• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.876-879
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• 1995

Parallel NC machines are a new generation of machine tools aimed at increasing maching accuracy and reducing part cycle time. In addition to their capacity to perform both milling and turning operations, these machine tools can perform multiple machining operations simultaneously,involving one or more parts at a time, and can completely finish a part in a single setup. Due to the lack of a computer-aided process planning system, these machines are used in industry today as dedicated, mass-production machines. This pape presents methodology for generating optimal process plan for each parallel machine tool using a genetic algorithm.

• 한국산업융합학회 논문집
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• 제21권6호
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• pp.369-378
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• 2018

This study proposes a new approach to real time implimemtation of shape recognition technology of die casting and forging parts based on robot vision for smart factory. The proposed shape recognition and inspection technology for forging and die casting parts is very useful for manufacturing process automatiom and smart factory including external form's automatic inspection of machanical or electronic panrs for the precision verification. The reliabiblity of proposed technology Ihas been illustrated through experiments.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.490-493
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• 2004

There is great difficulty in machine below 10 micrometers by conventional machining methods, such as micro-EDM. However, ultra micro machining using focused ion beam(FIB) is able to machine to 50 nanometers. Bie ＆ moulds techniques are better than one-to-one machining techniques in regards to production costs in the mass production of ultra size structures. Also, it is advantageous to machine die ＆ moulds to the 10 micrometers level by FIB technique rather than other techniques. It is difficult to machine the three dimensional machining, such as micro lens, using FIB system because of their machining characteristics. In this paper, three dimensional machining techniques were properly introduced, and also experiments showed effectiveness of their techniques.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.809-813
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• 2000

In this study, screw machining system by use of a rotational tool such as an end-mill or a face cutter with Y axis off-set on a CNC turing center was developed for quick machining. In this system, It was possible to use different tools for different processes, and by off-setting the tool in Y direction by calculated amount it was possible to avoid tool interference problem which could occur within the central area at the end of a tool. In addition, machining a screw with a helix of up to 3 different leads combined and with tapered minor diameter was possible.

• 한국산업융합학회 논문집
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• 제25권6_3호
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• pp.1127-1133
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• 2022

Recently, the use of aircraft structures using Ti alloy (Ti-6Al-4V), a lightweight high-strength alloy material, is rapidly increasing due to the weight reduction of aircraft. However, high-strength materials such as Ti alloys require high energy for cutting and are classified as difficult-to-cut materials. Also, research on Laser Assisted Machining (hereinafter referred to as LAM), a cutting processing technology that utilizes improved machinability, is being actively researched. Therefore, in this paper, in order to confirm the proper temperature distribution using a laser, the finite element method is used to determine the temperature distribution according to the calorific value condition to derive the appropriate condition, and the thermal load generated at this time is used as a structural analysis. It is intended to be used as basic data for LAM processing conditions by measuring the amount of residual stress and thermal deformation caused by heat.

• 한국정밀공학회지
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• 제10권2호
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• pp.178-189
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• 1993

Engineering ceramics have some excellent properties as the material for the mechanical components. It is, however, very difficult to grind ceramics with high efficiency because of their high strength, hardness and brittleness. In this paper experiments are carried out to obtain the effect of "In-process dressing" to grind the Engineering ceramics with high efficiency. To save running time for dressing process and obtain restraint effect of diamond grain wear, "In-process dressing" system usint WA stick type honing stone is proposed. Representative High Strength Engineering ceramics A1$_{2}$O$_{3}$ and Si$_{3}$N$_{4}$are ground with diamond wheel. Also bending strengrh test is carried out to check upward tendancy of mecahnical properties as the result of machining defact restraint through the grinding maching method using "In-process dressing" process. Some results obtained in this study provide useful information to attain the high efficency grinding and the high mechanical properties of Engineering ceramics.rties of Engineering ceramics.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 춘계학술대회
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• pp.367-370
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• 2015

본 논문은 자동차 자율주행에 필요한 신호등 신호의 검출 성능을 개선시키는 방법을 제안한다. 일반적인 교통신호등 검출연구는 색상 임계치, 템플릿 매칭, 학습기 기반 등의 방법을 사용한다. 그러나 조도 차이로 인한 인식률 저하와 느린 처리속도 문제가 있다. 제안한 방법은 형태학적 전처리 후 검출마스크를 통해 교통신호등 영역검출 및 인식을 제안한다. 먼저 영상을 조도에 강건하게 하기 위해 입력 영상을 YCbCr로 변환하고, Y채널에서 수평에지 성분을 추출한다. 그 후 신호등의 형태학적 특징을 이용하여 영역을 검출한다. 마지막으로 색상을 이용하여 신호등을 검출한다. 제안 방법을 다양한 환경에서 적용하여 기존 알고리즘보다 검출율과 처리 속도가 향상되었음을 확인하였다.

• 대한공간정보학회지
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• 제4권1호
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• pp.93-102
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• 1996

수치표고모델(DEM, Digital Elevation Model)을 컴퓨터를 이용하여 자동으로 생성할 때 입체영상매칭(stereo matching) 연산은 많은 수행시간이 소요된다. 매칭연산은 일반적으로 상관계수(correlation)에 의한 방법이 사용되고 있으며, 매칭점 분포가 균등한 지역기반방식(area-based method)이 주로 이용되고 있다. 본 논문에서는 지형을 식별하여 매칭연산에서 검색영역(search area)과 기준윈도우(mask window)의 크기를 조정하여 효율적인 매칭을 수행하는 방안을 제시하였다. 영상을 분할하기 위하여 경계보호평활화 필터(edge-preserving smoothing filter)를 사용하여 전처리를 수행하였으며, 필터를 거친 영상에 대해서 영역성장 알고리듬을 적용하였다. 분할된 영역은 MRF(Markov Random Field) 모델에 의한 식별과정을 통하여 산악, 평야, 수계지역으로 식별된다. 영상매칭은 예비시차(predicted parallex) 계산과 상세매칭(fine matching)의 두 단계를 거치며, 예비시차를 이용하여 상세매칭단계에서 검색영역의 위치를 결정한다. 검색영역과 기준윈도우의 크기는 화소에 대한 지형식별정보에 의해 결정된다. 주변화소와 시차가 유사한 평야지역과 수계지역의 검색영역을 축소함으로서 매칭연산시간을 단축시켰다. 대전-금산지역의 $10km{\times}10km(1024{\times}1024)$ 영상을 4개 사용하여 실험한 결과 지형식별정보를 이용하지 않았을 경우보다 영상매칭 수행시간이 $25%{\times}35%$정도 단축시킬 수 있음을 보였다.