• Title/Summary/Keyword: Multivariate Regression

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Which Alarm Symptoms Are Associated With Abnormal Gastrointestinal Endoscopy Among Thai Children?

  • Anundorn Wongteerasut
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.27 no.2
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    • pp.113-124
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    • 2024
  • Purpose: Alarm symptoms (red flag signs) are crucial indications for management decisions on pediatric gastrointestinal endoscopy. We aimed to identify items in the alarm symptoms and pre-endoscopic investigations that predict abnormal endoscopy results. Methods: A retrospective descriptive study was conducted among children aged under 18 years undergoing endoscopy. The patients were classified into normal and abnormal endoscopic groups. The incidence of alarm symptoms and pre-endoscopic investigations were compared between the groups. Univariate and multivariate logistic regression analyses were performed to determine independent risk factors for abnormal endoscopy. Results: Of 148 participants, 66 were classified in the abnormal endoscopy group. Compared with the normal group, the abnormal group had a significantly higher prevalence of alarm symptoms. Moreover, hematemesis/hematochezia, anemia, low hemoglobin level, hypoalbuminemia, rising erythrocyte sedimentation rate, increased serum lipase, and blood urea nitrogen/creatinine ratio were significantly higher in the abnormal endoscopy group than in the normal group. Multivariate logistic regression analysis indicated that hematemesis/hematochezia and low hemoglobin level were independent risk factors for abnormal endoscopy. Conclusion: The alarm symptoms and pre-endoscopic investigations were evaluated using predictive factors for abnormal pediatric endoscopic findings. According to multivariate logistic regression analysis, hematemesis/hematochezia and low hemoglobin levels were independent risk factors for abnormal endoscopy.

Nonparametric Regression with Left-Truncated and Right-Censored Data

  • Park, Jinho
    • Communications for Statistical Applications and Methods
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    • v.6 no.3
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    • pp.791-800
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    • 1999
  • Gross and Lai(1996) proposed a new approach for ordinary regression with left-truncated and right-censored (I.t.r.c) data. This paper shows how to apply nonparametric algorithms such as multivariate adaptive regression splines to 1.t.r.c data.

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Analyzing Operation Deviation in the Deasphalting Process Using Multivariate Statistics Analysis Method

  • Park, Joo-Hwang;Kim, Jong-Soo;Kim, Tai-Suk
    • Journal of Korea Multimedia Society
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    • v.17 no.7
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    • pp.858-865
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    • 2014
  • In the case of system like MES, various sensors collect the data in real time and save it as a big data to monitor the process. However, if there is big data mining in distributed computing system, whole processing process can be improved. In this paper, system to analyze the cause of operation deviation was built using the big data which has been collected from deasphalting process at the two different plants. By applying multivariate statistical analysis to the big data which has been collected through MES(Manufacturing Execution System), main cause of operation deviation was analyzed. We present the example of analyzing the operation deviation of deasphalting process using the big data which collected from MES by using multivariate statistics analysis method. As a result of regression analysis of the forward stepwise method, regression equation has been found which can explain 52% increase of performance compare to existing model. Through this suggested method, the existing petrochemical process can be replaced which is manual analysis method and has the risk of being subjective according to the tester. The new method can provide the objective analysis method based on numbers and statistic.

Unit Nonresponse Weighting Adjustment Using Regression Tree (회귀나무를 이용한 무응답 가중치 조정)

  • Kim, Se-Mi;Lee, Seok-Hun
    • Proceedings of the Korean Association for Survey Research Conference
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    • 2005.12a
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    • pp.169-183
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    • 2005
  • This paper considers formation of nonresponse weighting adjustment cell for handling unit nonresponse in sample surveys. We propose a multivariate regression tree mehtod for segmentation using the variable of interest and the estimated response probability simultaneously to construct effective nonresponse adjustment cell. One is using only response data and the other is using response and nonresponse data. These two cases are compared in terms of bias.

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Marginal Likelihoods for Bayesian Poisson Regression Models

  • Kim, Hyun-Joong;Balgobin Nandram;Kim, Seong-Jun;Choi, Il-Su;Ahn, Yun-Kee;Kim, Chul-Eung
    • Communications for Statistical Applications and Methods
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    • v.11 no.2
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    • pp.381-397
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    • 2004
  • The marginal likelihood has become an important tool for model selection in Bayesian analysis because it can be used to rank the models. We discuss the marginal likelihood for Poisson regression models that are potentially useful in small area estimation. Computation in these models is intensive and it requires an implementation of Markov chain Monte Carlo (MCMC) methods. Using importance sampling and multivariate density estimation, we demonstrate a computation of the marginal likelihood through an output analysis from an MCMC sampler.

Multivariate Analysis and Determinants of Youth Depression through Logistic Regression (로지스틱 회귀분석을 통한 청년 우울감의 다변량 분석 및 영향 요인 연구)

  • Seong Eum LEE
    • Journal of Korea Artificial Intelligence Association
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    • v.1 no.2
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    • pp.7-13
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    • 2023
  • In this paper, Depression is a mental disorder characterized by a lack of enthusiasm and feelings of sadness, which significantly impairs daily functioning. In 2018, there was an increase in book sales in the essay genre, particularly the popularity of "healing essays." This trend is seen as challenging the negative image and prejudices associated with depression. In 2021, a significant rise in the proportion of 20-year-old patients with depression is attributed to factors like job-related stress, interpersonal issues, and financial burdens. Additionally, there is a strong correlation between depression and suicidal thoughts, particularly among individuals who have experienced feelings of depression. Despite the increasing prevalence of depression among young adults, research in this area is lacking. To address this gap, statistical tools such as logistic regression and chi-squared tests are employed. The analysis reveals various independent variables associated with feelings of depression, shedding light on the relationships between these factors.

A predictive model for compressive strength of waste LCD glass concrete by nonlinear-multivariate regression

  • Wang, C.C.;Chen, T.T.;Wang, H.Y.;Huang, Chi
    • Computers and Concrete
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    • v.13 no.4
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    • pp.531-545
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    • 2014
  • The purpose of this paper is to develop a prediction model for the compressive strength of waste LCD glass applied in concrete by analyzing a series of laboratory test results, which were obtained in our previous study. The hyperbolic function was used to perform the nonlinear-multivariate regression analysis of the compressive strength prediction model with the following parameters: water-binder ratio w/b, curing age t, and waste glass content G. According to the relative regression analysis, the compressive strength prediction model is developed. The calculated results are in accord with the laboratory measured data, which are the concrete compressive strengths of different mix proportions. In addition, a coefficient of determination $R^2$ value between 0.93 and 0.96 and a mean absolute percentage error MAPE between 5.4% and 8.4% were obtained by regression analysis using the predicted compressive analysis value, and the test results are also excellent. Therefore, the predicted results for compressive strength are highly accurate for waste LCD glass applied in concrete. Additionally, this predicted model exhibits a good predictive capacity when employed to calculate the compressive strength of washed glass sand concrete.

New Dispersion Function in the Rank Regression

  • Choi, Young-Hun
    • Communications for Statistical Applications and Methods
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    • v.9 no.1
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    • pp.101-113
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    • 2002
  • In this paper we introduce a new score generating (unction for the rank regression in the linear regression model. The score function compares the $\gamma$'th and s\`th power of the tail probabilities of the underlying probability distribution. We show that the rank estimate asymptotically converges to a multivariate normal. further we derive the asymptotic Pitman relative efficiencies and the most efficient values of $\gamma$ and s under the symmetric distribution such as uniform, normal, cauchy and double exponential distributions and the asymmetric distribution such as exponential and lognormal distributions respectively.

Quantitative Analysis by Derivative Spectrophotometry (III) -Simultaneous quantitation of vitamin B group and vitamin C in by multiple linear regression analysis-

  • Park, Man-Ki;Cho, Jung-Hwan
    • Archives of Pharmacal Research
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    • v.11 no.1
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    • pp.45-51
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    • 1988
  • The feature of resolution enhancement by derivative operation is linked to one of the multivariate analysis, which is multiple linear regression with two options, all possible and stepwise regression. Examined samples were synthetic mixtures of 5 vitamins, thiamine mononitrate, riboflavin phosphate, nicotinamide, pyridoxine hydrochloride and ascorbic acid. All components in mixture were quantified with reasonably good accuracy and precision. Whole data processing procedure was accomplished on-line by the development of three computer programs written in APPLESOFT BASIC language.

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Evaluation of Water Quality on the Upstreams of the Soyanggang Dam by using Multivariate Analysis (다변량 분석법을 이용한 소양강댐 상류 유역의 하천 수질 평가)

  • Choi, Han-Kyu;Baek, Hyo-Sun;Heo, Joon-Young
    • Journal of Industrial Technology
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    • v.22 no.A
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    • pp.201-210
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    • 2002
  • The object of this study is to evaluate the factors affecting the water quality and to propose the influence of dominant factor quantitatively. The correlation analysis was performed to know the correlationship among the water quality items As a result of partial correlation analysis, it was shown that the water quality items are affected by the rainfall item directly. The factor analysis was performed to grasp some number of factors on each point for deducing the items of similar variable characteristics. The four points were divided into different factor groups. It was grasped that $NH_3-N$ and $NO_3-N$ Items have different variable characteristics after comparing the items. The Multiple regression analysis can decrease the number of observation. In the deduced multiple regression formula, it was shown that the rate of T-N, $NH_3-N$ and $NO_3-N$ in the independent variable took about 60% among all the regression formulas.

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