全文获取类型
收费全文 | 580篇 |
免费 | 154篇 |
国内免费 | 31篇 |
出版年
2024年 | 2篇 |
2023年 | 3篇 |
2022年 | 8篇 |
2021年 | 30篇 |
2020年 | 13篇 |
2019年 | 4篇 |
2018年 | 6篇 |
2017年 | 20篇 |
2016年 | 9篇 |
2015年 | 29篇 |
2014年 | 29篇 |
2013年 | 21篇 |
2012年 | 24篇 |
2011年 | 41篇 |
2010年 | 40篇 |
2009年 | 46篇 |
2008年 | 63篇 |
2007年 | 51篇 |
2006年 | 39篇 |
2005年 | 30篇 |
2004年 | 19篇 |
2003年 | 16篇 |
2002年 | 13篇 |
2001年 | 18篇 |
2000年 | 11篇 |
1999年 | 29篇 |
1998年 | 22篇 |
1997年 | 27篇 |
1996年 | 25篇 |
1995年 | 15篇 |
1994年 | 9篇 |
1993年 | 7篇 |
1992年 | 15篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1988年 | 5篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有765条查询结果,搜索用时 0 毫秒
51.
52.
计算机网络日益复杂和异构化,迫切需要提高可靠、跨平台的网络管理系统保证网络稳定、高效运行。分析了传统网络管理系统的不足,提出了一层次分布式网络管理系统故障管理算法,并讨论了算法的性能。最后采用CORBA,Web和Java技术实现了该算法。 相似文献
53.
54.
Magnetic resonance imaging and other multifunctional diagnostic facilities, which are considered as scarce resources of hospitals, typically provide services to patients with different medical needs. This article examines the admission policies during the appointment management of such facilities. We consider two categories of patients: regular patients who are scheduled in advance through an appointment system and emergency patients with randomly generated demands during the workday that must be served as soon as possible. According to the actual medical needs of patients, regular patients are segmented into multiple classes with different cancelation rates, no‐show probabilities, unit value contributions, and average service times. Management makes admission decisions on whether or not to accept a service request from a regular patient during the booking horizon to improve the overall value that could be generated during the workday. The decisions should be made by considering the cancelation and no‐show behavior of booked patients as well as the emergency patients that would have to be served because any overtime service would lead to higher costs. We studied the optimal admission decision using a continuous‐time discrete‐state dynamic programming model. Identifying an optimal policy for this discrete model is analytically intractable and numerically inefficient because the state is multidimensional and infinite. We propose to study a deterministic counterpart of the problem (i.e., the fluid control problem) and to develop a time‐based fluid policy that is shown to be asymptotically optimal for large‐scale problems. Furthermore, we propose to adopt a mixed fluid policy that is developed based on the information obtained from the fluid control problem. Numerical experiments demonstrate that this improved policy works effectively for small‐scale problems. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 287–304, 2016 相似文献
55.
Considering a supply chain with a supplier subject to yield uncertainty selling to a retailer facing stochastic demand, we find that commonly studied classical coordination contracts fail to coordinate both the supplier's production and the retailer's procurement decisions and achieve efficient performance. First, we study the vendor managed inventory (VMI) partnership. We find that a consignment VMI partnership coupled with a production cost subsidy achieves perfect coordination and a win‐win outcome; it is simple to implement and arbitrarily allocates total channel profit. The production cost subsidy optimally chosen through Nash bargaining analysis depends on the bargaining power of the supplier and the retailer. Further, motivated by the practice that sometimes the retailer and the supplier can arrange a “late order,” we also analyze the behavior of an advance‐purchase discount (APD) contract. We find that an APD with a revenue sharing contract can efficiently coordinate the supply chain as well as achieve flexible profit allocation. Finally, we explore which coordination contract works better for the supplier vs. the retailer. It is interesting to observe that Nash bargaining solutions for the two coordination contracts are equivalent. We further provide recommendations on the applications of these contracts. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 305–319, 2016 相似文献
56.
57.
Elman动态递归神经网络具有很强的记忆能力,特别适用于火控系统传感器的故障诊断.提出了一种收敛速度快、精度高、可靠性好的PRP(Polak-Ribiere-Polyak)网络训练方法,增强网络在线学习能力.将该方法运用于Elman动态递归神经网络,并运用该网络对火控系统传感器量测信号进行预测和故障诊断.仿真实验和实际应用表明,提出的Elman动态递归神经网络火控系统传感器系统故障诊断方法有效性好,故障诊断率高. 相似文献
58.
59.
为了研究弹丸对武器装备的损伤,建立弹丸侵彻多层靶板的有限元模型,对不同初速弹丸侵彻多层靶板进行仿真试验,引入等效应变及等效应力参量以精确描述靶板损伤,提出一种基于多元统计分析对靶板损伤进行评估的方法。结果表明:利用该方法所得到的计算结果与理论分析结果完全一致。这说明基于多元统计分析的靶板损伤评估方法能够正确地评价仿真实验中目标靶板的战损程度,因而可以进一步应用于装备侵彻损伤评估与易损性研究中。 相似文献
60.
当前在武器装备研制生产过程中,普遍存在着产品标准化大纲编写太笼统、单一及缺乏实用性等问题,本文分析了这一问题存在的现状及产生的原因,并进行深入思考,提出了几点建议,以使产品标准化大纲在型号研制工作中真正起到承上启下、承前启后的指导作用。 相似文献