• The Journal of the Korea Contents Association
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• v.12 no.11
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• pp.9-19
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• 2012

Time-varying tempo of a song is one of the error sources for the identification of a note duration in automatic music recognition. This paper proposes an improved music transcription scheme equipped with the identification of note duration considering the time-varying tempo. In the proposed scheme the measures are found at first and the tempo, the playing time of each measure, is then estimated. The tempo is then used for resizing each IOI(Inter Onset Interval) length and considered to identify the accurate note duration, which increases the degree of correspondence to the music piece. In the experiment the proposed scheme found the accurate measure position for 14 monophonic children songs out of 16 ones recorded by men and women. Also, it achieved about 89.4% and 84.8% of the degree of matching to the original music piece for identification of note duration and pitch, respectively.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.4
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• pp.371-377
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• 2013

This paper proposes three methods for improving the accuracy of auto-music transcription considering with time-varying tempo from monophonic sound. The first one that uses TV(Total Variation) filter for smoothing the pitch data reduces the fragmentation in the pitch segmentation result. Also, the measure finding method that combines three different ways based on pitch and energy of sound data, respectively as well as based on rules produces more stable result. In addition the temporal result of note-length encoding is corrected in optimal way that the resulted encoding minimizes the sum of quantization error in a measure while the sum of note-lengths is equal to the number of beats. In the experiment with 16 children songs, we obtained the improved result in which measure finding was complete, the accuracy of encoding for note-length and pitch was about 91.3 and 86.7, respectively.

• Animal Systematics, Evolution and Diversity
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• v.30 no.1
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• pp.39-43
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• 2014

In this brief report, alternative time-varying diversification rate models were fitted onto the phylogeny of global amphibians by considering one-constant-rate (OCR), one-continuous-shift (OCS) and multiple-discrete- shifts (MDS) situations. The OCS diversification model was rejected by ${\gamma}$ statistic (${\gamma}=-5.556$, p<0.001), implying the existence of shifting diversification rates for global amphibian phylogeny. Through model selection, MDS diversification model outperformed OCS and OCR models using "laser" package under R environment. Moreover, MDS models, implemented using another R package "MEDUSA", indicated that there were sixteen shifts over the internal nodes for amphibian phylogeny. Conclusively, both OCS and MDS models are recommended to compare so as to better quantify rate-shifting trends of species diversification. MDS diversification models should be preferential for large phylogenies using "MEDUSA" package in which any arbitrary numbers of shifts are allowed to model.