With the increasing use of non-linear loads, the harmonic problems have become of great concerns. One of the solutions to harmonics is the application of shunt active power filters (APFs). The APF reference compensati...
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ISBN:
(纸本)9781509041695
With the increasing use of non-linear loads, the harmonic problems have become of great concerns. One of the solutions to harmonics is the application of shunt active power filters (APFs). The APF reference compensation strategy proposed in this paper adopts the backpropagation neural network (BPNN) to train the control algorithm and calculate the reference compensation current under steady state and varying load levels. Simulation results obtained by using MATLAB/Simulink show that the proposed BPNN-based APF control strategy can effectively mitigate harmonic currents generated by the nonlinear load.
Vehicular ad hoc network (VANET) has gained much attention recently to improve road safety, reduce traffic congestion, and enable efficient traffic management because of its many important applications in transportati...
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Vehicular ad hoc network (VANET) has gained much attention recently to improve road safety, reduce traffic congestion, and enable efficient traffic management because of its many important applications in transportation. In this paper, an early warning intelligence broadcasting algorithm is proposed, EW-ICAST, to disseminate a safety message for VANETs. The proposed EW-ICAST uses not only the early warning system on the basis of time to collision (TTC) but also the intelligent broadcasting algorithm on the basis of fuzzy logic. Thus, the EW-ICAST resolves effectively broadcast storm problem and meets time-critical requirement. The performance of EW-ICAST is evaluated through simulation and compared with that of other alert message dissemination algorithms. From the simulation results, we know that EW-ICAST is superior to Simple, P-persistence, and EDB algorithms.
In the present article, a new surrogate-assisted evolutionary algorithm for dynamic identification problems with unknown parameters is presented. It is based on the combination of the response surface (RS) approach (t...
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In the present article, a new surrogate-assisted evolutionary algorithm for dynamic identification problems with unknown parameters is presented. It is based on the combination of the response surface (RS) approach (the surrogate model) with differential evolution algorithm for global search. Differential evolution (DE) is an evolutionary algorithm where N different vectors collecting the parameters of the system are chosen randomly or by adding weighted differences between vectors obtained from two populations. In the proposed algorithm (called DE-Q), the RS is introduced in the mutation operation. The new parameter vector is defined as the one minimizing the second-order polynomial function (RS), approximating the objective function. The performances in terms of speed rate are improved by introducing the second-order approximation;nevertheless, robustness of DE algorithm for global minimum search of objective function is preserved, because multiple search points are used simultaneously. Numerical examples are presented, concerning: search of the global minimum of analytical benchmark functions;parameter identification of a damaged beam;parameter identification of mechanical properties (masses and member stiffnesses) of a truss-girder steel bridge starting from frequencies and eigenvectors obtained from an experimental field test.
We proposed the combination of signal denoising technology and Hankel transforms algorithm which were both based on Haar wavelet decomposition. Therefore, one can achieve above two purposes simultaneously while the wa...
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We proposed the combination of signal denoising technology and Hankel transforms algorithm which were both based on Haar wavelet decomposition. Therefore, one can achieve above two purposes simultaneously while the wavelet decomposition is carried out just for once. The principle and its derivation of the Haar wavelet method for Hankel transforms were put forward. Numerical examples and engineering application showed that the precision of Haar wavelet method is about magnitude of 1.0E - 4 and 1.0E - 5;it can maintain good accuracy when using fewer wavelet coefficients. Moreover, it has better anti-noise performance and better computational stability than the filter method, so it can be applied to the Hankel transforms with noisy data.
We present a hardware implementation of the Jacobi algorithmto compute the eigenvalue decomposition (EVD). The computation of eigenvalues and eigenvectors has many applications where real time processing is required, ...
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We present a hardware implementation of the Jacobi algorithmto compute the eigenvalue decomposition (EVD). The computation of eigenvalues and eigenvectors has many applications where real time processing is required, and thus hardware implementations are often mandatory. Some of these implementations have been carried out with field programmable gate array (FPGA) devices using low level register transfer level (RTL) languages. In the present study, we used the Xilinx Vivado HLS tool to develop a high level synthesis (HLS) design and evaluated different hardware architectures. After analyzing the design for different input matrix sizes and various hardware configurations, we compared it with the results of other studies reported in the literature, concluding that although resource usage may be higher when HLS tools are used, the design performance is equal to or better than low level hardware designs.
With the advantages such as high security and far responding distance, the passive location has a broad application in military and civil domains such as radar and aerospace. However, most of the current passive locat...
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With the advantages such as high security and far responding distance, the passive location has a broad application in military and civil domains such as radar and aerospace. However, most of the current passive location methods are based on the framework of the probability theory and cannot be used to deal with fuzzy uncertainty in the passive location systems. Though the fuzzy Kalman filter can be used in the uncertainty systems, it could not deal with the abrupt change of state like the maneuvering target which will lead to the filter divergence. Therefore, in order to track the maneuvering target in the fuzzy passive system, we proposed a robust fuzzy extended Kalman filter based on the orthogonality principle and the fuzzy filter in the paper. Conclusion can be made based on the simulation result that this new approach is more precise and more robust than the fuzzy filter.
Spread-Doppler clutter caused by multi-mode propagation seriously affects the over-the-horizon radar detection performance for slow ships. To solve this problem, the authors propose to suppress multi-mode clutter usin...
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Spread-Doppler clutter caused by multi-mode propagation seriously affects the over-the-horizon radar detection performance for slow ships. To solve this problem, the authors propose to suppress multi-mode clutter using spatial information in the multiple-input-multiple-output over-the-horizon radar system. Traditional processing algorithms need prior information of the target direction. However, it is often not readily available. In this study, they propose a novel multi-mode clutter suppression algorithm based on the second-order blind identification (SOBI) technique. The proposed algorithm does not need prior information of the target direction and can effectively suppress the multi-mode clutter. Considering that the SOBI algorithm affected by the similarity in sources spectra, they improve the proposed algorithm using the spatial smoothing technique. Simulation results show that, in the single target scene, the improved algorithm can effectively eliminate the spectrum burrs caused by incomplete separation, making separated signals smoother. Signal-to-clutter-noise ratio is greatly improved. The good multi-mode clutter suppression performance is obtained. In the multi-mode scenario that double targets with the same radial velocity, that is, sources spectra have similarities, the algorithm based on SOBI cannot separate all targets. Although the improved algorithm can make all targets visible and effectively suppresses the multi-mode clutter.
The area of metaheuristic optimization algorithms has been attracting researchers for many years. These algorithms have built in capability to explore a large region of the solution space, are computationally robust, ...
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The area of metaheuristic optimization algorithms has been attracting researchers for many years. These algorithms have built in capability to explore a large region of the solution space, are computationally robust, efficient and can avoid premature convergence. They have been extensively tested and applied on many hard optimization problems where conventional computing techniques perform unsatisfactorily. They are capable of solving general N-dimensional, linear, nonlinear and complex global optimization problems. One of the latest entrants in this field is the Bat algorithm which is based on the echolocation behaviour of bats. It has been proven to have good convergence properties on different benchmark functions and seems promising for dealing with optimization problems. The aim of this paper is to provide a survey of the state of the art on Bat algorithm. A concise effort has been made so that the readers get a rapid insight into some of the applications upon which bat algorithm has been applied till date in specialized fields of science and engineering. Some of the variants of the bat algorithm as reported in the literature have also been discussed.
By exploiting the direction of arrival (DoA) information of azimuth ambiguity, an innovative algorithm for the adaptive suppression of azimuth ambiguity for multichannel synthetic aperture radar (SAR) wide-swath imagi...
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By exploiting the direction of arrival (DoA) information of azimuth ambiguity, an innovative algorithm for the adaptive suppression of azimuth ambiguity for multichannel synthetic aperture radar (SAR) wide-swath imaging is presented. It firstly estimates the DoA value of each azimuth component within a Doppler cell using the efficient noise subspace-based iterative estimation technique. Then the spatial filter for sequentially extracting the desired azimuth component is derived, which is designed to be used with the newly estimated DoA information within each Doppler bin. Finally, the azimuth ambiguities can be suppressed via the implementation of spatial filtering. The proposed approach is robust to aircraft velocity errors, and its effectiveness is validated via simulation results.
One of the most exciting applications of V2X technologies, that is envisioned, is the platooning of a series of autonomous vehicles led by a manually driven vehicle. However, the realization of this application depend...
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ISBN:
(纸本)9781509018901
One of the most exciting applications of V2X technologies, that is envisioned, is the platooning of a series of autonomous vehicles led by a manually driven vehicle. However, the realization of this application depends entirely on the efficacy of a platoon control algorithm and the communication channel amongst the platoon members. There are many different control algorithms that are being considered to maintain a constant distance/time Gap amongst the platoon members based on the speed and acceleration profile of the other vehicles in the platoon. However, before a particular control algorithm can be deployed, it needs to be thoroughly analysed to see if it can indeed produce the desired effect under all sorts of traffic conditions and with varying penetration rates of V2X technology. In addition, one would also need to collect data on data packet delivery rate and the amount of delay, using different platoon management protocols. This information can then be utilized as a feedback to fine tune both the protocol and the control algorithm itself. This work aims to provide a holistic platform which integrates three simulators VISSIM (Traffic Simulation), NS-3 (Network Simulation) and MATLAB (Platoon control algorithm) that allows testing control algorithm stability in the presence of realistic communication constraints. To illustrate the usability of this co-simulation framework, we have presented results on velocity tracking of leader by follower vehicles while maintaining a specified inter-vehicular gap, for a small platoon along with results on data packet delivery for larger platoons.
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