Using Expressive and Flexible Action Representations to Reason about Capabilties for Intelligent Agent Cooperation

Centre for Intelligent Systems and their ApplicationsThe aim of this thesis is to adress the problem of capability brokering. A capability-brokering agent recieves capability advertisements from problem-solving agents and problem descriptions from problem-holding agents. The amin task for the broker is to find problem-solving agents that have the capabilities to address problems described to the broker by a problem-holding agent. Capability brokering poses two problems: for advertisements, and matching problems and capabilities, to find capable problem-solvers. For the representation part of the problem, there have been a number of representations in AI that address similar issues. We review various logical representations, action representations, and representations for models of problem solving and conclude that, while all of these areas have some positive features for the representation of capabilities, they also all have serious drawbacks. We describe a new capability description language, CDL, which shares the positive features of previous languages while avoiding their drawbacks. CDL is a decoupled action representation into which arbitrary state representations can be plugged, resulting in the expressiveness and flexibility needed for capability brokering. Reasoning over capability descriptions takes place on two levels. The outer level deals with agent communication and we have devloped the Knowledge Query and Manipulation Language (KQML) here. At the inner level the main task is to decide whether a capability description subsumes a problem description. In CDL thee subsumtion relation for achievable objectives is defined in terms of the logical entailment relation betwenn sentences in the state language used within CDL. The definition of subsumption for performable tasks in turn is based on this definition for achievable objectives. We describe algoritms in this thesis which have all been implemented and incorporated into he Java Agent Template where they proved sufficient to operationalise anumber of example scenarios. The two most important featues of CDL are its expressiveness and its flexibility. By expressiveness we mean the ability to express more than is possible in other representations. By flexibility we mean the possibility to delay decisions regarding the compromises that have to be made to knowledge representation time. The scenarions we ahve implemted illustrate the importance of the features and we have shown in this thesis that CDL indeed possess thease features. Thus, CDL is an expressive and flexible capability description language that can be used to address the problem of capability brokering

Policy-based asset sharing in collaborative environments

Resource sharing is an important but complex problem to be solved. The problem is exacerbated in a dynamic coalition context, due to multi-partner constraints (imposed by security, privacy and general operational issues) placed on the resources. Take for example scenarios such as emergency response operations, corporate collaborative environments, or even short-lived opportunistic networks, where multi-party teams are formed, utilizing and sharing their own resources in order to support collective endeavors, which otherwise would be difficult, if not impossible, to achieve by a single party. Policy-Based Management Systems (PBMS) have been proposed as a suitable paradigm to reduce this complexity and provide a means for effective resource sharing. The overarching problem that this thesis deals with, is the development of PBMS techniques and technologies that will allow in a dynamic and transparent way, users that operate in collaborative environments to share their assets through high-level policies. To do so, it focuses on three sub-problems each one of which is related to a different aspect of a PBMS, making three key contributions. The first is a novel model, which proposes an alternative way for asset sharing, better fit than the traditional approaches when dealing with collaborative and dynamic environments. In order for all of the existing asset sharing approaches to comply with situational changes, an extra overhead is needed due to the fact that the decision making centre – and therefore, the policy making centre – is far away from where the changes take place unlike the event-driven approach proposed in this thesis. The second contribution is the proposal of an efficient, high-level policy conflict analysis mechanism, that provides a more transparent – in terms of user interaction – alternative way for maintaining unconflicted PBMS. Its discrete and sequential execution, breaks down the analysis process into discrete steps, making the conflict analysis more efficient compared to existing approaches, while eases human policy authors to track the whole process interfacing with it, in a near to natural language representation. The contribution of the third piece of research work is an interest-based policy negotiation mechanism, for enhancing asset sharing while promoting collaboration in coalition environments. The enabling technology for achieving the last two contributions (contribution 2 & 3) is a controlled natural language representation, which is used for defining a policy language. For evaluating the proposed ideas, in the first and third contributions we run simulation experiments while we simulate and also conduct formal analysis for the second one

Adaptation of multimodal outputs

Tese de mestrado em Engenharia Informática (Sistemas de Informação), apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2011Este documento centra-se em sistemas multimodais adaptativos mais especificamente nas suas técnicas de adaptação das saídas, ou seja, cisão de diferentes modalidades de saída de forma a permitir uma melhor adaptação ao utilizador. O primeiro capítulo faz uma pequena introdução às interfaces multimodais e as suas vantagens, tais como ao possibilitarem o uso de modalidades alternativas, e oferecerem aos seus utilizadores opções de interacção naturais. Ao recorrer a modalidades como a voz ou gestos, é possível ter uma interacção mais próxima daquilo a que as pessoas estão habituadas na sua interacção diária com outras pessoas. Este aspecto é ainda mais relevante quando o grupo de utilizadores alvo é composto por pessoas idosas, o que é o acontece no âmbito do projecto GUIDE, em que o trabalho relatado neste documento se insere. A motivação e os principais objectivos deste projecto estão descritos neste primeiro capítulo e passam por desenvolver uma framework para os programadores de software integrarem facilmente características de acessibilidade nas suas aplicações de TV. O foco deste projecto é a televisão e as suas mais recentes capacidades de processamento (Set-top boxes). Estas plataformas têm o potencial para se tornarem nos dispositivos de media mais usados devido à sua fácil aceitação e especialmente quando se trata de utilizadores idosos que podem ter à sua disposição aplicações de conferência audiovisual, controlo remoto da casa entre outras aplicações que têm como base simplificar a sua vida quotidiana e afastar da solidão, um problema muito presente nesta faixa etária. Os utilizadores podem assim empregar modalidades com que já estão familiarizados e optar por aquelas com que são mais eficazes. Utilizadores com limitações de audição podem optar por modalidades visuais, por exemplo. A adaptação envolve assim várias áreas do sistema humano como as capacidades físicas do utilizador, ou seja, a sua capacidade de movimentar os seus braços ou mãos, a sua percepção táctil, as limitações visuais tais como miopia, daltonismo ou visão em túnel, capacidades auditivas e também as cognitivas, ou seja, a capacidade de se concentrarem, perceberem o ambiente ao seu redor ou recordarem. As possíveis soluções face a estes problemas estão também descritas no documento. Esta flexibilidade proporcionada pelas interfaces multimodais, não significa que estes sistemas não necessitem de operações de selecção e configuração, de natureza técnica, que não é expectável que os utilizadores realizem devido à sua complexidade. De modo a conseguir realizar estas operações, o recurso a interfaces adaptativas é uma solução a considerar. Ainda neste capítulo é descrito o papel que a Faculdade de Ciências da Universidade de Lisboa desempenha neste projecto e mais especificamente as minhas responsabilidades e os meus objectivos definidos para este projecto. Ao longo do desenvolvimento deste projecto surgiram várias ideias, estudos e desenvolvimentos que culminaram na escrita de alguns artigos e também aplicações que estão descritas na secção de contribuições. Na seccão de planeamento é discutido o que estava inicialmente planeado e as alterações que surgiram. Com este projecto pretende-se encontrar um mecanismo de adaptação que seja capaz de melhorar o desempenho da cisão multimodal por diferentes saídas. O mecanismo de adaptacão de saídas multimodais é responsável por decidir qual a melhor estratégia para, primeiro, seleccionar as melhores modalidades para apresentar conteúdo (baseado no perfil do utilizador, as características do conteúdo e as modalidades disponíveis), segundo, distribuir o conteúdo pelas modalidades seleccionadas (usando estratégias de redundância e/ou complementaridade) e, terceiro, ajustar o conteúdo a cada modalidade. Para o estudo dessas mesmas estratégias a serem usadas foi realizado um trabalho de pesquisa a projectos relacionados com sistemas multimodais e consequentemente cisão multimodal (parte constituinte de uma arquitectura multimodal adaptativa). Descrito ao longo do segundo capítulo estão as arquitecturas usadas e técnicas de cisão e adaptação da informação apresentada. No terceiro capítulo são apresentados estudos realizados aos utilizadores alvo deste projecto, com o objectivo de conhecer e entender como estes interagem com um sistema capaz de oferecer diferentes modos de interacção e de apresentar conteúdo. Padrões de comportamentos, características e preferências dos utilizadores foram resgistadas de modo a encontrar uma correlação¸ ao e agrupá-las em diferentes perfis de utilizador. Para este efeito foi concebido uma aplicação multimodal que gera ecrãs a partir de um ficheiro XML de modo a facilmente se criar, modificar ou remover testes. Os utilizadores podiam interagir por gestos (apontando para o ecrã), usando um controlo remoto ou por voz, podendo combinar estas modalidades diferentes. O conteúdo era apresentado através de elementos visuais (texto, botões, imagens e vídeos), áudio (sintetizadores de voz) e recorrendo a um avatar. Esta aplicação regista o sucesso ou não na realização dos testes como também o percurso de interacção do utilizador em cada teste (a ordem em que os elementos foram selecionados e o tempo que demorou a realizar as tarefas). Os resultados e as conclusões retiradas deste estudo estão descritas no final do capítulo. Depois de definidos os perfis de utilizador concluiu-se que é necessário que o sistema GUIDE consiga ligar novos utilizadores a um perfil. Com essa finalidade foi desenvolvida uma aplicação que serve de inicialização ao sistema. Essa ferramenta, descrita no capítulo 4, introduz as capacidades de interaccão ao utilizador e de seguida apresenta diferentes tarefas de modo a avaliar as características e preferências do utilizador. Ao concluir as tarefas, a ferramenta é capaz de atribuir um perfil ao utilizador que mais se adequa ao mesmo. Sendo as características do perfil genéricas, o perfil vai sendo moldado e actualizado conforme o utilizador vai interagindo com o sistema GUIDE. O capítulo 5 começa por apresentar a arquitectura do sistema GUIDE e descreve todos os seus principais componentes. Neste capítulo é demonstrado como funciona o módulo de cisão multimodal começando por definir diferentes níveis de profundidade na adaptação das interfaces das aplicações e cujo nível é selecionado de acordo com as necessidades do utilizador. A cisão é responsável então por decidir em que modalidades apresentar o conteúdo da apresentação. Depois de atribuídas as modalidades a usar, a informação é enviada aos respectivos dispositivos de saídas para gerar a apresentação. A geração da apresentação é coordenada e gerida pelo módulo de cisão que está em constante comunicação com os dispositivos de saída de modo a garantir uma apresentação coerente. No fim do capítulo é descrito um protótipo do modulo de cisão onde tenta na prática realizar todo o processamento definido nas secções anteriores. Como forma de conclusão do documento são distinguidas as contribuições desta tese para o projecto bem como o trabalho futuro a realizar na continuação deste trabalho.This document main focus is on multimodal adaptive systems more specifically in its techniques for adjusting the outputs, i.e., split the information by different output modes to allow the best adaptation to the user. By using modalities such as voice or gestures, it is possible to have interaction closer to what people are used in their interaction with others. This is even more relevant when the target user group consists of elderly people, which is the case with the GUIDE project described in the document. This project aims to develop a framework for software developers to easily integrate accessibility features into their TV based applications. Users can thus use modalities that are more familiar and choose the ones that are most effective when interacting. Users with limited hearing can choose visual modes, for example. Adaptation involves so many areas of the human system as the physical capabilities of the user, i.e., its ability to move their arms or hands, their tactile sense, the visual limitations such as low vision, blindness or tunnel vision, hearing and cognitive capabilities, i.e., the ability to concentrate, remember or understand. Possible solutions that address these issues are also described in the document. This flexibility afforded by multimodal interfaces, does not mean that these systems do not require operations of selection and configuration of a technical nature, which is not expected that users perform due to its complexity. In order to accomplish these operations, the use of adaptive interfaces is a solution to consider. The aim of the work reported in this document is to find an adaptive mechanism that is capable of improving the performance of multimodal fission for different outputs. The mechanism of adaptation of multimodal outputs is responsible for deciding the best strategy to first select the best means to present content (based on user profile, the characteristics of content and modalities available) second, distribute the content by the modalities selected (using strategies for redundancy and / or complementarity) and third, adjust the contents of each modality. To perform the correct adaptation the system needs to know its users, thus user trials were carried out to understand their characteristics, behaviours and interaction patterns and to group different type of users into clusters. This document presents an application developed to assist in those trials. A prototype of an initialisation application to tutor users and match them with a user profile is also described on this document

Instantaneous multi-sensor task allocation in static and dynamic environments

A sensor network often consists of a large number of sensing devices of different types. Upon deployment in the field, these sensing devices form an ad hoc network using wireless links or cables to communicate with each other. Sensor networks are increasingly used to support emergency responders in the field usually requiring many sensing tasks to be supported at the same time. By a sensing task we mean any job that requires some amount of sensing resources to be accomplished such as localizing persons in need of help or detecting an event. Tasks might share the usage of a sensor, but more often compete to exclusively control it because of the limited number of sensors and overlapping needs with other tasks. Sensors are in fact scarce and in high demand. In such cases, it might not be possible to satisfy the requirements of all tasks using available sensors. Therefore, the fundamental question to answer is: “Which sensor should be allocated to which task?", which summarizes the Multi-Sensor Task Allocation (MSTA) problem. We focus on a particular MSTA instance where the environment does not provide enough information to plan for future allocations constraining us to perform instantaneous allocation. We look at this problem in both static setting, where all task requests from emergency responders arrive at once, and dynamic setting, where tasks arrive and depart over time. We provide novel solutions based on centralized and distributed approaches. We evaluate their performance using mainly simulations on randomly generated problem instances; moreover, for the dynamic setting, we consider also feasibility of deploying part of the distributed allocation system on user mobile devices. Our solutions scale well with different number of task requests and manage to improve the utility of the network, prioritizing the most important tasks.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Instantaneous multi-sensor task allocation in static and dynamic environments

A sensor network often consists of a large number of sensing devices of different types. Upon deployment in the field, these sensing devices form an ad hoc network using wireless links or cables to communicate with each other. Sensor networks are increasingly used to support emergency responders in the field usually requiring many sensing tasks to be supported at the same time. By a sensing task we mean any job that requires some amount of sensing resources to be accomplished such as localizing persons in need of help or detecting an event. Tasks might share the usage of a sensor, but more often compete to exclusively control it because of the limited number of sensors and overlapping needs with other tasks. Sensors are in fact scarce and in high demand. In such cases, it might not be possible to satisfy the requirements of all tasks using available sensors. Therefore, the fundamental question to answer is: “Which sensor should be allocated to which task?", which summarizes the Multi-Sensor Task Allocation (MSTA) problem. We focus on a particular MSTA instance where the environment does not provide enough information to plan for future allocations constraining us to perform instantaneous allocation. We look at this problem in both static setting, where all task requests from emergency responders arrive at once, and dynamic setting, where tasks arrive and depart over time. We provide novel solutions based on centralized and distributed approaches. We evaluate their performance using mainly simulations on randomly generated problem instances; moreover, for the dynamic setting, we consider also feasibility of deploying part of the distributed allocation system on user mobile devices. Our solutions scale well with different number of task requests and manage to improve the utility of the network, prioritizing the most important tasks

Proceedings der 11. Internationalen Tagung Wirtschaftsinformatik (WI2013) - Band 1

The two volumes represent the proceedings of the 11th International Conference on Wirtschaftsinformatik WI2013 (Business Information Systems). They include 118 papers from ten research tracks, a general track and the Student Consortium. The selection of all submissions was subject to a double blind procedure with three reviews for each paper and an overall acceptance rate of 25 percent. The WI2013 was organized at the University of Leipzig between February 27th and March 1st, 2013 and followed the main themes Innovation, Integration and Individualization.:Track 1: Individualization and Consumerization Track 2: Integrated Systems in Manufacturing Industries Track 3: Integrated Systems in Service Industries Track 4: Innovations and Business Models Track 5: Information and Knowledge ManagementDie zweibändigen Tagungsbände zur 11. Internationalen Tagung Wirtschaftsinformatik (WI2013) enthalten 118 Forschungsbeiträge aus zehn thematischen Tracks der Wirtschaftsinformatik, einem General Track sowie einem Student Consortium. Die Selektion der Artikel erfolgte nach einem Double-Blind-Verfahren mit jeweils drei Gutachten und führte zu einer Annahmequote von 25%. Die WI2013 hat vom 27.02. - 01.03.2013 unter den Leitthemen Innovation, Integration und Individualisierung an der Universität Leipzig stattgefunden.:Track 1: Individualization and Consumerization Track 2: Integrated Systems in Manufacturing Industries Track 3: Integrated Systems in Service Industries Track 4: Innovations and Business Models Track 5: Information and Knowledge Managemen

Rethinking the risk matrix

So far risk has been mostly defined as the expected value of a loss, mathematically PL (being P the probability of an adverse event and L the loss incurred as a consequence of the adverse event). The so called risk matrix follows from such definition. This definition of risk is justified in a long term “managerial” perspective, in which it is conceivable to distribute the effects of an adverse event on a large number of subjects or a large number of recurrences. In other words, this definition is mostly justified on frequentist terms. Moreover, according to this definition, in two extreme situations (high-probability/low-consequence and low-probability/high-consequence), the estimated risk is low. This logic is against the principles of sustainability and continuous improvement, which should impose instead both a continuous search for lower probabilities of adverse events (higher and higher reliability) and a continuous search for lower impact of adverse events (in accordance with the fail-safe principle). In this work a different definition of risk is proposed, which stems from the idea of safeguard: (1Risk)=(1P)(1L). According to this definition, the risk levels can be considered low only when both the probability of the adverse event and the loss are small. Such perspective, in which the calculation of safeguard is privileged to the calculation of risk, would possibly avoid exposing the Society to catastrophic consequences, sometimes due to wrong or oversimplified use of probabilistic models. Therefore, it can be seen as the citizen’s perspective to the definition of risk