16 research outputs found

    Ramon Llull's Ars Magna

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    Abstract State Machines 1988-1998: Commented ASM Bibliography

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    An annotated bibliography of papers which deal with or use Abstract State Machines (ASMs), as of January 1998.Comment: Also maintained as a BibTeX file at http://www.eecs.umich.edu/gasm

    Generative learning for nonlinear dynamics

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    Modern generative machine learning models demonstrate surprising ability to create realistic outputs far beyond their training data, such as photorealistic artwork, accurate protein structures, or conversational text. These successes suggest that generative models learn to effectively parametrize and sample arbitrarily complex distributions. Beginning half a century ago, foundational works in nonlinear dynamics used tools from information theory to infer properties of chaotic attractors from time series, motivating the development of algorithms for parametrizing chaos in real datasets. In this perspective, we aim to connect these classical works to emerging themes in large-scale generative statistical learning. We first consider classical attractor reconstruction, which mirrors constraints on latent representations learned by state space models of time series. We next revisit early efforts to use symbolic approximations to compare minimal discrete generators underlying complex processes, a problem relevant to modern efforts to distill and interpret black-box statistical models. Emerging interdisciplinary works bridge nonlinear dynamics and learning theory, such as operator-theoretic methods for complex fluid flows, or detection of broken detailed balance in biological datasets. We anticipate that future machine learning techniques may revisit other classical concepts from nonlinear dynamics, such as transinformation decay and complexity-entropy tradeoffs.Comment: 23 pages, 4 figure

    Soluciones para la autenticaci贸n y gesti贸n de subredes en manets y vanets

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    En los 煤ltimos a帽os las redes inal谩mbricas est谩n ganando cada vez m谩s popularidad conforme sus prestaciones aumentan y se descubren nuevas aplicaciones. Dichas redes permiten a sus usuarios acceder a informaci贸n y recursos en tiempo real sin necesidad de estar f铆sicamente conectados. Adem谩s, ofrecen una gran flexibilidad a un bajo coste ya que en general no hay necesidad de usar instalaciones cableadas lo que implica que sean f谩cilmente desplegables. Es por eso que resultan muy 煤tiles en entornos donde es muy costoso instalar infraestructuras fijas, como son entornos militares, agr铆colas, situaciones de emergencia, etc. Las redes m贸viles ad-hoc o MANETs (Mobile Ad-hoc NETworks) son un tipo de red inal谩mbrica, distribuida y sin autoridad central en las que los nodos son m贸viles. El comportamiento de una MANET es en muchos aspectos similar al de una red Peer-TO-Peer (P2P) pues en ambos casos los nodos de la red reciben y env铆an informaci贸n de forma descentralizada. La gesti贸n de las MANETs conlleva muchas dificultades ya que por ejemplo su topolog铆a cambia constantemente debido a la movilidad de los nodos y a la inexistencia de una infraestructura fija. Las redes ad-hoc vehiculares o VANETs (Vehicular Ad-hoc NETworks) pueden considerarse un subconjunto de las MANETs en las que los nodos m贸viles son veh铆culos. En su definici贸n cl谩sica, las VANETs permiten comunicar informaci贸n no solo entre las unidades a bordo u OBUs (On Board Units) situadas en los veh铆culos, sino tambi茅n con la infraestructura de la carretera o RSU (Road Side Unit). El objetivo principal de estos sistemas es proporcionar un mejor conocimiento de las condiciones de las carreteras a los conductores para reducir el n煤mero de accidentes y lograr que la conducci贸n sea m谩s c贸moda y fluida, reduciendo con ello la cantidad de CO2 que los veh铆culos expulsan a la atm贸sfera. Las redes ad-hoc son especialmente vulnerables a varios tipos de ataques, tanto activos como pasivos. Por ejemplo, un atacante puede intentar emular a un nodo leg铆timo y capturar paquetes de datos y de control, destruir tablas de encaminamiento, etc. En particular, los efectos de los ataques a las VANETs pueden ser muy destructivos, ya que pueden llegar incluso a causar muertes. Por este motivo, el prop贸sito fundamental de la presente Tesis es la propuesta de nuevas herramientas que permitan proteger las redes m贸viles ad-hoc contra diferentes ataques, asegurando en la medida de lo posible que la generaci贸n de informaci贸n, as铆 como su retransmisi贸n se realizan correctamente. Para ello, se proponen y analizan aqu铆 nuevos esquemas de autenticaci贸n y gesti贸n de subredes en MANETs y VANETs. Hay que destacar que las simulaciones juegan un papel fundamental en este trabajo ya que permiten analizar y evaluar el comportamiento de las propuestas realizadas a gran escala y en diversas condiciones. En particular, gran parte de los algoritmos dise帽ados en esta Tesis han sido simulados con el simulador de redes NS-2 y el simulador de tr谩fico SUMO. Tambi茅n son de gran inter茅s en esta Tesis las implementaciones de algunas de las propuestas en dispositivos reales, ya que no s贸lo permiten evaluar su comportamiento en entornos reales, sino descubrir problemas que las simulaciones no detectan, y obtener datos reales para alimentar simulaciones a gran escala. Las implementaciones en dispositivos reales se han llevado a cabo en particular en la plataforma Windows Mobile usando Visual Studio 2008. Como resultado pr谩ctico de este trabajo, y en colaboraci贸n con otras investigaciones, surge VAiPho (VANET in Phones), que es una herramienta para la asistencia a la conducci贸n. VAiPho permite crear una red vehicular real utilizando 煤nicamente tel茅fonos m贸viles inteligentes, sin necesidad de instalar ning煤n tipo de infraestructura ni en los veh铆culos ni en la carretera. VAiPho cuenta ya con varias aplicaciones en entornos urbanos, tales como la detecci贸n de atascos, plazas de aparcamiento libres y veh铆culo aparcado. Dicha herramienta es el producto de la implementaci贸n de una patente presentada

    An Assertional Proof System for Multithreaded Java - Theory and Tool Support

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    Besides the features of a class-based object-oriented language, Java integrates concurrency via its thread classes, allowing for a multithreaded flow of control. The concurrency model includes shared-variable concurrency via instance variables, coordination via reentrant synchronization monitors, synchronous message passing, and dynamic thread creation. To reason about safety properties of multithreaded Java programs, we introduce a tool-supported assertional proof method for JavaMT ("Multi-Threaded Java"), a small sublanguage of Java, covering the mentioned concurrency issues as well as the object-based core of Java. The verification method is formulated in terms of proof-outlines, where the assertions are layered into local ones specifying the behavior of a single instance, and global ones taking care of the connections between objects. We establish the soundness and the completeness of the proof system. From an annotated program, a number of verification conditions are generated and handed over to the interactive theorem prover PVS.IST project Omega (IST-2001-33522) NWO/DFG project Mobi-J (RO 1122/9-1, RO 1122/9-2)UBL - phd migration 201

    Advances in Evolutionary Algorithms

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    With the recent trends towards massive data sets and significant computational power, combined with evolutionary algorithmic advances evolutionary computation is becoming much more relevant to practice. Aim of the book is to present recent improvements, innovative ideas and concepts in a part of a huge EA field

    An Assertional Proof System for Multithreaded Java - Theory and Tool Support

    Get PDF
    Besides the features of a class-based object-oriented language, Java integrates concurrency via its thread classes, allowing for a multithreaded flow of control. The concurrency model includes shared-variable concurrency via instance variables, coordination via reentrant synchronization monitors, synchronous message passing, and dynamic thread creation. To reason about safety properties of multithreaded Java programs, we introduce a tool-supported assertional proof method for JavaMT ("Multi-Threaded Java"), a small sublanguage of Java, covering the mentioned concurrency issues as well as the object-based core of Java. The verification method is formulated in terms of proof-outlines, where the assertions are layered into local ones specifying the behavior of a single instance, and global ones taking care of the connections between objects. We establish the soundness and the completeness of the proof system. From an annotated program, a number of verification conditions are generated and handed over to the interactive theorem prover PVS.IST project Omega (IST-2001-33522) NWO/DFG project Mobi-J (RO 1122/9-1, RO 1122/9-2)UBL - phd migration 201

    Advances in Robotics, Automation and Control

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    The book presents an excellent overview of the recent developments in the different areas of Robotics, Automation and Control. Through its 24 chapters, this book presents topics related to control and robot design; it also introduces new mathematical tools and techniques devoted to improve the system modeling and control. An important point is the use of rational agents and heuristic techniques to cope with the computational complexity required for controlling complex systems. Through this book, we also find navigation and vision algorithms, automatic handwritten comprehension and speech recognition systems that will be included in the next generation of productive systems developed by man

    Mobile Ad-Hoc Networks

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    Being infrastructure-less and without central administration control, wireless ad-hoc networking is playing a more and more important role in extending the coverage of traditional wireless infrastructure (cellular networks, wireless LAN, etc). This book includes state-of the-art techniques and solutions for wireless ad-hoc networks. It focuses on the following topics in ad-hoc networks: vehicular ad-hoc networks, security and caching, TCP in ad-hoc networks and emerging applications. It is targeted to provide network engineers and researchers with design guidelines for large scale wireless ad hoc networks
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