全文获取类型
收费全文 | 9785篇 |
免费 | 935篇 |
国内免费 | 779篇 |
专业分类
电工技术 | 1172篇 |
技术理论 | 3篇 |
综合类 | 988篇 |
化学工业 | 189篇 |
金属工艺 | 156篇 |
机械仪表 | 567篇 |
建筑科学 | 232篇 |
矿业工程 | 133篇 |
能源动力 | 180篇 |
轻工业 | 102篇 |
水利工程 | 62篇 |
石油天然气 | 110篇 |
武器工业 | 93篇 |
无线电 | 1531篇 |
一般工业技术 | 441篇 |
冶金工业 | 121篇 |
原子能技术 | 66篇 |
自动化技术 | 5353篇 |
出版年
2024年 | 31篇 |
2023年 | 71篇 |
2022年 | 97篇 |
2021年 | 138篇 |
2020年 | 172篇 |
2019年 | 188篇 |
2018年 | 155篇 |
2017年 | 200篇 |
2016年 | 249篇 |
2015年 | 315篇 |
2014年 | 528篇 |
2013年 | 568篇 |
2012年 | 573篇 |
2011年 | 683篇 |
2010年 | 510篇 |
2009年 | 599篇 |
2008年 | 664篇 |
2007年 | 742篇 |
2006年 | 694篇 |
2005年 | 634篇 |
2004年 | 523篇 |
2003年 | 445篇 |
2002年 | 386篇 |
2001年 | 358篇 |
2000年 | 303篇 |
1999年 | 275篇 |
1998年 | 225篇 |
1997年 | 222篇 |
1996年 | 188篇 |
1995年 | 156篇 |
1994年 | 145篇 |
1993年 | 102篇 |
1992年 | 85篇 |
1991年 | 70篇 |
1990年 | 37篇 |
1989年 | 36篇 |
1988年 | 24篇 |
1987年 | 18篇 |
1986年 | 21篇 |
1985年 | 17篇 |
1984年 | 9篇 |
1983年 | 15篇 |
1982年 | 8篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1973年 | 2篇 |
1957年 | 2篇 |
1951年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
Fuzzy boundary layer tuning for sliding mode systems as applied to the control of a direct drive robot 总被引:1,自引:0,他引:1
Kemalettin Erbatur Berk Çallı 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2009,13(11):1099-1111
Chattering in the control signal is a significant problem in sliding mode control (SMC). The boundary layer approach is one
of the many modifications proposed in the literature to avoid the chattering. In this approach, instead of the discontinuous
SMC, a continuous feedback control law is employed in a boundary layer around the sliding surface. The thickness of the boundary
layer is an important design parameter. This paper proposes a fuzzy online tuning method to adjust the boundary layer thickness
for the best system performance without chattering. The method features the measurement of the chattering in the control signal.
The paper validates the performance of the algorithm by experiments on a direct drive robot with a range of different payloads. 相似文献
102.
ZHANG Xiao-yu 《通讯和计算机》2009,6(1):53-60
Sliding mode-like fuzzy logic control (SMFC) algorithm for nonlinear systems is presented in this paper. Firstly dead zone parameters of sliding mode control (SMC) are selftuned by proper adaptive laws and then combined into fuzzy logic system (FLS) to compose the opportune fuzzy logic control (FLC), which is equivalent to the predesigned SMC controller with self-tuning parameters. Robustness and invariance to the uncertainties of the closed-loop systems are improved and chattering of the SMC is eliminated. Finally simulation results of numerical examples show that the proposed control algorithm is efficient and feasible. 相似文献
103.
Devinder Thapa Chang Mok Park Sang C. Park Gi-Nam Wang 《International Journal of Control, Automation and Systems》2009,7(2):165-174
The objective of this paper is to reduce the development time of a PLC (Programmable Logic Controller) by automating the task
of code generation. For this purpose, we applied t-MPSG (Timed-Message Based Part State Graph). The t-MPSG is an extended finite state automata used to model and generate an execution module for a real-time shop floor controller
system. In our proposed method, t-MPSG is used to model the formal specification of the controller system that can be translated into textual structure. After
the verification of the t-MPSG model, it can be used as an input to the plc-builder tool. The plc-builder tool is an extended version of a conventional MPSG simulator. It can be used to translate the textual structure of
the t-MPSG into an IEC standard PLC code. Finally, the generated code can be downloaded to a PLC emulator or a PLC device for the
purpose of simulation and execution. The similarity in the hierarchical structure of the t-MPSG and the IEC standard PLC program has made it convenient to transform from one form to another. Furthermore, an illustration
of the methodology to auto-generate IEC standard PLC code using t-MPSG is explained with a suitable example.
Recommended by Editorial Board member Young Soo Suh under the direction of Editor Jae Weon Choi. This work was partially supported
by Defense Acquisition Program Administration and Agency for Defense Development under the contract (UD080042AD).
Devinder Thapa is a Postdoc Research Fellow in the Department of Industrial & information systems at Ajou University, Korea. He completed
his Ph.D. from Ajou University in Industrial and Information Systems Engineering. His area of research is related to manufacturing
automation and intelligent decision support systems.
Chang Mok Park is a Professor in the Department of Technology & Systems Management at Induk Institute of Technology. He completed his Ph.D.
in 2002 from Ajou University in Industrial Engineering. His research interest is related to manufacturing optimization, discrete
event system simulation and signal analysis.
Sang C. Park is an Associate Professor in the Department of Industrial & Information Systems Engineering at Ajou University. He received
his B.S., M.S., and Ph.D. degrees from KAIST in 1994, 1996, and 2000, respectively, all in Industrial Engineering. His research
interests include geometric algorithms in CAD/CAM, process planning, engineering knowledge management, and discrete event
system simulation.
Gi-Nam Wang is the Head and a Professor in the Department of Industrial & Information Systems Engineering at Ajou University, Korea.
He completed his Ph.D. in 1992 from Texas A&M University, in Industrial Engineering. He has worked as Visiting Professor at
University of Texas at Austin during 2000–2001. His area of research is related to Intelligent Information & manufacturing
systems, system integration & automation, e-Business solutions and image processing. 相似文献
104.
In this paper, a method for writing composable TLA+ specifications that conform to the formal model called Masaccio is introduced. Specifications are organized in TLA+ modules that correspond to Masaccio components by means of a trace-based semantics. Hierarchical TLA+ specifications are built from atomic component specifications by parallel and serial composition that can be arbitrary nested.
While the rule of parallel composition is a variation of the classical joint-action composition, the authors do not know about
a reuse method for the TLA+ that systematically employs the presented kind of a serial composition. By combining these two composition rules and assuming
only the noninterleaving synchronous mode of an execution, the concurrent, sequential, and timed compositionality is achieved. 相似文献
105.
106.
人工智能实验教学探讨 总被引:4,自引:3,他引:1
本文一方面简单介绍人工智能的基本理论及知识体系结构,另一方面则结合笔者的理论实践与实验教学经验,总结出目前在整个教学过程所存在的一些问题,目的在于不断总结经验,力争能更好地完成人工智能的整个教学工作,从而提高人才培养的质量,同时也可以为其他高校提供参考。 相似文献
107.
A novel probabilistic fuzzy control system is proposed to treat the congestion avoidance problem in transmission control protocol (TCP) networks. Studies on traffic measurement of TCP networks have shown that the packet traffic exhibits long range dependent properties called self-similarity, which degrades the network performance greatly. The probabilistic fuzzy control (PFC) system is used to handle the complex stochastic features of self-similar traffic and the modeling uncertainties in the network system. A three-dimensional (3-D) membership function (MF) is embedded in the PFC to express and describe the stochastic feature of network traffic. The 3-D MF has extended the traditional fuzzy planar mapping and further provides a spatial mapping among "fuzziness-randomness-state". The additional stochastic expression of 3-D MF provides the PFC an additional freedom to handle the stochastic features of self-similar traffic. Simulation experiments show that the proposed control method achieves superior performance compared to traditional control schemes in a stochastic environment. 相似文献
108.
Yan Wang Kwei-Jay Lin Duncan S. Wong Vijay Varadharajan 《Service Oriented Computing and Applications》2009,3(2):129-146
In service-oriented computing (SOC) environments, service clients interact with service providers for services or transactions.
From the point view of service clients, the trust status of a service provider is a critical issue to consider, particularly
when the service provider is unknown to them. Typically, the trust evaluation is based on the feedback on the service quality
provided by service clients. In this paper, we first present a trust management framework that is event-driven and rule-based.
In this framework, trust computation is based on formulae. But rules are defined to determine which formula to use and what
arguments to use, according to the event occurred during the transaction or service. In addition, we propose some trust evaluation
metrics and a formula for trust computation. The formula is designed to be adaptable to different application domains by setting
suitable arguments. Particularly, the proposed model addresses the incremental characteristics of trust establishment process.
Furthermore, we propose a fuzzy logic based approach for determining reputation ranks that particularly differentiates new
service providers and old (long-existing) ones. This is further incentive to new service providers and penalize poor quality
services from service providers. Finally, a set of empirical studies has been conducted to study the properties of the proposed
approaches, and the method to control the trust changes in both trust increment and decrement cases. The proposed framework
is adaptable for different domains and complex trust evaluation systems.
相似文献
Vijay VaradharajanEmail: |
109.
采用PLC和触摸屏PT组合的方案实现了对生物质热解装置的现场控制。控制程序由手动和自动控制两个部分组成,并且可以根据需要实现它们之间的无痕迹切换。自动控制程序主要由燃烧、冷凝和热解三个子系统组成,其中温度等模拟量的控制根据调试经验采取分段控制的方法。现场运行表明,本系统具有调节灵活、稳定性好、造价低等优点。 相似文献
110.
描述逻辑是语义Web的逻辑基础,是形式化表达领域知识的工具.但是描述逻辑只能表达单调推理,不能处理不完全知识.认知描述逻辑因其非单调特性和良好的时间复杂度等特点在处理不完全知识方面有较好的优势.本文在认知描述逻辑ALCK的基础上提出了新的认知描述逻辑语言ALCKR ,保留了描述逻辑原有的优点,加入传递角色属性,增强了表达能力,并通过认知查询拥有了非单调推理的能力.设计了ALCKR 的语法、语义以及表算法. 相似文献