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Attribute reduction in interval-valued information systems based on information entropies

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Frontiers of Information Technology & Electronic Engineering 2016年第9期17卷 919-928页

作者： Jian-hua dai Hu HU Guo-jie ZHENG Qing-hua HU Hui-feng HAN Hong SHI School of Computer Science and Technology Tianjin University College of Computer Science and Technology Zhejiang University

Interval-valued data appear as a way to represent the uncertainty affecting the observed values. Dealing with interval-valued information systems is helpful to generalize the applications of rough set theory. Attribute reduction is a key issue in analysis of interval-valued data. Existing attribute reduction methods for single-valued data are unsuitable for interval-valued data. So far, there have been few studies on attribute reduction methods for interval-valued data. In this paper, we propose a framework for attribute reduction in interval-valued data from the viewpoint of information theory. Some information theory concepts, including entropy, conditional entropy, and joint entropy, are given in interval-valued information systems. Based on these concepts, we provide an information theory view for attribute reduction in interval-valued information systems. Consequently, attribute reduction algorithms are proposed. Experiments show that the proposed framework is effective for attribute reduction in interval-valued information systems.

关键词： Rough set theory Interval-valued data Attribute reduction Entropy

Improvement on a Michelson interferometer for bunch length measurement of a femtosecond accelerator

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Nuclear Science and Techniques 2009年第1期20卷 1-4页

作者： LIN Xuling ZHANG Jianbing BEI hua dai Zhimin Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 China Graduate School of Chinese Academy of Sciences Beijing 100049 China

Based on the femtosecond accelerator facility at Shanghai Institute of Applied Physics (SINAP), a conventional far-infrared Michelson interferometer was built to measure the bunch length by means of optical autocorrelation. However, according to the preliminary experiment result, the resolution of interferometer is not good enough, because the mirror-driving mechanism makes the moving mirror tend to tilt or wobble as it retards. Considering of the allowable errors, we calculate the maximum allowable titling angle of the moving mirror, and discuss the alignment plan in this paper.

关键词：辐射原子核超热电子固体靶输运过程放射性

ESL-SELO:A Robust Image Denoising Algorithm with Penalty

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Acta Mathematicae Applicatae Sinica 2017年第3期33卷 753-770页

作者： Guo-hua WANG San-guo ZHANG Peng-jie dai School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China Key Laboratory of Big Data Mining and Knowledge Management Chinese Academy of SciencesBeijing100049China School of Business Remin University of ChinaBeijing 100872China

Robust image recovery methods have been attracted more and more attention in recent decades for its good property of tolerating system errors or measuring noise. In this paper, we propose a new robust method （ESL-SELO） to recover nosing image, which combine exponential loss function and seamless-L0 （SELO） penalty function to guarantee both accuracy and robustness of the estimator. Theoretical result showed that our method has a local optimal solution and good asymptotic properties. Finally, we compare our method with other methods in simulation which shows better robustness and takes much less time.

关键词： denoising algorithm penalty function robust SELO

A Golden Decade of Polar Codes:From Basic Principle to 5G Applications

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China Communications 2023年第2期20卷 94-121页

作者： Kai Niu ping Zhang Jincheng dai Zhongwei Si Chao Dong The Key Laboratory of Universal Wireless Communications Ministry of EducationBeijing University of Posts and TelecommunicationsBeijing 100876China The State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China Department of Broadband Communication Peng Cheng LaboratoryShenzhen 518055China

After the pursuit of seventy years,the invention of polar codes indicates that we have found the first capacity-achieving coding with low complexity construction and decoding,which is the great breakthrough of the coding theory in the past two *** this survey,we retrospect the history of polar codes and summarize the advancement in the past ten ***,the primary principle of channel polarization is investigated such that the basic construction,coding method and the classic successive cancellation(SC)decoding are ***,in order to improve the performance of the finite code length,we introduce the guiding principle and conclude five design criteria for the construction,design and implementation of the polar code in the practical communication system based on the exemplar schemes in the ***,we explain the design principle behind the concatenated coding and rate matching of polar codes in 5G wireless ***,the improved SC decoding algorithms,such as SC list(SCL)decoding and SC stack(SCS)decoding etc.,are investigated and ***,the research prospects of polar codes for the future 6G communication system are explored,including the optimization of short polar codes,coding construction in fading channels,polar coded modulation and HARQ,and the polar coded transmission,namely polar ***,as a new coding methodology,polar codes will shine a light on communication theory and unveil a revolution in transmission technology.

关键词： polar codes channel polarization successive cancellation decoding polar coded modulation polar processing

Simulation of coherent spontaneous emission in a FEL with a groove guide

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Nuclear Science and Techniques 2009年第6期20卷 321-324页

作者： LUO Feng BEI hua LIN Xuling dai Zhimin Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 China Graduate School of Chinese Academy of Sciences Beijing 100049 China

Based on a femtosecond linear accelerator, here we present a study of the use of a groove guide as the FEL interaction structure for high power FEL experiment. The transmission and attenuation characteristics of the dominant mode in the groove guide are discussed. And the coherent spontaneous emission in the FEL is simulated by Gover theory.

关键词：自由电子激光自发辐射指南模拟相干凹槽直线加速器激光实验

Variable Selection of Generalized Regression Models Based on Maximum Rank Correlation

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Acta Mathematicae Applicatae Sinica 2014年第3期30卷 833-844页

作者： Peng-jie dai Qing-zhao ZHANG Zhi-hua SUN School of Business Renmin University of China Department of Mathematics University of Chinese Academy of Sciences

In this paper, we investigate the variable selection problem of the generalized regression models. To estimate the regression parameter, a procedure combining the rank correlation method and the adaptive lasso technique is developed, which is proved to have oracle properties. A modified IMO （iterative marginal optimization） algorithm which directly aims to maximize the penalized rank correlation function is proposed. The effects of the estimating procedure are illustrated by simulation studies.

关键词： maximum rank correlation estimation adaptive LASSO oracle properties generalized regression models.

Synthesis　and　Characterization　of　Tri(organotin)Substituted　Heteropolytungstates

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Chemical Research in Chinese Universities 1998年第1期14卷 6-11页

作者： Yang, Qi-hua dai, Hui-cong Liu, Jing-fu NE Normal Univ Dept Chem Changchun 130024 Peoples R China

ＳｙｎｔｈｅｓｉｓａｎｄＣｈａｒａｃｔｅｒｉｚａｔｉｏｎｏｆＴｒｉ（ｏｒｇａｎｏｔｉｎ）ＳｕｂｓｔｉｔｕｔｅｄＨｅｔｅｒｏｐｏｌｙｔｕｎｇｓｔａｔｅｓＹＡＮＧＱｉ－ｈｕａ，ＤＡＩＨｕｉ－ｃｏｎｇ，ＬＩＵＪｉｎｇ－ｆｕ... 详细信息

ＳｙｎｔｈｅｓｉｓａｎｄＣｈａｒａｃｔｅｒｉｚａｔｉｏｎｏｆＴｒｉ（ｏｒｇａｎｏｔｉｎ）ＳｕｂｓｔｉｔｕｔｅｄＨｅｔｅｒｏｐｏｌｙｔｕｎｇｓｔａｔｅｓＹＡＮＧＱｉ－ｈｕａ，ＤＡＩＨｕｉ－ｃｏｎｇ，ＬＩＵＪｉｎｇ－ｆｕ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍ...

关键词： organotin)Substituted Heteropolytungstates Synthesis Tri Characterization

Effect of Bimodal Quasicrystal Phase on the Dynamic Recrystallization of Mg–Zn–Gd Alloy during High-Pressure Torsion

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Acta Metallurgica Sinica(English Letters) 2024年第7期37卷 1128-1134页

作者： ping Li Shuangwu Xia Junfu Dong Liangwei dai Zhicheng Luo Kemin Xue School of Material Science and Engineering Hefei University of TechnologyHefei230009China

The Mg–Zn–Gd alloy with quasicrystal icosahedral phase was processed by high-pressure torsion (HPT). The effect of bimodal I-phase on the dynamic recrystallization was analyzed by transmission electron microscopy. The results showed that the block I-phase can stimulate obvious particle-stimulated nucleation and dynamic recrystallization (DRX) grains were preferentially formed after HPT for 5 turns, while the granular I-phase only promoted the generation of sub-grains. The orientation relationship was determined as twofold//[1210] and fivefold//(0002)_(Mg). Moreover, after HPT for 9 turns, the DRX grains induced by block I-phase appeared to grow up and coarsened. Compared with block I-phase, the grains induced by granular I-phase presented much smaller size and distributed more homogeneous due to the strong pinning effect.

关键词： High-pressure torsion(HPT)-Quasicrystal phase Dynamic recrystallization Particle-stimulated nucleation Orientation relationship

Ultrafine PdAg alloy nanoparticles anchored on NH2-functionalized 2D/2D TiO_(2) nanosheet/rGO composite as efficient and reusable catalyst for hydrogen release from additive-free formic acid at room temperature

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Journal of Energy Chemistry 2021年第8期30卷 455-464,I0010页

作者： Xi Zhao ping dai Dongyan Xu Xumei Tao Xien Liu Qingjie Ge State Key Laboratory Base of Eco-chemical Engineering College of Chemical EngineeringQingdao University of Science&TechnologyQingdao 266042China Shandong Provincial Key Laboratory Of Polymer Material Advanced Manufacturing Technology College of Electromechanical EngineeringQingdao University of Science&TechnologyQingdao 266061China Dalian National Laboratory for Clean Energy Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China State Key Laboratory of High-efficiency Coal Utilization and Green Chemical Engineering College of Chemistry and Chemical EngineeringNingxia University750021 YinchuanChina

A 2 D-2 D titanium dioxide nanosheet-reduced graphene oxide(TNS-r GO)composite with better electronic conductivity and hydrophilicity was prepared by the hydrothermal *** as-obtained TNS-r GO composite was further functionalized with 3-aminopropyltriethoxysilane(APTES)to provide a large amount of-NH2 groups on the surface for anchoring ultrafine Pd Ag alloy nanoparticles with an average particle size of 1.69 nm by a facile wet reduction *** from the combined effects of well-dispersed Pd Ag alloy nanoparticles,facilitated electron transfer from TNS-r GO to Pd,and increased electron density of active sites,the Pd8 Ag_(1)/NH_(2)-TNS-r GO catalyst exhibited excellent activity towards dehydrogenation of formic acid without adding any additives at 298 K,corresponding to an initial turn over frequency as high as 1090 h-1,which is much higher than that of most other state-of-theart catalysts.

关键词： Formic acid Dehydrogenation TNS-rGO composite PdAg alloy Amine-functionalization