• Journal of IKEEE
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• v.28 no.1
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• pp.72-77
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• 2024

In this paper, a triple-mode frequency-tunable filter is proposed to meet the recent demands of various frequency bands of mobile communication services. This filter has a tunable structure that can adjust the resonance frequency using a variable capacitor. To improve the quality factor, a SIW(Substrate Integrated Waveguide) structure was introduced and a structure that induces three resonance modes was implemented through a circular hole located in the center. The change in electric field distribution and resonance frequency by the variable capacitor was simulated using HFSS, and the change in electric field distribution and resonance frequency of Triple Mode mode was confirmed.

• Journal of electromagnetic engineering and science
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• v.12 no.3
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• pp.210-215
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• 2012

This paper presents a compact microstrip triple-mode filter with enhanced skirt characteristics. The presented triple-mode filter configuration supports three transmission poles and three transmission zeros within the nearby passband. Two of transmission zeros are generated by a triple-mode resonator itself, and the third one is generated by small cross-couplings between the I/O ports. Each resonance condition and the transmission zero generation conditions are analyzed using an equivalent circuit. The bandpass filter is designed for a 2.4 GHz WLAN. The filter was fabricated with a relative dielectic constant of 3.5 and a thickness of 0.76 mm. The fabricated filter has a small size ($7.9mm{\times}7.2mm$, i.e., $0.107{\lambda}_g{\times}0.098{\lambda}_g$, where ${\lambda}_g$ is guided wavelength at a center frequency) and shows high performing skirt characteristics.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.4
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• pp.447-452
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• 2011

In this paper, we present a compact triple-mode resonator. The resonator itself can provide three transmission poles and one transmission zero. The resonance condition of each mode is analyzed theoretically, and the transmission zero is generated by open stub. Using this proposed resonator, a compact three pole bandpass filter for 2.4 GHz WLAN application with one transmission zero is designed and fabricated. The fabricated triple-mode filter shows 3 dB bandwidth of 15.8 % with the center frequency 2.4 GHz and less then 1.17 dB in 2.4~2.5 GHz passband. The size of fabricated triple-mode filter including the feed lines is 15.9 mm${\times}$9.7 mm and very compact compared with previous reported triple-mode filter.

• Journal of the Korean Magnetic Resonance Society
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• v.10 no.2
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• pp.175-187
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• 2006

Binding interactions between a positively charged porphyrin derivative TMAP(meso-tetra(p-trimethylanilinium-4-yl)porphyrin) and triple helical $(dT)_{12}{\cdot}(dA)_{12}{\cdot}(dT)_{12}$, as well as double helical $(dA)_{12}{\cdot}(dT)_{12}$ have been studied with NMR, UV and CD spectroscopy to obtain the detailed information about the binding mode and binding site. UV melting studies showed both DNA duplex and triple helix represented very similar UV absorption patterns upon binding TMAP, but the presence of third strand of triple helical $(dT)_{12}{\cdot}(dA)_{12}{\cdot}(dT)_{12}$, inhibited improvement in thermal stability in terms of melting temperature, $T_m$. In addition, the TMAP molecule is thought to bind to the major groove, according to CD and NMR data. But absence of the clear isosbestic point in UV absorption spectra represented that binding of TMAP to DNA duplex as well as DNA triplex did not show a single binding mode, rather complex binding modes.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.6
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• pp.899-905
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• 2001

This paper presents a triple-mode dielectric resonator far low loss and simple structure filter design. The BPF(Band Pass Filter) was designed using HFSS simulation results an4 fabricated using proposed resonators. The filter (3-stage BPF) has an insertion loss of about 0.9 dB at the center frequency of 1.93 GHz and a 3 dB bandwidth of about 25 MHz. If more complex characteristic is required, slot coupling between resonators can be used. Especially, the proposed BPF can be applied to the next generation mobile communication IMT-2000 system.

• Journal of the Korean Magnetic Resonance Society
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• v.27 no.2
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• pp.5-9
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• 2023

t ENOD40B, a plant peptide hormone, was doubly labeled with C-13 and N-15 by recombinant production in Escherichia coli. The peptide was prepared by affinity chromatography followed by protease cleavage and reverse-phase chromatography. To elucidate the mode of action against its receptor, sucrose synthase, we proceeded to assign the backbone and side-chain resonances using a set of double and triple resonance experiments. This result will be used to determine the three-dimensional structure of the peptide at its bound state as well as to observe the chemical shift changes upon binding.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.8
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• pp.854-861
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• 2007

In this paper, a compact L-shaped shorted pin patch to be used at local oscillator port in radar detector is proposed. Shorted pin patch operates as short-open cavity while conventional patch operates as open-open cavity. Shorted pins are L-shaped to obtain quarter wave length and three-quarter wave length resonance for the fundamental(X-band) and $2^{nd}(3^{rd})$(K- and Ka-band) mode resonance frequency, respectively. Thus, the proposed patch can be compact. It is also possible to operate at triple band(X-, K-, Ka-band) with small return loss in radar detector, It is expected that shorted pin patch could improve radar detector sensitivity.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.7
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• pp.579-589
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• 2015

This study aims to understand the internal flow and the evaporation characteristics of a deionized water droplet subjected to vertical forced vibrations. To predict and evaluate its resonance frequency, the theories of Lamb, Strani, and Sabetta have been applied. To visualize the precise mode, shape, and internal flow inside a droplet, the experiment utilizes a combination of a high-speed camera, macro lens, and continuous laser. As a result, a water droplet on a hydrophobic surface has its typical shape at each mode, and complicated vortices are observed inside the droplet. In particular, large symmetrical flow streams are generated along the vertical axis at each mode, with a large circulating movement from the bottom to the top and then to the triple contact line along the droplet surface. In addition, a bifurcation-shaped flow pattern is formed at modes 2 and 4, whereas a large ellipsoid-shape flow pattern forms at modes 6 and 8. Mode 4 has the fastest internal flow speed and evaporation rate, followed by modes 8 then 6, with 2 having the slowest of these properties. Each mode has the fastest evaporation rate amongst its neighboring frequencies. Finally, the droplet evaporation under vertical vibration would lead to more rapid evaporation, particularly for mode 4.