• Imaging Science in Dentistry
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• v.44 no.3
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• pp.199-205
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• 2014

Purpose: This study aimed to investigate the effect of changing the kilovoltage peak (kVp) on the radiographic assessment of dental caries. Materials and Methods: Seventy-five extracted posterior teeth with proximal caries or apparently sound proximal surfaces were radiographed with conventional E-speed films and a photostimulable phosphor system using 60 kVp and 70 kVp for the caries assessment. The images were evaluated by three oral radiologists and compared with the results of the stereomicroscope analysis. Results: No statistically significant difference was found between 60 kVp and 70 kVp for the caries detection, determination of caries extension into dentin, and caries severity in either the conventional or the digital images. Good to very good inter-observer and intra-observer agreements were found for both kilovoltage values on the conventional and digital images. Conclusion: Changing the kilovoltage between 60 kVp and 70 kVp had no obvious effect on the detection of proximal caries or determination of its extension or severity.

• Journal of Power Electronics
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• v.18 no.5
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• pp.1523-1535
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• 2018

High-performance Phase-Locked Loops (PLLs) are critical for grid synchronization in grid-tied power electronic applications. In this paper, a new single-phase All Digital Phase-Locked Loop (ADPLL) is proposed. It features fast transient response and good robustness under distorted grid conditions. It is designed for Field Programmable Gate Array (FPGA) implementation. As a result, a high sampling frequency of 1MHz can be obtained. In addition, a new OSG is adopted to track the power frequency, improve the harmonic rejection and remove the dc offset. Unlike previous methods, it avoids extra feedback loop, which results in an enlarged system bandwidth, enhanced stability and improved dynamic performance. In this case, a new parameter optimization method with consideration of loop delay is employed to achieve a fast dynamic response and guarantee accuracy. The Phase Detector (PD) and Voltage Controlled Oscillator (VCO) are realized by a Coordinate Rotation Digital Computer (CORDIC) algorithm and a Direct Digital Synthesis (DDS) block, respectively. The whole PLL system is finally produced on a FPGA. A theoretical analysis and experiments under various distorted grid conditions, including voltage sag, phase jump, frequency step, harmonics distortion, dc offset and combined disturbances, are also presented to verify the fast dynamic response and good robustness of the ADPLL.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.10a
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• pp.602-605
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• 2000

This paper describes the development and utilization of digital telesounder system. The digital telesounder system consists of two parts. The one is sea station part, which consist of power, single board computer, A/D converter, and RF modem. The two is land station part, which consist of RF modem, color display, memory system and printer. We obtained good results at the two times of sea experiments. The digital telesounder system is sufficiently good and clear to color display the information of fish school in setnet.

• Journal of the Korean Society of Costume
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• v.58 no.6
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• pp.42-53
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• 2008

This study is about the development of Fashion Design using of Korean Motive applied Digital Medium. With rapid change during the 21st century, digital media has emerged as the most important communication tool to facilitate speedy and interactive conversation. The recent emergence of 'Mass Customization' is a good reflection of digital transition's interactive features, realizing product variation and customization through flexibility and immediate responsiveness. In this so-called digital era, fashion is a tool that facilitates the use of digital media, while acting as the object, or the purpose, where digital media can be applied. This study looked at the development situations and future utilization method regarding digital fashion, which was recreated through digital media. In this study, a new design process was developed through digital media and actually manufactured Korean image clothing to reflect the motif of plant found in Korean folk paintings. Three-Dimensional(3D) digital shape was dressed in virtual clothing for comparison, thereby adding some features of textile design to three-Dimensional(3D) shape. Through the process, the study can provide various potential accesses to future development of fashion design utilizing digital media.

• Proceedings of the Acoustical Society of Korea Conference
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• 1984.12a
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• pp.63-65
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• 1984

In this paper, the implementation of the real time LPC synthesizer using NEC 77p20, the DSP (Digital Signal Processor) chip which facilitates and simplifies the digital hardware, is considered. This method shows the good quality with the low bit rate below 9.6kbps and has the advantage of the flexibility and the simplicity.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.259-259
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• 2004

To date, induction motors have mainly been used for heating, ventilation, and air conditioning (HVAC) applications, however, there is significant research being done world-wide on the use of switched reluctance motor(SRM) in household home appliances. This papers proposes three phase SRM for the air-conditioner blower that has cost merit and good performance respectively compared with conventional induction motor.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.324-327
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• 2010

This article has briefed some important roles Scene Design plays in cartoon games (CG). Then it analyzes some fundamental principles of Scene Design in CG. It also discusses how to produce a suitable scene by centering on the theme and images in CG, and how to create appropriate ambience by making good use of Scene Design. Finally it introduces some frequently-used software for digital scene design.

• International Commerce and Information Review
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• v.8 no.2
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• pp.79-98
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• 2006

With shifting the paradigm to digital economy, the digital industry becomes one of the national strategic industries. The digital industry has not only significant effects on forward and backward related industries but is also creating its own value. Furthermore, the effects of conversion with diverse products also play an important role in adding value. Since the early 2000s, Korea's culture so called 'Hallyu' (Korean wave) has been spreading to neighboring Asian countries such as China, Japan, Hong Kong, Therefore we have a good opportunity to increase our competitiveness with the development of the digital content industry using various base resources in conjunction with the spread of Hallyu culture in the Southeast Asian region. In this paper we attempt to suggest several schemes to promote our exports of digital contents while analyzing the current status of the Korean digital industry and addressing some problems and barriers to the export of the digital content industry. There are several schemes to be proposed in order to promote Korean exports of digital contents, as follows: 1) to foster global digital contents, 2) to establish a supporting system, 3) to build a marketing and R&D center, 4) to operate a test-bed of digital contents and 5) to fund expenses such as marketing.

• Journal of the Korean Graphic Arts Communication Society
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• v.22 no.2
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• pp.163-178
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• 2004

In this study, the CIE RGB color space which was one of the most popular device-dependent application program in digital image processing was adopted to make the profile with the device information. The profile was applied to the digital image of a JPEG file format. The result was compared with the color reproduction of another digital image of a JPEG file format, which was made in the e-sRGB color space that had the color spaces allocated to each reproduced color of an image and device-independent colors. In this way it was investigated which color space was more appropriate for digital image processing for web printing and if the e-sRGB color space was good as a color management tool that didn't depend on a device in processing a digital image for web printing.

• Journal of ILASS-Korea
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• v.15 no.2
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• pp.53-60
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• 2010

This study presents development of digital particle holographic system and its application to spray field to measure three-dimensional velocities and sizes of spray droplets. A double exposure hologram recording system with synchronization system for time control was established and digital holograms can be recorded in a short time interval. To process recorded holograms, the correlation coefficient method was used for focal plane determination of particles. To remove noises and improve the quality of holograms and reconstructed images, the Wiener filter was adopted. The two-threshold and image segmentation methods were used in binary image transformation. For particle pairing, the match probability method was adopted. The developed system was applied to spray field and three-dimensional velocities and sizes of spray droplets were measured. The measurement results of digital holographic system were compared with those made by laser instruments, PDPA(Phase Doppler Particle Analyzer), which proved the feasibility of in-line digital particle holographic system as a good measurement tool for spray droplets.