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A New Inversion-free Iterative Method for Solving the Nonlinear Matrix Equation and Its Application in Optimal Control
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作者 GAO Xiangyu XIE Weiwei ZHANG Lina 《应用数学》 北大核心 2026年第1期143-150,共8页
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
关键词 Nonlinear matrix equation Maximal positive definite solution Inversion-free iterative method Optimal control
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A New Image Encryption Algorithm Based on Cantor Diagonal Matrix and Chaotic Fractal Matrix
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作者 Hongyu Zhao Shengsheng Wang 《Computers, Materials & Continua》 2026年第1期636-660,共25页
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
关键词 Image encryption spatiotemporal chaotic system chaotic fractal matrix cantor diagonal matrix
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Cancer cell-dependent increase in senescence-like populationsfollowing exosome treatment:The role of extracellular matrix andcellular glycocalyx
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作者 Ilya D Klabukov Anastas Kisel +2 位作者 Elena Yatsenko Yana Sulina Denis S Baranovskii 《World Journal of Stem Cells》 2026年第1期108-111,共4页
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
关键词 Cancer Extracellular matrix GLYCOCALYX EXOSOMES Extracellular vesicles Tumor microenvironment
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A Kind of Fast Iterative Methods With the Application Based on Diagonal Matrix Splitting
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作者 XU Qiuyan 《宁夏大学学报(自然科学版中英文)》 2026年第1期1-13,共13页
The fast solution of linear equations has always been one of the hot spots in scientific computing.A kind of the diagonal matrix splitting iteration methods are provided,which is different from the classical matrix sp... The fast solution of linear equations has always been one of the hot spots in scientific computing.A kind of the diagonal matrix splitting iteration methods are provided,which is different from the classical matrix splitting methods.Taking the decomposition of the diagonal elements for coefficient matrix as the key point,some new preconditioners are constructed.Taking the tri-diagonal coefficient matrix as an example,the convergence domains and optimal relaxation factor of the new method are analyzed theoretically.The presented new iteration methods are applied to solve linear algebraic equations,even 2D and 3D diffusion problems with the fully implicit discretization.The results of numerical experiments are matched with the theoretical analysis,and show that the iteration numbers are reduced greatly.The superiorities of presented iteration methods exceed some classical iteration methods dramatically. 展开更多
关键词 ITERATION matrix splitting diffusion equation CONVERGENCE optimal relaxation factor
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Matrix effect of hydroxycinnamic acids on chromatic properties and phenolic profile of Cabernet Sauvignon dry red wine
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作者 Lulu Wu Yu Zhang +5 位作者 Mario Prejanò Tiziana Marino Nino Russo Guojie Jin Yongsheng Tao Yunkui Li 《Journal of Integrative Agriculture》 2026年第1期339-351,共13页
The effect of adding hydroxycinnamic acids(caffeic acid,sinapic acid,p-coumaric acid and chlorogenic acid)in Cabernet Sauvignon dry red wine before and after fermentation was investigated,taking into account the color... The effect of adding hydroxycinnamic acids(caffeic acid,sinapic acid,p-coumaric acid and chlorogenic acid)in Cabernet Sauvignon dry red wine before and after fermentation was investigated,taking into account the color parameters,anthocyanin content,and overall polyphenol levels in the wine samples.The copigmentation effect of malvidin-3-Oglucoside and sinapic acid was further explored in model solution and through theoretical calculations.The results indicated that the addition of hydroxycinnamic acids significantly enhanced the wine's color with sinapic acid(before the fermentation)showing the most pronounced color protection effect.Compared to control samples,the addition of hydroxycinnamic acids resulted in a 36%increase in total phenolic content and a 28% increase in total anthocyanin content.Thermodynamic analysis revealed that the interaction between sinapic acid and malvidin-3-O-glucoside was spontaneous and exothermic.Theoretical studies identified hydrogen bonding(HB)and dispersion forces as the main primary stabilizing forces,with the carboxyl group of sinapic acid playing a critical role while the anthocyanin backbone also influenced the interaction. 展开更多
关键词 matrix effect dry red wine POLYPHENOL hydroxycinnamic acids anthocyanins
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Preparation of digital-encoded and analog-encoded quantum states corresponding to matrix operations
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作者 Kaitian Gao Youlong Yang Zhenye Du 《Chinese Physics B》 2026年第1期332-344,共13页
Efficient implementation of fundamental matrix operations on quantum computers,such as matrix products and Hadamard operations,holds significant potential for accelerating machine learning algorithms.A critical prereq... Efficient implementation of fundamental matrix operations on quantum computers,such as matrix products and Hadamard operations,holds significant potential for accelerating machine learning algorithms.A critical prerequisite for quantum implementations is the effective encoding of classical data into quantum states.We propose two quantum computing frameworks for preparing the distinct encoded states corresponding to matrix operations,including the matrix product,matrix sum,matrix Hadamard product and division.Quantum algorithms based on the digital encoding computing framework are capable of implementing the matrix Hadamard operation with a time complexity of O(poly log(mn/ε))and the matrix product with a time complexity of O(poly log(mnl/ε)),achieving an exponential speedup in contrast to the classical methods of O(mn)and O(mnl).Quantum algorithms based on the analog-encoding framework are capable of implementing the matrix Hadamard operation with a time complexity of O(k_(1)√mn·poly log(mn/ε))and the matrix product with a time complexity of O(k_(2)√1·poly log(mnl/ε)),where k_(1)and k_(2)are coefficients correlated with the elements of the matrix,achieving a square speedup in contrast to the classical counterparts.As applications,we construct an oracle that can access the trace of a matrix within logarithmic time,and propose several algorithms to respectively estimate the trace of a matrix,the trace of the product of two matrices,and the trace inner product of two matrices within logarithmic time. 展开更多
关键词 quantum algorithm matrix operation digital and analog-encoded states quantum computing
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Anisotropic thermal conductivity of aluminum matrix composites reinforced by graphene nanoplates and ZrB_(2) nanoparticles
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作者 Chuang Guan Xizhou Kai +3 位作者 Wei Qian Ran Tao Gang Chen Yutao Zhao 《International Journal of Minerals,Metallurgy and Materials》 2026年第2期636-646,共11页
This study investigates the anisotropic thermal conductivity of aluminum matrix composites reinforced with graphene nano-plates(GNPs)and in situ ZrB_(2) nanoparticles,while simultaneously maintaining high strength and... This study investigates the anisotropic thermal conductivity of aluminum matrix composites reinforced with graphene nano-plates(GNPs)and in situ ZrB_(2) nanoparticles,while simultaneously maintaining high strength and toughness.A discontinuous layered GNPs-ZrB_(2)/AA6111 composite was prepared using in situ melt reactions and semi-solid stirring casting technology,combined with hot rolling deformation processing.Microstructural analysis revealed that the GNPs were aligned parallel to the rolling direction-transverse direction(RD-TD)plane,whereas the ZrB_(2) nanoparticles aggregated into cluster strips,collectively forming a discontinuous layered structure.This multilayer arrangement maximized the in-plane thermal conductivity of the GNPs.The tightly bonded GNP/Al interfaces with the locking of CuAl_(2) nanoparticles ensured that the GNPs fully exploited their high thermal conductivity.Therefore,the GNPs-ZrB_(2)/AA6111 composite achieved high in-plane thermal conductivity(230 W/(m·K)),which is higher than that of the matrix(206 W/(m·K)).The improved in-plane thermal conductivity is primarily attributed to the exceptionally high intrinsic in-plane thermal conductivity of the GNPs and their two-dimensional layered structure.However,the composite exhibited pronounced thermal conductivity anisotropy in the in-plane and through-plane directions.The reduced through-plane thermal conductivity is predominantly caused by the intrinsically low through-plane thermal conductivity of the GNPs and the increased interfacial thermal resistance from the additional grain boundaries. 展开更多
关键词 aluminum matrix composites graphene nanoplates microstructure anisotropic thermal conductivity heat transport mechanisms
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Tailoring Dielectric Properties of Polymer Matrix Composites for High-performance Flexible Sensors
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作者 Jun Li Kit-Ming Ma +1 位作者 Li-Sha Zhang Xiao-Ming Tao 《Chinese Journal of Polymer Science》 2026年第1期116-126,I0012,共12页
Polymer matrix composites with high dielectric constants and low dielectric losses are in high demand for flexible electronics.However,simultaneously satisfying these requirements poses a significant scientific challe... Polymer matrix composites with high dielectric constants and low dielectric losses are in high demand for flexible electronics.However,simultaneously satisfying these requirements poses a significant scientific challenge owing to the intrinsic trade-off relationship.Herein,we utilized the in situ controllable reduction of graphene oxide(GO)within a poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene)(P(VDF-Tr FE-CFE))matrix to regulate the dielectric properties.The as-obtained composite exhibited a high relative dielectric constant of 1415coupled with a low loss tangent of 0.380 at 100 Hz.Experimental and theoretical studies indicate that the increased degree of electron conjugation and conductivity of the reduced GO(RGO)are responsible for the high-k.The constrained reduction degree of GO,combined with its homogeneous dispersion in the polymer matrix,effectively suppresses long-range charge carrier migration,thereby minimizing dielectric loss.This novel strategy could be successfully applied to both organic and aqueous systems.Furthermore,a high-performance flexible capacitive proximity sensor was exemplified by the optimization of both the dielectric layer and electrode pattern,exhibiting excellent sensitivity and stability.The fundamental mechanisms elucidated in this study provide crucial design principles for developing dielectric PMCs with tailored properties,thereby opening new avenues for advanced flexible electronic applications. 展开更多
关键词 Dielectric property regulation HIGH-K Polymer matrix composites(PMCs) Capacitive proximity sensor
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Porcine decellularized nerve matrix hydrogel attenuates neuroinflammation after peripheral nerve injury by inhibiting the TLR4/MyD88/NF-κB axis
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作者 Rui Li Jianquan Liu +7 位作者 Liuxun Li Guotian Luo Xinrong Yuan Shichao Shen Yongpeng Shi Jianlong Wu Bin Yan Lei Yang 《Neural Regeneration Research》 2026年第3期1222-1235,共14页
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
关键词 anti-inflammatory reaction macrophage polarization NEUROINFLAMMATION peripheral nerve injury porcine decellularized nerve matrix hydrogel
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TMF inhibits extracellular matrix degradation in osteoarthritis cartilage by regulating the Sirt1/STAT3 signaling pathway
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作者 CHENG Qilai JIAO Linhui WU Longhuo 《赣南医科大学学报》 2026年第1期7-15,共9页
Objective:Osteoarthritis(OA)is a degenerative joint disease characterized by extracellular matrix(ECM)degradation,chondrocyte apoptosis,and chronic inflammation.Cartilage destruction and ECM degeneration contribute to... Objective:Osteoarthritis(OA)is a degenerative joint disease characterized by extracellular matrix(ECM)degradation,chondrocyte apoptosis,and chronic inflammation.Cartilage destruction and ECM degeneration contribute to joint function loss and disability.Signal transducer and activator of transcription 3(STAT3)up-regulates the expression of MMP-13,which degrades collagen Ⅱ.Our previous study found that 5,7,3',4'-tetramethoxyflavone(TMF)exhibited protective effects on OA chondrocytes.This study aims to investigate the protective role of TMF in inhibiting ECM degradation by mediating the Sirt1/STAT3 signaling pathway.Methods:Rat OA models were established by the injection of monosodium iodoacetate(MIA).Hematoxylin&eosin(HE)staining and immunohistochemistry(IHC)analysis were performed.IL-1β stimulated C28/I2 cells were used as OA-like chondrocyte cell model.Western blotting assays were used to determine the protein expression.Results:The expression of MMP-13 was upregulated while type Ⅱ collagen expression is downregulated,and the phosphorylation level of STAT3 is increased in rat OA models.TMF reverses the STAT3-mediated expression of MMP-13 and type v collagen.Activation of STAT3 or inhibition of Sirt1 function attenuates the inhibitory effect of TMF on ECM degradation.Conclusion:TMF can inhibit ECM degradation mediated by the STAT3 signal pathway by activating Sirt1 expression in OA cell and animal models. 展开更多
关键词 OSTEOARTHRITIS Extracellular matrix degradation CHONDROCYTES 5 7 3' 4'-tetramethoxyflavone Signal transduction and activator of transcription
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HE4 Might Participate in Extracellular Matrix Remodeling in Ovarian Cancer via Activation of Fibroblasts
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作者 Yimin Liu Bin Liu +8 位作者 Huabin Gao Jinlong Wang Jingya Duan Xiaolan Huang Yuexi Liu Ying Huang Wenjing Liao Ruonan Li Hua Linghu 《Oncology Research》 2026年第1期364-381,共18页
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
关键词 Ovarian cancer extensive extracellular matrix(ECM) FIBROBLAST human epididymis protein 4(HE4) α-smooth muscle actin(α-SMA)
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基于Matrix Core的高性能多维FFT设计与优化 被引量:1
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作者 陆璐 祝松祥 +2 位作者 田卿燕 林海山 郭逸劼 《华南理工大学学报(自然科学版)》 北大核心 2025年第3期20-30,共11页
快速傅里叶变换(FFT)算法广泛应用于科学计算等领域。为了充分挖掘图形处理器(GPU)的计算能力并进一步提高FFT的计算效率,该文针对矩阵形式的Stockham FFT,提出了一种基于Matrix Core的高性能多维FFT计算方案。在计算优化方面,该方案利... 快速傅里叶变换(FFT)算法广泛应用于科学计算等领域。为了充分挖掘图形处理器(GPU)的计算能力并进一步提高FFT的计算效率,该文针对矩阵形式的Stockham FFT,提出了一种基于Matrix Core的高性能多维FFT计算方案。在计算优化方面,该方案利用Matrix Core加速FFT计算中的矩阵乘运算,同时通过编译器内部指令完成小粒度的矩阵乘加,使得Matrix Core支持更多尺寸的FFT计算。在内存优化方面,该方案使用2层迭代策略,以充分利用共享内存,减少与全局内存的数据交换;根据Matrix Core的矩阵数据在各个线程寄存器中的分布规律,直接在寄存器上完成FFT计算中大量存在的矩阵逐元素乘操作;通过对共享内存中的数据进行重排来缓解存储体冲突,并采用双缓冲策略缓解访存瓶颈。该文还提出了高效的矩阵转置策略,以加速多维FFT计算。在AMD MI250 GPU平台上将该方案与GPU上主流的高性能FFT计算库rocFFT和VkFFT进行了比较实验,结果表明:该方案在AMD MI250上的1维、2维和3维FFT平均计算效率均优于rocFFT和VkFFT,3维FFT的平均计算效率为rocFFT的1.5倍,为VkFFT的2.0倍,具有较好的性能提升;mcFFT的计算精度与rocFFT和VkFFT保持在相同水平。 展开更多
关键词 图形处理器 matrix Core 快速傅里叶变换 矩阵乘法
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基于Matrix Core的小尺寸批量矩阵乘法设计与优化
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作者 陆璐 赵容 +1 位作者 梁志宏 索思亮 《华南理工大学学报(自然科学版)》 北大核心 2025年第9期48-58,共11页
通用矩阵乘法(GEMM)是线性代数中最重要的运算,来自不同科学领域的许多应用程序都将其关键部分转换为使用GEMM的形式。GEMM广泛应用于大模型、机器学习、科学计算和信号处理等领域。特别是半精度的批处理GEMM(即FP16)一直是许多深度学... 通用矩阵乘法(GEMM)是线性代数中最重要的运算,来自不同科学领域的许多应用程序都将其关键部分转换为使用GEMM的形式。GEMM广泛应用于大模型、机器学习、科学计算和信号处理等领域。特别是半精度的批处理GEMM(即FP16)一直是许多深度学习框架的核心操作。目前AMD GPU上半精度批处理GEMM的访存和计算利用率不足,急需优化。为此,该文提出了一种半精度批处理GEMM(HGEMM)的图形处理器(GPU)优化方案。分块策略方面,根据输入矩阵块大小为线程分配相同的访存量和计算量,同时线程计算多个矩阵乘法,以提高计算单元的利用率。访存优化方面,以多读数据为代价,为每个线程分配相同访存量以便于编译器优化,保证访存和计算时间相互掩盖。对于矩阵尺寸小于16的极小尺寸批处理HGEMM,该文利用4×4×4的Matrix Core及其对应的分块方案,在提升访存性能的同时减少Matrix Core计算资源的浪费,并提供是否使用共享内存的选项来达到最高性能。在AMD GPU MI210平台上,将该方案与rocBLAS的2个算子进行性能对比,结果表明:该方案在AMD GPU MI210上的平均性能为rocBLASHGEMMBatched的4.14倍,rocBLASGEMMExBatched的4.96倍;对于极小尺寸批处理HGEMM,平均性能为rocBLASHGEMMBatched的18.60倍,rocBLASGEMMExBatched的14.02倍。 展开更多
关键词 图形处理器 matrix Core 矩阵乘法 访存优化
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Walsh Spectral Characteristics and the Auto-Correlation Function Characteristics of Forming Orthomorphic Permutations of Multi-Output Functions 被引量:4
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作者 ZHAO Yaqun WANG Jue 《Wuhan University Journal of Natural Sciences》 CAS 2006年第6期1895-1898,共4页
Orthomorphic permutations have good characteristics in cryptosystems. In this paper, by using of knowledge about relation between orthomorphic permutations and multi-output functions, and conceptions of the generalize... Orthomorphic permutations have good characteristics in cryptosystems. In this paper, by using of knowledge about relation between orthomorphic permutations and multi-output functions, and conceptions of the generalized Walsh spectrum of multi-output functions and the auto-correlation function of multi-output functions to investigate the Walsh spectral characteristics and the auto-correlation function characteristics of orthormophic permutations, several results are obtained. 展开更多
关键词 orthomorphic permutation multi-output functions walsh spectral auto-correlation function
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Biometric feature extraction using local fractal auto-correlation 被引量:3
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作者 陈熙 张家树 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第9期335-340,共6页
Image texture feature extraction is a classical means for biometric recognition. To extract effective texture feature for matching, we utilize local fractal auto-correlation to construct an effective image texture des... Image texture feature extraction is a classical means for biometric recognition. To extract effective texture feature for matching, we utilize local fractal auto-correlation to construct an effective image texture descriptor. Three main steps are involved in the proposed scheme: (i) using two-dimensional Gabor filter to extract the texture features of biometric images; (ii) calculating the local fractal dimension of Gabor feature under different orientations and scales using fractal auto-correlation algorithm; and (iii) linking the local fractal dimension of Gabor feature under different orientations and scales into a big vector for matching. Experiments and analyses show our proposed scheme is an efficient biometric feature extraction approach. 展开更多
关键词 fractal auto-correlation fractal dimension Gabor filter biometric recognition
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SPEECH ENHANCEMENT BASED ON DYNAMIC NOISE ESTIMATION WITHIN AUTO-CORRELATION DOMAIN
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作者 WU Ya-dong(吴亚栋) +1 位作者 WU Xu-hui(吴旭辉) 《Journal of Shanghai Jiaotong university(Science)》 EI 2002年第2期211-214,共4页
Most noise suppression algorithms of single channel use the mean of noisy segments to estimate the characteristics of noise spectrum, ignoring the estimation of noise in speech segments. Therefore, when the energy lev... Most noise suppression algorithms of single channel use the mean of noisy segments to estimate the characteristics of noise spectrum, ignoring the estimation of noise in speech segments. Therefore, when the energy level of noise varies with the time, the performance of removing noise will be degraded. To solve this problem, a speech enhancement approach based on dynamic noise estimation within correlation domain was proposed. This method exploits the characteristics that noise energy mainly concentrates on 0 th order correlation coefficients, signal is auto correlated but signal and noise, noise and noise are uncorrelated, then estimates and decomposes the noise, thus helps to solve the above mentioned problem. The results of recognition experiments on speech signals of 15 Chinese cities’ names corrupted by noise of exhibition hall shows, this approach is better than SS (Spectral Subtraction) method, adapts better to the variances of energy levels of speech signal corrupted by noise, has some practicability to improve the robustness of recognition systems under noisy environment. 展开更多
关键词 SPEECH enhancement noise SUPPRESSION auto-correlation DOMAIN SPECTRAL SUBTRACTION
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Chrestenson Spectrum and Auto-Correlation Function of Inverse Permutations of Quick Trickle Permutations
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作者 WANG Jue LI Zhengchao ZHAO Yaqun 《Wuhan University Journal of Natural Sciences》 CAS 2008年第5期587-590,共4页
In this paper, a sufficient and necessary condition of quick trickle permutations is given from the point of inverse permutations. The bridge is built between quick trickle permutations and m-value logic functions. By... In this paper, a sufficient and necessary condition of quick trickle permutations is given from the point of inverse permutations. The bridge is built between quick trickle permutations and m-value logic functions. By the methods of the Chrestenson spectrum of m-value logic functions and the auto-correlation function of m-value logic functions to investigate the Chrestenson spectral characteristics and the auto-correlation function charac- teristics of inverse permutations of quick trickle permutations, a determinant arithmetic of quick trickle permutations is given. Using the results, it becomes easy to judge that a permutation is a quick trickle permutation or not by using computer. This gives a new pathway to study constructions and enumerations of quick trickle permutations. 展开更多
关键词 quick trickle permutation chrestenson spectrum auto-correlation function m-value logic function
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Cyclic-Auto-Correlation Based Timing Estimation Algorithm for Time-Frequency Overlapping Multi-Carrier Signals
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作者 Xing Zhang Jian-Hao Hu 《Journal of Electronic Science and Technology》 CAS CSCD 2020年第3期223-233,共11页
In recent years,the time-frequency overlapping multi-carrier signal has been a novel and valuable topic in blind signal processing,especially in the non-cooperative receiving field.But there is little related research... In recent years,the time-frequency overlapping multi-carrier signal has been a novel and valuable topic in blind signal processing,especially in the non-cooperative receiving field.But there is little related research in public published papers.This paper proposes two timing estimation algorithms,which are non-data-aided and based on the cyclic auto-correlation function.In order to evaluate the performance of the proposed algorithms,the theoretical bound of the timing estimation is derived.According to the analyses and simulation results,the effectiveness of the proposed algorithms has been demonstrated.It shows that MethodⅠhas better performance than MethodⅡ.However,MethodⅡdoes not need prior information,so it has a wider range of applications. 展开更多
关键词 Cyclic auto-correlation orthogonal frequency division multiplexing(OFDM) time-frequency overlapping signal timing estimation
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Monitoring Bridge Deformation Using Auto-Correlation Adjustment Technique for Total Station Observations
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作者 Ashraf Abd El-Wanis Beshr Mosbeh R. Kaloop 《Positioning》 2013年第1期1-7,共7页
Bridges are omnipresent in every society and they affect its human, social, ecological, economical and cultural aspects. This is why a durable and safe usage of bridges is an imperative goal of structural management. ... Bridges are omnipresent in every society and they affect its human, social, ecological, economical and cultural aspects. This is why a durable and safe usage of bridges is an imperative goal of structural management. Measurement and monitoring have an essential role in structural management. The benefits of the information obtained by monitoring are apparent in several domains. In deformation analysis, the functional relationship between the acting forces and the resulting deformations should be established. If time depending observations are given, a regression could be used as a functional model. In case of stochastic model uncorrelated observations with identical variance are assumed. Due to the high sampling rate, a small time difference arises between two observations. Thus the assumed stochastic model is not suitable. The calculation has to be effected by means of auto-correlated observations. This paper investigates an integrated monitoring system for the estimation of the deformation (i.e., static, quasi-static) behavior of bridges from total station observations and studies the effect of autocorrelation technique on the accuracy of the estimated parameters and variances. The results have shown that autocorrelation technique is reduced the standard deviation of X&Y-direction about 6.7% to 29.4% and 6.5% to 15.5% of the original value, respectively, but the situation was differ in Z direction;the standard deviation in vertical component Z was increased. 展开更多
关键词 MONITORING TOTAL STATION auto-correlation BRIDGES DEFORMATION
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Fingerspelling Recognition by Hand Shape Using Higher-Order Local Auto-Correlation Features
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作者 Yoshihiro Mitani Takuya Kanemura +1 位作者 Yusuke Fujita Yoshihiko Hamamoto 《Computer Technology and Application》 2012年第12期784-788,共5页
The fingerspelling recognition by hand shape is an important step for developing a human-computer interaction system. A method of fingerspelling recognition by hand shape using HLAC (higher-order local auto-correlat... The fingerspelling recognition by hand shape is an important step for developing a human-computer interaction system. A method of fingerspelling recognition by hand shape using HLAC (higher-order local auto-correlation) features is proposed. Furthermore, in order to use HLAC features more effectively, the use of image processing techniques: reducing an image resolution, dividing an image, and image pre-processing techniques, is also proposed. The experimental results show that the proposed method is promising. 展开更多
关键词 Image processing techniques fingerspelling recognition HLAC (higher-order local auto-correlation features.
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