• 제목/요약/키워드: Over pressure

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족근 관절 외과 부위의 압박궤양과 괴사 (Pressure Sore and Necrosis over the lateral malleolus of the Ankle)

  • 박인헌;송경원;신성일;이진영;서동현
    • 대한족부족관절학회지
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    • 제6권1호
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    • pp.21-27
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    • 2002
  • Pressure sores are an ulceration and necrosis of the skin and underlying tissue usually occur after prolonged or repeated pressure by interruption of blood flow from the small. vessels to the skin and deep tissue. The management of pressure sores is mostly difficult and requires prolonged hospitalization or repeated surgical interventions with a high recurrence rate. In this article we reviewed 14 cases of National Pressure Ulcer Advisory Pannel staging III, IV over the lateral malleolar area of the ankle in 2 years period from January 1999 to October 2001. The pressure over lateral malleolar area was mainly due to unique Korean sitting position with cross legs at flexed hips and knees or supine position of patient with external rotation of low extremity. Male to female ratio was 11: 3 and ages were between 36 and 83 (mean age: 67.1 years). Associated diseases were DM(7 cases), Hemiparesis caused by CVA(2 cases), Liver cirrhosis(2 cases), disarticulation of opposite hip due to squamous cell ca.(1 case), Intertrochanteric Fx.(1 case). Wound cultures reported Staphylococus, Pseudomonas and others. Abnormally elevated ESR and CRP were seen in 6 cases. Operative treatments were irrigation and debridement, direct closure with gravity drainage and skin grafting. The most important aspect of pressure sore treatment is pressure relief of the lateral malleolar area. Pressure-relieving Cast or Brace was helpful for local management and preventing recurrence.

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Study on Fault Detection of a Gas Pressure Regulator Based on Machine Learning Algorithms

  • Seo, Chan-Yang;Suh, Young-Joo;Kim, Dong-Ju
    • 한국컴퓨터정보학회논문지
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    • 제25권4호
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    • pp.19-27
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    • 2020
  • 본 논문에서는 정압기의 이상 상태 진단을 위한 기계학습 방법을 제안한다. 일반적으로 설비의 이상 상태 탐지를 위한 기계학습 모델 구현에는 관련 센서의 설치와 데이터 수집 과정이 동반되나, 정압기는 설비 특성상 안전문제에 매우 민감하여 추가적인 센서 설치가 매우 까다롭다. 이에 본 논문에서는 센서의 추가 설치 없이 정압기 설비에서 자체 수집되는 유량과 유압 데이터만을 가지고 정압기의 이상 상태를 조기에 판단하는 기계학습 모델을 제안한다. 본 논문에서는 정압기의 비정상데이터가 충분하지 않은 관계로, 모델 학습 시 오버 샘플링(Over-Sampling)을 적용하여 모델이 모든 클래스에 균형적으로 학습하도록 하였다. 또한, 그레이디언트 부스팅(Gradient Boosting), 1차원 합성곱 신경망(1D Convolutional Neural Networks), LSTM(Long Short-Term Memory) 등의 기계학습 알고리즘을 적용하여 정압기의 이상 상태를 판단하는 분류모델을 구현하였고, 실험 결과 그레이디언트 부스팅 알고리즘이 정확도 99.975%로 가장 성능이 우수함을 확인하였다.

도시 성인 여성의 연령 및 건강지각에 따른 비만과 심폐기능 정도 (Obesity and Cardiopulmonary Function in Urban Adult Females)

  • 정승교;김춘길
    • 여성건강간호학회지
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    • 제6권4호
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    • pp.594-605
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    • 2000
  • The purpose of this study is to collect fundamental data for adult female health improvement based on urban adult female obesity and cardiopulmonary function. Surveyed were 859 adult females who visited a health improvement center in D district in Seoul between April, 1999, and December, 1999, and the resulting data are as follows: 1. The adult female mean BMI was $23.97{\pm}3.11kgm^2$, which comes within the range of overweight. Among them, BMI of the females aged 41-60, and over 60, were significantly higher. Mean percentage of body fat was $32.07{\pm}4.63$, and it significantly increased in accordance with age, recording the highest among those aged over 60. 2. The systolic blood pressure significantly increased in accordance with age, recording highest among those aged over 60. Those aged 41-60 and over 60 showed significantly higher diastolic blood pressure than those in their 20s and 30s; however, they had a significantly lower heart rate. Vital capacity and maximum oxygen intake significantly decreased in accordance with age, and those aged over 60 were lowest. 3. As to health perception, 20.6% of the subjects perceived themselves as healthy, and those who perceived themselves as unhealthy showed significantly higher BMI than those who perceived themselves to be of moderate health. 4. There were no significant differences in blood pressure, heart rate and maximum oxygen intake in accordance with health perception, but those who perceived themselves as healthy showed significantly higher vital capacity than those who didn't. 5. As to cardiopulmonary function in accordance with obesity, the obese group showed significantly higher systolic blood pressure than those whose weight was normal to overweight. The diastolic blood pressure of the normal weight group was the lowest, while the obese group showed significantly lower vital capacity and maximum oxygen intake. These findings indicate that the womens' health promotion program must include an effective strategy for preventing obesity, and strengthening cardiopulmonary function.

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고 받음각 ONERA 70도 삼각날개 와류 유동의 압력 섭동 분석 (NUMERICAL ANALYSIS OF PRESSURE PERTURBATION OF DELTA WING VORTEX FLOW AT A HIGH ANGLE OF ATTACK)

  • 손미소;사정환;박수형;변영환
    • 한국전산유체공학회지
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    • 제20권2호
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    • pp.73-80
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    • 2015
  • Delayed Detached-Eddy Simulation was conducted to investigate surface pressure coefficient distribution and surface pressure fluctuation over an ONERA 70-degree delta wing at a high angle of attack. Time-averaged surface pressure distribution is directly affected by the primary vortices, whereas the pressure fluctuation is influenced by the unsteady fluctuating boundary layer over the surface. And pressure coefficient, velocity, pressure fluctuation, and turbulent kinetic energy were analyzed along the vortex core in order to investigate the process of vortex breakdown. Consequently, strong pressure fluctuations were found where the vortex breakdown was occurred at x~620 mm. The turbulent kinetic energy abruptly increased and followed after the vortex breakdown.

R-404A/POE 오일 혼합물의 증기압과 혼화성 (Vapor Pressure and Miscibility for R474A/POE Oil Mixtures)

  • 이정훈;박영무
    • 설비공학논문집
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    • 제14권4호
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    • pp.285-292
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    • 2002
  • The vapor pressure and miscibility measurement apparatus was developed and used to obtain data for refrigerant/oil mixture. The vapor pressure and miscibility data for R-404A/32 ISO VG polyol ester (POE) oil mixture and R-404A/46 ISO VG polyol ester oil mixture are obtained over the temperature range from -20 to $60^{\circ}$ with at $10^{\circ}$ intervals and the oil concentration range from 0 to 70 wt%. Using the experimental data, an empirical model was developed to predict the temperature vapor pressure-concentration relations for R-404A/46 ISO VG polyol ester oil mixtures at equilibrium. In the R-404A/32 ISO VG polyol ester oil mixture, the average root-mean-square deviation between measured data and calculated results from the empirical model is 1.24% and in the R-404A/46 ISO VG polyol ester oil mixture, that is 1.37%. Miscibility for R-404A/32 ISO VG polyol ester oil mixture was observed all over the experimental conditions. Immiscibility for R-404A/So1est 46 oil mixture was observed at the low oil concentrations (20~30 wt%) over the high experimental temperature range (50~$60^{\circ}$).

수열 압력 제조 조건이 MoS2 촉매 특성과 직접 메탄화 반응에 미치는 영향 (Hydrothermal Pressure Effect over Preparation of MoS2: Catalyst Characterization and Direct Methanation)

  • 박정환;김성수;김진걸
    • 한국수소및신에너지학회논문집
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    • 제29권2호
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    • pp.170-180
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    • 2018
  • After $MoS_2$ catalyst was prepared at 1, 30, and 70 atm, the hydrothermal pressure effect over preparation of $MoS_2$ was investigated in terms of catalyst characterization and direct methanation. Multifaceted characterization techniques such as XRD, BET, SEM, TPR, EDS, and XPS were used to analyze and investigate the effect of high pressure over the preparation of surface and bulk $MoS_2$ catalyst. Result from XRD, SEM, and BET demonstrated that $MoS_2$ was more dispersed as preparation pressure was increased, which resulted finer $MoS_2$ crystal size and higher surface area. EDS result confirmed that bulk composition was $MoS_2$ and XPS result showed that S/Mo mole ratio of surface was about 1.3. TPR showed that $MoS_2$ prepared at 30 atm possessed higher active surface sites than $MoS_2$ prepared at 1 atm and these sites could contribute to higher CO yield during methanation. Direct methanation was used to evaluate the CO conversion of the both catalysts prepared at 1 atm and 30 atm and reaction condition was at feed mole ratio of $H_2/CO=1$, GHSV=4800, 30 atm, temperature($^{\circ}C$) of 300, 350, 400, and 450. $MoS_2$ prepared at 30 atm showed more stable and higher CO conversion than $MoS_2$ prepared at 1 atm. Faster deactivation was occurred over $MoS_2$ prepared at 1 atm, which indicated that preparation pressure of $MoS_2$ catalyst was the dominant factor to improve the yield of direct methanation.

성인남녀의 커피 섭취 상태 및 혈압, 혈중 지질과의 관련성 (The Relationships among Coffee Consumption, Blood Pressure, and Serum Lipids in Korean Adult Men and Women)

  • 최미경;이윤신
    • 한국식품영양학회지
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    • 제20권4호
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    • pp.460-466
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    • 2007
  • The purpose of this study was to estimate coffee consumption and it's relationship to blood pressure and blood lipid profiles in Korean adult men and women. Antheropometrics, dietary intake by 24-hour recall, and serum lipid profiles were measured in 354 subjects. The average subject ages for the age ranges of $20{\sim}49$, $50{\sim}64$, and over 65 years, were 39.7, 57.5, and 70.6 years for the men, and 40.7, 56.9, and 70.9 years for the women, respectively. Mean height and weight were significantly higher in the men and decreased with increasing of age. Thirty percent and 28% of the men and women, respectively, consumed coffee. The proportions of coffee consuming subjects in the age rangers of $20{\sim}49$ years(34.9%) and $50{\sim}64$ years(35.6%) were significantly higher than in the group over 65 years(11.5%). The mean daily intakes of food and energy were showed the same results according to sex and age. Mean daily coffee intake was not significantly different between the men and women, but it was significantly lower in the over 65 age group. Systolic blood pressure was significantly higher in the men and increasing age. The atherogenic index was significantly higher in the $20{\sim}49$ year-old men, and in the women over 65 years. There were no significant correlations among coffee consumption, blood pressure, and the serum lipid profile. In conclusion, the daily coffee consumption by adult men and women, with the exception of the elderly, was $50{\sim}90m{\ell}$, and it was not significantly correlated to blood pressure or blood lipids.

난류 경계층에서 컴플라이언트 코팅과 점탄성 벽면의 방사 소음에 관한 실험적 연구 (Radiated Sound from Compliant and Viscoelastic Plates in a Turbulent Boundary Layer)

  • 이승배;이창준;권오섭;전우평
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2002년도 학술대회지
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    • pp.779-782
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    • 2002
  • We examine the problem in which porous/viscoelastic compliant thin plates are subject to pressure fluctuations under transitional or turbulent boundary layer. Measurements are presented of the frequency spectra of the near-field pressure and radiated sound by compliant surface. A porous plate consisting of 5mm thick, open-cell foam with fabric covering and a viscoelastic painted plate of 1mm thick over an acoustic board of 4m thick were placed over a rigid surface in an anechoic wind tunnel. Streamwise velocity and wall pressure measurements were shown to highly attenuate the convective wall pressure energy when the convective wavenumber ($k_{ch}$) was 3.0 or more. The sound source localization on the compliant walls is applied to the measurement of radiated sound by using an acoustic mirror system.

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난류 경계층에서 컴플라이언트 코팅된 벽면과 점탄성 벽면의 방사 소음에 관한 실험적 연구 (Radiated Sound from Compliant and Viscoelastic Plates in a Turbulent Boundary Layer)

  • 이창준;이승배;권오섭;전우평
    • 대한기계학회논문집B
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    • 제27권3호
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    • pp.294-301
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    • 2003
  • We examine a problem in which porous/viscoelastic compliant thin plates are subject to pressure fluctuations under transitional or turbulent boundary layer. Measurements are presented of the frequency spectra of the near-field pressure and radiated sound by compliant surface. A porous plate consisting of 5mm thick. open-cell foam with fabric covering and a viscoelastic-painted plate of 1mm thick over an acoustic board of 4mm thick were placed over a rigid surface in an anechoic wind tunnel. Streamwise velocity and wall pressure measurements were shown to highly attenuate the convective wall pressure energy when the convective wavenumber (k$_{c}$h) was 3.0 or more. The sound source localization on the compliant walls is applied to the measurement of radiated sound by using an acoustic mirror system.

아음속 횡단 유동장으로 펄스 분사된 액체 제트의 분무특성 (Spray Characteristics of a Pulsed Liquid Jet into a Cross-flow of Air)

  • 이인철;변용우;구자예
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2008년도 춘계학술대회논문집
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    • pp.61-64
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    • 2008
  • The present study of these experiments are close examination of spray characteristics that are continuous liquid jet and modulated pressure pulse liquid jet. The experiments were conducted using water, over a range of cross-flow velocities from 42${\sim}$136 m/s, with injection frequencies of 35.7${\sim}$166.2 Hz. Between continuous cross-flow jet and pressure pulsed cross-flow jet for characteristics of penetration, breakup point, spray angle and macro spray shape are investigated experimentally. In cross-flow field, main parameter of liquid jet for breakup was cross-flow stream rather than pressure pulse frequency. As oscillation of the periodic pressure that could make liquid jet moved up and down, the mixing efficiency was increased. Also, a bulk of liquid jet puff was detected at upper field of liquid surface. So, this phenomenon has a good advantage of mixing spray from concentration of center area to outer area. Because of pressure pulsation frequency, an inclination of SMD for the structured layer was evanescent. Cross-sectional characteristics of SMD at downstream area were non-structured distributions. Then cross-sectional characteristics of SMD size were about same tendency over a range that is effect of spray mixing. The tendency of volume flux value for various frequency of pressure pulse was same distribution. And volume flux was decreased when the frequency of pressure pulse increase.

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