树状分支传热结构层次生长优化设计技术

为了有效设计小空间高热流密度电子元器件的传热结构,需要合理分布其散热通道。针对现有传热结构拓扑优化设计结果形态过于复杂、加工制造困难等局限,基于自然界叶脉分支系统的分层生长特征,提出一种层次生长树状分支散热通道的优化设计方法。主通道和次通道分别采用不同的生长控制策略,依次生长形成传热结构,由基于温度信息的空间殖民算法控制主通道的生长,由最小热阻原理控制次通道的生长。对典型的二维和三维散热通道设计问题展开研究,并与SIMP方法设计结果进行对比。研究结果表明,所得到的散热通道形态简单、清晰,无细小分支和灰度单元,具有较好的散热性能和可制造性。

基于纹理特征与区域生长的高分辨率遥感影像分割算法

影像分割是面向对象影像分析中的重要步骤。为了提高高分辨率遥感影像(high-resolution remote sensing image,HRI)分割算法的性能,提出一种新的影像分割算法,包含种子确定、基于种子区域生长(seeded region growing,SRG)的过分割(advanced SRG,ASRG)和层次区域生长(hierarchical region growing,HRG)3个步骤。利用Gabor纹理特征定义纹理均匀性,将种子自动放置在HRI中同一纹理组成区域的中心位置;在SRG阶段,将HRI光谱信息与斑块形状信息相结合,提出了一种新的合并规则,以提高SRG过分割的精度与分割结果中各个斑块排列的紧凑性;在HRG阶段,提出了一种自适应的阈值,可以更好地保持多尺度分割的特性;在实验部分,采用3景HRI验证了上述方法。利用监督的影像分割评价方法定量评价了该方法的分割精度,并与另外2种主流的遥感影像分割算法进行了对比。结果表明,该方法可以得到令人满意的分割效果。

Dominance hierarchy and social relationships in a group of Captive black-and-white snub-nosed monkeys (Rhinopithecus bietl)

Different types of dominance hierarchies reflect different social relationships in primates. In this study, we clarified the hierarchy and social relationships in a one-male unit of captive Rhinopithecus bieti observed between August 1998 and March 1999. Mean frequency of agonistic behaviour among adult females was 0.13 interactions per hour. Adult females exhibited a linear hierarchy with a reversal of 10.9%, indicating an unstable relationship; therefore, R. bieti appears to be a relaxed/tolerant species. The lack of a relationship between the agonistic ratio of the adult male towards adult females and their ranks indicated that males did not show increased aggression towards low-ranking females. Differentiated female affiliative relationships were loosely formed in terms of the male, and to some extent influenced by female estrus, implying that relationships between the male and females is influenced by estrus and not rank alone. A positive correlation between the agonistic ratio of adult females and their ranks showed that the degree to which one female negatively impacted others decreased with reduction in rank. Similarly, a positive correlation between the agonistic ratio of females and differences in rank suggests that a female had fewer negative effects on closely ranked individuals than distantly ranked ones. These data indicate that rank may influence relationships between females. A steeper slope of regression between the agonistic ratio and inter-female rank differences indicated that the extent of the power difference in high-ranking females exerting negative effects on low-ranking ones was larger during the mating season than the birth season, suggesting that rank may influence the mating success of females.

基于改进GH-SOM的可接受航班编队调度优化

针对可接受航班编队调度优化问题,从最大当量航程约束和最大允许延误约束出发,推导出可接受编队模式的统计判别边界,将编队调度优化问题转化为最优层次聚类问题,利用改进的层次生长型自组织映射(GH-SOM)神经网络实现对可接受编队调度聚类的递归求精。仿真结果表明:与经验判别边界相比,基于可接受编队统计判别边界的识别量提高了92.14%,平均扁率和平均时间同步偏差分别降低了25.00%和26.23%,扁率标准差和时间同步偏差标准差分别降低了12.50%和18.75%;与自组织映射、标准GH-SOM相比,基于改进GH-SOM的识别量分别提高了303.49%、162.87%,平均扁率分别降低了34.25%、22.58%,平均时间同步偏差分别降低了47.06%、36.62%,扁率标准差分别降低了45.10%、6.67%,时间同步偏差分别降低了46.94%、3.70%,因此,可接受编队模式的统计判别边界与改进GH-SOM是有效性的。