A complete mesh free adaptive algorithm （MFAA）, with solution adaptation and geometric adaptation, is developed to improve the resolution of flow features and to replace traditional global refinement techniques in s...
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A complete mesh free adaptive algorithm （MFAA）, with solution adaptation and geometric adaptation, is developed to improve the resolution of flow features and to replace traditional global refinement techniques in structured grids. Unnecessary redundant points and elements are avoided by using the mesh free local clouds refinement technology in shock influencing regions and regions near large curvature places on the boundary. Inviscid compressible flows over NACA0012 and RAE2822 airfoils are computed. Finally numerical results validate the accuracy of the above method.
A multi-channel adaptive active noise control system is studied in this paper, which involves a multiple number of primary noise sources, noise reference microphones, secondary control sources and cancelling error det...
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A multi-channel adaptive active noise control system is studied in this paper, which involves a multiple number of primary noise sources, noise reference microphones, secondary control sources and cancelling error detection microphones. First, a general structure of the multi-channel active noise control system is clarified and a perfect cancellation condition by a feedforward controller is presented. Secondly, a new LMS type of robust adaptive algorithm for updating the feedforward controllers is proposed, which can assure a stability of the adaptation and keep the each cancelling error within a tight bound by efficiently using prior information on each upper bound of the uncertainty terms. In experimental studies using an air duct, the proposed algorithm is compared with an ordinary filtered-x algorithm which does not always possess the property of stable convergence.
The vertex cover (VC) problem has been studied for past few years, and some centralized and distributed algorithms have been proposed. In this paper, we propose the so-called random memory length adaptive (RMLA) algor...
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The vertex cover (VC) problem has been studied for past few years, and some centralized and distributed algorithms have been proposed. In this paper, we propose the so-called random memory length adaptive (RMLA) algorithm for the VC problem in networks. Any initial state can reach the stable pure strict Nash equilibrium state through finite iterations by the RMLA algorithm. We find that by setting the minimum edge-keeping probability reasonably, the convergence rapidity and accuracy can be improved simultaneously. Our algorithm also removes the requirement for consistent node memory length. Through theoretical analysis and intensive numerical simulations, we verify the convergence and effectiveness of the RMLA algorithm.
The paper searches for solutions to the problem of detecting a signal from low-flying small-sized objects against the background of interference in the urban environment using radar stations. We propose an adaptive al...
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The paper searches for solutions to the problem of detecting a signal from low-flying small-sized objects against the background of interference in the urban environment using radar stations. We propose an adaptive algorithm that can be used in modern radar systems for detecting and tracking small objects. The developed adaptive algorithm for resolving signals reflected from low-flying objects allows us to take into account the multipath effect. A variant of the practical realization of the adaptive detection algorithm, implemented on an experimental sample of the X-range radar of wavelength, is presented.
The aim of this work is to compare different marking strategies, their influence on the work of adaptive algorithms with a posteriori error control for plane elasticity problems. The error control was performed using ...
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The aim of this work is to compare different marking strategies, their influence on the work of adaptive algorithms with a posteriori error control for plane elasticity problems. The error control was performed using a functional error majorant. The implemented adaptive algorithms were based on the functional error majorant with no symmetry limitation on the free tensor, computed using the zero-order Raviart–Thomas approximations on triangular meshes. The four most commonly used element-marking criteria were used in adaptation. Numerical results for several plane-strain problems have been presented, including the case of different materials and geometry. A comprehensive analysis of the obtained results was given.
作者：
Bu, WeipingQu, MinXiangtan Univ
Sch Math & Computat Sci Xiangtan 411105 Hunan Peoples R China Xiangtan Univ
Hunan Key Lab Computat & Simulat Sci & Engn Xiangtan 411105 Hunan Peoples R China
This study proposes a time-stepping L-1 scheme to approximate the linear fractional dynamical systems based on nonuniform mesh. The developed numerical scheme is unconditionally stable, and exhibits second-order accur...
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This study proposes a time-stepping L-1 scheme to approximate the linear fractional dynamical systems based on nonuniform mesh. The developed numerical scheme is unconditionally stable, and exhibits second-order accuracy when the suitable graded mesh is used. A posteriori error estimation is derived for the obtained numerical scheme and the corresponding adaptive algorithm is devised. Finally, two numerical examples are provided to demonstrate the effectiveness of our approach and verify the theoretical results.
By using a liquid crystal shutter to periodically modulate the infrared energy received by the on-board passive infrared (PIR) sensor, the synchronized low energy electronically chopped PIR sensor recently developed b...
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By using a liquid crystal shutter to periodically modulate the infrared energy received by the on-board passive infrared (PIR) sensor, the synchronized low energy electronically chopped PIR sensor recently developed by our team can detect stationary occupancy. However, the fixed threshold value-based detection accuracy is largely dependent on environmental settings, such as the room and floor surface temperature. In this letter, we first developed a thermoelectric model to quantify the environmental impact on the threshold value and then created an adaptive algorithm to generate temperature-sensitive threshold values to compensate environmental effects. We validated our thermoelectric model and tested our adaptive algorithm in two uncontrolled environmental settings, and results show that the detection accuracy reaches over 92%, which is much higher than that using the fixed threshold approach.
An analysis is made of the behavior of a block orthogonal projection algorithm (BOPA) applied to a practical system in which the input signal is smooth-colored and additive noise is observed at the output of an unknow...
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An analysis is made of the behavior of a block orthogonal projection algorithm (BOPA) applied to a practical system in which the input signal is smooth-colored and additive noise is observed at the output of an unknown filter. Using this result, a block adaptive algorithm is presented. This algorithm is based on singular-value decomposition and obtained by truncating several smaller singular values.< >
In this paper, a new fast convergence adaptive algorithm with variable step size is proposed for FIR adaptive filter. This new proposed algorithm is derived based on the quasi-Newton family. Simulation results are pre...
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In this paper, a new fast convergence adaptive algorithm with variable step size is proposed for FIR adaptive filter. This new proposed algorithm is derived based on the quasi-Newton family. Simulation results are presented to compare the convergence of the proposed algorithm with least mean square (LMS) algorithm and RLS algorithm. It shows that the proposed new algorithm has comparable convergence speed to the other known adaptive algorithms
We propose a load balancing algorithm that adapts its strategies for allocating Web requests based on the Web servers' status. The system used in our experiment comprises of two components: (1) a Prober and (2) an...
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ISBN:
(纸本)9781424452125
We propose a load balancing algorithm that adapts its strategies for allocating Web requests based on the Web servers' status. The system used in our experiment comprises of two components: (1) a Prober and (2) an Allocator. The Prober gathers the status information from the Web servers every 50 milliseconds. The status information consists of the load on each Web server and a check for a cache hit. Based on this status information, the Allocator calculates a weighted metric for each server. This metric has three components: (1) CPU load on the server, (2) server's response rate, and (3) the number of requests served by the server. The Allocator chooses the Web server with the least value for this metric. Unique features of this approach are (1) consideration of both the global information (consisting of status at other Web servers) and local information at each Web server to choose the best server to allocate a request, and (2) the algorithm passes the IP address of the chosen Web server to the client that initiated the request and then allows the client to establish a connection with the server directly, thereby eliminating the participation overhead of the intermediate redirector. We compare our algorithm with three different methods: (1) random allocation scheme, (2) round robin allocation scheme, and (3) a recently reported scheme that uses neural networks. Our method is as good as or better (in most cases) in response time, than the other three approaches.
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