• Journal of Distribution Science
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• v.12 no.4
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• pp.31-39
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• 2014

Purpose - This study investigates the following two issues. First, we attempt to find the important determinants of housing investment and to identify their significance rank using survey panel data. Recently, the expansion of global uncertainty in the real estate market has directly and indirectly influenced the Korean housing market; households demonstrate a sensitive reaction to changes in that market. Therefore, this study aims to draw conclusions from understanding how the impact of financial strength of the household is related to house investment. Second, we attempt to verify the effectiveness of diverse indices of financial strength such as DTI, LTV, and PIR as measures to monitor the housing market. In the continuous housing market recession after the global crisis, the government places top priority on residence stability. However, the government still imposes forceful restraints on indices of financial strength. We believe this study verifies the utility of these regulations when used in the housing market. Research design, data, and methodology - The data source for this study is the "National Survey of Tax and Benefit" from 2007 (1st) to 2011 (5th) by the Korea Institute of Public Finance. Based on this survey data, we use panel data of 3,838 households that have been surveyed continuously for 5 years. We sort the base variables according to relevance of house investment criteria using the decision tree model (DTM), which is the standard decision-making model for data-mining techniques. The DTM method is known as a powerful methodology to identify contributory variables for predictive power. In addition, we analyze how important explanatory variables and the financial strength index of households affect housing investment with the binary logistic multi-regressive model. Based on the analyses, we conclude that the financial strength index has a significant role in house investment demand. Results - The results of this research are as follows: 1) The determinants of housing investment are age, consumption expenditures, income, total assets, rent deposit, housing price, habits satisfaction, housing scale, number of household members, and debt related to housing. 2) The impact power of these determinants has changed more or less annually due to economic situations and housing market conditions. The level of consumption expenditure and income are the main determinants before 2009; however, the determinants of housing investment changed to indices of the financial strength of households, i.e., DTI, LTV, and PIR, after 2009. 3) Most of all, since 2009, housing loans has been a more important variable than the level of consumption in making housing market decisions. Conclusions - The results of this research show that sound financing of households has a stronger effect on housing investment than reduced consumption expenditures. At the same time, the key indices that must be monitored by the government under economic emergency conditions differ from those requiring monitoring under normal market conditions; therefore, political indices to encourage and promote the housing market must be divided based on market conditions.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.84.2-84.2
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• 2015

Growing market of electric vehicles such as hybrid, plug-in hybrid, and bare electric vehicles in the world is accelerating the significance of Li-ion batteries as a renewable green energy. According to such market flow, the developing components such as cathode, anode, electrolyte, and separator, composing the Li-ion batteries, is significantly important tasks for the commercialization. In particular, development of the cathode material having high capacity and stable thermal stability is essential for long-distance electric vehicle in the near future. Herein we introduce various applications of Li-ion batteries such as portable electronics, electric vehicles, and energy storage system, and also its research trend, in particular on the cathode materials.

• ETRI Journal
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• v.30 no.3
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• pp.469-479
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• 2008

This study analyzes factors affecting the competitiveness of broadband over power line communication (BPLC) and predicts demand for the service, based on quantitative information about consumer preferences drawn from a survey of Korean consumers. Findings from the estimation suggest that, although consumers value some beneficial features of BPLC, to be competitive the speed and stability of its data transmission needs to be improved. Moreover, on the basis of a market simulation, we expect BPLC to occupy only a small portion of Korea's Internet access market in the future, a finding we expect would hold true for other developed countries whose Internet access markets are already mature.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2004.11a
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• pp.367-371
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• 2004

Bio-degradable hydraulic oil using polyolester base oil is formulated for the applications of heavy duty hydraulic machineries. It has proved quality and market price competitiveness by assessment of reliability test in vehicle manufacturer and specific vehicle related institute. Contribution of bio-degradable oil keep the working environment clean and increase export competitiveness in European market. Leakage or waste of mineral types of hydraulic oils in heavy duty machineries causes pollution of river, ocean, underground water. Drinkable-water pollution is serious problem in Europe. In some European countries, using bio-degradable hydraulic oils become an obligation in heavy duty machineries. New product of bio-degradable oils satisfy the European regulations(OECD 302B) and shows excellent performance in compare with European products.

• 한국태양에너지학회:학술대회논문집
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• 2008.11a
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• pp.21-24
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• 2008

In this paper, we introduce the status of concentration photovoltaic system. Currently, crystalline silicon solar has 90% of total solar market. But in a few years, the concentration solar system is expected to be main one because cost increasement of silicon material is not stabilized unit now. At 2012, it will take 5% of the whole solar market. Less expensive, material requirement and high system efficiency give high driving force for intensive research on concentration system. It is time for us to initiate the basic study and evaluate the long term stability compared to crystalline silicon system. The detail discussion will be shown in the following paper.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.580-583
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• 2008

As the construction of renewable energy generators is on the rise and gets bigger in size, researchers pay more and more attention to the impact of such facilities on the power market as well as on the stability of power grid system. In Korea, while studies on the latter, including calculating the marginal capacity of renewable energy generators, is being made, those on the former has not yet been performed. As such, this paper analyses the impact of a big renewable energy generators on the price and transaction cost of domestic power market and proposes ideas to minimize such influence by applying the technology of forecasting renewable energy.

• Journal of Food Hygiene and Safety
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• v.12 no.1
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• pp.47-54
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• 1997

Fried vegetable mix, fried fish mix and fried chicken which prepared as convenient style at traditional market in Chonju were collected and evaluated their chemical composition, lipid and microbial changes during storage at different temperaturefor confirming those fried food stability. The POV and AV of oil in samples and total bacterial count during storage at 5, 15, 20 and 3$0^{\circ}C$ were monitered. The POV, AV and total bacterial count tested of each sample, shelf-life can be suggested as within 1 day at 3$0^{\circ}C$, 2~3 days at 15~2$0^{\circ}C$ and over 5 days at 5$^{\circ}C$.

• Journal of Korea Technology Innovation Society
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• v.8 no.3
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• pp.1060-1086
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• 2005

In this paper, we attempt to predict the future of broadband access market where new convergence access technologies and additional services are introduced, based on consumer preferences. Conjoint analysis and mixed logit model is used for estimation, From the results, consumers value convergence access technologies such as PLC and wireless LAN, and TV-related service, However, valuation on new beneficial features of convergence access technologies is not enough to overcome their technological inferiorities in data transfer speed and quality stability at current technological stage, Additionally, consumer preferences are so heterogeneous that differentiated business strategies are required, Finally, some managerial and policy implications are presented.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.612-614
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• 2003

현재 시행 중인 부하관리 프로그램들은 거의 대부분 간접부하관리 방식에 의존하고 있으며, 이러한 간접부하관리 프로그램들은 요금혜택에 기반을 두고 있다. 직접부하관리가 우리나라에 도입된 것은 2001년 5월이며, 이러한 직접부하관리 프로그램은 간접부하관리 프로그램에 비하여 다음과 같은 다양한 장점을 가지고 있다. 1) 부하관리 자원의 이용 가능성(availability)이 간접부하관리에 비하여 상대적으로 높다는 것과, 2) 기존의 간접부하관리 프로그램에서의 성과계량, 즉, 부하관리 실시에 따른 피크 수요감소량을 명확하게 알 수 있으므로 전력회사가 장단기 수급계획을 수립하는데 보다 확실하게 이를 고려할 수 있다는 것과, 3) 부하차단의 주체가 전력회사가 되므로 간접부하관리 방식이 안고 있는 수용가 부하차단의 불확실성이 낮아지며, 4) 궁극적으로 비용효과가 간접부하관리보다 큰 유용한 자원이다. 본 논문에서는 이러한 직접부하제어자원의 개요와 전력시장 참여 현황 및 해외사례를 소개하고자 한다.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.134-136
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• 2003

The deregulated electricity market is operated with respect to theory of economical efficiency, and therefore, the system operator requires data with fast contingency ranking for security of the bulk power system. This paper compares the weather dependant probabilistic risk index(PRI) with the system performance index for power flow in the IEEE-RBTS. also, the system performance index for power flow presents the power system stability. The probabilistic risk index can be classified into normal weather and adverse weather. This paper proposes calculation method using the probabilistic risk index in determining contingency ranking requiring for security under the deregulated electricity market.