• Title/Summary/Keyword: GLMS

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Matrix Formation in Univariate and Multivariate General Linear Models

  • Arwa A. Alkhalaf
    • International Journal of Computer Science & Network Security
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    • v.24 no.4
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    • pp.44-50
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    • 2024
  • This paper offers an overview of matrix formation and calculation techniques within the framework of General Linear Models (GLMs). It takes a sequential approach, beginning with a detailed exploration of matrix formation and calculation methods in regression analysis and univariate analysis of variance (ANOVA). Subsequently, it extends the discussion to cover multivariate analysis of variance (MANOVA). The primary objective of this study was to provide a clear and accessible explanation of the underlying matrices that play a crucial role in GLMs. Through linking, essentially different statistical methods, by fundamental principles and algebraic foundations that underpin the GLM estimation. Insights presented here aim to assist researchers, statisticians, and data analysts in enhancing their understanding of GLMs and their practical implementation in diverse research domains. This paper contributes to a better comprehension of the matrix-based techniques that can be extended to GLMs.

Influential Points in GLMs via Backwards Stepping

  • Jeong, Kwang-Mo;Oh, Hae-Young
    • Communications for Statistical Applications and Methods
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    • v.9 no.1
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    • pp.197-212
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    • 2002
  • When assessing goodness-of-fit of a model, a small subset of deviating observations can give rise to a significant lack of fit. It is therefore important to identify such observations and to assess their effects on various aspects of analysis. A Cook's distance measure is usually used to detect influential observation. But it sometimes is not fully effective in identifying truly influential set of observations because there may exist masking or swamping effects. In this paper we confine our attention to influential subset In GLMs such as logistic regression models and loglinear models. We modify a backwards stepping algorithm, which was originally suggested for detecting outlying cells in contingency tables, to detect influential observations in GLMs. The algorithm consists of two steps, the identification step and the testing step. In identification step we Identify influential observations based on influencial measures such as Cook's distances. On the other hand in testing step we test the subset of identified observations to be significant or not Finally we explain the proposed method through two types of dataset related to logistic regression model and loglinear model, respectively.

Age Estimation with Panoramic Radiomorphometric Parameters Using Generalized Linear Models

  • Lee, Yeon-Hee;An, Jung-Sub
    • Journal of Oral Medicine and Pain
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    • v.46 no.2
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    • pp.21-32
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    • 2021
  • Purpose: The purpose of the present study was to investigate the correlation between age and 34 radiomorphometric parameters on panoramic radiographs, and to provide generalized linear models (GLMs) as a non-invasive, inexpensive, and accurate method to the forensic judgement of living individual's age. Methods: The study included 417 digital panoramic radiographs of Korean individuals (178 males and 239 females, mean age: 32.57±17.81 years). Considering the skeletal differences between the sexes, GLMs were obtained separately according to sex, as well as across the total sample. For statistical analysis and to predict the accuracy of the new GLMs, root mean squared error (RMSE) and adjusted R-squared (R2) were calculated. Results: The adjusted R2-values of the developed GLMs in the total sample, and male and female groups were 0.623, 0.637, and 0.660, respectively (p<0.001), while the allowable RMSE values were 8.80, 8.42, and 8.53 years, respectively. In the GLM of the total sample, the most influential predictor of greater age was decreased pulp area in the #36 first molar (beta=-26.52; p<0.01), followed by the presence of periodontitis (beta=10.24; p<0.01). In males, the most influential factor was the presence of periodontitis (beta=9.20; p<0.05), followed by the number of full veneer crowns (beta=2.19; p<0.001). In females, the most influential predictor was the presence of periodontitis (beta=18.10; p<0.001), followed by the tooth area of the #16 first molar (beta=-11.57; p<0.001). Conclusions: We established acceptable GLM for each sex and found out the predictors necessary to age estimation which can be easily found in panoramic radiographs. Our study provides reference that parameters such as the area of tooth and pulp, the number of teeth treated, and the presence of periodontitis should be considered in estimating age.

Analysis of Income-led Growth Path Induced by Government and Consumption Expenditures (정부지출과 소비지출에 의한 소득주도성장 경로 분석)

  • Rhee, Hyun-Jae
    • The Journal of the Korea Contents Association
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    • v.20 no.7
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    • pp.602-617
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    • 2020
  • The aim of this study is to evaluate the effects of income-led growth path induced by government and consumption expenditures. Six of Nordic countries, Latin American countries and South Korea are selected for this purpose due to the fact that these countries have been pursuing income-led growth policy for more than the last decade except South Korea. The structural equation is formulated based on the government and consumption expenditures with lagged variable, and the GLMs estimation is employed for empirical analysis. Although the impacts are not overwhelmingly effective, empirical evidence suggests that income-led growth path contributes to stimulate economic activities which are associated with increasing in national income in Nordic countries and South Korea. However, the income-led growth path is quite weakly operated. Furthermore, it is even unstable in Latin American countries. In addition to this, the policy target would rather be focused on middle consumption group than low consumption group. Overall, it would be concluded that the income-led growth policy should be implemented for complementary purpose. And, it also has to be mentioned that sustainable growth may not be achievable by this policy.

Development and Validation of Generalized Linear Regression Models to Predict Vessel Enhancement on Coronary CT Angiography

  • Masuda, Takanori;Nakaura, Takeshi;Funama, Yoshinori;Sato, Tomoyasu;Higaki, Toru;Kiguchi, Masao;Matsumoto, Yoriaki;Yamashita, Yukari;Imada, Naoyuki;Awai, Kazuo
    • Korean Journal of Radiology
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    • v.19 no.6
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    • pp.1021-1030
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    • 2018
  • Objective: We evaluated the effect of various patient characteristics and time-density curve (TDC)-factors on the test bolus-affected vessel enhancement on coronary computed tomography angiography (CCTA). We also assessed the value of generalized linear regression models (GLMs) for predicting enhancement on CCTA. Materials and Methods: We performed univariate and multivariate regression analysis to evaluate the effect of patient characteristics and to compare contrast enhancement per gram of iodine on test bolus (${\Delta}HUTEST$) and CCTA (${\Delta}HUCCTA$). We developed GLMs to predict ${\Delta}HUCCTA$. GLMs including independent variables were validated with 6-fold cross-validation using the correlation coefficient and Bland-Altman analysis. Results: In multivariate analysis, only total body weight (TBW) and ${\Delta}HUTEST$ maintained their independent predictive value (p < 0.001). In validation analysis, the highest correlation coefficient between ${\Delta}HUCCTA$ and the prediction values was seen in the GLM (r = 0.75), followed by TDC (r = 0.69) and TBW (r = 0.62). The lowest Bland-Altman limit of agreement was observed with GLM-3 (mean difference, $-0.0{\pm}5.1$ Hounsfield units/grams of iodine [HU/gI]; 95% confidence interval [CI], -10.1, 10.1), followed by ${\Delta}HUCCTA$ ($-0.0{\pm}5.9HU/gI$; 95% CI, -11.9, 11.9) and TBW ($1.1{\pm}6.2HU/gI$; 95% CI, -11.2, 13.4). Conclusion: We demonstrated that the patient's TBW and ${\Delta}HUTEST$ significantly affected contrast enhancement on CCTA images and that the combined use of clinical information and test bolus results is useful for predicting aortic enhancement.

Cumulative Sums of Residuals in GLMM and Its Implementation

  • Choi, DoYeon;Jeong, KwangMo
    • Communications for Statistical Applications and Methods
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    • v.21 no.5
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    • pp.423-433
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    • 2014
  • Test statistics using cumulative sums of residuals have been widely used in various regression models including generalized linear models(GLM). Recently, Pan and Lin (2005) extended this testing procedure to the generalized linear mixed models(GLMM) having random effects, in which we encounter difficulties in computing the marginal likelihood that is expressed as an integral of random effects distribution. The Gaussian quadrature algorithm is commonly used to approximate the marginal likelihood. Many commercial statistical packages provide an option to apply this type of goodness-of-fit test in GLMs but available programs are very rare for GLMMs. We suggest a computational algorithm to implement the testing procedure in GLMMs by a freely accessible R package, and also illustrate through practical examples.

Modeling Approaches for Dynamic Robust Design Experiment

  • Bae, Suk-Joo
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2006.11a
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    • pp.373-376
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    • 2006
  • In general, there are three kinds of methods in analyzing dynamic robust design experiment: loss model approach, response function approach, and response model approach. In this talk, we review the three modeling approaches in terms of several criteria in comparison. This talk also generalizes the response model approach based on a generalized linear model. We develop a generalized two-step optimization procedure to substantially reduce the process variance by dampening the effect of both explicit and hidden noise variables. The proposed method provides more reliable results through iterative modeling of the residuals from the fitted response model. The method is compared with three existing approaches in practical examples.

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FSAL MONO-IMPLICIT NORDSIECK GENERAL LINEAR METHODS WITH INHERENT RUNGE-KUTTA STABILITY FOR DAES

  • OLATUNJI, P.O.;IKHILE, M.N.O.
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.25 no.4
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    • pp.262-295
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    • 2021
  • This paper introduces mono-implicit general linear methods, a special class of general linear methods, which are implicit in the output solution for the numerical integration of differential algebraic equations. We show how L-stable inherent Runge-Kutta members can be derived. The procedures for implementation have been discussed. The numerical test on the problem considered shows that the methods have improved accuracy when compared to RADAU IIA and the results from MATLAB ode15s, which have been taken as our reference solution.

Effects of Hook and Bait Types on Bigeye Tuna Catch Rates in the Tuna Longline Fishery (다랑어 연승어업에서 눈다랑어 어획률에 미치는 낚시 및 미끼의 효과)

  • Kim, Soon-Song;Moon, Dae-Yeon;An, Doo-Hae;Hwang, Seon-Jae;Kim, Yeong-Seung;Bigelow, Keith;Curran, Daniel
    • Korean Journal of Ichthyology
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    • v.20 no.2
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    • pp.105-111
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    • 2008
  • A pelagic tuna longline research cruise in the eastern and central Pacific Ocean from September to October of 2006 was conducted to compare catch rates with the use of different hook type and bait combinations. Traditional tuna hooks (J 4) and three circle hook types (C15, C16, C18), along with five bait types (chub mackerel (CM), jack mackerel (JM), milkfish (MF), sardine (SD), and squid (SQ)) and hook number as a proxy for hook depth were evaluated for their effect on bigeye tuna catch rates (fish per 1,000 hooks) using Generalized Linear Models (GLMs). Results from 28 sets indicated significant differences in bigeye catch rates between individual longline sets and hook number. The GLM explained 33% of the deviance in bigeye catch rates with these two factors. An alternative model formulation included bait type which had a small effect (explaining 2.7% of the deviance) on catch rates. Hook type had a negligible and non-significant effect in the GLMs. These results indicate that all of the hooks and baits tested are equally effective at catching bigeye tuna and that hook number (depth) was the paramount operational factor in explaining bigeye tuna catch rates.

Gamified Contents Management System design for continuous and voluntary participation of Users (사용자의 지속적이며 자발적인 참여를 위한 게임화 기반의 콘텐츠 관리 시스템 설계)

  • Choi, Won-Kyum;Yun, Chan;Woo, Tack
    • Journal of Korea Game Society
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    • v.18 no.6
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    • pp.5-16
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    • 2018
  • It is very difficult, but important, to induce and maintain voluntary user engagement in content. For example, many Internet contents provide financial rewards for the user's participation and maintenance. However, there are limitations to methods such as stimulating only external motivations, such as monetary rewards, and sophisticated design and management are needed to obtain sustained and voluntary user participation in content. For this purpose, we propose a Gamified CMS that extends the existing Content Management System (CMS) by referring to the example of the Gamified Learning Management System. This will ultimately increase the participation and commitment of users in content.