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基于改进遗传算法的TSP问题研究 总被引:9,自引:1,他引:9
周涛 《微电子学与计算机》2006,23(10):104-106,110
通过对遗传算法和TSP问题的研究.提出了离散赌轮选择算子EPMX交叉算子和Dmutation变异算子等,对遗传算法的各个算子进行了改进。利用改进的遗传算法有效的解决了TSP问题.实验验证其与传统的解决方式相比有更好的收敛特性,解的准确性更好。 相似文献
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遗传算法在图像重建中的应用 总被引:4,自引:1,他引:3
针对从不完全投影重建图像的问题,根据图像连续性的假设,建立优化模型用遗传算法求解。针对遗传算法的早熟现象提出了多样性原则,分析了选择算子、交叉算子,以及变异算子对多样性的影响,构建了自适应遗传算法,并进行了仿真试验,试验结果比较满意。 相似文献
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简要介绍了舵机的工作特性,利用自适应遗传算法对舵机传递函数进行了辨识,与传统遗传算法相比,自适应遗传算法的选择算子采用最优保存和赌轮盘相结合,并在进行赌轮盘前对适应度进行排序,交叉变异算子采用自适应交叉和变异算子,终止条件也分为两类,适应度小于设定的值时就会跳出遗传算法和达到代数上限时跳出遗传算法。自适应遗传算法的辨识的结果和遗传算法相比较,仿真结果表明:自适应遗传算法在运行速度和收敛方面有较好的效果。 相似文献
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为有效地解决遗传算法收敛速度和局部最优解的矛盾,本文提出了一种具有自识别交叉算子和基于海明距离的动态变异算子的遗传算法.自识别交叉算子保证父代的优良模式遗传到下一代,加快了算法的收敛速度;而动态变异算子扩大了搜索范围,增强了算法跳离局部最优解的能力.实验证明,两种改进算子的有效结合保证算法能以较快速度收敛于全局最优解. 相似文献
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为了解决多输入多输出(MIMO)天线阵列由于阵元间隔过大造成的阵列方向图出现栅瓣,在雷达回波成像时出现影响目标识别的虚假目标的问题,提出了一种改进的遗传算法对阵列排布进行优化。在传统标准遗传算法上进行改进,用多个矩阵组合表示MIMO阵列,针对在矩形平面随机分布的稀疏阵列的方向图旁瓣问题进行优化设计,并采用基于Logistic混沌序列的方法产生种群扰动,避免优化过程进入局部最优状态。通过实例对比22发射天线22接收天线的均匀规则排布MIMO阵列和经改进遗传算法优化的稀布MIMO阵列,结果表明,改进遗传算法可以有效解决规则排布阵列方向图中出现的栅瓣,并且降低方向图旁瓣,提高雷达成像性能。该优化算法变量可控,具有很强的实用性,为MIMO雷达的阵列排布提供了解决方法。 相似文献
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Adaptation of an antenna array controlled by digital-phase shifters using an advanced operator genetic algorithm is demonstrated. The genetic algorithm continuously optimizes the antenna's received signal-to-noise-plus-interference ratio (SINR) (Applebaum (1976) criterion) under changing interference conditions. Unlike earlier attempts to control adaptive array antennas using evolutionary optimization techniques, the current study uses a genetic algorithm with a population composed of individuals characterized by two chromosomes. Several numerical examples demonstrate that this “diploid” structure improves the ability of the genetic algorithm to adapt to changing conditions when compared with a simple genetic algorithm 相似文献
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最小均方(LMS)算法是自适应阵列天线中得以广泛应用的阵列天线加权算法。提出了一种基于遗传优化的LMS改进算法,该基于遗传优化的最小均方(GA—LMS)算法充分结合了遗传算法的并行处理和全局搜索的优点。实验结果表明,与传统的LMS算法相比,GA—LMS算法具有良好的收敛性能,并可更好地抑制干扰信号,有效改善自适应阵列天... 相似文献
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An improved adaptive genetic algorithm is presented in this paper.It primarily includes two modified methods:one is novel adaptive probabilities of crossover and mutation,the other is truncated selection approach.This algorithm has been validated to be superior to the simple genetic algorithm (SGA) by a complicated binary testing function.Then the proposed algorithm is applied to optimizing the planar retrodirective array to reduce the cost of the hardware.The fitness function is discussed in the optimization example.After optimization,the sparse planar retrodirective antenna array keeps excellent retrodirectivity,while the array architecture has been simplified by 34%.The optimized antenna array can replace uniform full array effectively.Results show that this work will gain more engineering benefits in practice. 相似文献
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提高主瓣的能量集中度和抑制栅瓣问题是当前光纤激光相控阵技术面向应用的关键。文中从说明激光相控阵在技术上难以满足/2的阵元间隔,由此导致诸多栅瓣产生的原因入手,并考虑到目前常用不等间隔栅瓣抑制方法将导致相控阵口径增大的难题,提出了一种将遗传算法引入到光纤激光相控阵阵元分布优化的设想。主要方法是从最大限度抑制栅瓣的角度提出一个与主瓣能量集中度和主瓣/旁瓣对比度相关的适应度函数;将遗传算法中的特征参数与光纤激光相控阵的主要参数相对应;然后以20路阵元/阵元间隔为3倍波长、50路阵元/阵元间隔为20倍波长两种线阵情况为例,分别仿真计算了传统的等间距阵元和不等间距阵元分布,及遗传算法优化阵元分布三种情况,得到的光纤激光相控阵远场能量分布、主瓣能量集中度和主瓣与最大栅瓣对比度,并对其进行了比较。结果表明,遗传算法较等间距、不等间距方法的主瓣能量集中度分别提高了9.69%、3.33%,主瓣与第一栅瓣能量对比度分别提高了13.12%、9%。由此可预期基于遗传算法优化的相控阵有望在同等激光发射总功率下获得更远的作用距离。 相似文献
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Optimization of thinned aperiodic linear phased arrays using genetic algorithms to reduce grating lobes during scanning 总被引:4,自引:0,他引:4
Bray M.G. Werner D.H. Boeringer D.W. Machuga D.W. 《Antennas and Propagation, IEEE Transactions on》2002,50(12):1732-1742
The scan volume of a thinned periodic linear phased array is proportional to the spacing between array elements. As the spacing between elements increases beyond a half wavelength, the scan range of the array will be significantly reduced due to the appearance of grating lobes. This paper investigates a method of creating thinned aperiodic linear phased arrays through the application of genetic algorithms that will suppress the grating lobes with increased steering angles. In addition, the genetic algorithm will place restrictions on the driving-point impedance of each element so that they are well behaved during scanning. A genetic algorithm approach is also introduced for the purpose of evolving an optimal set of matching networks. Finally, an efficient technique for evaluating the directivity of an aperiodic array of half-wave dipoles is developed for use in conjunction with genetic algorithms. 相似文献
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Array pattern nulling by operating on the roots of the array polynomial in the complex plane using a genetic algorithm (GA) is demonstrated. A pattern envelope constraint and an array efficiency criterion are applied. The algorithm is much faster than a similar GA operating on the complex weights of the array factor 相似文献
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An optimization model of circle array was set up from the basic optical synthetic aperture imaging principle. The circle array was optimized by adopting a genetic algorithm with an improved real coding method coding the location of sub-apertures. The measure function was designed based on maximizing the distances between u-v coverage dots and minimizing the redundant array. The point spread function, optical transfer function and diffractive imaging were analyzed with the circle array synthetic aperture imaging system. The optimized result of 8 to 16 sub-apertures on a circle array was obtained, and they were compared to the results achieved through simulated annealing algorithm. Using the emulator program, the point spread function was analyzed and contrasted to that of a uniform circle array. Results show that the real coding genetic algorithm can resolve the array optimization well, cost less time and get a better optimization compared with the simulated annealing algorithm. 相似文献