全文获取类型
收费全文 | 2280篇 |
免费 | 144篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 14篇 |
综合类 | 10篇 |
化学工业 | 676篇 |
金属工艺 | 31篇 |
机械仪表 | 37篇 |
建筑科学 | 151篇 |
矿业工程 | 5篇 |
能源动力 | 45篇 |
轻工业 | 337篇 |
水利工程 | 35篇 |
石油天然气 | 9篇 |
无线电 | 207篇 |
一般工业技术 | 355篇 |
冶金工业 | 222篇 |
原子能技术 | 6篇 |
自动化技术 | 287篇 |
出版年
2024年 | 4篇 |
2023年 | 39篇 |
2022年 | 80篇 |
2021年 | 107篇 |
2020年 | 61篇 |
2019年 | 81篇 |
2018年 | 85篇 |
2017年 | 74篇 |
2016年 | 87篇 |
2015年 | 68篇 |
2014年 | 107篇 |
2013年 | 174篇 |
2012年 | 138篇 |
2011年 | 178篇 |
2010年 | 137篇 |
2009年 | 117篇 |
2008年 | 106篇 |
2007年 | 111篇 |
2006年 | 75篇 |
2005年 | 79篇 |
2004年 | 67篇 |
2003年 | 63篇 |
2002年 | 44篇 |
2001年 | 31篇 |
2000年 | 32篇 |
1999年 | 27篇 |
1998年 | 32篇 |
1997年 | 34篇 |
1996年 | 21篇 |
1995年 | 17篇 |
1994年 | 12篇 |
1993年 | 18篇 |
1992年 | 20篇 |
1991年 | 7篇 |
1990年 | 10篇 |
1989年 | 8篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1986年 | 8篇 |
1985年 | 6篇 |
1984年 | 8篇 |
1983年 | 3篇 |
1982年 | 7篇 |
1981年 | 5篇 |
1980年 | 3篇 |
1977年 | 4篇 |
1976年 | 4篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1972年 | 4篇 |
排序方式: 共有2427条查询结果,搜索用时 15 毫秒
21.
Caroline ConcattoAuthor VitaeJoão AlmeidaAuthor Vitae Guilherme FachiniAuthor VitaeMarcos HervéAuthor Vitae Fernanda KastensmidtAuthor Vitae Érika CotaAuthor VitaeMarcelo LubaszewskiAuthor Vitae 《Journal of Parallel and Distributed Computing》2011,71(5):664-674
We propose an effective and low cost method to increase the yield and the lifetime of torus NoCs. The method consists in detecting and diagnosing NoC interconnect faults using BIST structures and activating alternative paths for the faulty links. Alternative paths use the inherent redundancy of the torus topology, thus leading to minimal performance, area, and power overhead. We assume an extended interconnect fault model comprising stuck-at and pairwise shorts within a single link or between any two links in the network. Experimental results for a 3×3 NoC show that the proposed approach can correctly diagnose 93% of all possible interconnect faults and can mitigate 42% of those faults (representing 94.4% of the solvable faults) with a worst case performance penalty of 8% and 1% of area overhead. We also demonstrate the scalability of the method by presenting its application to larger NoCs. 相似文献
22.
A comprehensive quality model for service-oriented systems 总被引:2,自引:0,他引:2
In a service-oriented system, a quality (or Quality of Service) model is used (i) by service requesters to specify the expected
quality levels of service delivery; (ii) by service providers to advertise quality levels that their services achieve; and
(iii) by service composers when selecting among alternative services those that are to participate in a service composition.
Expressive quality models are needed to let requesters specify quality expectations, providers advertise service qualities,
and composers finely compare alternative services. Having observed many similarities between various quality models proposed
in the literature, we review these and integrate them into a single quality model, called QVDP. We highlight the need for
integration of priority and dependency information within any quality model for services and propose precise submodels for
doing so. Our intention is for the proposed model to serve as a reference point for further developments in quality models
for service-oriented systems. To this aim, we extend the part of the UML metamodel specialized for Quality of Service with
QVDP concepts unavailable in UML.
Ivan J. Jureta has, after graduating, summa cum laude, received the Master in Management and Master of International Management, respectively, at the Université de Louvain, Belgium, and the London School of Economics, both in 2005. He is currently completing his Ph.D. thesis at the University of Namur, Belgium, under Prof. Stéphane Faulkner’s supervision. His thesis focuses on quality management of adaptable and open service-oriented systems enabling the Semantic Web. Caroline Herssens received a Master Degree in Computer Science in 2005 at the Université de Louvain. In 2006, she graduated a Master in Business and Administration from the University of Louvain, with a supply chain management orientation. She is currently a teaching and research assistant and has started a Ph.D. thesis at the information systems research unit at Université de Louvain. Her research interests comprise service-oriented computing, conceptual modeling and information systems engineering. Stéphane Faulkner is an Associate Professor in Technologies and Information Systems at the University of Namur (FUNDP) and an Invited Professor at the Louvain School of Management of the Université de Louvain (UCL). His current research interests revolve around requirements engineering and the development of modeling notations, systematic methods and tool support for the development of multi-agent systems, database and information systems. 相似文献
Stéphane FaulknerEmail: |
Ivan J. Jureta has, after graduating, summa cum laude, received the Master in Management and Master of International Management, respectively, at the Université de Louvain, Belgium, and the London School of Economics, both in 2005. He is currently completing his Ph.D. thesis at the University of Namur, Belgium, under Prof. Stéphane Faulkner’s supervision. His thesis focuses on quality management of adaptable and open service-oriented systems enabling the Semantic Web. Caroline Herssens received a Master Degree in Computer Science in 2005 at the Université de Louvain. In 2006, she graduated a Master in Business and Administration from the University of Louvain, with a supply chain management orientation. She is currently a teaching and research assistant and has started a Ph.D. thesis at the information systems research unit at Université de Louvain. Her research interests comprise service-oriented computing, conceptual modeling and information systems engineering. Stéphane Faulkner is an Associate Professor in Technologies and Information Systems at the University of Namur (FUNDP) and an Invited Professor at the Louvain School of Management of the Université de Louvain (UCL). His current research interests revolve around requirements engineering and the development of modeling notations, systematic methods and tool support for the development of multi-agent systems, database and information systems. 相似文献
23.
User Activities Outliers Detection; Integration of Statistical and Computational Intelligence Techniques 下载免费PDF全文
In this article, a hybrid technique for user activities outliers detection is introduced. The hybrid technique consists of a two‐stage integration of principal component analysis and fuzzy rule‐based systems. In the first stage, the Hamming distance is used to measure the differences between different activities. Principal component analysis is then applied to the distance measures to find two indices of Hotelling's T2 and squared prediction error. In the second stage of the process, the calculated indices are provided as inputs to the fuzzy rule‐based systems to model them heuristically. The model is used to identify the outliers and classify them. The proposed system is tested in real home environments, equipped with appropriate sensory devices, to identify outliers in the activities of daily living of the user. Three case studies are reported to demonstrate the effectiveness of the proposed system. The proposed system successfully identifies the outliers in activities distinguishing between the normal and abnormal behavioral patterns. 相似文献
24.
Ton HellingsJohan S.H. van Leeuwaarden Sem C. Borst Dee Denteneer 《Performance Evaluation》2011,68(8):728-746
CSMA is the predominant distributed access protocol for wireless mesh networks. Originally designed for single-hop settings, CSMA can exhibit severe performance problems in multi-hop networks in terms of stability and end-to-end throughput. To ensure a smoother flow of packets, we examine an enhancement referred to as Extra Back-off (EB) flow control. In this enhanced scheme a node remains silent for a certain extra back-off time (imposed on top of the usual back-off time that is part of CSMA) after it has transmitted a packet, to give both the downstream and upstream neighbors the opportunity to transmit. EB flow control entails only a small modification to CSMA, preserving its distributed character. In order to examine the performance of EB flow control, we analyze a novel class of Markov models at the interface between classical tandem queues and interacting particle systems. The results demonstrate that EB flow control provides an effective mechanism for improving the end-to-end throughput performance. 相似文献
25.
Ziemkiewicz C Kosara R 《IEEE transactions on visualization and computer graphics》2008,14(6):1269-1276
The nature of an information visualization can be considered to lie in the visual metaphors it uses to structure information. The process of understanding a visualization therefore involves an interaction between these external visual metaphors and the user's internal knowledge representations. To investigate this claim, we conducted an experiment to test the effects of visual metaphor and verbal metaphor on the understanding of tree visualizations. Participants answered simple data comprehension questions while viewing either a treemap or a node-link diagram. Questions were worded to reflect a verbal metaphor that was either compatible or incompatible with the visualization a participant was using. The results suggest that the visual metaphor indeed affects how a user derives information from a visualization. Additionally, we found that the degree to which a user is affected by the metaphor is strongly correlated with the user's ability to answer task questions correctly. These findings are a first step towards illuminating how visual metaphors shape user understanding, and have significant implications for the evaluation, application, and theory of visualization. 相似文献
26.
Random multispace quantization as an analytic mechanism for BioHashing of biometric and random identity inputs 总被引:2,自引:0,他引:2
Teoh AB Goh A Ngo DC 《IEEE transactions on pattern analysis and machine intelligence》2006,28(12):1892-1901
Biometric analysis for identity verification is becoming a widespread reality. Such implementations necessitate large-scale capture and storage of biometric data, which raises serious issues in terms of data privacy and (if such data is compromised) identity theft. These problems stem from the essential permanence of biometric data, which (unlike secret passwords or physical tokens) cannot be refreshed or reissued if compromised. Our previously presented biometric-hash framework prescribes the integration of external (password or token-derived) randomness with user-specific biometrics, resulting in bitstring outputs with security characteristics (i.e., noninvertibility) comparable to cryptographic ciphers or hashes. The resultant BioHashes are hence cancellable, i.e., straightforwardly revoked and reissued (via refreshed password or reissued token) if compromised. BioHashing furthermore enhances recognition effectiveness, which is explained in this paper as arising from the random multispace quantization (RMQ) of biometric and external random inputs 相似文献
27.
Tanya Goette Caroline Collier Jennifer Daniels White 《Universal Access in the Information Society》2006,5(1):41-50
This paper focuses on Web accessibility. Relevant legislation and judicial decisions are reviewed, and prior empirical research is presented. This study presents the results from the Web accessibility analysis of the home pages of the 50 states and the District of Columbia. It found that twenty-nine percent of the home pages do not meet the requirements for Conformance Level A Web accessibility. Only one state meets Conformance Level AA standards, which are the minimum standards recommended for Web accessibility, and no state meets Conformance Level AAA standards. This paper also discusses how to address common accessibility problems.
相似文献
Tanya GoetteEmail: Phone: +1-478-4455721 |
28.
Witnessing in merging biological, social and algorithmic realities is crucial to trust, as modelled in the YUTPA framework.
Being witness and bearing witness is fundamental to human interaction. System participation in human communities of practice
challenges the notion of witnessing and therefore the ability to build trust. Nevertheless, through trial and error, people
in a variety of practices have found ways to establish the presence and develop trust in merging realities. This paper presents
the results of 20 in-depth interviews with professionals from a variety of disciplines and nations. The conclusion of cumulative
analysis is that systems do not witness themselves, but their output deeply affects the mental maps that human beings make
of each other, the world around them and their own self. Essential qualities human beings seek when being involved with other
beings are defined by granularity and reciprocity in the design of time (duration of engagement, synchronizing performance,
integrating rhythms and moments to signify), place (body sense, material interaction, emotional space and situated agency),
relation (shared meaning, engagement, reputation and use) and action (tuning, reciprocity, negotiation and quality of deeds).
By designing granular interaction in 4 dimensions, reciprocity in witnessing obtains significance and the basis for establishing
trust in a variety of presences emerges while human agency acquires potential. 相似文献
29.
Viet-Phuong Nguyen Christian Prins Caroline Prodhon 《Engineering Applications of Artificial Intelligence》2012,25(1):56-71
The two-echelon location-routing problem (LRP-2E) is raised by the design of transportation networks with two types of trips: first-level trips serving from one main depot a set of satellite depots, to be located, and second-level trips supplying customers from these satellites. In the proposed multi-start iterated local search (MS-ILS), three greedy randomized heuristics are used cyclically to get initial solutions. Each ILS run alternates between two search spaces: LRP-2E solutions, and travelling salesman (TSP) tours covering the main depot and the customers. The number of iterations allotted to a run is reduced whenever a known solution (stored in a tabu list) is revisited. MS-ILS can be reinforced by a path-relinking procedure (PR), used internally for intensification, as post-optimization, or both. On two sets with 24 and 30 LRP-2E instances, MS-ILS outperforms on average two GRASP algorithms and adding PR brings a further improvement. Our metaheuristic also surpasses a tabu search on 30 instances for a more general problem with several main depots. It is still effective on a particular case, the capacitated location-routing problem (CLRP): In a comparison with four published metaheuristics, only one (LRGTS, Prins et al., 2007) does better. 相似文献
30.
Jonathan Keller Damian Carr Frances Love Paul Grabill Hieu Ngo Perumal Shanthakumaran 《Journal of Intelligent Manufacturing》2012,23(2):205-211
The US Army has launched an aggressive program to implement condition based maintenance on its rotary wing assets. Condition
Based Maintenance takes advantage of technology developments in the areas of machinery monitoring, signal processing and fault
modeling to reduce the cost of ownership through improved maintenance procedures. Documenting the reduction in maintenance
burden, cost savings and increased safety through early detection of helicopter faults is an important step in justifying
the program. This paper describes a novel technique used to detect a serious fault in the accessory section of the AH-64D
Apache main transmission. The technique determines if the primary or secondary clutch system is driving the aircraft accessories
through a tachometer speed ratio. The method has identified three aircraft operating on the secondary system allowing Army
maintenance crews to replace the affected transmissions and quickly restore the aircraft to operational status. 相似文献