• 제목/요약/키워드: enviroment

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A study on the Comparison of the Heavy Metal in Abandoned mine Soil by Sequential Extraction Exthaction Methods (폐광산 주변 토양 내 중금속의 연속추출법과 토양오염공정시험기준에 대한 비교 연구)

  • Lee, Jong-Deuk;Kim, Tae-Dong;Jeon, Gee-Seok;Kim, Hee-Joung
    • Journal of Soil and Groundwater Environment
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    • v.16 no.6
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    • pp.95-105
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    • 2011
  • Total extraction method and environmental standards for heavy metals in soils were revised in regulation recently. In case of Area 3, as the law amended, the soil pollution level has gone up to 4 to 13 times higher depending on the type of heavy metal. In this study, it compares the properties of heavy metals of soil by sequential extraction and total extraction methods depending on the analysis method, using the soil around mine. In case of arsenic, the soil pollution level has gone up to 4 times higher, but 6 to 10 times in the sample soil. Also, according to the results of portability evaluation depending on the type of existence form of heavy metal it exists as residual form in mine waste rock, which is less likely to move, while it exists as migrated form in tailing. Therefore, it should be considered to evaluate the soil pollution and decide the contaminated bounds depending on the existence form of heavy metals on soil to restore the polluted soil.

Environmental Mobilization Characteristics of Total Gaseous Mercury in the Western Coast of Korea During the Yellow Sand Period, 2001 (2001년 봄철 황사기간 중 서해안지역에서 관측한 대기 중 수은의 환경유동특성 연구)

  • Kim, Min-Young;Shin, Jae-Young;Cho, Suk-Choo;Kim, Joon;Lee, Gang-Woong;Kim, Ki-Hyun
    • Journal of the Korean earth science society
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    • v.22 no.6
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    • pp.480-490
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    • 2001
  • The soil-air exchange processes of Hg were investigated from the Hari area of Kang Hwa Island during the late March 2001. In the course of our study, we determined the concentration gradients of Hg and combined these gradient data with micrometeorological components to derive its fluxes. Results of our study indicate that the concentration levels of Hg in the study area are notably lower than those typically found in urbanized areas of Korea. However, the computed fluxes were seen to be significantly larger for relatively remote areas, reaching over 200 ng/m$^2$/hr. Comparison of environmental conditions shows that the concentrations of most pollutant species including NO$_X$ and PM were significantly higher during emission, while meteorological conditions were characterized by high temperature and low humidity. Results of correlation analysis also indicate that such pollutants as hydrocarbons, nitrogen oxides, and PM generally exhibit strong positive correlations with Hg-related parameters during emission events, while such relationships were reversed during dry deposition events. The results of our present study suggest the possibility that the concentrations and fluxes of total gaseous Hg observed during deposition events can be influenced by the processes that are also important for the fine, rather than coarse, size fraction of particles.

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Marine Algal Assemblages on Artifical Reefs in Jeju-do Before and After Rocky Cleaning and the Growth Pattern of Ecklonia cava with Water Depth (갯닦기 전후 제주도 인공어초의 해조상 및 수심별 감태의 생장양상)

  • Kwak, Cheol-Woo;Chung, Ee-Yung;Gim, Tae-Yeon;Lee, Jong-Hwa;Kim, Young-Sik
    • Journal of Fisheries and Marine Sciences Education
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    • v.26 no.1
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    • pp.34-48
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    • 2014
  • Marine algal assemblages on the artificial reefs at three stations (Haengwon, Geumneung, Pyoseon in Jeju-do) and the growth pattern of Ecklonia cava with water depth were studied before and after rocky cleaning. Nine algal species occurred at three artificial reefs before rocky cleaning in July 2012, however, 19 algal species were found at three artificial reefs after rocky cleaning in July 2013. In particular, 13 of 19 species in 2013 were replaced by different species which were not found in July 2012. Algal biomass rapidly increased in July 2013 after rocky cleaning. The nMDS plot based on the presence and absence data of macro-algal assemblages on the artificial reefs showed that the species compositions between artificial reefs were similar to each other before rocky cleaning operations in July of 2012. However, after rocky cleaning, the species composition of macro-algal assemblages in Haengwon region was similar to that in Pyoseon region while that in Geumneung region was different to those in Haengwon and Pyseon regions in July 2013. It is needed to clarify the suitable water depth for transplantation of perennial Phaeophyta E. cava. According to the data on seasonal changes in total length, total weight, blade length, blade width, blade weight of E. cava, it began to grow rapidly from April and reached to the maximum value in June, and then degeneration of the blade occurred in July and continued to early August. Although the total length of E. cava at 10m water depth was larger than those at 5 m and 15 m water depths, there was no significant difference statistically among water depths by ANOVA test. However, in the values of total weight, blade length, blade width, and blade weight, the growth patterns at 5 m water depth were larger than those at 10 m and 15 m. Thus, it is assumed that the most suitable water depth for transplantation and its maximum growth and effective release of zoospores of E. cava will be 7~10 m water depth.

The Physiological Responses and Subjective Sensation in the Subjects Wearing Dust-free Garment for Semiconductor Industrial Environments (방진복 착용에 따른 인체의 온열생리적 특성 및 주관적 감각)

  • 권오경;이창미
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 1998.04a
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    • pp.255-263
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    • 1998
  • Dust-free garment prevents contamination which otherwise is caused by skin and clothes to protect from dust or dirt. Therefore, it requires high performance and should function as a working clothes. Clothes are a medium between human and thermal environmental system, and it is required to study human enviroment to ensure comfortableness of clothes and to satisfactorily go along with enviroment .This study investigates the physical and physiological features of dust-free garment used in the clean room at a semiconductor factory in oredr to scientifically clarify what the dust-free garmint is as well as to contribute to the design and development of high performance material and clothes. Three kinds of dust-free fabrics (DFG-I, DFG-II, DFG-III) which are being developed by a local company are used to manufacture dust-free garment. These dust-free garments are dressed and tested in such an enviroment as similar to semiconmemts with temperature at 23${\pm}$1$^{\circ}C$ and humidity at 50${\pm}$5%RH in order to investigate the thermo physiological and psychological features of human body. The results of this study are as follows. The results of this study are as follows. 1.The mean skin temperature was significantly different among the clothes, subjects and experimental time. Temperature tends to rise from the time of exercising load. Continuous motion coupled sealed clothes prevents heat transmittance, and temperature rises in the order of DFG-l, DFG-ll and DFG-lll as time course. 2.As for the skin temperature by local timperature is minimun on the head and torso and increares remarkably at the terminal part of human body. 3. As for the body mass loss was significantly higher in DFG-lll than DFG-l and DFG-ll. 4. Though there is no significant difference in the temperature within clothes among the kind of clothes temperature is 1$^{\circ}C$ higher in the back. Temperature within all the dust-free garments 29.7$^{\circ}C$ in the back and 31.3$^{\circ}C$ in the chest which belong to the comfort zone(31-33$^{\circ}C$). The relative humidity is 39.7%RH in the chest and 33.8%RH in the back which is slightly below the comfort zone(40-60%RH) 5. The thermal sensation belong to the comfort zone regardless of the kinds of clothes. The subjects feels a slight fatigue as times goes. As for the subjective sense of subjects the mean skin temperature as well as temperature and humidity within clothes show similar tendency. This means that they relate with each other.

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Analysis of Influenza Virus Isolates in Seoul during 2003-2004 Season (2003-2004 절기 서울지역의 인플루엔자 바이러스 분리 및 아형 분석)

  • Hwang Young-Ok;Lee Jae-In;Seo Byung-tae
    • Korean Journal of Microbiology
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    • v.41 no.1
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    • pp.53-59
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    • 2005
  • Influenza is an important public health problem which occurs almost every winter in temperate climates and is often associated with increased rates of hospitalization and death. In 1999, our influenza surveillance was initiated with 4 voluntary sentinel physicians and the Public Health Center. During the 2003-2004 influenza season, 124 influenza viruses were isolated from 401 clinical specimens, which were collected from patients with Influenza-like illness(ILI) in Seoul. The case definition of ILI is a case with fever more than $38^{\circ}C$ and systemic symptoms; cough, or sore throat. ILI was the highest at the 20-49 age $group(23\%)$ and the rate of virus isolation was the highest at the 7-19 age $group(50\%)$. Among 124 influenza viruses, isolates 83 were identified as A/H3N2 type and others were subtyped as influenza B viruses in 2003-2004 season. Influenza viruses were collected $39.1\%$ at Nowon-Gu, $13.5\%$ Gangnam-Gu and Seocho-Gu etc. and the isolate rate of virus had the area difference; Yongsan-Gu $66.7\%$, Gangnam-gu $50.0\%$, Nowon-Gu $39.9\%$, Kangbuk-Gu $36.8\%$, Seocho-Gu $27.8\%$, Dongjak-Gu $21.2\%$. Out of 401 individuals, 160 was vaccinated $(40\%)$ and the vaccination rate was the highest at the 20-49 age $group(32\%)$. These findings may contribute to the recommondation of the influenza vaccine formulation and the development of influenza control measure.

Distributed CAD/CAE Environment Using STEP (STEP을 이용한 분산 CAD/CAE 환경)

  • 권기억;박명진;조성옥
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.04a
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    • pp.395-399
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    • 1997
  • An international standard for the product model data, STEP, and a standard for the distributed object technology. CORBA, will play a very important role in the future manufacturing environment. These two technologies provide background for the sharing of product data and the integration of applications on the network. This paper describes a prototype CAD/CAE enviroment that is integrated on the network by STEP and CORBA. Several application servers and client software were developed to verify the proposed concept.

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A Study on the Integrated Simulator Scheme for Communication Networks (통신망 통합시뮬레이터의 구축방안에 관한 연구)

  • Kwon, Ho-Yeol;Kim, Hwa-Jong
    • Journal of Industrial Technology
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    • v.12
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    • pp.37-49
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    • 1992
  • We proposed an integrated simulator scheme for communication networks. The network modeling and Analysis methologies are firstly discussed along the design procedure of a network simulator, and then, the structure, kernel, and user interfaces are defined for the simulator. Finally, for the verification of our approach, simulations are performed for a simple queueing network and a pure ALOHA system using Ptolemy, a multi-paradigm simulation enviroment.

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A Method for Finding Articulation Points on a Mobile Agent Enviroment (이동 에이전트를 갖는 네트워크 환경에서 단절점을 찾기 위한 방법)

  • 김영균;김경하;김영학;오길호
    • Proceedings of the Korean Information Science Society Conference
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    • 2000.04a
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    • pp.214-216
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    • 2000
  • 분산 네트워크 환경에서 단절점의 존재는 신뢰성을 떨어뜨리는 주요한 요인이며, 통신 트래픽의 부하가 집중될 수 있는 지점이다. 본 논문에서는 분산 이동 컴퓨팅 환경을 갖는 네트워크상에서 분산 깊이 우선 탐색 방법을 이용하여 단절점을 찾는 효율적인 방법을 제안 한다. 시작 노드는 단절점을 발견하기 위한 이동 에이전트를 인접한 노드에 보내고, 파견된 이동 에이전트는 네트워크상의 각 노드들을 차례로 방문하여 깊이 우선 번호를 기본으로 하여 단절점을 찾게 된다.

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