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Sliced Average Variance Estimation for Tensor Data

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 630-655页

作者： Chuan-quan LI Pei-wen xiao Chao YING xiao-hui liu School of Statistics Jiangxi University of Finance and EconomicsNanchang 330013China Key Laboratory of Data Science in Finance and Economics Jiangxi University of Finance and EconomicsNanchang 330013China Biostatistics and Medical Informatics University of Wisconsin MadisonMadison 53726USA

Tensor data have been widely used in many fields,e.g.,modern biomedical imaging,chemometrics,and economics,but often suffer from some common issues as in high dimensional *** to find their low-dimensional latent structure has been of great interest for *** this end,we develop two efficient tensor sufficient dimension reduction methods based on the sliced average variance estimation(SAVE)to estimate the corresponding dimension reduction *** first one,entitled tensor sliced average variance estimation(TSAVE),works well when the response is discrete or takes finite values,but is not■consistent for continuous response;the second one,named bias-correction tensor sliced average variance estimation(CTSAVE),is a de-biased version of the TSAVE *** asymptotic properties of both methods are derived under mild *** and real data examples are also provided to show the superiority of the efficiency of the developed methods.

关键词： tensor data sliced average variance estimation sufficient dimension reduction central subspace

Statistical Inferences in a Partially Linear Model with Autoregressive Errors

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Acta Mathematicae Applicatae Sinica 2022年第4期38卷 822-842页

作者： xiao-hui liu Yu WANG Ya-wen FAN Yu-zi liu School of Statistics Jiangxi University of Finance and EconomicsNanchang 330013China Key Laboratory of Data Science in Finance and Economics Jiangxi University of Finance and EconomicsNanchang 330013China

In this paper,we consider the statistical inferences in a partially linear model when the model error follows an autoregressive process.A two-step procedure is proposed for estimating the unknown parameters by taking into account of the special structure in *** the asymptotic matrix of the estimator for the parametric part has a complex structure,an empirical likelihood function is also *** derive the asymptotic properties of the related statistics under mild *** simulations,as well as a real data example,are conducted to illustrate the finite sample performance.

关键词： partially linear model autoregressive errors two-step procedure profile empirical likelihood

The Limit of Finite Sample Breakdown Point of Tukey’s Halfspace Median for General Data

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Acta Mathematica Sinica,English Series 2018年第9期34卷 1403-1416页

作者： xiao hui liu Shi Hua LUO Yi Jun ZUO School of Statistics Jiangxi University of Finance and Economics Nanchang 330013 P. R. China Research Center of Applied Statistics Jiangxi University of Finance and Economics Nanchang 330013 P. R. China Department of Statistics and Probability Michigan State University East Lansing MI 48823 USA

Under special conditions on data set and underlying distribution, the limit of finite sample breakdown point of Tukey＇s halfspace median （1） has been obtained in the literature. In this paper, we establish the result under weaker assumptions imposed on underlying distribution （weak smoothness） and on data set （not necessary in general position）. The refined representation of Tukey＇s sample depth regions for data set not necessary in general position is also obtained, as a by-product of our derivation.

关键词： Tukey's halfspace median limit of finite sample breakdown point smooth condition,halfspace symmetry

A Unit Root Test for an AR(1)Process with AR Errors by Using Random Weighted Bootstrap

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Acta Mathematica Sinica,English Series 2023年第9期39卷 1834-1854页

作者： xiao hui liu Ya Wen Fan Yu Zi liu Shi Hua Luo School of Statistics and Data Science Jiangxi University of Finance and EconomicsNanchang330013P.R.China Key Laboratory of Data Science in Finance and Economics Jiangxi University of Finance and EconomicsNanchang330013P.R.China

A great deal of economic problems are related to detecting the stability of time series data,where the main interest is in the unit root *** this paper,we consider the unit root testing problem with errors being long-memory processes with the LARCH structure.A new test statistic is developed by using the random weighted bootstrap *** turns out that the proposed statistic has a chisquared distribution asymptotically regardless of the process being stationary or nonst at ionary,and with or without an intercept *** simulation results show that the statistic has a desired finite sample performance in terms of both size and power.A real data application is also given relying on the inflation rate data of 17 countries.

关键词： Autoregressive model random weighted bootstrap autoregressive errors unit root test

Oracle Inequality for Sparse Trace Regression Models with Exponentialβ-mixing Errors

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Acta Mathematica Sinica,English Series 2023年第10期39卷 2031-2053页

作者： Ling PENG Xiang Yong TAN Pei Wen xiao Zeinab RIZK xiao hui liu School of Statistics and Data Science Jiangxi University of Finance and EconomicsNanchang 330013P.R.China Key Laboratory of Data Science in Finance and Economics Jiangxi University of Finance and EconomicsNanchang 330013P.R.China

In applications involving,e.g.,panel data,images,genomics microarrays,etc.,trace regression models are useful *** address the high-dimensional issue of these applications,it is common to assume some sparsity *** the case of the parameter matrix being simultaneously low rank and elements-wise sparse,we estimate the parameter matrix through the least-squares approach with the composite penalty combining the nuclear norm and the *** extend the existing analysis of the low-rank trace regression with *** to exponentialβ-mixing *** explicit convergence rate and the asymptotic properties of the proposed estimator are ***,as well as a real data application,are also carried out for illustration.

关键词： Trace regression model low-rank matrix oracle inequality exponentialβ-mixing errors

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Potassium Acetate/18-Crown-6 Pair:Robust and Versatile Catalyst for Synthesis of Polyols from Ring-Opening Copolymerization of Epoxides and Cyclic Anhydrides

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Chinese Journal of Chemistry 2023年第1期41卷 83-92页

作者： xiaoqing Dou xiao-hui liu Bin Wang Yue-Sheng Li School of Materials Science and Engineering Tiangong UniversityTianjin 300387China Tianjin Key Lab of Composite&Functional Materials School of Materials Science and EngineeringTianjin UniversityTianjin 300350China

Efficient synthesis of polyester polyols with tunable molecular weight and microstructures from cyclic anhydride/epoxide mixtures by taking advantage of chain transfer reaction remains a great challenge,because most of the catalysts exhibit poor tolerance to chain transfer agent(CTA).In this contribution,we demonstrated that potassium acetate(KOAc)and 18-crown-6(18-C-6)combination has great potential in the synthesis of diverse polyester polyols with controllable molecular weight and high-end group ***-pared with KOAc,KOAc/18-C-6 pair could induce a much faster chain transfer between the active and dormant chains,and thus produce polyester polyols with narrow and monomodal *** addition,polyester polyols could be efficiently prepared in laboratory by using commercially available cyclic anhydride without further purification(containing about 2%diacid residual as CTA)with an extremely low catalyst loading([catalyst pair]:[anhydride]:[epoxide]=1:50000:250000,[catalyst pair]=0.0004 mol%).KOAc/18-C-6 could also promote the self-switchable copolymerization of cyclic anhydride/epoxide/cyclic ester ***-opening copolymerization of cyclic ester was initiated automatically after the full conversion of cyclic anhydride,finally producing polyester polyols with ABA-type block structure.

关键词： Ring-opening polymerization Macrocyclic ligands Block copolymer Cyclic Anhydride Epoxide

Hyperoside protects the blood-brain barrier from neurotoxicity of amyloid beta 1–42

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Neural Regeneration Research 2018年第11期13卷 1974-1980页

作者： Chen-Yang liu Kuan Bai xiao-hui liu Li-Mi Zhang Gu-Ran Yu Department of Neurology Jiangsu Traditional Chinese Medicine Hospital the Affiliated Hospital of Nanjing University of Traditional Chinese Medicine Nanjing Jiangsu Province China Graduate School of Nanjing University of Traditional Chinese Medicine Nanjing Jiangsu Province China

Mounting evidence indicates that amyloid β protein（Aβ） exerts neurotoxicity by disrupting the blood-brain barrier（BBB） in Alzheimer＇s disease. Hyperoside has neuroprotective effects both in vitro and in vivo against Aβ. Our previous study found that hyperoside suppressed Aβ1-42-induced leakage of the BBB, however, the mechanism remains unclear. In this study, bEnd.3 cells were pretreated with 50, 200, or 500 μM hyperoside for 2 hours, and then exposed to Aβ1-42 for 24 hours. Cell viability was determined using 3-（4,5-dimethyl-2-thiazolyl）-2,5-diphenyl-2-H-tetrazolium bromide assay. Flow cytometry and terminal deoxynucleotidyl transferase-mediated d UTP nick-end labeling assay were used to analyze cell apoptosis. Western blot assay was carried out to analyze expression levels of Bax, Bcl-2, cytochrome c, caspase-3, caspse-8, caspase-9, caspase-12, occludin, claudin-5, zonula occludens-1, matrix metalloproteinase-2（MMP-2）, and MMP-9. Exposure to Aβ1-42 alone remarkably induced bEnd.3 cell apoptosis; increased ratios of cleaved caspase-9/caspase-9, Bax/Bcl-2, cleav ed caspase-8/caspase-8, and cleaved caspase-12/caspase-12; increased expression of cytochrome c and activity of caspase-3; diminished levels of zonula occludens-1, claudin-5, and occludin; and increased levels of MMP-2 and MMP-9. However, hyperoside pretreatment reversed these changes in a dose-dependent manner. Our findings confirm that hyperoside alleviates fibrillar Aβ1-42-induced BBB disruption, thus offering a feasible therapeutic application in Alzheimer＇s disease.

关键词： nerve regeneration Alzheimer's disease amyloid beta 1-42 blood-brain barrier bEnd.3 cells tight junction proteins hyperoside anti-apoptosis neural regeneration

Relationship between red blood cell distribution width and intermediate-term mortality in elderly patients after percutaneous coronary intervention

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Journal of Geriatric Cardiology 2015年第1期12卷 17-22页

作者： Xin-Min liu Chang-Sheng MA xiao-hui liu Xin DU Jun-Ping KANG Yin ZHANG Jia-hui WU Department of Cardiology Beijing An Zhen Hospital Capital Medical University Beijing 100029 China

Background Large-scale clinical research on the relationship between red blood cell distribution width （RDW） and intermediate-term prognosis in elderly patients with coronary artery disease （CAD） is lacking. Thus, this study investigated the effects of RDW on the intermediate-term mortality of elderly patients who underwent elective percutaneous coronary intervention （PCI）. Methods Data from 1891 patients 〉 65 years old underwent elective PCI from July 2009 to September 2011 were collected. Based on preoperative median RDW （12.3%）, the patients were divided into two groups. The low RDW group （RDW 〈 12.3%） had 899 cases; the high RDW group （RDW 〉 12.3%） had 992 cases. The all-cause mortality rates of the two groups were compared. Results Patients in the high RDW group were more likely to be female and accompanied with diabetes, had lower hemoglobin level. The mean follow-up period was 527 days. During follow-up, 61 patients died （3.2%）. The postoperative mortality of the high RDW group was significantly higher than that of the low RDW group （4.3% vs. 2.0%, P = 0.004）. After adjusting other factors, multivariate Cox regression analysis revealed that preoperative high RDW was significantly associated with postoperative all-cause mortality （hazard ratio： 2.301, 95% confidence interval： 1.106-4.785, P = 0.026）. Conclusions Increased RDW was an independent predictor of the increased intermediate-term all-cause mortality in elderly CAD patients after elective PCI.

关键词： Coronary artery disease Elderly patients Percutaneous coronary intervention Red blood cell distribution width

Erosion-corrosion investigation of high chromium cast irons using newly designed jet type tester

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中国有色金属学会会刊：英文版 2004年第Z1期14卷 405-412页

作者： TU xiao-hui liu Jun-quan LI Wei ZHANG Feng-hua SU Jun-yi School of Materials Science and Engineering Xi''an Jiaotong University Xi''an 710049 China Wear Materials Research Center Guangzhou Research Institute of Nonferrous Metals Guangzhou 510651 China College of Industrial Equipment and Control Engineering South China University of Technology Guangzhou 510640 China Department of Chemistry Ji''nan University Guangzhou 510632 China Wear Materials Research Center Guangzhou Research Institute of Nonferrous Metals Guangzhou 510651 China School of Materials Science and Engineering Xi''an Jiaotong University Xi''an 710049 China

A jet type erosion-corrosion tester was developed for the erosion-corrosion investigation of high-chromium cast irons. During tests the size and the shape of particles in the slurry can be maintained stable. The jet velocity and attack angle can be accurately controlled. The repeatability and ranking consistency of the test results are satisfactory. The test parameters can be adjusted in a wide range, so that the tester can simulate various practical working conditions. Electrochemical test data can be automatically collected and processed. Dynamic polarization curves can be obtained during erosion-corrosion test, which can be used to study the dynamic corrosion *** high chromium cast irons were studied in hot concentrated alkaline slurry. The results show that the erosioncorrosion mass loss rate and dynamic corrosion rate of 295Cr26 iron is lower than that of 185Cr13 under the conditions similar to alumyte processing. The mechanism of erosion-corrosion of 295Cr26 and 185Cr13 was studied by using the tester. The interaction between erosion and corrosion was also quantitatively evaluated.

关键词： erosion-corrosion tester repeatability chromium cast iron hot concentrated alkali