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101.
论文以2007年《涌现》杂志发表物为分析对象,讨论了当今复杂性科学探索的若干特征,对2007复杂性研究的境况做了综述,对未来的复杂性研究做了进一步的展望。 相似文献
102.
The singularly perturbed bifurcation subsystem is described, and the test conditions of subsystem persistence are deduced. By use of fast and slow reduced subsystem model, the result does not require performing nonlinear transformation. Moreover, it is shown and proved that the persistence of the periodic orbits for Hopf bifurcation in the reduced model through center manifold. Van der Pol oscillator circuit is given to illustrate the persistence of bifurcation subsystems with the full dynamic system. 相似文献
103.
基于凸多面体不确定网络化系统的鲁棒无源滤波 总被引:1,自引:0,他引:1
研究一类同时具有时变时延和测量数据丢失的不确定网络化系统的鲁棒无源滤波器设计问题。时变时延假设在一个已知的界内随机变化。测量数据的丢失是随机发生的,假设满足Bernoulli分布随机序列。采用线性矩阵不等式方法,给出了全阶和降阶的鲁棒无源滤波器存在的充分条件。所设计的滤波器使得滤波误差系统是均方指数稳定并满足给定的无源指标。最后数值仿真表明所提方法的有效性。 相似文献
104.
A new vertical handoff decision algorithm is proposed to maximize the system benefit in heterogeneous wireless networks which comprise cellular networks and wireless local area networks (WLANs). Firstly the block probability, the drop probability and the number of users in the heterogeneous networks are calculated in the channel-guard call admission method, and a function of the system benefit which is based on the new call arrival rate and the handoff call arrival rate is proposed. Then the optimal radius of WLAN is obtained by using simulation annealing (SA) method to maximize the benefit. All the nodes should handoff from cellular network to WLAN if they enter WLAN’s scope and handoff fromWLAN to cellular network if they leave the scope. Finally, the algorithm in different new call arrival rates and handoff call arrival rates is analyzed and results show that it can achieve good effects. 相似文献
105.
Automatic patent document summarization for collaborative knowledge systems and services 总被引:1,自引:0,他引:1
Engineering and research teams often develop new products and technologies by referring to inventions described in patent
databases. Efficient patent analysis builds R&D knowledge, reduces new product development time, increases market success,
and reduces potential patent infringement. Thus, it is beneficial to automatically and systematically extract information
from patent documents in order to improve knowledge sharing and collaboration among R&D team members. In this research, patents
are summarized using a combined ontology based and TF-IDF concept clustering approach. The ontology captures the general knowledge
and core meaning of patents in a given domain. Then, the proposed methodology extracts, clusters, and integrates the content
of a patent to derive a summary and a cluster tree diagram of key terms. Patents from the International Patent Classification
(IPC) codes B25C, B25D, B25F (categories for power hand tools) and B24B, C09G and H011 (categories for chemical mechanical
polishing) are used as case studies to evaluate the compression ratio, retention ratio, and classification accuracy of the
summarization results. The evaluation uses statistics to represent the summary generation and its compression ratio, the ontology
based keyword extraction retention ratio, and the summary classification accuracy. The results show that the ontology based
approach yields about the same compression ratio as previous non-ontology based research but yields on average an 11% improvement
for the retention ratio and a 14% improvement for classification accuracy. 相似文献
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109.
研究了山东省奶业发展中存在的问题,并通过战略研究寻找解决问题的办法。提出了山东省奶业发展10项战略措施,可供政府部门、加工企业和饲养业决策参考。图1,表1,参2。 相似文献
110.