• Journal of Industrial Technology
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• v.32 no.A
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• pp.39-45
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• 2012

In this paper the digital control scheme of interleaved PFC for 3-phase modular UPS is presented. The interleaved PFC is composed of two identical PFC connected in parallel and each PFC is controlled by the interleaved switching signals which have the same switching frequency and the $180^{\circ}$ phase difference. As a consequence of the interleaving operation, the Interleaved PFC exhibits both lower current ripple at the input side and lower voltage ripple at the outside. Therefore, the switching and conduction losses as well as EMI levels can be significantly decreased. Simulation and experimental results verify the usefulness of the interleaved PFC.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.12
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• pp.1351-1358
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• 2012

In this paper, an analytical technique is proposed for the design of interleaved thinned planar array with well-behaved and predictable sidelobes. The interleaved arrays are composed of thinned planar subarrays based on cyclic difference sets(DSs). Becauce sidelobes of thinned planar subarrays based on DS are predictable by DS parameters, the subarrays exhibit very similar sidelobe levels by utilizing DS and complementary DS with similar autocorrelations each other. The combinatorial method also allows the design of interleaved placements with simultaneously optimum peak sidelobe levels(PSLs) of subarrays using cyclic shift-a property of DSs. The optimized PSLs of the interleaved array are -12.47 dB and -10.34 dB.

• Communications of Mathematical Education
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• v.37 no.2
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• pp.199-212
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• 2023

The purpose of this study is to find out whether there is a difference in achievement between blocked practice and interleaved practice according to the difference in domain and type of learning content in mathematics subject, and through this result, it is to confirm whether the effect of interleaved practice in mathematics learning is due to the 'Discriminative-contrast Hypothesis' or the 'Distributed-practice Hypothesis'. Although interleaved practice is more effective than blocked practice, previous studies have not shown consistent results regarding the cause. Therefore, in this study, 103 first-year middle school students were randomly assigned to blocked practice, interleaved practice, remote blocked practice, and remote interleaved practice groups had learning activities over 4 times. The results reveals that the effect of interleaved practice appeared in similar types in the same domain, but the effect of interleaved practice did not appear in different types in different domain. In addition, through this result, it was confirmed that the effect of interleaved practice was due to the 'Discriminative-contrast hypothesis' rather than the 'Distributed-practice hypothesis'. Further research topics were suggested after the issues on the research method and the findings were discussed.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.363-364
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• 2016

In this paper, a novel bridgeless interleaved power factor correction circuit with single current sensor is proposed. The proposed control strategy requires only one current sensor for the interleaved bridgeless PFC. By sampling the output current, all the boost indictor currents can be calculated and used to control the input current according to the input voltage. The reduced number of current sensors and associated feedback circuits helps reduce the cost of system. The problem caused by the unequal current gain between current sensors inherently does not exist in the proposed topology. Thus, current sharing between converters can be achieved more accurately and the high frequency distortion is decreased. In addition, the proposed technique can be applied to the other kinds of interleaved PFC topologies. Performance of the proposed control strategy is verified by the experimental results with 6.6kW bridgeless interleaved PFC circuit.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.1
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• pp.80-85
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• 2015

In the issues of interleaved topology which have been in limelight as high power converter, various soft-switching methods are studied to reduce switching losses in high power application. The interleaved ZCT converter has an additional filter inductor to reduce losses of diodes during reverse recovery process. However, additional current conduction modes are occurred by the inductor, we need to analyze switching losses with inductor values on each mode. In this paper, current conduction modes and boundary conditions of interleaved ZCT converter are analyzed. In the conclusion, the minimum of switching losses in converter operation modes is analyzed by calculating switching losses.

• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.5
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• pp.350-357
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• 2020

This study presents the design of an 18 kW two-phase interleaved buck converter that uses a coupled inductor for an electric vehicle rapid charger. The designs of a two-phase coupled inductor for current ripple and physical size reduction and a two-phase interleaved buck converter based on silicon carbide metal - oxide - semiconductor field-effect transistor for high efficiency were described in detail. The operating principle of the two-phase interleaved buck converter was analyzed, and the coupled inductor was investigated using a magnetized equivalent circuit. Simulation and experiments were conducted to verify the validity of the proposed two-phase interleaved buck converter, and the theoretical design method and experimental results were confirmed.

• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.4
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• pp.263-269
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• 2008

In this paper, an interleaved boost converter (IBC) with ZVT cell using a single resonant inductor in continuous conduction mode (CCM) is proposed. The IBC with the proposed ZVT cell has advantages such as a simple circuit, reduced size and low cost by using a single resonant inductor. It is more suitable for high power applications. The proposed ZVT cell circuit and principles for the IBC are explained in detail. The validity of the IBC with proposed ZVT cell is verified through experimental results.

• Journal of Advanced Navigation Technology
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• v.27 no.5
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• pp.540-545
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• 2023

AESA radar is able to instantaneously and adaptively position and control the beam, and this enables to have interleaved mode in modern airborne AESA radar which can maximize situational awareness capability. Interleaved mode provides two or more modes simultaneously, such as Air to Air mode and Sea Surface mode by time sharing technique. In this interleaved mode, performance degradation is inevitable, compared with single mode operation, and effective resource allocation is the key component for the success of interleaved mode. In this paper, we identified performance evaluation items for each mode to analyze interleaved mode performance and proposed effective resource allocation methodology to achieve graceful performance degradation of each mode, focusing on detection range. We also proposed beam scheduling techniques for interleaved mode.

• Journal of Power Electronics
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• v.14 no.5
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• pp.815-826
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• 2014

An improved bridgeless interleaved boost power factor correction (PFC) rectifier to improve power efficiency and component utilization is proposed in this study. With combined conventional bridgeless PFC circuit and interleaved technology, the proposed rectifier consists of two interleaved and magnetic inter-coupling boost bridgeless converter cells. Each cell operates alternatively in the critical conduction mode, which can achieve the soft-switching characteristics of the switches and increase power capacity. Auxiliary blocking diodes are employed to eliminate undesired circulating loops and reduce current-sensing noise, which are among the serious drawbacks of a dual-boost PFC rectifier. Magnetic component utilization is improved by symmetrically coupling two inductors on a unique core, which can achieve independence from each other based on the auxiliary diodes. Through the interleaved approach, each switch can operate in the whole line cycle. A simple control scheme is employed in the circuit by using a conventional interleaved controller. The operation principle and theoretical analysis of the converter are presented. A 600 W experimental prototype is built to verify the theoretical analysis and feasibility of the proposed rectifier. System efficiency reaches 97.3% with low total harmonic distortion at full load.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.98-99
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• 1998

In this paper, an interleaved spiral scan imaging is investigated for an ultra fast MR imaging. The interleaved spiral technique has relative advantage over single shot spiral imaging with improved resolution and less inhomogeneity-related artifact. An improved reconstruction algorithm is devised with DC-offset correction. Some preliminary experimental results are shown at 1.0 Tesla and 3.0 Tesla whole body MRI system.