The standard DP ( dynamicprogramming) algorithms are limited by the substantial computational demands they put on contemporary serial computers. In this work, the theory behind the solution to serial monadic dynamic ...
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The standard DP ( dynamicprogramming) algorithms are limited by the substantial computational demands they put on contemporary serial computers. In this work, the theory behind the solution to serial monadic dynamicprogramming problems highlights the theory and application of parallel dynamic programming on a general-purpose architecture ( Cluster or Network Of Workstations). A simple and well-known technique, message passing, is considered. Several parallel serial monadic DP algorithms are proposed, based on the parallelization in the state variables and the parallelization in the decision variables. Algorithms with no interpolation are also proposed. It is demonstrated how constraints introduce load unbalance which affect scalability and how this problem is inherent to DP.
dynamicprogramming is a classic method to solve reservoir optimized operation. However, with the increasing number of reservoir power stations, computation amount is increasing exponentially, resulting in a dramatic ...
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ISBN:
(纸本)9781479948604
dynamicprogramming is a classic method to solve reservoir optimized operation. However, with the increasing number of reservoir power stations, computation amount is increasing exponentially, resulting in a dramatic decrease in the timeliness of solving and even causing "curse of dimensionality". In response to this, we improved the serial recursion calculation process of dynamicprogramming and introduced parallel dynamic programming based on stage reconstruction. Through the proposed algorithm a multistage decision problem can be repeatedly reconstructed in a parallel environment and gradually transferred to a single stage issue. This algorithm was then applied to solve the optimized operation of cascade reservoirs in the lower reach of Yalong River in China. Analog computation was carried out to evaluate the effects of parameter control on the parallel calculation performance of the algorithm. Results indicate that the calculating efficiency, compared with serial dynamicprogramming, can be significantly improved without sacrificing the accuracy with parallel dynamic programming based on stage reconstruction.
We improved the serial recursion calculation process of dynamicprogramming and introduced parallel dynamic programming based on stage reconstruction. Through the proposed algorithm a multistage decision problem can b...
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We improved the serial recursion calculation process of dynamicprogramming and introduced parallel dynamic programming based on stage reconstruction. Through the proposed algorithm a multistage decision problem can be repeatedly reconstructed and gradually transferred to a single stage issue. This algorithm was applied to solve the optimized operation of cascade reservoirs in the lower reach of Yalong River in China. Results indicate that the calculating efficiency, compared with serial dynamicprogramming, can be significantly improved without sacrificing accuracy.
We examine a very simple asynchronous model of parallel computation that assumes the time to compute a task is random, following some probability distribution. The goal of this model is to capture the effects of unpre...
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We examine a very simple asynchronous model of parallel computation that assumes the time to compute a task is random, following some probability distribution. The goal of this model is to capture the effects of unpredictable delays on processors, due to communication delays or cache misses, for example. Using techniques from queueing theory and occupancy problems, we use this model to analyze two parallel dynamic programming algorithms. We show that this model is simple to analyze and correctly predicts which algorithm will perform better in practice. The algorithms we consider are a pipeline algorithm, where each processor i computes in order the entries of rows i, i + p, and so on, where p is the number of processors;and a diagonal algorithm, where entries along each diagonal extending from the left to the top of the table are computed in turn. It is likely that the techniques used here can be useful in the analysis of other algorithms that use barriers or pipelining techniques.
The joint optimal operation of cascade reservoir system can greatly improve the utilization of water resources. However, the complex high-dimensional and non-linear features and calculated costs often hinder the refin...
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The joint optimal operation of cascade reservoir system can greatly improve the utilization of water resources. However, the complex high-dimensional and non-linear features and calculated costs often hinder the refined operation and management of reservoirs. Recently, the local parallel computing has become an effective way to alleviate the "curse of dimensionality". Current local parallel computing has hardware limitations, which is difficult to adapt to large-scale computing. This study proposes a novel parallel dynamic programming algorithm based on Spark (PDPoS) via cloud computing. The simulation experiments are carried out for a comparative analysis of the solution efficiency, influence factors and stability of cloud computing. The results are as follows: (1) The efficiency of the cloud-based PDPoS is related to some factors;the number of CPU cores is the main influencing factor, followed by the operator, and the architecture has the least influence. (2) The runtime variance of cloud computing is 2.03, indicating cloud computing has high stability. (3) Under the same configuration (i.e., CPU and memory), the runtime of cloud computing is 41.5% similar to 110.3% longer than that of physical machines. However, cloud computing has rich resources, good scalability, and good portability of online operations, which is an attractive alternative for optimal operation of large-scale reservoir system.
in this paper the possibility of including automatic optimization techniques in the design of parallel dynamic programming algorithms in heterogeneous systems is analyzed. The main idea is to automatically approach th...
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in this paper the possibility of including automatic optimization techniques in the design of parallel dynamic programming algorithms in heterogeneous systems is analyzed. The main idea is to automatically approach the optimum values of a number of algorithmic parameters (number of processes, number of processors, processes per processor), and thus obtain low execution times. Hence, users could be provided with routines which execute efficiently, and independently of the experience of the user in heterogeneous computing and dynamicprogramming, and which can adapt automatically to a new network of processors or a new network configuration. (c) 2005 Elsevier B.V. All rights reserved.
in this paper the possibility of including automatic optimization techniques in the design of parallel dynamic programming algorithms in heterogeneous systems is analyzed. The main idea is to automatically approach th...
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ISBN:
(纸本)0769522106
in this paper the possibility of including automatic optimization techniques in the design of parallel dynamic programming algorithms in heterogeneous systems is analyzed. The main idea is to automatically approach the optimum values of a number of algorithmic parameters (number of processes, number of processors, processes per processor), and thus obtain low execution times. Hence, users could be provided with routines which execute efficiently, and independently of the experience of the user in heterogeneous computing and dynamicprogramming, and which can adapt automatically to a new network of processors or a new network configuration. (c) 2005 Elsevier B.V. All rights reserved.
A parallel dynamic programming algorithm, basing on the matrix calculation, is used to develop the optimum energy management strategy for a fuel cell and lithium-ion battery hybrid train. In this paper, besides the st...
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ISBN:
(纸本)9781728112497
A parallel dynamic programming algorithm, basing on the matrix calculation, is used to develop the optimum energy management strategy for a fuel cell and lithium-ion battery hybrid train. In this paper, besides the state of charge of the battery, the power from the fuel cell is defined as the other state variable. Then, the control variable is the power change rate in the fuel cell system. With the help of this problem formulation, an efficient parallel dynamic programming is easy to implement. The parallel calculation requires only one loop over the time stages. To make the parallel dynamic programming basing on the matriculated calculation successful, a semi-physical soft constraints mechanism is developed to initialize the cost function at the end time stage properly. With this parallel dynamic programming, the effect of a weighting factor between maximizing the fuel economy and avoiding high dynamic power change of fuel cell, on the total hydrogen consumption is investigated time efficiently.
The optimal impoundment operation of cascade reservoirs can dramatically improve the utilization of water resources. However, their complex non-convexity and computational costs pose challenges to optimal hydroelectri...
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The optimal impoundment operation of cascade reservoirs can dramatically improve the utilization of water resources. However, their complex non-convexity and computational costs pose challenges to optimal hydroelectricity output and limit further development of joint operation within larger-scale cascade reservoirs. In recent decades, parallel dynamic programming (PDP) has emerged as a means of alleviating the 'curse of dimensionally' in the mid-long term reservoir operation with more involved computing processors. But it still can't effectively solve the daily impoundment operation of more than three reservoirs. Here, we propose a novel method called importance sampling-PDP (IS-PDP) algorithm in which the merits of PDP are integrated with importance sampling and successive approximation strategy. Importance sampling is first used to construct the state vectors of each period by introducing 'Manhattan distance' in the discrete state space. Then the PDP recursive equation is used to find an improved solution during the iteration. The IS-PDP method is tested to optimize hydropower output for the joint operation of an 11-reservoir system located in the upper Yangtze River basin of China after establishing impoundment operation by advancing impoundment timings and rising water levels. We find that our methodology could effectively deal with the 'curse of dimensionally' for such mega reservoir systems and make better use of water resources in comparison to the Standard Operation Policy (SOP). Given its computational efficiency and robust convergence, the methodology is an attractive alternative for non-convex operation of large-scale cascade reservoirs.
The dataset contains reservoir characteristic parameters, stream-flow series of reservoirs in the upper Yangtze River, the standard operating rules (SORs) and the seasonal top of buffer pools (seasonal TBPs) for these...
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The dataset contains reservoir characteristic parameters, stream-flow series of reservoirs in the upper Yangtze River, the standard operating rules (SORs) and the seasonal top of buffer pools (seasonal TBPs) for these reservoirs, which were provided by the Yangtze River Commission. Moreover, annual hydropower of these reservoirs is tested to evaluate operation performance. These research materials are related to the research article in Advances in Water Resources, entitled 'Optimal impoundment operation for cascade reservoirs coupling parallel dynamic programming with importance sampling and successive approximation' (He et al., 2019). The dataset could be used to derive optimal operating rules to explore the potential benefits of water resources via our proposed algorithm (importance sampling - parallel dynamic programming, IS-PDP) in different runoff scenarios. It can also be further applied for water resources management and other potential users. (C) 2019 The Authors. Published by Elsevier Inc.
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