• Journal of the Korean Data and Information Science Society
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• v.16 no.2
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• pp.195-205
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• 2005

In decision tree analysis, C4.5 and CART algorithm have some problems of computational complexity and bias on variable selection. But QUEST algorithm solves these problems by dividing the step of variable selection and split point selection. When input variables are continuous, QUEST algorithm uses ANOVA F-test under the assumption of normality and homogeneity of variances. In this paper, we investigate the influence of violation of normality assumption and effect of the transformation of variables in the QUEST algorithm. In the simulation study, we obtained the empirical powers of variable selection and the empirical bias of variable selection after transformation of variables having various type of underlying distributions.

• The Journal of the Korean dental association
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• v.57 no.8
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• pp.448-455
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• 2019

This study aims to apply the Generalizability Theory (G-theory) for estimation of reliability of evaluation scores between raters on Patient Dentist Interaction. Selecting a number of raters as multiple error sources, this study was analyzed the error sources caused by relative magnitude of error variances of interaction between the factors and proceeded with D-study based on the results of G-study for optimal determination of measurement condition. The estimated outcomes of variance component for accuracy among the Patient Dentist Interaction evaluation with G-theory showed that impact of error was the biggest influence factor in students. The second influence was the item effect, and the rater effect was relatively small. The Generalizability coefficients for case1 and case2 which were estimated through the D- study were calculated relatively low.

• The Korean Journal of Ecology
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• v.17 no.2
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• pp.213-222
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• 1994

Songs recorded in Chirisam(1990~1993) and $Ull\v{u}ngdo$(1992~1993) areas were analyzed to investigate the features and variances in songs of Great tit, Parus major. Songs of Great tits were identified, most of which were repetitions of phrases composed of high-frequency note and low-frequency note. The CV range of the Chirisan Great tit group was wider than that of the $Ull\v{u}ngdo$ area. ANOVA analysis level was highly significant (p<0.0001) for Chirisan area and $Ull\v{u}ngdo$ area. Inter-regional variance level was significant (p<0.05) in the maximum of low-frequency.

• Journal of Korean Academy of Nursing
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• v.33 no.6
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• pp.812-819
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• 2003

Purpose: This study was to identify factors that influence the health care needs of that over 65 years of age in Mokpo, Korea. Method: The data was collected from June 2002 to September 2002. The subjects were 120 homebound solitude elderly(age=76.8). Subjects were interviewed with structured questionnaire in order to identify the health care needs, health variables (perceived health status, risk of malnutrition, K-IADL), psychological variables(self-esteem, depression) and demographic variables. physiological health variables (height, weight, blood pressure, pulse, blood sugar)were assessed after the interview. Result: In general perceived health status was poor, risk of malnutrition was high, number of disease was 3 disease, self-esteem was low but depression was high and health care needs were relatively high. Among the elderly education & counseling needs topped the list. In regression analysis, health care needs were significantly influenced by IADL(23%), duration of solitudes(4%), sex(3%), and education(l%). These variables explained 31% of the variances in health care needs. Conclusion: The result identified that health care needs should be a considered in IADL, female, duration of solitudes and education for the solitude elderly.

• Structural Engineering and Mechanics
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• v.2 no.3
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• pp.285-294
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• 1994

Based on a fast and accurate method for the stationary random seismic response analysis for discretized structures(Lin 1992, Lin et al. 1992), a Ritz method for dealing with such responses of continuous systems in developed. This method is studied quantitatively, using cantilever shear beams for simplicity and clarity. The process can be naturally extended to deal with various boundary conditions as well as non-uniform Bernoulli-Euler beams, or even Timoshenko beams. Algorithms for both proportionally and non-proportionally damped responses are described. For all of such damping cases, it is not necessary to solve for the natural vibrations of the beams. The solution procedure is very simple, and equally efficient for a white or a non-white ground excitation spectrum. Two examples are given where various power spectral density functions, variances, covariances and second spectral moments of displacement, internal force response, and their derivatives are calculated and analyses. Some Ritz solutions are compared with "exact" CQC solutions.

• Korean Journal of Child Studies
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• v.26 no.4
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• pp.157-171
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• 2005

Causal relationships between school maladjustment and related variables were examined in 371 5th grade elementary school students. School maladjustment was ascertained by revised the School Adjustment Test(Lim, 1993; Song, 1999). After analysis of differences in internal locus of control, academic stress, and academic achievement between the school maladjusted and adjusted groups, the study built a structural equation model of school maladjustment-related variables goodness of fit was tested with LISREL 8 for Windows. Significant differences were found in internal locus of control, academic stress, and academic achievement by level of school maladjustment. Internal locus of control, academic stress, and academic achievement both directly and/or indirectly influenced school maladjustment. These variables explained 64% of the variances in school maladjustment.

• IE interfaces
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• v.11 no.2
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• pp.107-117
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• 1998

This paper presents a useful method of registration in manufacturing of shadow color mask for cathode ray tubes of the FTM (Flat Tension Mask) type, wherein the shadow mask and front panel are interchangeable when mask-panels are assembled, which is called ICM system. Theoretical analysis and alignment process are presented. The pattern of mask aperture is registered with a screen pattern of corresponding geometry of the panel in flat tension mask tube. Registration accuracy of panel and mask affects the purity of color cathode ray tube concerned with mislanding. It tries to minimize the misregistration caused by variances, which are mechanical error, mask stretching position error, restrictive number of fiducial point, etc.

• International Journal of Reliability and Applications
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• v.2 no.1
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• pp.37-48
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• 2001

This paper presents a new dynamic human reliability analysis method and its application for quantifying the human error probabilities in implementing management action. For comparisons of current HRA methods with the new method, the characteristics of THERP, HCR, and SLIM-MAUD, which are most frequency used method in PSAs, are discussed. The action associated with implementation of the cavity flooding during a station blackout sequence is considered for its application. This method is based on the concepts of the quantified correlation between the performance requirement and performance achievement. The MAAP 3.0B code and Latin Hypercube sampling technique are used to determine the uncertainty of the performance achievement parameter. Meanwhile, the value of the performance requirement parameter is obtained from interviews. Based on these stochastic obtained, human error probabilities are calculated with respect to the various means and variances of the things. It is shown that this method is very flexible in that it can be applied to any kind of the operator actions, including the actions associated with the implementation of accident management strategies.

• Journal of Korean Society for Quality Management
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• v.23 no.3
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• pp.140-155
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• 1995

This paper proposes a quality control method of assembly parts based on parts inspection information. We use the parts inspection information for reduction of defective fraction in assembly and prediction of assembly quality. At first, we build the functional relationship between parts and assembled unit by regression analysis. Secondly, if we use the inspection informations of parts which are estimators of means and variances, we can predict the nonconforming probability of assembled unit and propose the best assembly method. In a case study, we showed the efficency of the proposed method in two part assembly.

• Journal of the Korean Operations Research and Management Science Society
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• v.32 no.2
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• pp.1-15
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• 2007

This paper proposes a method for determining the number of storage rooms and designing the storage layout in warehouses for pyramid type stacks whose example are slacks for steel coils, paper rolls, and drums for oils. Formulas are derived for estimating the expected values and the variances of various handling times by cranes. From the derived formulas, the expected queuing time of road trucks is estimated. Base on the derived formulas, this study derives the cost function for determining the optimal numbers of rows, bays, and tiers of stacks and sizing cranes under the condition that the requirement for storage space is satisfied. Results of numerical analysis are provided.