• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2017.11a
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• pp.59-60
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• 2017

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.252-252
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• 2016

수자원에 대한 효율적 활용 요구가 증대됨에 따라 한반도 수리적 특성을 보다 정밀하게 모의하고 이를 활용한 의사결정이 요구되고 있다. 한반도는 지리적 특성상 약 70%가 산학 구조로 되어 있어서 지형적 기상 현상이 복잡하여 가뭄지수의 공간 보간에 어려움이 있다. 따라서 지형적 특성-거리, 고도, 해양에서의 거리, 지향면 등을 고려할 수 있는 PRISM 기법을 기존의 공간 보간 기법과 비교 분석하여 한반도 전역의 가뭄 특성에 적합한 공간 보간 기법을 검출하고자 하였다. 자료의 분석은 기상청에서 제공하는 강우 관측소중 40년 이상의 연한을 가지고 있는 60개 지점을 선정하여 분석하였으며 방법 간의 비교는 지점을 선정하여 추정된 오차를 기초로 하여 판단하였다. 분석결과 PRISM 기법이 복잡한 지형적 특성을 가진 지역에서 더 적합한 방법으로 나타났다. 향후 연구에서는 미개측 지역의 가뭄지수 분석을 시행하여 관측소가 설치되지 않은 지역의 적합한 가뭄 특성을 분석하여 효율적인 수자원 활용을 위한 적절한 의사결정 지표를 선정하고자한다.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.18-18
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• 2017

우리나라뿐만 아니라 세계의 여러 국가에서 과거 발생 했던 강수의 통계적 특성에서 벗어나는 극치사상이 빈번 하게 관측되고 있다. 이와 같은 현상에 가장 큰 영향을 미치고 있는 요인중 하나로서 지구온난화가 원인으로 고려되고 있으며 실제 산업화 이후 온실가스의 증가와 더불어 극한 기상현상의 발생 빈도가 증가하였다. 우리나라는 과거 발생패턴과는 다른 극치 강우 사상이 빈번하게 관측되고 있으며 이로 인한 피해도 증가되고 있는 상황이다. 이러한 점에서 기존의 연구에서 개발한 계절강수량을 입력 자료로 하여 극치강수량을 추정할 수 있는 비정상성 Four - Parameter(4P)-Beta분포를 이용한 알고리즘을 본 연구에서는 기상인자를 이용하여 모형 내에서 계절강수량을 직접적으로 예측할 수 있는 알고리즘을 추가하여, 이를 직접적으로 일단위 이하의 극치강수량을 상세화 시킬 수 있는 모형으로 확장하고자 하며, 이를 통해 기상변동성을 다양한 시간규모에서 고려하기 위한 정보로 활용하고자 하였다.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.194-198
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• 2006

In this study, numerical modeling was performed to analyze air flow including radiation heat transfer inside a small chamber. Characteristics of heat transfer between source plate and target through glass are investigated for various surface temperature of heat source plate with buoyancy effect due to gravity force. Conduction heat transfer through the glass is considered and heat source plate is assumed to be a black body. Target surface temperature is largely affected by the radiation heat transfer. It can also be seen that as the source temperature increases target surface is dominated by radiation rather than convective heat transfer by air.

• Progress in Superconductivity and Cryogenics
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• v.8 no.1
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• pp.34-38
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• 2006

There are many parameters that should be considered from the viewpoint of real power system operation and planning in designing HTS power devices. Especially, in the power system with HTS-FCL(fault current limiter) and TR(transformer), there is close correlation between parameters of the HTS power devices. This paper describes some considerations in determining parameters of HTS power devices, which are related to technical and economical aspects. The main parameters in this study are the quench resistance of HTS-FCL and the % impedance of HTS-TR. The results may give basic information for developing the devices.

• Progress in Superconductivity and Cryogenics
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• v.10 no.3
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• pp.14-18
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• 2008

This paper deals with the conceptual design and characteristic analysis of core type superconducting motor using iron cores in the field. As the objective function of conceptual design, the flux quantity per pole is selected. In order to reduce the quantity of superconductors, the variations of flux quantity per pole by changing the design variables and area are investigated. Finally, the quantity of superconductors between air-cored and core type superconducting motor is compared under the same motor capacity. In addition, the dimensions and volumes of motors are compared.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.1
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• pp.211-218
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• 1994

Grinding is considered as a very effective machining technology to attain high production rates and a good surface quality of hard and brittle components. However, the grinding operations till needs the skill and the experience of an operator because of a lack of scientific knowledge and engineering principles. This is the reason why grinding operations are not completley intergrated in CIMS(Computer Intergrated Manufacturing System. Recent develop- ment focus on expert system which deals with domain specific knowledge in order to solve this problem. Firstly, in this study, a basic strategy to develop the grinding knowledge-base for grinding is discussed. Next, the architecture of knowledge-base and management of the grinding knowledge-base(GKB) is described.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.1
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• pp.219-229
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• 1994

This paper describes an expert system on the cylindrical grinding operations in order to establish the optimum grinding conditions, which satisfy the maximum removal rates, considering the several constraints of grinding power, workpiece burn, chatter vibration and surface roughness. Specialized knowledge of the grinding operations are acquired from the actual operation database. Coefficientis in the experimental equations are obtaines through the fuzzy regression model based on the fuzzy set theory, and are stored in the actual operation database. The developed system is capable of determining the optimum grinding conditions taking into account some problems, and practical examples of implementaion are described.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.2
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• pp.190-196
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• 1993

Internal high speed grinding under several high grinding wheel speed condition has been performed in this study for the effects have analyzed and compared with the grinding power, grinding tangential force and accuracy of surface with the carbon tool steel(SK3). The following results have been obtained: (1) Under the workpiece speed constant condition, increasing the grinding speed, the tangential force is decreased, and on the contrary, accuracy of surface is improved. (2) Under the speed ratio (V$_{w}$/V$_{s}$) contant condition it is possible to increase the high machining efficiency constraint to tangential grinding force constant.ant.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.153-154
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• 2020

This study aims to find out the reason that tile adhesive(type III) for ceramic tile does not harden under some conditions especially high humidity even though long curing time. Bonding strength of adhesive between substrate and ceramic tile is evaluated depending on bonding conditions such as substrate kind(concrete, board), bonding material (tile adhesive, tile cement) and curing condition(humidity 50, 70%). Based on the results, this study aimed to establish the quality of tile adhesion strength under the relevant conditions.