• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1999년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring
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• pp.35-40
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• 1999

In order to know the characteristics of attenuation of coda wave in the Kyungsang Sedimentary Basin quality factor for coda wave or coda Q is estimated from the earthquake data recorded in the KIGAM microearthquake network. The single scattering model for coda wave generation is adopted in estimating coda Q. Coda Q appears to be largely dependent on the normalized time(a) which is the ratio of elapsed time to S-wave travel time. In the present study coda Q(Qc) is estimated in the range of a=1.5-3.Q and expressed in terms of frequency(f). The deduced function in the range of 1 to 25 Hz is Qc=36.8283 f1.15095 to represent the strong dependence of coda Q on frequency. It is found that the difference of Qc between U-D N-S and E-W components is negligible, This face supports the back-scattering theory that coda were originates from scattered waves by randomly distributed heterogeneities in the crust. On the other hand it is observed that the coda Q increases with depth.

• 자원환경지질
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• 제32권4호
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• pp.379-384
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• 1999

In order to know the characteristics of attenuation of coda wave in the Kyungsang Sedimetary Basin, quality faclity factor for coda wave (coda Q) is estimated from the earthquake data recorded in the KIGAM local seismic network. Thesingle scattering model for coda wave generation is adopted is adopted in estimating coda Q. In the present study, coda Q(Qc)is estimated in the range of $\alpha$=1.5~3.0, where $\alpha$ denotes the normalized time to S-wave travel time and expressed in terms of frequency (f). The deduced function in the range of 1 to 25 Hz is Qc=36.8283$f^{1.15095}$ which represents the strong dependence of coda Q on frequency. It is found that the difference of Qc between U-D, N-S, and E-W components is negligible. This fact suports the back scattering therory that coda wave originates from scattered waves by randomly distributed heterogenities in the crust On the other hand, it is observed that the coda Q increases with increasing epicentral distence. This observation suggests that QC increases with depth.

• 음성과학
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• 제6권
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• pp.103-117
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• 1999

This paper suggests that the onset-coda asymmetry found in languages like Korean and others should be dealt with in terms of one acoustic feature rather than other articulatory features, claiming that the acoustic feature involved here is [noise], i.e., 'aperiodic waveform energy'. It determines the structural well-formedness of the languages in question whether a coda ends in [noise] or not, regardless of the intensity, the frequency, and the time duration of the [noise]. Fricatives, affricates, aspirated stops, tense stops, and released stops are all disallowed in the coda position due to the acoustic feature [noise] they, commonly end with if they were, posited in the coda. The proposal implies that the three seemingly separate prohibitions of consonants in the coda position -- i) no fricatives/affricates, ii) no aspirated/tense stops, and iii) no released stops -- are directly correlated with each other. Incorporation of the one acoustic feature [noise] in the feature theory enables us to see that the aspects of onset-coda asymmetry are derived from one single source: ban, of [noise] in the coda.

• 말소리와 음성과학
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• 제2권2호
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• pp.17-25
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• 2010

This study explores whether Koreans exploit their native coda-neutralization process when recognizing words in Korean continuous speech. According to the phonological rules in Korean, coda-neutralization process must come before the liaison process, as long as the latter(i.e. liaison process) occurs between 'words', which results in liaison-consonants being coda-neutralized ones such as /b/, /d/, or /g/, rather than non-neutralized ones like /p/, /t/, /k/, /ʧ/, /ʤ/, or /s/. Consequently, if Korean listeners use their native coda-neutralization rules when processing speech input, word recognition will be hampered when non-neutralized consonants precede vowel-initial targets. Word-spotting and word-monitoring tasks were conducted in Experiment 1 and 2, respectively. In both experiments, listeners recognized words faster and more accurately when vowel-initial target words were preceded by coda-neutralized consonants than when preceded by coda non-neutralized ones. The results show that Korean listeners exploit the coda-neutralization process when processing their native spoken language.

• 말소리와 음성과학
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• 제8권4호
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• pp.79-87
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• 2016

The purpose of this study aimed to examine the perceptual pattern of the Korean coda consonants by Chinese learners of Korean. Given that Mandarin allows only two nasals (/n, ŋ/) in the coda position, it was predicted that Chinese learners of Korean had difficulty in discriminating Korean coda consonants. In the experiment, the subjects were 21 beginner-level Chinese learners of Korean. They participated in the discrimination task four times a year in which they were asked to choose the right Korean coda consonants after listening the word from Korean native speakers. The results demonstrated that 1) Chinese learners of Korean improved their perception of the Korean coda consonants. 2) But Chinese learners of Korean performed differently according to the type of Korean coda consonants. Korean consonants /n, p, k, m/ showed significant differences, but /l, ŋ, t/ did not.

• 말소리와 음성과학
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• 제2권1호
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• pp.59-68
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• 2010

This study addresses the issue of whether Korean(L1)-English(L2) non-proficient bilinguals are affected by the native coda-neutralization process when recognizing words in English continuous speech. Korean phonological rules require that if liaison occurs between 'words', then coda-neutralization process must come before the liaison process, which results in liaison-consonants being coda-neutralized ones such as /b/, /d/, or /g/, rather than non-neutralized ones like /p/, /t/, /k/, /$t{\int}$/, /$d_{\Im}$/, or /s/. Consequently, if Korean listeners apply their native coda-neutralization rules to English speech input, word detection will be easier when coda-neutralized consonants precede target words than when non-neutralized ones do. Word-spotting and word-monitoring tasks were used in Experiment 1 and 2, respectively. In both experiments, listeners detected words faster and more accurately when vowel-initial target words were preceded by coda-neutralized consonants than when preceded by coda non-neutralized ones. The results show that Korean listeners exploit their native phonological process when processing English, irrespective of whether the native process is appropriate or not.

• 말소리와 음성과학
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• 제5권3호
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• pp.73-81
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• 2013

Coda in the word-medial position plays an important role in acquisition of our speech. Accuracy of the coda in the word-medial position is important as a diagnostic indicator since it has a close relationship with degrees of disorder. Coda in the word-medial position only appears in condition of connecting two vowels and the sequence causes diverse phonological processes to happen. The coda in the word-medial position differs in production difficulty by the initial sound in the sequence. Accordingly, this study aims to examine the tendency of producing a coda in the word-medial position with consideration of an optional phonological process in spontaneous speech of three and four year old children. Data was collected from 24 children (four groups by age) without speech and language delay. The results of the study are as follows: 1) Sonorant coda in the word-medial position showed a high production frequency in manner of articulation, and alveolar in place of articulation. When the coda in the word-medial position is connected to an initial sound in the same place of articulation, it revealed a high frequency of production. 2) The coda in word-medial position followed by an initial alveolar stop revealed a high error rate. Error patterns showed regressive assimilation predominantly. 3) The order of difficulty that Children had producing codas in the word-medial position was $/k^{\neg}/$, $/p^{\neg}/$, /m/, /n/, /ŋ/ and /l/. Those results suggest that in targeting coda in the word-medial position for evaluation, we should consider optional phonological process as well as the following initial sound. Further studies would be necessary which codas in the word-medial position will be used for therapeutic purpose.

• 말소리와 음성과학
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• 제7권1호
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• pp.67-77
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• 2015

The purpose of this study was to investigate how deaf parents influence the speech sounds of their normal-hearing children. Twenty four normal hearing children of deaf adults (CODA) and normal hearing parents (NORMAL) aged 3 to 4 participated in the study. The F1, F2, and the vowel triangle area in 7 vowels and the voice onset times (VOTs) and closure durations in 9 stops were measured. The results of the study are as follows. First, the F1 and F2 for all vowels were higher and the vowel triangle area was larger in CODA than in NORMAL although they were not statistically significant. Second, VOTs in $C_{stop}V$ for $/t^*/$ and in $VC_{stop}V$ for $/t^*/$, $/t^h/$, and $/k^h/$ were longer in CODA than in NORMAL. Most stops in CODA appeared to be longer VOTs for most phonemes. Third, the manner and place of articulation in stops did not make a difference between CODA and NORMAL in VOTs and closed durations. CODA does not demonstrate the speech characteristics of deaf people, however, they seem to speak differently than NORMAL, which means CODA might be influenced by a different linguistic environment created by deaf parents in some way.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2005년도 공동학술대회 논문집
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• pp.37-42
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• 2005

한반도 남부 지각에서의 지진파 감쇠 양상을 나타내는 Q값을 구하기 위해 한국지질자원연구원(KIGAM)과 기상청(KMA)의 지진파 자료 중 진앙거리가 100km 이내이고 Sampling 비가 80Hz 이상인 NS방향의 540개 자료를 분석하였다. 각각의 자료에 대해 단일 산란 모델을 적용하여, S파 주시의 두 배부터 20초 길이를 가지는 시간창 위에서 1Hz, 1.5Hz, 3Hz, 6Hz, 9Hz, 12Hz, 15Hz, 18Hz의 주파수 별 coda Q 값을 구하였다. 이렇게 구한 각각의 coda Q, 즉 $Q_c$값으로부터 주파수 관계식(f> 1Hz 일 때 $Q_c=Q_{0}f^n$)을 이용하여 1Hz 에서의 coda Q, $Q_0$를 구하였다. 한반도의 $Q_0$값은 50과 250사이 그리고 n 값은 0.5 와 1.0 사이에 있고 그 지역적 분포는 반도 내 지질구조와 잘 연관됨이 밝혀졌다. 또한 반도 서해부근의 Q 값은 중국 동쪽의 값과 잘 연결되는 것을 볼 수 있었다.

• 말소리와 음성과학
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• 제3권4호
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• pp.23-31
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• 2011

This paper examines the production patterns of the acquisition of coda consonants in monosyllabic words in English-speaking children with cochlear implants. The data come from the transcribed speech of children with cochlear implants. This study poses three questions. First, do children with cochlear implants acquire onset consonants earlier than codas? Second, do children's productions have a bimoraic-sized constraint that maintains binary feet? Third, what patterns emerge from production of coda consonants? The results revealed that children with cochlear implants acquire onset consonants earlier than codas. With regard to the bimoraic-sized constraints, the productions of vowel type (i.e., monomoraic and bimoraic) were more accurate for monomoraic vowels than bimoraic ones for some children with cochlear implants, although accuracy in vowel productions showed high proportion regardless of vowel types. The variations of coda production exhibited individual differences. Some children produced less sonorant consonants with high frequency and others produced more sonorant ones. The results of this study were similar to those pertaining to children with normal hearing. In the process of coda consonant acquisition, the error patterns of prosody-sensitive production may be regarded as articulatory challenges to produce higher-level prosodic structures.