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941.
In this paper we study a class of CQ Horn functions introduced in Boros et al. (Ann Math Artif Intell 57(3–4):249–291, 2010). We prove that given a CQ Horn function f, the maximal number of pairwise disjoint essential sets of implicates of f equals the minimum number of clauses in a CNF representing f. In other words, we prove that the maximum number of pairwise disjoint essential sets of implicates of f constitutes a tight lower bound on the size (the number of clauses) of any CNF representation of f. 相似文献
942.
Idilio Drago Rafael R. R. Barbosa Ramin Sadre Aiko Pras Jürgen Schönwälder 《Journal of Network and Systems Management》2011,19(2):298-304
Following the success of the First Workshop on the Usage of NetFlow/IPFIX (Pras et al. in J Netw Syst Manag 17(4), 2009) in 2008, the European EMANICS Network of Excellence organized a second workshop
in October 2009, held at Jacobs University Bremen. This report summarizes the workshop and presents its main conclusions. 相似文献
943.
Christos Bouras Apostolos Gkamas Georgios Kioumourtzis 《Journal of Network and Systems Management》2011,19(2):143-177
In this paper, we present Adaptive Smooth Simulcast Protocol (ASSP) for simulcast transmission of multimedia data over best-effort
networks. ASSP is a new multiple-rate protocol that implements a single rate TCP-friendly protocol as the underlying congestion
control mechanism for each simulcast stream. The key attributes of ASSP are: (a) TCP-friendly behavior, (b) adaptive per-stream
transmission rates, (c) adaptive scalability to large sets of receivers and (d) smooth transmission rates that are suitable
for multimedia applications. We evaluate the performance of ASSP under an integrated simulation environment which combines
the measurements of both network and video performance metrics. We also compare ASSP against other proposed solutions and
the results demonstrate that the performance of ASSP is significantly better than the tested solutions. Finally, ASSP is a
practical solution with very low implementation complexity for video transmission over best-effort networks. 相似文献
944.
945.
Anirban Sengupta Chandan Mazumdar Aditya Bagchi 《Journal of Network and Systems Management》2011,19(3):319-342
From information security point of view, an enterprise is considered as a collection of assets and their interrelationships.
These interrelationships may be built into the enterprise information infrastructure, as in the case of connection of hardware
elements in network architecture, or in the installation of software or in the information assets. As a result, access to
one element may enable access to another if they are connected. An enterprise may specify conditions on the access of certain
assets in certain mode (read, write etc.) as policies. The interconnection of assets, along with specified policies, may lead
to managerial vulnerabilities in the enterprise information system. These vulnerabilities, if exploited by threats, may cause
disruption to the normal functioning of information systems. This paper presents a formal methodology for detection of managerial
vulnerabilities of, and threats to, enterprise information systems in linear time. 相似文献
946.
Carol Fung Jie Zhang Issam Aib Raouf Boutaba 《Journal of Network and Systems Management》2011,19(2):257-277
The accuracy of detecting an intrusion within a network of intrusion detection systems (IDSes) depends on the efficiency of
collaboration between member IDSes. The security itself within this network is an additional concern that needs to be addressed.
In this paper, we present a trust-based framework for secure and effective collaboration within an intrusion detection network
(IDN). In particular, we design a trust model that allows each IDS to evaluate the trustworthiness of other IDSes based on
its personal experience. We also propose an admission control algorithm for the IDS to manage the acquaintances it approaches
for advice about intrusions. We discuss the effectiveness of our approach in protecting the IDN against common attacks. Additionally,
experimental results demonstrate that our system yields significant improvement in detecting intrusions. The trust model further
improves the robustness of the collaborative system against malicious attacks. The experimental results also support that
our admission control algorithm is effective and fair, and creates incentives for collaboration. 相似文献
947.
We present two new classifiers for two-class classification problems using a new Beta-SVM kernel transformation and an iterative
algorithm to concurrently select the support vectors for a support vector machine (SVM) and the hidden units for a single
hidden layer neural network to achieve a better generalization performance. To construct the classifiers, the contributing
data points are chosen on the basis of a thresholding scheme of the outputs of a single perceptron trained using all training
data samples. The chosen support vectors are used to construct a new SVM classifier that we call Beta-SVN. The number of chosen
support vectors is used to determine the structure of the hidden layer in a single hidden layer neural network that we call
Beta-NN. The Beta-SVN and Beta-NN structures produced by our method outperformed other commonly used classifiers when tested
on a 2-dimensional non-linearly separable data set. 相似文献
948.
Javier Sánchez-Monedero Pedro A. Gutiérrez F. Fernández-Navarro C. Hervás-Martínez 《Neural Processing Letters》2011,34(2):101-116
Recently, a multi-objective Sensitivity–Accuracy based methodology has been proposed for building classifiers for multi-class problems. This technique is especially suitable for imbalanced and multi-class datasets. Moreover, the high computational cost of multi-objective approaches is well known so more efficient alternatives must be explored. This paper presents an efficient alternative to the Pareto based solution when considering both Minimum Sensitivity and Accuracy in multi-class classifiers. Alternatives are implemented by extending the Evolutionary Extreme Learning Machine algorithm for training artificial neural networks. Experiments were performed to select the best option after considering alternative proposals and related methods. Based on the experiments, this methodology is competitive in Accuracy, Minimum Sensitivity and efficiency. 相似文献
949.
Chung-Ming Kuo Wei-Han Chang Min-Yuan Fang Ching-Hsuan Lin 《Multimedia Tools and Applications》2011,55(3):399-422
In this paper, we present an effective and efficient framework for baseball video scene classification. The results of scene
classification can be able to provide the ground for baseball video abstraction and high-level event extraction. In general,
most conventional approaches are shot-based, which shot change detection and key-frame extraction are necessary prerequisite
procedures. On the contrary, we propose a frame-based approach. In our scene classification framework, an efficient playfield
segmentation technique is proposed, and then the reduced field maps are utilized as scene templates. Because the shot change
detection and the key-frame extraction are not required in proposed method, the new framework is very simple and efficient.
The experimental results have demonstrated that the effectiveness of our proposed framework for baseball videos scene classification,
and it can be easily extended the template-based approach to other kinds of sports videos. 相似文献
950.
Feature Extraction Using Laplacian Maximum Margin Criterion 总被引:1,自引:0,他引:1
Feature extraction by Maximum Margin Criterion (MMC) can more efficiently calculate the discriminant vectors than LDA, by
avoiding calculation of the inverse within-class scatter matrix. But MMC ignores the local structures of samples. In this
paper, we develop a novel criterion to address this issue, namely Laplacian Maximum Margin Criterion (Laplacian MMC). We define
the total Laplacian matrix, within-class Laplacian matrix and between-class Laplacian matrix by using the similar weight of
samples to capture the scatter information. Laplacian MMC based feature extraction gets the discriminant vectors by maximizing
the difference between between-class laplacian matrix and within-class laplacian matrix. Experiments on FERET and AR face
databases show that Laplacian MMC works well. 相似文献