针对迭代局部搜索(iterated local search,ILS)算法求解旅游线路时间花费较长的问题,提出了一种ILS结合布谷鸟搜索(cuckoo search,CS)的优化算法,来优化旅游线路的时间花费。该算法首先根据相关目标和约束采用ILS算法求解旅游景点及初...针对迭代局部搜索(iterated local search,ILS)算法求解旅游线路时间花费较长的问题,提出了一种ILS结合布谷鸟搜索(cuckoo search,CS)的优化算法,来优化旅游线路的时间花费。该算法首先根据相关目标和约束采用ILS算法求解旅游景点及初始旅游线路,然后在满足旅游景点时间窗约束及景点总数不变的情况下采用CS算法进一步最小化旅游线路的时间花费。该研究获得的线路更符合旅游习惯,并且旅游时间花费更少。通过Daminaos数据集和桂林景点数据集进行验证,结果表明该优化算法相比于仅使用ILS算法所规划出的旅游线路,平均时间花费减少8%,更符合用户旅游选择习惯。展开更多
A robust H∞ directional controller for a sampled-data autonomous airship with polytopic parameter uncertainties was proposed. By input delay approach, the linearized airship model was transformed into a continuous-ti...A robust H∞ directional controller for a sampled-data autonomous airship with polytopic parameter uncertainties was proposed. By input delay approach, the linearized airship model was transformed into a continuous-time system with time-varying delay. Sufficient conditions were then established based on the constructed Lyapunov-Krasovskii functional, which guarantee that the system is mean-square exponentially stable with H∞ performance. The desired controller can be obtained by solving the obtained conditions. Simulation results show that guaranteed minimum H∞ performance γ=1.4037 and fast response of attitude for sampled-data autonomous airship are achieved in spite of the existence of parameter uncertainties.展开更多
The grain size, textures and grain boundary plane distributions in a cold-rolled and annealed ferritic stainless steel were investigated by means of EBSD techniques. The results show that, following cold rolling with ...The grain size, textures and grain boundary plane distributions in a cold-rolled and annealed ferritic stainless steel were investigated by means of EBSD techniques. The results show that, following cold rolling with the thickness reduction of 85%, relatively low temperature （780℃） annealing brings an extremely sluggish grain growth and no grain texture develops when the annealing time varies from 5 min to 480 min. The free energy reduction of the system is mainly caused by the grain boundary plane re-orientation in addition to minor grain growth because the distributions of grain boundary planes are moderately preferred on { 100} according to the five parameter analyses （FPA） concerning the grain boundary plane characteristics. However, in the case of high-temperature （1 000 ℃） annealing, the average grain size does not increase until annealing time is prolonged to 90 min, after which extensive grain growth occurs and strong {100}（hkl） texture emerges whereas nearly random grain boundary plane distributions are observed. The free energy reduction of the system is most likely attributed to the selective growth.展开更多
文摘针对迭代局部搜索(iterated local search,ILS)算法求解旅游线路时间花费较长的问题,提出了一种ILS结合布谷鸟搜索(cuckoo search,CS)的优化算法,来优化旅游线路的时间花费。该算法首先根据相关目标和约束采用ILS算法求解旅游景点及初始旅游线路,然后在满足旅游景点时间窗约束及景点总数不变的情况下采用CS算法进一步最小化旅游线路的时间花费。该研究获得的线路更符合旅游习惯,并且旅游时间花费更少。通过Daminaos数据集和桂林景点数据集进行验证,结果表明该优化算法相比于仅使用ILS算法所规划出的旅游线路,平均时间花费减少8%,更符合用户旅游选择习惯。
基金Projects(51205253,11272205)supported by the National Natural Science Foundation of ChinaProject(2012AA7052005)supported by the National High Technology Research and Development Program of China
文摘A robust H∞ directional controller for a sampled-data autonomous airship with polytopic parameter uncertainties was proposed. By input delay approach, the linearized airship model was transformed into a continuous-time system with time-varying delay. Sufficient conditions were then established based on the constructed Lyapunov-Krasovskii functional, which guarantee that the system is mean-square exponentially stable with H∞ performance. The desired controller can be obtained by solving the obtained conditions. Simulation results show that guaranteed minimum H∞ performance γ=1.4037 and fast response of attitude for sampled-data autonomous airship are achieved in spite of the existence of parameter uncertainties.
基金Project(50974147)supported by the National Natural Science Foundation of ChinaProject(2009ZRB01176)supported by the Natural Science Foundation of Shandong Province,China
文摘The grain size, textures and grain boundary plane distributions in a cold-rolled and annealed ferritic stainless steel were investigated by means of EBSD techniques. The results show that, following cold rolling with the thickness reduction of 85%, relatively low temperature （780℃） annealing brings an extremely sluggish grain growth and no grain texture develops when the annealing time varies from 5 min to 480 min. The free energy reduction of the system is mainly caused by the grain boundary plane re-orientation in addition to minor grain growth because the distributions of grain boundary planes are moderately preferred on { 100} according to the five parameter analyses （FPA） concerning the grain boundary plane characteristics. However, in the case of high-temperature （1 000 ℃） annealing, the average grain size does not increase until annealing time is prolonged to 90 min, after which extensive grain growth occurs and strong {100}（hkl） texture emerges whereas nearly random grain boundary plane distributions are observed. The free energy reduction of the system is most likely attributed to the selective growth.
