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基于聚类中值比较的WSNs故障检测算法 被引量:3
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作者 张成 《传感器与微系统》 CSCD 北大核心 2014年第4期135-138,共4页
无线传感器网络(WSNs)中的传感器件容易失效而导致测量数据不准确,因而,高效、实用的故障检测算法对于保证WSNs的感知质量非常重要。提出一种基于聚类中值比较(CBMC)的故障检测算法。不同于传统的中值比较的思想,该算法引入聚类方法对... 无线传感器网络(WSNs)中的传感器件容易失效而导致测量数据不准确,因而,高效、实用的故障检测算法对于保证WSNs的感知质量非常重要。提出一种基于聚类中值比较(CBMC)的故障检测算法。不同于传统的中值比较的思想,该算法引入聚类方法对待检测节点的邻居节点测量数据进行分组,根据分组信息计算该节点状态。仿真实验表明:CBMC算法具有较高的故障检测率(DR)和较低的故障误检率(FPR)。 展开更多
关键词 无线传感器网络 类中值比较 故障诊断 故障检测 故障容错
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几类新型中值定理中值点的渐近性
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作者 张树义 《南阳师范学院学报》 CAS 2024年第3期42-51,共10页
研究几类新型中值定理中值点的渐近性,利用比较函数和引理,在一定条件下,建立了几类新型中值定理中值点更广泛的渐近估计式,所得结果推广和改进了有关文献中的相应结果。
关键词 比较函数 新型中值定理 中值 渐近性
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基于改进K中值聚类的苹果病害叶片分割方法 被引量:8
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作者 张善文 张晴晴 +1 位作者 齐国红 周伟 《江苏农业科学》 北大核心 2017年第18期205-208,共4页
针对复杂背景下的苹果病害叶片分割问题,提出一种基于改进的K均值聚类的苹果病害叶片病斑分割方法。首先将原始叶片图像由RGB(R为红,G为绿,B为蓝)颜色空间转换到Lab(L为亮度,a为从洋红色至绿色的范围,b为从黄色至蓝色的范围)颜色空间,... 针对复杂背景下的苹果病害叶片分割问题,提出一种基于改进的K均值聚类的苹果病害叶片病斑分割方法。首先将原始叶片图像由RGB(R为红,G为绿,B为蓝)颜色空间转换到Lab(L为亮度,a为从洋红色至绿色的范围,b为从黄色至蓝色的范围)颜色空间,然后在Lab颜色空间中利用ab二维数据空间的颜色差异,以欧式距离度量像素间的相似度,使用K均值对图像进行聚类,利用数学形态学中的开闭交替滤波方法对聚类后的灰度图像进行校正,最后得到图像病斑。对3种常见苹果病害叶片图像进行分割,并与其他分割方法进行比较。结果表明,该方法效果好,其误分率为8.41%。 展开更多
关键词 K均值聚 苹果病害叶片图像 病斑分割 改进的K中值
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改进k中值聚类及其应用 被引量:1
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作者 谢明霞 郭建忠 陈科 《烟台大学学报(自然科学与工程版)》 CAS 北大核心 2010年第3期217-222,共6页
文章对划分方法、层次聚类方法以及小波变换进行了介绍,并详细分析了划分方法和层次聚类方法中存在的不足,将划分方法和层次聚类方法相结合,各取所长,提出改进的中值聚类,该方法分别从相似性度量、初始聚类簇及其簇中心的获取两方面对... 文章对划分方法、层次聚类方法以及小波变换进行了介绍,并详细分析了划分方法和层次聚类方法中存在的不足,将划分方法和层次聚类方法相结合,各取所长,提出改进的中值聚类,该方法分别从相似性度量、初始聚类簇及其簇中心的获取两方面对原始的基于划分的聚类方法进行改进.通过在混合数据聚类以及图像分割中的具体应用,验证了本文算法聚类的有效性及适用性.其中,在图像分割应用中,由于数据量的大小直接与图像本身的大小相关,当处理大型图像时,考虑首先对图像进行小波变换,通过对低频信号进行层次聚类从而能够快速有效地获取初始的聚类簇及其中心. 展开更多
关键词 划分方法 层次方法 小波变换 k中值
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达布定理和比较定理思想在中值定理类问题中的运用 被引量:1
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作者 楼红卫 《大学数学》 2017年第2期79-84,共6页
微分达布定理表明区间内的导函数具有介值性,这使得我们在考虑一些数学分析问题时,往往可以不需要最高阶导函数的连续性.而在微分方程理论中,比较定理的思想对于解的估计非常重要.本文利用比较定理的思想将中值定理类问题转化为微分方... 微分达布定理表明区间内的导函数具有介值性,这使得我们在考虑一些数学分析问题时,往往可以不需要最高阶导函数的连续性.而在微分方程理论中,比较定理的思想对于解的估计非常重要.本文利用比较定理的思想将中值定理类问题转化为微分方程解的估计问题,对于在数学分析的学习中提高学生的认识和兴趣很有意义. 展开更多
关键词 微分达布定理 比较定理 中值定理问题
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高维空间第一类曲面积分的计算及中值定理 被引量:1
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作者 刘昶 《沈阳理工大学学报》 CAS 2012年第3期42-46,共5页
目前的数学分析教材中,关于曲线积分和曲面积分的内容大多在三维欧氏空间中论述,对于高维空间中的曲面积分问题很少提及,而在许多工程应用中又需要在高维空间中计算曲面积分。讨论了高维欧氏空间中第一类曲面积分问题,推导出将光滑曲面... 目前的数学分析教材中,关于曲线积分和曲面积分的内容大多在三维欧氏空间中论述,对于高维空间中的曲面积分问题很少提及,而在许多工程应用中又需要在高维空间中计算曲面积分。讨论了高维欧氏空间中第一类曲面积分问题,推导出将光滑曲面的第一类曲面积分转化为重积分的一般公式,并将三维空间中的第一类曲面积分中值定理推广到高维的情况。 展开更多
关键词 第一曲面积分:重积分:积分中值定理
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基于非线性分数阶中值鉴别空间学习的岩爆预测方法
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作者 樊腾悦 苏树智 朱彦敏 《湖北民族大学学报(自然科学版)》 CAS 2024年第4期480-485,513,共7页
针对岩爆样本数据噪声高、数量少从而导致岩爆等级预测准确率较低的问题,提出了基于非线性分数阶中值鉴别空间学习(nonlinear fractional-order median discriminative space learning,NFMDSL)的岩爆预测方法。该方法用类中值代替类均值... 针对岩爆样本数据噪声高、数量少从而导致岩爆等级预测准确率较低的问题,提出了基于非线性分数阶中值鉴别空间学习(nonlinear fractional-order median discriminative space learning,NFMDSL)的岩爆预测方法。该方法用类中值代替类均值,构建了中值鉴别空间学习方法,更好地保留了样本的有效信息,降低了噪声对预测效果的影响。为了有效捕捉岩爆数据间的非线性鉴别结构,进一步借助核技术将样本数据投影到核空间中。此外,引入分数阶对散度矩阵的特征值和奇异值进行重新估计,可以从少量样本中提取出具有良好区分能力的岩爆特征。结果表明,NFMDSL方法在岩爆等级预测中的平均准确率达到了95.75%,相比其他方法具有更高的准确率和更强的鲁棒性。该方法能够有效应用于矿山和隧道工程领域的岩爆预测。 展开更多
关键词 岩爆预测 类中值 核技术 散度矩阵 奇异值 少量样本 矿山和隧道工程
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鉴别的局部中值保持投影及其在人脸识别中的应用 被引量:7
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作者 黄璞 唐振民 《计算机辅助设计与图形学学报》 EI CSCD 北大核心 2012年第11期1420-1425,1439,共7页
针对已有的鉴别的局部保持投影算法在特征提取问题中存在的不足,提出了鉴别的局部中值保持投影,通过最大化类间距离同时最小化类内距离寻找最佳投影矩阵,并将其用于人脸识别.该算法利用样本的类中值计算类间距离,有效地保留了图像信息;... 针对已有的鉴别的局部保持投影算法在特征提取问题中存在的不足,提出了鉴别的局部中值保持投影,通过最大化类间距离同时最小化类内距离寻找最佳投影矩阵,并将其用于人脸识别.该算法利用样本的类中值计算类间距离,有效地保留了图像信息;设计了一种不同的相似性度量机制,以保持受噪声影响较小的类内样本之间的邻域关系,从而进一步加强识别效果的鲁棒性.最后通过在ORL,Yale及AR人脸库上的实验,验证了文中算法的有效性. 展开更多
关键词 人脸识别 特征提取 线性鉴别分析 鉴别的局部保持投影 类中值
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基于文本聚类搜索引擎的查询扩展算法 被引量:3
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作者 袁津生 程超然 《计算机工程与应用》 CSCD 2012年第3期129-132,共4页
目前多数基于文本聚类搜索引擎的研究对于聚类产生的小聚类簇查询未能给出深入查询解决方案,针对此类问题提出了一种基于聚类的查询扩展算法。此算法利用簇关系树结构改进相似度公式,对目标簇提取主题词并进行二次查询后,通过K中值聚类... 目前多数基于文本聚类搜索引擎的研究对于聚类产生的小聚类簇查询未能给出深入查询解决方案,针对此类问题提出了一种基于聚类的查询扩展算法。此算法利用簇关系树结构改进相似度公式,对目标簇提取主题词并进行二次查询后,通过K中值聚类算法对查询结果进行聚类以对其进行扩展。此算法全部过程均为离线运算,旨在避免在线运算影响查询响应效率,并通过实验验证了该算法的有效性。 展开更多
关键词 K中值 主题词提取 相似度计算 查询扩展
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地震数据高维统计滤波方法 被引量:5
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作者 王福 王华忠 《石油物探》 EI CSCD 北大核心 2019年第3期335-345,共11页
地震数据的信噪比是地震波反演成像算法收敛性和结果精度的重要制约因素。基于线性信号模型的最佳预测滤波方法和基于随机信号概率分布特征的统计滤波方法是两种典型的滤波方法。重点讨论了地震数据统计滤波方法,基于实测数据的统计特征... 地震数据的信噪比是地震波反演成像算法收敛性和结果精度的重要制约因素。基于线性信号模型的最佳预测滤波方法和基于随机信号概率分布特征的统计滤波方法是两种典型的滤波方法。重点讨论了地震数据统计滤波方法,基于实测数据的统计特征(或概率分布),在局部信号缓变的假设下,设计了各种高斯加权滤波器和中值类滤波器。高维空间中的地震信号具有显著的结构特征,为满足信号缓变的假设,需要发展沿着信号结构方向的高维统计滤波器。分析了邻域滤波器、双边滤波器、非局部均值滤波器三类各向异性高斯(加权)滤波器的设计思想。在非局部均值滤波算法的基础上设计了自适应搜索窗的非局部均值滤波方法,该方法采用局部数据窗的相关算法检测出滤波点附近的信号结构特征,依据地震数据变化自适应地改变非局部均值滤波器中的搜索窗。理论模型的数据测试表明,相比于固定搜索窗的非局部均值滤波算法,自适应搜索窗的非局部均值滤波方法能够在压制随机噪声的同时更好地保护有效地震信号。 展开更多
关键词 反演成像 信噪比 噪声统计特征 统计去噪方法 统计滤波器设计 高斯加权滤波器 中值滤波器 非局部均值滤波器
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A numerical study on the generation of a distinct type of nonlinear internal wave packet in the South China Sea 被引量:4
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作者 杜涛 严晓海 Timothy DUDA 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2010年第3期658-666,共9页
A distinct type of nonlinear internal-wave packet, with the largest internal solitary wave in the middle of the packet, was regularly observed in the South China Sea during the Asian Seas International Acoustics Exper... A distinct type of nonlinear internal-wave packet, with the largest internal solitary wave in the middle of the packet, was regularly observed in the South China Sea during the Asian Seas International Acoustics Experiment in 2001. Data analysis shows that the occurrence of the distinct internal wave packet is closely related with the occurrence of lower-high internal tides; the internal tides are mixed in the experimental area and, thus, there is diurnal inequality between the heights of two neighboring internal tides. Modeling of internal tides and internal solitary waves in a shoaling situation suggests that this type of wave packet can be generated in the South China Sea by the large shoaling of internal solitary waves and internal tides. Both the internal solitary waves and the internal tides come from the direction of Luzon Strait. The initial large internal solitary waves contribute to the occurrence of the largest internal solitary wave in the middle of the packet and the waves behind the largest intemal solitary wave, while the shoaling internal tides bring about the nonlinear internal waves in front of the largest internal solitary wave via interaction with the local shelf topography. 展开更多
关键词 nonlinear internal wave packet internal tide South China Sea
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Heavy mineral stratigraphy of sediments from the southern outer shelf of the East China Sea since the last glaciation using fuzzy C-means cluster method 被引量:1
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作者 林晓彤 李巍然 +1 位作者 杜树杰 林振宏 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2010年第1期183-189,共7页
Correspondence analysis and fuzzy C-means cluster methods were used to divide the stratigraphy of heavy mineral assemblages, and the sediment sources and depositional dynamics of the environment reconstructed. The ass... Correspondence analysis and fuzzy C-means cluster methods were used to divide the stratigraphy of heavy mineral assemblages, and the sediment sources and depositional dynamics of the environment reconstructed. The assemblages were taken from marine sediments from the late Pleistocene to the Holocene in Core Q43 situated on the outer shelf of the East China Sea. Based on the variable boundaries of the mineral assemblage at 63 and 228 cmbsf (cm below sea floor), the core might have previously been divided into three sediment strata marked with units Ⅰ, Ⅱ and Ⅲ, which would be consistent with the divided sediment stratum of the core using minor element geochemistry. The downcore distribution of heavy minerals divided the sedimentary sequence into three major units, which were further subdivided into four subunits. The interval between 0 and 63 cmbsf of the core (unit Ⅰ), which spans the Holocene and the uppermost late Pleistocene, is characterized by a hornblende-epidote-pyroxene assemblage, and contains relatively a smaller amount of schistic mineral and authigenic pyrite. In comparison, the interval between 63 and 228 cmbsf (unit Ⅱ), is representative of the Last Glacial Maximum (LGM), and features a hornblende-epidote-magnetite-ilmenite assemblage containing the highest concentrations of heavy minerals and opaque minerals. However, the interval between 228 and 309 cmbsf (unit Ⅲ), which spans the subinterglacial period, is characterized by a hornblende-authigenic-pyrite-mica assemblage. Relative ratios of some heavy minerals can be used as tracers of clastic sediment sources. The lower part of the sediment core shows the highest magnetite/ilmenite ratio and relatively high hornblende/augite and hornblende/epidote ratios. The middle core shows the highest hornblende/augite and hornblende/epidote ratios, and the lowest magnetite/ilmenite ratio. The upper part exhibits a slightly higher magnetite/ilmenite ratio, and also the lowest hornblende/augite and hornblende/epidote ratios. The distribution of the mineral ratio is consistent with stratigraphic division in heavy mineral data using correspondence analysis and fuzzy C-means clustering. Variations in heavy mineral association and mineral ratio in core Q43 revealed changes in provenance and depositional environment of the southern outer shelf of the East China Sea since the late Pleistocene, well corresponding to interglacial and glacial cycles. 展开更多
关键词 the Last Glacial Period stratigraphic division heavy mineral East China Sea fuzzy C-meanscluster
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Knowledge Innovation of Great Tradition of Chinese Literary Anthropology
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作者 HU Jian-sheng YUE Jian-feng 《Journal of Literature and Art Studies》 2016年第6期597-602,共6页
It is very innovative significance that Chinese Literary Anthropology invents the Great Tradition in the new century and puts forward series of theoretical propositions and academic points based on it. The new Great T... It is very innovative significance that Chinese Literary Anthropology invents the Great Tradition in the new century and puts forward series of theoretical propositions and academic points based on it. The new Great Tradition transforms the opposition between the Great and Little Tradition of American anthropology, and makes the new concepts gain the legitimacy of the cultural values transferred from the old terms. It dates the second coded significance of the written culture from the material narrative and the image narrative of the oral tradition, and highlights the generative and primary of the symbolic significance. It also questions the authenticity of the written representation, endows the truth and credibility to the material and image representation, and manifests the imaginative and expression of the early human culture. Though its theoretical innovation inverts the binary opposition structure, and it wants to jump out of knowledge limits of dual structure such as structure and destruction, objective and subjective, material and spiritual. 展开更多
关键词 Chinese Literary Anthropology Ye Shuxian Great Tradition Little Tradition theoretical innovation
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3-Phase Fault Finding in Oil Field MV Distribution Network Using Fuzzy Clustering Techniques
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作者 Muhammad M.A.S. Mahmoud 《Journal of Energy and Power Engineering》 2013年第1期155-161,共7页
This paper studies an existing 13.8 kilovolt distribution network which, serves an oil production field spread over an area of approximately 60 kilometers square, in order to locate any fault that may occur anywhere i... This paper studies an existing 13.8 kilovolt distribution network which, serves an oil production field spread over an area of approximately 60 kilometers square, in order to locate any fault that may occur anywhere in the network using fuzzy c-mean classification techniques. In addition, Sections 5 and 6 introduce two different methods for normalizing data and selecting the optimum number of clusters in order to classify data. Results and conclusions are given to show the feasibility for the suggested fault location method. Suggestion for future related research has been provided in Section 8. 展开更多
关键词 Fault finding fault location distribution network fuzzy clustering applications.
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Analysis of a Class of Symmetric Equilibrium Configurations for a Territorial Model
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作者 Michael Busch Jeff Moehlis 《Numerical Mathematics(Theory,Methods and Applications)》 SCIE 2010年第2期143-161,共19页
Motivated by an animal territoriality model,we consider a centroidal Voronoi tessellation algorithm from a dynamical systems perspective.In doing so,we discuss the stability of an aligned equilibrium configuration for... Motivated by an animal territoriality model,we consider a centroidal Voronoi tessellation algorithm from a dynamical systems perspective.In doing so,we discuss the stability of an aligned equilibrium configuration for a rectangular domain that exhibits interesting symmetry properties.We also demonstrate the procedure for performing a center manifold reduction on the system to extract a set of coordinates which capture the long term dynamics when the system is close to a bifurcation.Bifurcations of the system restricted to the center manifold are then classified and compared to numerical results.Although we analyze a specific set-up,these methods can in principle be applied to any bifurcation point of any equilibrium for any domain. 展开更多
关键词 Territorial behavior Voronoi tessellations BIFURCATION center manifold reduction.
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Intrinsic Value of the Natural Environment: An Ethical Roadmap to Protect the Environment
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作者 Nader Ghotbi 《Journal of Philosophy Study》 2014年第4期315-320,共6页
The environment in the sense of all the ecosystems on Earth, has been polluted, harmed, and put at risk of degradation to some extent. Nevertheless, the mainstream ethical philosophies have found it difficult to assig... The environment in the sense of all the ecosystems on Earth, has been polluted, harmed, and put at risk of degradation to some extent. Nevertheless, the mainstream ethical philosophies have found it difficult to assign an intrinsic value to the environment itself, and most environmental ethics is based on an "enlightened" anthropocentrism which values environmental protection for the sake of other humans including the future generations. Philosophically speaking, the concept of moral obligations towards generations, who have not been born yet, can be challenged. This vicious circle is a fundamental issue for "environmental ethics." The current paper is an attempt to help correct this broken cycle of arguments using three lines of argument: (1) The harmful impact of human activity on the environment does not benefit all humans; the question is not over the selfishness and short-sightedness of humankind regarding the environment as much as it is regarding "environmental" justice among humans. The pursuit of self-interest and wealth by some humans, but not all, should not lead philosophers to ignore the insufficiencies of our economic and capitalist systems in the delineation of morally correct human-environment interaction. The right to a livable environment is a universal human right and morality has to support it. (2) The moral obligation of humankind toward the environment is similar to any situation where a party, such as a child, does not have the ability to protect itself or defend its rights; this is the principle of "due care." Humans have the knowledge to understand the complexity of ecosystem interrelationships and the harm which industrial activity has caused. Therefore they have a moral obligation to exercise due care to prevent it from being harmed irreversibly. (3) The third argument is concerned with human morality and the spirituality of the environment. It can be argued that the natural instinct of the love of the environment, biophilia, is not a cause but a symptom of the grand spiritual value in the environment, even though this spiritual value may not be confined to humans, but be accrued to all life forms that have and/or show a genuine interest in the environment. 展开更多
关键词 environmental ethics instrumental vs intrinsic value natural environment
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