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The linear self-attracting diffusion driven by the weighted-fractional Brownian motion II: The parameter estimation

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Science China Mathematics 2025年

作者： Litan Yan Rui Guo Wenyi Pei Department of statistics College of Science Donghua University School of statistics and Mathematics Zhejiang Gongshang University

Let Ba,bbe a weighted-fractional Brownian motion with Hurst indexes a and b such that a>-1and 0≤b<1∧（1+a）.In this paper,we consider the linear self-attracting diffusion ■ interacting diffusion (see Cranston and Le Jan （1995）).Under the continuous observation,we study asymptotic ■ converges in distribution to the sum of the chi-square random variable with 1 degree of freedom and the random variable Z1a,b.

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Orbits of Jacobi forms and theta relations

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Science China Mathematics 2025年

作者： Valery Gritsenko Haowu Wang Laboratoire Paul Painlevé Université de Lille International Laboratory for Mirror Symmetry and Automorphic Forms National Research University Higher School of Economics School of Mathematics and statistics Wuhan University

Jacobi theta functions with rational characteristics can be viewed as vector-valued Jacobi *** relations usually correspond to different constructions of certain Jacobi forms. From this observation, we extract a new approach, which is called orbits of Jacobi forms, to produce identities on Jacobi theta *** approach not only provides simple proofs of many known theta relations but also produces a large number of new identities, which can be considered as generalizations of Riemann’s theta relations.

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High-dimensional large-scale mixed-type data imputation under missing at random

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Science China Mathematics 2025年

作者： Wei Liu Guizhen Li Ling Zhou Lan Luo School of Mathematics Sichuan University Center of Statistical Research and School of statistics Southwestern University of Finance and Economics Department of statistics and Actuarial Science University of Iowa

Missingness in mixed-type variables is commonly encountered in a variety of areas. The requirement of complete observations necessities data imputation when a moderate or large proportion of data is ***, inappropriate imputation would downgrade the performance of machine learning algorithms, leading to bad predictions and unreliable statistical inference. For high-dimensional large-scale mixed-type missing data, we develop a computationally efficient imputation method, missing value imputation via generalized factor models（MIG）, under missing at random. The proposed MIG method allows missing variables to be of different types,including continuous, binary, and count variables, and are scalable to both data size n and variable dimension p while existing imputation methods rely on restrictive assumptions such as the same type of missing variables,the low dimensionality of variables, and a limited sample size. We explicitly show that the imputation error of the proposed MIG method diminishes to zero with the rate Op(max{n-1/2, p-1/2}) as both n and p tend to infinity. Five real datasets demonstrate the superior empirical performance of the proposed MIG method over existing methods that the average normalized absolute imputation error is reduced by 5.3%–34.1%.

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Asymptotic false discovery control of the Benjamini-Hochberg procedure for pairwise comparisons

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Science China Mathematics 2025年第1期 223-252页

作者： Weidong Liu Dennis Leung Qi-Man Shao School of Mathematical Sciences Shanghai Jiao Tong University School of Mathematics and statistics University of Melbourne Department of statistics and Data Science SICMSouthern University of Science and Technology

In a one-way analysis-of-variance(ANOVA) model,the number of pairwise comparisons can become large even with a moderate number of *** by this,we consider a regime with a growing number of groups and prove that,when testing pairwise comparisons,the Benjamini-Hochberg(BH) procedure can asymptotically control false discoveries,despite the fact that the involved t-statistics do not exhibit the wellknown positive dependence structure required for exact false discovery rate(FDR) *** Tukey's perspective that the difference between the means of any two groups cannot be exactly zero,our main result provides control over the directional false discovery rate and directional false discovery proportion.A key technical contribution of our work is demonstrating that the dependence among the t-statistics is sufficiently weak to establish the convergence result typically required for asymptotic FDR *** analysis does not rely on conventional assumptions such as normality,variance homogeneity,or a balanced design,thereby offering a theoretical foundation for applications in more general settings.

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Practical approach for detecting k-nonseparability of multipartite quantum states

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 32-48页

作者： Jie Guo Jinchuan Hou Xiaofei Qi Kan He College of Mathematics Taiyuan University of Technology School of Mathematics and statistics Shanxi University Key Laboratory of Complex Systems and Data Science of Ministry of Education Shanxi University

The instantaneous detection of entanglement in quantum states poses a significant challenge in the fields of quantum computation and quantum information, and there are no practical methods or tools to complete this task satisfactorily so far. We propose a sufficient and necessary criterion of k-nonseparability for any n-partite finite or infinite dimensional systems, 2 ≤ k ≤ n. This criterion serves as the foundation for a practical scheme designed to detect entanglement and k-nonseparability across multipartite finite-dimensional systems. To exemplify the application of our scheme, we have developed a software tool that facilitates swift and precise identification of entanglement, k-nonseparability, and genuine entanglement within n-qubit systems, specifically tailored for systems with 2 ≤ n ≤ 4.

关键词： multipartite systems entanglement states entanglement witnesses ${\bm~k}$-nonseparability

Dynamic behaviors of graphene platelets-reinforced metal foam piezoelectric beams with velocity feedback control

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 63-80页

作者： Jie CHEN Xinyue ZHANG Mingyang FAN School of Mathematics Statistics and Mechanics Beijing University of Technology College of Mechanical & Energy Engineering Beijing University of Technology

Graphene platelets(GPLs)-reinforced metal foam structures enhance the mechanical properties while maintaining the lightweight characteristics of metal foams. Further bonding piezoelectric actuator and sensor layers on the surfaces of GPLs-reinforced metal foam beams enables active vibration control, greatly expanding their applications in the aerospace industry. For the first time, this paper investigates the vibration characteristics and active vibration control of GPLs-reinforced metal foam beams with surfacebonded piezoelectric layers. The constant velocity feedback scheme is used to design the closed-loop controller including piezoelectric actuators and sensors. The effects of the GPLs on the linear and nonlinear free vibrations of the beams are numerically *** Newmark-β method combined with Newton's iteration technique is used to calculate the nonlinear responses of the beams under different load forms including harmonic loads,impact loads, and moving loads. Additionally, special attention is given to the vibration reduction performance of the velocity feedback control on the responses of the beam.

关键词： Piezoelectric actuators

Experimental Observing Damage Evolution in Cement Pastes Exposed to External Sulfate Attack by in situ X-ray Computed Tomography

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Journal of Wuhan University of Technology(Materials Science) 2025年第1期40卷 164-170页

作者： WU Min CAO Kailei XIAO Weirong YU Zetai CAO Jierong DING Qingjun LI Jinhui China Railway Construction Corporation Harbour and Channel Engineering bureau Group Co. LTDZhuhai 519000China Con-struction Headquarters of Zhoushan Liuheng Bridge Phase II Project Zhoushan 316000China China Railway Construction Bridge En-gineering bureau Group Co. LTDTianjin 300000China State Key Laboratory of Silicate Material for Architecture(Wuhan University of Technology) Wuhan 430070China College of Materials Science and Engineering Wuhan Textile UniversityWuhan 430200China

The paper presents experimental investigation results of crack pattern change in cement pastes caused by external sulfate attack(ESA).To visualize the formation and development of cracks in cement pastes under ESA,an X-ray computed tomography(X-ray CT)was used,i e,the tomography system of Zeiss Xradia 510 *** results indicate that X-CT can monitor the development process and distribution characteristics of the internal cracks of cement pastes under ESA with attack *** addition,the C3A content in the cement significantly affects the damage mode of cement paste specimens during sulfate *** damage of ordinary Portland cement(OPC)pastes subjected to sulfate attack with high C3A content are severe,while the damage of sulfate resistant Portland cement(SRPC)pastes is much smaller than that of OPC ***,a quadratic function describes the correlation between the crack volume fraction and development depth for two cement pastes immermed in sulfate solution.

关键词： concrete external sulfate attack damage evolution situ X-ray computed tomography

Sharp Bounds for Upper and Bottom Spectrum of Hermitizable Tridiagonal Matrices

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Journal of Mathematical Research with Applications 2025年第1期 125-132页

作者： Yueshuang LI Lingdi WANG School of statistics Capital University of Economics and Business School of Mathematics and statistics Henan University

We display sharp bounds for upper and lower spectrum of a Hermitizable tridiagonal matrix. The representations are brought to light by exploiting the characteristic for eigenpairs(eigenvalue and its corresponding eigenvector) of tridiagonal matrices, isospectral transforms and sharp bounds for speed stability of birth-death processes.

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Survey and Monitoring Report of Migrant Workers in 2011

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China Population Today 2012年第4期29卷 21-30页

作者： national bureau of statistics national bureau of statistics

The Total Population Size of Migrant Workers 1. Number of migrant workers continue to increase with a total amount of 252.78 million Estimated from the result of sample survey, the number of migrant workers of China in 2011 totaled 252.78 million, an increase of 10.55 million compared with last year, 4.4% up. Of whom, 158.63 million

关键词：农民工监测报告人口规模抽样调查同比增长美元

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