• 한국방재학회:학술대회논문집
• /
• 한국방재학회 2008년도 정기총회 및 학술발표대회
• /
• pp.827-830
• /
• 2008

Enterococcus는 fecal indicator bacterium의 하나로서 환경내에서 fecal contamination을 탐지 하는 지표로서 사용되며, 현재 각 Enterococcus spp. 의 서로 다른 당 분해능을 이용한 분별법이 개발되었으며, 이를 위해 서로 다른지역의 소, 돼지, 닭, 오리 그리고 사람으로 부터 총 1826의 Enterococcus 샘플을 획득 하였음. 이 연구는 Enterococcus를 통해 microbial source tracking 의 가능성을 제시하고 있음.

• KIEAE Journal
• /
• 제7권5호
• /
• pp.29-34
• /
• 2007

Discomfort glare from windows is an important issue in window and daylighting design. This study aims to investigate the effect of luminance difference between the lower and the upper part of a large glare source. Experiments were conducted using a luminous body divided into two parts, the upper part and the lower part. The degree of discomfort glare from the luminous body was examined. The result shows that the part with lower luminance is perceived as a glare source when the part has higher luminance then the background luminance. The degree of discomfort glare was estimated for the experimental conditions, and compared to the observations. The estimation was made using two methods: one summed the glare sensation for each section, and the other used the average luminance of the whole luminous body. The result of the comparison shows that the method using the average luminance has approximate values to the observations. Consequently, the use of the average luminance was proposed for evaluation of discomfort glare from non-uniform large glare sources.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2005년도 추계학술대회논문집
• /
• pp.637-640
• /
• 2005

We propose a sound source localization method using the Head-Related-Transfer-Function (HRTF) to be implemented in a given platform. HRTFs contain not only the information regarding proper time delays but also phase and magnitude distortions due to diffraction and scattering by the shading object. Therefore, a set of HRTFs for any given platform provides a substantial amount of information as to the whereabouts of the source. In this study, we introduce new phase criterion in order to find the sound source location in accordance with the HRTF database empirically obtained in an anechoic chamber with the given platform. Using this criterion, we analyze the estimation performance of the proposed method in a household environment.

• 한국해양공학회지
• /
• 제22권1호
• /
• pp.30-36
• /
• 2008

Underwater ambient noise originating from geophysical, biological, and man-made acoustic sources contains information on the source and the ocean environment. Such noise affectsthe performance of sonar equipment. In this paper, three steps are used to identify the ambient noise source, detection, feature extraction, and similarity measurement. First, we use the zero-crossing rate to detect the ambient noisesource from background noise. Then, a set of feature vectors is proposed forthe ambient noise source using the Hilbert-Huang transform and the Karhunen-Loeve transform. Finally, the Euclidean distance is used to measure the similarity between the standard feature vector and the feature vector of the unknown ambient noise source. The developed algorithm is applied to the observed ocean data, and the results are presented and discussed.

• Spatial Information Research
• /
• 제20권5호
• /
• pp.25-35
• /
• 2012

본 연구에서는 공간정보 자료원에 따른 수질특성의 영향을 비교하였다. 먼저, 비점오염부하량 평가에 영향을 미치는 토지피복별 기대평균농도(EMC)를 효과적으로 계산하기 위해, 영상분류를 통해 대청댐유역의 토지피복도를 구축하였으며, 이를 환경부 대분류 자료와 비교한 결과 88.76%의 높은 정확도를 확보하였다. 또한 토양도와 영상분류에 의한 토지피복도를 공간 중첩하여 유출곡선지수와 직접유출을 계산하였으며, 분석 결과 석천과 대청댐 유역이 가장 높게 나타났다. 그리고 직접유출과 기대평균농도를 조합하여 계산한 BOD에 대한 비점오염부하량은 삼가천합류점과 소옥천하류 유역이 높게 나타났으며, TN과 TP에 대한 비점오염부하량에서는 삼가천합류점과 봉황천하류 유역이 높게 나타났다. 영상분류에 의한 비점오염부하량의 효용성 평가를 위해 환경부 토지피복도에 의한 비점오염부하량과 상호 비교한 결과, 대청댐상류 유역에서 BOD, TN, TP에 대한 오염부하량의 오차가 각각 10.64%, 11.70%, 20.00%로 가장 크게 나타났다. 따라서 유역내 수질특성을 효과적으로 모의하기 위해서는 논과 밭이 포함된 공간정보를 활용하는 것이 비점오염부하량 평가에 바람직하다고 본다.

• 대한환경공학회지
• /
• 제36권10호
• /
• pp.719-723
• /
• 2014

수질오염총량관리제의 효율적인 시행을 위해 본 연구에서는 비점오염원의 분류, 비점부하량(발생, 배출) 산정, 비점 오염원 관리지역의 선정, 비점오염물질 관리 등을 포함한 비점오염원 관리방안을 제시하고자 하였다. 무엇보다도 먼저 점오염원과 비점오염원의 정의는 학술적 법률적 관점에 기초하여 명확히 구분 관리하여야 한다. 특히, 사업활동과 사람의 활동에 의해서도 환경피해가 발생하지 않는 임야, 초지, 하천 등은 별도로 자연배경오염원으로 구분하여야 한다. 비점오염원 발생 및 배출부하량의 원단위는 유역의 실제여건에 맞도록 우선적으로 변경하여야 하며, 비점오염원 발생 및 배출부하량의 산정방법은 유역의 강수량 및 강수 지속시간을 고려하도록 수정하여야 한다. 한편, 수질오염총량관리제를 시행함에 있어 비점 오염원 관리지역은 강우시 하천의 오염물질 농도가 중권역 목표(관리목표)를 초과하거나 초과할 우려가 있는 유역을 대상으로 하며, 전체 유역 가운데 초지, 임야를 제외한 도시지역, 농경지, 그리고 대지 가운데 비점오염물질의 배출밀도가 높은 지역을 비점오염원 관리지역으로 최소화하여 선정하여야 한다. 비점오염물질저감시설은 단위면적당 비점오염물질 배출량, 오염물질 초과농도 지속시간, 처리의 실현가능성, 점오염원 대비 처리비용 효과 등을 고려하여 단위면적당 비점오염원 발생부 하량이 많은 지역과 강우시 수질농도가 중권역 목표를 초과하는 유역에 설치하여야 한다.

• KIEAE Journal
• /
• 제15권3호
• /
• pp.57-63
• /
• 2015

Purpose: Ground source heat pump system has been attracted in the horticulture industry for the reduction of energy costs and the increasing of farm income. Even though it has higher initial costs, if it uses in combination with heat storage, it is able to reduce the initial costs and operate efficiently. In order to have significant effect of heat storage type ground source heat pump system, it is required to design the capacity considering various conditions such as energy load pattern and operating schedule. Method: In this study, we have designed heat storage type ground source heat pump system in 5 cases by the operating schedule, and examined the system to find the most economic and having superb performance regarding the system COP(Coefficient of Performance) and energy consumption, using dynamic energy simulation, TRNSYS 17. Result: Conventional ground source heat pump system has lower energy consumption than heat storage type, but following the result of LCC(Life Cycle Cost) analysis, the heat storage type was more economic due to the initial costs. In addition, it has the most efficient performance and energy costs in the case of the smallest heat storage time.

• KIEAE Journal
• /
• 제17권4호
• /
• pp.33-39
• /
• 2017

Purpose: The use of renewable energy system is essential for building energy independence and saving energy consumption in the building sector. Among renewable energy technologies, ground source heat pump(GSHP) system is more energy-efficient and environmental-friendly than other heat source systems due to utilize stable ground heat source. However, the GSHP system requires a high initial installation cost and installation space in limited urban area, so it is difficult to have superiority in the market of heat source system. Therefore, it is necessary to develop the installation method of low-cost and improve system performance. This paper aims to evaluate the performance of double u-tube ground heat exchanger(GHX) and verify system feasibility through real-scale experiment. Method: In this study, the real-scale experiment of vertical closed-type GSHP system was conducted using double u-tube GHX and high-efficiency grout. Through the verification experiment, heat source temperature, heat exchange rate(HER) and seasonal performance factor(SPF) were measured according to the long-term operation. In addition, the feasibility analysis was conducted comparing to the single u-tube system. Result: In the results of experiment, average HER was 136.27 W/m and average SPF was 5.41. Furthermore, compared to the single u-tube, the installation cost of the developed system could be reduced about 70% in the same heating load condition.

• 환경영향평가
• /
• 제18권6호
• /
• pp.393-399
• /
• 2009

The water of rivers and lakes are affecting by point and nonpoint source pollutions. The point source pollution can be controlled by establishing the treatment plants. However, nonpoint source pollution by various human activities is not easy to be controlled because it is difficult to determine the exits of the water flow and have many exit points. Due to contribution of nonpoint source pollution, the achievement ratio of water quality in rivers and lakes is not high. TMDL is the outstanding water quality control policy because all of the pollutant loadings from the watershed area are counting on the input loads. Our aqua-ecosystem has self-purification process by biological, physical and ecological processes. The self-purification process can remove the pollutant load from background concentrations. Usually forest area is main source of background concentrations. In Korea, about 70% of the national boundary area consists of mountains. This study is conducting as part of long-term monitoring to determine the Event Mean Concentration during a storm. The monitoring was performed on a broad-leaved tree area.

• 한국환경보건학회:학술대회논문집
• /
• 한국환경보건학회 2004년도 International Conference Global Environmental Problems and their Health Consequences
• /
• pp.92-106
• /
• 2004

Elemental dry deposition fluxes were measured using dry deposition plates from March to June 1998 in Seoul, Korea. During this spring sampling period several yellow sand events characterized by long-range transport from China and Mongolia impacted the area. Understanding the impact of yellow-sand events on atmospheric dry deposition is critical to managing the heavy metal levels in the environment in Korea. In this study, the measured flux of a primarily crustal metal, Al and an anthropogenic metal, Pb was used with two hybrid receptor models, potential source contribution function (PSCF) and residence time weighted concentration (RTWC) for locating sources of heavy metals associated with atmospheric dry deposition fluxes during the yellow-sand events in Seoul, Korea. The PSCF using a criterion value of the 75th percentile of the measured dry deposition fluxes and RTWC results using the measured elemental dry deposition fluxes agreed well and consistently showed that there were large potential source areas in the Gobi Desert in China and Mongolia and industrial areas near Tianjin, Tangshan, and Shenyang in China. Major industrial areas of Shenyang, Fushun, and Anshan, the Central China loess plateau, the Gobi Desert, and the Alaskan semi-desert in China were identified to be major source areas for the measured Pb flux in Seoul, Korea. For Al, the main industrial areas of Tangshan, Tianjin and Beijing, the Gobi Desert, the Alashan semi-desert, and the Central China loess plateau were found to be the major source areas. These results indicate that both anthropogenic sources such as industrial areas and natural sources such as deserts contribute to the high dry deposition fluxes of both Pb and Al in Seoul, Korea during yellow-sand events. RTWC resolved several high potential source areas. Modeling results indicated that the long-range transport of Al and Pb from China during yellow-sand events as well as non yellow-sand spring daytimes increased atmospheric dry deposition of heavy metals in Korea.