• Journal of Welding and Joining
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• v.14 no.4
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• pp.24-32
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• 1996

용접공정 해석을 위한 접근방법중에서 우선적으로 결정해야할 사항으로는 비선형적인 요소와 복잡한 물리현상들을 실제적으로 해석하기위한 측정변수의 선정과 이러한 변수를 사용하여 물리적인 현상을 적절히 표현할 수 있는 알고리즘의 개발 등 을 들 수 있다. 최근까지의 연구결과를 바탕으로 해서 측정변수들의 예를 들면 용접 전류(welding current), 아크전압(arc voltage), 음향신호(acoustic signal), 아크 광(arc light) 그리고 온도(temperature)등이 있다. 용접공정을 분석하기 위한 알고 리즘으로는 확률론적 접근(statistical approach), 다양한 실험치를 이용한 인공지능 적 접근(artificial intelligence approach) 그리고 경험치를 바탕으로 인덱스(index) 을 선정하여 이를 직접 사용하는 방법 및 인공지능과 결합된 형태를 이용하는 방법등 이 있다. 또한 용접공정의 특성을 분석하기 위해서는 크게 금속이행모드(metal transfer mode), 아크의 안정성(arc stability) 그리고 용접품질(weld quality) 등을 판별할 수 있는 알고리즘의 개발이 필수적이라 할 수 있다. 본 논문에서는 용접공정 분석과 관련된 최근까지의 연구동향 및 용접신호의 특성을 좀더 심도있게 분석하기 위해 구축해야 할 필수 요건 등을 소개하고자 하며 이를 사용자가 손쉽게 이용할 수 있는 사용자 인터페이스 프로그램을 개괄적으로 설명하고자 한다.

• Korean Journal of Logic
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• v.18 no.1
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• pp.83-133
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• 2015

In this paper, I pose a problem for Hitchcock's arguments for two concepts of effects that are intended to explicate double causal effects, and put forth a theory that is intended not just to meet the problem but also to accommodate Hitchcock's theory and Eells' theory both. First, I introduce an example of dual causal effects, and examine the accounts of Otte(1985) and Eells(1987) on how to explicate the dual effects. I show that their accounts of the dual effects help us understand the problem of dual effects and see how different it is for Cartwright(1979, 1989, 1995), Eells(1991, 1995), and Hitchcock(2001a) to meet the problem. Second, I introduce two concepts of effects on Hitchcock(2001a), that is, net effect and component effect that are allegedly analogous to two effects of structural equation model. Third, I reveal the significance of homogeneous subpopulation and causal interaction regarding the problem of dual effects while examining Cartwright's theory and Elles' theory. Fourth, I critically examine the two concepts of effects on Hitchcock and argue against Hitchcock's criticism of Eells' theory. Fifth, I take a moderator variable of structural equation model and a moderator effect into the probabilistic theory of causality, and formally generalize causal interaction due to the dual effects in terms of disjunctive relation and counterfactual conditionals. I expect my account of disjunctive relation and counterfactual conditionals to contribute not just to several problems the received theories of causal modelling confront but also to the structural equation models many people exploit as a promising statistical methodology.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.2
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• pp.179-194
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• 2020

A Bayesian approach was introduced to improve the belief of prior distributions of input parameters for the probabilistic safety assessment of radioactive waste repository. A GoldSim-based module was developed using the Markov chain Monte Carlo algorithm and implemented through GSTSPA (GoldSim Total System Performance Assessment), a GoldSim template for generic/site-specific safety assessment of the radioactive repository system. In this study, sequential Bayesian updating of prior distributions was comprehensively explained and used as a basis to conduct a reliable safety assessment of the repository. The prior distribution to three sequential posterior distributions for several selected parameters associated with nuclide transport in the fractured rock medium was updated with assumed likelihood functions. The process was demonstrated through a probabilistic safety assessment of the conceptual repository for illustrative purposes. Through this study, it was shown that insufficient observed data could enhance the belief of prior distributions for input parameter values commonly available, which are usually uncertain. This is particularly applicable for nuclide behavior in and around the repository system, which typically exhibited a long time span and wide modeling domain.

• Korean Journal of Construction Engineering and Management
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• v.2 no.2 s.6
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• pp.98-108
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• 2001

This research proposes a new risk analysis model in order to guarantee successful performance of construction projects. The risk analysis model, called Construction Risk Analysis System(CRAS), is introduced to help contractors Identify project risks through RBS and through the procedures in risk analysis model. The proposed CRAS model consists of three phases. First step, CRAS model can help contractors decide whether or not they bid for a project by analysing risks involved in the project. Second step, the influence diagraming, decision tree and Monte Carlo simulation are used as tools to analyze and evaluate project risks quantitatively. Third step, Monte Carlo simulation is used to assess risk for groups of activities with probabilistic branching and calendars. Consequently, it will help contractors identify risk elements in their projects and quantify the impact of risk on project time and cost.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7708-7717
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• 2015

The purpose of this study was to determine the impact of cervical cancer knowledge, HPV knowledge, and health beliefs on HPV vaccination. The survey was conducted to undergraduate students of the university in Chungbuk province. Total 271 copies were used in the final analysis. The mean score of cervical cancer and HPV knowledge level was very low(5.34/26). The health beliefs about HPV, the perceived benefit(2.58), perceived barrier(2.52), perceived seriousness(2.49) were generally low level. Especially the perceived susceptibility(1.77) was very low. HPV vaccination rate should be rise 1.229 times(p<.01) and 1.567 times(p<.05), if the cervical cancer knowledge and perceived benefit of HPV vaccination would be that each rise 1unit. In conclusion, The educational strategy would be needed to strengthen the perceived benefit and as well as to increase the cervical cancer knowledge and perceived susceptibility about HPV.

• Culinary science and hospitality research
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• v.21 no.2
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• pp.85-102
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• 2015

The purpose of this study was to present the direction of the safety manual in the food service industry kitchen. The accident rate in food industry kitchens is around 87.2%, it meaning nearly 9 workers have accident among 10, considered to be very high. The most common accident is a knife cut wound (84.7%). And burns caused by hot water and oil (74.4%), then shown slip and falls (28.1%). The degree of fulfillment of kitchen safety awareness and safe environment varied based on gender, in which male are considered more likely to suffer from accidents than women. The level of safety perception varies between workers at different career points. Workers with 1~3 years of experience suffer the highest rate of accident, while workers with 7~10 years and more of experience are believed to be at lower risk of accident. Restaurant type did not exhibit a significant influence on accidents cases, although differences in the adoption of personal safety, even partially, were discovered, at significance of 0.01 < 0.027 < $0.05^*$. Based on these results, this paper has suggested preventive safety management validation model the food service industry based on kitchen management and incident management, and presented steps necessary.

• Korea journal of population studies
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• v.34 no.1
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• pp.129-157
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• 2011

This study attempts to analyze the effect of level of education on the attitudes toward immigrants or foreign workers. More specifically, we examine whether there is significant difference in the effects of the level of education and global mind on the attitude among three East Asian countries (South Korea, Japan, and Taiwan), controlling other socio-demographic factors in relation to increase in immigrants and foreign workers. Using EASS data, we employs sequential logit model to the general attitudes toward immigrant workers into the weighted sum of transition probability within each educational level. One major finding is that there is clear and significant difference in the relationship between the level of education and the attitudes toward foreign workers among three countries. In general, while Japanese and Taiwanese tend to have more open-minded attitudes toward foreign workers as they have higher level of education, Koreans are opposite case that they are little bit more hostile toward to foreign workers with higher level of education. Especially, there is strong positive effect of education on the attitude in Taiwanese case. Another finding is that while there is strong resistance against increase in migrant population in Korea and Taiwan, Japanese respondents want current level of foreign population to remain in the similar level. Our findings imply that there is no one converging pattern of relationship between the level of education and the positive attitudes toward foreign workers which can be applied to any country. Therefore, this paper suggests that unique political, social, and cultural characteristics of each country should be considered to better understand the effect of education on the attitude toward immigrants and foreign workers. Also, we conclude that systematic comparative-demographic analyses should be utilized to provide more comprehensive picture of how difference in educational level affects the attitude toward immigrants and foreign workers.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.4
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• pp.348-356
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• 2018

Most of fires were human-caused fires in Korea, but meteorological factors are also big contributors to fire behavior and its spread. Thus, meteorological factors as well as topographical and forest factors were considered in the fire danger rating systems. This study aims to develop an advanced national integrated daily weather index(DWI) using weather data in the spring and fall to support forest fire prevention strategy in South Korea. DWI represents the meteorological characteristics, such as humidity (relative and effective), temperature and wind speed, and we integrated nine logistic regression models of the past into one national model. One national integrated model of the spring and fall is respectively $[1+{\exp}\{-(2.706+(0.088^*T_{mean})-(0.055^*Rh)-(0.023^*Eh)-(0.014^*W_{mean}))\}^{-1}]^{-1}$, $[1+{\exp}\{-(1.099+(0.117^*T_{mean})-(0.069^*Rh)-(0.182^*W_{mean}))\}^{-1}]^{-1}$ and all weather variables significantly (p<0.01) affected the probability of forest fire occurrence in the overall regions. The accuracy of the model in the spring and fall is respectively 71.7% and 86.9%. One integrated national model showed 10% higher accuracy than nine logistic regression models when it is applied weather data with 66 random sampling in forest fire event days. These findings would be necessary for the policy makers in the Republic of Korea for the prevention of forest fires.

• Neonatal Medicine
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• v.17 no.2
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• pp.193-200
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• 2010

Purpose: Feeding desaturation is a common problem among preterm infants which can result in prolonged hospital stays, longterm feeding difficulties and growth delay. The purpose of this study was to identify the characteristics of premature infants with feeding desaturation and to examine the effect of orocutaneous stimulation on oral feeding. Methods: During the first phase of this study, 125 extremely low birth weight infants were reviewed retrospectively. Characteristics between infants with feeding desaturation (n=34) and those without feeding desaturation (n=91) were examined. During the second phase, 29 infants recruited from March, 2009 to May, 2010 were subjected to orocutaneous stimulation. The results of orocutaneous stimulation were compared to a control group (n=81). Results: The first phase of the study revealed that extremely low birth weight infants with feeding desaturation were significantly lower in gestational ages at birth, and had lower 5 minute apgar scores, more gastroesophageal refluxes and bronchopulmonary dysplasia. Infants without feeding desaturation reached full enteral feeding significantly earlier and showed shorter duration of hospital stay. At the second phase, infants in the intervention group showed shorter days to achieve initiation of bottle feeding, shorter days in achievement of full bottle feeding, last episodes of feeding desaturation and length of hospital stay compared to the control group of similar characteristics. Conclusion: Orocutaneous stimulation among extremely low birth weight infants results in earlier achievement of full bottle feedings without episodes of feeding desaturation hence shortens the length of hospital stay.

• Korean Journal of Social Welfare
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• v.59 no.3
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• pp.147-174
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• 2007

This study examines how path dependency of working poor labor market segmented from the primary and the secondary labor market affects employment and quality of employment of working poor. It Further examines how path dependency makes working poor to remain in the labor market and makes it difficult for them to escape from a vicious poverty cycle. Data is based on the $3{\sim}7th$ Korea Labor and Income Panel Study(KLIPS). Markov's transition probability and discrete-time hazard analysis are used for analysis. This study finds that Korea labor market is divided into three parts; the primary labor market, the secondary labor market and the working poor labor market. The proportion of employed poor has been reduced, but the proportion of non economically-active working poor has been increased and has become the main group among the working poor. This shows that labor demand of working poor is fundamentally lacking and there are structural barriers that block working poor's employment itself. The regression analysis shows that the longer working poor labor market participation is, the lower poverty-exit rate. This is an evidence of vicious poverty cycle that the poor have little chance to exit from working poor labor market, once they step into it. Therefore, the longer their participation in poor labor market, the more likely they would move only within the closed working poor labor market. Consequently, it is necessary to fundamentally reform labor market structure and to alleviate negative perception and discrimination about the poor labor while activating labor demand.