12 research outputs found

    Electronic institution : an e-contracting platform for virtual organization

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    Automated tools that assist contract drafting are mostly focused on the representation of contract documents. Multi-agent systems have been ap-plied in the e-business domain, namely for information discovery and contract negotiation. Work on contract monitoring and enforcement is less explored. In this paper we start from these two observations to expose our efforts towards the development of tools that enable the computational representation of con-tracts and furthermore their monitoring and enforcement. We are mostly inter-ested in Virtual Organization settings, where groups of agents representing dif-ferent business entities form consortiums that must be regulated by appropriate norms. We are pursuing the concept of an Electronic Institution as a platform providing a normative environment and a set of e-contracting related services. Within this environment, contracts are represented through norms. We intend to test the applicability of our approach through illustration with case-studies and comparison with other contract representation formalisms

    A contract model for electronic institutions

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    Electronic institutions are software frameworks integrating normative environments where agents interact to create mutual commitments. Contracts are formalizations of business commitments among a group of agents, and comprise a set of applicable norms. An electronic institution acts as a trusted third-party that monitors contract compliance, by integrating in its normative environment the contractual norms, which are applicable to the set of contractual partners. In this paper we present and explore a contract model that facilitates contract establishment by taking advantage of an institutional normative background. Furthermore, the model is flexible enough to enable the expansion of the underlying normative framework, making it applicable to a wide range of contracting situations

    Monitoring Multi-Party Contracts for E-Business.

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    "Monitoring Multi-party Contracts for E-business" investigates the issues involved in the performance of econtract monitoring of business automations in business to business e-commerce environment. A pro-active monitoring contract model and monitoring mechanism have been designed and developed. A new architecture and framework is proposed for pro-active monitorable contracts. This pro-active monitoring contract model is supported by a prototype

    Coalition based approach for shop floor agility – a multiagent approach

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    Dissertation submitted for a PhD degree in Electrical Engineering, speciality of Robotics and Integrated Manufacturing from the Universidade Nova de Lisboa, Faculdade de CiĂȘncias e TecnologiaThis thesis addresses the problem of shop floor agility. In order to cope with the disturbances and uncertainties that characterise the current business scenarios faced by manufacturing companies, the capability of their shop floors needs to be improved quickly, such that these shop floors may be adapted, changed or become easily modifiable (shop floor reengineering). One of the critical elements in any shop floor reengineering process is the way the control/supervision architecture is changed or modified to accommodate for the new processes and equipment. This thesis, therefore, proposes an architecture to support the fast adaptation or changes in the control/supervision architecture. This architecture postulates that manufacturing systems are no more than compositions of modularised manufacturing components whose interactions when aggregated are governed by contractual mechanisms that favour configuration over reprogramming. A multiagent based reference architecture called Coalition Based Approach for Shop floor Agility – CoBASA, was created to support fast adaptation and changes of shop floor control architectures with minimal effort. The coalitions are composed of agentified manufacturing components (modules), whose relationships within the coalitions are governed by contracts that are configured whenever a coalition is established. Creating and changing a coalition do not involve programming effort because it only requires changes to the contract that regulates it

    A toolkit for model checking of electronic contracts

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    PhD ThesisIn the business world, contracts are used to regulate business interactions between trading parties. In this context, an electronic contracting systems can be used to monitor business–to–business interactions to ensure that they comply with the rights (permissions), obligations and prohibitions stipulated in contract clauses. Such an electronic contracting system will require an executable version of the contract (e-contract) for compliance checking. It is important to be verify the correctness properties of an e- contract before deploying it for compliance checking. Model checkers are widely used for automatic verification of concurrent systems. However, such tools for e-contracts with means for expressing directly and intu- itively key concepts that appear recurrently in contracts, such as execu- tions of business operations, granting (cancellation, suspension, fulfilment, violation, etc.) of rights, obligations and prohibitions to role players are not yet available. This thesis rectifies the situation by developing a high-level e-contract verification toolkit using the Spin model checker. A formal Contractual Business-To-Business interaction (CB2B) model based on the concepts of contract compliance checking developed earlier at Newcastle university has been constructed. Further, Promela, the input language of the Spin model checker, has been extended in a manner that enables specification of contract clauses in terms of contract entities: role players, business operations, rights, obligations and prohibitions. A given contract can now be expressed using extended Promela as a set of declarations and a set of Event-Condition-Action rules. In addition, the designer can specify the correctness requirements to be verified in Linear-Temporal-Logic directly in terms of the contract entities. A notable feature is that the CB2B model automatically checks for contract independent properties: properties that must hold for all contracts. For example, at run time, a contract should not simultaneously grant a role player a right to perform an operation and also prohibit it. Thus, the toolkit hides much of the intricate details of dealing with Promela processes communicating through channels and enables a designer to build verifiable abstract models directly in terms of contract entities. The usefulness of the toolkit is demonstrated by trying out a number of contract examples used by researchers working on contract verification. The thesis also shows how the toolkit can be used for generating test cases for testing an implemented system

    ICTs in medium-sized farms in developing countries: a case study in Mexico: conventional banana and organic rice cultivation

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    This research examines how farmers working medium-sized farms in Mexico have adopted and enacted Information and Communication Technologies (ICT), and how these ICTs have impacted work practices. The effects of ICTs on farmers’ economic relations are explored from a business process perspective using a framework that combines Transaction Cost (TCT) and Social Embeddedness theories. A single case study in Mexico with two embedded units of analysis from different crop sectors, a cluster of banana producers from Tabasco and an organic rice grower from Campeche, provide an in-depth understanding of the adoption of ICTs and their impact. We examine issues of learning and co-operation, and how ICTs have affected production and distribution and the positioning of farmers in the context of their work practices and economic relations. The thesis discusses the ICTs used in the business process cycle of farming and their impact on business development and economic exchange. The research elaborates on and confirms the existence of network forms of organisation that operate in the farmers’ communities and analyses their social embeddedness. The findings show that information technologies bring improvements to the agricultural business process, facilitating not only the collection, collation and analysis of data to support informed decisions, but also innovative farming and business practices through learning and co-operation. We find that ICTs complement and support social relationships, both preexisting (traditional community connections and business links) and novel (virtual contacts and social media) to stimulate business development. The significance of social context is corroborated and should help inform development policy

    Le contrÎle d'accÚs des réseaux et grandes infrastructures critiques distribuées

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    La stabilitĂ© et le dĂ©veloppement des nations dĂ©pendent grandement de leurs Infrastructures Critiques (IC). Vu leur importance, de nombreuses menaces guettent leurs systĂšmes d’information - aussi appelĂ©s Infrastructures d’Information Critiques (IIC) -, parmi elles: les atteintes Ă  l’intĂ©gritĂ© de leurs donnĂ©es et processus informatisĂ©s ainsi que les abus pouvant survenir au cours des collaborations avec d’autres parties. L’intĂ©gritĂ© d’une information, qui est sa propriĂ©tĂ© de ne pas ĂȘtre altĂ©rĂ©e, est primordiale pour les IIC puisqu’elles manipulent et gĂ©nĂšrent des informations devant nĂ©cessairement ĂȘtre correctes et fiables. Dans un contexte de mondialisation et d’ouverture, les IC ne peuvent Ă©voluer sans collaborer avec leur environnement. Toutefois, cela n’est pas sans risques puisque les ressources qu’elles engagent peuvent faire l’objet de corruptions et de sabotages. Tentant de rĂ©duire les risques de corruptions pouvant Ă©maner de l’intĂ©rieur comme de l’extĂ©rieur, nous avons ƓuvrĂ© Ă  l’amĂ©lioration du mĂ©canisme de contrĂŽle d’accĂšs. Incontournable, il vise Ă  limiter les actions auxquelles peuvent prĂ©tendre les utilisateurs lĂ©gitimes du systĂšme, conformĂ©ment Ă  la politique de sĂ©curitĂ© de l’organisation. La pertinence et la finesse de cette derniĂšre impacte grandement l’efficacitĂ© du mĂ©canisme. Ainsi, les modĂšles de contrĂŽle d’accĂšs sont utilisĂ©s pour faciliter l’expression et l’administration desdites politiques. OrBAC est un modĂšle riche et dynamique, satisfaisant plusieurs besoins des IIC, en revanche il reste limitĂ© quant Ă  la prise en charge de l’intĂ©gritĂ©, aussi bien en contexte localisĂ© que distribuĂ©. Ainsi, nous avons proposĂ© une extension d’OrBAC pour les environnements localisĂ©s, Integrity-OrBAC (I-OrBAC), qui tient compte de contraintes rĂ©elles liĂ©es Ă  l’intĂ©gritĂ© pour statuer sur les requĂȘtes d’accĂšs. I-OrBAC intĂšgre des paramĂštres issus de l’application de mĂ©thodes d’analyse de risques pour reflĂ©ter les besoins des ressources passives et apprĂ©cier, Ă  leur juste valeur, les habilitations des sujets. Cela nous a orientĂ©s vers une modĂ©lisation en multi-niveaux d’intĂ©gritĂ© qui favorisera la priorisation des biens sensibles, comme la stipule les programmes de protection des IC. Dans I-OrBAC, les niveaux d’intĂ©gritĂ© servent aussi bien Ă  contraindre l’attribution des privilĂšges qu’à la rendre plus flexible : ces niveaux restreignent les accĂšs pour garantir que seuls les utilisateurs chevronnĂ©s accĂšdent aux ressources sensibles, mais permettent aussi aux sujets de diffĂ©rents rĂŽles de rĂ©aliser une mĂȘme tĂąche, Ă©tant bien sĂ»r assujettis Ă  des niveaux seuils diffĂ©rents. Pour rendre I-OrBAC proactif - non limitĂ© Ă  statuer uniquement sur les requĂȘtes d’accĂšs - nous avons proposĂ© un algorithme qui vise Ă  dĂ©terminer le sujet le plus adĂ©quat, parmi les rĂŽles prioritaires, pour la rĂ©alisation d’une tĂąche sans attendre que les sujets n’en fassent la requĂȘte. L’algorithme est dĂ©crit par un systĂšme d’infĂ©rence pour faciliter sa comprĂ©hension tout en favorisant la conduite de raisonnements logiques et la dĂ©rivation de conclusions. Nous avons proposĂ© une implĂ©mentation de notre modĂšle dans le cadre d’une Ă©tude de cas tirĂ©e du projet europĂ©en FP7 CRUTIAL relatif aux rĂ©seaux de transport et de distribution d’électricitĂ©. Finalement, pour pallier les problĂšmes issus des collaborations, nous avons fait appel aux contrats Ă©lectroniques pour Ă©tendre I-OrBAC aux environnements distribuĂ©s - l’extension Distributed IOrBAC (DI-OrBAC). Ces pactes servent non seulement Ă  dĂ©finir le contexte, les clauses ainsi que les activitĂ©s Ă  rĂ©aliser mais aussi Ă  prĂ©venir l’occurrence de litiges et Ă  les rĂ©soudre. Toutefois, nous avons dĂ» concevoir des mĂ©canismes adaptĂ©s Ă  notre modĂšle I-OrBAC pour leur nĂ©gociation et leur application
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