• Title/Summary/Keyword: reliability assessment test

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Reliability and Validity of the CAP for Computer Access Assessment of Persons with Physical Disabilities

  • Jeong, Dong-Hoon
    • The Journal of Korean Physical Therapy
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    • 제27권1호
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    • pp.30-37
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    • 2015
  • Purpose: The purpose of this study was to develop a computer access assessment tool for persons with physical disabilities and to evaluate reliability and validity. Methods: We developed a computerized Computer access Assessment Program (CAP) through many kinds of literature review and tools analysis for evaluation of computer access, task analysis of fundamental input devices operation and expert review. The CAP data were obtained from 105 normal university students and 16 students with physical disabilities. The test items of CAP are composed of four timed mouse tasks, four timed keyboard tasks, and a timed scanning task. Thus, the software measures user performance in skills needed for computer interaction, such as keyboard and pointer use, navigating through menus, and scanning. To determine the validity of these measurements, we compared data on CAP reports to a Compass report. Compass software allows an evaluator for assessment of an individual's computer input skills. Results: Results of this study showed that the CAP had high internal consistency, reliability of test-retest, concurrent validity, and convergent validity. Conclusion: Therefore, the CAP is appropriate for evaluation and determination of computer access skill of persons with physical disabilities. It is possible to get clear quantitative data on performance when providing computer access services if you can use the CAP data. Using this quantitative evidence, insights can be gained into the specific nature of any difficulties experienced by persons with physical disabilities and find wise solutions.

공작기계 핵심 Unit의 신뢰성 평가 기법 및 활용에 관한 연구 (Method and Application of Reliability Evaluation for Core Units of Machine Tools)

  • 이승우;송준엽;황주호;이현용;박화영
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1997년도 추계학술대회 논문집
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    • pp.43-46
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    • 1997
  • Reliability engineering is regarded as the major and important roll for all industry. And advanced manufacturing systems with high sped and intelligent have been developing for betterment of machining ability. In this study, we have systemized evaluation of reliability for machinery system. We proposed the reliability assessment and designed and manufactured reliability test-bed to evaluate reliability. In addition we acquired reliability data using test-bed system and made database to handle reliability data. And also we not only use reliability data by analyzing reliability, but also apply design review method using analyzing critical units of machinery system. Form this study, we will expect to guide and increase the reliability engineering in developing and processing phase of high quality product.

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Rock Permeability Estimation from Hydraulic Injection Tests in a Sealed Borehole Interval

  • Quach, Nghiep Q.;Jo, Yeonguk;Chang, Chandong
    • 지질공학
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    • 제28권1호
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    • pp.1-9
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    • 2018
  • We propose a borehole test technique to estimate permeability of rocks in borehole. The borehole tests are hydraulic injection tests such as leak-off test and hydraulic fracturing tests, which are originally conducted for stress or casing integrity assessment and not for permeability measurement. We use one-dimensional radial diffusion equation to interpret fluid injection test results in terms of permeability. We apply this technique to a leak-off test conducted at a depth of 700 m in a wellbore, where rock formation is mudstone. The estimated permeability is at an order of $10^{-16}m^2$, which is somewhat high but within the range reported for mudstones previously. Quantitative rick assessment suggests that an accurate measurement of open hole section length is important to improve reliability of results. More data may be needed to ensure the reliability of this technique. If validated, however, this technique can provide cost-effective estimation of in situ permeability without conducting independent permeability tests in borehole.

충격 압력을 받는 파워스티어링 시스템의 고압호스 수명 예측 (Life Prediction for High Pressure Hose of Power Steering System by Impulse Pressure Test)

  • 이기천;김형의;박종원;이종황;정원욱;임영한;황권태;이영신;김재훈
    • 대한기계학회논문집A
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    • 제34권1호
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    • pp.91-96
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    • 2010
  • 유압호스는 적용되는 압력에 따라서 저압, 중압, 고압으로 구분되어진다. 승용차의 파워스티어링 시스템은 저압부와 고압부 시스템으로 구분되어질 수 있다. 본 연구의 목적은 차량이 회전할 때 발생되는 충격압력이 고압호스부에 적용될 때 수명을 예측하는 것이다. 내부와 외부 조건을 조절하기 위해서 충격 압력과 작동유의 온도는 충격압력 시스템에서 제어되는 것이 필요하다. 충격압력 시험에서 압력과 작동유 온도만을 조절하여 얻은 결과는 고압호스의 수명을 예측하기 위한 조절형 가속수명시험을 적용하였으며, 또한 유한요소법으로 스웨이징부를 해석하였다.

중년기 요양 환자의 건강사정도구 개발 (Development of Health Assessment Tool for Middle-aged Adults in Long-term Care Settings)

  • 박윤진;김남초
    • 재활간호학회지
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    • 제20권1호
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    • pp.1-11
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    • 2017
  • Purpose: This was a methodological study to develop a valid and reliable health assessment tool for middle-aged adults in long-term care settings (HATMAL). Methods: At the first stage of this study, initial 56-items HATMAL were derived via literature review, survey for needs assessment, and focus group interviews with experts. At the second stage, 54 items HATMAL were finalized via content validity test with 5 experts and a pilot study with 30 nurses. At the third stage, validity and reliability tests were conducted with 100 middle-aged patients in a long-term care hospital. Data were analyzed by factor analysis using SPSS 18.0 program. Results: Exploratory factor analysis resulted in 3 factors; functional assessment, symptom assessment, and comfort assessment. These 3 factors explained 83.8% of total variance and construct validity was confirmed. Test-retest reliability was .67 for appetite changes, .76 for regulating for behavior problems, and 1.0 for other items. Conclusion: Results indicate that HATMAL is valid and reliable to assess the health for middle-aged patients in long-term care settings. This study would contribute to provide more effective personalized treatment and care for middle-aged patients in long-term care settings considering their own characteristics.

에너지절감형 대형기계류부품용 수명시험장치의 개발 (Development of energy saving type life testing device for large machinery parts)

  • 이용범;신석신;박종호
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제13권1호
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    • pp.55-63
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    • 2013
  • For a reliability assessment of large machinery parts, reliable data should be obtained from testing many samples for a long time. However, in case of testing these samples, testing cost is excessive; in case of life test for long time, power consumption is high; and in case of accelerated test by over load, very high cost is required to build the life testing device. Especially it is very frequent that the expensive device's life has ended during a accelerated test by over load. In this study, the design mechanism of the life testing device which excels in energy saving during the reliability test of large machinery parts has been introduced.

Fuzzy 개념을 이용한 RC도로교의 건전성평가 모델 개발 (Development of Integrity Assessment Model for Reinforced Concrete Highway Bridges Using Fuzzy Concept)

  • 나기현;박주원;이증빈;정철원
    • 한국구조물진단유지관리공학회 논문집
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    • 제2권2호
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    • pp.151-161
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    • 1998
  • In this study, an attempt is made to apply the concept of fuzzy-bayesian theory to the integrity assessment of RC highway bridge, and uncertainty states are represented in terms of fuzzy sets which define several linguistic variables such as "very good", "good", "average", "poor", "very poor", etc. Especially, the concept of fuzzy conditional probability aids to derive a new reliability analysis which includes the subjective assessment of engineers without introducing any additional correction factors. The fuzzy concept are also used as reliability indexes for the condition assessment based on the proposed models, the proposed fuzzy theory-based approach with the results of visual inspection and extensive field load tests are applied to the integrity assessment of a new RC highway bridge, namely, Jichok bridge.

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기계류부품의 고온상승, 고 토크와 미소토크의 시험장치 개발 (Development of machinery parts test device for the rising high temperature and measuring large and tiny scale torque)

  • 이용범;박종원;이근호
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제13권1호
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    • pp.11-18
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    • 2013
  • For a reliability assessment of machinery parts, accurate performance test, environmental test, life test, etc. are required on the sample. In the performance test conditions of various machinery parts, some problems happen such as needs to rise temperature rapidly with large flow of oil having very low thermal conductivity and to measure very high torque or tiny torque, etc. This study brings out the method to apply heat to rise temperature for large flow of oil without chemical change in a performance test of oil cooler. To measure large scale of torque in a performance test of planetary gearbox of excavator, the method of torque measurement is proposed by replacing the large torque meter priced very expensive. To measure very small torque on lubricated friction, a methode of force balance type test mechanism is introduced for tests of piston assembly.

A New Methodology for Software Reliability based on Statistical Modeling

  • Avinash S;Y.Srinivas;P.Annan naidu
    • International Journal of Computer Science & Network Security
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    • 제23권9호
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    • pp.157-161
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    • 2023
  • Reliability is one of the computable quality features of the software. To assess the reliability the software reliability growth models(SRGMS) are used at different test times based on statistical learning models. In all situations, Tradational time-based SRGMS may not be enough, and such models cannot recognize errors in small and medium sized applications.Numerous traditional reliability measures are used to test software errors during application development and testing. In the software testing and maintenance phase, however, new errors are taken into consideration in real time in order to decide the reliability estimate. In this article, we suggest using the Weibull model as a computational approach to eradicate the problem of software reliability modeling. In the suggested model, a new distribution model is suggested to improve the reliability estimation method. We compute the model developed and stabilize its efficiency with other popular software reliability growth models from the research publication. Our assessment results show that the proposed Model is worthier to S-shaped Yamada, Generalized Poisson, NHPP.

공압 전자밸브 신뢰성 평가기준 개발 (Reliability assessment standard development of pneumatic valves)

  • 강보식;성백주;김도식;조정대;김형의
    • 한국신뢰성학회:학술대회논문집
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    • 한국신뢰성학회 2001년도 정기학술대회
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    • pp.105-111
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    • 2001
  • In this study, for improvement of pneumatic valve reliability, we grasped the falling-off problem in efficiency of domestic valve and performed detailed analysis the relating International standards, and we also decided sampling method and reliability evaluation items to be evaluated valves. And, in addition, we describe the developed evaluation standard to increase the competition power and to improve the reliability of domestic pneumatic valve manufacturers through deciding of test conditions and thesis of evaluation procedures to each evaluation items.

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