195 research outputs found

    Machine learning and its applications in reliability analysis systems

    Get PDF
    In this thesis, we are interested in exploring some aspects of Machine Learning (ML) and its application in the Reliability Analysis systems (RAs). We begin by investigating some ML paradigms and their- techniques, go on to discuss the possible applications of ML in improving RAs performance, and lastly give guidelines of the architecture of learning RAs. Our survey of ML covers both levels of Neural Network learning and Symbolic learning. In symbolic process learning, five types of learning and their applications are discussed: rote learning, learning from instruction, learning from analogy, learning from examples, and learning from observation and discovery. The Reliability Analysis systems (RAs) presented in this thesis are mainly designed for maintaining plant safety supported by two functions: risk analysis function, i.e., failure mode effect analysis (FMEA) ; and diagnosis function, i.e., real-time fault location (RTFL). Three approaches have been discussed in creating the RAs. According to the result of our survey, we suggest currently the best design of RAs is to embed model-based RAs, i.e., MORA (as software) in a neural network based computer system (as hardware). However, there are still some improvement which can be made through the applications of Machine Learning. By implanting the 'learning element', the MORA will become learning MORA (La MORA) system, a learning Reliability Analysis system with the power of automatic knowledge acquisition and inconsistency checking, and more. To conclude our thesis, we propose an architecture of La MORA

    Backwards is the way forward: feedback in the cortical hierarchy predicts the expected future

    Get PDF
    Clark offers a powerful description of the brain as a prediction machine, which offers progress on two distinct levels. First, on an abstract conceptual level, it provides a unifying framework for perception, action, and cognition (including subdivisions such as attention, expectation, and imagination). Second, hierarchical prediction offers progress on a concrete descriptive level for testing and constraining conceptual elements and mechanisms of predictive coding models (estimation of predictions, prediction errors, and internal models)

    A Posture Sequence Learning System for an Anthropomorphic Robotic Hand

    Get PDF
    The paper presents a cognitive architecture for posture learning of an anthropomorphic robotic hand. Our approach is aimed to allow the robotic system to perform complex perceptual operations, to interact with a human user and to integrate the perceptions by a cognitive representation of the scene and the observed actions. The anthropomorphic robotic hand imitates the gestures acquired by the vision system in order to learn meaningful movements, to build its knowledge by different conceptual spaces and to perform complex interaction with the human operator

    On the Endogenous Generation of Emotion

    Get PDF
    The thesis investigates the endogenous generation of emotion (EnGE). Two main questions were pursued: 1) How is the volitional generation of emotion neurally and behaviourally implemented? and 2) How can this ability be used for emotional self- regulation? This was investigated in two projects: In the first project, neural, psychophysiological, and behavioural indices of EnGE were investigated in a large, representative sample. The second project investigated the behavioural, functional and structural correlates of meditation practices involving endogenous generation of positive emotion, in a sample of expert meditators. Answering the first question, the first project indicated that EnGE is neurally supported by the cooperation of nodes of the Default Mode (DMN), extended Salience (SN), and left Frontoparietal Control (FPCN) Networks. Results suggest dissociable functional component processes were implemented by these networks, with DMN supporting the generation of simulated representations, while SN supported the generation of core affective qualities of self-generated emotional experiences. FPCN co-activation patterns suggested it supports the coordination of the generation process. The second project showed similar activations during loving-kindness and compassion meditation. Moreover, expert meditators showed increased cortical thickness in, primarily, the left FPCN. This suggests endogenous emotion generation is neurally effected by left FPCN, entraining core affective processes supported by SN and simulation construction supported by DMN. EnGE-based emotional self-regulation was investigated in a second set of studies. Neural and behavioural measures indicated that expert meditators could successfully regulate their emotional reactions to negative external stressors. Comparing compassion with reappraisal-based emotion regulation, regulatory effects differed, with compassion-based regulation primarily increasing positive emotion while reappraisal primarily decreased negative emotion. Moreover, in the large, representative sample, EnGE-abilities were associated with trait affect and emotion management styles. Moreover, evidence was found that EnGE-abilities partially mediate the relationship between positive trait affect and adaptive, instrumental emotion management styles. These results suggest that EnGE can be used in a reactive fashion to regulate emotional reactions to negative stressors, and that EnGE-abilities support emotion management in the normal population.Die vorliegende Arbeit untersucht die endogene Generation von Emotionen (EnGE). Zwei Hauptfragen wurde verfolgt: 1) Wie die willentliche Erzeugung von Emotionen neuronal oder im Verhalten implementiert ist, und 2) wie diese Fähigkeit für die emotionale Selbstregulation verwendet werden kann. Dies wurde in zwei Projekten genauer untersucht: Im ersten Projekt wurden neuronale und psychophysiologische Mechanismen sowie Verhaltensweisen in Bezug auf EnGE in einer großen und repräsentativen Stichprobe untersucht. Das zweite Projekt untersuchte die verhaltensbedingten, funktionellen, und strukturellen Korrelate von bestimmten Meditationsübungen, die die endogene Erzeugung von positiven Emotionen beinhalten, in einer Stichprobe von Meditationsexperten. In Bezug auf die erste Forschungsfrage, haben wir im ersten Projekt Daten erhoben, die nahelegen, dass EnGE auf neuronaler Ebene durch die Kooperation von wichtigen Arealen des Default Mode Netzwerks (DMN), sowie des erweiterten Salience (SN) und des linken Frontoparietal Control (FPCN) Netzwerks unterstützt wird. Ergebnisse legen nahe, dass unterscheidbare funktionelle Komponenten-Prozesse durch diese Netzwerke implementiert werden. Das DMN unterstützt dabei die Erzeugung von simulierten Repräsentationen, während das SN die Generation der „core“ affektive Qualitäten von selbstgenerierten emotionalen Erfahrungen unterstützt. Das FPCN Ko-Aktivierungsmuster legt eine Rolle bei der Koordination von Erzeugungsprozessen nahe. Das zweite Projekt zeigte ähnliche Aktivierungen durch Loving-kindness und Mitgefühls-Meditation. Weiterhin zeigten Meditationsexperten eine erhöhte kortikale Dicke vor allem im linken FPCN. Diese Ergebnisse lassen vermuten, dass eine endogene Emotionsgeneration neuronal vom linken FPCN beeinflusst wird, dass eine SN Aktivierung „core“ affektive Prozesse unterstützt, und dass die Simulationskonstruktion vom DMN gesteuert wird. EnGE-basierte emotionale Selbstregulation wurde mittels dem zweiten Set von Experimenten genauer untersucht. Neuronale- und Verhaltensmaße weisen darauf hin, dass Meditationsexperten ihre eigenen emotionalen Reaktionen auf negative externe Stressoren erfolgreich regulieren konnten. Ein Vergleich von Mitgefühlsmeditation und Neubewertungs- basierter (reappraisal) Emotionsregulation zeigte, dass die Regulationseffekte insofern unterschiedlich sind, dass Mitgefühl-basierte Regulation zunächst positive Emotionen erhöht, während eine Neubewertungsstrategie hauptsächlich negative Emotionen reduziert. Außerdem wurden in der großen und repräsentativen Stichprobe EnGE-Fähigkeiten mit habituellem Affekt (trait affect) und Emotionsmanagement-Stilen assoziiert. EnGE- Fähigkeiten wurden teilweise durch die Beziehung zwischen positiven habituellem Affekt und adaptiven instrumentellen Emotionsmanagement-Stilen vermittelt. Diese Ergebnisse legen nahe, dass EnGE in einer reaktiven Weise für eine Regulation von Emotionsreaktionen auf negative Stressoren verwendet werden kann und das EnGE Fähigkeiten das Emotionsmanagement in einer normalen Population unterstützen

    Towards Data Wrangling Automation through Dynamically-Selected Background Knowledge

    Full text link
    [ES] El proceso de ciencia de datos es esencial para extraer valor de los datos. Sin embargo, la parte más tediosa del proceso, la preparación de los datos, implica una serie de formateos, limpieza e identificación de problemas que principalmente son tareas manuales. La preparación de datos todavía se resiste a la automatización en parte porque el problema depende en gran medida de la información del dominio, que se convierte en un cuello de botella para los sistemas de última generación a medida que aumenta la diversidad de dominios, formatos y estructuras de los datos. En esta tesis nos enfocamos en generar algoritmos que aprovechen el conocimiento del dominio para la automatización de partes del proceso de preparación de datos. Mostramos la forma en que las técnicas generales de inducción de programas, en lugar de los lenguajes específicos del dominio, se pueden aplicar de manera flexible a problemas donde el conocimiento es importante, mediante el uso dinámico de conocimiento específico del dominio. De manera más general, sostenemos que una combinación de enfoques de aprendizaje dinámicos y basados en conocimiento puede conducir a buenas soluciones. Proponemos varias estrategias para seleccionar o construir automáticamente el conocimiento previo apropiado en varios escenarios de preparación de datos. La idea principal se basa en elegir las mejores primitivas especializadas de acuerdo con el contexto del problema particular a resolver. Abordamos dos escenarios. En el primero, manejamos datos personales (nombres, fechas, teléfonos, etc.) que se presentan en formatos de cadena de texto muy diferentes y deben ser transformados a un formato unificado. El problema es cómo construir una transformación compositiva a partir de un gran conjunto de primitivas en el dominio (por ejemplo, manejar meses, años, días de la semana, etc.). Desarrollamos un sistema (BK-ADAPT) que guía la búsqueda a través del conocimiento previo extrayendo varias meta-características de los ejemplos que caracterizan el dominio de la columna. En el segundo escenario, nos enfrentamos a la transformación de matrices de datos en lenguajes de programación genéricos como R, utilizando como ejemplos una matriz de entrada y algunas celdas de la matriz de salida. También desarrollamos un sistema guiado por una búsqueda basada en árboles (AUTOMAT[R]IX) que usa varias restricciones, probabilidades previas para las primitivas y sugerencias textuales, para aprender eficientemente las transformaciones. Con estos sistemas, mostramos que la combinación de programación inductiva, con la selección dinámica de las primitivas apropiadas a partir del conocimiento previo, es capaz de mejorar los resultados de otras herramientas actuales específicas para la preparación de datos.[CA] El procés de ciència de dades és essencial per extraure valor de les dades. No obstant això, la part més tediosa del procés, la preparació de les dades, implica una sèrie de transformacions, neteja i identificació de problemes que principalment són tasques manuals. La preparació de dades encara es resisteix a l'automatització en part perquè el problema depén en gran manera de la informació del domini, que es converteix en un coll de botella per als sistemes d'última generació a mesura que augmenta la diversitat de dominis, formats i estructures de les dades. En aquesta tesi ens enfoquem a generar algorismes que aprofiten el coneixement del domini per a l'automatització de parts del procés de preparació de dades. Mostrem la forma en què les tècniques generals d'inducció de programes, en lloc dels llenguatges específics del domini, es poden aplicar de manera flexible a problemes on el coneixement és important, mitjançant l'ús dinàmic de coneixement específic del domini. De manera més general, sostenim que una combinació d'enfocaments d'aprenentatge dinàmics i basats en coneixement pot conduir a les bones solucions. Proposem diverses estratègies per seleccionar o construir automàticament el coneixement previ apropiat en diversos escenaris de preparació de dades. La idea principal es basa a triar les millors primitives especialitzades d'acord amb el context del problema particular a resoldre. Abordem dos escenaris. En el primer, manegem dades personals (noms, dates, telèfons, etc.) que es presenten en formats de cadena de text molt diferents i han de ser transformats a un format unificat. El problema és com construir una transformació compositiva a partir d'un gran conjunt de primitives en el domini (per exemple, manejar mesos, anys, dies de la setmana, etc.). Desenvolupem un sistema (BK-ADAPT) que guia la cerca a través del coneixement previ extraient diverses meta-característiques dels exemples que caracteritzen el domini de la columna. En el segon escenari, ens enfrontem a la transformació de matrius de dades en llenguatges de programació genèrics com a R, utilitzant com a exemples una matriu d'entrada i algunes dades de la matriu d'eixida. També desenvolupem un sistema guiat per una cerca basada en arbres (AUTOMAT[R]IX) que usa diverses restriccions, probabilitats prèvies per a les primitives i suggeriments textuals, per aprendre eficientment les transformacions. Amb aquests sistemes, mostrem que la combinació de programació inductiva amb la selecció dinàmica de les primitives apropiades a partir del coneixement previ, és capaç de millorar els resultats d'altres enfocaments de preparació de dades d'última generació i més específics.[EN] Data science is essential for the extraction of value from data. However, the most tedious part of the process, data wrangling, implies a range of mostly manual formatting, identification and cleansing manipulations. Data wrangling still resists automation partly because the problem strongly depends on domain information, which becomes a bottleneck for state-of-the-art systems as the diversity of domains, formats and structures of the data increases. In this thesis we focus on generating algorithms that take advantage of the domain knowledge for the automation of parts of the data wrangling process. We illustrate the way in which general program induction techniques, instead of domain-specific languages, can be applied flexibly to problems where knowledge is important, through the dynamic use of domain-specific knowledge. More generally, we argue that a combination of knowledge-based and dynamic learning approaches leads to successful solutions. We propose several strategies to automatically select or construct the appropriate background knowledge for several data wrangling scenarios. The key idea is based on choosing the best specialised background primitives according to the context of the particular problem to solve. We address two scenarios. In the first one, we handle personal data (names, dates, telephone numbers, etc.) that are presented in very different string formats and have to be transformed into a unified format. The problem is how to build a compositional transformation from a large set of primitives in the domain (e.g., handling months, years, days of the week, etc.). We develop a system (BK-ADAPT) that guides the search through the background knowledge by extracting several meta-features from the examples characterising the column domain. In the second scenario, we face the transformation of data matrices in generic programming languages such as R, using an input matrix and some cells of the output matrix as examples. We also develop a system guided by a tree-based search (AUTOMAT[R]IX) that uses several constraints, prior primitive probabilities and textual hints to efficiently learn the transformations. With these systems, we show that the combination of inductive programming with the dynamic selection of the appropriate primitives from the background knowledge is able to improve the results of other state-of-the-art and more specific data wrangling approaches.This research was supported by the Spanish MECD Grant FPU15/03219;and partially by the Spanish MINECO TIN2015-69175-C4-1-R (Lobass) and RTI2018-094403-B-C32-AR (FreeTech) in Spain; and by the ERC Advanced Grant Synthesising Inductive Data Models (Synth) in Belgium.Contreras Ochando, L. (2020). Towards Data Wrangling Automation through Dynamically-Selected Background Knowledge [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/160724TESI

    A Robotic System for Learning Visually-Driven Grasp Planning (Dissertation Proposal)

    Get PDF
    We use findings in machine learning, developmental psychology, and neurophysiology to guide a robotic learning system\u27s level of representation both for actions and for percepts. Visually-driven grasping is chosen as the experimental task since it has general applicability and it has been extensively researched from several perspectives. An implementation of a robotic system with a gripper, compliant instrumented wrist, arm and vision is used to test these ideas. Several sensorimotor primitives (vision segmentation and manipulatory reflexes) are implemented in this system and may be thought of as the innate perceptual and motor abilities of the system. Applying empirical learning techniques to real situations brings up such important issues as observation sparsity in high-dimensional spaces, arbitrary underlying functional forms of the reinforcement distribution and robustness to noise in exemplars. The well-established technique of non-parametric projection pursuit regression (PPR) is used to accomplish reinforcement learning by searching for projections of high-dimensional data sets that capture task invariants. We also pursue the following problem: how can we use human expertise and insight into grasping to train a system to select both appropriate hand preshapes and approaches for a wide variety of objects, and then have it verify and refine its skills through trial and error. To accomplish this learning we propose a new class of Density Adaptive reinforcement learning algorithms. These algorithms use statistical tests to identify possibly interesting regions of the attribute space in which the dynamics of the task change. They automatically concentrate the building of high resolution descriptions of the reinforcement in those areas, and build low resolution representations in regions that are either not populated in the given task or are highly uniform in outcome. Additionally, the use of any learning process generally implies failures along the way. Therefore, the mechanics of the untrained robotic system must be able to tolerate mistakes during learning and not damage itself. We address this by the use of an instrumented, compliant robot wrist that controls impact forces
    corecore