• Phonetics and Speech Sciences
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• v.9 no.1
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• pp.19-26
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• 2017

The main objective of this study is to investigate the influence of utterance internal pause in English speaking evaluation. To avoid possible confusion with other errors caused by segmental and prosodic inaccuracy, stem utterances with two different length obtained from a native speaker were manipulated to make a set of stimuli tokens through insertion of pauses whose length and position vary. After a total of 90 participants classified into three proficiency groups rated the stimuli, the scored data set was statistically analyzed in terms of the mixed effects model. It was confirmed that predictors such as pause length, pause position and utterance length significantly influence raters' evaluation scores. Especially, a dominating effect was found in such a way that raters gradually deducted scores in accordance with the increase of pause duration. In another experiment, a tree-based statistical learning technique was utilized to check which of the significant predictors played a more influential role than others. The findings in this paper are expected to be practically informative for both the test takers who are preparing for an English speaking test and the raters who desire to develop more objective rubric of speaking evaluation.

• MALSORI
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• no.67
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• pp.61-77
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• 2008

The purpose of this study is to blow the characteristics of disfluency in childhood. The subjects were 144 normal children at the age of between 3 to 8 years who lived in Seoul. All the subjects provided spontaneous conversational speech samples during free-play interactions with their friends. We investigated the patterns and the frequency of disfluency and its relevance with subject's age, speaking rate and MLU(mean length of utterance). The results of this study can be summarized as follows. (1) There was no difference in the frequency of disfluency with the speaker's age or speaking rate. (2) Interjection was the most frequently occurring pattern of disfluency. (3) Prolongation, revision, interjection increased with age while part-word repetition, single-syllable word repetition, multi-syllable word repetition decreased gradually. (4) A significant effect of MLU on the frequency of disfluencies were demonstrated. The regression analysis has shown that more disfluencies occurred in utterances of children whose MLU is longer.

• Speech Sciences
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• v.9 no.4
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• pp.143-148
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• 2002

This study examined the foreign accent of Korean speakers of English concerning vowel length and utterance position. It then attempts to explain the foreign accent of Koreans when they speak English. The method was to measure the sentence-initial and sentence-final vowels as spoken by Koreans. I chose these two positions, sentence-initial and sentence-final, in order to know if Korean speakers of English, compared with native English speakers, show a difference in sentence stress. I chose English diphthongs, because most Koreans have difficulty pronouncing these sounds. I found that Korean speakers of English as a second language do not know English sentence stress patterns and show a foreign accent, especially when using diphthongs.

• Phonetics and Speech Sciences
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• v.9 no.2
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• pp.85-94
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• 2017

Conventional speaker verification systems using time delay neural network, identity vector and probabilistic linear discriminant analysis (TDNN-Ivector-PLDA) are known to be very effective for verifying long-duration speech utterances. However, when test utterances are of short duration, duration mismatch between enrollment and test utterances significantly degrades the performance of TDNN-Ivector-PLDA systems. To compensate for the I-vector mismatch between long and short utterances, this paper proposes to use probabilistic linear discriminant analysis (PLDA) model adaptation with augmented data. A PLDA model is trained on vast amount of speech data, most of which have long duration. Then, the PLDA model is adapted with the I-vectors obtained from short-utterance data which are augmented by using vocal tract length perturbation (VTLP). In computer experiments using the NIST SRE 2008 database, the proposed method is shown to achieve significantly better performance than the conventional TDNN-Ivector-PLDA systems when there exists duration mismatch between enrollment and test utterances.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.16 no.2
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• pp.158-164
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• 2005

Melody intonation therepy (MIT) is to improve the linguistic aspects of the verbal utterance for aphasic patients utilizing the intact right brain. It is applied to the aphasic patients with good comprehension, poor fluency, and little available speech are thought to be ideal candidates. The purpose of the study was to investigate the effects of Korean Melody intonation therapy (kMIT) in patients with non-fluent aphasia. Five male non-fluent aphasic patients were participated in this study. Average ages were 49.9 years old. Each therapy took 45-50minutes once a week for six months. Aphasic Screen lest (RISS) was used to assess language parameter such as Auditory comprehension, oral expression, reading, writing and calculation ability before and after kMIT. Mean of Length Utterance, verbal intelligibility and articulation disorder were assessed also. Computerized Speech Lab was used to assess the acoustic characteristics of aphasic patients before and after kMIT. The results are as follows : 1) Auditory comprehension, oral expression, reading, writing and calculation ability of the subjects increased after UH'. However, only oral expression showed significant difference (p<0.05). 2) Mean of Length Utterance of five patients generally increased after Un. 3) After kMIT, verbal intelligibility increased and showed significant difference (p<0.05). 4) Misarticulation rate generally decreased after m. 5) Voice Onset Time of the alveolar lenis /t/ and velar lenis /k/ gradually decreased after kMIT. 6) However, intonation pattern were increased gradually in yes'no question after kMIT.

• Korean Journal of Childcare and Education
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• v.10 no.6
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• pp.43-56
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• 2014

The purpose of this study was to analyze the differences of preschoolers' utterance features by their gender and play situation type. For this purpose, a total of 40 5-year-old children participated in this study. Dyad were participated in each play session during 10 minutes. The play session was videotaped and the videotaped data were transcribed by CBS(2014). The collected data were analyzed by using a independent t-test and paired t-test. The main results are as follows. First, girls' MLU-e, MLU-w, MLU-m were longer than that of boys in a familiar play situation. Second, preschoolers' MLU-w was longer in an unfamiliar play situation than in familiar ones and preschoolers' type-token ratio were higher in an unfamiliar play situation than in familiar ones. Implications for the importance of preschoolers' spontaneous speech are discussed.

• Cross-Cultural Studies
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• v.22
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• pp.303-327
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• 2011

This study aims to uncover the learner's language proficiency shown in the writing data of Chinese elementary/intermediate level learners. Language proficiency of the learners acquired by error analysis provides only partial information, and thus this study analyses the interlanguage of Korean learners in terms of 'Mean Length of Utterance, MLU' to discover the overall aspect of learner's language proficiency more symmetrically. The analysis of vocabulary area is to be enforced after generally studying the learner's language development aspect in accordance with MLU-m(orpheme) and MLU-(w)ord found in compositions by Chinese speaking Korean language learners. In terms of MLU, it has been slightly increased as the level of proficiency between elementary level and intermediate level learners; however, the morpheme seemed to be difficult to use, since the difference between Chinese learners and Korean university students has been notably shown. Vocabulary diversity, using aspect for each word class, and using aspect of the predicate are studied for vocabulary area; more various and numerous vocabulary tend to be used as the level of proficiency increases. In terms of predicate use, Chinese learners use less numerous vocabulary types.

• Journal of the Korea Society of Computer and Information
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• v.13 no.7
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• pp.59-66
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• 2008

This paper describes a novel method for identifying the main topic and detecting topic changes in a text-based dialogue as in Instant Messaging (IM). Compared to other forms of text, dialogues are uniquely characterized with the short length of text with small number of words, two or more participants, and existence of a history that affects the current utterance. Noting the characteristics, our method detects the main topic of a dialogue by considering the keywords not only the utterances of the user but also the dialogue system's responses. Dialogue histories are also considered in the detection process to increase accuracy. For topic change detection, the similarity between the former utterance's topic and the current utterance's topic is calculated. If the similarity is smaller than a certain threshold, our system judges that the topic has been changed from the current utterance. We obtained 88.2% and 87.4% accuracy in topic detection and topic change detection, respectively.

• The Journal of the Acoustical Society of Korea
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• v.24 no.4E
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• pp.144-151
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• 2005

We evaluate the performance of emotion recognition via speech signals when a plain speaker talks to an entertainment robot. For each frame of a speech utterance, we extract the frame-based features: pitch, energy, formant, band energies, mel frequency cepstral coefficients (MFCCs), and velocity/acceleration of pitch and MFCCs. For discriminative classifiers, a fixed-length utterance-based feature vector is computed from the statistics of the frame-based features. Using a speaker-independent database, we evaluate the performance of two promising classifiers: support vector machine (SVM) and hidden Markov model (HMM). For angry/bored/happy/neutral/sad emotion classification, the SVM and HMM classifiers yield $42.3\%\;and\;40.8\%$ accuracy, respectively. We show that the accuracy is significant compared to the performance by foreign human listeners.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2454-2456
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• 2002

Since articuratory synthesis models the human vocal organs as precise as possible, it is potentially the most desirable method to produce various words and languages. This paper proposes a new type of an articulatory synthesizer using Mermelstein vocal tract model and Kelly-Lochbaum digital filter. Previous researches have assumed that the length of the vocal tract or the number of its cross sections dose not vary while uttering. However, the continuous utterance can not be easily implemented under this assumption. The limitation is overcomed by "Buffer Rearrangement" for dynamic vocal tract in this paper.