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   507篇
  免费   19篇
  2021年   5篇
  2019年   11篇
  2018年   11篇
  2017年   12篇
  2016年   11篇
  2015年   11篇
  2014年   10篇
  2013年   108篇
  2011年   4篇
  2009年   4篇
  2007年   8篇
  2006年   4篇
  2005年   8篇
  2004年   10篇
  2003年   7篇
  2002年   7篇
  2001年   7篇
  2000年   4篇
  1999年   7篇
  1998年   9篇
  1997年   10篇
  1996年   7篇
  1995年   13篇
  1994年   14篇
  1993年   11篇
  1992年   13篇
  1991年   12篇
  1990年   6篇
  1989年   7篇
  1988年   10篇
  1987年   9篇
  1985年   10篇
  1984年   12篇
  1983年   6篇
  1982年   6篇
  1981年   9篇
  1980年   7篇
  1979年   11篇
  1978年   6篇
  1977年   6篇
  1976年   7篇
  1975年   8篇
  1974年   9篇
  1973年   9篇
  1972年   9篇
  1971年   6篇
  1970年   4篇
  1969年   4篇
  1968年   5篇
  1967年   4篇
排序方式: 共有526条查询结果,搜索用时 15 毫秒
221.
A mean-squared error comparison of smooth empirical Bayes and Bayes estimators for the Weibull and gamma scale parameters is studied based on a computer simulation. The smooth empirical Bayes estimators are determined as functions of up to 15 past estimates of the parameter of interest. Results indicate that at best the mean-squared errors of the empirical Bayes estimators are about 20–40% larger than those of the corresponding squared-error optimal Bayes estimators.  相似文献   
222.
Planning for a cardiovascular disease reduction program, soon to be initiated by the United States Air Force, has required an evaluation of its expected cost effectiveness. During the course of this evaluation, it was necessary to consider manpower flows and their expected changes in response to the disease reduction program. This paper describes several manpower models that were applied: a simple expected value equilibrium model; a cross-sectional model that considered the length of service of personnel; and a staffing model used to optimize the allocation of paramedics to the many Air Force bases of various sizes. The relevance of these models to the cost effectiveness evaluation is shown but the detailed cost effectiveness results are not presented.  相似文献   
223.
224.
225.
In this paper we present some results in parametric studies on several transportation-type problems. Specifically, a characterization is obtained for the optimal values of the variables in the problem of determining an optimal growth path in a logistics system. We also derive an upper bound beyond which the optimal growth path remains the same. The results are then extended to the goal programming model and the prespecified market growth rate problem.  相似文献   
226.
This paper provides a method for solving mixed integer quadratic programs with the help of cutting-plane technique.  相似文献   
227.
This work considers a class of bimatrix games to which some well-known structure theorems of 0-sum matrix games can be made to generalize. It is additionally shown how to construct such games and how to generate the equilibrium points defining a given game as a member of that class.  相似文献   
228.
This article presents several single-echelon, single-item, static demand inventory models for situations in which, during the stockout period, a fraction b of the demand is backordered and the remaining fraction 1 - b is lost forever. Both deterministic and stochastic demand are considered. although the case of stochastic demand is treated heuristically. In each situation, a mathematical model representing the average annual cost of operating the inventory system is developed. and an optimum operating policy derived. At the extremes b=1 and b=0 the models presented reduce to the usual backorders and lost sales cases, respectively.  相似文献   
229.
The maximum likelihood estimator of the service distribution function of an M/G/∞ service system is obtained based on output time observations. This estimator is useful when observation of the service time of each customer could introduce bias or may be impossible. The maximum likelihood estimator is compared to the estimator proposed by Mark Brown, [2]. Relative to each other, Brown's estimator is useful in light traffic while the maximum likelihood estimator is applicble in heavy trafic. Both estimators are compared to the empirical distribution function based on a sample of service times and are found to have drawbacks although each estimator may have applications in special circumstances.  相似文献   
230.
Frequently in warfare, a force is required to attack a perishable enemy target system - a target system where the targets are detected seemingly at random, and if not immediately attacked, will shortly escape from detection. A conflicting situation arises when an attack element detects a target of relatively low value and has to decide whether to expend his resources on that particular target or to wait for a more lucrative one, hoping one will be found. This paper provides a decision rule giving the least valued target that should be attacked as well as the resources that should be expended as a function of the attack element's remaining mission time.  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