Solving the optimal control problem with a free final time, such as suborbital launch vehicle (SLV) trajectory optimization with two control variables and multi-constraints ones based on particle swarm optimization (P...
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Deblurring camera-based document image is an important task in digital document processing, since it can improve both the accuracy of optical character recognition systems and the visual quality of document images. Tr...
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In this paper, we formulate and investigate a memristor-based switching network which is directly extended from Itoh and Chua's chaotic circuit. Conditions are derived which ensure the existence of an equilibrium ...
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Reentry trajectory optimization is a multi-constraints optimal control problem which is hard to solve. To tackle it, we proposed a new algorithm named CDEN(Constrained Differential Evolution Newton-Raphson Algorithm) ...
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Reentry trajectory optimization is a multi-constraints optimal control problem which is hard to solve. To tackle it, we proposed a new algorithm named CDEN(Constrained Differential Evolution Newton-Raphson Algorithm) based on Differential Evolution(DE) and *** transform the infinite dimensional optimal control problem to parameter optimization which is finite dimensional by discretize control parameter. In order to simplify the problem, we figure out the control parameter's scope by process constraints. To handle constraints, we proposed a parameterless constraints handle process. Through comprehensive analyze the problem, we use a new algorithm integrated by DE and Newton-Raphson to solve it. It is validated by a reentry vehicle X-33, simulation results indicated that the algorithm is effective and robust.
An Echo State Network (ESN) based predictive control method for aircraft system is proposed to increase the flight quality. Aerocraft is a nonlinear and time-varying system and its controllers are usually designed by ...
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The analytical algorithm of program quaternion is studied, aiming at the problem of the arbitrary spacecraft attitude-adjusting control. It also provides the analytical constructor method of the program quaternion for...
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Nonnegative matrix factorization (NMF) is an increasingly popular technique for data processing and analysis. For an incomplete data matrix, the weighted nonnegative matrix factorization (WNMF) is employed to decompos...
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Nonnegative matrix factorization (NMF) is an increasingly popular technique for data processing and analysis. For an incomplete data matrix, the weighted nonnegative matrix factorization (WNMF) is employed to decompose it. But the searching step size in WNMF is not optimal along the given searching direction. This paper studies the incomplete nonnegative matrix factorization (INMF) and proposes an accelerated algorithm. First, INMF is transformed into solving alternatively two nonnegative least squares (NNLS) problems. For each NNLS problem, the exact step size is chosen along the searching direction. Then, the complexity of NNLS problems is analyzed. Finally, experimental results show that the proposed method outperforms WNMF.
A method based on multi-agents and ANN(Artificial Neural Network)was proposed to solve the pursuit-evasion task in continuous timevarying *** to this method,several autonomous agents with 8 circular sector sensors and...
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A method based on multi-agents and ANN(Artificial Neural Network)was proposed to solve the pursuit-evasion task in continuous timevarying *** to this method,several autonomous agents with 8 circular sector sensors and an ANN controller were used to form a coordinated behavior to capture the *** evolve the controller,NEAT(Neuro Evolution of Augmenting Topologies)and PSO(Particle Swarm Optimization)method were used to optimize the *** simulation experiments show that both methods can successfully evolve the controller to capture the evaders,while NEAT requires less swarm members and consume less time comparing to PSO method.
Transient faults are hard to be detected and located due to their unpredictable nature and short duration, and they are the dominant causations of system failures, which makes it necessary to consider transient fault-...
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This paper proposes a improved non-local means (NLM) filter for image denoising. Due to the drawback that the similarity is computed based on the noisy image, the traditional NLM method easily generates the artifacts ...
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This paper proposes a improved non-local means (NLM) filter for image denoising. Due to the drawback that the similarity is computed based on the noisy image, the traditional NLM method easily generates the artifacts in case of high-level noise. The proposed method first preprocesses the noisy image by Gaussian filter. Then, a moving window at each pixel of the noisy image is chosen as the search window, and meanwhile, a improved calculation method of spatial distance based on the preprocessed image is used for computing the similarity. Finally, combining the improved distance with search window based on the noisy image, the intensity of each pixel is restored as the traditional NLM method. The standard images are used to evaluate restoration performance of the proposed method. Additionally, the application on medical image denoising also demonstrates that our method is practical.
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