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THE EXISTENCE OF OVERLARGE SETS OF IDEMPOTENT QUASIGROUPS

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Acta Mathematica Scientia 2004年第2期24卷 165-170页

作者：常彦勋雷建国 DepartmentofMathematics BeijingJiaotongUniversityBeijing100044China

A idempotent quasigroup (Q, o) of order n is equivalent to an n(n-1)×3 partial orthogonal array in which all of rows consist of 3 distinct elements. Let X be a (n+1)-set. Denote by T(n+1) the set of (n+1)n(n-1) ordered triples of X with the property that the 3 coordinates of each ordered triple are distinct. An overlarge set of idempotent quasigroups of order n is a partition of T(n+1) into n+1 n(n-1)×3 partial orthogonal arrays A_x, x∈X based on X\{x}. This article gives an almost complete solution of overlarge sets of idempotent quasigroups.

关键词： Pairwise balanced design conjugate invariant subgroup overlarge set of idempotent quasigroups

Weighted Profile Least Squares Estimation for a Panel Data Varying-Coefficient Partially Linear Model

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Chinese Annals of Mathematics,Series B 2010年第2期31卷 247-272页

作者： Bin ZHOU Jinhong YOU Qinfeng XU Gemai CHEN School of Finance and Statistics East China Normal University Shanghai 200241 China. Department of Statistics Shanghai University of Finance and Economics Shanghai 200433 China. Corresponding Author. School of Management Fudan University Shanghai 200433 China. Department of Mathematics and Statistics University of Calgary Calgary Alberta T2N 1N4 Canada.

This paper is concerned with inference of panel data varying-coefficient partially linear models with a one-way error structure. The model is a natural extension of the well-known panel data linear model （due to Baltagi 1995） to the setting of semiparametric regressions. The authors propose a weighted profile least squares estimator （WPLSE） and a weighted local polynomial estimator （WLPE） for the parametric and nonparametric components, respectively. It is shown that the WPLSE is asymptotically more efficient than the usual profile least squares estimator （PLSE）, and that the WLPE is also asymptotically more efficient than the usual local polynomial estimator （LPE）. The latter is an interesting result. According to Ruckstuhl, Welsh and Carroll （2000） and Lin and Carroll （2000）, ignoring the correlation structure entirely and ＂pretending＂ that the data are really independent will result in more efficient estimators when estimating nonparametric regression with longitudinal or panel data. The result in this paper shows that this is not true when the design points of the nonparametric component have a closeness property within groups. The asymptotic properties of the proposed weighted estimators are derived. In addition, a block bootstrap test is proposed for the goodness of fit of models, which can accommodate the correlations within groups illustrate the finite sample performances of the Some simulation studies are conducted to proposed procedures.

关键词： Semiparametric Panel data Local polynomial Weighted estimation Block bootstrap

Particle swarm optimization with a leader and followers

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Progress in Natural Science:Materials International 2008年第11期18卷 1437-1443页

作者： Junwei Wang Dingwei Wang Institute of Systems Engineering,College of Information Science and Engineering,Northeastern university,Shenyang 110004,China Institute of Systems Engineering College of Information Science and Engineering Northeastern University Shenyang 110004 China

Referring to the flight mechanism of wild goose flock,we propose a novel version of Particle Swarm Optimization(PSO)with a leader and *** is referred to as Goose Team Optimization(GTO).The basic features of goose team flight such as goose role division, parallel principle,aggregate principle and separate principle are implemented in the recommended *** GTO,a team is formed by the particles with a leader and some *** role of the leader is to determine the search *** followers decide their flying modes according to their distances to the leader ***,a wide area can be explored and the particle collision can be really *** GTO is applied to four benchmark examples of complex nonlinear functions,it has a better computation perfor- mance than the standard PSO.

关键词： Particle swarm optimization Goose team optimization Role division Parallel principle Aggregate principle Separate principle

WAVELET TECHNIQUE RECOVERING IMAGE BLURRED BY MIXED GAUSSIAN AND SALT-PEPPER NOISE

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Analysis in Theory and Applications 2003年第2期19卷 185-192页

作者： Hu Junquan, Huang Daren, Wang Zhenwu and Zhang Zeyin (Zhejiang university,China) Department of Mathematics Zhejiang university Hangzhou 310027 P.R.China Zhejiang university Hangzhou China

In this paper, we propose a new method to removing the mixed Gaussian and salt-pepper noise based on wavelet. To estimate outlier, A scheme called max-min method is adopted after DWT. Experimental results show that this method is more effective than common image restoration methods, such as Median filter, center weighted median filter.

关键词： wavelet max-min method

Effect of Curing Regime on Bonding Strength of EVA Modified Mortar to Tile

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Journal of Wuhan university of Technology(Materials Science) 2010年第2期25卷 346-348页

作者：何代华 School of Materials Science & Engineering University of Shanghai for Science Technology Key Laboratory of Advanced Civil Engineering Materials Ministry of Education Tongji University

Ethylene-Vinyl Acetate （EVA） redispersible powder and latex were used to modify mortar. Three kinds of curing regimes： standard curing, high temperature curing and freeze-thaw circle curing were adopted to cure the bonded samples. Bonding strength of EVA modified mortar was tested at 28 days. The development of bonding strengths under all three curing regimes were discussed and compared. The experimental results show that bonding strength increases with the increase of EVA content in mortar. The curing regime used within 28 days is critical according to the bonding strengths values under three curing regimes for different ages. The reasons of that the EVA can improve the bonding strength were analyzed.

关键词： EVA redispersible powder latex bonding strength curing regime

Interpolating triangular meshes by Loop subdivision scheme

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Science China(Information Sciences) 2010年第9期53卷 1765-1773页

作者： DENG ChongYang1* & WANG GuoZhao2 1Institute of Applied Mathematics and Engineering Computations,Hangzhou Dianzi university,Hangzhou 310018,China 2Department of Mathematics,Zhejiang university,Hangzhou 310027,China Institute of Applied Mathematics and Engineering Computations Hangzhou Dianzi University Hangzhou China Department of Mathematics Zhejiang University Hangzhou China

Using the limit point formula of the Loop subdivision scheme,we propose a very simple and efficient method for constructing interpolation surface of triangular meshes by Loop subdivision *** excellent properties of the method are:(1) Locality:the perturbation of a given vertex only influences the surface shape near this vertex.(2) Efficiency:the locations of new points can be computed with explicit formulae.(3) Easiness in implementation:only the geometric rule of the first step should be modified.(4) Freedom:for each edge,there is one degree of freedom to adjust the shape of the interpolation surface.(5) Easiness in generalization:it is easy to generalize our method to other approximation subdivision schemes with explicit formulae to compute limit point.

关键词： computer aided geometric design subdivision surface approximating subdivision scheme Loop surface surface interpolating

BASE－CATALYZED　PROTODESILYLATION　OF　（2H）－PYRI－DAZINON－5－YL　SILYLMETHYL　SULFIDES

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Chinese Chemical Letters 1996年第7期7卷 603-604页

作者： Zheng Jie HE Zheng Ming LI(Institute of Elemento-Organic Chemistry, Nankai university. Tianjin 300071) Inst. of Elemento-Organic Chemistiy Nankai University Tianjin 300071

s:Protodesilylation of(2H)-pyridazinon-5-yl silylmethyl sulfides 1 proceeds smoothly withcleavage of sp3 hybridized carbon-silicon bond in the presence of catalytic amount of sodiumhydroxide at room temperature. The presence of aryl R on silicon atom and (2H)-pyridazinon-5-ylgroup on sulfur atom plays a critical role in the occurrence of this reaction.

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STRUCTURE AND FERROMAGNETIC RESONANCE OF Fe/Cu SUPERLATTICES

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Acta Metallurgica Sinica(English Letters) 1991年第8期4卷 127-133页

作者： BI Siyun MA Xiaoding SONG Ruitian MEI Liangmo ZHAO Jiangao GUO Yicheng Shandong university,Jinan,China Shandong Univ Jinan China

Metallic Fe/Cu superlattice films on glass substrates were prepared by a dc-magnetion sputtering *** modulation behaviors and the crystal structures of the films were ex- amined by X-ray diffraction and transmission electron microscopy(TEM)respectively. Their magnetic properties were studied by means of ferromagnetic resonnance spectrometer and the vibrating sample *** results show that there exists a strong magnetic coupling between the neighbouring Fe layers and it is the coupling that affectes the magnetic properties of these superlattice films.

关键词： superlattice ferromagnetic resonance interface spin-wave resonance

Infrared and Raman spectroscopic studies of rotational isomers of O,O-diethyl phosphorodithioic acid

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Chinese Journal of Chemistry 1984年第1期2卷 60-65页

作者： CHEN Wen-Ju SONG Shu-Gui Department of Physics,Nankai university,Tianjin JING Xu-Ying Institute of Elemental Organic Chemistry,Nankai university,Tianjin Department of Physics Nankai University Tianjin Institute of Elemental Organic Chemistry Nankai University Tianjin

Infrared and Raman spectra of O,O-diethyl phosphorodithioic acid have been studiedboth at and below room *** results show that the vibrations of P=S,P（-O）2,P-Sand S-H groups give multiple bands and the relative intensities of these bands vary as the tempera-ture of the sample *** to the experimental results,we suggest that there are fourrotational isomers of O,O-diethyl phosphorodithioic *** for splitting the vibrational bandsof these groups are also discussed.

关键词： SH acid