• Journal of the Korean Society for Precision Engineering
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• v.20 no.6
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• pp.123-129
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• 2003

Recently, the life cycle of products is rapidly shortened and then the disposal of the used mold applied in development of the product is a difficult thing. In this study, we proposed the feasibility of new three plate type mold structure for recycling by analyzing of the existing standard mold base. And in order to apply new three plate mold structure in mold design and making. we constructed the specifications for mold parts such as runner stripper plate, cavity plate, core plate and slide core unit. Also, we confirmed the possibility of recycling mold base by testing a used three plate mold for audio front panel.

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.1245-1248
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• 2010

플라스틱은 가공이 용이하기 때문에 우리 생활에 널리 이용되고 있다. 과거에는 단순히 제품의 외장제로 이용되었지만 산업이 발달함에 따라 금속을 대체 할 정도로 사용 범위가 증가하고 있다. 또한 사용량이 증가함에 따라 제품의 생산량을 증가시키기 위해선 다수 캐비티의 금형 사용이 필수적으로 되었다. 다수 캐비티 사출성형에서 각 캐비티 간 제품의 품질 및 물성을 향상시키기 위해선 각 캐비티로 충전되는 수지가 균형을 이루어야 한다. 하지만 기하학적으로 균형을 갖추고 있는 러너를 설계하여도 실제 사출성형에서는 불균형 충전이 일어나게 된다. 이러한 불균형 충전은 미국의 Beaumont에 의해서 처음 규명된 뒤 충전불균형 현상을 해결하기 위해 많은 연구가 진행되었다. 본 논문에서는 다수 캐비티 사출성형에서 균형충전을 위한 러너시스템을 제안하였다. 이 러너시스템은 온도가 불균일한 수지의 흐름을 혼합함으로써 수지의 흐름을 균일하게 하여 균형충전을 이루도록 하였다. 또한 사출성형해석프로그램인 Moldflow를 이용한 유동해석을 통해 그 효과를 나타내 보았다.

• Design & Manufacturing
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• v.2 no.3
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• pp.6-9
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• 2008

This paper describes the process of structure analysis and injection molding analysis to manufacture the forming injection dies for huge glass insert. Factors such as filling time, filling pressure, material temperature, shrinkage, warpage were investigated by using the analysis software, Moldflow. Runner system and cavity structure were designed and manufactured through the results of deformation analysis data for glass insert. Filling time and filling pressure were analyzed in 3.756sec and 43.37MPa.

• Design & Manufacturing
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• v.2 no.2
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• pp.33-37
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• 2008

This paper describes the optimization of injection molding conditions to minimize sink marks. Sink marks, which refer to a small depression on the surface opposite a thick wall thickness, are often encounted in injection molded plastic parts. Part geometry, material properties and processing conditions during injection molding can affect the sink mark depth. We designed the runner system which is possible balanced filling to cavities using CAE program and then obtained optimal processing conditions by Taguchi's Robust Design technique. By actual injection molding using optimized mold and molding conditions, it confirmed that sink mark depth decreased zero compared to 1mm level in the conventional mold and process.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.7
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• pp.111-115
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• 2008

This paper describes the optimization of injection molding conditions to minimize sink marks. Sink marks, which refer to a small depression on the surface opposite a thick wall thickness, are often encounted in injection molded plastic parts. Part geometry, material properties and processing conditions during injection molding can affect the sink mark depth. We designed the runner system which is possible balanced filling to cavities using CAE program $Moldflow^{TM}$ and then obtained optimal processing conditions by Taguchi's Robust Design technique. By actual injection molding using optimized mold and molding conditions, it confirmed that sink mark depth decreased zero compared to 1mm level in the conventional mold and process.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.09a
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• pp.141-146
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• 2005

In the present study, the characteristic of warpage and flow balance for family mould, which is able to mold parts with different shapes in a mold, is considered. To obtain an optimal gate and runner system, plastic injection molding analysis with commercial code is performed. Design and manufacturing of family mould is then carried out on the basis of this computer aided engineering result. Flow balance and warpage comparisons between experiment and numerical analysis give good agreement with each other. However, it was shown that results of warpage measured by CMM was about $20\~55\%$ lower than those of numerical analysis.

• International Journal of Fluid Machinery and Systems
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• v.4 no.1
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• pp.199-208
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• 2011

This work presents numerical results, using OpenFOAM, of the flow in the swirl flow generator test rig developed at Politehnica University of Timisoara, Romania. The work shows results computed by solving the unsteady Reynolds Averaged Navier Stokes equations. The unsteady method couples the rotating and stationary parts using a sliding grid interface based on a GGI formulation. Turbulence is modeled using the standard k-${\varepsilon}$ model, and block structured wall function ICEM-Hexa meshes are used. The numerical results are validated against experimental LDV results, and against design velocity profiles. The investigation shows that OpenFOAM gives results that are comparable to the experimental and design profiles. The unsteady pressure fluctuations at four different positions in the draft tube is recorded. A Fourier analysis of the numerical results is compared whit that of the experimental values. The amplitude and frequency predicted by the numerical simulation are comparable to those given by the experimental results, though slightly over estimated.

• The Research Journal of the Costume Culture
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• v.29 no.2
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• pp.185-203
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• 2021

The aim of this study was to reveal the modern succession and reinterpretation of brand identity through the case of Balenciaga design presented by Demna Gvasalia through a review of the literature, design collection, and design review analysis. The design collection analysis was conducted from 2016 F/W to 2020 F/W, when Demna Gvasalia commenced responsibility for the Balenciaga collection. A total of 12 articles from overseas fashion magazines and newspapers were analyzed. A modern reinterpretation of Demna Gvasalia's Balenciaga design is as follows. First, he introduced luxury mode to reflect a sense of the times and introduced luxury street looks based on street and sports sensibilities, showing various styles without specific concepts. Second, by sharing universal sensibilities based on pragmatism, he proposed an easy-to-wear outfit for daily life to demonstrate the everydayness of fashion. Third, as a new exploration of traditional structural beauty, the design of Cristobal Balenciaga was reinterpreted through the conversion of items, overlapping outfits, and the introduction of high-tech technologies. Fourth, by taking a conceptual approach to fashion, he has renewed the spirit of experimentation and modernity shown by Cristobal Balenciaga. Fifth, with the presentation of a new icon, new styles of sneakers such as Triple S and Speed Runner are presented as new icons. He inherited the original mindset and creative approach of the house's founder, Cristobal Balenciaga, and reinterpreted it from a contemporary street sensibility and pragmatic perspective.

• Fashion & Textile Research Journal
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• v.16 no.4
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• pp.532-542
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• 2014

This study developed a practical knitwear design with applying the pattern of Queen Yeong's pearl pouch. The ume flower pattern of pearl pouch was simplified to be one repeat pattern, and four simulated knit pattern samples of G-A, G-B, R-A, and R-Bwere made with cable, cross, and two background colors of gray and red using Texpro V.11.0. The items of design application were selected after an interview with a panel of university students in their twenties and knit samples were produced by hand knitting. The small sized G-A for the partial ornament of hat, sweater, skirt, kitchenware case and accessories; the long sized G-B for the tuck of sleeves, hem of skirt and one-piece dress, partial ornament of sweater, scarf, and curtain decoration: the small sized R-A was preferred for point ornament of pouch, boots, hat, partial ornament of children's fashion products and accessories: the long sized R-B for table runner, leg warmer, tuck of sleeves, skirt hem, necktie, and scarf. The knit samples were formulated with partial ornaments attached on dress and props or connected each other. Colors of pastel and navy were also presented to meet the demands of panels. The study placed a limit on the slight difference between the simulation samples and knit samples due to the characteristics of threads and hand tension. The color variation for multiple coordination and activation to reduce the piece rate for young customers remains to be discussed in the near future.

• Tribology and Lubricants
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• v.33 no.2
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• pp.65-70
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• 2017

In vertical hydro/hydraulic power turbine-generator applications, traditionally, cylindrical turbine guide bearings (TGBs) are widely used to provide turbine runner shafts with smooth rotation guides and supports. All existing cylindrical TGBs with simple plain pads have drawbacks such as having no pressure generation and film stiffness at the no-load condition and in addition, at the low-load/low-eccentricity condition, having very low film stiffness values and lacking design credibility in the stiffness values themselves. In this paper, in order to fundamentally improve the low-load/low-eccentricity performance of conventional cylindrical TGBs and thus enhance their design-application availability and usefulness, we propose to introduce a rotation-directional leading-edge taper to each partitioned pad, i.e., a pad leading-edge taper. We perform a design analysis of lubrication performance on $4-Pad{\times}4-Row$ cylindrical TGBs to verify an engineering/technical usefulness of the proposed pad leading-edge taper. Analysis results show that by introducing the leading-edge taper to each pad of the cylindrical TGB one can expect a constant high average direct stiffness with a high degree of design credibility, regardless of load value, even at the low-load/low-eccentricity condition and also control the average direct stiffness value by exploring the taper height as a design parameter. Therefore, we conclude that the proposed pad leading-edge tapers are greatly effective in more accurately predicting and controlling rotordynamic characteristics of vertical hydro-power turbine-generator rotor-bearing systems to which cylindrical TGBs are applied.