• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 가을 학술논문 발표대회
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• pp.171-172
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• 2022

This study aims to develop the hydration heat reducing material (powder type) to lower the heat of hydration of mass members in the extremely hot weather condition. In this study, we applied the developed material to the concrete that used two kinds of binders with cement and evaluate the concrete properties with it.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.140-141
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• 2022

CFD analysis was performed to analyze the temperature distribution of the inner space of the curing house according to blocking the opening of the gang-form with a tent in case of concrete pouring and heat curing of the apartment house during the winter season. If the gang-form opening is closed with a tent during internal heating using a hot air blower in the winter, the internal temperature rises compared to the non-reserved due to air-tightness of the curing spaces, and uniform temperature distribution can be ensured. In addition, it is possible to increase curing efficiency by reducing the amount of heat supplied and shortening the heating time.

• 대한수의학회지
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• 제63권2호
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• pp.10.1-10.5
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• 2023

A 6-month-old female Border Collie presented with a history of collapse after strenuous exercise. The dog was normal between episodes but experienced loss of focus and ataxia after exercise. This is particularly noticeable under hot weather conditions. No remarkable findings were observed in the diagnostic tests. Based on these results, the patient was tentatively diagnosed with Border Collie collapse (BCC). After exercise restriction, the dog had no episode of collapse and remained clinically well with no signs until the follow-up period of 8 months was complete. To our knowledge, this is the first case report of BCC in South Korea.

• 한국산학기술학회논문지
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• 제14권9호
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• pp.4602-4609
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• 2013

온도차가 극심한 하절기와 동절기 콘크리트 타설의 경우 각종 균열의 발생, 콘크리트 품질불량, 내구성 및 강도저하 등 다양한 문제를 야기 시키고 있다. 특히 원전콘크리트의 경우 대량의 타설로 인한 4계절 연속시공이 이루어져 서중환경에서 콘크리트 품질관리에 많은 문제점이 발생되고 있는 실정이다. 이에 본 연구에서는 서중환경에서 많이 사용되어지는 프리쿨링 공법 중 배합수 냉각방법과 지연제 사용이 원전콘크리트의 특성에 미치는 영향을 검토하였다. 배합수 냉각방법은 냉수 $5^{\circ}C$와 Ice Flake 50% 치환사용 하였으며, 지연제 사용에 따른 원전콘크리트의 굳지 않은 콘크리트 및 경화 후 콘크리트의 특성을 검토하였다. 굳지 않은 콘크리트 특성으로는 슬럼프, 공기량, 응결시간 및 경화 후 압축강도를 측정하였으며, 단열거푸집을 제작하여 손실되는 열을 최소화시켜 각 온도조건하에서 수화열을 측정하였다. 실험결과, 슬럼프 및 공기량 경시변화 종료시간은 $20^{\circ}C$에서 120분, $40^{\circ}C$에서 40분으로 나타났으며, 관입 저항에 의한 응결시간은 배합수 냉각방법 및 지연제 사용 모두 초결과 종결을 지연시키는 것으로 나타났으나, 외기온도가 상승할수록 지연폭은 감소하는 것으로 나타났다. 수화열은 배합수 냉각방법 모두 최고온도의 저감과 도달시간을 지연시키는 것으로 나타났으나, 지연제 사용의 경우 최고온도 저감효과는 없는 것으로 나타났다. 또한 재령별 압축강도의 경우 3일, 7일의 초기재령에서 Plain과 비교하여 낮은 강도 값을 나타내었으나, 재령 28일에서는 설계기준강도를 모두 만족시키는 것으로 나타났다.

• 한국환경과학회지
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• 제26권4호
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• pp.493-507
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• 2017

Since the late 20th century, the urbanization in Korea has been rapidly increasing, especially in major cities like Seoul, as a result of industrialization. One of the aspects of urbanization is coating the surfaces with impervious concrete or asphalt that water cannot penetrate. In addition, various urban, such as urban heat islands, which also have a great impact on the urban environment, occur within the cities. Therefore, the urban environment is gradually becoming hot and dry, and the need for more urban parks to compensate for these negative impacts is growing. Thus, several numerical studies have been conducted to assess these problems using coupled Numerical Weather Prediction (NWP) and Computational Fluid Dynamics (CFD). In this study, an experiment was conducted to determine the accuracy of the area of the input field using Weather Research and Forecasting (WRF) model, and applying the more accurate input field to a numerical simulation using ENVI-met, in order to investigate the effect of urban parks on the thermal comfort. The results showed that an input field with a larger area is more accurate than that with a smaller area, because the surrounding terrain and cities are considered in details in the experiment with the larger area. Subsequently, the more accurate input field was used in ENVI-met, and the results of this simulation showed that the presence of the urban park increased the thermal comfort and improved the humidity conditions.

• 한국방재학회 논문집
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• 제8권4호
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• pp.17-22
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• 2008

폭염을 포함한 기후변화에 의한 사망자가 2000년의 경우 15만 명에 달하였으며 외부환경 변화에 대응하는 인간은 자연적인 체온 조절기능이 감소되고 냉난방기에 의한 인공적인 환경조절 의존도가 높아지고 있다. 자연재해로서의 폭염에 대한 대응책으로서 우리나라에서도 2007년부터 폭염지수를 예보하고 이에 따른 폭염경보를 발령하고 있으며 각종 산업현장에서도 이에 대한 대응방안을 마련하고 있다. 그러나 결국 이러한 폭염재해대책은 소극적인 방법으로 시민 개개인에게 최종적인 폭염대응을 책임지게 하고 있는 것이다. 이를 보완하기 위해서 보다 체계적이고 능동적인 폭염 대응 시스템의 구축이 필요한 것으로 사료된다. 본 연구에서는 이러한 폭염의 대응방법으로서 쿨링센터의 체계적인 설치와 운영에 대한 대안을 제시하고자 한다. 특히 쿨링센터가 단순한 대피처로서의 역할이 아니라 폭염재난에 있어서 긴급재난통제소와 같은 역할을 수행하는 것을 제안한다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
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• pp.184-189
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• 2009

In order to improve the operation of energy systems, it is necessary for the urban communities to have reliable optimization routines, both computerized and manual, implemented in their organizations. However, before a production plan for the energy system units can be constructed, a prediction of the energy systems first needs to be determined. So, several methodologies have been proposed for energy demand prediction, but due to uncertainties in urban community, many of them will fail in practice. The main topic of this paper has been the development of a method for energy demand prediction at urban community. Energy demand prediction is important input parameters to plan for the energy planing. This paper presents a energy demand prediction method which estimates heat and electricity for various building categories. The method has been based on artificial neural networks(ANN). The advantage of ANN with respect to the other method is their ability of modeling a multivariable problem given by the complex relationships between the variables. Also, the ANN can extract the relationships among these variables by means of learning with training data. In this paper, the ANN have been applied in oder to correlate weather conditions, calendar data, schedules, etc. Space heating, cooling, hot water and HVAC electricity can be predicted using this method. This method can produce 10% of errors hourly load profile from individual building to urban community.

• Asian-Australasian Journal of Animal Sciences
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• 제27권10호
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• pp.1436-1442
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• 2014

Preservation of forage crops as silage offers opportunity to avoid the high risk of rain-damaged hay in the humid south-central USA. Recent developments with baled silage or baleage make silage a less expensive option than typical chopped silage. Silage has been important in the region primarily for dairy production, but baleage has become an option for the more extensive beef cattle industry in the region. Silage samples submitted to the Louisiana State University Agricultural Center Forage Quality Lab from 2006 through 2013 were assessed for dry matter (DM) and forage nutritive characteristics of chopped silage and baleage of the different forage types from commercial farms primarily in Louisiana and Mississippi. Of the 1,308 silage samples submitted, 1,065 were annual ryegrass (AR) with small grains (SG), the warm-season annual (WA) grasses, sorghums and pearl millet, and the warm-season perennial (WP) grasses, bermudagrass and bahiagrass, providing the remaining samples. Concentration of DM was used to indicate an effective ensiling opportunity, and AR silage was more frequently within the target DM range than was the WA forage group. The AR samples also indicated a high-quality forage with average crude protein (CP) of 130 g/kg and total digestible nutrient (TDN) near 600 g/kg. The cooler winter weather at harvest apparently complicated harvest of SG silage with chopped SG silage lower in both CP and TDN (104 and 553 g/kg, respectively) than either AR silage or baleage of SG (137 and 624 g/kg for CP and TDN, respectively). The hot, humid summer weather along with large stems and large forage quantities of the WA grasses and the inherently higher fiber concentration of WP grasses at harvest stage indicate that preservation of these forage types as silage will be challenging, although successful commercial silage samples of each forage type and preservation approach were included among samples of silages produced in the region.

• 한국산학기술학회논문지
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• 제19권9호
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• pp.288-297
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• 2018

보행은 사람들의 건강을 증진시키고 증가하는 교통 체증 해소에 중요한 역할을 한다. 기존 보행관련 연구는 유럽, 북미, 동아시아 등에서 진행하였으나, 베트남과 같은 덥고 습한 개발도상국 도시들의 경우, 걷기에 대한 연구가 비교적 많지않다. 따라서 본 연구는 베트남 호치민시 중심지구의 보행편의성과 건축 환경이 보행에 미치는 영향에 대하여 연구를 진행하였다. 본 연구는 대상지를 이용하는 사람들의 보행 빈도와 건축 환경 사이의 상관관계를 분석하고 있다. 기존 선행 연구에서 일반적으로 사용된 요소 외에도, 본 논문은 보행편의성 지수를 추정하기 위해 도시의 다른 특정한 건축 환경 요소를 사용하였다. 사용된 지표는 주거 밀도, 상업 비율, 혼합 토지이용, 교차로 간격, 블록 크기, 보행로 비율, 천장 유무, 온도 9가지를 사용하였으며, 이러한 지표는 지역 주민들을 대상으로 실시한 조사와 비교 분석을 실시하였다. 분석 결과 사람들은 보행편의성 지수가 높은 지역에서 더 많은 보행을 하는 것으로 분석되었다.

• Journal of Astronomy and Space Sciences
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• 제29권4호
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• pp.329-336
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• 2012

Korea Astronomy and Space Science Institute researchers have installed and operated magnetometers at Bohyunsan Observatory to measure the Earth's magnetic field variations in South Korea. In 2007, we installed a fluxgate magnetometer (RFP-523C) to measure H, D, and Z components of the geomagnetic field. In addition, in 2009, we installed a Overhauser proton sensor to measure the absolute total magnetic field F and a three-axis magneto-impedance sensor for spectrum analysis. Currently three types of magnetometer data have been accumulated. In this paper, we use the H, D, Z components of fluxgate magnetometer data to investigate the characteristics of mid-latitude geomagnetic field variation. To remove the temporary changes in Earth's geomagnetic filed by space weather, we use the international quiet days' data only. In other words, we performed a superposed epoch analysis using five days per each month during 2008-2011. We find that daily variations of H, D, and Z shows similar tendency compared to previous results using all days. That is, H, D, Z all three components' quiet intervals terminate near the sunrise and shows maximum 2-3 hours after the culmination and the quiet interval start from near the sunset. Seasonal variations show similar dependences to the Sun. As it becomes hot season, the geomagnetic field variation's amplitude becomes large and the quiet interval becomes shortened. It is well-known that these variations are effects of Sq current system in the Earth's atmosphere. We confirm that the typical mid-latitude geomagnetic field variations due to the Sq current system by excluding all possible association with the space weather.