• 대한디지털의료영상학회논문지
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• 제17권1호
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• pp.49-56
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• 2015

Temporal bone CT scan side skull fracture. In addition to the confirmation of the ossicles, such as fractures and dislocations, temporomandibular facial fractures, deformities surgery helps to establish a science plan. Cochlear implant surgery has been performed in the state before and after identifying purposes. Test methods are being implemented by the Conventional direct axial and Direct coronal scan, the basic method of Temporal bone CT. Helical scan is a fast Volumetric data obtained compared with the Conventional scan, the patient reduced the dose, and there are some advantages, such as reduced Beam hardening streak artifacts caused by dental fillings. This study is a comparative analysis by dose reduction for patients with a dose according to the conventional scan method and then effective from 2015 by helical scan method performed in 2014 through the retrospective survey, which was then optimized for the purpose of inspection.

• 복식문화연구
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• 제19권6호
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• pp.1347-1358
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• 2011

This study purposed to analyze differences in body measurement between the 2D direct body measuring method and the 3D body scan measuring method and to perform the appearance evaluation and cross-sectional evaluation of the fit of pants to which body measurements obtained by each measuring method were applied. Body measuring was conducted in 10 women in their 20s-30s using 2D direct body measuring and 3D automatic measuring with Hamamatsu body scanner. Among the 10 women, 3 participated in experimental garment wearing. Experimental pants were made using their 2D direct body measurements and 3D automatic measurements, and wearing tests were performed through expert evaluation and cross-sectional evaluation. The results of the experiment were as follows. According to the results of comparative analysis on differences between 2D direct body measurements and 3D scan measurements, 3D automatic measurements were significantly larger in bust circumference, ankle circumference, armscye circumference, shoulder length, scye depth, and arm length. As circumferences measured with the 3D body scanner were somewhat larger than directly measured ones, it is suggested to adjust ease when using existing pattern making methods. We prepared experimental garments by the same pattern making method through applying body measurements obtained with the two measuring methods, and assessed the fit of the garment comparatively through expert evaluation and 3D scan cross-sectional evaluation. According to the results, 2D-pants using 2D direct body measurements was slightly tighter than 3D-pants using 3D measurements in waist circumference, hip circumference, and abdominal circumference. In the results of comparing appearance in terms of the fit of the experimental garment in each subject, significant difference was observed in most of the compared items. This result suggests that 3D automatic body measuring data may show different accuracy according to body shape and therefore it is necessary to examine difference between 2D direct body measurements and 3D automatic measurements according to body shape.

• 한국통신학회논문지
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• 제41권6호
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• pp.631-639
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• 2016

현재 Wi-Fi Alliance에서 발표한 Wi-Fi Peer-to-Peer Technical Specification (v1.4, 2014) 기술은 Wi-Fi Direct 접속을 위하여 개발되었으며, 최근 출시되는 대부분의 스마트폰과 TV, 모니터, 셋톱박스, 게임콘솔 등의 장치에서 상용화되고 있다. 하지만, 위 기술 표준에서 정의되는 초기 접속 절차는 5~10 초의 시간이 소모되며, 이는 해당 기술의 성능과 더불어 사용의 편의성 측면에서도 문제가 될 수 있다. 이러한 문제는 현재 표준 기술의 Scan 절차와 Find 절차로 구성된 초기 Discovery 절차의 비효율성으로 인하여 발생되며, 본 고는 이와 같은 문제를 해결하기 위하여 Wi-Fi Direct 절차를 구성하는 Scan 및 Find 절차를 재구성하여 Discovery 소요 시간을 단축시키고 접속 환경에 대한 효율을 향상시켰으며, 객관적 검증을 위하여 성능분석과 실험을 진행하였다.

• 한국생산제조학회지
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• 제21권1호
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• pp.76-84
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• 2012

This paper presents the measurement system of arrow's point of impact using laser scan camera and describes the image calibration method. The calibration process of distorted image is primarily divided into explicit and implicit method. Explicit method focuses on direct optical property using physical camera and its parameter adjustment functionality, while implicit method relies on a calibration plate which assumed relations between image pixels and target positions. To find the relations of image and target position in implicit method, we proposed the performance criteria based polynomial theorem model that overcome some limitations of conventional image calibration model such as over-fitting problem. The proposed method can be verified with 2D position of arrow that were taken by SICK Ranger-D50 laser scan camera.

• 소성∙가공
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• 제20권8호
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• pp.575-580
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• 2011

Direct laser melting(DLM) is promising as a joining method for producing parts for automobiles, aerospace, marine and medical applications. An advantageous characteristic of DLM is that it affects the parent metal very little. The mechanical properties of parts made by DLM are strongly affected by the porosity and surface roughness of the laser melted beads. This is a systematic study of the effects of the porosity and surface roughness of laser melted beads using various processing parameters, such as laser power, scan rate and overlapping ratio of the fill spacing. The specimens were fabricated with 316L and 304L austenitic stainless steel powder. Dense parts with low porosity were obtained at low laser scan speed, as it increased the aspect ratio of the parental material and the depth of penetration. The variations of surface roughness were examined at various processing parameters such as overlapping ratio and laser power.

• 대한전자공학회논문지
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• 제26권2호
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• pp.112-117
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• 1989

본 논문은 패턴의 모양에 따라서 패턴 데이타 포멥변환시 분할되는 각종 矩形패턴을 크기에 구애됨이 없이 전자선 직접묘사 시간이 일정한 矩形단위로 전자선 직접묘사하는 방법을 제안하였다. 본 실험에서는 SEM을 사용하였으며 矩形의 크기에 따라 일정시간에 요구되는 전자선 전류를 변화시키기 위하여 집속렌즈의 공급전류를 BITMAP-IV CAD 시스템으로 제어하였다. 본방법에서는 패턴 데이타 포맵변환시 밀집된 패턴에 대한 resizing과정이 불필요하며 묘사시간에 근거한 through-put은 unit scan방식에 비하여 172배가 향상되었다.

• Journal of Welding and Joining
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• 제19권2호
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• pp.228-234
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• 2001

A methodology is developed and used to evaluate the response sensitivity of the thermal systems to variations in their design parameters. Technique for computing the sensitivity of temperature distributions to changes in processing parameters needed to decide the more effective laser input parameters for laser surface hardening treatment is considered. In this study, a state equation governing the heat flow in laser surface treatment is analyzed using a three-dimensional finite element method and sensitivity data of the processing parameter obtained using a direct differentiation method is applied to the sensitivity analysis. The interesting processing parameters are taken as the laser scan velocity and laser beam radius ( $r_{ b}$), and the sensitivities of the temperature T versus v and $r_{b}$ are analyzed. These sensitivity results are obtained with another parameters fixed. To verify the numerical analysis results, hardened layer dimensions (width and depth) of the numerical analysis are compared with the experimental ones.nes.

• 한국의류학회지
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• 제30권5호
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• pp.722-732
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• 2006

The pattern making of the tight-fitting collars which often used in diving suits, dance wear, or cycle wear has not been fully established. To develop tight-fitting collar pattern directly from 3D images from the representative somatotypes, dressforms developed by Jaeun Jung were used. The 3D scan data of the four male dressforms were obtained using Exyma-1200. Triangle Simplification and the Runge-Kutta method were applied to reduce the 3D scan data points and to make the segmented triangular patches in a plane from 3D data. As results, apparent differences between the tight-fitting collar patterns obtained from the 3D scan data and the ordinary 2D collar patterns were found around the center back line. The curvatures of the center back line were higher in all types of the tight-fitting collar than in the ordinary collar pattern. Relative differences in the shape of collar lines among four representative Korean men were reported. To fit the curved shape of the back neckline, 1.8 cm should be reduced from the upper neckline in average. We suggested the direct pattern making method for the 2D tight-fitting collar patterns considering the 3D shape of various types of men's dressform.

• 한국광학회지
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• 제11권2호
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• pp.73-79
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• 2000

사출성형법으로 제조된 $fheta$렌즈를 주사렌즈로 상요하는 Laser Scanning Unit의 주주사 및 부주사 방향의 빔경을 측정했다. 주주사 빔경의 경우 $62muextrm{m}$~ $68\mu\textrm{m}$로써 설계치와 유사한 성능을 보이지만 부주사 빔경의 경우 $78\mu\textrm{m}$~$115\mu\textrm{m}$로써 꽤 큰 빔경편차( $37\mu\textrm{m}$)를 나타내었다. 사출성형렌즈에서는 냉각.고화시 수축에 의한 형상오차와 불균일 냉각에 의한 내부왜곡(복굴절)이 발생하게 되는데, 이는 결국 파면수차(빔경확대)를 발생시키게 되고 결국 레이저프린터의 화상열화로 나타나게 된다. 본 논문에서는 부주사 빔경편차의 주요인을 밝혀내기 위해 복굴절(편광비) 및 $f\theta$렌즈의 비구면 형상을 측정하였다. 그리고 측정된 비구면 형상치를 CODE-V(미국 ORA사의 광학설계 프로그램)에 입력하여 부주사 상면만곡을 계산하고, 이와 설계 초점심도를 비교.분석함으로써 복굴절이 부주사 빔경편차의 주요인임을 알 수 있었다.

• 한국정밀공학회지
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• 제23권5호
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• pp.143-148
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• 2006

It is still very difficult to generate a geometry model and finite element model, which has complex and many free surface, even though 3D CAD solutions are applied. Furthermore, in the medical field, which is a big growth area of recent years, there is no drawing. For these reasons, making a geometry model, which is used in finite element analysis, is very difficult. To resolve these problems and satisfy the requests of the need to create a 3D digital file for an object where none had existed before, new technologies are appeared recently. Among the recent technologies, there is a growing interest in the availability of fast, affordable optical range laser scanning. The development of 3D laser scan technology to obtain 3D point cloud data, made it possible to generate 3D model of complex object. To generate CAD and finite element model using point cloud data from 3D scanning, surface reconstruction applications have widely used. In the early stage, these applications have many difficulties, such as data handling, model creation time and so on. Recently developed point-based surface generation applications partly resolve these difficulties. However there are still many problems. In case of large and complex object scanning, generation of CAD and finite element model has a significant amount of working time and effort. Hence, we concerned developing a good direct finite element model generation method using point cloud's location coordinate value to save working time and obtain accurate finite element model.