• 한국유체기계학회 논문집
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• 제12권4호
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• pp.44-53
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• 2009

Numerical design optimization of a fan-shaped hole for film-cooling has been carried out to improve film-cooling effectiveness by combining a three-dimensional Reynolds-averaged Navier-Stokes analysis with the radial basis neural network method, a well known surrogate modeling technique for optimization. The injection angle of hole, lateral expansion angle of hole and ratio of length-to-diameter of the hole are chosen as design variables and spatially averaged film-cooling effectiveness is considered as an objective function which is to be maximized. Twenty training points are obtained by Latin Hypercube sampling for three design variables. Sequential quadratic programming is used to search for the optimal point from the constructed surrogate. The film-cooling effectiveness has been successfully improved by the optimization with increased value of all design variables as compared to the reference geometry.

• KIEAE Journal
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• 제17권3호
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• pp.91-97
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• 2017

Purpose: Various studies on a light shelf are in progress, but it has the problem of glare occurrence. The present study suggested a diffusion film as the method for resolving the glare problem, and aimed to establish light shelf-related basic data by conducting the performance evaluation of a light shelf depending on the installation position of the diffusion film. Method: To carry out the light shelf performance evaluation depending on the diffusion film installation position, three cases were established: no diffusion film installation (Case 1), diffusion film installation on the reflector (Case 2), and diffusion film installation on the upper glass surface of the window for light shelf installation (Case 3); and the energy reduction performance, luminance, and luminance contrast were analyzed based on a testbed. Result: The conclusions of this study are as follows. 1) When the diffusion film was applied, the amount of light introduced through the light shelf decreased, and the average indoor illumination decreased accordingly. 2) For Case 3, the lighting energy reduction performance was identical to the lighting energy reduction efficiency of the existing light shelf; and for Case 2, it was found to be inappropriate as the lighting energy consumption increased compared to that of the existing light shelf. 3) The analysis of the glare for the cases established in this study showed that the luminance contrast was low for Case 3, and thus the glare problem could be minimized. 4) The specific angle of the light shelf could induce the glare problem by increasing the luminance depending on the external condition. 5) Based on the aforementioned contents, the installation position of the diffusion film for improving the lighting performance and glare problem of the light shelf was found to be the upper glass surface of the window for light shelf installation.

• 한국디자인학회:학술대회논문집
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• 한국디자인학회 2002년도 봄 학술발표회 논문집
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• pp.162-163
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• 2002

• 한국전기전자재료학회논문지
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• 제28권12호
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• pp.813-820
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• 2015

We have studied commercialization and process optimization of protective film on transparent conductive coated substrate, nano silver on flexible PET (poly ethylene terephthalate), by means of roll-to-roll micro-gravure coater. Nanosilver on flexible PET substrate is potential materials to replace ITO (indium tin oxide). Protective film is most important to maintain unique silver pattern on top of transparent PET. PSA pressure sensitive adhesives) was developed solely for nano silver on PET and protective film was successfully laminated. We have optimized all process conditions such as coating thickness, line speed and aging time & temperature via experimental design. Transparent conductive film and its protective film developed in this research are commercially available at this moment.

• 디자인학연구
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• 제17권2호
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• pp.451-462
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• 2004

디지털시대가 도래하면서 그래픽디자인의 영역이 확대되어 필름, DVD, 인터랙티브TV, 모바일, DMB 등 영상디자인의 새로운 분야들에서 디자이너의 역할을 요구하기 시작했다. 이는 보다 진화된 뉴미디어 환경을 기반으로 한다는 점에서 디지털 영상디자인의 적용과 사례로 볼 수 있다. 뉴미디어 환경은 젊은 계층이 주 타깃이 되기에 영상언어의 표현기법이 달라지는 것도 필연적이라고 하겠다. 시각커뮤니케이션이 창조되고 분배되어 온 방법들이 이제는 더 이상 정지되어 있는 것을 원하지 않고, 다이내믹한 움직임으로, 다시 상호작용(Interaction)이라는 변화를 거쳐오면서 영상의 적용과 활용은 비할 수 없이 다각화되었다. 변화와 발전을 거듭하는 학문으로서 디자인의 정체성이 뉴미디어 환경에서 어떻게 진화하고 있는지를 조사ㆍ분석하여 향후 영상ㆍ디지털미디어 대학원교육의 방향을 가늠하기 위한 것이 본 연구의 주된 목표이다. 이를 위해 사례조사 및 시각디자인 교육시스템에 대한 선행연구를 토대로 하여 디자인고등교육에 있어 합리적인 교육시스템의 방식을 수용자 조사를 통해 검증하고자 하였다. 본 연구는 영상ㆍ디지털미디어 분야의 고급인재 양성방안을 찾는 것을 목적으로, 이를 위해 기존의 디자인 교육과 디지털 영상교육의 융합으로 현실 사회의 요구에 부응하는 진화된 교육시스템을 도출하고, 사회의 요구를 앞서가는 디자인 고등교육기관으로서의 위상을 제시하고자 한다.

• 대한기계학회논문집B
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• 제32권12호
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• pp.954-962
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• 2008

This study presents a numerical procedure to optimize the shape of cylindrical cooling hole to enhance film-cooling effectiveness. The RBNN method is used as an optimization technique with Reynolds-averaged Navier-Stokes analysis of fluid flow and heat transfer with shear stress transport turbulent model. The hole length-to-diameter ratio and injection angle are chosen as design variables and film-cooling effectiveness is considered as objective function which is to be maximized. Twelve training points are obtained by Latin Hypercube Sampling for two design variables. In the sensitivity analysis, it is found that the objective function is more sensitive to the injection angle of hole than the hole length-to diameter ratio. Optimum shape gives considerable increase in film-cooling effectiveness.

• Journal of Mechanical Science and Technology
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• 제16권11호
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• pp.1477-1484
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• 2002

Various characteristics of a thin liquid film in its vapor-phase are investigated using the molecular dynamics technique. Local distributions of the temperature, density, normal and tangential pressure components, and stress are calculated for various film thicknesses and temperature levels. Distributions of local stresses change considerably with respect to film thicknesses, and interracial regions on both sides of the film start to overlap with each other as the film becomes thinner. Integration of the local stresses, i.e., the surface tension, however, does not vary much regardless of the interfacial overlap. The minimum thickness of a liquid film before rupturing is estimated with respect to the calculation domain sizes and is compared with a simple theoretical relation.

• 반도체디스플레이기술학회지
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• 제19권3호
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• pp.100-105
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• 2020

Recently, as display and semiconductor devices have been miniaturized and highly integrated, there is a demand for optimization of the structural characteristics of the thin film accordingly. The sputtering device has the advantage of stably obtaining a desired thin film depending on the material selected for the target. However, due to the structural characteristics of the sputtering equipment, the structural characteristics of the film may be different depending on the incidence angle of the sputtering target material to the substrate. In this study, the characteristics of the thin film material according to the scattering angle of the target material and the incidence position of the substrate were studied to find the optimization design rule of the sputtering equipment. To this end, a Si thin film of 1 ㎛ or less was deposited on the Si(100) substrate, and then the microstructure, reflectance, surface roughness, and thin film crystallinity of the thin film formed for each substrate location were investigated. As a result of the study, it was found that as the sputter scattering angle increased and the substrate incident angle decreased, the gap energy along with the surface structure of the thin film increased from 1.47 eV to 1.63 eV, gradually changing to a non-conductive tendency.

• 한국안전학회지
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• 제12권1호
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• pp.9-18
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• 1997

This paper is a study on the dynamic characteristics of truncated cone type squeeze film damper(SFD) bearing and rotor system. This model can alter the radial oil film gap which Is Important to the performance of rotor-bearing system and manufactured easily to change the shape concept of traditional circular type SFD bearing. In theoretical analysis, the oil film pressure distribution, the oil film force, the film damping coefficient and the eccentricity ratio, etc. were induced with regard to the film inertia effect. The film damping coefficients and optimum design parameters are calculated. When unbalance parameter U is greater than 0.2, the nonlinear vibration such as "Jump" phenomena appears in the vicinity of rotor critical speed. At this time, the increases of bearing parameter U, journal distance S, Reynolds number Re can control this unstable vibration. The experimental results show that SFD hearing and rotor system which are designed according to the design parameters in the stable region are operated stably in rotational speed 9,600rpm without nonsynchronous behavior.

• 패션비즈니스
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• 제21권4호
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• pp.1-20
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• 2017

Fashion film has become a significant communication medium in the $21^{st}$ century. Fashion film, that tells unique quality stories, is a means of communicating brand value emotionally. To examine characteristics of storytelling according to types of fashion film, this study categorizes fashion film and investigates storytelling elements in terms of content, form, and communication. For methodology, a literature review was conducted to examine the concept of storytelling and types of fashion film storytelling. Empirical research was conducted on 32 fashion films from 2007 to recent years of 2017. Results are as follow. First, theatrical fashion film, based on linear narrative structure and closed-ending, is characterized content-based storytelling. Second, avant-garde fashion film, based on unconventional and experimental cinematic techniques, is characterized form-based storytelling. Finally, documentary fashion film that minimizes distortion and reproduces reality of designers' originality, refers to interactive communication-based storytelling which using digital technologies.