• Journal of the Korean Data and Information Science Society
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• v.28 no.2
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• pp.361-369
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• 2017

This paper analyzes the causal relationship between dollar exchange rate and international oil price. Although large literature on the relationship has accumulated, results are not unique but diversified. Based on the idea that such diversified results may be due to different causality at different economic status, we considers an approach to test the causal relationship at each quantile. This approach is different from the mean causality analysis widely employed by the existing literature of the causal relationship. In this paper, monthly data from May 1987 to 2013 is used for the causal analysis in which Brent oil price and Major Currencies Dollar Index (MCDI) are considered. The test method is the nonparametric test for causality in quantile suggested by Jeong et al. (2012). The results show that although dollar exchange rate causes oil price in mean, the causal relationship does not exist at most quantiles.

• Korean Journal of Social Welfare Studies
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• v.48 no.3
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• pp.117-143
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• 2017

This study empirically analyzed the factors that intensify the unequal distribution of relational goods through the decomposition of relational gaps and the actual condition of relational goods. The results of the analysis are as follows. First, the average time for forming a relationship with family members or others is 158 minutes in 24 hours a day. Second, tobit regression analysis showed that relational goods time increased as they were employed, more family members, and ownership of their home. On the other hand, relational goods decreased when they were female, double-working, aged, divorced, and increased working time. The increase in household income decreased family relational goods, but increased the time with others. Based on the results of this analysis, this study proposed reduction of working time as a way to increase the happiness by sharing the relationship with meaningful people.

• Journal of Korean Elementary Science Education
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• v.26 no.3
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• pp.309-320
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• 2007

과학교육에서는 과학과 기술과 관련된 사회적 또는 환경 문제의 증가를 더 이상 간과할 수가 없게 되었고, 이로 인해 과학-기술-사회-환경(Science-Technology, Society-the Environment: STSE)교육을 통한 실천적 과학 소양의 중요성이 대두되고 있다. 본 연구는 환경 내용을 다룬 초등학교 6학년 2학기 과학 단원, 3. 쾌적한 환경을 학습하는 과정에서 환경 중심 STSE 교육의 어려움과 그 가능성에 대하여 고찰하고자 하였다. 초등학교 6학년 두 개의 반 아동 86명은 단원 학습에 참여하는 동안 설문, 그리기와 쓰기, 면담에 참여하였다. 수집된 자료는 아동들의 과학-기술-사회-환경의 관련성에 대한 인식과 과학 지식의 실천적 소양이라는 측면에서 분석되었다. 결과로는 첫째, 과학-기술-사회-환경의 관계에 대한 아동들의 인식은 현대 사회가 가지고 있는 가치관과 복잡하게 얽혀 있었으며, 이 안에서 과학/기술의 발전은 사회 발전과 환경 문제의 두 측면에서 다소 상반적인 관계를 보였다. 둘째, 환경 문제에 대한 아동의 인식은 높은 반면 실천적 소양의 측면은 상대적으로 낮았다. 셋째 과학-환경 지식은 환경 문제 인식과 문제 해결에 그다지 영향을 미치지 않았다. 이러한 결과들을 바탕으로 본 논문은 실천적 과학 소양을 위한 과학-기술-사회-환경 교육의 문제점과 어려움에 대해 논의한다.

• The Southeast Asian review
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• v.22 no.2
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• pp.269-303
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• 2012

이 연구는 1960년부터 2009년까지의 시계열횡단연구(cross-sectional time series) 자료를 이용하여 동남아시아의 각국의 자연자원에 대한 의존도와 정치체제 사이의 상관관계를 밝히고자 하였다. 동남아시아는 중동과 서부사하라 아프리카와 더불어 전 세계에서 가장 자연자원이 풍부한 지역 가운데 하나이나, 관련된 연구는 자료의 부족으로 인해 타 지역에 비해 그다지 축적되어 있지 못한 상태이며, 그나마 단일 사례 혹은 국가에 치중되어 있다. 따라서 본 연구는 기존 자연자원의존도와 정치체제와의 경험적 연구들에서 주장된 인과 관계들이 동남아시아에서도 적용될 수 있는지 살펴보고자 하였다. 분석 결과, 본 연구는 동남아시아에서도 한 국가의 자연자원에 대한 의존도의 증가가 민주주의 발전에 부정적인 영향을 끼친다는 것을 발견할 수 있었다. 구체적으로 본 연구에서 자연자원 의존도로 사용하였던 두 가지 지표인 총 수출 대비 자연자원 수출비율과 국민 총생산 대비 자연자원 수입비율 모두 민주주의 수준을 종속변수로 상정한 각 모델에서 음의 상관계수를 보여주었다. 기존 연구들에서 다루어졌던 주요 이론들인 지대추구(rent-seeking), 지대국가(rentier state), 근대화(modernization)이론을 대표하는 통제변수들을 사용한 대부분의 결과 역시 기존 문헌의 주장을 뒷받침 하고 있다. 그러나 내전 발발과 이슬람을 비롯한 일부 통제변수들의 경우에는 기존 민주화 관련 연구결과와는 상반된 결과를 나타내기도 하였다. 이러한 동남아시아의 지역적 특수성을 보여주는 결과는 후속 연구에 의미있는 시사점을 제시해 줄 것이다.

• 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.

• Management & Information Systems Review
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• v.34 no.3
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• pp.317-327
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• 2015

This study analyzed between the hospital's management performance and training expense by using five year financial statements data of the nation's total medical corporations, and The meaningful results of this study as follow. The relation between training expense and hospital's management performance in the rate of medical profit showed to have negative influence in year three of the five year, but in the rate of net income showed to have negative influence in only year one. And if you look the and analyze results differ by metropolitan and provincial, in the case of large cities there are showed that the relation between training expense and hospital's management performance in the rate of net income showed to have positive influence in year one. Even though not be consistent across the entire year, this study presented new results to be negative influence on training expense is the hospital's management performance. This study has a value in respects the first analysis to try using the financial statements data of nationwide medical corporation in the relation of the between training expense and management performance.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.22 no.1
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• pp.7-10
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• 1977

Positive correlations were observed between protein content and $\textrm{K}_2\textrm{O}$, protein and ash, protein and moisture content, and $\textrm{P}_2\textrm{O}_5$ and ash in soybean seeds. On the contrary, negative correlations were observed between fat and CaO, fat and ash, $\textrm{K}_2\textrm{O}$ and moisture content, CaO and moisture content, and MgO and ash content in soybean seeds.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.1
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• pp.308-322
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• 1991

A set of experiments of Counter-Current Flow Limit(CCFL or Flooding) was performed to improve the drawbacks of Wallis' Correlation which neglects the effects of channel size, channel length, injection method and the boundary conditions at the inlet of liquid and gas phase. In these experiments using water and air, the followings were found ; (i) The effects of channel size and length were quite significant. In large tubes(D>20mm), the flooding front occurred at the bottom of the channel and when the gas flow increased the front moved upward ; however, in small tubes(D<20mm), there were no upward movement of flooding front and the flooding just occurred at the liquid inlet. (ii) The effect of water inlet device was not as significant as that of channel length though the inlet boundary conditions could affect the flow development and flooding afterward. (iii) Once the flooding front reached the inlet of water injection device, an newly reduced flow condition was set up and resulted in another flooding corresponding to the new condition.

• Journal of Energy Engineering
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• v.11 no.2
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• pp.90-98
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• 2002

The effects of swirl and combustion parameters on the performance and emission in a turbo-charged D.I. diesel engine of the displacement 9.4L were studied experimentally in this paper. Generally the swirl in the combustion process of diesel engine promotes mixing of the injection fuel and the intake air. It is a major factor to improve the engine performance because the fuel consumption and NO$_{x}$ is trade-off according to the high temperature and high pressure of combustion gas in a turbocharged D.I. diesel engine, it's necessary to thinking over the intake and exhaust system, the design of combustion bowl and so on. In order to choose a turbocharger of appropriate capacity. As a result of steady flow test, when the swirl ratio is increased, the mean flow coefficient is decreased, whereas the gulf factor is increased. Also, through engine test its can be expected to meet performance and emissions by optimizing the main parameter's; the swirl ratio is 2.43, injection timing is BTDC 13$^{\circ}$ CA, compression ratio is 16, combustion bowl is re-entrant 5$^{\circ}$, nozzle hole diameter is $\Phi$0.28*6, turbocharger is GT40 model which are compressor A/R 0.58 and turbine A/R 1.19.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.373-379
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• 2016

This study examined the level-differentiated mathematic classes to offer basic data for effective college mathematics curriculum. Using the Kolb Learning Style, this study surveyed 213 college engineering students in 6 level-differentiated classes in one university and analyzed the significant consequence. The results showed that the ranking of the Learning Style in a superior mathematic class is Diverger, Accommodator, Assimilator, and Converger. Second, the ranking of the Learning Style in the inferior mathematics class was Accommodator, Diverger, Assimilator, and Converger. Third, for effective class of superior mathematics class, professors need to give sufficient time to analyze mathematics problems by the students themselves. Fourth, for an effective class of inferior mathematic class, professors need to use experimental and diverse teaching method to enhance the students' concentration and learning achievement. Based on this study, professors should develop teaching methods that fit the students' Learning Style and the properties of college mathematics curriculum.