• Journal of Advanced Navigation Technology
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• v.17 no.2
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• pp.196-201
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• 2013

In this paper, a dual-mode balanced filter with symmetric coupled composite right/left-handed transmission line is introduced. Unlike the other symmetric structure, this configuration has the ability to operate under both common- and differential-mode excitation. These properties are achievable through providing physical short circuit by means of ground vias at the center of each unit-cell along the symmetry plane of the structure. Because the CRLH unit-cells are operated under both common- and differential-mode excitation, we implemented a balanced filter using these properties. To validity these features, a five-cell four port coupled CRLH-TL is simulated, fabricated and measured and the obtained performances agree with the simulation results under both common- and differential-mode excitation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.8
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• pp.1653-1658
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• 2011

A novel circuit structure of dual-band bandstop filters is proposed in this paper. This structure comprises two shunt-connected tri-section stepped impedance resonators with a transmission line in between. Theoretical analysis from the equivalent circuit and design procedures are described. We represented graphs for filter design from the derived synthesis equations by resonance condition of circuits. Notably, advantages of the proposed filter structure are compact size in design, wide range of realizable resonance frequency ratio, and more realizable impedances.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.4 no.2
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• pp.119-125
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• 2011

A novel circuit structure of dual-band bandstop filters is proposed in this paper. This structure comprises two shunt-connected tri-section stepped impedance resonators with a transmission line in between. Theoretical analysis from the equivalent circuit and design procedures are described. We represented graphs for filter design from the derived synthesis equations by resonance condition of circuits. Notably, advantages of the proposed filter structure are compact size in design, wide range of realizable resonance frequency ratio, and more realizable impedances.

• Journal of the Korean Society of Radiology
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• v.4 no.3
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• pp.5-11
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• 2010

In this paper, we are suggested development of dual-mode detector for dual-energy digital radiography. Design of dual-energy radiography module for commercial BIS (Baggage Inspection System) is used in the spectrum of the X-ray generator and detector for dual-mode features and radiological characteristics were analyzed. BIS suggestl on the image detector module being used to target X-ray tube to simulate X-ray spectrum and simulated spectrum to offer through the new radiographic characteristics of the detector modules were investigated. Using X-ray experiments with an increase in the thickness of the copper filter low energy detector (LED) and high-energy detector (HED) as the difference between the output signal increases. HED, especially in the size of the output signal decreases with increasing thickness of the copper filter was found.

• Journal of Advanced Navigation Technology
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• v.27 no.1
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• pp.57-62
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• 2023

This paper proposes a tri-band bandpass filter using dual-mode stepped-impedance resonators (SIRs) with parallel coupled structures. The proposed filter adopts U-shaped SIRs with open stubs and parallel coupled lines (PCLs) that have inter-digital and comb-line shorted ends. Two U-shaped SIRs with open stubs build the first and third passband, and the central PCL resonators build the second passband. Five resonators and coupling structures are theoretically analyzed to derive the scattering parameters of the proposed filter. A novel tri-band bandpass filter is designed and fabricated using the induced scattering parameters. The measured result of the fabricated tri-band bandpass filter shows a good agreement with the simulated one.

• 한국ITS학회:학술대회논문집
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• v.2007 no.10
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• pp.330-333
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• 2007

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.725-728
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• 1988

Image restoration technique using dual sensor is presented in this paper. Digital Radiography image (1024xlO24) is obtained by conventional resolution sensor. We also obtain local DR image data by high resolution sensor. Two dimensional maximum entropy power spectrum estimation (2-D ME PSE) is applied to low resolution image and high resolution image for the purpose of the power spectrum estimation of each image. A class of linear algebraic restoration filter, parametric projection filter (PPF), is derived from the power spectrums of each image. It is shown that the noise energy may be considerably reduced through the PPF.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.4
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• pp.1048-1058
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• 1996

In this paper, a small duplexer is designed and implemented using a H-plane T-junction and Transmitting/Geceiving filte with a dual mode cavity resonator for Ku-band. Transmitting(TX) filter is designed at center frequeny 12.5 GHz and Receiving(RX) filter, at center frequency 14.5 GHz. Both filters have a 100 MHz bandwidth. This duplexer is reduced to about 40% by the conventional duplexer of cavity bandpass filter structure in size. Operating characteristics of duplexer is optimized in order not to distors matching characteristics of each filter when interfaced to a H-plane T-junction. Consequently, the responses of filter with H-plane T-junction nearly coincide with that of filter itself.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.76.1-76.1
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• 2021

Maemi Dual Field Telescope System (MDFTS) is a dual telescope system located at Kyung Hee University. The system consists of 0.4 m telescope and 0.1 m telescope for wide-field observation. The 0.4 m telescope provides photometric observation which covers a field of view of 21'×16'. It has been used for various purposes with Johnson-Cousins UBVRI broadband filter system, e.g., SomangNet and Intensive Monitoring Survey of Nearby Galaxies. In this poster, we present the standard calibration result for our broadband filter system. Also, we suggest a new usage of the KHAO 0.4m telescope which is narrowband photometry by demonstrating the standard calibration of H-alpha filter. For flux calibration, not only R filter but also V filter is used for compensating the central wavelength discrepancy between R filter and H-alpha filter.

• Journal of Environmental Health Sciences
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• v.37 no.2
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• pp.141-149
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• 2011

This study aimed for developing a two stage dual media filtration system. It has a sand and activated carbon layer above the under-drain system, and a sand layer above the middle-drain system for pretreatment. When retrofitting an old sand filter bed or designing a new one, this technology can substitute the existing sand filter bed without requiring a new plant site. The removal rate of total particle is 93, and 3~7 ${\mu}m$ and 5~15 ${\mu}m$ particles are all 97%. These high removal efficiencies of each pollutant due to adsorption and biological oxidation in activated carbon filter layer. The best backwashing method of two stage dual media filtration system is ascertained by air injection, air + water injection and water injection sequence. In this study, a pilot plant of two stage and dual filtration system was operated for 4 months in water treatment plant. The stability of turbidity was maintained below 1 NTU. The TOC, THMFP and HAAFP were removed about 90% by two stage and dual media filtration system, which is almost 2 times higher than existing water treatment plant.