• Journal of the Korea Concrete Institute
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• v.14 no.6
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• pp.1022-1031
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• 2002

This paper presents efficient models for bridge structures using CART-ANFIS (classification and regression tree-adaptive neuro fuzzy inference system). A fuzzy decision tree partitions the input space of a data set into mutually exclusive regions, each region is assigned a label, a value, or an action to characterize its data points. Fuzzy decision trees used for classification problems are often called fuzzy classification trees, and each terminal node contains a label that indicates the predicted class of a given feature vector. In the same vein, decision trees used for regression problems are often called fuzzy regression trees, and the terminal node labels may be constants or equations that specify the predicted output value of a given input vector. Note that CART can select relevant inputs and do tree partitioning of the input space, while ANFIS refines the regression and makes it continuous and smooth everywhere. Thus it can be seen that CART and ANFIS are complementary and their combination constitutes a solid approach to fuzzy modeling.

• Journal of Digital Policy
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• v.3 no.2
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• pp.15-22
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• 2024

This study was conducted to identify the cause of turtle neck syndrome that occurs in a pharmacists and the relationship between the height and table height and to suggest a table height appropriate for height. By conducting correlation and regression analysis of the turtle neck index, NDI, and VAS. As a result of calculating, the relationship between the pharmacist's height and table height, which is good for preventing turtle neck, is less than about 65cm, and it was proven that the height of the table is a major factor in causing or worsening turtle neck syndrome. It is believed that further follow-up research is needed to determine whether the calculated through this paper is effective and can be applied to other occupational groups.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.17 no.2
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• pp.131-140
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• 2004

It really needs fuzzy decision making of integrity assessment considering about both durability and load carrying capacity for maintenance and administration, such as repairing and reinforcing. This thesis shows efficient models about reinforced concrete structure using CART-ANFIS. It compares and analyzes decision trees parts of expert system, using the theory of fuzzy, and applying damage & diagnosis at reinforced concrete structure and decision trees of integrity assessment using established artificial neural. Decided the theory of reinforcement design for recovery of durability at damaged concrete ＆ the theory of reinforcement design for increasing load carrying capacity keep stability of damage and detection. It is more efficient maintenance and administration at reinforced concrete for using integrity assessment model of this study and can carry out predicting cost of life cycle.

• Journal of Korean Society of Forest Science
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• v.71 no.1
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• pp.27-32
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• 1985

Individual tree growth in a given stand is considerably affected by its neighbouring trees or surrounding density. This trend is appeared more clearly in the unthinned stand. Relationship between growth of individual trees and density around them was analyzed by the use of the angle-summation method(AS method), and then multiple regression equation including variables of center trees and measures of surrounding density by the AS method was given for estimating diameter increment for the last five years and the next few years of center trees.

• Journal of the Korean Data and Information Science Society
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• v.24 no.6
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• pp.1285-1296
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• 2013

The fundamental concerns of this paper are to analyze the effects of student course evaluation using subject characteristic and student characteristic variables. We use a 2-level hierarchical linear model since the data structure of subject characteristic and student characteristic variables is multilevel. Four models we consider are as follows; (1) null model, (2) random coefficient model, (3) mean as outcomes model, (4) intercepts and slopes as outcomes model. The results of the analysis were given as follows. First, the result of null model was that subject characteristics effects on course evaluation had much larger than student characteristics. Second, the result of conditional model specifying subject and student level predictors revealed that class size, grade, tenure, mean GPA of the class, native class for level-1, and sex, department category, admission method, mean GPA of the student for level-2 had statistically significant effects on course evaluation. The explained variance was 13% in subject level, 13% in student level.

• Communications for Statistical Applications and Methods
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• v.19 no.3
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• pp.367-379
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• 2012

In baseball rankings, prediction has been a subject of interest for baseball fans. To predict these rankings, (based on 2011 data from Korea Professional Baseball records) the arithmetic mean method, the weighted average method, principal component analysis, and principal component regression analysis is presented. By standardizing the arithmetic average, the correlation coefficient using the weighted average method, using principal components analysis to predict rankings, the final model was selected as a principal component regression model. By practicing regression analysis with a reduced variable by principal component analysis, we propose a rank predictability model of a pitcher part, a batter part and a pitcher batter part. We can estimate a 2011 rank of pro-baseball by a predicted regression model. By principal component regression analysis, the pitcher part, the other part, the pitcher and the batter part of the ranking prediction model is proposed. The regression model predicts the rankings for 2012.

• Journal of Korean Society of Forest Science
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• v.104 no.4
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• pp.527-535
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• 2015

With results from previous Korean studies on forest thinning, we conducted a meta-analysis on the effect of thinning on diameter at breast height (DBH) growth and carbon (C) stocks (tree, litter layer, coarse woody debris (CWD), and soils) in Korean forests. Thinning increased the DBH growth and the C stocks in soils by 39.2% and 12.8%, respectively, while it decreased the C stocks in tree by 30.9%. In contrast, thinning had no significant effect on the C stocks in litter layer and CWD. The DBH growth and the C stocks in tree showed significant correlations with thinning intensity and recovery time. The C stocks in litter layer correlated with recovery time while those in CWD and soils did not show significant correlation neither with thinning intensity nor with recovery time. Regression models of the DBH growth and the C stocks in tree were developed to quantify the effect of thinning intensity and recovery time. An integration of the regression model of the tree C stock into forest carbon models is expected to be essential to quantify the effect of thinning on the C stocks in litter layer, CWD, and soils. We also suggested expansion of study species, long-term and frequent monitoring, and investigation on understory vegetation in order to elucidate changes in Korean forests following thinning practices.

• Journal of the Korean Applied Science and Technology
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• v.38 no.6
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• pp.1445-1454
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• 2021

In this study, based on the expectation that beauty education based on VR experience of beauty majors will have on expertise and practical ability, it was attempted to develop VR-based beauty subjects and secure an educational environment. A total of 106 learners participated in the study, and the online questionnaire consisted of questions about the development of VR-based beauty subjects, recognition of expertisee and practical skills, and general characteristics. The collected data were verified at the significance level of .05 using the SPSS 21.0 statistical program. As a result of frequency analysis, factor analysis, correlation, and linear regression analysis, the higher the grade, the higher the perception of VR-based beauty subjects development (p<.01). The perception of VR-based beauty subject development was related to VR-based expertise and practical skills for each sub-factor of the recognition of expertise (r=.683, p<.001), practical skills (r=.676, p<.001), and industry-related awareness (r=.543, p<.001). It was found that there was a statistically significant positive (+) correlation with related perception. In addition, it was found that the higher the awareness of VR-based beauty subjects development, the higher the expectation that expertise, practical ability, and industry-related awareness would be improved. As a result, the necessity of developing VR-based beauty subjects and expectations for course operation of majors in the beauty subjects environment were confirmed. In follow-up studies, it is necessary to expand the scope of the sample.

• Journal of agriculture & life science
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• v.43 no.6
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• pp.19-27
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• 2009

This study was carried out to obtain the basic model to estimate damage degree from the correlation analysis between forest fire and site environment factors and to clarify the restoration trends thorough multi-temporal survey by observing species diversity followed by various treatments at damaged forest area over time. From the derived model, the damage degree of forest fire was higher in the area of dense coniferous stands composed of simple story at the elevation of about 100m and 200m, and on steeper slope area over 30 degree. As results of this study, fire damaged trees are needed to cut down and a mixed stand with deciduous and coniferous species from the same area is desirable for the future species composition on fire damaged forest. Thus, site characteristics, local species, and mixed stands are the main consideration to enhance the vegetation recovery.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.1
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• pp.30-35
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• 2003

The study of the scars formed on the bark of pine trees damaged by forest fire was carried out in the burned area of Samchuk and Donghae in 2000. Fire scars were formed on the bark of trees when fire passed by the tree. Fire scarring is usually found on the windward and leeward sides of the tree. Fire spread was analyzed topographically using the fire scars formed at the tree stem. Fire spread was closely related to the shape, slope and direction of the forestland. Four fire direction types are classified according to the shapes of the forestland. The height of the fire scar was higher on the leeward side than on the windward side of the trees studied. The burnt area of the total bark of the tree was over 30% in dead trees and below 12% in living trees. The regression model of the burnt stem area using the height of the fire scar, the diameter of breast height and the height of tree was Y=-2.484${\times}$Height＋0.04199${\times}$D.B.H-1.686${\times}$Windward＋11.172${\times}$Leeward＋23.432(r=0.936, F=409.968, P＞0.0001).