2,866 research outputs found

    Online Makespan Minimization with Parallel Schedules

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    In online makespan minimization a sequence of jobs σ=J1,...,Jn\sigma = J_1,..., J_n has to be scheduled on mm identical parallel machines so as to minimize the maximum completion time of any job. We investigate the problem with an essentially new model of resource augmentation. Here, an online algorithm is allowed to build several schedules in parallel while processing σ\sigma. At the end of the scheduling process the best schedule is selected. This model can be viewed as providing an online algorithm with extra space, which is invested to maintain multiple solutions. The setting is of particular interest in parallel processing environments where each processor can maintain a single or a small set of solutions. We develop a (4/3+\eps)-competitive algorithm, for any 0<\eps\leq 1, that uses a number of 1/\eps^{O(\log (1/\eps))} schedules. We also give a (1+\eps)-competitive algorithm, for any 0<\eps\leq 1, that builds a polynomial number of (m/\eps)^{O(\log (1/\eps) / \eps)} schedules. This value depends on mm but is independent of the input σ\sigma. The performance guarantees are nearly best possible. We show that any algorithm that achieves a competitiveness smaller than 4/3 must construct Ω(m)\Omega(m) schedules. Our algorithms make use of novel guessing schemes that (1) predict the optimum makespan of a job sequence σ\sigma to within a factor of 1+\eps and (2) guess the job processing times and their frequencies in σ\sigma. In (2) we have to sparsify the universe of all guesses so as to reduce the number of schedules to a constant. The competitive ratios achieved using parallel schedules are considerably smaller than those in the standard problem without resource augmentation

    Pengaruh Harga dan Penataan Produk (Display)terhadap Keputusan Pembelian dengan Kepuasan Konsumen sebagai Variabel Intervening pada Ud. Rejeki Agung Lamongan

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    This research was conducted at UD. REJEKI AGUNG Lamongan is engaged in marketing children\u27s toys. The purpose of this study was to determine how the influence of displays on purchasing decisions with customer satisfaction as an intervening variable at UD. REJEKI AGUNG Lamongan. The purpose of this study was to determine how much influence the display (product arrangement) on purchasing decisions with consumer satisfaction as an intervening variable. The population in this study were all consumers who had purchased the product in&nbsp; 2017. While the sample was 98 respondents using the Convinience Sampling method, which is a sampling technique that is easy to find. The results of this study indicate that the price and display partially affect Consumer satisfaction and Purchasing Decisions. And simultaneously also shows that price and display influences consumer satisfaction and purchasing decisions. Price variables give a greater influence on customer satisfaction and purchasing decisions

    EVALUATION OF THE ANTIOXIDANT ACTIVITY OF THE FLAVONOIDS ISOLATED FROM HELIOTROPIUM SINUATUM RESIN USING ORACFL, DPPH AND ESR METHODOLOGIES

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    Indexación: Web of Science; Scielo.The antioxidant capacity has been determined for a number of flavonoid compounds from Heliotropium sinuatum, a plant that grows in arid areas in the north of Chile. The methodologies used were: ORAC(FL) (oxygen radical absorbance capacity - fluorescein), DPPH (2,2-diphenyl-2-picrylhydrazyl) bleaching and electron spin resonance (ESR). These compounds were studied in homogeneous and heterogeneous media. The results showed that the 7-o-methyleriodictiol and 3-o-methylisorhamnetin are those with the highest antioxidant capacity.http://ref.scielo.org/m82cz

    Statistical mechanics of budget-constrained auctions

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    Finding the optimal assignment in budget-constrained auctions is a combinatorial optimization problem with many important applications, a notable example being the sale of advertisement space by search engines (in this context the problem is often referred to as the off-line AdWords problem). Based on the cavity method of statistical mechanics, we introduce a message passing algorithm that is capable of solving efficiently random instances of the problem extracted from a natural distribution, and we derive from its properties the phase diagram of the problem. As the control parameter (average value of the budgets) is varied, we find two phase transitions delimiting a region in which long-range correlations arise.Comment: Minor revisio

    Traffic Police Effectiveness and Efficiency Evaluations, an Overview of Methodological Considerations

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    Context: Every government implements various policies to mitigate road traffic injuries (RTIs). Many of these interventions are performed by traffic police. To evaluate effectiveness and efficiency of police enforcement, numerous studies have been conducted. Potential capabilities of epidemiology could get opportunity to improve these studies. The aim of this study was to extract and discuss some related methodological points of traffic police effectiveness and efficiency from related studies, in view of epidemiology discipline. Evidence Acquisition: Related articles were searched with “traffic police”, “effectiveness”, “efficiency” and “road safety” keywords in ScienceDirect, PubMed and Safetylit databases. Related papers were selected and read carefully to summarize and discuss the epidemiological points with aims of giving clues to improve quality of studies. Results: From a total of 797 articles, 20 were eligible which among them 17 articles were about effectiveness and 3 of them were about efficiency evaluations. Discussed points were the method of study, taking a holistic view to all positive and negative side effects, desired inputs and outputs, relation pattern between police enforcement and outcome and potential confounders. Conclusions: Better understanding of the effectiveness and efficiency mechanism and having valid evaluation required considering specific theories and points in this field. Applying a dynamic approach with considering epidemiological concepts and sophisticated statistical models could improve quality of studies in this field

    Biomassa e atividade microbiana do solo sob pastagem em sistemas de monocultura e silvipastoril.

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    A biomassa microbiana é um importante componente do solo que contribui para manutenção do ecossistema de pastagens, principalmente em solos tropicais. Neste sentido, o objetivo do trabalho foi avaliar a biomassa e atividade microbiana do solo sob pastagem em sistemas de monocultura de pasto de Brachiaria brizantha cv. Marandu, e em sistema silvipastoril formado por pasto e coqueiros (Cocos nucifera)

    A Case of Urogenital Human Schistosomiasis from a Non-endemic Area

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    © 2015 Calvo-Cano et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The attached file is the published version of the article
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