• Journal of Power Electronics
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• v.4 no.2
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• pp.117-126
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• 2004

This paper focuses on the electrical modeling techniques of renewable energy sources and storage devices such as batteries, fuel cells (FCs), photovoltaic (PVs) arrays, ultra-capacitors (UCs), and flywheel energy storage systems (FESS). All of these devices are being investigated recently for their typical storage and supply capabilities for various industrial applications. Hence, these devices must be modeled precisely taking into account the concerned practical issues. An obvious advantage of electrically modeling these renewable energy sources and storage devices is the fact that they can easily be simulated in real-time in any CAD simulation program. This paper reviews several types of suitable models for each of the above-mentioned devices and the most appropriate model amongst them is presented. Furthermore, a few important applications of these devices shall also be highlighted.

• Journal of Power Electronics
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• v.16 no.2
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• pp.621-630
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• 2016

In this paper, a single current sensor technique (SCST) is proposed for single-phase full-bridge inverters. The proposed SCST measures the currents of multiple branches at the same time, and reconstructs the average inductor, capacitor, and load current in a single switching cycle. Since all of the branches' current in the LC filter and the load are obtained using the SCST, both the inductor and the capacitor current feedback schemes can be selectively applied while taking advantages of each other. This paper also analyzes both of the current feedback schemes from the view point of the closed-loop output impedance. The proposed SCST and the analysis in this paper are verified through experiments on a 3kVA single-phase uninterruptible power supply (UPS).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.8B
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• pp.674-682
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• 2003

This paper presents the studies on wireless channel modeling and reverse link synchronization of CATV. This paper analyzes multi-path fading channel to the cause of signal distortion in the wireless communication environment. We represent the microwave link characteristics according to the channel model. Multi-path channel can affect fading.

• Proceedings of the KIPE Conference
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• 2015.11a
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• pp.151-152
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• 2015

This paper is research on design controller of grid connected 3-phase inverter. It confirms effects of high harmonics on controller and imposes repetitive controller to minimize effects on the high harmonics. The result of test in this paper is drawn by simulation tool.

• Journal of Power Electronics
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• v.12 no.1
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• pp.33-39
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• 2012

This paper describes operating and capacitor voltage balancing of the modular multilevel converter. The paper focuses on sizing of the cell capacitor and establishes approximate expressions for the capacitor voltage. Simulations and experiments results obtained from three-level modular converter are used to demonstrate its viability in medium voltage applications. It is shown that the modular converter can operate over the full modulation index linear range independent of load power factor.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.444-447
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• 2004

SNR(Signal to Noise Ratio) is one of the most important performance for the electro-optical camera system. This paper shows not only the SNR analyses for the MSC system, which is the payload in the KOMPSAT2 satellite, but also the trials for its improvement in the electronics circuit design. The MSC deals with one panchromatic band and four multi-spectral bands. The SNR analyses are performed based on the MSC design for the each band and assuming that the defined radiance reached directly to the sensor entrance pupil. In the SNR calculation, shot noise, dark current noise, analog electronics noise and ADC quantization noise are considered as noise sources. In these noise sources, especially, the electronics noise depends on the camera electronics design. This paper shows the camera electronics design to increase SNR and its test results as well as the SNR analyses.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.47-48
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• 2007

This paper presents an efficient and simple hardware design of signal to noise ratio (SNR) estimator for DVB-S2 system. The estimator investigates the distribution of the received symbols by simply using two comparators and a counter, and calculates the address of an LUT where the corresponding SNR value is located. In this paper, we demonstrate the functional and timing simulation results of the FPGA implementation of proposed structure.

• Proceedings of the KIEE Conference
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• 1997.07b
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• pp.521-523
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• 1997

With Extraction Transient Data from Booster Pump System, This paper establishs system model equation. and This equation is capable of PID control. Using Ziegler-Nichole tunning method of PID, Constantly estimated control method is done.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.881-882
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• 2008

This paper presents an algorithm of target detection of an underwater acoustic signal by estimating the background. At first, subtract the estimated background from the underwater acoustic signal. To estimate the background, this paper uses an algorithm of Denoising. By using Thresholding and Power analysis, we extract targets from the signal to eliminate the background. The proposed method is valuable as an algorithm to reduce calculation amounts of multi frames we will apply.

• Journal of Power Electronics
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• v.3 no.1
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• pp.40-48
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• 2003

In this paper, a hybrid power system with photovoltaic/wind/diesel generators is proposed to solve the defect of stand-alone type power system in a remote area. A hybrid power system has a power-balanced controller to equilibrate generation power with a given load demand and which is composed of common DC power system. To execute a power-balanced control, a hybrid power system is assumed that all of power generators have the characteristics of an equivalent current-source and load sharing control technique must be needed at the same time. So this paper discusses the structure of power-balance control for hybrid power system. And through the results of simulation, the proposed scheme was verified.