• Title/Summary/Keyword: Double bottom

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Strength Analysis of Double Bottom Structures in Stranding by Idealized Structural Unit Method (이상화(理想化) 구조요소법(構造要素法)에 의한 좌초시(坐礁時) 이중저(二重底) 구조(構造)의 손상 및 강도(强度) 해석(解析))

  • Jeom-K. Paik;Chang-Y. Kim
    • Journal of the Society of Naval Architects of Korea
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    • v.28 no.1
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    • pp.125-138
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    • 1991
  • In this paper, an efficient method for the analysis of damage and strength of double bottom structure in stranding is described by using idealized structural unit method. Also a procedure for the determination of the effective double bottom height which is required in order to protect the inner-bottom plate is proposed. In the comparison between the present solution and he existing experimental and numerical results in stranding, its observed that the present method gives reasonable results requiring very shorts computiong times. The present method is then applied to the double bottom structure of 40K product oil carrier which is designed by the double skin design concept as an example. By performing the series of analysis, the influence of vertical member space, plate thickness and double bottom height on the energy absorption capacity of the double bottom structure in stranding is investigated. Also the minimum double bottom height with varying each design variable Is calculated based on the above result.

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Cost-Benefit Analysis for Planting Type of Street Trees (가로수 조성 유형에 따른 비용편익 비교 분석)

  • Kim, Joon Soon;Lee, Dong Kun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.17 no.6
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    • pp.29-37
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    • 2014
  • The objective of this study is to estimate the cost and benefits of street trees for their planting types, specifically, single row, single row+bottom, double row, double row+bottom. Different planting types are compared and analyzed by using Net Present Value (NPV) and benefit-cost ratio (BCR). Existing data are collected from the literature reviews for the use of meta-analysis method for estimating cost and benefit. The elements for analyzing costs are management and planting costs, and benefits are air purification, energy saving and landscape view. The discount rate is applied at a minimum of 3% and a maximum of 5.5%. The unit used in this calculation is km/year. The result shows that the net benefit is highest in double row, followed by single row, double row+bottom, and single row+bottom. The BCR is the highest in double row, followed by single row, double row+bottom, and single row+bottom. The BCR reaches the break-even point from 9 to 17 years depending on the planting types.

Effects of Blending Ratio of Pigments on Properties and Printability of the Double Coated Paper (안료의 배합비가 더블 도공지의 물성 및 인쇄적성에 미치는 영향)

  • Kim, Chang-Keun;Lee, Yong-Kyu
    • Journal of Forest and Environmental Science
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    • v.18 no.1
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    • pp.97-105
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    • 2001
  • The main objective of this study was to investigate effects of pigment mixed with different ratio on the double coated paper. Mineral pigments such as clay and ground calcium carbonate(GCC) as well as hollow sphere plastic pigment were used to evaluate the physical, optical properties and printabilities of double coated paper. The physical properties such as gloss and smoothness, and the printability(ink gloss) of double coated paper were measured to evaluate the effects of the bottom layer on improving the properties of top layer. The data indicated that the usage of hollow sphere plastic pigment for the bottom layer coating improved the surface properties of double coated paper, and that ink gloss was significantly influenced by the structure of bottom layer even when hollow sphere plastic pigment was used for the bottom layer coating.

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A Study on Double Bottom Structural Criterion of Oil Tanker under DWT 500 (재화중량 500톤 미만 유조선의 이중저구조기준 연구)

  • Lee, Sang-Gab;Yoon, Yeo-Hoon;Bae, Jun-Yong
    • Journal of Korea Ship Safrty Technology Authority
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    • s.23
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    • pp.2-13
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    • 2007
  • With the effectuation of the amendment of MARPOL 73/78 on 5 April 2005, enforcement regulations of Marine Pollution Prevention Act were revised in domestic on 12 March 2005 that double hull structure was required to the small single bottom oil tankers under DWT(deadweight tonnage) 500 ton for the protection of the marine pollution casualties. The objective of this study is to develop the double bottom structure of small oil tanker under DWT 500 ton with superior crashworthiness and to establish its suitable standard to double bottom structure. The promoting strategy of this R&D is classified into the crashworthy structural analysis of small oil tankers using LS/DYNA3D code and the examination of their damage stabilities according to tonnage. It could be thought that the desirable inner bottom height should be above the B/7.5 and its minimum height 0.65m for the domestic small oil tanker under DWT 500ton.

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Measuring and Reporting Corporate Social Performance: An Exploratory Study for Practical Application of Double Bottom Line (기업의 사회적 성과 측정과 보고: 더블바텀라인의 실무 적용을 위한 탐색적 연구)

  • Jo, Illhyung
    • Knowledge Management Research
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    • v.21 no.2
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    • pp.1-19
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    • 2020
  • The purpose of this study is to suggest a practical way to measure and report corporate social performance as public interest in corporate social value pursuits increases. In particular, we will look for ways to measure and report on the financial and social performance of a company based on the concept of the Double Bottom Line (DBL), which has recently spread to big companies. For this purpose, this study analyzed the theoretical background and practical techniques related to measuring and reporting corporate social performance, and examined methods for measuring and reporting social performance in the existing financial performance measurement system. As a result, SROI was the most suitable method for measuring social performance of a company. It is recommended that social performance reporting follows the disclosure method of the accounting system, and the details of reporting suggest that using the standard of GRI Standard, an international standard related to sustainability reporting, is the most reasonable alternative to 'Double Bottom Line' performance reporting.

Analysis of Tunneling Current for Bottom Gate Voltage of Sub-10 nm Asymmetric Double Gate MOSFET (10 nm이하 비대칭 이중게이트 MOSFET의 하단 게이트 전압에 따른 터널링 전류 분석)

  • Jung, Hakkee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.1
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    • pp.163-168
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    • 2015
  • This paper analyzed the deviation of tunneling current for bottom gate voltage of sub-10 nm asymmetric double gate MOSFET. The asymmetric double gate MOSFET among multi gate MOSFET developed to reduce the short channel effects has the advantage to increase the facts to be able to control the channel current, compared with symmetric double gate MOSFET. The increase of off current is, however, inescapable if aymmetric double gate MOSFET has the channel length of sub-10 nm. The influence of tunneling current was investigated in this study as the portion of tunneling current for off current was calculated. The tunneling current was obtained by the WKB(Wentzel-Kramers-Brillouin) approximation and analytical potential distribution derived from Poisson equation. As a results, the tunneling current was greatly influenced by bottom gate voltage in sub-10 nm asymmetric double gate MOSFET. Especially it showed the great deviation for channel length, top and bottom gate oxide thickness, and channel thickness.

Analysis of Threshold Voltage for Symmetric and Asymmetric Oxide Structure of Double Gate MOSFET (이중게이트 MOSFET의 대칭 및 비대칭 산화막 구조에 대한 문턱전압 분석)

  • Jung, Hakkee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.12
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    • pp.2939-2945
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    • 2014
  • This paper has analyzed the change of threshold voltage for oxide structure of symmetric and asymmetric double gate(DG) MOSFET. The asymmetric DGMOSFET can be fabricated with different top and bottom gate oxide thickness, while the symmetric DGMOSFET has the same top and bottom gate oxide thickness. Therefore optimum threshold voltage is considered for top and bottom gate oxide thickness of asymmetric DGMOSFET, compared with the threshold voltage of symmetric DGMOSFET. To obtain the threshold voltage, the analytical potential distribution is derived from Possion's equation, and Gaussian distribution function is used as doping profile. We investigate for bottom gate voltage, channel length and thickness, and doping concentration how top and bottom gate oxide thickness influences on threshold voltage using this threshold voltage model. As a result, threshold voltage is greatly changed for oxide thickness, and we know the changing trend greatly differs with bottom gate voltage, channel length and thickness, and doping concentration.

Relation of Oxide Thickness and DIBL for Asymmetric Double Gate MOSFET (비대칭 이중게이트 MOSFET에서 산화막 두께와 DIBL의 관계)

  • Jung, Hakkee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.4
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    • pp.799-804
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    • 2016
  • To analyze the phenomenon of drain induced barrier lowering(DIBL) for top and bottom gate oxide thickness of asymmetric double gate MOSFET, the deviation of threshold voltage is investigated for drain voltage to have an effect on barrier height. The asymmetric double gate MOSFET has the characteristic to be able to fabricate differently top and bottom gate oxide thickness. DIBL is, therefore, analyzed for the change of top and bottom gate oxide thickness in this study, using the analytical potential distribution derived from Poisson equation. As a results, DIBL is greatly influenced by top and bottom gate oxide thickness. DIBL is linearly decreased in case top and bottom gate oxide thickness become smaller. The relation of channel length and DIBL is nonlinear. Top gate oxide thickness more influenced on DIBL than bottom gate oxide thickness in the case of high doping concentration in channel.

Spin Signals in Lateral Spin Valves with Double Nonmagnetic Bottom Electrodes

  • Lee, B.C.
    • Journal of Magnetics
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    • v.13 no.3
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    • pp.81-84
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    • 2008
  • Spin injection and detection in lateral spin valves with double nonmagnetic bottom electrodes are investigated theoretically. Spin-polarized current injected from a magnetic electrode is split to two bottom electrodes, and nonlocal spin signals between the other magnetic electrode and the nonmagnetic electrodes are calculated from drift-diffusion equations. It is shown that the spin signal is approximately proportional to the associated current in the electrode.

Dynamic Stress Analysis of a Bottom Gate TFT Having an Active Layer of Amorphous/Microcrystalline Si Double-Layers

  • Pak, Sang-Hoon;Jeong, Tae-Hoon;Kim, Si-Joon;Kim, Hyun-Jae
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08b
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    • pp.1344-1347
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    • 2007
  • We have fabricated bottom gate TFTs with active layers of amorphous/microcrystalline Si double layers (DL). Dynamic electric stresses were applied to DL TFTs and a-Si TFTs to compare their degradation characteristics. The DL TFTs were more stable under dynamic stresses than a-Si TFTs.

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