• Journal of the Korean Geosynthetics Society
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• v.13 no.2
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• pp.11-20
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• 2014

To create a large-scale complex, it is often the case to perform ground improvement by using vertical drain method after the reclamation of coastal soft ground, for construction period shortening and stable site renovation. During this process, the pore water migrates to the horizontal drainage layer of the ground surface through the vertical drain installed in the soft ground and discharged out to the open. In the past sand was used as the material for the horizontal drainage layer in numerous cases, however recently, due to material shortage and high pricing, the use of crushed stones has increased. To prevent mixing of the materials between the horizontal drainage layer and the upper landfill, geosynthetics (PPMat) are installed. However, the use of geosynthetics results in high additional cost for material purchase and installation, therefore it is necessary to examine the validity of the installation itself. In this study, to verify the necessity, model tests were performed. Results from the model tests indicate that the drainage ability of the horizontal drainage layer is barely affected by the application of geosynthetics.

• Journal of the Semiconductor & Display Technology
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• v.12 no.4
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• pp.21-25
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• 2013

This paper is for enhancing the breakdown voltage of MHEMTs with an InP-etchstop layer. The fully removed recess structure in the drain side of MHEMT shows that the breakdown voltage enhances from 2 V to 4 V in the previous work. This is because the surface effect at the drain side decreases the channel current and the impact ionization in the channel at high drain voltage. In order to increase the breakdown voltage at the same asymmetric gate-recess structure, the InGaAs channel structure is replaced with the InGaAs/InP composite channel in the simulation. The simulation results with InGaAs/InP channel show that the breakdown voltage increases to 6V in the MHEMT as the current decreases. In this paper, the simulation results for the InGaAs/InP channel are shown and analyzed for the InGaAs/InP composite channel in the MHEMT.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.9 no.3
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• pp.125-131
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• 1997

In order to analyze the feasibility of the drain layer construction method, which is one of the beach protection methods, a hybrid model is constructed by combining the wave model and the seepage flow model. The used wave model is the analytic solution given by Shuto (1972). and the seepage flow model is used by Richards equation which governs the saturated-unsaturated flow in the porous media. It is concluded by the sensitivity analysis of the hybrid model that the most sensitive parameter in the flow field within the beach is the saturated hydraulic conductivity. The developed hybrid model will be efficiently used in the analysis of the parameter when the drain layers are constructed in the beach, if the field datas are obtained more.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.3
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• pp.134-140
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• 2002

Deep submicron NMOSFETs with elevated source/drain can be fabricated using self-aligned selective epitaxial growth(SEG) of silicon for enhanced device characteristics with shallow junction compared to conventional MOSFETs. Shallow junctions, especially with the heartily-doped S/D residing in the elevated layer, give hotter immunity to Yt roll off, drain-induced-barrier-lowering (DIBL), subthreshold swing (SS), punch-through, and hot carrier effects. In this paper, the characteristics of both deep submicron elevated source/drain NMOSFETs and conventional NMOSFETs were investigated by using TSUPREM-4 and MEDICI simulators, and then the results were compared. It was observed from the simulation results that deep submicron elevated S/D NMOSFETs having shallower junction depth resulted in reduced short channel effects, such as DIBL, SS, and hot carrier effects than conventional NMOSFETs. The saturation current, Idsat, of the elevated S/D NMOSFETs was higher than conventional NMOSFETs with identical device dimensions due to smaller sheet resistance in source/drain regions. However, the gate-to-drain capacitance increased in the elevated S/D MOSFETs compared with the conventional NMOSFETs because of increasing overlap area. Therefore, it is concluded that elevated S/D MOSFETs may result in better device characteristics including current drivability than conventional NMOSFETs, but there exists trade-off between device characteristics and fate-to-drain capacitance.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.366-366
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• 2013

건식 박막증착 공정인 플라즈마 중합법을 이용하여 유기 재료인 Styrene을 절연 박막으로 제작하였다. 플라즈마 중합된 Styrene (ppS) 절연 박막의 정밀한 공정 제어를 위해 bubbler와 circulator를 이용하여 습식 공정과 비교하여도 절연 특성이 뛰어난 pps 절연 박막을 증착하고, 이를 활용하여 gate 전극으로 ITO, insulator layer로 pps, floating gate로 Au, tunneling layer로 ppMMA와 pps, semiconductor로 Pentacene, source/drain 전극으로 Au를 사용한 비휘발성 메모리 소자를 제작하였다. ppMMA와 pps의 서로 다른 tunneling layer의 두께 변화에 따른 비휘발성 메모리 특성 변화를 연구하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.658-660
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• 2004

In this paper, we have investigated electrical characteristics about doble gate MOSFET with changed oxide layer thickness of nam Sate and side gate, main gate and Si-substrate. We have known that optimum thickness of nam gate and side gate at 4nm, gate and Si-substrate at 3nm. We have applied for side gate voltage 3V, and drain voltage 1.5V. finally, we have known that importance of oxide layer thickness between main gate and Si-substrate better than main gate and side Sate.

• Asian Journal of Turfgrass Science
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• v.13 no.4
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• pp.181-190
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• 1999

This study was carried out to survey green system, area, green slope, green turfgrass variety, green section, and particle size of green construction materials, and to investigate and evaluate the characteristics of Design and Construction in Korean golf course green for improving the quality of Korean golf course into that of the international golf course held international tournament. The results were as follows. 1. The greens of 129 Korean golf courses consisted of 2(two) green system and 1(one) green system. 2(two) green system was 50.8%, 1(one) green system was 40.7%, and 1+2 green system was 8.5% of them. 2. In 48 Korean golf courses, the green area of 2(two) green system was mostly 400~$600\m^2$(56.5%) and the green area of 1(one) green system was mostly 600~$800\m^2$(47.8%). In 48 Korean golf courses, 1.5~3% green slope appeared the highest frequency(50.0%) and the next was 3~5%(29.4%). 3. Penncross variety was the highest frequency(71.2%). The next was mixed variety (Penncross+Crenshaw, Penn A-1, Pennlinks, or Penneagle/SR 1020+SR 1019) and the frequency of mixed variety was 7.6%. 4. In 48 Korean golf courses, 70~80cm total thickness of green appeared the highest frequency(36.1%), 10~20cm thickness of green mixed sandy layer appeared the highest frequency(43.6%), and 10~20cm thickness of green coarse sandy layer appeared the highest frequency(55.6%). 0~10cm thickness of green gravel layer appeared the highest frequency(67.6%), 20~30cm thickness of green drain layer appeared the highest frequency(52.8%), and 20~30cm width of green drain layer appeared the highest frequency(44.4%). Below 1mm sand diameter used in green mixed sandy layer appeared the highest frequency(46.2%), below 2mm or over 2mm sand diameter used in green coarse sandy layer appeared the highest frequency(31.4%). 20~40mm coarse gravel diameter used in green gravel layer appeared the highest frequency(43.2%) and 0~20mm fine gravel diameter used in green gravel layer appeared the highest frequency(65.8%). 20~40mm gravel diameter used in green drain layer appeared the highest frequency(64.1%).

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.108-109
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• 2014

본 논문에서는 gate와 drain bias stress하에서의 a-IGZO thin-film transistors (TFTs)의 비대칭 열화 메커니즘 분석을 진행하였다. Gate와 drain bias stress하에서의 a-IGZO TFT의 열화 현상은 conduction band edge 근처에 존재하는 oxygen vacancy-related donor-like trap의 발생으로 예상되며, TFT의 channel layer 내에서의 비대칭 열화현상은 source의 metal과 a-IGZO layer간의 contact에 전압이 인가되었을 경우, reverse-biased Schottky diode에 의한 source 쪽에서의 높은 electric field가 trap generation을 가속화시킴으로써 일어나는 것임을 확인할 수 있었다.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.930-937
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• 2008

From the result of precise field investigation and stability analysis for the cut slope, following results were acquired. 1. The cause of the collapse of cut slope came from circle sliding collapse by fault zone which remained inner weathering zone. 2. The existing destructed soil and rock can be removed by reinforcement. And to prevent the additional destruction, it is judged that applying the method after relaxing the slope would be reasonable. 3. To make cut slope stable, soft rock layer should be done cutting 1:1.5 and 1:2.0 ~ 1:2.5 for weathered rock and soil layer. 4. Heavy water leakage section should be applied horizontal drain method so that water pressure should not act to the cut slope.

• Transactions on Electrical and Electronic Materials
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• v.18 no.3
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• pp.141-143
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• 2017

Novel structured thin film transistors (TFTs) of amorphous silicon zinc tin oxide (a-SZTO) were designed and fabricated with a thin metal layer between the source and drain electrodes. A SZTO channel was annealed at $500^{\circ}C$. A Ti/Au electrode was used on the SZTO channel. Metals are deposited between the source and drain in this novel structured TFTs. The mobility of the was improved from $14.77cm^2/Vs$ to $35.59cm^2/Vs$ simply by adopting the novel structure without changing any other processing parameters, such as annealing condition, sputtering power or processing pressure. In addition, stability was improved under the positive bias thermal stress and negative bias thermal stress applied to the novel structured TFTs. Finally, this novel structured TFT was observed to be less affected by back-channel effect.