• The Research Journal of the Costume Culture
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• v.18 no.1
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• pp.80-92
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• 2010

This research aims at developing the dress form for the aged women based on their body shapes using the three-dimensional body scan data with the body shape categorization(according to the previous research). To accomplish this goal, the sample group of representative body shape of the 50% of median was selected by using the high frequency proportion range of each type of body shape of the aged women, and the sample group of representative body shape of each type was averaged in a three-dimensional way by using the morphing method of a three-dimension reverse-engineered software. RP in the form of torso was produced based on the shape data of the final model and the data was formed into an actual object, by which an aged women's dress form model was drawn out. The differences of the girth of the bust, hip and waist between the developed dress form model and the existing dress form model were examined. The result showed that the developed dress form had a bigger size of waist girth than that of bust and hip girth, compared to the existing dress form, which shows that it reflects the aged women's tendency of abdomen obesity, so it's expected to be more proper for the human bodies of the targeted age group than the existing dress form. These research results may help design the clothing suitable for the body shape of the aged women so that their demand for the clothing of good fit will be satisfied in the future.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.2
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• pp.43-50
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• 2018

The camera is a key element in image-based three-dimensional positioning, and camera calibration, which properly determines the internal characteristics of such a camera, is a necessary process that must be preceded in order to determine the three-dimensional coordinates of the object. In this study, a new methodology was proposed to determine interior orientation parameters of a camera semi-automatically without being influenced by size and shape of checkerboard for camera calibration. The proposed method consists of exterior orientation parameters estimation using quaternion, recognition of calibration target, and interior orientation parameter determination through bundle block adjustment. After determining the interior orientation parameters using the chessboard calibration target, the three-dimensional position of the small 3D model was determined. In addition, the horizontal and vertical position errors were about ${\pm}0.006m$ and ${\pm}0.007m$, respectively, through the accuracy evaluation using the checkpoints.

• Journal of the Korea Computer Graphics Society
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• v.3 no.2
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• pp.27-34
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• 1997

3-D image modeling is in high demand for automated visual inspection and non-destructive testing. It also can be useful in biomedical research, medical therapy, surgery planning, and simulation of critical surgery (i.e. cranio-facial). Image processing and image analysis are used to enhance and classify medical volumetric data. Analyzing medical volumetric data is very difficult In this paper, we propose a new image modeling method based on tetrahedrization to improve the visualization of three-dimensional medical volumetric data. In this method, the trivariate piecewise linear interpolation is applied through the constructed tetrahedral domain. Also, visualization methods including iso-surface, color contouring, and slicing are discussed. This method can be useful to the correct and speedy analysis of medical volumetric data, because it doesn't have the ambiguity problem of Marching Cubes algorithm and achieves the data reduction. We expect to compensate the degradation of an accuracy by using an adaptive sub-division of tetrahedrization based on least squares fitting.

• Proceedings of the Korea Contents Association Conference
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• 2006.05a
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• pp.530-534
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• 2006

A great deal of handling time, expertise and huge investment are required to express oriental paintings three-dimensionally. This is because pictures are usually converted digitally and then reconstructed three-dimensionally. During this process we depend highly on expert's handiwork and specialized skills. This paper presents an idea to standardize the techniques that oriental pictures can be expressed as they are and a more effective method for their three-dimensional reconstruction.

• Korean Journal of Applied Biomechanics
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• v.15 no.2
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• pp.83-92
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• 2005

Computer-assisted motional analysis is a popular method in biomechanical studies. Validation of the specific system and its measurement are fundamental to its application in the areas. Because the accuracy and consistency of a particular system provide the researchers with critical information to assist in making judgements regarding the degree to which inferences can be drawn from measurement data. The purpose of this study was to assess the accuracy and consistency of the Kwon3D motion analysis system. Validation parameters were five lengths from eight landmarkers in combination with the DLT reconstruction error values, digitizing monitor resolutions, and numbers of control points. With the best setting, Kwon3D's estimations of 260cm, 200cm, 140cm, 100cm, and 20cm were $260.33{\pm}.688cm$, $199.98{\pm}.625cm$, $139.89{\pm}.537cm$, $99.75{\pm}.466cm$, $20.08{\pm}.114$, respectively. There was no significant DLT error value difference between two monitor resolutions, but 0.27cm significant difference in 260cm estimation. There were significant differences in 260cm and 200cm estimations between with 33-control-point DLT error and with 17-control-point DLT error, but no in 140cm, 100cm, and 20cm estimations. Test-retest results showed that Kwon3D measurements were highly consistent with reliability coefficients alpha of .9263 and above.

• The korean journal of orthodontics
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• v.49 no.6
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• pp.349-359
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• 2019

Objective: The aim of this study was to analyze three-dimensional (3D) changes in maxillary dentition in Class II malocclusion treatment using arch wire with continuous tip-back bends or compensating curve, together with intermaxillary elastics by superimposing 3D virtual models. Methods: The subjects were 20 patients (2 men and 18 women; mean age 20 years 7 months ${\pm}$ 3 years 9 months) with Class II malocclusion treated using $0.016{\times}0.022-inch$ multiloop edgewise arch wire with continuous tip-back bends or titanium molybdenum alloy ideal arch wire with compensating curve, together with intermaxillary elastics. Linear and angular measurements were performed to investigate maxillary teeth displacement by superimposing pre- and post-treatment 3D virtual models using Rapidform 2006 and analyzing the results using paired t-tests. Results: There were posterior displacement of maxillary teeth (p < 0.01) with distal crown tipping of canine, second premolar and first molar (p < 0.05), expansion of maxillary arch (p < 0.05) with buccoversion of second premolar and first molar (p < 0.01), and distal-in rotation of first molar (p < 0.01). Reduced angular difference between anterior and posterior occlusal planes (p < 0.001), with extrusion of anterior teeth (p < 0.05) and intrusion of second premolar and first molar (p < 0.001) was observed. Conclusions: Class II treatment using an arch wire with continuous tip-back bends or a compensating curve, together with intermaxillary elastics, could retract and expand maxillary dentition, and reduce occlusal curvature. These results will help clinicians in understanding the mechanism of this Class II treatment.

• Journal of Surface Science and Engineering
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• v.56 no.1
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• pp.104-114
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• 2023

Three dimensional (3D) porous structures consisting of Cu@CoO core-shell-type nano-dendrites were synthesized and tested as the anode materials in lithium secondary batteries. For this purpose, first, the 3D porous films comprising Cu@Co core-shell-type nano-dendrites with various thicknesses were fabricated through the electrochemical co-deposition of Cu and Co. Then the Co shells were selectively anodized to form Co hydroxides, which was finally dehydrated to get Cu@CoO nanodendrites. The resulting electrodes exhibited very high reversible specific capacity almost 1.4~2.4 times the theoretical capacity of commercial graphite, and excellent capacity retention (~90%@50^th cycle) as compared with those of the existing transition metal oxides. From the analysis of the cumulative irreversible capacity and morphology change during charge/discharge cycling, it proved that the excellent capacity retention was attributed to the unique structural feature of our core-shell structure where only the thin CoO shell participates in the lithium storage. In addition, our electrodes showed a superb rate performance (70.5%@10.8 C-rate), most likely due to the open porous structure of 3D films, large surface area thanks to the dendritic structure, and fast electron transport through Cu core network.

• Annals of Hepato-Biliary-Pancreatic Surgery
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• v.26 no.3
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• pp.285-288
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• 2022

Three-dimensional (3D) modeling of the liver can be especially useful for both the surgeon and patient to understand the actual location of the tumor and planning the resection plane. Virtual reality (VR) can enhance the understanding of 3D structures and create an environment where the user can focus on contents provided. In the present study, a VR platform was developed using Unreal Engine 4 software (Epic Games, Potomac, MD, USA). Patient's liver based on magnetic resonance image was imported as a 3D model that could distinguish liver parenchyma, vascular structure, and cancer. Preoperative education videos for patients were developed. They could be viewed inside the VR platform. To evaluate the usefulness of VR education program for patients undergoing liver resection for hepatocellular carcinoma, a randomized clinical trial evaluating the knowledge and anxiety of the patient was designed. The case presented in this report was the first experience of performing the VR education program and examining the knowledge and anxiety using questionnaires. When the knowledge score increased, the anxiety score also increased after the education program. Based on findings of this pilot case study, the timing and place where the questionnaire will be answered can be modified for formal initiation of the randomized controlled study to examine the usefulness of VR in patient education.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.2
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• pp.362-373
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• 2002

A stereoscopic PIV (SPIV) measurement system based on the translation configuration was developed and applied to the flow behind a forward-swept axial-fan. Measurement of three orthogonal velocity components is essential for flow analysis of three-dimensional flows such as flow around a fan or propeller. In this study, the translation configuration was adopted to calculate the out-of-plane velocity component from 2-D PIV data obtained from two CCD cameras. The error caused by the out-of-plane motion was estimated by direct comparison of the 2-D PIV and 3-D SPIV results that measured from the particle images captured simultaneously. The comparison shows that the error ratio is relatively high in the region of higher out-of-plane motion near the axial fan blade. The turbulence intensity measured by the 2-D PIV method is bigger by about 5.8% in maximum compared with that of the 3-D SPIV method. The phase-averaged velocity field results show that the wake behind an axial fan has a periodic flow structure with respect to the blade phase and the characteristic flow structure is shifted downstream in the next phase.

• Journal of Fashion Business
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• v.24 no.5
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• pp.106-124
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• 2020

The purpose of this study was to analyze the three-dimensional (3D) characteristics and reproducibility of the effective expression of North American smocking pleats in the process of making clothes using a 3D virtual clothing system (CLO) and present a method of expression according to the types of North American smocking. In this study, lattice, lozenge, and flower smocking were produced as real smocking and 3D virtual content, and actual muslin properties were measured using a Fabric Kit and reflected using an emulator. The results of this study confirmed that a dense puckered design such as North American smocking could be expressed depending upon the internal line, fold angle, and reinforcement setting for 3D smocking. To partially apply pleats to flat fabrics, it was necessary to set fold lines. The fold line setting could be expressed by designing the internal line in horizontal, vertical, and diagonal directions according to the North American smocking design, and then setting the fold angle for each internal line. By setting fold angles of 0 degrees and 360 degrees according to the folding direction of the set internal line, the fabric was clearly folded and stable pleats were created. This study will contribute to the vitalization of the 3D virtual fashion content industry by analyzing and presenting the optimal expression method of sophisticated and complex pleats generated according to the North American smocking design pattern.