• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.4
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• pp.515-525
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• 1998

In this paper, for both transmission and reception with single antenna system of satellite communication, dual-frequency antennas which operate simultaneously at 12.5 GHz and at 14.25 GHz are designed, constructed and measured. Also by using dual feeding structure, the problems of single-fed dual-frequency antenna such as the separation of transmitting and receiving signals and single polarization, are solved. Microstrip patch as a radiation element of dual-fed dual-frequency antenna has width and length which are the resonance lengths of the corresponding frequencies for transmission and reception, respectively. The effects of the feed line on the other frequency feeding are minimized with the optimal matching scheme for the feed lines. For solving the space problems of dual-fed two-dimensional array antennas, microstrip-line and coaxial probe feedings are used for each frequency and a two-dimensional $2\times2$ array antenna was designed and measured their characteristics. The experimental results show that errors of resonance frequencies are less than 1.44%, the return losses are less than -21 dB and the isolations between two feeding ports are less than -21 dB. The characteristics of radiation patterns of dual frequency microstrip antenna are measured and evaluated. The directivities, sidelobe levels and cross polarizations are also measured and compared with the simulations. The results show some errors due to the misalignment of coaxial probe feeding.

• (The) Research of the performance art and culture
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• no.36
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• pp.223-253
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• 2018

The purpose of this study is to examine how the Korean classic novel "Shimcheong-jeon" has transformed in juvenile literature since the 2000s. Classical novels are far from modern and temporal, differ from modern cultures. Classic novels are also different from the lives and thoughts of modern children. It is therefore difficult for modern child readers to easily understand or agree with classical novels. In order for classical novels to have the meaning in the present, it is necessary to pay attention to the encounter between classical novels and children's literature. In the case of "Shimcheong-jeon", unlike other classical novels, there are many creative fairy tales. There are seven kinds of fairy tales that transformed "Shimcheong-jeon". They are diverse in genres such as picture books, fairy tales, and juvenile fiction, and are intended for a variety of ages. These works are described in various perspectives such as, Shimcheong who is full of desire, Shim Hakgyu who is disabled, Ppaengdeog's mother who has maternity and subjectivity, The dragon of the dragon king and Byeogdeog who loves Shimcheong, and Shin Cheong who has a dream. The themes of the works vary. So, These works extend our expectations for classical literature. Fairy tales that transformed "Shimcheong-jeon" reflect the lives of children and youths, this is important because it can reduce the distance between classical novels and children and youth readers. Classical novels are modernized and give new meaning to modern children and youths. And it reflects the characteristics of the novels of Pansori's "Shimcheong-jeon", preserving the value of classics. Tears of Paengdeok is a story that explains the origin of Pansori "Shimcheong-ga", and inserts some lyrics of Pansori, in the case of Cheong, Cheong, Pansori style is used. Although humor is the greatest feature of pansori, there are few of Fairy tales that transformed "Shimcheong-jeon". It is a direction to worry and to orient when transforming "Shimcheong-jeon" into a fairy tale.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.8
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• pp.905-911
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• 2012

To establish a floating offshore wind turbine simulation model, a tension leg platform is added to an onshore wind turbine. The wind load is calculated by using meteorological administration data and a power law that defines the wind velocity according to the height from the sea surface. The wind load is applied to the blade and wind tower at a regular distance. The relative Morison equation is employed to generate the wave load. The rated rotor speed (18 rpm) is applied to the hub as a motion. The dynamic behavior of a 2-MW floating offshore wind turbine subjected to the wave excitation and wind load is analyzed. The flexible effects of the wind tower and the blade are analyzed. The flexible model of the wind tower and blade is established to examine the natural frequency of the TLP-type offshore wind turbine. To study the effect of the flexible tower and blade on the floating offshore wind turbine, we modeled the flexible tower model and flexible tower-blade model and compared it with a rigid model.