47 research outputs found

    Energy-efficient, On-demand Reprogramming of Large-scale Sensor Networks

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    As sensor networks operate over long periods of deployment in difficult to reach places, their requirements may change or new code may need to be uploaded to them. The current state of the art protocols (Deluge and MNP) for network reprogramming perform the code dissemination in a multi-hop manner using a three way handshake whereby meta-data is exchanged prior to code exchange to suppress redundant transmissions. The code image is also pipelined through the network at the granularity of pages. In this paper we propose a protocol called Freshet for optimizing the energy for code upload and speeding up the dissemination if multiple sources of code are available. The energy optimization is achieved by equipping each node with limited non-local topology information, which it uses to determine the time when it can go to sleep since code is not being distributed in its vicinity. The protocol to handle multiple sources provides a loose coupling of nodes to a source and disseminates code in waves each originating at a source, with mechanism to handle collisions when the waves meet. The protocol’s performance with respect to reliability, delay, and energy consumed, is demonstrated through analysis, simulation, and implementation on the Berkeley mote platform

    The “Wireless Sensor Networks for City-Wide Ambient Intelligence (WISE-WAI)” Project

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    This paper gives a detailed technical overview of some of the activities carried out in the context of the “Wireless Sensor networks for city-Wide Ambient Intelligence (WISE-WAI)” project, funded by the Cassa di Risparmio di Padova e Rovigo Foundation, Italy. The main aim of the project is to demonstrate the feasibility of large-scale wireless sensor network deployments, whereby tiny objects integrating one or more environmental sensors (humidity, temperature, light intensity), a microcontroller and a wireless transceiver are deployed over a large area, which in this case involves the buildings of the Department of Information Engineering at the University of Padova. We will describe how the network is organized to provide full-scale automated functions, and which services and applications it is configured to provide. These applications include long-term environmental monitoring, alarm event detection and propagation, single-sensor interrogation, localization and tracking of objects, assisted navigation, as well as fast data dissemination services to be used, e.g., to rapidly re-program all sensors over-the-air. The organization of such a large testbed requires notable efforts in terms of communication protocols and strategies, whose design must pursue scalability, energy efficiency (while sensors are connected through USB cables for logging and debugging purposes, most of them will be battery-operated), as well as the capability to support applications with diverse requirements. These efforts, the description of a subset of the results obtained so far, and of the final objectives to be met are the scope of the present paper

    Eutrophication in marine waters: harmonization of MSFD methodological standards at EU level

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    The Marine Strategy Framework Directive (MSFD) establishes the framework for the protection, conservation and sustainable use of the marine environment at the Union level. Because of its potential negative effects on the marine water quality, eutrophication is one of the criteria assessed under MSFD. This report presents the results of the joint work between JRC and a network of Member States (MS) eutrophication designated experts to assess the level of harmonization in Eutrophication methodological standards and threshold definition at regional and EU level. The information compiled at regional and national level showed that although methodologies are defined already for all the criteria, the degree of harmonization of methodological approaches across MS and regions is in some cases very low. In addition further developments are needed for some regions to agree on common indicators and threshold values. Based on these results the report highlights existing gaps and proposes recommendations to improve the eutrophication assessment framework at EU level.JRC.D.2-Water and Marine Resource

    Teaching Technical Communication - Unexpected Experience

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    In 1998, a course on technical communication was introduced at the Faculty of Electronics and Information Technology, Warsaw University of Technology. Some of its characteristic features are: (a) the course has been developed and taught by a team of a university professor and a senior engineer from a marketing division of a large industrial company; (b) the lectures cover several non-traditional topics, such as "Internet as a source of information" and "legal and ethical aspects of technical writing"; (c) self- and peer-reviewing of student assignments is employed. Our observations indicate that some assumptions underlying the development of the course were incorrect. In particular, contrary to our expectations, the students have been much better technical speakers than technical writers. Based on such observations, several changes in the contents and organization of the course have been made

    THE DERIVATION AND APPLICATION OF MEASURES OF REVENUE CAPACITY AND RELATIVE EFFORT FOR LOCAL GOVERNMENTS IN INDIANA

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