• Journal of Electrical Engineering and Technology
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• v.12 no.4
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• pp.1519-1528
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• 2017

The paper proposes a well structured, component count waned single phase multilevel inverter (MLI) topology, which drives three different modules viz. Stipulation Based Sources Insertion (SBSI) module, Level Count Increasing (LCI) module and Inter-Linking H-Bridge (ILHB) module. The SBSI module confronts the number of basic sources needed in series/parallel to achieve required magnitude for any particular level. The LCI possesses an offsetting dc source and opuses to increase the number of levels and the ILHB module links the SBSI and LCI modules. A developed Hybrid Pulse Width Modulation (HPWM) strategy has PWM pulses for the switches of LCI module while the switches of the remaining two modules function at fundamental switching frequency. A fifteen level version of the proposed stipulation based sources insertion MLI (SBSIMLI) topology is simulated in MATLAB R2010a and a prototype of the similar specifications is constructed to validate the performance by experimental results. The comparison between the developed SBSIMLI topology and the competent topologies shows many interesting facts.

• Journal of Electrical Engineering and Technology
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• v.10 no.4
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• pp.1552-1557
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• 2015

The paper unleashes a new idea to arrive at reduced switch count topological structures configured in the form of a matrix for a cascaded Multi level inverter (CMLI). The theory encircles to minimize the number of switches involved in the conduction path and there from acclaim reduced input current distortion, lower switching losses and electromagnetic interference. The focus extends to standardize the number of power devices required for reaching different levels of output voltage from the same architecture. It includes appropriate pulse width modulation (PWM) strategy to generate firing pulses and ensure the desired operation of the power modules. The investigative study carries with it MATLAB based simulation and experimental results obtained using suitable prototypes to illustrate the viability of the proposed concept. The promising nature of the performance projects a new dimension in the use of single phase MLIs for renewable energy related applications.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.10a
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• pp.577-580
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• 2000

The aim of this paper is to develop a high stable measuring device for radioactive pulses. The device consists of a high voltage supply unit using a fly-back converter principle, and a pulse detection unit for gamma-rays and neutrons. The high voltage supply unit designed can generate DC voltage up to 1,500v at 5V-input, and have a series voltage regulator to maintain the output voltage constantly, resulting in less than 1.63% of voltage regulation. The pulse detection parts consists of an active integrator, a pole-zero circuit, and a 3-stage amplifier of 60 dB, and its frequency bandwidth is from 37 Hz to 300 kHz. From the experimental results, it is confirmed that the measuring device can count at least 10,000 pulses in a second.

• Journal of Power Electronics
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• v.14 no.6
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• pp.1314-1321
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• 2014

A new simplified topology for a dynamic voltage restorer (DVR) based on direct converter with a reduced number of switches is presented. The direct converter is fabricated using only three bi-directional controlled switches. The direct converter is connected between the grid and center-tapped series transformer. The center-tapped series transformer is used to inject the compensating voltage synthesized by the direct converter. The DVR can properly compensate for long-duration, balanced, and unbalanced voltage sag and swell by taking power from the grid. The switches are driven by ordinary pulse width modulation signals. Simulation and hardware results validate the idea that the proposed topology can mitigate sag of 50% and swell of unlimited quantity.

• Journal of Industrial Technology
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• v.29 no.B
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• pp.127-131
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• 2009

This paper presents the development of smart counting system that is proper for grains with uneven unit weight or shape. This device can detect the small differences of a light beam and count the pulse from wave shape control, when the grain is going on the light screen, which is made by the light beam screen sensor. It can, different from the former conventional device, distinct the uneven grains for counting detect, by using the dedicated hardware and the software algorithm of the light sensor.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.211-214
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• 2002

We present gray scale implementation method based on QMA driving technique. We clarified the mechanism of wall charge quantization through discharge current measurement. We used three wall charge states to implement gray scale. The cells would be one of fully-ON, half-On, and OFF states. We built a five sub-fields 243 level gray scale with sustain pulse count of 2, 6, 18, 54, and 162.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1425-1427
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• 1994

Laser ablation of glass substrates (8K-7 and synthetic quartz) using a transversely excited atmospheric (TEA) $CO_2$ laser has been inverstigated to obtain high speed etching. The ablation occurs by local heating of a substrate with a focused TEA-$CO_2$ laser beam. The dependence of ablation rate on pulse count and repetition-rate of laser has been discussed.

• Nuclear Engineering and Technology
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• v.55 no.11
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• pp.3925-3934
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• 2023

The importance of fast neutron detection for nuclear safeguards purposes has increased due to its potential advantages such as reasonable cost and higher precision for larger sample masses of nuclear materials. Pulse-shape discrimination (PSD) is inevitably used to discriminate neutron- and gamma-ray- induced signals from organic scintillators of very high gamma sensitivity. The light output (LO) threshold corresponding to several MeV of recoiled proton energy could be necessary to achieve fine PSD performance. However, this leads to neutron count losses and possible distortion of results obtained by neutron multiplicity counting (NMC)-based nuclear material accountancy (NMA). Moreover, conventional PSD techniques are not effective for counting of neutrons in a high-gamma-ray environment, even under a sufficiently high LO threshold. In the present work, PSD performance (figure-of-merit, FOM) according to LO bands was confirmed using a conventional charge comparison method (CCM) and compared with results obtained by convolution neural network (CNN)-based PSD algorithms. Also, it was attempted, for the first time ever, to reject fake neutron signals from distorted PSD regions where neutron-induced signals are normally detected. The overall results indicated that higher neutron detection efficiency with better accuracy could be achieved via CNN-based PSD algorithms.

• The KIPS Transactions:PartC
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• v.11C no.3
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• pp.395-400
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• 2004

Being aware of growing needs for wireless communication led to the development of UWB systems, this study proposed an impulse for single band UWB systems which does not count a carrier; analyzed the characteristics and the problems of pulses suggested by the existing poise of the Un system; finally, proposed TDMG(Time Delay Multiple Gaussian) pulse that generates signals of UWB without attenuation of pulse width. The hardware structure of the TDMC pulse for the single band UWB system was modelled after describing the pulse in a mathematical method in an attempt to compare with performances of the existing pulses through computer simulation. The outcome of the test unveiled the fact that each center frequency of the TDMG pulse rose approximately 1GHz, and also each l0dB fractional bandwidth of the TDMG pulse was widened over 1GHz. In the case of derivative, center frequencies of the TDMG pulse rose over 1GHz each. As a consequence, the TDMG pulse appeared to have better quality frequency, satisfying the characteristics of spectrum and the band of frequency recommended by the FCC and decreasing interference with other wireless communication systems.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.2
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• pp.136-141
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• 2021

Heating cables, widely used in office buildings, factories, streets and railways, deteriorate in electrical insulation during operation. The insulation deterioration of heating cables leads to electric discharges that can cause electrical fires. With this background, this paper dealt with a condition monitoring technique for heating cables by the analysis of discharge signals to prevent electrical fires. Insulation deterioration was simulated using an arc generator specified in UL1699 under AC operation, and the characteristic and propagation of discharge signals were analyzed on a 100 meter-long heating cable. Discharge signals produced by insulation deterioration were detected as a voltage pulse because they are as small as a few mV and they are attenuated through propagation path. The frequency spectrum of discharge signals mainly existed in the range from 70 kHz to 110 kHz, and the maximum attenuation of the signal was 84.8% at 100 meters away from the discharge point. Based on the experimental results, a monitoring device, which is composed of a high pass filter with the cut-off frequency of 70 kHz, a comparator, a wave shaper and a microprocessor, was designed and fabricated. Also, an algorithm was designed to discriminate the discharge signal in the presence of noise, compared with the pulse repetition period and the number of pulse counts per 100ms. In the experiment, the result showed that the prototype monitoring device could detect and discriminate the discharge signals produced at every discharge point on a heating cable.