• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2010년도 춘계학술대회 논문집
• /
• pp.491-492
• /
• 2010

• Journal of Mechanical Science and Technology
• /
• 제19권12호
• /
• pp.2213-2223
• /
• 2005

In order to reconstruct a full 3D human model in reverse engineering (RE), a 3D scanner needs to be placed arbitrarily around the target model to capture all part of the scanned surface. Then, acquired multiple scans must be registered and merged since each scanned data set taken from different position is just given in its own local co-ordinate system. The goal of the registration is to create a single model by aligning all individual scans. It usually consists of two sub-steps: rough and fine registration. The fine registration process can only be performed after an initial position is approximated through the rough registration. Hence an automated rough registration process is crucial to realize a completely automatic RE system. In this paper an automated rough registration method for aligning multiple scans of complex human face is presented. The proposed method automatically aligns the meshes of different scans with the information of features that are extracted from the estimated principal curvatures of triangular meshes of the human face. Then the roughly aligned scanned data sets are further precisely enhanced with a fine registration step with the recently popular Iterative Closest Point (ICP) algorithm. Some typical examples are presented and discussed to validate the proposed system.

• 한국전자거래학회지
• /
• 제10권3호
• /
• pp.1-19
• /
• 2005

협업적 제품 거래 (CPC: Collaborative Product Commerce) 환경에서는, 여러 부품 공급자의 이질적인 부품 라이브러리들을 통합하여 사용자에게 마치 하나의 부품 정보 시스템을 사용하는 것과 같은 환경을 제공해야 한다. 온톨로지 기반 정보 통합에서는 정보 소스의 메타데이터를 엄밀하고 명시적으로 표현한 온톨로지를 병합 (aligning 또는 merging)하여 여러 정보 소스에 대한 단일한 글로벌 뷰를 제공한다 이때 소스온톨로지 간 매핑이 중요한 역할을 한다. 온톨로지 간 매핑이 복잡하지 않고 단순하며, 매핑을 정의하는 방식이 정형화되기 위해서는, 온톨로지들이 일관된 모델링 관점과 일관된 의미적 표현 방식으로 모델링되어야 한다. 본 논문은 상위 온톨로지에 기반한 부품 라이브러리 온톨로지 모델링 프레임워크를 소개하고, 이를 실제 금형 부품 라이브러리의 정보통합에 적용하여, 소스 온톨로지 간 매핑이 단순해지고 정형화되며, 결과적으로 소스 온톨로지들을 자동 병합하는 프로그램을 쉽게 구현할 수 있음을 설명한다.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2007년도 추계학술대회 논문집
• /
• pp.398-398
• /
• 2007

The Liquid Crystal (LC) alignment uniformity is very important in LC devices. The alignment mechanism of LC molecules on a rubbed polyimide (PI) surface is very important for both LC fundamental research and application. So, Generally a rubbing method to align LC has been widely used to mass-produce LCD panels. But because rubbing method is contact method between rubbing fabric and indium-tin-oxide glass or flexible substrate, rubbing method has some defects, such as the electrode charges and the creation of contaminating particles. Thus we strongly recommend a non-contact alignment technique for getting rid of some defects of rubbing method. Most recently, the LC aligning capabilities achieved by ion-beam exposure on the organic and nonorganic thin film surface have been reported successfully. In this research, we studied the tilt angle generation and electro-optical performances for a NLC on homeotropic polyimide surfaces with ion-beam exposure. The LC aligning capabilities of a nematic liquid crystal (NLC) on a homeotropic PI surface using a new ion-beam method were studied. On the homeotropic PI surface, the tilt angle of the NLC by exposure ion-beam had a tendency to decrease as increased ion-beam energy density. And, on the homeotropic PI surface, the alignment character of the NLC with respect to ion-beam energy was good. And we achieved satisfactory result for EO character.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2001년도 춘계학술대회 논문집
• /
• pp.15-19
• /
• 2001

A dedicated reverse engineering(RE) system for rapid manufacturing of human head in a 3D bust has been developed. The first step in the process is to capture the surface details of a human head and shoulder by three scanners based upon the digital moire fringe technique. Then the multiple scans captured from different angles are aligned and merged into a single polygonal mesh, and the aligned data set is refined by smoothing, subdividing or hole filling process. Finally, the refined data set is sent to a 4-axis computer numerically control(NC) machine to manufacture a replica. In this paper, we mainly describe on the algorithms and software for aligning multiple data sets. The method is based on the recently popular Iterative Closest Point(ICP) algorithm that aligns different polygonal meshes into one common coordinate system. The ICP algorithm finds the nearest positions on one scan to a collection of points on the other scan by minimizing the collective distance between different scans. We also integrate some heuristics into the ICP to enhance the aligning process. A typical example is presented to validate the system and further research work is also discussed.

• 한국광학회지
• /
• 제22권1호
• /
• pp.30-34
• /
• 2011

본 연구에서는 현재 대부분 작업자에 의해 수동으로 이루어지고 있는 단색화장치 내 광학 요소간 광학정렬을 높은 반복도와 고속으로 수행할 수 있는 자동화 방안에 대해 논의하고자 한다. 단색 분광기의 시준거울 자동정렬을 위해 CCD센서를 이용한 위상이미지 상관기법을 핵심기술로 사용하였다. 실험결과 약 10초 내에 시준거울을 정밀하게 자동정렬 할 수 있다.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
• /
• pp.378-378
• /
• 2007

In this study, liquid crystal (LC) aligning capabilities for homeotropic alignment on the $ZrO_x$ thin film by electron beam evaporation method were investigated. Also, the control of pretilt angles and thermal stabilities of the NLC treated on $ZrO_x$ thin film were investigated. The uniform LC alignment on the $ZrO_x$ thin film surfaces and good thermal stabilities with electron beam evaporation can be achieved. It is considerated that the LC alignment on the $ZrO_x$ thin film by electron beam evaporation is attributed to elastic interaction between LC molecules and micro-grooves at the $ZrO_x$ thin film surface created by evaporation. In addition, it can be achieved the good electro-optical (EO) properties of the VA-LCD on $ZrO_x$ thin film layer with. oblique electron beam evaporation.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
• /
• pp.1719-1722
• /
• 2006

We proposed a soft-lithographic method for aligning a liquid crystal (LC) in patterned azimuthal orientations. It is demonstrated that a thermoplastic polystyrene layer is patterned from a thermally stable polyimide layer via pressure-assisted capillary force lithography, which provides multidirectional LC alignment condition simply followed by a unidirectional rubbing process.

• 한국전기전자재료학회논문지
• /
• 제13권2호
• /
• pp.157-162
• /
• 2000

The electro-optical characteristics of TN(twisted nematic)-LCD(liquid crystal display) with photo-dimerized on a PMCh(poly(4'methacryoyloxylchalcone)) surface using a new photo-dimerization method was studied. The excellent voltage-transmittance(V-T) curve of TN-LCD with photo-dimerized on a PNCh surface for 1 min. using a new photo-dimerization method was observed. Also, the voltage-hold-ing-ratio(VHR) of TN-LCD with photo-dimerized on a PMCh surface using a new photo-dimerization method is higher than that of conventional photo-dimerization method. Consequently, we suggest that the new photo-dimerization method. Consequently, we suggest that the new photo-dimerization method for LC aligning is the most promising rubbing-free techniques.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1995년도 추계학술대회 논문집
• /
• pp.355-360
• /
• 1995

In order to align the shaft, the dialgauge method has used as a means of solution until now. The method using a dialgauge require a great deal of labour and money due to making by hand, the accurate alignmentis not up to the expectation. For aligning the shaft, all the rotor must come to accord. It means that the moment of the point of coupling must keep being "Zero". The ideal measurement method as to material on the zero is used by straingauge which can gauge the moment at any point of the shaft. Also, the dialgauge method cannot be compared with straingauge measurement method, form the viewpoint, which can gauge in short time.hort time.