• Phonetics and Speech Sciences
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• v.9 no.2
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• pp.31-38
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• 2017

This study aims to examine the acoustic characteristics of Korean sibilant, especially aspiration in Korean fricatives (plain: /s/, fortis: /s'/) and affricates (aspirated: /$ts^h$/, lenis: /ts/, and fortis: /ts'/). Duration values (closure duration, frication duration, aspiration duration), center of gravity (COG) (of the total duration, of the two portions, in 10 ms), H1-H2 values (at the vowel onset) were examined in order to investigate the phonetic feature of aspiration in frication noise. This study further discusses how to define criteria for identifying aspiration in sibilant sounds by adopting 3 visual criteria for assessing aspiration. This visually-designated aspiration onset points are further matched with the COG decline points in 10 ms windows. The result shows that all the non-fortis sounds (/s/, /$ts^h$/, /ts/) contain aspiration, causing similar values of COG and H1-H2.

• MALSORI
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• no.44
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• pp.61-72
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• 2002

The purpose of this research is to investigate how Japanese speakers perceive and produce Lenis, Aspirated and Fortis consonants in Korean. Identification tasks and production tasks were performed. The error analysis of both task showed that the participants had a significant difficulty in discriminating between Lenis and Aspirated sounds. And it was observed that there was a positive correlation between identification scores and production scores.

• Proceedings of the KSPS conference
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• 2007.05a
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• pp.84-87
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• 2007

The final purpose of this paper is to prove that, under noisy environment, there is significant difference of perceptibility of the place of articulation between fortis plosives and aspirated plosives in Korean. For this research, a perceptual experiment had been made. Two groups of subjects heard stimuli with noise and were required to answer which sound they had heard. The result is that, with noise, aspirated plosives cannot be heard clearly whereas fortis plosives can be heard well.

• MALSORI
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• no.47
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• pp.73-84
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• 2003

This study investigates differences in intensity across the three different Korean obstruent types in terms of the RMS amplitude of both the entire section and the first 512 samples of the immediately following vowel in two positions. The results showed that for the utterance initial position the RMS amplitude of both the entire section and the first 512 samples of the vowel was greatest for fortis obstruents, intermediate for aspirated ones, and weakest for lenis ones, with a significant difference between each pair of them. For the intervocalic position, in contrast, the intensity of the entire vowel was greatest for fortis obstruents, intermediate for lenis ones, and weakest for aspirated ones, with no significant difference between the last two groups, whereas the intensity of the first 512 samples of the vowel was greatest for fortis obstruents, intermediate for lenis ones, and weakest for aspirated ones, with a significant difference between each pair of the three groups. This means that the intensity of the earlier part of the vowel functions as a discriminator of Korean obstruents. The positional difference is due to the different behavior of the lenis obstruents in the intervocalic position, such that the intensity build-up is already on its way with voice lead.

• MALSORI
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• no.spc1
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• pp.24-32
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• 2002

• MALSORI
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• no.64
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• pp.53-76
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• 2007

This study investigates phonation types of Korean obstruents associated with the vowels immediately following singletons or geminates in intervocalic positions. F0, H1-H2, and spectral tilt were measured from the 20 ms segment at the onset of the vowels for the tokens of /paCa/ and /paCCa/, where Cs are of the same manner and place of articulation. The results showed a remarkable change in the values of F0, H1-H2, and spectral tilt as the preceding obstruents shifts from the lenis singletons to the lenis geminates, which suggests that the spectral characteristics of the vowels following the lenis geminates are not different from those of the vowels following fortis singletons or geminates. Significantly enough, this study adds data about the spectral characteristics of Korean phonation types.

• Journal of Cardiovascular Imaging
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• v.31 no.1
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• pp.1-17
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• 2023

The Coronary Artery Calcium Data and Reporting System (CAC-DRS) is a standardized reporting method for calcium scoring on computed tomography. CAC-DRS is applied on a per-patient basis and represents the total calcium score with the number of vessels involved. There are 4 risk categories ranging from CAC-DRS 0 to CAC-DRS 3. CAC-DRS also provides risk prediction and treatment recommendations for each category. The main strengths of CAC-DRS include a detailed and meaningful representation of CAC, improved communication between physicians, risk stratification, appropriate treatment recommendations, and uniform data collection, which provides a framework for education and research. The major limitations of CAC-DRS include a few missing components, an overly simple visual approach without any standard reference, and treatment recommendations lacking a basis in clinical trials. This consistent yet straightforward method has the potential to systemize CAC scoring in both gated and non-gated scans.

• Journal of Cardiovascular Imaging
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• v.30 no.1
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• pp.1-24
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• 2022

The Coronary Artery Disease Reporting and Data System (CAD-RADS) is a standardized reporting method for coronary computed tomography angiography (CCTA). It summarizes the findings of CCTA in 6 categories ranging from CAD-RADS 0 (complete absence of coronary artery disease) to CAD-RADS 5 (total occlusion of at least one vessel). It is applied on per patient basis for the highest grade of the stenotic lesion. The CAD-RADS also provides categoryspecific treatment recommendations, helping patient management. The main objectives of the CAD-RADS are to improve the consistency in reporting, facilitate the communication between interpreting and referring clinicians, recommend the best course of patient management, and produce consistent data for quality improvement, research and education. However, CAD-RADS has many limitations, resulting into the misclassification of the observed findings, misinterpretation of the final category, and misguidance for the treatment based upon the single score. In this review, the authors discuss the CAD-RADS categories and modifiers, along with the strengths and limitations of this new classification system.

• Clinics in Shoulder and Elbow
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• v.10 no.1
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• pp.150-154
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• 2007

• Cross-Cultural Studies
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• v.27
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• pp.497-523
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• 2012

Characteristics of the Listening and Pronunciation of Korean Obstruents of Chinese Learners -Based on the Phonetic Experiments Using Kalvin and Praat- This study aims at investigating the characteristics of confrontation in three ways, lax/ fortis/ aspirated consonants, in Korean obstruents through experimental phonetic analysis for the Chinese Korean language learners. On one hand, as a result of comparing Korean and Chinese obstruent systems, there is no big difference regarding the articulatory location. On the other hand, in regards to the articulatory method there is a difference. In a Korean obstruent system, the confrontation presented in three ways by the strength of aspiration. On the contrary, the Chinese obstruent system showed confrontation in two ways by the existence of aspiration. To examine the difficulty of the learners caused by the above-mentioned reason objectively, this paper studied the relationship between input and output of sound through the experimental phonetic analysis such as Kalvin and Praat. To research the input of sound, the listening ability of the learners was examined by 'Choosing Consonant' among the Menu of Kalvin. As a result of that experiment, many errors were shown. They recognized the fortis as lax in the area of affricates and plosives. In the area of fricatives, they recognized affricatives as fricatives. To investigate the output of sound, the section of aspiration and the section of friction of a plosive, an affricate and a fricative in Praat, were expressed numerically. The learners' VOT of lax and affricate represented that lax was pronounced close to the fortis, and the VOT of fricatives was not shown the section of aspiration and friction clearly, and also the result showed that they pronounced a fricative like affricative-aspirated one. The result shows that the learners' pronunciation is related to the listening ability. The consequence is caused by the characteristics of the difference between Korean obstruents and Chinese ones. If the training pronunciation is conducted based on above result, it would be a better methodology in teaching Korean.