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排序方式: 共有685条查询结果,搜索用时 15 毫秒
81.
为了有效解决专利文献中术语抽取问题,提出采用字符串之间的结合强度融合词性过滤法抽取术语的方法.根据专利文献中术语出现的特点,提出了字符串之间的边界结合度方法和字符串之间的串边结合度方法,度量了字符串间的结合强度.在此基础之上,根据术语内部结构中词性的组成特点,提出了术语双字词性过滤的方法,并与结合强度的计算方法进行融合.实验结果表明,该方法对中文专利术语抽取有很好的效果,平均正确率为80.24%,平均召回率为80.61%. 相似文献
82.
In this paper, we investigate the robust exponential stability for stochastic reaction-diffusion uncertain fuzzy neural networks with mixed delays and Markovian jump parameters. By constructing a suitable Lyapunov functional and utilizing some inequality techniques, we obtain sufficient conditions for the exponential stability of the equilibrium solution. The obtained stability criteria can be easily checked by linear matrix inequality (LMI) techniques. Finally numerical examples are provided to illustrate the obtained theoretical result. 相似文献
83.
Note that the conservatism of the delay-dependent stability criteria can be reduced by increasing the integral terms in Lyapunov–Krasovskii functional (LKF). This brief revisits the stability problem for a class of linear time-delay systems via multiple integral approach. The novelty of this brief lies in that a Wirtinger-based multiple integral inequality is employed to estimate the derivative of a class of LKF with multiple integral terms. Based on these innovations, a new delay-dependent stability criterion is derived in terms of linear matrix inequalities. Two numerical examples are exploited to demonstrate the effectiveness and superiority of the proposed method. 相似文献
84.
Utilizing Genetic Algorithms to Optimize Membership Functions for Fuzzy Weighted Association Rules Mining 总被引:1,自引:2,他引:1
It is not an easy task to know a priori the most appropriate fuzzy sets that cover the domains of quantitative attributes
for fuzzy association rules mining. In general, it is unrealistic that experts can always provide such sets. And finding the
most appropriate fuzzy sets becomes a more complex problem when items are not considered to have equal importance and the
support and confidence parameters required for the association rules mining process are specified as linguistic terms. Existing
clustering based automated methods are not satisfactory because they do not consider the optimization of the discovered membership
functions. In order to tackle this problem, we propose Genetic Algorithms (GAs) based clustering method, which dynamically
adjusts the fuzzy sets to provide maximum profit based on user specified linguistic minimum support and confidence terms.
This is achieved by tuning the base values of the membership functions for each quantitative attribute with respect to two
different evaluation functions maximizing the number of large itemsets and the average of the confidence intervals of the
generated rules. To the best of our knowledge, this is the first effort in this direction. Experiments conducted on 100 K
transactions from the adult database of United States census in year 2000 demonstrate that the proposed clustering method
exhibits good performance in terms of the number of produced large itemsets and interesting association rules. 相似文献
85.
无机非金属增强铸造金属复合材料常用术语分析 总被引:1,自引:0,他引:1
总结了用无机非金属材料增强金属材料液态成形中所遇到的常用概念、术语及定义,介绍了复合材料铸造中所用材料、工艺方法的基本分类。 相似文献
86.
Grounding spatial language in perception: An empirical and computational investigation. 总被引:1,自引:0,他引:1
The present paper grounds the linguistic categorization of space in aspects of visual perception; specifically, the structure of projective spatial terms such as above are grounded in the process of attention and in vector-sum coding of overall direction. This is formalized in the attentional vector-sum (AVS) model. This computational model accurately predicts linguistic acceptability judgments for spatial terms, under a variety of spatial configurations. In 7 experiments, the predictions of the AVS model are tested against those of 3 competing models. The results support the AVS model and disconfirm its competitors. The authors conclude that the structure of linguistic spatial categories can be partially explained in terms of independently motivated perceptual processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
87.
John P. Borg Dennis Grady John R. Cogar 《International Journal of Impact Engineering》2001,26(1-10):65-76
This analysis pursues the underlying physics governing the expansion, dispersal and breakup of a thin walled steel right circular cylinder filled with liquid after being impacted by a high velocity aluminum sphere. The impact generates a radially expanding coherent thin shell of liquid which stays together to at least a diameter 8 times that of the original cylinder. An instability criterion is proposed and developed based on the opposing forces of stabilizing inertial pressures and destabilizing viscous resistance. This criterion is compared to test data where possible in order to ascertain its ability to predict liquid breakup of the shell. The breakup theory developed here predicts the extensive expansion of the unthickened liquid prior to fragmentation as observed in the experiments. This result lends some credence to the underlying physics pursued here and its ability to predict the onset of liquid fragmentation. 相似文献
88.
通过对国外大型纸业公司的生产、营销、管理等方面的分析,探讨了我国纸业公司与国外大企业的差距及今后的发展对策。 相似文献
89.
《Journal of Nuclear Science and Technology》2013,50(5):476-487
If an accident resulting in an emergency occurs at a nuclear facility, the emergency technical advisory body (ETAB) is asked to make technical advice to the national government for emergency response. In order for the ETAB to carry out its role, a significant amount of materials containing information on nuclear power plants is prepared in the ETAB. These materials are all paper copies and very voluminous. Therefore it is required that they should be computerized for more effective use. Further, methods should be developed which aid the ETAB to understand the status of the affected facility and to predict potential radioactivity release to the environment. To support the ETAB's activities in an emergency, the materials have been computerized as databases for more effective and quick use of them, and an expert system has been developed to quickly predict accident progression and environmental fission product release with the multivariate analysis method. The databases and the expert system have been unified to be a system of COSTA. The first phase of developing COSTA has been completed in FY1992. This paper describes the present status of development of COSTA. 相似文献
90.
西气东输工程及其管线管的选择 总被引:9,自引:3,他引:6
介绍了“西气东输”工程概况,对“西气东输”工程所用管线管在材质、钢管类型的选择输送及压力等选择原则方面做了介绍与分析,并对我国天然气地干线管网发展规划及管线管需求做了预测,提出了推进国产管线管技术发展的建议。 相似文献