17,626 research outputs found

    A File System Abstraction for Sense and Respond Systems

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    The heterogeneity and resource constraints of sense-and-respond systems pose significant challenges to system and application development. In this paper, we present a flexible, intuitive file system abstraction for organizing and managing sense-and-respond systems based on the Plan 9 design principles. A key feature of this abstraction is the ability to support multiple views of the system via filesystem namespaces. Constructed logical views present an application-specific representation of the network, thus enabling high-level programming of the network. Concurrently, structural views of the network enable resource-efficient planning and execution of tasks. We present and motivate the design using several examples, outline research challenges and our research plan to address them, and describe the current state of implementation.Comment: 6 pages, 3 figures Workshop on End-to-End, Sense-and-Respond Systems, Applications, and Services In conjunction with MobiSys '0

    A framework for proving the self-organization of dynamic systems

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    This paper aims at providing a rigorous definition of self- organization, one of the most desired properties for dynamic systems (e.g., peer-to-peer systems, sensor networks, cooperative robotics, or ad-hoc networks). We characterize different classes of self-organization through liveness and safety properties that both capture information re- garding the system entropy. We illustrate these classes through study cases. The first ones are two representative P2P overlays (CAN and Pas- try) and the others are specific implementations of \Omega (the leader oracle) and one-shot query abstractions for dynamic settings. Our study aims at understanding the limits and respective power of existing self-organized protocols and lays the basis of designing robust algorithm for dynamic systems

    Evaluating indoor positioning systems in a shopping mall : the lessons learned from the IPIN 2018 competition

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    The Indoor Positioning and Indoor Navigation (IPIN) conference holds an annual competition in which indoor localization systems from different research groups worldwide are evaluated empirically. The objective of this competition is to establish a systematic evaluation methodology with rigorous metrics both for real-time (on-site) and post-processing (off-site) situations, in a realistic environment unfamiliar to the prototype developers. For the IPIN 2018 conference, this competition was held on September 22nd, 2018, in Atlantis, a large shopping mall in Nantes (France). Four competition tracks (two on-site and two off-site) were designed. They consisted of several 1 km routes traversing several floors of the mall. Along these paths, 180 points were topographically surveyed with a 10 cm accuracy, to serve as ground truth landmarks, combining theodolite measurements, differential global navigation satellite system (GNSS) and 3D scanner systems. 34 teams effectively competed. The accuracy score corresponds to the third quartile (75th percentile) of an error metric that combines the horizontal positioning error and the floor detection. The best results for the on-site tracks showed an accuracy score of 11.70 m (Track 1) and 5.50 m (Track 2), while the best results for the off-site tracks showed an accuracy score of 0.90 m (Track 3) and 1.30 m (Track 4). These results showed that it is possible to obtain high accuracy indoor positioning solutions in large, realistic environments using wearable light-weight sensors without deploying any beacon. This paper describes the organization work of the tracks, analyzes the methodology used to quantify the results, reviews the lessons learned from the competition and discusses its future

    A contrasting look at self-organization in the Internet and next-generation communication networks

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    This article examines contrasting notions of self-organization in the Internet and next-generation communication networks, by reviewing in some detail recent evidence regarding several of the more popular attempts to explain prominent features of Internet structure and behavior as "emergent phenomena." In these examples, what might appear to the nonexpert as "emergent self-organization" in the Internet actually results from well conceived (albeit perhaps ad hoc) design, with explanations that are mathematically rigorous, in agreement with engineering reality, and fully consistent with network measurements. These examples serve as concrete starting points from which networking researchers can assess whether or not explanations involving self-organization are relevant or appropriate in the context of next-generation communication networks, while also highlighting the main differences between approaches to self-organization that are rooted in engineering design vs. those inspired by statistical physics

    Experimental Results and Evaluation of SmartBox Stimulation Device in a P2P E-learning System

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    In this paper, we present the experimental results and evaluation of the SmartBox stimulation device in P2P e-learning system which is based on JXTA-Overlay. We also show the design and implementation of the SmartBox environment that is used for stimulating the learners motivation to increase the learning efficiency. The SmartBox is integrated with our P2P system as a useful tool for monitoring and controlling learners¿ activity. We found by experimental results that the SmartBox is an effective way to increase the learner¿s concentration. We also investigated the relation between learner¿s body movement, concentration, and amount of study. From the experimental results, we conclude that the use of SmartBox is an effective way to stimulate the learners in order to continue studying while maintaining the concentration.En aquest article es presenten els resultats experimentals i l'avaluació del dispositiu d'estimulació SmartBox en un sistema d'aprenentatge en línia P2P que es basa en la superposició de JXTA. També es mostra el disseny i implementació de l'ambient de l'SmartBox que s'utilitza per a estimular la motivació dels estudiants per augmentar l'eficiència en l'aprenentatge. L'SmartBox s'integra amb el nostre sistema de P2P com una eina útil per al monitoratge i per controlar l'activitat dels alumnes. Pels resultats experimentals trobem que l'SmartBox és una forma efectiva d'augmentar la concentració de l'alumne. També es va investigar la relació entre el moviment del cos de l'alumne, la concentració i la quantitat d'estudis. Dels resultats experimentals es conclou que l'ús de l'SmartBox és una manera efectiva d'estimular els estudiants per tal que continuïn els seus estudis mentre es manté la seva concentració.En este artículo se presentan los resultados experimentales y la evaluación del dispositivo de estimulación SmartBox en un sistema de aprendizaje en línea P2P que se basa en la superposición de JXTA. También se muestra el diseño e implementación del ambiente del SmartBox que se utiliza para estimular la motivación de los estudiantes para aumentar la eficiencia en el aprendizaje. El SmartBox se integra con nuestro sistema de P2P como una herramienta útil para la monitorización y para controlar la actividad de los alumnos. Por los resultados experimentales encontramos que la SmartBox es una forma efectiva de aumentar la concentración del alumno. También se investigó la relación entre el movimiento del cuerpo del alumno, la concentración y la cantidad de estudios. De los resultados experimentales se concluye que el uso del SmartBox es una manera efectiva de estimular a los estudiantes para que continúen sus estudios mientras se mantiene su concentración

    A new wireless underground network system for continuous monitoring of soil water contents

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    A new stand-alone wireless embedded network system has been developed recently for continuous monitoring of soil water contents at multiple depths. This paper presents information on the technical aspects of the system, including the applied sensor technology, the wireless communication protocols, the gateway station for data collection, and data transfer to an end user Web page for disseminating results to targeted audiences. Results from the first test of the network system are presented and discussed, including lessons learned so far and actions to be undertaken in the near future to improve and enhance the operability of this innovative measurement approac
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