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851.
本文以我校研制的PDV-Ⅲ型、 PDV-Ⅰ型数字阀及其组成系统为对象,建立了它们的数学模型,提出了一种解液压系统非线性微分方程的实用型方法——变微分方程等数法,并以阶跃和脉冲输入,进行了动态数字仿真。所得的结论,具有一定的指导意义。 相似文献
852.
853.
KANGDa-zhou XUBao-wen LUJian-jiang WANGPeng LIYan-hui 《武汉大学学报:自然科学英文版》2004,9(5):575-579
This paper introduces the definition and calculation of the association matrix between ontologies, h uses the association matrix to describe the relations between concepls ill different ontologics and uses concept vectors to represent queries; then computes the vectors with the association matrix in order to rewrite queries, This paper proposes a simple method of querying through heterogeneous Ontology using association matrix. This method is based on the correctness of approximate information filtering theory; and it is simple to be implemented and expected to run quite fast. 相似文献
854.
杭州市"构筑大都市,建设新天堂"人才战略的思考 总被引:1,自引:0,他引:1
王康 《杭州师范学院学报(自然科学版)》2004,3(6):464-466
在分析杭州市人才战略的宏观背景、杭州市人才工作现状的基础上,比较系统地论述了杭州市"构筑大都市,建设新天堂"的人才战略育人战略、引智战略、人才市场发展战略、创业环境营造战略. 相似文献
855.
This paper discusses the existence and uniqueness of the generalized solution in the sense of Colombeau to the Benjamin-Ono (B-O) equation and the relationship between the new generalized solution and the classical solution. 相似文献
856.
Intrusion detection using rough set classification 总被引:6,自引:0,他引:6
Recently machine learning-based intrusion detection approaches have been subjected to extensive researches because they can detect both misuse and anomaly. In this paper, rough set classification (RSC), a modern learning algorithm, is used to rank the features extracted for detecting intrusions and generate intrusion detection models. Feature ranking is a very critical step when building the model. RSC performs feature ranking before generating rules, and converts the feature ranking to minimal hitting set problem addressed by using genetic algorithm (GA). This is done in classical approaches using Support Vector Machine (SVM) by executing many iterations, each of which removes one useless feature. Compared with those methods, our method can avoid many iterations. In addition, a hybrid genetic algorithm is proposed to increase the convergence speed and decrease the training time of RSC. The models generated by RSC take the form of "IF-THEN" rules, which have the advantage of explication. Tests and comparison of RSC with SVM on DARPA benchmark data showed that for Probe and DoS attacks both RSC and SVM yielded highly accurate results (greater than 99% accuracy on testing set). 相似文献
857.
Beer fermentation is a dynamic process that must be guided along a temperature profile to obtain the desired results. Ant colony system algorithm was applied to optimize the kinetic model of this process. During a fixed period of fermentation time, a series of different temperature profiles of the mixture were constructed. An optimal one was chosen at last. Optimal temperature profile maximized the final ethanol production and minimized the byproducts concentration and spoilage risk. The satisfactory results obtained did not require much computation effort. 相似文献
858.
介绍纳米晶软磁合金的各向异性理论及FINEMET、NANOPERM、HITPERM等3种典型纳米晶软磁材料的研究进展,对于高温条件下使用的Fe Co基纳米晶软磁合金进行了讨论及展望. 相似文献
859.
康承华 《福州大学学报(自然科学版)》1982,(1):79-86
本文系统化了非平衡热力学和耗散结构的若干辩证法问题,同时,提出了平衡热力学、线性热力学和非线性热力学的适用条件及关系.这些关系写成一表以便互相比较.文章认为非线性热力学是普遍的理论,它能应用到远离平衡态,然而,这远离平衡仍是有限的.远离平衡是相对于近平衡的概念,其精确定义是不满足JK=∑iLKiXi的非平衡态. 相似文献
860.
Calcineurin (CN) is thought to play a role in the synaptic plastivity and long-term potentiation (LTP) in the hippocampus.
Based on two LTP models in vivo, a specific inhibitor cyclosporin A (CsA) of CN was observed, which affected LTP in the hippocampal dentate gyrus of the
rats. The results indicated that CsA blocked LTP induced by high frequency stimulation (HFS) partly, but it had no effect
on the decrease of the onset and peak latency of population spikes (PS) except that it reduced the increase of the amplitude
after HFS. On the other hand, CsA blocked LTP induced by ginsenosides (GSS) completely. It suppressed the GSS-enhanced amplitude
of PS reversibly and blocked the decrease of the peak latency of PS induced by the GSS. These results suggest that the postsynaptic
CN plays a role in the induction of LTP in the hippocampus of the rats. 相似文献