受湍流影响,室内通风环境下的烟羽分布表现出波动变化且不连续的特性;在一些角落处,较大的漩涡会产生长时间的局部浓度极值区;另外室内的障碍物也会改变烟羽的分布状况.因此室内有障碍通风环境下的机器人气味源搜索问题变得很复杂.本文...受湍流影响,室内通风环境下的烟羽分布表现出波动变化且不连续的特性;在一些角落处,较大的漩涡会产生长时间的局部浓度极值区;另外室内的障碍物也会改变烟羽的分布状况.因此室内有障碍通风环境下的机器人气味源搜索问题变得很复杂.本文提出了基于概率适应度函数的粒子群优化(Probability-fitness-function based particle swarm optimization,P-PSO)算法并用于多机器人气味源搜索.P-PSO算法的特点是采用概率而非确定数来表达适应度函数值.针对气味源搜索问题,P-PSO算法的适应度函数值由贝叶斯和变论域模糊推理估计的气味源概率表达.为验证提出的搜索策略,构建了对应实际边界条件的室内通风环境的烟羽模型.仿真研究证明了本文提出的P-PSO搜索算法用于解决气味源搜索问题的可行性.展开更多
Aim To introduce a new method of adaptive shape optimization (ASOP) based on three-dimensional structure boundary strength and optimize an engine bearing cap with the method. Methods Using the normal substance's p...Aim To introduce a new method of adaptive shape optimization (ASOP) based on three-dimensional structure boundary strength and optimize an engine bearing cap with the method. Methods Using the normal substance's property of thermal expansion and cooling shrinkage,the load which is proportional to the difference between the nodes' stress and their respective objective stress were applied to the corresponding variable nodes on the boundary.The thermal load made the nodes whose stress is greater than their objective stress expand along the boundary's normal direction and the nodes whose stress is less than objec- tive stress shrink in the opposite direction , This process would repeat until the stress on the boundary nodes was converge to the objective stress. Results The satisfied results have been obtained when optimizing an engine bearing cap.The mass of the bearing cap is reduced to 55 percent of the total. Conclusion ASOP is an efficient,practical and reliable method which is suitable for optimizing the shape of the continuous structures.展开更多
To effectively predict the permeability index of smelting process in the imperial smelting furnace, an intelligent prediction model is proposed. It integrates the case-based reasoning (CBR) with adaptive par- ticle ...To effectively predict the permeability index of smelting process in the imperial smelting furnace, an intelligent prediction model is proposed. It integrates the case-based reasoning (CBR) with adaptive par- ticle swarm optimization (PSO). The nmnber of nearest neighbors and the weighted features vector are optimized online using the adaptive PSO to improve the prediction accuracy of CBR. The adaptive inertia weight and mutation operation are used to overcome the premature convergence of the PSO. The proposed method is validated a compared with the basic weighted CBR. The results show that the proposed model has higher prediction accuracy and better performance than the basic CBR model.展开更多
文摘受湍流影响,室内通风环境下的烟羽分布表现出波动变化且不连续的特性;在一些角落处,较大的漩涡会产生长时间的局部浓度极值区;另外室内的障碍物也会改变烟羽的分布状况.因此室内有障碍通风环境下的机器人气味源搜索问题变得很复杂.本文提出了基于概率适应度函数的粒子群优化(Probability-fitness-function based particle swarm optimization,P-PSO)算法并用于多机器人气味源搜索.P-PSO算法的特点是采用概率而非确定数来表达适应度函数值.针对气味源搜索问题,P-PSO算法的适应度函数值由贝叶斯和变论域模糊推理估计的气味源概率表达.为验证提出的搜索策略,构建了对应实际边界条件的室内通风环境的烟羽模型.仿真研究证明了本文提出的P-PSO搜索算法用于解决气味源搜索问题的可行性.
文摘Aim To introduce a new method of adaptive shape optimization (ASOP) based on three-dimensional structure boundary strength and optimize an engine bearing cap with the method. Methods Using the normal substance's property of thermal expansion and cooling shrinkage,the load which is proportional to the difference between the nodes' stress and their respective objective stress were applied to the corresponding variable nodes on the boundary.The thermal load made the nodes whose stress is greater than their objective stress expand along the boundary's normal direction and the nodes whose stress is less than objec- tive stress shrink in the opposite direction , This process would repeat until the stress on the boundary nodes was converge to the objective stress. Results The satisfied results have been obtained when optimizing an engine bearing cap.The mass of the bearing cap is reduced to 55 percent of the total. Conclusion ASOP is an efficient,practical and reliable method which is suitable for optimizing the shape of the continuous structures.
基金supported by the by the National Natural Science Foundation(No.60874069,60634020)the National High Technology Research and Development Programme of China(No.2009AA04Z124)Hunan Provincial Natural Science Foundation of China(No.09JJ3122)
文摘To effectively predict the permeability index of smelting process in the imperial smelting furnace, an intelligent prediction model is proposed. It integrates the case-based reasoning (CBR) with adaptive par- ticle swarm optimization (PSO). The nmnber of nearest neighbors and the weighted features vector are optimized online using the adaptive PSO to improve the prediction accuracy of CBR. The adaptive inertia weight and mutation operation are used to overcome the premature convergence of the PSO. The proposed method is validated a compared with the basic weighted CBR. The results show that the proposed model has higher prediction accuracy and better performance than the basic CBR model.