6,324 research outputs found

    Surrogate Assisted Optimisation for Travelling Thief Problems

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    The travelling thief problem (TTP) is a multi-component optimisation problem involving two interdependent NP-hard components: the travelling salesman problem (TSP) and the knapsack problem (KP). Recent state-of-the-art TTP solvers modify the underlying TSP and KP solutions in an iterative and interleaved fashion. The TSP solution (cyclic tour) is typically changed in a deterministic way, while changes to the KP solution typically involve a random search, effectively resulting in a quasi-meandering exploration of the TTP solution space. Once a plateau is reached, the iterative search of the TTP solution space is restarted by using a new initial TSP tour. We propose to make the search more efficient through an adaptive surrogate model (based on a customised form of Support Vector Regression) that learns the characteristics of initial TSP tours that lead to good TTP solutions. The model is used to filter out non-promising initial TSP tours, in effect reducing the amount of time spent to find a good TTP solution. Experiments on a broad range of benchmark TTP instances indicate that the proposed approach filters out a considerable number of non-promising initial tours, at the cost of omitting only a small number of the best TTP solutions

    Adsorption and Diffusion of Pt and Au on the Stoichiometric and Reduced TiO2 Rutile (110) Surfaces

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    A comparative first principles pseudopotential study of the adsorption and migration profiles of single Pt and Au atoms on the stoichiometric and reduced TiO2 rutile (110) surfaces is presented. Pt and Au behave similarly with respect to (i) most favorable adsorption sites, which are found to be the hollow and substitutional sites on the stoichiometric and reduced surfaces, respectively, (ii) the large increase in their binding energy (by ~1.7 eV) when the surface is reduced, and (iii) their low migration barrier near 0.15 eV on the stoichiometric surface. Pt, on the other hand, binds more strongly (by ~2 eV) to both surfaces. On the stoichiometric surface, Pt migration pattern is expected to be one-dimensional, which is primarily influenced by interactions with O atoms. Au migration is expected to be two-dimensional, with Au-Ti interactions playing a more important role. On the reduced surface, the migration barrier for Pt diffusion is significantly larger compared to Au.Comment: 3 figures, 1 table, submitted to PR

    Soeharto and the Politicization of Indonesian Islam (1968-1998)

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    Soeharto treated Indonesian Muslim Communities with two different ways. On the one side, he has given them full freedom to conduct Islamic rituals such as prayers, almsgivings, fasting during Ramadhan, pilgrim and so on. On the other side, however, he has not given them full freedom to exercise politics at the practical level because it would raise problems in the long run. He handled their political activities tightly. Therefore he put whatever efforts necessary to safeguard his power interests such as launching Pancasila as the sole basis (asas tunggal) for all political parties and mass organizations, merging four Islamic political parties into one party, PPP and so on. After more than 30 years he conducted the politicization of Islam, the big mutiny and turbulences happened everywhere which was supported by all university students and caused the fall of his power in 1998 with sad ending and Indonesian reform era started

    Pengaruh Motivasi, Lingkungan Kerja dan Budaya Kerja terhadap Prestasi Kerja di Dinas Pendapatan Daerah Kota Palembang

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    Design / Methodology / Approach: the data used for analysis in this study isqualitative data , the variables in this study are motivation , workenvironment , work culture and performance achievement . The population inthis study is the Regional Revenue Service Employees Palembang ,amounting to 256 employees . The sampling technique used in this study issimple random sampling . The sample in this study using the formulaobtained slovin to 156 people . The method of analysis in this study usingOLS regression ( Ordinary Least Square ) Findings : Overall variablemotivation , work environment and work culture have a significant effect onthe performance of the Regional Revenue Service employee Palembang .But individually , motivation significant effect on work performance , workenvironment variables have a significant effect on work performance andwork culture variables significantly influence the achievement of RegionalRevenue Office of Palembang
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