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Statistical Inference for Self-Exciting Threshold INAR Processes with Missing Values

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Communications in Mathematics and Statistics 2023年第4期11卷 795-814页

作者： Han Yan dehui wang College of Mathematics Jilin UniversityChangchun 130012People’s Republic of China College of Economics Liaoning UniversityShenyang 110036People’s Republic of China

The time series model with threshold characteristics under fully observations has been explored intensively in recent *** this article,several methods are proposed to estimate the parameters of the self-exciting threshold integer-valued autoregressive(SETINAR(2,1))process in the presence of completely random missing *** order to dispose of the non-equidistance in the observed data,we research the conditional least squares and conditional maximum likelihood inference based on the p-stepahead conditional distribution of incomplete observations;in addition,three kinds of imputation methods are investigated to deal with the missing values for estimating the parameters of *** groups of stochastic simulation studies are carried out to compare the proposed approaches.

关键词： SETINAR process Integer-valued threshold models Missing data Imputation

Order shrinkage and selection for the INGARCH(p,q)model

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International Journal of Biomathematics 2021年第5期14卷 295-309页

作者： Yuan Tian dehui wang Xinyang wang Mathematics School of Jilin University Changchun 130012 P.R.China School of Economics Liaoning University Shenyang 110036P.R.China School of Mathematics and Systematic Sciences Shenyang Normal University Shenyang 110034 P.R.China

The integer-valued generalized autoregressive conditional heteroskedastic(INGARCH)model is often utilized to describe data in biostatistics,such as the number of people infected with dengue fever,daily epileptic seizure counts of an epileptic patient and the number of cases of campylobacterosis infections,*** the structure of such data is generally high-order and sparse,studies about order shrinkage and selection for the model attract many *** this paper,we propose a penalized conditional maximum likelihood(PCML)method to solve this *** PCML method can effectively select significant orders and estimate the parameters,*** simulations and a real data analysis are carried out to illustrate the usefulness of our method.

关键词： INGARCH(p,q)model penalized conditional maximum likelihood oracle properties epidemiology

Analyzing the general biased data by additive risk model

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Science China Mathematics 2017年第4期60卷 685-700页

作者： LI YanFeng MA HuiJuan wang dehui ZHOU Yong College of Mathematics Jilin University Department of Biostatistics and Bioinformatics Emory University School of Statistics and Management Shanghai University of Finance and Economics Academy of Mathematics and Systems Science Chinese Academy of Sciences

This paper proposes a unified semiparametric method for the additive risk model under general biased sampling. By using the estimating equation approach, we propose both estimators of the regression parameters and nonparametric function. An advantage is that our approach is still suitable for the lengthbiased data even without the information of the truncation variable. Meanwhile, large sample properties of the proposed estimators are established, including consistency and asymptotic normality. In addition, the finite sample behavior of the proposed methods and the analysis of three groups of real data are given.

关键词： additive risk model unified method length-biased data case-cohort design

Quantitative Determination of Composition of Quaternary Cementitious Materials

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Journal of Wuhan University of Technology(Materials Science) 2014年第2期29卷 314-320页

作者：刘书艳史才军 wang dehui XIAO Jiangfan College of Civil Engineering Hunan University State Key Laboratory of Green Building Materials China Building Materials Academy

Based on the principle of ENV 196-4 ＂Methods of testing cement - Part 4 Quantitative determination of constituents or Chinese Standard GB/12960-2007 Quantitative measurement of mineral admixtures in cement, methods were developed for quantitative determination of fly ash, slag and limestone powder in fresh cement pastes, mortars and concretes. Limestone powder was determined using thermal analysis method. The residue content of fly ash on an 80um sieve, and silt contents of aggregate were also considered during the quantitative determination of mineral composition of quaternary cementitious system. With the developed methods, the deviations between the measured and the actual mineral contents of the constituent in the eemantitious material in fresh cement paste, mortar and concrete, were within 3%.

关键词： quaternary cementitious material mineral composition selective dissolution thermal analysis quantitative measurement

Experimental Study on the Chloride Ion Concentration of Cement Pastes Prepared with Limestone Powder

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Journal of Wuhan University of Technology(Materials Science) 2024年第6期39卷 1474-1483页

作者： ZHANG Kaijian HUANG Zeping JIA Xuxiu wang dehui College of Civil Engineering Fuzhou UniversityFuzhou 350108China

To investigate the impact of limestone powder on the chloride ion concentration coefficient of cement pastes,various techniques such as scanning electron microscopy(SEM),X-ray diffraction(XRD),thermogravimetric analysis(TGA),and mercury-porosimetry(MIP)were employed in this *** findings demonstrate that the creation of Friedel's salt is inversely associated with the addition of limestone powder,that is,Friedel's salt production is lessened by adding more limestone powder,however,the coefficient of chloride ion concentration initially decreased and then increased again,as does the porosity,and most likely the pore size as *** specific surface area of limestone powder has increased,and the content of Friedel’s salt increased first and then ***,the shifting trend of Friedel's salt and chloride ion concentration coefficient is in direct opposition,and the pore structure was therefore significantly *** results of this study offer robust theoretical backing for the inclusion of limestone powder in concrete and provide a positive assessment of its potential applications.

关键词： limestone powder specific surface area content friedel's salt chloride ion concentration coefficient

THE LIMIT THEOREM FOR DEPENDENT RANDOM VARIABLES WITH APPLICATIONS TO AUTOREGRESSION MODELS

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Journal of Systems Science & Complexity 2011年第3期24卷 565-579页

作者： Yong ZHANG Xiaoyun YANG Zhishan DONG dehui wang College of Mathematics Jilin University (Qianwei Campus) Changchun 130012 China

This paper studies the autoregression models of order one, in a general time series setting that allows for weakly dependent innovations. Let {Xt} be a linear process defined by Xt =∑k=0^∞ψ kεt-k, where {ψk, k ≥ 0} is a sequence of real numbers and {εk, k = 0, ±1, ±2,...} is a sequence of random variables. Two results are proved in this paper. In the first result, assuming that {εk, k ≥ 1} is a sequence of asymptotically linear negative quadrant dependent （ALNQD） random variables, the authors find the limiting distributions of the least squares estimator and the associated regression t statistic. It is interesting that the limiting distributions are similar to the one found in earlier work under the assumption of i.i.d, innovations. In the second result the authors prove that the least squares estimator is not a strong consistency estimator of the autoregressive parameter a when {εk, k ≥ 1} is a sequence of negatively associated （NA） random variables, and ψ0 = 1, ψk = 0, k ≥ 1.

关键词： ALNQD autoregression models least squares estimator negatively associated unit root test.

Aerodynamic Super-Repellent Surfaces

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Research 2024年第2期2023卷 115-122页

作者： Fanfei Yu Jinlong Yang Ran Tao Yao Tan Jinpei wang dehui wang Longquan Chen Zuankai wang Xu Deng Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054P.R.China Department of Mechanical Engineering City University of Hong KongKowloonHong Kong Special Administrative Region 999077P.R.China School of Physics.University of Electronic Science and Technology of China Chengdu 610054P.R.China Department of Mechanical Engineering Hong Kong Polytechnic UniversityKowloonHong Kong Special Administrative Region 999077P.R.China Shenzhen Institute for Advanced Study University of Electronic Science and Technology of ChinaShenzhen 518110P.R.China

Repelling liquid drops from engineering surfaces has attracted great attention in a variety of *** achieve efficient liquid shedding,delicate surface textures are often introduced to sustain air pockets at the liquid-solid ***,those surfaces are prone to suffer from mechanical failure,which may bring reliability issues and thus limits their ***,inspired by the aerodynamic Leidenfrost effect,we present that impacting drops are directionally repelled from smooth surfaces supplied with an exogenous air *** theoretical analysis reveals that the synchronized nonwetting and oblique bouncing behavior is attributed to the aerodynamic force arising from the air *** versatility and practicability of our approach allow for drop repellency without the aid of any surface wettability treatment and also avoid the consideration of mechanical stability issues,which thereby provides a promising candidate for the applications that necessitate liquid shedding,e.g.,resolve the problem of tiny raindrop adhesion on the automobile side window during driving.

关键词： thereby driving attributed

Salvinia-like slippery surface with stable and mobile water/air contact line

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National Science Review 2021年第5期8卷 119-129页

作者： Xiaomei Li Jinlong Yang Kaixuan Lv Periklis Papadopoulos Jing Sun dehui wang Yanhua Zhao Longquan Chen Dapeng wang Zuankai wang Xu Deng Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of China State Key Laboratory of Polymer Physics and Chemistry Institute of Applied ChemistryChinese Academy of Sciences Physics Department University of Ioannina University Research Center of Ioannina (URCI) Institute of Materials Science and Computing Department of Mechanical Engineering City University of Hong Kong School of Physics University of Electronic Science and Technology of China

Superhydrophobic surfaces are widely used in many industrial settings, and mainly consist of rough solid protrusions that entrap air to minimize the liquid/solid area. The stability of the superhydrophobic state favors relatively small spacing between protrusions. However, this in turn increases the lateral adhesion force that retards the mobility of drops. Here we propose a novel approach that optimizes both properties simultaneously. Inspired by the hydrophobic leaves of Salvinia molesta and the slippery Nepenthes pitcher plants, we designed a Salvinia-like slippery surface(SSS) consisting of protrusions with slippery heads. We demonstrate that compared to a control surface, the SSS exhibits increased stability against pressure and impact, and enhanced lateral mobility of water drops as well as reduced hydrodynamic drag. We also systematically investigate the wetting dynamics on the SSS. With its easy fabrication and enhanced performance, we envision that SSS will be useful in a variety of fields in industry.

关键词： slippery Cassie state Salvinia molesta stability low adhesion drag reduction

Estimation of Partial Linear Error-in-Variables Models under Martingale Difference Sequence

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Journal of Mathematical Research with Applications 2015年第4期35卷 463-472页

作者： Zhuoxi YU dehui wang Na HUANG School of Management Science and Information Engineering Jilin University of Finance and Economics Department of Statistic College of MathematicsJilin University School of Information Management and Engineering Shanghai University of Finance and Economics

Consider the partly linear model Y = xβ + g(t) + e where the explanatory x is erroneously measured,and both t and the response Y are measured exactly,the random error e is a martingale difference *** x be a surrogate variable observed instead of the true x in the primary survey *** that in addition to the primary data set containing N observations of {(Yj,xj,tj)j=n+1n+N,the independent validation data containing n observations of {(xj,xj,tj)j=1n} is *** this paper,a semiparametric method with the primary data is employed to obtain the estimator of β and g(·) based on the least squares criterion with the help of validation *** proposed estimators are proved to be strongly *** sample behavior of the estimators is investigated via simulations too.

关键词： partial linear error-in-variables models martingale difference sequence validation data strong consistency