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   957篇
  免费   16篇
  2019年   18篇
  2018年   10篇
  2017年   27篇
  2016年   17篇
  2015年   18篇
  2014年   19篇
  2013年   209篇
  2010年   10篇
  2009年   14篇
  2008年   11篇
  2007年   11篇
  2006年   11篇
  2005年   13篇
  2004年   16篇
  2003年   10篇
  2002年   15篇
  2001年   7篇
  2000年   11篇
  1999年   11篇
  1998年   15篇
  1997年   10篇
  1996年   14篇
  1995年   14篇
  1994年   22篇
  1993年   20篇
  1992年   15篇
  1991年   24篇
  1990年   14篇
  1989年   19篇
  1988年   23篇
  1987年   25篇
  1986年   25篇
  1985年   21篇
  1984年   10篇
  1983年   13篇
  1982年   17篇
  1981年   12篇
  1980年   12篇
  1979年   11篇
  1978年   14篇
  1976年   11篇
  1975年   9篇
  1974年   15篇
  1973年   14篇
  1972年   14篇
  1971年   11篇
  1970年   13篇
  1969年   12篇
  1968年   10篇
  1967年   10篇
排序方式: 共有973条查询结果,搜索用时 15 毫秒
891.
Initial provisioning decisions (inventory stocking requirements) for low demand items often have to be made without much knowledge of what future demand rates will be. When the nature of an item is such that little demand for it is expected, the problem of whether to stock initially or risk not stocking the item is most critical. This report discusses this problem and presents decision procedures which can be used to handle this aspect of initial provisioning. The procedures relate an item's provisioning desirability to its provisioning characteristics, such as expected cost, expected resupply time, current information on its likely demand rate, and to an overall operating policy or criterion. The criterion function measures the total system degredation as a function of the events of having items out of stock when demand occurs. Several different policy functions are discussed and the provisioning decision rules which apply to each are presented. Demand rate information is handled through a Bayesian type approach. The decision rules presented in this report can be utilized to either determine stocking requirements within a budgetary constraint, or determine the relative stocking desirability on an item-by-item basis.  相似文献   
892.
893.
Detailed combat simulations can produce effectiveness tables which measure the effectiveness of each weapon class on one side of an engagement, battle, or campaign to each weapon class on the other. Effectiveness tables may also be constructed in other ways This paper assumes that effectiveness tables are given and shows how to construct from them a system of weapon weights each of which is a weighted average of the effects of a given weapon against each of the enemy's weapons. These weights utilize the Perron- Frobenius theory of eigenvectors of nonnegative matrices. Methods of calculation are discussed and some interpretations are given for both the irreducible and reducible cases.  相似文献   
894.
It is shown that the monotone multivariate failure rates of Brindley and Thompson have no natural analog involving the multivariate failure rate function of Basu for absolutely continuous distributions. Quantities related to the multivariate failure rate function are used to define monotone failure rates. It is shown that these are equivalent to the monotone failure rates of Brindley and Thompson. Based on these quantities, the loss of memory property of Marshall and Olkin is characterized.  相似文献   
895.
This paper considers situations in which jobs require only one operation on a single machine, or on one of a set of identical machines. Penalty-free interruption is allowed. Some simple algorithms are given for finding optimum schedules to minimize maximum lateness and total delay, for the single-machine case, and maximum lateness for a restricted multi-machine case. A simple flow problem formulation permits minimizing maximum lateness for the more general multimachine case.  相似文献   
896.
This paper presents a simple algorithm for finding the number of restricted k-partitions of a natural number n. The unrestricted k-partitions of n are expressed as the sum of these restricted k-partitions, called inadmissible, and the admissible k-partitions. The simplicity of the algorithm is striking, though all the implications are unclear.  相似文献   
897.
In this paper, the existence of a saddle point for two-person zero-sum infinite games of a special type is proved. The games have continuous bilinear payoff functions and strategy sets which are convex, noncompact subsets of an infinite-dimensional vector space. The closures of the strategy sets are, however, compact. The payoff functions satisfy conditions which allow the use of dominance arguments to show that points in the closure of a strategy set are dominated by or are strategically equivalent to points in the strategy set itself. Combining the dominance arguments with a well-known existence theorem produces the main result of the paper. The class of games treated is an extension of a class studied by J. D. Matheson, who obtained explicit solutions for the saddle points by using necessary conditions.  相似文献   
898.
This paper describes the construction of a mathematical model structure in a particular area of management. In addition it is intended as an illustration of how appropriate levels of mathematics can be utilized in management research when original formulations lack sufficient precision for conducting quantitative analyses. The specific area studied deals with the formulation and analysis of contract types. In particular the award fee type contract is treated. At present mathematical structure models for other contract types have received considerable attention, but award fee types have not been structured in mathematical terms. The paper provides a discussion of model formulation for award fee contracts, develops a detailed example of such a structure, and illustrates that model by numerical examples indicating the application of such models to the formulation and analysis of award fee contracts.  相似文献   
899.
The stochastic duel is extended to include the possibility of a near-miss on each round fired, which causes the opponent to displace. During displacement, the displacing contestant cannot return the fire but is still a target for his opponent. An alternative interpretation of this model is to consider the displacement time as the time a contestant's fire is suppressed by his opponent's fire and that he does not move, but merely ceases fire temporarily. All times are exponentially distributed.  相似文献   
900.
A mean-variance portfolio selection model with limited diversification is formulated in which transaction and management costs are incorporated as the sum of a linear cost and a fixed cost. The problem is a fixed charge integer programming problem solved by hypersurface search using dynamic programming. Fathoming is performed in the forward pass of dynamic programming so that values of the state variable which correspond to infeasible solutions are eliminated from the tables. This logic permits the solution of problems with 20–30 possible investments.  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