• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.7 s.94
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• pp.1751-1760
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• 1993

The squeeze casting process is considered as an attractive way to form the primary product of near net shape metal matrix composites for wide use in automobile industry. To understand for infiltration limit in squeeze casting processes, the SAFFIL short fiber preform of volume fraction $10%{\sim}23%$ were fabricated by vaccum pumping and speed control press, and the optimal condition for fiber preform fabrication had been experimentally obtained. The composite materials were fabricated by forced infiltration of molten metals such as Al6061, Al7075, pure Al, AC8A, and Al2024. The infiltration distance and deformation of fiber preform are observed, and tensile strength were measured from at the room temperature.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.297-298
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• 2003

Linear density regularity is one of the important characteristics of fiber bundle and yarns, influencing the process performance and the product quality. Analysis on the variation of bundle thickness for various draft ratios and frequencies is therefore of great significance, because an optimum drafting condition can be obtained by establishing the effect of major process factors on the output. (omitted)

• International Journal of Aerospace System Engineering
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• v.3 no.1
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• pp.21-24
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• 2016

In this study, a optimal design on the hood automotive using eco-friendly natural fiber composites is performed. The hood of an automobile is determined by dividing the Inner panel shape through optimization phase to outer panel and inner panel. It was performed to optimize the size of the thickness of the inner panel and the outer panel by applying a flax/epoxy composite materials. The optimized shape was evaluated for weight-lightening, stability and the pedestrian collision safety. Through the resin flow analysis are confirmed to molding possibility judgment of product.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.25 no.2
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• pp.35-41
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• 2002

This paper describes an automatic transplantation machine of optical fiber controlled by PLC. The transplantation operations is a key operation for the optical fiber application products, such as bag, cap, and others. To transplant 200∼500 optical fibers, there are many recurrent manual operation needed with conventional process. In this paper. we propose an automatic machine that reduce transplanting time and enhance product quality. Developed machine includes transplantation, heat cutting and ultraviolet coating operation. Also proposed Machine is controlled by PLC to adjust operation parameters such as pulling length, cycle time, coating time and others. Developed Machine has been applied in the field and found to be a useful system.

• Annals of Clinical Neurophysiology
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• v.9 no.2
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• pp.43-50
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• 2007

Analysis of intraepidermal nerve fibers using skin biopsy is a recently developed technique, providing diagnostic information on small fiber neuropathies. The specimens are obtained by 3 mm punch biopsy, which is safe and minimally invasive. Immunohistochemical staining by Protein gene product (PGP) 9.5 demonstrate not only intraepidermal nerve fibers but dermal structures, such as sweat gland and erector papillae. Up to now, many studies agree that intraepidermal nerve fiber density is dramatically reduced in various sensory neuropathies. The utility of density measure was confirmed with high sensitivity in the diagnosis of sensory neuropathy, comparable to sural nerve biopsy or quantitative sensory testing. Besides quantitative methods, morphological changes like axonal swelling and fragmentation can be used as predegenerative markers. This article reviews the technique of skin biopsy and clinical and experimental usefulness of skin biopsy in diagnosing and monitoring peripheral neuropathies.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.4
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• pp.693-699
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• 2013

Environmental issues are attracting increasing interest worldwide, and accordingly, environmental regulations for vehicles are being made more stringent. As a result, the car industry is conducting studies focusing on fuel efficiency and lightweight vehicles. To manufacture lightweight vehicles, existing steel parts are replaced by composite materials and lightweight metals. In this study, the fatigue life of a new material for manufacturing lightweight car door hinges was predicted using a finite-element analysis program. The existing steel material was replaced by carbon-fiber-reinforced plastic (CFRP) and aluminum alloy 6061, and the test results were analyzed. The maximum stress decreased by approximately three times, whereas the fatigue life and safety factor increased. When only CFRP was used, its allowable stress, safety factor, and fatigue life were excellent, but the sagging of the product exceeded the allowable value, which posed a limitation in use. Therefore, it seems desirable to use an appropriate combination of steel, AA6061, and CFRP for this product.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.30 no.3
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• pp.46-56
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• 1998

The objective of this study was to investigate the relationship between water vapor diffusion properties and the pore structure of paper. Gas-phase molecular diffusivity of water vapor through pores was determined based on the kinetic theory of gas. A mathematical model was derived to characterize the dimensional changes of the pore caused by the fiber-swelling mechanism. A modified-Fickean diffusion model was designed to simulate the water-vapor diffusion phenomena in porous paper web. Structural characterisocs of paper pores including the tortuosity and the shape factor was studied on a theoretical basis of Knudsen flow diffusion. Results are summarized as follows: 1. The theoretical water vapor diffusivity in gas-phase was 0.092$cm^2$ /min, 2. Porosity was inversely proportional to the degree of wet-swelling of paper, 3. Solid-phase water-diffusivity of fiber was 1.2 $ \times 10^{-5}cm^2/min$, 4. Modified diffusion model was fairly consistent to the experimental data (from part I), and 5. The Fickean pore tortuosity, ranging from 1,000 to 2,500, was in inverse proportion to the porosity of paper, and the Knudsen shape factor and length-angle factor for micro-pores in paper were 0.5~3.5 and about 340, respectively.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.4
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• pp.585-595
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• 2008

Process design of multi-stage forging for a bolt with nonaxisymmetric washer cam has been studied by using finite element method. For shape complexity of the bolt, it is impossible to manufacture in a single stage forging. To design multi-stage forging for the bolt the forging load and fiber flow of each step have been analyzed by using commercial finite element code DEFORM-3D. Simulated results have been compared with experimental ones. Multi-stage forging process has been designed with four stages. The workpiece should be eccentric shape until third forging stage. And then bolt head and washer of eccentrical shape is created in last stage. As a results, It was predicted that shape of product would be good and effective strain would be uniformly distributed in the product. Also, it was predicted whether defects would exist or not by reviewing the fiber flow.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.1
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• pp.74-82
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• 2011

The bast fiber of Paper mulberry has been generally used as a fibrous raw material in traditional Hanji-making. Nowadays, its uses is expanded to different special purposes such as paper mulberry yarn, laminated paper, antimicrobial paper depending on its application. Despite the wide array of the use of mulberry fibers, it is still limited due to some difficulties in the automation process of manufacturing works. This study is focused on the analysis of chemical components and morphological properties of paper mulberry bark for the automation of bark peeling process. The bast tissue of paper mulberry was separated in three plies; black outer layer, green inner layer, and white inner layer. The total lignin content, holocelluloses, extractives and ashes, and the anatomical structure of the three layers in mulberry bark tissue were investigated. The analysis showed that the black outer layer is composed of about 50% of total lignin content, whereas the white inner layer is composed of about 90% of holocellulose content.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.30 no.6
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• pp.264-270
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• 2020

Design was developed through user-oriented service design methodology and survey was conducted on material selection criteria for prototype production to select CFRP (Carbon Fiber Reinforced Plastics) CNT (Carbon Nano Tube), which was applied to animal X-ray detector panel to design product and develop prototype. Completed prototype with the application of CFRP CNT panel was tested in drop test, frontal external pressure test, and dustproof/waterproof performance to confirm that it can be utilized as a portable animal X-ray detector used in outdoor environment.