3,001 research outputs found

    Evaluation methods and decision theory for classification of streaming data with temporal dependence

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    Predictive modeling on data streams plays an important role in modern data analysis, where data arrives continuously and needs to be mined in real time. In the stream setting the data distribution is often evolving over time, and models that update themselves during operation are becoming the state-of-the-art. This paper formalizes a learning and evaluation scheme of such predictive models. We theoretically analyze evaluation of classifiers on streaming data with temporal dependence. Our findings suggest that the commonly accepted data stream classification measures, such as classification accuracy and Kappa statistic, fail to diagnose cases of poor performance when temporal dependence is present, therefore they should not be used as sole performance indicators. Moreover, classification accuracy can be misleading if used as a proxy for evaluating change detectors with datasets that have temporal dependence. We formulate the decision theory for streaming data classification with temporal dependence and develop a new evaluation methodology for data stream classification that takes temporal dependence into account. We propose a combined measure for classification performance, that takes into account temporal dependence, and we recommend using it as the main performance measure in classification of streaming data

    CHORUS Deliverable 2.2: Second report - identification of multi-disciplinary key issues for gap analysis toward EU multimedia search engines roadmap

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    After addressing the state-of-the-art during the first year of Chorus and establishing the existing landscape in multimedia search engines, we have identified and analyzed gaps within European research effort during our second year. In this period we focused on three directions, notably technological issues, user-centred issues and use-cases and socio- economic and legal aspects. These were assessed by two central studies: firstly, a concerted vision of functional breakdown of generic multimedia search engine, and secondly, a representative use-cases descriptions with the related discussion on requirement for technological challenges. Both studies have been carried out in cooperation and consultation with the community at large through EC concertation meetings (multimedia search engines cluster), several meetings with our Think-Tank, presentations in international conferences, and surveys addressed to EU projects coordinators as well as National initiatives coordinators. Based on the obtained feedback we identified two types of gaps, namely core technological gaps that involve research challenges, and “enablers”, which are not necessarily technical research challenges, but have impact on innovation progress. New socio-economic trends are presented as well as emerging legal challenges

    New Directions in Compensation Research: Synergies, Risk, and Survival

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    We describe and use two theoretical frameworks, the resource-based view of the firm and institutional theory, as lenses for examining three promising areas of compensation research. First, we examine the nature of the relationship between pay and effectiveness. Does pay typically have a main effect or, instead, does the relationship depend on other human resource activities and organization characteristics? If the latter is true, then there are synergies between pay and these other factors and thus, conclusions drawn from main effects models may be misleading. Second, we discuss a relatively neglected issue in pay research, the concept of risk as it applies to investments in pay programs. Although firms and researchers tend to focus on expected returns from compensation interventions, analysis of the risk, or variability, associated with these returns may be essential for effective decision-making. Finally ,pay program survival, which has been virtually ignored in systematic pay research, is investigated. Survival appears to have important consequences for estimating pay plan risk and returns, and is also integral to the discussion of pay synergies. Based upon our two theoretical frameworks, we suggest specific research directions for pay program synergies, risk, and survival

    Characterization of Internet Traffic in UUM Wireless Networks

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    The development in communication technology and the propagation of mobile devices, lightweight, with built-in, high-speed radio access in wireless are making wireless access to the Internet the popular situation rather than a wire line. Whereas, the growth of the wireless network with additional mobile devices in the UUM and increasing number of users led to slow wireless connection. Therefore, understanding the behavior of traffic analysis helps us to develop, manage WLAN technology, and deploy. It help us to apply our workload analysis results to issues in wireless network deployment, such as capacity planning, and potential network optimizations, such as algorithms for load balancing across multiple Access Points (APs) in a wireless network. The trace composes of two parts: firstly, one that connects to the core switch in computer center which is connected with the distribution switches that link the Access Point (APs) with the wireless network at campus, and secondly, another one for the measurement of bulk data transfers and interactive data exchange between two nodes in UUM library, which had been initiated at that time. This thesis investigates the performance network and users' behavior in UUM wireless network

    The Ten-Year Rule: Allocation of Emission Allowances in the EU Emission Trading System

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    In its guidance on National Allocation Plans (NAPs), the European Commission has discouraged Member States from adopting allocation methodologies that would provide incentives to firms affecting their compliance behavior. The purpose is to promote economic efficiency and to prevent strategic behavior that deviates from individual and collective cost-minimization. For example, some methodologies would reward one type of compliance investment over another. To discourage such actions, the EU Emission Trading System guidelines prohibit ex post redistribution of emission allowances within an allocation period based on behavior in that period. Similarly, the Commission has indicated that decisions about the initial distribution of allowances in the second phase (2008-2012) must depend on measures prior to 2005 so as not to give companies an incentive to adjust their behavior to receive a larger allowance allocation. However, two other aspects of the NAPs—the treatment of closures and new entrants—may also affect firm behavior. An undercurrent in these guidelines is the question of whether Member States should allow incumbent emitters to hold infinitely lived, once-and-for-all property rights to a share of the emission allowances in the future. This paper develops an approach for balancing efficiency considerations with perceived issues of fairness. We propose a ten-year rule to guide policy regarding closure of existing sources and the status of new sources and to guide the initial distribution of emission allowances in general. A ten-year rule would address issues of fairness and capture an important part of the potential gains that could be achieved through an efficient initial distribution of allowances.emission trading, allowance allocations, closures, new entrants, tradable permits, air pollution, cost-effectiveness, greenhouse gases, climate change, global warming, carbon dioxide
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