• Title/Summary/Keyword: physical measurement

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A Study on Quantitative Visualization and Measurement of Physical Properties of Radial Symmetric Fluids Using Electronic Speckle Pattern Interferometry (전자 스체클 패턴 간섭법을 이용한 반경방향 대칭 유체의 정량적 가시화 및 물성치 측정에 관한 연구)

  • Gang, Yeong-Jun;Chae, Hui-Chang;Kim, Gyeong-Seok
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.2
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    • pp.217-224
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    • 2002
  • It is very important to measure and visualize the changes in the physical properties of fluid flow because this is the foundation of measurement techniques used in aerodynamics, heat transfer, plasma diagnostics, and stress analysis of transparent models. The optical methods are advantageous over probe-based techniques in the optical methods are of high speed, non-contact and are capable of providing full-field results with high spatial resolution. Therefore we propose the electronic speckle pattern interferometry(ESPI) that gives us a solution to overcome those limitations. In this paper the experimental results show qualitative and quantitative visualization of changes in the physical properties of the candle and alcohol lamp with 3D plotting. And we obtained the refractive index, mass density and temperature distribution of fluids. The results clearly show the process of flow phenomena and give the feasibility of quantitative interpretation of gasdynamics.

The Effect of Dual-task Training on a Serial Reaction Time Task for Motor Learning

  • Choi, Jin-Ho;Park, So Hyun
    • The Journal of Korean Physical Therapy
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    • v.24 no.6
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    • pp.405-408
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    • 2012
  • Purpose: We examined the effect of dual-task and single-task training on serial reaction time (SRT) task performance to determine whether SRT is based more on motor or perception in a dual-task. Methods: Forty healthy adults were divided into two groups: the dual-task group (mean age, $21.8{\pm}1.6$ years) and the single-task group (mean age, $21.7{\pm}1.6$ years). SRT task was conducted total 480 trial. The four figures were presented randomly 16 times. A unit was set as 1 block that would repeat 10 times. Thus, there were a total of 160 trials for each of the three color conditions. The dual-task group performed an SRT task while detecting the color of a specific shape. The end of the task, subjects answered the specific shape number; the single-task group only performed the SRT task. The study consisted of three parts: pre-measurement, task performance, and post-measurement. Results: Differences of pre and post reaction time between two group was higher for the dual-task group as compared to the single task group and there was a significant interaction between time and group (p<0.05). Conclusion: Our results indicate that. short term period SRT is not quiet effective under dual-task conditions, individuals need additional cognitive processes to successfully navigate a task This suggests that dual-task training might not be appropriate for motor learning enhancement, at least when the training is over a short period.

Comparison of Subjects with and without Pes Planus during Short Foot Exercises by Measuring Muscular Activities of Ankle and Navicular Drop Height

  • Park, Du-Jin;Park, Se-Yeon
    • Journal of the Korean Society of Physical Medicine
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    • v.13 no.3
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    • pp.133-139
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    • 2018
  • PURPOSE: Despite the abundant literature available regarding the activity of intrinsic muscles, few studies have investigated the muscle activity of extrinsic muscles. Therefore, the present study compared the muscle activity of the peroneus longus, tibialis anterior, and abductor hallucis during short foot exercise in subjects with and without flat feet. METHODS: Twelve subjects with and without pes planus participated in this study. During the short foot exercises, muscular activity of the tibialis anterior, fibularis longus, and abductor hallucis longus were measured in both groups. To identify the effects of short foot exercises, navicular drop height was also investigated in pre and post short foot exercises. RESULTS: In a symptomatic group, the navicular drop height was significantly reduced at post measurement compared with pre-measurement. During the short foot exercise, the pes planus group showed significantly lower activities of the fibularis longus than the control group (p<.05). CONCLUSION: Similar to previous studies and clinical literature, short foot exercise was effective for alleviating navicular drop for a population with pes planus. In addition, subjects with pes planus showed decreased muscular activities of the fibularis longus, which suggests that considering extrinsic muscles such as fibularis longus is also important for rehabilitation of pes planus patients.

Magnetic Resonance Imaging as a Biomarker for Duchenne Muscular Dystrophy

  • Lim, Woo-taek
    • Physical Therapy Korea
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    • v.22 no.3
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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.

Evaluation of Daily Jump Compensation Methods for GPS Carrier Phase Data

  • Lee, Young Kyu;Yang, Sung-Hoon;Lee, Chang Bok;Lee, Jong Koo
    • Journal of Positioning, Navigation, and Timing
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    • v.4 no.1
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    • pp.25-31
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    • 2015
  • In this paper, we described the timing-offset comparison results between various daily jump compensation methods for GPS carrier phase (CP) measurement data. For the performance comparison, we used about 70 days GPS measurement data obtained from two GPS geodetic receivers which share the reference 1 PPS and RF signals and closely located in each other within a few meters. From the experiment results, the followings were observed. First, daily jumps existed in CP measurements depend on not only the environment but also the receiver which will make a full compensation be very hard or impossible. Second, clock bias can be occurred in the case of using a simple compensation with accumulation of daily jumps but it could be used in a short-period frequency comparison campaign (less than about 7 days) despite of its drawback.

Methodological Development of Physical Environment Rating Scale for Interior Space of Child Care Facility (아동 보육시설 실내환경 평가 도구 개발)

  • 이수진
    • Korean Institute of Interior Design Journal
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    • no.33
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    • pp.27-35
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    • 2002
  • The qualify of preschool education is related to the qualify of the physical environment, This research is aiming to develop and validate the set of scales for the measurement of physical quality of the interior spaces in child care facilities. The research has been in three major phases: (1)the development of indicative sub-scales for the description, measurement and evaluation of the physical designed quality of early childhood environments (2)two rounds of iterative phases of reliability and validity testing of the scales through expert panels and observational field-testing and (3)implications for future research to be done. 13 sub-scales were developed, which are based on Moore's 15 design principal for child care environments. And each sub-scale includes several evaluation items based upon developmental theory, existing empirical literature, and Korean, Australian and American child care standards. This set of scales will (1)aid research on the effects of environmental variables on quality of child care facilities for infants, toddlers, and preschoolers; (2)permit evaluation of such environments to identify areas of needed improvement; and (3)provide information for policy makers, parents, administrators, and designers/architects.

Impact of Respiratory Muscle Exercises on Pulmonary Function and Quality of Sleep among Stroke Patients (호흡근 훈련이 뇌졸중환자의 폐기능과 수면의 질에 미치는 영향)

  • Cho, Yo-Han;Lee, Sang-Bin
    • Journal of the Korean Society of Physical Medicine
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    • v.10 no.4
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    • pp.123-131
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    • 2015
  • PURPOSE: This study attempts to examine the impact of respiratory muscle exercises on the respiratory function and quality of sleep among stroke patients. METHODS: A total of 20 stroke patients were randomly divided into a breathing-exercise training group(n=10) and a breathing-device-training group(n=10). Changes in pulmonary function, as well as the quality, were measured before and after the intervention. The breathing exercise was performed three times a week for a total of eight weeks. Breathing-device exercises made use of a lung-capacity-strengthening device and were performed for three times a week for eight weeks. One Flow FVC was used as a measurement tool for the pulmonary function test. The Pittsburgh Sleep Quality Index(PSQI) and a sleep measurement tool were used for sleep evaluation. RESULTS: In a comparison of changes in pulmonary function before and after the training, the breathing-exercise group and the breathing-device-training group showed a significant difference. In changes of sleeping measure and PSQI, the breathing-exercise group and the breathing-device-training group also showed significant differences. CONCLUSION: Diverse index analyses confirmed that breathing exercises and exercises using a lung-capacity-strengthening device, were effective in improving respiratory function and quality of sleep among stroke patients experiencing respiratory function disorders and sleep disorders.

The Study of Asymmetrical of the Serratus Anterior and Lower Trapezius Muscles in Chronic Stroke Patients (만성 뇌졸중 환자의 앞 톱니근과 하부 등세모근의 비대칭성 연구)

  • Jeong, Ju-Ri;Lee, Wan-Hee
    • Journal of the Korean Society of Physical Medicine
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    • v.10 no.4
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    • pp.81-90
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    • 2015
  • PURPOSE: The purpose of this study was to compare the muscle architecture of serratus anterior and lower trapezius using rehabilitative ultrasound imaging (RUSI) in affected and unaffected side of chronic stroke patients. METHODS: The participants were thirty five patients with stroke hemiplegia in this study. RUSI was used to measure the muscle thickness of the serratus anterior and lower trapezius muscles. We compared the muscle thickness according to affected side and sex, determined the reliability of the measurement image. Independent t-test, intra-class correlation coefficient (ICC) and standard error of measurement (SEM) were used for statistical analysis. RESULTS: Significant difference in muscle thickness of serratus anterior was observed between affected and unaffected side (p<.001). Muscle thickness according to gender showed a significant difference in unaffected side of serratus anterior (p<.05). Compare asymmetry ratio of serratus anterior and lower trapezius muscle thickness showed a significant difference (p<.001). ICC for intra-reliability was .944~.962 in serratus anterior and .873~.925 in lower trapezius muscle thickness, respectively. SEM was .001~.004 in serratus anterior and .002~.008 in lower trapezius muscle. CONCLUSION: This study, using RUSI, showed significant difference in muscle thickness of serratus anterior in affected and unaffected side of stroke patients. RUSI is a practical tool for measuring soft-tissue thickness in the scapular region muscle of stroke.

The Determination of Temperature and Humidity Sensitivity Coefficients of Torque Transducers using Seasonal Climatic Changes of Ambient Conditions in the Laboratory (계절에 따른 실험실 환경변화를 이용한 토크측정기의 온도 및 습도 감도계수 결정)

  • Derebew, Mulugeta;Kim, Min Seok;Park, Yon Kyu;Lee, Ho Young
    • Journal of the Korean Society for Precision Engineering
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    • v.32 no.2
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    • pp.185-190
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    • 2015
  • This paper presents a new method to determine sensitivity coefficients of temperature and humidity of torque transducers by using a natural and seasonal variation of ambient conditions at the laboratory. We had measured the sensitivities of the torque transducers over almost one year using the KRISS 2 kN m torque standard machine. The sensitivity data acquired at various ambient conditions were processed using our measurement model to extract the sensitivity coefficients of temperature and humidity simultaneously with high precision. A comparison with a previous method using an environmental control chamber was carried out to test the feasibility of using our new method. Two results agreed within the uncertainty. We revealed that the torque measuring errors could be 8 times higher than the measurement and calibration capability of KRISS torque standard machine if the sensitivity changes due to the temperature and humidity are not properly corrected during a calibration.

Inter-Rater Reliability of Stroke Rehabilitation Assessment of Movement for Patients With Stroke (뇌졸중 환자 평가를 위한 Stroke Rehabilitation Assessment of Movement의 측정자간 신뢰도)

  • Yun, Sung-Joon;Weon, Jong-Hyuck;Lee, Chung-Hwi
    • Physical Therapy Korea
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    • v.17 no.3
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    • pp.48-58
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    • 2010
  • The aim of this study was performed to determine the inter-rater reliability of the Stroke Rehabilitation Assessment of Movement (STREAM) translated in Korean. This was a new clinical measurement tool for evaluating the recovery of voluntary movement and basic mobility following stroke. A direct-observation reliability study was conducted on 20 patients who had strokes and were in a rehabilitation setting. Subjects were assessed by two physical therapists. The reliability of the STREAM scores was demonstrated by weighted kappa statistics for inter-rater agreement on scores for individual items ranged from .83 to 1.0, intraclass correlation coefficients for total score was .99, and for subscale scores was ranged from .96 to .99. The internal consistency of the STREAM scores was demonstrated by Cronbach alphas of greater than .99 on the subscales and overall. These high levels of reliability support the use of the STREAM translated in Korean instrument for the measurement of motor recovery following stroke.