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Approximation Algorithms for Graph Partition into Bounded Independent Sets

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Tsinghua Science and Technology 2023年第6期28卷 1063-1071页

作者： Jingwei Xie Yong Chen An Zhang Guangting chen Department of Mathematics Hangzhou Dianzi UniversityHangzhou 310018China Zhejiang University of Water Resources and Electric Power Hangzhou 310018China

The partition problem of a given graph into three independent sets of minimizing the maximum one is studied in this paper.This problem is NP-hard,even restricted to bipartite graphs.First,a simple 3/2-approximation algorithm for any 2-colorable graph is presented.An improved 7/5-approximation algorithm is then designed for a tree.The theoretical proof of the improved algorithm performance ratio is constructive,thus providing an explicit partition approach for each case according to the cardinality of two color classes.

关键词： graph partition independent set 2-colorable graph approximation algorithm

Skeleton-trimmed leggero pillar[5]arene:Amorphous and non-porous material for highly-selective haloalkane separation

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Chinese Chemical Letters 2023年第2期34卷 1-2页

作者： Xiao-yong Yu Yong Chen College of Chemistry State Key Laboratory of Elemento-Organic ChemistryNankai UniversityTianjin 300071 China

Halogenated alkanes are high-value chemical feedstocks in synthetic chemistry and petrochemical industry[1,2].Therefore,the separation of halogenated alkane isomers is one of the necessary chemical processes in the petrochemical industry.However,the isomers normally have close boiling points due to the same molecular weight and similar chemical structure,which makes it difficult to separate the isomers with high purity by traditional methods such as distillation.Consequently,it is of great significance for petrochemical industry to find an efficient and energy-saving scheme to separate halogenated alkanes isomers.

关键词： isomers separation alkanes

Integrability and Exact Solutions of the(2+1)-dimensional KdV Equation with Bell Polynomials Approach

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Acta Mathematicae Applicatae Sinica 2022年第4期38卷 861-881页

作者： Jun-cai PU Yong Chen School of Mathematical Sciences Shanghai Key Laboratory of Pure Mathematics and Mathematical PracticeEast China Normal UniversityShanghai 200062China College of Mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590China

In this paper,the bilinear formalism,bilinear B?cklund transformations and Lax pair of the(2+1)-dimensional KdV equation are constructed by the Bell polynomials approach.The N-soliton solution is derived directly from the bilinear form.Especially,based on the two-soliton solution,the lump solution is given out analytically by taking special parameters and using Taylor expansion formula.With the help of the multidimensional Riemann theta function,multiperiodic(quasiperiodic)wave solutions for the(2+1)-dimensional KdV equation are obtained by employing the Hirota bilinear method.Moreover,the asymptotic properties of the one-and two-periodic wave solution,which reveal the relations with the single and two-soliton solution,are presented in detail.

关键词： the bilinear formalism bilinear B?cklund transformations Lax pair lump solution periodic wave solution the asymptotic properties

Strongly HN-positivity, uniformly RC k-positivity and rational connectedness

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Acta Mathematica Sinica,English Series 2024年

作者： Yong Chen Nanjing University of Science and Technology School of Mathematics and Statistics

In this paper,we discuss the concept of HN-semipositive(HN-positive) vector bundle and also introduce strongly HN-semipositive vector bundle over compact complex manifold.Let M be a projective manifold with HN-semipositive tangent bundle.If M is rationally connected,we show that T1,0M is strongly HN-positive.We give a characterization of rationally connected compact K?hler manifolds with strongly HN-semipositive tangent bundle.In the second part,we show that a uniformly RC k-positivity implies mean curvature positivity.

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Linker-activated covalent organic frameworks with azo bridges

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中国化学快报:英文版 2023年第8期34卷 3-5页

作者： Wei-Lei Zhou Yong Chen College of Chemistry and Material Science Inner Mongolia Key Laboratory of Chemistry for Nature Products and Synthesis for Functional MoleculesInnovation Team of Optical Functional Molecular DevicesInner Mongolia Minzu UniversityTongliao 028000China College of Chemistry State Key Laboratory of Elemento-Organic ChemistryNankai UniversityTianjin 300071China

As an important functional group,azo derivatives(-N=N-)have attracted wide attention due to their excellent properties,for their narrow bandgap,Lewis base property,photo-isomerization and redox activity,in chemistry and materials science fields[1].Among them,azo-benzene is one of the most popular candidates of optical molecular devices including easy synthesis,high quantum yields and fast switching.Generally,azo-benzene exists in two conformations,i.***.trans-state and cis-state,which are reversibly conversed via-N=N-bond transformation in the presence of appropriate stimuli including temperature,mechanical stress,electric field,and especially photoirradiation[2].In addition,the azo group can not only endow the derivatives with narrow bandgap properties.

关键词： properties narrow benzene

Sustainable growth research–A study on the telecom operators in China

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Journal of Management Analytics 2022年第1期9卷 17-31页

作者： Hong chena Ling Li Yong Chen School of Business and Economics Indiana University EastRichmondINUSA College of Business and Public Administration Old Dominion UniversityNorfolkVAUSA Department of Management Information Systems and Data Analytics Texas A&M International UniversityLaredoTXUSA

In recent years,the telecom industry has faced digital transformation challenges and fierce market competition.The challenges push telecom operators to grow their subscriber bases by offering lower prices and improved services and new features,which puts pressure on operators’profitability.In addition,the rise of Internet companies gradually erodes the profit of the traditional telecom operators.Therefore,paying attention to the critical factors impacting firm sustainable growth can help operators get out of the predicament.Based on the resource-based view(RBV),this study explores the factors that influence the firm sustainable growth.Multiple regression model is applied to empirically test the hypotheses with longitudinal time-series panel data from major telecom operators in China.The study provides empirical evidence for sustainable growth research and useful insights for practitioners on the way to keep sustainable growth.

关键词： Sustainable growth telecom operator multiple regression model

Explore success factors that impact artificial intelligence adoption on telecom industry in China

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Journal of Management Analytics 2021年第1期8卷 36-68页

作者： Hong chen Ling Li Yong Chen Indiana University East RichmondIN 47374USA Old Dominion University Strome College of BusinessNorfolkVA 23529USA Texas A&M International University LaredoTX 78041USA

As the core driving force of the new round of informatization development and industrial revolution,the disruptive achievements of artificial intelligence(AI)are rapidly and comprehensively infiltrating into various fields of human activities.Although technologies and applications of AI have been widely studied and factors that affect AI adoption are identified in existing literature,the impact of success factors on AI adoption remains unknown.Accordingly,this paper proposes a framework to explore the impacts of success factors on AI adoption in telecom industry by integrating the technology,organization,and environment(TOE)framework and diffusion of innovation(DOI)theory.Particularly,this framework consists of factors regarding external environment,organizational capabilities,and innovation attributes of AI.The framework is empirically tested with data collected by surveying telecom companies in China.Structural equation modeling is applied to analyze the data.The study provides support for firms’decision-making and resource allocation regarding AI adoption.

关键词： Artificial intelligence(AI) adoption telecom industry TOE DOI structural equation modeling

Randomized Algorithms for Orthogonal Nonnegative Matrix Factorization

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Journal of the Operations Research Society of China 2023年第2期11卷 327-345页

作者： yong-Yong Chen Fang-Fang Xu College of Mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590ShandongChina

Orthogonal nonnegative matrix factorization(ONMF)is widely used in blind image separation problem,document classification,and human face recognition.The model of ONMF can be efficiently solved by the alternating direction method of multipliers and hierarchical alternating least squares method.When the given matrix is huge,the cost of computation and communication is too high.Therefore,ONMF becomes challenging in the large-scale setting.The random projection is an efficient method of dimensionality reduction.In this paper,we apply the random projection to ONMF and propose two randomized algorithms.Numerical experiments show that our proposed algorithms perform well on both simulated and real data.

关键词： Orthogonal nonnegative matrix factorization Random projection method Dimensionality reduction Augmented lagrangian method Hierarchical alternating least squares algorithm

PARAMETER ESTIMATION FOR AN ORNSTEIN-UHLENBECK PROCESS DRIVEN BY A GENERAL GAUSSIAN NOISE

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Acta Mathematica Scientia 2021年第2期41卷 573-595页

作者： Yong Chen Hongjuan ZHOU School of Mathematics and Statistics Jiangxi Normal UniversityNanchang 330022China School of Mathematical and Statistical Sciences Arizona State UniversityArizona 85287USA

In this paper,we consider an inference problem for an Ornstein-Uhlenbeck process driven by a general one-dimensional centered Gaussian process(G_(t))t≥0.The second order mixed partial derivative of the covariance function R(t,s)=E[GtGs]can be decomposed into two parts,one of which coincides with that of fractional Brownian motion and the other of which is bounded by(ts)^(β-1)up to a constant factor.This condition is valid for a class of continuous Gaussian processes that fails to be self-similar or to have stationary increments;some examples of this include the subfractional Brownian motion and the bi-fractional Brownian motion.Under this assumption,we study the parameter estimation for a drift parameter in the Ornstein-Uhlenbeck process driven by the Gaussian noise(G_(t))t≥0.For the least squares estimator and the second moment estimator constructed from the continuous observations,we prove the strong consistency and the asympotic normality,and obtain the Berry-Esséen bounds.The proof is based on the inner product's representation of the Hilbert space(h)associated with the Gaussian noise(G_(t))t≥0,and the estimation of the inner product based on the results of the Hilbert space associated with the fractional Brownian motion.

关键词： Fourth moment theorem Ornstein-Uhlenbeck process Gaussian process Malliavin calculus