• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.1043-1046
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• 2002

In this paper, drill tests were carried out by modifying drill geometry for burr minimization. Final objective of this study is to develop compatible drill shape for minimization of burr formation. These experimented results with modified drill are measured with laser sensor after performing drilling with variable material. Simultaneously, the cutting force and the torque of various drill geometry have been observed with same cutting condition to judge drill stability. As a result, burr was minimized in step drill with 75$^{\circ}$ step angle at every material.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.10
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• pp.132-140
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• 2000

In conventional drilling, burr geometry can be changed according to the variation of drill geometry like point angle, rake angle. Step drilling is proposed to minimize the burr formation in drilling operation. The burr formed in first cutting can be removed in second cutting by the edge in step. The burr formed in second cutting by the edge in step can be minimized according to the change of geometry like, step angle and depth. The mechanism in step drilling is analyzed. Some step drills are applied to drilling the input shaft which is used for vehicle steering. To measure the burr formed in drilling, laser and height gage are used.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.3
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• pp.114-121
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• 2000

A new concept drill was developed recently (or increasing accuracy and productivity in drilling operation. The burr formation in drilling causes many problems in deburring operation because burrs are formed inside holes and it is difficult to remove them. Burr formations are observed in drilling operation with a new concept drill and are compared with conventional HSS drill. Several workpieces with different materials are drilled with several cutting conditions, velocity and feed rate. The burr in drilling can be classified into three types according to the location of crack. To observe the burr formation mechanism, the cap which is formed with the new concept drill is observed and measured.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.3
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• pp.28-34
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• 1997

The side burrs and shape distortion resulting from the micromachining of an array of V-shape microgrooves in fresnel lens mould were experimentally invesigated. The focus of this study is on the influence of depth of cut and prism angle on the burr growing rate. The main experiments were con- ducted on the single prism cutting for the convinient of measuring the burr shape and cutting force. From the observation of the burr shape and burr growing rate, it was found that there exits a critical depth of cut below which the burrs are more or less irregular and weak. But above that critical value, the burrs are re- latively clear and stiff.

• Journal of the Korean Society of Safety
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• v.13 no.2
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• pp.164-169
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• 1998

Burrs can be formed on the feed marks ridges as well as on the edges of the machined parts in machining operations. These burrs are undesirable in terms of the surface quality, the precise dimensioning of machined parts and the safety of operators. This paper experimentally investigates the sideward burr formation in 3-dimensional cutting. In particular, the experimental relationships between the size of sideward burr and the cutting parameters are established and suggestions are made for minimizing sideward burr formation.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.09a
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• pp.137-143
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• 1995

현 전력 시스템 및 전기 전자 시스템의 대용량 단락 설비의 대형화에 따른 부수적인 시스템 구성을 초전도체 화이버를 이용하여 전력 손실과 빠른 차 단 시간을 가지는 차단기가 절대적으로 요구되고 있으며, 본 연구는 초전도 선재가 시스템에 코일로 구성하였을 때 자체에서 흐를수 있는 전류의 양을 검출하여 수치화하여 일반적인 전류계로써의 특징과 오실로스코프의 나타난 파형으로 시스템 자체에서 발생하는 이상 현상을 검색하여 시스템의 여러가 지 현상을 파악하고 또한 폐회로를 구성하여 계기의 부하로 인한 사고를 방 지하기 위하여 내부에 환 코일을 장착하여 단선되는 것을 방지하고 일정 전 류 이상이 되면 초전도체 화이버 자체가 trigger코일로 작동하여 전체 시스 템을 보호하고 전류제한장치의 개발 초기에 적용 가능한 평가 모델을 설계 구현하였다.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.201-202
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• 2009

The objective of this paper is to develop nonlinear analysis method using fiber element. The program is based on flexibility method and developed for analyzing bernoulli's beam element. Using fiber element, three dimensional effects, such as concrete confinement can be incorporated into the uniaxial stress-strain relationship. In addition, most appropriate modeling method is used for application of bond-slip and shear effects.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.987-992
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• 1997

Burrs always come out with the machining of ducterial with small size. Though the size of burrs is small, burrs dominate deterioration of the accuracy of the micro grooves. So the burr generation model especially side burr generation model was investigated to predict the size of the burrs at the given cutting conditions. The side shear plane is introduced to build the burr generation model and the width of side shear plane nomalized with cutting depth is defined with the shear angle. From the theoretical observation, the width of side shear plane can vary up 40% of the cutting depth. To determine the size of burr and stiffness, single groovings were carried out and it was found that there exist a critical depth of cut that the size or stiffness of the burr vary.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.717-720
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• 2000

Burr makes troubles on manufacturing process due to of deburring cost, quality of products and automation. This paper described the results of experimental study on the influence of the cutting parameters on the formation of exit burrs in face milling. Using the results of experimental study, we classified the burr type and developed data bases to predict burr formation result. This program will be used to predict burr type and geometry at a specified location. Simulation results on deformation strain and temperature are also available. Also algorithm which calculate the exit angle is proposed.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.9
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• pp.166-173
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• 2000

A system for burr measurement is developed to measure the geometry of the burr formed in metal cutting or shearing operations. laser system is selected according to the required measuring accuracy and burr size. A specific program for calculating the burr geometry from measured laser data is developed. The raw data is obtained by scanning cross the burr. The height and width of burr are calculated. Due to the specific characteristic of laser peak or valley are formed in measuring sharp edges or small sharp cracks. Compensation for the peak or valley is carried out to make it possible to calculate the burr, burr geometry is measured in 3 dimension.