• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(II)
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• pp.52-57
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• 2003

This study suggests several ways to improve the railroad facilities in the urban areas so as to maintain the urban railroad facilities and minimize their adverse impact on the roads around the facilities. Environmental problems such as noise and vibration can be minimized by constructing soundproofing walls and improving railway and train systems. To reduce the traffic congestion at the railroad crossings, current at-grade crossings should be changed to separated crossings. Moreover, the criteria by where railroad crossings are located should be revised. In the long term, the land use development for the railroad station and the surrounding areas needs to be changed. Several case studies of Japan's and France's major cities show the potential of successfully integrating the development of railroad facilities and their surrounding areas. In addition, there is a need to .consider institutional aspects, to improve the railroad facilities in the urban areas and to allow the integrated development of the railroad facilities and the surrounding areas.

• 대한기계학회논문집
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• 제18권6호
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• pp.1567-1571
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• 1994

Under the assumption that thermal conductivity of the fin is constant and the conditions ate steady state, effects of non-constant and thermally asymmetric root temperature and unequal surrounding convection coefficients of the fin on the heat loss from a fin of rectangular profile are investigated. The heat loss form a rectangular fin becomes maximum when the highest root temperature deviates from the fin center to the fin side which has a higher convection coefficient as surrounding convection coefficients of the fin increase and as the difference between the convection coefficient of fin top side and that of fin bottom side increases.

• 한국해양공학회지
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• 제32권3호
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• pp.192-201
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• 2018

In this study, a qualitative evaluation of the morphological changes in the seabed surrounding Jinwoo-Island due to the construction of the new Busan port were determined through a numerical simulation. Various scenarios for the discharge of the Nakdong river estuary dam and construction stage of the new Busan port were established and utilized for an indirect and qualitative investigation through simulation using the numerical model implemented in this study. It was concluded through a qualitative study that the morphological changes in the seabed surrounding Jinwoo-Island were typical estuary seabed changes due to the discharge of the Nakdong river estuary dam and waves from the open sea. The effects from the construction of the new Busan port were relatively small.

• 대한치과교정학회지
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• 제12권2호
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• pp.109-117
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• 1982

The author has observed the gross reactions of surrounding maxillary sutures to the widening of midpalatal suture in comparison of young dog with adult dog. Experimental animals used was two young dog and two adult dog with normal palate. After midpalatal suture was seperated with rapid palatal expansion device, experimental animals were sacrificed to observe the surrounding maxillary sutures. The following results were obtained. 1. In adult dog, nasoincisive suture was not expanded, while in young dog it was expanded. 2. In adult dog, pterygopalatine suture was hardly expanded, while in young dog it was expanded definitely. 3. In adult dog, frontomaxillary suture was not expanded, while in young dog it was expanded unilaterally. 4. In adult dog, palatoethmoidal suture was not expanded, while in young dog it was expanded unilateraily.

• 한국산학기술학회논문지
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• 제13권1호
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• pp.412-418
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• 2012

본 논문은 원인천의 중심이었던 경인선 동인천역 및 동인천역세권을 대상으로 20세기 도시성장에 따른 원인천의 쇠퇴와 함께 불합리한 민자역사 개발로 낙후된 지역을 재활성화하기 위하여, 철도에 의해 양분된 지역생활권의 단절 해소 및 철도시설 연변부지의 효율적 토지이용을 통한 입체적인 철도 환승시스템을 제안함과 동시에 철도 이용객의 편의를 도모하며 기존 지역상권의 복원 및 활용을 통한 지역활성화 방안을 모색하는 것에 있다.

• 오토저널
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• 제12권4호
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• pp.75-82
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• 1990

To study on the behavior of the early stage of the spark kernel at constant pressure condition, the expressions of the thermal properties such as compressibility factor, thermal conductivity, and electrical conductivity of the high temperature air were newly suggested. The newly suggested simple expressions of the thermal properties of the high temperature air showed good results. Under the assumption of constant pressure, one dimensional numerical analysis was executed by varying surrounding conditions and discharging current of electrical spark. Numerical results show tat high surrounding pressure suppresses the growth of the spark kernel but supplies much electrical energy into the air, on the other hand high surrounding temperature increases the growth of the spark kernel but supplies less electrical energy. Also the result shows that , in case of direct current discharge, deposited electrical energy is able to be expressed in linear function of time approximately.

• JSTS:Journal of Semiconductor Technology and Science
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• 제8권3호
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• pp.221-226
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• 2008

A new two dimensional (2-D) analytical model for the Threshold Voltage on dual material surrounding gate (DMSG) MOSFETs is presented in this paper. The parabolic approximation technique is used to solve the 2-D Poisson equation with suitable boundary conditions. The simple and accurate analytical expression for the threshold voltage and sub-threshold swing is derived. It is seen that short channel effects (SCEs) in this structure is suppressed because of the perceivable step in the surface potential which screens the drain potential. We demonstrate that the proposed model exhibits significantly reduced SCEs, thus make it a more reliable device configuration for high speed wireless communication than the conventional single material surrounding gate (SMSG) MOSFETs.

• JSTS:Journal of Semiconductor Technology and Science
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• 제11권2호
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• pp.111-120
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• 2011

A two-dimensional analytical model for deriving the threshold voltage of a short channel fully depleted (FD) cylindrical/surrounding gate MOSFET (CGT/SGT) is suggested. By taking into account the lateral variation of the surface potential, introducing the natural length expression, and using the Bessel functions of the first and the second kinds of order zero, we can derive potentials in the gate oxide layer and the silicon core fully two-dimensionally. Making use of these potentials, the minimum surface potential can be obtained to derive the threshold voltage as a closed-form expression in terms of various device parameters and applied voltages. Obtained results can be used to explain the drain-induced threshold voltage roll-off of a CGT/SGT in a unified manner.

• 한국전자통신학회논문지
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• 제7권1호
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• pp.171-180
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• 2012

이 연구는 도시철도역 주변영역 개발에 대한 연구이다. 예를 들어, 역세권 재산의 가치는 이전과 도시 철도의 개통 이후에 근거하여 상승 가능성이 높다. 도시철도 시스템은 도쿄 시내의 교통 문제를 해결하기 위해 중요한 해결책이라 생각된다. 또한 도시 철도의 개통은 도시공간구조의 변화에 영향을 주며, 역세권의 토지 가격에 대해 영향을 미친다.

• Journal of Electrical Engineering and Technology
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• 제9권2호
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• pp.649-654
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• 2014

In this paper, an analytical model for Surrounding Gate (SG) metal-oxide- semiconductor field effect transistors (MOSFETs) considering quantum effects is presented. To achieve this goal, we have used variational approach for solving the Poission and Schrodinger equations. This model is developed to provide an analytical expression for inversion charge distribution function for all regions of device operation. This expression is used to calculate the other important parameters like inversion charge density, threshold voltage, drain current and gate capacitance. The calculated expressions for the above parameters are simple and accurate. This paper also focuses on the gate tunneling issue associated with high dielectric constant. The validity of this model was checked for the devices with different dimensions and bias voltages. The calculated results are compared with the simulation results and they show good agreement.