• Proceedings of the IEEK Conference
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• 2000.07b
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• pp.773-776
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• 2000

Traffic monitoring plays an important role in intelligent transportation systems. It can be used to collect real-time traffic data concerning traffic flow. Passive shadows resulted from roadside buildings or trees and active shadows caused by moving vehicles, are one of the factors that arise errors in vision based vehicle detection. In this paper, a land mark based method is proposed for vehicle detection and shadow rejection, and finally vehicle count are achieved based on the land mark detection method.

• Journal of the Korean institute of surface engineering
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• v.35 no.3
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• pp.113-120
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• 2002

Injection molded plastic parts have many surface defects. These include a weld line, sink mark, flow mark, gloss, shading, scratching etc. Because these surface faults are not aesthetically acceptable, plastic parts are produced through painting or texturing. The purpose of this paper is to develop paintless molded parts using a flow control method. Computer aided injection mold filling simulations were used in order to minimize the number of defects from injection molding. Based on the numerical results, FR(Flame Retardant) HIPS was developed and the guidelines for part design, mold design, and the processing conditions were established. The effects of cost savings, improvements in productivity, and recycling were considered by reducing the number of surface faults and eliminating the painting process.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1710-1714
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• 2005

Micro Cellular Plastics create a sensation at polymer industrial for lowering product cost & overcoming a lowering of mechanical intensity. This research is surface quality research of MCPs product Through surface rough measurement. This experiment is carried out according to injection speed control with the surface rough & Product surface quality are searched

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.583-586
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• 2002

Molding properties of etched surface pattern are presented. Specimens, whose surface patterns are made by print-type etching, are investigated. The molding properties of surface pattern are estimated with roughness deviation of surface pattern on part and mold. The etching properties are related to physical properties of plastic materials and surface roughness of etched pattern. Also, flow mark and gate location can give influence on surface pattern molding. The experimental result can contribute to good molding of surface pattern in injection molding.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.05b
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• pp.807-810
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• 2003

EMFG(Extended Mark Flow Graph)는 이산시스템을 개념설계하거나 상세설계할 수 있는 좋은 도구이다. 시스템을 설계함에 있어서 마크흐름을 분석하는 것은 시스템의 성능향상과 직결되므로 상당히 중요한 작업이다. 본 논문에서는 EMFG의 각 박스들간의 상태변화를 박스추이가중행렬을 통하여 확인, 분석하는 기법을 제안하고자 한다. EMFG로 설계한 시스템의 상태변화를 쉽게 분석함으로써 시스템의 설계 및 분석이 쉬워지므로 자동화된 시스템 개발시 유용하게 사용될 것으로 기대된다.

• The Transactions of the Korea Information Processing Society
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• v.5 no.7
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• pp.1896-1907
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• 1998

확장된 마크흐름선도(EMFG: Extednded Mark Flow Graph)는 기존의 MFG를 개선한 그래프로서, 회로변수식에 의해 실제회로로 쉽게 구현가능하므로 이산제어시스템의 모델링과 설계 및 구현의 강력한 도구로 사용될 수 있다. 본 논문은 EMFG의 트랜지션들이 점화하는 과정 및 트랜지션들이 점화완료하였을 때 각 박스들의 마크수 변화를 부울함수식과 벡터를 사용하여 표현하였다. 또한 시스템의 상태변화를 쉽게 판단할 수 있게 하는 EMFG의 동작알고리듬을 제안하였으며, 제안된 알고리듬은 3-비트 증가계수기를 설계한 EMFG와 시간트랜지션이 포함된 가상의 EMFG에서 잘 수행되었다. EMFG의 동작이 부울함수로 해석가능해짐으로 인해 시스템의 분석 및 설계가 용이하며 컴퓨터를 이용한 자동화된 시스템의 분석과 설계가 가능하다.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.2
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• pp.25-32
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• 2003

Molding properties of etched surface pattern are presented. Injection molding has given attention on improving dimensional accuracy and productivity. However, the molding of etched surface pattern on plastic parts is not researched relatively for its additional values, which can meet design function and customer's attraction. Specimens, whose surface patterns are made by print-type etching, are investigated. The molding properties of surface pattern are estimated with roughness deviation of surface pattern on part and mold. The etching properties are related to physical properties of plastic materials and surface roughness of etched pattern. Also, flow mark and gate location can give influence on surface pattern molding. The experimental result can contribute to good molding of surface pattern in injection molding.

• The KIPS Transactions:PartA
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• v.9A no.3
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• pp.371-378
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• 2002

The EMFG (Extended Mark Flow Graph) is known as a graph model for representing the discrete event systems. In this paper, we introduce input/output matrixes representing the marking variance of input/output boxes when each transition fires in an EMFG, and compute an incidence matrix. We represent firing conditions of transitions to a firing condition matrix for computing a firable vector, and introduce the firing completion vector to decide completion of each transition’s firing. By using them, we improve an analysis algorithm of the EMFG’s operation to be represented all the process of EMFG’s operation mathematically. We apply the proposed algorithm to the system repeating the forward and reverse revolution, and then confirm that it is valid. The proposed algorithm is useful to analysis the variant discrete event systems.

• Elastomers and Composites
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• v.44 no.2
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• pp.156-163
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• 2009

Our objective is to increase the flowability of Polypropylene(PP) compounds and achieve flow mark free surface in injection molded specimen. We have investigated flowabilities of PP compounds which were composed of PP, rubber, talc, and trace amount of additives. Flowability measurement was performed with four types PPs of which molecular weight distributions(MWD) and melt indexes(MI) were different. Rheological properties of the PP compounding materials, such as spiral flow(SF) length, MI, and shear viscosity, were evaluated. When PP with the broad MWD was used, there were remarkable cases where the spiral flow length of low MI PP compound was longer than that of higher MI PP compound. The PP compound having low MI but broad MWD PP has more flowability than the compound with only high MI.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.4
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• pp.44-53
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• 2002

Injection molding process factors such as molding temperature, injection pressure, flow rate and flow velocity, must be controlled properly in filling and packing phases in the injection molding process. In this study, effects of these factors on the injection molding were investigated through the flow analysis for the filling and packing phases. Molding troubles like flow mark weld line, sink ma가 short shot and warpage car be caused by these injection molding process factors. Among them the short shot was caused by the fact that the packing pressure could not reach properly to the filling end part in the packing phase and hence the flow rate could not be supplied to the full. In addition as the flow rate for the volumetric shrinkage during the f개zen phase could not be supplied Properly by the packing pressure, the short shot appeared. Here, the volumetric shrinkage reduced with increasing the packing pressure and also the warpage of molded part increased with increasing the packing Pressure.