• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.10
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• pp.1840-1844
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• 2008

In this paper, the influence of channel doping concentration, which the most important factor is as double gate MOSFET is fabricated, on transport characteristics has been analyzed in the subthreshold region. The analytical model is used to derive transport model based on Poisson equation. The thermionic omission and tunneling current to have an influence on subthreshold current conduction are analyzed, and the relationship of doping concentration and subthreshold swings of this paper are compared with those of Medici two dimensional simulation, to verify this model. As a result, transport model presented in this paper is good agreement with two dimensional simulation model, and the transport characteristics have been considered according to the dimensional parameters of double gate MOSFET.

• Archives of design research
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• v.13 no.3
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• pp.191-200
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• 2000

Recently, as the form of media has been various and computer graphic technology has developed, it has been possible and attempted to present database information 3-dimensionally and dynamically. However, there was not many studies done regarding how to present 3-dimensional and dynamic information. Therefore, this study was conducted to develop presentation techniques and languages of 3-dimensional and dynamic information. This paper consists of four section. First, it was introduced by secondary research that fundamental knowledge and functions for presenting the information by the computer graphics. In other words, it was stated what is possible to present 3-dimensional information on the 2-dimensional screen and which functins becomes better as computer graphic technology has developed. Second, computer graphic model that present database information should also have hierarchical structure that database information has. Thus, it was discussed how to present information regarding how to make a structure of graphic model that present database information. There are two ways to present information- by changing structure of information and by changing graphical presentation techniques. Third, all the graphical presentation language was collected and explained. Finally, the case study of presenting statistical data for baseball players demonstrated concrete example of using graphical presentation language.

• The Journal of Engineering Geology
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• v.19 no.1
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• pp.15-23
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• 2009

The site effects relating to the amplification of ground motion under earthquake loading are strongly influenced by both the subsurface soil condition and geologic structure. In this study, the site effects at the Hongseong area in Korea were examined by both the site investigation including borehole drilling and in-situ seismic tests and the site visit for acquiring geologic information of ground surface. Subsurface of Hongseong area with a major instrumental earthquake event in 1978 is composed of weathered layers of a maximum of 45 m thickness overlying bedrock. A geotechnical information system based on GIS framework was implemented to effectively find out spatial geologic structure of study area and it indicated Hongseong is a shallow and wide shaped basin. Two-dimensional finite element (FE) analyses for a representative cross-section of the Hongseong area were performed to evaluate seismic site responses. From the results of seismic responses, it was observed that the ground motions were amplified during the propagation of shear waves through the soil layer overlying the bedrock and the duration of shaking near the basin edges was prolonged due to the surface waves generated by interactions of shear waves with basin geometry. Furthermore, one-dimensional FE seismic response analyses were additionally conducted for soil sites selected in the basin, and it gives similar results to the two-dimensional seismic responses at most locations in the basin with the exception of the locations near the basin edges, because the basin in this study is very shallow and wide.

• Computational Structural Engineering
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• v.9 no.3
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• pp.115-123
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• 1996

A finite element analysis of a trunnion pipe anchor is presented. The structure is analyzed for the case of internal pressure and moment loadings. The stress results are categorized into the average (membrance) and the linearly varying(bending) stresses through the thickness. The resulting stresses are interpreted per Section III of the ASME Boiler and Pressure Vessel Code from which the Primary (B/sub 1/) and Secondary(C/sub 1/) stress indices for pressure, the Primary(B/sub 2R/, B/sub 2T/) and Secondary(C/sub 2R/, C/sub 2T/) stress indices for moment are developed. Several analyses were performed for various structural geometries in order to obtain empirical representation for the stress indices in terms of dimensionless ratios.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1996.04a
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• pp.27-39
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• 1996

A finite element analysis of a trunnion pipe anchor is presented. The structure is analyzed for the case of internal pressure and moment loadings. The stress results are categorized as average and linearly varying(through the thickness) stresses. The resulting stresses are interpreted per Section 111 of the ASME Boiler and Pressure Vessel Code from which the Primary(B$_1$) and Secondary(C$_1$) stress indices for pressure, the Primary(B$_2$) and Secondary(C$_2$) stress indices for moment are developed. Several analysis were peformed on various structural geometries in order to determine empirical relationships for the stress indices as a function of dimensionless ratios.

• Economic and Environmental Geology
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• v.49 no.1
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• pp.31-41
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• 2016

A program code was developed to calculate block hydraulic conductivity of the 2-D DFN(discrete fracture network) system based on equivalent pipe network, and implemented to examine the effect of joint orientation distribution on the hydraulic characteristics of fractured rock masses through numerical experiments. A rock block of size $32m{\times}32m$ was used to generate the DFN systems using two joint sets with fixed input parameters of joint frequency and gamma distributed joint size, and various normal distributed joint trend. DFN blocks of size $20m{\times}20m$ were selected from center of the $32m{\times}32m$ blocks to avoid boundary effect. Twelve fluid flow directions were chosen every $30^{\circ}$ starting at $0^{\circ}$. The directional block conductivity including the theoretical block conductivity, principal conductivity tensor and average block conductivity were estimated for generated 180 2-D DFN blocks. The effect of joint orientation distribution on block hydraulic conductivity and chance for the equivalent continuum behavior of the 2-D DFN system were found to increase with the decrease of mean intersection angle of the two joint sets. The effect of variability of joint orientation on block hydraulic conductivity could not be ignored for the DFN having low intersection angle between two joint sets.

• Journal of Adhesion and Interface
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• v.22 no.2
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• pp.57-62
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• 2021

Recently, the atomically thin two-dimensional transition-metal dichalcogenides (TMDs) have received considerable attention for the application to next-generation semiconducting devices, owing to their remarkable properties including high carrier mobility. However, while a technique for growing graphene is well matured enough to achieve a wafer-scale single crystalline monolayer film, the large-area growth of high quality TMD monolayer is still a challenging issue for industrial application. In order to enlarge the size of single crystalline MoS₂ monolayer, here, we systematically investigated the effect of process parameters in molten-salt-assisted chemical vapor deposition method. As a result, with optimized process parameters, we found that single crystalline monolayer MoS₂ can be grown as large as 420 ㎛.

• Geotechnical Engineering
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• v.4 no.2
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• pp.56-64
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• 1988

軟弱地盤의 數値解析結果의 精度 확인과 기타 壓密試料의 제작 및 각종 軟弱地盤工法의 硏究를 위해 2次元載荷試驗裝置의 개발이 시급한데 외국산일 경우 매우 高價이다. 따라서 국내 생산으로 외국산의 1/5의 값으로 裝置를 개발하려고 한 것이다. 구조는 載荷틀과 荷重驅動裝置, 壓密裝置, 土壓 및 間隙水壓測定裝置 등으로 大別되는데 모두 국산으로 구입 또는 設計製作하여 만족할 만한 精度를 얻었다. 특히 土壓 및 間隙水壓計는 美製의 foil strain gage만을 구입하여 나머지 裝置는 직접 設計製作한 것으로 성능시험 결과도 良好하였다. 앞으로 地盤數値解析結果의 精度 확인에 利用되고 기타 硏究, 講義등에도 記錄裝置만 保有하고 있으면 700~800萬원으로 製作될 수 있을 것으로 기대된다.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1349-1351
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• 1997

TFT2DS was utilized to provide the usefulness as an analytic and design tool. In this paper, the general effects of channel length of an inverted staggered amorphous silicon thin film transistor on its characteristics were investigated. The results obtained from these experiments would be adopted to the optimized device designs and advanced simulations of their electrical properties.

• Proceedings of the Optical Society of Korea Conference
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• 2003.02a
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• pp.180-181
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• 2003

주기적인 유전율의 변화를 가지는 광결정에 대한 연구가 최근 10여년간 활발하게 이루어지고 있다. 광결정에 존재하는 특성인 광 밴드갭(photonic bandgap) 효과를 이용한 단일 결함 구조의 레이저나 선결함의 도파로에 응용성이 활발하게 이루어지는 가운데 새로운 시도로 표면파(surface wave)를 이용한 광결정의 응용성을 고찰해 보았다. 주기적으로 층이 진 물질과 균일한 물질의 경계면에서 전자기파가 구속 될 수 있다는 것이 보고된 바 있다. (중략)