• Title/Summary/Keyword: 공기역학적 평가

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Spectral & Aerodynamic Analysis of Cries in Infants with Cleft Lip and Palate. (구순구개열 환아의 crying에 대한 음향학적 및 공기역학적 분석)

  • Kim Eun-Ju;Ko Seung-O;Shin Hyo-Keun;Kim Hyun-Ki
    • Korean Journal of Cleft Lip And Palate
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    • v.5 no.2
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    • pp.95-108
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    • 2002
  • 언어 발달의 조기 단계를 이해하기 위한 일환으로 crying은 언어전 발달의 기초 단계로서 여러 학문적 분야에서 많은 연구가 있어왔다. 그러나 구순구개열(CLP))환아의 경우는cry-producing/control mechnism에 variation이 많은 이유로 이 분야의 연구는 거의 없는 실정이다. 이에 본 연구에서는 다음과 같은 의문점을 가지고 CLP환아의 cry feature에 대한분석을 하였다. 첫째, 정상아와 CLP환아의 cry에 전형적인 차이가 있는가? 둘째, CLP환아의 술전, 술후 cry feature에 변화가 있는가? 셋째, cry분석이 CLP환아의 이후 speech disorder에 대한 언어전 평가로서의 가치가 있는가? 넷째, 특정 parameter가 언어전 평가에 적절한 도구로 작용할 수 있는가? 생후 15개월 이내의 CLP 환아 3명과 유사한 나이대의 정상아 8명의 cry에 대한 공기역학 및 음향음성학적 분석을 통해 CLP 환아와 정상아, CLP환아의 술전, 술후 cry특성을 비교 분석하였다. 결과는 다음과 같다. 1 공기역학적 분석 1) airflow는 CLP 환아의 경우 정상아보다 약간 높았고 술 후 약간 증가하였다. 2)폐활량을 나타내는volume에서는 정상아보다 술전 CLP환자의 경우 보상적으로 더 큰 수치를 보였고 술후 약간 증가하였다. 3)강도를 나타내는 parameter(SPL)에서는 정상아 보다 술전 CLP환자의 계측치가 약간 작았으나 술 후 증가하는 양상을 보였다. 2. 음향음성학적 분석 1)기저 주파수 분석시 정상아에 비해 술 전 CLP환자의 경우 계측치가 약간 낮았으나 술 후 증가하여 정상군의 계측치에 근접하였다. 2)강도를 나타내는energy 측정시 정상아에 비해 술 전 CLP계측치가 보상성으로 약간 큰수치를 나타내었고 술 후 약간 더 증가하였다. 3) Shimmer에서는CUI환자의 술후계측치가술전에 비해 현저히 감소하여 정상군의 수치에 근접하였다.

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Comparison of mean airflow rate before and after treatment in patients with sulcus vocalis according to aerodynamic analysis methods (성대구증 환자의 공기역학적 검사 방법에 따른 치료 전과 후의 평균호기류율 비교)

  • Seung Yeon Lee;Hong-Shik Choi;Jaeock Kim
    • Phonetics and Speech Sciences
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    • v.15 no.4
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    • pp.61-69
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    • 2023
  • Sulcus vocalis is characterized by incomplete closure of the vocal folds, with a high mean airflow rate (MFR) as a distinctive feature. The MFR is measured using two aerodynamic analysis methods [the maximum sustained phonation protocol (MXPH) and voicing efficiency protocol (VOEF)] of the phonatory aerodynamic system (PAS), and the results may vary depending on the method. This study compared the differences in MFR before and after treatment (microsurgery and voice therapy) according to the MXPH and VOEF of the PAS in 30 patients with sulcus vocalis. Additionally, we examined whether there were differences in the subjective voice evaluation (voice handicap index, VHI), perceptual voice evaluation (GRBS), and fundamental frequency (F0) before and after treatment. The results showed significant differences between the two methods, both before and after treatment, in patients with sulcus vocalis. However, there were no significant differences by methods in the changes before and after treatment. The VHI and GRBS scores significantly decreased after treatment; however, F0 showed no significant differences before and after treatment. This study indicates that when evaluating MFR changes in patients with sulcus vocalis, it is acceptable to use either aerodynamic analysis (MXPH or VOEF).

Stability Analysis of Unsaturated Soil Slope by Coupled Hydro-mechanical Model Considering Air Flow (공기흐름을 고려한 수리-역학적 연동모델에 의한 불포화 토사사면의 안정해석)

  • Cho, Sung-Eun
    • Journal of the Korean Geotechnical Society
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    • v.32 no.1
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    • pp.19-33
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    • 2016
  • Stability analysis based on the limit equilibrium method combined with the result of infiltration analysis is commonly used to evaluate the effect of rainfall infiltration on the slope stability. Soil is a three-phase mixture composed of solid particle, water and air. Therefore, a fully coupled mixture theories of stress-deformation behavior and the flow of water and air should be used to accurately analyze the process of rainfall infiltration through soil slope. The purpose of this study is to study the effect of interaction of air and water flow on the mechanical stability of slope. In this study, stability analyses based on the coupled hydro-mechanical model of three-phases were conducted for slope of weathered granite soil widespread in Korea. During the process of hydro-mechanical analysis strength reduction technique was applied to evaluate the effect of rainfall infiltration on the slope stability. The results showed an increase of air pressure during infiltration because rain water continuously displaced the air in the unsaturated zone. Such water-air interaction in the pore space of soil affects the stress-deformation behavior of slope. Therefore, the results from the three-phase model showed different behavior from the solid-water model that ignores the transport effect of air in the pores.

Performance of High-Flowable Retaining Wall Material Using Ground Granulated Blast-Furnace Slag and Steel Fiber (고로슬래그미분말 및 강섬유를 적용한 고유동 흙막이 벽체 재료의 성능 평가)

  • Kim, Donggyou;Yu, Kangmin;Lee, Seungtae
    • Journal of the Korean GEO-environmental Society
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    • v.23 no.11
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    • pp.5-11
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    • 2022
  • The objective of this study is to evaluate the mechanical properties of high-flowable retaining wall material (RWM) incorporated with ground granulated blast-furnace slag (SG) and steel fiber (SF) based on a comparison with those of ordinary portland cement (OPC). To produce the specimens of RWM, some chemical agents such as superplasticizer (SP), air-entrained agent (AEA) and viscosity modifying agent (VMA) are added in the fresh RWM. The compressive, split tensile and flexural strength measurements were performed on the hardened RWM specimens. Additionally, surface electric resistivity and absorption tests according to ASTM standards were carried out at predetermined periods after water curing. It was found that the mechanical properties of slag cement concrete (SGC) RWM mix are better than those ordinary portland cement concrete (OPC) RWM mix. The effect of SF is remarkable to improve the mechanical properties of RWM mixes. It is noted that the usage of SG shows a beneficial effect to resist water penetration as well as long-term strength development of RWM mixes.

The Perceptual Evaluation and Aerodynamic Analysis of Spasmodic Dysphonia (연축성발성장애의 청지각적 평가 및 공기역학적 특성)

  • Park, Sun-Young;Kim, Jae-Ock;Lim, Sung-Eun;Nam, Do-Hyun;Choi, Hong-Shik
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.19 no.1
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    • pp.38-42
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    • 2008
  • Background and Objectives : This study was performed to investigate the perceptual and aerodynamic characteristics and the relation between vocal efficiency and the severity of strained voice. of adductor spasmodic dysphonia. Materials and Methods : 13 female patients with adductor spasmodic dysphonia were examined and compared with 10 normal female control group. MPT, MFR, Psub, Sound Intensity, VE(vocal efficiency) were obtained using PAS(Phonatory Aerodynamic System). GRBA(S) scale was used for Perceptual evaluation. Results : Psub(subglottic pressure) of SD was significantly higher than normal group. MPT, MFR, Sound Intensity, VE were not significantly different between two groups. Correlation between VE and 'S'(strained) was not significant. Conclusion : The results of this study show that certain aerodynamic parameters(Psub) distinguish adductor spasmodic dysphonia from normal voice.

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Numerical Study on the Internal Flow in the Cyclone Vacuum Cleaner (사이클론 청소기 내부 유동에 관한 수치해석적 연구)

  • Lee, Chanhyun;Chang, Hyuksang
    • Clean Technology
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    • v.20 no.3
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    • pp.283-289
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    • 2014
  • General household vacuum cleaners consist of dust collector, pre filter, motor and exhaust filter, and the filtered clean air is discharged to the atmosphere. By using the CFD methods, we estimated the internal flow in two types of commercial cyclone vacuum cleaners to evaluate the dust collection performance. From the analysis, it was known that the number of revolution had higher values in cyclone cone region. CFD analysis in a specific showed non-uniform velocity distribution at outlet, which results in the deterioration of particle collection performance. In order to improve flow condition, the installation of baffle was proposed and the values of velocity RMS were estimated.

Mean Value of Aerodynamic Study in Normal Korean (음성검사 중 공기역학적 검사에서 한국인 정상 평균치)

  • 서장수;송시연;권오철;정옥란
    • Proceedings of the KSLP Conference
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    • 1996.11a
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    • pp.79-79
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    • 1996
  • 최근 들어 음성에 대한 일반인들의 관심이 높아지면서 음성이상을 호소하며 이비인후과 외래를 방문하는 환자가 점차적으로 증가하는 추세에 있다. 그러나 이러한 음성이상을 객관적으로 평가할 수 있는 기준이 국내에는 거의 없는 실정이다. 이에 저자들은 본 연구에서 기왕력 상 폐질환이나 신경계질환, 후두질환을 앓은 적이 없으며 음성조율 기관에 이상이 없고 정상적인 청력을 가진 10세에서 69세까지의 무작위 추출된 정상 한국인 남자 112명과 여자 122명을 대상으로 Aerophone II voice function analyzer를 이용하여 공기역동학적 검사 중 최대발성지속시간(maximum phonation time), 평균호기류율(mean airflow rate), 발성율(phonation quotient), 발성시 기류량(phonatory flow volume) 및 성문하압(subglottal pressure)의 정상 한국인의 남녀 년령별 평균치를 측정하고자 하였다. (중략)

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Development of a Numerical Algorithm for the Evaluation of Aerodynamic Driving Stability of a Vehicle (주행차량의 공기역학적 주행안전성 평가를 위한 알고리즘 개발연구)

  • Kim, Chul-Ho;Kim, Chang-Sun;Lee, Seung-Hyun
    • Transactions of the Korean Society of Automotive Engineers
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    • v.24 no.3
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    • pp.265-272
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    • 2016
  • The objective of vehicle aerodynamic design is on the fuel economy, reduction of the harmful emission, minimizing the vibration and noise and the driving stability of the vehicle. Especially for a sedan, the driving stability of the vehicle is the main concern of the aerodynamic design of the vehicle indeed. In this theoretical study, an evaluation algorithm of aerodynamic driving stability of a vehicle was made to estimate the dynamic stability of a vehicle at the given driving condition on a road. For the stability evaluation of a driving vehicle, CFD simulation was conducted to have the rolling, pitching and yawing moments of a model vehicle and compared the values of the moments to the resistance moments. From the case study, it is found that a model sedan running at 100 km/h in speed on a straight level road is stable under the side wind with 45 m/s in speed. But the different results may be obtained on the buses and trucks because those vehicles have the wide side area. From the case study of the model vehicle moving on 100 km/h speed with 15 m/s side wind is evaluated using the numerical algorithm drawn from the study, the value of yawing moment is $608.6N{\cdot}m$, rolling moment $-641N{\cdot}m$ and pitching moment $3.9N{\cdot}m$. These values are smaller than each value of rotational resistance moment the model vehicle has, and therefore, the model vehicle's driving stability is guaranteed when driving 100 km/h with 15 m/s side wind.

Effect of Steel Fiber Addition on the Mechanical Properties and Durability of High-Flowable Retaining Wall Material (고유동 흙막이 벽체 재료의 역학적 성능 및 내구성에 대한 강섬유 혼입률의 영향)

  • Donggyu Kim;Seungtae Lee
    • Journal of the Korean GEO-environmental Society
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    • v.24 no.6
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    • pp.13-20
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    • 2023
  • This paper is aimed to evaluate the mechanical properties and durability of high-flowable retaining wall material (RWM) with different levels of steel fiber (SF) content. To produce the specimens of RWM, some chemical agents such as superplasticizer (SP), air-entrained agent (AEA) and viscosity modifying agent (VMA) were added in the fresh RWM. The compressive and split tensile strength measurements were performed on the hardened RWM specimens at the predetermined periods. Additionally, surface electric resistivity and absorption tests according to ASTM standards were carried out to examine mechanical properties of RWM mixes. The durable performances such as chloride ions penetrability and freezing-thawing resistance of RWM mixes were experimentally investigated. As resutls, it was found that the performance of RWM mix with SF were much better than that without SF, especially at the 2% addition of SF. Thus, it is noted that the proper addition of SF in the RWM mix may have a beneficial effect to improve mechanical properties and durability of RWM mixes.

발성치료

  • 남도현
    • Proceedings of the KSLP Conference
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    • 2003.11a
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    • pp.215-218
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    • 2003
  • 발성치료는 약400여년간 내려오고 있는 성악발성법 (벨칸토 발성)을 이용하여 음성을 교정하고 치료하는 방법으로 과학적이고 의학적으로 인정된 방법을 통하여 음성을 교육하고 교정하는 약물적이고 비 수술적인 치료 방법이다. 음성크리닉검사 1) 공기역학검사(Phonatory function analyzer test) 2) 최대발성지속시간(Maximum phonation time) 3) 컴퓨터 음성검사(Dotor speech. MDVP) 4) 듣기평가 5) 내시경검사(Stroboscopy) 6) 전기성문파형검사(EGG) 7) 호흡근력검사. (MIP. MEP. 등)및 호흡검사(FVC. FEVI. PF. 등) 8) 음성전문의사의 확진 후 발성치료권유 (중략)

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