全文获取类型
收费全文 | 541篇 |
免费 | 12篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 86篇 |
机械仪表 | 3篇 |
建筑科学 | 14篇 |
能源动力 | 19篇 |
轻工业 | 21篇 |
水利工程 | 4篇 |
无线电 | 97篇 |
一般工业技术 | 59篇 |
冶金工业 | 11篇 |
原子能技术 | 1篇 |
自动化技术 | 233篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 4篇 |
2021年 | 8篇 |
2020年 | 3篇 |
2019年 | 6篇 |
2018年 | 12篇 |
2017年 | 7篇 |
2016年 | 22篇 |
2015年 | 14篇 |
2014年 | 26篇 |
2013年 | 32篇 |
2012年 | 35篇 |
2011年 | 48篇 |
2010年 | 42篇 |
2009年 | 42篇 |
2008年 | 39篇 |
2007年 | 31篇 |
2006年 | 32篇 |
2005年 | 19篇 |
2004年 | 16篇 |
2003年 | 17篇 |
2002年 | 18篇 |
2001年 | 9篇 |
2000年 | 7篇 |
1999年 | 6篇 |
1998年 | 8篇 |
1997年 | 6篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1990年 | 2篇 |
1989年 | 7篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1981年 | 2篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1975年 | 1篇 |
1973年 | 2篇 |
排序方式: 共有553条查询结果,搜索用时 15 毫秒
21.
A survey and taxonomy on energy efficient resource allocation techniques for cloud computing systems
Abdul Hameed Alireza Khoshkbarforoushha Rajiv Ranjan Prem Prakash Jayaraman Joanna Kolodziej Pavan Balaji Sherali Zeadally Qutaibah Marwan Malluhi Nikos Tziritas Abhinav Vishnu Samee U. Khan Albert Zomaya 《Computing》2016,98(7):751-774
In a cloud computing paradigm, energy efficient allocation of different virtualized ICT resources (servers, storage disks, and networks, and the like) is a complex problem due to the presence of heterogeneous application (e.g., content delivery networks, MapReduce, web applications, and the like) workloads having contentious allocation requirements in terms of ICT resource capacities (e.g., network bandwidth, processing speed, response time, etc.). Several recent papers have tried to address the issue of improving energy efficiency in allocating cloud resources to applications with varying degree of success. However, to the best of our knowledge there is no published literature on this subject that clearly articulates the research problem and provides research taxonomy for succinct classification of existing techniques. Hence, the main aim of this paper is to identify open challenges associated with energy efficient resource allocation. In this regard, the study, first, outlines the problem and existing hardware and software-based techniques available for this purpose. Furthermore, available techniques already presented in the literature are summarized based on the energy-efficient research dimension taxonomy. The advantages and disadvantages of the existing techniques are comprehensively analyzed against the proposed research dimension taxonomy namely: resource adaption policy, objective function, allocation method, allocation operation, and interoperability. 相似文献
22.
Athanasios Karagiannidis Konstantinos Lagouvardos Vassiliki Kotroni Nikos Mazarakis 《International journal of remote sensing》2016,37(20):5001-5020
An analysis of selected spatiotemporal characteristics of isolated thunderstorms in relation to cloud-to-ground (CG) lightning over part of the eastern Mediterranean is performed. The purpose of the study is twofold: to better understand and improve the basic knowledge of the physical mechanisms of the phenomenon and to offer new means of nowcasting the lightning activity in such thunderstorms. Meteosat Second Generation (MSG) Rapid Scan Service (RSS) infrared imagery which offers the option of tracking the examined storms with a time frequency of 5 minutes is one of the two utilized datasets, the other being ZEUS very low frequency (VLF) lightning detection system’s CG discharge data. It was shown that a cloud top temperature of about ?20°C is required for the onset of lightning activity. A rapid drop of the cloud-top temperature of about 11°C in 5 minutes on average is observed a few minutes before or during lightning initiation. The maximization of the activity is usually quite close to the overall minimum cloud-top temperature of the cell. A temperature increase of 3.5°C from this overall minimum can mark the end of the activity, which is also associated to the time evolution of the cell’s horizontal extent. In fact, after the cell’s horizontal area stops to increase and/or starts to gradually diminish, CG lightning activity is expected to stop. 相似文献
23.
The problem of channel sharing by rate adaptive streams belonging to various classes is considered. Rate adaptation provides
the opportunity for accepting more connections by adapting the bandwidth of connections that are already in the system. However,
bandwidth adaptation must be employed in a careful manner in order to ensure that (a) bandwidth is allocated to various classes
in a fair manner (system perspective) and (b) bandwidth adaptation does not affect adversely the perceived user quality of
the connection (user quality). The system perspective aspect has been studied earlier. This paper focuses on the equally important
user perspective. It is proposed to quantify user Quality of Service (QoS) through measures capturing short and long-term
bandwidth fluctuations that can be implemented with the mechanisms of traffic regulators, widely used in networking for the
purpose of controlling the traffic entering or exiting a network node. Furthermore, it is indicated how to integrate the user
perspective metrics with the optimal algorithms for system performance metrics developed earlier by the authors. Simulation
results illustrate the effectiveness of the proposed framework.
Nikos G. Argiriou received the Diploma degree in Electrical Engineering from the Department of Electrical Engineering, Telecommunication Division, Aristotle University of Thessaloniki, Greece, in 1996. He worked as a researcher, on secure medical image transmission over networks, at the Image Processing Lab at the same university during 1996–1997. During 1998–2000 he was a researcher for the European Project Esprit Catserver concerning the use of advanced Quality of Service techniques in CATV networks. He received his Ph.D. degree at Aristotle University of Thessaloniki in 2007. His current research interests are in the development and implementation of QoS techniques for wired and wireless networks. Leonidas Georgiadis received the Diploma degree in Electrical Engineering from Aristotle University, Thessaloniki, Greece, in 1979, and his M.S. and Ph.D degrees both in Electrical Engineering from the University of Connecticut, in 1981 and 1986, respectively. From 1986 to 1987 he was Research Assistant Professor at the University of Virginia, Charlottesville. In 1987 he joined IBM T. J. Watson Research Center, Yorktown Heights as a Research Staff Member. Since October 1995, he has been with the Telecommunications Department of Aristotle University, Thessaloniki, Greece. His interests are in the area of wireless networks, high speed networks, routing, scheduling, congestion control, modeling and performance analysis. 相似文献
Leonidas GeorgiadisEmail: |
Nikos G. Argiriou received the Diploma degree in Electrical Engineering from the Department of Electrical Engineering, Telecommunication Division, Aristotle University of Thessaloniki, Greece, in 1996. He worked as a researcher, on secure medical image transmission over networks, at the Image Processing Lab at the same university during 1996–1997. During 1998–2000 he was a researcher for the European Project Esprit Catserver concerning the use of advanced Quality of Service techniques in CATV networks. He received his Ph.D. degree at Aristotle University of Thessaloniki in 2007. His current research interests are in the development and implementation of QoS techniques for wired and wireless networks. Leonidas Georgiadis received the Diploma degree in Electrical Engineering from Aristotle University, Thessaloniki, Greece, in 1979, and his M.S. and Ph.D degrees both in Electrical Engineering from the University of Connecticut, in 1981 and 1986, respectively. From 1986 to 1987 he was Research Assistant Professor at the University of Virginia, Charlottesville. In 1987 he joined IBM T. J. Watson Research Center, Yorktown Heights as a Research Staff Member. Since October 1995, he has been with the Telecommunications Department of Aristotle University, Thessaloniki, Greece. His interests are in the area of wireless networks, high speed networks, routing, scheduling, congestion control, modeling and performance analysis. 相似文献
24.
25.
Three-dimensional face recognition in the presence of facial expressions: an annotated deformable model approach 总被引:1,自引:0,他引:1
Kakadiaris IA Passalis G Toderici G Murtuza MN Lu Y Karampatziakis N Theoharis T 《IEEE transactions on pattern analysis and machine intelligence》2007,29(4):640-649
In this paper, we present the computational tools and a hardware prototype for 3D face recognition. Full automation is provided through the use of advanced multistage alignment algorithms, resilience to facial expressions by employing a deformable model framework, and invariance to 3D capture devices through suitable preprocessing steps. In addition, scalability in both time and space is achieved by converting 3D facial scans into compact metadata. We present our results on the largest known, and now publicly available, face recognition grand challenge 3D facial database consisting of several thousand scans. To the best of our knowledge, this is the highest performance reported on the FRGC v2 database for the 3D modality 相似文献
26.
Panos Vassiliadis Zografoula Vagena Spiros Skiadopoulos Nikos Karayannidis Timos Sellis 《Information Systems》2001,26(8)
Extraction-Transformation-loading (ETL) tools are pieces of software responsible for the extraction of data from several sources, their cleansing, customization and insertion into a data warehouse. Literature and personal experience have guided us to conclude that the problems concerning the ETL tools are primarily problems of complexity, usability and price. To deal with these problems we provide a uniform metamodel for ETL processes, covering the aspects of data warehouse architecture, activity modeling, contingency treatment and quality management. The ETL tool we have developed, namely
, is capable of modeling and executing practical ETL scenarios by providing explicit primitives for the capturing of common tasks.
provides three ways to describe an ETL scenario: a graphical point-and-click front end and two declarative languages: XADL (an XML variant), which is more verbose and easy to read and SADL (an SQL-like language) which has a quite compact syntax and is, thus, easier for authoring. 相似文献
27.
Vangelis Gazis Nancy Alonistioti Nikos Houssos Maria Koutsopoulou Stefan Gessler Juergen Quittek 《Journal of Network and Systems Management》2006,14(2):221-241
Mobile communications beyond 3G will integrate different (but complementary) access technologies into a common platform to deliver value-added services and multimedia content in an optimum way. However, the numerous possible configurations of mobile networks complicated the dynamic deployment of mobile applications. Therefore, research is intensely seeking a service provisioning framework that is technology-independent, supports multiple wireless network technologies, and can interwork high-level service management tasks to network management operations. This paper presents an open value chain paradigm, a model for downloadable applications and a mediating platform for service provisioning in beyond 3G mobile settings. Furthermore, we introduce mechanisms that support a coupled interaction between service deployment and network configuration operations, focusing on the dynamic provisioning of QoS state to data path devices according to the requirements of dynamically downloadable mobile value-added services (VAS).
相似文献
Vangelis GazisEmail: |
28.
Panagiotis Papadakos Nikos Armenatzoglou Stella Kopidaki Yannis Tzitzikas 《Knowledge and Information Systems》2012,30(3):493-525
Most Web Search Engines (WSEs) are appropriate for focalized search, i.e., they make the assumption that users can accurately
describe their information need using a small sequence of terms. However, as several user studies have shown, a high percentage
of search tasks are exploratory, and focalized search very commonly leads to inadequate interactions and poor results. This
paper proposes exploiting static and dynamically mined metadata for enriching web searching with exploration services. Online results clustering, which is a mining task of dynamic nature since it is based on query-dependent snippets, is useful for providing users with
overviews of the top results and thus allowing them to restrict their focus to the desired parts. On the other hand, the various
static metadata that are available to a search engine (e.g., domain, language, date, and filetype) are commonly exploited only through the
advanced (form-based) search facilities that some WSEs offer (and users rarely use). We propose an approach that combines
both kinds of metadata by adopting the interaction paradigm of dynamic taxonomies and faceted exploration, which allows the users
to restrict their focus gradually using both static and dynamically derived metadata. Special focus is given on the design
and analysis of incremental algorithms for speeding up the exploration process. The experimental evaluation over a real WSE
shows that this combination results to an effective, flexible, and efficient exploration experience. Finally, we report the
results of a user study indicating that this direction is promising in terms of user preference, satisfaction, and effort. 相似文献
29.
Nikos Papadakis Dimitris Plexousakis Myron Papadakis Harris Manifavas 《Journal of Intelligent Information Systems》2012,38(1):41-94
In this paper we study the ramification problem in the setting of temporal databases. Standard solutions from the literature
on reasoning about action are inadequate because they rely on the assumption that fluents persist, and because actions have
effects on the next situation only. In this paper we provide a solution to the ramification problem based on an extension
of the situation calculus and the work of McCain and Turner. More specifically, we study the case where there are conflicting
effects of an action, a particularly complex problem. Also we present a tool which implements the proposed solution. 相似文献
30.
Efthimios Badekas Nikos Nikolaou Nikos Papamarkos 《International journal of imaging systems and technology》2006,16(6):262-274
This article presents a new method for the binarization of color document images. Initially, the colors of the document image are reduced to a small number using a new color reduction technique. Specifically, this technique estimates the dominant colors and then assigns the original image colors to them in order that the background and text components to become uniform. Each dominant color defines a color plane in which the connected components (CCs) are extracted. Next, in each color plane a CC filtering procedure is applied which is followed by a grouping procedure. At the end of this stage, blocks of CCs are constructed which are next redefined by obtaining the direction of connection (DOC) property for each CC. Using the DOC property, the blocks of CCs are classified as text or nontext. The identified text blocks are binarized properly using suitable binarization techniques, considering the rest of the pixels as background. The final result is a binary image which contains always black characters in white background independently of the original colors of each text block. The proposed document binarization approach can also be used for binarization of noisy color (or gray‐scale) document images. Several experiments that confirm the effectiveness of the proposed technique are presented. © 2007 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 16, 262–274, 2006 相似文献