• Journal of international Conference on Electrical Machines and Systems
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• 제2권1호
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• pp.57-64
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• 2013

The functional characteristic of LISN circuit, which is used for measurements of conductive noise in mains power line, is basically related to frequency characteristics of passive elements like inductors used in the circuit as well as the frequency response of inductors is highly related to the resins used in the varnishing process. The significant problem in determination of an inductor's frequency characteristic is the intrinsic resistance, inductance and parasitic capacitance. In this triplet, the parasitic capacitance is the major limiting factor of inductor's frequency range. This capacitance depends on inductor design parameters and materials filling the spaces of coil like resin and its coherency after curing process. In this paper, two similar inductors were designed and built. The first inductor was not varnished while the second one was varnished with VPI technology. VPI, or Vacuum, Pressure, Impregnation technology is one of the most reliable methods performing good insulating conditions for electrical circuits and windings based on resins. The measured results show that implying varnishing technology does not significantly affect the frequency response. However, due to mechanical solidity aspects and improved environmental protection, it is better to varnish the inductors.

• 대한후두음성언어의학회지
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• 제33권3호
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• pp.188-192
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• 2022

Velopharyngeal insufficiency (VPI) is a phenomenon that can occur due to anatomical or neurological causes of the soft palate. VPI can make the patient difficult to articulate through hypernasality and nasal emission. There has been needed the customized treatment, as VPI can occur for many causes. We present the case of 21-year-old male who took palate plastic surgery 20 years ago for congenital submucosal cleft palate. As he had poor contraction of both lateral side of velopharynx, he was diagnosed with coronal type VPI. Through sphincter pharyngoplasty, he can obtain improvement of articulation accuracy. We would like to share this challenged case.

• 대한구순구개열학회지
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• 제8권1호
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• pp.39-44
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• 2005

Velopharyngeal incompetence(VPI) is that soft palate and muscle of posterolateral pharyngeal wall can not close velopharyngeal port properly. Thing that prior to treatment for patient with VPI is to evaluation about nasopharyngeal closing function. This data is important for making a treatment plan and assesment of treatment effect to improve nasopharyngeal closing function. There are two ways of VPI assessment. The one is subjective method by auditory finding, the other is objective method by using equipment for language test. Using only subjective way is not adequate for evaluation of VPI because of low trust, so doing both two methods simultaneously help to make a diagnosis and assessment exactly. CPAP is effective method to treat hypernasality. This new treatment technique intensify oropharyngeal muscle for nasopharyngeal closing by direct resistance training. Becase conventional treatments have limitation, so many research about treatment effectiveness of CPAP are being studied. This study aims that we compare our result from Korean VPI patients with result about treatment effect in other advanced country, to make CPAP Treatment Questionares and to find ways that improve oropharyngeal closing function an[1 maximally increase language treatment effect.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제13권3호
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• pp.338-345
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• 1991

선천성 혹은 술후성 기형으로 발생하는 구개인두 부전증은 구강과 비강사이의 부적절한 폐쇄기능으로 인해 과비음 등의 발음장애를 초래한다. 그 원인으로는 구개파열, 인두비대증, 편도선절제술후의 구개와 인두의 비율 부조화, 구개인두 괄약근의 기형, 구래부전마비, 연구개 결손, 상악골 전진 절단술 등이 있다. 구개인두 부전증의 진단에는 임상적, 방사선학적 검사와 더불어 섬유광학 비내시경을 이용한 구개인두의 기능검사가 강조된다. 수술방법으로는 구개성형술, 인두증강술, 인두성형술, 인두피판술 등이 있다. 근자에는 상부기저형 인두피판술이 널리 사용되고 있는데, Hogan등이 개선시킨 술식에 의하면, 넓고 긴 피판을 얻을 수 있고 피판의 Raw surface를 연구개의 비강측 점막으로 덮을 수 있으며 측방 통로를 조절할 수 있다는 장점이 있다. 이에 저자등은 본인에 내원한 구개인두 부전증 환자 7례에서 상부기저형 인두피판을 이용하여 구강과 비강 사이의 측방 통로를 적절히 조절함으로서 발음을 개선시켜 본 바 양호한 임상성적을 얻었기에 보고하는 바이다.

• 전력전자학회논문지
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• 제22권3호
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• pp.263-269
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• 2017

This paper proposes a novel circulating current control method for an MMC-HVDC system based on Vector PI control. The method can suppress second-order harmonics of the circulating currents under balanced and unbalanced grid conditions. The proposed method is robust to grid frequency variation. The effectiveness of the proposed method is verified through frequency response and time domain simulation.

• Korean Chemical Engineering Research
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• 제59권4호
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• pp.521-531
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• 2021

진공가압함침공정(Vacuum Pressure Impregnation, VPI)은 발전기, 전동기 등 대형 회전기에 사용되는 고정자 권선에 에폭시 계열의 레진을 코팅시켜 물성을 강화하는 공정이다. VPI 공정 중 진공과 가압과정에서 에폭시 레진의 기화에 의해 레진 가스가 발생하고, 함침공정이 끝나고 경화를 위해 탱크 개방 시 레진 가스가 제거되지 않고 탱크 밖으로 유출된다. 유출된 레진 가스가 작업장 전체에 확산 시 화재, 폭발 및 호흡기 문제와 같은 안전 환경 문제가 있으므로 공정 내 레진 가스 배출시스템이 필요하다. 따라서, 본 연구에서는 VPI 공정에서 발생한 레진 가스를 배출하는 시스템을 설계하기 위해 전산유체역학(Computational Fluid Dynamics, CFD)을 이용하여 공기 유입구·배출구의 위치에 따른 배출효율에 대한 사례연구를 진행하였다. 본 연구의 최적의 배출시스템을 활용 시 1,800초 이내 90%이상의 레진 가스를 배출할 수 있으며, 레진 가스의 폭발하한계(Low Explosive Limit, LEL)이하로 레진 가스의 분율을 낮출 수 있었다.

• 대한후두음성언어의학회지
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• 제14권1호
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• pp.51-53
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• 2003

Amyotrophic lateral sclerosis Is an unusual pattern of distal muscular atrophy with permanent bulbar sign. Vocal fold paralysis and velopharyngeal insufficiency(VPI) due to soft palate paralysis Is occasionally associated with distal muscular atrophy. Recently we experienced a case of amyotrophic lateral sclerosis whose symptom was initially expressed with hoarseness and VPI. So we report a case with review of literature.

• 대한두개안면성형외과학회지
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• 제11권2호
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• pp.73-76
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• 2010

Purpose: There are several surgical methods for correcting a velopharyngeal insufficiency (VPI) but in some cases, it is not possible to achieve complete recovery of the velopharyngeal function. This paper introduces a new therapy for treating hypernasality without further surgery using continuous positive airway pressure (CPAP). Methods: CPAP therapy was applied to seven VPI patients for eight weeks from April of 2007 to September of 2009. All patients underwent palatoplasty for the cleft palate and six patients underwent palatal lengthening for VPI before CPAP therapy. A speech pathologist performed an auditory perceptual evaluation to evaluate the improvement in hypernasality after 8-week CPAP therapy. Results: Six patients showed an improvement in hypernasality after CPAP therapy according to the auditory perceptual evaluation. One patient with severe hypernasality responded to the early part of therapy but the hypernasality did not improve after therapy. Conclusion: CPAP therapy might be effective in reducing the hypernasality in patients with VPI by providing resistance training to strengthen the velopharyngeal closure muscles. In particular, CPAP therapy could be more effective for patients who show mild to moderate hypernasality after surgery.

• Archives of Plastic Surgery
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• 제40권2호
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• pp.97-103
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• 2013

Background Velopharyngeal insufficiency (VPI) may persist after primary repair of the cleft palate, and surgical correction is necessary in many cases. The purpose of this study is to evaluate the effect of double opposing Z-plasty (DOZ) in cleft palate patients suffering from VPI after primary two-flap palatoplasty. Methods Between March 1999 and August 2005, we identified 82 patients who underwent two-flap palatoplasty for cleft palate repair. After excluding the patients with congenital syndrome and mental retardation, 13 patients were included in the final study group. The average age of the patients who underwent DOZ at was 5 years and 1 month. Resonance, nasal emission, and articulation were evaluated by a speech pathologist. The velopharyngeal gaps were measured before and after surgery. Results Six patients attained normal speech capabilities after DOZ. The hypernasality grade was significantly improved after surgery in all of the patients (P=0.0015). Whereas nasal emission disappeared in 8 patients (61.5%), it was diminished but still persisted in the remaining 5 patients. Articulation was improved in all of the cases. In two cases, the velopharyngeal gap was measured using a ruler. The gap decreased from 11.5 to 7 mm in one case, and from 12.5 to 8 mm in the second case. Conclusions The use of DOZ as a surgical option to correct VPI has many advantages compared with other procedures. These include short surgery time, few troublesome complications, and no harmful effects on the dynamic physiological functioning of the pharynx. This study shows that DOZ can be another option for surgical treatment of patients with VPI after two-flap palatoplasty.

• 미생물학회지
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• 제35권3호
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• pp.180-184
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• 1999

Agaricus 속의 계통분류학적 유연관계를 알아보기 위하여 Internal transcribed spacers 1,2, 와 5.8S rDNA 에 해당하는 부위를 PCR 기법으로 증폭하여 염기서열을 비교 조사하였다. 본 실험에 사용되어진 aGARICUS 속 5균주에 대한 염기서열을 분석한 결과, 이들 속은 크게 두 개의 군으로 분류되었다. 첫 번째 분류군은 aGARICUS BLAZEI atcc 76739, 현재 우리나라에서 배양중인 Agaricus blazei, agaricus arvensis IMSNU 32049, 그리고 Agaricus campestris VPI-OKM 25665로 이루어 졌다. 특히, Agaricus blazei ATCC 76739와 현재 우리나라 농가에서 배양중인 Agaricus blazeisms ITS 부위에서 5개의 염기서열에서 변이가 발견되었다. 이러한 변이는 지리적 또는 배양상의 변이로 인하여 특정염기서열에서 변이가 발생한 것으로 간주되므로 이들은 상호 동일종일 것으로 추정된다. 또한, Agaricus arvensis IMSNU 32049 와 Agaricus ampestris VPI-LKM 25665는 Agaricus blazei 하위 분류군을 형성하였다. 두 번째 분류군은 Agaricus bisporus CH 3004와 Agaricus pocillator DUKE-J 173 으로 이루어졌다.