• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.10
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• pp.885-894
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• 2013

In this study, a new hybrid mount with a moving-coil-type electromagnetic actuator is developed to reduce the vibration transmitted from naval shipboard equipment to the ship hull structure. The detailed design of the hybrid mount is determined through several design stages with electromagnetic numerical analysis using Maxwell software. The hybrid mount, which combines a rubber mount with an electromagnetic actuator, has a fail-safe function for shock resistance. The mount is fabricated and tested using a universal testing machine to check the design specifications. Finally, control tests are carried out on the hybrid mount to confirm its performance and applicability.

• MALSORI
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• no.45
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• pp.23-33
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• 2003

This is a study on perception errors of Korean stops in word initial position. This study will show how listeners perceive manipulated Korean stops through two experiments and I will analyze why they are confused. In addition, 1 will show those perception errors not only reflect the relationship between the place and manner of articulation but also ate deeply related to the length of aspiration.

• The Journal of the Acoustical Society of Korea
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• v.41 no.1
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• pp.99-107
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• 2022

This study attempted to analyze the consonant perception ability and errors and to verify compatibility items for hearing impaired children wearing hearing aids and cochlear implants using the Phoneme Perception Test for School-Aged children (PPT-S). As a result of the study, it was found that children with hearing impairments have more difficulty in perceiving final consonants than initial consonants. The hard type of PPT-S, in which the articulation method and articulation place of the target and foil words are similar, felt more difficult than the easy type. Among the initial consonants, the incorrect response rate for aspiration sound was higher. In the case of final consonants, the incorrect answer rate for 'ㄷ' and 'ㅁ' was relatively higher. There was no significant difference in the percentage of correct response rate according to the gender of the speaker. The above results can be usefully used as basic data for standardizing of PPT-S and evaluating the intervention effects before and after hearing rehabilitation with hearing impaired children.

• Phonetics and Speech Sciences
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• v.6 no.3
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• pp.121-130
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• 2014

This study investigates the acoustic property of aspiration realized in English voiceless stops of /Cr/ and /sCr/ clusters. VOT is measured from stops in these clusters produced by two groups; one from native speakers of English and the other from Korean native speakers. Aspiration of stops in different types of clusters is compared to various phonological factors such as location of stress, syllable type, and position in word. Pursuing the idea that phonetic realization is correlated with phonological representation, attempts are made to account for the gradient nature of aspiration of stops on the basis of syllable structure at the phonetic level, which may vary in the wake of resyllabification. Voiceless stops in /Cr/ and /sCr/ clusters are further compared to results obtained in the previous study on /sC/ cluster. Variations in aspiration are also characterized in terms of segmental precedence relation of stops in the clusters, namely, post-[s], pre-[r], or both.

• Phonetics and Speech Sciences
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• v.11 no.4
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• pp.45-53
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• 2019

The purpose of this work was to examine the factors affecting the identities of the voiceless plosives, i.e. English [p, t, k] and Korean [p^h, t^h, k^h], from the spontaneous speech corpora. The factors were automatically extracted by a Praat script and the percent correctness of the discriminant analyses was incrementally assessed by increasing the number of factors used in predicting the identities of the plosives. The factors included the spectral moments and tilts of the plosive release bursts, the post-burst aspirations and the vowel onsets, the durations such as the closure durations and the voice onset times (VOTs), the locations within words and utterances and the identities of the following vowels. The results showed that as the number of factors increased up to five, so did the percent correctness of the analyses, resulting in 74.6% for English and 66.4% for Korean. However, the optimal number of factors for the maximum percent correctness was four, i.e. the spectral moments and tilts of the release bursts and the following vowels, the closure durations and the VOTs. This suggests that the identities of the voiceless plosives are mostly determined by their internal and vowel onset cues.