• Title, Summary, Keyword: deflation

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PERTURBATION ANALYSIS OF DEFLATION TECHNIQUE FOR SYMMETRIC EIGENVALUE PROBLEM

  • JANG, HO-JONG
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.5 no.2
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    • pp.17-23
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    • 2001
  • The evaluation of a few of the smallest eigenpairs of large symmetric eigenvalue problem is of great interest in many physical and engineering applications. A deflation-preconditioned conjugate gradient(PCG) scheme for a such problem has been shown to be very efficient. In the present paper we provide the numerical stability of a deflation-PCG with partial shifts.

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Blood Pressure Measurement using the Modified Step-wise Deflation Method (개선된 계단 배기 방법을 이용한 혈압 측정)

  • Oh, Hong-Sic;Lee, Jong-Shill;Chee, Young-Joon;Kim, In-Young
    • Journal of Biomedical Engineering Research
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    • v.31 no.5
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    • pp.351-358
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    • 2010
  • In the automatic non-invasive blood pressure measurement device, the oscillometric method iswidely used. In the oscillometric method, the step-wise deflation has the advantage of the robustness for the motion artifacts than the linear deflation method. But it has the disadvantage of its longer measurement time because we need to detect two or more pulses in a certain cuff pressure step. In this study, we suggest the modified step-wise deflation method to overcome this limitation while maintaining the general concept of step-wise deflation. Using one valid pulse in each step and the deflating valve control during the diastolic period, the measurement time could be reduced. In order to verify the accuracy of the proposed algorithm, we compared the blood pressure values from the suggested method and the blood pressure values from the conventional auscultation method. The mean and standard deviation were -0.50${\pm}$5.3mmHg and 2.08${\pm}$4.75mmHg, for systolic and diastolic blood pressure respectively. The measurement time can be reduced up to the half of conventional step-wise deflation method.

Clinical Durability and Deflation of Saline-Filled Breast Implant in Breast Reconstruction (유방재건술에 사용된 식염수 보형물의 임상적 내구성과 누출)

  • Kim, Il-Kug;Lee, Jun-Ho;Kim, Yong-Ha;Kim, Tae-Gon;Lee, Soo-Jung;Kang, Soo-Hwan
    • Archives of Plastic Surgery
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    • v.38 no.6
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    • pp.808-814
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    • 2011
  • Purpose: Despite wide clinical use of breast implants, there is continued concern about the lifespan of these devices. The causes of explantation were infection, deflation of implant and patient's want. The deflation of saline-filled breast implant was related to strength and durability of implant shell. The purpose of this study is to evaluate the clinical durability of saline-filled breast implant through the analysis of duration until deflation occurred, causes, incidence and influencing factors. Methods: Retrospective analyses were conducted on clinical records for 19 cases of deflation of saline-filled breast implant from 201 cases of breast reconstruction with saline-filled implant between May 1995 and June 2011. The authors had been analyzed the causes of deflation, survival duration, symptom, sign, nipple excision, volume of implant, saline filling, method of reoperation, breast cancer stage and combined capsular contracture. Results: The causes of deflation were attributed to the cases that cannot be evaluated the causes in 15 cases, fall down in 1 case, mammography in 2 cases, accidental needle injury in 1 case. Mean survival duration was 4 years and 5 months. The duration of survival was less than 1 year for 5 cases, 1 year to 10 years for 10 cases, more than 10 years for 4 cases. The volume between 201 and 250 cc of deflated breast implant was rated as high by 14.0 percent. The deflation rate of underfilled implants was 11.4 percent, adequate filled implants was 9.3 percent. None of overfilled implant was deflated. The deflation of smooth surface implant was 5 of 152 cases. Textured implant was 14 of 49 cases. The capsular contracture of non-deflated breast implant was 28 of 182 cases and that of deflated breast implant was 6 of 19 cases. Conclusion: The patients who underwent saline-filled breast implant implantation should be informed that their implant could deflate. The analysis of clinical durability and causes of deflation in breast implant was important for the prediction and prevention of reopeation. The authors could suppose the causes of deflation of saline-filled breast implant through history, duration of survival, inspection of the shell of implant.

A Review on the Formation of Desert Pavements in High School Textbooks of World Geography (고등학교 세계지리 교과서의 사막포도 형성에 대한 고찰)

  • Kim, Taeho
    • Journal of The Geomorphological Association of Korea
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    • v.23 no.3
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    • pp.93-104
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    • 2016
  • High school textbooks of world geography show geomorphic featuresin arid environments such as sand dune, yardang and ventifact which are largely created by aeolian processes. Desert pavements, ubiquitous armored surfaces composed of a mosaic of clasts in hot and arid regions, are introduced as a major landform which can be attributed to wind erosion. However, they are formed by a variety of processes including deflation, surface runoff, upward clast migration and dust accretion that cause coarse particles concentration at the surface. The deflation by wind leaving a lag of coarse clasts has been solely regarded at home, even though the classical mechanism of deflation has been evaluated as a relatively unimportant process of pavement formation abroad through empiricalstudies. The accretionary model is gaining wider acceptance, thus implying that desert pavements could be formed through deposition of aeolian material. In addition, sheetflood and upward migration of clasts, irrelevant to the aeolian processes, could also create stone pavements. As a consequence, the deflation process in high school textbooks has to be urgently modified into a range of processes including aeolian mantling. By stressing that desert pavements are an exceptional geomorphic feature in deserts where wind is a predominant geomorphic agent, they can be used as a good example to demonstrate that a landform is not monogenetic.

Measurements of Temperature Characteristics of The Lung Inflation and Deflation Reflexes Using Automated Vagal Cooling System in Anesthetized Dogs (자동신경 냉각장치를 이용한 흡식반사와 호식반사의 온도특성 측정)

  • 송영진;차은종
    • Journal of Biomedical Engineering Research
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    • v.12 no.3
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    • pp.177-184
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    • 1991
  • Characteristics of the lung inflation and deflation reflexes were measured at various temperatrues on the cervical vagi in five anesthetized mongrel dogs. Nerve temperature was maintained at the body temperature, and $2-14^{\circ}C$ with $2^{\circ}C$ apart using a specially designed automated vagal cooling apparatus with an accuracy to within ${\pm}0.1^{\circ}C$ at each temperature. The inflation reflex was blocked abruptly at $8-10^{\circ}C$. The deflation reflex started weakened at $14^{\circ}C$, thereafter showed a gradual blockade with the temperature decreased with a substantial variance among the animals. It was approximately 75% blocked at $2-6^{\circ}C$. 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 $6-8^{\circ}C$. This suegests that differential cold blockade of the vagal reflexes can be done only in selected subjects. Fur- thermore, 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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Extended PASTd (Projection Approximation Subspace Tracking with Deflation) Algorithm for time-varying DOA estimation (시변 방위 추정을 위한 Extended PASTd (Projection Approximation Subspace Tracking with Deflation) 알고리즘)

  • Lim Jun-Seok;Lee Jong-Myong
    • Proceedings of the Acoustical Society of Korea Conference
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    • pp.189-192
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    • 2000
  • 본 논문은 Nonstationary 환경에서 동작하는 소나의 DOA추정의 정확도를 높이기 위하여 가변 망각인자를 도입한 새로운 Extended PASTd (Extended Projection Approximation of Subspace Tracking with deflation) 을 제안하고 기존 알고리즘과 비교함으로써 새로운 알고리즘의 향상된 성능을 보인다.

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ON NUMERICAL PROPERTIES OF COMPLEX SYMMETRIC HOUSEHOLDER MATRICES

  • Smoktunowicz, Alicja;Grabarski, Adam
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.7 no.2
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    • pp.51-64
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    • 2003
  • Analysis is given of construction and stability of complex symmetric analogues of Householder matrices, with applications to the eigenproblem for such matrices. We investigate numerical properties of the deflation of complex symmetric matrices by using complex symmetric Householder transformations. The proposed method is very similar to the well-known deflation technique for real symmetric matrices (Cf. [16], pp. 586-595). In this paper we present an error analysis of one step of the deflation of complex symmetric matrices.

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AN ACCELERATED DEFLATION TECHNIQUE FOR LARGE SYMMETRIC GENERALIZED EIGENPROBLEMS

  • HYON, YUN-KYONG;JANG, HO-JONG
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.3 no.1
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    • pp.99-106
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    • 1999
  • An accelerated optimization technique combined with a stepwise deflation procedure is presented for the efficient evaluation of a few of the smallest eigenvalues and their corresponding eigenvectors of the generalized eigenproblems. The optimization is performed on the Rayleigh quotient of the deflated matrices by the aid of a preconditioned conjugate gradient scheme with the incomplete Cholesky factorization.

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Effective Teaching of Deflation using Computer Practice (실습을 통한 수축방법의 효과적인 이해)

  • Lee, Gyou-Bong
    • Communications of Mathematical Education
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    • v.20 no.4
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    • pp.575-586
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    • 2006
  • Both theory and experiment are very important parts in sciences. Especially in mathematics, theory seems to be very important, but experiment or practice doesn't. Numerical analysis of many parts in mathematics needs practice in computer. In this paper, I suggest that computer-practicing in teaching power method, inverse power method and deflation to calculate eigenvalues and eigenvectors is good in understanding the theory. It also makes students sure that mathematics is helpful.

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

  • Kim, Eun-Ju;Yoon, Hae-Sang
    • Journal of Korean Academy of Nursing
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    • v.40 no.3
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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.