제주시 대기부유분진 중 수용성 이온성분의 입경별 분포특성

허철구,송정화,이기호 한국환경과학회 2004 한국환경과학회지 Vol.13 No.12

Atmospheric particulate matters were collected by 8-stage non viable cascade impactor from October 2002 to August at Jeju City. Eight water-soluble ionic components (Na^(+), NH₄^(+), K^(+), Ca^(2+), Mg^(2+), Cr^(-) NO₃^(-) and SO₄^(2-)) were analyzed by Ion Chromatography. The concentration of particulate matters and eight water-soluble ionic components were determined to investigate their size distributions. Particulate matters exhibited a tri-modal distribution with peak value around 0.9, 4.0㎛ and 9.5㎛. In summer, the last peak value was lower than other season values likely due to particulate matter scavenged by rain water. Four ionic components (Na^(+), Ca^(2+) Mg^(2+) and Cl^(-)) exhibited a bi-modal distribution in the coarse mode whereas three ionic components (NH₄^(+), K^(+) and SO₄^(2-)) in the fine mode, with maximum peak value around 0.9um. NO₃ was found in both the coarse and the fine mode. The enrichment factor (E.F.) of each ionic components was calculated. Based upon E.F., it is considered that Na^(+), Cr, and K^(+) in coarse paricle mode were delivered form oceanic source, but other components might have other source origins.

대기환경지수를 이용한 제주지역 대기질 평가에 관한 기초적 연구

허철구,이기호,박용이 제주대학교 환경연구소 1997 환경연구논문집 : 제주대 Vol.5 No.-

The assessment of the air quality of Cheju area was carried out by AI(Air Index) and AEI(Air Environment Index). The air quality data, which measured at two air pollution monitoring network(Idodong ; located at Cheju city, Yongsuri ; located at western coastal region of Cheju island), were used in this study. The average concentration of major air pollutants(SO_(2), NO_(2), CO, TSP(PM-10)) were very low, but the ozone(O_(3)) concentration remarkably high. The monthly A1 values at Idodong and at Yongsuri were 7.0 ± 1.8 and 4.7 ± 1.4, respectively, therefore the air quality was classified as 'Good' level. And the monthly AEI values at same regions were in the range of 16.9-20 and 20.1-28, respectively, so the air quality was classified as 'Moderate' level. We found that the same air quality data was assessed at different level according to estimating mothod by A1 or by AEI. It seemed that the modification of the subindex and/or standard level was necessary to estimate A1 and AEI practically. Also, it was found that the critical pollutant was ozone in estimating A1 and AEI at Cheju area. But it assumed the ozone at Cheju area was caused by natural sources but anthropogenic sources. Thus, it seemed that the local background level of air pollutants was considered in estimating AI and AEI.

아래턱뼈 계측을 통한 한국인의 체질인류학적 특징 및 남녀판별함수 분석

허경석,고기석,정한성,강민규,최병영,김희진 대한췌담도연구회 2000 대한췌담도연구회지 Vol.5 No.4

제주도의 대기오염 현황 및 장래예측

허철구,이기호,강창희 제주대학교 환경연구소 1993 환경연구논문집 : 제주대 Vol.1 No.-

This study deals with the air pollution status, the characteristics of air pollution sources and the prediction of future air quality in Cheju. The present air quality is estimated very satisfactorily in comparison with the air quality standard. And the concentration of sulfur dioxide in ambient air has been increased little for the last five years. The primary major source of air pollution is transportation which include 57% of total emissions of air pollutants. Also. air pollution sources are rnaldistributed on the seashore, especially concentrated on Cheju city, The emission rate of air pollutants in Cheju is 43,766 ton/year. but emissions per uint area (24ton/year. ㎢) is of very small quantity in comparison with that of other region. On the other hand, the ambient air quality a t the year 2001 is predicted by Val-ley model is lower than the air quality standard, althought emission rate is increased due to increasing in air pollution sources.

제주도 해안가에서 측정된 에어로졸의 성분별 입경분포 특성

이기호,양희준,허철구 한국환경과학회 2003 한국환경과학회지 Vol.12 No.10

During the period from April to September 2002, the size distributions of ambient aerosol were measured at the coastal site at Hamduk in Jeju Island. Na^(+), K^(+), Mg^(2+), Ca^(2+) and CF exhibited mostly a bimodal coarse mode size distribution, while ammonium and sulfate were mainly in the fine size range, with maximum at around 0.54um. The average molar concentration ratio of ammonium to sulfate for fine particles was equal to 2.0±0.9. Nitrate was evenly found in both the coarse and fine modes. Elements like Al, Fe, Cu, Mg. Na. Ti. Sr and Mn were dominant in coarse particles, with the maximum at around 5.25㎛. S and Pb were mainly in the submicrometer size range. Other elements with a fine and coarse modes were V. Ni, Cu, Ba and Mo. The patterns of the size distributions of trace elements measured at the downtown in Jeju City were very similar to those at the coastal site in Hamduk. However, the amplitude of size fractional concentrations at Jeju City was narrower than that at Hamduk. While the mass median diameters for the chemical species originated from the natural origin such as marine and crust were relatively large, those for ammonium, sulfate, S and Pb were very small.

국내 레미콘사의 부순모래 사용실태 조사

김기훈,金虎林,金光華,윤기원,한천구 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1(구조계)

Crushed sand is made by crushing the rock artificially. With the wide shortage of natural fine aggregates at all regions in Korea. crushed sand has been increasingly consumed as a alternative aggreagtes of natural sand. But there is insufficient information related to the actual situation on the produce. quality and manufacturing company of crushed sand. In this paper. survey is performed in order to know actual consumption situation of crushed sand through ready mixed concrete company in domestic. The remicon companies using crushed sand were estimated with 55%. According to the using method of crushed sand. most remicon company used fine aggregates by mixing natural sand and crushed sand. It is found that natural sand is replaced by crushed sand by about 20~50%. For quality problems in using crushed sand. grain shape. grade and fine particles shall be improved to meet the quality requirement of remicon and wide application. Therefore. it is found that quality improvement of crushed sand is required.

한국어 자료 사전 구축을 위한 데이터 구조와 노드 구성 형태

박기홍,이태헌,정정후 群山大學校 1996 論文集 Vol.23 No.-

Korean analysis systems require a large-scale data dictionary and the built dictionary is very frequently searched during the morphological analysis. For the more efficient system, we must construct the dictionary that has fast size- independent search time and makes efficient use of storage which preserves the basic characteristics of Trie. As regards both side of search time and memory space, we know that search time of double Trie structure using double array is suitable for construction of Korean data dictionary, and the type which we separate each mode by phoneme-unit is more useful to Korean processing.

Developpe devant 수행시 하지 관절 모멘트 분석

박기자,신성휴,권문석,김태완,이형나 한국운동역학회 2004 한국운동역학회지 Vol.14 No.1

K. J. PARK, S. H. SHIN, M. S. KWON, T. H. KIM, H. N. LEE. Analysis on lower extremity joint moment during a developpe devant. Korean Journal of Sport Biomechanics, Vol. 14, No. 1, pp. 133-144, 2004. The purpose of this study was to analyze the joint moment on lower extremity during a developpe devant. Data were collected by Kwon3D, KwonGRF program. Two professional modem female dancers were participated in this experiment. Subjects performed a developpe devant in meddle heights. On the axes of X, Y, Z, it was shown that the maximum joint moment was occurred in hip joint. The moments are plotted during developpe devant. The ankle muscles generate a plantar flexion moment and the knee muscles generate a flexion moment and The hip muscles generate a extension moment. So these muscles of joint muscles were known to play a key role in keeping the body balance while doing developpe devant. In addition adduction moment occurred at hip, knee, an ankle in the order of amount, we could assume from this data that turn out motion started from the hip joint. There was small active turn out possible below the hip joint. A small amount of extra turn out could be obtained when standing because of flexion between the foot and floor, which could be used to give a passive external rotation force to the whole leg and this could produce a rotation between the knee and foot. This passive external rotation could produce very damaging results. Therefore, lower extremity joint muscles such as hip, knee, and ankle muscle should be trained to keep the body balance and prevent injury during developpe devant performance. And for the safe and perfect turn ort performance, hip joint abduction, the most important external rotating muscle for turn out is needed to train and full stretching should be done in advance.

제주지역 지표 오존 농도의 시·공간적 분포 특성

이기호,김대준,허철구 한국환경과학회 2004 한국환경과학회지 Vol.13 No.4

This study has been performed to clarify the characteristics of temporal and spatial distribution of surface ozone concentration over Jeju Island, one of the cleanest areas in Korea with low emissions of air pollutants. Ozone data are monitored at four sites in Jeju Island. These monitoring sites are located at two urban area(referred to Ido and Donghong), coastal area(Gosan site) and forest site(Chuna site). Ozone data has been routinely collected at these sites for the late four years. The patterns of seasonal cycle of ozone concentrations at all stations show the bimodal with the peaks on spring and autumn and a significant summer minimum. However, the patterns of diurnal variations at rural station, i.e., Gosan and Chuna sites are considerably different to those at urban stations such as Ido and Donghong sites. The patterns of ΔO₃ variations are very similar with those of monthly mean ozone concentrations and ΔO₃ values are exceeded 30 ppb, at urban stations. This may be that urban stations are more influenced by local photochemical reactions rather than rural stations. In order to assess the potential roles of meteorological parameters on ozone formation, the meteorological parameters, such as radiation, temperature, and wind are monitored together with ozone concentrations at all stations. The relationships of meteorological parameters to the corresponding ozone concentration are found to be insignificant in Jeju Island. However, at Gosan and Donghong stations, when the sea breeze blew toward the station, the ozone concentration is considerably increased.

Developpe derriere 수행시 하지 관절 모멘트 분석

신성휴,박기자,권문석 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.1

The purpose of this study was to analyze the joint moment on lower extremity using during a developpe deerriere. Data were collected by Kwon3D, KwonGRF program. Two females professional modern dancer were participated in this experiment. Subjects performed a developpe devant in meddle heights(90 deg.). On the axes of X, Y, Z, it wsa shown that the maximum joint moment was occured in hip joint. The moments are plotted during developpe devant. The ankle muscles generate a plantar flexion moment and the knee muscles generate a flexion moment and The hip muscles generate a extension moment. So these muscles of joint were kept the balance going. There is small active turn out possible a level of the leg below the hip joint. A small amount of extra turn out can be obtained when standing because of flexion between the foot and floor which can be used to give a passive external rotation force to the whole leg and this can produce a rotation between the knee and foot. This passive external rotation can produce very damaging results. So, the most important external rotator muscles shoud be trained the adductor group of muscles at hip joint, and be done stretch before performance.