정상안압 녹내장환자에서 OPTN 유전자의 돌연변이

정도현 ( Jeong Do Hyeon ) , 김미랑 ( Kim Mi Lang ) , 문연경 ( Mun Yeon Gyeong ) , 기창원 ( Gi Chang Won ) 대한안과학회 2003 대한안과학회지 Vol.44 No.8

한국 남해 동부 연안 해역에서 홍수기와 갈수기 동안 수질환경 특성과 변동

정도현 ( Do Hyeon Jeong ),신현호 ( Hyeon Ho Shin ),정승원 ( Seung Won Jung ),임동일 ( Dhong Il Lim ) 한국환경생물학회 2013 환경생물 : 환경생물학회지 Vol.31 No.1

남해 동부해역에서 해수는 계절에 따라 서로 다른 수질환경 특성의 수괴들에 의해 조절되는 것으로 밝혀졌다. 홍수기인 여름철 표층수는 북한한류 기원의 동해 냉수괴 특성의 수괴-A (East Sea Cold Water), 담수의 영향이 강한 연안성 수괴-B (river-dominated coastal water), 연안 염하구성 수괴-C (coastal pseudo-estuarine water)로 구분된다. 특징적으로 높은 영양염과 엽록소 농도를 갖는 저염의 염하구성 수괴-B는 홍수기인 여름철에 해안선에서 수 십 km 떨어진 해역까지 짧은 기간 일시적으로 형성되며, 집중호우 등 몬순(monsoon)기후 특성을 갖는 우리나라 연안역에서 육지-해양간 물질 순환에 상당한 역할을 할 것으로 사료된다. 여름철 저층수는 저온-고염의 냉수인 저층 냉수괴-D(bottom cold water)가 지배적이며, 표층수의 수괴들과 비교하여 전체적으로 수온, pH, 용존 산소량은 낮은 반면, 높은 영양염 농도 특성을 갖는다. 여름철 저층 냉수괴의 높은 영양염 농도는 강한 성층과 낮은 수온으로 인하여 식물플랑크톤 번식이 제한되어 보존-축적된 결과로, 갈수기인 겨울철 영양염의 주요 공급원으로 작용한다. 갈수기인 겨울철 연구해역의 해수환경은 여름철과 다르게 대마난류수 (수괴-E)가 광범위하게 분포하며, 해안선을 따라 연안역의 좁은 범위에 대마난류수가 약간 변질된 연안성 수괴-F가 분포한다. 특히 광양만, 마산만 등의 반폐쇄성 지형의 여러 만(bay)들에 위치하는 연안성 수괴-F에서는 갈수기인 겨울철에도 낮은 수심과 느린 유속 등에 의해 기초생산력이 높으며, 이로 인한 겨울철 영양염 고갈(depletion) 현상이 뚜렷하게 나타난다. 또한 남해 연안성 수괴와 대마난류 수괴사이에 연안전선이 발달하며, 이러한 전선은 직간접적으로 남해의 기초생산력을 조절하는 중요 환경요소로 작용할 것으로 예상된다. 결론적으로 연구해역은 계절적으로 다른특성의 수괴의 수괴가 복합적으로 분포하며, 여름철의 수질환경과 일차 생태계는 크게 연안 염하구성 수괴와 저층의 냉수괴 발달 정도에 따라 변화할 것으로 예상되며, 겨울철에는 외양에서 유입되는 대마난류 수괴의 특성에 따라 지배될 것으로 분석된다. 또한 용존무기인이 잠재적 제한영양염으로 작용하는 서해 연안역과 달리 남해 연안역은 대부분 용존무기질소가 잠재적 제한영양염으로 작용하는 것으로 밝혀졌다. 이러한 제한영양염의 차이는 서해와 남해 연안역이 서로 다른 환경과 다른 생태계 구조를 갖고 있음을 지시한다. Physiochemical characters of sea waters during summer flood- and winter dry-seasons and their spatial variations were investigated along the coastal area off the eastern South Sea, Korea. Using the hierarchical clustering method, in this study, we present comprehensive analyses of coastal waters masses and their seasonal variations. The results revealed that the coastal water of the study area was classified into six water masses (A to F). During summer season, the surface water was mainly occupied by the coastal pseudo-estuarine water (water mass B) with low salinity and high nutrients and the river-dominated coastal water (water mass C) with low nutrients, respectively. The bottom water was dominated by cold water (water mass D) with very low temperature, high salinity and high nutrients, compared to masses of surface water. Notably, the water mass B, with high concentrations of nutrients (silicate and nitrogen) and low salinity, which is strongly controlled by the water quality of river freshwater, seems to play an important role in controlling the water quality and further regulating physical processes on ecosystem in the eastern coastal area of South Sea. The water mass D (bottom cold water) coupled with a strong thermocline, which exists in near-bottom layer along the western margin of Korea Strait, has a low temperature, pH and DO, but abundant nutrients. This water mass disappears in winter owing to strong vertical mixing, and subsequently may act as a pool for nutrients during winter dry-season. On the other hand, vertically well-mixed water column during the winter season was typically occupied by the Tsushima (water mass E) and the coastal water (water mass F) with a development of coastal front formed in a transition zone between them. These winter water masses were characterized by low nutrient concentration and balance in N/P ratio, compared with summer season with high nutrient concentrations and strong N-limitation. Accordingly, the analysis of water masses will help one to better chemical and biological processes in coastal area. In most of the study area, characteristically, the growth of phytoplankton community is limited by nitrogen, which is clearly different with coastal environment of West Sea of Korea, with a relative lack of phosphorus. It showed the western and the southern coasts in Korea are substantially different from each other in environmental and ecological characteristics.

임도 절토비탈면의 식생천이 -충청도를 중심으로-

이미정 ( Lee Mi Jeong ),송호경 ( Song Ho Gyeong ),이준우 ( Lee Jun U ),전권석 ( Jeon Gwon Seog ),김효정 ( Kim Hyo Jeong ),정도현 ( Jeong Do Hyeon ) 한국산림과학회 2003 한국산림과학회지 Vol.92 No.4

This study was carried out to select proper species for early stage replantation in forest road cut-slope. From one to fifteen year elapsed forest roads in four regional areas of Chungchung-do, sample plots were selected, and their vegetations and environmental factors were investigated. Invaded species with high frequency ordered Lespedeza bicolor, Rubus crataegifolius, Pueraria thunbergiana, Lysimachia clethroides, Pinus densiflora, Youngia denticulata, Patrinia villosa, and Spodiopogon sibiricus. North cut-slope have the highest value of invaded species number and plant coverage, and so, north aspect cuould be best for plant invasion. According to ordination, distribution of species was influenced by elapsed year and cut-slope aspect. Dactylis glomerata, Eragrostis curvula, Lespedeza bicolor, Lespedeza cuneate, Amorpha fruticosa, Patrinia scabiosaefolia, Artemisia princeps var. orienfalis, Miscanthus sinensis, and Pinus densiflora were considered as proper species for replantation at south slope. Lolium perenne, Dactylis glomerata, Eragrostis curvula, Lespedeza bicolor, Lespedeza cuneata, Amorpha fruticosa, Pueraria thunbergiana, Carex humitis, Patrinia scabiosaefolia, Artemisia princeps var. orientalis, Artemisia keiskeana, Clematis apiifolia, Zanthoxylum schinifolium, Rhus chinensis, Rubus crataegifolius, Rhododendron mucronulatum, Weigela subsessilis, and Pinus densiflora were considered as proper species for replantation at north slope. Sowing herbs(Eragrostis curvula, Lolium perenne, Dactylis glomerata) that were seeded in early stage have changed into invasive herbs, parachute shrubs, and gravitative trees. Naturalized plants(Eragrostis curvula, Dactylis glomerata) that were seeded excessively in early stage have disturbed ecological succession in forest road cut-slope.

지능형 차량 안전시스템 개발 동향

정도현,Jeong, Do-Hyeon 한국전기전자재료학회 2009 전기전자재료 Vol.22 No.9

기계 구조의 강건 설계를 위한 최적화 기법의 개발

정도현,이병채,Jeong, Do-Hyeon,Lee, Byeong-Chae 대한기계학회 2000 大韓機械學會論文集A Vol.24 No.1

In order to reduce the variation effects of uncertainties in the engineering environments, new robust optimization method, which considers the uncertainties in design process, is proposed. Both design variables and system parameters are considered as random variables about their nominal values. To ensure the robustness of performance function, a new objective is set to minimize the variance of that function. Constraint variations are handled by introducing probability constraints. Probability constraints are solved by the advanced first order second moment (AFOSM) method based on the reliability theory. The proposed robust optimization method has an advantage that the second derivatives of the constraints are not required. The suggested method is examined by solving three examples and the results are compared with those for deterministic case and those available in literature.

확률조건의 근사화를 통한 효율적인 강건 최적설계 기법의 개발

정도현,이병채,Jeong, Do-Hyeon,Lee, Byeong-Chae 대한기계학회 2000 大韓機械學會論文集A Vol.24 No.12

Alternative formulation is presented for robust optimization problems and an efficient computational scheme for reliability estimation is proposed. Both design variables and design parameters considered as random variables about their nominal values. To ensure the robustness of objective performance a new cost function bounding the performance and a new constraint limiting the performance variation are introduced. The constraint variations are regulated by considering the probability of feasibility. Each probability constraint is transformed into a sub-optimization problem and then is resolved with the modified advanced first order second moment(AFOSM) method for computational efficiency. The proposed robust optimization method has advantages that the mean value and the variation of the performance function are controlled simultaneously and the second order sensitivity information is not required even in case of gradient based optimization. The suggested method is examined by solving three examples and the results are compared with those for deterministic case and those available in literature.

부 최적화 문제의 근사적인 계산을 통한 신뢰도 최적설계 방범의 효율개선

정도현,이병채,Jeong, Do-Hyeon,Lee, Byeong-Chae 대한기계학회 2001 大韓機械學會論文集A Vol.25 No.10

Alternative computational scheme is presented fur reliability based optimal design using a modified advanced first order second moment (AFOSH) method. Both design variables and design parameters are considered as random variables about their nominal values. Each probability constraint is transformed into a sub -optimization problem and then is resolved with the modified Hasofer- Lind-Rackwitz-Fiessler (HL-RF) method for computational efficiency and convergence. A method of design sensitivity analysis for probability constraint is presented and tested through simple examples. The suggested method is examined by solving several examples and the results are compared with those of other methods.

덮개 함수를 이용한 강건 최적설계의 제한 조건 단일화

이정준,정도현,이병채,Lee, Jeong-Jun,Jeong, Do-Hyeon,Lee, Byeong-Chae 대한기계학회 2002 大韓機械學會論文集A Vol.26 No.8

Design variables and design parameters are rarely deterministic in practice. Robust optimal design takes into consideration of the uncertainties in the design variables and parameters. Robust optimization methodology with probability constraints requires a lot of system analyses fer calculating failure probability of each constraint. By introducing an envelope function to reduce the number of constraints, efficiency of robust optimization techniques can be considerably improved. Through four illustrative examples, it is shown that the number of system analyses is greatly decreased while little differences in the optimum results are observed.

좌굴을 고려한 적층 복합재 구조의 강건 최적설계에 관한 연구

이병채,이정준,정도현,Lee, Byeong-Chae,Lee, Jeong-Jun,Jeong, Do-Hyeon 대한기계학회 2001 大韓機械學會論文集A Vol.25 No.9

A robust optimization procedure is applied to determine the design of the laminated composite plates with buckling constraints. In order to investigate the variation effect to the whole performance of a structure, both design variables and system parameters are assumed as random variables about their nominal values. The robust optimization method has advantages that the mean value and the variation of the performance function are controlled simultaneously and the second order sensitivity information is not required. Considering the information of uncertainty, robust optima for the buckling load of the laminated composite plates with cut-out is obtained. The robustness of the structures is compared to that of the deterministic optimization using scaling factors.

성숙임목벌채지에서 (成熟林木伐採地) 운재로의 (運材路) 침식에 (浸蝕) 미치는 환경요인의 영향

박재현(Jae Hyeon Park),우보명(Bo Myeong Woo),정도현(Do Hyun Jeong) 한국산림과학회 1995 한국산림과학회지 Vol.84 No.2

This research aimed at the contribution to obtaining the scientifical data which were required for planning she environmentally sound and sustainable management, particularly in the field of the logging road construction. Main natural environmental variables including natural vegetation, rainfall, soil runoff were measured in the logging road on-sites and analysed. This project was carried out at the (mt.)Paekunsan Research sorest of Seoul National University, located in Gwangyang. Chollanam - do in southern part of Korea, from 1993 to 1994. 1. The explanatory variables for erosion and sedimentation on logging road surface were accumulated rainfall, erosion distance, cross - sectional gradient, and soil hardness. The erosion and sedimentation on logging road was increasing positively in proportion to the accumulated rainfall, soil distance from starting point of the logging road, and cross - sectional gradient. 2. On cut - slope of logging road, cut - slope shape, part of the slope, plant coverage, soil hardness, sand content, accumulated rainfall, clay content, and silt content were effective factors. Cut - slope erosion and sedimentation on logging roam increased as with the lower plant coverage, the lower accumulated rainfall, the high sand content in the soil. 3. On fill - slope of logging road, there were three significant variables such as total rainfall and number of rainfall - storm. Fill - slope erosion and sedimentation had a positive .correlation with the amount of rainfall, the number of rainfall, the soil hardness. 4. The total erosion and sedimentation on logging road were 5.04 × 10^(-2)㎡/㎡ in logging road construction year, 7.37 × 10^(-2)㎡/㎡ in next year. The erosion and sedimentation on logging road surface were 32.7% of total erosion and sedimentation on Logging road in construction year, and 57.1% in next year, respectively. The erosion and sedimentation on cut - slopes were 30.4% on logging road in construction year, fill - slopes of total erosion and sedimentation and 21.0% in next year, respectively. The erosion and sedimentation on fill - slopes were 36.9% on logging road in construction year, 21.9 in next year. To decrease the erosion and sedimentation at the logging road from the beginning stage of construction, the effective revegetation works should be implemented on the cut - slope and fill slopes, and erosion control measures such as optima. road design must be constructed on read surface.