• Title/Summary/Keyword: inflation pressure

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Design of the Blood Pressure Measurement System Using the Inflatable Oscillometric Method (가압식 오실로메트릭 방법을 사용한 혈압측정 시스템의 설계)

  • 노동곤;이윤선;지정호;박성빈;이계형;김해관
    • Journal of Biomedical Engineering Research
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    • v.24 no.4
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    • pp.281-286
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    • 2003
  • Blood Pressure is one of the most fundamental Parameters which reflects physical conditions medically and the blood pressure measurement system using oscillometric method is a Non-Invasive Blood Pressure measurement device by measuring arterial Pressure through a cuff. In this paper. we designed a inflatable wrist blood pressure system which measures blood Pressure during the stepping inflation in the wrist cuff. The hardware system consists of a main power unit, a bladder in cuff unit, signal detection units, signal Processing units. a wireless data transmission unit, and a data display unit. We evaluated the reliability of this system by comparing and analyzing systolic. diastolic blood Pressure, and heart rate with other commercial blood Pressure measurement devices. Characteristic ratio values used to determine systolic and diastolic blood Pressure using MAA(Maximum Amplitude Algorithm) were 0.436 and 0.671 respectively.

General inflation and bifurcation analysis of rubber balloons (고무풍선의 일반화 팽창 및 분기 해석)

  • Park, Moon Shik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.12
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    • pp.14-24
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    • 2018
  • Several typical hyper-elastic constitutive models that encompass both conventional and advanced ones were investigated for the application of instability problems, including the biaxial tension of a rubber patch and inflation of spherical or cylindrical balloons. The material models included the neo-Hookean model, Mooney-Rivlin model, Gent model, Arruda-Boyce model, Fung model, and Pucci-Saccomandi model. Analyses can be done using membrane equations with particular strain energy density functions. Among the typical strain energy density functions, Kearsley's bifurcation for the Treloar's patch occurs only with the Mooney-Rivlin model. The inflation equation is so generalized that a spherical balloon and tube balloons can be taken into account. From the analyses, the critical material parameters and limit points were identified for material models in terms of the non-dimensional pressure and inflation volume ratio. The bifurcation was then identified and found for each material model of a balloon. When the finite element method was used for the structural instability problems of rubber-like materials, some careful treatments required could be suggested. Overall, care must be taken not only with the analysis technique, but also in selecting constitutive models, particularly the instabilities.

Effect of Betamethasone on the Pulmonary Pressure-Volume Curve in Unilateral Pneumonectomized Rabbits (Betamethasone이 일측폐장절제 가토폐장의 압력-용적곡선에 미치는 영향)

  • Lee, Young-Man;Lee, Suck-Kang
    • The Korean Journal of Physiology
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    • v.17 no.1
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    • pp.23-28
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    • 1983
  • In order to clarify the effect of steroid on the pulmonary pressure-volume curve in the pneumonectomized rabbit, the right side pneumonectomy was performed under general anesthesia with pentobarbital sodium and the remaining lung was excised on the fifth day after surgery. The intrapulmonic pressure in the excised left lung was measured at 20, 25, and 30 ml lung volume during inflation and deflation period. In the steroid treated group, the intrapulmonic pressure at 20, 25, and 30 ml lung volume during inflation was significantly decreased compared with intrapulmonic pressure of the control group. But in the pneumonectomy group the decreasing tendency of the pressure was observed. During deflation, the intrapulmonic pressure at 25 ml and 20 ml was not significantly different from the control group in pneumonectomy and steroid treated pneumonectomy group. And the lung weight was measured in each experimental group and also the lung weightbody weight ratio(L/B) was calculated. The lung weight was significantly increased in both pneumonectomy and steroid treated pneumonectomy group. Calculated L/B was increased significantly in both group. Above results suggest that steroid increases the secretion of pulmonary surfactant or affects the catabolic effect on protein metabolism of connective tissue in lung parenchyma.

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Relationships Between Fermentative Gas Pressure and Quality Changes of Packaged Kimchi at Different Temperatures (저장온도에 따른 포장김치의 기체압력변화와 품질과의 관계)

  • Hong, Seok-In;Park, Jin-Sook;Park, Noh-Hyun
    • Korean Journal of Food Science and Technology
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    • v.26 no.6
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    • pp.770-775
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    • 1994
  • Kimchi packed in polypropylene(PP) tray was stored at different temperatures (0, 10, $20^{\circ}C$) to investigate the relationships between fermentative gas pressure and quality changes. The quality of Kimchi during storage was evaluated in terms of pH, titratable acidity, color, and sensory properties. The fermentative gas pressure changes due to $CO_2$ evolution showed typical sigmoidal curves at each temperature. Accordingly, inflation of Kimchi packages caused by increasing gas pressure occurred in 40 hours, 5 and 30 days at 20, 10, $0^{\circ}C$ , respectively, at which gas pressure inside the packages ranged $1.2{\sim}1.4\;psig$. Following inflation, Kimchi packages stored at 20 and $10^{\circ}C$ were burst out on 3 and 8 days, but those at $0^{\circ}C$ were not. As the fermentative gas pressure increased, pH decreased (r > 0.968) and titratable acidity increased (r > 0.973) proportionally. Regarding to the color change of crushed Kimchi juice, L and b values were decreased exponentially, but a value remained constant during storage. Among sensory properties, the sourness and texture scores showed good accordance with pH changes. In conclusion, although Kimchi kept optimal tastes during storage, the inflation of package restricted shelf-life of Kimchi.

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A New Airbag Modeling Using a Sphere and a Torus and the Occupant Analysis in the Out-of-position (구와 원환체를 이용한 에어백의 모델링 및 비정상위치시의 승객 거동 해석)

  • 임재문;김창환;박경진
    • Transactions of the Korean Society of Automotive Engineers
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    • v.4 no.1
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    • pp.96-109
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    • 1996
  • The airbag system is known to be extremely efficient for the protection in an automobile crash. The performance of the airbag system is evaluated by real tests. However, the test is very difficult and expensive. Therefore, the computational simulations are carried out with low cost. The airbag analysis is included in the anlysis of the full-car crashworthiness. The behavior of the airbag can be predicted by a thermodynamic analysis. The contact force between the occupant and the airbag is calculated from the contact volume and the pressure in the airbag. The injury rate is evaluated from the contact force and the acceleration of dummies. So far, the contact is defined after the airgag is fully inflated. In many cases, the occupant is seated in the out-of-position and the contact can happen during the inflation process. A new algorithm has been developed for the out-of-position. To describe the inflation process precisely, the airbag is defined by a sphere and a torus. The injury is evaluated for the contact happened at any time. The developed algorithm is coded and interfaced with an existing software in the public domain. The full-car modeling is adopted from the previous study which is tuned for the regular position and real tests. Numerical experimentation have been carried out with a couple of dummies in the out-of-position and the injury processes are analyzed.

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Effect Oxygen in Inflation Gas for Warm Ischemia-reperfusion Injury in the Lung of a Mongrel Dog (황견에서 폐장의 산소가 온열 허혈후 재관류 시폐손상에 미치는 영향)

  • 성숙환;김현조;김영태
    • Journal of Chest Surgery
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    • v.33 no.2
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    • pp.125-131
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    • 2000
  • Background: Hyperinflation during lung ischemia has been known to improve pulmonary functions after reperfusion which may be exerted through a pulmonary vasodilation and avoidance of atelectasis by an increased surfactant release and been known whether the improvement of pulmonary function was the effect of hyperinflation itself or the oxygen content in inflation gas. Therefore we attempted to clarify the effect of hyperinflation with oxygen in pulmonary inflation gas during warm ischemia on pulmonary function after reperfusion to solve the problem of ischemia-reperfusion injury after lung transplantation. Material and Method: sixteen mongrel dogs were randomly divided into two groups: the left lung was inflated to 30-35 cm H2O with 100% oxygen in oxygen group and 100% nitrogen in nitrogen group. The inflated left lung was maintained with warm ischemia for 100 minutes. Arterial and mixed venous blood gas analysis and hemodynamics were measured before ischemia and 30, 60, 120, 180 and 240 minutes afer reperfusion. Lung biopsy was taken for the measurement of lung water content after the end of reperfusion. Result: In oxygen group arterial oxygen tension the difference of arterial and mixed venous oxygen tension and the difference of alveolar-arterial oxygen tension at 30-minute after reperfusion were not significantly different from those before ischemia and were stable during the 40hour reperfusion. However in nitrogen group these values were significantly deteriorated at 30-minute after reperfusion. there was no significant difference between two groups in hemodynamic data peak airway pressure and lung water content. Conclusion : The results indicated that the oxygenation one of the most important pulmonary functions was improved by pulmonary inflation with 100% oxygen during warm ischemia but the hemodynamics were not. Oxygen as a metabolic substrate during warm ischenia was believed to make the pulmonary tissues to maintain aerobic metabolism and to prevent ischemic damage of alveoli and pulmonary capillary.

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Optimal Monetary Policy under Regime Switches - the case of US Housing Market - (상태 변환하의 최적 통화 정책 - 미국 주택 시장의 경우 -)

  • Kim, Jangryoul;Lim, Gieyoung
    • International Area Studies Review
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    • v.12 no.3
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    • pp.49-67
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    • 2008
  • In this paper, we address the problem of optimal monetary policy rule in the presence of abrupt shifts in the structure of the economy. To do so, we first estimate a Markov switching model for the US housing price inflation, and find evidence supporting the presence of two distinct regimes for the US housing price inflation. One of the two regimes identified appears 'usual', in that housing price inflation negatively responds to higher real interest rate. The other regime is 'unusual', in that the housing price inflation is positively related with real interest rate. We then solve an optimal control problem of the FRB under the presence of the two regimes thus identified. The optimal policy is 'asymmetric' in that the optimal responses in the 'usual' regime require the FRB to lean against the wind to inflationary pressure, while the FRB is recommended to accommodate it in the unusual regime. It is also found that the optimal degree of responses is more conservative when the FRB acknowledges the uncertainty about future regime.

Asymmetric Effects of US Housing Price Inflation on Optimal Monetary Policy (미국 주택 가격 상승률의 비대칭성과 최적통화정책)

  • Kim, Jangryoul;Kim, Minyoung;Lim, Gieyoung
    • International Area Studies Review
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    • v.13 no.2
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    • pp.66-88
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    • 2009
  • This paper studies optimal discretionary monetary policy in the presence of uncertainty in the housing sector. In particular, we allow two possible regimes regarding the evolution of housing price inflation and the effects of housing price inflation on the aggregate demand. Estimation results with the US data confirm the presence of two distinctive regimes, one 'normal' and the other more akin to the housing price 'bubble' state. The optimal policy is 'asymmetric' in that the optimal responses in the 'normal' regime require the central bank to lean against the wind to inflationary pressure from CPI and housing inflation, while the central bank is recommended to accommodate it in the other regime.

Finite Element Analysis of Air Springs with Fiber-Reinforced Rubber Composites Using 3-D Shell Elements (3차원 셸 요소를 이용한 섬유보강 고무모재 공기 스프링의 유한요소해석)

  • Lee, Hyoung-Wook;Huh, Hoon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.4
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    • pp.602-609
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    • 2001
  • This paper is concerned with the orthotropic problem of diaphragm-type air springs which consist of rubber linings, nylon reinforced rubber composite and bead ring. The analysis is carried out with a finite element method developed to consider the orthotropic properties, geometric nonlinearity using four-node degenerated shell element with reduced integration. Physical stabilization scheme is used to control the zeroenergy mode of the element. The analysis includes an inflation analysis and a lateral analysis of an air spring for the deformed shape and the spring load with respect to the vertical and l ateral deflection. Numerical results demonstrate the variation of the outer diameter, the fold height, the vertical force and the lateral force with respect to the inflation pressure and the lateral deflection.