• Kyungpook Mathematical Journal
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• v.56 no.3
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• pp.807-817
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• 2016

The aim of this paper is to introduce the notion of ${\epsilon}$-compatible maps and obtain some common fixed point theorems. Also, our results generalize some well known fixed point theorems.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.10
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• pp.2738-2750
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• 1994

The Effects of radiative heat transfer on turbulent flow in a partitioned enclosure is studied numerically. The enclosure is partially divided by a thin, poorly conducting vertical divider projecting from the ceiling of the enclosure. The low Reynolds number $k-{\epsilon}$ model is adopted to calculate the turbulent flow field. The solutions to the radiative transfer equations are obtained by the discrete ordinates method(DOM). This method is based on control volume method and is compatible with the SIMPLER algorithm used to solve the momentum and energy equations. The effects of optical thickness and Planck number on the flow, temperature fields and heat transfer rates are investigated for a moderate Rayleigh number($=10^9$). The changes in buoyant flow fields and temperature distributions due to the variation of baffle length are also analyzed. From the predictions, radiant heat exchange between the baffle and the sidewalls strongly influences the temperature distribution in the baffle and its vicinity and total heat transfer increases as the optical thickness and the baffle length decrease. It is possible to neglect the radiative heat transfer effect when Planck number is over one.

• Journal of Navigation and Port Research
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• v.28 no.4
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• pp.293-297
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• 2004

In this papers, an S-band oscillator of the low phase noise property using a miniaturized micro-strip hairpin shaped ring resonator is presented The substrate has a dielectric constant $\epsilon_\gamma$＝3.5, a thickness h＝0.508 mm, and loss tangent $tan\delta$＝0.002. A designed and fabricated oscillator shows low phase noise performance of 99. 71 dBc/Hz at 100 KHz offset frequency and of output power 19.584 dBm at center frequency 2.450 GHz. This circuit was fabricated with hybrid technique, but can be fully compatible with the MMIC due to its entirely planar structure.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.7
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• pp.49-59
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• 2014

Effects of the dielectric constant and thickness of a feed substrate on the bandwidth and radiation characteristics of an aperture coupled microstrip patch antenna (ACMPA) are investigated. The optimized return loss bandwidth of an ACMPA increases without the degradation of radiation characteristics as the feed substrate dielectric constant increases for the same feed substrate thickness. The optimized return loss bandwidth of an ACMPA with the dielectric constant of a feed substrate of 10, which is compatible with the high dielectric constant monolithic microwave integrated circuit (MMIC) materials, increases without the degradation of radiation characteristics as the thickness of a feed substrate decreases. The ACMPA configuration is suitable for integration with MMICs.