• Journal of Astronomy and Space Sciences
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• v.18 no.1
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• pp.21-26
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• 2001

As part of a long-term program for polar upper atmospheric studies, temperatures and intensities of the OH(3-1) bands were derived from spectrometric observations of airglow emissions over King Sejong station($62.22^{circ}S,\;301.25^{circ}E$). These measurements were made with a Michelson interferometer to cover wavelength regions between 1000nm and 2000 nm. A spectral analysis was performed to individual nights of data to acquire information on the waves in the upper mesosphere/lower thermosphere. It is assumed that the measured fluctuations in the intensity and temperature of the OH (3-1) airglow were caused by gravity waves propagating through the emission layer. Correlation of intensity and temperature variation revealed oscillations with periods ranging from 2 to 9 hours. We also calculated Krassovsky’s parameter and compared with published values.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.1075-1076
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• 2013

• International conference on construction engineering and project management
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• 2015.10a
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• pp.674-675
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• 2015

A 3D indoor model becomes an indiscernible component of BIM (Building Information Modeling) and GIS (Geographic Information System). However, a huge amount of time and human resources are inevitable for collecting spatial measurements and creating such a 3D indoor model. Also, a varied forms of 3D indoor models exist depending on their purpose of use. Thus, in this study, three different 3D indoor models are defined as 1) omnidirectional images, 2) a 3D realistic model, and 3) 3D indoor as-built model. A series of reconstruction methods is then introduced to construct each type of 3D indoor models: they are an omnidirectional image acquisition method, a hybrid surveying method, and a terrestrial LiDAR-based method. The reconstruction methods are applied to a large and complex atrium, and their 3D modeling results are compared and analyzed.

• The Research Journal of the Costume Culture
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• v.22 no.6
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• pp.943-954
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• 2014

The purpose of this study was to analyze the breast growth variation trends and characteristics of Korean adolescent girls based on 3D body measurements. Subjects were 174 girls aged between 13 and 18. 3D body scanning data were collected and the data were measured by Geomagic Design X program. The total of 18 anthropometric measurements and 4 index items were analyzed. The main results of this study are as follows: 1) Overall, the breast growth of adolescent girls got out of children's body shapes at the age of 14 and the adult's body shapes appeared remarkably at the age of 18. Before the age of 15, the adolescent girls' breast enlarged. 2) The surface lengths of upper body, which means the breast volume, showed significant growth above B cup groups rather than under A cup groups. The demand of B cup size (32.2%) was higher than A cup size (25.9%). And 35.6% of subjects' brassiere band size was 70. 3) The thorax grew evenly in the circumference, depth and breadth. The thoracic development related to the breast volume as well as the whole upper body's development. These results reveal that it is necessary to develop adolescent girls' brassiere reflecting on adolescent girls' breast growth variation trends and characteristics by age, breast size and thoracic development.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.4
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• pp.168-174
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• 2013

Objectives: The aim of this study is to investigate the correlation between 2-dimensional (2D) cephalometric measurement and 3-dimensional (3D) cone beam computed tomography (CBCT) measurement, and to evaluate the availability of 3D analysis for asymmetry patients. Materials and Methods: A total of Twenty-seven patients were evaluated for facial asymmetry by photograph and cephalometric radiograph, and CBCT. The 14 measurements values were evaluated and those for 2D and 3D were compared. The patients were classified into two groups. Patients in group 1 were evaluated for symmetry in the middle 1/3 of the face and asymmetry in the lower 1/3 of the face, and those in group 2 for asymmetry of both the middle and lower 1/3 of the face. Results: In group 1, significant differences were observed in nine values out of 14 values. Values included three from anteroposterior cephalometric radiograph measurement values (cant and both body height) and six from lateral cephalometric radiographs (both ramus length, both lateral ramal inclination, and both gonial angles). In group 2, comparison between 2D and 3D showed significant difference in 10 factors. Values included four from anteroposterior cephalometric radiograph measurement values (both maxillary height, both body height) and six from lateral cephalometric radiographs (both ramus length, both lateral ramal inclination, and both gonial angles). Conclusion: Information from 2D analysis was inaccurate in several measurements. Therefore, in asymmetry patients, 3D analysis is useful in diagnosis of asymmetry.

• Archives of Plastic Surgery
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• v.43 no.1
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• pp.32-37
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• 2016

Background We conducted this study to analyze the values of the key cephalometric angular measurements of the mandible using 3-dimensional (3D) computed tomography scans. Methods In the 106 enrolled patients, a 3D cephalometric analysis was performed to measure the angular variables of the mandible. These values were compared between the two sides and between the two sexes. Results The frontal measurements revealed that the mandibular body curve angle was larger on the left (Lt) side (right [Rt], $141.24{\pm}7.54$; Lt, $142.68{\pm}6.94$; P=0.002) and the gonial angle was larger on the right side (Rt, $134.37{\pm}8.44$; Lt, $131.54{\pm}7.14$; P<0.001). The sagittal measurements showed that the gonial angle was larger on the right side (Rt, $134.37{\pm}8.44$; Lt, $131.54{\pm}7.14$; P>0.05). Further, the transverse measurements revealed that the mandibular body curve angle was larger on the right side (Rt, $140.28{\pm}7.05$; Lt, $137.56{\pm}6.23$; P<0.001). Conclusions These results provide an average of the mandibular angular measurements for the Korean population, establishing a standard for determining surgical patient groups and outcome evaluations in the field of mandible contour surgery.

• Imaging Science in Dentistry
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• v.32 no.1
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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.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.6 s.165
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• pp.892-901
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• 2007

This research is the initial step for establishing a convertible body sizing table applicable to the Korean and American female apparel industry. All 3D female measurement data of the two countries were obtained from Size Korea Project and SizeUSA Project. The sample subjects used in this study were 1,988 Korean and 6,306 American females. Thirty-four(34) variables were chosen as the principal measurements in making garments. The conclusion of this research was as follow: First, it was determined that American women were larger and longer than Korean women in all measurement except shoulder slope measurement. Second, according to the differences analysis of the each age group in Korean Females, all measurements except hip girth had significant differences among the age groups. In case of American females, all measurements except arm length(shoulder to wrist) had significant differences among the age groups. Third, in the comparison of differences between the age groups of the two countries' women, some dimensions varied significantly with age, while others did not show any statistical significance among the age groups. Fourth, according to the t-tests of same age groups between Korean & American female measurements, American female measurements were larger and longer than Korean in all measurements except crotch length total, shoulder slope, hip girth-bust girth and hip girth-waist girth.

• Journal of the Korean Society of Clothing and Textiles
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• v.36 no.6
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• pp.631-640
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• 2012

This research project investigates the differences of various body locations (between 3D body models) and drapes garments digitally onto 3D body models. Three different subject models will be given explication. It consisted of (1) data collection of three-dimensional scans (2) creation of 3D body representations (3) comparison of avatar shapes and measurements (4) visualization and assessment of 3D body models and their 3D virtual garments. The study tests a theory of impact by differences in avatars by pattern design. A visual inspection of avatars showed clear differences between the six avatar types (in the generating process); however, there was notably less difference between 3D garment simulations based upon the six avatars produced. This demonstrated that there was less influence on the 3D garments than was predicted after a visual inspection of the avatars.

• Journal of Ocean Engineering and Technology
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• v.35 no.3
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• pp.183-190
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• 2021

Tomographic particle image velocimetry (PIV) is a widely used method that measures a three-dimensional (3D) flow field by reconstructing camera images into voxel images. In 3D measurements, the setting and calibration of the camera's mapping function significantly impact the obtained results. In this study, a camera self-calibration technique is applied to tomographic PIV to reduce the occurrence of errors arising from such functions. The measured 3D particles are superimposed on the image to create a disparity map. Camera self-calibration is performed by reflecting the error of the disparity map to the center value of the particles. Vortex ring synthetic images are generated and the developed algorithm is applied. The optimal result is obtained by applying self-calibration once when the center error is less than 1 pixel and by applying self-calibration 2-3 times when it was more than 1 pixel; the maximum recovery ratio is 96%. Further self-correlation did not improve the results. The algorithm is evaluated by performing an actual rotational flow experiment, and the optimal result was obtained when self-calibration was applied once, as shown in the virtual image result. Therefore, the developed algorithm is expected to be utilized for the performance improvement of 3D flow measurements.