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Global Optimization of Polynomials over Real Algebraic Sets

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Journal of Systems Science & Complexity 2019年第1期32卷 158-184页

作者： WANG Chu YANG zhi-hong zhi Lihong Beijing Jinghang Computation and Communication Research Institute KLMM Academy of Mathematics and Systems Science Chinese Academy of Sciences University of Chinese Academy of Sciences

Let f, g_1, ···, g_s be polynomials in R[X_1, ···, X_n]. Based on topological properties of generalized critical values, the authors propose a method to compute the global in?mum f~? of f over an arbitrary given real algebraic set V = {x ∈ R^n| g_1(x) = 0, ···, g_s(x) = 0}, where V is not required to be compact or smooth. The authors also generalize this method to solve the problem of optimizing f over a basic closed semi-algebraic set S = {x ∈ R^n| g_1(x) ≥ 0, ···, g_s(x) ≥ 0}.

关键词： Polynomial optimization real algebraic set generalized critical value

Impacts of Dirty Data on Classification and Clustering Models:An Experimental Evaluation

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Journal of Computer Science & Technology 2021年第4期36卷 806-821页

作者： zhi-Xin Qi hong-zhi Wang An-Jie Wang School of Computer Science and Technology Harbin Institute of TechnologyHarbin 150001China

Data quality issues have attracted widespread attentions due to the negative impacts of dirty data on data mining and machine learning *** relationship between data quality and the accuracy of results could be applied on the selection of the appropriate model with the consideration of data quality and the determination of the data share to ***,rare research has focused on exploring such *** by this,this paper conducts an experimental comparison for the effects of missing,inconsistent,and conflicting data on classification and clustering *** the experimental results,we observe that dirty-data impacts are related to the error type,the error rate,and the data *** on the findings,we suggest users leverage our proposed metrics,sensibility and data quality inflection point,for model selection and data cleaning.

关键词： data quality classification clustering model selection data cleaning

SiS_(2)/ZnO范德华异质结光催化水分解第一性原理研究

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原子与分子物理学报 2025年第6期42卷 31-36页

作者：李家豪黄欣杨志红南京邮电大学电子与光学工程学院、柔性电子(未来技术)学院南京210023 南京邮电大学理学院南京210023

基于第一性原理方法,研究了SiS_(2)/ZnO范德华异质结的电子结构和光催化性质.结果表明,SiS_(2)/ZnO异质结是带隙值为1.32 eV的半导体材料,表现出交错排列的能带结构.在异质结界面处,形成了从ZnO指向SiS_(2)的内置电场,该内置电场的存在... 详细信息

基于第一性原理方法,研究了SiS_(2)/ZnO范德华异质结的电子结构和光催化性质.结果表明,SiS_(2)/ZnO异质结是带隙值为1.32 eV的半导体材料,表现出交错排列的能带结构.在异质结界面处,形成了从ZnO指向SiS_(2)的内置电场,该内置电场的存在使得SiS_(2)/ZnO异质结中形成了特殊的“Z-型”载流子迁移模式,有利于电子空穴对的有效分离,同时增强了载流子的氧化还原能力.异质结构具有良好的热力学稳定性,且带边位置跨越水的氧化还原电位.与单层材料相比,SiS_(2)/ZnO异质结光吸收谱出现红移现象,表现出更宽的光吸收范围(从可见光到紫外光)及更强的光吸收强度(达到10~5 cm^(-1)量级).另外,通过施加双轴应变,可以有效调控SiS_(2)/ZnO异质结的带隙值.以上结果表明SiS_(2)/ZnO异质结有潜力成为新型光催化剂用于全解水.

关键词： SiS_(2)/ZnO Z-型范德华异质结光催化电子结构第一性原理

Hierarchical Management Scheme by Local Fields

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Acta Mathematica Sinica,English Series 2011年第1期27卷 155-168页

作者： zhi hong YUE Mao zhi XU School of Mathematical Sciences Peking University Beijing 100871 P. R. China Key Laboratory of Network and Software Security Assurance School of Mathematical Sciences Peking University Beijing 100871 P. R. China

In the present paper we propose a new hierarchical management scheme within suitable extensions of 2-adic numbers, in which the subfields are treated as classes, and the communications are realized by computation on elliptic curves. The security of our system is much stronger than that of the traditional public key cryptographic systems.

关键词： Hierarchical management local fields elliptic curves

Some New Lie Symmetry Groups of Differential-Difference Equations Obtained from a Simple Direct Method

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Communications in Theoretical Physics 2009年第9期52卷 385-388页

作者： zhi hong-Yan School of Mathematics and Computational S~iences China University of Petroleum （East China） Dongying 257061China

In this paper,based on the symbolic computing system Maple,the direct method for Lie symmetry groupspresented by Sen-Yue Lou [***.A:***.38 (2005) L129] is extended from the continuous differential equationsto the differential-difference *** the extended method,we study the well-known differential-difference KPequation,KZ equation and (2+1)-dimensional ANNV system,and both the Lie point symmetry groups and the non-Liesymmetry groups are obtained.

关键词： symmetry group differential-difference equation direct method

Symmetry Reductions of a Lax Pair for(2+1)-Dimensional Differential Sawada-Kotera Equation

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Communications in Theoretical Physics 2009年第5期51卷 777-780页

作者： zhi hong-Yan School of Mathematics and Computational Sciences China University of Petroleum Dongying 257061 China

Based on the symbolic computational system Maple, the similarity reductions of a Lax pair for the （2＋1 ）-dimensional differential Sawada Kotera （SK） equation by the classical Lie point group method, are presented. We obtain several interesting reductions. Comparing the reduced Lax pair＇s compatibility with the reduced SK equation under the same symmetry group, we find that the reduced Lax pairs do not always lead to the reduced SK equation. In general, the reduced equations are the subsets of the compatibility conditions of the reduced Lax pair.

关键词： classical Lie group approach symmetry reduction Lax pair Sawada-Kotera equation

Recent Progress in Arabidopsis Research in China： A Preface

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Journal of Integrative Plant Biology 2006年第1期48卷 1-4页

作者： zhi-hong Xu College of Life Sciences Peking University Beijing 100871 China Shanghai Institute of Plant Physiology and Ecology the Chinese Academy of Sciences Shanghai 200032 China

In 2002, a workshop on Arabidopsis research in China was held in Shanghai, when a small group of Chinese plant scientists was working on this model species. Since then, we have witnessed the rapid growth of Arabidopsis research in China. This special issue of Journal of Integrative Plant Biology is dedicated exclusively to the Fourth Workshop on Arabidopsis Research in China, scheduled on November 30, 2005, in Beijing. In addition to reports collected in this special issue, the Chinese Arabidopsis community has been able to make significant contributions to many research fields. Here, I briefly summarize recent advances in Arabidopsis research in China.

关键词： Arabidopsis research in China Shanghai plant

New Formal Solutions of Davey-Stewartson Equation via Combined tanh Function Method with Symmetry Method

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Communications in Theoretical Physics 2007年第4期47卷 587-593页

作者： zhi hong-Yan ZHANG hong-Qing Department of Applied Mathematics Dalian University of Technology Dalian 116024 China

We combine the tanh function method with the symmetry group method to construct new type of solutions of Davey-Stewartson equation and implemente it in a computer algebraic system. As a result, some new types of solutions are obtained. This method is also applied to other differential equations if the nonlinear evolution equations admit nontrivial one-parameter group of transformation.

关键词： tanh function method symmetry group method Davey-Stewartson equation exact solution

COSSET＋： Crowdsourced Missing Value Imputation Optimized by Knowledge Base

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Journal of Computer Science & Technology 2017年第5期32卷 845-857页

作者： hong-zhi Wang zhi-Xin Qi Ruo-Xi Shi Jian-Zhong Li hong Gao School of Computer Science and Technology Harbin Institute of Technology Harbin 150001 China

Missing value imputation with crowdsourcing is a novel method in data cleaning to capture missing values that could hardly be filled with automatic approaches. However, the time cost and overhead in crowdsourcing are high. Therefore, we have to reduce cost and guarantee the accuracy of crowdsourced imputation. To achieve the optimization goal, we present COSSET+, a crowdsourced framework optimized by knowledge base. We combine the advantages of both knowledge-based filter and crowdsourcing platform to capture missing values. Since the amount of crowd values will affect the cost of COSSET+, we aim to select partial missing values to be crowdsourced. We prove that the crowd value selection problem is an NP-hard problem and develop an approximation algorithm for this problem. Extensive experimental results demonstrate the efficiency and effectiveness of the proposed approaches.

关键词： crowdsourcing missing value imputation knowledge base optimization