62 research outputs found

    Service Replication in Wireless Mobile Ad Hoc Networks

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    Die vorliegende Arbeit beschäftigt sich mit dem Management von Diensten im mobilen ad-hoc Netzwerken (MANETs). MANETs sind drahtlose Netzverbände mobiler Einheiten die sich dezentral ohne eine übergeordnete Organisation selbst verwalten. Die Netztopologie eines MANET verändert sich dabei dynamisch mit der Bewegung der autonomen Teilnehmer. Sensor Netzwerke, Personal Area Networks und Satelliten Netzwerke sind typische Beispiele für derartige MANETs. Mit der wachsenden Bedeutung der drahtlosen Vernetzung mobiler Geräte haben sich MANETs in den vergangenen Jahren zu einem wichtigen Forschungsgebiet entwickelt. Im Katastrophenmanagement, bei zivilen Rettungsfällen oder in militärischen Szenarien kann ihre infrastrukturlose Selbstorganisation MANETs zum einzig möglichen Kommunikationsmittel machen. Die mobilen Knoten eines MANETs kooperieren um essenzielle Netzwerkdienste wie das Routing und den Datentransport gemeinschaftlich zu gewährleisten. Ressourcen wie die Bandbreite zwischen Knoten, die Rechenleistung der mobilen Geräte und ihre Batterieleistung sind dabei typischerweise stark begrenzt und zudem wechselnd. Das Teilen der verfügbaren Ressourcen ist daher eine Notwendigkeit für das effiziente Funktionieren eines MANETs. Dienstorientierte Architekturen (SOAs) stellen ein geeignetes Paradigma dar, um geteilte Ressourcen zu verwalten. Wenn verfügbare Ressourcen als Dienst aufgefasst werden, lässt sich ihre Nutzung als Dienstabfrage bearbeiten. In diesem Zusammenhang ermöglichen SOAs Abstraktion, Kapselung, lose Koppelung, Auffindbarkeit von Ressourcen und dir für MANETs essenzielle Autonomie. Die Anwendung von SOAs auf MANETs findet daher zunehmend Beachtung in der Forschung

    Emerging research directions in computer science : contributions from the young informatics faculty in Karlsruhe

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    In order to build better human-friendly human-computer interfaces, such interfaces need to be enabled with capabilities to perceive the user, his location, identity, activities and in particular his interaction with others and the machine. Only with these perception capabilities can smart systems ( for example human-friendly robots or smart environments) become posssible. In my research I\u27m thus focusing on the development of novel techniques for the visual perception of humans and their activities, in order to facilitate perceptive multimodal interfaces, humanoid robots and smart environments. My work includes research on person tracking, person identication, recognition of pointing gestures, estimation of head orientation and focus of attention, as well as audio-visual scene and activity analysis. Application areas are humanfriendly humanoid robots, smart environments, content-based image and video analysis, as well as safety- and security-related applications. This article gives a brief overview of my ongoing research activities in these areas

    Detecting Abnormal Behavior in Web Applications

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    The rapid advance of web technologies has made the Web an essential part of our daily lives. However, network attacks have exploited vulnerabilities of web applications, and caused substantial damages to Internet users. Detecting network attacks is the first and important step in network security. A major branch in this area is anomaly detection. This dissertation concentrates on detecting abnormal behaviors in web applications by employing the following methodology. For a web application, we conduct a set of measurements to reveal the existence of abnormal behaviors in it. We observe the differences between normal and abnormal behaviors. By applying a variety of methods in information extraction, such as heuristics algorithms, machine learning, and information theory, we extract features useful for building a classification system to detect abnormal behaviors.;In particular, we have studied four detection problems in web security. The first is detecting unauthorized hotlinking behavior that plagues hosting servers on the Internet. We analyze a group of common hotlinking attacks and web resources targeted by them. Then we present an anti-hotlinking framework for protecting materials on hosting servers. The second problem is detecting aggressive behavior of automation on Twitter. Our work determines whether a Twitter user is human, bot or cyborg based on the degree of automation. We observe the differences among the three categories in terms of tweeting behavior, tweet content, and account properties. We propose a classification system that uses the combination of features extracted from an unknown user to determine the likelihood of being a human, bot or cyborg. Furthermore, we shift the detection perspective from automation to spam, and introduce the third problem, namely detecting social spam campaigns on Twitter. Evolved from individual spammers, spam campaigns manipulate and coordinate multiple accounts to spread spam on Twitter, and display some collective characteristics. We design an automatic classification system based on machine learning, and apply multiple features to classifying spam campaigns. Complementary to conventional spam detection methods, our work brings efficiency and robustness. Finally, we extend our detection research into the blogosphere to capture blog bots. In this problem, detecting the human presence is an effective defense against the automatic posting ability of blog bots. We introduce behavioral biometrics, mainly mouse and keyboard dynamics, to distinguish between human and bot. By passively monitoring user browsing activities, this detection method does not require any direct user participation, and improves the user experience

    Sensing and Signal Processing in Smart Healthcare

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    In the last decade, we have witnessed the rapid development of electronic technologies that are transforming our daily lives. Such technologies are often integrated with various sensors that facilitate the collection of human motion and physiological data and are equipped with wireless communication modules such as Bluetooth, radio frequency identification, and near-field communication. In smart healthcare applications, designing ergonomic and intuitive human–computer interfaces is crucial because a system that is not easy to use will create a huge obstacle to adoption and may significantly reduce the efficacy of the solution. Signal and data processing is another important consideration in smart healthcare applications because it must ensure high accuracy with a high level of confidence in order for the applications to be useful for clinicians in making diagnosis and treatment decisions. This Special Issue is a collection of 10 articles selected from a total of 26 contributions. These contributions span the areas of signal processing and smart healthcare systems mostly contributed by authors from Europe, including Italy, Spain, France, Portugal, Romania, Sweden, and Netherlands. Authors from China, Korea, Taiwan, Indonesia, and Ecuador are also included

    Advances in Information Security and Privacy

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    With the recent pandemic emergency, many people are spending their days in smart working and have increased their use of digital resources for both work and entertainment. The result is that the amount of digital information handled online is dramatically increased, and we can observe a significant increase in the number of attacks, breaches, and hacks. This Special Issue aims to establish the state of the art in protecting information by mitigating information risks. This objective is reached by presenting both surveys on specific topics and original approaches and solutions to specific problems. In total, 16 papers have been published in this Special Issue

    Using MapReduce Streaming for Distributed Life Simulation on the Cloud

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    Distributed software simulations are indispensable in the study of large-scale life models but often require the use of technically complex lower-level distributed computing frameworks, such as MPI. We propose to overcome the complexity challenge by applying the emerging MapReduce (MR) model to distributed life simulations and by running such simulations on the cloud. Technically, we design optimized MR streaming algorithms for discrete and continuous versions of Conway’s life according to a general MR streaming pattern. We chose life because it is simple enough as a testbed for MR’s applicability to a-life simulations and general enough to make our results applicable to various lattice-based a-life models. We implement and empirically evaluate our algorithms’ performance on Amazon’s Elastic MR cloud. Our experiments demonstrate that a single MR optimization technique called strip partitioning can reduce the execution time of continuous life simulations by 64%. To the best of our knowledge, we are the first to propose and evaluate MR streaming algorithms for lattice-based simulations. Our algorithms can serve as prototypes in the development of novel MR simulation algorithms for large-scale lattice-based a-life models.https://digitalcommons.chapman.edu/scs_books/1014/thumbnail.jp

    Human reproduction in space. Late results

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    Objectius de Desenvolupament Sostenible::3 - Salut i BenestarPostprint (published version

    Short papers of the 10th Conference on Cloud Computing, Big Data & Emerging Topics

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    Compilación de los short papers presentados en las 10mas Jornadas de Cloud Computing, Big Data & Emerging Topics (JCC-BD&ET2022), llevadas a cabo en modalidad híbrida durante junio de 2021 y organizadas por el Instituto de Investigación en Informática LIDI (III-LIDI) y la Secretaría de Posgrado de la Facultad de Informática de la UNLP, en colaboración con universidades de Argentina y del exterior.Facultad de Informátic

    An Introduction to Zooarchaeology

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    zooarchaeology is a self-reproducing field taught in many university departments of anthropology or archaeology. As archaeologists have literally taken faunal analysis into their own hands, they have debated how best to use animal remains to study everything from early hominin hunting or scavenging to animal production in ancient market economies. Animal remains from archaeological sites have been used to infer three kinds of information: the age of deposits (chronology); paleoenvironment and paleoecological relations among humans and other species; human choices and actions related to use of animals as food and raw materials. Methods for reconstructing human diet and behavior have undergone the greatest growth over the last four decades, and most of this book addresses the second and third areas. This book deals with what I know best: vertebrate zooarchaeology, and within that, analysis of mammalian bones and teeth

    ENERGY CONSUMPTION OF MOBILE PHONES

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    Battery consumption in mobile applications development is a very important aspect and has to be considered by all the developers in their applications. This study will present an analysis of different relevant concepts and parameters that may have an impact on energy consumption of Windows Phone applications. This operating system was chosen because limited research related thereto has been conducted, even though there are related studies for Android and iOS operating systems. Furthermore, another reason is the increasing number of Windows Phone users. The objective of this research is to categorise the energy consumption parameters (e.g. use of one thread or several threads for the same output). The result for each group of experiments will be analysed and a rule will be derived. The set of derived rules will serve as a guide for developers who intend to develop energy efficient Windows Phone applications. For each experiment, one application is created for each concept and the results are presented in two ways; a table and a chart. The table presents the duration of the experiment, the battery consumed in the experiment, the expected battery lifetime, and the energy consumption, while the charts display the energy distribution based on the main threads: UI thread, application thread, and network thread
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