• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.7061-7070
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• 2015

Multi-Response Surface Optimization aims at finding the optimal setting of input variables considering multiple responses simultaneously. The Weighted Mean Squared Error (WMSE) minimization approach, which imposes a different weight on the two components of mean squared error, squared bias and variance, first obtains WMSE for each response and then minimizes all the WMSEs at once. Most of the methods proposed for the WMSE minimization approach to date are classified into the prior preference articulation approach, which requires that a decision maker (DM) provides his/her preference information a priori. However, it is quite difficult for the DM to provide such information in advance, because he/she cannot experience the relationships or conflicts among the responses. To overcome this limitation, this paper proposes a posterior preference articulation method to the WMSE minimization approach. The proposed method first generates all (or most) of the nondominated solutions without the DM's preference information. Then, the DM selects the best one from the set of nondominated solutions a posteriori. Its advantage is that it provides an opportunity for the DM to understand the tradeoffs in the entire set of nondominated solutions and effectively obtains the most preferred solution suitable for his/her preference structure.

• Phonetics and Speech Sciences
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• v.5 no.3
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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.

• Proceedings of the KSPS conference
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• 2007.05a
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• pp.155-157
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• 2007

Objective : There are close relationship between intraoral abnormal structure and speech-functional problem. Patients with cleft palate & ankyloglossia are typical examples. Patients with abnormal structure can be repaired toward normal structure by operation. Ankyloglossia may cause functional limitation - for example, speech disorder - even if adequate surgical treatment were done. And, each individuals have each speech disorders. The objective of this study is to evaluate the speechs of childrens with ankyloglossia, and to determine whether ankyloglossia is associated with articulation problem. We wanted to present criteria for indication of frenectomy. Study design The experimental group is composed of 10 childrens who visited our department of oral and maxillofacial surgery, dental hospital, Chonbuk university, due to ankyloglossia and articulation problem,. The average age is 5 Y 7M, M : F ratio is 4 : 1 at the time of speech test. The VPI consonant discrimination degree, PPVT, PCAT, Nasometer II, Visi-Pitch test result were obtained from each group. Result : There was significant difference for 'language development' through PPVT. Except 3 members of experimental group, all remainder showed retardation for 'language development'. For 'errored consonant rate', data showed more higher scores in alveolar consonant. There 'consonant error' in experimental group, mostly showed 'alveolar consonant', also a major modality of 'consonant error' was mostly distortion. Conclusion : We can judge the severity of ankyloglossia patient by examinig language development degree & speech test of 'alveolar consonant' . And we can make a decision for frenulotomy using these results.

• Phonetics and Speech Sciences
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• v.3 no.3
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• pp.181-189
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• 2011

The present study aimed to determine the phonological errors of children in Korean-Vietnamese speaking multicultural families through comparison analyses with those of Korean monolingual peers with phonological disorders. The subjects were 38 children aged about 4-6 years. To examine phonological errors, the Urimal Test of Articulation and Phonation (words) was used. Performances were analyzed by frequency. The results showed some differences between the two groups. There was a tendency for children in Korean-Vietnamese speaking multicultural families to show a higher frequency of phonological errors than Korean monolingual children with phonological disorders. However, the former showed lower error percentages in a few error patterns than the latter such as syllable final consonant deletion, showing similar patterns to those of the normal children. They also showed very unique error patterns such as the highest error percentage in palatal affricates. It remains to be seen if these error patterns are just delay in acquisition or phonological disorders.

• Clinical and Experimental Pediatrics
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• v.53 no.4
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• pp.579-584
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• 2010

Purpose : The number of the repatriated Korean students who had overseas study at early ages is increasing. They received foreign education, they can speak international languages, but they have many difficulties in articulation and intonation of the Korean language. This study aims to measure closure and aspiration duration, length of consonants, length of subsequent vowels, and ratio of consonants against subsequent vowels in vowel-consonant-vowel (VCV) syllables. Methods : This study compares the acoustic and phonetic characteristics of repatriated and native students, the ratio of articulation error of Korean plosives, the closure and aspiration duration, and the ratio of the aspiration duration against the closure duration. Results : The ratio of articulation error of Korean plosives between repatriated and native students is 19% and 2%, respectively. The closure duration was significantly longer in repatriated students than in native students. The aspiration duration was significantly longer in repatriated students than in native students. No difference was found in the ratio of aspiration duration against closure duration between the native and repatriated students. Conclusion : This study can be a good reference for estimating the phonetic difficulties of Korean elementary students who had overseas study at early ages.

• Phonetics and Speech Sciences
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• v.7 no.2
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• pp.3-8
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• 2015

Denasalization that nasals are replaced by stops is an unusual error pattern related to manner of articulation. The purpose of this study is to investigate the prevalence of denasalization and to scrutinize the nasal production according to phonological context for typically developing children and children with speech sound disorders(SSD). 220 typically developing children and 48 SSD children from 2~6 years of age were tested with a formal word test, and those who demonstrate denasalization were selected. In addition, the nasal production of SSD children with denasalization were analyzed for the correctness and the error types using the formal word test and spontaneous conversation. The results were as follows: (1) Denasalization was shown in below 10% of 2-3 years of age with typically developing children and in above 20% of 2-5 years of age with SSD. (2) The SSD children who demonstrate denasalization were categorized into 4 types according to the error context of nasals; nasal errors with all word positions, nasal errors with word-final and word-medial positions, nasal errors with word-medial position preceding vowels, and nasal errors with word-medial position preceding obstruents. These results indicate that denasalization is a clinically important error pattern, and word-medial position preceding obstruents is an essential context for denasalization in terms of Korean phonotactics.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.10
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• pp.1816-1823
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• 1992

In order to develop general CMAC training technique applicable to any CMAC, characteristics of CMAC learning algorithm and training problems of CMAC are studied. Neighborhood Sequential Training technique which is general and free fro CMAC learning interference is proposed. The technique is used to generate mathematical functions and found to be effective.

• Phonetics and Speech Sciences
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• v.5 no.1
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• pp.47-54
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• 2013

The aim of this study was to analyze consonant articulation errors produced by 90 speakers with cerebral palsy (CP). Phonetic transcriptions were made for 37 single-word utterances containing 70 phonemes: 48 initial consonants and 22 final consonants. Errors of substitution, omission, and distortion were analyzed using a confusion matrix paradigm showing the visualization of error patterns. Results showed that substitution errors in initial and final consonants were most frequent, followed by omission and distortion. Consonant omission occurred more frequently on final consonants. In both initial and final consonants, the within-place errors were more prominent than the within-manner errors. The current results suggest that consonant confusion matrices for dysarthric speech may provide useful information for evaluating speech intelligibility and developing automatic speech recognition system of adults with CP associated dysarthria.

• The Journal of Korean Physical Therapy
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• v.1 no.1
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• pp.47-61
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• 1989

This paper presents the event approach to motor skill acquisition as a theoretical treatment of the learning and relearning of motor skill. 1) The use of norm-referenced developmental assesment tools and standardized qualitative assessment tool is an important component of infant movement evaluation. 2) The kinesthetic modality relaying movement and position imformation to the central nervous system is important for the detection and corretion of movement error. 3) The event approach treats the actor and the environment as inseparable in the acquisition of skills. 4) Motoy learning focuses almost entirely on how the skill is learned, contRolled and reTained. 5) Developmental assessment have needed an assessment of motor development. 6) A significant difference was found between articulation disorders children and motor coordination problem. 7) verbal ability is not essential for the learning of motor skills. 8) The Control of motor skills is a cognitive ability.

• Speech Sciences
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• v.8 no.2
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• pp.93-106
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• 2001

The pronunciation of English l and r was a consistent problem in learning English in Korea as well as Japan. This problem occurs from the fact that in Korea and Japan there is only one liquid sound. Substituting the Korean liquid for English l and r was a common error. The pronunciation of the dark l causes a further problem in pronouncing the English l sound. To see the relationship between the English l, r, and the Korean liquid sound, an electropalatographic (EPG) experiment was done. The findings were (1) there were no tongue contacts either on the alveolar ridge or on the palate during the articulation of the dark l. (2) The Korean liquid sound was different in the tongue contact points either from English l or r. The English clear l consistently touched the alveolar ridge in the forty tokens, but the Korean liquid sound in the intervocalic and word-final position touched mainly the alveopalatal area. The English r touched exclusively the velum area. The Korean intervocalic /l/ was similar to English flap in EPG and spectrographic data. There was evidence that the word-final Korean /l/ is a lateral.