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1.
肖志娇  常会友  衣杨 《系统仿真学报》2006,18(11):3320-3323
时间是衡量工作流性能的重要指标。通过对工作流的资源配置的优化,可以改善工作流的时间性能。资源配置优化可以从资源专业化/一般化程度和资源数量两个方面来进行。为了优化资源的这两个方面,提出了一种基于分层嵌套遗传算法的资源优化方法。它采用工作流实例平均响应时间作为评价指标,在成本的约束下,正确配置各类资源专业化/一般化的程度及资源数量,从而最优化工作流时间性能。并通过实例,说明了该方法的可行性和有效性。  相似文献   
2.
2005年4-6月,对四川南充市市郊的3个样地,共11个棕背伯劳巢的育雏行为进行了观察,重点观察其中4个巢,其它巢为补充观察.结果显示:育雏期15±1d,育雏期亲鸟的喂食模式有a,b,c3种,育雏前期,中期,后期,分别以模式c,模式b,模式a所占比重最大.雌鸟在3个育雏时期的暖雏高峰主要出现在8∶00-9∶00时和16∶00-17∶00时.喂食高峰在育雏前期和育雏中期都出现在10∶00-12∶00时和14∶00-16∶00时,育雏后期出现在12∶00-14∶00时和16∶00-18∶00时  相似文献   
3.
Nesting behaviour of a large-sized dung beetle, Scarabaeus catenatus (Gerstaecker), was observed at the Tsavo West National Park, south-eastern Kenya. Although this species is taxonomically a member of a dung-roller group (that is, subfamily Scarabaeinae), it had not only a rolling behaviour but also a tunneller behaviour for nesting. In the former case, the scarab rolled a chunk or a ball of dung some distance (0·5–15·5m) away from the dung pat and buried it under the ground. In the latter case, it dug a tunnel near the dung pat (0–1 m) and transported several pieces of dung into the burrow. In both cases, brood nests were completed by a female alone or by male-female co-operation. Four days after dung burial, the female made one to four brood balls out of buried dung, in each of which she deposited an egg. On the other hand, the male left the nest soon after the female completed oviposition. Even after oviposition, the female stayed in the nest and cared for her progeny until they emerged. This indicates that S. catenatus is subsocial. A major source of offspring mortality was likely to be predation by driver ants (Dorylus sp.). Most females seemed to breed one time in each of two or more successive rainy seasons.  相似文献   
4.
The nesting problem in the leather manufacturing is the problem of placing a set of irregularly shaped pieces (called stencils) on a set of irregularly shaped surfaces (called leathers sheets). This paper presents a novel and promising processing approach. After the profile of leather sheets and stencils is obtained with digitizer, the discretization makes the processing independent of the specific geometrical information. The constraints of profile are regarded thoroughly. A heuristic bottom-left placement strategy is employed to sequentially locate stencils on sheets. The optimal placement sequence and rotation are deterimined by genetic algorithms (GA). A natural concise encoding method is developed to satisfy all the possible requirements of the leather nesting problem. The experimental results show that the proposed algorithm can not only be applied to the normal two-dimensional nesting problem, but also especially suitable for the placement of multiple twodimensional irregular stencils on multiple two-dimensional irregular sheets.  相似文献   
5.
应用任务Agent和巡航Agent构造了移动Agent分布式网络管理模型,采用进程代数方法p演算对该模型中Agent间的嵌套过程、交互行为和验证过程等部分行为进行了形式化的描述,从理论上验证了在大型网络中使用嵌套式移动Agent进行分布式管理的可能性.  相似文献   
6.
《Journal of Natural History》2012,46(27-28):1841-1847
Bees of the genus Megalopta have gained attention as a result of their social nesting and nocturnal foraging. Seventeen nests of Meglaopta atra from the highlands of Chiriqui Province, Panama, were collected at the end of the dry season when brood rearing is expected to be at its peak. Most nests contained single females; within multifemale nests only one female possessed enlarged ovarioles, although some non‐reproductive individuals were inseminated. In two of these nests reproductive individuals were clearly larger in body size than nestmates, but body size variation and macrocephaly were equivalent to those found in other Neotropical augochlorines. There was no evidence of a non‐reproductive worker‐like caste and multifemale nests did not appear to be more productive than solitary nests, which may represent pre‐reproductive assemblages. Megalopta atra appears to be isolated by altitude from co‐geners common in Panama, this is discussed in comparison with temperate halictine bees, in which environmental clines separate solitary from social populations.  相似文献   
7.
HLA/RTI中分布资源的存取机制研究   总被引:2,自引:1,他引:1  
胡亚海  彭晓源  林新 《系统仿真学报》2004,16(8):1762-1764,1767
HLA(High Level Architecture)作为分布交互仿真领域最新的技术规范,促进了不同领域、不同类型仿真应用的互操作与可重用,RTI(Run Time Infrastmcture)是HLA的软件实现,其运行效率直接影响仿真应用的整体性能。我们对RTI中涉及的数据资源进行了定义,探讨了资源管理所面临的问题,设计出高效存储、快速索引这些资源的存储方案,改善了RTI数据管理效率,并成功地应用于自行开发的分布仿真支撑平台AST—RTI中。  相似文献   
8.
阐述了如何用少量的汇编代码,对MCS51单片机的硬件中断功能进行扩展,实现多级中断的仿真。  相似文献   
9.
将中断控制器8259A用于MCS-51系统会大大增加51系列单片机的外中断源个数,特别是能实现中断嵌套提出了实现这种方案的硬件及软件设计,并提出了解决8259A与MCS-51之间兼容性问题的方法  相似文献   
10.
气候嵌套模式的进展及双向嵌套模式对降水的模拟   总被引:1,自引:0,他引:1  
区域气候模式发展的回顾表明区域气候模式在近20年来取得了长足的进步,将它与全球大气环流模式进行嵌套是研究区域气候变化的有效方法。单向嵌套是目前区域气候研究的主要手段,对区域气候的模拟和预测有明显的改进,加深了人们对区域气候变化的认识;双向嵌套能够体现不同尺度大气运动之间的相互作用,是区域气候变化研究的发展方向,尽管实现的难度很大,但模拟的结果明显优于单向嵌套。利用一个双向嵌套模式进行数值试验,结果表明它能够成功模拟我国南方的降水。  相似文献   
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