• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.287-293
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• 2017

The purpose of the study was to analyze the effects of work experience during higher education on employment. In particular, the study analyzed the difference in employment and permanent employment according to work experience or internship. In addition, the effects of the relatedness of college major and work experience as well as internship on college graduates' employment or permanent employment were investigated. The data came from the 2013 Graduates Occupational Mobility Survey (GOMS). The study covered the chi-square test and logistic regression analysis. The study found that there was a significant difference in the employment and permanent employment among the groups classified by work experience or internship. Internship had a positive effect on college graduates' permanent employment. Based on the study results, this study suggests that policies for internship during higher education need to be enhanced. The match between employment and the field of study in college needs to be increased. Interventions and policies for the establishment of competency-based employment should be improved.

• Journal of the Korean Geotechnical Society
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• v.35 no.6
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• pp.17-26
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• 2019

In this study, the statistical characteristics of the resistance bias factors were analyzed using a high-quality field load test database, and the total resistance bias factors were estimated considering the soil uncertainty and construction errors for the application of the limit state design of aggregate pier foundation. The MLR model by Bong and Kim (2017), which has a higher prediction performance than the previous models was used for estimating the resistance bias factors, and its suitability was evaluated. The chi-square goodness of fit test was performed to estimate the probability distribution of the resistance bias factors, and the normal distribution was found to be most suitable. The total variability in the nominal resistance was estimated including the uncertainty of undrained shear strength and construction errors that can occur during the aggregate pier construction. Finally, the probability distribution of the total resistance bias factors is shown to follow a log-normal distribution. The parameters of the probability distribution according to the coefficient of variation of total resistance bias factors were estimated by Monte Carlo simulation, and their regression equations were proposed for simple application.

• Journal of radiological science and technology
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• v.39 no.3
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• pp.353-359
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• 2016

This study were to evaluate risk factors of GB polpy in Busan and Gyeongnam area. This study was performed with patients by abdominal ultrasonography among the patients who came to the P hospital from January to May 2016. Among them, risk factors were analyzed on 399 people at the same time when abdominal ultrasonography and hematological test. The statistical analysis of risk factors related to the GB ployp was performed by independent t-test and chi-square test. In consider of difference verification result for calculations odds ratio about independent variables, multiple logistic regression analysis to conduct verify adequacy by calculating forecasting model from variable. As a result, GB polyp risk factors have relevance to male, HBsAg positive, triglyceride. GB polyp risk factors confirmed to male, HBsAg positive, triglyceride were calculated forecasting model and forecasting probability value. Forecasting probability sensitivity 61.0%, specificity 76.8%, ROC area under curve 0.735 showed, it confirmed validity of forecasting model. When analyzing the GB polyps morphologically, among the GB polyp types observed from abdominal ultrasonography, the hyperechoic and homogeneous pattern with neck was the largest as shown from 27.5% and two GB polyps were shown most from 38%, sizes were shown most by maximum diameter, 5 to 10mm from 53%. As a disease accompany with GB polyp showed mild fatty liver(23%), diffuse hepatopathy(21%).

• The Korean Journal of Applied Statistics
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• v.29 no.1
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• pp.123-132
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• 2016

We can achieve the principle of parsimony and efficiency if homogeneity for panel time series model is satisfied. We suggest a Rao test statistic and a Wald test statistic for the test of homogeneity for panel AR(1) and derived the limit distribution. We performed a simulation to examine statistics with the same chisquare distribution when number of the individual is small and in common with large. We also simulated to compare the empirical power of the statistics in a small panel. In application, we fit panel AR(1) model using regional monthly economical active population data and test homogeneity for panel AR(1). It is satisfied homogeneity, so it could be fitted AR(1) using the sample mean at the time point. We also compare the power of prediction between each individual and pooled model.

• Journal of Korean society of Dental Hygiene
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• v.10 no.4
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• pp.765-775
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• 2010

Objectives : 노인 환자들이 제공받고 있는 치과 의료서비스 만족도를 평가하여 노인 환자에게 양질의 구강보건진료 서비스를 제공하고 노인의 구강보건향상에 기여하기 위하여 실시하였다. 이와 같은 연구목적을 달성하기 위하여 노인관련 일반적 특성을 알아보고, 치과 병 의원을 이용하는 노인 환자의 만족도에 미치는 요인 및 병 의원 선택이유를 조사하였다. Methods : 서울특별시와 경기도, 경상도, 전라도 일부지역의 치과병원 및 치과의원을 이용하는 노인 환자 300명을 편의추출 하였으며, 2009년 4월 1일부터 5월 8일까지 면접 및 자기기입법으로 설문조사를 실시하였다. 설문지는 4개영역으로 구분하여 치과 의료서비스 만족도 22문항, 치과위생사의 의료서비스 만족도 14문항, 재이용 권유의사 4문항 및 일반적 특성과 치과이용에 관한 8문항으로 구성하였다. 노인환자의 일반적인 특성에 따른 치과 의료서비스 만족도, 연구대상자의 병원인지경로, 치과선택이유에 따른 치과의료서비스 만족도는 일원배치분산분석(One-way ANOVA)을 실시하였다. 치과의료서비스 만족도 영향인자, 만족도에 미치는 치과위생사 요인 등은 다중회귀분석을 실시하였다. 연구대상자의 성별과 병원내원기간에 따른 치과선택이유는 카이제곱 (${\chi}^2$) 분포를 따르는 정확검정(exact test)을 실시하였다. Results : 1. 노인환자들이 병원을 선택할 때 가족, 친척으로부터 추천을 받는 경우가 가장 많으며 이 경우 다른 인지경로에 비하여 치과에 대한 만족도가 가장 높았다. 2. 치과선택 이유에 따른 만족도를 비교하였을 때 첫째, 의사의 높은 진료수준, 둘째, 친절한 서비스에 만족도가 높았다. 또한 치과선택이유가 의사의 높은 진료수준과 친절함을 포함한 의사요인이 가장 중요한 것으로 나타났다. 3. 치과위생사의 높은 진료수준과 친절도는 치과의료서비스 만족도에 유의한 차이를 나타내었다. 노인환자들의 만족도를 높이기 위해 노인에 대한 치위생교육이 필요하고 노인에 대한 지식뿐만 아니라 태도에 대한 교육도 실시되어야 한다. 4. 동일한 치과를 계속적으로 다니는 이유는 첫 번째 의사의 높은 진료수준, 두 번째 친절도로 의사요인과 관련이 가장 높은 것으로 나타났다. 또한 3-4년 이상의 장기내원환자는 의사의 높은 진료수준 다음으로 친절도를 중요한 이유로 선택하였다. Conclusions : 이상의 결과로 노인 환자가 만족하는 치과는 치과의사와 치과위생사의 진료수준이 높아야 하겠고, 다음으로 친절한 서비스가 중요함을 알 수 있었다. 또한 노인환자들의 만족도를 높이기 위해 노인에 대한 치위생교육이 필요하고 노인에 대한 지식뿐만 아니라 태도에 대한 교육도 실시되어야 한다.

• The Journal of the Korean bone and joint tumor society
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• v.19 no.2
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• pp.50-55
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• 2013

Purpose: The purpose of this study is to determine the usefulness of arterial embolization on sacral and pelvic giant cell tumor (GCT). Materials and Methods: We retrospectively reviewed the medical records of 9 patients who had undergone serial arterial embolization between December 1996 and May 2008. We analyzed the clinical outcomes and therapeutic responsiveness of arterial embolization on sacral and pelvic GCT. Results: Six of 9 cases showed progression of disease (PD) status, even if 5 cases showed PD status despite of additional treatments including surgery and radiation, implying that serial arterial embolization on sacral and pelvic GCT is not effective. Three of 9 cases showed stable disease (SD) or continuous disease free (CDF) status and we analyzed associated factors with these good responses for embolization by ${\chi}^2$ test. The number of feeding vessels under six (p=0.048) and the number of collateral arterial supply under three (p=0.048) in the first angiogram showed significant relationships with good response for embolization, while remaining tumor staining by contrast after the first embolization and repeated embolization times were not significant. Conclusion: Although serial arterial embolization is not an effective modality on sacral and pelvic giant cell tumors, it may be a pilot modality under narrow indication of tumors with poor vascularity at first angiogram.

• The korean journal of orthodontics
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• v.37 no.5
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• pp.364-375
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• 2007

The purpose of this study was to compare arch dimensions and frequency distribution of arch forms between Korean and Japanese Class I, II, and III malocclusion groups. Methods: The sample consisted of 368 Korean cases (114 Class I, 119 Class II, and 135 Class III malocclusion) and 160 Japanese cases (60 Class I, 50 Class II, and 50 Class III malocclusion). The most facial portion of 13 proximal contact areas was digitized from photocopied images of the mandibular dental arches. Clinical bracket slot points were calculated for each tooth based on mandibular tooth thickness data. Four linear and two proportional measurements were taken. Measurements are statistically analyzed in each malocclusion group. The dental arches were classified into square, ovoid, and tapered forms to determine and compare the frequency distributions between the two ethnic groups. Results: The findings of this study showed that Japanese females in Class I and II groups had a statistically significant narrower mandibular dental arch width compared with the Japanese males, Korean males and Korean females. But in the Class III group, there was no significant difference in the mandibular dental arch size according to the two ethnic groups and genders. Conclusions: The majority of Koreans and Japanese in all the malocclusion groups exhibited square and ovoid arch forms. The most frequent arch forms found in Koreans was square but ovoid for Japanese.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.252-266
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• 2019

The purpose of this study was to identify the type of health behaviors in Korean adults and to identify related factors. The data used in the analysis was the Korea Health and Nutrition Examination Survey 2014., which was representative of the Korean population. Cluster analysis was used to find the pattern of clustering of smoking, drinking, exercising and nutrition. Differences in the pattern of clustering was examined, first by bivariate chi-square test, and then by multinomial logit regression. Lastly, the association between the clusters of health behaviors and other behavioral risk factors was tested by chi-square test and logistic regression. The distribution of the clusters varied not only across socioeconomic characteristics and local size, but also between individuals with certain chronic diseases and those without. The results of this study can be used as a basis for the usefulness of approaching the cluster rather than individually approaching the health behavior.

• Korean Journal of Cognitive Science
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• v.31 no.1
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• pp.1-23
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• 2020

This paper introduces SNUDM, an analysis program for Ratcliff's diffusion model, which has been one of the most important models in cognitive psychology over the past 35 years and which has come to occupy an important place in cognitive neuroscience in recent years. The analysis tool is designed with the basic principles of easy comprehension and simplicity in use. A diffusion process was programmed as the limit of a simple random walk in a manner resembling Ratcliff & Tuerlinckx(2002). The response time distribution of the model was constructed by simulating the time taken by a random walk until it reaches a threshold with small steps. The optimal parameter values in the model are found to be the smallest value of the chi-square values obtained by comparing the resulting distribution and the experimental data using Simplex method. For simplicity and ease of use, the input file used here is created as a file containing the quantile of the reaction time, the trials and other information. The number of participants and the number of conditions required for such work programs are given in a way that answers the question. Using this analysis tool, the experimental data of Ratcliff, Gomez, & McKoon(2004) were analyzed. We found the very similar pattern of parameter values to Ratcliff et al.(2004) found. When comparing DMAT, fast-dm and SNUDM with the generated data, we found that when the number of trials is small, SNUDM estimates the boundary parameter to a value similar to fast-dm and less than the DMAT. In addition, when the number of trials was large, it was confirmed that all three tools estimate parameters similarly.

• Journal of Korean Society of Transportation
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• v.34 no.5
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• pp.437-448
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• 2016

Some previous researches suggested a transit trip destination inference method by constructing trip chains with incomplete(missing destination) smart card dataset obtained on the entry fare control systems. To explore the feasibility of the transit trip destination inference method, the transit trip chains are constructed from the pre-paid smart card tagging data collected in Busan on October 2014 weekdays by tracing the card IDs, tagging times(boarding, alighting, transfer), and the trip linking distances between two consecutive transit trips in a daily sequences. Assuming that most trips in the transit trip chains are linked successively, the individual transit trip destination zones are inferred as the consecutive linking trip's origin zones. Applying the model to the complete trips with observed OD reveals that about 82% of the inferred trip destinations are the same as those of the observed trip destinations and the inference error defined as the difference in distance between the inferred and observed alighting stops is minimized when the trip linking distance is less than or equal to 0.5km. When applying the model to the incomplete trips with missing destinations, the overall destination missing rate decreases from 71.40% to 21.74% and approximately 77% of the destination missing trips are the single transit trips for which the destinations can not be inferable. In addition, the model remarkably reduces the destination missing rate of the multiple incomplete transit trips from 69.56% to 6.27%. Spearman's rank correlation and Chi-squared goodness-of-fit tests showed that the ranks for transit trips of each zone are not significantly affected by the inferred trips, but the transit trip distributions only using small complete trips are significantly different from those using complete and inferred trips. Therefore, it is concluded that the model should be applicable to derive a realistic transit trip patterns in cities with the incomplete smart card data.