• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1483-1485
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• 2005

In recent years, customers and power supplies are interested in power quality. Demands of customers are change from standard quality of distribution power system to various high quality of distribution power system. so, it is necessary to apply power quality compensator. in our project, we develop the UPQC(Unfied Power Quality Compensator of 45kVA which compensates power factor and voltage sag, interruption. it is very frequently occurred power quality problems. As a series and shunt compensator, UPQC consists of two inverters with common dc link capacitor bank. It compensates the current quality in the shunt part and the voltage quality in the series part. In this paper, we present simulation and test result of developed UPQC system. Test for UPQC are performed at voltage sag, flickers and non-linear load conditions. For voltage sag and ficker generation, we use RTDS(Real Time Digital Simulator) and power amplifier system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.11
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• pp.1531-1537
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• 2021

The quality of the game can be evaluated by its fun and functional stability. Among them, the quality area for fun is the essence of the game, so it is a very important factor to be considered from the point of view of a game designer. Usually, fun games with high originality and immersion are designed in the early stages of development, such as idea generation and concept setting. At this time, making it possible to verify the fun factor of the game has an important influence on the success of the game. In this study, the case of using PIT technique when teaching fun element design to students who are starting to study game design was introduced and the effect was analyzed. It is expected that the PIT technique will be used more actively in the game design education field for high-quality and fun game design.

• Journal of Environmental Science International
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• v.14 no.2
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• pp.251-258
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• 2005

Statistical analysis between operating parameters and effluent quality on advanced wastewater treatment plant was performed. Through factor analysis four factors derived varimax rotation were selected each plant. Four components explained $80\%,\;82\%$ of the total variance of the process, respectively. The components on MLE plant were identified in the following order: 1) HRT increase and BOD load decrease by influent decrease, 2) Biomass, 3) SVI increase by internal return increase, 4) Microbial diversity by SRT increase. On $A_2O$ plant, we defined them as follows: factor 1, high MLSS by return rate increase, HRT increase by influent decrease; factor 2, biomass; factor 3, BOD of influent; factor 4 was relate to DO.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.257-261
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• 2008

The Digital Radio Mondiale (DRM) system is a digital broadcasting standard designed for use in the LF, MF and HF bands of the broadcasting bands below 30 MHz. The system provides both superior audio quality and improved user services / operability compared with existing AM transmissions. In this paper, we propose a variable point Prime Factor FFT design method for Digital Radio Mondiale (DRM) system. Proposed method processes a various size IFFT/FFT of Robustness Mode on DRM standard efficiently by composing Radix-Prime Factor FFT Processing Unit of form similar to Radix-4 by insertion of a variable Prime Factor Twiddle Factor and Garbage data. So, we improved limitation that cannot process 112/176/256/288 FFT of each mode of DRM system with a existent Radix Processor and increase memory size and memory access time for IFFT/FFT processing by software processing in case of implementation with a existent high speed DSP.

• Restorative Dentistry and Endodontics
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• v.30 no.6
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• pp.450-460
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• 2005

The aim of this study was to evaluate the effect of cavity shape, bond quality of bonding agent and volume of resin composite on shrinkage stress developed at the cavity floor. This was done by measuring the shear bond strength with respect to iris materials (cavity shape , adhesive-coated dentin as a high C-factor and Teflon-coated metal as a low C-factor), bonding agents (bond quality: $Scotchbond^{TM}$ Multi-purpose and Xeno III) and iris hole diameters (volume; 1mm or 3mm in $diameter{\times}1.5mm$ in thickness). Ninety-six molars were randomly divided into 8 groups ($2{\times}2{\times}2$ experimental setup). In order to simulate a Class I cavity, shear bond strength was measured on the flat occlusal dentin surface with irises. The iris hole was filled with Z250 restorative resin composite in a bulk-filling manner. The data was analyzed using three-way ANOVA and the Tukey test. Fracture mode analysis was also done When the cavity had high C-factor, good bond quality and large volume, the bond strength decreased significantly The volume of resin composite restricted within the well-bonded cavity walls is also be suggested to be included in the concept of C-factor, as well as the cavity shape and bond quality. Since the bond quality and volume can exaggerate the effect of cavity shape on the shrinkage stress developed at the resin-dentin bond, resin composites must be filled in a method, which minimizes the volume that can increase the C-factor.

• Journal of Oriental Neuropsychiatry
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• v.21 no.1
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• pp.89-108
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• 2010

Objectives: This study was to investigate the relation of Pittsburgh Sleep Quality Index(PSQI) and Diagnos system of oriental medicine(DSOM) in the Insomnia Patients. Methods: For this study, we carried out PSQI and DSOM of 92 patients with insomnia who have come to Kijang public health center and Donguei oriental hospital of Donguei university from November 2008 to October 2009. We verified the association of PSQI and DSOM using crosstabulation analysis, independent sample T-test, one-way ANOVA and correlation analysis. Results: 1. Blood-deficiency(血虛) is the most frequent pathogenic factor and frequency of nightmare has positive correlation with that factor including heart(心) in total insomnia patients. 2. Female patients have a higher percentage of chronic insomnia than male patients. 3. As patients aged, maintaining sleep gets harder, sleep time is lessening, taking hypnotics is increasing and quality of sleep gets worse. 4. There is high frequency of chronic insomnia in 40~50 years and over 60 years old. Also, the people who are over 60 years of age tend to sleepless and urinated frequently during the middle of the night. The people with the age of 20~30 years tend to take less sleeping pills and frequency of sleeping during daytime is higher than the other age groups but the quality of sleep is quite good. 5. The patient with over 6 months of chronic insomnia tend to be older in age than the patient with less than 6 months. And the patient with chronic sleeping disorder has frequent pain and the quality of sleep is very poor. 6. The patient who took hypnotics tend to be older than hypnotics non-user and frequency of urination was relatively high. 7. The patient who visited oriental medical hospital were tend to be older and get difficult in maintaining sleep. And frequency of taking hypnotics and urinating during night were tend to be higher and the quality of sleep was poor compared with the patient who visited public health center. Conclusions: This study provides insights into the complicated relations of the associated symptom of insomnia with Diagnos system of oriental medicine. And especially this study showed apparent correlation between nightmare in insomnia patients and pathogenic factor of blood-deficiency and heart. Specific correlations and characteristics in this study could be connect develop of new questionaire of insomnia.

• The Transactions of the Korean Institute of Power Electronics
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• v.2 no.3
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• pp.26-36
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• 1997

An single stage AC/DC converter based on half bridge topology suitable for low power level applications is proposed. The proposed converter has high power factor, low harmonic distortion, and tight output regulations. Asymmetrical control and synchronous rectification are adopted to reduce the switching loss and rectification loss, respectively. The modelling employing average modelling method and detailed analysis are performed to derive the design equations. According to these design equations, a prototype converter has been designed and experimented. This prototype meets the IEC 555-2 regulations with near unity power factor and high efficiency.

• Journal of Power Electronics
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• v.8 no.1
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• pp.51-59
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• 2008

This paper addresses several issues concerning the analysis, design, modeling, simulation and development of single-phase, single-switch, power factor corrected AC-DC high frequency switching converter topologies with transformer isolation. A detailed analysis and design is presented for single-switch topologies, namely forward buck, flyback, Cuk, Sepic and Zeta buck-boost converters, with high frequency isolation for discontinuous conduction modes (DCM) of operation. With an awareness of modem design trends towards improved performance, these switching converters are designed for low power rating and low output voltage, typically 20.25W with 13.5V in DCM operation. Laboratory prototypes of the proposed single-switch converters in DCM operation are developed and test results are presented to validate the proposed design and developed model of the system.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.11a
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• pp.15-16
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• 2011

Construction automation and robotics are being taken notice as an alternative to improve productivity and quality. Reflecting on these purpose, automation system, called RCA(Robotic-crane based Construction Automation) system, is developed and have been verified through a pilot project recently in Korea. To apply the RCA system in high-rise building effectively, each management factors of element technologies in the system is derived and assessed critical factor. The purpose of this study, management factors of element techniques, consisted of RCA system, is classified through questionnaires/interviews targeting system developers and construction managers in pilot project site, and critical factors is selected using AHP.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.04a
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• pp.7-10
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• 2002

We designed the flyback planar transformer, which had 8W capacity, with 70V input voltage and 8.2V output voltage for the establishment of design method and the confirmation of application possibility. The numerical value of inductance measured under the switching frequency of 120 kHz was 1650 ${\mu}H$, which was the inductance efficiency of 85~87% against theoretical value. The A.C. resistance of primary and secondary coil was 4.2 ${\Omega}$ and 0.25 ${\Omega}$ respectively. On the other hand, the quality factor for each wound numbers showed quite a high value of 158 and 75 respectively. And the Coupling Factor was 0.96~0.97 under 120 kHz switching frequency. And the shape of the output wave of the planar transformer at 70V input voltage was a stable square wave.