• Bulletin of the Korean Chemical Society
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• 제33권12호
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• pp.3931-3932
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• 2012

• 한국전자현미경학회:학술대회논문집
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• 한국현미경학회 2001년도 제32차 추계학술대회
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• pp.18-22
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• 2001

A technique to characterize specific site of materials using a combination of a dedicated focused ion beam system(FIB), and Intermediate-voltage scanning transmission electron microscope(STEM) or transmission electron microscope(TEM) equipped with a scanning electron microscope(SEM) unit has been developed. The FIB system is used for preparation of electron transparent thin samples, while STEM or TEM is used for localization of a specific site to be milled in the FIB system. An FIB-STEM(TEM) compatible sample holder has been developed to facilitate thin sample preparation with high positional accuracy Positional accuracy of $0.1{\mu}m$ or better can be achieved by the technique. In addition, an FIB micro-sampling technique has been developed to extract a small sample directly from a bulk sample in a FIB system These newly developed techniques were applied for the analysis of specific failure in Si devices and also for characterization of a specific precipitate In a metal sample.

• 대한치과교정학회지
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• 제44권6호
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• pp.281-293
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• 2014

Objective: Esthetic improvements during orthodontic treatment are achieved by changes in positions of the lips and surrounding soft tissues. Facial soft-tissue movement has already been two-dimensionally evaluated by cephalometry. In this study, we aimed to three-dimensionally assess positional changes of the adult upper lip according to simulated maxillary anterior tooth movements by white light scanning. Methods: We measured changes in three-dimensional coordinates of labial landmarks in relation to maxillary incisor movements of normal adults simulated with films of varying thickness by using a white light scanner. Results: With increasing protraction, the upper lip moved forward and significantly upward. Labial movement was limited by the surrounding soft tissues. The extent of movement above the vermilion border was slightly less than half that of the teeth, showing strong correlation. Most changes were concentrated in the depression above the upper vermilion border. Labial movement toward the nose was reduced significantly. Conclusions: After adequately controlling several variables and using white light scanning with high reproducibility and accuracy, the coefficient of determination showed moderate values (0.40-0.77) and significant changes could be determined. This method would be useful to predict soft-tissue positional changes according to tooth movements.

• 대한치과보철학회지
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• 제36권5호
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• pp.738-747
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• 1998

The purpose of this study was to compare the positional stability of removable dies using several dowel pin systems. The removable dies were made by using five dowel pin systems: single dowel pin(Group I), single dowel pin and prepared groove on the die base(Group II), two-single dowel pin(Group III), two separate parallel dowel pins with plastic sleeves(Group IV), double straight dowel pins with metal sleeve(Group V). Special aluminum mold was made for specimens, and the dies of specimens removed and replaced thirty times with universal testing machine. Horizontal and vertical shift of dies was measured by Olympus monocular scanning tunneling microscope(STM5). The results were as follows: 1. The vertical shift was larger than the horizontal shift in all the other groups except Group I. 2. Single dowel pin system(Group I) was the most unstable of five dowel pin systems. 3. Double dowel pin systems with steeve(group IV, V) were the most stable of five dowel pin systems. 4. This study indicates that excellent horizontal positional stability is attainable with use of additional groove on the die base or double dowel pin. and excellent vertical positional stability is attainable with use of sleeve.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2007년도 춘계학술발표회 논문집
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• pp.379-382
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• 2007

Laser scanning technology with high positional accuracy and high density automation will be widely applied in vast range of fields including geomatics. Especially, the development of laser scanning technology enabling long range information extraction is increasing its full use in civil engineering. The purpose of this study is to extract accurate highway geometric information taking the advantages of scanning technology. Fulfilling this goal, the information of target highway's three-dimensional data was obtained through terrestrial laser scanning technology. In accordance with the result from target highway's geometric information extraction using the information above, laser scanning technology showed faster speed and better accuracy on highway geometric information extraction with reduced cost compared to traditional methods.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.383-386
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• 2002

It is very important to inspect color of printed texture in the textile process. To distinguish the color of the printed texture, RGB color values obtained from a scanner must be transformed to the standard colorimetric system used in the textile industry. It is XYZ color system that is defined by CIE(Commission Internationale do 1Eclairage). The mapping from RGB to XYZ color values is not simple and the scanner has even a positional deviation of RGB colors. In this paper an automatic color inspection method using a general scanning machine is presented. We used a U(neural network) model to map RGB to XYZ and compensate the positional error. In the real experiments, this inspection system shows to get very exact XYZ values from the traditional scanner regardless of the measuring position.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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• pp.137-140
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• 1996

Finding line segments in an intensity image has been one of the most fundamental issues in computer vision. In complex scenes, it is hard to detect the locations of point features. Line features are more robust in providing greater positional accuracy. In this paper we present a robust "line features extraction" algorithm which extracts line feature in a single pass without using any assumptions and constraints. Our algorithm consists of five steps: (1) edge scanning, (2) edge normalization, (3) line-blob extraction, (4) line-feature computation, and (5) line linking. By using edge scanning, the computational complexity due to too many edge pixels is drastically reduced. Edge normalization improves the local quantization error induced from the gradient space partitioning and minimizes perturbations on edge orientation. We also analyze the effects of edge processing, and the least squares-based method and the principal axis-based method on the computation of line orientation. We show its efficiency with some real images.al images.

• 한국측량학회지
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• 제20권2호
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• pp.137-143
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• 2002

본 연구에서는 레이저스캐닝 데이터의 일종인 LIDAR 데이터를 이용하여 수치정사사진 제작에 관한 연구를 수행하였다. 이를 위하여 LIDAR를 이용하여 얻은 XYZ 절점자료(point data)로부터 TIN(Triangular Irregular Network)을 형성한 후. 이로부터 DSM(Digital Surface Model) 을 제작하였다. 그러나 이 과정에서 수치정사사진의 품질에 악영향을 줄 수 있는 절단선(break line)에서의 노이즈가 DSM에서 발생하였다. 따라서 본 연구에서는 이러한 절단선에서의 노이즈를 처리할 수 있는 여러 가지 기법을 적용하였다. 그 결과 건물을 추출하여 저지대(低地帶)에 대한 LIDAR DEM과 합성하는 기법이 가장 적절하다는 결론을 도출하였으며, 이렇게 제작된 LIDAR DSM으로 수치정사사진을 제작하고 품질을 평가해 본 결과 도화축척 1:5,000보다 높은 위치정확도를 지닌 수치정사사진의 제작이 가능하였다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제38권
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• pp.13.1-13.12
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• 2016

Background: Mandibular motion tracking system (ManMoS) has been developed for orthognathic surgery. This article aimed to introduce the ManMoS and to examine the accuracy of this system. Methods: Skeletal and dental models are reconstructed in a virtual space from the DICOM data of three-dimensional computed tomography (3D-CT) recording and the STL data of 3D scanning, respectively. The ManMoS uniquely integrates the virtual dento-skeletal model with the real motion of the dental cast mounted on the simulator, using the reference splint. Positional change of the dental cast is tracked by using the 3D motion tracking equipment and reflects on the jaw position of the virtual model in real time, generating the mixed-reality surgical simulation. ManMoS was applied for two clinical cases having a facial asymmetry. In order to assess the accuracy of the ManMoS, the positional change of the lower dental arch was compared between the virtual and real models. Results: With the measurement data of the real lower dental cast as a reference, measurement error for the whole simulation system was less than 0.32 mm. In ManMoS, the skeletal and dental asymmetries were adequately diagnosed in three dimensions. Jaw repositioning was simulated with priority given to the skeletal correction rather than the occlusal correction. In two cases, facial asymmetry was successfully improved while a normal occlusal relationship was reconstructed. Positional change measured in the virtual model did not differ significantly from that in the real model. Conclusions: It was suggested that the accuracy of the ManMoS was good enough for a clinical use. This surgical simulation system appears to meet clinical demands well and is an important facilitator of communication between orthodontists and surgeons.

• 한국의학물리학회지:의학물리
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• 제17권4호
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• pp.192-200
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• 2006

CT와 치료계획시스템 및 다엽콜리메이터(Multi Leaf Collimator, MLC)를 이용한 방사선 치료의 전 과정을 팬텀에 대해 재현해 봄으로써, 치료계획상의 표적과 조사빔의 일치 정도를 평가해 보았다. 이를 위해, CT 및 그 레이저 정렬을 위한 팬텀을 제작하였으며, 치료실의 레이저 정렬을 손쉽게 할 수 있는 방법을 고안하였다. 조사빔의 확인에는 필름을 이용하였고, 조사빔과 실제 표적위치 사이의 정량적인 분석은 자체 제작한 프로그램을 이용하였다. 표적과 빔 중심의 불일치 정도는 테이블 각도에 따라 차이가 있었으며 시험에 이용된 치료기의 경우, 테이블 각도 에서 최대 2.0 mm의 차이를 보였다. MLC field에 대해 Winston-Lutz 테스트를 시행하여 $295^{\circ}$얻은 isocenter를 기준으로 다시 시험한 결과는 측정한 모든 테이블 각도에서 1.35 mm 이하였다. 표적과 빔 중심의 차이에 관한 이러한 평가는 실제 환자의 치료 계획 설정에 유용하게 이용될 수 있다.