• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1335-1342
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• 2005

In this paper, there is intended to introduce the new tunnel face shape, that is concave shaped face, and discusses its effects on the tunnel stabilization. Therefore, a comparative analysis in which the stability of a concave face was compared to that of a conventional plane face on the basis of displacement patterns in the tunnel face was conducted using a model test. In order to check and confirm displacement patterns on the concave face according to the radius of curvature as well as those around the face according to lateral pressure coefficient(k), two experimental concave models, produced at a scale of 1:2 and 1:5(tunnel radius), of the forefront of the curved area extended from plane face was built and tested.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.245-248
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• 1997

The distilled water is used for the ultrasonic wave propagating material in the measurements of broadband ultrasonic attenuation (BUA) that is applied in industrial and medical applications, The acoustic impedance of water is significantly changed with its temperature. Therefore, the quantitative evaluation of BUA with temperature and the ultrasonic wave propagating distance is highly needed. In this study, we evaluated the variation of attenuation with change in temperature. To measure the variation of BUA in the low frequency region at the temperatures, 27$^{\circ}C$, 29$^{\circ}C$, and 31$^{\circ}C$, we tested the Plyethylene, Teflon, MC-Nylon, Urethane specimens and analyzed the center frequency, frequency bandwidth, spectral peak amplitude. The results showed that BUA value appeared to be lower with increasing temperature. This may be due to the fact that the frequency feature of ultrasonic wave is affected by not only the specific gravity, acoustic impedence, but material crystalline, porosity, the distance of ultrasonic wave propagation in water.

• Structural Engineering and Mechanics
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• v.29 no.6
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• pp.643-658
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• 2008

In this paper, we present a quadratic element model based on non-conforming displacement modes and modified shape functions. This new and refined 8-node hybrid stress plane element consists of two additional non-conforming modes that are added to the translational degree of freedom to improve the behavior of a membrane component. Further, the modification of the shape functions through quadratic polynomials in x-y coordinates enables retaining reasonable accuracy even when the element becomes considerably distorted. To establish its accuracy and efficiency, the element is compared with existing elements and - over a wide range of mesh distortions - it is demonstrated to be exceptionally accurate in predicting displacements and stresses.

• The Magazine for Energy Service Companies
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• s.67
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• pp.24-27
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• 2010

'2010 대한민국 녹색에너지대전'이 지식경제부 주최, 에너지관리공단 주관으로 지난 10월 13일부터 16일까지 4일간 서울 삼성동 코엑스홀에서 개최되었다. 올해로 30번째를 맞이한 대한민국 녹색에너지대전은 그 어느 해보다 의미가 크다고 할 수 있다. 30년이라는 긴 역사에 걸맞게 LG전자 현대중공업 삼성중공업 OCI 효성 등 대한민국을 대표하는 에너지 관련 기업들이 대거 참여하였고, 정부가 2010년까지 온실가스 배출전망량(BAU) 대비 30% 감축하겠다는 목표를 제시함은 물론 그에 맞춰 에너지온실가스 목표관리제가 도입돼 에너지 절약에 대한 관심이 그 어느 때보다 높기 때문이다. 더욱이 올해 처음 개최되는 신재생에너지대전이 함께 열리면서 참가기업이 251개, 총 1,008개 부스로 확대되었고, 에너지 효율 향상에 관한 대표적 프로젝트로 성장하고 있는 ESCO 산업 특별 테마관이 마련되기도 하였다. ESCO 산업 특별 테마관은 국내 ESCO 업체인 삼성에버랜드 LIG엔설팅 금호이엔지 에너지솔루션즈 지멘스 테크윈 등이 직접 참여하여 최신 기술과 정보를 전달하고 관련 상담을 진행하였다. 또한 최근 각광을 받고 있는 LED 고효율 조명관을 특별 조성해 국가 경제의 차세대 성장동력인 친환경 조명기술을 선보이기도 했다.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.3
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• pp.321-324
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• 1994

One hundred and twenty indigenous pigeons of either sexes of different age groups were sacrificed in different seasons to assess the interactions of sex, age and seasons on the proximate composition and gross energy values of fresh boneless meat. The dry matter and protein contents decreased but the fat, ash and energy contents increased linearly as the birds aged. Seasons and age had significant influences on either of these two performance traits. Meat of growing pigeons of both sexes was found to contain high protein and low fat throughout the year.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.2
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• pp.197-200
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• 1994

The study was conducted in the Bangladesh Agricultural University campus, Mymensingh, from July 1988 to June 1990. Five grazing fields consisting of five different vegetations were selected for this study. The specimen were collected from this study. The specimen were collected from the grazing fields by dragging method. The results revealed that two species of ticks namely Boophilus microplus and Haemaphysalis bispinosa were collected from five different vegetation. The highest incidence of both B. microplus and H. bispinosa were recorded during winter season and lowest in Monsoon for the year of 1988-89 and 1989-90. These two species were significantly occurred in Winter followed by Monsoon and Autumn.

• Proceedings of the Korea Society for Simulation Conference
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• 2005.11a
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• pp.77-83
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• 2005

기후변화협약에 의해 탄소세가 부과될 경우 한국의 에너지 집약 산업에 어떠한 영향을 미치며 그에 대한 대응방안이 어떻게 마련되어야 하는지에 대한 관심이 증대되고 있다. 이에 본 연구에서는 탄소세가 부과됨으로 인하여 에너지 다소비 업종인 시멘트산업의 각 에너지원별 사용량에 미치는 파급효과를 시스템 다이내믹스 방법론에 의한 시뮬레이션 모델을 이용하여 분석하였다. 시뮬레이션 모델은 환경모듈, 경제모듈, 에너지모듈로 구성하였고 모델의 예측력 검증을 위해 의태분석을 수행하였다. BAU 시나리오와 탄소세 부과 시나리오를 설정하여 각 시나리오의 총수요의 예측치, 이산화탄소 배출량의 추이, 에너지원의 사용변화를 분석하였다. 본 연구는 향후 기후변화협약의 부담이 큰 에너지 집약산업에 있어서 에너지원의 사용 및 수요를 예측하고 이를 평가하기 위한 지침을 제시할 수 있을 것으로 기대된다.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.181-184
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• 2009

This study aimed at framing alternative urban planning scenarios reflecting urban planning factors, performing urban climate simulation and evaluating eco-friend and low energy characteristics of each scenario on the viewpoint of urban temperature and energy savings on the target of the costal city including Haeundae District in Busan The results are as follows. 1)The fact that urban higher temperature is approximately 2.5 times higher in the building constructed area than whole urban area was represented severe higher temperature phenomenon in the built-up area. Ground greening, water scenario and soil scenario could be expected peek air temperature alleviating effect in order. Especially water scenario had significant effect(maximum $2.5^{\circ}C$) on lowering of air temperature.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.10
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• pp.67-72
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• 2010

G8 summit meeting held in July 2008 decided to set up a long-term goal, by 2050, reducing the world greenhouse emissions by half of those emitted in 1990. In November 2009, the Government announced to reduce the national $CO_2$ emission by 30[%] of BAU by 2020. Electric power industries in Korea produce most of their electricity by burning fossil fuels, and emit approximately 28[%] of national $CO_2$ emissions. Monitoring the $CO_2$ emissions. Monitoring the $CO_2$ emission of electric power plants is very important. This paper presents a method to calculate the hourly $CO_2$ emission for a thermal power plant burning mixture of coal and oil using the performance test data and coal-oil mix rate. An example of $CO_2$ emission calculation is also demonstrated.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.4
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• pp.268-276
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• 2007

Urban atmosphere may play as a harbinger for the future climate change with respect to temperature and $CO_2$ concentration. The Seoul metropolitan area is unique in rapid urbanization and industrialization during the last several decades, providing a natural $CO_2$ dome with increased temperature. This study was carried out to evaluate the feasibility of using the urban-rural environmental gradient in replacement of the IPCC mid-term scenario (after 30-50 years). For this, we measured atmospheric $CO_2$ concentration and air temperature at three sites with different degree of urbanization (Seoul, Suwon, and Icheon). Results from 11-month measurement can be summarized as follows: (1) The annual mean $CO_2$ concentration across 3 sites was in the order of Seoul (439 ppm) > Suwon (419 ppm) > Icheon (416 ppm), showing a substantial urban-rural environmental gradient. (2) The diurnal fluctuation in $CO_2$ concentration was greater in summer than in winter, showing the effect of photosynthesis on local $CO_2$ concentration. (3) The daily maximum $CO_2$ concentration was observed at 0500 LST in spring and summer, 0800 LST in autumn, and 0900 LST in winter, showing the sunrise-time dependence. (4) The observed hourly maximum $CO_2$ concentration averaged for the whole period was 446 ppm in Seoul at 0700 LST, while the minimum was 407 ppm in Suwon at 1500 LST. (5) Compared with the background atmospheric concentration of $CO_2$ in Anmyeon-do (377.4 ppm annual mean), $CO_2$ concentration of the study sites was higher by 14% in Seoul, by 10% in Suwon, and by 9% in Icheon. The observed $CO_2$ concentration in Seoul reached already 98% of the 2030-2040 projection (450 ppm) and 80% of the 2040-2050 projection (550 ppm) under the IPCC BAU scenario, showing a feasibility of using the $CO_2$ dome of Seoul as a natural experimental setting for the mid-term climate change impact assessment.