• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.1
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• pp.64-75
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• 2009

The shipbuilder's requirement for a higher power output rating has led to the development of a super large two stroke low speed diesel engines. Usually a large-sized bore engine ranging from $8{\sim}14$ cylinders, this engine group is capable of delivering power output of more than 100,000 bhp at maximum continuous rating(mcr). Other positive aspects of this engine type include higher thermal efficiency, reliability, durability and mobility. This plays a vital role in meeting the propulsion requirement of vessels, specifically for large container ships, of which speed is a primary concern to become more competitive. Consequently, this also resulted in the modification of engine parameters and new component designs to meet the consequential higher mean effective pressure and higher maximum combustion pressure. Even though the fundamental excitation mechanisms unchanged, torsional vibration stresses in the propulsion shafting are subsequently perceived to be higher. As such, one important viewpoint in the initial engine design is the resulting vibration characteristic expected to prevail on the propulsion shafting system(PSS). This paper investigated the torsional vibration characteristics of these super large engines. For the two node torsional vibration with a nodal point on the crankshaft, a tuning damper is necessary to reduce the torsional stresses on the crankshaft. Hence, the tuning torsional vibration damper design and compatibility to the shafting system was similarly reviewed and analyzed.

• Journal of the Korea Society of Computer and Information
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• v.24 no.10
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• pp.139-147
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• 2019

In this paper, we propose to explore ways to create internal motivation to enhance the job disposition of Korean and Chinese employees. In order to achieve this goal, we would like to select parameters that may trigger an increasing number of internal motivations for interest in recent years: perceived organisational support, perceived provider support, and perceived peer support, and to explore the impact on job embeddedness. I would like to find out the effect of job embodiedness on involved beauty. The process also seeks to verify that China and South Korea are different. To verify the research theory of this research, we will use a questionnaire to researchers of automotive companies using VR technology in Gyeonggi-do, Korea and Hadong-seong, China, and conducted a survey. A total of 200 pairs of questionnaires were distributed to the study subjects, 195 of which were retrieved, 191 of which eliminated unfaithful responses were used for the final analysis. The collected data were used for frequency analysis, exploratory factor analysis, reliability analysis, confirmatory factor analysis, correlation analysis, structural equation analysis. The results of this study, identified through empirical analysis, can be summarized as follows: First, Perceived Organizational Support, Perceived Supervisor Support will have a positive impact on Job Embeddedness. Second, Job Embeddedness will have a positive influence on the Innovative Beehivior. Third, Perceived Organizational Support, Perceived Supervisor Support will have a partial positive effect on Innovative Behavior. Fourth, the formation process and influence of Job Embeddedness of corporate employees in Korea and China are partly different, the report showed.