• Journal of Power Electronics
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• v.10 no.6
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• pp.587-594
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• 2010

The paper reports about methodology at design of interactive e-learning modules that are suitable both for teaching and learning. They cover special topics of electrical engineering, starting from the fundamentals, through electrical machines, power electronics to the fields of controlled electromechanical energy conversion, like electrical drives, complex drive systems, application of drives, mechatronic systems, telemanipulation, and robotics. In the paper, the emphasis is devoted in detail to philosophy and realization of the modules from fields of Power Electronics and Electrical Drives. On several examples there are explained main principles and specialties at their development.

• Journal of Power Electronics
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• v.4 no.1
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• pp.46-55
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• 2004

This paper presents a high-frequency ZVS-PWM boost chopper-fed DC-DC converter with a single active auxiliary edge resonant snubber in the load-side which can be designed for power conditioners such as solar photovoltaic generation, fuel cell generation, battery and super capacitor energy storages. Its principle operation in steady-state is described in addition to a prototype setup. The experimental results of ZVS-PWM boost chopper-fed DC-DC converter proposed here, are evaluated and verified with a practical design model in terms of its switching voltage and current waveforms, the switching v-i trajectory, the temperature performance of IGBT module, the actual power conversion efficiency and the EMI of radiated and conducted emissions. And then discussed and compared with the hard switching scheme from an experimental point of view. Finally, this paper proposes a practical method to suppress parasitic oscillation due to the active auxiliary resonant switch at ZCS turn off mode transition with the aid of an additional lossless clamping diode loop, and reduced the EMI conducted emission in this paper.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.2 no.1
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• pp.37-49
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• 2008

At the present time the task of designing a highly integrated ZigBee radio frequency (RF) receiver with an excellent coexistence performance is still very demanding and challenging. This paper presents a number of system issues and design considerations for a ZigBee RF receiver, namely IEEE 802.15.4, for coexistence with wireless devices in the 2.4-GHz ISM-band. With regard to IEEE 802.15.4, the paper analyzes receiver performance requirements for; system noise figure (NF), system third-order intercept point (system-IIP3), local oscillator phase noise and selectivity. Based on some assumptions, the paper illustrates the relationship between minimum detectable signal (MDS) and various situations that involve the effects of electromagnetic interference generated by other wireless devices. We infer the necessity of much more stringent specification requirements than the published standard for various wireless communication field environments

• Particle and aerosol research
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• v.6 no.3
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• pp.131-138
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• 2010

Flexible electronics are the electronics on flexible substrates such as a plastic, fabric or paper, so that they can be folded or attached on any curved surfaces. They are currently recognized as one of the most innovating future technologies especially in the area of portable electronics. The conventional vacuum deposition and photolithographic patterning methods are well developed for inorganic microelectronics. However, flexible polymer substrates are generally chemically incompatible with resists, etchants and developers and high temperature processes used in conventional integrated circuit processing. Additionally, conventional processes are time consuming, very expensive and not environmentally friendly. Therefore, there are strong needs for new materials and a novel processing scheme to realize flexible electronics. This paper introduces current research trends for flexible electronics based on (a) nanoparticles, and (b) novel processing schemes: nanomaterial based direct patterning methods to remove any conventional vacuum deposition and photolithography processes. Among the several unique nanomaterial characteristics, dramatic melting temperature depression (Tm, 3nm particle~$150^{\circ}C$) and strong light absorption can be exploited to reduce the processing temperature and to enhance the resolution. This opens a possibility of developing a cost effective, low temperature, high resolution and environmentally friendly approach in the high performance flexible electronics fabrication area.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.413-416
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• 2002

On the TDD system, the uplink and downlink transmission share the same frequency but are seperated in time. In this paper we just consider the uplink transmission. The BWA system in this paper should be accepted the adaptive modulation. Each uplink burst shall begin with an uplink preamble. The reception of an uplink burst is the most challenging from a synchronization perspective. The burst detection, power estimation, symbol synchronization and carrier synchronization should be obtained from the preamble. It will be shown in this paper, how can get a burst detection by preambles and extract the synchronization parameter from preamble.

• Journal of IKEEE
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• v.19 no.1
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• pp.80-86
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• 2015

There are many studies and products using a test paper impregnated with chemical solution can react with ozone. The color of a test paper can indicate the concentration of ozone. The purpose of this research is to design and manufacture a system using ultraviolet light source to measure the ozone density. This new technique is based on the characteristic of decomposition from ozone into oxygen under ultraviolet light. We used two sources of ultraviolet light including UV lamp and UVLED to determine the decomposition of ozone. This system is built with the electronic components, sensors and sealed pump tube to measure the ozone density in units of $g/cm^3$,ppm,ppb. In this paper,, we present some initial results of measuring the ozone density from ozone generator after completing inspection for safety.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.279-280
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• 2006

This paper describes a method for reconstructing 3D feet in a real time vision based marker free motion capture system. The proposed method is developed based on the visual hull and model fitting. For a real time computing, a special lookup table is employed in this paper. This method is implemented and tested using three CCD cameras and preliminary results are presented in this paper.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.5
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• pp.799-805
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• 2015

In this paper, an inkjet-printed capacitive touch pad is proposed. This touch pad detects contacts of human finger by detecting changes in effective capacitance due to electrical impedance of human finger. A flexible, low-cost and disposable paper is used as a substrate. Inkjet printing technology makes the fabrication fast, simple and environmentally friendly. Measured capacitances of the touched and untouched states are in the range of 163 to 182pF and 218 to 272pF, respectively. The differences in the measured capacitance of each state are sufficiently large to recognize that a finger has made contact with touch pad.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.190-191
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• 2011

This paper proposes new topology of discharge system. Proposed system can discharge until battery reaches zero voltage. The validity of proposed discharge system is verified by simulations.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.194-194
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• 2004

This paper presents Single Phase SRM for the vacuum cleaner. The advantage of SRM is long life time, high suction power.