401 research outputs found

    Locating fire-stations: an integrated approach for Belgium

    Get PDF
    This paper demonstrates the potential of a decision-support system developed for Belgium by a consortium of universities and a private firm, in the framework of a public call by the Ministry of the Interior. The system is designed to provide the Belgian emergency management administration with a complete decision-aid tool for the location of fire-stations. The originality of the project is that it includes a risk-modeling approach developed at a national scale. This analysis involves a multiscale GIS system which includes a thorough representation of the physical, human and economic spatial realities, a risk modeling approach, an adequate optimal location and allocation model (taking into account both queuing and staffing problems). The final result is an interactive operational tool for defining locations, equipment allocations, staffing, response times, the cost/efficiency trade-off, etc. which can be used in an assessment as well as a prospective context. It has numerous functionalities including rapid modification of the modeling conditions to allow for quick scenario analysis, multiscale analysis, and prospective analysis.ocation-allocations, GIS, fire-stations, Belgium

    EBDP BUFFER SIZING STRATEGY 802.11 BASED WLANS

    Get PDF
    In this paper we present wired routers, for whom the sizing of buffers is an active research topic. The classical rule of thumb for sizing wired buffers is to set buffer sizes to be the product of the bandwidth and the average delay of the flows utilizing this link, namely the Bandwidth-Delay Product (BDP) rule. Surprisingly, however the sizing of buffers in wireless networks (especially those based on 802.11/802.11e) appears to have received very little attention within the networking community. Exceptions include the recent work in relating to buffer sizing for voice traffic in 802.11e WLANs, work in which considers the impact of buffer sizing on TCP upload/download fairness, and work in which is related to 802.11e parameter settings

    Wavelet and Multiscale Analysis of Network Traffic

    Get PDF
    The complexity and richness of telecommunications traffic is such that one may despair to find any regularity or explanatory principles. Nonetheless, the discovery of scaling behaviour in tele-traffic has provided hope that parsimonious models can be found. The statistics of scaling behavior present many challenges, especially in non-stationary environments. In this paper we describe the state of the art in this area, focusing on the capabilities of the wavelet transform as a key tool for unravelling the mysteries of traffic statistics and dynamics

    Characteristics of WAP traffic

    Get PDF
    This paper considers the characteristics of Wireless Application Protocol (WAP) traffic. We start by constructing a WAP traffic model by analysing the behaviour of users accessing public WAP sites via a monitoring system. A wide range of different traffic scenarios were considered, but most of these scenarios resolve to one of two basic types. The paper then uses this traffic model to consider the effects of large quantities of WAP traffic on the core network. One traffic characteristic which is of particular interest in network dimensioning is the degree of self-similarity, so the paper looks at the characteristics of aggregated traffic with WAP, Web and packet speech components to estimate its self-similarity. The results indicate that, while WAP traffic alone does not exhibit a significant degree of self-similarity, a combined load from various traffic sources retains almost the same degree of self-similarity as the most self-similar individual source

    PoissonProb: A new rate-based available bandwidth measurement algorithm.

    Get PDF
    Accurate available bandwidth measurement is important for network protocols and distributed programs design, traffic optimization, capacity planning, and service verification. Research on measuring available bandwidth falls into two basic classes: the network traffic modeling algorithms and the self-induced algorithms. The self-induced algorithms are based on packet dispersion techniques. The currently available bandwidth measurement algorithms face the problems of distortion of measurement on multi-hop paths, system resource limitations, probe traffic intrusiveness and measurement accuracy. We have developed a new rate-based self-induced algorithm---PoissonProb. The intervals between probe packets of this algorithm are in Poisson distribution format and the algorithm infers the available bandwidth according to the average of probe packets rate. The algorithm has been implemented as the PoissonProb Available Bandwidth (PAB) measurement tool. The PAB tool can be operated in either sender-based or receiver-based mode. (Abstract shortened by UMI.) Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2005 .X56. Source: Masters Abstracts International, Volume: 44-03, page: 1418. Thesis (M.Sc.)--University of Windsor (Canada), 2005

    Self-Evaluation Applied Mathematics 2003-2008 University of Twente

    Get PDF
    This report contains the self-study for the research assessment of the Department of Applied Mathematics (AM) of the Faculty of Electrical Engineering, Mathematics and Computer Science (EEMCS) at the University of Twente (UT). The report provides the information for the Research Assessment Committee for Applied Mathematics, dealing with mathematical sciences at the three universities of technology in the Netherlands. It describes the state of affairs pertaining to the period 1 January 2003 to 31 December 2008

    Optimal sampling strategies for multiscale stochastic processes

    Full text link
    In this paper, we determine which non-random sampling of fixed size gives the best linear predictor of the sum of a finite spatial population. We employ different multiscale superpopulation models and use the minimum mean-squared error as our optimality criterion. In multiscale superpopulation tree models, the leaves represent the units of the population, interior nodes represent partial sums of the population, and the root node represents the total sum of the population. We prove that the optimal sampling pattern varies dramatically with the correlation structure of the tree nodes. While uniform sampling is optimal for trees with ``positive correlation progression'', it provides the worst possible sampling with ``negative correlation progression.'' As an analysis tool, we introduce and study a class of independent innovations trees that are of interest in their own right. We derive a fast water-filling algorithm to determine the optimal sampling of the leaves to estimate the root of an independent innovations tree.Comment: Published at http://dx.doi.org/10.1214/074921706000000509 in the IMS Lecture Notes--Monograph Series (http://www.imstat.org/publications/lecnotes.htm) by the Institute of Mathematical Statistics (http://www.imstat.org

    INCITE: Edge-based Traffic Processing and Inference for High-Performance Networks

    Full text link
    • 

    corecore