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دانلود رایکان مقاله انگلیسی ISI با موضوع برنامه ریزی سیاست های ساختاری بازرسی و نگهداشت از طریق برنامه نویسی پویا و فرآیندهای مارکوف

عنوان فارسی مقاله:

برنامه ریزی سیاست های ساختاری بازرسی و نگهداشت از طریق برنامه نویسی پویا و فرآیندهای مارکوف. بخش 2: پیاده سازی POMDP

عنوان انگلیسی مقاله:

Planning structural inspection and maintenance policies via dynamic programming and Markov processes. Part II: POMDP implementation

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بخشی از مقاله انگلیسی :

4. Results

Having presented the POMDP framework in a detailed manner, simulation results and Perseus performance are now demonstrated and discussed. All numerical experiments were run on a desktop PC with 32-bit windows, Intel Core2Quad processor at 2.33GHz and 3GB RAM. As stated earlier, Perseus builds a set of reachable belief points B, at the beginning of the algorithm, by performing random walks over the belief space, through simulation of random trajectories of possible actions and observations, starting from an initial belief point. For the specific example, a set of 120000 belief points is finally used by performing random simulations, based on action selection probabilities equal to 0.84/3 for all the do-nothing/no-repair actions and 0.08/3 for all minor- and major-repair actions. Every 124 simulation steps each random trajectory was terminated and a new one was initiated from the initial belief point. The initial point of the system is the state with condition level 1 and the first deterioration rate, with certainty. Due to the continuous restarting of new trajectories the replace action was not sampled during the runs. All these parameters were finally chosen because they provide an adequate coverage of the whole reachable belief simplex. For the backup part of the algorithm, we have set Perseus to terminate after it had completed a backup stage beyond 86400s (24h), in order to check the algorithmic behavior for prolonged time.