• Journal of Science and Technology Studies
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• v.2 no.1 s.3
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• pp.135-156
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• 2002

The view of technology is largely divided into 2 theories: (1) the theory of autonomous technology that claims technology's own development logic and momentum, (2) the theory of social determinism that regards technology as reflection of political choices. Autonomous technologists read our society in the language of technology and social determinists read our technology in the language of society. This paper tries to analyze that conflicts between government and environmental group in nuclear policy, especially radioactive waste disposition policy reflect collisions between autonomous technologists and social determinists representing technology and politics, respectively. On the surface, such collisions are occurred in rational, ethical and economical aspects. It maintains, however, in depth, they are about solution means to problems from which technologies derived. Also, it suggests that one of the alternatives to avoid inevitable collision may be interaction approach based on intertwining technology with society. More understanding of political natures and control possibilities for technology is needed because interaction approach is founded on this understanding. Finally, to help forming the Korea's nuclear utilization policy from now on, it gives 2 case studies compared France with Germany where expanding and contracting nuclear utilization policy, respectively.

• Korean Journal of Agricultural Science
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• v.4 no.2
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• pp.191-198
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• 1977

This study was conducted to determine the inheritance to bacterial leaf blight in rice. Varieties used in the study were IR1544-349-2, IR1698-237-2, IR1529-680-3, IR28, IR29, RP663-337-7-8-4-1-1, RP291-20, 62-595 and Kele. The isolate of bacteial leaf blight used was 71-23, 76-1 of Xanthomonas oryzae. $F_1s$ were obtained from crosses between resistant and susceptible varieties. Field observation was made from the Parents, $F_1s$ and $F_2$ sagregating population. The result is summaryzed as fallow: 1) The resistance to the bacterial leaf blight (71-23) derived from cultivars IR1529-680-3, IR28, IR29, RP663-337-7-8-4-1-1, RP291-20 and 62-595 was controlled by a single dominant gene. 2) The resistance to the bacterial leaf blight (71-23) derived from cultivars IR1545-339-2, IR1544-340, IR1698-237-2 and Kele was controlled by a single recessive gene. 3) The resistance to the bacterial leaf blight (76-1) derived from cultivars IR1545-339-2, IR1544-340, IR 1698-237-2 was controlled by a single dominant gene. 4) Degree of resistance to the bacterial leaf blight and genetic type were different depending on isolates within the same resistant cultivar. 5) There was no relation between resistance to the bacterial leaf blight and heading days.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.89-93
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• 2006

횡월류식 천변 저류지를 포함하는 하천수계의 흐름 모의를 위한 준2차원 계산모형을 수립하였다. 수립된 모형은 횡월류 흐름에 대해서는 수량보존에 관한 연속방정식 및 월류형 수위-유량 관계식을, 하도에 대해서는 1차원 부정류에 대한 St. Venant 방정식을 각각 지배방정식으로 하여 흐름을 모의하는 폐합형 계산모형이다. 남한강 구간의 가상의 천변 저류지를 설치한 경우에 대하여 개발된 모형을 적용, 횡월류식 천변저류지의 설계변수들을 결정하기 위한 분석 방법을 제시하기 위한 연구가 진행 중에 있다.

• Electrical & Electronic Materials
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• v.5 no.1
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• pp.89-98
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• 1992

가스절연개폐장치에서 단로기의 조작시에 발생하는 과도과전압의 측정은 최적절연설계, 신뢰성 향상, 고장탐지 등에 있어 대단히 중요하다. 본 논문은 과도과전압과 시변전계의 정확한 측정이 가능한 용량성 전계센서에 관한 것으로 측정이론, 설계, 교정기술과 실규모 GIS실험장치에서의 과도과전압의 측정에 관한 모의 실험에 대하여 기술하였다. 시제작된 센서의 변환특성은 응답매개변수에 의하여 지배되어지며 센서와 측정계의 주파수대역폭은 수 Hz~ 약 200MHz정도이었다. 실규모 GIS실험장치에 적용하여 과도과전압을 측정한 결과 센서의 우수한 응답특성이 확인되었다.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.402-407
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• 2006

본 연구는 곡선좌표계에서 유한차분기법(finite difference method)을 이용하여 2차원 흐름이 모의가능한 수치모형을 개발하는 것이다. 기존의 연구는 대부분 직교좌표계(cartesian coordinate system)에서의 격자망을 대상으로 개발되고 적용되었기 때문에 불규칙한 흐름의 경계 및 형상을 올바로 표현하기 어려웠다. 유한요소법이나 유한체적법같은 수치모의기법들이 개발되어 비구조격자체계를 구성하고 자연현상에 가까운 경계 표현할 수 있도록 개발되었다. 하지만 위의 기법들은 질량과 운동량과 같은 물리량을 보존하기 위해서 매우 조밀한 격자체계를 가져야만 한다. 이에 본 연구에서는 기존의 문제점들을 해결하기 위하여 곡선좌표계(curvilinear coordinate system)를 이용하여 지배방정식을 표현하고 2차원 흐름을 모의할 수 있는 모형을 구축한다. 수치모형은 leap-frog기법과 1차 정확도의 풍상차분기법(upwind scheme)을 사용하여 구성하였다. 본 연구에서 개발된 모형을 사각수조 및 만곡수로흐름에 적용하여 모의결과를 해석해 및 실험관측값과 비교하였다. 이로부터 본 수치모형이 해석해 및 실측치와 잘 일치하고 있음을 알 수 있었다.

• Journal of the Society of Naval Architects of Korea
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• v.34 no.2
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• pp.39-47
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• 1997

In the present paper, viscous flow fields around a wigley hull with appendages are analysed to study interactions between the hull and appendages. Navier-Stokes and continuity equations are solved by a finite volume method in a body-fitted coordinate system which conforms three dimensional ship geometries with appendages. A Sub-Grid Scale(SGS) turbulent model is used for a calculation of high Reynolds number flow. Numerical computations has been done for a Wigley hull form at $Rn=1.0{\times}10^6$. The results show that the present approach can predict, at least in qualitative sense, the influence of the appendages upon the flow field around a ship.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.88-89
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• 2016

선택적 환원 촉매(SCR : Selective Catalytic Reduction) 시스템은 대기오염을 예방하기 위한 배기가스 처리장치 중 하나이다. 본 연구에서는 전산유체역학(CFD : Computational Fluid Dynamics)를 사용하여 SCR 시스템 의 효율향상을 위하여 ANSYS-CFX package를 이용하여 점성 유동 해석을 수행하였다. SCR 시스템의 점성 유동 흐름의 전산 유체 역학을 이용하여 시뮬레이션하기 위하여 Navier-Stokes 방정식을 지배방정식으로 사용하였다. CATIA V5를 사용하여 SCR 시스템의 형상을 3D 모델링을 하였고, 암모니아와 배기가스의 혼합 비율을 확인하기 위해 요소수 분사 노즐의 위치를 변경하였다. 요소수 분사 노즐은 배기관의 입구로부터 1/3, 1/2, 2/3에 위치한다. 또한, 분사 노즐의 위치가 배기관 입구의 1/3에 위치할 때 노즐의 분사구수에 따른 효율을 확인하기 위하여 분사구수를 4Hole, 6Hole, 8Hole일 경우를 확인하여 비교하였다. 시뮬레이션의 결과로는 배기관 입구에 가까울수록, 분사구수가 많을수록 효율이 좋아짐을 확인하였다.

• Journal of Korean Society of Forest Science
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• v.68 no.1
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• pp.32-36
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• 1985

Megagametophyte tissues of Pinus densiflora were subjected to study the inheritance of acid phosphatase (ACP), alcohol dehydrogenase (ADH) and catalase (CAT) isozymes by starch gel zone-electrophoresis. At least three or four zones were segregated for ACP isozyme. However, as one isozyme of ACP-A zone was separated clearly, only that isozyme was analysed. Five isozyme phenotypes (A1-A5), observed in ACP-A zone, were segregated to a simple Mendelian ratio, suggesting that these are controlled by five codominant alleles existed at ACP-A locus. Two zones of activity were segregated in the gels after staining for ADH, the more anodal zone (ADH-A) of the two was invariant in our materials. Three isozyme phenotypes (B1-B3) were observed in ADH-B zone and these variants showed a 1:1 segregation pattern, suggesting that each variant is controlled by three codominant alleles at ADH-B locus. A total of five isozyme phenotypes, composed of multiple bands, were observed in CAT isozyme. The segregation of these phenotypes in heterozygous trees did not show any significant deviation from a 1:1 segregation. Therefore, the genetic control of CAT isozyme in Pinus densiflora seeds seems to be based on a single locus (CAT-A) with Five codominant alleles ($A_1-A_5$).

• Environmental and Resource Economics Review
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• v.20 no.2
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• pp.335-356
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• 2011

In this paper, we attempted to suggest a way to evaluate appropriateness and efficiency for the energy consumption structure. For this, based on Markowitz (1952)' mean-variance portfolio model, we constructed an optimal fossil fuel mix. In constructing the optimal mix, we first defined returns on fossil fuels (oil, coal and natural gas) as TOE (Ton of Oil Equivalent) per $1. Then, by using the dynamic latent common factor model, we decomposed the growth rates of the returns on each fossil fuel into two parts : the common part and the idiosyncratic part. Finally, based on the results from the dynamic latent common factor model, we constructed the optimal fossil fuel mix implied by the mean-variance portfolio model. Our results indicate that for the fossil fuel mix to be on the efficient frontier, it is crucial to reduce oil consumption as low as possible. Moreover, our results imply that it is more efficient to increase natural gas consumption rather than coal consumption in reducing oil consumption. These results are in line with the strategies for the future energy consumption structure pursued by Korea and indicate that reduction in oil use can improve overall efficiency in energy consumption.

• Journal of Korea Water Resources Association
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• v.46 no.12
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• pp.1169-1180
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• 2013

The objectives of this study are to construct the natural streamflow in the Bokhacheon middle-upper watershed using the SWAT-K model and to assess the impacts of groundwater withdrawals, water intake, treated sewage water release on streamflow. The simulated natural streamflow from 2006 to 2013 showed the minimum discharge of $1.7m^3/s$, the annual average discharge of $26.2m^3/s$, the drought flow of $2.0m^3/s$ at the outlet of the study area. The simulated results indicated that the groundwater pumping has induced the decrease of 34% in drought flow against the natural condition and the net water release has caused the increase of 15%, while the combined effects of the groundwater pumping and the net water release have induced the decrease of 19%. It was found out from the simulated natural streamflow data that the specific discharges of the abundant flow, normal flow, low flow, drought flow in the upper-middle channels of the Bokha-cheon watershed have a tendency to increase as the drainage area increases, but the specific discharges showed almost constant values at any downstream point with drainage area more than about 180 $km^2$.