• Journal of the Korean Society of Costume
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• v.58 no.4
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• pp.1-12
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• 2008

The expansion of media art has not only developed the digital technology but also given lots of environmental evolution to improve various fields of design as the main topic of the 21st century. The purpose of this study is aimed at proposing the new design that integrates fashion accessaries with media art technology. This will be done by understanding the social environment in digital ages and studying technology of design based on a variety of literature about changes in our society, neo value, vision, culture and art with fundamental notion of media art. First stage for this study, put an idea into just fashion accessary design because it is not sufficient to incoporate fashion and media art technology. The presented OLED(Organic Light Emitting Diodes) in this study is a kind of display to be in a limelight in the next generation and can be applied to various field of design. media art simultaneously moved into the scope of artistic debates. As a result, we can found that the use of audiovisual introduced numerous new aspects to the conceptual and aesthetic engagement with questions of conception. Today, the presented forms of art and inter-action from the closed -circuit work to interactive media art installations to open process-exist as parallel possibilities.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.68-71
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• 2003

To be able to show moving images without visual problems like blurring and tailing, the response time of liquid crystal display (LCDs) must be improved. In this paper we will discuss our progress in improving the response time by optimizing the cell configuration and the use of new liquid crystal mixtures. A 20.1inch diagonal UXGA IPS TFT-LCD has been developed having a response time as fast as l-frame time (16msec) for white-black operation and less than 16msec in all gray levels without applying ODC (Over Driving Circuit). This is very important because one of the technology to reduce motion blurring, the use of scanning backlight is conditioned by 16msec for all grays. The excellent gray-to-gray response can be explained by virtue of fundamental characteristics of S-IPS mode and makes a good contrast with the results of VA mode.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.5C
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• pp.530-534
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• 2002

In the thesis, For improving the Stability of VCHRO(Voltage Controlled Hair-pin Resonator Oscillator) the new structure using the parallel feedback of the second harmonic is proposed for self-phase locking effect. This module is composed of wilkinson divider, frequency doubler, directional coupler, and bandpass filter using a hair-pin resonator, which are integrated into miniaturized hybrid circuit. The module exhibits output power of 2.5 dBm at 19.5 GHz, -29.83 dBc fundamental frequency suppression and -76.52 dBc/Hz phase noise at 10 kHz offset frequency from carrier of center frequency 19.5 GHz.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.296-300
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• 1989

The paper proposes a method to eliminate harmonics of PWM inverter fed induction motor system using Walsh series. In other words, this paper presents technique of the selective harmonics elimination(SHE) by W-FT series in three phase PWM inverter output waveform. A microprocessor(8086 CPU) - controlled three phase induction motor system in order to verify this algorithm is present. It is designed for a three output voltage in the 1$\sim$60 Hz inverter with the 5th and 7th harmonics, 5th, 7th, 11th, and 13th, harmonics eliminated, and with the fundamental wave amplitude proportional to the output frequency. In the PWM inverter, dead time circuit is inserted in the switching si gnats to prevent the de link shortage. This paper is deals with quantative prediction of dead-time effect and its compensation in PWM inverters. The performance of the compensation circuits is confirmed by the experiment.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.7
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• pp.756-759
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• 2014

DC/DC converters are commonly used to generate regulated DC output voltages with high-power efficiencies from different DC input sources. The converters can be applied in the regenerative braking of DC motors to return energy back to the supply, resulting in energy savings for the systems at periodic intervals. The fundamental converter studied here consists of an IGBT (Insulated Gate Bipolar mode Transistor), an inductor, a capacitor, a diode, a PWM-IC (Pulse Width Modulation Integrated Circuit) controller with oscillator, amplifier, and comparator. The PWM-IC is a core element and delivers the switching waveform to the gate of the IGBT in a stable manner. Display of the DC/DC converter output depends on the IGBT's changes in the threshold voltage and PWM-IC's pulse width. The simulation was conducted by PSIM software, and the hardware of the DC/DC converter was also implemented. It is necessary to study the fact that the output voltage depends on the duty rate of D, and to compare the output of experimental result with the theory and the simulation.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.331-332
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• 2015

Since $20^{th}$ century, along with the rapid industrial advancement, the concentrated urban development in specific large cities have made people migrate to those cities, thus causing problems in the power system stability. In case of Korea, more than 40% of the power system demand comes from the consumers in Seoul Metropolitan area and the rate is expected to increase. With the continuous increase of power demand, in order to meet the demand for system reliability improvement, the power system was multi-looped for reliability enhancement, the problem of fault current happened. In this situation, there are several methods for fault current reduction likes current limiting reactor, replacing circuit breaker, splitting busses, etc. But these methods reached its limit, power system needs more fundamental solutions such as grid segmentation. In this paper, we assume grid segmentation already has been progressed using VSC BTB HVDC. Then, this paper discusses operating point of HVDC in metropolitan area considering loss minimization and handy flow control. The simulation is proceeded on 2027 KEPCO system.

• Journal of the Korean Society of Safety
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• v.32 no.5
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• pp.13-19
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• 2017

In this paper, study of vehicle fire cases caused by connector and power wiring of anti-lock brake system(ABS) module damage is presented. The purpose of ABS module is to improve braking and steering ability under sudden stop of the vehicle by repeatedly activating and releasing the brake with electric signal via electric control unit. The electric control unit for ABS may experience incomplete contact between power line and signal line or electrical breakdown on the printed circuit board by undergoing repetitive signal change which would consequently result in electrical heat and spark, eventually leading to automotive fire. Therefore, the purpose of this paper is to provide fundamental data by analyzing connector and power wiring of ABS module damage conducive to the precise investigation on the cause of vehicle fire.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.909-911
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• 1999

Metalization technology of the fine patterns by electroless plating is required in place of electrodeposition as high-density printed circuit boards (PCB) become indispensable with the miniaturization of electronic components. Electroless nickel plating is a suitable diffusion barrier between conductor metals, such as Al and Cu, and solder is essetional in electronic packaging in order to sustain a long period of service. Moreover, Electroless nickel has particular characteristics including non-magnetic property, amorphous structure, wear resistance, corrosion protection and thermal stability. In this study fundamental aspects of electroless nickel deposition were studied with effect of complexeing agents of different kinds. Then, the property of electroless deposit are controlled by the composition of the deposition solution, the deposition condition such as temperature and pH value and so on. the characteristics of the deposits has been carried out.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.1051-1053
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• 1999

In this work, thermal phenomena and temperature rise due to thermal source in electric switchboard were investigated using analytical measures. Electric switchboards are assemblies of panels on which are mounted switches, circuit breakers, high current busbars, meter, fuses and terminals essential to the operation of electric equipment. It is very difficult to predict the temperature rise in switchboard due to the existence of several heat sources. To overcome this situations, we focused on the eddy current distribution on the panel of switchboard caused by high current busbars as a fundamental basis. And thermal sources including busbar and switchgear have been considered. Furthermore, thermal transfer phenomena in switchboard was considered theoretically. Finally, three-dimensional thermal model for eddy current analysis has been adopted and FEM analysis was conducted. As a result, three-dimensional numerical analysis found to be applicable to the analysis of thermal phenomena in switchboard.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.6
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• pp.560-566
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• 2004

In this paper, active frequency doubler with broadband characteristics from 6 ㎓ to 12 ㎓ was designed and fabricated using PHEMT. The designed frequency multiplier has a bias point near pinch-off and a proposed series RC circuit between bias line and input matching network far the improvement of stability. With 0 ㏈m input power, second harmonic of 1.7 ㏈m at 12 ㎓ -27.5 ㏈c suppression of 6 ㎓ fundamental, -18 ㏈c suppression of 18 ㎓ 3rd harmonic, and the 3 ㏈ output bandwidth of 1,8 ㎓ have been measured.