共查询到19条相似文献，搜索用时 125 毫秒
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运用启发式方法和RBFNN方法分别建立了描述65个胺类和酚类衍生物的结构与其生物分配胶束色谱保留值之间的线性和非线性QSRR模型.RBFNN模型的训练集、预测集的判定系数（R2）分别为0.9301和0.9046.结果表明,RBFNN模型性能要优于HM.用这两种方法建立起来的模型,可以用来尝试预测更多的有机污染物在模拟的生物环境——生物分配胶束色谱中的保留值.如果预测的污染物的保留值越小,初步可以判断出该化合物越容易透过生物膜,对生物就具有更强的毒性. 相似文献
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文章对径向基神经元网络（Radial Basis Function Neural Networks,以下简称为RBFNN）结构进行了分析,提出了应用遗传算法训练径向基网络的算法,并将该算法训练的网络用于10个数字的识别,相对于最近邻聚类学习算法和BP网络来说,识别效果和精度均有提高。 相似文献
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Calculation method of ship collision force on bridge using artificial neural network 总被引：1，自引：0，他引：1
Ship collision on bridge is a dynamic process featured by high nonlinearity and instantaneity. Calculating ship-bridge collision force typically involves either the use of design-specification-stipulated equivalent static load, or the use of finite element method （FEM） which is more time-consuming and requires supercomputing resources. In this paper, we proposed an alternative approach that combines FEM with artificial neural network （ANN）. The radial basis function neural network （RBFNN） employed for calculating the impact force in consideration of ship-bridge collision mechanics. With ship velocity and mass as the input vectors and ship collision force as the output vector, the neural networks for different network parameters are trained by the learning samples obtained from finite element simulation results. The error analyses of the learning and testing samples show that the proposed RBFNN is accurate enough to calculate ship-bridge collision force. The input-output relationship obtained by the RBFNN is essentially consistent with the typical empirical formulae. Finally, a special toolbox is developed for calculation effi- ciency in application using MATLAB software. 相似文献
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项目加权关联规则挖掘中,权值反映了数据的重要程度,权值对项目支持度有加强或减弱作用.通过比较M INWAL（O）、M INWAL（W）等加权关联规则挖掘模型,分析了权值对加权关联规则挖掘产生的影响,并针对M INWAL（W）模型在加权候选频繁项目集剪枝方面存在的不足,利用支持度下界对剪枝策略进行了改进,从而有效地减少挖掘过程的计算量. 相似文献
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澄清工段是亚硫酸法生产蔗糖的关键过程之一,而pH值又是该过程最关键的工艺指标,能否将其pH值稳定地控制在要求范围将影响整个糖厂产量和白糖质量．由于该过程是一个复杂的物理、化学过程,具有多输入、大滞后、强非线性、时变参数等特点,因此该过程pH值的稳定控制和优化问题一直没有得到很好的解决．采用径向基函数神经网络（RadialBasisFunctionNeuralNetwork,RBFNN）来建立该过程的神经网络模型．然后利用RBFNN来设计基于启发式动态规划（HeuristicDynamicProgramming,HDP）方法的优化控制器．仿真结果表明该方法可以取得满意的控制效果,为解决复杂非线性动态系统的优化控制问题提供了一种新途径． 相似文献
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题目.（2005年江苏高考）如图1所示,固定的光滑竖直杆上套着一个滑块,用轻绳系着滑块绕过光滑的定滑轮,以大小恒定的拉力F拉绳,使滑块从A点起由静止开始上升.若从A点上升至B点和从B点上升至C点的过程中拉力F做的功分别为W1、W2,滑块经B、C两点时的动能分别为EkB、EkC,图中AB=BC,则一定有（A） W1＞W2.（B） W1＜W2.（C） EkB＞EkC.（D） EkB＜EkC. 相似文献
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支持向量机作为一种分类算法,虽然具有避免局部最优解、鲁棒性好等优点,但由于核函数、参数的选择等问题经常导致分割结果不理想。针对以上问题,将遗传算法（GA）和支持向量机（SVM）结合,通过遗传算法选取最优参数训练支持向量机模型,使用训练好的模型分割图像。实验结果表明,采用该算法能够得到理想的分割结果。 相似文献
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晏杰 《河北职业技术学院学报》2011,(5)
对贪婪算法的概念、特性、及其解决问题的步骤进行了阐述,结合0/1背包问题重点对贪婪算法进行了分析,总结归纳传统贪婪算法的解决方案,提出改进的贪婪算法解决策略。 相似文献
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晏杰 《廊坊师范学院学报(自然科学版)》2011,11(5)
对贪婪算法的概念、特性、及其解决问题的步骤进行了阐述,结合0/1背包问题重点对贪婪算法进行了分析,总结归纳传统贪婪算法的解决方案,提出改进的贪婪算法解决策略。 相似文献
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Li-juan XIE Xing-qian YE Dong-hong LIU Yi-bin YING 《Journal of Zhejiang University. Science. B》2008,9(12):982-989
Near-infrared (NIR) spectroscopy combined with chemometrics techniques was used to classify the pure bayberry juice and the one adulterated with 10% (w/w) and 20% (w/w) water. Principal component analysis (PCA) was applied to reduce the dimensions of spectral data, give information regarding a potential capability of separation of objects, and provide principal component (PC) scores for radial basis function neural networks (RBFNN). RBFNN was used to detect bayberry juice adulterant. Multiplicative scatter correction (MSC) and standard normal variate (SNV) transformation were used to preprocess spectra. The results demonstrate that PC-RBFNN with optimum parameters can separate pure bayberry juice samples from water-adulterated bayberry at a recognition rate of 97.62%, but cannot clearly detect water levels in the adulterated bayberry juice. We conclude that NIR technology can be successfully applied to detect water-adulterated bayberry juice. 相似文献
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Peter Bowen 《Open Learning》2013,28(2):29-31
Corporate training strategies which seek to improve the performances of organisations and their employees are now likely to incorporate a number of open learning formats. Where training strategies are geared to improving skill performances, and where the productivity of organisations depends upon such improvements, the use of open learning becomes vital. In this article, Peter Bowen, Company Training Manager of W. H. Smith & Son Limited and a Director of Management Performance Limited, considers the practice and promise of open learning as an instrument of performance training. His argument is based upon recent experience with print and computer‐based learning systems in W. H. Smith. 相似文献
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0／1背包问题属于动态规划问题，部分背包问题属于贪心算法的范畴，通过比较两种算法的联系和区别，来寻求0／1背包问题的贪心算法的条件，用贪心算法来解决部分0／1背包问题的求解。 相似文献
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曹建 《南通职业大学学报》2014,(4):99-101
通过对移动基站基本频率分配要求的分析,抽象出基本数据类型,并结合贪婪算法特性,提出一种多重贪婪实现移动基站频率分配算法,并对分配方案进行多重分析。结果表明,三次贪婪以后,扣分不会下降,在时间允许情况下,可继续进行多次贪婪,以确定最优的分配方案。 相似文献
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Hazel R. Wright 《Gender and education》2013,25(2):206-219
Reporting on a study of mature women training to work in childcare, this article demonstrates how some women choose to be part-time mothers, workers and students, wanting ‘the best of both worlds’. It presents a theory of integrated lives that contrasts with customary deficit models and shows how a series of reciprocal links bind the women's different roles together, introducing an adaptation of Coser's theory of greedy institutions to demonstrate how this is an inherently stable position. Whilst the theory can stand alone, it is usefully recast as a localised example of a capability set as it frames the co-realisable choices open to the women. Making further links with Amartya Sen's capability approach, it is suggested that we should encourage governmental interventions that enable individual choice and support those women who want to integrate their lives alongside those who seek parity in the public sphere. 相似文献
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为了提高求解0-1背包问题的效率,提出了两种贪心局部搜索算法,分别称为固定候选算法和变化候选算法.算法都以有效的方式构造好的初始解,随后执行局部搜索对其进行解质量上的改进.实验结果表明了两种算法的有效性、可行性及与价值密度贪心算法相比的优越性,同时进一步看出两种算法中变化候选算法相对较优,能够取得更好的结果. 相似文献
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为有效解决组合拍卖问题,从下模集函数最大值问题的基本结论出发,将部分穷举法与贪婪算法相结合,给出了一种求解组合拍卖问题的新算法——改进的贪婪算法,并从理论上证明了所给算法具有更好的性能保证. 相似文献