• 한국기계가공학회지
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• 제11권2호
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• pp.13-19
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• 2012

Ultra Precision Machining Techniques, such as manufacturing Micro Lens Array(MLA), off-axis mirror, $F-{\theta}$ lens for laser printer, are achieved, based on technologies in consequence of development of modern high-precision machining mechanism. Above all, FTS(Fast Tool Servo) and STS(Slow Tool Servo) are more innovative technologies for reducing time and development costs. In this paper, it is described that MLA machining technique by FTS, off-axis mirror machining technique by STS, optics for observing space, and development of infrared aspheric lens for a thermal imaging microscope.

• 헤리티지:역사와 과학
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• 제50권3호
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• pp.64-87
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• 2017

조선시대 끈을 일컫는 다회는 우리의 복식사, 문화사, 생활사가 녹아있는 산물로서 지역과 계층을 불문하고 다양한 분야에서 전반적으로 사용되었다. 국내외 다수의 유물이 현존하고 있으나 연구의 주요대상으로 선정되지 못하여 연구가 미흡하고 기법 전승 등에서도 접근성이 낮아 연구에 어려움이 많다. 본 연구에서는 도검의 패용(佩用)을 위해 사용된 광다회의 제작기법을 분석하여 다회의 비파괴적인 제작기법 분석 방안을 마련하고, 다회의 올바른 보존 및 계승에 기여하고자 하였다. 패용 광다회는 물건의 패용을 위한 용도로 사용되는 끈이며, 매듭을 맺기 위해 사용되기도 하여 현재는 매듭장에 의해 전승되고 있다. 제작원리는 원다회와 동일하고 다회틀 상판의 심지가 지지대 역할을 하기 때문에 제작된 다회의 중앙에 빈 공간이 존재하는 것이 특징이다. 이와 같은 다회는 3차원적으로 제작되어 제작기법이 복잡하고 현재까지 올의 개수와 배열에 따라 제작되는 다회에 관한 기초자료가 마련되어있지 않아 제작기법의 규명에 어려움이 많았다. 특히 제작기법의 추정을 위해 올을 해체하는 경우가 존재하지만 제작기법의 규명에는 어려움이 있고, 본래의 상태로 되돌릴 수 없다는 문제점도 있다. 따라서 다회의 비파괴적인 제작기법 분석방안 마련과 실제 유물에 대한 적용 가능성 평가의 필요성이 크다. 유물의 제작기법 분석은 다회 제작기법의 DB구축 결과를 바탕으로 하였고, DB구축을 위하여 다회의 도식화 및 복원샘플 제작, 형태적 특징 분석을 진행하였다. 또한 DB의 신뢰도를 높이기 위하여 유물의 X-ray CT 촬영으로 분석결과를 뒷받침할 근거를 마련하였으며, 촬영결과는 다회치기기법에 근거하여 제작기법을 해석하였다. 제작기법 분석의 대상으로 선정한 패용 광다회는 경인미술관 소장 도검(녹칠어피갑금동장별운도, 어피갑금동장곡병환도)의 패용을 위한 것으로 다회의 예술성, 기능성과 상징성을 겸비한 유산이며 광다회가 온전히 남아있어 띠돈을 비롯한 패용장식이 모두 온전한 유물이다. 유물의 제작기법 분석결과를 토대로 짜임형태를 관찰하였고 2점 모두 좌우측면에서 1회 교차된 것임을 알 수 있었다. 짜임형태 길이비 측정을 통해 20개의 올을 사용하여 제작된 것으로 확인되었다. X-ray CT 촬영결과 DB의 분석결과와 동일한 결과가 도출되어 차후 국내외에 산재되어있는 다회의 분석 및 연구를 위한 기초자료로서 활용이 가능할 것으로 사료된다. 이번 연구를 통해 미력하게나마 소중한 전통문화의 보존 및 계승, 발전에 도움이 되기를 바란다.

• 스마트미디어저널
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• 제10권3호
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• pp.23-30
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• 2021

제조 시계열 데이터 클러스터링 기법은 제조 대용량 데이터 기반 군집화를 통한 설비 및 공정 이상 탐지 분류를 위한 중요한 솔루션이지만 기존 정적 데이터 대상 클러스터링 기법을 시계열 데이터에 적용함에 있어 낮은 정확도를 가지는 단점이 있다. 본 논문에서는 진화 연산 기반 시계열 군집 분석 접근 방식을 제시하여 기존 클러스터링 기술에 대한 정합성 향상하고자 한다. 이를 위하여 먼저 제조 공정 결과 이미지 형상을 선형 스캐닝을 활용하여 1차원 시계열 데이터로 변환하고 해당 변환 데이터 대상으로 Pearson 거리 매트릭을 기반으로 계층적 군집 분석 및 분할 군집 분석에 대한 최적 하위클러스터를 도출한다. 해당 최적 하위클러스터 대상 유전 알고리즘을 활용하여 유사도가 최소화되는 최적의 군집 조합을 도출한다. 그리고 실제 제조 과정 이미지 대상으로 기존 클러스터링 기법과 성능 비교를 통하여 제안된 클러스터링 기법의 성능 우수성을 검증한다.

• 대한기계학회논문집A
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• 제26권5호
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• pp.813-821
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• 2002

Glass fiber reinforced PET matrix composite was manufactured by rapid press consolidation technique as functions of temperature, pressure and time in pre-heating, consolidation and solidification stages. The optimal manufacturing conditions for this composite were discussed based on the void content, tensile, interlaminar shear and impact properties. In addition, the levels of crystallinity with various manufacturing conditions were measured using differential scanning calorimetry to investigate the mechanical properties of this composite material as a function of crystallinity. Among many processing parameters, the mold temperature and the cooling rate after forming were found to be the most critical factors in determining the level of crystallinity and mechanical properties. The level of crystallinity affects the tensile properties to some degree. However, impact properties are affected much more. It also affects the degree of ductility, which determines the impact energy of this material.

• 한국기계가공학회지
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• 제14권4호
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• pp.134-139
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• 2015

PolyJet technology is an additive manufacturing (AM) technology commonly used for modeling, prototyping, and production applications. It is one of the techniques used for 3D printing. The PolyJet technique is a process that joins materials to fabricate a product from 3D CAD data in a layer-by-layer manner. The orientation of a layer can affect the mechanical properties of the product manufactured by the PolyJet technique because of its anisotropy. In this paper, tensile and shearing tests of specimens were developed with the PolyJet technique in order to study the mechanical properties according to the orientation of a layer. The mechanical properties of the specimens were determined on the basis of true stress-strain curves from tensile and shearing tests. In addition, the tensile and shearing tests were simulated under the same conditions as those of experiment, and the experiment and simulated results were compared. Through this study, the fracture criteria could be established.

• 산업경영시스템학회지
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• 제32권2호
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• pp.132-139
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• 2009

Yield is a very important measure that can expresses simply for productivity and performance of company. So, yield is used widely in many industries nowadays. With the development of the information technology and online based real-time process monitoring technology, many industries operate the production lines that are developed into automation system. In these production lines, the product structures are very complexity and variety. So, there are many multi-variate processes that need to be monitored with many quality characteristics and associated process variables at the same time. These situations have made it possible to obtain super-large manufacturing process data sets. However, there are many difficulties with finding the cause of process variation or useful information in the high capacity database. In order to solve this problem, neural networks technique is a favorite technique that predicts the yield of process for process control. This paper uses a neural networks technique for improvement and maintenance of yield in manufacturing process. The purpose of this paper is to model the prediction of a sub process that has much effect to improve yields in total manufacturing process and the prediction of adjustment values of this sub process. These informations feedback into the process and the process is adjusted. Also, we show that the proposed model is useful to the manufacturing process through the case study.

• 기술사
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• 제33권2호
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• pp.62-67
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• 2000

The trouble rank of business management of the small-medium manufacturing enterprises in Korea is constituted by that average 28.6% of production management in the worst trouble of business management from 1982 to 1999. The status of production management approaching problem is analyzed for Korean small-medium manufacturing enterprises and it us checked productivity improvement and requirement facts impede productivity improvement. It is expected to contribute much productivity improvement through a new established model of production management system and technique or tool for small-medium manufacturing enterprises in Korea.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2003년도 춘계학술대회 논문집
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• pp.428-432
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• 2003

The technical combination of RP and RT has a potential for rapid manufacturing of three-dimensional parts. In the present work a new RP system, $VLM-_{ST}$, is proposed to manufacture net shapes of 3D prototypes. ㅁ human head shape and a kob shape are manufactured by the $VLM-_{ST}$ apparatus. In addition, a new RT technology, which utilizes a RTV molding technique and a triple reverse process technique, is proposed to manufacture net shapes of 3D plastic parts using prototypes of $VLM-_{ST}$. A plastic part of the knob shape os produced by the proposed RT technology. The combination of the proposed RP and RT enables the manufacturing of a plastic knob within two days.

• 대한안전경영과학회지
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• 제7권4호
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• pp.27-38
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• 2005

In manufacturing industry of the modem industrial society, people increasingly become concerned the awareness of safety increasingly although they have regarded production the most important factor. Even though, as people make efforts on accident preventions, the number of accidents is decreasing, fatal major industry accidents are rather thanincreasing so that the number of deaths has not decreased. Under these conditions, there is an attempt to introduce and perform the process safety management system as a means for keeping from major industry accidents. However, it leaves to be desired on the methods of measuring process safety in the general manufacturing industry, while it is available to do that in the chemistry industry. Therefore, in this paper, we analysis processes of manufacturing industry in safety point of view and suggest the technique efficiently measuring and managing each process. Proposed the technique shows that the specification on safety determines AHP weight through the managers of firms and each process is suggested by using normalized matrix.

• 한국분말재료학회지
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• 제24권4호
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• pp.285-291
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• 2017

We propose a custom analysis technique for the dark field (DF) image based on transmission electron microscopy (TEM). The custom analysis technique is developed based on the $DigitalMicrograph^{(R)}$ (DM) script language embedded in the Gatan digital microscopy software, which is used as the operational software for most TEM instruments. The developed software automatically scans an electron beam across a TEM sample and records a series of electron diffraction patterns. The recorded electron diffraction patterns provide DF and ADF images based on digital image processing. An experimental electron diffraction pattern is recorded from a IrMn polycrystal consisting of fine nanograins in order to test the proposed software. We demonstrate that the developed image processing technique well resolves nanograins of ~ 5 nm in diameter.