• Journal of Dental Rehabilitation and Applied Science
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• v.16 no.2
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• pp.105-112
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• 2000

In-Ceram system is one of contemporary esthetic all ceramic restorations and has relatively high flexural strength. The purpose of this study was to evaluate the marginal fit of In-Ceram crown according to shoulder width and measuring position. In this study, twenty seven In-Ceram crowns devided into three groups, each prepared with shoulder width of 0.6mm, 0.9mm and 1.2mm. All specimens were cemented with glass ionomer cement. After cementation, specimens were measured marginal gap between the margin of the In-Ceram crown and the finishing line of resin master die by using a refrective microscope. Marginal gaps were recorded at the labial, lingual, mesial and distal measuring points on the resin master die. The results of this study were as follows: 1. Mean marginal fits of each group were $81.28{\mu}m$ in 0.6mm shoulder width, $70.78{\mu}m$ in 0.9mm shoulder width and $67.75{\mu}m$ in 1.2mm shoulder width. 2. There was significant difference between group 0.6mm and 0.9mm, 1.2mm.(p<0.05). 3. In comparison of marginal fit according to the measuring points, there was no significant difference.

• Journal of the Korean Geosynthetics Society
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• v.16 no.2
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• pp.139-148
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• 2017

Ground subsidence caused by damaged water pipe and sewer is recently increasing due to the aging of city and pipeline in many city. Although many recent studies have verified characteristics of ground subsidence due to wastewater pipe breakdown, research about characteristics of ground subsidence due to water pipe is insignificant. subsidence due to water pipe is insignificant. This study aims to identify the ground failure mechanism caused by water and sewer pipe breakdown. Accordingly, we conducted an indoor model experiment to verify characteristics of ground subsidence considering characteristics of ground and ground failure. The water pipe pressure and velocity head was considered to find out ground subsidence mechanism. Also comparative analysis is conducted by analyzing relative density and fine-grain content considering embedded condition of water pipe. When the relative density and seepage pressure is low, small scale ground subsidence can occur, but when the conditions are opposite, ground subsidence occur in large scale and expands to ground level over time. Furthermore, it is acknowledgeable that ground cavity that is formed after soil run off due to seepage in deep earth, maintains steady strength and stays on the ground level for long period.

• KDI Journal of Economic Policy
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• v.20 no.3_4
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• pp.175-222
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• 1998

본 논문에서는 우리나라 국방예산 운영의 국민경제적 파급효과에 대한 실증분석에 기초하여 국방예산 규모논쟁에 대한 검토, 지출구조의 개선방안, 그리고 지출구조 개성을 위한 국방부문의 효율화 방향을 제시하였다. 실증분석을 위해 Feder-Ram 2부문-외부효과모형에 기초하여 1970년대 이후 총국방비 운영유지비 방위력개선비 등 3가지의 국방부문 지표를 이용한 실증분석 결과, 방위력개선비가 국민총생산에 대해 유의한 정(正)의 효과를 갖는 것으로 나타났다. 총국방비의 경우 유의성이 없었으며, 운영유지비의 경우 유의한 부(負)의 효과를 갖는 것으로 나타났다. 국방예산 규모논쟁과 관련하여, 최근 GDP 대비 국방비 비중과 안보위협을 고려한 국가군별 비교 등을 통해볼 때, 지금까지의 우리나라 국방비규모의 상대적 비중이 하락하는 추세를 더 이상 기대하기는 어렵다고 보는 것이 현실적인 인식이라고 판단된다. 이제 국방예산 관련 논의의 초점은 상대적 규모를 포함하여 국방예산규모 자체보다는 국방예산의 지출구조와 내역에 맞추어져야 하고, 국방예산 운영의 낭비사례를 방지하고 효율성 투명성을 높여서 적절한 지출구조와 배분내역 방식을 이루는 것이 되어야 한다고 판단된다. 국방예산 지출구조의 개선을 위해서 투자비 성격의 방위력개선비 비중을 높이는 예산구조상의 개선이 매우 중요한 과제이다. 이를 위해 각종 경사경비에 대한 영점기준의 검토작업과 더불어 인력과 장비의 대체, 인력구조의 조정 등을 통해 기술집약형 전력구조를 지향하는 보다 근본적인 구조조정노력이 이루어져야 할 것이다. 미래전 양상에 대비한 군 첨단화의 핵심인 해상방위력 및 항공력 증강 등이 필수적이며, 지상군 위주에서 상대적으로 해 공군 중심의 군 구조로 개선되어야 할 것이다. 구조개선의 완급조절과 군별배분의 수평적 구조개선을 통해서 예산규모의 커다란 증대 압력 없이 추진 할 수 있는 구조개선은 시급히 실현되어야 할 것이며, 구조조정 재원의 상당부분은 군 내부의 낭비사례를 막고 생산성을 획기적으로 제고해서 확보할 수 있어야 할 것이다. 국방예산 운영의 효율성 투명성 제고를 위해서는 군 내부 자원관리기능이 강화되어야 하고, 군조직 운영에 있어서도 민간부문에 상응하는 경영효율성 개념의 과감한 도입이 요구된다. 지금까지의 '국방전력 극대화'를 위한 군인중심의 획일적 폐쇄적 군조직 운영에서 벗어나 조직 인사 예산 운영 전반에 걸친 경영혁신이 이루어져야 한다. 국방부문에 경영효율성 개념을 도입하여 경영혁신을 이루어나가는 주요 정책방향은 일부 기능 조직의 민영화 및 민간위탁의 확대, 민간전문인력의 활용도 제고, 자율적 책임경이 필요한 부문을 대상으로 한 "책임경영사업소(Agency)제도"의 도입 등이다. 또한 유사기능을 갖는 조직과 각군별로 별도로 설립되어 중복되는 기능을 수행하는 기관을 통폐합해야 할 것이다.

• Environmental and Resource Economics Review
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• v.20 no.4
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• pp.859-882
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• 2011

Since two oil crises in the 1970s, Korea has actively engaged in overseas E&P projects to increase energy diversity as well as its self-development rate of energy resources. Korea's energy self-development rate, an index that indicates the ratio of resources acquired through overseas development compared to direct imports. Currently, Korea is conducting a total of 180 promising overseas oil development projects in 36 countries as of the end of 2010. By now, it has secured a reserve of around 1.63 billion barrels and production of around 176 thousand barrels of oil per day. The self-development rate for oil rose from 2.8% in 2006 to 7.4% in 2010. Not content with these remarkable successes, the korean government is planning to raise its self-development rate in oil to 25% by 2019, by promoting the active participation of Korean companies in overseas oil development projects. This paper is concerned with estimation of the required amount of government subsidies that includes loans and financial support through state-controlled banking institutions in order to reach the target 25% rate by 2019. The estimation results shows that government subsidies of at least 268 million dollars are needed for the current rate of 7.4% in oil. However, the amount sharply increases up to 1.25 billion dollars in 2019 when domestic oil demand rises to 1.02 billion barrels.

• Environmental and Resource Economics Review
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• v.28 no.4
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• pp.527-556
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• 2019

In Korea, nearly 100 billion won is spent annually under the name of energy voucher on 600,000 households for the last five years, and this is a unique case and hard to monitor worldwide. Therefore, no studies have been conducted to assess impacts of the energy voucher on energy consumption and cost burden alleviation for beneficiaries. This paper aims to demonstrate the effectiveness of energy vouchers in terms of energy expense. The propensity score matching was conducted on samples of low-income households based on the Korea Welfare Panel. Then, simple Difference-In-Differences and Fixed-Effect Difference-In-Differences models were applied to estimate the effect of energy vouchers. In results, the beneficiaries of energy vouchers would spend an additional 4,371~4,870 won per month on energy consumption. The ratio is equivalent to 51.9~57.7 percent of the aid, which is also the highest when compared with 23~56 percent of U.S. Food Stamp. In terms of energy welfare, voucher payment could become one of the best management practices. However, identifying the blind spots as non-reciprocal households and expanding the differential support mechanism that reflects the energy consumption environment should be solved in the future.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.401-404
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• 2010

Researches on prodigies and education for those have recently been progressing in many fields. Education for the gifted, which was basically on Math and Science on the start, now includes Intelligence, Invention, Cultural Sciences, Art, and so on. With the progression towards extremely developed information society, interests in and importance on the courses for the talented get more and more focused. The problem is, however, choosing the gifted and educating them is not an easy matter, since the history of Intelligence Technology is relatively short and it is hard to identify prodigies and categorize what kinds of courses they need. Also, from 2010 "Science Education Institute for the Gifted" freshmen draft, paper-based admission test has been discarded and teacher-recommendation through long-term observation introduced. Therefore needs have been increasing for quality selection methods including observation records, recommendation letters, and portfolios. Reformation on teaching and creative selection methods has been accentuated because of lack of academic base for selecting candidates for education for the gifted. Because of all those mentioned above, reliances for the selection processes during the last three years and the one in 2010, observation records, recommendations and portfolios included, have been analyzed and evaluated. Several factors which can be used instead of paper-based tests were coordinated. Based on it, it was highly possible and has been successful to draft all the applicants in cognitive, sentimental, and creative fields.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.987-994
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• 2015

This study examines how single-person household expenditure patterns are different with respect to age and income groups using Tobit model. The expenditure data of the national household survey from 2006 to 2012 were used. The results show that income elasticities of all items are greater than 1 except for food & beverage, housing, water, electricity & gas, and Communication. Income elasticities are significantly different among consuming items. Additionally the income elasticities are also different between various age and income groups of single-person households. Therefore governments and businesses have to take this into account when devising their policies or strategies regarding single-person households. Especially, businesses need to adopt a strategy targeted at single-person households with high income and buying power such as unmarried professional people. As the number of single-person household increases the proportion of expenditures on necessities such as beverage, food, and energy is expected to decrease while that on services increases. Consequently policy responses are required to prepare for the expansion of service industries such as health, hospital, and housekeeping services.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.2
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• pp.1126-1139
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• 2014

World is experiencing abnormal weather caused by urbanization and industrialization increasing greenhouse gas and one of these phenomenon domestically happening is flood and drought. The increase of green-house gases is due to urbanization and industrialization acceleration which are causing abnormal climate changes such as the El Nino and a La Nina phenomenon. It is expected that there will be many difficulties in water management, especially considering the topography and seasonal circumstances in Korea. Unlike in the past, a variety of water conservation initiatives have been undertaken like the river-management flow and water capacity expansion projects. To meet the increasing demand for water resources, new environmentally-friendly small and medium-sized dams have been built. Therefore, the development of a new paradigm for water resources management is essential. This study shows that additional security is needed for potential water resources through diversion tunnels and is very important to consider for future water supplies and situations. Using RCP 6.0 and RCP 8.5 in representative concentration pathway climate change scenario, specific hydrologic data of study basin was produced to analyze past observed basin rainfall tendency which showed both scenario 5%~9% range increase in rainfall. Through sensitivity analysis using objective function, population in highest goodness was 1000 and cross rate was 80%. In conclusion, it is expected that the results from this study will help to make long-term and stable water supply plans by using the potential water resource evaluation model which was applied in this study.

• The Transactions of the Korea Information Processing Society
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• v.6 no.12
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• pp.3447-3455
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• 1999

Database correctness is guaranteed by standard transaction scheduling schemes like two-phase locking for the context of concurrent execution environment in which short-lived ones are normally mixed with long-lived ones. Traditional syntax-oriented serializability notions are considered to be not enough to handle in particular various types of transaction in terms of duration of execution. To deal with this situation, altruistic locking has attempted to reduce delay effect associated with lock release moment by use of the idea of donation. An improved form of altruism has also been deployed in extended altruistic locking in a way that scope of data to be early released is enlarged to include even data initially not intended to be donated. In this paper, we first of all investigated limitations inherent in both altruistic schemes from the perspective of alleviating starvation occasions for transactions in particular of short-lived nature. The idea of two-way donation locking(2DL) has then been experimented to see the effect of more than single donation in distributed database systems. Simulation experiments shows that 2DL outperforms the conventional two-phase locking in terms of the degree of concurrency and average transaction waiting time under the circumstances that the size of long-transaction is in between 5 and 9.

• Journal of Korean Society of Transportation
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• v.35 no.3
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• pp.169-182
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• 2017

This research reviews regulations on logistics/transport industry and attempts to quantify the effects of regulation mitigation on GDP per capita. South Korea's transport industry has been gradually expanding, however, the industrial structure is still short rooted. In 2014, average number of hours worked is 5th highest and wage margin 12th smallest out of 18 industries. Furthermore, the regulations for this industry appear to be stricter than those of other industries. OECD's logistics/transport industry regulatory index for South Korea has been decreasing for the last 40 years but still exceeds those of EU, Japan, US, and other countries. This paper provides supporting reasons for regulatory reforms by analyzing the ripple effects on real GDP. Factors such as the ratio of trade among GDP, the enrollment rate to primary school, energy usage per capita, and population are controlled in the fixed-effect model. Estimation results showed that 1 unit decrease in transport/logistics regulatory index is correlated with 8.1% increase of the real GDP per capita, that is, 10% of deregulation is expected to yield 2.16% increase in GDP per capita. Thus, it is expected that mitigating regulations on market entries, price determination, ownership structures of network industry, vertical integrations can improve the economy of South Korea.