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Isoparametric hypersurfaces in Funk spaces

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science China mathematics 2017年第12期60卷 2447-2464页

作者： HE Qun YIN SongTing SHEN YiBing School of Mathematical sciences Tongji University department of mathematics and computer science Tongling University department of mathematics Zhejiang University

Funk metrics are a kind of important Finsler metrics with constant negative flag curvature. In this paper, it is proved that any isoparametric hypersurface in Funk spaces has at most two distinct principal curvatures.... 详细信息

关键词： Finsler-Laplacian isoparametric hypersurfaces Funk metric principal curvature

Subordination and Superordination Properties for a Class of Integral Operators

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Acta Mathematica Sinica,English Series 2010年第3期26卷 515-522页

作者： Nak Eun CHO Teodor BULBOACA department of Applied mathematics Pukyong National University Faculty of mathematics and computer science Babes-Bolyai University

In the present paper, we obtain some subordination- and superordinatiompreserving properties of certain integral operators defined on the space of normalized analytic functions in the open unit disk. The sandwich-type... 详细信息

关键词： differential subordination differential superordination univalent functions convex functions integral operators

Advances in therapies using mesenchymal stem cells and their exosomes for treatment of peripheral nerve injury:state of the art and future perspectives

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Neural Regeneration Research 2025年第11期20卷 3151-3171页

作者： Fatima Aldali Chunchu Deng Mingbo Nie Hong Chen department of Rehabilitation Medicine Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubei ProvinceChina department of Orthopedics Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubei ProvinceChina

“Peripheral nerve injury”refers to damage or trauma affecting nerves outside the brain and spinal *** nerve injury results in movements or sensation impairments,and represents a serious public health *** severed peripheral nerves have been effectively joined and various therapies have been offered,recovery of sensory or motor functions remains limited,and efficacious therapies for complete repair of a nerve injury remain *** emerging field of mesenchymal stem cells and their exosome-based therapies hold promise for enhancing nerve regeneration and *** stem cells,as large living cells responsive to the environment,secrete various factors and *** latter are nano-sized extracellular vesicles containing bioactive molecules such as proteins,microRNA,and messenger RNA derived from parent mesenchymal stem *** have pivotal roles in cell-to-cell communication and nervous tissue function,offering solutions to changes associated with cell-based *** ongoing investigations,mesenchymal stem cells and mesenchymal stem cell-derived exosome-based therapies are in the exploratory stage.A comprehensive review of the latest preclinical experiments and clinical trials is essential for deep understanding of therapeutic strategies and for facilitating clinical *** review initially explores current investigations of mesenchymal stem cells and mesenchymal stem cell-derived exosomes in peripheral nerve injury,exploring the underlying ***,it provides an overview of the current status of mesenchymal stem cell and exosomebased therapies in clinical trials,followed by a comparative analysis of therapies utilizing mesenchymal stem cells and ***,the review addresses the limitations and challenges associated with use of mesenchymal stem cell-derived exosomes,offering potential solutions and guiding future directions.

关键词： clinical trials exosome extracellular vesicles mesenchymal stem cells nerve regeneration peripheral nerve injury pre-clinical experiments

Imputing missing values using cumulative linear regression

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CAAI Transactions on Intelligence Technology 2019年第3期4卷 182-200页

作者： Samih M. Mostafa Faculty of science Mathematics DepartmentComputer ScienceSouth Valley UniversityQena 83523Egypt

The concept of missing data is important to apply statistical methods on the dataset. Statisticians and researchers may end up to an inaccurate illation about the data if the missing data are not handled properly. Of late, Python and R provide diverse packages for handling missing data. In this study, an imputation algorithm, cumulative linear regression, is proposed. The proposed algorithm depends on the linear regression technique. It differs from the existing methods, in that it cumulates the imputed variables;those variables will be incorporated in the linear regression equation to filling in the missing values in the next incomplete variable. The author performed a comparative study of the proposed method and those packages. The performance was measured in terms of imputation time, root-mean-square error, mean absolute error, and coefficient of determination (R^2). On analysing on five datasets with different missing values generated from different mechanisms, it was observed that the performances vary depending on the size, missing percentage, and the missingness mechanism. The results showed that the performance of the proposed method is slightly better.

关键词： Imputing missing values cumulative linear regression statistical methods

A different approach for conformable fractional biochemical reaction–diffusion models

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Applied mathematics(A Journal of Chinese Universities) 2020年第4期35卷 452-467页

作者： Anas Arafa department of mathematics and computer science Faculty of SciencePort Said UniversityPort SaidEgypt

This paper attempts to shed light on three biochemical reaction-diffusion models:conformable fractional Brusselator,conformable fractional Schnakenberg,and conformable fractional *** is done using conformable residual power series(hence-form,CRPS)technique which has indeed,proved to be a useful tool for generating the ***,CRPS is an effective method of solving nonlinear fractional differential equations with greater accuracy and ease.

关键词： Brusselator model Schnakenberg model Gray-Scott model conformable fractional derivatives residual power series method

A probabilistic framework for optimizing projected clusters with categorical attributes

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science China(Information sciences) 2015年第7期58卷 144-158页

作者： CHEN LiFei School of mathematics and computer science Fujian Normal University

The ability to discover projected clusters in high-dimensional data is essential for many machine learning applications. Projective clustering of categorical data is currently a challenge due to the difficulties in learning adaptive weights for categorical attributes coordinating with clusters optimization. In this paper,a probability-based learning framework is proposed, which allows both the attribute weights and the centerbased clusters to be optimized by kernel density estimation on categorical attributes. A novel algorithm is then derived for projective clustering on categorical data, based on the new learning approach for the kernel bandwidth selection problem. We show that the attribute weight substantially connects to the kernel bandwidth, while the optimized cluster center corresponds to the normalized frequency estimator of the categorical *** results on synthesis and real-world data show outstanding performance of the proposed method,which significantly outperforms state-of-the-art algorithms.

关键词： projective clustering projected cluster categorical data probabilistic framework kernel density estimation attribute weighting

Decomposing Triples of Z_(p^n) and Z_(3p^n) into Cyclic Designs

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Acta Mathematica Sinica,English Series 2013年第11期29卷 2111-2128页

作者： Zi Hong TIAN Rui Zhong WEI College of mathematics and Information science Hebei Normal University department of computer science Lakehead University

In this paper, we give some decompositions of triples of Zp^n or Z3p^n into cyclic triple systems. New constructions of difference families are given. Some infinite classes of simple cyclic triple systems are obtained... 详细信息

关键词： Decomposition cyclic designs triple systems simple designs difference families

Second-order nonlinear differential operators possessing invariant subspaces of submaximal dimension

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Chinese Physics B 2011年第1期20卷 42-49页

作者：朱春蓉 College of mathematics and computer science Anhui Normal University

The invariant subspace method is used to construct the explicit solution of a nonlinear evolution equation. The second-order nonlinear differential operators that possess invariant subspaces of submaximal dimension are described. There are second-order nonlinear differential operators, including cubic operators and quadratic operators, which preserve an invariant subspace of submaximal dimension. A full. description, of the second-order cubic operators with constant coefficients admitting a four-dimensional invariant subspace is given. It is shown that the maximal dimension of invaxiant subspaces preserved by a second-order cubic operator is four. Several examples are given for the construction of the exact solutions to nonlinear evolution equations with cubic nonlinearities. These solutions blow up in a finite

关键词： nonlinear evolution equations cubic operators invariant subspace method submaximal dimension blow-up solution

EXISTENCE AND ANALYTICAL APPROXIMATIONS OF LIMIT CYCLES IN A THREE-DIMENSIONAL NONLINEAR AUTONOMOUS FEEDBACK CONTROL SYSTEM

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Journal of Systems science & Complexity 2014年第6期27卷 1158-1171页

作者： CHEN Huaxiong SHEN Jianhe ZHOU Zheyan School of mathematics and computer science Fujian Normal University

This paper is concerned with the existence and the analytical approximations of limit cycles in a three-dimensional nonlinear autonomous feedback control *** on three-dimensional Hopf bifurcation theorem,the existence of limit cycles is first *** the homotopy analysis method(HAM) is applied to obtain the analytical approximations of the limit cycle and its *** deriving the higher-order approximations,the authors utilized the idea of a perturbation procedure proposed for limit cycles' approximation in van der Pol *** comparing with the numerical integration solutions,it is shown that the accuracy of the analytical results obtained in this paper is very high,even when the amplitude of the limit cycle is large.

关键词： Homotopy analysis method Hopf bifurcation limit cycle three-dimensional nonlinearautonomous system.