• 사상체질의학회지
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• 제20권1호
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• pp.42-47
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• 2008

1. Objectives The Body Shape and Feature is one of the important standard for classification of Sasang Constitutions. In order to evaluate one's Body Shape and Feature objectively we have been developing the Body Measuring Machine. Now we develop the 3D Automatic Body Measuring Machine(3D-ABMM). So we make an analysis of the 3D-ABMM's Accuracy. 2. Methods By using the 3D-ABMM and Vivid 9i(3D laser scanner, Konica Minolta) we have a surface scan of the three objects which are the upper body of the female and male Manikin and a male model. We overlap each scan data using the RapidForm2006 (3D scan data solution, INUS Technology) and calculate the average distance and standard deviation between the same point of each scan data. 3. Results and Conclusions In the female Manikin, the average distance is 0.84mm and the standard deviation is 1.16mm and the maximum distance is 10.68mm. In the male Manikin, the average distance is 1.12mm and the standard deviation is 1.19mm and the maximum distance is 12.00mm. In the male model, the average distance is 3.26mm and the standard deviation is 2.59mm and the maximum distance is 12.75mm. From the results, 3D-ABMM has good accuracy for scanning body and will be a usable hardware of the 3D Automatic Body Analysis Machine.

• 한국콘텐츠학회논문지
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• 제8권1호
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• pp.212-227
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• 2008

3D 얼굴 모델링은 33공간에서 얼굴을 자유롭게 회전 시켜 다양한 얼굴 자세를 표현하고 조명 효과도 적절하게 모델링 할 수 있으므로, 얼굴 자세, 조명, 표정 등의 표현에 있어서 2D 얼굴 모델링에 비해 보다 정교하며 사실감이 뛰어나 얼굴 인식, 게임, 아바타 등에서 많은 요구가 존재한다. 본 논문에서는 3D 변형 가능 형상 모델에 기반을 둔 3D 얼굴 모델링 방법을 제안한다. 제안된 3D 얼굴 모델링 방법은 먼저 3D 스캐너를 통하여 획득한 3D 얼굴 스캔 데이터를 이용하여 3D 얼굴 변형 가능 형상 모델을 구축한다. 다음, 3D 얼굴 모델링을 하고자 하는 얼굴의 2D 이미지 시퀀스로부터, 해당 얼굴의 특징점들을 검출하고 이들을 매칭하여, 매칭된 특징점들로부터 인수분해 기반 SfM 기법을 이용하여 해당 특징점의 3D 버텍스 좌표 값을 구한다. 이후, 구한 3D 버텍스들을 3D 변형 가능 형상 모델에 정합하여 해당 얼굴의 3D 형상 모델을 얻는다. 또한, 2D 얼굴 이미지 시퀀스들로부터 뷰 독립적인 2D 원통 좌표 텍스쳐 맵을 구하고 이를 이용하여 3D 형상 모델을 렌더링 함으로써, 최종적으로 3B 얼굴 모델을 완성한다. 제안된 3D 얼굴 모델링 방법에 의한 3D 얼굴 모델 생성 과정을 통해서, 본 논문에서 제안한 3D 얼굴 모델링 방법이 기존의 얼굴 모델링 방법들에 비해 상대적으로 빠르고 비교적 정교하게 수행됨을 볼 수 있었다.

• The Journal of Advanced Prosthodontics
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• 제11권5호
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• pp.271-279
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• 2019

PURPOSE. The newest technologies for digital implant impression (DII) taking are developing rapidly and showing acceptable clinical results. However, scientific literature is lacking data from clinical studies about the accuracy of DII. The aim of this study was to compare digital and conventional dental implant impressions (CII) in a clinical environment. MATERIALS AND METHODS. Twenty-four fixed zirconia restorations supported by 2 implants were fabricated using conventional open-tray impression technique with splinted transfers (CII group) and scan with Trios 3 IOS (3Shape) (DII group). After multiple verification procedures, master models were scanned using laboratory scanner D800 (3Shape). 3D models from conventional and digital workflow were imported to reverse engineering software and superimposed with high resolution 3D CAD models of scan bodies. Distance between center points, angulation, rotation, vertical shift, and surface mismatch of the scan bodies were measured and compared between conventional and digital impressions. RESULTS. Statistically significant differences were found for: a) inter-implant distance, b) rotation, c) vertical shift, and d) surface mismatch differences, comparing DII and CII groups for mesial and distal implant scan bodies ($P{\leq}.05$). CONCLUSION. Recorded linear differences between digital and conventional impressions were of limited clinical significance with two implant-supported restorations.

• 복식문화연구
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• 제23권2호
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• pp.294-309
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• 2015

This study aims to clarify the aesthetic values between emotion of human and expression of technology in contemporary fashion as it analyzes formative characteristics of related cases in fashion based on principles of 3D Printing technology and the viewpoint of mechanic aesthetics. The conclusions of this study are as follows. First, 3D Printing fashion is not only expressed diverse variations by its principles of formative methods, materials and properties, but also changes of silhouette by applying system of designers. Second, general characteristics of 3D Printing fashion is represented by various applications in SLS system, and it can be specifically explained application to a portion of clothing, decorative roles of clothing, complicated pattern making through crossing fabrics using 3D scanner and displaying a certain object changing fashion styles, and so forth. Third, the formative characteristics of 3D Printing fashion from the perspective of mechanic aesthetics is as follows. It can be analyzed as the integration of metaphysical values through compared symbolization of natural feature and technical evolution, partial dynamics and interactive velocity-based, formative combinations for abstract expression using architectural components, cosmos images and substantialized structures through images of organic space interacted human shapes. As the mention above, 3D Printing technology can creative a diverse area of fashion, and express images of new technological fashion through various works with continuous development of techniques.

• 한국의류학회지
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• 제29권11호
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• pp.1507-1519
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• 2005

The purpose of this study was to compare two methods of measuring body surface area (BSA). The BSA of Korean adults was measured using both three-dimensional (3D) scanning and an alginate method. Two males (one overweight and one lean) and one overweight female participated as subjects. The results were as follows: First, the 3D scanned BSA of all three subjects was smaller than the BSA measured using the alginate method by as much as $6-14\%$. The difference in methods was greater in the overweight participants than in the lean subject. Second, the results comparing the BSA obtained using these two methods and the BSA estimated by 10 previously developed formulas, showed that the 3D scanned BSA was the smallest among the 12 BSAs. Third, in comparing the regional differences between these two methods, the regional BSA of the lean subject (male 2) did not show any significant difference, but the overweight subjects (male 1, female 1) showed a significant difference. Forth, the biggest difference in regional BSA obtained through these two methods was in the hand, for all three subjects. The 3D scanned hand surface area was smaller than the hand surface area measured by the alginate method by as much as $24-34\%$. Fifth, in the percentage of regional BSA, there was no significant difference in these two methods. The reasons for the underestimation in the 3D scanning might be because: 1) the 3D scanner can not recognize the folding and shading of body parts, such as the finger, toe, ear, armpit, crotch and breast, 2) 3D patching and smoothing processes depend on researchers. However, the 3D scanning method is applicable to the estimation of the entire BSA, if the surface area of the hands is known, and the participant is not overweight.

• Imaging Science in Dentistry
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• 제32권1호
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• pp.27-33
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• 2002

Purpose: To evaluate the influence of threshold value of computed tomography on the accuracy of rapid prototyping (RP) medical model Material and Methods : CT datas of a human dry skull were transferred from CT scanner via compact disk to a personal computer (PC). 3-dimensional image reconstruction on PC by V-works/sup TM/ 3.0 (CyberMed. Inc.) software and RP models fabrication were followed. 2-RP models were produced by threshold value of 500 and 800 selected in surface rendering process. Linear measurements between arbitrary 12 anatomical landmarks on dry skull, 3-D image model, and 2-RP models were done and compared. Thus, the accuracy of 500 RP and 800RP models was respectively evaluated. Results: There was mean difference (% difference) in absolute value of 2.27 mm (2.73%) between linear measurements of dry skull and 500 RP model. There was mean difference (% difference) in absolute value of 1.94 mm (2.52%) between linear measurements of dry skull and 800 RP model. Conclusion: Slight difference of threshold value in rendering process of 3-D modelling made a influence on the accuracy of RP medical model.

• 통합자연과학논문집
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• 제1권2호
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• pp.79-83
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• 2008

As a new standard for performance measurement, NEMA NU2-2001 was presented recently. In this study, I investigated the spatial resolution, sensitivity, scatter fraction, and noise equivalent count ratio (NECR) in order to know the information of physical characteristics and system performance of GE discovery ST using this new standard. Bismuth germinate crystals ($6{\times}6$ array, $6.3mm{\times}6.3mm{\times}30mm$) were used in discovery ST (energy window:375-650 keV, coincidence window:11.7 nsec). To measure the sensitivity, five aluminum sleeves (Data Spectrum Corp., Chapel Hill, NC., USA, thickness:1.25 mm)-NEMA sensitivity phantom- filled with F-18 solution were used. Successive measurements in 2D and 3D acquisition mode were made with a line source at the center of transaxial field of view and 10 cm off from the center until the count was over 500,000. Spatial resolution was estimated using a point source (F-18, 0.1 mCi) at different locations in the FOV. Scatter fraction and NECR was tested using a NEMA scatter phantom. Dynamic data were acquired for 7 half-lives using F-18 solution. And true to background ratio was averaged at last three frames when the random rate was as small as ignorable for the calculation of scatter fraction. We anticipate this overall evaluated results could be used for the quality assurance and optimized image acquisition for clinical research.

• 전기학회논문지
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• 제65권2호
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• pp.342-348
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• 2016

We propose an obstacle detection algorithm for unmanned ground vehicle on uneven terrain. The key ideas of the proposed algorithm are the use of two-layer laser range data to calculate the gradient of a target, which is characterized as either ground or obstacles. The proposed obstacle detection algorithm includes 4-steps: 1) Obtain the distance data for each angle from multiple lidars or a multi-layer scan lidar. 2) Calcualate the gradient for each angle of the uneven terrain. 3) Determine ground or obstacle for each angle on the basis of reference gradient. 4) Generate a new distance data for each angle for a virtual laser scanner. The proposed algorithm is verified by various experiments.

• 한국레이저가공학회지
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• 제16권3호
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• pp.27-31
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• 2013

To engrave high-density circuit-line patterns in IC substrates, we applied a projection ablation technique in which a dielectric ($ZrO_2/SiO_2$) mask, a DPSS UV laser instead of an excimer laser, a refractive beam shaping optics and a galvo scanner are used. The line/space dimension of line patterns of the dielectric mask is $10{\mu}m/10{\mu}m$. Using a ${\pi}$ -shaper and a square aperture, the Gaussian beam from the laser is shaped into a square flap-top beam; and a telecentric f-${\theta}$ lens focuses it to a $115{\mu}m{\times}105{\mu}m$ flat-top beam on the mask. The galvo scanner before the f-${\theta}$ lens moves the beam across the scan area of $40mm{\times}40mm$. An 1:1 projection lens was used. Experiments showed that the widths of the engraved patterns in a buildup film ranges from $8.1{\mu}m$ to $10.2{\mu}m$ and the depths from $8.8{\mu}m$ to $11.7{\mu}m$. Results indicates that it is required to increase the projection ratio to enhance profiles of the engraved patterns.

• 한국기계가공학회지
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• 제17권6호
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• pp.170-176
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• 2018

Recently, weapon system requires personal protection products due to the explosion of rapid-fire explosion, which is considered to be multi threat in modernization, complication and war against terrorism. However, the conventional Korean military bullet protection helmets are not suitable for wearing convenience and combatant interoperability in terms of ergonomic. In this paper, we propose a suitable 3D Scanning method for the head, and compare the measured 3D dimension with the existing 2D measurement value to identity the reliability. Reverse engineered soldier head using the quick surface method was realized with a perfect free-form surface and satisfactory tolerance range (${\pm}0.2mm$). Through the comparison of 3D and 2D measured head dimensions, the absolute error value was 0.73 mm on average and relative error was 0.35 %, confirming the high accuracy of the 3D scan modeling. Also, quick surface method using 3D scanner is suggested a fast and accurate skill for ergonomics in obtaining the head modeling needed for military's personal bullet protection helmet design.