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   543篇
  免费   12篇
  555篇
  2021年   13篇
  2019年   10篇
  2018年   8篇
  2017年   5篇
  2016年   10篇
  2014年   9篇
  2013年   81篇
  2012年   5篇
  2009年   11篇
  2007年   16篇
  2005年   4篇
  2004年   7篇
  2003年   9篇
  2002年   13篇
  2001年   7篇
  2000年   7篇
  1999年   5篇
  1998年   10篇
  1997年   11篇
  1996年   10篇
  1995年   9篇
  1994年   8篇
  1993年   12篇
  1992年   10篇
  1991年   14篇
  1990年   14篇
  1989年   21篇
  1988年   17篇
  1987年   13篇
  1986年   17篇
  1985年   7篇
  1984年   8篇
  1983年   6篇
  1982年   11篇
  1981年   10篇
  1980年   10篇
  1979年   11篇
  1978年   11篇
  1977年   10篇
  1976年   6篇
  1975年   6篇
  1974年   10篇
  1973年   9篇
  1972年   4篇
  1971年   8篇
  1970年   8篇
  1969年   8篇
  1968年   3篇
  1967年   6篇
  1948年   4篇
排序方式: 共有555条查询结果,搜索用时 0 毫秒
311.
In this paper we consider an inventory model in which the retailer does not know the exact distribution of demand and thus must use some observed demand data to forecast demand. We present an extension of the basic newsvendor model that allows us to quantify the value of the observed demand data and the impact of suboptimal forecasting on the expected costs at the retailer. We demonstrate the approach through an example in which the retailer employs a commonly used forecasting technique, exponential smoothing. The model is also used to quantify the value of information and information sharing for a decoupled supply chain in which both the retailer and the manufacturer must forecast demand. © 2003 Wiley Periodicals, Inc. Naval Research Logistics 50: 388–411, 2003  相似文献   
312.
The absence of formal diplomatic relations between India and Israel from India's hesitant recognition of Israel in 1950 and the establishment of full relations in January 1992, was the result of a complex interplay between two sets of tensions. The first involved the Arab–Israeli dispute, and India's sympathies with a post-colonial Arab world and with the Non-Aligned Movement; the second involved accommodating Muslim opinion within India. Normalization has proceeded more strongly as the growth of Hindu nationalism has weakened Muslim leverage on Indian foreign policy.  相似文献   
313.
In this study, a nonlinear three-dimensional hydrocode numerical simulation was carried out using AUTODYN-3D to investigate the effect of blasting of a high explosive material (TNT) against several configurations of the composite structure. Several numerical models were carried out to study the effect of varying the thickness of the walls and the effect of adding an air layer or aluminum foam layer inside two layers of concrete in mitigating the effect of blast waves on the structure walls. The results showed that increasing the thickness of walls has a good effect on mitigating the effect of blast waves. When a layer of air was added, the effect of blast waves was exaggerated, while when a layer of aluminum foam was added the blast wave effects were mitigated with a reasonable percentage.  相似文献   
314.
Torture requires careful definition, because of the degree to which its definition often entails its moral condemnation. Torture involves the deliberate infliction of (intense) pain for coercive or punishment reasons. While emphasizing that the act of torture is indeed naturally seen as repulsive and ideally should not take place, I offer a non-utilitarian argument to ethically justify torture in specific kinds of interrogative cases. This argument closely examines the moral isomorphism between cases of immediate and delayed self-defense, showing that in both cases lethal force is justified. I further show that, once one’s life is forfeit, one’s other rights pertaining to the defense of one’s intended victims are likewise forfeit. As such, any form of interrogative torture necessary to procuring relevant information from persons involved in a lethal attack upon innocent persons is ethically justified. However, that an action is strictly ethically justified does not entail that it ought to be generally adopted. Several potent constitutional and sociological concerns are raised and considered.  相似文献   
315.
316.
We consider the problem of deciding whether to keep a piece of equipment or replace it with a more advanced technology in an environment of technological change. Our model assumes that the costs associated with the presently available technology and future technologies are known, but that the appearance times of future technologies are uncertain. We develop a procedure for computing the optimal keep-or-replace decision that iteratively incorporates a technological forecast. For a certain class of situations, we show that our approach requires the minimum possible amount of forecasted data.  相似文献   
317.
318.
319.
In this article is studied a stochastic linear fractional programming problem, in which the parameters of both the numerator and the denominator are assumed to be mutually independent Cauchy variates. The deterministic equivalent of the problem is obtained and is shown to be a linear fractional program. A numerical example is also added for illustration.  相似文献   
320.
The problem of developing good schedules for Navy C-Schools has been modeled as a combinatorial optimization problem. The only complicating feature of the problem is that classes must be grouped together into sequences known as pipelines. An ideal schedule will have all classes in a pipeline scheduled in consecutive weeks. The objective is to eliminate the nonproductive time spent by sailors at C-Schools who are waiting for the next class in a pipeline. In this investigation an implicit enumeration procedure for this problem was developed. The key component of our algorithm is a specialized greedy algorithm which is used to obtain a good initial incumbent. Often this initial incumbent is either an optimal schedule or a near optimal schedule. In an empirical analysis with the only other competing software system, our greedy heuristic found equivalent or better solutions in substantially less computer time. This greedy heuristic was extended and modified for the A-School scheduling problem and was found to be superior to its only competitor. © 1998 John Wiley & Sons, Inc. Naval Research Logistics 45: 533–551, 1998  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