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关键词： Categorical regressors   Regularization   Smoothing kernels   Model averaging  

摘要： This paper introduces a flexible regularization approach that reduces point estimation risk of group means stemming from e.g. categorical regressors, (quasi-)experimental data or panel data models. The loss function is penalized by adding weighted squared l(2)-norm differences between group location parameters and informative first stage estimates. Under quadratic loss, the penalized estimation problem has a simple interpretable closed-form solution that nests methods established in the literature on ridge regression, discretized support smoothing kernels and model averaging methods. We derive risk-optimal penalty parameters and propose a plug-in approach for estimation. The large sample properties are analyzed in an asymptotic local to zero framework by introducing a class of sequences for close and distant systems of locations that is sufficient for describing a large range of data generating processes. We provide the asymptotic distributions of the shrinkage estimators under different penalization schemes. The proposed plug-in estimator uniformly dominates the ordinary least squares estimator in terms of asymptotic risk if the number of groups is larger than three. Monte Carlo simulations reveal robust improvements over standard methods in finite samples. Real data examples of estimating time trends in a panel and a difference-in-differences study illustrate potential applications. (C) 2020 Elsevier B.V. All rights reserved.

关键词： Personal care products   Race   ethnicity   Endocrine disrupting chemicals   Pregnancy   Socioeconomic status  

摘要： Personal care products (PCPs) are important and modifiable sources of exposure to endocrine disrupting chemicals (EDCs). Research is limited on how EDC-associated PCP use differs by race/ethnicity and socioeconomic status (SES), particularly during the sensitive period of pregnancy. We investigated differences in PCP use by race/ethnicity and SES among 497 participants in the LIFECODES pregnancy cohort (Boston, Massachusetts). Participants self-reported race/ethnicity, SES indicators (maternal education;insurance status), and recent PCP use via questionnaire at <= 4 prenatal visits. We evaluated trimester-specific differences in use of individual PCP categories by race/ethnicity and SES indicators. We used Poisson regression to estimate trimester-specific mean total product categories used by race/ethnicity and SES indicators. In the first trimester, compared to nonHispanic White women, Hispanic women reported higher use of hair gel (45% vs. 28%), perfume (75% vs. 39%), and "other" hair products (37% vs. 19%). Compared to women with a college degree, women without a college degree reported higher use of perfume (79% vs. 41%) and bar soap (74% vs. 56%);patterns were similar for insurance status. The estimated mean total product categories used was significantly lower in Asian compared to non-Hispanic White women in all trimesters (e.g., Trimester 1: 4.8 vs. 6.7 categories;p<0.001). Patterns of PCP use differed by race/ethnicity and SES, with implications for potentially modifiable differential EDC exposure and associated pregnancy outcomes.

关键词： false discovery rate   knockoff filter   psoriatic arthritis   sequential knockoffs   variable selection  

摘要： Knockoffs provide a general framework for controlling the false discovery rate when performing variable selection. Much of the Knockoffs literature focuses on theoretical challenges and we recognize a need for bringing some of the current ideas into practice. In this paper we propose a sequential algorithm for generating knockoffs when underlying data consists of both continuous and categorical (factor) variables. Further, we present a heuristic multiple knockoffs approach that offers a practical assessment of how robust the knockoff selection process is for a given dataset. We conduct extensive simulations to validate performance of the proposed methodology. Finally, we demonstrate the utility of the methods on a large clinical data pool of more than 2000 patients with psoriatic arthritis evaluated in four clinical trials with an IL-17A inhibitor, secukinumab (Cosentyx), where we determine prognostic factors of a well established clinical outcome. The analyses presented in this paper could provide a wide range of applications to commonly encountered datasets in medical practice and other fields where variable selection is of particular interest.

关键词： Sustainable food consumption   Different labels   Organic food   Consumer preferences   Brazil  

摘要： Purpose Organic food consumption is growing, increasing the need for studies investigating the importance of organic certification labels in emerging countries. The research aims to identify the influence of certification labels and fresh organic produce categories (greenery, vegetable or fruit) on consumer trust and purchase intention. Design/methodology/approach An online experimental survey 3 x 3 was administered among 349 Brazilian consumers. Certification label and fresh organic produce category were designated as independent variables and manipulated to explore consumer trust and purchase intention. The authors performed a multivariate covariance analysis (MANCOVA) to analyze the data. Findings Results show that the certification label does not directly affect the dependent variables. It acts as a moderator and indirectly affects both consumer trust and purchase intention. Moreover, depending on the fresh organic produce category considered (greenery, vegetable or fruit), consumer trust changes. Sociodemographic characteristics, age and household income are also important. Finally, the greater the purchase frequency (the main predictor of the model), the greater the purchase intention and consumer trust. Originality/value The study contributes to deepen and expand studies involving organic food and to pave the way for future studies that aim to investigate the importance of certification labels of organic foods for consumers.

关键词： Variation of Hodge structures   Noncommutative Hodge structures   Matrix factorizations  

摘要： Let W is an element of C[x(1), . . ., x(N)] be an invertible polynomial with an isolated singularity at origin, and let G subset of SLN boolean AND(C*)(N) be a finite diagonal and special linear symmetry group of W. In this paper, we use the category MFG(W) of G-equivariant matrix factorizations and its associated VSHS to construct a G-equivariant version of Saito's theory of primitive forms. We prove there exists a canonical categorical primitive form of MFG(W) characterized by G(W)(max)-equivariance. Conjecturally, this G-equivariant Saito theory is equivalent to the genus zero part of the FJRW theory under LG/LG mirror symmetry. In the marginal deformation direction, we verify this for the FJRW theory of (1/5(x(1)(5) + . . . + x(5)(5)), Z/5Z) with its mirror dual B-model Landau-Ginzburg orbifold (1/5( x(1)(5) + . . . + x(5)(5)), ( Z/5Z)(4)). In the case of the Quintic family W= 1/5( x(1)(5)+ . . . + x(5)(5)) - psi x(1)x(2)x(3)x(4)x(5), we also prove a comparison result of B-model VSHS's conjectured by Ganatra-Perutz-Sheridan[14]. (C) 2021 Elsevier Inc. All rights reserved.

关键词： SO(3)   Module categories   Modular tensor categories   Subfactors   Quantum subgroups  

摘要： The main goal of this paper is to classify *-module categories for the SO(3)(2m) modular tensor category. This is done by classifying SO(3)(2m) nimrep graphs and cell systems, and in the process we also classify the SO(3) modular invariants. There are module categories of type A, E and their conjugates, but there are no orbifold (or type D) module categories. We present a construction of a subfactor with principal graph given by the fusion rules of the fundamental generator of the SO(3)(2m) modular category. We also introduce a Frobenius algebra A which is an SO(3) generalisation of (higher) preprojective algebras, and derive a finite resolution of A as a left A-module along with its Hilbert series. (C) 2021 Elsevier Inc. All rights reserved.

关键词： 投资建设管理   范畴   重要性  

摘要： 伴随着我国经济社会的不断发展,越来越多的建筑工程也开始了新一轮的施工建设工作。许许多多对施工建设单位也已经注意到了投资建设过程之中的相关问题,然而由于投资建设过程自身的原因导致一部分施工建设单位面对着非常复杂的投资建设问题也只能是“望而却步”。投资建设之中的财务管理问题也属于投资建设整体管理问题之中的一个重要组成部分。相比于一般的投资建设管理过程而言,财务管理的过程也具有复杂性和多样性的特点。也正因如此笔者也将在文章的以下内容中重点分析投资建设过程中相关财务管理的一系列具体方法。

摘要： This study examined characteristics of cisgender people who use non-traditional sexual orientation labels and investigated minority stress in these groups. Pansexual (n = 160), queer (n = 80), and asexual (n = 98) participants were compared with heterosexual (n = 1,021), bisexual (n = 1,518), and lesbian/gay (n = 2,730) individuals recruited from a cross-sectional survey. Participants were compared on sexual attraction, age, gender and childhood gender nonconformity. Hierarchical regression models with psychological distress as the dependent variable and outness, prejudice events, expectations of rejection, self-stigma, and rumination as independent variables were then tested in pansexual, queer, and asexual individuals. Sexual attraction, age, gender and recalled childhood gender nonconformity were significant predictors of group identity. Pansexual individuals were not significantly distinct from bisexual individuals in sexual attraction. Queer individuals fell between bisexual and lesbian/gay individuals in sexual attraction scores. Prejudice events and rumination were significantly associated with distress in all three non-traditional groups. Rumination scores attenuated the relationship between prejudice events and distress in all groups. These findings help characterize pansexual, asexual and queer individuals and suggest indirect effects of prejudice events on distress via rumination represent a worthy avenue for future minority stress research in these groups.

关键词： Change detection   Nonstationary categorical time series   Nonhomogeneous Markov models   Water consumption behavior  

摘要： Categorical sequences are widely used in various domains to describe the evolutionary state of the process under study. This article addresses the problem of behavioral change detection for multiple categorical time series. Relying on the sequential likelihood ratio test, an online change detection method is proposed based on the joint modeling of all the categorical sequences. To model the joint probability density, a nonhomogeneous Markov model is used. It allows modeling the transition dynamics over time and considering their dependence on some exogenous factors that may influence the behavior changes. An adaptive threshold is learned using Monte Carlo simulations to detect different changes and reduce false alarms. The performance of the proposed method is evaluated using two real-world and four synthetic datasets. It is compared with two state-of-the-art change detection methods, namely logistic regression and homogeneous Markov model. The experimentation using synthetic datasets highlights the proposed method's effectiveness in terms of both the detection precision and the detection delay. The real-world data are issued from a water network and school-to-work transition. The analysis of the model estimated parameters allows us to characterize the detected changes in a real-world context. (c) 2021 Elsevier B.V. All rights reserved.