• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.4
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• pp.118-127
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• 1998

In this paper, we propose a voice personality transformation method which makes one person's voice sound like another person's voice. In order to transform the voice personality, vocal tract transfer function is used as a transformation parameter. Comparing with previous methods, the proposed method can obtain high-quality transformed speech with low computational complexity. Conversion between the vocal tract transfer functions is implemented by a linear mapping based on soft clustering. In this process, mean LPC cepstrum coefficients and mean removed LPC cepstrum modeled by the low dimensional vector are used as transformation parameters. To evaluate the performance of the proposed method, mapping rules are generated from 61 Korean words uttered by two male and one female speakers. These rules are then applied to 9 sentences uttered by the same persons, and objective evaluation and subjective listening tests for the transformed speech are performed.

• Proceedings of the KSPS conference
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• 2005.11a
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• pp.67-70
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• 2005

Voice conversion (VC) is a technique for modifying the speech signal of a source speaker so that it sounds as if it is spoken by a target speaker. Most previous VC approaches used a linear transformation function based on GMM to convert the source spectral envelope to the target spectral envelope. In this paper, we propose several nonlinear GMM-based transformation functions in an attempt to deal with the over-smoothing effect of linear transformation. In order to obtain high-quality modifications of speech signals our VC system is implemented using the Harmonic plus Noise Model (HNM)analysis/synthesis framework. Experimental results are reported on the English corpus, MOCHA-TlMlT.

• Proceedings of the KSLP Conference
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• 1998.11a
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• pp.220-221
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• 1998

My experience in the treatment of vocal disorders among professional singers within the past year revealed the importance of vocal hygience for the maintenance of a better quality of voice. Therefore, the importance of vocal hygiene is discussed. (omitted)

• Proceedings of the Korean Society for Quality Management Conference
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• 2004.04a
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• pp.611-617
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• 2004

QFD (Quality Function Development) provides a great tool not only to arrange and evaluate VoC(Voice of Customers) and ) and (Voice of Engineers), but also to link and combine VoC and VoE, thereby present ing explicit direct ions for quality improvement. There have been, however, few researches on QFD in the IT industry The case study discussed here serves an illustration of the applicability and usefulness of the QFD approach to website quality improvement . The proposed QFD framework shows great potentials since customers needs are explicitly considered in the framework, and it helps network administrators develop better web services by providing guidelines for redesigning or reengineering the website operations.

• MALSORI
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• no.43
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• pp.101-112
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• 2002

In real time packetized voice application, missing packets are major source of voice quality degradation. Thus packet loss concealment (PLC) algorithms are needed to guarantee QoS of VoIP. In this paper, we describe packet loss concealment scheme utilizing the next good frame which follows loss packets. When this scheme is combined with other PLC algorithms, such as G.711 pitch waveform replication recommended by ITU-T LP based PLC algorithm, additional voice quality improvement is obtained for consecutive packet loss larger than 60 msec.

• Proceedings of the IEEK Conference
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• 2000.09a
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• pp.157-160
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• 2000

In the generally a voice conversion has used VQ(Vector Quantization) for partitioning the spectral feature and has performed by adding an appropriate offset vector to the source speaker's spectral vector. But there is not represented the target speaker's various characteristics because of discrete characteristics of transformed parameter. In this paper, these problems are solved by using the LMR(Linear Multivariate Regression) instead of the mapping codebook which is determined to the relationship of source and target speaker vocal tract characteristics. Also we propose the method for solved the discontinuity which is caused by applying to time aligned parameters using Dynamic Time Warping the time or pitch-scale modified speech. In our proposed algorithm for overcoming the transitional discontinuities, first of all, we don't change time or pitch scale and by using the LMR change a speaker's vocal tract characteristics in speech with non-modified time or pitch. Compared to existed methods based on VQ and LMR, we have much better voice quality in the result of the proposed algorithm.

• Proceedings of the KSPS conference
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• 2005.04a
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• pp.81-84
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• 2005

This purpose of the present study was to determine the effects of yawn-sigh technique in voice quality of a cleft palate child. A 9-year old cleft palate child participated in the study 3 times a week for a month. The assessments were done by Dr. Speech (Version 4.0, Tiger DRS) on $F_{0}$, jitter, shimmer and NNE. The results showed that there was a tendency that the voice improved in terms of NNE. However, it did not reach a statistical significance.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.19 no.1
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• pp.16-20
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• 2008

Excising part or all part of a larynx as a cancer operation results in changes that transgress anatomic, physiologic, psychologic, and social priciples. The quality of life of a patient's life after any given cancer surgery usually is regarded as a second-priority consideration after oncologic safety. With laryngeal surgery, excision of malignant disease typically results in change that significantly influence an individual for the duration of his or her life. Nonetheless, with appropriate rehabilitation the surgical side effects can be minimized to allow for an excellent quality of life. Successful conservation surgery for laryngeal cancer requires careful interdependent selection for patients, lesions and procedure. The technical goal is to minimize trauma to uninvolved tissue and to wisely utilized local tissues or tree flap for reconstruction, while insuring for oncologically sound procedure. Rehabilitation should aim to produce a glottal sound source if possible, however voice therapy to promote false vocal fold vibration and arytenoid to epiglottis source of vibration can produce very satisfactory phonatory results.

• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.164-167
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• 2003

In this paper, we aim to communicate wirelessly as appling the Bluetooth technology to the VoIP system, and we select the embedded system which can be guaranteed performance and economical efficiency for implementation that system. So we implemented embedded Bluetooth AP and embedded VoIP system based on Bluetooth. For voice quality improvement in the implemented system, the Bluetooth ACL link and the appropriate Bluetooth packet was selected. Also, it was designed about the handling method of voice packet by using variable jitter buffer and then tested on embedded VoIP system based on Bluetooth.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.33 no.2
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• pp.89-96
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• 2022

Background and Objectives The quality of life after thyroidectomy, such as voice change, is considered to be as important as control of the disease. In this study, we aimed to evaluate changes in both subjective and objective voice parameters after thyroidectomy resulting in normal morbidity of the vocal cords. Materials and Method In this prospective cohort study, 204 patients who underwent thyroidectomy with or without central neck dissection at a single referral center from Feb 2015 to Aug 2016 were enrolled. All patients underwent prospective voice evaluations including both subjective and objective assessments preoperatively and then at 2 weeks, 3, 6, and 12 months postoperatively. Temporal changes of the voice parameters were analyzed. Results Values of the subjective assessment tool worsened during the early postoperative follow-up period and did not recover to the preoperative values at 12 months postoperatively. The maximal phonation time gradually decreased, whereas most objective parameters, including maximal vocal pitch (MVP), reached preoperative values at 3-6 months postoperatively. The initial decrease in MVP was significantly greater in patients undergoing total thyroidectomy, and their MVP recovery time was faster than that of patients undergoing lobectomy (p=0.001). Patients whose external branch of the superior laryngeal nerve was confirmed intact by electroidentification showed no difference in recovery speed compared with patients without electroindentification (p=0.102), although the initial decrease in MVP was lower with electroidentification. Conclusion Subjective assessment in voice quality and maximal phonation time after thyroidectomy did not show recovery to preoperative values. Aggravation of MVP was associated with surgical extent and electroidentification.