• 제목/요약/키워드: Relaxation time measurement

검색결과 69건 처리시간 0.019초

Magnetic Resonance Imaging as a Biomarker for Duchenne Muscular Dystrophy

  • Lim, Woo-taek
    • 한국전문물리치료학회지
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    • 제22권3호
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    • pp.98-105
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    • 2015
  • Muscular dystrophy is a hereditary musculoskeletal disorder caused by a mutation in the dystrophin gene. Duchenne muscular dystrophy (DMD) is one of the most common, and progresses relatively faster than other muscular dystrophies. It is characterized by progressive myofiber degeneration, muscle weakness and ultimately ambulatory loss. Since it is an X-linked recessive inheritance, DMD is mostly expressed in males and rarely expressed or less severe in females. The most effective measurement tool for DMD is magnetic resonance imaging (MRI), which allows non-invasive examination of longitudinal measurement. It can detect progressive decline of skeletal muscle size by measuring a maximal cross-sectional area of skeletal muscle. Additionally, other techniques in MRI, like $T_2$-weighted imaging, assess muscle damage, including inflammation, by detecting changes in $T_2$ relaxation time. Current MRI techniques even allow quantification of metabolic differences between affected and non-affected muscles in DMD. There is no current cure, but physical therapist can improve their quality of life by maintaining muscle strength and function, especially if treatment (and other forms of medical intervention) begins in the early stages of the disease.

SRP(Stress Reduction Program)을 적용하여 호전된 공황장애 48세 남환 치험 1례 (A Clinical Report about Panic Disorder Patient imporved by Stress Reduction Program)

  • 서진우;김종우;정선용;박소정
    • 동의신경정신과학회지
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    • 제18권3호
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    • pp.157-164
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    • 2007
  • The SRP program(stress reduction program) is reported has a good effect to patient to escape from anxiety. To reduce several symptoms due to anxiety, we performed some SRP programs to our patient who had suffered anxiety disorder. The measurement tools of patient's improvement we used are Heart Rate Variability and State-Trait Anxiety Inventory. Through this programs, symptoms and feeling of anxiety were decreased than first time and Autonomic nerve system balance was much improved. this is caused by effort of self-control meditation, mindfullness, breathing instruction and muscle relaxation program.

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변형 힘을 받는 p형 $Si_{1-x}Ge_x$의 이동도 연구 (Study of the Mobility for Strained p-type $Si_{1-x}Ge_x$ Alloys)

  • 전상국
    • 한국전기전자재료학회논문지
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    • 제11권3호
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    • pp.181-187
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    • 1998
  • The ionization energy and degree of ionization for p-type $Si_{1-x}Ge_x$ with boron doping are calculated taking into account the screening and broadening effects. The drift and Hall mobilities are then calculated using the relaxation time approximation and compared with the previously reported measurement data for relaxed and strained $Si_{1-x}Ge_x$ alloys to estimate the alloy scattering potential. From a fit, the alloy scattering potential is found to be 0.5 eV. The in-plane drift mobility for p-type strained $Si_{1-x}Ge_x$ grown on (001) Si substrate is approximately 1+$10x^2$ times higher than that for bulk Si in the high doping range.

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Semantic Differential Analysis of the Soundscape in Urban Park

  • Song, Xiu-Hua;Cho, Tae-Dong;Piao, Yong-Ji
    • 한국환경과학회지
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    • 제21권9호
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    • pp.1053-1058
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    • 2012
  • In this study, soundscape was analyzed through physical measurement and social surveys. The results showed that, soundscape components were related to functional partitions and tourist activities, at the same time influenced by ambient noise. The sound pressure levels showed daily regular changes. Semantic differential analysis showed that the evaluation of the soundscape in urban park was rather complicated. It was still possible to identify major factors including relaxation, spatiality and environment. The results provided theoretical basis for improving urban park soundscape, and called attention to this problem.

Study on Residual Stress in Viscoelastic Thin Film Using Curvature Measurement Method

  • Im, Young-Tae;Park, Seung-Tae;Park, Tae-Sang;Kim, Jae-Hyun
    • Journal of Mechanical Science and Technology
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    • 제18권1호
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    • pp.12-19
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    • 2004
  • Using LSM (laser scanning method) , the radius of curvature due to thermal deformation in polyimide film coated on Si substrate is measured. Since the polyimide film shows viscoelastic behavior, i.e., the modulus and deformation of the film vary with time and temperature, we estimate the relaxation modulus and the residual stresses of the polyimide film by measuring the radius of curvature and subsequently by performing viscoelastic analysis. The residual stresses relax by an amount of 10% at 100$^{\circ}C$ and 20% at 150$^{\circ}C$ for two hours.

The rheological properties of poly(vinylidene fluoride-co-hexafluoropropylene) solutions in dimethyl acetamide

  • Lee, Ki-Hyun;Song, In-Kyu;Kim, Byoung-Chul
    • Korea-Australia Rheology Journal
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    • 제20권4호
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    • pp.213-220
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    • 2008
  • The effects of temperature on the rheological properties of the solutions of poly(vinylidene fluoride-co-hexafluopropylene) (PVDF-HFP) in dimethyl acetamide (DMAc) were investigated in terms of frequency and concentration. The effects of temperature on the intrinsic viscosity of the solutions were discussed. In dynamic rheological measurement, the concentrated solutions showed a little unexpected rheological response; as temperature was increased dynamic viscosity was increased and the solutions exhibited more noticeable Bingham body character over the temperature range, 30 to $70^{\circ}C$. In addition, the solution gave longer relaxation time, lower value of loss tangent and higher value of yield stress at higher temperature and at higher concentration. On the other hand, the dilute solutions revealed that intrinsic viscosity was decreased and its Huggins constant was increased with increasing temperature. These physical parameters suggested that the increase of viscosity with increasing temperature resulted from the localized gelation of PVDF-HFP due to reduced solubility to the solvent.

자외선조사에 의한 다공질 실리콘 알코올 센서의 감도 개선 (Improvement of Sensitivity in Porous Silicon Alcohol Gas Sensors by UV Light)

  • 김성진;최복길
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제48권9호
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    • pp.676-680
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    • 1999
  • To do breath alcohol measurement, a sensor is necessary that it can detect low alcohol gas concentration of 0.01% at least. In this work, a capacitance-type alcohol gas sensor using porous silicon layer is developed to measure low alcohol gas concentration. The sensor using porous silicon layer has some sensitivity at room temperature by very large effective surface area, but there is still much room for improvement. In this experiment, we measured the capacitance of the sensor under 254 nm UV light on the porous silicon layer, in which alcohol solution was kept in a flask at 25, 35, and $45^{\circ}C$ by a heater. As the result, the improvement of sensitivity by illuminating UV light was observed. The increasing rate of the capacitance was shown to be double more than those measured under UV-off state. It is supposed that UV light activates response of the oriental and interfacial polarizations which have slow relaxation time for AC field.

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MAGNETIC FIELD DEPENDENCE OF MAGNETIZATION REVERSAL BEHAVIOR IN Co/Pt MULTILAYERS.

  • Cho, Yoon-Chul;Choe, Sug-Bong;Shin, Sung-Chul
    • 한국자기학회:학술대회 개요집
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    • 한국자기학회 2000년도 International Symposium on Magnetics The 2000 Fall Conference
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    • pp.279-286
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    • 2000
  • Magnetic field dependence of magnetization reversal in Co/Pt multilayers has been quantitatively investigated. Serial samples of Co/Pt multilayers have been prepared by dc-magnetron sputtering under various Ar pressure. Magnetization reversal was monitored by magnetization viscosity measurement and direct domain observation using a magneto-optical microscope system, and the wall-motion speed and the nucleation rate R were determined using a domain reversal model based on time-resolved domain reversal patterns. Both and R were found to be exponentially dependent on the reversing applied field. From the exponential dependencies, the activation volumes of the wall motion and nucleation could be determined based on a thermally activated relaxation model, and the wall-motion activation volume was revealed to be slightly larger than the nucleation activation volume.

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Unequal Activation Volumes of Wall-motion and Nucleation Process in Co/Pt Multilayers

  • Cho, Yoon-Chul;Choe, Sug-Bong;Shin, Sung-Chul
    • Journal of Magnetics
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    • 제5권4호
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    • pp.116-119
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    • 2000
  • Magnetic field dependence of magnetization reversal in Co/Pt multilayers was quantitatively investigated. Serial samples of Co/Pt multilayers were prepared by dc-magnetron sputtering under various Ar pressures. Magnetization reversal was monitored by magnetization viscosity measurement and direct domain observation using a magneto-optical microscope system, and the wall-motion speed V and the nucleation rate R were determined using a domain reversal model based on time-resolved domain reversal patterns. Both V and R were found to be exponentially dependent on the applied reversing field. From the exponential dependencies, the activation volumes for wall motion and nucleation could be determined, based on a thermally activated relaxation model, and the wall-motion activation volume was found to be slightly larger than the nucleation activation volume.

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CONTINUOUS DATA ASSIMILATION FOR THE THREE-DIMENSIONAL LERAY-α MODEL WITH STOCHASTICALLY NOISY DATA

  • Bui Kim, My;Tran Quoc, Tuan
    • 대한수학회보
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    • 제60권1호
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    • pp.93-111
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    • 2023
  • In this paper we study a nudging continuous data assimilation algorithm for the three-dimensional Leray-α model, where measurement errors are represented by stochastic noise. First, we show that the stochastic data assimilation equations are well-posed. Then we provide explicit conditions on the observation density (resolution) and the relaxation (nudging) parameter which guarantee explicit asymptotic bounds, as the time tends to infinity, on the error between the approximate solution and the actual solution which is corresponding to these measurements, in terms of the variance of the noise in the measurements.