• Ocean and Polar Research
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• 제23권4호
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• pp.419-424
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• 2001

The Antarctic clam Laternula elliptica, is one of the most representative benthic invertebrates in the Antarctic nearshore waters. Endemic to the Antarctic, L. elliptica is widely distributed around the Antarctica occurring as dense patches in shallow sheltered areas and exhibits high biomass. Despite its apparent ecological importance, L. elliptica has rarely been studied until recently probably due to difficulties in sampling in the ice-impacted waters. Recent studies have revealed various aspects of its ecology and physiology. In this review, some physiological and ecological characteristics of this species are discussed in relation to some prevailing features of its habitat environment, in particular physical instability of habitat substrates and extreme seasonality of food availability.

• 한국소음진동공학회논문집
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• 제25권5호
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• pp.321-328
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• 2015

최근 극지 선박의 수요가 늘어나고 있고 IACS(국제선급연합)에서는 대빙 선박에 대한 새로운 기준이 적용되고 있다. 이 선박에서는 추진시스템에 대한 대빙 설계 기준으로 빙 충격 토크는 프로펠러 날개 수를 중심으로 한 조화 함수로 규정되어 있다. 그러나 실 상황에서는 이러한 주기적인 기진 토크보다는 불규칙한 빙의 충격 토크가 발생할 수 있는 확률이 오히려 크다. 이 논문에서는 비틀림진동이 비교적 큰 6개의 실린더를 갖는 디젤엔진을 주 기관으로 한 추진시스템의 안정성을 검토하고자 한다. 특히 불규칙한 빙 충격 토크와 디젤엔진에서 발생하는 진동토크를 동시에 고려하여 비틀림진동의 공진점을 통과할 과도 비틀림 진동 응답을 이론적으로 해석하였다. 여기서 빙 충격토크는 빙이 프로펠러에 부딪칠 때를 여러 유형별로 가상하여 선급에서 규정된 방법에 의해서 구하였다. 전체적인 시스템의 과도응답 해석은 직접적분방법의 하나인 뉴마크(Newmark) 법을 이용하였다.

• Asian review of World Histories
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• 제1권1호
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• pp.85-116
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• 2013

The theory of terrestrial impact which has been developed by the astronomy scientists since 1970s is employed for this article in a new angle that atmospheric conditions of our planet should be adopted in the interpretation of the history of mankind. Large and small terrestrial impacts must be acknowledged as key tasks in terms of the study of 'world history'. The Society of Interdisciplinary Studies has already advocated that the 'Bronze Age Civilization' was strongly influenced by the long term terrestrial impact phenomena. Based on historical materials from Korea, the present study was able to identify the years 680-880, 1100-1220, 1340-1420, and 1490-1760 as periods in which territorial impacts occurred.

• Asia-Pacific Journal of Atmospheric Sciences
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• 제54권4호
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• pp.587-598
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• 2018

The impacts of aerosol loading on surface precipitation from mid-latitude deep convective systems are examined using a bin microphysics model. For this, a precipitation case over north central Mongolia, which is a high-altitude inland region, on 21 August 2014 is simulated with aerosol number concentrations of 150, 300, 600, 1200, 2400, and $4800cm^{-3}$. The surface precipitation amount slightly decreases with increasing aerosol number concentration in the range of $150-600cm^{-3}$, while it notably increases in the range of $600-4800cm^{-3}$ (22% increase with eightfold aerosol loading). We attempt to explain why the surface precipitation amount increases with increasing aerosol number concentration in the range of $600-4800cm^{-3}$. A higher aerosol number concentration results in more drops of small sizes. More drops of small sizes grow through condensation while being transported upward and some of them freeze, thus increasing the mass content of ice crystals. The increased ice crystal mass content leads to an increase in the mass content of small-sized snow particles largely through deposition, and the increased mass content of small-sized snow particles leads to an increase in the mass content of large-sized snow particles largely through riming. In addition, more drops of small sizes increase the mass content of supercooled drops, which also leads to an increase in the mass content of large-sized snow particles through riming. The increased mass content of large-sized snow particles resulting from these pathways contributes to a larger surface precipitation amount through melting and collision-coalescence.

• 대기
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• 제28권2호
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• pp.153-162
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• 2018

The statistical prediction model for wintertime surface air temperature, that is based on snow cover extent and Arctic sea ice concentration, is updated by considering $El-Ni{\tilde{n}}o$ Southern Oscillation (ENSO) and Quasi-Biennial Oscillation (QBO). These additional factors, representing leading modes of interannual variability in the troposphere and stratosphere, enhance the seasonal prediction over the Northern Hemispheric surface air temperature, even though their impacts are dependent on the predicted month and region. In particular, the prediction of Korean surface air temperature in midwinter is substantially improved. In December, ENSO improved about 10% of prediction skill compared without it. In January, ENSO and QBO jointly helped to enhance prediction skill up to 36%. These results suggest that wintertime surface air temperature in Korea can be better predicted by considering not only high-latitude surface conditions (i.e., Eurasian snow cover extent and Arctic sea ice concentration) but also equatorial sea surface temperature and stratospheric circulation.

• 한국초지조사료학회지
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• 제28권2호
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• pp.129-138
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• 2008

Demand for alternatives to petroleum is increasing the production of biofuels from food crops such as corn, soybeans, sorghum and sugarcane, etc. At least for the next 5 years, ethanol demand will be increased greatly in the United States and in the world. Presently, most ethanol produced in the United States is corn (Zea mays) ethanol. As a result, especially in the Americas and Southeast Asia, agricultural land is diverted to biofuel production. Even though biofuel industry has many advantage including national security, economical, energetical and sustainable impacts, it is driving grain prices up and creating considerable concern about the potential negative impacts on a wide range of food products that depend on gain : chicken, pork, beef, and dairy products such as milk, cheese, yoghurt, cream and ice cream. Feedstock crops are crops such as switchgrass(Panicum virgatum, L.), corn stover and grasses that can be used in industrial processes such as fermentation into alcohol fuels. Feedstock is no compete with food. Furthermore it is friendly environmental bioenergy crops. In Korea, with increasing demand for fossil fuels the exploration of alternative sources of liquid fuel is inevitable. I suggest Korea need to research and to develop actively on feedstock for biofuel production through this review.

• East Asian Economic Review
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• 제18권4호
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• pp.425-461
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• 2014

This paper analyzes the impact of the Canada-Korea Free Trade Agreement on the basis of the published text and agreed schedule of commitments. We find that the Agreement reinforces existing patterns of comparative advantage between Canada (agriculture and resource-based sectors) and Korea (autos and other industries). The sensitive sectors that held up the deal for years - autos into Canada and beef into Korea - witness major trade gains, but are not unduly disrupted. In both economies, the major output gains otherwise come in non-traded services sectors, driven by income effects. We find that trade diversion effects are quite significant; this lends support for the domino theory of major free trade agreements - since the Korea-EU agreement broke the ice, the pressure has intensified on third parties to re-level playing fields by striking their own deals. The study breaks new ground in modelling services trade by developing policy impacts based on the extent to which the text of the Agreement modifies Korea's and Canada's scores on the OECD's Services Trade Restrictiveness Index and by providing estimates of Mode 3 Services trade impacts. The analysis of the Agreement as negotiated, the present study, in our view, is a step forward in understanding the impact of modern free trade agreements.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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• pp.253-256
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• 2006

This paper shows the study on application of the law temperature energy in the deep seawater. Deep, cold seawater has long been recognized as a valuable ocean energy resource. Recently, research and experimentation has been conducted on energy systems using deep seawater: deep seawater air conditioning system, ice-making device, salt and fresh-water manufacturing system and the Spray freeze drying system for extracting valuable material of the deep seawater. They are technically and economically feasible today: once installed, the energy is inexhaustible and there are no adverse environmental impacts. Because of the economy of scale in the air conditioning system, the seawater A/C system is most appropriate for supplying multiple buildings or hotels in a coastal area.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.226-229
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• 2006

Use of deicing chemicals has been and will continue to be a major part of highway snow and ice control methods. Chloride-containing chemicals such as calcium chloride or rock salt are main deicers for the road. Extensive use of chloride deicers is, however, not only the source of substantial cost penalties due to their corrosive action and ability to deterioration roadway surface materials but also the source of environmental damages. Finding the deicing chloride agents impacts on the environment and develop the minimizing strategies, we evaluated that chloride deicing agents influence on highway roadside soil and establish the optimun strategies.

• 자원ㆍ환경경제연구
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• 제25권2호
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• pp.321-349
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• 2016

2015년은 기후관측이 시작된 이래 평균기온이 최고치를 기록한 해이다. 특히 북극은 어느 지역보다도 빠른 속도로 온난화가 진행되고 있어, 빙하가 계속 감소추세에 있다. 이러한 북극의 급격한 기후변화는 해수면의 상승은 물론 북극의 생태계 균형까지 위협할 뿐만 아니라 한국을 비롯한 중위도권 겨울한파의 원인으로 지목되고 있다. 생물다양성은 기후변화-생태시스템의 복잡한 상호관계를 함축적으로 나타내는 생태학적 개념으로, 본 논문에서는 이를 북극에 적용하여 북극이 보유하고 있는 생물다양성에 대한 경제적 가치를 대한민국 시민을 대상으로 조건부가치추정 방식을 시도하였다. 분석 결과, 북극 생물다양성 개선을 통해 대한민국 시민이 얻는 총 편익은 최소 연간 3,186억 원에서 최대 7,159억 원 정도인 것으로 추정되었다. 본 연구는 생물다양성에 대한 속성을 세부적으로 분류하는데 의도가 있는 것이 아니라 기후변화에 따라 훼손될 우려가 있는 북극의 생태계 전반에 대한 가치평가에 그 목적이 있다. 따라서 북극이 제공하는 생태서비스와 생물다양성을 각기 다른 속성으로 구분할 경우 그 경제적 가치는 본 연구에서 제시하는 편익과 상이할 수 있다.