• 대한수학회논문집
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• 제27권2호
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• pp.385-397
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• 2012

The purpose of this paper is to improve certain results proved in a recent paper of Soliman et al. [20]. These results are the outcome of utilizing the idea of absorbing pairs due to Gopal et al. [6] as opposed to two conditions namely: weak compatibility and the peculiar condition initiated by Pant [15] to ascertain the common fixed points of Lipschitzian mappings. Some illustrative examples are also furnished to highlight the realized improvements.

• The Journal of the Acoustical Society of Korea
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• 제25권2E호
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• pp.79-84
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• 2006

Acoustic characteristics of a sound absorbing material can be identified, if the characteristic impedance and propagation constants are known, which have generally been determined experimentally. One easy method determining these two essential parameters is to measure the one dimensional wave characteristics in the impedance tube. In th udy, the effects of backing conditions on the impedance tube measurement have been examined using several pairs of generally used end conditions. The results showed that the measured values are similar for most pairs of end conditions: however, it was observed that the measured characteristic impedance for different thickness did not agree well for some pairs. In this work, the multi termination method, using three or more known backing con ns, was suggested to reduce such random errors, which are mostly caused by the test procedure. Employing three terminations as a set, comprised of a rigid end, an end with porous material, and an end with a backing cavity, it was demonstrated that improved measured results could be obtained for an open cell PU foam varying widely with three different thicknesses.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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• pp.888-891
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• 2001

Effects of backing conditions on the impedance tube measurement are investigated experimentally, by using several pairs of generally employed end conditions. The results show that the measured values are similar for most of pairs, except the case of using an open pipe condition. In addition, the random error is investigated in the viewpoint of the variation of test conditions. The multi-termination method is suggested for minimizing such a random error.

• 한국광학회지
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• 제1권1호
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• pp.40-45
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• 1990

반도체 실리콘은 띠간격 근처의 에너지를 갖는 광자를 흡수하여 생성된 전자-정공쌍에 의해 굴절률이 비선형적으로 변하며 이에 따라 입사한 광펄스를 변조시킨다. Finesse가 큰 실리콘 Fabry-Perot 간섭계를 형성할 때, 이를 투과하는 광펄스가 실리콘의 굴절률을 변화시켜 스스로 간섭계의 보강간섭조건을 만족시킴으로써 반치폭이 1/5까지 축약되는 현상을 관측하였다. 그리고 관측된 결과는 수치해석으로 구한 결과와 잘 일치하였다.