• 한국의류산업학회지
• /
• 제14권2호
• /
• pp.277-285
• /
• 2012

This research studied how to develop tight upper sportswear from 3D scan data considering fabric stretch property. Subjects were five Korean men of average figure in their 20's. Scanning was done for ten postures via vitus smart/pro(Techmath LTD). Analyzing from 3D scan data, more than 70% of the upper body surface showed surface change rate under 20%. It was shoulder and under arm side part that showed most noticeable body surface change when moving. A parametric model with convex surface was generated and flattened onto the plane, resulting 2D pattern. The error rate occurring in the process of 3D to 2D conversion was 0.2% for outline and 0.13% for area, respectively. Thirteen kinds of stretchable fabrics in the market were collected for this study. Stretch property was in the range of 16.0~58.2% for wale direction; 23.1~78.4% for course. Based on wear trial test, four fabrics were chosen for making the 1st experimental garment and finally one fabric was chosen for the 2nd one, which was developed applying 4 kinds of crosswise reduction rate on 2D pattern: 0, 5, 10, and 15%. Through wear trial test and garment pressure measurement, experimental garment applied with 10% pattern reduction rate was evaluated as most comfortable and considerable.

• Restorative Dentistry and Endodontics
• /
• 제46권1호
• /
• pp.2.1-2.8
• /
• 2021

Objectives: New premixed bioceramic root repair materials require moisture for setting. Using micro-computed tomography (micro-CT), this study evaluated the filling ability and volumetric changes of calcium silicate-based repair materials (mineral trioxide aggregate repair high-plasticity [MTA HP] and Bio-C Repair, Angelus), in comparison with a zinc oxide and eugenol-based material (intermediate restorative material [IRM]; Dentsply DeTrey). Materials and Methods: Gypsum models with cavities 3 mm deep and 1 mm in diameter were manufactured and scanned using micro-CT (SkyScan 1272. Bruker). The cavities were filled with the cements and scanned again to evaluate their filling capacity. Another scan was performed after immersing the samples in distilled water for 7 days to assess the volumetric changes of the cements. The statistical significance of differences in the data was evaluated using analysis of variance and the Tukey test with a 5% significance level. Results: Bio-C Repair had a greater filling ability than MTA HP (p < 0.05). IRM was similar to Bio-C and MTA HP (p > 0.05). MTA HP presented the largest volumetric change (p < 0.05), showing more volume loss than Bio-C and IRM, which were similar (p > 0.05). Conclusions: Bio-C Repair is a new endodontic material with excellent filling capacity and low volumetric change. The gypsum model proposed for evaluating filling ability and volumetric changes by micro-CT had appropriate and reproducible results. This model may enhance the physicochemical evaluation of premixed bioceramic materials, which need moisture for setting.

• 한국산학기술학회논문지
• /
• 제17권8호
• /
• pp.8-16
• /
• 2016

본 논문은 대형구조물의 형상관리를 위해 3D 레이저 스캐닝을 이용하여 옥트리기반 구조물 형상정보 가시화를 진행하였다. 이를 위해 3D스캔데이터를 옥트리 데이터 구조로 변환할 수 있는 프로세스를 정립하고, 메쉬기법과 래스터/백터변환 처리를 통해 점(point) 데이터가 2차원 면 형태를 거처 3D객체로 생성되는 프로세스를 진행하였다. 생성된 3D객체는 옥트리 데이터 구조로 전달할 수 있는 형식인 Binary file type로 변환하는 작업이 진행되었고, 변환된 Binary file을 옥트리 최상의 노드인 Root노드로 전달하였다. Root 노드를 시작으로 옥트리 내부에서의 세부분할 작업 후 내부노드 데이터 저장과 비어있는 영역제거를 통해 옥트리기반 구조물 형상정보모델을 구축하였다. 본 연구가 수행된 Test-bed는 성균관대학교 내에 위치한 강교량 구조물로, 구축된 옥트리기반 형상정보는 스캔데이터를 89.3% 압축하였으며 독일의 사무용빌딩, 대학캠퍼스와 미국 소재 단과대학건물 스캔데이터와의 비교를 통하여 옥트리 데이터 압축률을 확인하였다. 본 연구를 통해 대형구조물 및 복층터널의 내부형상정보관리를 위한 형상정보 가시화의 기반을 마련하였으며, 형상정보 가시화를 통해 구조물 모니터링 및 유지관리 효율을 높일 수 있을 것이라 기대한다.

• 전자공학회논문지
• /
• 제53권11호
• /
• pp.114-122
• /
• 2016

EIS (Electro interstitial scan, 전기체간스캔법)는 전극을 이용해 미세전류를 인체에 인가하고 그에 따른 전기적 반응을 분석하여 생리적인 정보를 얻는 방법으로, 비침습적이고 간단한 검사가 가능하다는 장점이 있다. 특히 당뇨병 진단을 위한 스크린용으로 적합하다는 연구들이 진행되어 왔으나 대부분 진단 원리에 대한 구체적인 논의가 이루어지지 않았다. 본 연구에서는 EIS 방법이 당뇨병 스크리닝 및 임상에 유용하게 활용될 수 있을지 분석해 보기위해 당뇨병 환자와 정상인을 대상으로 EIS 장비의 원 신호인 전압 변동 데이터를 특정경로에서 측정하였다. 전압 신호의 특징점을 추출하고 두 그룹 사이의 AUC (Area under the curve)를 계산한 결과 7개의 변수들이 60% 이상의 분류 정확도를 보였다. 또한 이 변수들을 k-NN 분류기로 학습한 결과, 왼쪽 손에서의 전압 변동 크기를 기준으로 분석했을 때 분류 정확도를 76.2%까지 높일 수 있었다. EIS 기반의 전압신호 분석법으로 비침습적인 당뇨병 스크리닝의 가능성을 보였다.

• 비파괴검사학회지
• /
• 제23권1호
• /
• pp.45-52
• /
• 2003

최근 터빈 로타 디스크 키웨이에서 많은 응력부식균열이 발견되었으며, 터빈설비의 중대한 파손을 예방하기 위해 이러한 균열은 조기에 검출 및 평가되어야 한다. 본 연구에서는 초음파탐상의 RF(radio frequency) 신호를 역전파 알고리즘에 근거한 신경회로망에 적용하여 키웨이 주변의 균열에 대한 위치, 크기 및 방향성을 평가하였다. 각 반사영역에서 수신된 여러개의 피크로 나타나는 RF 신호를 각 반사영역에 대해 하나의 최대 피크를 가지도록 처리한 후, 트랜스듀서의 위치 정보와 각 반사파의 도달시긴이 들어있는 주사 데이터를 작성하였다. 이 주사 데이터로부터 각 반사영역 사이의 시간차이와 트랜스듀서의 위치 정보를 신경회로망에 적용한 결과 키웨이에서 시작된 균열의 위치, 크기 및 방향성을 평가하는데 유용함을 알 수 있었다.

• The Journal of Advanced Prosthodontics
• /
• 제14권4호
• /
• pp.212-222
• /
• 2022

PURPOSE. To evaluate and compare the effect of impression type (conventional vs digital) and the number of implants on the time from the impressions to the generation of working casts of mandibular implant-supported fixed completearch frameworks, as well as on patient satisfaction. MATERIALS AND METHODS. 17 participants, 3 or 4 implants, received 2 types of digital impression methods (DI) and conventional (CI). In DI, two techniques were performed: scanning with the scan bodies (SC) and scanning with a device attached to the scan bodies (SD) (BR 10 2019 026265 6). In CI, the making of a solid index (SI) and open-tray impression (OT) were used. The outcomes were used to evaluate the time and the participant satisfaction with conventional and digital impressions. The time was evaluated through the timing of the time obtained in the workflow in the conventional and digital impression. The effect of the number of implants on time was also assessed. Satisfaction was assessed through a questionnaire based on seven. The Wilcoxon test used to identify the statistical difference between the groups in terms of time. The Mann-Whitney test was used to analyze the relationship between the time and the number of implants. Fisher's test was used to assess the patient satisfaction (P<.05). RESULTS. The time with DI was shorter than with CI (DI, $\tilde{x}=02:58$; CI, $\tilde{x}=31:48$) (P<.0001). The arches rehabilitated with 3 implants required shorter digital impression time (3: $\tilde{x}=05:36$; 4: $\tilde{x}=09:16$) (P<.0001). Regarding satisfaction, the DI was more comfortable and pain-free than the CI (P<.005). CONCLUSION. Digital impressions required shorter chair time and had higher patient acceptance than conventional impressions.

• 한국의류산업학회지
• /
• 제13권4호
• /
• pp.600-613
• /
• 2011

The purpose of this study is to provide Torso pattern for Korean middle-aged women using 3D human body scan data. 155 women in their 40's or 50's were measured by Martin's anthropometry. Merging the data of 914 middle aged women provided by Korean agency for technology and standards, total of 1,069 subjects' data were analyzed. For data analysis, ANOVA, factor analysis and cluster analysis were done using SPSS PC+. And representative subject of each cluster was selected and they participated in 3D scanning and Torso pattern suggested for middle-aged women Torso pattern which investing the amount of ease according to each group for diffuse front interscye 30%, armscye circumference 30%, back interscye 40% using 3D human body scan data. The results of this study are as follows. Firstly, as a result of the factor analysis, the first factor was 'obesity index of body', The second factor was 'verticality size of body', The third factor was 'verticality length of upper bodice', The fourth factor was 'drop value to represent silhouette', and the fifth factor was 'physique of upper bodice'. And, middle-aged women type were classified 3 types according to the cluster analysis. Type 1(Y-type) was the long upper Torso with wide shoulder. Type 2(H-type) was flat-body type with comparatively thin upper bodice and thin lower bodice. And type 3(A-type) was the obese type with comparatively thin upper bodice and fat lower bodice. Secondly, using CAD program, point filtering was performed and approximated surface model was made. It used that generated surface smoothing corrected for abnormally extruded points and scattered points based on the curvature information. And 3D surfaces were flatted onto the plane by the internal tools of CAD program. Difference ratios of outline length and area between 3D curves and 2D plane were 0.42% and 0.54%, respectively. Third, wearing test by the sensory evaluation showed that distinct difference almost every category. The movement functionality test shows that, in all the tests which reveal significant differences, especially, 'comparison pattern A' experienced inconvenience to neck width and neck depth.

• 핵의학기술
• /
• 제26권1호
• /
• pp.33-37
• /
• 2022

¹⁸F-FBB 판독은 회백질과 백질의 신호강도를 육안으로 비교하여 이루어진다. 정량화된 영상분석을 판독과 비교하여 영상분석의 유용성을 평가하고자 한다. 환자는 판독결과를 기준으로 음성과 양성을 100명씩 나누었고 FBB 300 MBq 주입하고 90분 뒤 20분간 촬영했다. 장비는 Discovery 600 (GE Healthcare, MI, USA)을 사용하였다. 제조사에서 제공하는 아밀로이드 판독 기준을 근거하여 4개의 관심영역을 설정하였다. 영상분석은 각 SUVmean을 소뇌로 나누어 SUVr를 산출하고 전체 영역에서의 평균 SUVr로 진행하였다. 통계분석은 ROC Curve를 통한 Cutoff 도출과 독립표본 t-test의 그룹간 차이, 그리고 Kappa test를 통한 판독결과와 일치도를 분석하였다. 전체 영역에서의 평균 SUVr의 Cutoff는 1.23으로 나왔다. Cutoff를 사용한 판독결과와 일치도는 음성에서 95/100 (95 %), 양성에서 92/100 (92 %)로 나왔다. t-test 결과 그룹 간에 통계적으로 유의한 차이가 있었고(P < 0.05) Kappa 통계 결과 0.867로 높은 일치도를 나타냈다(P < 0.05). 영상분석의 결과가 통계적으로 유의하며 판독결과에도 높은 일치도를 보여 주었다. 추가적으로 FBB 영상분석은 아밀로이드가 축적된 부위를 3D 매핑하여 볼 수 있고 위치추정이 가능하며 정량분석 결과를 세분화하여 볼 수 있다. 정량화된 FBB 영상분석을 보조지표로 활용한다면 판독에 도움이 될 것으로 사료된다.

• 대한기계학회논문집A
• /
• 제26권8호
• /
• pp.1709-1718
• /
• 2002

It is well recognized that improving capacity of positive grid in battery is one of key factors for controlling the expected long lift-time of Battery Energy Storage System(B.E.S.S). Thus it is really important to characterized material properties of positive grid which are mainly affected by fabrication process. In this study, two kinds of positive grids, which were fabricated by gravity casting and die-casting technique were used. Micro-structural observation and tensile test were conducted to investigate the effect of fabrication process of positive grid. Ultrasonic measurement based on pulse-echo method and ultrasonic C-scan technique also performed to correlate ultrasonic velocity with porosity ratio in positive grid. It was found that the porosity ratio of grid fabricated by gravity casting technique increased significantly compared to the grid fabricated by die-casting technique. It was also shown that ulrasonic technique is effective to evaluate the porosity ratio in positive grid.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2000년도 추계학술대회논문집A
• /
• pp.231-237
• /
• 2000

A15052/AFRP laminates were developed principally to obtain a material with good fatigue strength, in which possible cracks would grow very slowly. Weight savings of more than 30% should be attainable in practice. Also, the crack bridging fibers could still was carry a significant part of the load over the crack, thus the COD and stress intensity factor was reduced at the crack tip. A15052/ AFRP laminates consists of three thin sheets of 5052-H34 aluminum alloy and two layers of [0] unidirectional aramid fiber prepreg. The cyclic-bending moment test was investigated based on applying the five kinds of bending moments. The size of the delamination zone produced between 5052-H34 aluminum alloy sheets and fiber-adhesive layers was measured from ultrasonic C-scan pictures taken around the fatigue crack. In addition, the relationship between the cyclic-bending moment and the delamination zone size was studied and the effect of fiber bridging mechanism was also considered.