Using fuzzy set approach in multi-attribute automated auctions

This paper designs a novel fuzzy attributes and competition based bidding strategy (FAC-Bid), in which the final best bid is calculated on the basis of the assessment of multiple attributes of the goods and the competition for the goods in the market. The assessment of attributes adapts the fuzzy sets technique to handle uncertainty of the bidding process. The bidding strategy also uses and determines competition in the market (based on the two factors i.e. no. of the bidders participating and the total time elapsed for an auction) using Mamdani's Direct Method. Then the final price of the best bid will be determined based on the assessed attributes and the competition in the market using fuzzy reasoning technique

Automated Service Negotiation Between Autonomous Computational Agents

PhDMulti-agent systems are a new computational approach for solving real world, dynamic and open system problems. Problems are conceptualized as a collection of decentralised autonomous agents that collaborate to reach the overall solution. Because of the agents autonomy, their limited rationality, and the distributed nature of most real world problems, the key issue in multi-agent system research is how to model interactions between agents. Negotiation models have emerged as suitable candidates to solve this interaction problem due to their decentralised nature, emphasis on mutual selection of an action, and the prevalence of negotiation in real social systems. The central problem addressed in this thesis is the design and engineering of a negotiation model for autonomous agents for sharing tasks and/or resources. To solve this problem a negotiation protocol and a set of deliberation mechanisms are presented which together coordinate the actions of a multiple agent system. In more detail, the negotiation protocol constrains the action selection problem solving of the agents through the use of normative rules of interaction. These rules temporally order, according to the agents' roles, communication utterances by specifying both who can say what, as well as when. Specifically, the presented protocol is a repeated, sequential model where offers are iteratively exchanged. Under this protocol, agents are assumed to be fully committed to their utterances and utterances are private between the two agents. The protocol is distributed, symmetric, supports bi and/or multi-agent negotiation as well as distributive and integrative negotiation. In addition to coordinating the agent interactions through normative rules, a set of mechanisms are presented that coordinate the deliberation process of the agents during the ongoing negotiation. Whereas the protocol normatively describes the orderings of actions, the mechanisms describe the possible set of agent strategies in using the protocol. These strategies are captured by a negotiation architecture that is composed of responsive and deliberative decision mechanisms. Decision making with the former mechanism is based on a linear combination of simple functions called tactics, which manipulate the utility of deals. The latter mechanisms are subdivided into trade-off and issue manipulation mechanisms. The trade-off mechanism generates offers that manipulate the value, rather than the overall utility, of the offer. The issue manipulation mechanism aims to increase the likelihood of an agreement by adding and removing issues into the negotiation set. When taken together, these mechanisms represent a continuum of possible decision making capabilities: ranging from behaviours that exhibit greater awareness of environmental resources and less to solution quality, to behaviours that attempt to acquire a given solution quality independently of the resource consumption. The protocol and mechanisms are empirically evaluated and have been applied to real world task distribution problems in the domains of business process management and telecommunication management. The main contribution and novelty of this research are: i) a domain independent computational model of negotiation that agents can use to support a wide variety of decision making strategies, ii) an empirical evaluation of the negotiation model for a given agent architecture in a number of different negotiation environments, and iii) the application of the developed model to a number of target domains. An increased strategy set is needed because the developed protocol is less restrictive and less constrained than the traditional ones, thus supporting development of strategic interaction models that belong more to open systems. Furthermore, because of the combination of the large number of environmental possibilities and the size of the set of possible strategies, the model has been empirically investigated to evaluate the success of strategies in different environments. These experiments have facilitated the development of general guidelines that can be used by designers interested in developing strategic negotiating agents. The developed model is grounded from the requirement considerations from both the business process management and telecommunication application domains. It has also been successfully applied to five other real world scenarios

Mobile-agent based multi-constraint one-to-many bilateral e-Negotiation framework

The thesis proposes a multi-constraint one-to-many bilateral e-Trade negotiation framework. It deploys mobile agents in negotiation, considers trading competition between vendors and search space, efficiently manages the risk of losing top utility offers that expire before the negotiation deadline, accurately evaluates offers, and truly maintains the security of negotiation data

Kasbah, an agent-based marketplace for buying and selling goods

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.Includes bibliographical references (leaves 85-86).by Anthony S. Chavez.M.Eng

Multi-Agent Systems

A multi-agent system (MAS) is a system composed of multiple interacting intelligent agents. Multi-agent systems can be used to solve problems which are difficult or impossible for an individual agent or monolithic system to solve. Agent systems are open and extensible systems that allow for the deployment of autonomous and proactive software components. Multi-agent systems have been brought up and used in several application domains

Multi-agent system for consumer-oriented electronic commerce

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.With the advent of the information superhighway and the exponential growth of the Internet usage, the importance of multi-agent systems is proliferating. The central theme of this thesis is to demonstrate the benefits of adopting multi-agent system (MAS) paradigm to implement consumer oriented electronic commerce system. The discipline of computational science is exploited to provide insights into the behaviour of a model of consumer behaviour that reflect the cognitive notion that the thesis has developed. For this, a multi-agent system computational environment is used to model and investigate the consumer purchase over the Internet. The MAS is developed based on a presented taxonomy, that is most relevant to the thesis application. The thesis also presents a novel approach to negotiation. Results of empirical evaluations provide a strong support that agents using the proposed approach would achieve higher payoff than human subjects. An empirical evaluation for the usability of the prototype system is also presented. Reported results are very encouraging to implement a fieldable system. To complement the perspective for a complete consumer-oriented EC system, the thesis addresses and develops approaches for searching and extracting relevant information. Example experiments are also reported to act as indicators for the effectiveness of the developed approaches

Adaptive learning in agents behaviour: a framework for electricity markets simulation

Electricity markets are complex environments with very particular characteristics. A critical issue regarding these specific characteristics concerns the constant changes they are subject to. This is a result of the electricity markets’ restructuring, which was performed so that the competitiveness could be increased, but it also had exponential implications in the increase of the complexity and unpredictability in those markets scope. The constant growth in markets unpredictability resulted in an amplified need for market intervenient entities in foreseeing market behaviour. The need for understanding the market mechanisms and how the involved players’ interaction affects the outcomes of the markets, contributed to the growth of usage of simulation tools. Multi-agent based software is particularly well fitted to analyze dynamic and adaptive systems with complex interactions among its constituents, such as electricity markets. This dissertation presents ALBidS – Adaptive Learning strategic Bidding System, a multiagent system created to provide decision support to market negotiating players. This system is integrated with the MASCEM electricity market simulator, so that its advantage in supporting a market player can be tested using cases based on real markets’ data. ALBidS considers several different methodologies based on very distinct approaches, to provide alternative suggestions of which are the best actions for the supported player to perform. The approach chosen as the players’ actual action is selected by the employment of reinforcement learning algorithms, which for each different situation, simulation circumstances and context, decides which proposed action is the one with higher possibility of achieving the most success. Some of the considered approaches are supported by a mechanism that creates profiles of competitor players. These profiles are built accordingly to their observed past actions and reactions when faced with specific situations, such as success and failure. The system’s context awareness and simulation circumstances analysis, both in terms of results performance and execution time adaptation, are complementary mechanisms, which endow ALBidS with further adaptation and learning capabilities.Os mercados de electricidade sofreram um processo de reestruturação que originou um aumento considerável da competitividade neste sector e, consequentemente, criou novos desafios na operação das entidades nele envolvidas. De forma a ultrapassar estes desafios é essencial para os profissionais uma compreensão detalhada dos princípios destes mercados e de como gerir os seus investimentos num ambiente tão dinâmico e competitivo. A crescente necessidade de entender estes mecanismos e a forma como a interacção das entidades envolvidas afecta os resultados destes mercados levou a uma grande procura de ferramentas de software, nomeadamente simulação, para analisar possíveis resultados de cada contexto de mercado para as várias entidades participantes. Os sistemas multi-agente são adequados à análise de sistemas dinâmicos e adaptativos com interacções complexas entre os seus constituintes, e portanto, várias ferramentas de modelação dirigidas para o estudo dos mercados reestruturados de electricidade usam este tipo de técnicas. Tirando partido destes simuladores, é possível estudar vários tipos de mercados e a interacção entre as entidades neles envolvidas. No entanto, todos estes simuladores apresentam lacunas no que diz respeito ao apoio à decisão a essas entidades, nomeadamente na gestão dos seus investimentos. Um aspecto tão relevante como é a utilização de todo este suporte de simulação para permitir aos agentes de mercado realmente aprenderem com a experiência de mercado e desenvolveram capacidades para analisar contextos de negociação e adaptar automaticamente os seus comportamentos estratégicos de acordo com as circunstâncias, não é considerado na amplitude que é requerida. É neste âmbito que esta dissertação contribui, utilizando técnicas de inteligência artificial para oferecer um apoio relevante e eficaz às decisões estratégicas das empresas envolvidas nestes tipos de negociação. O principal objectivo deste trabalho é dotar essas entidades de capacidades que lhes permitam apresentar comportamentos inteligentes e adaptativos na sua actuação nos mercados de electricidade de forma a serem capazes de atingir os seus objectivos da melhor forma possível, sendo capazes de reconhecer e actuar em conformidade com os contextos em que estão inseridas. De forma a atingir este objectivo, foi desenvolvido o sistema ALBidS – Adaptive Learning strategic Bidding System (sistema de aprendizagem adaptativa para licitações estratégias). Este sistema está implementado como um sistema multi-agente independente, em que cada agente é responsável pela execução de uma abordagem estratégica diferente. Este sistema está integrado com o simulador MASCEM, para que seja possível testar e validar as contribuições dadas num contexto de simulação de mercados já implementado e consolidado. Sendo este simulador uma ferramenta que simula mercados de electricidade permitindo a utilização de informação obtida a partir de mercados de electricidade reais, garante-se, assim, também que as conclusões retiradas deste trabalho são apoiadas por experimentação baseada em casos reais ou quase reais. A definição das estratégias de oferta dos agentes de mercado é baseada na aprendizagem adaptativa por parte das entidades, considerando o histórico do sistema, através da informação disponível, incluindo informação recolhida durante a utilização do próprio sistema multi-agente. Para isso são propostos e testados vários algoritmos e metodologias de aprendizagem e análise de dados, para que conjuntamente contribuam para que os agentes possam tomar as melhores decisões em cada momento de acordo com o contexto identificado. Um contributo importante do trabalho está na proposta destes algoritmos, na sua combinação e na obtenção de conhecimento relativo à utilização criteriosa dos algoritmos considerados em função do contexto, utilizando o conceito de context awareness. A análise destes contextos é efectuada por um mecanismo desenvolvido para esse efeito, analisando as características específicas de cada dia e período de negociação. São estudados e analisados vários algoritmos baseados em abordagens diversas, para que seja possível contemplar formas distintas de resolver problemas, dependendo de circunstâncias concretas. Entre estas abordagens, podem referir-se: redes neuronais artificiais dinâmicas; teoria de jogos; médias/regressões lineares; abordagens económicas, tendo em conta a análise macroeconómica e sectorial, e também a análise interna das empresas no que diz respeito aos seus investimentos e perspectivas de crescimento; algoritmos de Inteligência Artificial (IA), como os algoritmos Roth-Erev e o Q-Learning de aprendizagem por reforço; uma abordagem baseada na teoria do determinismo, em que são analisadas todas as variáveis intervenientes na obtenção dos resultados pelo simulador; e outras propostas de algoritmos de aprendizagem e análise de dados específicos para determinadas situações, bem como a combinação de algoritmos de tipos diversos. Numa camada superior aos algoritmos mencionados foi implementado um mecanismo de aprendizagem por reforço, baseado em estatísticas e em probabilidades, que é responsável por escolher em cada altura a proposta de licitação que dá mais garantias de sucesso. Com o passar do tempo, vão sendo actualizadas as estatísticas, através da análise dos resultados de cada proposta. Este mecanismo permite que em cada momento sejam escolhidos os algoritmos que estão a ter os melhores resultados para cada situação e contexto. Ao serem considerados vários algoritmos, de naturezas completamente distintas, consegue-se uma maior probabilidade de haver sempre algum a oferecer bons resultados. Existe também a possibilidade de se definir as preferências e parametrizações relativas a cada algoritmo individualmente, e também de se definirem preferências relativas ao desempenho dos algoritmos no que diz respeito à eficiência computacional, permitindo que o utilizador escolha a relação eficiência/probabilidade de sucesso, de acordo com as suas preferências. O sistema excluirá então, automaticamente, os algoritmos que usualmente requerem um maior tempo de processamento, quando esse tempo não corresponde a soluções proporcionalmente melhores. Desta forma, garante-se que o sistema estará a utilizar o seu tempo de processamento em abordagens que oferecem melhores respostas no menor tempo possível. Como apoio ao funcionamento adequado das estratégias implementadas foi criado um mecanismo de definição de perfis dos agentes competidores. Desta forma é possível obter previsões acerca das acções esperadas dos outros agentes participantes no mercado, tendo em conta as suas acções passadas e as reacções verificadas quando confrontados com situações específicas, como o sucesso ou o falhanço

The First 25 Years of the Bled eConference: Themes and Impacts

The Bled eConference is the longest-running themed conference associated with the Information Systems discipline. The focus throughout its first quarter-century has been the application of electronic tools, migrating progressively from Electronic Data Interchange (EDI) via Inter-Organisational Systems (IOS) and eCommerce to encompass all aspects of the use of networking facilities in industry and government, and more recently by individuals, groups and society as a whole. This paper reports on an examination of the conference titles and of the titles and abstracts of the 773 refereed papers published in the Proceedings since 1995. This identified a long and strong focus on categories of electronic business and corporate perspectives, which has broadened in recent years to encompass the democratic, the social and the personal. The conference\u27s extend well beyond the papers and their thousands of citations and tens of thousands of downloads. Other impacts have included innovative forms of support for the development of large numbers of graduate students, and the many international research collaborations that have been conceived and developed in a beautiful lake-side setting in Slovenia

Rationality Concepts in Environmental Valuation

Survey based valuation techniques like the Contingent Valuation Method (CVM) rely particularly on the premise of respondents’ rationality when answering willingness to pay (WTP) questions. Results of CVM surveys have repeatedly put this fundamental assumption into question. This study adopts a more realistic view of rationality accounting for respondents’ limited capacities to process information. Based on cognitive psychology a technique to detect and analyze the bounds of rationality inherent in WTP statements is developed. Using an empirical example, the influence of bounded rationality on the validity of CVM results is analyzed. It is shown that individual differences in information processing play a major role. From these results recommendations for future survey design are developed