• Proceedings of the KOSOMBE Conference
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• v.1996 no.11
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• pp.114-117
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• 1996

In this study, remote articulation training system which connects the hearing disabled trainee and the speech therapist via B-ISDN is introduced. The hearing disabled does not have the hearing feedback of his own pronunciation, and the chance of watching his speech organs' movement trajectory will offer him the self-training of articulation. So the system has two purposes of self articulation training and trainer's on-line checking in remote place. We estimate the vocal tract articulatory movements from the speech signal using inverse modelling and display the movement trajectory on the sideview of human face graphically. The trajectories of trainees' articulation is displayed along with the reference trajectories, so the trainee can control his articulating to make the two trajectories overlapped. For on-line communication and ckecking training record, the system has the function of video conferencing and transferring articulatory data.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1797-1798
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• 2007

In field of voice pathology, diverse statistics extracted form pitch estimation were commonly used to assess voice quality. In this study, we proposed robust pitch detection algorithm which can estimate pitch of pathological voices in benign vocal fold lesions. we also compared our proposed algorithm with three established pitch detection algorithms; autocorrelation, simplified inverse filtering technique, and nonlinear state-space embedding methods. In the database of total pathological voices of 99 and normal voices of 30, an analysis of errors related with pitch detection was evaluated between pathological and normal voices, or among the types of pathological voices. According to the results of pitch errors, gross pitch error showed some increases in cases of pathological voices; especially excessive increase in PDA based on nonlinear time-series. In an analysis of types of pathological voices classified by aperiodicity and the degree of chaos, the more voice has aperiodic and chaotic, the more growth of pitch errors increased. Consequently, it is required to survey the severity of tested voice in order to obtain accurate pitch estimates.

• Journal of Chest Surgery
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• v.21 no.4
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• pp.681-691
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• 1988

Fifty-five patients with primary mediastinal tumors and cysts which were seen at T.S. Dept., HYUH, were analyzed clinically, histologically, in an incidence of anatomic location and therapeutic results. The results were summarized as follows; 1] The ages of the patients in this series ranged from 15 months to 79 years with the highest incidence in the age group of third decade, and there were no sex distribution[M:F=0.96]. 2] The most frequently encountered tumors were teratodermoid tumors[29%] followed by neurogenic tumors[22%], thymomas[15%] and benign cysts[11%] in decreasing order of frequency. 3] Based on the subdivision of the mediastinum, 62% of the tumors were in the antero-superior mediastinum, 7% in the middle mediastinum and 31% in the posterior mediastinum. 4] The most frequent symptom was chest pain and others were dyspnea, cough, chest tightness and dysphagia. Asymptomatic patients were 29%. 5] Benign tumors and cysts were 71% and malignant tumors were 29%. 6] The successful removal was possible in all the benign mediastinal tumors and cysts[39 cases] and partial removal or biopsy was performed in the 12 cases among 16 cases of malignant mediastinal tumors. 7] Postoperative complications were bleeding, chylothorax, vocal cord paralysis, wound infection and hypothyroidism. 8] The most frequent mediastinal tumor in the West is neurogenic tumor but is teratoma in Korea.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.31 no.1
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• pp.45-48
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• 2020

Granular cell tumor is rare tumor origination from Schwann cell. It occurs extremely rarely in pediatric age. Treatment is complete resection, but this may not always be possible because of the risk of airway stenosis or vocal cord paralysis. Six year-old male patient visited otolaryngology clinic due to dyspnea and stridor. Posterior glottis mass was indentified and was partially resected to confirm histology and resolve airway obstruction. One year after operation, the patient was living well without re-growing of tumor. We report a case of granular cell tumor in pediatric larynx with a review of literature.

• Journal of Korean Neurosurgical Society
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• v.39 no.6
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• pp.419-422
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• 2006

Objective : Endotracheal tube cuff-pressure[ETCP] increases significantly during anterior cervical spine surgery with neck retraction. Clinically, postoperative hoarseness with sore throat is correlated with vocal cord edema due to longer intubation time and higher ETCP during neck retraction. Methods : Fifty patients of anterior cervical spine surgery were randomized to a control [no adjustment, 25 cases] and a treatment group [ETCP adjusted to 20mmHg, 25 cases]. Patients were blinded to their group assignments. They were questioned about the presence of ischemic symptoms [sore throat, dysphagia, hoarseness] postoperatively at different time points; 4 hours, 24 hours, and 1 week postoperatively. Results : No differences between groups at 4 hours and 1 week postoperatively were demonstrated. At 24 hours, 36% of patients in the treatment group complained of sore throat while 56% of control group patients did [p < 0.05]. Female patients correlated with development of all ischemic discomfort [p < 0.05 : sore throat, hoarseness, dysphagia]. Conclusion : Our results suggest that postoperative ischemic symptom following anterior cervical spine surgery may be associated with the two predictors; increased ETCP during neck retraction and female. The simple procedure of maintaining ETCP to 20mmHg can prevent postoperative tracheal ischemic symptom.

• Proceedings of the Acoustical Society of Korea Conference
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• 1994.06a
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• pp.893-898
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• 1994

In this paper, the influence of voice source estimation and modeling on speech synthesis and coding is examined and then their new estimation and modeling techniques are proposed and verified by computer simulation. It is known that the existing speech synthesizer produced the speech which is dull and inanimated. These problems are arised from the fact that existing estimation and modeling techniques can not give more accurate voice parameters. Therefore, in this paper we propose a new voice source estimation algorithm and modeling techniques which can not give more accurate voice parameters. Therefore, in this paper we propose a new voice source estimation algorithm and modeling techniques which can represent a variety of source characteristics. First, we divide speech samples in one pitch region into four parts having different characteristics. Second, the vocal-tract parameters and voice source waveforms are estimated in each regions differently using sequential SVD. Third, we propose composite source model as a new voice source model which is represented by weighted sum of pre-defined basis functions. And finally, the weights and time-shift parameters of the proposed composite source model are estimeted uning EM(estimate maximize) algorithm. Experimental results indicate that the proposed estimation and modeling methods can estimate more accurate voice source waveforms and represent various source characteristics.

• The Journal of the Acoustical Society of Korea
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• v.40 no.5
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• pp.473-478
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• 2021

Vibrato corresponds to a modulation of frequency and is one of the most frequently used techniques to enrich vocal and musical instrument sounds. Whereas the fundamental frequency trajectories of vibrato tones are generally modeled as a sinusoid, they are sometimes observed to be non-sinusoidal. In this paper, we propose a method to analyze the characteristics of non-sinusoidal fundamental frequency trajectories of vibrato sounds. The proposed method performs Fast Fourier Transform (FFT)-based harmonic analysis on the frequency trajectory, analyzes vibrato parameters, and calculates a sinusoid purity factor. We applied the proposed method to flute, viola, and saxophone vibrato tones, whose results showed the effectiveness of the proposed method.

• Phonetics and Speech Sciences
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• v.10 no.4
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• pp.31-37
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• 2018

Pitch trajectories reflect a continuous variation of vocal fold movements over time. This study examined the pitch trajectories of English vowels produced by 139 American English speakers, statistically analyzing their trajectories using the Generalized Additive Mixed Models (GAMMs). First, Praat was used to read the sound data of Hillenbrand et al. (1995). A pitch analysis script was then prepared, and six pitch values at the corresponding time points within each vowel segment were collected and checked. The results showed that the group of men produced the lowest pitch trajectories, followed by the groups of women, boys, then girls. The density line showed a bimodal distribution. The pitch values at the six corresponding time points formed a single dip, which changed gradually across the vowel segment from 204 to 193 to 196 Hz. The normality tests performed on the pitch data rejected the null hypothesis. Nonparametric tests were therefore conducted to discover the significant differences in the values among the four groups. The GAMMs, which analyzed all the pitch data, produced significant results among the pitch values at the six corresponding time points but not between the two groups of boys and girls. The GAMMs also revealed that the two groups were significantly different only at the first and second time points. Accordingly, the methodology of this study and its findings may be applicable to future studies comparing curvilinear data sets elicited by experimental conditions.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.30 no.1
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• pp.34-38
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• 2019

Background and Objectives : The aim of this study is verify the correlation between benign laryngeal mucosal disease and metabolic syndrome. Materials and Method : Data for patients diagnosed with benign laryngeal mucosal disease and metabolic syndrome from 2006 to 2015 were selected for analysis from the National Health Insurance Service database. Results : The prevalence of Metabolic syndrome was 2,179,785 out of 6,437,051 patients (33.86%). The prevalence of benign laryngeal mucosal disease was 516,594 out of 6,437,051 patients (8.03%). Metabolic syndrome was a risk factor for benign laryngeal mucosal disease [hazard ratio: 0.99, 95% confidence interval: 0.984-0.997] after adjusting for age and other variables including age, gender, smoking status, alcohol intake, exercise, body mass index, and diabetes. The number of metabolic syndrome components was also risk factor. Conclusion : Metabolic syndrome was related to the incidence of benign laryngeal mucosal disease. However this correlation did not seem to be high.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.32 no.1
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• pp.35-38
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• 2021

Laryngeal lymphoepithelial carcinoma (LEC) is a rare tumor with only 34 cases in the published literature. Epidemiologically, laryngeal LEC is extremely rare in Asian. Originally, LEC is a common type of carcinoma in nasopharynx. Laryngeal LEC resembles nasopharyngeal LEC, except that most cases of laryngeal LEC are not associated with Epstein-Barr virus. We present a case of laryngeal LEC which developed at the left false cord extending to true vocal cord, para-glottic space and pre-epiglottic space. Total laryngectomy with bilateral neck dissection was performed. LEC was reported as biopsy confirmation result. The patient underwent postoperative radiotherapy and showed no evidence of recurrence during follow-up period of 42 months. In consideration that LEC in larynx have not been reported in South Korea yet, we introduce the clinical features and treatment outcomes of laryngeal LEC with literature review.