• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.1380-1384
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• 2006

Sediments deposited on lateral drain pipes in a tunnel make lateral porous pipes clogged. Since the safety of the tunnel can be affected by this phenomenon, it requires a regular maintenance of the lateral drain pipes. In this study, a series of centrifugal tests were conducted in order to find out the method which can reduce the clogging effect considerably. Four different types of tunnel drain configurations were selected in the experiments. By analysis of sediments for each configuration, the optimum drain configuration that can minimize sedimentation of cement constituents was investigated. As a results, the existing drain configuration which uses filter concrete appear to produce much sediments. In contrast, the new drain configuration appears to be able to reduce sedimentation ratio up to almost 50% comparing with the existing one. From these observations, it may be concluded that the new drain configuration, in which the lateral porous pipes of a tunnel are surrounded by gravel layer and non-woven geotextile, has high efficiency in maintenance.

• 한국지반공학회논문집
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• 제24권10호
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• pp.5-15
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• 2008

본 연구의 목적은 연약지반개량을 위한 수평배수층 재료로 순환골재의 적용가능성을 검증함에 있다. 최근 모래의 수급불균형이 초래되고 있으며, 이는 단순히 가격 상승의 문제에서 그치는 것이 아닌 전체 공정의 지연을 초래하게되어 문제의 심각성이 크다. 이러한 상황에서 순환골재는 그 수요를 충족시킬 수 있는 적절한 대체재료로 인식되고 있으며, 이를 검증하기 위해 우선 이미 제정된 각종기준과 규정을 찾아 비교 정리하였고, 다음으로 기존의 수평배수층 재료인 모래와의 공학적 특성에 대한 비교 및 검토를 시행하였다. 결과로써 순환골재는 모래에 비해 큰 투수계수 및 단위중량으로 인해 수평배수층으로써의 대부분 기준을 만족하였으며, 클로깅에 대한 문제는 수평배수층 상부에 필터층을 추가 설치하는 방안으로 해결할 수 있어, 현장적용이 가능한 것으로 판단되었다. 또한 모래에 비해 순환골재의 구입단가가 상대적으로 낮아 공사비 절감이 가능하여, 수평배수층 재료로 순환골재는 매우 경쟁력있는 대체재료라 할 수 있다.

• 전자공학회논문지A
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• 제31A권1호
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• pp.54-60
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• 1994

In this paper, we present the analytical models for the change of the lateral electric field distribution and the velocity saturation region length with the electron trapping of stressed SC-PMOSFET in the saturation region. To derive the hot-electron-induced lateral electric field of stressed SC-PMOSFET. Ko's pseudo two dimensional box model in the saturation region which illustrates the analysis of the velocity saturation region is modified under the condition of electron trapping in the oxide near the drain region. From the results, we have the following lateral electric field in the y-direction, that is, E(y) ES1satT.cosh(y/l) qNS1tT.sinh(y/l)/lCox. It is shown that the trapped electrons influence the field in the drain region. decreasing the lateral electric field. Calculated velocity saturaion length increases with the trapped electrons. increasing the drain current of stressed SCPMOSFET. This results well explain the HEIP phenomenon of PMOSFET's.

• 전기학회논문지
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• 제57권2호
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• pp.235-238
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• 2008

This paper explores 28 nm MOSFET design for LSTP(Low Standby Power) applications using TCAD(Technology Computer Aided Design) simulation. Simulated results show that the leakage current of the MOSFET is increasingly dominated by GIDL(Gate Induced Drain Leakage) instead of a subthreshold leakage as the Source/Drain extension doping increases. The GIDL current can be reduced by grading lateral abruptness of the drain at the expense of a higher Source/Drain series resistance. For 28 nm MOSFET suggested in ITRS, we have shown Source/Drain design becomes even more critical to meet both leakage current and performance requirement.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.342-343
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• 2012

We studied the Drain-Induced-Barrier-Lowering (DIBL) effect by different drain engineering. One other drain engineering is symmetric source-drain n-channel MOSFETs (SSD NMOSs), the other drain engineering is asymmetric source-drain n-channel MOSFETs (ASD NMOSs). Devices were fabricated using state of art 40 nm dynamic-random-access-memory (DRAM) technology. These devices have different modes which are deep drain junction mode in SSD NMOSs and shallow drain junction mode in ASD NMOSs. The shallow drain junction mode means that drain is only Lightly-Doped-Drain (LDD). The deep drain junction mode means that drain have same process with source. The threshold voltage gap between low drain voltage ($V_D$=0.05V) and high drain voltage ($V_D$=3V) is 0.088V in shallow drain junction mode and 0.615V in deep drain junction mode at $0.16{\mu}m$ of gate length. The DIBL coefficients are 26.5 mV/V in shallow drain junction mode and 205.7 mV/V in deep drain junction mode. These experimental results present that DIBL effect is higher in deep drain junction mode than shallow drain junction mode. These results are caused that ASD NMOSs have low drain doping level and low lateral electric field.

• 대한전기학회논문지
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• 제38권6호
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• pp.401-415
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• 1989

A simple but accurate analytical model for the lateral channel electric field in gate-offset structured Lightly Doped Drain MOSFET has been developed. Our model assumes Gaussian doping profile, rather than simple uniform doping, for the lightly doped region and our model can be applied to LDD structures where the junction depth of LDD is not identical to the heavily doped drain. The validity of our model has been proved by comparing our analytical results with two dimensional device simulations. Due to its simplicity, our model gives a better understanding of the mechanisms involved in reducing the electric field in the LDD MOSFET. The model shows clearly the dependencies of the lateral channel electric field on the drain and gate bias conditions and process, design parameters. Advantages of our analytical model over costly 2-D device simulations is to identify the effects of various parameters, such as oxide thickness, junction depth, gate/drain bias, the length and doping concentration of the lightly doped region, on the peak electric field that causes hot-electron pohenomena, individually. Our model can also find the optimum doping concentration of LDD which minimizes the peak electric field and hot-electron effects.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.293-299
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• 2008

If a conventional type of Plastic Board Drain (PBD) is installed to the deep clay deposit, it is subjected to a high lateral earth pressure. a flow channel of PBD may be reduced by the collapse of cores and clogged by the intrusion of filter into the space between cores which are made by lateral pressure. It could decrease the ability of initial discharge capacity and the reliability of long term discharge capacity. A cylindrical plastic board drain (C-PBD) considered in this study consists of cylindrical core and several supports so that it can prevent the reduction of area of flow channel from the higher lateral earth pressure effectively. The discharge capacity of C-PBD was compared to that of a conventional PBD through performing experiments using the composite discharge capacity apparatus which can consider in-situ condition such as penetration of drains, ground settlement and discharge capacity. As a result, C-PBD showed much better performance than PBD in the ability of discharge. It was observed that the C-PBD was folded whereas the conventional PBD was folded after the experiment.

• 대한전자공학회논문지SD
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• 제48권10호
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• pp.62-66
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• 2011

본 연구에서는 측정된 S-파라미터를 사용하여 드레인-소스 전압 Vds에 무관한 게이트-소스 overlap 캐패시턴스를 추출하고, 이를 바탕으로 deep-submicron MOSFET의 Vds 종속 게이트-벌크 캐패시턴스 곡선을 추출하는 RF 방법이 새롭게 개발 되었다. 추출된 캐패시턴스 값들을 사용한 등가회로 모델과 측정된 데이터가 잘 일치하는 것을 관찰함으로써 추출방법의 정확도가 검증되었다. 추출된 데이터로부터 overlap과 depletion 길이의 Vds 종속 곡선이 얻어졌으며, 이를 통해 drain 영역의 채널 도핑 분포를 실험적으로 측정하였다.

• 한국지반신소재학회논문집
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• 제4권3호
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• pp.3-10
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• 2005

본 연구는 연직 배수재의 통수능력 저감 요인인 측방토압, 동수경사, 배수재의 변형에 의한 통수능력의 저감을 밝히기 위하여 현장조건에 가장 부합되는 고무 멤부레인 안에 하모니카형, 성곽형, 파이버형 드레인을 설치한 후 드레인 주변에 슬러리 상태의 점토를 넣고 통수능 특성에 관한 실험을 실시하였다. 그 결과 배수재의 종류에 따른 통수능력은 하모니카형, 성곽형, 파이버형 순으로 통수능력이 컸으며, 또한 측압 보다 동수경사에 대한 통수능력 감소가 높게 나타났다.

• 한국농공학회지
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• 제44권1호
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• pp.142-154
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• 2002

This study was performed to investigate constraint effects of deformation (heaving, lateral displacement) of clayey foundation reinforced with sheet pile at the tip of banking on soft ground, under intact state (natural) and the state of vertical drain respectively. The following results are obtained. 1. In view of reduction in heaving or lateral displacement, sheet pile is not supposed to be of use. 2. Sheet pile is effective only when vertical drain is installed for acceleration of consolidation and gradual loading is applied.