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Nonparametric Estimation of the Number of Drug Users in Hong Kong Using Repeated Multiple Lists

AUSTRALIAN & NEW ZEALAND JOURNAL OF STATISTICS 2016年第1期58卷 1-13页

作者： Huggins, Richard M. Yip, Paul S. F. Stoklosa, Jakub Univ Melbourne Dept Math & Stat Melbourne Vic 3010 Australia Univ Hong Kong Dept Social Work & Social Adm Hong Kong Hong Kong Peoples R China Univ New S Wales Sch Math & Stat Sydney NSW 2052 Australia Univ New S Wales Evolut & Ecol Res Ctr Sydney NSW 2052 Australia

We update a previous approach to the estimation of the size of an open population when there are multiple lists at each time point. Our motivation is 35years of longitudinal data on the detection of drug users by the Central Registry of Drug Abuse in Hong Kong. We develop a two-stage smoothing spline approach. This gives a flexible and easily implemented alternative to the previous method which was based on kernel smoothing. The new method retains the property of reducing the variability of the individual estimates at each time point. We evaluate the new method by means of a simulation study that includes an examination of the effects of variable selection. The new method is then applied to data collected by the Central Registry of Drug Abuse. The parameter estimates obtained are compared with the well known Jolly-Seber estimates based on single capture methods.

关键词： log-linear models model selection population size estimation smoothing splines

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Combining local and global smoothing in multivariate density estimation

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STAT 2016年第1期5卷 338-348页

作者： Azzalini, Adelchi Univ Padua Dept Stat Sci I-35121 Padua Italy

Non-parametric estimation of a multivariate density is tackled via a method that combines traditional local smoothing with a form of global smoothing but without imposing a rigid structure. Simulation work delivers encouraging indications on the effectiveness of the method. An application to density-based clustering illustrates a possible usage. Copyright (C) 2016 John Wiley & Sons, Ltd.

关键词： density-based clustering kernel method log-linear models non-parametric density estimation

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On the occurrence of boundary solutions in multidimensional incomplete tables

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STATISTICS & PROBABILITY LETTERS 2016年第0期119卷 63-75页

作者： Ghosh, S. Vellaisamy, P. Indian Inst Technol Dept Math Bombay Maharashtra India

We provide sufficient conditions for the occurrence of boundary solutions under nonignorable nonresponse models in arbitrary three-way and n-dimensional incomplete tables with one or more variables missing. These conditions involve only the observed counts, and avoid solving likelihood equations. (C) 2016 Elsevier B.V. All rights reserved.

关键词： Incomplete tables Boundary solutions log-linear models NMAR models

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Exploring the non-linear association between BMI and mortality in adults with and without diabetes: the US National Health Interview Survey

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DIABETIC MEDICINE 2016年第12期33卷 1691-1699页

作者： Wang, Z. Dong, B. Hu, J. Adegbija, O. Arnold, L. W. Univ Queensland Sch Med Ctr Chron Dis Herston Qld Australia

AimsTo assess the non-linear relationship between BMI and mortality and to determine the BMI values with the lowest mortality risk in adults with and without diabetes. MethodsThis observational study assessed the relationship between BMI and mortality with flexible parametric survival models using data from the US National Health Interview Survey. Participants included 25 458 adults with diabetes and 315 939 adults without diabetes, aged 18-84 years at baseline surveys, conducted from 1997 to 2009. Mortality status data were obtained from the linked mortality data up to 2011. ResultsWe observed a U-shaped relationship between BMI and mortality in both adults with and without diabetes. With the BMI 25-29.9 kg/m(2) group as reference, hazard ratios (95% CI) of mortality for those with BMI < 18.5, 18.5-24.9, 30-34.9, 35-39.9 and 40 kg/m(2) were 2.67 (2.12, 3.35), 1.26 (1.18, 1.35), 1.04 (0.98, 1.12), 1.12 (1.02, 1.22) and 1.37 (1.24, 1.51), respectively, for adults with diabetes, adjusting for age, sex, race and survey year. The corresponding hazard ratios for adults without diabetes were 2.97 (2.78, 3.17), 1.27 (1.23, 1.30), 1.07 (1.03, 1.12), 1.36 (1.27, 1.45), and 1.77 (1.62, 1.92), respectively. The BMI values associated with the lowest mortality were 29.1 kg/m(2) for adults with diabetes and 26.7 kg/m(2) for those without diabetes. ConclusionsRegardless of the presence of diabetes, there is a U-shaped relationship between BMI and mortality. The BMI values associated with the lowest mortality were above the current normal' range for adults with and without diabetes.

关键词： DIAGNOSIS of diabetes MORTALITY OBESITY complications GOVERNMENT agencies BODY weight CARDIOVASCULAR diseases CONFIDENCE intervals DIABETICS ETHNIC groups log-linear models OBSERVATION (Scientific method) RACE FINANCING of research SMOKING SURVEYS TUMORS DATA analysis BODY mass index CONTROL groups (Research) ACQUISITION of data CROSS-sectional method PROPORTIONAL hazards models RISK factors

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Are the kinship networks a resource or a curse for small firms in post-communist countries? The case of Albania

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POST-COMMUNIST ECONOMIES 2016年第2期28卷 268-279页

作者： Gassie-Falzone, Esmeralda Conservatoire Natl Arts & Metiers Paris France

Cross-sectional data are compiled from the 2002, 2005, 2008 and 2012 World Bank Living Standards Measurement Study databases for Albania. Based on responses from 1169 firms, the entrepreneurs' kinship networks are found to influence firm activity in a positive and negative way. The positive contribution occurs through employment, be it formal or informal. The persisting impact of the kinship networks fades away, and business and friendship networks have gained importance in recent years.

关键词： Albania kinship network non-agricultural small firms LSMS log-linear models

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Social Association and Social Inequality in Poland, 1988-2013

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INTERNATIONAL JOURNAL OF SOCIOlogY 2016年第4期46卷 288-319页

作者： Karpinski, Zbigniew Polish Acad Sci Inst Philosophy & Sociol 72 Nowy Swiat St PL-00330 Warsaw Poland

The present study contributes to the study of educational and occupational homophily in marital and friendship relations in Poland. Using data from the most recent installment of an ongoing longitudinal study, the article adds to the existing body of findings on the topic and also (a) applies a novel conceptual framework to the data to obtain estimates of homophily for the different characteristics and relations, and (b) tests hypotheses specifying a link between the amount of homophily and the overall degree of inequality. The conceptual framework models homophily in terms of the probability that a member of a given group will reject an out-group member as an associate. The hypotheses build on work on the so-called Matthew effect by Slomczynski et al. (2007) and a theoretical argument derived from status and exchange theories. Empirical analyses presented in the second part of the study suggest that there has been some change in the degree of homophily, but the magnitude of that change depends on the distance separating the categories: while the estimates of the rejection probabilities for relations between distant categories are more or less stable across the period under study, we observe a decrease in homophily in social associations between categories that are close to one another in the social hierarchy.

关键词： Homophily log-linear models quasi-symmetry repulsion mechanism social inequality

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Decrease in (Major) Amputations in Diabetics: A Secondary Data Analysis by AOK Rheinland/Hamburg

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JOURNAL OF DIABETES RESEARCH 2016年第1期2016卷 6247045-6247045页

作者： May, Melanie Hahn, Sebastian Tonn, Claudia Engels, Gerald Hochlenert, Dirk AOK Rheinland Hamburg Unternehmensbereich Ambulante Versorgung Geschaftsbereich Selektivvertrage Kasernenstr 61 D-40213 Dusseldorf Germany AOK Rheinland Hamburg Unternehmensbereich M RSA Finanzen Controlling Geschaftsbereich Controlling Kasernenstr 61 D-40213 Dusseldorf Germany Chirurg Praxis Bayenthalgurtel Bayenthalgurtel 45 D-50968 Cologne Germany Wundchirurg St Vinzenz Hosp Koln Ltd Arzt Abt Merheimer Str 221 D-50733 Cologne Germany Ctr Diabetol Endoskopie & Wundheilung Merheimer Str 217 D-50733 Cologne Germany

Aim. In two German regions with 11.1 million inhabitants, 6 networks for specialized treatment of DFS were implemented until 2008. Data provided for accounting purposes was analysed in order to determine changes in the rate of diabetics requiring amputations in the years before and after the implementation. Method. Data covering 2.9 million people insured by the largest insurance company between 2007 and 2013 was analysed by the use of log-linear Poisson regression adjusted for age, gender and region. Results. The rate of diabetics needing major amputations fell significantly by 9.5% per year (p < 0.0001) from 217 to 126 of 100,000 patients per year. The rate of diabetics needing amputations of any kind fell from 504 to 419 of 100,000 patients per year (p = 0.0038). Discussion. The networks integrate health care providers in an organised system of shared care. They educate members of the medical community and the general public. At the same time, a more general disease management program for people with diabetes was implemented, which may also have contributed to this decrease. At the end of the observation period, the rate of diabetics requiring amputations was still high. For this reason, further expansion of organised specialized care is urgently needed.

关键词： AMPUTATION DIABETICS DATA analysis log-linear models DISEASE management HEALTH programs INSURANCE companies

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Detection, Identification, and Quantification of Hydroxylated Bis(2-ethylhexyl)-Tetrabromophthalate Isomers in House Dust

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ENVIRONMENTAL SCIENCE & TECHNOlogY 2015年第5期49卷 2999-3006页

作者： Peng, Hui Saunders, David M. V. Sun, Jianxian Codling, Garry Wiseman, Steve Jones, Paul D. Giesy, John P. Univ Saskatchewan Toxicol Ctr Saskatoon SK S7N 5B3 Canada Sch Environm & Sustainabil Saskatoon SK S7N 5C8 Canada Univ Saskatchewan Dept Vet Biomed Sci Saskatoon SK S7N 5B3 Canada Michigan State Univ Dept Zool Ctr Integrat Toxicol E Lansing MI 48824 USA City Univ Hong Kong Dept Biol & Chem Kowloon Hong Kong Peoples R China Univ Hong Kong Sch Biol Sci Pok Fu Lam Hong Kong Peoples R China Nanjing Univ Sch Environm State Key Lab Pollut Control & Resource Reuse Nanjing 210008 Jiangsu Peoples R China

Ultra-High Resolution LC/mass spectrometry (LC-UHRMS;Thermo Fisher Q-Exactive) was used to identify two novel isomers of hydroxylated bis(2-ethylhexyl)-tetrabromophthalate (OH-TBPH) which were unexpectedly observed in a commercial standard of TBPH. By combining ultra-high resolution (UHR) mass spectra (MS1), mass errors to theoretical [TBPH-Br+O](-) were 2.1 and 1.0 ppm for the two isomers, UHR-MS2 spectra and NMR analysis;the structures of the two compounds were identified as hydroxylated TBPH with a hydroxyl group on the aromatic ring. Relatively great proportions of the two isomers of OH-TBPH were detected in two technical products, Firemaster 550 (FM-550;0.1% and 6.2%, respectively) and Firemaster BZ 54 (BZ-54;0.1% and 7.9%), compared to a commercial standard (0.4% and 0.9%). To simultaneously analyze OH-TBPH isomers and TBPH in samples of dust, a method based on LC-UHRMS was developed to quantify the two compounds, using negative and positive ion modes, respectively. The instrumental limit of detection for TBPH was 0.01 mu g/L, which was 200-300 times better than traditional methods (2.5 mu g/L) based on gas chromatography-mass spectrometry. The analytical method combined with a Florisil cleanup was successfully applied to analyze TBPH and OH-TBPH in 23 indoor dust samples from Saskatoon, Saskatchewan, Canada. Two OH-TBPH isomers, OH-TBPH1 and OH-TBPH2, were detected in 52% and 91% of dust samples, respectively. Concentrations of OH-TBPH2 (0.35 +/- 1.0 ng/g) were 10-fold greater than those of OH-TBPH1 (0.04 +/- 0.88 ng/g) in dust, which was similar to profiles in FM-550 and BZ-54. TBPH was also detected in 100% of dust samples with a mean concentration of 733 +/- 0.87 ng/g. A significant (p < 0.001) log-linear relationship was observed between TBPH and OH-TBPH isomers, further supporting the hypothesis of a common source of emission. Relatively small proportions of OH-TBPH isomers were detected in dust (0.01% +/- 0.67 OH-TBPH1 and 0.1% +/- 0.60 OH-TBPH2), which

关键词： ISOMERS HYDROXYL group log-linear models DUST -- Environmental aspects GAS chromatography/Mass spectrometry (GC-MS)

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EXISTENCE OF H-MATRIX APPROXIMANTS TO THE INVERSES OF BEM MATRICES: THE SIMPLE-LAYER OPERATOR

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MATHEMATICS OF COMPUTATION 2015年第297期85卷 119-152页

作者： Faustmann, Markus Melenk, Jens Markus Praetorius, Dirk Vienna Univ Technol Inst Anal & Sci Comp Inst 101 A-1040 Vienna Austria

We consider the question of approximating the inverse W = V-1 of the Galerkin stiffness matrix V obtained by discretizing the simple-layer operator V with piecewise constant functions. The block partitioning of W is assumed to satisfy any one of several standard admissibility criteria that are employed in connection with clustering algorithms to approximate the discrete BEM operator V. We show that W can be approximated by block-wise low-rank matrices such that the error decays exponentially in the block rank employed. Similar exponential approximability results are shown for the Cholesky factorization of V.

关键词： BOUNDARY element methods GALERKIN methods BOOLEAN matrices WAVELETS (Mathematics) log-linear models DISCRETIZATION methods

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SHAYLE R. SEARLE: PIONEER IN linear MODELLING

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AUSTRALIAN & NEW ZEALAND JOURNAL OF STATISTICS 2015年第1期57卷 1-14页

作者： Hunter, Jeffrey J. Auckland Univ Technol Auckland New Zealand

This article is based on a transcript of the Memorial Session held on 14 August 2013 at the 22nd International Workshop on Matrices and Statistics held at the University of Toronto, Toronto, Canada, to honour the life and contributions of Professor Emeritus Shayle Searle. The speakers were Jeffrey J. Hunter, David A. Harville, Jon N. K. Rao, Robert Rodriguez, and Shayle's daughters, Susan Searle and Heather Selvaggio.

关键词： linear models (Statistics) FAILURE time data analysis log-linear models

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