全文获取类型
收费全文 | 893篇 |
免费 | 21篇 |
出版年
2021年 | 14篇 |
2019年 | 29篇 |
2018年 | 19篇 |
2017年 | 20篇 |
2016年 | 20篇 |
2015年 | 20篇 |
2014年 | 11篇 |
2013年 | 166篇 |
2011年 | 8篇 |
2009年 | 9篇 |
2008年 | 8篇 |
2007年 | 11篇 |
2006年 | 11篇 |
2005年 | 15篇 |
2004年 | 16篇 |
2003年 | 10篇 |
2002年 | 8篇 |
2000年 | 14篇 |
1999年 | 10篇 |
1998年 | 12篇 |
1997年 | 24篇 |
1996年 | 19篇 |
1994年 | 18篇 |
1993年 | 7篇 |
1992年 | 11篇 |
1991年 | 22篇 |
1990年 | 12篇 |
1989年 | 19篇 |
1988年 | 12篇 |
1987年 | 21篇 |
1986年 | 16篇 |
1985年 | 16篇 |
1984年 | 12篇 |
1983年 | 15篇 |
1982年 | 13篇 |
1981年 | 13篇 |
1980年 | 16篇 |
1979年 | 17篇 |
1978年 | 14篇 |
1977年 | 15篇 |
1976年 | 14篇 |
1975年 | 12篇 |
1974年 | 18篇 |
1973年 | 18篇 |
1972年 | 15篇 |
1971年 | 19篇 |
1970年 | 9篇 |
1969年 | 11篇 |
1968年 | 10篇 |
1967年 | 8篇 |
排序方式: 共有914条查询结果,搜索用时 15 毫秒
31.
32.
33.
John A. Muckstadt 《海军后勤学研究》1978,25(3):377-394
The optimization problem as formulated in the METRIC model takes the form of minimizing the expected number of total system backorders in a two-echelon inventory system subject to a budget constraint. The system contains recoverable items – items subject to repair when they fail. To solve this problem, one needs to find the optimal Lagrangian multiplier associated with the given budget constraint. For any large-scale inventory system, this task is computationally not trivial. Fox and Landi proposed one method that was a significant improvement over the original METRIC algorithm. In this report we first develop a method for estimating the value of the optimal Lagrangian multiplier used in the Fox-Landi algorithm, present alternative ways for determining stock levels, and compare these proposed approaches with the Fox-Landi algorithm, using two hypothetical inventory systems – one having 3 bases and 75 items, the other 5 bases and 125 items. The comparison shows that the computational time can be reduced by nearly 50 percent. Another factor that contributes to the higher requirement for computational time in obtaining the solution to two-echelon inventory systems is that it has to allocate stock optimally to the depot as well as to bases for a given total-system stock level. This essentially requires the evaluation of every possible combination of depot and base stock levels – a time-consuming process for many practical inventory problems with a sizable system stock level. This report also suggests a simple approximation method for estimating the optimal depot stock level. When this method was applied to the same two hypotetical inventory systems indicated above, it was found that the estimate of optimal depot stock is quite close to the optimal value in all cases. Furthermore, the increase in expected system backorders using the estimated depot stock levels rather than the optimal levels is generally small. 相似文献
34.
A. Victor Cabot 《海军后勤学研究》1978,25(3):473-481
In this paper we consider the problem of maximizing the sum of certain quasi-concave functions over a convex set. The functions considered belong to the classes of functions which are known as nonlinear fractional and binonlinear functions. Each individual function is quasi-concave but the sum is not. We show that this nonconvex programming problem can be solved using Generalized Benders Decomposition as developed by Geoffrion. 相似文献
35.
In this paper we address the question of deriving deep cuts for nonconvex disjunctive programs. These problems include logical constraints which restrict the variables to at least one of a finite number of constraint sets. Based on the works of Balas. Glover, and Jeroslow, we examine the set of valid inequalities or cuts which one may derive in this context, and defining reasonable criteria to measure depth of a cut we demonstrate how one may obtain the “deepest” cut. The analysis covers the case where each constraint set in the logical statement has only one constraint and is also extended for the case where each of these constraint sets may have more than one constraint. 相似文献
36.
The bounded interval generalized assignment model is a “many-for-one” assignment model. Each task must be assigned to exactly one agent; however, each agent can be assigned multiple tasks as long as the agent resource consumed by performing the assigned tasks falls within a specified interval. The bounded interval generalized assignment model is formulated, and an algorithm for its solution is developed. Algorithms for the bounded interval versions of the semiassignment model and sources-to-uses transportation model are also discussed. 相似文献
37.
Inspection procedures may at times pose a hazard to the system being monitored. In this article, a simple hazardous-inspection model is considered. The character of the optimal ongoing inspection policy (for inspections subsequent to the first) is reviewed, and the possible forms of the optimal initiation policy are established. Efficient computational procedures are developed for calculating optimal policies. Some discussion is included of the counterintuitive nature of some of the results. 相似文献
38.
Consider a birth and death process starting in state 0. Keilson has shown by analytical arguments that the time of first passage into state n has an increasing failure rate (IFR) distribution. We present a probabilistic proof for this. In addition, our proof shows that for a nonnegative diffusion process, the first passage time from state 0 to any state x is IFR. 相似文献
39.
40.
Laurence A. Baxter 《海军后勤学研究》1982,29(3):403-410
An availability measure is the probability that a two-state system modeled by an alternating renewal process is available at one or more points or intervals. The concept of availability measures is extended to formulae for the joint prediction of availability and numbers of breakdowns (or repairs) of the system during a fixed interval. 相似文献