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用改进的模拟退火算法设计二元光学阵列器件 总被引:3,自引:2,他引:1
为提高收敛速率,本文对模拟退火(SA)算法进行改进,并用此改进算法设计用于产生大扇出系数、任意形状分布光阵列的二元光学器件,其衍射效率设计值达85%以上,输出阵列不均匀性小于3%。 相似文献
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针对传统的标准遗传算法应用于传感器阵列的波束图设计时,存在收敛速度慢和计算结果稳定性低的问题,文中提出了一种模拟退火遗传算法.该算法对标准遗传算法的适应度函数、交叉算子和异化算子等多个要素分别进行了改进,并融入了模拟退火算法.模拟退火遗传算法应用于波束图设计时,具有较快的收敛速度和较高的稳定性.仿真结果表明基于该算法的波束图设计方法,获得了比传统方法旁瓣级更低的波束图. 相似文献
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结合遗传算法(GA)的并行搜索结构和模拟退火(SA)的概率突跳性,并结合使用自适应的交叉算子和变异算子,提出了一种高效的自适应的SAGA混合优化算法。在自主开发的结构性测试工具WBoxTool中,使用自适应SAGA混合优化策略进行测试数据自动生成,并通过实例对基本遗传算法、自适应遗传算法和自适应SAGA进行了比较,结果表明自适应SAGA具有更强的搜索能力,可以更快的发现全局最优解。 相似文献
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叙述紫外均匀照明光学系统构成原理和光能分布模拟计算设计方法。举例说明用开发的模拟设计软件OPTENG,设计和模拟计算了一个大视场均匀照明光学系统,在照明面积为100mm×100mm范围内,照明光能分布不均匀性小于±2%。 相似文献
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Yang Meng A.E.A. Almaini Wang Pengjun 《电子科学学刊(英文版)》2006,23(4):632-636
Genetic Algorithm (GA) is a biologically inspired technique and widely used to solve numerous combinational optimization problems. It works on a population of individuals, not just one single solution. As a result, it avoids converging to the local optimum. However, it takes too much CPU time in the late process of GA. On the other hand, in the late process Simulated Annealing (SA) converges faster than GA but it is easily trapped to local optimum. In this letter, a useful method that unifies GA and SA is introduced, which utilizes the advantage of the global search ability of GA and fast convergence of SA. The experimental results show that the proposed algorithm outperforms GA in terms of CPU time without degradation of performance. It also achieves highly comparable placement cost compared to the state-of-the-art results obtained by Versatile Place and Route (VPR) Tool. 相似文献
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Shidrokh Goudarzi Wan Haslina Hassan Mohammad Hossein Anisi Seyed Ahmad Soleymani 《Wireless Personal Communications》2017,92(2):399-436
The hybrid algorithm for real-time vertical handover using different objective functions has been presented to find the optimal network to connect with a good quality of service in accordance with the user’s preferences. Markov processes are widely used in performance modelling of wireless and mobile communication systems. We address the problem of optimal wireless network selection during vertical handover, based on the received information, by embedding the decision problem in a Markov decision process (MDP) with genetic algorithm (GA), we use GA to find a set of optimal decisions that ensures the best trade-off between QoS based on their priority level. Then, we emerge improved genetic algorithm (IGA) with simulated annealing (SA) as leading methods for search and optimization problems in heterogeneous wireless networks. We formulate the vertical handoff decision problem as a MDP, with the objectives of maximizing the expected total reward and minimizing average number of handoffs. A reward function is constructed to assess the QoS during each connection, and the AHP method are applied in an iterative way, by which we can work out a stationary deterministic handoff decision policy. As it is, the characteristics of the current mobile devices recommend using fast and efficient algorithms to provide solutions near to real-time. These constraints have moved us to develop intelligent algorithm that avoid the slow and massive computations. This paper compares the formulation and results of five recent optimization algorithms: artificial bee colony, GA, differential evolution, particle swarm optimization and hybrid of (GA–SA). Simulation results indicated that choosing the SA rules would minimize the cost function, and also that, the IGA–SA algorithm could decrease the number of unnecessary handovers, and thereby prevent the ‘Ping-Pong’ effect. 相似文献
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Shao Wei Qian Zuping Yuan Feng 《电子科学学刊(英文版)》2007,24(4):560-566
A robust phase-only Direct Data Domain Least Squares (D3LS) algorithm based on generalized Rayleigh quotient optimization using hybrid Genetic Algorithm (GA) is presented in this letter. The optimization efficiency and computational speed are improved via the hybrid GA composed of standard GA and Nelder-Mead simplex algorithms. First, the objective function, with a form of generalized Rayleigh quotient, is derived via the standard D3LS algorithm. It is then taken as a fitness function and the unknown phases of all adaptive weights are taken as decision variables Then, the nonlinear optimization is performed via the hybrid GA to obtain the optimized solution of phase-only adaptive weights. As a phase-only adaptive algorithm, the proposed algorithm is simpler than conventional algorithms when it comes to hardware implementation. Moreover, it proc- esses only a single snapshot data as opposed to forming sample covariance matrix and operating matrix inversion. Simulation results show that the proposed algorithm has a good signal recovery and interferences nulling performance, which are superior to that of the phase-only D3LS algorithm based on standard GA. 相似文献
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一种基于改进的遗传算法的块匹配运动估计方法 总被引:4,自引:0,他引:4
块匹配方法(Block Matching Algorithm,简称BMA)是目前广泛使用的运动估计方法,但该方法的最大缺点是容易陷于局部最优,这主要是由搜索模式决定的。而遗传算法(Genetic Algorithm,简称GA)是一种具有广泛适应性的全局最优的搜索算法。将块匹配方法的局域性搜索与遗传算法的全局性搜索结合起来,本文提出了一种基于改进的遗传算法的块匹配运动估计方法。实验证明,该方法的平均绝对误差(MAE)接近全搜索(FSS),优于三步法(TSS),而运算量相对较低,接近三步法。 相似文献
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本文针对CDMA系统中多用户检测的组合优化问题,提出一种结合遗传算法和Hopfield神经网络的检测方法。该方法首先由遗传算法给神经网络提供一个初始解,神经网络在此基础上再进行局部寻优。研究表明:这种方法具有平方的计算复杂度,优于Hopfield神经网络检测方法、以及单独采用遗传算法的检测方法,对远近问题不敏感,具有良好的误码率性能和抗多址干扰性能。 相似文献
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近年来,时延受限的代价最小组播树问题备受关注。作为全局优化算法,遗传算法(GA)越来越多的用于解决组播路由问题。GA拥有比经典算法更强的搜索能力,但是它容易陷入"早熟",很难得到最优组播树。基于量子计算的机理和特性并结合进化计算,提出了一种新颖的量子进化组播路由算法(QEA),有效地解决了遗传组播路由算法中的"早熟"问题,并且在每代个体更新中采用量子旋转门策略加速了算法的收敛速度。算法实现简单,控制灵活。仿真结果表明QEA算法性能优于改进的进化算法即克隆多播路由算法(CS)和传统的遗传算法(GA)。 相似文献
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手征媒质是双各向同性媒质的一种,其手征参数具有可调性。首先,在标准粒子群
算法(PSO)和模拟退火(SA)算法的基础上进行了改进,并利用混合算法优化设计手征参数
及媒质
厚度,以在给定的频率范围内获得较高的吸收率。然后,仿真计算了某一个参数取不同值而
其它参数固定情况下电磁波垂直入射到手征媒质时的反射系数。结果证明,只有在最优化参
数条件下才可以在频带内获得较理想的吸收率和反射系数。 相似文献