• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.03a
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• pp.155-158
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• 1997

The investigation deals with of a intermediate process condition hving a bolt-shaped final product where it is required to extend tool-life in forging. In this study, optimization of the design variables is conducted by a genetic algorithm, where the fitness values are evaluated on the basis of FEM analysis model. The approach is applied to the determination of the intermediate process conditions which are optimal with regard to minimization of peak die pressure.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.676-680
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• 1994

Recently the needs for the experts who can solve the complex problem arising at the special areas are continuously increasing in our social life. So many researchers have studied about the expert systems as a part of an artificial intelligence during last two decades. This study was carried out in order to develope an expert system, ESSM, for the NC data generation to machine the curved surface of a forming die to fabricate the shadow mask of TV Brown Tube.

• Journal of Korean Philosophical Society
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• v.142
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• pp.221-241
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• 2017

I try to elucidate the essence of cinematic art in terms of Nietzsche's physiological philosophy of art. According to Nietzsche, the mise-en-$sc{\grave{e}}nes$ in the film are expressions of willingness to the power of the author, the director. These are not re-imitations of the imitations with Platonic measure, sinker, number, but framing the elan vital Erde, die $urspr{\ddot{u}}ngliche$ Vorstellung with the director's body-camera. In this context, the film is essentially die Kunst des Lebens, in which the body and the earth are mediated by cameras. Therefore, it is not the eyes or the head, but the body that is necessary to appreciate film art. But the body at this time does not mean the heavy body of Hollywood standard audiences manipulated, controlled, or transformed by capital. We should stand in front of the film work with body shaking between trauma and Rausch, a dancing body, and a light and fresh body. Only by watching film with the body, can we achieve the small revolutions in everyday life. For example, if we watch $B{\acute{e}}la$ Tarr's film The Turin Horse in such a way, we can no longer be the dwarfed human beings, der Herde-Mensch. Also, $B{\acute{e}}la$ Tarr's mise-en-scene will make us realize why Nietzsche had said that there is art to us not to be destroyed by the platonic truth.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.50-55
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• 2018

The important thing in extrusion technology is the design and production of molds. Appropriate design of the molds is essential for achieving the desired extrusion of molds at the same time to maximize the life of the molds and increase their efficiency. The extrusion temperature and extrusion speed are the main parameters at the time of extrusion. Different extrusion conditions should be added depending on the extrusion ratio, physical properties of the material, and type of extrusion. In this study, the extrusion process of various 6xxx series aluminum cast alloys for high speed train interior or exterior parts were investigated. The extruded die design was performed for the 6063, 6061, 6N01, 6005, 5083 and 6060 alloy profiles and an extrusion test was conducted. In addition, the extrusion conditions, such as extrusion pressure following as the billet temperature, extrusion temperature, and materials change, were analyzed. Although the 6063 aluminum alloy can be extruded at the lowest temperature and pressure, the 6061 alloy can be extruded at the highest temperature and pressure. From these results, the successful extruded products were manufactured from these established conditions.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.1
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• pp.71-81
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• 2009

Die steel for plastic molding were used as mold material of automobile parts and electronic component industry. The material of this paper has superior to mechanical properties, such as repair weldability, corrosion resistance and high temperature strength, required mold parts for semitransparent. Laser-induced surface hardening technology is widely adopted to improver fatigue life and wear resistance via localized hardening at the surface of mold parts. The objective of this research work is to investigate on the characteristics of surface hardening of the laser process parameters, such as beam travel speed, laser power and defocsued spot position, for the case of die steel for plastic molding. Lens for surface hardening of large area is plano-convex type with elliptical profile to maintain uniform laser irradiation. According to the experimental results, large size of hardened layer at the surface of die steel for plastic molding was achieved, and microstructure of this layer was lath martensite. Optimal surface status and mechanical property of hardened layer could be obtained at 1095Watt, $0.25{\sim}0.3m/min$, 0mm (focal length: 232mm) for laser power, beam travel speed, and focal position. Where, heat input was $0.793{\times}10^{3}J/cm^2$, and width of hardened layer was 27.58mm.

• New & Renewable Energy
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• v.18 no.3
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• pp.23-31
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• 2022

This study evaluated the potential of coffee waste (CW) and used frying oil (UFO) as an additive in the production of pitch pine (PIP) and Mongolian oak (MOK) pellets. Ash contents obtained from CW and UFO were 0.5% and <0.1%, respectively. The calorific values of UFO (31.4 MJ/kg) and CW (26.3 MJ/kg) are higher than PIP (20.6 MJ/kg) and MOK (19.1 MJ/kg). For pellets fabricated using a pilot-scale flat-die pellet mill, regardless of fabricating conditions, moisture content (MC) and bulk density of PIP and MOK pellets satisfied the A1 wood pellet standard for residential and small-scale commercial uses, as designated by the National Institute of Forest Science (NIFOS) of the Republic of Korea. When CW was used as an additive, durability of PIP pellets made with 12%-MC sawdust and MOK pellets increased. The optimal conditions for producing PIP and MOK pellets could be by adding 20 mesh CW as an additive and the using of 12%-MC sawdust. However, durability of PIP pellets and ash content MOK pellets did not satisfy the A1 wood pellet standard of NIFOS. Thus, further research is needed to improve the properties of wood pellets with additives.

• Journal of the Korean Society of Radiology
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• v.83 no.5
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• pp.1121-1127
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• 2022

Endometriosis-related symptoms are believed to be alleviated during pregnancy. However, pregnancy complications, such as pseudoaneurysm of the uterine artery, rupture of ovarian or uterine vessels, and intraabdominal bleeding from decidualized deep infiltrating endometriosis (DIE) lesion have been rarely reported. Owing to the potential risk of rupture and resultant life-threatening complications, proper diagnosis and close monitoring of decidualized endometriotic lesion are very important despite its low relative risk. Till date, massive vaginal bleeding from decidualized rectovaginal DIE during pregnancy has not been in English literatures. Here, we present the first case of spontaneous massive vaginal bleeding due to decidualized rectovaginal DIE that occurred in the late third trimester of pregnancy.

• Design & Manufacturing
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• v.9 no.1
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• pp.31-35
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• 2015

Recently, life expectancy increased in the development of medicine, the need for health has increased. Market for medical equipment is growing rapidly to an increase in the interest in health and aging worldwide. It is a device intended for ultra sensitive cleavage process of bone during joint replacement surgery on a technical advanced surgery, finishing, and hole. Domestic demand of the hand piece is a necessary condition on an ongoing basis. However, hand piece was made on the basis of the experience of many years in the country Japan, Germany, and the United States has spread to more than 90% domestic market. Feel the need for the development of the hand piece in the country, many companies are trying to in-house production hand piece. In an attempt to solve the problems with the hand piece of the present, in this paper, it was supposed to be a study of rechargeable hand piece to replace the existing pneumatic.

• Transactions of Materials Processing
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• v.20 no.3
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• pp.214-221
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• 2011

In recent years, automotive seat components have been manufactured by the fine blanking process, allowing an improvement of dimensional accuracy at sheared surface in series production. However, the rollover has increased and die failures have occurred more frequently when manufacturing gears by fine blanking. Consequently, important goals for manufacturing seat recliner parts with gears have been to decrease the rollover as well as to improve the tool life. In this study, the half blanking and shaving processes were introduced to improve aforementioned problems for the lower tooth, the main component of a seat recliner. For this purpose, the half blanking process was optimized using the finite element (FE) analysis and design of experiment (DOE). The optimized conditions resulting from this study were an offset of 0.2 mm, a clearance of 0.1 mm and a penetration depth of 4.5 mm. Fine blanking experiment conducted under the optimal condition resulted in a rollover depth decrease from 1.9 to 1.3 mm, and no die failure occurrence.

• Resources Recycling
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• v.20 no.3
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• pp.3-11
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• 2011

Magnesium has been used as parts of vehicles, case materials of notebook PC and mobile phone, and its demand has been increasing recently. So until now, there has little magnesium scraps from the end of life vehicles or electronic parts, and most scraps has been generated from magnesium processing lines such as melting, die casting and machining. It is to review the present status of magnesium recycling. Here, domestic demand of magnesium, recycling amount and technologies used in domestic recycling companies were surveyed in recent years. In 2010, 8,840 tons of magnesium scraps were processed and used as raw materials for die casting products. The recycling ratio was estimated as 32.5%.