• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.646-649
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• 2008

This study deals with mechanism of relay operation and modeling of transfer function between impact force and sound pressure due to the impact force in order to reduce relay noise. A collision between a moving-contact and fix-contact produces impact noise. Therefore impact noise of relay is determined by not only excitation force but also transfer function from impact force to noise. In this study, we find mechanism of relay operation, make impact force model and measure characteristic of relay noise. And also we find transfer function of relay noise.

• Korean journal of communication and information
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• v.48
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• pp.211-230
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• 2009

This study aims to trace the main tendency found in Korean broadcasting news coverage of terror throughout the kidnapping of Sun Il Kim. For this purpose, this study analyzed the contents of 386 news stories found in KBS, MBC, and SBS. Through this process, it investigated the main theme and source found in the coverage of kidnapping. In addition, it analyzed how the press described Al Tawhid Al Jihad, known as the organization who kidnapped Mr. Kim and how well the press transmit the social, historical background of terror. As a result, the dominant theme found in three news company was that which dealt with investigations about suspicions about kidnapping and suspicions related to the kidnapping. However, the voice against dispatching armed forces and the demand of terrorist were seldom found in the coverage. The news sources which three broadcasting news depended on heavily was governmental officials and the media including Al Jazeera was also main source. The description of Al Tawhid Al Jihad by the press was somewhat negative and the expression 'militarized forces' were found mostly. The news which announced the social, historical background of terror were minimal, which indicated that the coverage of terror in Korean broadcasting was still episodic.