检索结果-内蒙古大学图书馆

The additive and block decompositions about the WLSEs of parametric functions for a multiple partitioned linear regression model

引用

JOURNAL OF MULTIVARIATE ANALYSIS 2015年 133卷 123-135页

作者： Huang, Yunying Zheng, Bing Lanzhou Univ Sch Math & Stat Lanzhou 730000 Peoples R China

The necessary and sufficient conditions for the weighted least-squares estimators (WLSEs) of parametric functions K-1 beta(1) + K-2 beta(2) + ... + K-m beta(m) under a multiple partitioned linear model M = {y, X-1 beta(1) + ... + X-m beta(m), sigma(2)Sigma} to be the sum of the WLSEs of K-i beta(i), under the m small models M-1 = {y, X-i beta(i), sigma(2)Sigma}, i = 1, 2,..., m, and for the WLSEs of parametric functions K-i beta(i) under the linear model M to be equal to the WLSEs of parametric function K-i beta(i) under its small model M-i, i = 1, 2,..., m are derived. Some statistical properties about the WLSEs of parametric functions are also described. (C) 2014 Elsevier Inc. All rights reserved.

关键词： Multiple partitioned linear model WLSEs BLUE parametric functions Matrix rank method Moore-Penrose inverse of matrix

来源：评论

学校读者我要写书评

暂无评论

Application of parametric function in construction of particle shape and discrete element simulation

引用

POWDER TECHNOLOGY 2021年 387卷 481-493页

作者： Zhao, Chuang Gao, Qingqing Chen, Yuchao Li, Chengbo Guizhou Univ Coll Phys Guiyang 550025 Peoples R China Nanyang Normal Univ Dept Civil Engn Nanyang 473000 Peoples R China Anyang Inst Technol Coll Mat Sci & Engn Anyang 455000 Peoples R China

In previous studies, particles, such as ellipsoids and super-ellipsoids, are mainly described by implicit functions. However, parametric functions can define more surfaces that can be used to represent a wider variety of particle shapes. In this study, parametric functions are used to construct particles, and the algorithm to determine the multi-point contact between concave particles is also given. Furthermore, the geometric parameters at the contact point, for instance, normal vectors, curvatures, and overlapping, are formulated by the parameters in the parametric function. To verify the proposed method, we use the discrete element method to simulate the systems of torus-shaped particles nested within each other, and analyze the momentum and kinetic energy changes with time. The equilibrium state with approximately zero energy is obtained, which means that the algorithm for multi-point contact of concave particles is suitable and stable. In addition to the torus-shaped particle, another two concave particles defined by parametric function are modeled. The simulation results indicate that the method is universal. Any plane curve can be used to construct surfaces by using the method provided in this work, and computational efficiency of simulations of particles defined by parametric function is higher because calculations of the inverse Jacobian matrix in the Newton-Raphson method are unnecessary. The parametric function method extends the scope of previous studies on particle shape. (c) 2021 Elsevier B.V. All rights reserved.

关键词： parametric functions Torus-shaped particles Discrete element method

来源：评论

学校读者我要写书评

暂无评论

On relations between weighted least-squares estimators of parametric functions under a general partitioned linear model and its small models

引用

METRIKA 2013年第5期76卷 707-722页

作者： Lu, Changli Sun, Yuqin Tian, Yongge Shanghai Maritime Univ Coll Econ & Management Shanghai Peoples R China Cent Univ Finance & Econ CEMA Beijing Peoples R China

We study relations between the weighted least-squares estimators (WLSEs) of given parametric functions under a general partitioned linear model and the WLSEs of and under the two small models and . Some consequences o... 详细信息

关键词： Partitioned linear model Small models parametric functions WLSE BLUE Decomposition of estimator Moore-Penrose inverse of matrix

来源：评论

学校读者我要写书评

暂无评论

Genomic-based genetic parameters for daily milk yield and various lactation persistency traits in American Holstein cattle

引用

Journal of dairy science 2025年

作者： Patrick R Fotso-Kenmogne Paulo L S Carneiro Delvan A Silva Jaime A Cobuci Pedro F C Aponte Hinayah R Oliveira Luiz F Brito Postgraduate Program in Animal Sciences State University of Southwestern Bahia Itapetinga BA 45700-000 Brazil Ministry of Employment and Vocational Training (MINEFOP) Yaoundé CE P.O. Box 16273 Cameroon. Department of Biology State University of Southwestern Bahia Jequié BA 45206-190 Brazil. Electronic address: plscarneiro@***. Department of Animal Sciences Federal University of Viçosa Viçosa MG 36570-000 Brazil. Department of Animal Science Federal University of Rio Grande do Sul Porto Alegre RS 91540-000 Brazil. Postgraduate Program in Animal Sciences State University of Southwestern Bahia Itapetinga BA 45700-000 Brazil. Department of Animal Sciences Purdue University West Lafayette IN 47907. Department of Animal Sciences Purdue University West Lafayette IN 47907. Electronic address: britol@purdue.edu.

Genomic-based genetic parameters for daily milk yield and lactation persistency were estimated for the first 3 lactations in American Holstein cattle. Data included 5,235,411 daily milk yield records on automatic milking systems and milking parlors from 11,788 genotyped cows that calved from 2012 to 2019. A total of 62,029 SNPs remained after quality control. Single-trait random regression models were used to estimate variance and covariance components based on Bayesian inference. The systematic effects in the model included calving year, calving season, milking system, and calving age as linear and quadratic covariates. Random effects included additive genetic, permanent environment, and residual effects modeled with parametric (i.e., Wood, Wilmink, and Ali and Schaeffer) and non-parametric functions (i.e., Legendre orthogonal polynomials and B-splines). The same number of coefficients was considered for all fixed and random regressions in each analysis. Twenty-six models were compared for each lactation and models were selected based on goodness of fit and parsimony, estimates of variance components, heritabilities, correlations, credibility and interpretation of the results, and computational demand and time. Consequently, the model using fourth-order Legendre orthogonal polynomials and 10 classes of heterogeneous residual variance was considered the optimal model. The daily heritability estimates across DIM ranged from 0.12 to 0.22 for milk yield in parity 1 (MY1), 0.11 to 0.19 for milk yield in parity 2 (MY2), and from 0.03 to 0.15 for milk yield in parity 3 (MY3). For lactation persistency, the heritability estimates ranged from 0.05 to 0.18 for MY1, from 0.06 to 0.20 for MY2, and from 0.05 to 0.16 for MY3. Overall, the heritability estimate values were of low to moderate magnitude. In general, null to moderate genetic correlations were observed between lactation persistency and 305-d milk yield, indicating weak association between lactation persistency and mi

关键词： automatic milking systems extended lactation longitudinal data parametric functions random regression models

来源：评论

学校读者我要写书评

暂无评论

An improved operation-based reservoir scheme integrated with Variable Infiltration Capacity model for multiyear and multipurpose reservoirs

引用

JOURNAL OF HYDROLOGY 2019年 571卷 365-375页

作者： Wang, Keyi Shi, Haiyun Chen, Ji Li, Tiejian Tsinghua Univ State Key Lab Hydrosci & Engn Beijing Peoples R China Univ Hong Kong Dept Civil Engn Hong Kong Peoples R China Southern Univ Sci & Technol Sch Environm Sci & Engn State Environm Protect Key Lab Integrated Surface Shenzhen Peoples R China Southern Univ Sci & Technol Sch Environm Sci & Engn Guangdong Prov Key Lab Soil & Groundwater Pollut Shenzhen Peoples R China Qinghai Univ State Key Lab Plateau Ecol & Agr Xining Qinghai Peoples R China

Multiyear and multipurpose reservoirs generally need to adjust operational functions for different storage levels;most existing reservoir schemes lack the pertinence to model the complex behaviors of such reservoirs. This paper proposes an improved operation-based reservoir scheme to simulate the storage and outflow variations for multiyear and multipurpose reservoirs at a daily time step. In this improved reservoir scheme, the new parametric functions to represent the weights of the outflow through considering various operation purposes (e.g., hydropower generation, flood control, and water supply) are introduced. Then, the improved reservoir scheme is integrated into a macroscale hydrological model, i.e., Variable Infiltration Capacity (VIC) model. In this study, the performance of the proposed reservoir scheme is evaluated with the observed storage and outflow of a multiyear and multipurpose reservoir (Xinfengjiang Reservoir) in South China and compared to two other reservoir schemes (i.e., a multilinear regression reservoir scheme and an operation-based reservoir scheme). In addition, through uncertainty analysis, this study shows that the time-varying operation-based parameters can reflect the changes of reservoir storage but not reservoir outflow, indicating that the parameters for establishing functional relationships need further exploration. Results reveal that the proposed reservoir scheme has a wide applicability for reservoir storage and outflow simulation, especially for the reservoirs with limited reservoir management data.

关键词： Reservoir scheme Variable Infiltration Capacity (VIC) parametric functions Generalized likelihood uncertainty estimation (GLUE) Xinfengjiang Reservoir

来源：评论

学校读者我要写书评

暂无评论

On the equality of estimators under a general partitioned linear model with parameter restrictions

引用

STATISTICAL PAPERS 2019年第1期60卷 273-292页

作者： Jiang, Bo Sun, Yuqin Shandong Inst Business & Technol Coll Math & Informat Sci Yantai Peoples R China Shanghai Maritime Univ Coll Econ & Management Shanghai Peoples R China

Assume that a linear regression model is written as a partitioned form. In such a case, it is quite convenient to determine the role of each subset of regressors, and to derive estimators of unknown partial parameters in the partitioned model. In this paper, we consider the relationships between the well-known ordinary least-squares estimators (OLSEs) and the best linear unbiased estimators (BLUEs) of the whole and partial mean parameter vectors in a general partitioned linear model with parameter restrictions. We first review some known results on the OLSEs and the BLUEs and their properties under general linear models. We then present a variety of necessary and sufficient conditions for OLSEs to be BLUEs under a general partitioned linear model with parameter restrictions.

关键词： Partitioned linear model parametric functions Estimability OLSE BLUE Estimator equality

来源：评论

学校读者我要写书评

暂无评论

On equivalence of predictors/estimators under a multivariate general linear model with augmentation

引用

JOURNAL OF THE KOREAN STATISTICAL SOCIETY 2017年第4期46卷 551-561页

作者： Jiang, Bo Tian, Yongge Shandong Inst Business & Technol Coll Math & Informat Sci Yantai Peoples R China Cent Univ Finance & Econ China Econ & Management Acad Beijing Peoples R China

Assume that a true multivariate general linear model for an observed random matrix is over-parameterized by adding some new regressors due to model uncertainty. Then predictors and estimators of parameter spaces in the true and over-parameterized models are not necessarily the same. In this article, we study the comparison problem of predictors/estimators of parameter spaces under the two models. In particular, we derive necessary and sufficient conditions for the best linear unbiased predictors/best linear unbiased estimators of the parameter spaces to be equivalent under the two models. (C) 2017 The Korean Statistical Society. Published by Elsevier B.V. All rights reserved.

关键词： True model Over-parameterized model parametric functions Kronecker product BLUP BLUE

来源：评论

学校读者我要写书评

暂无评论

Estimations of parametric functions under a System of Linear Regression Equations with Correlated Errors

引用

Acta Mathematica Sinica,English Series 2010年第10期26卷 1927-1942页

作者： Yong Ge TIAN China Economics and Management Academy Central University of Finance and Economics Beijing 100081 P. R. China

Estimations of parametric functions under a system of linear regression equations with correlated errors across equations involve many complicated operations of matrices and their generalized inverses. In the past several years, a useful tool -- the matrix rank method was utilized to simplify various complicated operations of matrices and their generalized inverses. In this paper, we use the matrix rank method to derive a variety of new algebraic and statistical properties for the best linear unbiased estimators （BLUEs） of parametric functions under the system. In particular, we give the necessary and sufficient conditions for some equalities, additive and block decompositions of BLUEs of parametric functions under the system to hold.

关键词： Linear regression equations SUR model parametric functions estimability BLUE equalities of estimators decompositions of estimators matrix rank method

来源：评论

学校读者我要写书评

暂无评论

Weighted least-squares estimators of parametric functions of the regression coefficients under a general linear model

引用

ANNALS OF THE INSTITUTE OF STATISTICAL MATHEMATICS 2010年第5期62卷 929-941页

作者： Tian, Yongge Cent Univ Finance & Econ China Econ & Management Acad Beijing 100081 Peoples R China

The weighted least-squares estimator of parametric functions K beta under a general linear regression model {y, X beta, sigma(2)Sigma} is defined to be K (beta) over cap , where (beta) over cap is a vector that minimizes (y - X beta)'V(y - X beta) for a given nonnegative definite weight matrix V. In this paper, we study some algebraic and statistical properties of K (beta) over cap and the projection matrix associated with the estimator, such as, their ranks, unbiasedness, uniqueness, as well as equalities satisfied by the projection matrices.

关键词： General linear regression model parametric functions WLSE Projection matrix Unbiasedness of estimator Uniqueness of estimator

来源：评论

学校读者我要写书评

暂无评论

Some remarks on general linear model with new regressors

引用

STATISTICS & PROBABILITY LETTERS 2015年 97卷 16-24页

作者： Lu, Changli Gan, Shengjun Tian, Yongge Shanghai Maritime Univ Coll Econ & Management Shanghai Peoples R China Ctr Univ Finance & Econom China Econom & Management Acad Beijing Peoples R China

Assume that an original general linear model is misspecified by adding some new regressors. We investigate in such a case relationships between the best linear unbiased estimators under the two models. In particular, we give necessary and sufficient conditions for the best linear unbiased estimators to be equal under the two models. (C) 2014 Elsevier B.V. All rights reserved.

关键词： Linear model Misspecified model parametric functions New regressors BLUE

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：