• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.624-627
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• 2002

A study on machining electrode for LEO(Light Emitted Diode) mold with shaped end-mill is presented. The electrode machining by shaped end-mill has been used for maximizing the productivity in manufacture of semiconductor mold. However, it has not been researched systematically for many difficulties such as the making of shaped end-mill, generation of tool path due to distinctive tool geometry, and so on. Tool path is generated on the shaped end-mill geometry and cutting force to provide accurate and efficient machining of electrode. The verification program can drive enhancement of productivity, selecting cutting conditions from experiment function of cutting force. Also, compensation of tooting and machina error can make the electrode accurate by modifying tool path. Therefore, the research on machining with shaped end-mill can contribute to enhancement of accuracy and productivity in building semiconductor mold.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.10
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• pp.187-194
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• 2002

A study on machining electrode for LED (Light Emitted Diode) mold with shaped end-mill is presented. The electrode machining by shaped end-mill has been used for maximizing the productivity in manufacturing semiconductor mold. However, it has not been researched systematically for many difficulties such as the making of shaped end-mill, generation of tool path due to distinctive tool geometry, and so on. Tool path is generated on geometry of the shaped end-mill and cutting force to provide accurate and efficient machining of electrode. The verification program can drive enhancement of productivity, selecting cutting conditions from experiment function of cutting force. Also, compensation of tooling and maching error can make the electrode accurately by modifying tool path. Therefore, the research on machining with shaped end-mill can contribute to enhancement of accuracy and productivity in building semiconductor mold.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.05a
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• pp.240-244
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• 1999

This paper deals with the establishment of the cutting direction on inclined plane by using ball end mill. Ball-end milling is widely used for free form surface die and mold. In these machining, the cutting parts vary because the tool tip is hemisphere shaped. The cutting characteristics, such as cutting force, surface roughness and surface profile are varied according to the variation of cutting directions. The effective tool diameter was calculated on different tilt angles and tool-path. Tool life and cutting characteristics were estimated on variation of cutting directions in the same cutting speed. In this paper, the optimal cutting direction which can be applied 3-D sculpture surface cutting is suggested.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.6
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• pp.38-43
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• 2006

A slot cut in end milling processes is one of the laborious works because the cutting force is likely to deflect the tools excessively, then to make large errors or to fracture the tool. This difficulty is owing to the poor stiffness of slender shaped end mills. Though, in most cases, additional finish cuts are followed after rough cuts, the accuracy of rough cuts is still important because it affects the final accuracy after finish cuts and productivity. The accuracy in slot cuts depends on the tool stiffness and the cutting conditions including depth of cut and feed. In order to meet the desired accuracy, diameter of end mill and cutting allowance have to be selected carefully. This study suggests several guidances for selecting the end mill diameter and the slot cut allowance to improve machining accuracy and productivity in slot end millings. Some experiments were done with the various cutting parameters of tool diameter, depth of cut and feed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.253-254
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• 2013

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.6
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• pp.26-32
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• 2019

Ball end mills used for high-speed and high-precision machining require longer machining time than flat end mills or face cutters, since the tool diameter is limited and the rigidity is reduced by the characteristics of the tool's cutting edge: at the top end of the tool, the cutting speed approaches zero and hardly removes any material. Because there is little material removal at the top end of the ball end mill, the outer cutting edge performs the majority of the work; this irregular cutting force deforms the tool and shortens its life. In this study, we attached an eddy-current sensor to a tool to measure the deformation from the cutting force and we used a tool dynamometer to measure the cutting force. We found that the change in cutting force is dependent on the change in feed rate during square-shaped processing and, as the feed rate is accelerated, the cutting force also increases. Higher cutting forces increase tool deformation.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.5
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• pp.79-84
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• 2006

In modem manufacturing, many products that have geometrically complicated features, including three-dimensional sculptured surfaces, are designed and produced. In the production of these complex-shaped mechanical components, e.g. automobile dies, molds, and various engineering applications, the ball-end milling process is one of the most widely used NC machining processes that consists of roughing, semi-finishing and finishing. In semi-finishing, cusps remained after roughing according to the used tools that have two patterns of stairs and wave shapes. These cusp shapes have air-cut in cutting and instability caused by high cutting speed that affects the cutting characteristics such as cutting force and tool wear. Cutting characteristics are measured and analyzed through cutting force, FFT analysis of cutting force and tool wear along cutting length according to low tool paths with same metal removal rate. As a results of the experiments, this study suggests the optimal conditions of tool path and cutting direction. This approach for the cutting characteristics of semi-finishing provides a useful aid for the productivity and efficiency improvements of NC machining processes.

• Journal of Fashion Business
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• v.5 no.2
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• pp.105-115
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• 2001

When restoring a tomb of Songeun, Park Ik that damaged by typhoon in Kobubri, Chungdomyon, Mill Yang, Kyoung Nam in October 2000, a flower designed stone and fresco was discovered. Soneun Park Ik passed the civil service examination in Kongmin dynasty and was consecutively occupied Sajaedogam(司宰少監; regarded as one of second highest official rank). The fresco realistically depicts custom of ordinary people in end of Koryo, beginning of Chosun dynasty that it is considered as an important research material in study of ostumes. Therefore, this research intend to contribute to study of costumes in general public of Koryo that has insufficient study materials through study and analyze of costumes in the fresco with literature research. The number of figures in the fresco is presumed as 26-27 in all but clearly observed figures is only five women and four men and partly damaged figures are two men and two women. Women are worn relatively long yoo that can cover hip as an upper garment and Sang(裳) as trousers. The upper garments are all adjusted to right and has Jikryoung gik (straight collars) but there are strip attached collars or double collars among the Jikryoung gik. The length of Sang reaches to ankle and a waistband is trailed to below the knees. Most of hair are combed in the two sides and made a ring, moreover worn ceremonial coronet, which imply the ceremonial parade. Distinguished from the frescos of Koguryo, there are no women wearing Po(袍) also Yoo with Dae(帶) and without were coexisted. The mens costume is mainly appeared in two types. One(元) is Danryoungpo, Po with round collar and wearing a lozenge shaped crest with a brim, the other is Jikryoung Po, Po with straight collar, and wearing Ballib(拔笠), the latter is a costume of two man presumed as envoys. In the case of Danryoungpo, its length reached to ankle that shows decorum and in Jikryoungpo its length is below the knees that seem to offer practicality for envoys to guide a long journey. Both man and women are in decent cloth with a crest, which simple costume for ordinary people as a Chaksoopo that has comfortable length for movement and narrow sleeves. Songeun Park Ik actively worked under regency of One dynasty that influence of Mongol is seen in mans crest. There are some changes but including womens costume most of cloth are followed Korean traditional costume style.