• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1035-1036
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• 2011

직구동방식 고속 솔레노이드 액추에이터는 자동차, 항공산업 등의 고정밀을 요구하는 산업시스템에 주요부품으로 사용되기 때문에 고신뢰성이 요구된다. 본 연구에서는 직구동방식 고속 솔레노이드 액추에이터의 신뢰성 평가를 위하여 2단계 품질기능전개를 통해 신뢰성시험항목을 결정하였다. 신뢰성평가 시험 중에서 가장 큰 우선도를 차지하는 수명시험에 대해 문헌, 연구계 및 현장실무자를 통한 무고장 수명시험 시간을 산출하였다. 또한 장기간 소요되는 무고장 수명시험 시간의 시간을 단축하기 위해 가속모델을 제안하고 실제 조건을 충족하는 가속수명 시험시간을 산출하였다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.234-234
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• 2003

MgTiO$_3$와 ZnTiO$_3$ 같은 ilmenite형 세라믹스는 유용한 유전특성 때문에 MLCC와 RF/microwave 장치와 같은 유전체 세라믹 부품에 사용될 수 있다. 그러나, 이 두 ilmenite형 세라믹스는 저온에서 hexagonal 구조를 띄는 ilmenite 합성에서의 난점들 때문에 LTCC에 사용되기 어려운데, 본 연구에서는 ilmenite형 세라믹스의 합성을 개선시키는데 Mechanically Activated Syntheses법(이하 MAS법)을 이용했다. MAS법으로 합성온도를 낮출 수 있었고 원치 않는 2차상의 형성을 방지할 수 있었으며, LTCC에 이용될 수 있는 분말들의 소결온도를 95$0^{\circ}C$ 이하로 내릴 수 있었다. 또한, MAS법을 이용했을 때와 기존의 방법을 이용했을 때의 여러 특성들을 비교 분석했다.

• Journal of Korean Institute of Industrial Engineers
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• v.31 no.1
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• pp.20-26
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• 2005

This paper proposes the heuristic algorithm for the generalized GT problems to consider the restrictions which are given the number of machine cell and maximum number of machines in machine cell as well as minimum number of machines in machine cell. This approach is split into two phase. In the first phase, we use the similarity coefficient which proposes and calculates the similarity values about each pair of all machines and sort these values descending order. If we have a machine pair which has the largest similarity coefficient and adheres strictly to the constraint about birds of a different feather (BODF) in a machine cell, then we assign the machine to the machine cell. In the second phase, we assign parts into machine cell with the smallest number of exceptional elements. The results give a machine-part grouping. The proposed algorithm is compared to the Modified p-median model for machine-part grouping.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.2 no.2
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• pp.39-43
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• 2001

This paper aims to manufacturing of connecting rod die using CAD/CAM systems. CAD/CAM systems are consist of CAD(MDT4.0), CAM(Z-MASTER) software and CNC milling machine. CAM software is purpose to G-code generation for CNC programming. Then CAM software and CNC milling machine are connect to RS-232-C cable for data network.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.3
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• pp.312-316
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• 2003

This paper is aim to the design and manufacture for wheelchair ABS using the rachet wheel. Quick and logical evaluations on the design and manufacture of wheelchair ABS can be judged from design to manufacture process. In generally, design change is occur to change of process order. Also, this paper is object to reduced process errer.

• Journal of Korean Institute of Industrial Engineers
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• v.30 no.3
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• pp.175-180
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• 2004

The machine-part group formation is to group the sets of parts having similar processing requirements into part families, and the sets of machines needed to process a particular part family into machine cells using grid computing. It forms machine cells from the machine-part incidence matrix by means of Self-Organizing Maps(SOM) whose output layer is one-dimension and the number of output nodes is the twice as many as the number of input nodes in order to spread out the machine vectors. It generates machine-part group which are assigned to machine cells by means of the number of bottleneck machine with processing part. The proposed algorithm was tested on well-known machine-part grouping problems. The results of this computational study demonstrate the superiority of the proposed algorithm.

• Proceedings of the KWS Conference
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• 2006.10a
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• pp.202-204
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• 2006

The reliability of insert mounted components has been considered as their life time was getting increased. The spread of crack and the growth of IMC(intermetallic compound) were observed by SEM(scanning electron microscope) and EDS(energy dispersive spectroscope). The cracks in Sn-37wt%Pb under thermal shock test were found earlier than other solders(Sn-3.0wt%Ag-0.5wt%Cu and Sn-0.7wt%Cu-0.01wt%P). The IMC thickness was increased with increasing number of thermal shock cycles in the following order : Sn-0.7Cu-0.01P; Sn-3.0Ag-0.5Cu; Sn-37Pb

• Transactions of Materials Processing
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• v.15 no.9 s.90
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• pp.673-678
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• 2006

Demands for micro parts have increased with recent advances in IT and machinery industries. However, the present technology loaves much to be desired to effectively produce parts with the volume of $1mm^{3}$ and less by mechanical method in large quantities. This paper provides a method for efficient quantity production of complete micro 3D structure using micro end-milling cutting process. The possibility has proven via manufacturing experiment of a multistage micro complex gear structure of $500{\mu}m$ in length, $500{\mu}m$ in maximum external diameter and a volume of $1mm^{3}$ and less.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.3
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• pp.29-34
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• 2012

This paper reports some experimental results in high speed rigid tapping of magnesium alloy(AZ91D). M3 spiral tap and high speed spindle tapping center of gantry type were used in experiments and thrust forces were measured. The experimental results indicate that the thrust forces are proportional to the spindle speed and depth of cut. The thrust forces increase as the depth of cut increases. M3 Tapping was achieved at the spindle speed of 10,000rpm, depth of cut of 1.5D and total stroke of 32mm.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.167-172
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• 2003

The machining method by using end-milling tool has been applying in machining structures of various shapes because of the availability. Recently, all kinds of industries based on the parts of micro shape are developing, and the demands of mechanical micro machining technology are Increasing suddenly to produce these parts. According to such changes, the technology of the micro end-milling machining is applying as one of the most important machining means. This research is to aim at developing machining technology for various micro structures using micro end-mill. This paper introduces micro mechanical machining system with ultra precision, and demonstrates methods manufacturing all sorts of parts and moldings for industry and examples of applicable machining by using micro end-milling tool of micro sizes from hundreds to tens in diameter.