An ownership-base message admission control mechanism for curbing spam

Unsolicited e-mail has brought much annoyance to users, thus, making e-mail less reliable as a communication tool. This has happened because current email architecture has key limitations. For instance, while it allows senders to send as many messages as they want, it does not provide adequate capability to recipients to prevent unrestricted access to their mailbox. This research develops a new approach to equip recipients with ability to control access to their mailbox.This thesis builds an ownership-based approach to control mailbox usage employing the CyberOrgs model. CyberOrgs is a model that provides facilities to control resources in multi-agent systems. We consider a mailbox to be a precious resource of its owner. Any access to the resource requires its owner's permission. Thus, we give recipients a capability to manage their valuable resource - mailbox. In our approach, message senders obtain a permission to send messages through negotiation. In this negotiation, a sender makes a proposal and the intended recipient evaluates the proposal according to their own policies. A sender's desired outcome of a negotiation is a contract, which conducts the subsequent communication between the sender and the recipient. Contracts help senders and recipients construct a long-term relationship.Besides allowing individuals to control their mailbox, we consider groups, which represent organizations in human society, in order to allow organizations to manage their resources including mailboxes, message sending allowances, and contracts.A prototype based on our approach is implemented. In the prototype, policies are separated from the mechanisms. Examples of policies are presented and a public policy interface is exposed to allow programmers to develop custom policies. Experimental results demonstrate that the system performance is policy-dependent. In other words, as long as policies are carefully designed, communication involving negotiation has minimal overhead compared to communication in which senders deliver messages to recipients directly

Automatic negotiation of multi-party contracts in agricultural supply chain

Orientador: Edmundo Roberto Mauro MadeiraTese (doutorado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: Uma cadeia produtiva agropecuária 'e constituída por diversos tipos de atores que estabelecem uma rede de relacionamentos bastante complexa. Estes relacionamentos variam de ad hoc e de curta duração até altamente estruturado e de longa duração. As cadeias produtivas agropecuárias possuem algumas particularidades, tais como, regulamentação estrita e dependência cultural, e possuem relevância social e econômica. A utilização de contratos 'e a forma natural para expressar os relacionamentos entre os membros de uma cadeia. Desta forma, contratos e a atividade de negociá-los são de grande importância numa cadeia produtiva. Esta tese propõe um modelo para cadeias produtivas agropecuárias que integra suas principais características, incluindo seus aspectos estruturais e sua dinâmica. Em particular, a tese propõe um formato para contratos multi-laterais e um protocolo de negociação que os constrói. Contratos multi-laterais são importantes neste contexto, pois vários atores de uma cadeia produtiva podem construir alianças que compreendem direitos e obrigações mútuos. Um conjunto de contratos bi-laterais não 'e adequado para tal propósito. A tese também apresenta uma implementação do protocolo de negócio baseado em serviços Web e numa máquina de workflow (YAWL)Abstract: An agricultural supply chain comprises several kinds of actors that establish a complex net of relationships. These relationships may range from ad hoc and short lasting ones to highly structured and long lasting. This kind of chain has a few particularities like strict regulations and cultural influences, and presents a quite relevant economical and social importance. Contracts are the natural way of expressing relationships among members of a chain. Thus, the contracts and the activity of negotiating them are of major importance within a supply chain. This thesis proposes a model for agricultural supply chains that integrates seamlessly their main features, including their structure and their dynamics. Specifically, the thesis proposes a multi-party contract format and a negotiation protocol that builds such kind of contracts. Multi-party contracts are important in this context because several actors of a supply chain may build alliances comprising mutual rights and obligations. A set of bilateral contracts is not well-fitted for such a purpose. The thesis also presents an implementation of the negotiation protocol that builds on Web services and a workflow engine (YAWL)DoutoradoSistemas de ComputaçãoDoutor em Ciência da Computaçã

Multi Agent Coordination for Demand Management with Energy Generation and Storage

In this paper, we focus on demand side management in consumer collectives with community owned renewable energy generation and storage facilities for effective integration of renewable energy with the existing fossil fuelbased power supply system. The collective buys energy as a group through a central coordinator who also decides about the storage and usage of renewable energy. produced by the collective. Our objective is to design coordination algorithms to minimize the cost of electricity consumption of the consumer collective while allowing the consumers to make their own consumption decisions based on their private consumption constraints and preferences. Minimizing the cost is not only of interest to the consumers but is also socially desirable because it reduces the consumption at times of peak demand (since differential pricing mechanisms like time-of-use pricing is usually used by electricity companies to discourage consumption at times of peak demand). We develop an iterative coordination algorithm in which the coordinator makes the storage decision and shapes the demands of the consumers by designing a virtual price signal for the agents. We prove that our algorithm converges, and it achieves the optimal solution under realistic conditions We also present simulation results based on real world consumption data to quantify the performance of our algorithm

Climate change in game theory

The study provides an overview of the application possibilities of game theory to climate change. The characteristics of games are adapted to the topics of climate and carbon. The importance of uncertainty, probability, marginal value of adaptation, common pool resources, etc. are tailored to the context of international relations and the challenge of global warming

Climate change in game theory context

The aim of this paper is to survey the game theory modelling of the behaviour of global players in mitigation and adaptation related to climate change. Three main fields are applied for the specific aspects of temperature rise: behaviour games, CPR problem and negotiation games. The game theory instruments are useful in analyzing strategies in uncertain circumstances, such as the occurrence and impacts of climate change. To analyze the international players’ relations, actions, attitude toward carbon emission, negotiation power and motives, several games are applied for the climate change in this paper. The solution is surveyed, too, for externality problem

Using the event calculus for tracking the normative state of contracts

In this work, we have been principally concerned with the representation of contracts so that their normative state may be tracked in an automated fashion over their deployment lifetime. The normative state of a contract, at a particular time, is the aggregation of instances of normative relations that hold between contract parties at that time, plus the current values of contract variables. The effects of contract events on the normative state of a contract are specified using an XML formalisation of the Event Calculus, called ecXML. We use an example mail service agreement from the domain of web services to ground the discussion of our work. We give a characterisation of the agreement according to the normative concepts of: obligation, power and permission, and show how the ecXML representation may be used to track the state of the agreement, according to a narrative of contract events. We also give a description of a state tracking architecture, and a contract deployment tool, both of which have been implemented in the course of our work.

Advances in Negotiation Theory: Bargaining, Coalitions and Fairness

Bargaining is ubiquitous in real-life. It is a major dimension of political and business activities. It appears at the international level, when governments negotiate on matters ranging from economic issues (such as the removal of trade barriers), to global security (such as fighting against terrorism) to environmental and related issues (e.g. climate change control). What factors determine the outcome of negotiations such as those mentioned above? What strategies can help reach an agreement? How should the parties involved divide the gains from cooperation? With whom will one make alliances? This paper addresses these questions by focusing on a non-cooperative approach to negotiations, which is particularly relevant for the study of international negotiations. By reviewing non-cooperative bargaining theory, non-cooperative coalition theory, and the theory of fair division, this paper will try to identify the connection among these different facets of the same problem in an attempt to facilitate the progress towards a unified framework.Negotiation theory, Bargaining, Coalitions, Fairness, Agreements

A Two-sided Matching System Design for Dynamic Labor Markets

This thesis designs an automatic two-sided matching system for dynamic labor markets with large scale of data. Such markets consist of a group of vacancies and applicants, a matching function, a set of events causing transitions of the state of the market. Due to the dynamic nature of the labor markets, matching systems based on the classical deferred acceptance algorithm are not sufficient for producing stable matching solutions. Therefore, the central theme of this thesis is to address the effectiveness and efficiency of generating matching results in dynamic large labor markets. The main contribution of this thesis consists of three dynamic matching algorithms and a agent-based matching system design. The dynamic matching algorithms are extensions of the classical deferred acceptance algorithm. The first algorithm generates a vacancyoptimal stable matching result without considering locking or break-up constrains. The second algorithm considers locking period constraints in the matching process and the third algorithm computes applicant-optimal stable matchings with the consideration of break-up penalties in dynamic environments. To verify the effectiveness and efficiency of the proposed matching algorithms, theoretical proofs and experimental results are presented as well. The results indicate that the designed system can be used as an efficient and effective tool for recruitment management in today’s dynamic and internet based labor markets to reduce administrative work load of human resource departments and produce stable job allocations. ii

A theoretical and computational basis for CATNETS

The main content of this report is the identification and definition of market mechanisms for Application Layer Networks (ALNs). On basis of the structured Market Engineering process, the work comprises the identification of requirements which adequate market mechanisms for ALNs have to fulfill. Subsequently, two mechanisms for each, the centralized and the decentralized case are described in this document. These build the theoretical foundation for the work within the following two years of the CATNETS project. --Grid Computing