• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.1
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• pp.71-77
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• 2005

In this paper we implement a headphone-based 5.1 channel 3-dimensional (3D) sound generation system using HRTF (Head Related Transfer Function). Each mono sound source in the 5.1 channel signal is localized on its virtual location by binaural filtering with corresponding HRTFs, and reverberation effect is added for spatialization. To reduce the computational burden, we reduce the number of taps in the HRTF impulse response and model the early reverberation effect with several tens of impulses extracted from the whole impulse sequences. We modified the spectrum of HRTF by weighing the difference of front-back spec01m to reduce the front-back confusion caused by non-individualized HRTF DB. In informal listening test we can confirm that the implemented 3D sound system generates live and rich 3D sound compared with simple stereo or 2 channel down mixing.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.2
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• pp.83-88
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• 2011

Rapid transition to aging society faces many problems. Also there are so many issues related people with disabilities. Disabled and elderly population growth is causing serious social problems. The purpose of this study is to solve the graying society-problem and improve old people's quality of life as well as the disabled's. The main goal of this study is the design of the master plan for ubiquitous-city by referring the 'Ubiquitous urban planning guidelines' of MLTM(Ministry of Land, Transport and Maritime Affairs). For research and development, there is divided by a spatial scope and content scope. As reference model-type, the spatial scope is to pursue maximum function by using minimum system organization and virtual city-set. The content scope consists of services for the disabled and aged, information management, construction management, compatible & connection and Executive Management. The result of this study will contribute to solve the social problems with aged and disabled and advance ubiquitous-environment by improving people's quality of life.

• Geomechanics and Engineering
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• v.21 no.5
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• pp.471-487
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• 2020

In this work, the buckling analysis of material sandwich plates based on a two-parameter elastic foundation under various boundary conditions is investigated on the basis of a new theory of refined trigonometric shear deformation. This theory includes indeterminate integral variables and contains only four unknowns in which any shear correction factor not used, with even less than the conventional theory of first shear strain (FSDT). Applying the principle of virtual displacements, the governing equations and boundary conditions are obtained. To solve the buckling problem for different boundary conditions, Galerkin's approach is utilized for symmetric EGM sandwich plates with six different boundary conditions. A detailed numerical study is carried out to examine the influence of plate aspect ratio, elastic foundation coefficients, ratio, side-to-thickness ratio and boundary conditions on the buckling response of FGM sandwich plates. A good agreement between the results obtained and the available solutions of existing shear deformation theories that have a greater number of unknowns proves to demonstrate the precision of the proposed theory.

• The Journal of Korean Academy of Prosthodontics
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• v.55 no.3
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• pp.305-310
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• 2017

Nowadays, the development of dental scanner and CAD/CAM technology can facilitate the fabrication of hybrid prosthesis. Double scanning technique, scanning a trial prosthesis and master model, made it possible to realize virtual design and simplify the laboratory work. Instead of using the metal or zirconia framework with composite, ceramic or denture tooth, the new high performance polymer Polyetherketoneketone (Pekkton, Cendres+$M{\acute{e}}taux$, Biel, Switzerland) as a framework with Polymethyl methacrylate (PMMA) veneering teeth (Visio-lign, Bredent, Senden, Germany) was used in this case. This case report showed an acceptable treatment outcome and satisfaction of patient using Pekkton and Visio-lign. However, long term clinical evaluation is needed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.9
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• pp.1802-1807
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• 2015

The cloud computing service provides physical IT resources to VM instances to users using virtual technique and the users pay cost of VM instances to service provider. The auction model based on cloud computing provides available resources of service provider to users through auction mechanism. The users bid spot instances to process their a job until its deadline time. If the bidding price of users is higher than the spot price, the user will be provided the spot instances by service provider. In this paper, we propose a new bidding strategy to minimize the total cost for job completion. Typically, the users propose bidding price as high as possible to get the spot instances and the spot price get high. we lower the spot price using proposed strategy and minimize the total cost for job completion. To evaluate the performance of our strategy, we compare the spot price and the total cost for job completion with real workload data.

• Structural Engineering and Mechanics
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• v.67 no.5
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• pp.527-544
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• 2018

In this paper, the effect of homogenization models on stress analysis is presented for functionally graded plates (FGMs). The derivation of the effective elastic proprieties of the FGMs, which are a combination of both ceramic and metallic phase materials, is of most of importance. The majority of studies in the last decade, the Voigt homogenization model explored to derive the effective elastic proprieties of FGMs at macroscopic-scale in order to study their mechanical responses. In this work, various homogenization models were used to derive the effective elastic proprieties of FGMs. The effect of these models on the stress analysis have also been presented and discussed through a comparative study. So as to show this effect, a refined plate theory is formulated and evaluated, the number of unknowns and governing equations were reduced by dividing the transverse displacement into both bending and shear parts. Based on sinusoidal variation of displacement field trough the thickness, the shear stresses on top and bottom surfaces of plate were vanished and the shear correction factor was avoided. Governing equations of equilibrium were derived from the principle of virtual displacements. Analytical solutions of the stress analysis were obtained for simply supported FGM plates. The obtained results of the displacements and stresses were compared with those predicted by other plate theories available in the literature. This study demonstrates the sensitivity of the obtained results to different homogenization models and that the results generated may vary considerably from one theory to another. Finally, this study offers benchmark results for the multi-scale analysis of functionally graded plates.

• The Journal of the Korea Contents Association
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• v.9 no.12
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• pp.1-9
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• 2009

A doll created by various materials is a miniature based on human model, and it has been one of components in a puppet show to take some responsibility for human's culture activity. However, demand and supply keeps on the decrease in the puppet show industry, since professional puppeteer has been reduced rapidly, and also it is difficult to initiate into the skill. Therefore, many studies related Robotic Marionette for automation of puppet show have been internationally accompanied, and more efficient structure design and process development are required for better movement and express of puppet with motor based controller. In this research, we suggest the effective way to enable to express the marionette's motion using motion data based on motion capture and 3D graphic program, and through applying of 3D motion data and proposal of simulation process, it will be useful to save time and expenses when the Robotic Marionette System is practically built.

• Journal of The Korean Association of Information Education
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• v.9 no.3
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• pp.387-396
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• 2005

The purpose of this research was to find differences of children's behavioral pattern between players and non players of the online game "Lineage" in on-line and off line space. As a result, social behaviors of children who play online games were less active than who don't. Based on their motive and behavior pattern in online world, four behavior patterns in online world were identified; "Single-Oriented", "Community-Oriented", "Off-Real World" and "Discriminative." Off-Real World and Discriminative players were more sociable than Single-Oriented and Community-Oriented players. And Discriminative player has more self assertive attitude than others. This study may serve as a model to understand how players will respond to the various game features and how they adopt the virtual world for their interpersonal relationships.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.38 no.7
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• pp.22-27
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• 2001

In this paper, the complex permittivity of various dielectrics such as powder(sugar and flour) and solid(teflon and acrvl) are measured by using an open ended coaxial-line probe, which is self designed and manufactured, The probe is connected to a vector network analyzer(VNA) through a coaxial cable, The end of the cable is corrected by using an OSL(open, short, and load) calibration kit, The phase difference, which is produced by inserting the probe at the end of the line. is compensated by using the numerically calculated reflection coefficient of distilled water, The complex permittivity is reconstructed by inserting the measured reflection coefficient, which is produced at the interface between the probe and measuring material, into ,an virtual conical cable conversion model. Over a wide frequency range from 30 MHz to 3 GHz, the measured complex permittivitis of various powder and solid using the our method are compared with the results, which are measured by using an transmission-line method of the Korea Research Institute of Standards and Science(KRISS).

• Journal of the Korea Society of Computer and Information
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• v.10 no.6 s.38
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• pp.1-8
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• 2005

Facial analysis is used in many applications like face recognition systems, human-computer interface through head movements or facial expressions, model based coding, or virtual reality. In all these applications a very precise extraction of facial feature points are necessary. In this paper we presents a method for automatic extraction of the facial features Points such as mouth corners, eye corners, eyebrow corners. First, face region is detected by AdaBoost-based object detection algorithm. Then a combination of three kinds of feature energy for facial features are computed; valley energy, intensity energy and edge energy. After feature area are detected by searching horizontal rectangles which has high feature energy. Finally, a corner detection algorithm is applied on the end region of each feature area. Because we integrate three feature energy and the suggested estimation method for valley energy and intensity energy are adaptive to the illumination change, the proposed feature extraction method is robust under various conditions.