• 설비공학논문집
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• 제12권3호
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• pp.235-243
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• 2000

A theoretical model for laminar filmwise condensation along an isothermal vertical wall at constant pressure has been formulated on the basis of conservation laws and other fundamental physical principles. The model was applied to the prediction of the influences of variable thermophysical properties of liquid and vapor layers in the filmwise condensation of superheated vapor of Rl2, R134a, R142b and R152a. The dimensionless velocity component method was employed in the transformation of the governing equations and their boundary conditions, and the polynomial method was used for treating variable thermophysical properties of liquid and vapor. Physical quantities, such as the dimensionless thickness of the liquid layer, local heat transfer rate and mean heat transfer coefficient, were investigated for different values of the superheated temperature of the stagnant vapor far from the wall. It was found that the value of mean heat transfer coefficient of R134a was higher than other refrigerants for the change of the superheated temperature.

• 천문학회지
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• 제34권4호
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• pp.191-201
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• 2001

My contribution to these proceedings summarizes a general overview on High Resolution Shock Capturing methods (HRSC) in the field of relativistic hydrodynamics with special emphasis on Riemann solvers. HRSC techniques achieve highly accurate numerical approximations (formally second order or better) in smooth regions of the flow, and capture the motion of unresolved steep gradients without creating spurious oscillations. In the first part I will show how these techniques have been extended to relativistic hydrodynamics, making it possible to explore some challenging astrophysical scenarios. I will review recent literature concerning the main properties of different special relativistic Riemann solvers, and discuss several 1D and 2D test problems which are commonly used to evaluate the performance of numerical methods in relativistic hydrodynamics. In the second part I will illustrate the use of HRSC methods in several astrophysical applications where special and general relativistic hydrodynamical processes play a crucial role.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제27권4호
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• pp.207-231
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• 2023

This paper aims to improve the alternative formulation of the fifth- and sixth-order accurate weighted essentially non-oscillatory (AWENO) finite difference schemes. The first is to derive the AWENO scheme with sixth-order accuracy in the smooth region of the solution. Second, a new weighted polynomial functions combining the perturbed forms with conserved variable to the AWENO is constructed; the new form of tunable functions are invented to maintain non-oscillatory property. Detailed numerical experiments are presented to illustrate the behavior of the new perturbational AWENO schemes. The performance of the present scheme is evaluated in terms of accuracy and resolution of discontinuities using a variety of one and two-dimensional test cases. We show that the resulted perturbational AWENO schemes can achieve fifth- and sixth-order accuracy in smooth regions while reducing numerical dissipation significantly near singularities.

• 환경영향평가
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• 제6권2호
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• pp.61-80
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• 1997

This study tried to propose the guidelines for the ecological preservation zoning in Korea. So some related laws and regulations were inspected, which were Natural Environment Preservation Act, Nature Park Act, Cultural Asset Conservation Act, Forest Act and Urban Planning Act. In these acts, I could find several concepts related to the ecosystem that are described as the protection area. But there aren't detailed and practical characteristics in those concepts. So for making the practical concept of ecosystem preservation, I considered Multiple Use Module, Wildlife habitat model, and Environmental evaluation model. Thorough this step, the process and methodology was established for evaluating and analysing. The potentiality of the GIS system was inspected. So the TM5 scene of the site was acquired and processed by ER-Mapper, Idrisi, Arc/Info and Arcview. And several digitized data were input by scanning and vecterizing. The Erdas format was mostly exchangeable to any program. The site is the Byonsan Peninsula National Park. The forest stand information and topographic data were digitized, types of which are forest year, DBH, density, slope, aspect etc. And also the watershed boundary, roads and paths, natural and cultural resources were mapped and analysed. Modelling of preservation suitability found the dispersed patterns for the best suitable zone through all the site. And the development potential areas were checked on downwatershed. This patterns are thought to result from the forest location for the wildlife habitat and the low altitude and no-steep slopes for developing. And Early warning system concept was introduced by overlapping these two patterns on the both potential area. As the conclusions, I proposed that the preservation zone be assigned according to the watershed unit as the main ecosystem zone. This main area should be linked by the eco-corridor through the point type eco-system. Finally, I thought the comprehensive information system should be established for making the rational and efficient decision making in natural area.

• 한국조경학회지
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• 제34권4호
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• pp.84-95
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• 2006

This study begins by examining the reason for the lack of urban planning that takes the water cycle into consideration. While there are institutions that support environmentally friendly development or smooth water circulation, these designs are not reflected in planning nor in the real world. After reviewing foreign case studies, policy suggestions and possible policy implications for Korea are derived. In Korea, there is not a sufficient level of relevant laws or institutions systematically established to make it possible to deal with rainwater in a decentralized way. Instead, facility standards or guidelines are considered separately for the control of water and for preventing natural disasters. And even though an environmentally friendly approach is stipulated in relevant laws in terms of spatial planning, there are no planning systems or implementation tools to actualize this kind of approach. The factors that make decentralized rainwater management possible in urban planning are analyzed based on the case study of Germany. Germany requires developers to plan in order to achieve ecological urban development. In addition, as a detailed implementation tool to promote conservation of the water cycle, the law provides for various kinds of measures such as restrictions on the proportion of impervious surface area according to the use of the land, required compensation measures for environmental degradation following development, introduction of a fee for rainwater runoff and the establishment of ecological landscape planning. The actual reason these measures can be implemented however is the provision of planning guidelines and design criteria for rainwater utilization, absorption and containment, and the construction of a database for various environmental information.

• 수산경영론집
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• 제53권3호
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• pp.43-64
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• 2022

Efforts to prevent IUU fishing began in 1996 as the IUU Antarctic Marine Living Resources Conservation Committee reported the multilateral efforts of the international community and related international organizations to prevent IUU fishing. Korea has recently been pointed out by the international community as to many problems regarding its will to eradicate IUU fishing. It is true that Korea has ever been designated as an 'IUU participating country' or a 'non-cooperative third country' by the international community and that there have been considerable difficulties in exporting seafood and using ports along with the deterioration of the national image. In 2020, with the efforts of related organizations and fisheries companies, Korea is now free from being known as a that Korea has recovered some degrees of trust from the international community through strengthening legal sanctions against IUU fishing and thorough implementation of follow-up measures is now free from non-cooperating country it cannot be said that the basic problems have been completely resolved just because it has emerged as a disgraceful country, and the current state of IUU fishing of Korea leaves a room for designation as a 'non-cooperative third country' again at any time in the future. Accordingly, there is an urgent need to examine the problems of the IUU fishing-related legal system in Korea and to come up with an improvement plan. Therefore, this paper reviews international norms for IUU fishing regulation (PSMA etc.) and domestic laws with the Distant Water Fisheries Development Act and Propose the improvement methods for related legal systems in Korea.

• Spatial Information Research
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• 제8권1호
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• pp.51-67
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• 2000

본 연구는 서울시 생태·자연도의작성방안 마련을 위한 기초연구로서 도시생태계에 적합한 생태적 보전가치 평가모형의 개발이 시도되었으며, 서울시 소재 관악산을 대상지로 하여 생물종 현황자료 및 자연환경 GIS자료를 이용한 보전가치 평가결과를 토대로 생태·자연도가 시험적으로 작성되었다. 연구결과를 요약하면 다음과 같다. 첫째, 법정 생태·자연도 등급기준의 문제점은 전국규모의 우수생태계 중심의 등급기준으로서 도시생태계의 보전가치를 평가하기에는 미흡하며, 등급기준이 모두 정상적이다. 그리고 법정 생태·자여도 상의 별도관리지역 체계는 효과적인 도시생태계 관리에 부적합하다는 점이다. 둘째, 앞으로 생태·자연도 등급기준의 개선방향은 1 등급의 경우 복원대상지역과 시관리야생동·식물 및 서식지를 포함하고, 2등급에 생태통로지역을 추가하는 것이 필요하다. 셋째, 생태·자연도 평가과정은 순수 보존가치 평가에 의한 생태등급 평가와 행위규제를 포함하는 생태·자연도 작성과정을 분리하는 것이 바람직하다. 평가모형 개발에서는 위계분석기법에 의한 평가인자선정과 쌍체비교기법에 의한 가중치 선정과정을 거치는 것이 평가모형의 객관성 논란을 줄이는 방법이 될 수 있다. 넷째, 시생태·자연도는 도시생태계의 규모 및 특성에 맞게 구역별 행위규제기준이 재조정되어야 할 것이다.

• 한국환경생태학회지
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• 제29권3호
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• pp.474-484
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• 2015

본 연구는 중국 자연보호구의 현행 법률 및 법체계와 역사, 조직, 예산 등 관리체계를 분석하여 중국의 보호지역 관리를 위한 기초적 자료를 제공할 목적으로 수행되었다. 법체계는 "중화인민공화국 헌법(1954)"에 의거하여 "환경보호법(1989)", "자연보호구 조례(1994)", "자연보호구 토지 관리 방법(1995)"이 제정되었다. 자연보호구의 발전과정은 시작단계(1956-1965), 정지단계(1966-1978), 발전 단계(1979-1998), 급증 단계(1999-2006), 안정 단계(2007-현재)로 나눌 수 있으며, 안정단계에서는 생태 환경의 보호, 감독, 관리 강화 등 5단계로 분류된다. 중국 자연보호구는 법에 의거하여 국가급, 성급, 시급, 현급으로 분류하고, 자원유형별로는 자연생태체계류, 야생생물류, 자연유적류로 나누고 있다. 전체 자연보호구 2,640개소 중 임업부가 관리하고 있는 자연보호구는 1,958개(전국 수량의 74.2%) 로 가장 높은 비율을 차지하고 있다. 자연보호구 1,384개소(52.4%)에 관리조직이 건립되어 있으며, 관리조직 유 무에 상관없이 관리인원을 배치한 자연보호구는 1,702개소(64.47%)로 관리조직이 있는 비율보다 높게 나타났다.

• 대한기계학회논문집
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• 제17권5호
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• pp.1227-1236
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• 1993

본 연구에서는 또하나의 새로운 서술방식을 제시하게 되는데, 먼저 에너지 이동현상으로서의 일중에서 가용일을 분리하고, 가역과정만이 가능한 세계 즉 가역세 계 안에서 측정과 산정이 가능하도록 열역학의 가장 중요한 물리량인 온도와 엔트로피, 열 등을, 가용일의 가측성을 이용하여 정의한 다음, 그러한 제한조건하에서 기존 열역 학의 기본 법칙들이 어떻게 표시되는가 살펴보고, 이것을 비가역과정에 확장하는 식의 순서에 따라 열역학의 기존원리들에 대한 서술을 재구성하고자 한다.

• 한국환경생태학회지
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• 제22권3호
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• pp.280-288
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• 2008

본 연구는 생태관광 개발과 지속적인 발전에 있어 가장 중요한 요소 중의 하나인 주민참여 부분에 대한 연구로서 지역 생태관광 개발에 있어 우선 고려되어야 할 주민참여 방법과 선행 해결과제들을 조사 분석하였다. 조사는 국내 산촌지역으로 자연환경이 우수하고 접근성이 좋아 개발가능성이 높은 지역을 선정하여 현지 방문조사를 실시하였다. 장기 부재중인 주민을 제외하고 각 지역에 거주하고 있는 190명의 주민을 대상으로 조사 분석한 결과 지역주민들은 생태관광 개발에 대해 긍정적이며, 관광개발계획 수립단계부터 적극적인 참여를 원했다. 또한 생태관광 개발에 있어 가장 중요한 것은 자연환경보전을 전제로 한 지역경제 및 개인소득의 증대로서 이를 위해서는 가장 먼저 관련 법 제도적 정비와 함께 지역주민에 대한 교육이 선행되어야 한다고 나타났다.