基于遗传算法对PID控制飞行器射程优化

最大射程是飞行器地面发射试验的重要指标,综合控制与优化算法可对其进行系统设计.首先,根据飞行器动力学方程进行品质分析,确定用短周期参数进行最大射程设计;其次,设定时域目标参数,采用根轨迹方法实现关键时刻飞行器PID控制器调参;然后,以仿真参数为基础,采用遗传算法优化飞行器俯仰角指令;最后,根据综合设计的仿真结果,分析出不同飞行阶段最显著干扰产生的作用,为飞行器动力学性能分析奠定基础.     

Evaluation of genetic diversity and relationships within and between two breeds of duck based on microsatellite markers

The genetic diversity of two natural populations (M, N) of Beijing duck (Anas platyrhynchos) and 11 artificially selected lines of Beijing duck (A, B, E-L, O) from China Gold Star Duck Production Ltd., along with two Cherry Valley duck lines (C and D) from the British Cherry Valley Livestock Division, was evaluated using 18 microsatellite markers covering 16 linkage groups. A phylogenetic tree of the 15 populations of duck, formed of four main branches, was constructed from Nei’s D_A genetic distance. The mean genetic differentiation index (F_ST) in all loci, Nei’s standard genetic distance (Ds), and the genetic distance D_A between the Beijing duck and the Cherry Valley duck were 0.075, 0.143 and 0.142, respectively. These results demonstrated a high degree of genetic similarity between the two breeds and supported the hypothesis that the Cherry Valley duck was derived from the Beijing duck. The F_ST matrix of seven clusters of Beijing duck suggested that the efficiency of selection was not significant to some extent and should be supplemented by marker-assisted selection.     

基于agent的并行GA

采用遗传进化技术和多智能体技术相结合的方法，实现了基于粗粒度的并行GA，该方法有利于改进遗传算法的性能，提高遗传算法搜索的效率，文中讨论的并行模型，最大的特点是通讯开销小。     

网络远程教育发展与应用的思考

网络远程教育是近年来高等教育领域讨论的热点之一，对于网络远程教育的优势和不足、定位及发展前景众说纷纭，本文试从网络远程教育发生发展的背景出发，通过与传统教育进行对比分析，指出网络远程教育的特点与优势，并就现阶段在开展网络远程教育过程中出现的一些问题给出建议，旨在探讨网络远程教育良性发展的对策。     

Relationships of Aegilops tauschii revealed by DNA fingerprints: The evidence for agriculture exchange between China and the West

Genetic diversity and relationships of wild goat grass (Aegilops tauschii Cosson) from Iran and Xinjiang,west China,as well as its weedy type from the Yellow River region of Shaanxi and Henan provinces in China were analyzed by simple sequence repeat (SSR) fingerprints.A high level of genetic diversity in Aegilops tauschii accessions from Iran was observed,and the richness of genetic diversity was followed by accessions from Shaanxi,Henan,and Xinjiang.The weedy type of Aegilops tauschii showed a close genetic relationship with the wild type from different regions in Iran.The results indicated that the weedy Aegilops tauschii found in the Yellow River region was most likely introduced from lran-the diversity center of Aegilops tauschii.The weedy Aegilops tauschii populations found in the Yellow River region may be brought into the central part of China as a weed species together with common wheat (Triticum aestivum L.) from the West during various periods of time in history.This finding has provided strong evidence for the introduction of common wheat from the West into China via the Silk Road,and also demonstrated the important role of the Silk Road in the exchange of agri-culture and other relevant technologies between China and the West.     

基于多散射中心模型的雷达目标识别方法

针对宽带毫米波雷达目标识别要求 ,提出了一种基于目标光学区多散射中心模型进行目标匹配识别的新方法。该方法首先基于多散射中心理论建立待识别目标的模型、利用遗传算法的全局优化能力进行目标识别。与常规的全姿态角匹配识别方法比较 ,具有需要的存储量、计算量较少的特点。仿真试验验证了该算法的有效性。     

Genetic determinants of individual differences in avoidance learning: Behavioral and endocrine characteristics

Bidirectional genetic selection for good and poor active avoidance learning in a shuttle box has been carried out in three independent laboratories using remarkably similar discrete-trial training procedures. The resulting strains are known as the Roman High and Low Avoidance (RHA and RLA), the Syracuse High and Low Avoidance (SHA and SLA) and the Australian High and Low Avoidance (AHA and ALA) strains, respectively. An additional unidirectionally selected strain, known as the Tokai High Avoider (THA) strain was developed in Japan using a free-operant Sidman avoidance procedure in a Skinner box. This paper reviews the selection of the Syracuse strains, enumerates the various behavioral and endocrine characteristics of the strains, and compares them to the other similarly selected strains. The behavioral work suggests that genetic selection from diverse breeding stocks has resulted in common characteristics that differentiate the strains in the emotional, not learning, domain. The endocrine data, however, are somewhat at odds. The Syracuse strains differentiate one way with respect to endocrine function, and the Roman strains differentiate in the opposite way. We suggest, therefore, that the endocrine correlates are not tightly linked to the avoidance genotype. Genetic analysis of all of the selected strains for both the avoidance phenotype and the endocrine correlates will be needed to test this hypothesis.Preparation of this paper was supported by research grant MH-39230-3 from the National Institute of Mental Health.     

正交试验遗传算法及其在函数优化中的应用

针对遗传算法参数多且配置困难的问题，本文提出一种利用正交试验优化选择参数的方法，它使得对于不同领域的优化问题只需用正交试验进行一次参数配置，然后用遗传算法进行具体寻优即可取得较好效果。这种正交试验遗传算法易于编程实现且在一定程度上避免了遗传算法参数配置的盲目性。     

求最佳生物序列并置排列的算法和程序

本文提出了计算最佳生物序列并置排列的程序和算法。程序使用计算进化距离的改进算法,在IBM-PC/AT上用Turbo-Pascal 4.0版开发。程序有友好的用户界面、操作简便、通用性强,可以移植到多种计算和操作环境。本文以蛋白质分子序列为例,给出了复杂赋权情形下计算进化距离和最佳并置排列的算法,证明了不同赋权方式本质上不改变改进算法的时间和空间复杂性。     

硬件进化的快速算法模型研究

针对硬件进化(evolvable hardware，EHW)存在的进化规模的扩展能力问题，研究了以内嵌式EHW的自适应要求为条件的染色体表示及计算复杂性问题．为提高遗传机器学习计算效率，根据FPGA(field programmable gate array)内部的结构特点，将可重构硬件的结构映射为遗传学习的染色体表示，提出一种符合EHW要求的二雏染色体的遗传机器学习方法——ISPitts，构造了一种动态遗传机器学习框架．实验结果显示，新方法不仅完成了四位比较器的内嵌式EHW实现，而且具有较高的进化效率．