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다중 다공판 시스템에서 직관요소에 대한 전기음향등가회로법의 오류
이동훈,권영필 한국소음진동공학회 2003 한국소음진동공학회 논문집 Vol.13 No.3
The equivalent electroacoustic circuit approach has been conventionally used for the analysis of the multiple layer perforated plate system. However, it is found that an analogy error has been involved in the equivalent electroacoustic approach proposed by previous researchers for the element of straight pipe. Although the pipe between the perforated layers is a distributed element in the analogy, it has been treated as a parallel element by previous investigators. The analogy error is demonstrated by comparing the calculated absorption coefficients based on the parallel circuit and the distributed circuit, respectively, with the measured values by the two-microphone impedance tube method.

이동훈,김영준,강현삼,이병재 한국유전학회 1986 Genes & Genomics Vol.8 No.2
The nucleotide sequences of tRNAs were compared and the homologies between a pair of sequences were calculated. The homology is high between phylogenically related organisms, but low between eukaryote and prokaryote. The organelle's tRNA sequence shows very lower homology with chromosomal tRNA sequence. The homology and evolotionary distance was obtained by the method of Kimura (1980) with the sequences of chromosomal tRNAs which have the same anticodon (GUC) to compare orthologous genes. The phylogenic tree was constructed by unweighted pairgroup method using arithmatic average (UPGMA). The time of divergence of prokaryote and eukaryote was estimated to be 6.4×10^(10) years ago and the branching order in this phylogenic tree was in good agreement with that obtained by primary protein structures and 5S rRNA sequences.

이동훈,뢰호방총,Lee, Dong-Hoon,Seto, Kunisato 대한기계학회 2000 大韓機械學會論文集B Vol.24 No.1
The objective of this study is to experimentally investigate the noise propagating characteristics, the noise reduction mechanism and the performance of a slotted tube attached at the exit plane of a circular convergent nozzle. The experiment is performed through the systematic change of the jet pressure ratio and the slot length under the condition of two kinds of open area ratios, 25% and 51%. The open area ratio calculated by the tube length equivalent for the slot length is defined as the ratio of the total slot area to the surface area of a slotted tube. The experimental results for the near and far field sound, the visualization of jet structures and the static pressure distributions in the jet passing through a slotted tube are presented and explained in comparison with those for a simple tube. The propagating characteristics of supersonic jet noises from the slotted tube is closely connected with the slot length rather than the open area ratio, and its propagating pattern is similar to the simple tube. It is shown that the slotted tube has a good performance to suppress the shock-associated noise as well as the turbulent mixing noise in the range of a limited jet pressure and slot dimension. The considerable suppression of the shock‘associated noise is mainly due to the pressure relief caused by the high-speed jets passing through the slots on the tube. Both the strength of shock waves and the interval between them in a jet plume are decreased by the pressure relief. Moreover, the pressure relief is divided into the gradual and the sudden relief depending upon the open area ratio of the slotted tube. Consequently, the shock waves in a jet plume are also changed by the type of pressure relief. The gradual pressure relief caused by the slotted tube with the open area ratio 25% generates the weak oblique shock waves. On the contrary, the weak normal shock waves appear due to the sudden pressure relief caused by the slotted tube with the open area ratio 51%.