首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   570篇
  免费   8篇
  2021年   7篇
  2019年   8篇
  2018年   11篇
  2017年   7篇
  2016年   14篇
  2015年   4篇
  2014年   7篇
  2013年   132篇
  2012年   5篇
  2010年   4篇
  2009年   5篇
  2007年   12篇
  2005年   7篇
  2004年   4篇
  2003年   11篇
  2002年   11篇
  2000年   6篇
  1999年   5篇
  1998年   8篇
  1997年   12篇
  1996年   11篇
  1995年   5篇
  1994年   8篇
  1993年   14篇
  1992年   10篇
  1991年   12篇
  1990年   11篇
  1989年   19篇
  1988年   15篇
  1987年   13篇
  1986年   14篇
  1985年   8篇
  1984年   6篇
  1983年   4篇
  1982年   12篇
  1981年   8篇
  1980年   8篇
  1979年   11篇
  1978年   14篇
  1977年   6篇
  1976年   8篇
  1975年   6篇
  1974年   11篇
  1973年   5篇
  1972年   6篇
  1971年   10篇
  1970年   8篇
  1969年   8篇
  1967年   7篇
  1948年   4篇
排序方式: 共有578条查询结果,搜索用时 15 毫秒
481.
Given a positive integer R and a weight for each vertex in a graph, the maximum-weight connected graph (MCG) problem is to find a connected subgraph with R vertices that maximizes the sum of the weights. The MCG problem is strongly NP-complete, and we study a special case of it: the constrained MCG (CMCG) problem, which is the MCG problem with a constraint of having a predetermined vertex included in the solution. We first show that the Steiner tree problem is a special case of the CMCG problem. Then we present three optimization algorithms for the CMCG problem. The first two algorithms deal with special graphs (tree and layered graphs) and employ different dynamic programming techniques, solving the CMCG problem in polynomial times. The third one deals with a general graph and uses a variant of the Balas additive method with an imbedded connectivity test and a pruning method. We also present a heuristic algorithm for the CMCG problem with a general graph and its bound analysis. We combine the two algorithms, heuristic and optimization, and present a practical solution method to the CMCG problem. Computational results are reported and future research issues are discussed. © 1996 John Wiley & Sons, Inc.  相似文献   
482.
Control charts are widely used for process surveillance. The design of a control chart refers to the choice of sample size, the width of the control limits, and the interval between samples. Economic designs have been widely investigated and shown to be an effective method of determining control chart parameters. This article describes two different manufacturing process models to which the X¯ control chart is applied: The first model assumes that the process continues in operation while searches for the assignable cause are made, and the second assumes that the process must be shut down during the search. Economic models of the control chart for these two manufacturing process models are developed, and the sensitivity of the control chart parameters to the choice of model is explored. It is shown that the choice of the proper manufacturing process model is critical because selection of an inappropriate process model may result in significant economic penalties.  相似文献   
483.
Some Principles of Maritime Strategy. Julian S. Corbett. Longmans, London, 1911  相似文献   
484.
485.
Nature of Renyi's entropy and associated divergence function is discussed in terms of concave (convex) and pseudoconcave (pseudoconvex) functions.  相似文献   
486.
487.
488.
489.
Izbrannye Proizvedennia. By M. V. Frunze. Moscow (1957)  相似文献   
490.
For multiresponse simulations requiring point and confidence-region estimators of the mean response, we propose control-variate selection criteria that minimize mean-square confidence-region volume in two situations: (a) Only the mean control vector is known, and standard linear control-variate estimation procedures are used. (b) Covariances among controls are also known and are incorporated into new linear control-variate estimation procedures. An example illustrates the performance of these selection criteria.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号