全文获取类型
收费全文 | 199篇 |
免费 | 23篇 |
国内免费 | 21篇 |
专业分类
电工技术 | 3篇 |
综合类 | 11篇 |
机械仪表 | 2篇 |
建筑科学 | 2篇 |
矿业工程 | 1篇 |
轻工业 | 1篇 |
武器工业 | 1篇 |
无线电 | 32篇 |
一般工业技术 | 9篇 |
冶金工业 | 1篇 |
自动化技术 | 180篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 6篇 |
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 1篇 |
2016年 | 9篇 |
2015年 | 5篇 |
2014年 | 9篇 |
2013年 | 10篇 |
2012年 | 11篇 |
2011年 | 13篇 |
2010年 | 12篇 |
2009年 | 11篇 |
2008年 | 19篇 |
2007年 | 19篇 |
2006年 | 14篇 |
2005年 | 12篇 |
2004年 | 9篇 |
2003年 | 11篇 |
2002年 | 10篇 |
2001年 | 5篇 |
2000年 | 6篇 |
1999年 | 4篇 |
1998年 | 3篇 |
1997年 | 4篇 |
1996年 | 6篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 4篇 |
1992年 | 12篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1983年 | 1篇 |
排序方式: 共有243条查询结果,搜索用时 31 毫秒
1.
为了进一步考虑X结构,并充分利用障碍内可用布线资源,文中提出考虑布线资源松弛的X结构Steiner最小树算法.为了能够求解离散问题,在粒子的更新操作中引入交叉算子和变异算子.通过构建查找表,为整个算法流程提供快速的信息查询.提出角点选取策略,通过引入一些障碍角点,使粒子满足约束.最后构建精炼策略,进一步提高最终布线树的质量.实验表明,文中算法充分利用障碍内可用布线资源,有效缩短总布线长度,取得较佳的总布线长度. 相似文献
2.
3.
The obstacle-avoiding rectilinear Steiner minimal tree (OARSMT) problem is a hot topic in very-large-scale integration physical design. In practice, most of the obstacles occupy the device layer and certain lower metal layers. Therefore, we can place wires on top of the obstacles. To maximize routing resources over obstacles, we propose a heuristic for constructing a rectilinear Steiner tree with slew constraints. Our algorithm adopts an extended rectilinear full Steiner tree grid as the routing graph. We mark two types of Steiner point candidates, which are used for constructing Steiner trees and refining solutions. A shortest path heuristic variant is designed for constructing Steiner trees and it takes into account slew constraint by inhibiting growth. Furthermore, we use a pre-computed strategy to avoid calculating slew rate repeatedly. Experimental results show that our algorithm maximizes routing resources over obstacles and saves routing resources outside obstacles. Compared with the conventional OARSMT algorithm, our algorithm reduces the wire length outside obstacles by as much as 18.74% and total wire length by as much as 6.03%. Our algorithm improves the latest related algorithm by approximately 2% in terms of wire length within a reasonable running time. Additionally, calculating the slew rate only accounts for approximately 15% of the total runing time. 相似文献
4.
最小生成树数据描述方法在刻画高维空间样本点分布时,将所有图形的边作为新增虚拟样本以提供同类样本分布描述,这种描述存在分支多覆盖模型复杂,且局部覆盖不够合理的问题.针对该问题,依据特征空间中同类样本分布的连续性规律,提出基于高维空间典型样本Steiner最小树覆盖模型的一类分类算法,该算法首先对目标类训练集进行样本修剪,去除冗余信息和噪声信息,选择最具代表性的样本作为训练集,然后对保留的典型样本构建Steiner最小树覆盖模型.算法分析和仿真实验结果表明,相比最小生成树数据描述,文中提出的方法能在较低覆盖模型复杂度的前提下更合理的描述目标类样本空间分布,构建更合理的覆盖模型,在分类正确率和适用样本规模上都表现出一定的优越性. 相似文献
5.
6.
The paper presents a new approach to deal with combinatorial problems. It makes use of a biological analogy inspired by the performance of viruses. The replication mechanism, as well as the hosts’ infection processes is used to generate a metaheuristic that allows the obtention of valuable results. The viral system (VS) theoretical context is described and it is applied to a library of medium-to-large-sized cases of the Steiner problem for which the optimal solution is known. The method is compared with the metaheuristics that have provided the best results for the Steiner problem. The VS provides better solutions than genetic algorithms and certain tabu search approaches. For the most sophisticated tabu search approaches (the best metaheuristic approximations to the Steiner problem solution) VS provides solutions of similar quality. 相似文献
7.
Relay sensor placement in wireless sensor networks 总被引:4,自引:0,他引:4
This paper addresses the following relay sensor placement problem: given the set of duty sensors in the plane and the upper
bound of the transmission range, compute the minimum number of relay sensors such that the induced topology by all sensors
is globally connected. This problem is motivated by practically considering the tradeoff among performance, lifetime, and
cost when designing sensor networks. In our study, this problem is modelled by a NP-hard network optimization problem named
Steiner Minimum Tree with Minimum number of Steiner Points and bounded edge length (SMT-MSP). In this paper, we propose two approximate algorithms, and conduct detailed performance analysis. The first algorithm has
a performance ratio of 3 and the second has a performance ratio of 2.5.
Xiuzhen Cheng is an Assistant Professor in the Department of Computer Science at the George Washington University. She received her MS
and PhD degrees in Computer Science from the University of Minnesota - Twin Cities in 2000 and 2002, respectively. Her current
research interests include Wireless and Mobile Computing, Sensor Networks, Wireless Security, Statistical Pattern Recognition,
Approximation Algorithm Design and Analysis, and Computational Medicine. She is an editor for the International Journal on
Ad Hoc and Ubiquitous Computing and the International Journal of Sensor Networks. Dr. Cheng is a member of IEEE and ACM. She
received the National Science Foundation CAREER Award in 2004.
Ding-Zhu Du received his M.S. degree in 1982 from Institute of Applied Mathematics, Chinese Academy of Sciences, and his Ph.D. degree
in 1985 from the University of California at Santa Barbara. He worked at Mathematical Sciences Research Institutea, Berkeley
in 1985-86, at MIT in 1986-87, and at Princeton University in 1990-91. He was an associate-professor/professor at Department
of Computer Science and Engineering, University of Minnesota in 1991-2005, a professor at City University of Hong Kong in
1998-1999, a research professor at Institute of Applied Mathematics, Chinese Academy of Sciences in 1987-2002, and a Program
Director at National Science Foundation of USA in 2002-2005. Currently, he is a professor at Department of Computer Science,
University of Texas at Dallas and the Dean of Science at Xi’an Jiaotong University. His research interests include design
and analysis of algorithms for combinatorial optimization problems in communication networks and bioinformatics. He has published
more than 140 journal papers and 10 written books. He is the editor-in-chief of Journal of Combinatorial Optimization and
book series on Network Theory and Applications. He is also in editorial boards of more than 15 journals.
Lusheng Wang received his PhD degree from McMaster University in 1995. He is an associate professor at City University of Hong Kong. His
research interests include networks, algorithms and Bioinformatics. He is a member of IEEE and IEEE Computer Society.
Baogang Xu received his PhD degree from Shandong University in 1997. He is a professor at Nanjing Normal University. His research interests
include graph theory and algorithms on graphs. 相似文献
8.
9.
图的Steiner最小树问题是经典的组合优化问题,是一个NP难题,在不同的领域有着广泛的应用。研究该问题的部分数学性质,在此基础上给出了该问题的初步降阶方法和下界子方法,形成一个新的回溯算法。该算法具有较低的时间复杂度,还给出了应用实例及其分析。 相似文献
10.