• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.2
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• pp.166-171
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• 2013

The method proposed in this paper can improve the performance of the Boosting algorithm in machine learning. The proposed Boundary AdaBoost algorithm can make up for the weak points of Normal binary classifier using threshold boundary concepts. The new proposed boundary can be located near the threshold of the binary classifier. The proposed algorithm improves classification in areas where Normal binary classifier is weak. Thus, the optimal boundary final classifier can decrease error rates classified with more reasonable features. Finally, this paper derives the new algorithm's optimal solution, and it demonstrates how classifier accuracy can be improved using the proposed Boundary AdaBoost in a simulation experiment of pedestrian detection using 10-fold cross validation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.3
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• pp.31-39
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• 2012

This paper presents a high efficiency coupled inductor boost DC-DC converter that uses a simple clamp circuit and the coupled inductor and thus overcomes output voltage limit of the conventional boost converter. The proposed converter solves problems of voltage stress of the power semiconductor switch and reverse recovery of the output diode using a simple clamp circuit composed of a diode and a capacitor, and thus the converter improves its total efficiency. In this paper, the operational principle of the proposed converter is explained by each mode and then a design example for the prototype converter based on the explanation is shown. And good performance of the proposed converter is verified through experimental results of the prototype converter that is implemented with the designed circuit parameters.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.393-396
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• 2001

산업분야에서 많이 사용되고 있는 컴퓨터나 자동화 제조공정 둥은 전압저하나 이상전압에 민감하게 반응한다. 전력품질의 문제가 증가함에 따라 수용가 측에서는 무정전 전원장치(UPS)와 같은 일정전압을 유지할 수 있는 전압조절장치 들을 사용하고 있다. 본 논문에서는 전압조절기 응용을 위한 PWM Buck-Boost AC/AC 컨버터가 제안된다. 제안된 컨버터는 IGBT 스위칭 모듈을 사용하고 입력전압의 저하나 증가시, 그리고 부하의 변동시에 PWM 제어에 의하여 일정한 전압을 유지할 수 있다. 본 논문에서는 제안된 PWM Buck-Boost AC/AC 컨버터의 회로구성과 특징을 설명하고 이를 PSPICE 시뮬레이션을 통하여 동작특성을 보인다.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.61 no.4
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• pp.192-198
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• 2012

Switch losses directly affect the efficiency of power conversion systems and those have big differences according to the power consumed by load systems and the structures of power conversion circuits. In this paper, analyses for switch losses in DC link converter are performed based on the circuit structures of the DC/DC converter in photovoltaic generation system whose output power is varied according to the amount of solar radiation, temperature and partial shade on the solar modules. Boost converter is adopted as a DC link converter topology of the photovoltaic generation system and the loss analyses for the switches used in the boost converters are performed according to the circuit structures. Analyses like the things performed in this paper will be a prerequisite to designing the photovoltaic generation system whose output power is changed according to the environmental variations.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.292-294
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• 2005

A new zero voltage switching (ZVS) 2-transformer boost converter is proposed in this paper. The proposed converter has the advantage that the magnetizing inductor of the transformer acts for the boost inductor without additional inductor. Moreover, ZVS of main switches and auxiliary switches can be achieved, and the switch turn-off surge problem of conventional isolated boost converter is effectively solved. The operational principle, DC voltage gain, and ZVS characteristics are analyzed. To confirm the validity of the proposed converter, simulation results with 200w, 24Vdc/200Vdc specification are presented.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.647-650
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• 2005

The paper aims on an analysis for dc boost control using Z-source inverter. The modified space vector PWM method is used for controlling both the dc boost and ac output controls in the Z-source inverter. The capacitor voltage and the voltage stress of device with both the shoot-through time and modulation index are analyzed considering the zero state time of inverter. The theoretical analysis is verified with the simulation studies and experiments with 32-bit DSP.

• Journal of Power Electronics
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• v.16 no.3
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• pp.925-935
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• 2016

This paper proposes a new interleaved double-input three-level Boost (DITLB) converter, which is composed of two boost converters indirectly in series. Thus, a high voltage gain, together with a low component stress and a small input current ripple due to the interleaved control scheme, is achieved. The operating principle of the DITLB converter under the individual supplying power (ISP) and simultaneous supplying power (SSP) mode is analyzed. In addition, closed-loop control strategies composed of a voltage-current loop and a voltage-balance loop, have been researched to make the converter operate steadily and to alleviate the neutral-point imbalance issue. Experimental results verify correctness and feasibility of the proposed topology and control strategies.

• Journal of Power Electronics
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• v.14 no.5
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• pp.834-841
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• 2014

This paper proposes new active switched-capacitor and switched-inductor Z-source inverter (ASC/SL-ZSI) topologies, which can provide a higher boost ability with a small shoot-through time. The proposed ASC/SL-ZSIs inherit all of the advantages of the classical ZSI, and have a stronger voltage boost inversion ability when compared with the classical ZSI. Thus, the output ac voltage quality is significantly improved. In addition, more cells can be cascaded in the impedance network in order to obtain a very high boost ability. The proposed topologies can be applied to photovoltaic or fuel-cell generation systems with low-voltage renewal sources due to their wide range of obtainable voltages. Both simulations and the experimental results are carried out in order to verify performance of the proposed topologies.

• Journal of Power Electronics
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• v.14 no.5
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• pp.899-907
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• 2014

This paper proposes a single-phase bidirectional AC/DC converter topology applied in V2G systems, which consists of an inverter and a bidirectional non-inverting buck-boost converter. This topology can operate in four modes: buck charging, boost charging, buck discharging and boost discharging with high input current quality and unity input power factor. The inverter switches at line frequency, which is different from conventional voltage source inverters. A bidirectional buck-boost converter is utilized to adapt to a wider charging voltage range. The modulation and control strategy is introduced in detail, and the switching patterns are optimized to reduce the current ripple. In addition, the semiconductor losses are analyzed. Simulation and experimental results demonstrate the validity and effectiveness of the proposed topology.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.1
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• pp.67-76
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• 2012

This paper proposes the aggregated modeling and control of integated boost-flyback converter (IBFC) for understanding of dynamics characteristic and designing of relevant controller. The basic concept of the aggregated modeling is to substitute the boost or the flyback converter with an equivalent current source. Since each converter with equivalent current source corresponds to the basic boost and flyback converters, the overall mathematical process is significantly simplified for the modeling. Afterwards each result is combined to construct the complete model of the IBFC, and the relevant controller is designed through the achieved small-signal model. Simulation and experimental results show excellent agreement with the theoretical expectations.