• Title/Summary/Keyword: Distribution environment

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Analysis of Thermal Comfort Factor′s Distribution in Convective Heating Space (대류난방공간에서 온열쾌적조건의 분포상태 분석에 관한 연구)

  • 공성훈
    • Journal of the Korean housing association
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    • v.6 no.1
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    • pp.31-37
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    • 1995
  • The purpose of this study is to analyse the distribution of thermal sensation response and thermal environment condition in convective heating space. The contents of this study are as follows: 1)the spatial distributions of thermal conditions are measured 2)the thermal sensation vote of residents is taken in order to investigate the relation between thermal condition and human thermal sensation in sedentary condition 3)to analyse the distribution of subject's thermal sensation vote and thermal environment condition by two methods-regression method and graph method.

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A Study of Size Distribution of Sulfate and Nitrate in Urban Air (都市大氣中 黃酸鹽과 窒酸鹽 關한 硏究)

  • 신상은;김승학;김희강
    • Journal of Korean Society for Atmospheric Environment
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    • v.2 no.1
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    • pp.33-39
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    • 1986
  • Particulate matter was collected by Andersen Air Sampler in the Seoul area during February-October, 1985, in order to investigate size distribution of sulfate and nitrate in aerosol, and conversion of sulfur dioxide to sulfate and that of nitrogen dioxide to nitrate. The size distribution of sulfate and nitrate had fine mode. The ratio of fine sulfate to total sulfate in aerosol and that of fine nitrate to total nitrate showed between 54.6% and 86%, and 55.7% and 95%, respectively, which presumably originated from gaseous reaction of sulfur dioxide and nitrogen dioxide in the atmosphere.

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A plan to harmonize the equipments of power distribution with its environment (배전설비의 환경조화방안)

  • Lee, Jae-Gwan;Kim, Sang-Yul
    • Proceedings of the KIEE Conference
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    • 1998.07c
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    • pp.1206-1209
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    • 1998
  • For 21th Century, the assignment of power distribution will be the expansion of equipments to supply electric power and harmony with its environment, in process of approving value consciousness of land, space, and the preservation of surroundings. This paper proposes a plan to match with the requirement about equipments, having ability to supply electric power, being harmonized itself with its surroundings by applying a general concept of "Amenity" when we choose an established form of power distribution.

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Distribution and Antibiotic Resistance of Vibrio vulnificus isolated in Incheon Coastal Area (인천지역 해양환경에서 분리된 비브리오패혈증군의 분포 및 항생제 내성 양성)

  • Hwang, Kyoung-Wha;Oh, Bo-Young;Gong, Young-Woo;Lee, Jae-Mann;Go, Jong-Myoung;Kim, Yong-Hee
    • Journal of environmental and Sanitary engineering
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    • v.22 no.4
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    • pp.55-63
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    • 2007
  • We investigated the distribution and drug susceptibility test of V. vulnificus isolated from environmental sources in Incheon. In this survey, total 4,302 samples were obtained from different sites of the Incheon coastal area during the periods from march 2004 to November 2006. Among the 4,302 samples, 310 strains were isolated. The isolation rates of Vibrio vulnificus from fish, shellfish, estuarine water and sediment were 6.7%, 4.7%, 12.4% and 23.2%, respectively. The highest isolation rate was 14.6% in September and in spite of low temperature the isolation rate was 5.1% in November. The highest rate of antibiotic resistance was observed against streptomycin(15.3%), cefazolin(8.5%), cephalothin(8.3%), amikacin(8.3%), cefoxitin(6.7%) and nalidixic acid(6.7%). Seventeen percent of isolates were observed to be resistant to two or more of the antibiotics tested.

Field Measurements and CFD Simulations of Indoor Thermal Environments in the Assembly Hall (대형 강의실의 실내 열환경 실측 및 컴퓨터시뮬레이션 비교 연구)

  • Yoon, JaeOck
    • KIEAE Journal
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    • v.4 no.3
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    • pp.179-186
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    • 2004
  • The evaluation of the indoor environment of the Assembly Hall in the University, which is designed to be a large space, requires efficient design of its heating system that takes into consideration natural convection and the characteristics of the occupant's spaces. Indoor thermal environment was measured in the field and simulated with CFD code. The estimations of temperature distribution and indoor airflow distribution must be carried out simultaneously, as the thermal stratification is induced by natural convection flows. In order to simulate the even distribution of factors affecting the indoor environment, including temperature and airflow, Phoenics is used. The turbulent flow model adopted is the RNG k- model. The inlets and outlets of the air-conditioning systems, material and thermal properties, and the size of the test room ($35m{\times}18m{\times}10m$) are used for the simulation. Since the Assembly Hall is symmetric, half of the space is simulated. A Cartesian grid is used for calculation and the number of grids are respectively $60{\times}45{\times}35$. The results of the computer simulation during winter conditions are compared with the measurements at the typical points in the assembly hall with the heating system. After evaluating the results of the computer simulations, the methods of the heating system and layout are suggested.

Projecting Climate Change Impact on the Potential Distribution of Endemic Plants (Megaleranthis saniculifolia) in Korea (기후변화에 따른 우리나라 특산식물의 잠재적 분포적지 변화 예측 - 모데미풀을 중심으로 -)

  • Lee, Sang-Hyuk;Jung, Huicheul;Choi, Jaeyong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.15 no.3
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    • pp.75-84
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    • 2012
  • The importance of the genetic value of native plants has been raised recently after the adoption of Nagoya Protocol. In this stream, this research focused on the future distribution of Megaleranthis saniculifolia which has been evolved and adapted to Korean natural environment and classified as an endemic endangered species by IUCN. The distribution of the species in future are projected based on 'present potential distribution area' by adopting SRES (Special Report on Emission Scenarios) A1B climate change scenario using 6 types of GCM (General Circulation Model). The major results of the research are as follows : habitats of Megaleranthis saniculifolia. (1) will be reduced by 44% nation wide; (2) in Chungcheongngnam Do and Jeollanam Do will be the most affected; and (3) in high altitude in Chungcheongbuk Do, Gyunggi Do and Gangwon Do will be relatively less affected.

Optimal Design for Indoor Thermal Environment based on CFD Simulation and Genetic Algorithms (CFD 연성해석과 유전자 알고리즘을 이용한 실내 열환경 최적설계에 관한 연구)

  • 김태연;이윤규
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.16 no.2
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    • pp.111-120
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    • 2004
  • The optimal design method of indoor thermal environment using CFD coupled simulation and genetic algorithms (GA) is developed in this study. CFD could analyze the thermal environment considering the distribution of temperature, velocity, etc. in a room. Therefore, It would be appropriate to use CFD for the optimal design method considering their distribution. In this paper, the optimal design means the most appropriate boundary conditions of the room among the conditions where the design target of indoor therm environment is achieved. Two step optimal indoor thermal environment design method is proposed. It includes the GA for searching the optimal indoor thermal environment design. To examine the performance of this method, the optimal design of hybrid ventilation system, which uses the natural cross ventilation and the radiation-cooling panel is conducted. The optimal design which satisfies the design target (thermal comfort, minimum cooling load, minimum vertical temperature difference) is found using two step optimal design method.

Diversity and Distribution of Methanogenic Archaea in an Anaerobic Baffled Reactor (ABR) Treating Sugar Refinery Wastewater

  • Li, Jianzheng;Zhang, Liguo;Ban, Qiaoying;Jha, Ajay Kumar;Xu, Yiping
    • Journal of Microbiology and Biotechnology
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    • v.23 no.2
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    • pp.137-143
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    • 2013
  • The diversity and distribution of methanogenic archaea in a four-compartment anaerobic baffled reactor (ABR) treating sugar refinery wastewater were investigated by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). At an organic loading rate of 5.33 kg $COD/m^3{\cdot}day$, the ABR could perform steadily with the mean chemical oxygen demand (COD) removal of 94.8% and the specific $CH_4$ yield of 0.21 l/g $COD_{removed}$. The $CH_4$ content in the biogas was increased along the compartments, whereas the percentage of $H_2$ was decreased, indicating the distribution characteristics of the methanogens occurred longitudinally down the ABR. A high phylogenetic and ecological diversity of methanogens was found in the ABR, and all the detected methanogens were classified into six groups, including Methanomicrobiales, Methanosarcinales, Methanobacteriales, Crenarchaeota, Arc I, and Unidentified. Among the methanogenic population, the acid-tolerant hydrogenotrophic methanogens including Methanoregula and Methanosphaerula dominated the first two compartments. In the last two compartments, the dominant methanogenic population was Methanosaeta, which was the major acetate oxidizer under methanogenic conditions and could promote the formation of granular sludge. The distribution of the hydrogenotrophic (acid-tolerant) and acetotrophic methanogens in sequence along the compartments allowed the ABR to perform more efficiently and steadily.

Key Distribution Protocol Appropriate to Wireless Terminal Embedding IC Chip (IC 칩을 내장한 무선 단말기에 적용 가능한 키 분배 프로토콜)

  • 안기범;김수진;한종수;이승우;원동호
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.13 no.4
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    • pp.85-98
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    • 2003
  • Computational power of IC chip is improved day after day producing IC chips holding co-processor continuously. Also a lot of wireless terminals which IC chip embedded in are produced in order to provide simple and various services in the wireless terminal market. However it is difficult to apply the key distribution protocol under wired communication environment to wireless communication environment. Because the computational power of co-processor embedded in IC chip under wireless communication environment is less than that under wired communication environment. In this paper, we propose the hey distribution protocol appropriate for wireless communication environment which diminishes the computational burden of server and client by using co-processor that performs cryptographic operations and makes up for the restrictive computational power of terminal. And our proposal is satisfied with the security requirements that are not provided in existing key distribution protocol.

Probability Distribution of BOD EMC from Paddy Fields (논 유출수 BOD의 유량가중평균농도(EMC) 확률분포)

  • Jin, So-Hyun;Jung, Jae-Woon;Yoon, Kwang-Sik;Choi, Woo-Jung;Choi, Dong-Ho;Kim, Sang-Don;Kang, Jae-Hong;Choi, Yu-Jin
    • Journal of Environmental Science International
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    • v.19 no.9
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    • pp.1153-1159
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    • 2010
  • Identification of probability distribution for water quality constituents from specific land use is important to achieve successful implementation of TMDL program. In this 3-year study, distribution of discharge and BOD(Biological Oxygen Demand) concentration from paddy rice fields were monitored. Four probability distributions, normal, log-normal, Gamma and Weibull were fitted and the goodness-of-fit was assessed using probability plots and Kolmogorov-Smirnov test. $EMC_s$ of BOD in runoff from paddy field ranged 0.37 to $7.99\;mgL^{-1}$, and all four probability distributions were acceptable. But the normal distribution would be preferred for BOD from paddy fields considering nature of straight forward application.