digital Elevation Model (dEM) is data used for modeling water flow. dEM data is in the form of a grid with X and Y points as coordinates and Z representing the surface elevation. One of the challenges in modeling the ...
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The optimal power flow (OPF) is an important tool for the secure and economic operation of the power system. It attracts many researchers to pay close attention. Many d*algorithms are used to solve the OPF problem. The ...
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The optimal power flow (OPF) is an important tool for the secure and economic operation of the power system. It attracts many researchers to pay close attention. Many d*algorithms are used to solve the OPF problem. The decomposition-based multi-objective d*algorithm (MOEA/d) is one of them. However, the effectiveness of the d*algorithmdecreases as the size of the power system increases. Therefore, an improved MOEA/d (IMOEA/d) is proposed in this paper to solve the OPF problem. The main goal of IMOEA/d is to speed up the convergence of the d*algorithm and increase species diversity. To achieve this goal, three improvement strategies are introduced. Firstly, the competition strategy between the barnacle optimization d*algorithm anddifferential evolution d*algorithm is adopted to overcome the reduced species diversity. Secondly, an adaptive mutation strategy is employed to enhance species diversity at the latter stage of iteration. Finally, the selective candidate with similarity selection is used to balance the exploration and exploitation capabilities of the proposedd*algorithm. Simulation experiments are performed on IEEE 30-bus and IEEE 57-bus test systems. The obtained results show that the above three measures can effectively improve the diversity of the population, and also demonstrate the competitiveness and effectiveness of the proposedd*algorithm for the OPF problem.
Electrical impedance tomography (EIT) is a non-ionizing real-time imaging tool for bedside pulmonary imaging. dynamic cross-sectional images of ventilation and perfusion can be produced in real time with fast algorith...
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Electrical impedance tomography (EIT) is a non-ionizing real-time imaging tool for bedside pulmonary imaging. dynamic cross-sectional images of ventilation and perfusion can be produced in real time with fast d*algorithms from measured voltage data arising from current applied on electrodes placed around the circumference of the patient's chest. The d-bar method is a direct (non-iterative) reconstruction d*algorithm for EIT that uses equations of inverse scattering to independently reconstruct the conductivity at each point in the region of interest. However, this nonlinear reconstruction method has a computational complexity that makes real-time imaging a challenge. At the same time, it has the attributes that it does not require successive solutions of the forward problem, as is the case with iterative methods, and it is trivially parallelizable in the spatial variable. Here, we present a novel multithreaded implementation of the d-bar method with a front-end MATLAB/Octave program interfaced with C code that uses the pthreads library. The implementation is analyzed on several different platforms with concurrent threads ranging from 2 to 32 for spatial grids of several sizes. We demonstrate that on a CPU with many cores, very high frame rates (50 frames/s) with high resolution (6000 grid points) are achievable, and on a single AMd CPU real-time reconstructions (faster than 30 frames/s) are achieved with this implementation using 10 or more threads on a grid of 1969 points.
The indoor localization system is essential since the Global Positioning System cannot give an accurate position indoors, especially when several floor plans are considered. Wi-Fi received signal strength becomes an a...
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ISBN:
(纸本)9791188428069
The indoor localization system is essential since the Global Positioning System cannot give an accurate position indoors, especially when several floor plans are considered. Wi-Fi received signal strength becomes an alternative indicator for indoor localization systems. The experiment proposed a localization system created by integrating and working between the K-Nearest Neighbors d*algorithm and the d*d*algorithm. The result illustrates the optimal path from the start point to the target point by avoiding the obstacle performing exceptionally well. The K -Nearest Neighbors d*algorithm provide the result for localization with Root Mean Square Errors of displacement at 1.190 meters, 2.491 meters, and 1.363 meters of X-Axis Y-Axis, respectively. The proposed indoor localization system can have various applications considering different environmental factors in different applications, such as the size of unmanned aerial vehicles when applying indoor unmanned aerial vehicles.
To solve the problem of path planning for an unmanned surface vessel in an unknown environment, this paper proposes a path planning d*algorithm based on the improvedd*Lite d*algorithm. First, to improve the computational...
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To solve the problem of path planning for an unmanned surface vessel in an unknown environment, this paper proposes a path planning d*algorithm based on the improvedd*Lite d*algorithm. First, to improve the computational efficiency of the traditional d*Lite d*algorithm, the path cost function is improved to reduce the expansion range of nodes, and the node expansion direction is limited to avoiddouble node computation. Second, the path planned by the traditional d*Lite d*algorithm on the grid map is suboptimal;so, the inverse distance weighted (IdW) interpolation method is applied to shorten the path length. To improve the smoothness of the planned path by the traditional d*Lite d*algorithm, the dubins d*algorithm is introduced for local path smoothing, and a smooth collision-free path that conforms to the motion dynamics of the unmanned surface vessel is obtained. The proposedd*algorithm was verified by experiments in known and unknown environments. The performance of the proposedd*algorithm was compared with the traditional d*Lite d*algorithm in terms of planning time, path length, and path smoothness. The results revealed that the proposedd*algorithm has the shortest path length, a shorter planning time, and the best smooth path.
Aiming at the problem of slow planning speed of d*Lite d*algorithm in unmanned cruise ship path planning, an improvedd*Lite d*algorithm is proposed and applied to complex environments with dynamic obstacles. This method ...
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ISBN:
(纸本)9781728176871
Aiming at the problem of slow planning speed of d*Lite d*algorithm in unmanned cruise ship path planning, an improvedd*Lite d*algorithm is proposed and applied to complex environments with dynamic obstacles. This method reduces the unnecessary search area by improving the heuristic function, so as to shorten the path search time, and smooth the obtained path to reduce the path planning distance. Experiments show that the improvedd*Lite d*algorithm effectively improves the performance of path planning in many aspects.
Route optimization is used to determine which path is the most efficient among all the available paths. The study provided forklift operators with a graphical model of the warehouse. The goal of this study is to deter...
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ISBN:
(纸本)9781665419710
Route optimization is used to determine which path is the most efficient among all the available paths. The study provided forklift operators with a graphical model of the warehouse. The goal of this study is to determine the shortest path from the initial point to the destination point with d* Lite d*algorithm. To execute d* Lite d*algorithm Bluetooth Low Energy Triangulation was used. BLE Triangulation helpedd* Lite d*algorithm by mapping the warehouse and locating the real-time location of the forklift/s. The system is an effective path finding for forklift/s inside a warehouse. Through the implementation of the system the group was able to reduce the time needed for the operator to navigate the warehouse. The T-statistic value for tables IV,V and V is 13.0380, 14.0324, and 7.2088 respectively which is greater than the one-tailed critical value of 1.8331 that rejects the null ***, the implementation of the system is successful in reducing the time needed by forklift operators to navigate around the warehouse and that the system can be implemented with multiple forklifts.
Tongue image extraction is a primary and fundamental step in the objectification of the tongue diagnoses of traditional Chinese medicine. Aiming at the problems that some methods need to adjust parameters by manual an...
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ISBN:
(纸本)9781450387811
Tongue image extraction is a primary and fundamental step in the objectification of the tongue diagnoses of traditional Chinese medicine. Aiming at the problems that some methods need to adjust parameters by manual and their accuracy and efficiency are not high, in this paper, a kind of novel concurrent d-search d*algorithm fusing multi-dimensional information is proposed for the application of tongue image extraction in order to realize automatic, fast and accurate tongue image extraction. In our method, original tongue image is considered as a pixel network. Starting from the seed pixel of central region, according to the intensity, hue and relative position information of the pixels of tongue image, a novel d-search d*algorithm is utilized to search tongue body region in original tongue image. Because tongue coating is surrounded by tongue substance in most cases, we propose a novel position operator to decide whether current pixel is surrounded by tongue substance in our d-search d*algorithm so as to extract tongue image with coating accurately. In the same time, to improve the efficiency of our d*algorithm, the original tongue image is divided into several regions (i.e. sub-images), concurrent techniques are utilized to search different tongue regions separately, so as to get the tongue image templates of different regions quickly, and then they are combined into one template. In addition, morphological operators including closing and opening are applied to the template after combination, so that small holes in the template image can be filled. In the end, an and operation is applied to the ultimate template and original tongue image, in order to get extracted tongue image. In our study, we conduct the comparison experiments of 4 methods including the method of manual extraction, our method, tongue image extraction based on greedy rules and tongue image extraction based on random walk. The comparison experiments are conducted from the aspects of accuracy and efficiency
This paper proposes a dynamic path search method for collision avoidance of the unmanned surface vehicle (USV) based on d* d*algorithm to solve the problems of slow search speed, long route and low obstacle avoidance ef...
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This paper proposes a dynamic path search method for collision avoidance of the unmanned surface vehicle (USV) based on d* d*algorithm to solve the problems of slow search speed, long route and low obstacle avoidance efficiency faced by the USV in path planning with dynamic obstacles. The method uses the information of voyage environment based on the electronic sea chart. Firstly, it carries on the reverse calculation from the target point to the starting point and stores the information of each possible position on the path. Then, the USV is allowed to move from the starting point to the target point. When dynamic obstacles appear on the next path, it only needs to change the local path behind to avoid obstacles so that it is more efficient than other methods because of less computation. The part of model simulation is using MATLAB programming to realize the running program of dynamic collision avoidance path planning of USV based on d* d*algorithm, and comparing with the simulation results of path planning based on the traditional dijstra d*algorithm and A* d*algorithm. The test results show that the d* d*algorithm can significantly reduce the search time and the path length when USV meet dynamic obstacles.
Test generation for digital hardware is highly automated, scalable (in practice), and provides high test quality. In contrast, current software automatic test data generation approaches suffer from low test quality or...
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ISBN:
(纸本)9781728111704
Test generation for digital hardware is highly automated, scalable (in practice), and provides high test quality. In contrast, current software automatic test data generation approaches suffer from low test quality or high complexity. While mutation-oriented constraint-based test data generation for software was proposed to generate high quality test data for real program bugs, all existing approaches require symbolic analysis for the whole program, and hence are not scalable even for unit testing, i.e., testing the lowest-level software modules. We propose a new method inspired by hardware d-d*algorithm anddivide and conquer for software test data generation. To reduce runtime complexity and improve scalability, we combine global structural analysis and a sequence of small reusable symbolic analyses of parts of the program, instead of symbolically executing each mutated version of the entire program. We also propose a multi-pass test generation system to further reduce runtime complexity and compact test data. We compare our tools with one of the best software test generation tools (EvoSuite[20], which won the SBST 2017 tool competition) anddemonstrate that our approach generates higher quality unit tests in a scalable manner and provides a compact set of tests.
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