• Tribology and Lubricants
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• 제26권4호
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• pp.240-245
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• 2010

This paper describes the influence on engine main bearing behavior of the oil film when the fuel is diluted on a diesel engine equipped with DPF system. Oil film pressure and the thickness is calculated in accordance to the fuel dilution. The calculation is based on the numerical analysis of the engine main bearing. As a result, the engine oil viscosity decreased as the fuel dilution increased. This led the increment of the maximum oil thickness pressure. Verification of the minimum oil film thickness settlement by the engine gas pressure and the fuel dilution was confirmed. Destruction possibility of the engine main bearing was foreseen when the engine speed was 2000 rpm with the fuel dilution 15% and the 5W40 engine oil.

• 반도체디스플레이기술학회지
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• 제19권1호
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• pp.17-22
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• 2020

Recently, the decrease in thin film thickness has been actively studied by changing several physical elements such as the increase in revolution velocity of lower substrate equipped with AC or DC motor. In this paper, we propose a novel spin coater control system that changes AC or DC motor and common use software with limitation of velocity and position control into step motor and LABVIEW software based on GUI to control revolution velocity and position more precisely. By determining six input values of rotation velocity 1, 5, 10, 25, 50, 100 PPS, we fabricated six samples using coating target, TA(tantalum) on silicon substrate and measured their thin film thickness by SEM. Hence, this research can be applied to inferring thin film thickness of tantalum regarding any value of revolution velocity without additional experiments and for linear reference model via property analysis of thin film thickness using other thin-film materials.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.342.1-342
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• 2002

In this work, the dynamic characteristics of an oil-lubricated, short SFD with a central feeding groove are derived based on a theoretical analysis considering the effect of a groove. The validity of the analysis is investigated experimentally using an Active Magnetic Bearing (AMB) system as an exciter. For the theoretical solution, the fluid film forces of a grooved SFD are analytically derived so that the dynamic coefficients of a SFD are expressed in terms of its design parameters. (omitted)

• 한국토양비료학회지
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• 제47권6호
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• pp.457-463
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• 2014

This study was carried out to find out major factors to mitigate carbon emission using Life Cycle Assessment (LCA). System boundary of LCA was confined from sowing to packaging during vegetable production. Input amount of agri-materials was calculated on 2007 Income reference of white radish, chinese cabbage and chive produced at open field and film house published by Rural Development Administration. Domestic data and Ecoinvent data were used for emission factors of each agri-material based on the 1996 IPCC guideline. Carbon footprint of white radish was 0.19 kg $CO_2kg^{-1}$ at open fields, 0.133 kg $CO_2kg^{-1}$ at film house, that of chinese cabbage was 0.22 kg $CO_2kg^{-1}$ at open fields, 0.19 kg $CO_2kg^{-1}$ at film house, and that of chive was 0.66 kg $CO_2kg^{-1}$ at open fields and 1.04 kg $CO_2kg^{-1}$ at film house. The high carbon footprint of chive was related to lower vegetable production and higher fuel usage as compared to white radish and Chinese cabbage. The mean proportion of carbon emission was 35.7% during the manufacturing byproduct fertilizer; white radish at open fields was 50.6%, white radish at film house 13.1%, Chinese cabbage at outdoor 38.4%, Chinese cabbage at film house 34.0%, chive at outdoor 50.6%, and chive at film house 36.0%. Carbon emission, on average, for the step of manufacturing and combustion accounted for 16.1% of the total emission; white radish at open fields was 4.3%, white radish at film house 15.6%, Chinese cabbage at open fields 6.9%, Chinese cabbage at film house 19.0%, chive at open fields 12.5%, and chive at film house 29.1%. On the while, mean proportion of carbon footprint for the step of $N_2O$ emission was 29.2%; white radish at open fields was 39.2%, white radish at film house 41.9%, Chinese cabbage at open fields 34.4%, Chinese cabbage at film house 23.1%, chive at open fields 28.8%, and chive at film house 17.1%. Fertilizer was the primary factor and fuel was the secondary factor for carbon emission among the vegetables of this study. It was suggested to use Heug-To-Ram web-service system, http://soil.rda.go.kr, for the scientific fertilization based on soil testing, and for increase of energy efficiency to produce low carbon vegetable.

• International Journal of Precision Engineering and Manufacturing
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• 제5권1호
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• pp.13-18
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• 2004

In precision mechanical components that experience sliding, it is important to reduce the friction to minimize surface damage. Particularly, new lubrication methods are needed to reduce friction in silicon based micro-systems applications. In this work, the tribological characteristics of PFPE (Perfluoropolyether) Zdol lubricant on silicon were investigated based on the thickness of the film. The lubricant was coated on silicon wafer specimens by the dip coating method. It was shown that the friction coefficient as well as stiction decreased as the thickness of the film increased. The results of this work may be applied to improve the tribological performance of silicon based micro-system components.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.242-242
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• 2012

Transparent oxide semiconductors are increasingly becoming one of good candidates for high efficient channel materials of thin film transistors (TFTs) in large-area display industries. Compare to the conventional hydrogenated amorphous silicon channel layers, solution processed ZnO-TFTs can be simply fabricated at low temperature by just using a spin coating method without vacuum deposition, thus providing low manufacturing cost. Furthermore, solution based oxide TFT exhibits excellent transparency and enables to apply flexible devices. For this reason, this process has been attracting much attention as one fabrication method for oxide channel layer in thin-film transistors (TFTs). But, poor electrical characteristic of these solution based oxide materials still remains one of issuable problems due to oxygen vacancy formed by breaking weak chemical bonds during fabrication. These electrical properties are expected due to the generation of a large number of conducting carriers, resulting in huge electron scattering effect. Therefore, we study a novel technique to effectively improve the electron mobility by applying environmental annealing treatments with various gases to the solution based Li-doped ZnO TFTs. This technique was systematically designed to vary a different lithium ratio in order to confirm the electrical tendency of Li-doped ZnO TFTs. The observations of Scanning Electron Microscopy, Atomic Force Microscopy, and X-ray Photoelectron Spectroscopy were performed to investigate structural properties and elemental composition of our samples. In addition, I-V characteristics were carried out by using Keithley 4,200-Semiconductor Characterization System (4,200-SCS) with 4-probe system.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.188-188
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• 2011

Recently, scaling down of ULSI (Ultra Large Scale Integration) circuit of CMOS (Complementary Meta Oxide Semiconductor) based electronic devices, the electronic devices, become much faster and smaller size that are promising property of semiconductor market. However, very narrow interconnect line width has some disadvantages. Deposition of conformal and thin barrier is not easy. And metallization process needs deposition of diffusion barrier and glue layer for EP/ELP deposition. Thus, there is not enough space for copper filling process. In order to get over these negative effects, simple process of copper metallization is important. In this study, Cu-V alloy layer was deposited using of DC/RF magnetron sputter deposition system. Cu-V alloy film was deposited on the plane SiO2/Si bi-layer substrate with smooth surface. Cu-V film's thickness was about 50 nm. Cu-V alloy film deposited at $150^{\circ}C$. XRD, AFM, Hall measurement system, and AES were used to analyze this work. For the barrier formation, annealing temperature was 300, 400, $500^{\circ}C$ (1 hour). Barrier thermal stability was tested by I-V(leakage current) and XRD analysis after 300, 500, $700^{\circ}C$ (12 hour) annealing. With this research, over $500^{\circ}C$ annealed barrier has large leakage current. However vanadium-based diffusion barrier annealed at $400^{\circ}C$ has good thermal stability. Therefore thermal stability of vanadium-based diffusion barrier is desirable for copper interconnection.

• 항공우주시스템공학회지
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• 제15권6호
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• pp.1-9
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• 2021

In this study, a new design of an extension-type actuator (ExACT) is proposed based on a chevron structure with displacement amplification mechanisms by local heating. ExACT comprises diamond-shaped displacement amplification structures (DASs) containing axially oriented V-shaped chevron beams, a support bar that restricts lateral heat deformation, and a loading slot for thin-film heaters. On heating the thin film heater, the diamond-shaped DASs undergo thermal expansion. However, lateral expansion is restricted by the support bar, leading to displacement amplification in the axial direction. The performance parameters of ExACT such as temperature distribution and extended displacement is calculated using thermo-mechanical analysis methods with the finite element method (FEM) tool. Subsequently, the ExACTs are fabricated using a polymer-based 3D printer capable of reproducing complex structures, and the performance of ExACTs is evaluated under various temperature conditions. Finally, the performance evaluation results were compared with those of the FEM analysis.

• 한국엔터테인먼트산업학회논문지
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• 제14권5호
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• pp.37-48
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• 2020

영화 <기생충>은 한 가족의 삶을 부유한 가족에 기생하여 사는 기이한 삶의 방식으로 접근하고 있는 특이한 영화로 우리 사회의 빈부의 격차가 얼마나 큰지를 보여주는 암울하고 처절한 의미를 담고 있다. 따라서 본 연구는 이러한 영화 <기생충>에 들어 있는 집과 가족의 의미와 사회적 함의가 무엇인지 짚어 보고자 한 것이다. 그 결과 영화 <기생충>에 들어 있는 세 가족(기택네 집, 박 사장집, 가정부의 공간)의 집은 확실한 계층을 의미하며 그 집에 살고 있는 가족의 위치나 계급을 상징적으로 나타내고 있다. 그리고 이들 3가족에게 나타난 가족의 의미는 기생하듯 살고 있는 하층 계급은 가족끼리 상호조력의 개념은 가지고 있으나 양심이나 도덕개념은 없다. 또한 이 영화 <기생충>에 들어 있는 사회적 함의를 짚어 보면 빈부의 격차에 따른 계층의 의미와 영화에서 상징하는 수석의 의미, 그리고 비극적 결말로 볼 수 있다. 우리는 이 영화의 결말을 통해 빈부의 격차가 극심한 사회적 불균형에서 오는 우리의 미래를 예견해 볼 수 있다.

• 한국염색가공학회지
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• 제31권2호
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• pp.65-76
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• 2019

A multi-point touch input sensor having different sizes or different capacitance touch points connected by only one pair of signal transmission lines was fabricated using a polyimide film coated with a thin copper plate. The capacitance increases with the decrease in the number of sheets of fabric spacers placed between the two sheets of the polyimide film. Therefore, the touch input sensor could be manufactured without fabric spacers, which was possible by the action of the polyimide film as a dielectric material in the capacitor. On the multi-point touch sensor, higher capacitance was obtained when pressing wider-area touch points with 10mm to 25mm diameter on average. However, the capacitance of a system comprising two sheets of touch sensors was considerably low, causing a serious overlap of the capacitance values according to the data collected from the reliability test. Although the capacitance values could be increased by stacking several sheets of touch sensors, the overlap of data was still observed. After reducing the size of all touch points to 10mm and stacking up to eight sheets of sensors, reliable and consistent capacitance data was obtained. Five different capacitance signals could be induced in the sensors by pushing touch points simultaneously.