• Title/Summary/Keyword: Double bottom

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Analysis for Relation of Oxide Thickness and Subthreshold Swing of Asymmetric Double Gate MOSFET (비대칭 DGMOSFET의 산화막 두께와 문턱전압이하 스윙의 관계 분석)

  • Jung, Hakkee;Cheong, Dongsoo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2013.10a
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    • pp.698-701
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    • 2013
  • This paper has presented the change of subthreshold swings for gate oxide thickness of asymmetric double gate(DG) MOSFET, and solved Poisson equation to obtain the analytical solution of potential distribution. The symmetric DGMOSFET is three terminal device. Meanwhile the asymmetric DGMOSFET is four terminal device and can separately determine the bias voltage and oxide thickness for top and bottom gates. As a result to observe the subthreshold swings for the change of top and bottom gate oxide thickness, we know the subthreshold swings are greatly changed for gate oxide thickness. Especially we know the subthreshold swings are increasing with the increase of top and bottom gate oxide thickness, and top gate oxide thickness greatly influences subthreshold swings.

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Flexural Design of Double Composite Box Girder over Interior Pier by LRFD Method (LRFD법에 의한 이중합성 박스거더 최대부모멘트 단면 휨 설계)

  • Cho, Eun Young;Shin, Dong Ku
    • Journal of Korean Society of Steel Construction
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    • v.19 no.6
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    • pp.737-749
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    • 2007
  • Flexural design of double composite box girder over the interior pier for three-span continuous bridge was performed by the LRFD method. The maximum span length of the continuous bridge ranged from 80m to 120m and the relative ratio of the span length was assumed to be 1:1.25:1. The girder section was designed for the strength limit state and service limit state with additional design check for constructibility. Before the bottom concrete and compression flange showed a complete composite action, the buckling of lower compression flange was checked. The flexural stiffness and flexural resistance characteristics for the section and for the constituent members such as tension flange, compression flange, and web were analyzed for different thicknesses of the bottom concrete on top of the compression flange. The effect of the distribution ratio of steel between the top and bottom flanges was investigated by analyzing ductility behavior and stress distribution through the girder's depth for several different relative area ratios of steel between the top and bottom flanges. It was found that a total amount of 15% of steel can be saved by applying the double composite system compared with that of the conventional composite system.

attenuation pattern of the electromagnetic fields scattered by two empty circular cylinders in a dielectric medium (유전체 내의 두개의 빈 원기둥에 의해 산란된 전자파의 감쇄패턴)

  • 이택경;김세윤;라정웅
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.4
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    • pp.92-97
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    • 1996
  • The attenuation pattern of the E-polarized electromagnetic fields scattered by two empty circular cylinders in a dielectric medium is analyzed to calculate the effects of the inhomogenuity in hte background medium. Inthe amplitude pattern of the electromagnetic field scattered by one cylinder, double dips occur at the locations corresponding to its top and bottom boundaries. The distorton of the original double dip pattern is calculated when other air cavity approaches or its size increases.

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The Structure of Visual Cells in the Retina of the Pond Loach, Misgurnus anguillicaudatus (Pisces; Cobitidae)

  • Kim, Chi-Hong;Kim, Jae-Goo;Park, Jong-Young
    • Applied Microscopy
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    • v.45 no.4
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    • pp.254-258
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    • 2015
  • A histological study on the retina of Misgurnus anguillicaudatus was carried out by light microscopy and scanning electron microscopy as part of getting information about relation between its habitat and visual cells. The visual cells of the retina in M. anguillicaudatus, a bottom-dwelling freshwater pond loach in stagnant or slow waters such as swamps, reservoirs and paddy fields, consists of double cones and large rods. The cones form a row mosaic pattern in which the partners of double cones are linearly oriented with a large rod. In a double cone, the two members are unequal such that one cone may be longer than the other.

Improvement of source-drain contact properties of organic thin-film transistors by metal oxide and molybdenum double layer

  • Kim, Keon-Soo;Kim, Dong-Woo;Kim, Doo-Hyun;Kim, Hyung-Jin;Lee, Dong-Hyuck;Hong, Mun-Pyo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.270-271
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    • 2008
  • The contact resistance between organic semiconductor and source-drain electrode in Bottom Contact Organic Thin-Film Transistors (BCOTFTs) can be effectively reduced by metal oxide/molybdenum double layer structure; metal oxide layers including nickel oxide (NiOx/Mo) and moly oxide(MoOx) under molybdenum work as a high performance carrier injection layer. Step profiles of source-drain electrode can be easily achieved by simultaneous etching of the double layers using the difference etching rate between metal oxides and metal layers.

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A Study on Rescue Technique and Safe Tow of Damaged Ship (2) - Failure Mechanisms of Collision and Grounding of Double Hull Tanker - (손상된 선박의 구난 기술 및 안전 예항에 관한 연구 (2) - 이중선체 유조선의 충돌 및 좌초에 의한 손상역학거동 -)

  • Lee Sang-Gab;Choi Kyung-Sik;Shon Kyoung-Ho
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.1 no.2
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    • pp.82-95
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    • 1998
  • In this paper, two series of numerical simulations are performed using LS/DYNA3D: The first series of numerical simulations are collision events between a 310,000 DWT double hull VLCC (struck ship) and two 35,000 and 105,000 DWT tankers (striking ships). Collisions are assumed to occur at the middle of the VLCC with the striking ships moving at right angle to the YLCC centerline. The second ones, grounding accidents of two 40,000 DWT Conventional and Advanced Double Hull lanker bottom structures, CONV/PD328 and ADH/PD328 models. The overall objective of this study is to understand the structural failure and energy absorbing mechanisms during collision and grounding events for double hull tanker side and bottom structures, which lead to the initiation of inner shell rupture and cause the kinetic energy dissipation to bring the ship to a stop. These numerical simulations will contribute to the estimation of damage extents of collision and grounding accidents and the future improvements in lanker safety at the design stage.

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Effect of corrosion on the ultimate strength of double hull oil tankers - Part I: stiffened panels

  • Kim, Do Kyun;Park, Dae Kyeom;Kim, Jeong Hwan;Kim, Sang Jin;Kim, Bong Ju;Seo, Jung Kwan;Paik, Jeom Kee
    • Structural Engineering and Mechanics
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    • v.42 no.4
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    • pp.507-530
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    • 2012
  • Age-related problems especially corrosion and fatigue are normally suffered by weatherworn ships and aging offshore structures. The effect of corrosion is one of the important factors in the Common Structural Rule (CSR) guideline of the ship design based on a 20 or 25 years design life. The aim of this research is the clarification of the corrosion effect on ultimate strength of stiffened panels on various types of double hull oil tankers. In the case of ships, corrosion is a phenomenon caused by the ambient environment and it has different characteristics depending on the parts involved. Extensive research considering these characteristic have already done by previous researchers. Based on this data, the ultimate strength behavior of stiffened panels for four double hull oil tankers such as VLCC, Suezmax, Aframax, and Panamax classes are compared and analyzed. By considering hogging and sagging bending moments, the stiffened panels of the deck, inner bottom and outer bottom located far away from neutral axis of ship are assessed. The results of this paper will be useful in evaluating the ultimate strength of an oil tanker subjected to corrosion. These results will be an informative example to check the effect of ultimate strength of a stiffened panel according to corrosion addition from CSR for a given type of ship.

Evaluation on Flexural Behavior of Double-tee Slabs with the Least Depth from Optimization Process (최적이론에 의하여 설계된 최소 깊이 더블티 슬래브의 휨거동 평가)

  • 유승룡;김대훈;유재천
    • Journal of the Korea Concrete Institute
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    • v.11 no.3
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    • pp.141-152
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    • 1999
  • Precast prestressed double-tee slab may be designed by the PCI Design Handbook. It is based on the bridge construction and is required for reorganization for the use of buildings in the domestic construction environments. Much enhanced sections are developed from the reforming process on the determined design factors in the previous experimental works on double tees. Pre-determined shape, reinforcement detail, and 5000 psi concrete strength can not be expected as the best solution for the domestic construction requirements because large amount of use on that systems are anticipated. Flexural tests are performed on four full-scale 12.5m proto-type models, "least depth double tee", which are resulted from the optimization process. Domestic superimposed live load regulation, domestic material properties which is available to product, building design requirements and economy in construction are considered as the main factors to establish. the first two sections are double tee section for 1.2 ton/$\m^2$ market live load with straight and one-point depressed strands and the second two are for 0.6 ton/$\m^2$ parking live load with those strand types. All of the specimens tested fully comply with the flexural strength requirements as specified by ACI 318-95. However, the research has shown that following improved considerations are needed for better result in practice. The locations and method of connection for the lowest bottom mild bar, connection method between precast and cast-in-place concrete, and dap-end reinforcement are need to be improved.

Acoustic Analysis of High-Frequency Ultrasonic Cleaner

  • Choi, Sunghoon;Kim, Jin Oh;Kim, Yong-Hoon
    • The Journal of the Acoustical Society of Korea
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    • v.16 no.1E
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    • pp.49-56
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    • 1997
  • Ultrasonic cleaning at high frequency around 1 MHz, called megasonic cleaning, is commonly used to remove particles less than 1 ㎛ by generating high frequency accelerations on the cleaning objects. Cleaning is performed in an ultrasonically-excited liquid contained in a double-structured container. Ultrasonic waves generated by piezoelectric transducers propagate in the outer container and are transmitted through the inner container. The bottom of the inner container is inclined to make oblique incidence of the ultrasonic wave in order to raise the efficiency of the transmission through the bottom plate. This work deals with the efficiency of the transmission, which directly affects the cleaning performance. The transmission characteristics of the ultrasonic wave in the megasonic cleaner have been obtained analytically and numerically for the variations of some parameters, such as the thickness and inclined angle of the bottom plate of the inner container and the chemical ratio and temperature of the cleaning liquid. The calculated results have yielded the optimum cleaning condition in terms of the sound power transmitted into the cleaning liquid.

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