• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.829-830
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• 2010

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.37.3-37
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• 2002

$\textbullet$ Mobile robots $\textbullet$ Sensor-based motion planning $\textbullet$ Potential field $\textbullet$ Local minimum-free motion $\textbullet$ Virtual target point $\textbullet$ Set of linked line segments $\textbullet$ We build a sensor-based motion planning using virtual target point for free of local minimum

• Journal of Korea Multimedia Society
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• v.24 no.11
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• pp.1518-1525
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• 2021

Due to the growth of VR industry and rise of digital twin industry, the importance of implementing 3D data same as real space is increasing. However, the fact that it requires expertise personnel and huge amount of time is a problem. In this paper, we propose a system that generates point cloud data with same shape and color as a real space, just by scanning the space. The proposed system integrates 3D geometric information from lidar and color information from stereo camera into one point cloud. Since the number of 3D points generated by lidar is not enough to express a real space with good quality, some of the pixels of 2D image generated by camera are mapped to the correct 3D coordinate to increase the number of points. Additionally, to minimize the capacity, overlapping points are filtered out so that only one point exists in the same 3D coordinates. Finally, 6DoF pose information generated from lidar point cloud is replaced with the one generated from camera image to position the points to a more accurate place. Experimental results show that the proposed system easily and quickly generates point clouds very similar to the scanned space.

• Journal of the Korean Society of Costume
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• v.65 no.2
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• pp.157-175
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• 2015

The study was aimed to develop a torso-type dress form representing body features of the female fashion models in Korea. To fulfill this purpose, 5 female fashion models aged between 20 and 26 having the average body measurements of professional fashion models in Korea were selected and their 3-D whole body scanned data were analysed. The 3-D whole body scanning method enabled to generate a virtual female fashion model within the CAD system by measuring the subjects' body shapes and sizes. In addition, the virtual model's body data led the development of a standard female fashion model dress form for the efficient fashion show preparation. In order to manufacture the real dress form for female fashion models, 3-D printing technology was adopted. The consequent results are as follows: (1) the body measurements (unit: cm) of the developed dress form were: biacromion length, 36.0, bust point to bust point, 16.6, front/back interscye lengths, 32.0/33.0, neck point to breast point, 26.0, neck point to breast point to waist line, 41.5, waist front/back lengths, 34.5/38.5, waist to hip length, 24.0, bust circumference, 85.0, underbust circumference, 75.0, waist circumference, 65.0, hip circumference, 92.0. (2) the body measurements differences between the developed and existing dress forms were highlighted with the body measurements of neck point to breast point and waist to hip length. (3) the body shape features of the developed dress form showed that bust, shoulder blade, shoulder slope, abdomen and back waist line to hip line parts were more realistically manufactured.

• Journal of the Korean Geotechnical Society
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• v.29 no.7
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• pp.57-74
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• 2013

In this study, the virtual fixed point analysis and 3D full-modeling analysis for pile bent structures are conducted by considering various influencing factors and the applicability of the virtual fixed point theory is discussed. Also, a discrete analysis calculating separately both the superstructure and substructure of pile bent structures is performed on the basis of an equivalent base spring model by taking into account the major influencing parameters such as soil conditions, combined loading and pile diameter. The results show that the settlement and lateral deflection of the virtual fixed point theory are smaller than those of 3D full-modeling analysis. On the other hand, the virtual fixed point analysis overestimates the axial force and bending moment compared with 3D full-modeling analysis. It is shown that the virtual fixed point analysis cannot adequately predict the real behavior of pile bent structures. It is also found that discrete analysis gives similar results of lateral deflection and bending moment to those of unified analysis. Based on this study, it is found that discrete analysis considering column-pile interaction conditions is capable of predicting reasonably well the behavior of pile bent structures. It can be effectively used to perform a more economical design of pile bent structures.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.903-912
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• 2007

One of the crucial factors which determine the quality and the accuracy of SEA model is how subsystems are defined. Experimental SEA technique had been a unique way to divide entire systems accurately for mid-frequency range, until FEA based virtual FRF response technique, virtual SEA method presented. Virtaul SEA has been developed for predictive SEA tool in early design process. In this study, Modal analysis results from modified crash FE model is used for Statistical transfer matrix. Observation nodes on the cockpit are grouped by attractive substructuring method based on point to point transfer and correlation matrix. Complex cockpit structure is divided into subsystems by automatic substructuring. Comparison with experimental SEA results validates the application of Virtual SEA to cockpit.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.369-373
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• 2001

Multilevel inverter has attracted great interest in high-voltage high-power field because of its less distorted output. In this paper, a direct torque control (DTC) technique based on a three-level neutral-point-clamped (NPC) inverter is presented. In order to solve the intrinsic neutral-point voltage-balancing problem and to obtain a high performance DTC, a special vector selection method is introduced and the concept of virtual vector is developed. By using the proposed PWM strategy, a MRAS speed sensor-less DTC drive can be achieved without sensing the neutral-point voltage, The strategy can be verified by simulation and experimental results.

• The Journal of Korea Robotics Society
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• v.2 no.3
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• pp.212-220
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• 2007

This paper proposes a method of avoiding obstacles and tracking a moving object continuously and simultaneously by using new concepts of virtual tow point and fuzzy danger factor for differential wheeled mobile robots. Since differential wheeled mobile robot has smaller degree of freedom to control and are non-holonomic systems, there exist multiple solutions (trajectories) to control and reach a target position. The paper proposes 'fuzzy danger factor' for obstacles avoidance, 'virtual tow point' to solve non-holonomic object tracking control problem for unique solution and three kinds of fuzzy logic controller. The fuzzy logic controller is policy decision controller with fuzzy danger factor to decide which controller's result is more valuable when the mobile robot is tracking a moving object with obstacles to be avoided.

• Journal of Information Processing Systems
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• v.8 no.3
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• pp.421-436
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• 2012

Different types of fingerprint detection algorithms that are based on extraction of minutiae points are prevalent in recent literature. In this paper, we propose a new algorithm to locate the virtual core point/centroid of an image. The Euclidean distance between the virtual core point and the minutiae points is taken as a random variable. The mean, variance, skewness, and kurtosis of the random variable are taken as the statistical parameters of the image to observe the similarities or dissimilarities among fingerprints from the same or different persons. Finally, we verified our observations with a moment parameter-based analysis of some previous works.

• The Korean Journal of Community Living Science
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• v.24 no.3
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• pp.399-409
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• 2013

The purpose of this study is to compare how the number of panels, the amount of flare and the flare starting point affect the silhouette of the gored skirt. This study consisted of (1) creation of 3D body representations (2) comparison of silhouette between 3D virtual gored skirt and actual gored skirt by pilot experiment (3) pattern drafting of twenty-seven different gored skirts for 3D body representations (4) a computer simulation of twenty-seven different gored skirts for visualization and assessment (5) visual inspection of twenty-seven different 3D virtual gored skirts (6) comparison of ham shapes and measurements for the node and size analysis. A visual inspection of twenty-seven different 3D virtual gored skirts showed clear differences by the amount of flare and the flare starting point ; however, there was notably less difference in the width of ham among six-piece, eight-piece and ten-piece panels. This demonstrated that there was less influence on the number of panels than the amount of flare width of ham and extent of ham for the 3D virtual gored skirt.