全文获取类型
收费全文 | 989篇 |
免费 | 25篇 |
专业分类
1014篇 |
出版年
2021年 | 15篇 |
2019年 | 31篇 |
2018年 | 14篇 |
2017年 | 27篇 |
2016年 | 21篇 |
2015年 | 24篇 |
2014年 | 23篇 |
2013年 | 201篇 |
2011年 | 8篇 |
2010年 | 9篇 |
2009年 | 15篇 |
2007年 | 12篇 |
2006年 | 11篇 |
2005年 | 16篇 |
2004年 | 18篇 |
2003年 | 10篇 |
2002年 | 14篇 |
2000年 | 12篇 |
1999年 | 10篇 |
1998年 | 18篇 |
1997年 | 20篇 |
1996年 | 15篇 |
1994年 | 23篇 |
1993年 | 15篇 |
1992年 | 13篇 |
1991年 | 24篇 |
1990年 | 11篇 |
1989年 | 19篇 |
1988年 | 21篇 |
1987年 | 24篇 |
1986年 | 23篇 |
1985年 | 17篇 |
1984年 | 13篇 |
1983年 | 14篇 |
1982年 | 13篇 |
1981年 | 12篇 |
1980年 | 11篇 |
1979年 | 17篇 |
1978年 | 17篇 |
1977年 | 10篇 |
1976年 | 14篇 |
1975年 | 13篇 |
1974年 | 14篇 |
1973年 | 17篇 |
1972年 | 13篇 |
1971年 | 10篇 |
1970年 | 15篇 |
1969年 | 12篇 |
1968年 | 9篇 |
1967年 | 11篇 |
排序方式: 共有1014条查询结果,搜索用时 0 毫秒
11.
Under certain conditions, the re-supply capability of a combatant force may be limited by the characteristics of the transportation network over which supplies must flow. Interdiction by an opposing force may be used to reduce the capacity of that network. The effects of such efforts vary for differing missions and targets. With only a limited total budget available, the interdictor must decide which targets to hit, and with how much effort. An algorithm is presented for determining the optimum interdiction plan for minimizing network flow capacity when the minimum capacity on an arc is positive and the cost of interdiction is a linear function of arc capacity reduction. 相似文献
12.
M. E. Nightengale 《海军后勤学研究》1970,17(4):507-514
Frequently there exists an insufficient amount of actual data upon which to base a decision. In this paper a method is presented whereby the subjective opinions of a group of qualified persons are utilized to quantify the relative importance of a finite number of parameters or objectives. A means of testing the consistency among the judges is given which allows the decision maker to determine the validity of the opinions gathered. The application presented here is in the area of Multiple Incentive Contracting. Namely, a method is proposed to facilitate the answering of the question, “What is the value to the purchaser of an incremental change in the performance of a system?” Such a vehicle is not essential to the methodology proposed. 相似文献
13.
In some queueing systems the total service capacity utilized at any given time is a variable under the control of a decision maker. Management doctrines are examined which prescribe the actual service capacity as a function of the queue length and the recent history of the system. Steady state probabilities, expected queue lengths and frequencies of change in capacity are evaluated for a wide class of possible control schemes. Optimization procedures are outlined. 相似文献
14.
15.
An allocation problem is considered in lvhich different kinds of resources must be allocated to various activities, within a given time period. The opportunities for allo'cation appear randomly during this period. Certain assumptions about the values of possible allocations and the distribution of occurrences of opportunities lead to a dynamic programming formulation of the problem. This leads to a system of ordinary differential equations which are (in theory) solvable recursively, and can be solved numerically to any desired degree of precision. An example is given for the allocation of aircraft-carried weapons to targets of opportunity. 相似文献
16.
17.
Industrial situations exist where it is necessary to estimate the optimum number of parts to start through a manufacturing process in order to obtain a given number of completed good items. The solution to this problem is not straightforward when the expected number of rejects from the process is a random variable and when there are alternative penalties associated with producing too many or too few items. This paper discusses various aspects of this problem as well as some of the proposed solutions to it. In addition, tables of optimum reject allowances based on a comprehensive model are presented. 相似文献
18.
Classical inventory models generally assume either no backlogging of demands or unlimited backlogging. This paper treats the case wherein backlogged customers are willing to wait for a random period of time for service. A broad class of such models is discussed, with a more complete analysis performed on a simple subclass. Steady state equations are derived and solved assuming exponentially distributed interarrival times of customers, order delivery lead times, and customer patience. 相似文献
19.
This paper calls attention to an experimental design which enhances the efficiency of the technique described by B. F. Houston and R. A. Huffman [3]. This alternative design is a modification of the simplex lattice design developed by Scheffé [6] for the mixture problem. While not possessing the optimal statistical properties of the central composite design proposed in [3], such as minimum bias and minimum variance, this modified design is optimum with respect to the number of design points employed; hence, it is the minimum cost design. Further, the design proposed in this note is excellent for use in multiple-block experimentation, which is very often required with constrained systems. 相似文献
20.
Lisa J. Campbell 《Low Intensity Conflict & Law Enforcement》2002,11(2):299-315
Since the global war on terror began, the pursuit of Al Qaeda is widely considered as warfare and not the pursuit of criminals. In light of counter-terrorism being redefined as war, the criteria applied for tracking militaries of conventional enemies may also be applicable to Al Qaeda. Intelligence analysts have long used the nine order-of-battle (OB) criteria as part of the estimative process for conventional, or nation-state, enemies. Applying OB criteria to Al Qaeda may assist intelligence analysts in knowing the enemy and identifying changes that will allow for predictive analysis. Many elements of Al Qaeda's OB prior to the events of 11 September were viewed as clutter and not significant changes that might have otherwise alerted intelligence analysts to the impending attack. This essay suggests how one might go about applying the nine OB criteria to analysis of Al Qaeda. Although more difficult and requiring modification, using an analytical procedure that has been tested successfully over many years is a logical step in the war on Al Qaeda. If all OB changes are tracked and analyzed using a systematic approach as outlined in this essay, Al Qaeda attacks may be predicted and/or curtailed in the future. 相似文献