首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
 鉴于应用支持向量机进行说话人识别过度依赖于选择核函数的问题,提出一种基于组合核函数支持向量机(SVM)的说话人识别方法.对多项式核函数、径向基核函数进行线性加权,构建既具有全局核函数优点又具有局部核函数优点的组合核函数,并通过多重网格搜索调节权重系数使组合核函数适用于当前数据分布,确定组合核函数SVM 的最优参数,实现对说话人的有效识别.对TIMIT 数据集和含噪声数据集的仿真实验显示,基于组合核函数SVM 的说话人识别性能明显优于单一的多项式核函数、径向基核函数和线性核函数.  相似文献   

2.
基于支持向量机核函数的条件,将Sobolev Hilbert空间的再生核函数和Sig核函数进行有效的线性混合,给出一种新的支持向量机的混合核函数,并提出一种基于再生核的混合核函数支持向量机回归模型,该回归模型兼具了全局核函数与局部核函数的优点,且算法的复杂度被降低.仿真实验结果表明:最小二乘支持向量机的核函数采用基于再生核的混合核函数是可行的,回归的效果比单核函数可以更为细腻.  相似文献   

3.
多任务核的性质研究较少。应用多任务核的刻画定理,给出多任务核的若干性质,主要包括多任务核空间结构、沿对角线平移性质、多任务核的Kronecker乘积相关的几个性质,为多任务核学习实验中选择多任务核提供必要的方法和依据。  相似文献   

4.
 核数据特别是中子核数据是核物理基础研究、核能开发与利用以及核技术发展的基础数据,是连接核物理基础研究与核技术应用的重要桥梁,其质量直接关系到与核相关产品的有效性、安全性与经济性。概述了核数据、核数据用途以及国内外核数据发展动态,分析了国内核数据工作发展的差距,总结了国外相关核数据工作经验以及给中国核数据工作带来的启示,提出了在现有基础上如何发展中国的核数据研究工作的建议。  相似文献   

5.
射电源的流量密度与核主导系数的关系及相对论束流模型   总被引:1,自引:0,他引:1  
计算了2个河外射电源样本的核主导系数,并研究了核主导系数与核及延展元的流量密度的关系。结果显示:当核主导系数较小时,核主导系数与核流量密度线性相关;当核主导系数较大时,核流量密度与核主导系数没有相关,而与延展元流量有线性相关。因此,2个样本的这些关系依赖于流量密度与核主导系数,利用相对论喷流模型能解释用2个样本所得到的相关结果。  相似文献   

6.
针对图的相似性问题,提出了基于生成树的回路核,其中包括基于最小生成树的回路核、基于最大生成树的回路核、基于最小生成树或最大生成树的回路核、基于最小生成树与最大生成树的回路核、基于混合生成树的回路核、基于赋权混合生成树的回路核.结果表明,所定义的基于生成树的回路核是可计算的、正定的;在实验中,回路核的识别率高于通路核的识别率,最高可达100%.  相似文献   

7.
基于切比雪夫正交多项式,有人提出了第一类与第二类切比雪夫核函数,文章用反例证明了所提出的第二类切比雪夫核函数不是核函数,并重新建立了第二类切比雪夫核函数.并在双螺旋集和标准UCI数据集上与第一类切比雪夫核及常用的核函数(多项式核、高斯核)进行了对比试验,实验表明该核具有良好的泛化性能.  相似文献   

8.
核方法利用核函数可以有效地解决非线性问题,在药物构效关系领域得到了广泛的应用.本文提出了一种新的弹性核k-最近邻算法(EKk-NN).首先,基于加权多项式核和径向基函数核构造了一种信息丰富的弹性核,所构造的弹性核能有效地利用局部核和全局核的优点,同时也为构造核函数提供了一种可行的方法;然后,在核方法的框架下,将弹性核耦合到k-最近邻算法.实际数据集的实验和分析表明,EKk-NN能明显提高分类性能.  相似文献   

9.
针对大规模软件宏观拓扑结构体现出的层次特征,基于大量开源软件结构核数的统计数据,分析了节点核数的分布及与度值的相关性、最高核节点对各层的影响力,以及软件结构核数的演化趋势.分析结果表明,软件结构的核数普遍不大,节点核数分布具有无尺度特征,最高核节点影响力巨大;低度值节点的核数与其度值具有一定的正相关性,但是核数达到一定值后不再随节点度值增大,软件演化中其核数以及核心框架保持稳定.  相似文献   

10.
支持向量机及核函数研究   总被引:4,自引:0,他引:4  
对核函数进行了初步探讨,从理论上研究了多项式核函数参数的选择问题,从实验角度对多项式核函数与径向基核函数进行了比较分析,并阐述了Sigmoid核函数的特点,可作为一般SVM分类问题选择核函数及核函数参数范围的依据.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

19.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

20.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号