To improve the global search ability of particle swarm optimization （PSO）, a multi-population PSO based on pyramid model （PPSO） is presented. Then, it is applied to solve the layout optimization problems against t...To improve the global search ability of particle swarm optimization （PSO）, a multi-population PSO based on pyramid model （PPSO） is presented. Then, it is applied to solve the layout optimization problems against the background of an international commercial communication satellite （INTELSAT-Ⅲ） module. Three improvements are developed, including multi-population search based on pyramid model, adaptive collision avoidance among particles, and mutation of degraded particles. In the numerical examples of the layout design of this simplified satellite module, the performance of PPSO is compared to global version PSO and local version PSO （ring and Neumann PSO）. The results show that PPSO has higher computational accuracy, efficiency and success ratio.展开更多
The Development of 3D CAD technology presents a new effective tool in designing outdoor switch yard for power plant. A new layout pattern of 330 kV switch yard (SWYD) of aligned type was studied with this method. Some...The Development of 3D CAD technology presents a new effective tool in designing outdoor switch yard for power plant. A new layout pattern of 330 kV switch yard (SWYD) of aligned type was studied with this method. Some issues about computerized 3D modes applied in SWYD design are also discussed in this paper.展开更多
A rifle in a soldier’s system is often equipped with a grenade launcher,aiming device,etc.,which increases the weight of the rifle and changes its center of gravity.This study explores how the rifle weight,weight dis...A rifle in a soldier’s system is often equipped with a grenade launcher,aiming device,etc.,which increases the weight of the rifle and changes its center of gravity.This study explores how the rifle weight,weight distribution and layout(e.g.stock length,position of grip and forestock)affect aiming comfort.In the paper,the upper extremity muscle activity was used to characterize the aiming comfort.A human-rifle musculoskeletal model was developed,which was validated by the surface electromyography(EMG)data.The results showed that the design parameters of rifle(weight,distance of gravity center to body and layout)had a significant influence on aiming comfort.The greater the weight was,the stronger the muscle activity was.With the distance increasing,first the muscle activity decreased,and then increased when the distance is exceeding a certain value.In addition,the combined influences of weight and distance illustrated that there was an optimal distance to make the slightest muscle movements for certain weight.For designing a rifle’s layout,more muscular exertions were required to maintain the holding posture with the stock length increasing,which was suggested to be in the range of 0.1 8 m to 0.2 7 m.Results can be used to optimize the ergonomics design of rifle,improving the comfort of the rifle aiming process and the shooting accuracy.展开更多
Full face rock tunnel boring machine（TBM） has been widely used in hard rock tunnels, however, there are few published theory about cutter-head design, and the design criteria of cutter-head under complex geological ...Full face rock tunnel boring machine（TBM） has been widely used in hard rock tunnels, however, there are few published theory about cutter-head design, and the design criteria of cutter-head under complex geological is not clear yet. To deal with the complex relationship among geological parameters, cutter parameters, and operating parameters during tunneling processes, a cutter-head load model is established by using CSM（Colorado school of mines） prediction model. Force distribution on cutter-head under a certain geology is calculated with the new established load model, and result shows that inner cutters bear more force than outer cutters, combining with disc cutters abrasion; a general principle of disc cutters＇ layout design is proposed. Within the model, the relationship among rock uniaxial compressive strength（UCS）, penetration and thrust on cutter-head are analyzed, and the results shows that with increasing penetration, cutter thrust increases, but the growth rate slows and higher penetration makes lower special energy（SE）. Finally, a fitting mathematical model of ZT（ratio of cutter-head torque and thrust） and penetration is established, and verified by TB880 E, which can be used to direct how to set thrust and torque on cutter-head. When penetration is small, the cutter-head thrust is the main limiting factor in tunneling; when the penetration is large, cutter-head torque is the major limiting factor in tunneling. Based on the new cutter-head load model, thrust and torque characteristics of TBM further are researched and a new way for cutter-head layout design and TBM tunneling operations is proposed.展开更多
The layout effects and optimization of runoff storage and filtration facilities are crucial to the efficiency and management of the cost of runoff control, but related research is still lacking. In this study, scenari...The layout effects and optimization of runoff storage and filtration facilities are crucial to the efficiency and management of the cost of runoff control, but related research is still lacking. In this study, scenarios with different layouts were simulated using the storm water management model(SWMM), to investigate the layout effects on control efficiency with different precipitations. In a rainfall event with 50 mm of precipitation in two hours, 1820 scenarios with different layouts of four facilities constructed in 16 sub-catchments were simulated, the reduction rates of internal flow presented a standard deviation of 10.9%, and the difference between the maximum and minimum reduction rates reached59.7%. Based on weighting analysis, an integrated ranking index was obtained and used to determine the optimal layout scenarios considering different rainfall events. In the optimal scenario(storage and filtration facilities constructed in sub-catchments 14, 12, 7, and 2), the reduction rates of the total outflow reached 31.4%, 26.4%, and 14.7%, respectively, with 30, 50, and 80 mm of precipitation. The reduction rate of the internal outflow reached 95% with 50 mm of precipitation and approximately 56% with 80 mm of precipitation.展开更多
基金This project is supported by National Natural Science Foundation of China (No.50275019, No.50335040, No.50575031).
文摘To improve the global search ability of particle swarm optimization （PSO）, a multi-population PSO based on pyramid model （PPSO） is presented. Then, it is applied to solve the layout optimization problems against the background of an international commercial communication satellite （INTELSAT-Ⅲ） module. Three improvements are developed, including multi-population search based on pyramid model, adaptive collision avoidance among particles, and mutation of degraded particles. In the numerical examples of the layout design of this simplified satellite module, the performance of PPSO is compared to global version PSO and local version PSO （ring and Neumann PSO）. The results show that PPSO has higher computational accuracy, efficiency and success ratio.
文摘The Development of 3D CAD technology presents a new effective tool in designing outdoor switch yard for power plant. A new layout pattern of 330 kV switch yard (SWYD) of aligned type was studied with this method. Some issues about computerized 3D modes applied in SWYD design are also discussed in this paper.
基金Supported by the National Natural Science Foundation of China(651575279)the Basic Research of National Defense of China(A1020133013)
文摘A rifle in a soldier’s system is often equipped with a grenade launcher,aiming device,etc.,which increases the weight of the rifle and changes its center of gravity.This study explores how the rifle weight,weight distribution and layout(e.g.stock length,position of grip and forestock)affect aiming comfort.In the paper,the upper extremity muscle activity was used to characterize the aiming comfort.A human-rifle musculoskeletal model was developed,which was validated by the surface electromyography(EMG)data.The results showed that the design parameters of rifle(weight,distance of gravity center to body and layout)had a significant influence on aiming comfort.The greater the weight was,the stronger the muscle activity was.With the distance increasing,first the muscle activity decreased,and then increased when the distance is exceeding a certain value.In addition,the combined influences of weight and distance illustrated that there was an optimal distance to make the slightest muscle movements for certain weight.For designing a rifle’s layout,more muscular exertions were required to maintain the holding posture with the stock length increasing,which was suggested to be in the range of 0.1 8 m to 0.2 7 m.Results can be used to optimize the ergonomics design of rifle,improving the comfort of the rifle aiming process and the shooting accuracy.
基金Supported by National Natural Science Foundation of China(Grant No.51275339)National Basic Research Program of China(973 Program,Grant No.2013CB035402)
文摘Full face rock tunnel boring machine（TBM） has been widely used in hard rock tunnels, however, there are few published theory about cutter-head design, and the design criteria of cutter-head under complex geological is not clear yet. To deal with the complex relationship among geological parameters, cutter parameters, and operating parameters during tunneling processes, a cutter-head load model is established by using CSM（Colorado school of mines） prediction model. Force distribution on cutter-head under a certain geology is calculated with the new established load model, and result shows that inner cutters bear more force than outer cutters, combining with disc cutters abrasion; a general principle of disc cutters＇ layout design is proposed. Within the model, the relationship among rock uniaxial compressive strength（UCS）, penetration and thrust on cutter-head are analyzed, and the results shows that with increasing penetration, cutter thrust increases, but the growth rate slows and higher penetration makes lower special energy（SE）. Finally, a fitting mathematical model of ZT（ratio of cutter-head torque and thrust） and penetration is established, and verified by TB880 E, which can be used to direct how to set thrust and torque on cutter-head. When penetration is small, the cutter-head thrust is the main limiting factor in tunneling; when the penetration is large, cutter-head torque is the major limiting factor in tunneling. Based on the new cutter-head load model, thrust and torque characteristics of TBM further are researched and a new way for cutter-head layout design and TBM tunneling operations is proposed.
基金supported by the Major Science and Technology Program for Water Pollution Control and Management of China(Grant No.2011ZX07301-002)
文摘The layout effects and optimization of runoff storage and filtration facilities are crucial to the efficiency and management of the cost of runoff control, but related research is still lacking. In this study, scenarios with different layouts were simulated using the storm water management model(SWMM), to investigate the layout effects on control efficiency with different precipitations. In a rainfall event with 50 mm of precipitation in two hours, 1820 scenarios with different layouts of four facilities constructed in 16 sub-catchments were simulated, the reduction rates of internal flow presented a standard deviation of 10.9%, and the difference between the maximum and minimum reduction rates reached59.7%. Based on weighting analysis, an integrated ranking index was obtained and used to determine the optimal layout scenarios considering different rainfall events. In the optimal scenario(storage and filtration facilities constructed in sub-catchments 14, 12, 7, and 2), the reduction rates of the total outflow reached 31.4%, 26.4%, and 14.7%, respectively, with 30, 50, and 80 mm of precipitation. The reduction rate of the internal outflow reached 95% with 50 mm of precipitation and approximately 56% with 80 mm of precipitation.
