• Physical Therapy Korea
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• v.16 no.4
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• pp.1-7
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• 2009

The active-knee-extension (AKE) test has been used to measure hamstring muscle length. The traditional AKE test measures the popliteal angle to the point of resistance with a 90-degree flexion of the hip fixed by straps, while the stabilized AKE test measures the popliteal angle to the point of resistance with a 90-degree flexion of the hip stabilized using a pressure biofeedback unit providing lumbopelvic stabilization. The purpose of this study was to determine test-retest reliability of the traditional AKE test and stabilized AKE test. Twenty healthy adults participated in the study. The popliteal angles were measured with a digital inclinometer during each test. To assess the test-retest reliability between the 2 test sessions, intraclass correlation coefficients (ICCs) were calculated. The intrasubject coefficient of variation ($CV_{intra}$) was also calculated. To compare the traditional and stabilized AKE tests for changes in pressure, paired t-tests were applied. The results of this study were as follows: 1) ICCs(3,1) value for test-retest reliability was .96 in the traditional AKE test, and was .98 in the stabilized AKE test. 2) The maximal $CV_{intra}$ was 33.7% in the traditional AKE test and 15.7% in the stabilized AKE test. 3) Differences of $6.1{\pm}2.1$ mmHg in pressure were measured in the traditional AKE test, and differences of $1.2{\pm}1.0$ mmHg in pressure were measured in the stabilized AKE test. The results show the traditional and stabilized AKE test to be highly reliable, with test-retest reliability. However, the stabilized AKE test represented less variation and more stabilization than the traditional AKE test. Further study is needed to measure the inter-rater reliability of the stabilized AKE test for generalization and clinical application.

• Physical Therapy Rehabilitation Science
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• v.13 no.2
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• pp.143-151
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• 2024

Objective: This study aims to assess the test-retest reproducibility of the Short Form Berg Balance Scale (SF-BBS) and the Short Form Postural Assessment Scale for Stroke (SF-PASS) among chronic stroke survivors, focusing on their reliability for consistent measurements over time. Design: A cross-sectional study design Methods: Thirty chronic stroke survivors participated in this study, undergoing evaluations with SF-BBS and SF-PASS scales at two different points, separated by a seven-day interval. The analysis focused on test-retest reliability, employing statistical measures such as the Intra-Class Coefficient (ICC_2,1), Standard Error of Measurement (SEM), Minimal Detectable Change (MDC), and MDC%, the Bland-Altman plot to assess the limits of agreement and the extent of random measurement error. Results: The study found notable test-retest reproducibility for both SF-BBS and SF-PASS, with ICC values demonstrating strong reliability (0.932 to 0.941, with a confidence interval of 0.889 to 0.973). SEM values for SF-BBS and SF-PASS were reported as 1.34 and 0.61, respectively, indicating low measurement error. MDC values of 3.71 for SF-BBS and 1.69 for SF-PASS suggest that the scales have an acceptable level of sensitivity to change, with reliability metrics falling below 20% of the maximum possible score. Conclusions: The findings suggest that both SF-BBS and SF-PASS exhibit high intra-class correlation coefficients, indicating strong test-retest reliability. The SEM and MDC values further support the scales' reproducibility and reliability as tools for evaluating mobility and dynamic balance in chronic stroke survivors. Therefore, these scales are recommended for clinical use in this population, providing reliable measures for assessing progress in rehabilitation.

• Journal of Environmental Science International
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• v.14 no.3
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• pp.289-296
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• 2005

In this study aims is water supply criteria relations for evaluating the possible performance of water resources systems. These measures describe how likely a systems is to fail(reliability), how quickly it recovers from failure(resiliency), and how severe the consequences of failure may be(vulnerability). The performance of a criteria evaluating with a variety of operating policies illustrates their use. As a result study frequency reliability and quantitative reliability is linear relations and quantitative reliability is high reliability for equality water supply policy. As reliability and vulnerability are in inverse proportion to each other. Therefore these criteria relation analysis can be for Imha dam to variety water supply policy.

• Journal of Power Electronics
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• v.6 no.2
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• pp.104-113
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• 2006

Satellites have provided the impetus for the orderly development of reliability engineering research and analysis because they tend to have complex systems and hence acute problems. They were instrumental in developing mathematical models for reliability, as well as design techniques to permit quantitative specification, prediction and measurement of reliability. Reliability engineering is based on implementing measures which insure an item will perform its mission successfully. The discipline of reliability engineering consists of two fundamental aspects; $(1^{st})$ paying attention to details, and $(2^{nd})$ handling uncertainties. This paper uses some of the basic concepts, formulas and examples of reliability theory in application. This paper emphasizes the practical reliability analysis of a Low Earth Orbit (LEO) Micro-satellite power subsystem. Approaches for specifying and allocating the reliability of each element of the power system so as to meet the overall power system reliability requirements, as well as to give detailed modeling and predicting of equipment/system reliability are introduced. The results are handled and analyzed to form the final reliability results for the satellite power system. The results show that the Electric Power Subsystem (EPS) reliability meets the requirements with quad microcontrollers (MC), two boards working as main and cold redundant while each board contains two MCs in a hot redundant.

• Journal of the Ergonomics Society of Korea
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• v.22 no.3
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• pp.75-91
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• 2003

Evaluation of repetitiveness for hand-intensive tasks is essential to determine the level of risk for upper-extremity musculoskeletal disorders at the workplace. Many measures and methods have been introduced for repetitiveness assessment: however, our understanding of the differences among these measures and methods is lacking. The present study compared the repetitiveness measures and measurement/analysis methods to help practitioners apply the proper repetitiveness assessment methodology in the workplace. By reviewing 51 studies of repetitiveness assessment, measures and corresponding measurement/analysis methods were surveyed. Of the repetitiveness measures, two types of dimensions (frequency and time) and corresponding types of analysis scopes were identified. According to the dimensional and analysis-scope types. the repetitiveness measures were categorized and then the surveyed studies were counted for each measure. It is identified that frequency measures have used 2.7 times higher than time measures and the frequency of wrist motions has been most frequently used in repetitiveness assessment. Furthermore, the measurement methods were categorized into objective and subjective methods, and the analysis methods into statistical and spectral methods. Lastly, eight factors (accuracy, reliability. sensitivity. efficiency. ease of use. applicability. interference. and robustness) were listed to be considered in selecting the appropriate assessment methodology.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.12
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• pp.54-59
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• 2011

LED lightings typically do not fail catastrophically during use. However, over time the light output will gradually depreciate. Even if there are same LED lighting, they are so different at all. because of dissimilar the use and environment of each LED lighting. In this paper, we make a description of reliability analysis procedures for the degradation data using collected field data. Reliability analysis procedures are consisted of estimating degradation models and failure time, verification of distribution and parameters of the distribution, and reliability measures estimation. At some point in time, the light emitted from an LED lightings depreciates to a level where it is no longer considered adequate for a specific application.

• Physical Therapy Korea
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• v.8 no.3
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• pp.35-41
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• 2001

In-shoe measurement systems allow the clinician and researcher to examine the pressure parameters within the shoe. The purpose of this study was to investigate the test-retest reliability of plantar pressures using the Parotec system over speeds and plantar regions. Seventeen healthy subjects were recruited for the study. Sampling rate was 100 Hz, and data of six variables (pressure on medial heel, lateral heel, 1st metatarsal head, 5th metatarsal head, and great toe and total impulse) were collected in four different gait speed (1.0 m/sec, 1.5 m/sec, 2.0 m/sec, and comfortable walking speed) in each day. The result indicates fair to excellent reliability between the two day test. Intraclass correlation coefficients (ICCs) ranged from .693 to .979, and range of reliability was similar depending on the speed and plantar region. In most cases, data recorded by the Parotec systems provide good evidence for the reliability.

• International Journal of Reliability and Applications
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• v.11 no.1
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• pp.41-53
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• 2010

In the present paper we develop a mathematical model that facilitates the calculation of reliability of a complex repairable system having three units namely super priority, priority and ordinary. The system is analyzed with the application of Gumbel Hougaard copula when different types of repair possible at a particular state due to deliberate failure. Various reliability measures such as reliability, MTTF and profit function have been evaluated by using supplementary variable and Laplace transform techniques.

• KIEAE Journal
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• v.12 no.3
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• pp.69-75
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• 2012

Developing reliable measures of the environment is important to increase our understanding of the environmental effects on walking among seniors. As a preliminary study for developing an instrument for measuring walkability of seniors' environment, the purpose of this study are to identify important assessment indicators associated with seniors' walking and to test their reliability using inter-rater and intra-rater reliability methods. A set of assessment indicators was identified through literature review, and field studies by trained raters were conducted in three senior centers located in Seongnam area in order to test reliability of the audit tool. The results indicated high percent agreement for most indicators and overall 91.6% and 86.1% of items assessed had good or medium inter-rater and intra-rater reliability, respectively. The reliable assessment indicators would provide reliable data for use in community-based audits of built environment in relation to walking among older adults. The findings showed that the indicators of aesthetics had lower reliability compare to safety, convenience, and access. Rater training with various images would improve rater agreement while reduce rater bias.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.4
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• pp.435-441
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• 2012

This paper provides simulation-based results of effect analysis of sample size and sampling periods on accuracy of reliability estimation methods using multiple comparisons with analysis of variance. Sum of squared errors in estimated reliability measures were evaluated through applying seven estimation methods for one-shot systems to simulated quantal-response data. Analysis of variance was implemented to investigate change in these errors according to variations of sample size and sampling periods for each estimation method, and then the effect analysis on accuracy in reliability estimation was performed using multiple comparisons based on sample size and sampling periods. An efficient way to allocate both sample size and sampling periods for reliability estimation tests of one-shot systems is proposed in this paper from the effect analysis results.