• 제목/요약/키워드: Static expansion method

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정적법을 이용한 중진공 국가표준기 개발 (Development of a national medium vacuum standard by static expansion method)

  • 홍승수;임인태;신용현;정광화
    • 한국진공학회지
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    • 제14권2호
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    • pp.59-68
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    • 2005
  • 부피가 다른 세 개의 진공용기를 조합하여 정적법 (static expansion method)을 이용한 중진공영역의 국가표준기를 개발하였다. 이 장치를 이용하여 133pa 범위의 용량형 진공게이지 (capacitance diaphragm gauge)를 교정하여 국제표준화기구의 측정불확도 표현지침에 따라 분석하였다. 그 결과 표준압력 0.553Pa에서의 확장불확도 (expanded uncertainty)가 95% 신뢰수준 (confidence level), 포함인자 (coverage factor) k=2에서 $2.628\times10^{-3}Pa$로 우수한 성능을 보였다.

슈로스(Schroth)운동치료와 슬링운동치료가 척추측만증 환자의 유연성, 균형능력, 척추각 및 흉곽 확장에 미치는 효과 비교 (Comparative Effectiveness of Schroth Therapeutic Exercise Versus Sling Therapeutic Exercise in Flexibility, Balance, Spine Angle and Chest Expansion in Patient with Scoliosis)

  • 이준호;김선엽
    • 대한물리의학회지
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    • 제9권1호
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    • pp.11-23
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    • 2014
  • PURPOSE: The purpose of this study suggests the exercise programs for improving the function and structure by applying the Schroth exercise method and sling exercise method to the scoliosis patient. METHODS: The subjects were 16 patients who were diagnosed with scoliosis. They were randomly assigned either to a Schroth exercise group (n=8) that received Schroth exercise program or to a sling exercise group (n=8) that received sling exercise program. Flexibility, static balance, dynamic balance, and spinal angles were measured by using the modified sit and reach test, one leg standing with closed eyes, functional reach test, and Cobb's angle, respectively. The chest expansion were calculated using differences of chest circumference between maximum inspiration and maximum expiration measured under armpits, at the junction between the sternum and xiphoid process, and at the waist. RESULT: Schroth group before and after the intervention there was a difference in the static balance, spine angle, chest expansion (p<.05). sling group before and after the intervention there was a difference in the flexibility, static balance, spine angle, chest expansion (p<.05). There were significantly differences between the both groups for chest expansion thoracic level inspiratory variables at post-exercise. CONCLUSION: These results revealed that two exercise program improved flexibility, static standing balance, spine angle, chest expansion level and ability used as scoliosis management and intervention. Therefore, it is expected to be used as a method for the treatment and prevention in the process of rehabilitation of patients with scoliosis.

다점지지 계류시스템의 정적해석에 대한 연구 (A Study on the Analysis of Multi-let Spread Mooring Systems)

  • 신현경;김덕수
    • 한국해양공학회지
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    • 제9권2호
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    • pp.53-60
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    • 1995
  • A multi-leg spread mooring system for floating offshore structures is important, but the multi-leg static analysis is complicated due to the nonlinear behavior of each line and the effect of current which affects each line differently. The pretensioned position of the multi-leg mooring system obtained from the static equilibrium condition changes into a different position due to external loads and current. In this paper, the new position and the static tension at each line are caculated. The relation between the initial static equilibrium position and the new position due to the external loads is expressed in terms of the Taylor's series expansion. The Runge-Kutta $4^{th}$ method is employed in analyzing the 3-dimensional static cable nonlinear equations.

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Expansion of Measured Static and Dynamic Data as Basic Information for Damage Detection

  • Eun, Hee-Chang;Lee, Min-Su;Chung, Chang-Yong;Kwak, No-Hyun
    • Architectural research
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    • 제10권2호
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    • pp.21-26
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    • 2008
  • The number of measured degrees of freedom for detecting the damage of any structures is usually less than the number of model degrees of freedom. It is necessary to expand the measured data to full set of model degrees of freedom for updating modal data. This study presents the expansion methods to estimate all static displacements and dynamic modal data of finite element model from the measured data. The static and dynamic methods are derived by minimizing the variation of the potential energy and the Gauss's function, respectively. The applications illustrate the validity of the proposed methods. It is observed that the numerical results obtained by the static approach correspond with the Guyan condensation method and the derived static and dynamic approaches provide the fundamental idea for damage detection.

MUSP 운동치료와 전기치료가 척추측만증환자의 Cobb's angle, 유연성, 균형능력 및 흉곽확장에 미치는 효과 비교 (Comparative Effectiveness of MUSP Therapeutic Exercise Versus Electrical Therapeutic in Flexibility, Balance, Cobb's Angle and Chest Expansion in Patient with Scoliosis)

  • 정기훈;김은영
    • 대한통합의학회지
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    • 제4권1호
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    • pp.73-83
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    • 2016
  • PURPOSE : The purpose of this study to suggest the exercise programs for improving the function and structure by applying the Masan university scoliosis program exercise method and electrical therapy method to the scoliosis patient. METHODS : The subjects were 18 patients who were diagnosed with scoliosis. They were randomly assigned either to a Masan university scoliosis program exercise group (n=11) that received Masan university scoliosis program exercise program or to a electrical therapy group (n=7). Flexibility, static balance, dynamic balance, and spinal angles were measured by using one leg standing with closed eyes, functional reach test, and Cobb's angle, respectively. The chest expansion were calculated using differences of chest circumference between maximum inspiration and maximum expiration. RESULT : Masan university scoliosis program group before and after the intervention there was a difference in the static balance, spine angle(p<.05). Masan university scoliosis program group before and after the intervention there was a difference in the flexibility, static balance, spine angle, chest expansion (p<.05). CONCLUSION : These results revealed that Masan university scoliosis program exercise program improved flexibility, static standing balance, spine angle, used as scoliosis management and intervention. Therefore, it is expected to be used as a method for the treatment and prevention in the process of rehabilitation of patients with scoliosis.

초음파간섭 수은주압력계와 정적법 중진공 국가표준기 상호비교 (Inter-comparison between ultrasonic interferometer manometer and medium vacuum standards by static expansion method)

  • 홍승수;임인태;신용현;정광화
    • 한국진공학회지
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    • 제14권3호
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    • pp.103-109
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    • 2005
  • 정적법을 이용하여 새로운 중진공 국가표준기를 개발하였다. 이 장치의 성능평가를 위해 측정범위가 각각 133pa과 1,333pa인 두 개의 용량혈 진공게이지를 전달표준기로 사용하여 초음파간섭 수은주압력계와 중진공 표준을 상호비교하였다. Error normalized (En) 값으로 분석한 결과 교정압력 $3pa\;\sim\;100pa$에서 두 표준기는 합성불확도 범위 내에서 잘 일치하고 있음을 알 수 있었다.

정적법 고진공표준기에 의해 교정한 스피닝 로터 게이지 불확도 평가 (Uncertainty Analysis of Spinning Rotor Gauge Calibrated by High Vacuum Standard of Static Expansion Method)

  • 홍승수;임인태;신용현;정광화
    • 한국진공학회지
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    • 제14권4호
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    • pp.186-194
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    • 2005
  • 정적법 고진공 표준기를 이용하여 스피닝 로터 게이지를 $4.04\times10^{-3}$ $Pa\~1.11\times10^{-2}$Pa에서 교정하였으며, 그 결과를 국제표준화기구에서 권고한 측정불확도 표현지침에 따라 불확도를 계산 및 평가하였다. 평가 결과 기준압력 $7.5488\times10^{-3}$ Pa에서 교정된 SRG의 합성표준불확도는 $95\%$ 신뢰수준, 포함인자 k = 1에서 $3.0035\times10^{-5}$ Pa로 나타났다.

Nonlinear static analysis of composite cylinders with metamaterial core layer, adjustable Poisson's ratio, and non-uniform thickness

  • Eipakchi, Hamidreza;Nasrekani, Farid Mahboubi
    • Steel and Composite Structures
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    • 제43권2호
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    • pp.241-256
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    • 2022
  • In this article, an analytical procedure is presented for static analysis of composite cylinders with the geometrically nonlinear behavior, and non-uniform thickness profiles under different loading conditions by considering moderately large deformation. The composite cylinder includes two inner and outer isotropic layers and one honeycomb core layer with adjustable Poisson's ratio. The Mirsky-Herman theory in conjunction with the von-Karman nonlinear theory is employed to extract the governing equations which are a system of nonlinear differential equations with variable coefficients. The governing equations are solved analytically using the matched asymptotic expansion (MAE) method of the perturbation technique and the effects of moderately large deformations are studied. The presented method obtains the results with fast convergence and high accuracy even in the regions near the boundaries. Highlights: • An analytical procedure based on the matched asymptotic expansion method is proposed for the static nonlinear analysis of composite cylindrical shells with a honeycomb core layer and non-uniform thickness. • The effect of moderately large deformation has been considered in the kinematic relations by assuming the nonlinear von Karman theory. • By conducting a parametric study, the effect of the honeycomb structure on the results is studied. • By adjusting the Poisson ratio, the effect of auxetic behavior on the nonlinear results is investigated.

An improved interval analysis method for uncertain structures

  • Wu, Jie;Zhao, You Qun;Chen, Su Huan
    • Structural Engineering and Mechanics
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    • 제20권6호
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    • pp.713-726
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    • 2005
  • Based on the improved first order Taylor interval expansion, a new interval analysis method for the static or dynamic response of the structures with interval parameters is presented. In the improved first order Taylor interval expansion, the first order derivative terms of the function are also considered to be intervals. Combining the improved first order Taylor series expansion and the interval extension of function, the new interval analysis method is derived. The present method is implemented for a continuous beam and a frame structure. The numerical results show that the method is more accurate than the one based on the conventional first order Taylor expansion.