• 제목/요약/키워드: source environment

검색결과 4,245건 처리시간 0.035초

무선통신에서 각 처짐 신호 도래각 추정 (AOA Estimation of Angle-Perturbed Sources for Wireless Communications)

  • 김석찬
    • 한국통신학회논문지
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    • 제30권8C호
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    • pp.769-774
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    • 2005
  • 무선 이동통신 환경에서 몇 가지 까닭으로 말미암아 신호의 도래각이 통계적으로 퍼지게 될 때, 점신호원 모형대신 이러한 환경에 적합한 새로운 모형이 필요하다. 이 논문에서는 새로운 각 퍼짐 신호원 모형을 제안하고, 그 모형 아래에서 고유값 분해기법에 기초한 신호 도래각 추정방법을 제안할 것이다. 추정 에러의 근사적인 분포는 통계적 특성을 통해 알 수 있다.

대학시설에 대한 열원기기 대수 운전 제어의 에너지 절약 효과 (The energy-saving effect by controlling the number of operating chillers in university facility)

  • 이제헌;야스노리아카시;금종수;김동규
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2009년도 하계학술발표대회 논문집
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    • pp.1043-1048
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    • 2009
  • This paper proposes the new operation control method that let heat source system stop and circulate only hot water at low load, and verified the introduction effect. At first, we constructed simulation model of heat source system and examined the proposing method by using simulation model. At last, we examined the introduction effect of proposing method with actual building. As a result, the primary energy consumption of heat source system was reduced by about 13%.

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가죽, 모피 가공 및 제조업 폐수처리시설의 경제성 평가 (Economical Assessment of Wastewater Treatment Facilities in Leather Tanning and Finishing Industry)

  • 김재훈;양형재;권오상;이성종
    • 한국물환경학회지
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    • 제23권1호
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    • pp.131-137
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    • 2007
  • Industrial wastewater management guideline and evaluation model of Best Available Technologies for the leather tanning and finishing industry was developed as an economical evaluation model using evaluation of BAT including economical evaluation combined with cost analysis model and cost annualization model in considering of economical factors and non-water environmental factors. It was verified that approximately 10% will be increased annually to modify conventional treatment process ($3,700m^3/d$) of J leather wastewater treatment plant to advanced process of K leather wastewater treatment plant.

Position of Source Leaf Affects Translocation and Distribution of $C^{14}$ Photo-Assimilates in Tomato

  • Lee Sang-Gyu;Lee Chiwon W.
    • 생물환경조절학회지
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    • 제15권2호
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    • pp.173-176
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    • 2006
  • The relationship between source leaf position and photo-assimilate translocation and distribution was characterized for tomato (Lycopersicon esculentum Mill) grown in the greenhouse. Three different positions of source leaf on the stem (first node above or below the first fruit cluster and $5^{th}$ node above the first fruit cluster) were tested for their influence on $^{14}CO_2$ assimilation and transfer to different parts of the plant. The leaves at the $5^{th}$ node above the first fruit cluster transferred the highest (57%) proportion of $C^{14}$ to other plant parts, followed by leaves home on the first node below the first fruit cluster (50%), and the first node above the first fruit cluster (39%). In all treatments, fruits served as the strongest sink for $C^{14}$, followed by stem, leaf, and root tissues. The leaf home on the $5^{th}$ node above the first fruit cluster transferred the largest amount of $C^{14}$ to the second fruit cluster.

Analysis of Organic Molecular Markers in Atmospheric Fine Particulate Matter: Understanding the Impact of "Unknown" Point Sources on Chemical Mass Balance Models

  • Bae, Min-Suk;Schauer, James J.
    • 한국대기환경학회지
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    • 제25권3호
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    • pp.219-236
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    • 2009
  • Particle-phase organic tracers (molecular markers) have been shown to be an effective method to assess and quantify the impact of sources of carbonaceous aerosols. These molecular markers have been used in chemical mass balance (CMB) models to apportion primary sources of organic aerosols in regions where the major organic aerosol source categories have been identified. As in the case of all CMB models, all important sources of the tracer compounds must be included in a Molecular Marker CMB (MM-CMB) model or the MMCMB model can be subject to biases. To this end, the application of the MM-CMB models to locations where reasonably accurate emissions inventory of organic aerosols are not available, should be performed with extreme caution. Of great concern is the potential presence of industrial point sources that emit carbonaceous aerosols and have not been well characterized or inventoried. The current study demonstrates that emissions from industrial point sources in the St. Louis, Missouri area can greatly bias molecular marker CMB models if their emissions are not correctly addressed. At a sampling site in the greater St. Louis Area, carbonaceous aerosols from industrial point sources were found to be important source of carbonaceous aerosols during specific time periods in addition to common urban sources (i.e. mobile sources, wood burning, and road dust). Since source profiles for these industrial sources have not been properly characterized, method to identify time periods when point sources are impacting a sampling site, needs to avoid obtaining biases source apportionment results. The use of real time air pollution measurements, along with molecular marker measurements, as a screening tool to identify when point sources are impacting a receptor site is presented.

토양.지하수오염원 관리우선순위 개략평가기법 개발 (Development of Preliminary Assessment Methodology for Priority Listing of Soil and Groundwater Contamination Sources)

  • 정승우;김영주;김재훈;황상일
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제16권6호
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    • pp.106-112
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    • 2011
  • This study developed preliminary assessment methodology for priority listing of soil and groundwater contamination sources, considering source characteristics, local environments and risk receptors. Source characteristics were evaluated by scoring relative risk of contamination sources. Local environments were evaluated by scoring annual rainfall, hydraulic conductivity of aquifer, and annual groundwater use. Risk receptors were evaluated by scoring local population, direct distance to surface water, direct distance to drinking-water wells. Scores of each parameter were allocated by analysing distribution of parameter values obtained from government databases. Distributed scores of source characteristics local environments: risk receptors were 12 : 12 : 12. The preliminary assessment scored 0 to 36 for each soil and groundwater sources. Inventory of soil and groundwater sources consisted of 7 categories. This study applied the preliminary assessment methodology to Manan-Gu, Anyang City, Korea. The number of car repair and washing facility was the largest in the contamination source inventory. Petroleum storage facilities showed the highest assessment score. The preliminary assessment methodology also indicated that Anyang-Dong was the priority section among Anyang-Dong, Suksu-Dong, Bakdal-Dong. This study is the first trial for relative ranking soil and groundwater contamination sources by considering source and local characteristics. Therefore, further researches and revision of the preliminary assessment methodology need to be pursued for various applications.

토사유실 원인지역 검토를 위한 SPOT 5 위성영상과 토지피복도의 활용 (Application of SPOT 5 Satellite Image and Landcover Map for the examination of Soil Erosion Source Area)

  • 이근상;박진혁;황의호;고덕구
    • 한국수자원학회논문집
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    • 제38권11호
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    • pp.927-935
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    • 2005
  • 강우에 따른 토사유실은 호소내 저수용량 감소 및 탁수 등의 수질오염을 유발하기 때문에 유역관리 측면에서 중요한 인자가 된다. 최근 GIS를 활용한 토사유실평가 연구가 진행되고 있으나, 토사유실 원인지역에 대한 검토는 고려하지 않고 있다. 본 연구에서는 GIS 기반 토사유실모델을 활용하여 임하호 유역의 토사유실량을 산정하였으며, SPOT 5 고해상도 위성영상과 토지피복도 자료를 활용하여 토사유실원인지역을 검토하였다. 분석결과 토사유실이 높게 나타나는 지역의 대부분이 밭으로 확인되었으며 그 위치를 영상에서 효과적으로 확인할 수 있었다. 또한 위성영상에서 경계를 확인하기 곤란했던 밭과 과수원이 공통으로 나타나는 지역은 현장확인을 통해 그 적정성을 검토할 수 있었다.

지하수 상수원 활용의 타당성 고찰을 위한 상수도 취수원의 특성 비교 연구 (A Comparison Study of Various Water Sources for Feasibility of Expanding the use of Groundwater in Public Water Supply of South Korea)

  • 차은지;현윤정
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제22권4호
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    • pp.60-70
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    • 2017
  • As water sources become more vulnerable to the effects of climate change such as drought and contamination, the diversification of water sources is important for securing water supply. This study examines the properties of five water sources for public supply, including river and river-bed water, dams, reservoirs, and groundwater, while ensuring that the quantities available from such sources are stable and the water itself is safe for use. This study also analyzes the power, chemical, repair and maintenance, and labor costs associated with each water source. The results demonstrate that groundwater has high potential as a water source because it is readily available (about $12.89billion\;m^3/yr$), but only a small portion of it is currently used. Analyses indicated that groundwater is the most efficient source of water to meet water demand below $1,000,000m^3/yr$, which covers 62.5% of water supply facilicities. With the implementation of groundwater dams, groundwater can become cost-efficient even for larger water demand. Additionally, the water source protection areas are the smallest for groundwater among the five water sources. In conclusion, the use of groundwater as an alternative water source is feasible becasue it is readily available, safe, cost-efficient, and requires the lowest amount of environmental regulations for the diversification of water supply sources.

Source Identification and Estimation of Source Apportionment for Ambient PM10 in Seoul, Korea

  • Yi, Seung-Muk;Hwang, InJo
    • Asian Journal of Atmospheric Environment
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    • 제8권3호
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    • pp.115-125
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    • 2014
  • In this study, particle composition data for $PM_{10}$ samples were collected every 3 days at Seoul, Korea from August 2006 to November 2007, and were analyzed to provide source identification and apportionment. A total of 164 samples were collected and 21 species (15 inorganic species, 4 ionic species, OC, and EC) were analyzed by particle-induced x-ray emission, ion chromatography, and thermal optical transmittance methods. Positive matrix factorization (PMF) was used to develop source profiles and to estimate their mass contributions. The PMF modeling identified nine sources and the average mass was apportioned to secondary nitrate (9.3%), motor vehicle (16.6%), road salt (5.8%), industry (4.9%), airborne soil (17.2 %), aged sea salt (6.2%), field burning (6.0%), secondary sulfate (16.2%), and road dust (17.7%), respectively. The nonparametric regression (NPR) analysis was used to help identify local source in the vicinity of the sampling area. These results suggest the possible strategy to maintain and manage the ambient air quality of Seoul.

치과 수술용 LED 광원모듈의 최적화 (The Optimization of an Operating Dental LED Light Source Module)

  • 정연오;홍기태;김재열;김성현;안영진;한재호
    • 한국생산제조학회지
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    • 제20권4호
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    • pp.452-457
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    • 2011
  • The internal temperature of an operating room had to keep within $20^{\circ}C$. However, the doctor who is wearing operating gown and mask caused to rise temperature because of the thermal occurrence of dental LED light source. At first, the surgery environment is getting worse. And then last, it would increase bleeding rate by the expansion of patient's exposured blood vessel. A surgical operator can distribute the patient's tissue through such surgery environment, exactly. It can do accurate surgery. So, it gave to effect that surgical operator's eye condition is getting better and it could keep a mutual assistance system. For this research, we develop the LED dental light source module of high color rendition. It performed simulation for replacing established the method of Halogen lamp and Plazma lamp of light source. We analyzed intensity of illumination and the change of viability by changing the height of light source module.