirements and services. We also discuss the architecture of the prototype we are currently implementing. As part of the architecture we propose a mechanism for mapping our policies onto the WS-Policy standard which provides a standardized grammar for expressing Web services policies.     

Efficient Management of Multi-Linked Negotiation Based on a Formalized Model

A Multi-linked negotiation problem occurs when an agent needs to negotiate with multiple other agents about different subjects (tasks, conflicts, or resource requirements), and the negotiation over one subject has influence on negotiations over other subjects. The solution of the multi-linked negotiations problem will become increasingly important for the next generation of advanced multi-agent systems. However, most current negotiation research looks only at a single negotiation and thus does not present techniques to manage and reason about multi-linked negotiations. In this paper, we first present a technique based on the use of a partial-order schedule and a measure of the schedule, called flexibility, which enables an agent to reason explicitly about the interactions among multiple negotiations. Next, we introduce a formalized model of the multi-linked negotiation problem. Based on this model, a heuristic search algorithm is developed for finding a near-optimal ordering of negotiation issues and their parameters. Using this algorithm, an agent can evaluate and compare different negotiation approaches and choose the best one. We show how an agent uses this technology to effectively manage interacting negotiation issues. Experimental work is presented which shows the efficiency of this approach.     

Strategic agents for multi-resource negotiation

In electronic commerce markets where selfish agents behave individually, agents often have to acquire multiple resources in order to accomplish a high level task with each resource acquisition requiring negotiations with multiple resource providers. Thus, it is crucial to efficiently coordinate these interrelated negotiations. This paper presents the design and implementation of agents that concurrently negotiate with other entities for acquiring multiple resources. Negotiation agents in this paper are designed to adjust (1) the number of tentative agreements for each resource and (2) the amount of concession they are willing to make in response to changing market conditions and negotiation situations. In our approach, agents utilize a time-dependent negotiation strategy in which the reserve price of each resource is dynamically determined by (1) the likelihood that negotiation will not be successfully completed (conflict probability), (2) the expected agreement price of the resource, and (3) the expected number of final agreements. The negotiation deadline of each resource is determined by its relative scarcity. Agents are permitted to decommit from agreements by paying a time-dependent penalty, and a buyer can make more than one tentative agreement for each resource. The maximum number of tentative agreements for each resource made by an agent is constrained by the market situation. Experimental results show that our negotiation strategy achieved significantly more utilities than simpler strategies.     

Service-oriented architecture for ontologies supporting multi-agent system negotiations in virtual enterprise

This paper offers a service-oriented architecture (SOA) for ontology-based multi-agent system (MAS) negotiations in the context of virtual enterprises (VEs). The objective of this paper is fourfold. First, it is to design a SOA which utilizes ontology and MAS to provide a distributed and interoperable environment for automated negotiations in VE. In this architecture, individual ontologies for both the VE initiator and its potential partners are constructed to describe and store resources and service knowledge. Second, a series of semantic ontology matching methods are developed to reach agents’ interoperability during the negotiation process. Third, correspondence-based extended contract net protocol is presented, which provides basic guidelines for agents’ reaching mutual understandings and service negotiation. Last, a fuzzy set theory based knowledge reuse approach is proposed to evaluate the current negotiation behaviors of the VE partners. A walkthrough example is presented to illustrate the methodologies and system architecture proposed in this paper.     

引入基因簇求解TSP的P2P遗传算法

应用遗传算法求解旅行商问题时,极易破坏已经发现的较短线路片段.为此,引入基因簇以便保护较短的线路片段,基于P2P设计了TSP求解遗传算法P2PTSPGA.在交叉和变异操作的过程中,基因簇完整地遗传到下一代;在获得第一个近优解后粉碎基因簇,以避免算法陷入局部最优.使用CHN144找到了当前最优路径,并使用TSPLIB进行了串行和并行试验.TSP225实验获得了最短环路路径3859,优于目前已经公布的结果3916.实验表明,P2PTSPGA具有较高的求解性能,并具备5000左右城市的持续寻优能力.     

Evolution of SOA Concepts in Telecommunications

The telecommunications industry has always been service-oriented. However, the convergence-driven need to deliver seamless services across different access networks has forced operators to embrace new approaches, including the intelligent network, Web-services-based APIs, and, most recently, the IP multimedia subsystem. Today, SOA is considered state of the art for service-delivery platforms. Such platforms for value-added services have evolved from the intelligent network (IN) and object-oriented programming interfaces to recent Web-services-based platforms. They've exploited the most recent information technologies to implement an open set of service components. Web 2.0's recent emergence, meanwhile, has further pressured telecom companies to implement an open service market based on an open set of enabling services and service components.     

Multistep interactive convergence: an efficient approach to thefault-tolerant clock synchronization of large multicomputers

We present a new approach for fault-tolerant internal clock synchronization in multicomputer systems employing not completely connected networks (NCCNs). The approach is referred to as multistep interactive convergence and is locally implemented in each multicomputer node by a time server process (TSP). We describe a specific algorithm that uses multistep interactive convergence and bases its operation on a logical mapping of the system's TSPs into an m-dimensional array. A TSP executes m steps per round of synchronization, with each step including a call to an interactive convergence procedure. For any TSP, clock readings in step i are gathered only from TSPs with which it shares a row along dimension i of the array. Hence, a TSP reads clocks only from a small subset of the TSPs in the system, which reduces the number of messages by orders of magnitude over a conventional interactive convergence algorithm in which reliable all-to-all broadcast of clock values is done. The algorithm can be used in systems of arbitrary topology and provides the added benefit of increased locality of communication in regular NCCNs such as hypercubes and tori. These advantages can be combined with a variety of message staggering mechanisms to maintain network contention at a minimum. We present expressions for the maximum clock skew, maximum clock drift, maximum clock discontinuity, and number of messages produced by the algorithm, and show that it tolerates arbitrary faults. A comparison with other algorithms that elucidates the advantages of multistep interactive convergence is also provided     

基于博弈分析的电子商务自动协商系统

为提高基于拍卖机制的电子商务自动协商系统效率，该文以非合作博弈论为基础提出了基于博弈分析的自动协商Agent模型及基于拍卖机制和博弈分析的自动投标协商算法，实现了一个基于拍卖机制和博弈分析的电子商务自动协商原型系统，并应用在一个企业敏捷供应链管理系统中实现自动协商交易。     

A price- and-time-slot-negotiation mechanism for Cloud service reservations

When making reservations for Cloud services, consumers and providers need to establish service-level agreements through negotiation. Whereas it is essential for both a consumer and a provider to reach an agreement on the price of a service and when to use the service, to date, there is little or no negotiation support for both price and time-slot negotiations (PTNs) for Cloud service reservations. This paper presents a multi-issue negotiation mechanism to facilitate the following: 1) PTNs between Cloud agents and 2) tradeoff between price and time-slot utilities. Unlike many existing negotiation mechanisms in which a negotiation agent can only make one proposal at a time, agents in this work are designed to concurrently make multiple proposals in a negotiation round that generate the same aggregated utility, differing only in terms of individual price and time-slot utilities. Another novelty of this work is formulating a novel time-slot utility function that characterizes preferences for different time slots. These ideas are implemented in an agent-based Cloud testbed. Using the testbed, experiments were carried out to compare this work with related approaches. Empirical results show that PTN agents reach faster agreements and achieve higher utilities than other related approaches. A case study was carried out to demonstrate the application of the PTN mechanism for pricing Cloud resources.