199 research outputs found

    Visualization, Feature Selection, Machine Learning: Identifying the Responsible Group for Extreme Acts of Violence

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    The toll of human casualties and psychological impacts on societies make any study on violent extremism worthwhile, let alone attempting to detect patterns among them. This paper is an effort to predict which violent extremist organization (VEO), among 14 currently active ones throughout the world, is responsible for a violent act based on 14 features, including its human and structural tolls, its target type and value, intelligence, and weapons utilized in the attack. Three main steps in our paper include: 1) the visualization of the violent acts through linear and non-linear dimensionality reduction techniques; 2) sequential forward feature selection based on the generalization accuracy of three machine learning models–decision tree, and linear and nonlinear SVM; and 3) employing multilayer perceptron to predict the VEO based on the selected features of a violent act. Top-ranked selected features were related to the target type and plan and the multilayer perceptron achieved up to 40% test accuracy

    Charged scalar quasi-normal modes for higher-dimensional Born-Infeld dilatonic black holes with Lifshitz scaling

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    We study quasi-normal modes for a higher dimensional black hole with Lifshitz scaling, as these quasi-normal modes can be used to test Lifshitz models with large extra dimensions. Furthermore, as the effective Planck scale is brought down in many models with large extra dimensions, we study these quasi-normal modes for a UV completion action. Thus, we analyze quasi-normal modes for higher dimensional dilaton-Lifshitz black hole solutions coupled to a non-linear Born-Infeld action. We will analyze the charged perturbations for such a black hole solution. We will first analyze the general conditions for stability analytically, for a positive potential. Then, we analyze this system for a charged perturbation as well as negative potential, using the asymptotic iteration method for quasi-normal modes. Thus, we analyze the behavior of these modes numerically.Comment: 9 pages (two columns), 4 figures (including subfigures

    Weighted Machine Learning

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    A simple greedy approximation algorithm for the unit disk cover problem

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    Given a set P\mathcal P of nn points in the plane, the unit disk cover problem, which is known as an NP-hard problem, seeks to find the minimum number of unit disks that can cover all points of P\mathcal P. We present a new 44-approximation algorithm with running time O(nlogn)O(n \log n) for this problem. Our proposed algorithm uses a simple approach and is easy to understand and implement

    Growth performance, intestinal microflora, plasma fatty acid profile in broiler chickens fed herbal plant (Euphorbia hirta) and mix of acidifiers.

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    The aim of the current study was to evaluate two feed additives containing Euphorbia hirta and acidifiers on broiler chickens performance, gut microflora and blood fatty acid profiles. A total of 240 one-day-old male broiler chicks were randomly assigned in groups of 15-16 floor pens. On day one, the chicks were assigned to one of 4 dietary treatments; (1) basal diet (control), (2) basal diet. +. 7.5. g/kg E. hirta (EH7.5), (3) basal diet. +. 1.5. g/kg acidifier (OA) and (4) basal diet. +. 7.5. g/kg E. hirta+. 1.5. g/kg acidifier (EHOA). Body weight and feed intake were measured weekly and feed conversion ratio (FCR) was calculated. On days 21 and 42, eight birds from each dietary treatment were chosen at random for ileum viable bacterial counts. On day 42, thiobarbituric acid reactive species as an indicator of lipid peroxidation level were measured. The EH7.5, EHOA and OA supplementation improved overall FCR (P=0.0275). The serum of chickens fed with EH7.5, OA and EHOA showed the lower malondialdehyde value than that of chickens fed the control diet (P=0.0068). On day 42, the lowest total bacteria count and Escherichia coli was observed in EH7.5, OA and EHOA fed birds (P<0.0001). In conclusion, the results of the present study suggest that dietary supplementation with E. hirta in combination with acidifier have a positive impact on FCR and their combination displays antioxidant and antibacterial characteristics in broiler chickens

    Tobacco use preventional interventions among Iranian adolescents: A review study

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    Background and Aims: Considering the increasing trend of tobacco usage among adolescents, effective interventions are necessary for smoking prevention in this group. We, therefore, decided to investigate the status of preventive interventions on tobacco usage among Iranian adolescents, especially the theory/model-based interventions.Meanwhile, the authors surveyed among other related studies, and categorized them in terms of effect/no effect.Materials and Methods: A literature review was performed. We selected studies to include in our analyses via a search of Scientific Information Database-SID and google scholar (as a supporter motor researcher) on November of 2017, using the keywords “Tobacco, Smoking, Hookahs” in the title and abstract of all published articles. After removing repetitive and unrelated cases, the full text of a series of articles on the prevention of tobacco in adolescentswas reviewed and the results were presented in terms of the phrases and tables.Results: Out of 1078 extracted articles, 14 papers were finally evaluated. The interventions were divided into twomain categories. Totally, in 9 studies, health education models and theories were the basis for intervention, and otherapproaches had been used in the remaining five studies.Conclusion: In spite of the influence of both types of interventions, model/theoretic interventions have been usedmore than other interventions in smoking prevention, which could be due to the more favorable and clearer effects of these interventions in changing the various behaviors of the health sector.Keywords: tobacco, preventional intervention, adolescent, review stud
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