• 한국자동차공학회논문집
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• 제15권5호
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• pp.112-117
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• 2007

With the Euro-4 regulation coming into effect, the domestic car industry is forced to look for newer options to reduce NOX in the exhaust. EGR(Exhaust Gas Recirculation) Cooler is an effective method for the reduction of NOX form a diesel engine. High efficiency, low pressure loss and compactness are desirable features of an EGR Cooler. The cooling performance of EGR depends on the shape of tubes and the location of the entrance and exit. This paper reports the computational work conducted to estimate the performance of EGR cooler with three different cross section tubes and a triangular spiral tube. Three dimensional computation results show that the triangular tube is more effective than circular and rectangular tube. The most effective geometry is a triangular spiral tube with offset inlet and outlet locations.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 B
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• pp.558-560
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• 1999

For the high-rise buildings, the effective use of the buildings heavily depends on the transportation system inside the buildings. For a long period of time, elevators have been the most effective means for moving people residing in the buildings. As the number of elevators in the building grows, it is very complicated to control and manage the elevator system effectively. Since it is almost impossible to find the accurate mathematical model for the elevator systems, the conventional analysis method using the approximated equations is prone to error. In this work, the elevator simulator for the high-rise buildings is developed to assess the accurate behavior of the elevator systems. This simulator can be used to analyze the performance of the given system, or to facilitate the design of the effective elevator systems for new buildings. In this paper, the structure of the simulator has been explained and the simulation results are presented.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.653-660
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• 2007

South and North Koreas are putting forth efforts to overcome the distrust and animosity of the past 50 years to open an era of harmony and cooperation where the two halves can work together for mutual benefits. As part of those efforts, both parties are working now to reconnect the railways between the North and the South that remained broken for the past 60 years. The South and North have had different railway systems for more than 50 years. To solve these complicated issues, appropriate investigation and analysis of North Korea railway system should be proceeded. It is necessary to study the railway system and integration methodology for effective operation of the two korea's railway systems. Therefore, in this study, effective unification scheme of South and North Korea railway system is proposed based on appropriate investigation about operation of inter-Korea railway system.

• 한국농공학회지
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• 제35권4호
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• pp.106-118
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• 1993

The purpose of this study is to develop a multireservoir water balance model which may be used to evaluate rural water demands such as agricultural water, domestic water, industrial water and livestock water and to determine effective storage of reservoir. The model was verified to compare the observed reservoir release data with the simulated reservoir release data of the existing Munsan and Dongbu reservoirs located in the Gisan rural district for 3 years('87~'89). For model application, the effective storages of existing reservoirs(Munsan & Dongbu) were evaluated for 10-year frequency drought and that of newly planned reservoirs(Kumbok & Kudong) were determined for 10-year frequency drought. In addition, the behavior of effective storages for existing reservoirs were analyzed in the case of introducing new reservoirs in the existing system.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.270-273
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• 2002

This paper presents an effective cutting force model that enable us to predict the instantaneous cutting force in milling process from a knowledge of the work material properties and cutting conditions. The development of the model is based on the orthogonal machining theory with the effective rake angle which is defined in the plane containing the cutting velocity and chip flow vectors. Face milling tests are performed at different feeds and, a fairly good agreement is shown between the predicted cutting forces and test results.

• 한국지하수토양환경학회지:지하수토양환경
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• 제16권6호
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• pp.113-121
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• 2011

In this study, we suggested the management scheme of analyzing the national and oversea related policy against soil and groundwater contamination by radioactive materials due to nuclear accidents. In Korea, we need to remedy swiftly the contaminated land due to intensive land development demand. So, we need to develop more effective management scheme to recover actively the land contaminated by radioactive materials. We require to improve monitoring network, to expand media-specific monitoring system, to prepare management system for remediation of contaminated land, and to develop flow work for soil and groundwater remediation.

• 한국유기농업학회지
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• 제11권4호
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• pp.39-59
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• 2003

The purpose of this study is to introduce issues on agricultural policy of participatory government and to suggest some implications for national consensus. According to the finance and investment plan, 119 trillion won in total will be invested in the farming industry for improving the welfare system and development of the sector over the next 10 years. It is very important that this plan will make Korean farmers competitive and income per capita increased more and more. By the way, the plan has been argued by farmer’s organization(NGO) and some people of academic circles because there is a fair question as to how effective these investment aids will be. Therefore, the finance and investment plan must be established on the basis of effective execution system as well as additional discussion for national agreement. In addition, the 'Special Plan Committee for agriculture-fishery and farming-fishing communities' will work out an ideal framework for succeeding this plan.

• 천문학회보
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• 제38권1호
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• pp.77.2-77.2
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• 2013

xIn the present work, we explored the effect of the radiation on the effective impact parameter for capture in a fully general relativistic manner. To summarize our results, evidently due to the radiation drag (the Poynting-Robertson effect), critical impact parameter of point particle gets larger by the factor of two, thus, the effective cross section of the luminous relativistic star becomes 4 times larger than that of the star without radiation emission. In addition, the finite size effect of the star adds up to this growth of the effective cross section.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.244-246
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• 2003

The construction conditions of transmission line in Korea are very hard. Actually, the construction project is processed inefficiently with constant civil appeal and interference by local residents of a region and environment organization, not to speak of landlord, because it is regarded as antipathy facility and passes through a lot of regions. Especially, it is concluded that effective practice of a construction project is serious in the future because transmission power voltage was upgraded to 765kV according to a sharp increase of electric power demand. Therefore, with the background of the experience of the past, this paper is aimed to study and establish a reasonable improvement plan which enables to eliminate wasteful factors for effective construction work of transmission line.

• Structural Engineering and Mechanics
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• 제57권2호
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• pp.369-387
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• 2016

In this work, random homogenization analysis for the effective thermal properties of a three-dimensional composite material with unidirectional fibers is presented by combining the equivalent inclusion method with Random Factor Method (RFM). The randomness of the micro-structural morphology and constituent material properties as well as the correlation among these random parameters are completely accounted for, and stochastic effective thermal properties as thermal expansion coefficients as well as their correlation are then sought. Results from the RFM and the Monte-Carlo Method (MCM) are compared. The impact of randomness and correlation of the micro-structural parameters on the random homogenized results is revealed by two methods simultaneously, and some important conclusions are obtained.