• 제목/요약/키워드: Deflation

검색결과 63건 처리시간 0.025초

Imaging System Science Laboratory

  • Nalcioglu, O.;Cho, Z.H.
    • 대한의용생체공학회:의공학회지
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    • 제4권1호
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    • pp.3-8
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    • 1983
  • Characteristics of the lung inflation and deflation reflexes were measured at various temperatures on the cervical vagi in five anesthetized mongrel dogs. Nerve temperature was maintained at the body temperature, and 2-14˚C with 2˚C apart using a specially designed automated vagal cooling apparatus with an accuracy to within $\pm$ 0.1˚c at each temperature. The inflation reflex was blocked abruptly at 8-10˚C. The deflation reflex started weakened at 14˚C, thereafter showed a gradual blockade with the temperature decreased with a substantial variance among the animals.It was approximately 75% blocked at 2-5˚C. These differences in temperature characteristics made it hard to differentiate the deflation reflex from the inflation reflex. In one animal, however, the inflation reflex was completely blocked with the deflation reflex almost alive at 6-8˚C. This suggests that differential cold blockade of the vagal reflexes can be done only in selected subjects. Furthermore, the fact that these two reflexes were blocked at different temperatures may be due to the differences in the nerve fiber size and the changes in the conduction velocity with temperature.

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복강경 대장절제술에서 기복이 고혈압 환자의 심박수, 평균동맥압 및 심박출량에 미치는 영향 (The Effects of Pneumoperitoneum on Heart Rate, Mean Arterial Blood Pressure and Cardiac Output of Hypertensive Patients during Laparoscopic Colectomy)

  • 김은주;윤혜상
    • 대한간호학회지
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    • 제40권3호
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    • pp.433-441
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    • 2010
  • Purpose: This study was performed to identify effects of pneumoperitoneum on hemodynamic changes of hypertensive patients undergoing laparoscopic colectomy under general anesthesia. Methods: Data collection was done from January 2 to June 10, 2008. Seventy-six patients, including 38 hypertensive patients, who had taken antihypertensive drugs more than 1 month and 38 normotensive patients undergoing laparoscopic colectomy were enrolled in this study. The hemodynamic parameters were heart rate (HR), mean arterial pressure (MAP) and cardiac output (CO) which were measured 7 times from before induction of anesthesia to 5 min after deflation of the pneumoperitoneum. Collected data were analyzed using Repeated Measures ANOVA and Bonferroni comparison method. Results: HR in the hypertensive group was significantly decreased at deflation of the pneumoperitoneum and 5 min after deflation of the pneumoperitoneum (p=.012). MAP in the hypertensive group was not different from the normotensive group (p=.756). CO in hypertensive group was significantly lower than normotensive group (p<.001) from immediately after pneumoperitoneum to 5 min after deflation of the pneumoperitoneum. Conclusion: The results indicate that pneumoperitoneum during laparoscopic surgery does not lead to clinically negative hemodynamic changes in heart rate, mean arterial pressure or cardiac output of hypertensive patients, who have taken antihypertensive drugs for more than 1 month.

A NEW UNDERSTANDING OF THE QR METHOD

  • Min, Cho-Hong
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제14권1호
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    • pp.29-34
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    • 2010
  • The QR method is one of the most common methods for calculating the eigenvalues of a square matrix, however its understanding would require complicated and sophisticated mathematical logics. In this article, we present a simple way to understand QR method only with a minimal mathematical knowledge. A deflation technique is introduced, and its combination with the power iteration leads to extracting all the eigenvectors. The orthogonal iteration is then shown to be compatible with the combination of deflation and power iteration. The connection of QR method to orthogonal iteration is then briefly reviewed. Our presentation is unique and easy to understand among many accounts for the QR method by introducing the orthogonal iteration in terms of deflation and power iteration.

Rayleigh Quotient와 Deflation을 이용한 대형다기(多機)전력계통의 고유치 해석 (Modal Analysis of Large Scale Multi-Machine Power System using Rayleigh Quotient and Deflation)

  • 심관식;남해곤
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1993년도 하계학술대회 논문집 A
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    • pp.76-78
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    • 1993
  • This paper describes an efficient method of computing any desired number of the most unstable eigenvalues and eigenvectors of a large scale multi-machine power system. Approximate eigenvalues obtained by Hessenberg process are refined using Rayleigh quotient iteration with cubic convergence property. If further eigenvalues and eigenvectors are needed, the procedure described above are repeated with deflation. The proposed algorithm can cover all the model types of synchronous machines, exciters, speed governing system and PSS defined in AESOPS. The proposed algorithm applied to New England test system with 10 machines and 39 buses produced the results same with AESOPS in faster computation time. Also eigenvectors computed in Rayleigh quotient iteration makes it possible to make eigen-analysis for improving unstable modes.

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NUMERICAL STABILITY OF UPDATE METHOD FOR SYMMETRIC EIGENVALUE PROBLEM

  • Jang Ho-Jong;Lee Sung-Ho
    • Journal of applied mathematics & informatics
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    • 제22권1_2호
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    • pp.467-474
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    • 2006
  • We present and study the stability and convergence of a deflation-preconditioned conjugate gradient(PCG) scheme for the interior generalized eigenvalue problem $Ax = {\lambda}Bx$, where A and B are large sparse symmetric positive definite matrices. Numerical experiments are also presented to support our theoretical results.

에어셀을 이용한 손목 재활훈련 장치 (Wrist Rehabilitation Training Device Using Pneumatic Inflation and Deflation of Air Cells)

  • 이영진;정유진;구교인;지영준
    • 대한의용생체공학회:의공학회지
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    • 제36권2호
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    • pp.37-42
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    • 2015
  • In this paper, we propose a wrist rehabilitation training device using pneumatic inflation and deflation of air cells. By alternating inflation and deflation of upper and lower air cells, the device makes the flexional and extensional movement for wrist rehabilitation. With the angular displacement sensor, it measures the flexion-extension angle of the wrist during the training and the bending angle is used for the automatic control of the device. Using the sensor output, the regression equation was obtained to measure the bending angle of the wrist from a wrist rehabilitation training device. The measurement error of the device was evaluated by comparing the measurement output with the angle from the photograph. The measurement error of wrist bending angle between the sensor and photo was $3.2^{\circ}$ in average. With additional test and improvement, the pneumatic wrist rehabilitation training device might be used for rehabilitation training.

역타기둥 이음부의 공기포 배출을 위한 실험적 연구 (The Experimental Study on Deflation of Air for Top-Down Joint area)

  • 임형일;이동하;백민수;박병근;이영도;정상진
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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    • pp.763-768
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    • 2001
  • The purpose of this study is to research a specific material characteristics of top down concrete at column joint and to reduce column joint opening. Based on the established top down study, the experiment to apply an real construction case is performed. When the concrete placed into joint of top down column, raised air bubble is left as opening. This study is examined the incomplete packing reason in the top down column and found to air deflation method. The result of study is below (1) As the method to minimize column opening caused from confined air, it is required that an air exhaust port installation in joint column. (2) From air exhaust port installation, most of air bubble in column part is exhausted. As the concrete placing height is going up, air bubble size is going smaller.

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확장 PASTd 알고리즘을 이용한 블라인드 다중사용자 검출 (Blind Multiuser Detection using Extended PASTd Algorithm)

  • 전재진;임준석;성굉모
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 제13회 신호처리 합동 학술대회 논문집
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    • pp.37-40
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    • 2000
  • 기존의 신호 공간 추적 방법을 이용한 blind multiuser detector는 nonstationary 환경에서 새로운 환경에 적응하기 위해 비교적 긴 시간을 필요로 한다 본 논문은 가변 망각 인자를 도입한 확장 PASTd (Projection Approximation Subspace Tracking with Deflation) 알고리즘을 이용하여 환경 변화에 좀더 신속히 적응하는 성능 향상을 모의실험을 통해 보이고자 한다.

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한라산 아고산 초지대 나지의 확대속도와 침식작용 (Rates and Processes of Bare Patch Denudation in the Subalpine Grassland of Mt. Halla)

  • 김태호
    • 대한지리학회지
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    • 제41권6호
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    • pp.657-669
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    • 2006
  • 한라산 아고산대의 초지박리에 관여하는 침식작용을 규명하기 위하여 표고 1,710m와 1,600m 지점에 출현하는 나지를 대상으로 지형특성과 확대속도를 조사하였다. 나지는 가장자리에 단애가 출현하므로 와지형태를 이룬다. 단애의 높이는 최고 85cm부터 단차가 나타나지 않는 경우까지 다양하다. 단애 최상부는 앞쪽으로 $2\sim38cm$ 정도 튀어나와 있으며, 많이 돌출한 최상부는 시간이 지나면서 아래쪽으로 드리워져 단애를 가리게 된다. 나지 표면은 중력과 대력 크기의 각력으로 덮여 있으며 암괴도 산재한다. 2002년부터 2004년까지 2년간 발생한 단애의 평균후퇴량은 39.2mm로서 연간 19.6mm의 후퇴량을 기록하였다. 계측지점별로 후퇴량을 비교하면 최고치와 최소치는 각각 131mm와 0mm로서 차이가 크다. 단애 후퇴량은 계절에 따라서도 달라져 4월의 융해진행기에 가장 크고 10월, 11월의 동결진행기와 6월, 7월의 장마기에도 큰 편이다. 나지확대에는 동결작용을 비롯하여 취식, 우세, 우적침식 및 동물작용 등 다양한 유형의 침식작용이 관여하고 있다. 이 가운데 우세나 취식과 결합된 서릿발작용은 한라산 아고산대의 100일 이상으로 추정되는 동결융해 교대일, 융설, 강풍환경 등을 고려할 때 가장 탁월한 침식작용이다. 한라산은 국내 최다우지이므로 릴침식과 같은 우세도 간과하기 어렵다. 그러나 우적침식은 단애 위쪽에 출현하는 식생 돌출부로 인하여 미약하다 최근 개체수가 증가하고 있는 노루도 나지확대에 영향을 주고 있다.