• 한국음향학회지
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• 제38권6호
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• pp.703-709
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• 2019

본 논문에서는 구개인두부전증(VeloPharyngeal Insufficiency, VPI) 환자의 음성을 효과적으로 인식하기 위해 컨볼루션 신경망 (Convolutional Neural Network, CNN), 장단기 모델(Long Short Term Memory, LSTM) 구조 신경망을 은닉 마르코프 모델(Hidden Markov Model, HMM)과 결합한 하이브리드 구조의 음성 인식 시스템을 구축하고 모델 적응 기법을 적용하여, 기존 Gaussian Mixture Model(GMM-HMM), 완전 연결형 Deep Neural Network(DNN-HMM) 기반의 음성 인식 시스템과 성능을 비교한다. 정상인 화자가 PBW452단어를 발화한 데이터를 이용하여 초기 모델을 학습하고 정상인 화자의 VPI 모의 음성을 이용하여 화자 적응의 사전 모델을 생성한 후에 VPI 환자들의 음성으로 추가 적응 학습을 진행한다. VPI환자의 화자 적응 시에 CNN-HMM 기반 모델에서는 일부층만 적응 학습하고, LSTM-HMM 기반 모델의 경우에는 드롭 아웃 규제기법을 적용하여 성능을 관찰한 결과 기존 완전 연결형 DNN-HMM 인식기보다 3.68 % 향상된 음성 인식 성능을 나타낸다. 이러한 결과는 본 논문에서 제안하는 LSTM-HMM 기반의 하이브리드 음성 인식 기법이 많은 데이터를 확보하기 어려운 VPI 환자 음성에 대해 보다 향상된 인식률의 음성 인식 시스템을 구축하는데 효과적임을 입증한다.

• 한국정보과학회논문지:정보통신
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• 제28권1호
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• pp.173-181
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• 2001

최근 인터넷 사용자의 증가와 서비스의 다양화 그리고 이에 따른 고속 인터넷 엑세스 기술의 도입으로 인터넷 트래픽의 급격한 증가를 초래하고 있다. 이러한 이유로 인터넷 패킷 전달에 2계층 스위칭 기술과 3계층 라우팅 기술을 접목한 IP/ATM Hybrid system이 등장하게 되었다. 이러한 시스템에서의 중요한 자원은 2계층 스위칭 기술을 사용하기 위한 유한한 VCI/VPI 공간이다. 이 VCI/VPI 공간을 효과적으로 관리하기 위한 방안으로 많은 방안들이 제시되고 있다. 특히 흐름 기반의 IP/ATM Hybrid system에서의 흐름 분류기를 사용함으로서 VCI/CPI 공간을 관리하고 있다. 본 논문에서 주장하는 적응형X/Y 분류기가 유한한 VCI/VPI 공간을 효율적으로 관리하기 위한 방안임을 제시하고 이에 대하여 실험을 통하여 성능 평가를 실시하였다 특히 동일한 VCI/VPI 공간에서 X/Y분류기와의 비교실험에서 적응형 X/Y 분류기의 성능이 높은 스위칭 율로 나타나고 있다. 즉 적응형 X/Y 분류기가 X/Y분류기에 비하여 효율적으로 VCI/VPI를 관리함을 보이고 있다

• 대한구순구개열학회지
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• 제11권1호
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• pp.13-22
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• 2008

Velopharyngeal insufficiency(VPI), characterized by hypernasal resonance and nasal air emission, is a speech disorder that can significantly compromise speech intelligibility. Cleft palate, previously repaired cleft palate and submucous cleft palate are associated with VPI. Less commonly, patients may acquire it after adenoidectomy with or without tonsillectomy or as a result of neuromuscular dysfunction. Comprehensive evaluation by a VPI team includes medical assessment focusing on airway obstructive symptoms, perceptual speech analysis, MRI and instrumental assessment. Options for intervention include speech therapy, intraoral prosthetic devices and surgery. Surgical methods can be categorized as palatal, palatopharyngeal or pharyngeal procedures. Each surgical approach has its strengths and limitations. Oro-maxillofacial surgeons are increasingly involved in the referral, evaluation, and treatment of velopharyngeal function. Therefore, understanding of physiology, anatomic structures, evaluation and treatment protocols in VPI is very important. This article presents protocol for evaluation of velopharyngeal function with a focus on indications for surgical interventions.

• 한국통신학회논문지
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• 제24권9B호
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• pp.1661-1667
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• 1999

본 논문에서는 ATM 망에서의 ABR 다점 대 점 연결을 위한 효과적인 VP 확장 알고리즘을 제안한다. ABR 다점 대 점 연결은 VC 머징 (VC merging) 방식 또는 VP 머징 (VP merging) 기법을 이용하여 구현할 수 있다. 본 논문에서는 VP 머징 기법을 이용하며, VP 자원 부족 문제점을 해결하기 위해 VP 확장 알고리즘을 제안한다. 제안된 기법은 표준 VPI/VCI 구조를 따르기 때문에 VP 확장에 따른 별도의 VPI/VCI 테이블을 필요로 하지 않는다. 성능 평가를 위해서 VC 머징 방식과 제안한 기법의 성능을 비교한다. 실험 결과 제안한 기법은 다점 대 점 연결의 각 소스에 대역폭을 공평히 분배할 수 있음을 알 수 있었다.

• 대한음성언어의학회:학술대회논문집
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• 대한음성언어의학회 1996년도 제6회 학술대회 심포지움
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• pp.96-96
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• 1996

구개인두부전증(velopharyngeal insufficiency, VPI)에 의한 발음이상을 평가하는 방법에는 여러 가지 방법이 개발되어 왔으나 비강측정기(nasometry)에 의한 비성수치(naslance score)의 측정과 spectrography에 의한 음향분석이 최근 널리 사용되고 있다. 본 연구에서는 실험적으로 유발한 VPI군의 음향학적 결과와 비강측정기의 결과를 정상군과 비교함으로써 VPI환자의 보다 정확하고 객관적인 평가의 방법과 지표를 얻고자 하였다. (중략)

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 제5회 학술대회 논문집 일렉트렛트 및 응용기술연구회
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• pp.38-42
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• 2003

The use of VPI impregnated mica tape as high voltage insulation for large rotating electric machines requires a careful balance of processes and materials to obtain the desired electrical, mechanical and thermal characteristics. The stator insulation systems such as epoxy bonded high voltage mica tape have been produced for many years. One such system employing an epoxy and anhydride impregnating resin developed by Hyundai Heavy Industries, Co. (hereafter, HHI), to satisfy customer requests for an epoxy bonded insulation system. HHI applies the following electrical and thermal evaluations such as dielectric breakdown, voltage endurance, dissipation factor vs. temperature, isothermal weight loss, and so on. A detailed laboratory evaluation can describe specific physical limitations for an insulation system and permit development of long-term operation guidelines that permit full utilization of the proposed system. HHI has found these evaluations very helpful in qualifying insulation system for the repair of both large motors and generators.

• 음성과학
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• 제12권1호
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• pp.27-35
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• 2005

Differential instrumentation for the diagnoses of individuals with Cleft palate has been used to objectively measure speech problems. The Cepstrum Method was used to study the vocal tract transfer function. The vocal tract transfer function and the source spectrum should be considered in the evaluation of nasal resonance. The aim of this study was to collect quantitative data on the acoustic Instrumentation used for evaluating hypernasality. Normal subjects (9 male, 21 female; 37 male children, 20 female children) and individuals with VPI (13 male, 8 female; 16 male children, 9 female) participated in this study. The vowel /i/ was selected to gauge the severances of hypernasality Spectral and Cepstral studies using CSL was used to identify the acoustic characteristics. Cepstrum analysis shows significant differences in quefrency and amplitude. The quefrency of normal groups was shorter than that of the VPI groups, while the amplitude of normal groups was lower than that of the VPI groups. This may have significance in the evaluation 'of nasal resonance.

• 전기학회논문지P
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• 제59권3호
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• pp.311-316
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• 2010

According to increase of combined cycle power generation, the manufacturing market of gas turbine generator has become more competitive, so there is high pressure on the manufacturer to reduce generator price. Global VPI(vacuum pressure impregnation) method is effective to save the production cost and time for manufacturing stator windings, but it has an abrasion problem by vibration between stator windings and slots. This paper presents the insulation breakdown case, which is for VPI type generator during high voltage insulation tests, and also shows the cause analysis, repair works as well as reliability test. the purpose of this paper is to understand the insulation properties of VPI type generator and to know prevention of insulation weakness.

• Journal of Chest Surgery
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• 제57권1호
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• pp.44-52
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• 2024

Background: Visceral pleural invasion (VPI) is a poor prognostic factor that contributes to the upstaging of early lung cancers. However, the preoperative assessment of VPI presents challenges. This study was conducted to examine intraoperative pleural carcinoembryonic antigen (pCEA) level and maximum standardized uptake value (SUVmax) as predictive markers of VPI in patients with clinical T1N0M0 lung adenocarcinoma. Methods: A retrospective review was conducted of the medical records of 613 patients who underwent intraoperative pCEA sampling and lung resection for non-small cell lung cancer. Of these, 390 individuals with clinical stage I adenocarcinoma and tumors ≤30 mm were included. Based on computed tomography findings, these patients were divided into pleural contact (n=186) and non-pleural contact (n=204) groups. A receiver operating characteristic (ROC) curve was constructed to analyze the association between pCEA and SUVmax in relation to VPI. Additionally, logistic regression analysis was performed to evaluate risk factors for VPI in each group. Results: ROC curve analysis revealed that pCEA level greater than 2.565 ng/mL (area under the curve [AUC]=0.751) and SUVmax above 4.25 (AUC=0.801) were highly predictive of VPI in patients exhibiting pleural contact. Based on multivariable analysis, pCEA (odds ratio [OR], 3.00; 95% confidence interval [CI], 1.14-7.87; p=0.026) and SUVmax (OR, 5.25; 95% CI, 1.90-14.50; p=0.001) were significant risk factors for VPI in the pleural contact group. Conclusion: In patients with clinical stage I lung adenocarcinoma exhibiting pleural contact, pCEA and SUVmax are potential predictive indicators of VPI. These markers may be helpful in planning for lung cancer surgery.

• Archives of Plastic Surgery
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• 제37권2호
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• pp.175-177
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• 2010

Ppupose: Velopharyngeal insufficiency (VPI) during articulation development period can cause compensatory articulation like glottal stop, which can maintain VPI symptoms such as hypernasality and nasal emission despite of recovered velopharyngeal function. Methods: A girl visited our department with speech problems such as hypernasality, compensatory articulation patterns, and nasal air emission. She had history of postpalatoplasty fistula which was repaired after 1 year follow-up. Results: After treated with speech therapy without surgery, her hypernasal speech problem was corrected. From this, we could assume that the fistula during articulation development period induced VPI, which leads to glottal substitution and this compensatory articulation maintained VPI though the fistula was repaired. Conclusion: In this report, we could observe that palatal fistula in articulation development period can have detrimental effect on articulation, and also we could confirm that evaluation of soft palate mechanism with using speech sample without compensatory articulations prevent the patient from unnecessary operation.