• Korean Journal of Computational Design and Engineering
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• v.17 no.3
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• pp.156-163
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• 2012

Real-time three-dimensional shape measurement is becoming increasingly important in various fields, including medical sciences, high-technology industry, and microscale measurements. However, there are not so many 3D profile tools specially designed for specifically narrow space, for example, to scan the tooth shape of a human jaw. In this paper, a real-time 3D intraoral scanner is proposed for the measurement of tooth profile in the mouth cavity. The proposed system comprises a laser diode beam, a micro charge-coupled device, a graticule, a piezoelectric transducer, a set of optical lenses, and a polhemus device sensor. The phase-shifting technique is used along with an accurate calibration method for the measurement of the tooth profile. Experimental and theoretical inspection of the phase-to-coordinate relation is presented. In addition, a nonlinear system model is developed for collimating illumination that gives the more accurate mathematical representation of the system, thus improves the shape measurement accuracy. Experiment results are presented to verify the feasibility and performance of the developed system. The experimental results indicate that overall measurement error accuracy can be controlled within 0.4 mm with a variability of ${\pm}0.01$.

• Journal of the Korea Computer Industry Society
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• v.10 no.4
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• pp.135-142
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• 2009

In this thesis, we designed and implemented a tracking filter which can be used for FH/2-FSK communication system in band of 40~60[MHz]. After measuring a performance of a tracking filter, an insertion loss was measured from 3.7 to 4.3 dB, depending upon a hopping center frequency. The 3 dB bandwidth of a tracking filter was specified 5.1 to 5.33% depend upon a hopping and 30/3 dB shape factor indication for interrupting property of a filter shows 6.828 to 6.98 satisfying a required specification. Also the attenuation $2{\times}f_0$, the characteristic parameter for interference degree, was specified 46~52dB, not satisfying a required specification.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.737-740
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• 2009

3D VR modeling data can be used for powerful expression in construction, because it gives help to navigate a construction in 3D space easily. But the current status of VR technique visualizes only an external shape of a construction. A construction has not only its external shape data but also its constructive information. The constructive information is very important and can be expressed as the process of construction and deconstruction. Thus we research on recording and replay interface to manipulate 3D structured objects for the process of construction and deconstruction.

• The Research Journal of the Costume Culture
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• v.19 no.6
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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.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.1
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• pp.1-14
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• 2010

With the rapid growth of 3D content industry fields, 3D content-based hashing (or hash function) has been required to apply to authentication, trust and retrieval of 3D content. A content hash can be a random variable for compact representation of content. But 3D content-based hashing has been not researched yet, compared with 2D content-based hashing such as image and video. This paper develops a robust 3D content-based hashing based on key-dependent 3D surface feature. The proposed hashing uses the block surface coefficient using shape coordinate of 3D SSD and curvedness for 3D surface feature and generates a binary hash by a permutation key and a random key. Experimental results verified that the proposed hashing has the robustness against geometry and topology attacks and has the uniqueness of hash in each model and key.

• Journal of the Korea Computer Graphics Society
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• v.23 no.4
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• pp.31-40
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• 2017

As 3D cell culture has recently become possible, it has been able to observe a 3D shape of cell and volume. Generally, 3D information of a cell should be observed with a special microscope such as a confocal microscope or an electron microscope. However, a confocal microscope is more expensive than a conventional microscope and takes longer time to capture images. Therefore, there is a need for a method that can reconstruct the 3D shape of cells using a common microscope. In this paper, we propose a method of reconstructing 3D cells using the focus estimator value from multi-focal fluorescence images of cells. Initially, 3D cultured cells are captured with an optical microscope by changing the focus. Then the approximate position of the cells is assigned as ROI (Region Of Interest) using the circular Hough transform in the images. The MSBF (Modified Sliding Band Filter) is applied to the obtained ROI to extract the outlines of the cell clusters, and the focus estimator values are computed based on the extracted outlines. Using the computed focus estimator values and the numerical aperture (NA) of the microscope, we extract the outline of the cell cluster considering the depth and reconstruct the cells into 3D based on the extracted outline. The reconstruction results are examined by comparing with the combined in-focus portions of the cell images.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.2
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• pp.266-275
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• 2009

Variations of individual hip shapes are a major obstacle in pattern making for fitness. The drafting method is used for pattern making in today's apparel industry. Whilst catering to a limited number of information such as waist and hip sizes, this method does not cater to variations in hip shape. This paper describes the analysis of hip shapes using 3D body model and tries to make sure the relationship between hip shape and pattern by calculating hip angle and dart amount. We achieved results in analyzing various hip shapes by extracting hip angle. Moreover, various hip shapes can be divided into three types(A, B and C) by the hip angle value($K_{sh}-K_{wsh}$). When we use computerized draping method to make a personalized pattern for a tigth skirt, we easily create complex dart lines automatically. Therefore we achieve the result of individual dart amount such as distance between dart lines and dart areas. C type of hip shape had short dart length, long distance between dart lines and a large amount of dart area. On the other hand, A type had long dart length, short distance between dart lines and small amount of dart area. B type had long length and long distance between dart lines and large amount of dart area. In traditional pattern making, distance between dart lines is usually proportional to amount of dart area because of similarity in dart line shape. In our pattern, there is no proportional relationship between dart line distance and dart area. This means that variations in hip shapes result in a wide variety of dart line curvature resulting in a wide range of dart area. By ensuring an accurate relationship between hip shape and pattern, it is possible to make patterns which result in clothing that not only fits well, but also exhibits other desirable properties.

• Journal of the Korean Society of Costume
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• v.55 no.5 s.95
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• pp.55-64
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• 2005

The concern with three-dimensional measurement has been growing in recent years. And over the last few years, several studies have been made on three-dimensional measurement. Some of the studies using a three-dimensional measurement have focused on type of form of human body and evaluation of fitness. But there has been no study about applications of three-dimensional measurement system for shape analysis. So, the purpose of this study was to investigate about application of three-dimensional mea-surement system lot shape analysis. The instrument and tools for three-dimensional measurement was Whole Body 3D scanner(model name: Exyma-WBS2H). Analysis program used in experiment is Rapid Form 2004 PPI (INUS technology, Int, Korea). The following results were obtained; 1. The point data using three-dimensional measurement system built 3D model. 2. The three-dimensional data were used to analyze length and curvature of shape. 3. The shape using three-dimensional measurement system could be used in variety field.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.1 s.190
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• pp.93-100
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• 2007

In this study, an investigation was made on bristles for the prosthetic and periodontally involved patients based on the previous studies. The purpose of this study was to investigate the ideal location and dimensions of bristles for the patients who were installed with fixed prostheses and severely involved periodontitis. 3D scanner was used to develop 3D visual models of bristles and teeth. These models were developed to be used for designing the ideal bristles for the prosthetic and periodontally involved patients. For the ideal design of bristle, interproximal area of dental arch and bristle must get into maximum and standard teeth may have to be chosen from many gypsum molds. During the design process the factors should be considered that influence the removal of plaque by bristle.

• Journal of the Optical Society of Korea
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• v.13 no.4
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• pp.464-467
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• 2009

The grating projection method with phase-shifting technique is very useful in measuring the 3-dimensional (3D) shape with high accuracy and speed. In this work, we have developed an ultra high-speed digital laser grating projection system using a high-power laser diode and a highsensitivity CMOS camera. With our system, the optical measurement required to find out the profile of a 3D object could be carried out within 2.6 ms, which is a significant ($\sim$10 times) improvement compared with those of the previous studies.