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991.
根据多模型可以改善模型估计精度,提高泛化性的思想,提出了1种粗糙分类器的多模型软测量建模方法。该方法采用聚类、分类相结合的方式对数据进行分组训练,在一定程度上消除了矛盾样本点可能对模型精度造成的影响。对各组样本利用支持向量回归机建立回归子模型,得到多模型软测量系统。同时,通过向粗糙集引入相似度作为评价样本间相似性的指标,解决了传统粗糙集无法识别训练样本集中未出现过的模式的问题。通过引入概率测度,利用概率公式作为粗糙集分类的决策规则,简化了算法。基于上述理论构造的粗糙分类器,有效地提高了分类器的分类精度,确保了各子模型的估计精度。将该方法应用于双酚A生产过程的质量指标软测量建模,仿真结果表明了该算法的有效性。 相似文献
992.
本文对非平衡类数据分类问题进行了概述。首先在简单介绍非平衡类数据基本概念的基础上,分析了非平衡类数据引起的问题及其导致分类性能下降的原因;然后介绍了目前主要的解决方法,分析了现有处理方法的优缺点;最后讨论了未来的研究方向。 相似文献
993.
基于Stacking组合分类方法的中文情感分类研究 总被引:3,自引:1,他引:2
情感文本分类(简称情感分类)是一种面向主观信息分类的文本分类任务。目前,由于其广泛的应用前景,该任务在自然语言处理研究领域中得到了普遍关注,相继出现多种用于情感文本分类的有监督的分类方法。该文具体研究四种不同的分类方法在中文情感分类上的应用,并且采用一种基于Stacking的组合分类方法,用以组合不同的分类方法。实验结果表明,该组合方法在所有领域都能够获得比最好基分类方法更好的分类效果。从而克服了分类方法领域依赖的困境(不同领域需要选择不同基分类方法才能获得更好的分类结果)。 相似文献
994.
根据稀疏表示分类器的分类准则,提出了一种稀疏表示分类器最佳判别的投影方法。该方法优化两个目标,一是数据集的类间和类内稀疏重构误差,二是数据集中区分度。优化结果使样本投影到低维空间中,确保SRC具有更好的分类性能。在AR和Yale数据库上进行人脸识别实验,并与几种流行的方法进行了比较,结果表明所提出的方法具有良好的有效性和鲁棒性。 相似文献
995.
A dual‐tree complex wavelet transform‐based approach for recognition of power system transients 下载免费PDF全文
The present paper proposes a dual‐tree complex wavelet transform (DTCWT) based approach for recognition of power system transients. Several researchers, all over the world, have so far attempted to solve the problems of recognition of power system transients, hybridizing transform‐based techniques with popular computational intelligence based tools, for example, using wavelet transform and S‐transform for feature extraction, followed by artificial neural networks (ANN) or fuzzy logic‐based classifiers. The proposed method of hybridizing DTCWT‐based feature extraction with ANN‐based classification could efficiently detect several commonly occurring power quality (PQ) disturbance events. The PQ disturbance events considered include four different transient conditions, namely transients due to capacitor switching, transformer inrush currents, transients due to motor switching and transients due to short circuit faults. A detailed performance comparison with several contemporary, competing methods existing in the literatures for similar problems aptly demonstrates the suitability of the proposed method. 相似文献
996.
997.
Steganographic techniques accomplish covert communication by embedding secret messages into innocuous digital images in ways that are imperceptible to the human eye. This paper presents a novel passive steganalysis strategy in which the task is approached as a pattern classification problem. A critical part of the steganalyser design depends on the selection of informative features. This paper is aimed at proposing a novel attack with improved performance indices with the following implications: 1) employing higher order statistics from a curvelet sub-band image representation that offers better discrimination ability for detecting stego anomalies in images, as compared to other conventional wavelet transforms; 2) increasing the sensitivity and specificity of the system by the feature reduction phase; 3) realizing the system using an efficient classification engine, a neuro-C4.5 classifier, which provides better classification rate. An extensive experimental evaluation on a database containing 5600 clean and stego images shows that the proposed scheme is a state-of-the-art steganalyser that outperforms other previous steganalytic methods. 相似文献
998.
基于AdaBoost的眉毛检测与定位 总被引:1,自引:0,他引:1
文章利用Haar-Like小波及其扩展特征,把AdaBoost算法应用于眉毛的自动检测与定位。实验数据包括114人的228幅眉毛图像,每人闭眼和睁眼各一幅,分别用于训练和测试,大小均为768×586。通过把这些图像缩小1/10后进行AdaBoost训练,解决了其速度较慢和对内存需求较高的问题。实验结果表明,AdaBoost级联分类器的训练耗时约2.7s,测试耗时每幅图像约24ms,对眉毛检测和定位测试的精度达到了97.4%。 相似文献
999.
Sang-Woon Kim Author Vitae 《Pattern recognition》2009,42(11):2695-65
In most pattern recognition (PR) applications, it is advantageous if the accuracy (or error rate) of the classifier can be evaluated or bounded prior to testing it in a real-life setting. It is also well known that if the two class-conditional distributions have a large overlapping volume (almost all the available work on “overlapping of classes” deals with the case when there are only two classes), the classification accuracy is poor. This is because if we intend to use the classification accuracy as a criterion for evaluating a PR system, the points within the overlapping volume tend to lead to maximal misclassification. Unfortunately, the computation of the indices which quantify the overlapping volume is expensive. In this vein, we propose a strategy of using a prototype reduction scheme (PRS) to approximately, but quickly, compute the latter. In this paper, we demonstrate, first of all, that this is an extremely expedient proposition. Indeed, we show that by completely discarding (we are not aware of any reported scheme which discards “irrelevant” sample (training) points, and which simultaneously attains to an almost-comparable accuracy) the points not included by the PRS, we can obtain a reduced set of sample points, using which, in turn, the measures for the overlapping volume can be computed. The value of the corresponding figures is comparable to those obtained with the original training set (i.e., the one which considers all the data points) even though the computations required to obtain the prototypes and the corresponding measures are significantly less. The proposed method has been rigorously tested on artificial and real-life datasets, and the results obtained are, in our opinion, quite impressive—sometimes faster by two orders of magnitude. 相似文献
1000.
Toward a Model of Intelligence as an Economy of Agents 总被引:2,自引:0,他引:2
A market-based algorithm is presented which autonomously apportions complex tasks to multiple cooperating agents giving each agent the motivation of improving performance of the whole system. A specific model, called The Hayek Machine is proposed and tested on a simulated Blocks World (BW) planning problem. Hayek learns to solve more complex BW problems than any previous learning algorithm. Given intermediate reward and simple features, it has learned to efficiently solve arbitrary BW problems. The Hayek Machine can also be seen as a model of evolutionary economics. 相似文献