• Title/Summary/Keyword: Hierarchical Regression

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Development and application of a hierarchical estimation method for anthropometric variables (인체변수의 계층적 추정기법 개발 및 적용)

  • Ryu, Tae-Beom;Yu, Hui-Cheon
    • Journal of the Ergonomics Society of Korea
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    • v.22 no.4
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    • pp.59-78
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    • 2003
  • Most regression models of anthropometric variables use stature and/or weight as regressors; however, these 'flat' regression models result in large errors for anthropometric variables having low correlations with the regressors. To develop more accurate regression models for anthropometric variables, this study proposed a method to estimate anthropometric variables in a hierarchical manner based on the relationships among the variables and a process to develop and improve corresponding regression models. By applying the proposed approach, a hierarchical estimation structure was constructed for 59 anthropometric variables selected for the occupant package design of a passenger car and corresponding regression models were developed with the 1988 US Army anthropometric survey data. The hierarchical regression models were compared with the corresponding flat regression models in terms of accuracy. As results, the standard errors of the hierarchical regression models decreased by 28% (4.3mm) on average compared with those of the flat models.

Forecasting hierarchical time series for foodborne disease outbreaks (식중독 발생 건수에 대한 계층 시계열 예측)

  • In-Kwon Yeo
    • The Korean Journal of Applied Statistics
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    • v.37 no.4
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    • pp.499 -508
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    • 2024
  • In this paper, we investigate hierarchical time series forecasting that adhere to a hierarchical structure when deriving predicted values by analyzing segmented data as well as aggregated datasets. The occurrences of food poisoning by a specific pathogen are analyzed using zero-inflated Poisson regression models and negative binomial regression models. The occurrences of major, miscellaneous, and overall food poisoning are analyzed using Poisson regression models and negative binomial regression models. For hierarchical time series forecasting, the MinT estimation proposed by Wickramasuriya et al. (2019) is employed. Negative predicted values resulting from hierarchical adjustments are adjusted to zero, and weights are multiplied to the remaining lowest-level variables to satisfy the hierarchical structure. Empirical analysis revealed that there is little difference between hierarchical and non-hierarchical adjustments in predictions based on pathogens. However, hierarchical adjustments generally yield superior results for predictions concerning major, miscellaneous, and overall occurrences. Without hierarchical adjustment, instances may occur where the predicted frequencies of the lowest-level variables exceed that of major or miscellaneous occurrences. However, the proposed method enables the acquisition of predictions that adhere to the hierarchical structure.

Multi-Finger 3D Landmark Detection using Bi-Directional Hierarchical Regression

  • Choi, Jaesung;Lee, Minkyu;Lee, Sangyoun
    • Journal of International Society for Simulation Surgery
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    • v.3 no.1
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    • pp.9-11
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    • 2016
  • Purpose In this paper we proposed bi-directional hierarchical regression for accurate human finger landmark detection with only using depth information.Materials and Methods Our algorithm consisted of two different step, initialization and landmark estimation. To detect initial landmark, we used difference of random pixel pair as the feature descriptor. After initialization, 16 landmarks were estimated using cascaded regression methods. To improve accuracy and stability, we proposed bi-directional hierarchical structure.Results In our experiments, the ICVL database were used for evaluation. According to our experimental results, accuracy and stability increased when applying bi-directional hierarchical regression more than typical method on the test set. Especially, errors of each finger tips of hierarchical case significantly decreased more than other methods.Conclusion Our results proved that our proposed method improved accuracy and stability and also could be applied to a large range of applications such as augmented reality and simulation surgery.

Bayes Estimation in a Hierarchical Linear Model

  • Park, Kuey-Chung;Chang, In-Hong;Kim, Byung-Hwee
    • Journal of the Korean Statistical Society
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    • v.27 no.1
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    • pp.1-10
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    • 1998
  • In the problem of estimating a vector of unknown regression coefficients under the sum of squared error losses in a hierarchical linear model, we propose the hierarchical Bayes estimator of a vector of unknown regression coefficients in a hierarchical linear model, and then prove the admissibility of this estimator using Blyth's (196\51) method.

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Hierarchical Regression for Single Image Super Resolution via Clustering and Sparse Representation

  • Qiu, Kang;Yi, Benshun;Li, Weizhong;Huang, Taiqi
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.5
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    • pp.2539-2554
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    • 2017
  • Regression-based image super resolution (SR) methods have shown great advantage in time consumption while maintaining similar or improved quality performance compared to other learning-based methods. In this paper, we propose a novel single image SR method based on hierarchical regression to further improve the quality performance. As an improvement to other regression-based methods, we introduce a hierarchical scheme into the process of learning multiple regressors. First, training samples are grouped into different clusters according to their geometry similarity, which generates the structure layer. Then in each cluster, a compact dictionary can be learned by Sparse Coding (SC) method and the training samples can be further grouped by dictionary atoms to form the detail layer. Last, a series of projection matrixes, which anchored to dictionary atoms, can be learned by linear regression. Experiment results show that hierarchical scheme can lead to regression that is more precise. Our method achieves superior high quality results compared with several state-of-the-art methods.

Bayesian Curve-Fitting in Semiparametric Small Area Models with Measurement Errors

  • Hwang, Jinseub;Kim, Dal Ho
    • Communications for Statistical Applications and Methods
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    • v.22 no.4
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    • pp.349-359
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    • 2015
  • We study a semiparametric Bayesian approach to small area estimation under a nested error linear regression model with area level covariate subject to measurement error. Consideration is given to radial basis functions for the regression spline and knots on a grid of equally spaced sample quantiles of covariate with measurement errors in the nested error linear regression model setup. We conduct a hierarchical Bayesian structural measurement error model for small areas and prove the propriety of the joint posterior based on a given hierarchical Bayesian framework since some priors are defined non-informative improper priors that uses Markov Chain Monte Carlo methods to fit it. Our methodology is illustrated using numerical examples to compare possible models based on model adequacy criteria; in addition, analysis is conducted based on real data.

Semiparametric Bayesian Estimation under Structural Measurement Error Model

  • Hwang, Jin-Seub;Kim, Dal-Ho
    • Communications for Statistical Applications and Methods
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    • v.17 no.4
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    • pp.551-560
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    • 2010
  • This paper considers a Bayesian approach to modeling a flexible regression function under structural measurement error model. The regression function is modeled based on semiparametric regression with penalized splines. Model fitting and parameter estimation are carried out in a hierarchical Bayesian framework using Markov chain Monte Carlo methodology. Their performances are compared with those of the estimators under structural measurement error model without a semiparametric component.

Semiparametric Bayesian estimation under functional measurement error model

  • Hwang, Jin-Seub;Kim, Dal-Ho
    • Journal of the Korean Data and Information Science Society
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    • v.21 no.2
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    • pp.379-385
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    • 2010
  • This paper considers Bayesian approach to modeling a flexible regression function under functional measurement error model. The regression function is modeled based on semiparametric regression with penalized splines. Model fitting and parameter estimation are carried out in a hierarchical Bayesian framework using Markov chain Monte Carlo methodology. Their performances are compared with those of the estimators under functional measurement error model without semiparametric component.

The Moderating Effects of Emotional Intelligence in the Relations between Transformational Leadership and Organizational Commitment (조직 내 상사의 변혁적 리더십과 부하직원의 조직몰입 간의 관계에서 감성적 지능의 조절효과 분석)

  • Jang, Chung Seok;Park, Jong Oh
    • Journal of Digital Convergence
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    • v.10 no.11
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    • pp.209-223
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    • 2012
  • The purpose of this study is to examine the moderating effects of emotional intelligence in the relationship between transformational leadership and organizational commitment. To achieve the this research purpose, theoretical and empirical studies related to transformational leadership, organizational commitment, and emotional intelligence were carried out simultaneously. The established hypotheses related to transformational leadership, organizational commitment, and emotional intelligence were verified by the hierarchical regression analysis using SPSS. The result of this research are as followers : First, the hierarchical regression analysis revealed that moderation term was significant(${\beta}$=0.146, p<.01). The interaction term for charisma and emotional intelligence had a significant and positive relationship with organizational commitment. Second, the hierarchical regression analysis revealed that moderation term was insignificant(${\beta}$=2.295, p<.05) The interaction term for inspirational motivation and emotional intelligence had a significant and positive relationship with organizational commitment. Third, the hierarchical regression analysis revealed that moderation term was significant(${\beta}$=0.200, p<.001). The interaction term for intellectual stimulation and emotional intelligence had a significant and positive relationship with organizational commitment. Fourth, the hierarchical regression analysis revealed that moderation term was significant(${\beta}$=2.213, p<.01).

A Bayesian Method for Narrowing the Scope fo Variable Selection in Binary Response t-Link Regression

  • Kim, Hea-Jung
    • Journal of the Korean Statistical Society
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    • v.29 no.4
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    • pp.407-422
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    • 2000
  • This article is concerned with the selecting predictor variables to be included in building a class of binary response t-link regression models where both probit and logistic regression models can e approximately taken as members of the class. It is based on a modification of the stochastic search variable selection method(SSVS), intended to propose and develop a Bayesian procedure that used probabilistic considerations for selecting promising subsets of predictor variables. The procedure reformulates the binary response t-link regression setup in a hierarchical truncated normal mixture model by introducing a set of hyperparameters that will be used to identify subset choices. In this setup, the most promising subset of predictors can be identified as that with highest posterior probability in the marginal posterior distribution of the hyperparameters. To highlight the merit of the procedure, an illustrative numerical example is given.

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