국내 심부 암반지하수에서의 고농도 불소 산출과 관련된 수리지구화학 진화

김경호,윤성택,채기탁,김성용,권장순,고용권,Kim Kyoung-Ho,Yun Seong-Taek,Chae Gi-Tak,Kim Seong-Yong,Kwon Jang-Soon,Koh Yong-Kwon 대한자원환경지질학회 2006 자원환경지질 Vol.39 No.1

국내 심부 암반지하수에서의 고농도 불소의 산출을 지배하는 지질 및 수리지구화학적 환경을 이해하고자, 온천 개발 목적으로 착정한 심부지하수 관정(평균 심도 약 600m)에서 취득된 총 367개의 지하수 분석 자료에 대하여 지구화학적 고찰을 수행하였다. 이들 지하수에서의 불소 농도는 매우 높아 평균 5.65mg/L에 이르며, 특히 연구 대상 지하수 중 $72\%$에서 먹는 물 수질기준(1.5mg/L)을 초과하였다. 불소 함량은 일차적으로 지질 조건의 지배를 강하게 나타냄을 확인하였는데 가장 높은 농도는 화강암류 및 화강편마암 지역에서 산출되는 반면 화산암 및 퇴적암 지역에서는 가장 낮았다. 지하수의 수리지구화학상과 관련하여 보면, 중성 내지 약알칼리성인 $Ca-HCO_3$형 지하수에 비하여 알칼리성의 $Na-HCO_3$형 지하수가 현저히 높은 불소 함량을 나타내었다. 화강암류 및 화강편마암 지역에서 지하수의 심부 순환에 수반되는 장기간의 물-암석 반응이 고농도 불소 산출의 가장 중요한 이유로 생각된다. 방해석 침전 또는 양이온교환에 의한 Ca 이온의 감소, 그리고 뒤따라 발생하는 사장석과 불소 함유 수산화광물(특히 흑운모)의 용해로 특징되는 일련의 수리지구화학 반응이 이러한 환경 하에서의 고불소 지하수 생성의 원인으로 해석된다. 따라서 불소과다에 의한 물 공급 문제의 발생 가능성은 높은 pH 및 매우 높은 Na/Ca농도비를 나타내는 화강암류 및 화강편마암 지역의 지하수에서 가장 높다고 볼 수 있다 To understand the geologic and hydrogeochemical controls on the occurrence of high fluoride concentrations in bedrock groundwaters of South Korea, we examined a total of 367 hydrochemistry data obtained from deep groundwater wells (avg. depth=600 m) that were drilled fur exploitation of hot springs. The fluoride concentrations were generally very high (avg. 5.65mg/L) and exceeded the Drinking Water Standard (1.5 mg/L) in $72\%$ of the samples. A significant geologic control of fluoride concentrations was observed: the highest concentrations occur in the areas of granitoids and granitic gneiss, while the lowest concentrations in the areas of volcanic and sedimentary rocks. In relation to the hydrochemical facies, alkaline $Na-HCO_3$ type waters had remarkably higher F concentrations than circum-neutral to slightly alkaline $Ca-HCO_3$ type waters. The prolonged water-rock interaction occurring during the deep circulation of groundwater in the areas of granitoids and granitic gneiss is considered most important for the generation of high F concentrations. Under such condition, fluoride-rich groundwaters are likely formed through hydrogeochemical processes consisting of the removal of Ca from groundwater via calcite precipitation and/or cation exchange and the successive dissolution of plagioclase and F-bearing hydroxyl minerals (esp. biotite). Thus, groundwaters with high pH and very high Na/Ca ratio within granitoids and granitic gneiss are likely most vulnerable to the water supply problem related to enriched fluorine.

서울시 ESCO사업의 현재와 미래

김경호,Kim, Gyeong-Ho 에너지절약전문기업협회 2007 esco Vol.47 No.-

서울시가 앞으로 추진하는 건물개조사업은 조명, 냉난방, 공조시스템 뿐만 아니라, 단열, 지붕, 창문 개선 및 태양광 시설 등 신.재생 에너지 설치 등이 포함된 사업이며, 서울시의 계획은 건물 에너지 절약과 온실가스 배출 감축 등 환경적 효용 외에도 건물 운영비 절감을 통한 임대비용 절감, 관련 산업 육성 등 경제 유발과도 상당할 것으로 기대하고 있다.

BUSINESS GUIDE_이미지메이킹 - 친절한 사람에겐 웃음이 있다!

김경호,Kim, Gyeong-Ho 한국제품안전협회 2010 제품안전 Vol.197 No.-

고층건물의 효율적인 구조해석

김경호,이동근,Kim, Kyeong Ho,Lee, Dong Guen 대한토목학회 1987 대한토목학회논문집 Vol.7 No.2

고층 건물의 정확한 거동을 구하기 위한 구조 해석은 컴퓨터 적용의 중요한 분야로 취급되어 왔다. 본 논문에서는 건축구조물에 대한 3차원적인 해석방법을 연구하였다. 이 해석 방법은 건물을 각각의 독립된 프레임의 조합체로 보고 해석하므로 매우 효율적이며, 건물의 3차원적인 거동에 관한 고려는 건물이나 하중이 대칭이 아닐 때는 특히 중요하다. 그리고 matrix condensation 기법을 이용함으로써 컴퓨터의 용량과 해석 시간이 상당히 절약되므로 매우 경제적이다. 본 논문의 건물 구조해석 컴퓨터 프로그램 PFS의 정확성과 효율성을 증명하기 위해 여러가지 예제들에 대해서 SAPIV 에 의한 해석 결과와 비교하였다. 그러므로, 본 논문에서 제안한 해석방법은 고층 건물의 구조 설계에서 매우 효율적이라 할 수 있다. The prediction of the exact behavior of multistory building is one of the most complicated problem encountered in structural engineering practice. An efficient computer method for the three dimensional analysis of building structures is presented in this paper. A multistory building is idealized as an assemblage of a series of rectangular plane frames interconnected by rigid floor diaphragms. The matrix condensation technique is employed for the reduction of degrees of freedom, which results in a significant saving in computational efforts and the required memory size. Kinematical approach was used to assemble condensed stiffness matrices of plane frames into a three dimensional stick model stiffness matrix. The static analysis follows the modified tridiagonal approach. Since this procedure utilizes the condensed stiffness matrix of the structure, the dynamic equations of motion for the story displacement are developed by assigning proper mass for each story. Analysis results of several example structures are compared to those obtained by using the well-known SAP IV for verification of the accuracy and efficiency of the computer program PFS which was developed utilizing the method proposed in this study. The analysis method proposed in this study can be used as an efficient and economical means for the analysis of multistory buildings.

원발성 부갑상선 기능항진증의 치료 경험

김경호,박종대,홍석준,Kyung Ho Kim,M.D.,Chong Dae Park,M.D. and Suck Joon Hong,M.D. 대한갑상선-내분비외과학회 2003 The Koreran journal of Endocrine Surgery Vol.3 No.1

Purpose: The number of patients diagnosed with primary hyperparathyroidism has been increased owing to the routine biochemical screening of serum calcium since 1970's in the western countries as well as recently in Korea. However, the absolute number of surgically treated patients in Korea is still smaller than other developed countries in the incidence wise, and this could indicate the tendency of relatively late diagnosis and treatment of primary hyperparathyroidism in Korea. This study was performed to investigate the clinical character and post operative results of surgically treated Korean patients. Methods: 80 primary hyperparathyroidism patients surgically treated at Asan Medical Center from Jan 1996 to August 2002 were reviewed retrospectively. Results: The etiological proportion of the primary hyperparathyroidism (single adenoma 80%, hyperplasia or multiple adenoma 10%, MENI 9%, cancer 1%) was similar to the western countries. However, the proportion of the symptomatic patients (82%) to the asymptomatic patients (18%) was much higher compared to the recent data of western countries. 41 patients (single adenoma 36 case, hyperplasia 4 cases, cancer 1case) were followed up more than 3 months after surgery with monitoring the serum calcium and i-PTH. In 23 patients (44%), their i-PTH level was above normal range more than once during follow up period without hypercalcemia. The postoperative serum calcium level was lower and the preoperative i-PTH level was higher in these patients significantly compared to the patients with normal postoperative i-PTH level. The tumor size tended to be larger in these patients but statistically insignificant. These results suggest that these patients had more severe hyperparathyroidism. Conclusion: The proportion of the patients who were symptomatic and has persistent post operative high i-PTH level suggesting severe hyperparathyroidism was relatively high compared to the western countries. Earlier diagnosis and treatment is demanded in Korea. (Korean J Endocrine Surg 2003;3:1-6)

BUSINESS GUIDE_이미지메이킹 - 습관과 태도가 성공을 부른다.

김경호,Kim, Gyeong-Ho 한국제품안전협회 2010 제품안전 Vol.196 No.-

3D-FEMWATER 모델을 이용한 대창지역의 해수침투 범위추정

김경호,박재성,이호충,연주흠,Kim Kyoung-Ho,Park Jae-Sung,Lee Ho-Jin,Youn Ju-Heum 한국농공학회 2005 한국농공학회논문집 Vol.47 No.5

The present study examined the 3 dimensional space distribution characteristics of sea water intrusion using data available from previous observations. For this study, we used 3D FEMWATER, which is a 3 dimensional finite element model. The target area was around Daechang-ri, Gimje-si, Jeollabuk-do. The area is relatively easy to formulate a conceptual model and has observation wells in operation for surveying sea water intrusion. Considering the uncertainty of numerical simulation, we analyzed sensitivity to hydraulic conductivity, which has a relatively higher effect. According to the result of the analysis, the variation of TDS concentration had an error range of $-1,336{\~}+107 mg/{\iota}$. Taking note that the survey data from observation wells were collected when the boundary between fresh water and sea water in the aquifer was in equilibrium, we set the range of time for numerical simulation and estimated the spatial distribution of TDS concentration as the range of sea water intrusion. According to the result of estimation, the spatial distribution of TDS concentration calculated when 1,440 days were simulated was taken as the range of sea water intrusion. Using the result of calculation, we can draw not only vertical views for a certain section but also horizontal views of different depth. These views will be greatly helpful in understanding the spatial distribution of the range of sea water intrusion. In addition, the result of this study can be used rationally in proposing an optimal quantity of water pumping through investigating the moving route of sea water intrusion over time in order to prevent excessive water pumping and to maintain an optimal number of water pumping wells per interval.

국부 통계 특성을 이용한 적응 MAP 방식의 고해상도 영상 복원 방식

김경호,송원선,홍민철,Kim, Kyung-Ho,Song, Won-Seon,Hong, Min-Cheol 한국통신학회 2006 韓國通信學會論文誌 Vol.31 No.12C

본 논문에서는 국부 통계 특성을 이용한 적응 MAP 방식의 고해상도 영상 복원 알고리즘에 대해 제안한다. 고해상도 원 영상의 윤곽선을 보존하기 위해 저해상도 영상의 국부 특성을 이용하여 시각함수를 정의하였고, MAP(Maximum A Posteriori) 추정 방식을 이용하여 국부적인 열화 정도(smoothness)를 조절하였다. 또한 가중치가 부여된 함수를 이용하여 원 고해상도 영상에 가능한 가까운 최적의 해를 찾기 위하여 반복기법을 사용하였으며, 열화 요소는 매 반복 단계마다 부분적으로 복원된 고해상도 영상으로부터 이용하였다. 제안된 방식의 성능을 실험 결과를 통해 확인할 수 있었다. In this paper, we propose an adaptive MAP (Maximum A Posteriori) high-resolution image reconstruction algorithm using local statistics. In order to preserve the edge information of an original high-resolution image, a visibility function defined by local statistics of the low-resolution image is incorporated into MAP estimation process, so that the local smoothness is adaptively controlled. The weighted non-quadratic convex functional is defined to obtain the optimal solution that is as close as possible to the original high-resolution image. An iterative algorithm is utilized for obtaining the solution, and the smoothing parameter is updated at each iteration step from the partially reconstructed high-resolution image is required. Experimental results demonstrate the capability of the proposed algorithm.

미스트화학기상증착시스템의 전구체 수용액 혼합비 조절을 통한 (Al_xGa_1-x)₂O₃ 에피박막의 밴드갭 특성 제어 연구

김경호,신윤지,정성민,배시영,Kim, Kyoung-Ho,Shin, Yun-Ji,Jeong, Seong-Min,Bae, Si-Young 한국전기전자재료학회 2019 전기전자재료학회논문지 Vol.32 No.6

We investigated the growth of $(Al_xGa_{1-x})_2O_3$ thin films on c-plane sapphire substrates that were grown by mist chemical vapor deposition (mist CVD). The precursor solution was prepared by mixing and dissolving source materials such as gallium acetylacetonate and aluminum acetylacetonate in deionized water. The [Al]/[Ga] mixing ratio (MR) of the precursor solution was adjusted in the range of 0~4.0. The Al contents of $(Al_xGa_{1-x})_2O_3$ thin films were increased from 8 to 13% with the increase of the MR of Al. As a result, the optical bandgap of the grown thin films changed from 5.18 to 5.38 eV. Therefore, it was determined that the optical bandgap of grown $(Al_xGa_{1-x})_2O_3$ thin films could be effectively engineered by controlling Al content.

자유기고: 기적의 사과처럼, 기적의 나무를

김경호,Kim, Gyeong-Ho 한국조경수협회 2011 造景樹 Vol.120 No.-