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排序方式: 共有428条查询结果,搜索用时 31 毫秒
1.
在练球比赛中如何尽可能多地发动进攻,提高快攻的成功率在很大程度上决定着比赛的胜负。快攻是由防守转入进攻时,以最快的速度、最短的时间在人数上造成以多打少的优势,因此,快攻的训练成为篮球训练工作的重要组成部分。培养篮球运动员的快攻意识应在长期实践中从观察能力、判断能力、战术思维能力和灵活的应变能力的提高着手,结合专项技术战术循环渐进而成。 相似文献
2.
ZUO Dong-hong DU Xu YANG Zong-kai 《浙江大学学报(A卷英文版)》2007,8(8):1191-1198
Media streaming delivery in wireless ad hoc networks is challenging due to the stringent resource restrictions,po-tential high loss rate and the decentralized architecture. To support long and high-quality streams,one viable approach is that a media stream is partitioned into segments,and then the segments are replicated in a network and served in a peer-to-peer(P2P) fashion. However,the searching strategy for segments is one key problem with the approach. This paper proposes a hybrid ants-like search algorithm(HASA) for P2P media streaming distribution in ad hoc networks. It takes the advantages of random walks and ants-like algorithms for searching in unstructured P2P networks,such as low transmitting latency,less jitter times,and low unnecessary traffic. We quantify the performance of our scheme in terms of response time,jitter times,and network messages for media streaming distribution. Simulation results showed that it can effectively improve the search efficiency for P2P media streaming distribution in ad hoc networks. 相似文献
3.
LIU Peng XIA Bing-jie TENG Zhao-wei 《浙江大学学报(A卷英文版)》2007,8(4):631-637
Floorplan, clock network and power plan are crucial steps in deep sub-micron system-on-chip design. A novel di- agonal floorplan is integrated to enhance the data sharing between different cores in system-on-chip. Custom clock network con- taining hand-adjusted buffers and variable routing rules is constructed to realize balanced synchronization. Effective power plan considering both IR drop and electromigration achieves high utilization and maintains power integrity in our MediaSoC. Using such methods, deep sub-micron design challenges are managed under a fast prototyping methodology, which greatly shortens the design cycle. 相似文献
4.
刚性常微分方程的数值解法在化学动力学中的应用 总被引:1,自引:0,他引:1
解刚性常微分方程已成为复杂化学反应研究的重要途径,本介绍了化学动力学计算中的刚性问题和数值解法,并着重讨论常用的吉尔(Gear)法和半隐式龙格库塔(Semi-implicit Runge-Kutta)法及其在化学动力学中的应用。 相似文献
5.
许建豪 《南宁职业技术学院学报》2011,(4):97-100
随着科技的发展,电子商务日益活跃。现行的电子商务打折网站与生俱来的局限性,越来越跟不上时代的步伐。能否开发一个能够收集全球打折信息的电子商务网站,越来越引起人们的重视。采用精确搜索引擎算法的电子商务精确搜索引擎模型,具有很好的精确性和响应速度,能够查询到精确而全面的打折信息,有较高的实用价值。 相似文献
6.
Arbitrary topological curve network has no restriction in topology structure,so it has more powerful representing ability in defining complex surfaces.A complex surface modeling system is presented based on arbitrary topological curve network and the improved combined subdivision method,its functions including creating and editing curve network,and generating and modifying curve network's interpolated surface.This modeling system can be used to the process of products'concept design,and its applications is ... 相似文献
7.
File semantic has proven effective in optimizing large scale distributed file system. As a consequence of the elaborate and
rich I/O interfaces between upper layer applications and file systems, file system can provide useful and insightful information
about semantic. Hence, file semantic mining has become an increasingly important practice in both engineering and research
community. Unfortunately, it is a challenge to exploit file semantic knowledge because a variety of factors could affect this
information exploration process. Even worse, the challenges are exacerbated due to the intricate interdependency between these
factors, and make it difficult to fully exploit the potentially important correlation among various semantic knowledges. This
article proposes a file access correlation miming and evaluation reference (FARMER) model, where file is treated as a multivariate
vector space, and each item within the vector corresponds a separate factor of the given file. The selection of factor depends
on the application, examples of factors are file path, creator and executing program. If one particular factor occurs in both
files, its value is non-zero. It is clear that the extent of inter-file relationships can be measured based on the likeness
of their factor values in the semantic vectors. Benefit from this model, FARMER represents files as structured vectors of
identifiers, and basic vector operations can be leveraged to quantify file correlation between two file vectors. FARMER model
leverages linear regression model to estimate the strength of the relationship between file correlation and a set of influencing
factors so that the “bad knowledge” can be filtered out. To demonstrate the ability of new FARMER model, FARMER is incorporated
into a real large-scale object-based storage system as a case study to dynamically infer file correlations. In addition FARMER-enabled
optimize service for metadata prefetching algorithm and object data layout algorithm is implemented. Experimental results
show that is FARMER-enabled prefetching algorithm is shown to reduce the metadata operations latency by approximately 30%–40%
when compared to a state-of-the-art metadata prefetching algorithm and a commonly used replacement policy. 相似文献
8.
张福泉 《河北职业技术学院学报》2011,(4)
阐述了高校组卷系统的原理,重点研究了作为系统关键的组卷策略运算过程,提出了一个改进的动态分层遗传算法作为高校组卷系统的组卷策略,最后通过实验检验其性能。 相似文献
9.
Loop细分曲面的数控粗加工刀具路径生成方法 总被引:1,自引:0,他引:1
梁伟文 《深圳职业技术学院学报》2007,6(3):3-6
以Loop细分曲面为例,介绍了细分曲面的三轴数控刀具路径生成方法。首先根据细分曲面的网格迭代特性,提出了一种Z-map模型技术和一种包络细分曲面的覆盖曲面方法,然后根据极限曲面与覆盖曲面的关系,调整网格顶点生成最终覆盖曲面,讨论了细分曲面的粗加工刀具路径生成方法。同时,为了解决加工干涉问题,提出了一种加工干涉检查和纠正方法。 相似文献
10.
The Inductive Query By Example (IQBE) paradigm allows a system to automatically derive queries for a specific Information Retrieval System (IRS). Classic IRSs based on this paradigm [Smith, M., & Smith, M. (1997). The use of genetic programming to build Boolean queries for text retrieval through relevance feedback. Journal of Information Science, 23(6), 423–431] generate a single solution (Boolean query) in each run, that with the best fitness value, which is usually based on a weighted combination of the basic performance criteria, precision and recall. 相似文献