• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.4
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• pp.60-67
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• 2008

This paper presents a new full-bridge soft switching PWM DC-DC converter circuit topology that adding two switcher, two lossless snubber quasi-resonance capacity, two diode to power source for general welding machine. This half bridge soft switching Is low voltage hight current output that first coil current is smaller than second coil current in high frequency transformer can be obtained with decreasing path loss in conventional DC bus line switcher. As it operate ZCS/ZVS in full range, high frequency, high efficiency and high output are implemented at low voltage and high DC current switching power supplies. All of this items are got from simulation and the result of experiment. If make up for the weak points of this proposed circuit, it will be used more easily for next generation TIG, MIG and MAG type of arc-welding machine.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.6
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• pp.26-33
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• 2008

This paper presents a new full-bridge soft switching PWM DC-DC converter circuit topology that adding one switcher, one lossless snubber quasi-resonance capacity to power source for general welding machine This full-bridge soft switching DC-DC convoter· topology can applicable 600[V] switching device (IGBT)incase of AC 400[V] common power source because the voltage of active switcher is 1/2 of DC bus line voltage. And low voltage hight current out)ut that first coil current is smaller than second coil current in high frequency transformer can be obtained with decreasing path loss in conventional DC bus line switcher. As it operate ZCS/ZVS in full range, high frequency, high efficiency and high output are implemented at low voltage and high DC current switching power supplies. All of this items are got from simulation and the result of experiment. If make up for the weak points of this proposed circuit, it will be used more easily for next generation TIG, MIG and MAG type of arc-welding machine.

• Industry Promotion Research
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• v.9 no.4
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• pp.65-76
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• 2024

Recent international conflicts have evolved into hybrid warfare, combining conventional military operations with cyber warfare, public opinion manipulation, and psychological warfare. Hybrid warfare involves the unpredictable use of various forces and strategies that blur the lines between war and peace, targeting the vulnerabilities of adversary nations. Among these, cyber warfare is a key tool used to incite social chaos, weaken the enemy's resolve, and achieve political and military objectives before physical military attacks take place. This paper aims to analyze the cyber warfare tactics employed by Russia before and after its physical military engagements, focusing on key cases such as the 2007 cyberattack on Estonia, the 2008 invasion of Georgia, the 2014 annexation of Crimea, and the 2022 war in Ukraine. By examining the methods, processes, and patterns of Russia's cyber operations in these conflicts, the study seeks to predict potential cyberattack scenarios by North Korea and explore cyber warfare development strategies suitable for the security context of the Korean Peninsula. Based on these analyses, the paper suggests strategies tailored to South Korea's current situation, which involves a continuous standoff with North Korea. Proposed measures include establishing a global cyber defense cooperation framework with the United States, countering public opinion and psychological warfare through social media, and enhancing national-level civil-military cooperation to prepare for cyber-electronic warfare.