• 제목/요약/키워드: Direct Sampling

검색결과 465건 처리시간 0.023초

여수석유화학산단 내 VOCs에 대한 오염원 분류표의 개발 및 CMB 모델에 의한 기여도 산정 (Development of Source Profiles and Estimation of Source Contribution for VOCs by the Chemical Mass Balance Model in the Yeosu Petrochemical Industrial Complex)

  • 전준민;허당;김동술
    • 한국대기환경학회지
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    • 제21권1호
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    • pp.83-96
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    • 2005
  • The purposes of this study were to characterize the local levels of VOCs (volatile organic compounds), to develop source profiles of VOCs, and to quantify the source contribution of VOCs using the CMB (chemical mass balance) model. The concentration of VOCs had been measured every 6-day duration in the SRO monitoring site in the Yeosu Petrochemical Industrial Complex from September 2000 to August 2002. The total of 35 target VOCs, which were included in the TO-14 designated from the U.S. EPA, was selected to be monitored in the study area. During a 24-h period, the ambient VOCs were sampled by using canisters placing about 10 ~ 15 m above the ground level. The collected canisters were then analyzed by a GC-MS in the laboratory. Aside from ambient sampling at the SRO site, the VOCs had been intensively and massively measured from 8 direct sources and 4 general sources in the study area. The results obtained in the study were as follows; first, the annual mean concentrations of the target VOCs were widely distributed regardless of monitoring sites in the Yeosu Petrochemical Industrial Complex. In particular, the concentrations of BTX (Benzene, Toluene, Xylene), vinyl chloride were higher than other target compounds. Second, based on these source sample data, source profiles for VOCs were developed to apply a receptor model, the CMB model. Third, the results of source apportionment study for the VOCs in the SRO Site were as follows; The source of petrochemical plant was apportioned by 31.3% in terms of VOCs mass. The site was also affected by 16.7% from wastewater treatment plant, 14.0% from iron mills, 8.4% from refineries, 4.4% from oil storage, 3.8% from automobiles, 2.3% from fertilizer, 2.3% from painting, 2.2% from waste incinerator, 0.6% from graphic art, and 0.4% from gasoline vapor sources.

Body Mass Index Distributions and Sociodemographic Factors Affecting BMI of Children Living in Anyang, Korean

  • Yim, Kyeong-Sook;Nam, Ki-In
    • Journal of Community Nutrition
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    • 제1권2호
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    • pp.81-87
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    • 1999
  • Body mass index(BMI) is recognized as one of the most useful indexes for adiposity in children and adults. This study was conducted to provide information on BMI distribution by age and sex in Korean children, and to identify sociodemographic factors that affected BMI among children. The study was conducted on 2376 children(boys 1184, girls 1192) living in a middle-size city in Korea. Subjects were selected from the primary schoolchildren in grades 1-6 using the two-stage sampling method. Their mean age was 9.4 years. The percentile of BMI tended to increase as age increased in both sexes. The 85th percentile for boys, aged 6-12 years, was 19.8kg/㎡, and the 95th percentile was 22.5kg/㎡. The 85th percentile for girls, aged 6-12 years, was 18.9kg/㎡, and the 95th percentile was 21.5kg/㎡. Multiple regression analysis was carried out to predict BMI from percent ideal body weight (PIBW), age and sex. After adjusting PIBW and age, BMI for boys was 0.062kg/㎡ lower than that for girls. One year of age increased BIM by 0.55kg/㎡. The prevalence rate of overweight and obesity based on PIBW was 15.8% and 15.0% for boys, and 14.0% and 11.0% for girls, respectively. Demographic factors such as sex, age, and parents' obesity influenced children's BMI. After adjusting for sex, age and parents' BMI, the presence of another children in family, and mother's employment status showed a strong effect on children's BMI. The results suggest an age-sex specific BMI distribution of Korean children. The present study also provides direct evidence of a correlation between early life environmental factors, such as presence of siblings or mother's employment, and BMI level in Korean children.

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침수식생 개수로에서 난류 및 부유사 이동 특성 (Characteristics of Turbulent Flows and Suspended Sediment Transport in Open-channel with Submerged Vegetation)

  • 양원준;장지연;최성욱
    • 한국수자원학회논문집
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    • 제44권5호
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    • pp.417-427
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    • 2011
  • 침수식생 개수로 흐름은구조적으로상부영역과식생영역으로구분되는데, 상부영역은 일반 개수로의 흐름특성을 보이며 식생영역은 줄기에 의해 난류가 억제되어 정수식생 조건의 흐름과 유사하게 단순한 흐름특성을 보인다. 본 논문은 침수식생 개수로 흐름의 난류 및 유사이동 특성에 관한 실험연구이다. 이를 위해 폭 0.5m, 길이 12m인 개수로 실험장치를 이용하여수리실험을 실시하였다. 다양한 유량에 대하여 수심비 2~3인 흐름을 구현하였고, 나무원형 실린더를 이용하여 식생을 재현하였다. 평형상태에서 부유사 농도 분포를 측정하기 위해서중앙입경이 75 ${\mu}M$인 모래를 한계조건에 도달하기까지 지속적으로 투입하였다. 유속 성분의 계측을 위하여 레이저 도플러 유속계를 사용하였고, 튜브를 이용한 사이포닝 방식으로 시료를 직접 채취하여 부유사 농도를 측정하였다. 측정된 자료를 이용하여 실험조건에 따른 평균흐름과 난류량의 특성을 살펴보았고, Rouse 수에 따른 부유사 농도 분포를 제시하였다.

시뮬레이션 교육이 간호대학생의 교육실재감, 시스템사고능력 및 문제해결 적극성에 미치는 효과 (The Effects of Simulation-based Education on Nursing Students' Presence in Education, Systems Thinking and Proactivity in Problem Solving)

  • 조옥희;황경혜
    • 가정∙방문간호학회지
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    • 제23권2호
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    • pp.147-154
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    • 2016
  • Purpose: This study aimed to develop and apply simulation-based education, and to verify the effects of this type of education on nursing students' presence in education, systems thinking, and proactivity in problem solving. Method: Subjects were 69 senior college students recruited through convenient sampling. This study used a one-group pre-posttest quasi-experimental design. A structured survey was administered a week before and after provision of the simulation-based education once a week for 4 weeks. Data were analyzed using descriptive statistics and t-tests. Results: Teaching presence increased after the educational intervention; instructional design and organization, and aspect of direct facilitation subscales improved. Learning presence increased after the educational intervention; although cognitive presence did not change, emotional presence increased. With regard to emotional presence, perception and expression of one's emotional status increased, although emotional management did not change. Moreover, systems thinking increased. Among the subscales, team learning showed an increase after the educational intervention. However, there was no significant difference in proactivity in problem solving, although it showed an increase after the educational intervention. Conclusion: Based on the aforementioned study results, there is need to establish educational environments for qualitative teaching and learning presence, and devise strategies to increase learning effects with various teaching methods and type of content.

일부 농촌주민의 사회적지지, 사회조직망과 건강행태와의 관련요인 분석 (A Study on the Relationship between Social Support, Social Network and Health Behaviors among Some Rural Peoples)

  • 이무식;김대경;김은영;나백주;성태호
    • 보건교육건강증진학회지
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    • 제19권2호
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    • pp.73-98
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    • 2002
  • This study was carried out to investigate the relationship between social support, social network and health behaviors as surveyed by cross-sectional study in 744 rural people aged above 30 of a community dwelling sample of one county for 6 days of July in 2000. Objectives of this study was in order to establish an effective health promotion. The sample was accrued by face to face interview of direct visiting from clustered sampling method. Interview was conducted by trained medical students with the questionnaire consisted of socio-demographic data, health behavior, social support and social network based on previous literature. The summarized results were as follows: 1. There were significant difference in the level of social support and social network by general characteristic variables except occupation and residency type(p〈0.05). 2. There were significant difference in knowledge about hypertension, smoking status, status of physical exercise, diet patterns by social support and social network in spite of variation of social support and social network subconcept(p〈0.05). And there were significant difference in alcohol drinking status, body weight control and diet pattern according to level of social network(p〈0.05). But smoking status by social support and network results opposite direction(p〈0.05). 3. There were no regular or consistent result in the relationship between social support, social network and health behavior. 4. Major predictors for health behavior on the multiple logistic regression that included general characteristic, social support and social network were age, instrumental social support and worry about health. Significant variables of multiple logistic regression for health behavior that included social support(instrumental and emotional) and social network were instrumental social support and social network. These results suggest that only a instrumental element and social network may be associated with health behavior. Inconsistent with prior research in these some item, a positive consistent relationship was not found between social support, social network and health behavior. So the study should be replicated to determined the reliability of our findings.

Correlates of Depressive Symptoms among College Students on Jeju Island in Korea

  • Kim, Moon-Doo;Lee, Chang-In
    • 보건교육건강증진학회지
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    • 제20권4호
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    • pp.13-26
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    • 2003
  • Objectives: The aim of the present study was to determine the prevalence depressive symptoms, and the correlates of depressive symptoms, and to propose countermeasures for individual depression risk factors among college students. Methods: One university and three colleges in Jeju-do were selected as the study population and a total of 1000 students were selected by multiphasic cluster sampling to represent each department and year within each college. Of the 945 total respondents, 421 were men and 524 were women. The Beck Depression Inventory was used to evaluate depression and the BDI STEN score was used to assess depressive symptoms. Multiple logistic regression analysis was performed for comparisons. Results: 1. The prevalence of depressive symptoms among men was 14.4%, while among women the level rose to 26.8%. 2. Those with poor life satisfaction scores were significantly more likely to have depressive symptoms than those with good life satisfaction (odds ratio (OR) = 2.62; (95% confidence interval (95%CI), 1.483-4.629). 3. Students over 23 years old were significantly more likely to have low levels of depressive symptoms than those under 18 (OR = 0.439; 95%CI, 0.247-0.779). 4. Groups with poor body image satisfaction had higher levels of depressive symptoms when compared to respondents who had good body image (OR = 2.847; 95%CI, 1.341-6.045). 5. Students with poor perceived health status were significantly more likely to have high levels of depressive symptoms than those with good perceived health status (OR = 2.029; 95%CI, 1.157-3.557). Conclusion: Universities and colleges should provide education programs, such as health education that facilitates the development of a healthy body image. In addition, they should focus on various scholarships that could improve satisfaction with student life, especially for alienated students. Furthermore, colleges should help direct students towards engagement in more productive work, and lead social policies away from the dominance of appearance.

시화호 표층퇴적물의 중금속 및 퇴적상 변화 (Change of Heavy Metals and Sediment Facies in Surface Sediments of the Shihwa Lake)

  • 최만식;천종화;우한준;이희일
    • 한국환경과학회지
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    • 제8권5호
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    • pp.593-600
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    • 1999
  • In order to determine the changes of sediment facies and metal levels in surface sediments after the construction of Shiwha Lake, surface sediments were sampled at 8 sites located on the main channel monthly from June, 1995 to August, 1996 and analysed for 12 metals (Al, Fe, Mn, V, Cr, Co, Ni, Cu, Zn, Cd, As and Pb) by ICP/AES and ICP/MS. Two groups of sampling sites(the inner lake with 3 sites and the outer lake with 5 sites) are subdivided by the surface morphology ; the inner lake is a shallow channel area with a gentle slope, while the outer lake is relatively deep and wide channel with a steep slope which has many small distributaries. After the construction of dam, fine terrestrial materials were deposited near the outer lake, which resulted in the change of major sediment facies from sandy silt to mud. With the deposition of fine sediments in the outer lake, anoxic water column induced the formation of sulfide compounds with Cu, Cd, Zn and part of Pb. Metal (Cr, Ni, Cu, Zn and Cd) contents in sediments increased up to twice within 2 years after the construction of dam. This is due to the direct input of industrial and municipal wastes into the lake and the accumulation of metals within the lake. In addition, frequent resuspension of contaminated sediments in a shallow part of the lake may make metal-enriched materials transport near the outer lake with fine terrestrial materials. As the enrichment of Cu, Zn, Cd and part of Pb in the Shiwha Lake may be related to the formation of unstable sulfide compounds by sulfate reduction in anoxic water or sediment column, the effect of mixing with open coastal seawater is discussed.

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이종 해상도 스테레오 비디오 코딩 시스템 (Heterogeneous Resolution Stereo Video Coding System)

  • 박시내;심동규
    • 방송공학회논문지
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    • 제13권1호
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    • pp.162-173
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    • 2008
  • 본 논문에서는 스테레오 시점 및 디스플레이 특성을 고려한 효율적인 스테레오 비디오 코딩 방법을 제안한다. 현재 많은 스테레오 비디오 디스플레이 장치는 기존의 단일 시점 비디오 출력과 스테레오 비디오 출력이 모두 가능하다. 이러한 장치에서 스테레오를 비디오 출력 시에는 스테레오 디스플레이 패널의 특성으로 인하여, 두 개 시점 비디오 각각을 수평축으로 1/2 다운 샘플링된 비디오를 입력받는다. 본 논문에서는 기존의 단일 비디오와 스테레오 비디오 시스템을 동시에 고려하기 위하여, 좌측영상은 원래의 해상도로 코딩하고, 우측영상은 가로 방향으로 1/2 다운 샘플링 하여 코딩하는 방법을 제안한다. 우측 영상의 코딩 시 좌측영상을 참조하는 경우 참조 영상과 원 영상사이의 해상도가 일치하지 않아 시점 간 예측이 불가능하므로, 본 논문에서는 이를 위해 시점간 예측방법을 변경하여 부호화하는 방법을 제안한다. 실험결과 제안된 방법은 기존의 스테레오 비디오 부호화 방법에 비하여 $0.5{\sim}0.8\;dB$ 이상의 코딩 이득을 얻을 수 있었다.

농촌 고령자주택의 창고용부속사 계획 - 충청남도 지역의 사례를 중심으로 - (The Planning of the Storehouse affiliated with Rural Housing for the Elderly - Focused on the Cases in Chungcheongnam-do -)

  • 이윤재
    • 한국실내디자인학회논문집
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    • 제26권1호
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    • pp.114-123
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    • 2017
  • The objective of this paper is to investigate problems associated with the storehouse affiliated with rural housing for the elderly engaged in farming activities, and to suggest improvements with the examples of storehouse floor plans. The elderly in rural area still engage in farming even though they are suffering from aging problems. Therefore, the planning of storehouse which has relevance to agriculture is very important. The methods employed were a field survey and interviews with residents. 12 houses belonging to elderly people (60's and over) were selected by the convenient sampling in Cheonan, Chungcheongnam-do. The results are as follows. First, at least more than 3 storehouses have to be planned to store the goods separatedly according to their kinds and characteristics. Second, storehouses should be placed near or directly connected with the main house to support the accessibility of the elderly. Third, the open space has to be planned in front of the storehouse to park a truck for loading goods directly. Fourth, the storage equipments such as shelves should be planned inside of the storehouse for the space efficiency and user convenience. Fifth, the width of the door should be wide enough to carry agricultural products and goods. It is recommended to use double hinged doors or double pocket doors. Besides, the thresholds of the doors should be removed and, rather than using direct lighting system, it is better to use indirect lightings and task lightings together to minimize glare and to provide enough illumination.

민간경비업체 조직구성원의 조직 환경, 조직 문화가 조직 성과에 미치는 영향 (The Influence of the Organizational Environment and Culture of the Employees in Private Security Corporation on the Organizational Performance)

  • 정남주
    • 시큐리티연구
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    • 제29호
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    • pp.251-278
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    • 2011
  • 본 연구는 민간경비업체 조직구성원들의 조직환경, 조직문화가 조직성과에 미치는 영향을 규명하기 위하여 연구대상은 2011년 전라남 북도 경찰청에 등록된 민간경비업체에 재직하고 있는 조직구성원 중 민간경비원을 대상으로 판단표집법을 이용하여 총 200부의 표본을 추출하였다. 그 중 불성실한 응답 설문지 22부를 제외한 188부를 최종분석에 사용하였다. 수집된 자료는 SPSS 15.0 프로그램을 이용하여 빈도분석, 탐색적 요인분석, 신뢰도분석 및 상관관계분석, 경로분석을 하였다. 연구결과를 보면 다음과 같다. 첫째, 민간경비업체 조직구성원의 조직환경이 조직문화간에 상관관계가 있는 걸로 나타났다. 둘째, 민간경비업체 조직구성원의 조직환경은 조직문화 및 조직성과에 인과적 영향을 미치는 결과를 보였다. 즉, 조직환경은 조직성과에 직접적으로 영향을 미치지만, 조직문화를 통해서 간접적인 영향을 미치는 결과를 보였다.

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