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      • KCI등재

        제주도 지하수 질산염 농도의 시·공간적 변화 특성: 장기(1993-2015) 모니터링 자료의 평가

        김호림(Ho-Rim Kim),오준섭(Junseop Oh),도현권(Hyun-Kwon Do),이경진(Kyung-Jin Lee),현익현(Ik-Hyun Hyun),오상실(Sang-Sil Oh),감상규(Sang-Kyu Kam),윤성택(Seong-Taek Yun) 대한자원환경지질학회 2018 자원환경지질 Vol.51 No.1

        1993년부터 2015년까지 관측된 제주도 지하수 장기모니터링 관측정(N = 4,835)에서 수집된 지하수 수질자료(N = 21,568)를 기반으로 질산성질소의 시공간적 변동 특성을 평가하였다. 제주도 지하수의 질산성질소 농도의 중앙값은 2.5 mg/L로서 다른 국가나 대륙의 조사 결과에 비해 다소 높거나 유사한 것으로 나타났다. 또한 지하수 용도, 행정구역 및 고도 별로 유의한 차이를 보였다. 특히, 산간 지역에 비해 저지대 해안가에 위치한 농업 및 주거지역에서 농도가 높음을 확인하였다. Mann-Kendall 및 Sen’s slope 분석을 활용한 질산성질소 농도의 추세 분석 결과, 하류 저지 대에 비해 중산간지역에서의 질산성질소 농도 증가 경향이 뚜렷하였다. 제주도 내 토지 피복의 시계열 변화 특성과 결부 지어 보면, 중산간지역의 오염 증가 추세는 농업지역의 확장 등 인위적 활동 증가에 기인한 결과로 판단된다. 반면,기지정된 지하수자원특별관리구역에서는 전반적으로 질산성질소 농도의 감소 경향이 나타났는데, 이는 지하수 관리 측면에서 수질관리를 위한 적극적인 정책이 유효함을 시사한다. 본 연구에서는 제주도 지하수의 질산성질소 오염관리를 위한 적정 방안을 제안한다. The spatio-temporal variations of nitrate concentrations in groundwater of Jeju Island were evaluated by an analysis of time series groundwater quality data (N = 21,568) that were collected from regional groundwater monitoring (number of wells = 4,835) for up to 20 years between 1993 and 2015. The median concentration of NO 3 -N is 2.5 mg/L, which is slightly higher than those reported from regional surveys in other countries. Nitrate concentrations of groundwater in wells tend to significantly vary according to different water usage (of the well), administrative districts, and topographic elevations: nitrate level is higher in low-lying agricultural and residential areas than those in high mountainous areas. The Mann-Kendall trend test and Sen’s slope analysis show that nitrate concentration in mid-mountainous areas tends to increase, possibly due to the expansion of agricultural areas toward highland. On the other hand, nitrate concentrations in the Specially Designated Groundwater Quality Protection Zones show the temporally decreasing trend, which implies the efficiency of groundwater management actions in Jeju. Proper measures for sustainable groundwater quality management are suggested in this study.

      • 정상과 갑상선 종양조직에서 사람 IGF-I 유전자의 발현

        김성운,장현하,박상미,김덕윤,우정택,양인명,김진우,김영설,김광원,고석환,홍성화,최영길 경희대학교 유전공학연구소 1993 遺傳工學論文集 Vol.5 No.-

        Many of the growth-promoting properties of growth hormone(GH) are mediated by insulin-like growth factor-I(IGF-I), a highly conserved circulating 70-amino acid peptide. Recent studies have shown that multiple mechanisms influence IGF-I gene expression, including transcription from two promoters, alternative RNA splicing, and variable polyadenylation. In thyroid tissue, thyroid stimulating hormone(TSH) and IGF-I are the most possible candidates for follicular cell proliferation and hypertrophy. Actually IGF-I had autocrine and paracrine effect for tissue growing. We prepared thyroid tumor tissue mRNAs using single step method for detecting IGF-I levels according to different tissues, i.e., thyroid adenoma or papillary thyroid carcinoma. We used Northern blot analysis for IGF-I mRNA and RNase protection assay (RPA) for IGF-I transcription start sites. For Northern blot, we used whole human IGF-I cDNA as a DNA probe and for RPA, we used IGF-I exon 1 containing noncoding promoter 1 as a riboprobe. We got good RNA bands from Northern blot analysis around 1 kb (IGF-IA) and 7.5 kb (IGF-IB) region. To clarify the amount of both IGF-IA and IB mRNAs, we measured autoradiographied signal of IGF-I mRNAs bands using densitometer. In IGF-IA signals, there's no change among liver and thyroid tissues, but in case of IGF-IB mRNA bands, the signal was markedly increased in thyroid carcinoma tissues than that of normal thyroid tissue (85% vs 14%). In the study of RPA, all thyroid tissues used the same transcription start sites as those of liver's. We concluded that that this different regulation of IGF-I mRNA was originated from tissue specificity. That meant some tissue specific transcription factor/s were related to tissue IGF-I expression.

      • KCI등재후보

        소아의 상완골 원위부 과간 골절

        이우석,정환용,김우식,김용찬,전택수,김남현,김규태 대한골절학회 2004 대한골절학회지 Vol.17 No.4

        상완골 원위부 과간 골절은 소아에서는 매우 드물게 발생되는 골절로 대부분 주관절의 굴곡상태로 주관절 후방부에 직접적인 충격에 의해 발생하는 것으로 보고되고 있다. 전위가 없거나 경미한 경우 도수적 정복술 혹은 도수적 정복술 후 경피적 핀고정술을 시행하며, 전위가 심한 골절이거나 도수적 정복술이 불가능한 경우 관혈적 정복술 후 핀고정술을 시행하는 것으로 알려져 있다. 저자들은 전위된 상완골 원위부 과간 골절 환아 2예에서 각각 도수적 정복술과 관혈적 정복술 후 K 강선 고정술을 시행하여 만족한 결과를 얻었기에 보고하는 바이다. Intercondylar fractures of the distal humerus are very rare in children. The pattern of the fracture would suggest that the mechanism of injury involves a fall directly on the flexed elbow. Most agree that the undisplaced fracture can be managed conservatively. With increasing displacement and comminution, the opinions tend to differ. We suggest that closed reduction with percutaneous K wire pinning and open reduction with percutaneous K wire pinning offer a satisfactory methods by which to treat displaced intercondylar fracture in children.

      • KCI등재

        대칭형 보에 의해 보강된 등방성 평판의 음향방사에 관한 연구

        김택현,오택열,김종태 한국공작기계학회 1998 한국생산제조학회지 Vol.7 No.1

        The determination of sound pressure radiated from peoriodic plate structures is fundamental in the estimation of noise levels in aircraft fuselages and ship hull structures. As a robust approach to this problem, here a very general and comprehensive analytical model for predicting the sound radiated by a vibrating plate stiffened by periodically spaced orthogonal symmetric beams subjected to a sinusoidally time varying point load is developed. The plate is assumed to be infinite in extent, and the beams are considered to exert both line force and moment reactions on it. Structural damping is included in both plate and beam materials. A space harmonic series representation of the spatial variables is used in conjunction with the Fourier transform to find the sound pressure in terms of harmonic coefficients. From this theoretical model, The sound pressure levels on axis in a semi-infinite fluid (water) bounded by the plate with the variation in the loactions of an external time harmonic point force on the plate can be calculated efficiently using three numerical tools such as the Gauss-Jordan method, the LU decomposition method and the IMSL numerical package.

      • 염분이 함유된 폐수의 생물학적 처리시 염분농도가 오염물질의 제거에 미치는 영향

        김상수,문병현,이택순,서규태,공남식 7개 국립대학교 환경연구논문집 공동발행 위원회 2005 공업기술연구 Vol.5 No.-

        Effects of salt concentration and C/N ratio on pollutants removal efficiencies were investigated in treatment of seafood wastewater by sequence batch reactor(SBR). The synthetic seafood wastewater containing salinity from 3,000 to 10,000 mg/L NaCI and C/N ratio of 2 and 4 was treated by SBR. Removal efficiencies of COD_(Mn), T-N, and T-P decreased with increasing salt concentration, but eventually reached a pollutants removal a platrau. As systems adapted in salts until salts concentration of 8,000mg/L, the time required to reach the pollutants removal efficiencies at steady state was reduced. However, the removal efficiencies of pollutants sharply decreased and the time require to reach steady state was increased as salt concentration rose to 10,000mg/L, Removal efficiencies of COD_(Mn) were higher for C/N ratio of 4 than for 2. Effects of salt on the nitrogen removal were not faster than the organic removal but the time required to the nitrogen removal at steady state was ncreased. The removal efficiencies of phosphorus also were redueed as salt concentration increased, which inhibited the release of phosphorus than the uptake.

      • 대칭형 보강재 간격에 따른 주기구조물의 음향방사에 관한 연구

        김종태,김택현 朝鮮大學校 機械技術硏究所 2000 機械技術硏究 Vol.3 No.2

        The purpose of this research is to study the vibration and acoustic pressure radiation from a thin isotropic flat plate stiffened by a rectangular array of beams, and excited by a point harmonic force. Periodic constructions on aircraft and ship structures are often subjected to frequency dependent pressure fluctuations and forces. For example, the forces exerted by the wing attachments on the fuselage may be modeled as concentrated static forces arising from the dead weight of the attachments and dynamic forces from the engine moving parts, while a random acoustic pressure variation over the structure is realized around a jet efflux. Fluctuating pressure excitations are also caused by boundary layer pressure fields. These excitations induce structural vibrations in a wide range of frequencies, which may cause such things as acoustic fatigue and internal cabin noise in the aircraft. It is thus important that the response characteristics and vibration modes of such periodic structures be known. From this theoretical model, the sound pressure levels in a semi-infinite fluid(water) bounded by the plate with the variation in the locations of an external time harmonic point force on the plate can be calculated efficiently using three numerical tools such as the Gauss-Jordan method, the LU decomposition method and the IMSL numerical package.

      • 진양호 유입수의 홍수기 오염부하 및 수질특성

        김영충,서규태,문병현,이택순 7개 국립대학교 환경연구 논문집 공동발행 위원회 2001 환경연구논문집 Vol.1 No.1

        This study is to evaluate the characteristics of pollution load into lake Jinyang by flooding. Water quality of Kyongho and Duckcheon river, which are major tributary of lake Jinyang, was analyzed during rainy season. Increased pollution load was observed at initial stage of rainfall. This was caused by pollutants washed out of non-point sources at initial run off. It was considerable that much higher pollution load was measured during the flood than the value calculated using loading rate.

      • 생물학적 폐수처리시 휴지기간이 처리특성에 미치는 영향에 관한 연구

        김상수,문병현,서규태,이택수 7개 국립대학교 환경연구 논문집 공동발행 위원회 2004 공업기술연구 Vol.4 No.-

        Under recent situation of more stringent effluent regulations, small scale biological process for industrial wastewater treatment has on operational problems, such as highly variable loadings into the system. Especially, the seafood processing industry has difficulties to treat is because of its highly variable organic loading and high saline concentration (>30g/d㎥). High salt concentrations disrupt metabolic functions and cause plasmolysis and/or loss of activity of microbial flora, hence the biological treatment of the saline wastewaters could produce low COD removal efficiency. On the basis of background mentioned above, an appropriate operation of the existing treatment plant is required for stable effluent discharge at even highly influent loading. In this study, effects of long term ( days) idle periods on floc characteristics were investigated in treatment of saline wastewater by SBR. Temporal stop of feeding affects biological activity in the reactors and then floc structures such as size and fractal dimension. After a certain period of reoperation for orgnic activity, the size and fractal dimension of floc start to increase.

      • 도시공간구조에 따른 존별 첨두율 예측모형 연구 : 대구광역시 중존을 중심으로

        김태헌,김택근,김기혁 계명대학교 산업기술연구소 1998 産業技術硏究所 論文報告集 Vol.21 No.1

        The aim of this research is to find out the characteristics of peak hour rate and to estimate the peak hour by spatial structure and social factors in the urban area The data used to estimate peak rate was based on Taegu city's person trip survey in 1992. Multiple regression analysis have used to develop the prediction equations for the peak hour trip by various types of land use and urban characteristics data.

      • 兒童臺의 外部環境觀分析

        金龍洙,李鉉澤 COLLEGE OF AGRICULTURE KYUNGPOOK NATIONAL UNIVERSI 1984 慶北大農學誌 Vol.2 No.-

        Children's view of outdoor environments was studied by analyzing the drawings of elementary school children. The results obtained were as follows: More area of garden was expressed in drawings of city children than in those of rural children. There was no significant difference between the garden areas in the drawings of male and female children. Housing was expressed overwhelmingly more frequently in the drawings of rural children than in those of city children. Gate and fence were clearly expressed in the drawings of rural children, but not in the drawings of city children. The frequencies of lawn, pond and path as components of garden increased as school year got higher. Whereas flower and flower bed were decreased in frequency and the ratio of flower and flower bed area was decrease to a half in the drawings of sixth year children compared to that of second year children. City children expressed rocks, recreation and sports facilities frequently within their gardens. This obviously reflected the limited play space for city children. In preference of children, pine, ginko, juniper, hymalaya cedar were high in order among the trees, and rose, hibiscus, chrysanthemum, sunflower, goldenbell tree, and tulip were high in order among the flowers.

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