• International Journal of Concrete Structures and Materials
• /
• 제11권2호
• /
• pp.215-228
• /
• 2017

A new approach for measuring the specific fracture energy of concrete denoted modified disk-shaped compact tension (MDCT) test is presented. The procedure is based on previous ideas regarding the use of compact tension specimens for studying the fracture behavior of concrete but implies significant modifications of the specimen morphology in order to avoid premature failures (such as the breakage of concrete around the pulling load holes). The manufacturing and test performance is improved and simplified, enhancing the reliability of the material characterization. MDCT specimens are particularly suitable when fracture properties of already casted concrete structures are required. To evaluate the applicability of the MDCT test to estimate the size-independent specific fracture energy of concrete ($G_F$),the interaction between the fracture process zone of concrete andthe boundary of theMDCTspecimens at the end of the test is properly analyzed. Further, the experimental results of $G_F$ obtained by MDCT tests for normal- and high-strength self-compacting concrete mixes are compared with those obtained using the well-established three-point bending test. The procedure proposed furnishes promising results, and the $G_F$ values obtained are reliable enough for the specimen size range studied in this work.

• 한국가구학회지
• /
• 제20권5호
• /
• pp.431-439
• /
• 2009

When we look at the pattern techniques of wooden furniture in the 19th century Joeson Dynasty, we see that furniture patterns in the main living room were showy and colorful while furniture patterns in the library room, where noble men used to study, were natural and moderate, retaining the actual color of the material without any artificial coloring. Even the serial patterns in the Hwe-Jang technique, Which were used rarely, used moderate techniques. such as weaving in patterns with colorless woods - willow and black persimmon ets. - rather than using excessive techniques. However, considering the marquetry&intarsia technique of ceramic and the silver string intarsia technique of metal then current, wood work must also have been technically advanced. Korean modern wood furniture needs remedies to improve the standard of sound wood work techniques. This study shows that pattern unit production, composition techniques, and color effects etc. Using colored patterns bars, by improving the pattern composition techniques of Marquetry&Intarsia, can be substituted for the production logic of modern manufactured furniture.

• Clinical and Experimental Reproductive Medicine
• /
• 제40권3호
• /
• pp.122-125
• /
• 2013

Objective: The majority of embryo transfers (ETs) to date have been performed on day 3 to reduce the potential risk of developmental arrest of in vitro cultured embryos before ET. Development of sequential media has significantly improved culture conditions and allowed blastocyst transfer on day 5. While day 5 ET provides higher clinical pregnancy outcomes with reduced risks of multiple pregnancies, it still has potential risks of developmental arrest of IVF embryos. The aim of this study was to evaluate the clinical outcomes of day 4 ETs and compare the efficacy of day 4 ET with day 5 ET. Methods: From 2006 to 2009, a total of 747 fresh IVF-ET cycles were retrospectively analyzed (day 4, n=440 or and day 5, n=307). The cycles with any genetic factors were excluded. The rates of matured oocytes, fertilization, good embryos, and clinical pregnancy of the two groups were compared. The chi-square test and t-test were used for statistical analysis. Results: There were no significant differences between the two groups with respect to the mean age of the females and rates of matured oocytes. The pregnancy outcomes of day 4 ET (40.7%) were similar to those of day 5 ET (44.6%). The implantation rate of day 5 ET (24.2%) was significantly higher than that of day 4 ET (18.4%) (p=0.003). Conclusion: Day 4 ET can be chosen to avoid ET cancellation in day 5 ET resulting from suboptimal circumstances in the IVF laboratory, but the decremented quality of embryos for transfer and the decreased pregnancy rate must be taken into consideration.

• 항공우주기술
• /
• 제3권1호
• /
• pp.134-142
• /
• 2004

본 논문은 일본의 정지궤도 위성개발에 대한 조사 보고서이다. 1950년대부터 일본정부의 의욕적인 우주개발 덕분에, 일본은 많은 어려움을 극복하면서 1970년 일본 최초의 위성인 오수미를 발사하여 세계에서 네 번째로 자국 발사체로 위성을 성공적으로 발사하는 국가가 되었다. 그 이후 지속적인 기술축적이 이루어져 우주개발 선진국으로서의 위치를 유지하고 있다. 일본은 2003년 말까지 18기의 과학위성, 7기의 기술시험위성, 5기의 기상위성, 및 수많은 통신방송위성 등을 포함하여 총 97기의 위성을 궤도에 진입시킴으로써, 세계에서 3번째로 많은 위성 보유국이 되었다. MELCO사가 2003년 6월 Optus C1위성을 호주의 Sing Tel Optus사에 성공적으로 납품함으로써, 일본은 국제 정지궤도위성 시장에서 경쟁할 능력을 갖추었다.

• Asian Journal of Innovation and Policy
• /
• 제9권1호
• /
• pp.1-11
• /
• 2020

In 2015, the State Council of South Korea finalized its goal to reduce greenhouse gas emissions by "37% from the business-as-usual (BAU) level" by 2030 across all the economic sectors. Of that reduction, 4.5% will be achieved overseas by leveraging Emission Trading Systems (ETS) aided by international cooperation. In line with this, considering both the demand for and supply of the carbon market increased after the Paris agreement, the importance of public diplomacy in negotiating climate change actions also rose. This study aimed to analyze the impact of international discussions such as the United Nations Framework Convention on Climate Change (UNFCCC) on domestic policies and the types of public diplomatic climate change policies pursued by different government agencies, and draw implications from them. This study attempted to find implications from the Korean government's public diplomacy on climate change for developing countries. Lessons learned regarding Korea's public diplomacy would provide a practical guidance to the Asian developing countries, which are suffering from environmental crisis at a phase of rapid economic growth.

• 한국환경과학회지
• /
• 제19권2호
• /
• pp.255-260
• /
• 2010

A stabilization/solidification (S/S) process for lead (Pb) contaminated soils was evaluated using waste cow bone containing apatite like compounds. Soil samples obtained form firing range were treated with waste cow bone. The effectiveness of stabilization was evaluated based on the Korean Standard Leaching Test (KSLT) and soil pH. The leached concentration reduced with increased in dose of waste cow bone. Overall, the KSLT results showed that Pb concentration in soils are significantly affected by amount of waste cow bone. When soil amended with 20 % of waste cow bone, less than 0.1 mg/kg was leached, and soil pH was increased from 6.5 to 8.4. Same results were obtained when finer waste cow bone was applied. The reachable concentration of Pb in soil showed in inversely proportional to solid/liquid ratio. Aging periods indicate improving mix design was applied. Relatively high lead concentrations was observed at the first 1 days, however leaching profile are reduced significantly over time for all mix designs.

• 통상정보연구
• /
• 제10권2호
• /
• pp.305-323
• /
• 2008

Climate change is one of the broadest and the most complex issues of international environmental cooperation. Concern about climate change has been steadily increasing and has become a worldwide issue. According to IPCC(Intergovernmental Panel for Climate Change)'s recently report, global warming has accelerated vest serious problems. GHG(Green House Gas) emissions trading schemes, including the Kyoto mechanism that spread to solving the problems. Based on the evaluation on GHG emissions trading schemes, we also find some policy implications on the future development of emissions trading the conventional air pollutants in Korea which start to 2007. The regulatory authority needs to make clear how to allocate allowances to new entrants and also to keep the balance between the opportunity costs of reduction between potential shutdown facilities and new entrants. Under the current rule that does not allow shutdown credits, an equivalent level of allowances needs to be allocated to new entrants free of charge. We believe our policy recommendations may be useful not only for Korea but also for a the other countries, since they are facing a similar policy environment as Korea, particularly in the case of climate change.

• 한국항공운항학회지
• /
• 제20권2호
• /
• pp.32-38
• /
• 2012

The United Nations (UN) has tried to make international agreement to restrict artificial greenhouse gas emissions and the UN has concluded the UN Framework Convention Climate Change (UNFCCC) and the Kyoto protocol. Moreover, in 2012, the European Union announced that they will enforce the Directive 2008/101/EC. Therefore, after 2012, aircraft carriers that depart or arrive from EU will follow that regulation. For these reasons, Korea should prepare systematic and effective policy to reduce greenhouse gas emission from aviation activities. The purpose of this study is to find out effective measures to reduce greenhouse gas emission from aviation activities through research by countries all over the world. Here are the 4 measures to reduce greenhouse gas emission from Aviation activities that were found through research UK and Japan's policies. First, Korea should implement aggressive incentive policies. Providing proper incentive can attract voluntary participation of aircraft carriers to reduce greenhouse gas emission. Second, the government should adopt environmental tax on use of fossil fuels. Third, Korea should adopt the greenhouse gas Emissions Trading Scheme (ETS). Lastly, the Korea government should pull in with the international community to establish world-wide environmental policies.

• 대기
• /
• 제21권1호
• /
• pp.1-16
• /
• 2011

Numerical prediction capability has been improved over the decades, but progress of prediction for high-impact weather (HIW) was unsatisfactory. One reason of low predictability for HIW is lack of observation data. The National Institute of Meteorological Research (NIMR) has been performed observation program for improvement of predictability, and reduction in social and economical cost for HIW. As part of this observation program, summer intensive observation program (ProbeX-2009) was performed at the observation-gap areas from 25 August to 6 September 2009. Sounding observations using radiosonde were conducted in the Gisang2000 research vessel (R/V) from the Korea Meteorological Administration (KMA) over the West Sea and the Eardo R/V from the Korea Ocean Research and Development Institute (KORDI) over the South Sea. Observation System Experiment (OSE) is carried out to examine the effect of ProbeX-2009 data. OSEs using Korea Local Analysis and Prediction System (KLAPS) and Weather Research and Forecasting (WRF) Model are conducted to investigate the predictability for a short time forecast. And, OSEs using WRF/3DVAR system and WRF forecast model are conducted to study the predictability for an extended time. Control experiment (K_CTL and CNTL) used only GTS observation and experiment (K_EXP and SWEXP) used ProbeX-2009 data from two system are performed. ETS for 3hr accumulated rainfall simulated by KLAPS-WRF shows that K_EXP is higher than K_CTL. Also, ETS for 12hr accumulated rainfall of SWEXP from 3DVAR-WRF is higher than CNTL. The results indicate that observation over the ocean has positive impact on HIW prediction.

• 벤처창업연구
• /
• 제10권2호
• /
• pp.11-16
• /
• 2015

본 연구에서는 조직 내 생산부문에서 전개되는 혁신활동에 대한 최고경영자 및 구성원의 관심과 참여가 궁극적으로 기업경영성과에 어떤 영향을 미치는지를 구조방정식을 적용하여 살펴보고자 한다. 이를 바탕으로 기업 내 혁신활동의 성공을 위한 실천적인 방안을 찾고, 많은 기업에서 공유함으로써 보다 효율적인 혁신활동을 전개할 수 있도록 지원하기 위함이다. 본 연구는 중소기업 277개사를 대상으로 한 설문조사를 바탕으로 이루어졌으며, 수집된 설문자료는 데이터의 신뢰성과 타당성을 검토한 후 구조방정식을 이용한 모형의 설계 및 검증 과정을 통해 진행하였다. 그 결과 경영자에 의한 비전제시와 혁신활동지원 등에 대한 확고한 의지표명이 조직구성원 입장에서 혁신활동의 토대가 되는 교육 및 소집단활동, 제안활동 참여에 적극 가담하도록 영향을 미치고 있을 뿐만 아니라, 혁신활동의 성과 제고에도 유의한 영향을 미치는 것을 확인하였다. 또한 작업자의 교육 및 활동 참여의지가 혁신활동성과에 직접적인 영향을 끼치는 것도 확인할 수 있었으며, 결과적으로 매출액 증대, 영업이익률 증대, 원가절감 등과 같은 기업의 경영성과에도 긍정적인 작용을 하고 있음을 알 수 있다.