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1.
近年来, 在基于Q学习算法的作业车间动态调度系统中, 状态-行动和奖励值靠人为主观设定, 导致学习效果不理想, 与已知最优解相比, 结果偏差较大. 为此, 基于作业车间调度问题的特质, 对Q学习算法的要素进行重新设计, 并用标准算例库进行仿真测试. 将结果先与已知最优解和混合灰狼优化算法、离散布谷鸟算法和量子鲸鱼群算法在近似程度、最小值方面进行比较分析. 实验结果表明, 与国内求解作业车间调度问题的Q学习算法相比, 该方法在最优解的近似程度上显著提升, 与群智能算法相比, 在大多数算例中, 寻优能力方面有显著提升.  相似文献   

2.
System identification for stationary Gaussian processes includes an approximation problem. Currently, the subspace algorithm for this problem enjoys much attention. This algorithm is based on a transformation of a finite time series to canonical variable form followed by a truncation. There is no proof that this algorithm is the optimal solution to an approximation problem with a specific criterion. In this paper it is shown that the optimal solution to an approximation problem for Gaussian random variables with the divergence criterion is identical to the main step of the subspace algorithm. An approximation problem for stationary Gaussian processes with the divergence criterion is formulated.  相似文献   

3.
遗传算法在曲线多边形近似中的应用   总被引:8,自引:1,他引:7  
张鸿宾  郭建军 《计算机学报》1999,22(10):1100-1104
在平面数字曲线的多边形近似中,为克服顶点的检测只依靠部区域,缺 乏全局信息的弱点,文中把多边形近似问题作了寻找在满足一定的近似误差下使顶点数最少,或者使顶点数和近似误差都尽可能少的最优化问题来处理。  相似文献   

4.
针对灰狼优化算法(GWO)存在的求解精度较低、后期收敛速度较慢、易陷入局部最优的缺点,提出一种改进灰狼优化算法(EGWO)。该算法引进两种改进策略:用以平衡算法全局搜索性和局部开发性的非线性收敛因子调整策略和用以降低陷入局部最优风险的精英个体重选策略。通过在9个基准测试函数上的实验与标准GWO算法,以及文献提出的5种改进灰狼算法和4种其他算法进行对比,从算法寻优的精确性和鲁棒性两个方面验证两种算法改进策略的有效性。实验结果表明,两种改进策略都能提升算法性能,综合使用两种策略的EGWO在收敛速度和求解精度都明显优于其他比较算法。  相似文献   

5.
吕其诚 《软件学报》1992,3(4):19-23
本文提出了无向图(k,m)最优划分的一个近似算法,证明了这是一个产生近似最优解的多项式时间算法。在最坏情况下,该算法的性能保证为一个参数k所界定,这里k是与问题输入尺寸无关的。  相似文献   

6.
In this paper, an efficient sequential approximation optimization assisted particle swarm optimization algorithm is proposed for optimization of expensive problems. This algorithm makes a good balance between the search ability of particle swarm optimization and sequential approximation optimization. Specifically, the proposed algorithm uses the optima obtained by sequential approximation optimization in local regions to replace the personal historical best particles and then runs the basic particle swarm optimization procedures. Compared with particle swarm optimization, the proposed algorithm is more efficient because the optima provided by sequential approximation optimization can direct swarm particles to search in a more accurate way. In addition, a space partition strategy is proposed to constraint sequential approximation optimization in local regions. This strategy can enhance the swarm diversity and prevent the preconvergence of the proposed algorithm. In order to validate the proposed algorithm, a lot of numerical benchmark problems are tested. An overall comparison between the proposed algorithm and several other optimization algorithms has been made. Finally, the proposed algorithm is applied to an optimal design of bearings in an all-direction propeller. The results show that the proposed algorithm is efficient and promising for optimization of the expensive problems.  相似文献   

7.
本文主要讨论主子阵约束下矩阵方程AX=B的对称最小二乘解.基于投影定理,巧妙的把最小二乘问题转化为等式问题求解,并利用奇异值分解的方法,给出了该对称最小二乘解的一般表达式.此外,文章还考虑了此对称最小二乘解集合对任一给定矩阵的最佳逼近问题,得到了最佳逼近解,并给出了相应的算法步骤和数值例子.  相似文献   

8.
This paper presents a new near lossless compression algorithm for hyperspectral images based on distributed source coding. The algorithm is performed on blocks that have the same location and size in each band. Because the importance varies from block to block along the spectral orientation, an adaptive rate allocation algorithm that weights the energy of each block under the target rate constraints is introduced. A simple linear prediction model is employed to construct the side information of each block for Slepian–Wolf coding. The relationship between the quantized step size and the allocated rate of each block is determined under the condition of correct reconstruction with the side information at the Slepian–Wolf decoder. Slepian–Wolf coding is performed on the quantized version of each block. Experimental results show that the performance of the proposed algorithm is competitive with that of state-of-the-art compression algorithms, making it appropriate for on-board compression.  相似文献   

9.
This paper presents an economic lot-sizing problem with perishable inventory and general economies of scale cost functions. For the case with backlogging allowed, a mathematical model is formulated, and several properties of the optimal solutions are explored. With the help of these optimality properties, a polynomial time approximation algorithm is developed by a new method. The new method adopts a shift technique to obtain a feasible solution of subproblem and takes the optimal solution of the subproblem as an approximation solution of our problem. The worst case performance for the approximation algorithm is proven to be (4*2½+5)/7. Finally, an instance illustrates that the bound is tight.  相似文献   

10.
针对单一机制的灰狼优化算法(GWO)易陷于局部最优、收敛速度慢的问题,提出了一种改进灰狼优化(IGWO)算法来解决实际铁路物流配送中心选址的问题。首先,在基本的灰狼优化算法的基础上,引入佳点集理论初始化种群,从而提高了初始种群的多样性;然后,利用差值剔除策略(DES)来增加全局寻优能力,以达到一种高效的寻优模式。仿真实验结果表明:与标准的灰狼算法相比,所提出的IGWO适应度值提高了3%,在10个测试函数中最优值精度可最多提高7个单位;与粒子群优化(PSO)算法、差分进化(DE)算法和遗传算法(GA)比较,所提算法的运行速度分别提高了39.6%、46.5%和65.9%,选址速度也明显提高。可见所提算法可用于铁路物流中心的选址。  相似文献   

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