To solve vehicle routing problem with different fleets, two methodologies are developed. The first methodology adopts twophase strategy. In the first phase, the improved savings method is used to assign customers to a...To solve vehicle routing problem with different fleets, two methodologies are developed. The first methodology adopts twophase strategy. In the first phase, the improved savings method is used to assign customers to appropriate vehicles. In the second phase, the iterated dynasearch algorithm is adopted to route each selected vehicle with the assigned customers. The iterated dynasearch algorithm combines dynasearch algorithm with iterated local search algorithm based on random kicks. The second methodplogy adopts the idea of cyclic transfer which is performed by using dynamic programming algorithm, and the iterated dynasearch algorithm is also embedded in it. The test results show that both methodologies generate better solutions than the traditional method, and the second methodology is superior to the first one.展开更多
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
针对车辆路径问题,提出一种改进的迭代局部搜索(ILS)算法。该算法基于破坏再重建(Ruin and Recreate)的思想,设计了一种新的扰动机制。扰动过程包含破坏和重建两个阶段,即先使用一种兼顾随机性和相关性的破坏方法对解进行破坏,并引入扰...针对车辆路径问题,提出一种改进的迭代局部搜索(ILS)算法。该算法基于破坏再重建(Ruin and Recreate)的思想,设计了一种新的扰动机制。扰动过程包含破坏和重建两个阶段,即先使用一种兼顾随机性和相关性的破坏方法对解进行破坏,并引入扰动因子控制解的破坏强度,然后再随机选择基本贪婪插入和改进贪婪插入算法完成解的修复。利用国际标准测试案例对常规扰动机制和改进后的扰动机制进行了测试,并与量子进化算法、蜂群算法进行了比较,实验结果表明改进后的ILS算法更加有效。展开更多
Safety patrol inspection in chemical industrial parks is a complex multi-objective task with multiple degrees of freedom.Traditional pointer instruments with advantages like high reliability and strong adaptability to...Safety patrol inspection in chemical industrial parks is a complex multi-objective task with multiple degrees of freedom.Traditional pointer instruments with advantages like high reliability and strong adaptability to harsh environment,are widely applied in such parks.However,they rely on manual readings which have problems like heavy patrol workload,high labor cost,high false positives/negatives and poor timeliness.To address the above problems,this study proposes a path planning method for robot patrol in chemical industrial parks,where a path optimization model based on improved iterated local search and random variable neighborhood descent(ILS-RVND)algorithm is established by integrating the actual requirements of patrol tasks in chemical industrial parks.Further,the effectiveness of the model and algorithm is verified by taking real park data as an example.The results show that compared with GA and ILS-RVND,the improved algorithm reduces quantification cost by about 24%and saves patrol time by about 36%.Apart from shortening the patrol time of robots,optimizing their patrol path and reducing their maintenance loss,the proposed algorithm also avoids the untimely patrol of robots and enhances the safety factor of equipment.展开更多
Iterated local search(ILS)is used to construct the optimal experimental designs for multi-dimensional constrained spaces,in which the inner loop is based on the stochastic coordinate-exchange(SCE)algorithm.Every time ...Iterated local search(ILS)is used to construct the optimal experimental designs for multi-dimensional constrained spaces,in which the inner loop is based on the stochastic coordinate-exchange(SCE)algorithm.Every time a local optimal solution is found by the SCE algorithm,the perturbation operator is applied to it,and then a new solution is explored in the areas where the exchange of coordinates may produce improvement,so as to retain the features and attributes of the current optimal solution and avoid the defects of random restart.We implement the iterated local coordinate-exchange algorithm for experimental designs in the multi-dimensional constrained spaces.In addition,sensitivity analysis was conducted to analyze the impacts of the parameters on the performance of the proposed algorithm.Also we compared the performance of the proposed algorithm to the SCE algorithm using the random restart strategy.The analysis shows that the proposed algorithm is better than the SCE algorithm in terms of efficiency and quality,especially in the experimental designs for high-dimensional constrained space.展开更多
通过优化汽轮机叶片的安装顺序,来减少安装后的残余不平衡量。对此提出一种阈值式迭代局部搜索(threshold iterative local search,TILS)算法,该算法在迭代局部搜索(iterative local search,ILS)算法基础上,采用阈值限定扰动与随机扰动...通过优化汽轮机叶片的安装顺序,来减少安装后的残余不平衡量。对此提出一种阈值式迭代局部搜索(threshold iterative local search,TILS)算法,该算法在迭代局部搜索(iterative local search,ILS)算法基础上,采用阈值限定扰动与随机扰动相结合的方法来跳出局部最优解,减少了平均到达局部最优解所需的迭代步数。实验证明,该方法可以在短时间内找到一个近似最优叶片排序组合,相对于ILS算法,搜索效率提高了20%以上。计算得到的合成质径积的近似最优解,相对于现有分组排序法、遗传算法、云自适应遗传算法(CAGA)等方法,分别减小到其最优解的0.33%~31%,且计算时间也大幅度减小。展开更多
基金The National Natural Science Founda-tion of China ( No.70471039)the National Social Science Foundation of China (No.07BJY038)the Program for New Century Excellent Talents in University (No.NCET-04-0886)
文摘To solve vehicle routing problem with different fleets, two methodologies are developed. The first methodology adopts twophase strategy. In the first phase, the improved savings method is used to assign customers to appropriate vehicles. In the second phase, the iterated dynasearch algorithm is adopted to route each selected vehicle with the assigned customers. The iterated dynasearch algorithm combines dynasearch algorithm with iterated local search algorithm based on random kicks. The second methodplogy adopts the idea of cyclic transfer which is performed by using dynamic programming algorithm, and the iterated dynasearch algorithm is also embedded in it. The test results show that both methodologies generate better solutions than the traditional method, and the second methodology is superior to the first one.
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。
文摘针对车辆路径问题,提出一种改进的迭代局部搜索(ILS)算法。该算法基于破坏再重建(Ruin and Recreate)的思想,设计了一种新的扰动机制。扰动过程包含破坏和重建两个阶段,即先使用一种兼顾随机性和相关性的破坏方法对解进行破坏,并引入扰动因子控制解的破坏强度,然后再随机选择基本贪婪插入和改进贪婪插入算法完成解的修复。利用国际标准测试案例对常规扰动机制和改进后的扰动机制进行了测试,并与量子进化算法、蜂群算法进行了比较,实验结果表明改进后的ILS算法更加有效。
基金the National Key R&D Plan of China(No.2021YFE0105000)the National Natural Science Foundation of China(No.52074213)+1 种基金the Shaanxi Key R&D Plan Project(No.2021SF-472)the Yulin Science and Technology Plan Project(No.CXY-2020-036).
文摘Safety patrol inspection in chemical industrial parks is a complex multi-objective task with multiple degrees of freedom.Traditional pointer instruments with advantages like high reliability and strong adaptability to harsh environment,are widely applied in such parks.However,they rely on manual readings which have problems like heavy patrol workload,high labor cost,high false positives/negatives and poor timeliness.To address the above problems,this study proposes a path planning method for robot patrol in chemical industrial parks,where a path optimization model based on improved iterated local search and random variable neighborhood descent(ILS-RVND)algorithm is established by integrating the actual requirements of patrol tasks in chemical industrial parks.Further,the effectiveness of the model and algorithm is verified by taking real park data as an example.The results show that compared with GA and ILS-RVND,the improved algorithm reduces quantification cost by about 24%and saves patrol time by about 36%.Apart from shortening the patrol time of robots,optimizing their patrol path and reducing their maintenance loss,the proposed algorithm also avoids the untimely patrol of robots and enhances the safety factor of equipment.
基金This work was supported by the National Natural Science Foundation of China(72171231).
文摘Iterated local search(ILS)is used to construct the optimal experimental designs for multi-dimensional constrained spaces,in which the inner loop is based on the stochastic coordinate-exchange(SCE)algorithm.Every time a local optimal solution is found by the SCE algorithm,the perturbation operator is applied to it,and then a new solution is explored in the areas where the exchange of coordinates may produce improvement,so as to retain the features and attributes of the current optimal solution and avoid the defects of random restart.We implement the iterated local coordinate-exchange algorithm for experimental designs in the multi-dimensional constrained spaces.In addition,sensitivity analysis was conducted to analyze the impacts of the parameters on the performance of the proposed algorithm.Also we compared the performance of the proposed algorithm to the SCE algorithm using the random restart strategy.The analysis shows that the proposed algorithm is better than the SCE algorithm in terms of efficiency and quality,especially in the experimental designs for high-dimensional constrained space.
文摘通过优化汽轮机叶片的安装顺序,来减少安装后的残余不平衡量。对此提出一种阈值式迭代局部搜索(threshold iterative local search,TILS)算法,该算法在迭代局部搜索(iterative local search,ILS)算法基础上,采用阈值限定扰动与随机扰动相结合的方法来跳出局部最优解,减少了平均到达局部最优解所需的迭代步数。实验证明,该方法可以在短时间内找到一个近似最优叶片排序组合,相对于ILS算法,搜索效率提高了20%以上。计算得到的合成质径积的近似最优解,相对于现有分组排序法、遗传算法、云自适应遗传算法(CAGA)等方法,分别减小到其最优解的0.33%~31%,且计算时间也大幅度减小。
