8 research outputs found

    Applying COAALAS to SPiDer

    Get PDF
    Artificial Intelligence techniques and tools have been applied to Assistive Technologies (AT) in order to support elder or impeded people on their daily activities. A common application are intelligent pill dispensers and reminders that help the patient comply with his medication. This has become even more important, as patients suffering from multiple pathologies are prescribed cocktails of drugs that require strict compliance in order to achieve a successful treatment. Existing intelligent pill dispensers tend to focus in the user-tool interaction, neglecting user’s connection with its social environment and the possibility to monitor patient’s behaviour, effectively adapting to a dynamic environment and providing early response to potentially dangerous situations by detecting unexpected or undesired patterns of behaviour. In previous work we have presented COAALAS, an intelligent social and norm-aware device for elder people that is able to autonomously organize, reorganize and interact with the different actors involved in elder-care, either human actors or other devices. In this paper, we present SPiDer an intelligent pill dispenser integrated with the COAALAS architecture.Peer ReviewedPostprint (author's final draft

    Situated agents and humans in social interaction for elderly healthcare: the case of COAALAS

    Get PDF
    Assistive Technologies (AT) are an application area where several Artificial Intelligence techniques and tools have been successfully applied to support elder or impeded people on their daily activities. However, approaches to AT tend to center in the user-tool interaction, neglecting the user's connection with its social environment (such as care-takers, relatives and health professionals) and the possibility to monitor undesired behaviour providing both adaptation to a dynamic environment and early response to potentially dangerous situations. In previous work we have presented Coaalas, an intelligent social and norm-aware device for elder people that is able to autonomously organize, reorganize and interact with the different actors involved in elder-care, either human actors or other devices. In this paper we put our work into context, by first examining what are the desirable properties of such a system, analysing the state of the art on the relevant topics, and verifying the validity of our proposal.Postprint (author’s final draft

    NoMoDEI : A framework for Norm Monitoring on Dynamic Electronic Institutions

    Get PDF
    With the growth of the Internet, computational systems have become more and more complex, often including complicate interconnected networks of autonomous components. The need to bring some organisational structure into autonomous systems becomes urgent, as this allows regulating the behaviour of the different autonomous components to ensure their objectives are aligned with the holistic objectives of the system. Normative Systems are one of the mechanisms that can be applied to define and enforce acceptable behaviour within distributed electronic systems which should comply with some (human) regulations. One of the requirements to effectively implement Normative Systems is to be able to assess, at runtime, the state of the normative environment. Existing lines of research have already tried to tackle this issue on some simple scenarios. However, more complex scenarios may appear, for instance, scenarios where the normative context is not static, but it expands and contracts as new norms are added to the institution and removed from it respectively. As in human legal systems, it is easy to foresee that some of these electronic normative environments will not be static. They should be able to evolve through time as regulations change, effectively adapting to new situations and behaviours. Under these conditions, a monitoring system must be able to continue computing the state of the normative environment at runtime, as often we can not afford to perform the changes on the normative context off-line. Furthermore, it must be guaranteed the monitoring system can keep producing states of the normative environment that are consistent with the changes performed on the normative context. For instance, if a norm has been removed from the normative context, it does not make sense anymore to compute normative states where the norm has been violated. In this thesis we present NoMoDEI, a normative monitoring framework for dynamic Electronic Institutions. We formalize and develop an extended normative framework and architecture to cope with scenarios where the normative context is dynamic, therefore norms can be added, removed and updated. The operations are to be performed at run-time, without having to stop computing the normative state. The normative states computed are consistent with the expansion and contraction operations. NoMoDEI is introduced in three steps. First, we formally define the operations to be supported in order to allow for expanding and contracting the normative context. Then, we instantiate the formal operations, providing implementation details. Finally, we demonstrate our framework by applying it to two use cases: E-health systems and waste-water management on a river basin.Amb l'expansió d'Internet els sistemes computacionals han esdevingut més complexos, sovint incorporant complicades xarxes interconnectades de components autònoms. Es per això que la necessitat d'incorporar estructures organitzacionals en el sistemes autònoms s 'accentua, donat que aquestes estructures permeten regular el comportament dels diferents components autònoms, tot assegurant que els seus objectius es troben alineats amb els objectius generals del sistema. Els Sistemes Normatius (i.e. Normative Systems) són un dels mecanismes que podem aplicar per definir i imposar patrons acceptables de comportament dintre de sistemes electrònics distribuïts. Això esdevé especialment important quan el sistema es troba regimentat per regulacions (normalment humanes). Un dels requeriments per implementar Sistemes Normatius és ser capaços de determinar, en temps d'execució, l'estat de l'entorn normatiu. Existeixen línies de recerca que ja han tractat aquest problema en alguns escenaris simples. El món real però ens ofereix escenaris més complexes, com per exemple, escenaris on el context normatiu no és estàtic, si no que s'expandeix i contrau a mesura que noves normes són afegides o eliminades de la institució. Tal com passa als sistemes legals humans, és fàcil preveure que alguns contextos normatius electrònics no seran estàtics. Aquests contextos haurien de ser capaços d'evolucionar a través del temps a mesura que les regulacions canvien, adaptant-se a noves situacions i comportaments. Sota aquestes condicions, un sistema de monitorització ha de ser capaç de continuar calculant l'estat de l'entorn normatiu en temps d'execució, ja que sovint no ens podem permetre realitzar els canvis a l'entorn normatiu aturant el procés de monitorització. És més s'ha de garantir que el sistema de monitorització sigui capaç de continuar produint es tats de l’entorn normatiu de forma consistent amb els canvis realitzats. Per exemple, el fet d'eliminar una norma fa que no tingui gaire sentit continuar calculant es tats normatius on aquesta norma ha es tat violada. A aquesta Tesi presentem NoMoDEI, una infraestructura de monitorització normativa per institucions electròniques dinàmiques. Formalitzem i desenvolupem una infraestructura de monitorització normativa estesa capaç d'operar en escenaris on el context normatiu es dinàmic. Es a dir, diverses normes poden ser introduïdes, eliminades o actualitzades del context normatiu en qualsevol moment. Aquestes operacions s'han de poder realitzar en temps d'execució, es a dir, sense deixar de calcular l'estat normatiu. Es més, els estats normatius calculats han de ser consistents amb les respectives operacions d'extensió o contracció del context. Durant la Tesi presentem NoMoDEI en tres passos. Primer proporcionem una definició formal de les operacions que la infraestructura ha de suportar per permetre expandir i contraure el context normatiu. A continuació instanciem aquestes operacions proporcionant detalls d'implementació. Finalment demostrem que la nostra infraestructura pot ser aplicada a casos d'ús del món real introduint dos casos: sistemes de salut electrònics (i.e. E-health) i sistemes de tractament d’aigües residuals a la conca d’un riuPostprint (published version

    NoMoDEI : A framework for Norm Monitoring on Dynamic Electronic Institutions

    Get PDF
    With the growth of the Internet, computational systems have become more and more complex, often including complicate interconnected networks of autonomous components. The need to bring some organisational structure into autonomous systems becomes urgent, as this allows regulating the behaviour of the different autonomous components to ensure their objectives are aligned with the holistic objectives of the system. Normative Systems are one of the mechanisms that can be applied to define and enforce acceptable behaviour within distributed electronic systems which should comply with some (human) regulations. One of the requirements to effectively implement Normative Systems is to be able to assess, at runtime, the state of the normative environment. Existing lines of research have already tried to tackle this issue on some simple scenarios. However, more complex scenarios may appear, for instance, scenarios where the normative context is not static, but it expands and contracts as new norms are added to the institution and removed from it respectively. As in human legal systems, it is easy to foresee that some of these electronic normative environments will not be static. They should be able to evolve through time as regulations change, effectively adapting to new situations and behaviours. Under these conditions, a monitoring system must be able to continue computing the state of the normative environment at runtime, as often we can not afford to perform the changes on the normative context off-line. Furthermore, it must be guaranteed the monitoring system can keep producing states of the normative environment that are consistent with the changes performed on the normative context. For instance, if a norm has been removed from the normative context, it does not make sense anymore to compute normative states where the norm has been violated. In this thesis we present NoMoDEI, a normative monitoring framework for dynamic Electronic Institutions. We formalize and develop an extended normative framework and architecture to cope with scenarios where the normative context is dynamic, therefore norms can be added, removed and updated. The operations are to be performed at run-time, without having to stop computing the normative state. The normative states computed are consistent with the expansion and contraction operations. NoMoDEI is introduced in three steps. First, we formally define the operations to be supported in order to allow for expanding and contracting the normative context. Then, we instantiate the formal operations, providing implementation details. Finally, we demonstrate our framework by applying it to two use cases: E-health systems and waste-water management on a river basin.Amb l'expansió d'Internet els sistemes computacionals han esdevingut més complexos, sovint incorporant complicades xarxes interconnectades de components autònoms. Es per això que la necessitat d'incorporar estructures organitzacionals en el sistemes autònoms s 'accentua, donat que aquestes estructures permeten regular el comportament dels diferents components autònoms, tot assegurant que els seus objectius es troben alineats amb els objectius generals del sistema. Els Sistemes Normatius (i.e. Normative Systems) són un dels mecanismes que podem aplicar per definir i imposar patrons acceptables de comportament dintre de sistemes electrònics distribuïts. Això esdevé especialment important quan el sistema es troba regimentat per regulacions (normalment humanes). Un dels requeriments per implementar Sistemes Normatius és ser capaços de determinar, en temps d'execució, l'estat de l'entorn normatiu. Existeixen línies de recerca que ja han tractat aquest problema en alguns escenaris simples. El món real però ens ofereix escenaris més complexes, com per exemple, escenaris on el context normatiu no és estàtic, si no que s'expandeix i contrau a mesura que noves normes són afegides o eliminades de la institució. Tal com passa als sistemes legals humans, és fàcil preveure que alguns contextos normatius electrònics no seran estàtics. Aquests contextos haurien de ser capaços d'evolucionar a través del temps a mesura que les regulacions canvien, adaptant-se a noves situacions i comportaments. Sota aquestes condicions, un sistema de monitorització ha de ser capaç de continuar calculant l'estat de l'entorn normatiu en temps d'execució, ja que sovint no ens podem permetre realitzar els canvis a l'entorn normatiu aturant el procés de monitorització. És més s'ha de garantir que el sistema de monitorització sigui capaç de continuar produint es tats de l’entorn normatiu de forma consistent amb els canvis realitzats. Per exemple, el fet d'eliminar una norma fa que no tingui gaire sentit continuar calculant es tats normatius on aquesta norma ha es tat violada. A aquesta Tesi presentem NoMoDEI, una infraestructura de monitorització normativa per institucions electròniques dinàmiques. Formalitzem i desenvolupem una infraestructura de monitorització normativa estesa capaç d'operar en escenaris on el context normatiu es dinàmic. Es a dir, diverses normes poden ser introduïdes, eliminades o actualitzades del context normatiu en qualsevol moment. Aquestes operacions s'han de poder realitzar en temps d'execució, es a dir, sense deixar de calcular l'estat normatiu. Es més, els estats normatius calculats han de ser consistents amb les respectives operacions d'extensió o contracció del context. Durant la Tesi presentem NoMoDEI en tres passos. Primer proporcionem una definició formal de les operacions que la infraestructura ha de suportar per permetre expandir i contraure el context normatiu. A continuació instanciem aquestes operacions proporcionant detalls d'implementació. Finalment demostrem que la nostra infraestructura pot ser aplicada a casos d'ús del món real introduint dos casos: sistemes de salut electrònics (i.e. E-health) i sistemes de tractament d’aigües residuals a la conca d’un ri

    Bringing social reality to multiagent and service architectures : practical reductions for monitoring of deontic-logic and constitutive norms

    Get PDF
    As distributed systems grow in complexity, the interactions among individuals (agents, services) of such systems become increasingly more complex and therefore more difficult to constrain and monitor. We propose to view such systems as socio-technical systems, in which organisational and institutional concepts, such as norms, can be applied to improve not only control on the components but also their autonomy by the definition of soft rather than hard constraints. Norms can be described as rules that guide the behavior of individual agents pertaining to groups that abide to them, either by explicit or implicit support. The study of norms, and regulatory systems in general, in their many forms -e.g. social norms, conventions, laws, regulations- has been of interest since the beginning of philosophy, but has seen a lot of evolution during the 20th century due to the progress in the philosophy of language, especially concerning speech acts and deontic logic. Although there is a myriad of definitions and related terminologies about the concept of norm, and as such there are many perspectives on how to analyse their impact, a common denominator is that norms constrain the behaviour of groups of agents in a way that each individual agent can build, with a fair degree of confidence, expectations on how each of their counterparts will behave in the situations that the norms are meant to cover. For example, on a road each driver expects everybody else to drive on only one side of the road (right or left, depending on the country). Therefore, normative contexts, usually wrapped in the form of institutions, are effective mechanisms to ensure the stability of a complex system such as an organisation, a society, or even of electronic systems. The latter has been an object of interest in the field of Artificial Intelligence, and it has been seen as a paradigm of coordination among electronic agents either in multi-agent systems or in service-oriented architectures. In order to apply norms to electronic systems, research has come up with abstractions of normative systems. In some cases these abstractions are based on regimented systems with flexible definitions of the notion of norm, in order to include meanings of the concept with a coarse-grained level of logic formality such as conventions. Other approaches, on the other hand, propose the use of deontic logic for describing, from a more theoretical perspective, norm-governed interaction environments. In both cases, the purpose is to enable the monitoring and enforcement of norms on systems that include -although not limited to- electronic agents. In the present dissertation we will focus on the latter type, focusing on preserving the deontic aspect of norms. Monitoring in norm-governed systems requires making agents aware of: 1) what their normative context is, i.e. which obligations, permissions and prohibitions are applicable to each of them and how they are updated and triggered; and 2) what their current normative status is, i.e. which norms are active, and in what instances they are being fullfilled or violated, in order words, what their social -institutional- reality is. The current challenge is on designing systems that allow computational components to infer both the normative context and social reality in real-time, based on a theoretical formalism that makes such inferences sound and correct from a philosophical perspective. In the scope of multi-agent systems, many are the approaches proposed and implemented that full these requirements up to this date. However, the literature is still lacking a proposal that is suited to the current state-of-the-art in service-oriented architectures, more focused nowadays on automatically scalable, polyglot amalgams of lightweight services with extremely simple communication and coordination mechanisms- a trend that is being called “microservices”. This dissertation tackles this issue, by 1) studying what properties we can infer from distributed systems that allow us to treat them as part of a socio-technical system, and 2) analysing which mechanisms we can provide to distributed systems so that they can properly act as socio-technical systems. The main product of the thesis is therefore a collection of computational elements required for formally grounded and real-time e¬fficient understanding and monitoring of normative contexts, more specially: 1. An ontology of events to properly model the inputs from the external world and convert them into brute facts or institutional events; 2. A lightweight language for norms, suitable for its use in distributed systems; 3. An especially tailored formalism for the detection of social reality, based on and reducible to deontic logic with support for constitutive norms; 4. A reduction of such formalism to production rule systems; and 5. One or more implementations of this reduction, proven to e¬fficiently work on several scenarios. This document presents the related work, the rationale and the design/implementation of each one of these elements. By combining them, we are able to present novel, relevant work that enables the application of normative reasoning mechanisms in realworld systems in the form of a practical reasoner. Of special relevance is the fact that the work presented in this dissertation simplifies, while preserving formal soundness, theoretically complex forms of reasoning. Nonetheless, the use of production systems as the implementation-level materialisation of normative monitoring allows our work to be applied in any language and/or platform available, either in the form of rule engines, ECA rules or even if-then-else patterns. The work presented has been tested and successfully used in a wide range of domains and actual applications. The thesis also describes how our mechanisms have been applied to practical use cases based on their integration into distributed eldercare management and to commercial games.Con el incremento en la complejidad de los sistemas distribuidos, las interacciones entre los individuos (agentes, servicios) de dichos sistemas se vuelven más y más complejas y, por ello, más difíciles de restringir y monitorizar. Proponemos ver a estos sistemas como sistemas socio-técnicos, en los que conceptos organizacionales e institucionales (como las normas) pueden aplicarse para mejorar no solo el control sobre los componentes sino también su autonomía mediante la definición de restricciones débiles (en vez de fuertes). Las Normas se pueden describir como reglas que guían el comportamiento de agentes individuales que pertenecen a grupos que las siguen, ya sea con un apoyo explícito o implícito. El estudio de las normas y de los sistemas regulatorios en general y en sus formas diversas -normas sociales, convenciones, leyes, reglamentos- ha sido de interés para los eruditos desde los inicios de la filosofía, pero ha sufrido una evolución mayor durante el siglo 20 debido a los avances en filosofía del lenguaje, en especial los relacionados con los actos del habla -speech acts en inglés- y formas deónticas de la lógica modal. Aunque hay una gran variedad de definiciones y terminología asociadas al concepto de norma, y por ello existen varios puntos de vista sobre como analizar su impacto, el denominador común es que las normas restringen el comportamiento de grupos de agentes de forma que cada agente individual puede construir, con un buen nivel de confianza, expectativas sobre cómo cada uno de los otros actores se comportará en las situaciones que las normas han de cubrir. Por ejemplo, en una carretera cada conductor espera que los demás conduzcan solo en un lado de la carretera (derecha o izquierda, dependiendo del país). Por lo tanto, los contextos normativos, normalmente envueltos en la forma de instituciones, constituyen mecanismos efectivos para asegurar la estabilidad de un sistema complejo como una organización, una sociedad o incluso un sistema electrónico. Lo último ha sido objeto de estudio en el campo de la Inteligencia Artificial, y se ha visto como paradigma de coordinación entre agentes electrónicos, tanto en sistemas multiagentes como en arquitecturas orientadas a servicios. Para aplicar normas en sistemas electrónicos, los investigadores han creado abstracciones de sistemas normativos. En algunos casos estas abstracciones se basan en sistemas regimentados con definiciones flexibles del concepto de norma para poder influir algunos significados del concepto con un menor nivel de granularidad formal como es el caso de las convenciones. Otras aproximaciones proponen el uso de lógica deóntica para describir, desde un punto de vista más teórico, entornos de interacción gobernados por normas. En ambos casos el propósito es el permitir la monitorización y la aplicación de las normas en sistemas que incluyen -aunque no están limitados a- agentes electrónicos. En el presente documento nos centraremos en el segundo tipo, teniendo cuidado en mantener el aspecto deóntico de las normas. La monitorización en sistemas gobernados por normas requiere el hacer a los agentes conscientes de: 1) cual es su contexto normativo, es decir, que obligaciones permisos y prohibiciones se aplican a cada uno de ellos y cómo se actualizan y activan; y 2) cual es su estado normativo actual, esto es, que normas están activas, y que instancias están siendo cumplidas o violadas, en definitiva, cual es su realidad social -o institucional-. En la actualidad el reto consiste en diseñar sistemas que permiten inferir a componentes computacionales tanto el contexto normativo como la realidad social en tiempo real, basándose en un formalismo teórico que haga que dichas inferencias sean correctas y bien fundamentadas desde el punto de vista filosófico. En el ámbito de los sistemas multiagente existen muchas aproximaciones propuestas e implementadas que cubren estos requisitos. Sin embargo, esta literatura aun carece de una propuesta que sea adecuada para la tecnología de las arquitecturas orientadas a servicios, que están más centradas en amalgamas políglotas y escalables de servicios ligeros con mecanismos de coordinación y comunicación extremadamente simples, una tendencia moderna que lleva el nombre de microservicios. Esta tesis aborda esta problemática 1) estudiando que propiedades podemos inferir de los sistemas distribuidos que nos permitan tratarlos como parte de un sistema sociotécnico, y 2) analizando que mecanismos podemos proporcionar a los sistemas distribuidos de forma que puedan actuar de forma correcta como sistemas socio-técnicos. El producto principal de la tesis es, por tanto, una colección de elementos computacionales requeridos para la monitorización e interpretación e_cientes en tiempo real y con clara base formal. En concreto: 1. Una ontología de eventos para modelar adecuadamente las entradas del mundo exterior y convertirlas en hechos básicos o en eventos institucionales; 2. Un lenguaje de normas ligero y sencillo, adecuado para su uso en arquitecturas orientadas a servicios; 3. Un formalismo especialmente adaptado para la detección de la realidad social, basado en y reducible a lógica deóntica con soporte para normas constitutivas; 4. Una reducción de ese formalismo a sistemas de reglas de producción; y 5. Una o más implementaciones de esta reducción, de las que se ha probado que funcionan eficientemente en distintos escenarios. Este documento presenta el estado del arte relacionado, la justificación y el diseño/implementación para cada uno de esos elementos. Al combinarlos, somos capaces de presentar trabajo novedoso y relevante que permite la aplicación de mecanismos de razonamiento normativo en sistemas del mundo real bajo la forma de un razonador práctico. De especial relevancia es el hecho de que el trabajo presentado en este documento simplifica formas complejas y teóricas de razonamiento preservando la correctitud formal. El uso de sistemas de reglas de producción como la materialización a nivel de implementación del monitoreo normativo permite que nuestro trabajo se pueda aplicar a cualquier lenguaje o plataforma disponible, ya sea en la forma de motores de reglas, reglas ECA o incluso patrones si-entonces. El trabajo presentado ha sido probado y usado con éxito en un amplio rango de dominios y aplicaciones prácticas. La tesis describe como nuestros mecanismos se han aplicado a casos prácticos de uso basados en su integración en la gestión distribuida de pacientes de edad avanzada o en el sector de los videojuegos comerciales.Postprint (published version

    Link prediction in large directed graphs

    Get PDF
    The first chapter introduces an approach to machine learning (ML) were data is understood as a network of connected entities. This strategy seeks inter-entity information for knowledge discovery, in contrast with traditional intra-entity approaches based on instances and their features. We discuss the importance of this connectivist ML (which we refer to as graph mining) in the current context where large, topology-based data sets have been made available. Chapter ends by introducing the Link Prediction (LP) problem, together with its current computational and performance limitations. The second chapter discusses early contributions to graph mining, and introduces problems frequently tackled through this paradigm. Later the chapter focuses on the state-of-the-art of LP. It presents three different approaches to the problem of finding links in a relational set, and argues about the importance of the most computationally scalable one: similarity-based algorithms. It categorizes similarity-based algorithms in three types of LP scores. For the most scalable type, local similarity-based algorithms, the chapter identifies and formally describes the most competitive proposals according to the bibliography. Chapter three analyses the LP problem, partly as a classic binary classification problem. A list of graph properties such as directionality, weights and time are discussed in the context of LP. Follows a formal time and space complexity analysis of similarity-based scores of LP. The chapter ends with an study of the class imbalance found in LP problems. In chapter four a novel similarity-based score of LP is introduced. The chapter first elaborates on the importance of hierarchies for representing knowledge through directed graphs. Several modifications to the proposed score are also defined. This chapter presents a modified version of the most competitive undirected scores of LP, to adapt them to directed graphs. The evaluation methodologies of LP are analyzed in the fifth chapter. It starts by discussing the problem of evaluating domains with a huge class imbalance, identifying the most appropriate methodologies for it. A modification of the most appropriate evaluation methodology according to the bibliography is presented, with the goal of focusing on relevant predictions. Follows a discussion on the faithful estimation of the precision of predictors. Chapter six describes the graphs used for score evaluation, as well as how data was transformed into a directed graph. Reasons on why these particular domains were chosen are given, making a special case of webgraphs and their well known relation with hierarchies. The most basic properties of each resultant graph are shown. Tests performed are presented in chapter seven. The three most competitive LP scores currently available are tested among themselves, and against a proposed version of those same scores for directed graphs. Our proposed score and its modifications are tested against the scores obtaining the best results in the previous tests. The case of LP in webgraphs is considered separately, testing six different webgraphs. The chapter ends with a discussion on the limitations of this formal analysis, showing examples of predictions obtained. Chapter eight includes the computational aspects of the work done. It starts with a discussion on the importance of memory management for determining the computational cost of LP algorithms. A proposal on how to reduce this cost through precision reduction is presented. Follows a section focused on the parallelization of code, which includes two different implementations on one graph-specific programming model (Pregel) and on one generic programming model (OpenMP). The chapter ends with a specification of the computational resources used for the tests done. The conclusions of this thesis proposal are presented in nine. Chapter ten contains several future lines of work.El primer capítol introdueix una perspectiva de l'aprenentatge automàtic on les dades s'entén com una xarxa d'entitats connectades. Aquesta estratègia es centra en les relacions entre entitats per aprendre, en contrast amb les solucions tradicionals basades en instancies i els seus atributs. Discutim sobre la importància d'aquesta perspectiva connectivista (a la que ens referim com mineria de grafs) en el context actual on grans conjunts de dades basats en xarxes estan apareixent. El capítol finalitza amb la presentació del problema de Predicció d'Arestes (PA), junt amb una primera anàlisi de les seves limitacions actuals. El segon capítol presenta les primeres contribucions a la mineria de grafs, introduint problemes típicament solucionats mitjançant aquest paradigma. El capítol es centra en l'estat de l'art de PA. Presenta tres solucions diferents per al problema i argumenta la importància del més computacionalment escalable: els algoritmes basats en similitud. Categoritza aquests en tres tipus, i per als més escalables d'aquests, els algoritmes locals, s'identifica i es descriu formalment les propostes més competitives d'acord amb la bibliografia. El tercer capítol analitza el problema de PA, inicialment com a problema de classificació binari. Una llista de propietats de grafs són discutides en el context de la PA, com la direccionalitat o els pesos. Segueix una anàlisi del cost computacional en temps com en espai, dels algorismes basats en similitud. El capítol finalitza amb un estudi del desbalanceig de classes, freqüent en la PA. Al capítol quatre es presenta un nou algorisme basat en similitud per la PA. El capítol elabora sobre la importància de les jerarquies a la representació del coneixement a través de grafs dirigits. Varies modificacions es proposen per al nou algorisme. Aquest capítol també inclou una modificació sobre els actuals algorismes de similitud per a grafs no dirigits, per adaptar-los per a grafs dirigits. Les metodologies d'avaluació de la PA s'analitzen al cinquè capítol. Comença amb una discussió sobre els problemes que suposa avaluar un context amb un gran desbalanceig de classes, identificant les metodologies apropiades per aquests casos. Es proposa una modificació sobre el mètode més apropiat actualment disponible, per tal de centrar-se en les prediccions rellevants. Segueix una discussió sobre l'estimació fidedigna de la precisió dels predictors. El sisè capítol descriu els grafs usats per avaluar els algorismes, així com la metodologia usada per transformar-los en grafs dirigits. Les raons per triar aquest conjunt de grafs són exposades, posant especial interès al cas dels grafs web i a la seva ben coneguda relació amb les jerarquies. Les propietats més bàsiques de cada graf resultant són descrites. Els tests efectuats es mostren al capítol setè. Els tres algorismes actuals de PA més competitius són comparats amb ells mateixos i amb la versió per a grafs dirigits definida anteriorment. L'algorisme proposat anteriorment i les seves modificacions també són avaluats. El problema de la PA en grafs web es considera per separat, avaluant sis grafs web diferents. El capítol acaba amb una discussió sobre les limitacions de les avaluacions formals, mostrant exemples de prediccions obtingudes. El vuitè capítol inclou els aspectes computacionals de la tesi. Comença amb una discussió sobre la importància de la gestió de memòria per a la definició del cost computacional dels algorismes de PA. Inclou una proposta sobre com reduir aquest cost mitjançant una reducció en la precisió. Segueix una secció centrada en la paral·lelització del codi, que inclou dues implementacions diferents, una en un model de programació específic per grafs (Pregel) i una amb un model de programació paral·lela genèric (OpenMP). El capítol finalitza amb una especificació dels recursos computacionals usats per als tests realitzats. Les conclusions de la tesi es presenten al capítol novè, i les línies de treball futur al des

    Intelligent technologies for the aging brain: opportunities and challenges

    Get PDF
    Intelligent computing is rapidly reshaping healthcare. In light of the global burden of population aging and neurological disorders, dementia and elderly care are among the healthcare sectors that are most likely to benefit from this technological revolution. Trends in artificial intelligence, robotics, ubiquitous computing, neurotechnology and other branches of biomedical engineering are progressively enabling novel opportunities for technology-enhanced care. These Intelligent Assistive Technologies (IATs) open the prospects of supporting older adults with neurocognitive disabilities, maintain their independence, reduce the burden on caregivers and delay the need for long-term care (1, 2). While technology develops fast, yet little knowledge is available to patients and health professionals about the current availability, applicability, and capability of existing IATs. This thesis proposes a state-of-the-art analysis of IATs in dementia and elderly care. Our findings indicate that advances in intelligent technology are resulting in a rapidly expanding number and variety of assistive solutions for older adults and people with neurocognitive disabilities. However, our analysis identifies a number of challenges that negatively affect the optimal deployment and uptake of IATs among target users and care institutions. These include design issues, sub-optimal approaches to product development, translational barriers between lab and clinics, lack of adequate validation and implementation, as well as data security and cyber-risk weaknesses. Additionally, in virtue of their technological novelty, intelligent technologies raise a number of Ethical, Legal and Social Implications (ELSI). Therefore, a significant portion of this thesis is devoted to providing an early ethical Technology Assessment (eTA) of intelligent technology, hence contributing to preparing the terrain for its safe and ethically responsible adoption. This assessment is primarily focused on intelligent technologies at the human-machine interface, as these applications enable an unprecedented exposure of the intimate dimension of individuals to the digital infosphere. Issues of privacy, integrity, equality, and dual-use were addressed at the level of stakeholder analysis, normative ethics and human-rights law. Finally, this thesis is aimed at providing evidence-based recommendations for guiding participatory and responsible development in intelligent technology, and delineating governance strategies that maximize the clinical benefits of IATs for the aging world, while minimizing unintended risks

    Applying COAALAS to SPiDer

    No full text
    Artificial Intelligence techniques and tools have been applied to Assistive Technologies (AT) in order to support elder or impeded people on their daily activities. A common application are intelligent pill dispensers and reminders that help the patient comply with his medication. This has become even more important, as patients suffering from multiple pathologies are prescribed cocktails of drugs that require strict compliance in order to achieve a successful treatment. Existing intelligent pill dispensers tend to focus in the user-tool interaction, neglecting user’s connection with its social environment and the possibility to monitor patient’s behaviour, effectively adapting to a dynamic environment and providing early response to potentially dangerous situations by detecting unexpected or undesired patterns of behaviour. In previous work we have presented COAALAS, an intelligent social and norm-aware device for elder people that is able to autonomously organize, reorganize and interact with the different actors involved in elder-care, either human actors or other devices. In this paper, we present SPiDer an intelligent pill dispenser integrated with the COAALAS architecture.Peer Reviewe
    corecore