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   303篇
  免费   24篇
  国内免费   19篇
电工技术   59篇
综合类   26篇
化学工业   8篇
金属工艺   8篇
机械仪表   8篇
建筑科学   25篇
矿业工程   3篇
能源动力   1篇
水利工程   3篇
石油天然气   2篇
无线电   84篇
一般工业技术   22篇
冶金工业   3篇
自动化技术   94篇
  2024年   1篇
  2023年   3篇
  2022年   4篇
  2021年   5篇
  2020年   11篇
  2019年   9篇
  2018年   6篇
  2017年   8篇
  2016年   6篇
  2015年   23篇
  2014年   32篇
  2013年   20篇
  2012年   43篇
  2011年   23篇
  2010年   12篇
  2009年   20篇
  2008年   10篇
  2007年   12篇
  2006年   21篇
  2005年   9篇
  2004年   9篇
  2003年   6篇
  2002年   6篇
  2001年   5篇
  2000年   4篇
  1999年   3篇
  1998年   2篇
  1997年   2篇
  1996年   3篇
  1995年   5篇
  1994年   1篇
  1991年   1篇
  1990年   3篇
  1989年   1篇
  1987年   2篇
  1986年   1篇
  1985年   2篇
  1984年   3篇
  1983年   3篇
  1982年   1篇
  1981年   2篇
  1977年   1篇
  1976年   1篇
  1971年   1篇
排序方式: 共有346条查询结果,搜索用时 187 毫秒
1.
This paper investigates replanning strategies for container-transportation task allocation of autonomous Straddle Carriers (SC) at automated container terminals. The strategies address the problem of large-scale scheduling in the context of uncertainty (especially uncertainty associated with unexpected events such as the arrival of a new task). Two rescheduling policies–Rescheduling New arrival Jobs (RNJ) policy and Rescheduling Combination of new and unexecuted Jobs (RCJ) policy–are presented and compared for long-term Autonomous SC Scheduling (ASCS) under the uncertainty of new job arrival. The long-term performance of the two rescheduling policies is evaluated using a multi-objective cost function (i.e., the sum of the costs of SC travelling, SC waiting, and delay of finishing high-priority jobs). This evaluation is conducted based on two different ASCS solving algorithms–an exact algorithm (i.e., branch-and-bound with column generation (BBCG) algorithm) and an approximate algorithm (i.e., auction algorithm)–to get the schedule of each short-term planning for the policy. Based on the map of an actual fully-automated container terminal, simulation and comparative results demonstrate the quality advantage of the RCJ policy compared with the RNJ policy for task allocation of autonomous straddle carriers under uncertainty. Long-term testing results also show that although the auction algorithm is much more efficient than the BBCG algorithm for practical applications, it is not effective enough, even when employed by the superior RCJ policy, to achieve high-quality scheduling of autonomous SCs at the container terminals.  相似文献   
2.
当前,电力用户终端管理中出现的问题越来越多,已经影响到供电企业的发展和社会的和谐。如何解决这些问题并建立有效的电力终端管理机制,是目前电力企业面临的首要问题。  相似文献   
3.
智能手机上的恶意软件数量呈现爆炸式增长,目前迫切需要一个安全分析与检测方法.一个有效的检测与分析方法需要解决的最大问题就是如何从应用程序和恶意软件的汪洋大海中识别重新包装的应用程序.论文提出了基于三级签名的恶意软件分析方法MSAnalytics,根据API调用序列,提取在操作码级的恶意软件特征,生成应用程序三级签名.实验证明,MSAnalytics对重新包装恶意软件具有良好的分析能力.  相似文献   
4.
电力企业移动安全接入平台   总被引:1,自引:0,他引:1  
电力企业承担着为社会经济发展提供安全、可持续电力供应的重要使命,因此,电力企业信息系统的安全要求比普通企业要高。随着电力企业信息化的快速推进,各种远程移动终端与信息内网的数据交换需求日益增长。如何保证移动终端远程接入的安全已成为电力企业信息化建设中的关键问题。在分析传统 SSL VPN 技术的基础上,针对电力企业信息安全建设的特点和特殊需求,设计了一种适用于电力企业的新型移动安全接入平台。该平台能够支持多种移动终端的多因素认证和访问控制,同时实现了SSL高速协议栈、数据隔离等功能,有效地解决了上面所提到的问题。  相似文献   
5.
From the viewpoint of service level agreements,data transmission accuracy is one of the critical performances for assessing Internet by service providers and enterprise customers.The stochastic computer network(SCN),in which each edge has several capacities and the accuracy rate,has multiple terminals.This paper is aimed mainly to evaluate the system reliability for an SCN,where system reliability is the probability that the demand can be fulfilled under the total accuracy rate.A minimal capacity vector allows the system to transmit demand to each terminal under the total accuracy rate.This study proposes an efficient algorithm to find all minimal capacity vectors by minimal paths.The system reliability can then be computed in terms of all minimal capacity vectors by the recursive sum of disjoint products(RSDP) algorithm.  相似文献   
6.
该文通过对ZigBee网络技术的介绍,阐述了ZigBee网络的拓扑结构和协议栈,利用ZigBee技术实现了无线抄表监控系统的总体设计,并对无线抄表监控系统中的采集终端、集中器和服务器三部分做了深入的研究。  相似文献   
7.
This paper proposes a practical job grouping approach, which aims to enhance the time related performance metrics of container transfers in the Patrick AutoStrad container terminal, located in Brisbane, Australia. It first formulates a mathematical model of the automated container transfers in a relatively complex environment. Apart from the consideration on collision avoidance of a fleet of large vehicles in a confined area, it also deals with many other difficult practical challenges such as the presence of multiple levels of container stacking and sequencing, variable container orientations, and vehicular dynamics that require finite acceleration and deceleration times. The proposed job grouping approach aims to improve the makespan of the schedule for yard jobs, while reducing straddle carrier waiting time by grouping jobs using a guiding function. The performance of the current sequential job allocation method and the proposed job grouping approach are evaluated and compared statistically using a pooled t-test for 30 randomly generated yard configurations. The experimental results show that the job grouping approach can effectively improve the schedule makespan and reduce the total straddle carrier waiting time.  相似文献   
8.
Motivated by observations from real world wireless local area network (WLAN) deployments, we develop in this paper a novel analytical model to characterize the saturation throughput of an IEEE 802.11-based access point (AP) and stations under the influence of hidden terminals. Unlike existing models, our model can accommodate different numbers of hidden nodes without increasing the model complexity. Given any number of hidden nodes, only four constraints are needed to describe the interaction between stations and the AP with the consideration of both uplink and downlink traffic. Simulation evaluation shows that our model predicts network performance accurately over a wide range of network sizes and indicates the existence of a throughput starvation problem. To address this problem, based on our model, we formulate a bandwidth allocation problem to optimize the network throughput and fairness under some predefined requirements by systematically tuning the AP and stations contention windows. Simulation results show that the starvation problem is resolved with our approach, and the target throughput is met.  相似文献   
9.
In this paper, we study stacking policies for containers at an automated container terminal. It is motivated by the increasing pressure on terminal performance put forward by the increase in the size of container ships. We consider several variants of category stacking, where containers can be exchanged during the loading process. The categories facilitate both stacking and online optimization of stowage. We also consider workload variations for the stacking cranes.  相似文献   
10.
嵌入式Java虚拟机的性能优化技术   总被引:7,自引:1,他引:7  
李允  罗蕾  雷昊峰  熊光泽 《计算机工程》2004,30(18):46-48,58
分析了线索化和直接线索化等基于解释运行的性能优化技术,实现了基于直接线索化技术的嵌入式Java虚拟机的解释器性能优化方案,并对嵌入式Java虚拟机的参考实现、线索化优化方案和基于直接线索化的优化方案进行了性能对比。  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