• Journal of applied mathematics & informatics
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• v.26 no.5_6
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• pp.1191-1205
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• 2008

We consider a delayed predator prey model. The local stability and Hopf bifurcation results are stated taking the time delay as a control parameter. We apply multiple scale analysis to analyze the effects of additive white noises near the Hopf bifurcation point at the positive interior equilibrium state. The governing equations for the amplitude of oscillations on a slow time scale are derived. We identify the process of amplitude of oscillations and derive its transient properties. We show that oscillations, which would decay in the deterministic system whenever time delay lies below its critical value, persists for long time under the validity of multiple scale analysis.

• Journal of the Korean Home Economics Association
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• v.32 no.1
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• pp.103-118
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• 1994

The purpose of this study was to develop the Parent Satisfaction Scale(PSS) to measure the various components of satisfaction related to parenting. The subjects were 1210 parents(249 fathers and 961 mothers) selected nation widely from 7 cities and several rural area in Korea. the statistics used for data analysis were Fisher's Exact Test, Cramer's V, factor analysis multiple regression, Cronbach's α,and Pearson's correlation. To begin with eighty of 100-item scale were selected through the item analysis and from that 48 items were abstracted through the multiple regression analysis conducted to reduce the length of the scale. Results of factor analysis indicated that the PSS comprised of five factors: general satisfaction parent-child relationship spouse support parent's role conflict support of children. Reliabilities for the domains ranged from 79 to 91. To determine the construct validity of this instrument the Marital Satisfaction Scale and the Proverb about child rearing were administered. The two creterion measures showed significant relationships with the PSS. The final 48 items scale from the current analysis were considered to be critical steps in the development of this assessment device.

• Journal of the Korean Geotechnical Society
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• v.29 no.11
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• pp.99-106
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• 2013

In this study, the correlation of evaluation items and safety rating for 104 of large-scale slopes along the general national road was analyzed. And, we proposed the regression model to predict the safety rating using the multiple regressions analysis. As the result, it is shown that the evaluation items of slope angle, rainfall and groundwater have a low correlation with safety rating. Also, the regression model suggested by multiple regression analysis shows high predictive value, and it would be possible to apply if the evaluation items of excavation condition and groundwater (rainfall) are not clear.

• Journal of the Korea Safety Management & Science
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• v.15 no.1
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• pp.249-258
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• 2013

Data Envelopment Analysis (DEA) is a useful tool to analyze the relative efficiency of decision making units (DMU) characterized by multiple inputs and multiple outputs. This method has been popularly used as an analytical tool to suggest some strategic improvement. To do this, the results of DEA provide decision makers with a single efficiency score, efficient frontier, return to scale, benchmarking decision making units, etc. The purpose of this paper is to evaluate research performance of 38 universities and provide an inefficient university with the way of organizational changes to be an efficient university by using DEA. Various input and output variables are used to identify technical and scale inefficiency. Additionally, we analyze how an inefficient DMU could be changed an efficient DMU based on a case university. This result will give an insight of constructive directions for increasing of research performance to university decision makers.

• Journal of the Korean Operations Research and Management Science Society
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• v.39 no.4
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• pp.51-69
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• 2014

Times to multiple events (TMEs) are a major data type in large-scale business and medical data. Despite its importance, the analysis of TME data has not been well studied because of the analysis difficulty from censoring of observation. To address this difficulty, we have developed a Bayesian-based multivariate survival analysis method, which can successfully estimate the joint probability density of survival times. In this work, we extended this method for the analysis of precedence, dependency and causality among multiple events. We applied this method to the electronic health records of 2,111 patients in a children's hospital in the US and the proposed analysis successfully shows the relation between times to two types of hospital visits for different medical issues. The overall result implies the usefulness of the multivariate survival analysis method in large-scale big data in a variety of areas including marketing, human resources, and e-commerce. Lastly, we suggest our future research directions based multivariate survival analysis method.

• Korean Journal of Child Studies
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• v.13 no.1
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• pp.16-37
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• 1992

The purpose of this study was the development of a scale to assess maternal anxiety after mother-child separation. Subjects consisted of 384 mothers who had children from 6 to .36 months of age. A questionnaire consisting of eighty Likert-type items and Spielberger's(1970) State Anxiety Scale were administered to mothers and data were analyzed using item analysis. factor analysis. multiple regression. Cronbach's ${\alpha}$. Pearson's correlation and F-test. Sixty of the eighty items were significant and deemed acceptible through item discrimination method with indices ranging from. 32 to .95. Factor analytic procedures have selected 54 items of the 60-item scale and supported a 5-factor solution. The subscales labeled 'Maternal Separation Anxiety'. 'Perception of Separation Effects on the Child', 'Desire for Physical Cuddling and Closeness'. 'Attitudes toward the Value or Importance of Exclusive Maternal Care' and 'Employment-related Separation Concerns,' Finally. a multiple regression analysis conducted to reduce the length of the scale yielded a 39-item form for the Maternal Separation Anxiety Scale(MSAS). Internal consistency of the MSAS was high(Cronbach's ${\alpha}$ =.85). The correlation of the MSAS with the Spielberger's State Anxiety measure yielded a coefficient of .36, revealing a moderate and positive relationship.

• Journal of Distribution Research
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• v.4 no.2
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• pp.21-39
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• 1999

This study investigates the general applicability of the measurement scale for assessing channel-member performance for the supplier's view that was proposed by Kumar, and Achrol (1992). First, we attempted to examine whether the measurement-scale could be used without any change; the results from the initial data-analysis proposed that the scale needed a certain amount of a revision for further utilization. It seemed that the scale needed some adjustment for being applied to this study; their scale was developed with the data collected from the network of independent dealers handling multiple product items or multiple brands in the U.S. and Canada, while the data of this study were provided by a Korean car manufacturer having a dealer network selling and servicing only its own brand without ownership. Accordingly, we determined that it was necessary to develop a newly finalized performance-measurement scale revising Kumar et al.'s. During the data-analysis of the data resulted in a scale of fifteen items measuring three facets-financial performance, behavioral performance, and competence, each of which consisted of five items respectively. This empirically developed scale looked more valid for the situation of this study than the Kumar, Stern, and Achrol's which was composed of twenty-one items measuring seven facets--three items each.

• Journal of Korean Academy of Nursing Administration
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• v.9 no.2
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• pp.251-264
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• 2003

Purpose : The expectations are defined as desired expectations in initial SERVQUAL scale(1985, 1988), but in modified SERVQUAL scale(1991), are defined as a feasible ideal point expectations. In assessment of nursing service quality by SERVQUAL scale, the definitions of expectations is important problem. The purpose of this study was to compare the feasible ideal point expectations with the desired expectations in assessment of nursing service quality using SERVQUAL scale. Methods : The subjects were 256 inpatients at 4 general hospitals in Jeju-do(123 for feasible ideal point and 133 for desired). The data were collected by two types of self-reporting questionnaires to measure the feasible ideal point and desired expectations. For data analysis, t-test, multiple regression, and comparative analysis of multiple Rs via Fishers Z transformation. Results : Compared with the SERVQUAL scores, the feasible ideal point expectations better explained the variations of the overall consumer satisfaction($R^2$=O.33) than the desired($R^2$=O.25). Conclusion : The feasible ideal point expectations were more suitable to the assessment of nursing service quality using SERVQUAL scale. It will be need to explore the conceptual definitions of expectations using SERVQUAL scale in different settings. Also, further study needs to be conducted to compare alternative service quality measurement scales.

• Journal of Korean Academy of Nursing
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• v.19 no.3
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• pp.273-284
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• 1989

The aim of this investigation was to delineate concepts contributing to the Exercise of Self-Care Agency (E.S.C.A.) Scale developed by Kearney & Fleischer (1979) and to test its construct validity and its predictors. The results are summarized as follows ; 1. By means of principal factor analysis and maximal likelihood factor analysis upon data generated from 280 undergraduate students, the factors of Concern about Health Knowledge, self-Concept, Information - Seeking Behavior, Decision -making and Responsibility, Self-esteem, and Passivity emerged. The total percent of variance explained by the 6 factors was 75.1% 2. To assess factor independence and instrument homogeneity, correlations among the 6 factors were computed. The correlations ranged from .24 to .46 indicating that the factors and the items were not too similar or redundant. 3. Test-retest reliability of the total scale is r＝.70. Cronbach's $\alpha$ coefficient for internal consistency of the total scale is .86 and that of the factors ranged from .750 to .661 (only factor 6 .497). 4. In additional analysis of the Exercise of Self-Care Agency Scale in relationship to Multiple Health Locus of Control, Family Environmental Scale, and Cornell Medical Index using stepwise multiple regression, the Internal Health Locus of Control Score predicted 21.8%(F＝53.34, p＝.0001), Family Environmental Score 8.3%(F＝22.59, P＝.0001), Modified Cornell Medical Index Score 5.4%(F＝15.74, P＝.0001) of the score of the E.S.C.A.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.366-371
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• 2001

Dynamic stability of an oscillating cantilever plate is investigated in this paper. The equations of motion include harmonically oscillating parameters which originate from the motion-induced stiffness variation. Using the multiple scale perturbation method is employed to obtain a stability diagram. The tability diagram shows that relatively large unstable regions exist when the frequency of oscillation is near twice the frequencies of the 1st torsion natural mode and the 1st chordwide bending mode.