• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.1
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• pp.19-27
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• 2010

Sky cover method can be used to determine sky condition by cloud amount of the Korea Meteorological Administration. And, HCI (Hourly Clearness Index) method is another method determined by measured horizontal global radiation data. The results of the HCI methods of Erbs et al. (1982), Orgill and Hollands (1977) seem to be not good enough because of the air pollution such as smog phenomenon or yellow sand phenomenon and so on. Therefore, HCI should be corrected. The aim of this study is to improve HCI. Therefore, this study is to analyze and compare on the sky conditions from Sky cover method and HCI, and then presents hourly correction factor based on Sky 채팩 method. The results of corrected HCI improved.

• Hwankyungkyoyuk
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• v.20 no.3
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• pp.63-75
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• 2007

This paper focused on examining the middle school students' perceptions of characteristics(personal knowledge, human responsibility, impact on personal life, and predicted trend, behavior will) of 10 global and 8 local environmental issues. Subjects(N=516) demonstrated by completing a survey that they perceived the characteristics of issues differently on global and local scales, and to a degree those characteristics are related. First, middle school students' perceptions of global and local environmental issues were above mid-point mainly, and perceptions of local environmental issues were higher than those of global environmental issues. At perceptions of characteristics, They perceived that the personal knowledge of global environmental issues were higher than those of local issues, that the human responsibility effects on global environmental issues more than local environmental issues, that global environmental issues in the future, will be more serious. For each environmental issues, the perception of global warming among the global issues was highest, the perception of yellow dust and air pollution among the local issues was highest. For perceptions of characteristics, behavior will to solve the environmental issues was lower than that of 4 characteristics(personal knowledge, human responsibility, impact on personal life, and predicted trend). Second, there was significant difference of the perceptions of two scale environmental issues for area and sex. It showed that Seoul students' perceptions were higher than Kong-ju students' perceptions according to area, and that girl students' perceptions were higher than boy students' perceptions according to sex. Third, correlations among issues were significant. Especially, it was positive relationship between knowledge and human responsibility, human responsibility and impact on personal human responsibility and predicted trend. Educators and communicators should take into account the perceived characteristics of environmental issues and choose effective information sources and teaching methods to improve students' understanding of human-induced environmental changes.

• KOREAN ASSOCIATION OF OCCUPATIONAL HEALTH NURSES
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• v.8 no.2 s.28
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• pp.10-18
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• 2001

우리나라 대기오염의 수준은 지난 90년대 초반 이후 아황산가스와 총부유분진의 농도가 감소하고, 대신 오존과 이산화질소의 농도가 증가하면서 점차 다른 선진국에서 경험하는 대기오염현황을 보이고 있다. 한편 PM10과 PM2.5와 같은 미세분진의 경우 그 측정기간이 짧고 자료가 제한적이지만, 일부 지역에서 증가추세를 보이고 있으며, 그 수준을 비교하였을 때 현재 선진국에서 책정한 미세분진의 규제농도를 훨씬 상회하는 것으로 판단된다. 대기오염으로 인한 건강영향으로는 급성으로 고농도에 수 시간에서 수 일 동안 노출되는 경우 폐기능의 저하, 심박동의 변화, 그리고 신체내 염증물질의 증가 등 인체 기능의 변화가 보고되고 있으며, 기존에 폐장질환이나 심혈관질환을 앓고 있는 사람들의 경우 증세의 악화와 의료이용의 증가 등을 경험하거나 더 나아가 사망에 이르러 수명이 단축되는 것이 보고되고 있다. 급성노출의 경우 미세분진 PM10 10 $\mu$m/m3 당 전체 사망률이 0.5-1$\%$ 가량 증가하는 것으로 보고되며, 만성노출을 조사한 코호트 연구에 근거하는 경우 대기오염에 노출되는 전체 인구에 있어 PM2.5 1 $\mu$m/m3 당 1개월의 수명이 단축되는 것으로 추정되고 있다. 아직 대기오염으로 인한 건강영향의 기전이 전부 밝혀진 것은 아니지만, 일부 연구에서 대기오염물질 중에서 전이금속의 역할이 보고되고 있으며, 대기오염에 노출되면서 기관지, 폐포 및 혈액 등에서 염증매개물질의 분비 및 확산 그리고 심장을 비롯한 각 장기 기능의 변화가 보고되고 있다. 한편 이러한 변화들이 증세와 건강상의 비가역적 변화를 야기하는데 있어 대기오염 수준의 역치는 없는 것으로 판단되고 있다. 이러한 대기오염의 영향에 대한 개인수준의 해결책으로서는 자동차 사용의 절제 및 개인적인 쓰레기 소각의 자제 등 오염원 발생의 감소와 함께 대기오염 수준에 따른 증세 및 투약의 적절한 조절과 신체 활동의 조절을 통하여 오염원을 회피하는 것이 강조되어야 하며, 또한 흡연 특히 실내흡연의 금지와 실내 주방기구 및 난방기구의 관리 등이 구체적으로 제시될 수 있다. 마지막으로 대기오염물질들이 신체에 들어와 산화제로 작용하는 만큼, 식품을 통한 항산화제의 섭취가 일반적인 건강관리 수준에서라도 반드시 강조되어야 할 것이다.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.6
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• pp.88-96
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• 2008

Currently, due to the serious world-wide air pollution by substances emitted from vehicles, emission control is enforced more firmly and it is expected that the regulation requirements for emission will become more severe. A new concept combustion technology that can reduce the NOx and PM in relation to combustion is urgently required. This study used a split injection method at a 4 cylinder common-rail direct injection diesel engine in order to apply the partially premixed charge compression ignition combustion method without significantly altering engine specifications And it is investigated that the effects of the injection ratio and SCV(swirl control valve) to emission characteristics. From these tests, soot(g) and NOx(g) emission could be reduced to 40% and 92% compared to base engine performance at specified engine driving conditions(6 points with weight factors) according to application of split injection and SCV(swirl control valve).

• The Journal of the Convergence on Culture Technology
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• v.6 no.2
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• pp.529-534
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• 2020

The development of civilization is in line with evolution of cities and transportation technology caused by industrialization. Up to now, a city has been developed owing to transportation cost reduction and needs for land utilization as a limited core business district. Continuous increase of urban population density has accompanied by lots of problems socioeconomically such as rise of land value, traffic congestion, gap between the rich and poor, air pollution, etc. Those issues are difficult to be solved in existing city ecosystem. However, a clue for solving the problems could be found in there. The design of Seoul mid-night bus route was from analysis of movement of people in the rural area by using ICT so that a city ecosystem should be firstly analyzed for solving rural issues. If the cause of those is found, big data platform construction is required to raise the life quality of citizen and the problems could be solved. Big data should be located in the middle of the platform connected with every element of city based on ICT for real-time collection, analysis and application. This paper addresses construction of big data platform and its application for sustainable smart city.

• Journal of Preventive Medicine and Public Health
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• v.37 no.3
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• pp.225-231
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• 2004

Objectives : This study was performed to examine the influence of smoking on the blood cadmium concentration in university students. Methods : The study included 300 university students. A questionnaire interview was used to collect data. The urine cotinine and blood cadmium levels were measured as biological exposure indices. The data were analyzed using t-tests ANOVA and ANCOVA. Results : The median value of blood cadmium concentration was equal in both males and females ($0.8{\mu}g/l$). This level was relatively low in comparison with the reference value suggested by WHO (2001). ANCOVA showed that smoking related variables, urine cotinine and smoking amount, were significantly associated with the blood cadmium level (P=0.004, 0.015). However, the values with regard to traffic related air pollution were not significantly associated with the blood cadmium level. Conclusions : Smoking is an important source of nonoccupational cadmium exposure in young people. The Blood cadmium level is at least 10% higher in active smokers than in passive or nonsmokers. The level of urine cotinine can be used as an indicator of non-occupational exposure of respirable cadmium due to smoking, as there is a good correlation bestween smoking amount and the urine cotinine level.

• Korean Journal of Ecology and Environment
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• v.41 no.1
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• pp.66-72
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• 2008

Total metals, soluble metals, and bioavailable metals were monitored at the sediments of urban lakes located in Seoul, Korea during spring season 2006. The metals measured were zinc, arsenic, chromium, copper, nickel, and cadmium, which are known to be toxic to human health and ecosystems. The main sources of heavy metals in the lakes were urban runoff and atmospheric deposition associated with air pollution in urban areas. Extraction by using a weak electrolyte solution (0.1 M $Ca(NO_3)_2$) was used to predict bioavailability of the metals. Among the six heavy metals studied, copper was the most bioavailable, based the weak electrolyte extraction techniques. Since metal toxicity is related to metal bioavailability, the results were consistent with the high ecotoxicity of copper, compared to other heavy metals. Overall results suggest that there was no direct relationship between total and bioavailable metal concentration, although zinc, copper and cadmium show some relationships.

• Journal of the Korean Society for Railway
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• v.20 no.1
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• pp.11-19
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• 2017

Since operation of railway trains is a major source of particle pollution in tunnel air, a particle removal device can be an effective measure to remove wear particles. To obtain design conditions of the particle removal device that will be installed underneath the railway trains, the wind speed and particle concentration underneath the trains were investigated using a three-dimensional ultrasonic anemometer and a DustTrak aerosol monitor, respectively. The measurements were made for the trains running on Seoul Metropolitan Subway Line 5 on February 10, 2015. The data were analyzed according to the track geometry (straight, curved) and train speed pattern (acceleration, cruising, and deceleration) between stations. Train speed was also analyzed. The average wind speed and $PM_{10}$ concentration underneath the trains were ~30% of the train speed and ${\sim}200{\mu}g/m^3$ for both straight and curved sections. Average $PM_{10}$ concentration for deceleration sections was higher than that for acceleration sections.

• Korean Journal of Environment and Ecology
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• v.9 no.1
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• pp.15-29
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• 1995

To investigate plant community structure of Uiryung valley, Harujae valley, Kugi valley, Songchu valley, Tobongsan valley in Bukhansan National Park, each thirty eight, forty, twenty six. twenty eight, thirty six plots (plot size 100$m^2$) were set up and surveyed. The surveyed data were integrated and classification by TWINSPAN and DCA ordination techniques were applied to the study area. The plant community were divided into nine groups in seventy nine plots by TWINBPAN and the dividing groups were Carpinus laxiflora community(I), Quercus mongolica community(II), Pinus densiflora community(III), Q. mongolica-P. densiflora community(IV) Q. mongolica-Q. serrata- Prunus sargentii community(V), Q. mongolica Q. variabilis community(Ⅵ), Robinia pseudoacacia-Q. serrata community(Ⅶ). P. rigida-Q. serrata community(Ⅷ), Q. mongolica- Q. variabilis- Styrax obassia community(Ⅸ). So the successional trends of tree species at the natural forest seem to be from P. densiflora to Q. mongolica and at the artificial forest seem to be from R. pseudoacacia, P. rigida to Q. acutissima, Fraxinus rhynchophylla in canopy layer And in the subtree and shrub layer, it wag supposed that from Deotzia prunifolia, Rhus trichocarpa. Rhododendron yedoense var. poukhasleilse, Euonymus oxyphyllous to Magnolia sieboldii, Acer psuedo-sieboldianum, Lindera obtusiloba. In comparing successional trends with past study, it was postulated that successtion is not progressed by human disturbance and soil acidification by the air pollution.

• Korean Journal of Environment and Ecology
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• v.35 no.6
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• pp.644-658
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• 2021

Understanding the functional traits of dominant species in urban ecosystems provides insight into species' trait adaptation and ecosystem function in response to fragmented and isolated urban vegetation and reduced biological interactions. This study compared means and variances of environmental factors (geographic, meteorological, and soil attributes) and 4 leaf traits (leaf area, specific leaf area, leaf dry mass content, and leaf shape index) and 7 reproductive traits (fruit width, fruit length, fruit shape, fruit dry weight, fruit dry matter content, seed weight, and seed ratio) measured of 40 Sorbus alnifolia individuals in four mountainous areas south of Seoul downtown, South Korea. We then performed the multivariate analysis of trait combinations. While the measured environmental factors indicated the individuality of the survey sites, the urban vegetation was drier and had a longer growth period. The leaves of S. alnifolia in the urban areas were smaller and heavier, and the fruits produced longer and lighter seeds, showing the traits affected by long urbanization. The study confirmed changes in the growth and reproduction mechanism of the S. alnifolia population under the urban environment, indicating reduced biological interaction due to vegetation fragmentation and isolation. This study provides limited but distinct ecological information about the function and persistence of key species in cities with a reduced scale of biological interactions and many negative environmental factors such as air pollution.