• 항공우주시스템공학회지
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• 제11권1호
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• pp.28-34
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• 2017

유한요소해석을 이용하여 이물질이 고무 오링과 구조물에 미치는 영향과 성능을 연구했다. 오래전부터 2D 해석을 이용하여 초탄성 오링을 연구해왔다. 오링 설계 시, 접촉응력은 중요한 설계 요소이다. 접촉 응력이 가해진 압력보다 낮으면 누수, 진동, 소음, 출력 저하의 원인이 된다. 이 연구에서는 초탄성 오링을 2D와 3D로 해석하고 결과를 비교한다. 2D와 3D의 접촉 응력 결과는 거의 비슷하게 나타난다. 이물질이 있는 오링은 3D로 모델링해야하는데 모든 방향의 접촉 응력을 고려해야하기 때문이다. 3D 해석에서 간극을 달리하여 10가지 경우로 나누어 이물질이 오링과 구조물에 미치는 영향을 확인했다. 또한 접촉 응력이 가해진 압력보다 높은지 확인하였다. 따라서, 이물질이 포함된 오링은 3D 모델로 해석되어야하며 이러한 결과는 오링 설계에 포함된다.

• 한국가정과교육학회지
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• 제10권1호
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• pp.137-151
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• 1998

The purpose of this study is (1)to develop the teaching plan based on Cooperative Learning approach and (2)to investigate the effect of students'Interest on Subject matter and Teaching method and Attitudes to others of the area of Foreign food in Home Economics class. Among those various types of Cooperative Learning's models, this study adopted 'Learning Together'developed by Johnsons. To investigate these purpose, subject matter were analyzed and reconstructed for Cooperative Learning. The tests were developed to evaluate the interest on the Subject matter and teaching methods, and the attitude to others of the students. 108 femail high school students were divided into two groups with 54 students-traditional learning condition, Cooperative Learning condition-and had a 5 session. The subject of the class was Foreign food including Western, Chinese, and Japanes food. Before and after the class, students were tested. The statistical methods used for the study methods used for the study were t-test. The research findings are as follows : When the students in the Cooperative Learning classes were compared before and after the test, (1)Interest on Subject matter were improved considerably(p〈.001) (2)Interest on Teaching methods were improved considerably(p〈.05) (3)Attitude to Others were improved considerably(p〈.001) Therefore when the teaching-learning model based on Cooperative Liarning was used in Home Economics class, their interest on the subject and teaching methods and attitude to others were improved.

• 한국대기환경학회지
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• 제32권6호
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• pp.593-602
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• 2016

The physicochemical characteristics of particulate matter emissions from various vehicle's fuel types were studied at the facility of Transport Pollution Research Center(TPRC), National Institute of Environmental Research (NIER), Korea. Three different types of fuels such as gasoline, liquefied petroleum gas (LPG) and diesel were tested on the NIER driving mode and the constant speed modes(30, 70, and 110 km/h). Chemical composition of submicron particles from vehicle emissions was measured by the High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) during running cycles. Organics were dominant chemical species of particulate matter emissions for all three different vehicles' fuel types. Moreover, regardless of fuel types, emission rate of organics and inorganics decreased as the average speed of vehicle increased. The portion of fully oxidized fragment families of $C_xH_yO_z$ accounted for over 98% of organic aerosol(OA) in LPG and diesel vehicles, while the relatively high fraction of $C_xH_y$ in OA was observed in gasoline vehicle.

• 농업과학연구
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• 제47권4호
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• pp.921-931
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• 2020

This study was carried out to determine the factor of a separating system according to the pepper varieties and the absence of a card cleaner system. The pepper varieties of Jeokyoung and AR-Legend were transplanted on November 20, 2019 and tested on March 18, 2020 with a harvesting speed of 0.2 m·s-1 for 10 pepper plants. The performance evaluation was determined by analyzing the separation efficiency of the peppers and the foreign matter mixing rate. The pepper harvester with a card cleaner showed a higher separation efficiency of the peppers compared to the pepper harvester without a card cleaner. The average separation efficiency of peppers on the pepper harvester with a card cleaner was higher at 13.5% for Jeokyoung and 1.9% for AR-Legend than that without a card cleaner. The mixing ratio of foreign materials on the pepper harvester with a card cleaner was lower at 8.7% and 2.5% for Jeokyoung and AR-Legend than that without a card cleaner, respectively. For the two-way ANOVA results according to the variety and the card cleaner, there was no effect on the separation efficiency of the peppers, but there was an effect on the foreign matter mixing rate.

• The Journal of Asian Finance, Economics and Business
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• 제7권2호
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• pp.157-168
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• 2020

Since the economic crisis sweeps across the world in 2008, the foreign direct investment of various countries has been greatly impacted. Therefore, this paper regards China as an example to analyze China's outward foreign direct investment patterns in terms of Asian financial markets with a panel data over the period 2003-2017. We mainly focus on the money market oriented outward foreign direct investment and foreign exchange market oriented outward foreign direct investment. Using the individual fixed effect model to conduct empirical analyses, the empirical findings indicate that China will reduce its foreign direct investment amount to a country with large money supply and China will increase its foreign direct investment amount to a country with large foreign exchange reserves. Furthermore, when a country has signed Free Trade Agreement with China, China will increase more foreign direct investment amount to these countries than that of a country who has not signed Free Trade Agreement with China. Moreover, the empirical findings indicate that no matter what the money market oriented outward foreign direct investment or foreign market oriented outward foreign direct investment, China will reduce its foreign direct investment amount to these Asian countries due to the global economic crisis.

• 월간포장계
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• 통권318호
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• pp.65-70
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• 2019

• 월간포장계
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• 통권318호
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• pp.71-76
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• 2019

• 한국식품영양학회지
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• 제26권3호
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• pp.470-475
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• 2013

The objective of this study was to investigate the perceptions and purchase behaviors on foreign matters in food. For that, we conducted a survey of 348 adults living in a metropolitan area. Concern over the presence of foreign matters in food was a lower than that for other harmful factors such as heavy metals, BSE, harmful microbes and so on. 70% of respondents would not take the snack which was detected a rat's head, including the manufacturer's product and similar products with it after the foreign matter incident. In contrast, about of 54% respondents were willing to buy canned tuna after the incident. It is necessary to prepare more detail management and policy on foreign matters in food.

• 한국물환경학회지
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• 제21권5호
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• pp.442-447
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• 2005

Concentrations of aliphatic hydrocarbons in water, particulate matter, and sediment phase were measured at five stations in Gyeongan River. Aliphatic hydrocarbons from $n-C_{10}$ to $n-C_{17}$ were detected in the water phase and they might be originated from not only biogenic hydrocarbons also petroleum hydrocarbon. $n-C_{17}$ aliphatic hydrocarbon and fatty acids were detected in the particulate matter phase. They might be originated from biological sources such as phytoplankton. Short alkane chains from $n-C_{10}$ to $n-C_{13}$ were detected in the sediment phase. They might be originated from sedimentation of biological hydrocarbons decomposed by bacteria or adsorption of petroleum hydrocarbon from the water phase.

• The Journal of Asian Finance, Economics and Business
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• 제8권8호
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• pp.487-496
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• 2021

This study examines the environmental performance of firms in Vietnam and its determinants. The contribution of the paper is on both theoretical and empirical aspects. On the theoretical matter, the research proposes a new index measuring environmental management at the firm level, namely the Environmental Management Index with a clear illustration for the case of Vietnam. On the empirical matter, the study points out and estimates determinants of the corporate environmental performance of Vietnamese firms measured by the newly proposed index. Due to data availability and the impossibility of getting more updated data, the empirical analysis covers only the period from 2004-2009. However, findings are still meaningful because, on the one hand, it provides some evidence for Vietnamese policymakers; on the other hand, with the robust methodology proposed, when more recent data are available, researchers can easily replicate the estimation for more insights. Empirical results show that factors having positive impacts on the environmental performance of Vietnamese firms are profit, capital stock, and interestingly public pressure proxied by the population of the province where the firm is located. Firm ownership does also matter in explaining the corporate environmental performance of Vietnam.