全文获取类型
收费全文 | 470篇 |
免费 | 10篇 |
专业分类
480篇 |
出版年
2021年 | 5篇 |
2019年 | 13篇 |
2018年 | 9篇 |
2017年 | 11篇 |
2016年 | 9篇 |
2015年 | 10篇 |
2013年 | 78篇 |
2011年 | 5篇 |
2010年 | 6篇 |
2009年 | 4篇 |
2007年 | 6篇 |
2006年 | 7篇 |
2005年 | 11篇 |
2004年 | 8篇 |
2003年 | 5篇 |
2001年 | 4篇 |
2000年 | 9篇 |
1999年 | 6篇 |
1998年 | 5篇 |
1997年 | 9篇 |
1996年 | 12篇 |
1995年 | 4篇 |
1994年 | 10篇 |
1993年 | 6篇 |
1992年 | 7篇 |
1991年 | 14篇 |
1990年 | 8篇 |
1989年 | 12篇 |
1988年 | 6篇 |
1987年 | 11篇 |
1986年 | 9篇 |
1985年 | 11篇 |
1984年 | 9篇 |
1983年 | 7篇 |
1982年 | 6篇 |
1981年 | 8篇 |
1980年 | 10篇 |
1979年 | 7篇 |
1978年 | 8篇 |
1977年 | 8篇 |
1976年 | 9篇 |
1975年 | 6篇 |
1974年 | 11篇 |
1973年 | 8篇 |
1972年 | 9篇 |
1971年 | 13篇 |
1970年 | 3篇 |
1969年 | 6篇 |
1968年 | 5篇 |
1967年 | 3篇 |
排序方式: 共有480条查询结果,搜索用时 0 毫秒
41.
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
42.
43.
In this paper, we derive new families of facet‐defining inequalities for the finite group problem and extreme inequalities for the infinite group problem using approximate lifting. The new valid inequalities for the finite group problem include two‐ and three‐slope facet‐defining inequalities as well as the first family of four‐slope facet‐defining inequalities. The new valid inequalities for the infinite group problem include families of two‐ and three‐slope extreme inequalities. These new inequalities not only illustrate the diversity of strong inequalities for the finite and infinite group problems, but also provide a large variety of new cutting planes for solving integer and mixed‐integer programming problems. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008 相似文献
44.
Using recent econometric techniques based on fractional integration, we find that developing countries recover their economic growth faster than developed countries in response to a shock. Following this methodology, we find that longer civil conflicts are associated with a faster recovery process. We further investigate this issue by exploring correlations with components of GDP, military spending, institutions and aid and find heterogeneous effects of these channels by duration of conflict. Higher government spending is correlated with faster recoveries post longer conflicts, and higher consumption spending is linked to faster recoveries following shorter conflicts. Military spending appears to be driving the government expenditure that makes countries recover from longer conflicts. More democratic institutions are associated with faster recoveries post short wars but slower recoveries following long wars. 相似文献
45.
In this article a bicriteria model, formed by the weighted sum of the minisum and minimax functions for a single-location problem, is investigated. It is shown that all efficient solutions generated by either constrained model are also properly efficient. The bicriteria model and the constrained models are theoretically equivalent, but it is more efficient and simpler to generate nondominated solutions using the constrained criterion approach. When solving the bicriteria model, a critical range is found for which all properly efficient solutions are generated. 相似文献
46.
While the traditional solution to the problem of meeting stochastically variable demands for inventory during procurement lead time is through the use of some level of safety stock, several authors have suggested that a decision be made to employ some form of rationing so as to protect certain classes of demands against stockout by restricting issues to other classes. Nahmias and Demmy [10] derived an approximate continuous review model of systems with two demand classes which would permit an inventory manager to calculate the expected fill rates per order cycle for high-priority, low-priority, and total system demands for a variety of parameters. The manager would then choose the rationing policy that most closely approximated his fill-rate objectives. This article describes a periodic review model that permits the manager to establish a discrete time rationing policy during lead time by prescribing a desired service level for high-priority demands. The reserve levels necessary to meet this level of service can then be calculated based upon the assumed probability distributions of high- and low-priority demands over lead time. The derived reserve levels vary with the amount of lead time remaining. Simulation tests of the model indicate they are more effective than the single reserve level policy studied by Nahmias and Demmy. 相似文献
47.
In this article we investigate situations where the buyer is offered discounted price schedules from alternative vendors. Given various discount schedules, the buyer must make the best buying decision under a variety of constraints, such as limited storage space and restricted inventory budgets. Solutions to this problem can be utilized by the buyer to improve profitability. EOQ models for multiple products with all-units discounts are readily solvable in the absence of constraints spanning the products. However, constrained discounted EOQ models lack convenient mathematical properties. Relaxing the product-spanning constraints produces a dual problem that is separable, but lack of convexity and smoothness opens the door for duality gaps. In this research we present a set of algorithms that collectively find the optimal order vector. Finally, we present numerical examples using actual data. to illustrate the application of the algorithms. © 1993 John Wiley & Sons, Inc. 相似文献
48.
49.
James A. Russell 《Small Wars & Insurgencies》2014,25(1):69-90
This article examines the complex legacy of David Petraeus who was a key figure in the emergence of the US military shift towards counterinsurgency doctrine in the years after 2006. Although Petraeus has been perceived by critics as a publicity seeker, he can be credited with laying the foundations for a more serious commitment to COIN involving in particular in integrating conventional and Special Forces in arenas like village stability operations. The article looks a Petraeus's role in both Iraq and Afghanistan: it concludes that, in the case of Afghanistan, it is too early to assess whether counterinsurgency has had a decisive impact of the outcome of the war against the Taliban. 相似文献
50.
We show the existence of a unique analytic single parameter limiting survival function arising from the repeated composition of a coherent structure as the number of components tends to infinity. Examples include the repeated composition process of the bridge structure. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2004. 相似文献