The main contribution of this paper is to present a simple exhaustive search algorithm for the quadratic unconstraint binary optimization (QUBO) problem. It computes the values of the objective function E(X) for all n...
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ISBN:
(数字)9781728174457
ISBN:
(纸本)9781728174570
The main contribution of this paper is to present a simple exhaustive search algorithm for the quadratic unconstraint binary optimization (QUBO) problem. It computes the values of the objective function E(X) for all n-bit input vector X in O(2 n ) time. Since Ω(2 n ) time is necessary to output E(X) for all 2 n vectors X, this sequential algorithm is optimal. We also present a work-time optimal parallel algorithm running O(log n) time using 2 n / log n processors on the CREW-PRAM. This parallel algorithm is work optimal, because the total number of computational operations is equal to the running time of the optimal sequential algorithm. Also, it is time optimal because any parallel algorithm using any large number of processors takes at least Ω(log n) time for evaluating E(X). Further, we have implemented this parallel algorithm to run on the GPU. The experimental results on NVIDIA GeForce RTX 2080Ti GPU show that our GPU implementation runs more than 1000 times faster than the sequential algorithm running on Intel Corei7-8700K CPU(3.70GHz) for the QUBO with nbit vector whenever n ≥ 33. We also compare our exhaustive search parallel algorithm with several non-exhaustive search approaches for solving the QUBO including D-Wave 2000Q quantum annealer, simulated annealing algorithm, and Gurobi optimizer.
One of the interesting problems in Bioinformatics is finding transcription start site in a gene. In fact, finding this site which separate promoter region from coding sequence, actually will end to promoter prediction...
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The paper is devoted to development and implementation of efficient parallel algorithm based on the conjugate gradient method for solving the nonlinear inverse potential problem of finding a boundary surface in two-la...
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The goal of this paper is to develop a parallel algorithm that, on input of a learning sample, identifies a regular language by means of a nondeterministic finite automaton (NFA). A sample is a pair of finite sets con...
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ISBN:
(数字)9781728189468
ISBN:
(纸本)9781728189475
The goal of this paper is to develop a parallel algorithm that, on input of a learning sample, identifies a regular language by means of a nondeterministic finite automaton (NFA). A sample is a pair of finite sets containing positive and negative examples. Given a sample, a minimal NFA or the range of possible sizes of such an NFA, that represents the target regular language is sought. We define the task of finding an NFA, which accepts all positive examples and rejects all negative ones, as a constraint satisfaction problem, and then propose a parallel algorithm to solve the problem. The results of computational experiments on the variety of test samples are reported.
Simultaneous equation models (SEM) are multivariate techniques that reflect the presence of jointly endogenous variables. Traditionally, these models have been used in economy, expanding in last decades into other dis...
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Simulation of the controlled motion of space tether systems differs significantly from the free motion case. Tether deployment increases its length and adds new points into the discrete model of the tether. A set of d...
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The paper is devoted to consideration of numerical global optimization methods in the framework of the approach of reducing dimensionality based on nested optimization schemes. For the adaptive nested scheme being mor...
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Monte-Carlo simulation (MCS) is the most accurate technique for considering the stochastic nature of renewable energy resources in power system analysis and planning. However, due to its heavy computational burden, MC...
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Monte-Carlo simulation (MCS) is the most accurate technique for considering the stochastic nature of renewable energy resources in power system analysis and planning. However, due to its heavy computational burden, MCS is rarely utilized when solving the multi-objective renewable distributed generation (DG) allocation problem. In order to address this problem, this paper proposes a novel methodology to exploit the massively parallel architecture of graphics processing units (GPU) in a way that enables the use of MCS when solving the multi-objective renewable DG allocation problem. First, the renewable DG allocation problem is formulated as a multi-objective optimization problem to minimize the lines losses and the costs pertaining to installing renewable DG units in the distribution network. Then, a parallelized implementation of NSGA-II using OpenCL is described in details to solve the formulated multi-objective renewable DG planning problem. The feasibility and effectiveness of the proposed methodology are validated using the IEEE 32-bus test system and two real distribution test systems. The results show that the proposed parallelized implementation can enable the use of MCS for modelling the generation and demand uncertainties when solving the multi-objective renewable DG allocation problem using a metaheuristic approach.
The determination of flow directions is an essential step for drainage network extraction, and flat surfaces are common features in flow direction determination. With the challenge of a massive volume of digital eleva...
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The determination of flow directions is an essential step for drainage network extraction, and flat surfaces are common features in flow direction determination. With the challenge of a massive volume of digital elevation models (DEMs), to reduce the running time and memory usage, there is a growing need to develop parallel algorithms to calculate flow directions over flat surfaces. We propose an efficient parallel algorithm for flow directions over flat surfaces based on the existing serial algorithm and three-step parallel framework. The proposed algorithm assigns pre-divided tiles to consumer processes to build local graphs. Then the producer process builds global graphs based on all the local graphs. Finally, consumer processes update the local graphs based on the global graphs and determine flow directions over flat surfaces. For all tested DEMs, the speed-up ratios are greater than 5 with 11 consumer processes. The strong scaling efficiencies are greater than 40% with 11 consumer processes. The proposed algorithm can run generally faster, use less memory, and process massive DEMs that cannot be successfully processed using the existing serial algorithm. This study shows that the proposed algorithm is an ideal parallel algorithm for determining flow direction over flat surfaces in massive DEMs.
Digital image processing is an actual task in the digital communication systems, IP-telephony and video conferencing, in digital television, and video surveillance. Digital processing of large video images takes a lot...
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ISBN:
(数字)9781728173863
ISBN:
(纸本)9781728173870
Digital image processing is an actual task in the digital communication systems, IP-telephony and video conferencing, in digital television, and video surveillance. Digital processing of large video images takes a lot of time, especially if it happens in a real-time system. And, processing speed plays an important role in recognition of objects in video images received from IP-cameras in real time. This requires the use of modern technologies, and fast algorithms that increase the acceleration of digital image processing. Acceleration problems have not been fully resolved till present. Today's realities are such that the development of accelerated image processing programs requires a good knowledge of parallel and distributed computing. Both of these areas are united by the fact that both parallel and distributed software consists of several processes that together solve one common problem. This article proposes an accelerated method for the tasks of recognizing objects in video images received from IP-cameras using parallel and distributed computing technologies.
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