• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.1
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• pp.45-52
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• 2000

The purpose of this research was developing an integrated way to solve two typical tolerance optimization problem i.e. optimal tolerance allotment and design centering. A new problem definition design centering-tolerance allotment problem (DCTA) was proposed here for the first time and solved. Genetic algorithm and coarse Monte Carlo simulation were used to solve the stochastic optimization problem. Optimal costs were compared with the costs from the previous optimization strategies Significant cost reductions were achieved by DCTA scheme.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.145-149
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• 1997

STEP AP224 includes the information of machining feature and tolerances. Machining features are machined from raw material. Tolerance constrain feasible methods of manufacture, strongly influence the cost of manufacture. And tolerances influence the machining process. We need to decide the precedence between features .tool radius and tool direction for minimum tool changes. This paper deals with the method of decision of precedence between features and process parameters using feature information and tolerances in STEP AP224.

• Journal of the korean Society of Automotive Engineers
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• v.4 no.1
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• pp.1-4
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• 1982

우리가 흔히 쓰는 관리도에도 X over bar-R관리도, P(또는 Pn)관리도, C(또는 U)관리도가관리 도의 대종을 이루고 있다. 그러나 기계공업 특히 자동차공업분야에서는 기계가공 부품을 일일이 재기가 어렵거나 시간이 걸리므로 고-노고우 게이지(go-no go gauge)를 써서 선별하는 경우가 많다. 또 금형베품의 조립시에는 측정개소가 많기 때문에 어느 한 부분만을 제어서 관리할 수 없으므로 여러곳을 제어서 관리해야 하는데 이때 금형전체를 어떻게 맞출것인가, 혹은 제품의 공차관리를 어떻게 해나갈 것인가 하는 문제가 생긴다. 다음에 이러한 경우에 유용하게 쓰일 수 있는 관리도의 예를 소개하고자 한다.

• Proceedings of the Optical Society of Korea Conference
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• 2003.02a
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• pp.102-103
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• 2003

최근에 주야간 관측이 가능한 열상카메라에 대한 관심이 날로 증가하고 있다. 특히 열상카메라는 빛이 전혀 없는 야간에도 선명한 영상을 획득할 수 있기 때문에 야간 영상획득을 위하여 반드시 사용하여야만 한다. 이러한 열상카메라는 가시광 보다 파장이 10배 또는 20배 가량 긴 파장을 사용하기 때문에 광학계 설계측면에서나 적외선 렌즈의 가공 측면에서 허용공차를 크게 할 수 있다는 유리한 점이 있다. (중략)

• The Bulletin of The Korean Astronomical Society
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• v.33 no.2
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• pp.43.1-43.1
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• 2008

• Korean Journal of Optics and Photonics
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• v.32 no.6
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• pp.259-265
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• 2021

Recently, lens manufacturing and assembly technology has greatly improved. However, tight requirements of manufacturing and assembly lead to an increase in cost and manufacturing time, and in some cases the performance of an optical system may deteriorate depending on the operating environment's conditions, such as temperature or vibration. In addition, the use of a compensator is an effective method to reduce sensitivity in an ultra-precision optical system, but in the case of a small lens, such as that in an endoscope, it is difficult to use a compensator due to the size limitation of the lens barrel. Therefore, minimizing lens sensitivity is the most important technology in lens design. For this reason, there have been various attempts to reduce the lens sensitivity, and there is a trend to add functions to reduce the sensitivity in the lens design S/W. In this paper, we introduce a design technology that minimizes lens sensitivity. We first design a lens with quite good performance, then analyze the sensitivity of this lens, make a multi-configuration with high-sensitivity element error, and then reoptimize it. We prove with an example that this design technique is very effective.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.11
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• pp.112-119
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• 2002

Generally, it is very difficult to inspect geometric shape of large 2D objects after machining. To maintain the accuracy for inspection, a robot vision is used to divide overall shape into several enlarged images, and image processing technique is applied to acquire one minute geometric contour. The inspection is to compare the NC data with the measured contour data by the vision system, and the algorithm is to rotate to minimize the maximum deviation after coinciding two geometric centers. This paper experimentally shows that the proposed algorithm is very useful for inspection of large machined objects.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.5
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• pp.145-151
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• 2016

We consider the position and thickness of reinforcement with respect to fatigue fracture of welded bogie frames and propose an appropriate reinforcement method for many cases. The bogie frame is usually designed in accordance with JIS and KS, and operates under harsh load conditions: dynamic loads generated while driving, various loads during operation, and large load differences between loading and unloading. Consequently, fatigue failure often occurs throughout the bogie frame. We modelled the reinforcing method using ANSYS software and reviewed stress in the vicinity of common fatigue failure sites through computer simulation, optimizing the position and thickness of reinforcement.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.95-99
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• 1996

The form accuracy of parts has become an important parameter. Therefore dimensional tolerance and geometric tolerance are used in design to satisfy required quility and functions of parts. But the informations for machining conditions, which can satisfy the assigned geometric tolerance in design, are insufficient. The objectives of this research are to study the effects of the grinding parameters such as traverse speed, work speed, depth of cut, and dwell time on the after-ground workpiece shape, and to find out the major parameters among these parameters. Finally, a methodology is proposed for getting the optimal grinding condition for precision workpiece The results are as follows; The effects of work speed and depth of cut on workpiece shape are ignorable compared to the effect of traverse speed. These is the optimal dwell time depending on the traverse speed. The optimal dwell time is decreasing when the traverse speed is increased.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.3
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• pp.82-91
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• 1995

The purpose of this research is to develop a new real-time process control system. In this paper, a theoretical method for acquiring the control limit of cutting process(cutting surface) according to the required value(geometric tolerance) based on geometrical relations was propsed. In particular, the three following points are amphasized. Firstly, the process control was based on the cutting process, and the control limit was determined from the analysis of geometrical relations. Secondly, AMGD(Actual Measured Geometrical Deviation) was used as a new substitute value in process analysis. Thirdly, fuzzy reasoning was introduced to get the control limit flexibility according to the variations in the required value and general consideration of each measurememnt items.