• Title/Summary/Keyword: retardation function

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The Bobath Approach for Walking Improvement on Child with Mental Retardation (정신지체 아동의 보행능력 향상을 위한 보봐스 접근법 : 개별실험연구)

  • Ro, Hyo-Lyun
    • Journal of the Korean Society of Physical Medicine
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    • v.3 no.2
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    • pp.113-119
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    • 2008
  • Purpose : In this case report, we demonstrated the improvement of gait ability on the child who has mental retardation with incomplete gait pattern. Methods : The subject was a 4 years old boy with mental retardation. We applied the Bobath approach to the subject. Treatments included to facilitate trunk alignment and stability, and to train weight bearing and shifting, to facilitate pelvis posterior-anterior movement, and to train walk especially stance phase and assist up-down stairs locomotion in environment similar to actual daily life. It was performed 24 sessions for 12 weeks. Results : With this treatment, he could accomplish dynamic standing stability and he could independent walk at the out door after 12 weeks. In gross motor function measure(GMFM), total motor function was improved to 85.6% from 75.7%. Conclusion : The gait ability of child with mental retardation was improved by using the bobath approach.

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Fatigue Crack Growth Retardation Using Ring Indentation (링압인을 이용한 피로균열의 성장지연효과)

  • Im,Won-Gyun;Song,Jeong-Hun
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.10
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    • pp.27-33
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    • 2003
  • A method for the retardation of fatigue crack growth using ring indentation at the vicinity of a crack is examined. Residual stresses near crack tip are evaluated using fracture mechanics approach using the Bueckner weight function. The motivation is to develop a simple and effective method for obtaining an increase in fatigue lives to total failure of materials with crack. Fatigue testing of aluminum specimen showed that the retardation effects are observed after the application of the method.

Residual Stress Fields and Fatigue Crack Growth Retardation Induced by Ring-Indentation (균열선단에 링압인 부가에 의한 잔류응력장분포와 피로균열성장지연)

  • Lim, W.K.;Song, J.H.
    • Proceedings of the KSME Conference
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    • 2001.06a
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    • pp.597-602
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    • 2001
  • A method for the retardation of fatigue crack growth using ring indentation at the vicinity of a crack is examined. Residual stresses near crack tip are evaluated using fracture mechanics approach. The motivation is to develop a simple and effective method for obtaining an increase in fatigue lives to total failure of materials with crack. Fatigue testing of aluminum specimen showed that the retardation effects are observed after the application of the method.

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The Retardation Behaviors due to a Single Overload and High-Low Block Loads, and Retardation Model in 7075-T73 Aluminum Alloy (7075-T73 알루미늄 합금의 단일과대 및 고-저블럭하중에 의한 지연거동과 수명예측 모델)

  • 김정규;송달호;박병훈
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.9
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    • pp.1605-1614
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    • 1992
  • The effects of % overload (% O.L), baseline stress intensity factor range (.DELTA. $K_{b}$) and dimension-less crack depth (a/W) are examined for the retardation behaviors after a single overload and high-low block loads in 7075-T73 aluminum alloy. And wheeler model, which is one of the fatigue life prediction models, is modified to predict retardation life using these test results. The retardation cycles( $N_{d}$) increased with a decrease in a/W and an increase in % O.L. and (.DELTA. $K_{b}$) These effects are more severe after high-low block loads than single overload. In the case of single overload, the main mechanisms of the retardation are the crack closure and the relaxation of K due to crack branching. But in the case of high-low block loads, that of the main mechanism is the crack closure caused by the accumulated compressive residual stree at the crack tip, which is related with the contact of fracture surfaces. Test results were multiple regression analyzed and got regressed shaping correction factors, (n)$_{REG}$, as function of %O.L., a/W and (.DELTA. $K_{b}$) Wheeler model is modified by using these (n)$_{REG}$. The number of delay cycles calculated by modified Wheeler model were in good agreement with the test results of this study.y.udy.y.y.y.

Influence of overload on the fatigue crack growth retardation and the statistical variation (강의 피로균열지연거동에 미치는 과대하중의 영향과 통계적 변동에 관한 연구)

  • 김선진;남기우;김종훈;이창용;박은희;서상하
    • Journal of Ocean Engineering and Technology
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    • v.11 no.3
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    • pp.76-88
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    • 1997
  • Constant .DELTA.K fatigue crack growth rate experiments were performed by applying an intermediate single and multiple overload for structural steel, SM45C. The purpose of the present study is to investigate the influence of multiple overloads at various stress intensity factor ranges and the effect of statistical variability of crack retardation behavior. The normalized delayed load cycle, delayed crack length and the minimum crack growth rate are increased with increasing baseline stress intensity factor range when the overload ratio and the number of overload application were constant. The crack retardation under low baseline stress intensity factor range increases by increasing the number of overload application, but the minimum crack growth rate decreases by increasing the number of overload application. A strong linear correlation exists between the minimum crack growth rate and the number of overload applications. And, it was observed that the variability in the crack growth retardation behavior are presented, the probability distribution functions of delayed load cycle, delayed crack length and crack growth life are 2-parameter Weibull. The coefficient of variation of delayed load cycle and delayed crack length for the number of 10 overload applications data are 14.8 and 9.2%, respectively.

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Effect of Chain Orientation on the Optical Properties and Dimensional Stability of Polyethersulfone Film (주사슬 배향이 폴리에테르설폰 필름의 광학 특성 및 치수안정성에 미치는 영향)

  • Kim, Jae-Hyun;Kim, In-Sun;Kim, Yang-Kook;Kang, Ho-Jong
    • Polymer(Korea)
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    • v.34 no.3
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    • pp.220-225
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    • 2010
  • The optical properties and dimensional stability of polyethersulfone(PES) retardation film have been studied as function of chain orientation and the temperature applied to PES retardation film. It was confirmed that the appropriate retardation values of $R_e$ and $R_{th}$ for the retardation film application were able to obtain by the chain orientation and these values could be controlled by the chain relaxation through the thermal annealing process. It was found that unstable $R_e$ and $R_{th}$ values were shown by the repeated cooling and heating applied to the retardation films but this could be stabilized by means of the annealing process after stretching of PES film. The dimensional shrinkage due to the chain orientation was found as temperature increase and the intrinsic thermal expansion of PES appeared after shrinking. The shrinkage of PES films affected by the chain orientation and thermal annealing dramatically but the effect on the coefficient of thermal expansion was found to be negligible.

Tunable Quarter-wave Plate Consisting of Two Phase Retarders and the Design of a Circular Polarizer (두 개의 위상지연판이 중첩된 가변 4분파장 위상지연자 및 원편광자의 설계)

  • Kim, Sang Youl
    • Korean Journal of Optics and Photonics
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    • v.25 no.3
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    • pp.150-154
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    • 2014
  • The conditions under which a composite retarder consisting of two different retardation plates can be operated as a tunable quarter-wave plate are derived. The explicit expressions for the azimuthal angle of a linear polarizer and those of two retardation plates to generate circularly polarized light are presented as a function of retardation angles. Those expressions for the azimuthal angles derived using the Jones matrix formalism are verified as identical to the expressions derived from the analysis of the trajectory on a Poincar$\acute{e}$ sphere. A couple of examples are presented for generating circularly polarized light when two identical retardation plates are used.

Physiological Function in vitro of ${\beta}-Glucan$ Isolated from Barley (보리가루에서 분리한 ${\beta}-Glucan$의 생리적 기능성)

  • Oh, Hee-Jung;Lee, Su-Rae
    • Korean Journal of Food Science and Technology
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    • v.28 no.4
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    • pp.689-695
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    • 1996
  • In order to prove physiological function of ${\beta}-Glucan$ isolated from barley flour by enzymatic method, in vitro experiments simulating the passive membrane transport of gastrointestinal tract were carried out using dialysis membrane. The yield of ${\beta}-Glucan$ from barley flour was $6.2{\%}$ and its constituents were determined to give $81.6{\%}$ total dietary fiber, $72.9{\%}$ soluble dietary fiber, $8.7{\%}$ insoluble dietary fiber, $8.5{\%}$ moisture, $2.5{\%}$ protein and $7.4{\%}$ ash. The water holding capacity of the ${\beta}-Glucan$ preparation was 6 g water/g dry material. The glucose retardation index after 30 minute dialysis was $13.5{\%}$ in the presence of $3{\%}$ ${\beta}-Glucan$. As the dialysis period became longer, the retarding effect toward glucose absorption decreased and the effect was close to zero after 2 hour dialysis. The bile acid retardation index after 30 minute dialysis was 3, 12 and $18{\%}$ in the presence of 1, 3 and $5{\%}$ ${\beta}-Glucan$, respectively. The effect was higher than the glucose retardation index and decreased as the dialysis time elapsed.

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Relationship Between Brain Injury and Head Circumference Growth in Extremely Premature Infants (중증 미숙아의 뇌병변과 머리둘레 성장 간의 관계)

  • Ahn, Young-Mee;Lee, Sang-Mi
    • Child Health Nursing Research
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    • v.17 no.4
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    • pp.281-287
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    • 2011
  • Purpose: The study was done to explore growth variation in head circumference (HC) in extremely premature infants (EPI) with brain injury. Methods: A retrospective cohort study was conducted with 79 cohort samples from the archives of the catch-up growth project. Mean age of the infants was 29.2 weeks of gestation and mean HC, 27.1 cm at birth. Their HC measurements were retrieved from the archives up to 6 month of corrected age (CA) and analyzed against history of brain injury during hospitalization. Results: Overall growth retardation in HC was observed in the cohort sample compared to longer gestation premature infants. EPI with brain injury showed decreased HC compared to infants without brain injury, and resulting growth variation across 6 month of CA. Highest retardation in HC growth was observed in male infants with brain injury. Conclusion: Extreme preterm birth itself may function as a major obstacle against HC growth toward term age in EPI. Sustainability of brain injury could be observed with higher HC growth retardation after term. Evolutionary favor to female infants may exist in HC growth of EPI. Intensive education on HC monitoring is highly suggested for parents of EPI, particularly with children with brain injury.