期刊文献+
共找到526篇文章
< 1 2 27 >
每页显示 20 50 100
Minimum Cycle of Row Vector of a Generalized Circulant Fuzzy Matrix
1
作者 冼国荣 陈卓荣 《Chinese Quarterly Journal of Mathematics》 CSCD 1997年第1期104-110, ,共7页
In this paper,we intreduce the concept and discuss the properties of minimum cycle of row vector in a generalized circulant Fuzzy matrix. We present a new expression for circulant Fuzzy matrix,and discuss some propert... In this paper,we intreduce the concept and discuss the properties of minimum cycle of row vector in a generalized circulant Fuzzy matrix. We present a new expression for circulant Fuzzy matrix,and discuss some properties of the idempotent elements of the semigroup of generalized circulant Fuzzy matrixes in connection with minimum cycle of row vector. 展开更多
关键词 广义循环模糊矩阵 行向量最小周期 半群
下载PDF
A quantum algorithm for Toeplitz matrix-vector multiplication
2
作者 高尚 杨宇光 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第10期248-253,共6页
Toeplitz matrix-vector multiplication is widely used in various fields,including optimal control,systolic finite field multipliers,multidimensional convolution,etc.In this paper,we first present a non-asymptotic quant... Toeplitz matrix-vector multiplication is widely used in various fields,including optimal control,systolic finite field multipliers,multidimensional convolution,etc.In this paper,we first present a non-asymptotic quantum algorithm for Toeplitz matrix-vector multiplication with time complexity O(κpolylogn),whereκand 2n are the condition number and the dimension of the circulant matrix extended from the Toeplitz matrix,respectively.For the case with an unknown generating function,we also give a corresponding non-asymptotic quantum version that eliminates the dependency on the L_(1)-normρof the displacement of the structured matrices.Due to the good use of the special properties of Toeplitz matrices,the proposed quantum algorithms are sufficiently accurate and efficient compared to the existing quantum algorithms under certain circumstances. 展开更多
关键词 quantum algorithm Toeplitz matrix-vector multiplication circulant matrix
下载PDF
The primitive matrices of sandwich semigroups of generalized circulant Boolean matrices
3
作者 LIU Jian-ping CHEN Jin-song 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2013年第3期311-320,共10页
Let Gn(C) be the sandwich semigroup of generalized circulant Boolean matrices with the sandwich matrix C and Gc(Jr~) the set of all primitive matrices in Gn(C). In this paper, some necessary and sufficient condi... Let Gn(C) be the sandwich semigroup of generalized circulant Boolean matrices with the sandwich matrix C and Gc(Jr~) the set of all primitive matrices in Gn(C). In this paper, some necessary and sufficient conditions for A in the semigroup Gn(C) to be primitive are given. We also show that Gc(Jn) is a subsemigroup of Gn(C). 展开更多
关键词 generalized circulant Boolean matrix sandwich semigroup primitive matrix.
下载PDF
ONTHEPROPERTIESOFZCIRCULANTMATRICES
4
作者 DING Xueren  WANG Peili (Dept. of Mathematics) 《Transactions of Tianjin University》 EI CAS 1996年第1期91-93,共3页
本文给出了Z循环矩阵的一些性质
关键词 z循环矩阵 正规矩阵 方阵函数
下载PDF
EIGENVALUES OF A SPECIAL KIND OF SYMMETRIC BLOCK CIRCULANT MATRICES 被引量:3
5
作者 WangLigong LiXueliang HoedeC 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2004年第1期17-26,共10页
In this paper, the spectrum and characteristic polynomial for a special kind of symmetric block circulant matrices are given.
关键词 block circulant matrix EIGENVALUE characteristic polynomial integr al graph.
下载PDF
On the Circulant and Aperiodic Models of Deconvolution 被引量:1
6
作者 Zou Mouyan & Rolf Unbehauen 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1995年第1期16-24,共9页
The popularly used circulant matrix model of deconvolution is mostly heavily ill-posed or singular and it is not suitable to many blind deconvolution problems. The aperiodic matrix model can improve the condition numb... The popularly used circulant matrix model of deconvolution is mostly heavily ill-posed or singular and it is not suitable to many blind deconvolution problems. The aperiodic matrix model can improve the condition number of deconvolution problems and its accommodation is much wider than the circulant one's. This paper discusses a comparison of the two models including their ill-posedness, the rationality of the approximation by the models, and their computational efficiency. The comparison shows that the aperiodic model is promising in the development of new restoration algorithms. 展开更多
关键词 circulant matrix model aperiodic model DECONVOLUTION
下载PDF
Algorithms for Finding the Inverses of Factor Block Circulant Matrices 被引量:1
7
作者 Zhaolin Jiang Zongben Xu Shuping Gao 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 2006年第1期1-11,共11页
In this paper,algorithms for finding the inverse of a factor block circulant matrix, a factor block retrocirculant matrix and partitioned matrix with factor block circulant blocks over the complex field are presented ... In this paper,algorithms for finding the inverse of a factor block circulant matrix, a factor block retrocirculant matrix and partitioned matrix with factor block circulant blocks over the complex field are presented respectively.In addition,two algorithms for the inverse of a factor block circulant matrix over the quaternion division algebra are proposed. 展开更多
关键词 逆矩阵 分块矩阵 算法 循环矩阵
下载PDF
Effects of Activating Blood Circulation to Resolve Blood Stasis and Glucosamine Capsules Therapy on the Expression of Matrix Metalloproteinase in Post-traumatic Knee Osteoarthritis
8
作者 Mingguang CHEN Shiqiang CHEN +5 位作者 Ning YANG Jin YANG Yingang LI Xiaoxia CAO Chunfeng CHANG Xuelan WU 《Medicinal Plant》 CAS 2019年第3期77-81,86,共6页
[Objectives] To observe the clinical effects of activating blood circulation to resolve blood stasis and glucosamine hydrochloride capsules therapy on post-traumatic knee osteoarthritis treatment,to measure the expres... [Objectives] To observe the clinical effects of activating blood circulation to resolve blood stasis and glucosamine hydrochloride capsules therapy on post-traumatic knee osteoarthritis treatment,to measure the expression of matrix metalloproteinase in post-traumatic knee osteoarthritis patients before and after treatment,and to explore its relevant molecular mechanisms. [Methods]A total of 60 patients with posttraumatic knee osteoarthritis in early stage in Affiliated Hospital of Shannxi University of Chinese Medicine from January 2015 to December2017 were selected and randomly divided into the control group( n = 30) and the observation group( n = 30). The control group was given oral administration of glucosamine hydrochloride capsules for 6 courses of the treatment. The observation group was using the activating blood circulation to resolve blood stasis therapy for 6 courses of treatment. The recovery of traumatic knee osteoarthritis and the symptom of traditional Chinese medicine( TCM) in 2 groups was compared before and after treatment. The symptoms and the quantitative assessment rating scale of knee osteoarthritis,the pain index of knee and the TCM symptom scores were recorded in both groups. And the synovial fluid and serum of patients were collected to detect the expression of matrix metalloproteinase. [Results]The symptoms and the quantitative assessment rating scale of knee osteoarthritis,the pain index of knee and TCM symptom scores of the 2 groups in the 1 st week,the 12 th week and the 24 th week after the treatment were significantly lower than those before the treatment,and the difference was statistically significant( P < 0. 05). Two therapeutic methods had certain therapeutic effects on the recovery from traumatic knee osteoarthritis,and could significantly improve the TCM syndrome. There were better therapeutic effects on oral decoction of traditional Chinese medicine than oral glycosaminoglycans hydrochloride capsules on treating traumatic knee osteogenesis( P < 0. 05). The expression level of MMP3 was decreased significantly in both groups( P <0. 001),while the expression level of MMP13 had no significant change in both groups( P >0. 05). The expression level of MMP1 was decreased significantly in the observation group( P < 0. 001),but there was no significant change in the control group after treatment( P >0. 05). [Conclusions]Two treatment methods have been effective in this clinical study. We found that the expression level of MMP3 was decreased significantly after treatment in 2 therapies,which can be clinically applied. 展开更多
关键词 Activating BLOOD circulATION to RESOLVE BLOOD stasis GLUCOSAMINE hydrochloride Osteoarthritis Knee joint matrix metalloproteinases-1 matrix metalloproteinases-3 matrix metalloproteinases-13 Therapeutic effects
下载PDF
Moore-Penrose Inverses and Group Inverses of Block k-Circulant Matrices 被引量:1
9
作者 Chen Jianlong(Department of Mathematics and Mechanics, Southeast University, Naming, 210018) 《Chinese Quarterly Journal of Mathematics》 CSCD 1996年第1期86-99,共14页
Moore-Penrose Inverses and Group Inverses of Block k-Circulant MatricesMoore-PenroseInversesandGroupInverses... Moore-Penrose Inverses and Group Inverses of Block k-Circulant MatricesMoore-PenroseInversesandGroupInversesofBlockk-Circulan... 展开更多
关键词 MOORE-PENROSE逆 分块K-循环矩阵 群逆
下载PDF
Applications of Symmetric Circulant Matrices to Isotropic Markov Chain Models and Electrical Impedance Tomography
10
作者 Eugene Demidenko 《Advances in Pure Mathematics》 2017年第2期188-198,共11页
Symmetric circulant matrices (or shortly symmetric circulants) are a very special class of matrices sometimes arising in problems of discrete periodic convolutions with symmetric kernel. First, we collect major proper... Symmetric circulant matrices (or shortly symmetric circulants) are a very special class of matrices sometimes arising in problems of discrete periodic convolutions with symmetric kernel. First, we collect major properties of symmetric circulants scattered through the literature. Second, we report two new applications of these matrices to isotropic Markov chain models and electrical impedance tomography on a homogeneous disk with equidistant electrodes. A new special function is introduced for computation of the Ohm’s matrix. The latter application is illustrated with estimation of the resistivity of gelatin using an electrical impedance tomography setup. 展开更多
关键词 circulant matrix Electrical Impedance TOMOGRAPHY LAPLACE Equation MARKOV Chain Ohm’s Law
下载PDF
Non-Singularity Conditions for Two Z-Matrix Types
11
作者 Shinji Miura 《Advances in Linear Algebra & Matrix Theory》 2014年第2期109-119,共11页
A real square matrix whose non-diagonal elements are non-positive is called a Z-matrix. This paper shows a necessary and sufficient condition for non-singularity of two types of Z-matrices. The first is for the Z-matr... A real square matrix whose non-diagonal elements are non-positive is called a Z-matrix. This paper shows a necessary and sufficient condition for non-singularity of two types of Z-matrices. The first is for the Z-matrix whose row sums are all non-negative. The non-singularity condition for this matrix is that at least one positive row sum exists in any principal submatrix of the matrix. The second is for the Z-matrix which satisfies where . Let be the ith row and the jth column element of , and be the jth element of . Let be a subset of which is not empty, and be the complement of if is a proper subset. The non-singularity condition for this matrix is such that or such that for? . Robert Beauwens and Michael Neumann previously presented conditions similar to these conditions. In this paper, we present a different proof and show that these conditions can be also derived from theirs. 展开更多
关键词 z-matrix M-matrix Non-Negative matrix DIAGONAL DOMINANCE
下载PDF
Circulant矩阵构造准循环LDPC码的旋转环长分析法(英文)
12
作者 齐行行 DOUGLAS Leith 《吉林大学学报(信息科学版)》 2011年第3期213-220,共8页
低密度奇偶检验(QC-LDPC:Quasi-Cyclic Low-Density Parity-Check)码的环长分布影响决定着LDPC码的解码效果和编码复杂度,但其分析较困难。为此,首次提出旋转距离分析法,用于分析基于Circulant矩阵构造的准循环低密度奇偶校验码(QC-LDPC... 低密度奇偶检验(QC-LDPC:Quasi-Cyclic Low-Density Parity-Check)码的环长分布影响决定着LDPC码的解码效果和编码复杂度,但其分析较困难。为此,首次提出旋转距离分析法,用于分析基于Circulant矩阵构造的准循环低密度奇偶校验码(QC-LDPC码)的环分布,并给出了任何一个基于Circulant矩阵构造出的QC-LDPC码中的最小环长(girth)的上限(12)。同时,运用该方法,分析出一种权重为(3,5)的QC-LD-PC码的译码效果与该码环分布的关系。由于LDPC码奇偶校验矩阵中的Circulant子矩阵,可以被当成1个矩阵节点的单一节点看待,从而简化了整个码的特纳图,使寻找QC-LDPC码中闭环的方法变得简单。 展开更多
关键词 准循环低密度奇偶校验码(QC-LDPC) circulant矩阵 旋转距离分析 最小环长 环分布 矩阵Tanner图
下载PDF
海上风电单芯海缆接地环流影响因素分析
13
作者 杨玉新 王劲松 +1 位作者 朱永利 李岩 《南方电网技术》 CSCD 北大核心 2024年第3期56-64,共9页
单芯海缆在生产、施工方面相对于三芯海缆更具优势,但是其接地环流异常引起的海缆故障频繁发生。单芯海缆接地环流运行机理及检测策略有待深入研究。建立了基于阻抗矩阵的单芯海缆数学模型,揭示了铠装电阻率、铠装层相对磁导率、接地电... 单芯海缆在生产、施工方面相对于三芯海缆更具优势,但是其接地环流异常引起的海缆故障频繁发生。单芯海缆接地环流运行机理及检测策略有待深入研究。建立了基于阻抗矩阵的单芯海缆数学模型,揭示了铠装电阻率、铠装层相对磁导率、接地电阻、短路电阻等因素对阻抗矩阵内参数和接地环流的影响规律。结合实际工程案例分析了海缆接地环流分配不均的机理,为海缆的运行状态评估及检修提供了参考依据。 展开更多
关键词 单芯海缆 接地环流 阻抗矩阵 PSCAD仿真
下载PDF
单芯海缆两端环流不匹配问题及评价方法研究
14
作者 李岩 王毛桃 +2 位作者 乔俊杰 刘鑫月 宋浩源 《电网技术》 EI CSCD 北大核心 2024年第4期1770-1778,I0100,共10页
海缆是海上风电系统重要构成部分,接地环流是制约海缆设计及运行状态的关键要素。实际运行经验表明部分海上风场的单芯海缆存在陆上段和海上段接地环流严重不匹配现象,但是造成这种不匹配工况的原因不明,更无法根据这一现象对海缆运行... 海缆是海上风电系统重要构成部分,接地环流是制约海缆设计及运行状态的关键要素。实际运行经验表明部分海上风场的单芯海缆存在陆上段和海上段接地环流严重不匹配现象,但是造成这种不匹配工况的原因不明,更无法根据这一现象对海缆运行状态进行清晰判断。该文依据现场海缆实际结构建立其分布参数模型,针对铠装接地和铠装金属护套全线接地两种接地方式对海缆接地环流进行分析,指出铠装全线接地时出现不匹配接地环流的原因为铠装和金属护套之间存在短路电阻;而铠装和金属护套全线接地情况下,出现不匹配接地环流的原因为铠装和金属护套之间存在短路电阻或者海缆两端接地电阻不匹配。在此基础上,提出基于环流的海缆运行情况评价方法,为实际海缆运行状态的判断提供参考依据。 展开更多
关键词 海缆 分布阻抗矩阵 环流 海缆缺陷
下载PDF
基于时空码和数联网技术的新型“可信数据空间”体系构想
15
作者 李林 任伏虎 +2 位作者 蔡华谦 董锦华 叶自燊 《信息通信技术与政策》 2024年第6期89-96,共8页
梳理回顾欧盟“国际数据空间”和我国“可信数据空间”的发展由来,针对当前“可信数据空间”存在的制度和技术层面的瓶颈问题,引入一个新的“时空码+数联网”底层技术框架,在此基础上较为系统地提出新型“可信数据空间”的概念内涵、系... 梳理回顾欧盟“国际数据空间”和我国“可信数据空间”的发展由来,针对当前“可信数据空间”存在的制度和技术层面的瓶颈问题,引入一个新的“时空码+数联网”底层技术框架,在此基础上较为系统地提出新型“可信数据空间”的概念内涵、系统架构、功能视图以及有特色的融合底座等体系化设计。其主要创新体现在可信体系与实现路径、技术框架与系统架构、平台定位与生态培育等层面。并建议以新型“可信数据空间”作为我国数据流通基础设施建设的关键技术路线,协同开展技术攻关,加快试点验证示范。 展开更多
关键词 可信数据空间 数据流通 数据基础设施 时空码 数联网
下载PDF
搭接长度对Z-pins增强陶瓷基复合材料接头连接性能的影响 被引量:7
16
作者 陶永强 矫桂琼 +1 位作者 王波 常岩军 《材料科学与工程学报》 CAS CSCD 北大核心 2008年第4期593-598,共6页
本文对搭接长度分别为15mm,20mm,23mm,37mm,60mm的Z-pins增强陶瓷基复合材料接头在单向载荷作用下的连接性能进行了试验研究和数值模拟。试验结果表明接头的最终失效形式有两种:(1)搭接长度大于、等于20mm的接头由搭接板断裂而失效;(2)... 本文对搭接长度分别为15mm,20mm,23mm,37mm,60mm的Z-pins增强陶瓷基复合材料接头在单向载荷作用下的连接性能进行了试验研究和数值模拟。试验结果表明接头的最终失效形式有两种:(1)搭接长度大于、等于20mm的接头由搭接板断裂而失效;(2)搭接长度等于15mm的接头由搭接面的脱胶而失效。在搭接长度为20mm^60mm之间,接头的最大破坏载荷与搭接长度之间呈线性关系变化。采用有限元的方法对搭接接头的破坏过程进行了数值模拟,模拟结果与试验结果吻合较好,进而得到了介于上述两种破坏模式之间的搭接接头的搭接长度。 展开更多
关键词 陶瓷基复合材料(CMC) 接头 z-PINS 搭接长度 连接性能
下载PDF
Z-矩阵最小特征值及特征向量的数值算法 被引量:8
17
作者 段复建 张可村 《工程数学学报》 CSCD 北大核心 2007年第3期563-566,共4页
基于Z-矩阵与非负矩阵的关系,给出了不可约Z-矩阵最小特征值及特征向量的同步数值算法,数值实验表明算法是可行有效的。
关键词 z-矩阵 最小特征值 特征向量 不可约 对角变换
下载PDF
Z-pin增强陶瓷基复合材料拉伸性能及损伤研究 被引量:3
18
作者 刘韡 矫桂琼 +1 位作者 管国阳 常岩军 《机械强度》 EI CAS CSCD 北大核心 2008年第2期339-342,共4页
研究Z-pin横向增强平纹编织陶瓷基复合材料的拉伸性能及损伤。碳纤维平纹编织物和碳纤维Z-pin制备的预制体,通过化学气相渗透(chemical vapor infiltration,CVI)工艺制成Z-pin增强平纹编织陶瓷基复合材料。采用单轴拉伸试验及加—卸载... 研究Z-pin横向增强平纹编织陶瓷基复合材料的拉伸性能及损伤。碳纤维平纹编织物和碳纤维Z-pin制备的预制体,通过化学气相渗透(chemical vapor infiltration,CVI)工艺制成Z-pin增强平纹编织陶瓷基复合材料。采用单轴拉伸试验及加—卸载试验研究材料拉伸力学性能参数及破坏机理。结果表明,Z-pin嵌入引起的面内纤维断裂、损伤以及弯曲变形,降低了平纹编织陶瓷基复合材料的抗拉强度;Z-pin增强平纹编织陶瓷基复合材料抗拉应力应变曲线具有非线性特性;卸载再加载过程中损伤基本没有增加,残余应变与卸载应力成二次关系,卸载模量与卸载应力成Boltzmann关系。 展开更多
关键词 z-PIN 陶瓷基复合材料 拉伸性能 损伤
下载PDF
Z-矩阵的预条件方法 被引量:12
19
作者 李继成 黄廷祝 《数学物理学报(A辑)》 CSCD 北大核心 2005年第1期5-10,共6页
通过对方程组Ax=b的系数矩阵施行初等行变换,该文提出了解线性方程组Ax=b的一种新的预条件Gauss-Seidel迭代方法,理论上证明了新的预条件Gauss-Seidel迭代方法较经典的Gauss-Seidel迭代法收敛速度快.该文提出的新预条件方法推广了文[1-2... 通过对方程组Ax=b的系数矩阵施行初等行变换,该文提出了解线性方程组Ax=b的一种新的预条件Gauss-Seidel迭代方法,理论上证明了新的预条件Gauss-Seidel迭代方法较经典的Gauss-Seidel迭代法收敛速度快.该文提出的新预条件方法推广了文[1-2]中提出的预条件方法,具体的数值例子说明了新预条件方法的有效性. 展开更多
关键词 GAUSS-SEIDEL迭代法 预条件方法 z-矩阵 对角占优
下载PDF
具有高电压传输比且能抵御非正常输入的Z-源双级矩阵变换器 被引量:11
20
作者 宋卫章 钟彦儒 孙向东 《中国电机工程学报》 EI CSCD 北大核心 2010年第24期21-28,共8页
针对传统矩阵变换器存在电压传输比低和输出性能易受非正常输入影响的两个固有缺陷,提出一种Z-源双级矩阵变换器(Z-source two-stage matrix converter,ZSTSMC)及其调制方法。利用Z-源网络的升压特性以提高电压传输比,通过Z-源网络电容... 针对传统矩阵变换器存在电压传输比低和输出性能易受非正常输入影响的两个固有缺陷,提出一种Z-源双级矩阵变换器(Z-source two-stage matrix converter,ZSTSMC)及其调制方法。利用Z-源网络的升压特性以提高电压传输比,通过Z-源网络电容电压闭环对直通因子进行自适应地调节,从而有效抑制非正常输入对输出性能的影响。闭环控制中采用一种非线性PID算法,削弱了Z-源网络表现出的非最小相位特性带来的不良影响,提高了系统动态性能和抗扰能力。仿真和实验验证了该拓扑的可行性和正确性。 展开更多
关键词 z-源双级矩阵变换器 电压传输比 非正常输入 闭环控制 非最小相位
下载PDF
上一页 1 2 27 下一页 到第
使用帮助 返回顶部