In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to ...In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to obtain the maximal positive definite solution of nonlinear matrix equation X+A^(*)X|^(-α)A=Q with the case 0<α≤1.Based on this method,a new iterative algorithm is developed,and its convergence proof is given.Finally,two numerical examples are provided to show the effectiveness of the proposed method.展开更多
Driven by advancements in mobile internet technology,images have become a crucial data medium.Ensuring the security of image information during transmission has thus emerged as an urgent challenge.This study proposes ...Driven by advancements in mobile internet technology,images have become a crucial data medium.Ensuring the security of image information during transmission has thus emerged as an urgent challenge.This study proposes a novel image encryption algorithm specifically designed for grayscale image security.This research introduces a new Cantor diagonal matrix permutation method.The proposed permutation method uses row and column index sequences to control the Cantor diagonal matrix,where the row and column index sequences are generated by a spatiotemporal chaotic system named coupled map lattice(CML).The high initial value sensitivity of the CML system makes the permutation method highly sensitive and secure.Additionally,leveraging fractal theory,this study introduces a chaotic fractal matrix and applies this matrix in the diffusion process.This chaotic fractal matrix exhibits selfsimilarity and irregularity.Using the Cantor diagonal matrix and chaotic fractal matrix,this paper introduces a fast image encryption algorithm involving two diffusion steps and one permutation step.Moreover,the algorithm achieves robust security with only a single encryption round,ensuring high operational efficiency.Experimental results show that the proposed algorithm features an expansive key space,robust security,high sensitivity,high efficiency,and superior statistical properties for the ciphered images.Thus,the proposed algorithm not only provides a practical solution for secure image transmission but also bridges fractal theory with image encryption techniques,thereby opening new research avenues in chaotic cryptography and advancing the development of information security technology.展开更多
We read with the great interest the study by Ababneh et al in which inducedmesenchymal stem cell-derived exosomes were shown to exhibit a stronger andmore sustained anti-proliferative effect by inducing a senescence-l...We read with the great interest the study by Ababneh et al in which inducedmesenchymal stem cell-derived exosomes were shown to exhibit a stronger andmore sustained anti-proliferative effect by inducing a senescence-like state withoutapoptosis.The results obtained by the authors highlight the features of theeffects of senescent drift induction in surrounding tissues.In the light of thesefindings,the role of the properties of extracellular matrix and cellular glycocalyxin responses of human tumors to therapy remain uninvestigated.These extracellularbarriers appear to be significant obstacles to effective cancer therapy,especiallyin relation to the use of unique properties of tumor microenvironment forthe immunotherapy-resistant cancer treatment.展开更多
Peripheral nerve injury causes severe neuroinflammation and has become a global medical challenge.Previous research has demonstrated that porcine decellularized nerve matrix hydrogel exhibits excellent biological prop...Peripheral nerve injury causes severe neuroinflammation and has become a global medical challenge.Previous research has demonstrated that porcine decellularized nerve matrix hydrogel exhibits excellent biological properties and tissue specificity,highlighting its potential as a biomedical material for the repair of severe peripheral nerve injury;however,its role in modulating neuroinflammation post-peripheral nerve injury remains unknown.Here,we aimed to characterize the anti-inflammatory properties of porcine decellularized nerve matrix hydrogel and their underlying molecular mechanisms.Using peripheral nerve injury model rats treated with porcine decellularized nerve matrix hydrogel,we evaluated structural and functional recovery,macrophage phenotype alteration,specific cytokine expression,and changes in related signaling molecules in vivo.Similar parameters were evaluated in vitro using monocyte/macrophage cell lines stimulated with lipopolysaccharide and cultured on porcine decellularized nerve matrix hydrogel-coated plates in complete medium.These comprehensive analyses revealed that porcine decellularized nerve matrix hydrogel attenuated the activation of excessive inflammation at the early stage of peripheral nerve injury and increased the proportion of the M2 subtype in monocytes/macrophages.Additionally,porcine decellularized nerve matrix hydrogel negatively regulated the Toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-κB axis both in vivo and in vitro.Our findings suggest that the efficacious anti-inflammatory properties of porcine decellularized nerve matrix hydrogel induce M2 macrophage polarization via suppression of the Toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-κB pathway,providing new insights into the therapeutic mechanism of porcine decellularized nerve matrix hydrogel in peripheral nerve injury.展开更多
Objectives:High-grade serous ovarian cancer(HGSOC),the most common subtype of epithelial ovarian cancer(EOC),exhibits a mesenchymal phenotype characterized by fibrotic stroma and poor prognosis.Human epididymis protei...Objectives:High-grade serous ovarian cancer(HGSOC),the most common subtype of epithelial ovarian cancer(EOC),exhibits a mesenchymal phenotype characterized by fibrotic stroma and poor prognosis.Human epididymis protein 4(HE4),a key diagnostic biomarker for ovarian cancer,is involved in fibrotic processes in several non-malignant diseases.Given the clinical significance of stromal fibrosis in HGSOC and the potential link between HE4 and fibrosis,this study aimed to investigate the role of HE4 in the formation of stromal fibrosis in HGSOC.Methods:A total of 126 patients with gynecological conditions were included and divided into normal,benign,and EOC groups.Tissue stiffness was quantitatively measured and analyzed for its correlation with clinicopathological features.We further investigated the correlation between tumor stiffness and the expression levels of HE4 and fibroblast activation markers(α-smooth muscle actin(α-SMA)and fibroblast activation protein(FAP))in tumor tissues from 22 HGSOC patients.In vitro,primary fibroblasts were treated with recombinant HE4(rHE4)or conditioned media from HE4-knockdown ovarian cancer cells to assess fibroblasts activation and matrix contractility(Collagen gel contraction assays).In vivo,a subcutaneous xenograft model using HE4-knockdown cells was established to evaluate the effects of HE4 suppression on tumor growth and extensive extracellular matrix(ECM)remodeling.Results:Ovarian cancer tissues showed significantly increased stiffness compared to benign/normal groups,showing positive correlation with serum HE4 levels.High-stiffness HGSOC tumors exhibited upregulated expression of HE4,α-SMA,FAP,and collagen I.rHE4 stimulated fibroblast activation and enhanced matrix contractility,whereas HE4 knockdown in cancer cells abrogated these pro-fibrotic effects.In vivo,HE4-silenced xenografts displayed restricted tumor growth accompanied by reduced stromal expression ofα-SMA,FAP,and collagen I.Conclusion:Our findings suggest that HE4 may facilitate ECM remodeling in HGSOC through promoting fibroblast activation and increasing collagen deposition.展开更多
第五代移动通信技术(5th-generation mobile communication technology,5G)网络对高速率、低时延、高可靠性的移动通信处理需求不断增加,对终端基带信道估计算法的高性能和低复杂度设计、矩阵处理动态范围提出挑战。针对上述问题,本文...第五代移动通信技术(5th-generation mobile communication technology,5G)网络对高速率、低时延、高可靠性的移动通信处理需求不断增加,对终端基带信道估计算法的高性能和低复杂度设计、矩阵处理动态范围提出挑战。针对上述问题,本文提出一种基于相关矩阵托普利兹(Toeplitz)特性的信道估计算法。依据信道的相干带宽特性计算信道相关矩阵并保留必要的较低矩阵阶数;基于相关矩阵的Toeplitz特性设计低复杂度的递归求逆算法,并针对加权矩阵乘法的元素重复性将矩阵乘法化简为矩阵点乘,简化加权矩阵运算;同时引入跟踪信噪比变化的缩放补偿因子对计算过程和结果分别进行缩放和补偿。理论分析和仿真结果显示,本文所提算法可在达到优异的信道估计性能条件下,有效降低运算复杂度,并极大降低算法矩阵处理的动态范围。展开更多
In this paper,we study real symmetric Toeplitz matrices commutable with tridiagonal matrices, present more detailed results than those in [1], and extend them to nonsymmetric Toeplitz matrices. Also, complex Toeplitz ...In this paper,we study real symmetric Toeplitz matrices commutable with tridiagonal matrices, present more detailed results than those in [1], and extend them to nonsymmetric Toeplitz matrices. Also, complex Toeplitz matrices, especially the corresponding matrices of lower order, are discussed.展开更多
An effective numerical algorithm for computing the determinant of a pentadiagonal Toeplitz matrix has been proposed by Xiao-Guang Lv and others [1]. The complexity of the algorithm is (9n + 3). In this paper, a new al...An effective numerical algorithm for computing the determinant of a pentadiagonal Toeplitz matrix has been proposed by Xiao-Guang Lv and others [1]. The complexity of the algorithm is (9n + 3). In this paper, a new algorithm with the cost of (4n + 6) is presented to compute the determinant of a pentadiagonal Toeplitz matrix. The inverse of a pentadiagonal Toeplitz matrix is also considered.展开更多
In this advanced exploration, we focus on multiple parameters estimation in bistatic Multiple-Input Multiple-Output(MIMO) radar systems, a crucial technique for target localization and imaging. Our research innovative...In this advanced exploration, we focus on multiple parameters estimation in bistatic Multiple-Input Multiple-Output(MIMO) radar systems, a crucial technique for target localization and imaging. Our research innovatively addresses the joint estimation of the Direction of Departure(DOD), Direction of Arrival(DOA), and Doppler frequency for incoherent targets. We propose a novel approach that significantly reduces computational complexity by utilizing the TemporalSpatial Nested Sampling Model(TSNSM). Our methodology begins with a multi-linear mapping mechanism to efficiently eliminate unnecessary virtual Degrees of Freedom(DOFs) and reorganize the remaining ones. We then employ the Toeplitz matrix triple iteration reconstruction method, surpassing the traditional Temporal-Spatial Smoothing Window(TSSW) approach, to mitigate the single snapshot effect and reduce computational demands. We further refine the highdimensional ESPRIT algorithm for joint estimation of DOD, DOA, and Doppler frequency, eliminating the need for additional parameter pairing. Moreover, we meticulously derive the Cramér-Rao Bound(CRB) for the TSNSM. This signal model allows for a second expansion of DOFs in time and space domains, achieving high precision in target angle and Doppler frequency estimation with low computational complexity. Our adaptable algorithm is validated through simulations and is suitable for sparse array MIMO radars with various structures, ensuring higher precision in parameter estimation with less complexity burden.展开更多
In this paper, we construct one of the forms of totally positive Toeplitz matrices from upper or lower bidiagonal totally nonnegative matrix. In addition, some properties related to this matrix involving its factoriza...In this paper, we construct one of the forms of totally positive Toeplitz matrices from upper or lower bidiagonal totally nonnegative matrix. In addition, some properties related to this matrix involving its factorization are presented.展开更多
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
A fast Cholesky decomposition and a fast inverse Cholesky decomposition method for A T A are presented,where A is an m×n rectangular Toeplitz block matrix,we give the FCD algorithm for computing...A fast Cholesky decomposition and a fast inverse Cholesky decomposition method for A T A are presented,where A is an m×n rectangular Toeplitz block matrix,we give the FCD algorithm for computing R , and the FICD algorithm for computing R -1 ,both allow for an efficient parallel implementation,for solving a least squares problem and require only O(mn) operations.展开更多
船载高频地波雷达(High Frequency Surface Wave Radar, HFSWR)的平台机动运动会使目标回波信号发生展宽,引起目标回波幅度和信噪比降低,进而对目标波达方向估计(Direction of Arrival, DOA)产生不利的影响。针对船载地波雷达展宽目标DO...船载高频地波雷达(High Frequency Surface Wave Radar, HFSWR)的平台机动运动会使目标回波信号发生展宽,引起目标回波幅度和信噪比降低,进而对目标波达方向估计(Direction of Arrival, DOA)产生不利的影响。针对船载地波雷达展宽目标DOA估计问题,本文提出了一种基于时频信息Toeplitz协方差重构的展宽目标DOA估计方法。该方法首先采用结合航向补偿的时频分析处理,来提取展宽目标信号的脊线,可为充分利用展宽目标时频信息来构建协方差矩阵奠定基础。然后对构建的协方差矩阵进行Toeplitz化,实现了非平稳噪声的抑制,提高了目标信噪比,解决了展宽目标信噪比下降的问题,从而实现目标的方位角估计。最后,通过仿真和实测数据对本文提出的方法进行验证,结果表明本文所提方法在相同信噪比和目标展宽程度下均方根误差比单峰值MUSIC和DBF方法减小了1.2°,证明了本文所提方法的有效性。展开更多
为提升互质阵列对相干信号的估计性能,提出了基于多重Toeplitz矩阵重构的互质阵列相干信号波达方向(direction of arrival,DOA)估计方法。该方法首先将互质阵列构造为共轭增广虚拟阵列;其次,通过插值补零将共轭增广虚拟阵列变为虚拟均...为提升互质阵列对相干信号的估计性能,提出了基于多重Toeplitz矩阵重构的互质阵列相干信号波达方向(direction of arrival,DOA)估计方法。该方法首先将互质阵列构造为共轭增广虚拟阵列;其次,通过插值补零将共轭增广虚拟阵列变为虚拟均匀线阵;然后,利用窄带信号在不同快拍数下的强相关性和噪声的弱相关性构造时空相关矩阵,并使用时空相关矩阵的所有行重构Toeplitz矩阵;最后,使用子空间方法得到DOA估计结果。理论分析和试验结果表明,与现有的矩阵重构方法相比,该方法在低信噪比和少快拍数的情况下具有良好的估计性能和分辨能力。展开更多
基金Supported in part by Natural Science Foundation of Guangxi(2023GXNSFAA026246)in part by the Central Government's Guide to Local Science and Technology Development Fund(GuikeZY23055044)in part by the National Natural Science Foundation of China(62363003)。
文摘In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to obtain the maximal positive definite solution of nonlinear matrix equation X+A^(*)X|^(-α)A=Q with the case 0<α≤1.Based on this method,a new iterative algorithm is developed,and its convergence proof is given.Finally,two numerical examples are provided to show the effectiveness of the proposed method.
基金supported by the National Natural Science Foundation of China(62376106)The Science and Technology Development Plan of Jilin Province(20250102212JC).
文摘Driven by advancements in mobile internet technology,images have become a crucial data medium.Ensuring the security of image information during transmission has thus emerged as an urgent challenge.This study proposes a novel image encryption algorithm specifically designed for grayscale image security.This research introduces a new Cantor diagonal matrix permutation method.The proposed permutation method uses row and column index sequences to control the Cantor diagonal matrix,where the row and column index sequences are generated by a spatiotemporal chaotic system named coupled map lattice(CML).The high initial value sensitivity of the CML system makes the permutation method highly sensitive and secure.Additionally,leveraging fractal theory,this study introduces a chaotic fractal matrix and applies this matrix in the diffusion process.This chaotic fractal matrix exhibits selfsimilarity and irregularity.Using the Cantor diagonal matrix and chaotic fractal matrix,this paper introduces a fast image encryption algorithm involving two diffusion steps and one permutation step.Moreover,the algorithm achieves robust security with only a single encryption round,ensuring high operational efficiency.Experimental results show that the proposed algorithm features an expansive key space,robust security,high sensitivity,high efficiency,and superior statistical properties for the ciphered images.Thus,the proposed algorithm not only provides a practical solution for secure image transmission but also bridges fractal theory with image encryption techniques,thereby opening new research avenues in chaotic cryptography and advancing the development of information security technology.
文摘We read with the great interest the study by Ababneh et al in which inducedmesenchymal stem cell-derived exosomes were shown to exhibit a stronger andmore sustained anti-proliferative effect by inducing a senescence-like state withoutapoptosis.The results obtained by the authors highlight the features of theeffects of senescent drift induction in surrounding tissues.In the light of thesefindings,the role of the properties of extracellular matrix and cellular glycocalyxin responses of human tumors to therapy remain uninvestigated.These extracellularbarriers appear to be significant obstacles to effective cancer therapy,especiallyin relation to the use of unique properties of tumor microenvironment forthe immunotherapy-resistant cancer treatment.
基金supported by the Shenzhen Hong Kong Joint Funding Project,No.SGDX20230116093645007(to LY)the Shenzhen Science and Technology Innovation Committee International Cooperation Project,No.GJHZ20200731095608025(to LY)+7 种基金Shenzhen Development and Reform Commission’s Intelligent Diagnosis,Treatment and Prevention of Adolescent Spinal Health Public Service Platform,No.S2002Q84500835(to LY)Shenzhen Medical Research Fund,No.B2303005(to LY)Team-based Medical Science Research Program,No.2024YZZ02(to LY)Zhejiang Provincial Natural Science Foundation of China,No.LWQ20H170001(to RL)Basic Research Project of Shenzhen Science and Technology from Shenzhen Science and Technology Innovation Commission,No.JCYJ20210324103010029(to BY)Shenzhen Second People’s Hospital Clinical Research Fund of Guangdong Province High-level Hospital Construction Project,Nos.2023yjlcyj029(to BY),2023yjlcyj021(to LL)Guangdong Basic and Applied Basic Research Foundation,No.2022A1515110679(to LL)China Postdoctoral Science Foundation,No.2022M722203(to GL).
文摘Peripheral nerve injury causes severe neuroinflammation and has become a global medical challenge.Previous research has demonstrated that porcine decellularized nerve matrix hydrogel exhibits excellent biological properties and tissue specificity,highlighting its potential as a biomedical material for the repair of severe peripheral nerve injury;however,its role in modulating neuroinflammation post-peripheral nerve injury remains unknown.Here,we aimed to characterize the anti-inflammatory properties of porcine decellularized nerve matrix hydrogel and their underlying molecular mechanisms.Using peripheral nerve injury model rats treated with porcine decellularized nerve matrix hydrogel,we evaluated structural and functional recovery,macrophage phenotype alteration,specific cytokine expression,and changes in related signaling molecules in vivo.Similar parameters were evaluated in vitro using monocyte/macrophage cell lines stimulated with lipopolysaccharide and cultured on porcine decellularized nerve matrix hydrogel-coated plates in complete medium.These comprehensive analyses revealed that porcine decellularized nerve matrix hydrogel attenuated the activation of excessive inflammation at the early stage of peripheral nerve injury and increased the proportion of the M2 subtype in monocytes/macrophages.Additionally,porcine decellularized nerve matrix hydrogel negatively regulated the Toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-κB axis both in vivo and in vitro.Our findings suggest that the efficacious anti-inflammatory properties of porcine decellularized nerve matrix hydrogel induce M2 macrophage polarization via suppression of the Toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-κB pathway,providing new insights into the therapeutic mechanism of porcine decellularized nerve matrix hydrogel in peripheral nerve injury.
文摘Objectives:High-grade serous ovarian cancer(HGSOC),the most common subtype of epithelial ovarian cancer(EOC),exhibits a mesenchymal phenotype characterized by fibrotic stroma and poor prognosis.Human epididymis protein 4(HE4),a key diagnostic biomarker for ovarian cancer,is involved in fibrotic processes in several non-malignant diseases.Given the clinical significance of stromal fibrosis in HGSOC and the potential link between HE4 and fibrosis,this study aimed to investigate the role of HE4 in the formation of stromal fibrosis in HGSOC.Methods:A total of 126 patients with gynecological conditions were included and divided into normal,benign,and EOC groups.Tissue stiffness was quantitatively measured and analyzed for its correlation with clinicopathological features.We further investigated the correlation between tumor stiffness and the expression levels of HE4 and fibroblast activation markers(α-smooth muscle actin(α-SMA)and fibroblast activation protein(FAP))in tumor tissues from 22 HGSOC patients.In vitro,primary fibroblasts were treated with recombinant HE4(rHE4)or conditioned media from HE4-knockdown ovarian cancer cells to assess fibroblasts activation and matrix contractility(Collagen gel contraction assays).In vivo,a subcutaneous xenograft model using HE4-knockdown cells was established to evaluate the effects of HE4 suppression on tumor growth and extensive extracellular matrix(ECM)remodeling.Results:Ovarian cancer tissues showed significantly increased stiffness compared to benign/normal groups,showing positive correlation with serum HE4 levels.High-stiffness HGSOC tumors exhibited upregulated expression of HE4,α-SMA,FAP,and collagen I.rHE4 stimulated fibroblast activation and enhanced matrix contractility,whereas HE4 knockdown in cancer cells abrogated these pro-fibrotic effects.In vivo,HE4-silenced xenografts displayed restricted tumor growth accompanied by reduced stromal expression ofα-SMA,FAP,and collagen I.Conclusion:Our findings suggest that HE4 may facilitate ECM remodeling in HGSOC through promoting fibroblast activation and increasing collagen deposition.
文摘第五代移动通信技术(5th-generation mobile communication technology,5G)网络对高速率、低时延、高可靠性的移动通信处理需求不断增加,对终端基带信道估计算法的高性能和低复杂度设计、矩阵处理动态范围提出挑战。针对上述问题,本文提出一种基于相关矩阵托普利兹(Toeplitz)特性的信道估计算法。依据信道的相干带宽特性计算信道相关矩阵并保留必要的较低矩阵阶数;基于相关矩阵的Toeplitz特性设计低复杂度的递归求逆算法,并针对加权矩阵乘法的元素重复性将矩阵乘法化简为矩阵点乘,简化加权矩阵运算;同时引入跟踪信噪比变化的缩放补偿因子对计算过程和结果分别进行缩放和补偿。理论分析和仿真结果显示,本文所提算法可在达到优异的信道估计性能条件下,有效降低运算复杂度,并极大降低算法矩阵处理的动态范围。
文摘In this paper,we study real symmetric Toeplitz matrices commutable with tridiagonal matrices, present more detailed results than those in [1], and extend them to nonsymmetric Toeplitz matrices. Also, complex Toeplitz matrices, especially the corresponding matrices of lower order, are discussed.
文摘An effective numerical algorithm for computing the determinant of a pentadiagonal Toeplitz matrix has been proposed by Xiao-Guang Lv and others [1]. The complexity of the algorithm is (9n + 3). In this paper, a new algorithm with the cost of (4n + 6) is presented to compute the determinant of a pentadiagonal Toeplitz matrix. The inverse of a pentadiagonal Toeplitz matrix is also considered.
基金supported in part by the National Natural Science Foundation of China(No.62071476)in part by China Postdoctoral Science Foundation(No.2022M723879)in part by the Science and Technology Innovation Program of Hunan Province,China(No.2021RC3080)。
文摘In this advanced exploration, we focus on multiple parameters estimation in bistatic Multiple-Input Multiple-Output(MIMO) radar systems, a crucial technique for target localization and imaging. Our research innovatively addresses the joint estimation of the Direction of Departure(DOD), Direction of Arrival(DOA), and Doppler frequency for incoherent targets. We propose a novel approach that significantly reduces computational complexity by utilizing the TemporalSpatial Nested Sampling Model(TSNSM). Our methodology begins with a multi-linear mapping mechanism to efficiently eliminate unnecessary virtual Degrees of Freedom(DOFs) and reorganize the remaining ones. We then employ the Toeplitz matrix triple iteration reconstruction method, surpassing the traditional Temporal-Spatial Smoothing Window(TSSW) approach, to mitigate the single snapshot effect and reduce computational demands. We further refine the highdimensional ESPRIT algorithm for joint estimation of DOD, DOA, and Doppler frequency, eliminating the need for additional parameter pairing. Moreover, we meticulously derive the Cramér-Rao Bound(CRB) for the TSNSM. This signal model allows for a second expansion of DOFs in time and space domains, achieving high precision in target angle and Doppler frequency estimation with low computational complexity. Our adaptable algorithm is validated through simulations and is suitable for sparse array MIMO radars with various structures, ensuring higher precision in parameter estimation with less complexity burden.
文摘In this paper, we construct one of the forms of totally positive Toeplitz matrices from upper or lower bidiagonal totally nonnegative matrix. In addition, some properties related to this matrix involving its factorization are presented.
基金supported by the National Natural Science Foundation of China(Grant Nos.62071015 and 62171264)。
文摘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.
文摘A fast Cholesky decomposition and a fast inverse Cholesky decomposition method for A T A are presented,where A is an m×n rectangular Toeplitz block matrix,we give the FCD algorithm for computing R , and the FICD algorithm for computing R -1 ,both allow for an efficient parallel implementation,for solving a least squares problem and require only O(mn) operations.
文摘船载高频地波雷达(High Frequency Surface Wave Radar, HFSWR)的平台机动运动会使目标回波信号发生展宽,引起目标回波幅度和信噪比降低,进而对目标波达方向估计(Direction of Arrival, DOA)产生不利的影响。针对船载地波雷达展宽目标DOA估计问题,本文提出了一种基于时频信息Toeplitz协方差重构的展宽目标DOA估计方法。该方法首先采用结合航向补偿的时频分析处理,来提取展宽目标信号的脊线,可为充分利用展宽目标时频信息来构建协方差矩阵奠定基础。然后对构建的协方差矩阵进行Toeplitz化,实现了非平稳噪声的抑制,提高了目标信噪比,解决了展宽目标信噪比下降的问题,从而实现目标的方位角估计。最后,通过仿真和实测数据对本文提出的方法进行验证,结果表明本文所提方法在相同信噪比和目标展宽程度下均方根误差比单峰值MUSIC和DBF方法减小了1.2°,证明了本文所提方法的有效性。
文摘为提升互质阵列对相干信号的估计性能,提出了基于多重Toeplitz矩阵重构的互质阵列相干信号波达方向(direction of arrival,DOA)估计方法。该方法首先将互质阵列构造为共轭增广虚拟阵列;其次,通过插值补零将共轭增广虚拟阵列变为虚拟均匀线阵;然后,利用窄带信号在不同快拍数下的强相关性和噪声的弱相关性构造时空相关矩阵,并使用时空相关矩阵的所有行重构Toeplitz矩阵;最后,使用子空间方法得到DOA估计结果。理论分析和试验结果表明,与现有的矩阵重构方法相比,该方法在低信噪比和少快拍数的情况下具有良好的估计性能和分辨能力。
