全文获取类型
收费全文 | 1512篇 |
免费 | 154篇 |
国内免费 | 148篇 |
专业分类
电工技术 | 47篇 |
综合类 | 56篇 |
化学工业 | 18篇 |
金属工艺 | 12篇 |
机械仪表 | 73篇 |
建筑科学 | 18篇 |
矿业工程 | 8篇 |
能源动力 | 13篇 |
轻工业 | 4篇 |
水利工程 | 6篇 |
石油天然气 | 6篇 |
武器工业 | 4篇 |
无线电 | 154篇 |
一般工业技术 | 82篇 |
冶金工业 | 7篇 |
原子能技术 | 18篇 |
自动化技术 | 1288篇 |
出版年
2025年 | 1篇 |
2024年 | 11篇 |
2023年 | 12篇 |
2022年 | 25篇 |
2021年 | 35篇 |
2020年 | 35篇 |
2019年 | 33篇 |
2018年 | 36篇 |
2017年 | 45篇 |
2016年 | 57篇 |
2015年 | 68篇 |
2014年 | 97篇 |
2013年 | 113篇 |
2012年 | 135篇 |
2011年 | 125篇 |
2010年 | 65篇 |
2009年 | 84篇 |
2008年 | 115篇 |
2007年 | 127篇 |
2006年 | 90篇 |
2005年 | 86篇 |
2004年 | 73篇 |
2003年 | 77篇 |
2002年 | 52篇 |
2001年 | 50篇 |
2000年 | 26篇 |
1999年 | 23篇 |
1998年 | 24篇 |
1997年 | 19篇 |
1996年 | 14篇 |
1995年 | 6篇 |
1994年 | 9篇 |
1993年 | 6篇 |
1992年 | 5篇 |
1991年 | 6篇 |
1990年 | 9篇 |
1989年 | 5篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1984年 | 2篇 |
1982年 | 2篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1973年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有1814条查询结果,搜索用时 15 毫秒
31.
本文应用随机数直接搜索的单纯形最优化方法将系统高阶模型简化为低阶等效模型,并对控制系统调节器参数进行在线寻优,该方法的主要特点是:编程简单,有较宽的初值选择范围,搜索的结果可靠。 相似文献
32.
《Expert systems with applications》2014,41(10):4939-4949
Optimization techniques known as metaheuristics have been applied successfully to solve different problems, in which their development is characterized by the appropriate selection of parameters (values) for its execution. Where the adjustment of a parameter is required, this parameter will be tested until viable results are obtained. Normally, such adjustments are made by the developer deploying the metaheuristic. The quality of the results of a test instance [The term instance is used to refer to the assignment of values to the input variables of a problem.] will not be transferred to the instances that were not tested yet and its feedback may require a slow process of “trial and error” where the algorithm has to be adjusted for a specific application. Within this context of metaheuristics the Reactive Search emerged defending the integration of machine learning within heuristic searches for solving complex optimization problems. Based in the integration that the Reactive Search proposes between machine learning and metaheuristics, emerged the idea of putting Reinforcement Learning, more specifically the Q-learning algorithm with a reactive behavior, to select which local search is the most appropriate in a given time of a search, to succeed another local search that can not improve the current solution in the VNS metaheuristic. In this work we propose a reactive implementation using Reinforcement Learning for the self-tuning of the implemented algorithm, applied to the Symmetric Travelling Salesman Problem. 相似文献
33.
34.
一种基于区间约束的折半查找算法 总被引:1,自引:0,他引:1
针对变化范围很大而又相对稳定的查找对象,给出一种基于区间约束的折半查找算法。当后一个查找对象在前一个查找对象附近时,在最坏状态和平均状态下,该算法与标准的折半查找算法比较,其查找长度元旦显著减少,而且代价很小。此算法适合用于类似过程控制中的对低频信号的实时查有处理,并在国家级新产品WPJ-3微机频率事故记录装置和WQP-4微机频率继电器中得到了成功的应用。 相似文献
35.
Yan Ma Ming Li 《通讯和计算机》2005,2(7):24-28
The rapid development of the WWW has made the exploration of new types of Search Engine become the urgent problem in the process of the Web development. Combining the latest development of information search and AI, the author in this paper puts forward a new solution: Web Intelligence Meta Search. Based on the review of the current technology of search engine, the author firstly brings forward the basic framework of the Intelligence Meta Search, and introduces the key technologies to realize it in detail, including Textual Study, Indicative Technology of Chinese Words, Information Filtration, Individual User Modeling, etc. in the machine learning. 相似文献
36.
Kim S. Larsen 《Journal of Computer and System Sciences》2003,66(4):657-670
Data structures with relaxed balance differ from standard structures in that rebalancing can be delayed and interspersed with updates. This gives extra flexibility in both sequential and parallel applications. We study the version of multi-way trees called (a,b)-trees (which includes B-trees) with the operations insertion, deletion, and group insertion. The latter has applications in for instance document databases, WWW search engines, and differential indexing. We prove that we obtain the optimal asymptotic rebalancing complexities of amortized constant time for insertion and deletion and amortized logarithmic time in the size of the group for group insertion. These results hold even for the relaxed version. This is an improvement over the existing results in the most interesting cases. 相似文献
37.
38.
对遗传算法(GA)贝叶斯网络(BN)结构学习和禁忌搜索算法(TS)进行分析,提出遗传禁忌搜索贝叶斯网络结构学习算法GATS_BNSL。把禁忌搜索思想引入到遗传算法BN结构学习由父代种群产生后代种群的演化过程中,以禁忌搜索交叉和禁忌搜索变异改进传统的遗传算子,对比实验分析表明了GATS_BNSL的学习优势。应用此方法,基于真实数据,建立了大型枢纽机场航班离港延误模型。该模型切实反映了导致航班延误的多因素之间的因果关系,而且建模时间少,学习正确率高。 相似文献
39.
Semplore: A scalable IR approach to search the Web of Data 总被引:1,自引:0,他引:1
Haofen Wang Qiaoling Liu Thomas Penin Linyun Fu Lei Zhang Thanh Tran Yong Yu Yue Pan 《Journal of Web Semantics》2009,7(3):177-188
The Web of Data keeps growing rapidly. However, the full exploitation of this large amount of structured data faces numerous challenges like usability, scalability, imprecise information needs and data change. We present Semplore, an IR-based system that aims at addressing these issues. Semplore supports intuitive faceted search and complex queries both on text and structured data. It combines imprecise keyword search and precise structured query in a unified ranking scheme. Scalable query processing is supported by leveraging inverted indexes traditionally used in IR systems. This is combined with a novel block-based index structure to support efficient index update when data changes. The experimental results show that Semplore is an efficient and effective system for searching the Web of Data and can be used as a basic infrastructure for Web-scale Semantic Web search engines. 相似文献
40.
《国际计算机数学杂志》2012,89(1-4):177-188
Systematic prefix codes play an important role in coding theory, we relate them with the problem of the partition of a free (sub-) monoid into two free sub-monoids. We show too that among the dual codes of a systematic prefix code A there exists one and only one which appears in the automaton recognizing A *. The characterization of this automaton and some corollaries stated here will allow us to show in further note that systematic prefix codes are involved in the structure of any regular prefix code. Work done under CNR contract No. R-l7-02-417-0-A. 相似文献