• Journal of information and communication convergence engineering
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• v.22 no.3
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• pp.173-180
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• 2024

This study proposed an interdigital band-pass filter based on the microstrip transmission line. When designing a conventional structure for an interdigital filter based on the characteristics of the 5th order transmission line, seven resonators are required. By changing the impedance of the resonator adjacent to the feed line, the proposed interdigital band-pass filter was designed to reduce the number of resonators compared to conventional interdigital band-pass filters. Consequently, the resonator order decreased, and return and insertion losses become comparable to that in case of a conventional interdigital filter design. The proposed band-pass filter was designed with a center frequency of 2.75 GHz and a bandwidth of 1.5 GHz. Furthermore, based on various transmission characteristics such as group delay and coupling coefficient, two band-pass filters were designed, compared, and analyzed.

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.17.2-17.2
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• 2007

• Proceedings of the Materials Research Society of Korea Conference
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• 1999.11a
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• pp.55-55
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• 1999

• 한국초전도학회:학술대회논문집
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• v.16
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• pp.28-28
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• 2006

• Proceedings of the Optical Society of Korea Conference
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• 2007.07a
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• pp.235-236
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• 2007

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.783-784
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• 2012

• Proceedings of the Korean Ceranic Society Conference
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• 2002.10a
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• pp.98.1-98
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• 2002

• The Journal of the Acoustical Society of Korea
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• v.21 no.1
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• pp.47-55
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• 2002

This paper proposes a new improved lumped element equivalent circuit analysis method to analyze withdrawal weighted SAW resonators of irregular electrode configurations, which enables to calculate the frequency response of withdrawal weighted SAW resonators. This method has led to the derivation of Smith equivalent circuit's y-parameters for a single ground electrode and formulated the resonator's admittance by calculating the total current into an IDT assembly. To illustrate the effectiveness of the technique, this method was applied to the design of a simple ladder filter and the change of the filter performance was investigated in relation to the weighting of the series and parallel resonators, respectively. The results shows that the withdrawal weighted resonator ladder filters provide better performance in their bandwidth and transition characteristics than normal ones. This new equivalent circuit analysis method can also serve as a better tool to design and analyze general SAW resonator filters.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.2 no.1
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• pp.15-19
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• 1986

Our report refers to occidental vocal techniques from Greece until today. It is remarkable that even with poor anatomy knowledge, there were advices on styles given from very early periods, for both church and secular singing. During the 18th century, the names of "vox pectoris", "vox guturris" and "vox capitis" appear, nominations that somehow remain nowadays with great confusion about source of sound production and results of resonance. Vocal occidental styles developed different kinds of requirements from the singers, that had to adapt their vocal Possibilities to them. The same happened with "pop" song. Nowadays, all kinds of singers must have a conscious knowledge of its voice management to prevent vocal disturbances. We consider that the technique is the same, even when the singer has to sing Wagner, Debussy, Sconberg, Piazzola or Gershwin. The big changes occured at resonance levels, and because these different use of the vocal resonators the effects are quite different. In summary, the big differences on classical the effects are quite different. In summary, the big differences on classical and pop song are done on the different use of the resonators and its effects on the vocal tract. "Pop" singers, men and women, should be taught to use both registers, "modal" and "falsetto" to be able to reach the complete range of their songs without any harm to their larynxes. In our opinion, a good singing technique means that it could be adapted to every stylistic need. The same technique is adapted to the popular singer as well. The main difference lays on the use of resonators, pretty strong in the classic singer, weaken in the popular singer, on the volume and on the total extension of the voice. Breathing control, effortless emission and the use of "passage" at the right point should be taught to all singers, regardless of their style. (omitted)

• Progress in Superconductivity
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• v.11 no.2
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• pp.106-111
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• 2010

Sapphire resonators with $YBa_2Cu_3O_{7-\delta}$ (YBCO) endplates have provided a way to realize extremely high quality factor due to the extremely low dielectric loss of sapphire and conductive loss of YBCO films, which enables to measure the low surface resistance of superconductor films at microwave frequencies. We present microwave properties of HTS sapphire resonators designed for measuring the surface resistance of HTS films at millimeter-wave frequencies by using the two-resonance mode dielectric resonator method. Despite enhanced surface resistance ($R_S$) of YBCO films due to the quadratic frequency dependence of the $R_S$, the unloaded quality factor ($Q_0$) of the $TE_{021}$ mode sapphire resonator still appears to be well above $1\;{\times}\;10^6$ at a mm-wave frequency of 38 GHz at 10 K. However, it appears that the $TE_{012}$ mode $Q_0$ is unexpectedly low despite that the corresponding resonance peak looks uncoupled with parasitic modes. We discuss possible reasons for the unexpected results using the surface resistance at the $TE_{021}$, $TE_{012}$, and $TE_{011}$ mode frequencies.