• 전기학회논문지P
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• 제67권2호
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• pp.63-69
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• 2018

In this paper, the operation principle of a bi-directional switch type resonant AC link snubber circuit was described, together with the practical design procedure, which employs in the proposed power module bridge package type resonant AC link snubber. The novel prototype of power module bridge package type resonant AC link snubber-assisted voltage type sinewave soft switching PWM inverter using IGBT power module was demonstrated herein. It was verified that both the auxiliary power switches in this resonant AC link snubber circuit and the main power switches commutate under the condition of soft switching commutation principle. In addition, the power losses of the new soft switching inverter treated here were analyzed by implementing the experimental data of the IGBT and diode v-i characteristics in addition to switching power loss characteristics into our original computer simulation software developed by the authors. Then, the voltage type sinewave soft switching PWM inverter was high efficiency than that of hard switching PWM inverter, along with performance operation waveforms. In the future, the comparative feasibility study of power module bridge type resonant AC link snubber and its related soft switching inverter in addition to the other types resonant snubber assisted soft switching inverter should be done from a practical point of view.

• Journal of Power Electronics
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• 제4권4호
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• pp.237-245
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• 2004

In this paper, a two-switch high frequency flyback transformer linked zero voltage soft switching PWM DC-DC power converter implemented for distributed DC- feeding power conditioning supplies is proposed and discussed. This switch mode power converter circuit is mainly based on two main active power semiconductor switches and a main flyback high frequency transformer linked DC-DC converter in which, two passive lossless quasi-resonant snubbers with pulse current regeneration loops for energy recovery to the DC supply voltages composed of a three winding auxiliary high frequency pulse transformer, auxiliary capacitors and auxiliary diodes for inductive energy recovery discharge blocking due to snubber capacitors are introduced to achieve zero voltage soft switching from light to full load conditions. It is clarified that the passive resonant snubber-assisted soft switching PWM DC-DC power converter has some advantages such as simple circuit configuration, low cost, simple control scheme, high efficiency and lowered noises due to the soft switching commutation. Its operating principle is also described using each mode equivalent circuit. To determine the optimum resonant snubber circuit parameters, some practical design considerations are discussed and evaluated in this paper. Moreover, through experimentation the practical effectiveness of the proposed soft switching PWM DC-DC power converter using IGBTs is evaluated and compared with a hard switching PWM DC-DC power converter.

• 산업과 과학
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• 제3권2호
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• pp.1-7
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• 2024

본 논문은 감성분석을 통한 소프트 파워의 수치화를 주제로 다루고 있다. 감성분석은 텍스트, 음성, 이미지 등 다양한 데이터에서 감정이나 감성을 탐지하고 분석하는 과정을 의미한다. 따라서, 본 논문에서는 감성분석을 통해 소프트 파워를 어떻게 수치화할 수 있는지에 대한 방법론과 그 의의를 탐구하였다. 소프트 파워는 국가나 단체가 다른 국가나 단체의 행동을 원하는 방향으로 영향을 주는 능력을 의미한다. 이는 군사적 또는 경제적 수단보다는 문화, 가치관, 정치체제 등의 부드러운 요소에 의해 구축되며, 감성분석은 이러한 부드러운 영역을 측정하고 이해하는 데 유용한 도구로 활용되고 있다.

• Journal of Contemporary Eastern Asia
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• 제17권1호
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• pp.27-49
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• 2018

Public Diplomacy (PD) is the third pillar of South Korean foreign policy. According to the Ministry of Foreign Affairs, PD aims to attract foreign audiences by means of art, knowledge transmission, media, language and foreign aid. When it comes to the Korean language, its global profile has seen an especially marked increase in recent years (Kim, 2009). Thus, this paper's objective is to explain the relevance of the Korean language in the generation of South Korea's soft power. I draw from $C{\acute{e}}sar$ Villanueva's reflections in order to problematize how language promotion can be translated into soft power at five different levels: the empathetic, the sympathetic, the geopolitical, the diplomatic and the utilitarian. I observe that in the case of the Korean language in Mexico City, soft power has the potential to be generated on three levels: it helps to increase knowledge of Korean culture (empathetic); it exercises symbolic persuasion (geopolitical), since the products of cultural industries are mostly in Korean; and it is used as a tool for economic transactions in Mexico City (utilitarian).

• Journal of Power Electronics
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• 제7권2호
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• pp.124-131
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• 2007

In this paper, a novel type of auxiliary switched capacitor assisted edge resonant soft switching PWM resonant DC-DC converter with two simple auxiliary commutation lossless inductor snubbers is presented. The operation principle of this converter is described using the switching mode equivalent circuits. This newly developed multi resonant DC-DC converter can regulate its DC output AC power under a principle of constant frequency edge-resonant soft switching commutation by an asymmetrical PWM duty cycle control scheme. The high frequency power regulation and actual power characteristics of the proposed soft switching PWM resonant DC-DC converter are evaluated and discussed. The operating performances of the newly proposed soft switching inverter are represented based on simulation results from an applications point of view.

• 수완나부미
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• 제16권1호
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• pp.271-301
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• 2024

Diplomatic relations between the United Arab Emirates and Indonesia have been going on for almost five decades. However, the cooperation between the two countries was still very limited at the beginning of diplomatic relations. As time went by, this cooperation began to expand, especially after Jokowi's visit to the United Arab Emirates in 2015. After this visit, the United Arab Emirates also showed increased interest in Indonesia and started to aggressively exercise soft power in Indonesia. Agreement after agreement have been signed, not only in the economic, political, and security sectors, but also in other areas. This phenomenon of increasing cooperation is one form of success in the soft power exercised by the United Arab Emirates towards Indonesia. Therefore, this research will look at the United Arab Emirates' soft power strategy towards Indonesia from 2015-2022. The concept developed by Joshua Kurlantzick is used to analyze using four important indicators that include educational cooperation, religious exchanges, humanitarian assistance, as well as cultural exchanges.

• Journal of Power Electronics
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• 제3권4호
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• pp.239-248
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• 2003

This paper presents a novel prototype of three-phase voltage source type zero voltage soft-switching inverter with the auxiliary resonant snubbers suitable for high-power applications with IGBT power module packages in order to reduce their switching power losses as well as electromagnetic conductive and radiative noises. A proposed single inductor-assisted resonant AC link snubber circuit topology as one of some auxiliary resonant commutation snubbers developed previously to achieve the zero voltage soft-switching (ZVS) for the three-phase voltage source type sinewave PWM inverter operating under the instantaneous space voltage vector modulation is originally demonstrated as compared with the other types of resonant AC link snubber circuit topologies. In addition to this, its operation principle and unique features are described in this paper. Furthermore, the practical basic operating performances of the new conceptual instantaneous space voltage vector modulation resonant AC link snubber-assisted three-phase voltage source type soft-switching PWM inverter using IGBT power module packages are evaluated and discussed on the basis of switching voltage and current waveforms, output line to line voltage quality, power loss analysis, actual power conversion efficiency and electromagnetic conductive and radiative noises from an experimental point of view, comparing with those of conventional three-phase voltage source hard-switching PWM inverter using IGBT power modules.

• Journal of Power Electronics
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• 제3권1호
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• pp.1-9
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• 2003

This paper presents a performance analysis of typical Auxiliary Resonant Commutation Snubber-assisted three phase voltage source soft switching inverter which can operate under a condition of Zero Voltage Switching (ZVS) using a digital control scheme which is suitable for high power applications compared with resonant DC link snubber assisted soft switching inverter. The system performances of this inverter are illustrated and evaluated on the basis of experimental results.

• Journal of Power Electronics
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• 제10권4호
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• pp.335-341
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• 2010

In this paper, an interleaved soft switching boost converter for a Photovoltaic Power Conditioning System (PV-PCS) with high efficiency is proposed. In order to raise the efficiency of the proposed converter, a 2-phase interleaved boost converter integrated with soft switching cells is used. All of the switching devices in the proposed converter achieve zero current switching (ZCS) or zero voltage switching (ZVS). Thus, the proposed circuit has a high efficiency characteristic due to low switching losses. To analyze the power losses of the proposed converter, two experimental sets have been built. One consists of normal devices (MOSFETs, Fast Recovery (FR) diodes) and the other consists of advanced power devices (CoolMOSs, SiC-Schottky Barrier Diodes (SBDs)). To verify the validity of the proposed topology, theoretical analysis and experimental results are presented.

• Journal of Power Electronics
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• 제4권2호
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• pp.77-86
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• 2004

This paper presents a novel three-phase power module bridge type auxiliary resonant AC link snubber for the three-phase voltage-fed sinwave soft switching PWM inverter operating under specific instantaneous space voltage vector modulation. The operating principle of this resonant snubber is described for current source load model during one switching period, along with its design approach based on the simulation data. The performance evaluations of space vector modulation three-phase sinewave soft switching inverter with a new three-phase active auxiliary resonant AC link snubber are discussed as compared with those of three-phase voltage source-fed sinewave hard switching PWM inverter with a standard space voltage vector modulation strategy. The power loss analysis and conventional efficiency estimation of three-phase soft switching PWM inverter using ICBT modules are carried out including all the conduction power losses based upon the measured v-i characteristics of IGBT and its antiparallel diode as well as their switching losses.