• 대한조선학회 특별논문집
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• 대한조선학회 2009년도 특별논문집
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• pp.123-129
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• 2009

Ship painting procedures can be divided into two categories; Out-shell plate painting of the hull and the interior painting of each double gull blocks. It is really hard to apply standardized and automated operations to the latter because the double hull blocks contains a variety of complicated supportive materials and pipes to strengthen the ship structure. In addition their poor working conditions cause painting workers to avoid working in them, resulting in the waste of paints and additional pollution issues. So this research, successfully focused on overcoming the difficulties in working in the complicated blocks and the tough working conditions introduces the main details of automatic equipment systems and their transfer algorism which show how the equipment paints the inner sides of a longitudinal stiffener and moves to another automatically.

• 의학교육논단
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• 제25권2호
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• pp.84-101
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• 2023

Longitudinal data can provide important evidence with the potential to stimulate innovation and affect policies in medical education and can serve as a driving force for further developments in medical education through evidence-based decisions. Tracking and observing cohorts of students and graduates using longitudinal data can be a way to link the past, present, and future of medical education. This study reviewed practical methods and technical, administrative, and ethical considerations for the establishment and operation of a longitudinal database and presented examples of longitudinal databases. Cohort study design methods and previous examples of research using longitudinal databases to explore major topics in medical education were also reviewed. The implications of this study are as follows: (1) a systematic design process is required to establish longitudinal data, and each university should engage in ongoing deliberation about this issue; (2) efforts are needed to alleviate "survey fatigue" among respondents and reduce the administrative burden of those conducting data collection and analysis; (3) it is necessary to regularly review issues of personal information protection, data security, and ethics regarding the survey respondents; and (4) a system should be established that integrates and manages a longitudinal database of medical education at the national level. The hope is that establishing longitudinal data and cohorts at individual medical schools will not be a temporary phenomenon, but rather that they will be well utilized at the national level to innovate and implement ongoing changes in medical education.

• 한국경영과학회지
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• 제26권1호
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• pp.109-116
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• 2001

The detection of corporate failures is a subject that has been particularly amenable to cross-sectional financial ratio analysis. In most of firms, however, the financial data are available over past years. Because of this, a model utilizing these longitudinal data could provide useful information on the prediction of bankruptcy. To correctly reflect the longitudinal and firm-specific data, the generalized linear model with assuming the first order AR(autoregressive) process is proposed. The method is motivated by the clinical research that several characteristics are measured repeatedly from individual over the time. The model is compared with several other predictive models to evaluate the performance. By using the financial data from manufacturing corporations in the Korea Stock Exchange (KSE) list, we will discuss some experiences learned from the procedure of sampling scheme, variable transformation, imputation, variable selection, and model evaluation. Finally, implications of the model with repeated measurement and future direction of research will be discussed.

• Journal of Welding and Joining
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• 제34권6호
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• pp.20-27
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• 2016

This study deals with the proper conditions of the trail rolling method (TRM) for the prevention of the buckling welding distortion at the AA5083 GMA butt weldment. For it, the effect of the working conditions of TRM including the rolling depth and the rolling distance between the welding torch and the roller on the longitudinal welding shrinkage force of the weldment was evaluated by using 3 dimensional thermo-mechanical FE analyses. The longitudinal welding shrinkage force inducing the buckling welding distortion at the GMA butt weldment was mitigated with an increase in the rolling depth and the rolling distance between the welding torch and the roller. Based on the results, the proper conditions of trail rolling method were established to reduce the longitudinal welding shrinkage force of the GMA butt weldment to below the critical value corresponding to the bucking distortion.

• 대한조선학회논문집
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• 제44권5호
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• pp.504-508
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• 2007

In the case of thin plate blocks, buckling deformation due to longitudinal shrinkage is the most important weld-induced deformation. This paper is concerned with developing the formula to predict the longitudinal shrinkage due to welding, in which mechanical tension effect in welding direction is accounted for. For this purpose, bead on plate welding test has been carried out for the 27 thin plate specimens with varying welding conditions and magnitude of tensile load. Empirical formula of predicting the longitudinal shrinkage has been derived based on the results of welding test, in which effect of mechanical tension is included. The derived formula can be usefully used in predicting the level of tensile load to reduce the longitudinal shrinkage.

• 한국컴퓨터정보학회논문지
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• 제24권7호
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• pp.153-160
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• 2019

This study aims to analyze the mutual influences between adolescents' multicultural acceptability and school adjustment. Research problems for research are as follows. First, is multicultural acceptability and school adjustment stable over time? Second, what is the longitudinal impact of school adjustment on multicultural acceptability over time? Third, what is the longitudinal impact of multicultural acceptability on school adjustment over time? The results of analyzing the research problems by applying the autoregressive cross-lagged model are as follows. First, the autoregressive model of school adjustment has a significant effect on the future time point and is stable over time. Second, the autoregressive model of multicultural acceptability have a significant effect on the future time point and is stable over time. Third, cross-lagged effect from school adjustment to multicultural acceptability has a statistically significant effect on the multicultural acceptability at a later time, and is stable over time. Fourth, cross-lagged effect from multicultural acceptability to school adjustment was not statistically significant at the time of multicultural acceptability, and there was no change with time. This study is meaningful to provide the theoretical and practical implications by verifying the influence of the three - year term data over time.

• 한국항해학회지
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• 제8권2호
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• pp.43-50
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• 1984

When the static load is applied to the ship's hull the deflection due to the bending moment from longitudinal direction has not been considered in the usual calculation of maximum bending moment. In fact, however, the deflection of ship's hull must be affected by the above-stated bending moment, and in this case the value of the maximum bending moment would be lessened in comparision with the result of usual calculation. In this paper, the author at first calculated the difference between the two values in case of rectangular barge, and suggested a practical criterion of longitudinal strength.

• 콘크리트학회논문집
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• 제15권5호
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• pp.679-688
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• 2003

종방향 텐던이 경사진 복부에 배치되는 박스 거더의 경우 프리스트레스 힘은 종방향 뿐만 아니라 횡방향 거동에도 영향을 미친다. 본 논문에서는 종방향 프리스트레싱에 의해 유발되는 횡방향 효과를 산정하는 기법을 제안하였다. 박스 거더의 유한요소 정식화 및 종방향 프리스트레싱 해석에 의해 프리스트레스 분포를 산정한 후, 이를 이용하여 횡방향 등가하중을 산정한다. 제안기법에 의한 수치해석결과와 기존의 접판법에 의한 수치해석결과는 유사하며, 이는 본 기법이 합리적임을 나타낸다. 제안기법을 이용하여 박스 거더 슬래브의 횡방향 거동을 분석하였다. 수치분석은 복부경사각, 텐던 편심에 대한 경간 길이비 등과 같은 주요 변수를 통해 수행되었다. 전형적인 단면 조건에서 종방향 프리스트레싱 효과만을 고려할 때, 박스 거더 슬래브의 횡방향 응력은 크지 않은 것으로 나타난다. 그러나, 복부 경사각이 50도 이하로 과도하게 작아지거나 텐던 편심에 대한 경간 길이비가 28이하로 작아지는 경우에는 교량 설계시 횡방향 응력의 크기를 고려할 필요가 있다고 사료된다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.383-386
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• 2005

An integrated analytical model which should have essential dynamics on the longitudinal railway vehicle is developed. The model consists of translational movement, rotational movement, brake actuator, adhesion force between rail and wheel, and brake friction force between wheel and pad. Thus, during the deceleration for stopping, a feedback controller controlling the brake cylinder pressure is designed to improve ride quality and to release friction problems. Through the developed model, the feasibility of controlling the cylinder pressure is verified for the better performances during braking.

• Asia pacific journal of information systems
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• 제15권2호
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• pp.121-148
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• 2005

This study focuses on MRO e-Marketplace and attempts to research how companies select the structure of e-Marketplace governance and how it influences purchasing performance. Furthermore, a longitudinal study is conducted to analyze the dynamic relationship between variables in our research model. The research gives the following results. First, as the utilization level of e-Marketplace increases, the level of relational exchange between purchasing company and e-Marketplace increases. The increased utilization level enhances purchasing efficiency rather than reducing purchasing price. Secondly, as the level of relational exchange between purchasing companies and e-Marketplace increases, system integration increases, whereas supply externality decreases. Accordingly, system integration improves purchasing efficiency, whereas the low supply externality does not help lower purchasing price. Third, compared to the initial growth stage, the stable stage of e-Marketplace has the significantly increased level of relational exchange and purchasing efficiency through system integration, rather than the reduction of purchasing price by supply externality.