• 한국정보통신학회논문지
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• 제6권6호
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• pp.904-908
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• 2002

본 논문에서는 강유전체 기반, 마이크로스트립 라인을 이용하여 13~170Hz에 걸친 넓은 주파수 범위에서 삽입 손실이 2dB 이하, 반사 손실이 10dB 이상인 4-coupled 가변 위상 천이기를 제안한다 특히, 15GHz에서 위상 천이 편이(DPS)는 0V를 인가하였을 때 $89{\circ}$ 이었고, 인가 전압을 150V로 증가시켰을 때 $115{\circ}$ 이었다. 그러므로 위상 천이 편이의 가변성은 $26{\circ}$에 달한다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제37회 하계학술대회 초록집
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• pp.250-250
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• 2009

• 한국문헌정보학회지
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• 제29권
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• pp.173-204
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• 1995

The purpose of this study is to promote understanding of the book selection theory by researching dialectically of its development process centering on the BSTv(value theory) and BSTd(demand theory). The results of this study are summarized as follows 1. In the period of enlightenment and education, the book selection theory of public libraries was the thesis state of BSTv(d). 2. Antithesis state of BSTv(d), that is, BSTd was raised to real central theory of book selection in the early 20th century. 3. In the 1930-40's, BSTv and BSTd were transformed into balance state or coexistence relations(BSTb $[v(d){\cdot}d(v)$]. 4. After World War II, BSTn(library needs theory) and BSTo(library objective theory) were evoked, and opposed to the existing selection theories. Now, they are developing into BSTbl$[n(d)\cdot\;o(v)\;or\;n(d){\cdot}v(o)]$.

• Journal of electromagnetic engineering and science
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• 제10권3호
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• pp.158-165
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• 2010

This study reviewed terahertz technologies of time domain spectroscopy, T-ray imaging, and high rate wireless data transfer. The main topics of the terahertz research area were investigation of materials and package modules for terahertz wave generation and detection, and setup of the terahertz system for time domain spectroscopy(TDS), T-ray imaging and sub-THz wireless communication. In addition to Poly-GaAs film as a photoconductive switching antenna material, a table-top scale for the THz-TDS/imaging system and terahertz continuous wave(CW) generation systems for sub-THz data transfer and narrow band T-ray imaging were designed. Dielectric properties of ferroelectric BSTO($Ba_xSr_{1-x}TiO_3$) films and chalcogenide glass systems were characterized with the THz-TDS system at the THz frequency range. Package modules for terahertz wave transmitter/receiver(Tx/Rx) photoconductive antenna were developed.