• Journal of the Korean Data and Information Science Society
• /
• 제15권4호
• /
• pp.743-752
• /
• 2004

In this paper, we develop the Bayesian model selection procedure using the reference prior for comparing two nested model such as the independent and intraclass models using the distance or divergence between the two as the basis of comparison. A suitable criterion for this is the power divergence measure as introduced by Cressie and Read(1984). Such a measure includes the Kullback -Liebler divergence measures and the Hellinger divergence measure as special cases. For this problem, the power divergence measure turns out to be a function solely of $\rho$, the intraclass correlation coefficient. Also, this function is convex, and the minimum is attained at $\rho=0$. We use reference prior for $\rho$. Due to the duality between hypothesis tests and set estimation, the hypothesis testing problem can also be solved by solving a corresponding set estimation problem. The present paper develops Bayesian method based on the Kullback-Liebler and Hellinger divergence measures, rejecting $H_0:\rho=0$ when the specified divergence measure exceeds some number d. This number d is so chosen that the resulting credible interval for the divergence measure has specified coverage probability $1-{\alpha}$. The length of such an interval is compared with the equal two-tailed credible interval and the HPD credible interval for $\rho$ with the same coverage probability which can also be inverted into acceptance regions of $H_0:\rho=0$. Example is considered where the HPD interval based on the one-at- a-time reference prior turns out to be the shortest credible interval having the same coverage probability.

• 대한기계학회논문집
• /
• 제14권5호
• /
• pp.1320-1329
• /
• 1990

본 연구에서는 토크로드의 여러가지 성능시험이 하능한 시험기의 설계와 개발 에 관하여 논하려 한다. 토크 로드의 정적 성능은, 반경방향 스프링 특성시험 및 비 틀림 방향 스프링 특성시험 그리고 회전토크 특성시험 등을 통하여 평가된다. 그러 나, 이들 세가지 성능시험을 위한 시험기를 각각 개발할 경우 소요비용이 과다해진다. 따라서, 한정된 예산과 시험기 개발후 시험평가 공정의 간소화 등을 고려하여, 본 시 험기는 3대의 시험기로써 하여야 할 기능을 한대의 시험기로써 할수 있도록 개발하였 다. 시험기 개발에 따른 기술적인 고찰과, 본 시험기로 정하중에서의 토크 로드 부 품의 성능시험을 수행하고 서어보 유압식 구조물 피로 시험기를 사용하여 동 부품의 피로 내구성 시험을 실시하고, 고무의 조성변화, 접착성 개선 등을 통해 내구성을 향 상시킴으로 국산화 개발을 가능케 한 기술적 내용들을 살펴 보고자 한다.

• 한국콘텐츠학회논문지
• /
• 제18권1호
• /
• pp.517-526
• /
• 2018

본 연구는 $G{\acute{a}}mez$, Chmielewski, Kotov, Ruggero와 Watson이 개발한 다차원적 체험회피 질문지를 한국어로 번안하여 신뢰도 및 타당도를 검증하기 위해 수행되었다. 대학생 285명을 대상으로 다차원적 체험회피 질문지를 실시하여 탐색적 요인분석을 실시한 결과, 6개 요인, 50문항이 확인되었다. 50문항 전체의 내적 합치도 계수는 .91이었다. 대학생 315명에게 다차원적 체험회피 질문지를 실시하여 확인적 요인분석을 실시한 결과, 6개 요인이 적합한 것으로 나타났다. 이 중 275명에게 수용 행동 질문지II, 사고억제 질문지, Toronto 감정표현 불능증 척도, 신경증, 회피적 대처, 한국판 CES-D, 한국판 Beck 불안 척도, 한국판 심리적 안녕감 척도, 삶의 만족도 척도를 함께 실시하여 다차원적 체험회피와의 상관을 살펴본 결과, 다차원적 체험회피 질문지는 수렴, 변별, 준거타당도를 가지는 것으로 나타났다.

• 대한조선학회 특별논문집
• /
• 대한조선학회 2015년도 특별논문집
• /
• pp.50-55
• /
• 2015

Application of newly conceptualized Anti-Splash Devices designed for COT vent pipes were studied on a P/V valve located on the upper deck of an oil carrier vessel. Anti-Splash devices are used in the shipbuilding industry in order to avoid oil overflow and spray accidents caused by excess pressure and vacuum condition in the cargo oil tanks. These conditions are caused by the transverse and longitudinal sloshing forces that arise from ship motion during sea voyages. The main issue with existing Anti-Splash device model is flux at the outlet of the Anti-Splash Device, and so, new conceptual models for the Anti-Splash device were developed and compared to existing Anti-Splash device model using CFD analysis. Transient analysis was used to capture the flow and velocity of each model and a comparative analysis was performed between old and new-concept models. This data was used to determine the optimal design parameters in order to develop an optimized Anti-Splash Device. A Factory acceptance test was performed on the new-concept models in order to verify the performance and efficiency against their design requirements and other criterion. The final step performed was to apply the optimized Anti-Splash Device models for COT vent pipes to an actual vessel and verify performance through a seawater cargo operation during a sea voyage as per the ship owner's request. The patent for the aforementioned device was obtained by the Korean Intellectual property Office dated Dec. 18th,2014.

• 한국안전학회지
• /
• 제33권6호
• /
• pp.102-114
• /
• 2018

The Railway Safety Management System is based on risk management and the basic purpose of risk management is safety management activities to prevent railway accidents and operational obstacles in advance. In order to manage risk, an acceptable risk standard must be established. This risk criterion is used to evaluate the railway risk with both frequency and severity. In the case of overseas railway or other industrial sectors, various factors are reflected in the main variables that constitute the occurrence frequency, but this is no the case in the domestic railway sector. In particular, the current risk assessment criteria in the railway sector remain at a level that exploits the incidents that have occurred in the past and the severity of the property damage and it dose not properly reflect complex and diverse environmental and situational changes in railway operations. Therefore, in this study, it is possible to calculate the potential occurrence of future events instead of occurrence frequency as a component of the risk assessment criteria, focusing on the High-Speed Railway. In addition to the property damage to the consequence, we suggest a rational methodology, development direction, and theoretical implications for constructing accurate and reasonable risk criteria including actual damage such as human injury and time loss.

• 한국산업보건학회지
• /
• 제33권2호
• /
• pp.145-155
• /
• 2023

Objectives: A fit test panel is needed to identify the fit performance of a respirator and its face seal. This is a criterion for selecting subjects that can represent the facial characteristics of users. Although anthropometry data has been developed for people in United States and China it is not yet present in Korea. This study aimed to develop a Korean fit test panel and test headform. Methods: For the 7th and 8th waves of the Size Korea anthropometry data, facial measurements of 11,429 people aged 15 to 69 years were used for analysis. PCA and bivariate panel were classified using the ISO16976-2:2022(E) anthropometrics analysis method. Based on this result, a static headform was developemed and a fit test chamber was constructed. Results: Of the 11,429 Korean people used for principal component analysis, 11,300 were included in the ellipse, marking an acceptance rate of 98.87% on PCA panel. The face types were classified into five types. Among them, a large, medium, and small static headform were printed using a 3D printer. In addition, 10,985 people (96.12%) were included in the bivariate panel based on face length and face width. The y-axis (face length) boundary was 97.87 to 134.59 mm, and the x-axis (face width) boundary was 120.75 to 158.23 mm. Conclusions: Compared to the ISO analysis, the Korean principal component was narrower in the width item (PC1) and longer in the length item (PC2). For the future, it is necessary to conduct a fit test using the developed headform and chamber device to confirm the usefulness of this Korean test panel. Therefore, this study is considered valuable as basic research for Korean test panels.

• 콘크리트학회지
• /
• 제10권6호
• /
• pp.335-343
• /
• 1998

현재 미국에서는 강한 지진지역에서의 골조구조에 대한 새로운 실험규정이 만들어지고 있으며, 이의 목적은 비교적 신뢰성이 높은 실험결과를 얻고 이들 실험결과를 다른 연구자들이 서로 이용 가능하도록 하는 것이다. 이 실험규정에서는 실험방법 뿐만 아니라, 실험후의 분석방법 특히, 실험체가 최소한 보유하여야 할 층위변각, 에너지 소산성능, 강성, 강도 등이 규정되어 있다. 이러한 지침이 설정됨으로 인하여, 여태까지 주관적으로 평가된 시험결과의 분석들이 비교적 객관적으로 평가될 수 있게 될 것으로 보여진다. 전단벽 구조 역시 지진저항에 매우 효과적인 시스템으로서, 이러한 실험지침이 필요하다. 그러나 전단벽 구조의 주 부재인 전단벽은 횡력에 의해서 발생하는 구조물의 횡변위를 억제시키고, 강성과강도를 증가시키는 역할을 하기 때문에 그 거동 특성이 골조주조와는 다소 다르다. 본 연구에서는 이러한 전단벽의 층변위와 에너지 소산성능에대하여 연구를 하고 구조실험시 요구된느 적정 값들을 제시하고자 하였다. 구조실험시(반복하중실험), 높은 지진지역의 전단벽 구조가 보유해야할 최소변형능력(횡변위)을 구하기 위해 기존 연구자들에 의해 실험된일련의실험자료들을 분석할 뿐만 아니라 전단벽을 켄틸레버로 이상화하여 층변위를 형상비, 변위 연성비로 관계로 나타내고, 현재 각 국가의 내진설계 규정에서 정하고 있는 건물의 층변위각을 고려하여 전단벽의 최소 층변위를 제시하였다. 또한 미국의 NEHRP 규준에서 규정하고 있는 소산에너지와 감쇠의 관계를 이용하고, 변위 연성비를 도입하여 구조실험시 요구되는 전단벽의 최소 소산에너지값을 제시하였다.

• Journal of Preventive Medicine and Public Health
• /
• 제32권2호
• /
• pp.113-122
• /
• 1999

Objectives: The purpose of this study was to describe the trends of original research in the Korean Journal of Preventive Medicine, and to evaluate the quality of original articles about lead poisoning. Method: The data for the analysis of trends in preventive medicine research was taker from a total of 829 original articles published in the Korean Journal of Preventive Medicine from 1968 to 1997, The qualitative meta-analysis was measured against a checklist of evaluation criteria, which were divided into 10 categories, with 46 articles on lead poisoning. The evaluation process was performed independently by two evaluators, Results: The number of articles per 100 members over the study period increased by almost 4 pieces in the early 1980s, and by more than 9 pieces in the mid-1990s. In the major classifications of subjects, environmental and industrial health, epidemiology and health statistics, and health policy and management published 370 pieces (44.0%), 137 pisces (16.5%), 322 pieces (38.9%) respectively. In the order of the number of articles, five themes about health significance, including metal exposure (73 pieces), diseases associated with exposure to organic solvents (45 pieces), air pollution (36 pieces), maternal and child health (32 pieces), and occupational health (3D pieces) received consistent attention throughout the years $1968\sim1997$. The overall mean score of article qualify about lead poisoning was 37.8 out of 50. Of the articles any information on the purpose and hypothesis described well, Of those the originality of the subjects, the form of article's (including tables and figures), and the number of inappropriate words of abstracts showed very low score. For multiple regression analyses, the number of joint research institutes and the acceptance of research grants about the article quality were statistically significant. Conclusions: The number of original research reports in the Korean J Prev Med has recently increased and their subjects bave diversified. Of the basis of this study, the articles need improvement in the areas of abstracts, tables and illustrations (figures), etc. The Korean Society for Preventive Medicine will revise contribution regulations for manuscripts submitted to the Korean J Prev Med. Future studies should address these issues and perform the quantitative mata-analysis about the specific subjects including the quality of articles.

• 한국산학기술학회논문지
• /
• 제18권3호
• /
• pp.408-417
• /
• 2017

본 연구는 여가스포츠에 참여중인 만 60세 이상 노인들을 대상으로 신체적 자기효능감, 우울감, 자아통합감의 구조적 관계를 규명하는데 그 목적이 있다. 또한 최근 자아통합감에 영향을 미치는 변인은 다차원적으로 제시되고 있으므로 변인들의 인과관계를 통합적 관점에서 살펴보는 것이 매우 중요하다. 이상의 목적을 달성하기 위하여 노인기관에서 여가스포츠 프로그램에 참여중인 노인 427명을 연구대상으로 설정하였으며, 구조방정식 모형분석을 실시하였다. 이를 위해 각 변인을 대상으로 확인적 요인분석과 신뢰도 분석을 실시하였으며, 직접효과, 간접효과, 총효과 등을 추정하였다. 모형 적합도는 TLI, CFI, RMSEA를 참고하였으며, 측정모형의 적합도와 연구모형의 적합도 모두 그 기준을 만족하였다. 연구가설 검증결과 첫째, 설문지에 관한 타당도와 신뢰도 검증 결과 신체적 자기효능감, 우울감, 자아통합감 변인 모두 적합한 것으로 나타났다. 둘째, 인지된 신체능력은 우울감, 현재생활만족, 지혜로운 삶, 생에 대한 태도에 긍정적인 영향을 미치는 것으로 나타났으며 신체적 자기표현 자신감은 현재생활만족, 생에 대한 태도에는 긍정적인, 지나온 삶 수용에는 부정적인 영향을 미치는 것으로 나타났다. 마지막으로 우울감은 현재생활만족에 부정적인 영향을 미치는 것으로 나타났다. 이상에서 나타난 결과는 노인들의 신체적 자기효능감, 우울감, 자아통합감의 통합적 관계를 규명하였다는 것에 의미가 있다.

• 한국의학물리학회지:의학물리
• /
• 제28권1호
• /
• pp.16-21
• /
• 2017

This study assessed the feasibility of a dual-channel (DC) compound method for film dosimetry. The red channel (RC) is usually used to ensure dosimetric quality using a conventional fraction dose because the RC is more accurate at low doses within 3 Gy than is the green channel (GC). However, the RC is prone to rapid degradation of sensitivity at high doses, while degradation of the GC is slow. In this study, the DC compound method combining the RC and GC was explored as a means of providing accurate film dosimetry for high doses. The DC compound method was evaluated at various dose distributions using EBT3 film inserted in a solid-water phantom. Measurements with $10{\times}20cm^2$ radiation field and $60^{\circ}$ dynamic-wedge were done. Dose distributions acquired using the RC and GC were analyzed with root-mean-squares-error (RMSE) and gamma analyses. The DC compound method was used based on the RC after correcting the GC for high doses in the gamma analysis. The RC and GC produced comparatively more accurate RMSE values for low and high doses, respectively. Gamma passing rates with an acceptance criterion of 3%/3 mm revealed that the RC provided rapid reduction in the high dose region, while the GC displayed a gradual decrease. In the whole dose range, the DC compound method had the highest agreement (93%) compared with single channel method using either the RC (80%) or GC (85%). The findings indicate that the use of DC compound method is more appropriate in dosimetric quality assurance for radiotherapy using high doses.