• 한국대기환경학회지
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• 제5권1호
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• pp.68-78
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• 1989

The heavy metal of suspended particulates with human health has long been studied in environmental interest concerned. This study was intended to identify harmful heavy metals of the ambient air borne dusts which were related with the respirable sizes in the aerodynamics. Two sampling sites were selected comparatively; one was in the Shinchon area, which is the commercial district with heavy traffic and the other site was in the Bulgwang area which is residential area. The supended particulates were sampled by high volume air sample with 6 cascade impactor stages. The heavy metals in terms of As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, V and Zn were determined by stomic absorption spectrometry or inductively coupled plasma emission spectrometry. The samples weretaken bimothly for seven consecutive days from May 1987 to March 1988. The annual average concentration of the respirable suspended dust of which diameter is less than 10$\mum$ was 152.59 $\mug/m^3$ of the Shinchon air samples; the respirable dust was equivalent to approximately 85% of the total suspended particulates. The annual average concentration of the respirable suspended dust of the Bulgwang air samples was 112.56 $\mug/m^3$; that was approximately 86% of the total suspended particulates. The concentration of heavy metals was investigated in relation to the particle size. The concentration of Cr, Fe, Mn and V were tended to be much more in the coarse particles than in the fine particles. Cd and Pb in the fine particles were more than in the coarse particles. In the partial correlation coefficients; in the Shinchon area, high correlations among Fe, Se and Mn were determined; it is assumed that those sources would be originated from coal, gasolineand diesel. In Bulgwang area, would be high correlation among Fe, Se, Hg and Mn considered to be originated from coal, Bunker-C and heavy oil as well. From the above results, the hazardous heavy merals in air should be measured and controlled in originally their sources.

• 한국균학회지
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• 제13권2호
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• pp.115-121
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• 1985

우리나라 서울 지역의 상업지역, 교통지역, 주택지역, 공장지역, 목욕탕, 백화점, 병원지역 등을 대상으로 open plate method를 사용하여 공중균을 분리한 결과 총 2,227개의 spore를 분리하였다. 그중 Cladosporium이 1,008 spores, Penicillium이 351 spores, Alternaria가 234s, Aspergillus가 84s이며 그리고 미동정된 spore수는 524이었다. 옥내와 옥외의 균의 분포를 비교 고찰한 결과 옥내보다 옥외에서 균의 종류가 더 다양하였다 옥내와 옥외에서 발견된 균중 빈도가 많은 네균류의 분포를 보면, Cladosporium, Penicillium, Alternaria, Aspergillus순으로 많이 나타났다. 그 중 Cladosporium, Penicillium, Aspergillus는 옥내에서, Alternaria고는 옥외에서 더 많이 분리 되였다. 옥외지역의 경우 상업지역, 교통지역, 주택지역 순으로 균이 많이 분포 되었고, 옥내에서는 공장지역, 백화점, 목욕탕, 병원지역의 순서로 많이 나타난다. 계절별로 보면 총 코로니수가 여름, 가을에 걸쳐 많았고, 봄과 겨울이 적은 편이었다. Cladosporium, Penicillium, Aspergillus 경우에는 가을에 많이 분포되어 있었으며, Alternaria는 여름에 많이 분리되었다. 그리고 Cladosporium은 계절별 커다란 차이가 나타나나 Penicillium, Alternaria는 계절별 차이가 적고 Aspergillus는 계절별 차이가 거의 없었다. 상업지역, 교통지역, 주택지역 등의 옥외 지역을 계절별로 조사한 결과 이들 세 지역 모두 여름과 가을에 걸쳐 많은 균의 분포를 나타내었다. 공장지역, 백화점, 병원지역 등의 옥내지역에서도 마찬가지로 여름과 가을에 가장 많은 균이 분리되었으나 계절 변화에 큰 영향을 미치지 못하는 목욕탕만은 계절적 차이가 현저하게 나타나지 많았다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 I
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• pp.403-408
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• 2001

Structure-borne noise and vibration is one of the main complaints of home appliances such as refrigerators, washing machines, air conditioners, etc. There have been many efforts to reduce the emitting noise and vibration. Mostly the efforts have been concentrated to optimize the mounts shape and its material properties realizing that the vibration power is mainly transmitted to the structure via mounts. It is known that softer mounts have the better vibration isolation effect. But mounts have another important function in addition to the vibration isolation. That is to support the motor and compressor safely. Thus mounts should be stiff enough to resist the supporting items. But the two properties, stiff and soft, are contradict each other. So the designer should compromise the two complicity properties properly in between. Noticing that, motors and compressors themselves are very quite until they are connected to the base structure via mounts, wire connecting idea was proposed in this work. Instead of using conventional mounts, as shown in Fig 4, compressor was mounted using six wires as shown in Fig 5. Since wire is very flexible in bending but stiff in tension, we can realize the ideal mount design requirements, stiff enough to support and soft enough to isolate vibration power. The suggesting idea was tested with an air conditioner outdoor unit.

• 한국소음진동공학회논문집
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• 제19권11호
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• pp.1222-1230
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• 2009

A theoretical model was developed to compute the effect of a bubble layer in reducing the radiation noise generated by a force applied on an infinite flat plate considering the noise of multi-bubbles. Using the model, the effectiveness of a bubble layer in reducing the structure-borne noise of the plate was evaluated to consider various parameters such as the source noise levels, the thickness of bubble layers, the volume fractions and the frequency characteristics of bubbly fluids. Considering the noise of multi-bubbles, the actual reduction effect of radiation noise using a bubble layer was expected in cases of high source levels, high volume fractions of bubbles and large thickness of the bubble layer above the resonance frequency of the bubble layer. Accordingly, it is recommended that the thickness of a bubble layer, the source noise level and the characteristics of bubbly fluids should be optimized cautiously to maximize noise reduction effects.

• 한국균학회지
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• 제21권1호
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• pp.77-84
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• 1993

Out of 210 tinea capitis cases studies, 16 were negative when examined with KOH, among the remaining 194 cases, 123 were males (63.4%) and 71 were females (36.6%) and the age of incidence ranged between 7 and 15 years. Microsporum was the main causal agent being identified in 82 cases (42.3%) and was represented by 5 species among which M. canis was common in Egypt (55 cases, 28.4%). Trichophyton constituted 32% and was represented by 8 species among which T. violaceum was the most common (24.2% of total cases). Candida were isolated from 3.6% of total cases. The 47 species and twenty-five genera from nondermatophyte-cyclohexamide resistant fungi were recovered from the diseased skin tissue. Penicillium and Aspergillus were the most abundant followed by Scopulariopsis, Alternaria, Thermoascus, Chrysosporium and Cladosporium. Studies of the air-borne fungi in-door the hospital wards revealed the occurrence of 57 species belonging to 28 genera, among which Aspergillus flavus, Penicillium chrysogenum, p. corylophilum, A. niger, Tritirachium rosum and Alternaria alternata were the most common. Results of the out-door experiments were basically similar to those of the in-door experiments.

• 대한원격탐사학회지
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• 제28권6호
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• pp.693-704
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• 2012

Space-born remote sensing camera systems tend to be developed to have very high performances. They are developed to provide extremely small ground sample distance, wide swath width, and good MTF (Modulation Transfer Function) at the expense of big volume, massive weight, and big power consumption. Therefore, the camera system occupies relatively big portion of the satellite bus from the point of mass and volume. However, the camera systems for lunar exploration don't need to have such high performances. Instead, it should be versatile for various usages under various operating environments. It should be light and small and should consume small power. In order to be used for national program of lunar exploration, electro-optical versatile camera system, called MAEPLE (Multi-Application Electro-Optical Payload for Lunar Exploration), has been designed after the derivation of camera system requirements. A ground model of the camera system has been manufactured to identify and secure relevant key technologies. The ground model was mounted on an aircraft and checked if the basic design concept would be valid and versatile functions implemented on the camera system would worked properly. In this paper, results of design and functional test performed with the field campaigns and air-born imaging are introduced.

• 대한조선학회 특별논문집
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• 대한조선학회 2011년도 특별논문집
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• pp.43-46
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• 2011

The noise characteristics of multi-purpose dive support vessel show the different patterns such as types of noise sources, accommodation arrangement and etc due to its operation. Especially, the tunnel and retractable thruster for the dynamic positioning should be considered at the noise analysis. The floating floor is selected as the main measure of noise reduction and is constructed at the deck near the noise sources. In this paper, the noise analysis of dive support vessel is based on the estimation of noise sources and floating floor and SEA (Statistical Energy Analysis) is used for analysis of the air-born noise and structure-borne noise. The noise analysis of air conditioning system is also carried out and the noise results of cabin room are reviewed.

• 한국전자통신학회논문지
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• 제16권5호
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• pp.969-974
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• 2021

우리나라는 국토교통 7대 신산업 중 하나로 무인 항공기의 하나의 종류인 드론 산업을 선정하여 드론 산업활성화를 위해 드론특별자유화구역을 선정하고 드론 관련 법안을 신설, 개정하는 등의 노력을 하고 있다. 이러한 노력을 통해 향후 드론 택배, 드론 택시 등이 운용될 것으로 보인다. 이에 드론과 고정익, 회전익 등의 기존 항공기들과의 다자간 충돌 회피 시스템을 구축하여 발생 가능한 드론과 항공기간 공중 충돌에 대비하여야 한다. 이에. 그 방안을 제시하려 한다.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.814-819
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• 2005

There is growing consciousness of the environmental performance of buildings in Hong Kong. The Buildings Department, the Lands Department and the Planning Department of the Hong Kong Government issued the first of a series of joint practice notes [1] to promote the construction of green and innovative buildings. Green features are architectural features used to mitigate migration of noise and various air-borne pollutants and to moderate the transport of heat, air and transmission of daylight from outside to indoor environment in an advantageous way. This joint practice note sets out the incentives to encourage the industry in Hong Kong to incorporate the use of green features in building development. The use of green features in building design not only improves the environmental quality, but also reduces the consumption of non-renewable energy used in active control of indoor environment. Larger window openings in the walls of a building may provide better natural ventilation. However, it also increases the penetration of direct solar radiation into indoor environment. The use of wing wall, one of the green features, is an alternative to create effective natural ventilation. This paper therefore presents a preliminary numerical study of its ventilation performance using Computational Fluid Dynamics (CFD). The numerical results will be compared with the results of the wind tunnel experiments of Givoni.

• Environmental Analysis Health and Toxicology
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• 제20권4호통권51호
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• pp.365-374
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• 2005

Ambient air particulate matters are classified into two distinct modes in sire distribution, namely the coarse and fine particles. Correlation between high particulate concentration and adverse effect on human populations has long been recognized. However, the toxicology of these adverse efforts has not been clarified. We investigated the genotoxic effect of PM 2.5 collected from urban area in Seoul by comet assay (A549 cells), CBMN assay (CHO-K1 cells) and EROD-microbioassay (H4IIE cells). Results from in vitro micronucleus assay and comet assay showed that PM 2.5 samples collected from traffic area, residential area and indoor air induced chromosomal damage and DNA breakage in a non-cytotoxic dose. The complex mixture effect of these PM 2.5 extracts was quantified by EROD-microbioassay in terms of its bio-TEQ (biologiral -TCDD equivalent concentration) which was 70.87$\pm$28.07, 93.55$\pm$21.80 and 14.31 $\pm$ 1.10 ng/g-PM 2.5 in traffic area, residental area and indoor air samples, respectively. Conclusively, we suggested that PM 2.5 collected from traffic area and residential area contains CYPIA inducer and genotoxic materials.