• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.281-284
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• 2009

In this paper, we propose a method that applies Adaptive Frequency Sampling(AFS) technique to the equivalent circuit model for RF passive components. Thes days wireless communication system is getting smaller and smaller. So EMI/EMC is an issue in RF. We can solve PI(Power Integrity)/SI(Signal Integrity) that one of EMI/EMC problem apply IFFT for 3D EM simulation multiple with input signal. That is time comuming task. Therefore equivalent circuit model using RF passive component is important. AFS schemes are implemented to obtain the rational functions. S parameters of the equivalent circuit moldel is compared to those of EM simulation in case of the microstrip line structure.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.1
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• pp.17-23
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• 2016

This paper presents the implementation of altitude and attitude measurement algorithm using stereo camera for an unmanned aerial vehicle (UAV). Depth images are generated by calibrating the stereo cameras, and converted into 3D point cloud data. By applying a plane fitting algorithm to the resultant point cloud, altitude from ground level, and roll and pitch angles are extracted. To verify the performance, experimental results are provided by comparing with those of the motion caption system.

• Structural Engineering and Mechanics
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• v.22 no.1
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• pp.53-70
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• 2006

The paper summarizes the dynamic-based assessment of a reinforced concrete arch bridge, dating back to the 50's. The outlined approach is based on ambient vibration testing, output-only modal identification and updating of the uncertain structural parameters of a finite element model. The Peak Picking and the Enhanced Frequency Domain Decomposition techniques were used to extract the modal parameters from ambient vibration data and a very good agreement in both identified frequencies and mode shapes has been found between the two techniques. In the theoretical study, vibration modes were determined using a 3D Finite Element model of the bridge and the information obtained from the field tests combined with a classic system identification technique provided a linear elastic updated model, accurately fitting the modal parameters of the bridge in its present condition. Hence, the use of output-only modal identification techniques and updating procedures provided a model that could be used to evaluate the overall safety of the tested bridge under the service loads.

• Journal of the Korea Fashion and Costume Design Association
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• v.24 no.2
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• pp.131-146
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• 2022

The purpose of this study is to implement the textile design applying the floral pattern shown in Korean traditional fabrics and the New-Hanbok Chulic Dress in 3D through a virtual fitting system. As a research method, first, we analyzed the floral pattern types of fabrics in the literature related to traditional Korean textiles. Second, we developed textile designs of traditional flower motifs using 13 extracted flower types. Third, we applied the floral textile designs to the 3D original form of new-Hanbok Dress produced based on design preference survey results. The findings derived through this study are as follows. First, among Korean traditional patterns, the type of flowers used in textiles were blossom of chrysanthemum, orchid, camellia, apricot, peony, peach, pomegranate, hydrangea, narcissus, lotus, plum, chinese rose, and rosa rugosa. Second, this study found that the value of traditional culture can be further increased by using traditional flower patterns as an infinite source of creative design. Third, it was confirmed that the new-Hanbok can be developed endlessly as a clothing design that combines various morphological modifications and patterns without departing from traditional designs. In the future, if the research on costume design using various items of traditional clothing and the development of textile designs based on traditional culture continues, the development of new clothes design that leads to the development of Korean traditional clothing culture and meets the sensibilities of modern people will be endless.

• Journal of Korean Society of Forest Science
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• v.96 no.1
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• pp.29-33
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• 2007

The objective of this research was to provide basic information of Thuja orientalis stand for prediction system, which consists of the best model of diameter and basal area. Data was from cores of 45 sample trees of Thuja orientalis stand that was designated as a natural monument (No. 62) in Yeongcheon, Chungbuk. Of the projection functions tested, polymorphic equation using the overlapping data showed higher precision of the fitting than anamorphic equation using. In diameter growth, Schumacher polymorphic equation of $D_2={\exp}({\ln}(D_1)(T_1/T_2)^{0.4495}+3.8535(1-(T_1/T_2)^{0.4495}))$, and in basal area growth, Schumacher polymorphic equation of $BA_2={\exp}({\ln}(BA_1)(T_1/T_2)^{0.1235}+11.3793(1-(T_1/T_2)^{0.1235}))$ showed the highest precision of the fitting among them. The equation, therefore, could be available as basic information for estimation of growth and management of Thuja orientalis stand.

• Journal of Power System Engineering
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• v.17 no.1
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• pp.42-49
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• 2013

The global movie industry is continuing rapid growth through application of the latest technology. 3D movies are being produced and shown for a more effective viewing experience. Special chairs for audiences are being experimentally manufactured and installed for the greatest viewing effect. This special chair has a structure that applies vibrating stimuli to specific parts of the body by attaching vibration transducers to theater chairs and synchronizing it with each scene of the movie. In a previous study, it has been confirmed that we can analyze the vibration transfer characteristics of sponge seats through the application of an experimental modal analysis method and obtain design variables easily. In this paper, we examine the major design parameters needed in the development of a foaming sponge seat in which auxiliary springs are inserted to improve the vibration transfer effect of a chair seat. Through analyzing several prototypes by applying experimentation as well as the experimental modal analysis method, it was confirmed that the effect of vibration transfer can be improved through the use of an auxiliary member.

• Nuclear Engineering and Technology
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• v.54 no.5
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• pp.1813-1824
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• 2022

This paper shows the verification work of SARAX code system in the reactor core transient calculation based on the simplified EBR-II Benchmark. The SARAX code system is an analysis package developed by Xi'an Jiaotong University and aims at the advanced reactor R&D. In this work, a neutron-photon coupled power calculation model and a spatial-dependent reactivity feedback model were introduced. To verify the models used in SARAX, the EBR-II SHRT-45R test was simplified to an ULOF transient with an input flowrate change curve by fitting from reference. With the neutron-photon coupled power calculation model, SARAX gave close results in both power fraction and peak power prediction to the reference results. The location of the hottest assembly from SARAX and reference are the same and the relative power deviation of the hottest assembly is 2.6%. As for transient analysis, compared with experimental results and other calculated results, SARAX presents coincident results both in trend and absolute value. The minimum value of core net reactivity during the transient agreed well with the reported results, which ranged from -0.3$ to -0.35$. The results verify the models in SARAX, which are correct and able to simulate the in-core transient with reliable accuracy.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.6
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• pp.354-362
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• 2006

This paper suggests a method for generating high qualify stereo video avatar to support visual communication in a CAVE$^{TM}$-like system. In such a system because of frequent change of light projected onto screens around user, it is not easy to extract user silhouette robustly, which is an essential step to generate a video avatar. In this study, we use an infrared reflective image acquired by a grayscale camera with a longpass filter so that the change of visible light on a screen is blocked to extract robust user silhouette. In addition, using two color cameras positioned at a distance of a binocular disparity of human eyes, we acquire two stereo images of the user for fast generation and stereoscopic display of a high quality video avatar without 3D reconstruction. We also suggest a fitting algorithm of a silhouette mask on an infrared reflective image into an acquired color image to remove background. Generated stereo images of a video avatar are texture mapped into a plane in virtual world and can be displayed in stereoscopic using frame sequential stereo method. Suggested method have advantages that it generates high quality video avatar taster than 3D approach and it gives stereoscopic feeling to a user 2D based approach can not provide.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.5
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• pp.1055-1061
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• 2011

In this study, main parameters: aperture, first bend and second bend which express a structure of ear canal are extracted in order to modeling and manufacture the ready-made ear shells of hearing aids. The proposed parameter extraction method consists of 2 important algorithms, aperture detection and feature detection. In the aperture detection algorithm, aperture of 3-D scanned virtual ear impression and parameters relating to ear shell of hearing aid are determined. The feature detection algorithm detects first bend, second bend, and related parameters. Through these two algorithms, parameters for aperture, first bend, and second bend are extracted to model the ready-made ear shell of hearing aid. The values of these extracted parameters from 36 people's right ear impression are analyzed and measured statistically. As a result of the analysis, it has been found that it is possible to classify ready-made ear shell parameters by age and size. The ready-made ear shell parameters are classified 3-size for 20 years old and 2-size for 60 years olde. Using 3D rhino program, virtual ready-made ear shell is reconstructed by parameters of every type, and simulated to model it. A final product was produced by transferring simulation result with rapid prototyping system. The modeled ready-made ear shell is evaluated with the objective and subjective method. Objective method is the comparison volume ratio and overlapped volume ratio of ear impression from randomly chosen 18 people and ready-made ear shell. And subjective method is that the final product of ready-made ear shell is used by users and the satisfaction number drawn from well fitting and comfortable testing was evaluated. In the result of the evaluation, it has been found that volume ration is 70%, big and middle size ready-made ear shell products are possible, and the satisfaction number is high.

• Journal of Institute of Convergence Technology
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• v.7 no.2
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• pp.13-16
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• 2017

The design of sealing mechanisms of a manual pressure valve was analyzed with FE analysis for a hydrogen fuels charge and discharge system of FCEV. The damage prediction of the O-ring with respect to the material models of rubbers was calculated by the gap analysis of the backup ring and O-ring according to the internal pressure. Two kinds of the rubber material characteristic models were adopted to the O-ring. One was the linear elastic and the other was hyperelastic of Ogden $3^{rd}$ order model. The experimental data of urethane of Shore hardness 90 was utilized to the curve fitting of hyperelastic properties. It was found that the contact pattern of the backup ring was different in two models and the sealing mechanism was better in the case of the hyperelastic characteristic model.