• 제목/요약/키워드: Reliability of Measurement

검색결과 2,422건 처리시간 0.037초

The DEVELOPMENT OF WORK PERFORMANCE ANALYSIS SYSTEM

  • Lim, Chul-Woo;Yu, Jung-Ho;Kim, Chang-Duk
    • 국제학술발표논문집
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    • The 3th International Conference on Construction Engineering and Project Management
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    • pp.738-746
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    • 2009
  • The purpose of this study is to develop the web-based system for work performance analysis(WPAS). The need of work performance analysis system has already been suggested in many previous researches on the computerization of the performance measurement in the construction site by using the indicators such as time, cost and quality. However, they had focused on measuring or analyzing the result when the project would be over. The WPAS suggests three indicators - work reliability, work effectiveness and work efficiency - to manage the performance of the construction site. It can help the manager more easily recognize the status of on-going work in the construction site by measuring and analyzing the work reliability rate, the work effectiveness and work efficiency every day. This research includes the procedures for WPAS measurement process, database structure of WPAS which was analyzed by the IDEF0 and the data flow diagram. Finally, this research introduces the result of WAPS's case studies and validation in the Korean construction site.

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Reliability of External Ear Measurements Obtained by Direct, Photocopier Scanning and Photo Anthropometry

  • Liu, Bor-Shong;Tseng, Hsien-Yu;Chia, Tung-Chung
    • Industrial Engineering and Management Systems
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    • 제9권1호
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    • pp.20-27
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    • 2010
  • The purpose of this study was to compare the consistency of external ear measurements obtained by electronic digital caliper, photocopier scanning and digital photographic methods. Photogrammetric measurements were made after image editing software was used to optimize the brightness, contrast, size and image clarity. The CorelDRAW dimension tool was used to create a dimension line that measured the vertical and horizontal length between any two landmarks. Results of repeated measures analysis of variance revealed no significant differences in length and width of the pinna between the three methods. The reliability of the three measurement techniques showed a high degree of consistency. Further study and efforts could be extended to measurement hands, foots and facial dimensions by present techniques.

Assessment Methodology of Junction Temperature of Light-Emitting Diodes (LEDs)

  • Chang, Moon-Hwan;Pecht, Michael
    • 마이크로전자및패키징학회지
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    • 제23권3호
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    • pp.7-14
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    • 2016
  • High junction temperature directly or indirectly affects the optical performance and reliability of high power LEDs in many ways. This paper is focused on junction temperature characterization of LEDs. High power LEDs (3W) were tested in temperature steps to reach a thermal equilibrium condition between the chamber and the LEDs. The LEDs were generated by pulsed currents with duty ratios (0.091% and 0.061%) in multiple steps from 0mA and 700mA. The diode forward voltages corresponding to the short pulsed currents were monitored to correlate junction temperatures with the forward voltage responses for calibration measurement. In junction temperature measurement, forward voltage responses at different current levels were used to estimate junction temperatures. Finally junction temperatures in multiple steps of currents were estimated in effectively controlled conditions for designing the reliability of LEDs.

방사선사의 직무 스트레스 측정도구 개발을 위한 요인별 신뢰도 분석 (An Analysis of Reliability by Factors for Development of Job Stress Measurement Tools of Radiological Technologists)

  • 정홍량;손부순;임청환
    • 한국환경보건학회지
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    • 제32권2호
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    • pp.103-110
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    • 2006
  • The present study is designed to analyze reliability and validity of the instruments used to measure job stress of radiological technologists mainly by means of the questionnaires from 'Korean edition of NIOSH check list'. The subjects of this study are 890 radiological technologists active at 44 general hospitals in 16 provinces and cities across the country. The item-total reliability revealed that 10 factors in 6 are the major causes of stress in job life of radiological technologists. The measuring instrument proved to be valid with reliability coefficient of internal consistency by factors being more than 0.7. The factors found to be applicable herewith include limit and authority of job (0.73), cohesion within departments (0.86), resources control (0.81), mental requirements (0.85), job load (0.82), and job stability (0.72). When job autonomy item of causes are modified for proper use to radiological technologists, the measuring instruments are expected to show high reliability. It seems, however, necessary to develop a measuring instrument to analyze and use the validity of related measuring instruments since the reliability here was rated low, with statistical coefficients lower than 0.7 in such factors as job management (0.57), conflicts within departments (-1.13), sense of responsibility for patients (0.66) and usage of education (0.26). As this study was intended to examine reliability and validity of the concepts related to measurement of job stress on the part of radiological technologists, it nay not be proper to apply the results of this study to general use, but is advised to utilize them as basis for developing instruments to verify reliability and validity by comparing with and analyzing other measuring instruments.

무릎뼈 높이에 대한 도수측정방법의 신뢰도와 타당도 (Reliability and Validity of the Manual Measurement Method for Patellar Height)

  • 김문환;윤성준;원종혁
    • 한국전문물리치료학회지
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    • 제20권3호
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    • pp.54-61
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    • 2013
  • This study was to determine the reliability and validity of manual measurements of patellar height to standard radiographic measurements in 30 knees of 15 subjects. Patellar height was measured using manual and radiographic methods. The manual measurements were performed by two examiners using digital vernier calipers with the subject sitting and the knees in $30^{\circ}$ of flexion. The radiographic measurements were performed in the same position. The reliability of the manual measurements was assessed by means of intraclass correlation coefficients [ICC(3,1)], and the validity was investigated using the Pearson's product-moment correlation coefficient and an independent t-test. The intra- and inter-rater reliabilities of the manual measurement of patellar height were excellent (ICC=.86 and .88 respectively). The validity of patellar height measured manually compared to the radiographic method was good (Pearson's r=.69). In conclusion, the manual method is an objective, qualitative measurement of patella height.

현장계측용 변위계의 환경영향 특성연구 (Environmental Stress on the Displacement Sensor for Infrastructure)

  • 이한준;최만용;박정학;임재학
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2004년도 추계학술대회 논문집
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    • pp.114-121
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    • 2004
  • The sensor and measuring instrument that are used for the infrastructure is discussed the reliability problem from the various environment factors. In the domestic infrastructure, the low reliability products are produced, because of lack of the pertinent test methods and equipments. To improve the practical use and accuracy of the sensor, it raises the measurement reliability about the sensor and measurement instrument. In this study, the variance of the displacement value according to temperature was investigated using the LVDT for the infrastructure. The experimental results showed that a sensor is affected by environment factor such as temperature.

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개방회로 상태 PEMFC 내부 온도와 습도 측정을 통한 수분투과 분석 (Analysis of Water Transport through Measurement of Temperature and Relative Humidity in PEMFC at OCV)

  • 김태형;한재수;유상석
    • 한국수소및신에너지학회논문집
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    • 제33권4호
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    • pp.353-362
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    • 2022
  • In this study, water diffusion in proton exchange membrane fuel cell at open circuit voltage (OCV) was analyzed through experiment. First, the reliability of the micro-sensor (SHT31) was verified. It was concluded the micro-sensor has an excellent reliability at 60℃ and 70℃. After the sensor reliability test, the temperature and relative humidity measurement in bipolar-plate was conducted at OCV. To analyze water distribution and water flux, the temperature and relative humidity was converted into dew point. To the end, it was found water concentration affects water diffusion.

한국어판 간호사 직무순환 스트레스 측정도구 타당도와 신뢰도 (Validity and Reliability of a Korean Version of Nurse Job Rotation Stress)

  • 한정원;이빛나;양보은
    • 임상간호연구
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    • 제22권3호
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    • pp.352-358
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    • 2016
  • Purpose: This study was a methodological research implemented to establish basic data for controlling the job rotation stress of nurses and effectively managing human resources by reflecting the Nurse Job Rotation Stress Scale (NJRS) developed by Huang and others into the domestic nursing environment and verifying the use of measurement tools. Methods: The study selected nurses working at four hospitals, with over 300 beds, in Seoul, Gyeongi-do, and Busan, as its research subjects and verified the content validity, construct validity, concurrent validity, and internal consistency reliability of the measurement tool. Results: The results ultimately formed eight questions from three sub-factors (3 emotional response questions, 2 daily life questions, and 3 communication questions). In terms of reliability, emotional response issued a Cronbach's of .78, daily life issued a Cronbach's of .75, and communication issued a Cronbach's of .86. Conclusion: This study is expected to be used as basic data for achieving effective human resource management by calculating the stress of clinical nurses resulting from job rotation, but the researcher believes that the measurement tools must be expanded by confirming additional job rotation stress questions which reflect the organizational culture of Korea.

자동차 현가 장치용 스프링의 신뢰성 평가를 위한 Lamb Wave 크랙검사 (Lamb Wave Inspection for Crack Detection in Coil Spring of Automobile Suspension System)

  • 문병준;김노유
    • 한국신뢰성학회:학술대회논문집
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    • 한국신뢰성학회 2002년도 정기학술대회
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    • pp.227-233
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    • 2002
  • Suspension system is one of the most important components indespensible for stability and reliability of automobiles. The demands to more safe and durable suspension system have been increased as the automobiles get popular and improve in quality. The crack in the coil spring of the suspension system produced during manufacturing may grow under a fatigue load and cause a severe safety problems which lead to a catastrophic damage to the passengers. Many conventional NDT techniques including ET, RT, and UT are less sensitive or hard to apply to detect the surface breaking crack in the suspension coils partly because the techniques are point-to-point measurement methods, thus take too long time to inspect the coil spring longer than 1m. Contrary to this, Lamb wave technique is full-field measurement method that make it possible to examine the whole coil spring in real time. In this paper, the Lamb wave is applied to the coil spring to investigate the possibility to detect the cracks on the surface of the coil spring.

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Reliability and validity of rehabilitative ultrasound images obtained using a hands-free fixed probe in measuring the muscle structures of the tibialis anterior and the gastrocnemius

  • Choi, Mun-Sang;Shin, Jang-Hoon;Park, Hye-Kang;Lee, Wan-Hee
    • Physical Therapy Rehabilitation Science
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    • 제8권4호
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    • pp.194-201
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    • 2019
  • Objective: This study aimed to investigate the reliability and validity of muscle thickness (MT) and pennation angle (PA) measurements of the ankle muscle, including the tibialis anterior (TA) and the medial gastrocnemius (MGCM), using a hands-free fixed probe and to compare it with the conventional linear probe. Design: Observational inter-rater reliability study. Methods: Thirty-three healthy subjects (20 male, 13 female) were included. In all subjects, ultrasound images were acquired from the TA and MGCM using a hands-free fixed probe and a conventional linear probe in random sequence by two examiners at two time-points within a 7-day interval. MT and PA were calculated on the taken images. Intra-class correlation coefficients (ICC), 95% confidence intervals, standard error of measurement and the Pearson's correlation coefficient were used to estimate reliability and validity. And also, Bland-Altman plots were generated for a visual representation of MT and PA at the TA and MGCM. Results: The ICC for all intra-rater reliability was 0.943 to 0.995 and that for all inter-rater reliability was 0.928 to 0.993, indicating excellent reliability. A significantly high correlation was observed between MT and PA at the TA and MGCM with use of the hands-free fixed probe and the conventional linear probe (r>0.938; p<0.001). Conclusions: The hands-free fixed probe provided excellent images for measurement of the MT and PA of the TA and MGCM and is a useful device for making clinical measurements of muscle structure without grasping of the probe.