• 대한임베디드공학회논문지
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• 제2권2호
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• pp.82-94
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• 2007

Wireless sensor networking technology is one of the basic infrastructures for ubiquitous environment. It enables us to gather various sensory data such as temperature, humidity, gas leakage, and speed from the remote sensor devices. To support these networking functions, IEEE WPAN working group makes standards for PHY and MAC, while ZigBee Alliance defines the standards for the network, security, and applications. The low-rate WPAN was emerged to have the characteristics of network resilience, low cost, and low power consumption. It has a broad range of applications including, but not limit to industrial control and monitoring, home automation, disaster forecast and monitoring, health care. In order to provide more intelligent and robust services, users want voice-based solutions to accommodate to low-rate WPAN. In this paper, we have evaluated voice quality of an IEEE 802.15.4 standard compliant voice node. Specifically, it includes the design of a voice node and experiments based on the prediction of voice quality using the E-model suggested by ITU-T G.107, and the network communication mechanisms considering beacon-enabled and nonbeacon-enabled networks for real-time voice communications.

• 말소리와 음성과학
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• 제1권2호
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• pp.37-42
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• 2009

The purpose of the present study was to determine the effect of the management program known as vocal function exercise (VFE) on voice quality. Typical VFE was modified and applied to patients with vocal nodules by controlling intensity of voice and relieving the vocal fold to solve hyperfunctional problems in VFE. Eight female subjects aged between 28 and 54 who had been diagnosed with vocal nodules took part in the study. The patients performed VFEs once a week for eight weeks. Vocal function exercises consist of voice hygiene, respiratory training, phonation training, and glide training. The subjects' voices were analyzed pre and post therapy on the aspects of acoustics, maximum phonation time (MPT), GRBAS, and voice handicap index (VHI). As a result, it was found that fundamental frequency ($F_o$) was significant increased, shimmer decreased remarkably and that noise to harmonic ratio (NHR) lowered obviously in the acoustic parameter. In addition, MPT was increased significantly. The scale of GRBAS indicated significant improvement in grade, roughness, and strained voice. VHI indicated significant improvement in an emotional part. In conclusion, VFE was effective in improving voice quality for patients with vocal nodules.

• 산업경영시스템학회지
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• 제28권4호
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• pp.55-62
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• 2005

This paper describes the experiment that investigated the possibility of design and evaluation of the usability of earcon applied to voice menu. The earcon has functions in providing navigational cue in the hierarchical menu, and also can be applied to voice menu for improving the recall rate and the response time. In this experiment, participants identified their location with the help of earcon applied to the voice menu with the various earcon parameters. In detail some participants listened to the good quality sound of voice menu using the structured earcon, and they recalled the location they heard. Other participants listened to the good quality sound of voice menu without earcon, and they recalled the location they heard in the same manner. And the response times were checked through their answers. On analyzing the results, we found the earcon applied to voice menu showed the increase of recalling rate from what they heard during experiment. That is the performance of task was better with earcon applied to voice menu than with voice menu without earcon. In the earcon applied to voice menu test, it showed the accuracy of 92.50%, but in voice menu without earcon test, people could only recall 66.25% among given questions. The response time was reduced from 4.98 sec to 3.85 sec. In addition, this experiment showed the 87.5% of participants preferred the earcon applied to voice menu.

• 대한전자공학회논문지TC
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• 제40권9호
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• pp.373-383
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• 2003

본 논문에서는 다양한 서비스가 복합적으로 운용되고 있는 인터넷 망에서PCM 및 ADPCM으로 압축된 음성 데이터를 전송할 경우, 패킷 크기와 한계 지연시간의 변화가 수신측의 음질에 미치는 영향을 분석하고 주어진 한계 지연시간에 대하여 최고의 음질을 제공하기 위한 전송 패킷의 크기에 대하여 논한다. 결과를 얻기 위한 실험은 공중 인터넷 망을 통하여 연결된 두 대의 PC 상에서 이루어졌다. 송신측은 마이크로부터의 음성신호를 PCM 및 ADPCM으로 부호화하고 이를 UDP 패킷을 이용하여 전송하였으며, 수신 측에서는 망에서 발생하는 전송 지연 및 패킷 손실 등을 거친 패킷이 음성신호로 재생된다. 음질 평가를 위하여 송수신 음성 데이터를 수집하여 오프라인에서 비교하며, 알고리즘으로는 객관성을 유지하기 위하여 MNB 방법을 이용하였다. 실험 결과에 의하면, 40Kbps, 32Kbps, 16Kbps의 ADPCM으로 압축된 음성의 전송에서 한계 전송 지연을 100ms로 하였을 경우 음질 열화를 최소화하기 위하여는 패킷 크기의 하한이 각각 300, 400, 500바이트, 패킷 크기의 상한은 공히 1200바이트인 것이 요구된다.

• 대한후두음성언어의학회지
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• 제15권1호
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• pp.16-20
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• 2004

Purpose : To assess perceptual, acoustic and aerodynamic measure of voice quality in patients with unilateral vocal cord paralysis before and after type I thyroplasty. Methods : The clinical records of patients operated type I thyroplasty in the Departement of otorhinoalryngolgy, Yongdong Severance hospital from November 2001 to November 2003 were reviewed. All patients uderwent a vocal function evaluation including perceptual, acoustic and aerodynamic measures of voice preoperative and on $60^{th}$ postoperative day. The perceptual and acoustic measures were obtained from recording of patients' reading a 'Sanchak' passage. The perceptual evaluation was performed by 2 speech pathologist using a 4-point rating scale. Acoustic parameters(voice range profile low(RAL), voice range profile high(RAH), average fundamental frequency(AFX), closed quotient, harmonic to noise ratio, jitter and shimmer) were investigated by Lx speech studio. Mean flow rate(MFR), subglottic pressure(Psub) and intensity were measured using the Phonatory function analyzer. The maximum phonation time was also measured. The data were statistically analyzed. A paired t-test (p<0.1) was used to compare preoperative and postoperative results. And multiple regression test was used to find which parameter was most correlated to improvement of postoperative voice quality. Results : Among aerodynamic parameters, Psub $(88.11mmH_2O{\rightarrow}58.7mmH_2O)$, MPT(7.87sec${\rightarrow}$12.53sec), MFR (359.8ml/sec${\rightarrow}$161.06ml/sec) were statistically improved. AFx(205.5Hz${\rightarrow}$163.27Hz), AQx(23.9%${\rightarrow}$48.3%), RAL, RAH. Jotter and shimmer were improved. In multiple regression test, AFx and AQx was noted as the two meost correlated parameters to improvement of postoperative breathiness. But general grade of voice quality was more correlated to Psub and shimmer. Conclusion : Vocal fold medialization procedures effectively reduce glottic gap. Increasing of contact area of both vocal folds induced improvement in aerodynamic parameters and leaded stabilizing of vocal fold vibration. That effect results in improvement in acoustic parameters (shimmer, jitter, signal-to-noise ratio, voice range profile) and voice quality.

• 대한후두음성언어의학회지
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• 제19권2호
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• pp.89-95
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• 2008

주관적 음성평가는 음향분석기기를 이용한 객관적 음성 평가와 함께 음성분석에 유용하고 의미있는 평가방법이며 현재 알려진 검시법정 중에서 GRBAS 음성평가, VHI, patient self-perceptual voice rating이 가장 널리 사용되고 있고 인정받는 방법이다. 주관적 음성평가는 음성의 상태를 모두 대변할 수은 없으며 객관적인 음성평가에 대한 보완적인 의미를 가진다. 현재 개발되어 있는 주관적 음성평가 방법들이 유용한 평가도구이긴 하지만 나름대로의 문제점과 제한점을 가지고 있기 때문에 이에 대한 개선과 보완을 위한 지속적인 연구와 개발이 요구된다.

• 재활복지
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• 제22권1호
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• pp.157-168
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• 2018

본 연구는 반폐쇄성도훈련에 기반을 둔 성대에어로빅치료(Vocal Aerobic Treatment: VAT)가 소프라노 성악가 음성개선에 미치는 영향을 알아보고자 하였다. 연구대상은 성대결절로 음성문제를 호소하는 소프라노 성악가 1명으로 연구를 진행하였다. 연구방법은 치료 전 후 음향학적평가와 주관적 음성평가를 실시하여 측정값을 비교하였으며, 성대에어로빅치료는 주 2회 총 32회기동안 진행하였다. 음향학적 평가는 MDVP (multi-dimensional voice program)와 VRP (voice range profile)를 사용하여 음도, 음질, 음역을 평가하였으며, 주관적 음성평가는 SVHI (singing voice handicap index)로 주관적인 음성만족도를 평가하였다. 음도 평가 결과 치료 후 소프라노 가수에 적절한 기본주파수(Fo)를 유지하였다. 음질평가 결과 주파수변동률(Jitter), 진폭변동률(Shimmer), 배음대소음비(NHR) 수치가 치료 전보다 감소하였다. 음역평가결과 음역의 범위가 넓어졌으며 반음의 개수가 30개에서 35개로 증가하였다. 주관적 음성평가는 설문 보고 후 획득한 총 점수를 문항수로 나눈 결과 3.6점에서 0.6점으로 감소하였으며, 본인이 느끼는 음성문제의 정도가 경미하다고 보고하였다. 이러한 결과를 정리해보면 성대에어로빅치료는 성악가 음성개선에 효과적인 것으로 사료된다. 그러나 본 연구는 소프라노 성악가 1명을 대상으로 한 성대에어로빅치료의 치료 효과에 관한 사례연구로 향후 더 많은 성악가를 대상으로 효과에 대한 연구가 이루어져야 할 것이다. 또한 성악가뿐만 아니라 다양한 직업적 음성사용자를 위한 음성관리 및 음성치료프로그램에 관한 후속 연구가 필요할 것이다.

• 대한후두음성언어의학회지
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• 제12권1호
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• pp.22-27
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• 2001

Backgrounds and Objectives : There have been reported many studies which evaluate the effectiveness of combined laryngomicrosurgery(LMS) and voice therapy for the patients with benign vocal cord lesions. But the difference of voice improvement by onset time of voice therapy has not been reported. The purpose of this study is to analyze the differences of voice improvement by voice analysis test between the two groups with different onset time of voice therapy. Materials and Methods : Two groups, each of which comprises 15 patients, were analyzed. For the one group, the voice therapy was initiated 1 day after LMS. For the other, the therapy was initiated 1 week after LMS. Voice analytic parameters of the two groups were statistically analized to identify difference in voice improvement. Results : All measured parameters improved after voice therapy in two groups and showed no significant difference between two groups. Conclusions : The onset time of voice therapy after LMS has no significant impact on post-operative voice quality in the patients with benign vocal cord lesions. Early onset of post-operative voice therapy may serve as treatment modality for patients with benign vocal cord lesions.

• 대한후두음성언어의학회지
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• 제7권1호
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• pp.32-38
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• 1996

The preservation of the voice-producing mechanism is an important feature in the management of laryngeal cancer by radiotherapy. But, radiation therapy has certain side effects such as mucositis, tissue edema, necrosis and fibrosis which could effect on normal voice production. Several subjective studies that used questionnaires and auditory perceptual judgements of voice have been interpreted to mean that radiation results in a normal or near-normal voice. Objective evidence of the status of vocal function after radiation treatment, however, is still lacking. We analyzed the changes that occur in voice parameters in a group of patients undergoing radiation therapy, in order to determine the effect of radiation on voice quality. In this study acoustic, aerodynamic measures of vocal function were used to determine the characteristics of voice production. We found that voice parameters in early glottic cancer changed meaningfully comparing to normal larynx with or without radiation and radiation therapy has an little effect on normal larynx.

• 한국시뮬레이션학회논문지
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• 제10권2호
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• pp.15-24
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• 2001

In this paper we study the delay patterns of voice traffic for end-to-end users Caused by serving the whole bunch of applications traffic at the same time on the Voice over Internet Protocol (VoIP) network. Given the current situation that voice traffic is served along with other application services on the VoIP network, it is quite necessary to figure out how and by what the voice traffic requiring high QoS is delayed. We compare the delay performance of voice traffic on the VoIP network under FIFO with the one under Weighted Fair Queuing(WFQ), and discover the differences of the delay performance resulting from the use of different voice codec algorithms. The results of our study show that using the voice codec algorithm with a higher coding rate nd the queuing algorithm of WEQ can provide users with high-quality voice traffic.