全文获取类型
收费全文 | 553篇 |
免费 | 43篇 |
国内免费 | 6篇 |
出版年
2022年 | 5篇 |
2021年 | 12篇 |
2020年 | 9篇 |
2019年 | 6篇 |
2018年 | 5篇 |
2017年 | 11篇 |
2016年 | 12篇 |
2015年 | 15篇 |
2014年 | 16篇 |
2013年 | 66篇 |
2012年 | 31篇 |
2011年 | 35篇 |
2010年 | 35篇 |
2009年 | 24篇 |
2008年 | 33篇 |
2007年 | 21篇 |
2006年 | 27篇 |
2005年 | 9篇 |
2004年 | 4篇 |
2002年 | 11篇 |
2001年 | 7篇 |
1999年 | 3篇 |
1998年 | 8篇 |
1997年 | 8篇 |
1996年 | 6篇 |
1995年 | 10篇 |
1994年 | 7篇 |
1993年 | 12篇 |
1992年 | 8篇 |
1991年 | 6篇 |
1989年 | 6篇 |
1986年 | 11篇 |
1985年 | 8篇 |
1983年 | 6篇 |
1982年 | 5篇 |
1981年 | 8篇 |
1980年 | 9篇 |
1979年 | 11篇 |
1978年 | 4篇 |
1977年 | 6篇 |
1976年 | 7篇 |
1975年 | 7篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1972年 | 12篇 |
1971年 | 3篇 |
1970年 | 3篇 |
1969年 | 9篇 |
1968年 | 7篇 |
1966年 | 3篇 |
排序方式: 共有602条查询结果,搜索用时 15 毫秒
21.
22.
本文概述了BYC—MIS系统应用情况,介绍了系统的硬件配置、软件环境;说明了各子系统的功能;介绍了系统逻辑模型的设计及网络数据传输及汇总分配的方法和网络数据共享安全性措施;论述了系统研制过程中解决的关键问题. 相似文献
23.
Condition monitoring and fault diagnosis is currently a very important problem in large-scale complicate power devices. Both scheme and realistic technology for monitoring system hardware and software have been present to solve the problem in this paper. The fault diagnostic model based on artificial neural network and state identification method based on fuzzy analysis are studied. 相似文献
24.
Adequate prediction of a response variable using a multiple linear regression model is shown in this article to be related to the presence of multicollinearities among the predictor variables. If strong multicollinearities are present in the data, this information can be used to determine when prediction is likely to be accurate. A region of prediction, R, is proposed as a guide for prediction purposes. This region is related to a prediction interval when the matrix of predictor variables is of full column rank, but it can also be used when the sample is undersized. The Gorman-Toman ten-variable data is used to illustrate the effectiveness of the region R. 相似文献
25.
An optimization method is given for solving problems where a portion of the explicit mathematical form is unknown but can be evaluated. The solution scheme is an iterative process utilizing optimization and subsystem evaluation (such as via simulation). Conditions for the convergence of the iterative process are given. Several published application articles are noted as using this basic methodology. The method is superior to most other numerical optimization procedures. However, the class of problems for which the method is applicable is restricted to problems with enough known structure to generate a convergent iterative procedure. Three numerical examples are given and comparisons made with several other methods of optimizing unknown systems. 相似文献
26.
本文论述了机载平显的抗振设计,重点阐述了振动对机载平显的影响及抗振设计措施,给出了元件及印制板的固有频率计算方法,对安装方式进行了分析比较,并简要论述了整机抗振设计方法,进而保证产品可靠性。 相似文献
27.
Preference for food in the function of the time since last consumption and total preference in the function of eating frequency are equivalent mathematical representations of attitudes governing food consumption. The observed and postulated properties of these functions imply a formal correspondence between preference maximizing and variety seeking behavior. 相似文献
28.
Edward L. Hannan 《海军后勤学研究》1982,29(1):113-118
This paper investigates the two-person zero-sum multiple payoff game in which the objective is to minimize a player's total underachievement from a fixed set of goals. It is demonstrated that a previous formulation of this problem can be substantially simplified. 相似文献
29.
The classical Economic Order Quantity Model requires the parameters of the model to be constant. Some EOQ models allow a single parameter to change with time. We consider EOQ systems in which one or more of the cost or demand parameters will change at some time in the future. The system we examine has two distinct advantages over previous models. One obvious advantage is that a change in any of the costs is likely to affect the demand rate and we allow for this. The second advantage is that often, the times that prices will rise are fairly well known by announcement or previous experience. We present the optimal ordering policy for these inventory systems with anticipated changes and a simple method for computing the optimal policy. For cases where the changes are in the distant future we present a myopic policy that yields costs which are near-optimal. In cases where the changes will occur in the relatively near future the optimal policy is significantly better than the myopic policy. 相似文献
30.
We formulate the set partitioning problem as a matching problem with simple side constraints. As a result we obtain a Lagrangian relaxation of the set partitioning problem in which the primal problem is a matching problem. To solve the Lagrangian dual we must solve a sequence of matching problems each with different edge-weights. We use the cyclic coordinate method to iterate the multipliers, which implies that successive matching problems differ in only two edge-weights. This enables us to use sensitivity analysis to modify one optimal matching to obtain the next one. We give theoretical and empirical comparisons of these dual bounds with the conventional linear programming ones. 相似文献