• Title/Summary/Keyword: Reliability analyses

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Validation of the Korean Functional Gait Assessment in Patients With Stroke (뇌졸중 환자를 대상으로 실시한 한글판 기능적 보행평가의 타당도)

  • Park, So-yeon
    • Physical Therapy Korea
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    • v.23 no.2
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    • pp.35-43
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    • 2016
  • Background: The Functional Gait Assessment (FGA) was developed to measure of gait-related activities. The FGA was translated in Korean but only a few psychometric characteristics had been studied. Objects: The purpose of this study was to evaluate the validity and reliability of the Korean version of FGA scale using Rasch analysis. Methods: The study included 120 patients with stroke (age range=30~83 years; mean${\pm}$standard deviation=$58.3{\pm}11.1$). The FGA and Berg Balance Scale were performed, and were analysed for dimensionality of the scale, item difficulty, scale reliability and separation, and item-person map using Rasch analysis. Results: The 4 rating scale categories of FGA were satisfied with optimal rating scale criteria. The most items of the FGA showed sound item psychometric properties except 2 items ('gait with the horizontal head turns', and 'gait with narrow base of support'), and the 2 misfit items were excluded for all further analyses. The 8 items were arranged in order of difficulty. The most difficult item was 'gait with eyes closed', the middle difficult item was 'gait level surface', and the easiest item was 'gait with vertical head turns.' A person separation reliability was .93 and the person separation index was 3.57. Conclusion: This study suggests that the 8-item Korean FGA are valid measure of assess the gait-related balance performance, and to set the goal of rehabilitation plan in patient with stroke.

The Development of the Teaching Competency Scale for Character Education in Early Childhood Teachers (영유아교사 인성교육지도역량 척도 개발)

  • Goh, Eun Kyoung;Jeon, Hyo Jeong
    • Korean Journal of Child Studies
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    • v.37 no.5
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    • pp.129-144
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    • 2016
  • Objective: This study's purpose was to develop a teaching competency scale for character education for early childhood teachers and to examine its reliability. Methods: The study procedure was as follows: First, scale items were generated by reviewing the literature as a deductive approach and focused interviews with 8 field experts in an inductive approach. Second, face validation was assessed by 7 academic experts, and statistical validation processes were done twice. The data used in the final statistical analyses included 206 questionnaires for early childhood teachers. Statistical validation included item response analysis, item discrimination analysis, exploratory factor analysis, confirmatory factor analysis, and reliability analysis. Results: The 3 factors identified were as follows: Communicate teaching competence, practical teaching competence, and instrumental teaching competence. The validity and reliability of the Teaching Competency Scale for Character Education in Early Childhood Teachers were acceptable. Conclusion: This new scale will be a useful tool to better support character education for early childhood teachers and contribute to providing a basis for developing more sophisticated tools.

Development of Environmental Attitude Scale for Korean Junior High School Students (한국 중학생의 환경태도 평가를 위한 측정도구 개발)

  • 우형택
    • Journal of Environmental Science International
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    • v.12 no.7
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    • pp.763-774
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    • 2003
  • This study was conducted to design long and short forms of reliable and valid Likert-type scales to measure environmental attitudes of Korean junior high school students. 8 tests were applied to the construction of a 32-item long form and 8-item short form of the scale. Two scales were field tested on 469 respondents consisting of male and female students in urban and rural areas and students participating in environmental programs. The 32-item scale was revealed to be highly reliable, content and construct valid. Reliability and homogeneity of this scale were evidenced by 0.92 coefficient alpha and positive interitem correlation values ranging from 0.10 to 0.52. Factor analysis and known-group comparison showed the sufficient validity of long form scale. Reliability and validity of short form scale were also evidenced by good results of 8 test analyses. The long and short forms were strongly correlated, ${\gamma}$-value of 0.90. Consequently, both long form and short form scales were evidenced very reliable and valid in measuring environmental attitudes of junior high school students in Korea. They can be useful for a variety of survey conditions and constraints and testing environmental attitude.

Development of Nursing Competence Scale for Graduating Nursing Students (졸업을 앞둔 간호학생의 핵심간호역량 측정도구 개발)

  • Joo, Ga Eul;Sohng, Kyeong-Yae
    • Journal of Korean Public Health Nursing
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    • v.28 no.3
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    • pp.590-604
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    • 2014
  • Purpose: The purpose of this study is to develop a nursing competence scale for soon to be graduate nursing students and to verify its validity and reliability. Methods: This study is a methodological study for development of a scale. Based on literature review and group discussion of 13 professional experts, 40 preliminary items were developed and the content validity was verified. Psychometric testing was performed and data were collected from 141 soon to be graduate nursing students of a university. Construct validity was verified by factor analysis and reliability was calculated. Results: The analyses resulted in a scale named the Nursing Competence Scale for Graduating Nursing Students (NCS-GNS), consisting of 30 items covering eight categories: nursing professionalism, integrated nursing through critical thinking, communication skills, nursing leadership, respect for life, stress management, nursing research, and core nursing skills. For the entire scale, the explained variance was 66.72% and Cronbach's alpha was 0.906. Conclusion: NCS-GNS was developed and its validity and reliability were verified. This scale can be used to evaluate nursing competence for graduating nursing students.

Reliabilities of distances describing bolt placement for high strength steel connections

  • Oztekin, Ertekin
    • Structural Engineering and Mechanics
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    • v.54 no.1
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    • pp.149-168
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    • 2015
  • In the bolted connections, bolt placements are generally described and are generally made in the direction of design effects and in the perpendicular direction to design effects. In these both directions, the reliability of the distance of bolts to the edges of connection plate and the distance of bolts to each other is investigated for high strength steel connections built up with high strength bolts in this study. For this purpose, simple SL (bearing type shear connection) and SLP (bearing type shear connection for body-fit bolts) type steel connections with St 52 grade steel plates with 8 different thicknesses and with 8.8D grade high strength bolts (HV) were constituted and analyzed under H (Dead Loads+Live Loads+Snow Loads+Roof Loads) and HZ (H Loads+Wind Loads+Earthquake Loads) loadings. Geometric properties, material properties and design actions were taken as random variables. Monte Carlo Simulation method was used to compute failure risk and the first order second moment method was used to determine the reliability indexes of those different distances describing the placement of bolts. Results obtained from computations have been presented in graphics and in a Table. Then, they were compared with some values proposed by some structural codes. Finally, new equations were constituted for minimum and maximum values of distances describing bolt placement by regression analyses performed on those results.

Parallel processing in structural reliability

  • Pellissetti, M.F.
    • Structural Engineering and Mechanics
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    • v.32 no.1
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    • pp.95-126
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    • 2009
  • The present contribution addresses the parallelization of advanced simulation methods for structural reliability analysis, which have recently been developed for large-scale structures with a high number of uncertain parameters. In particular, the Line Sampling method and the Subset Simulation method are considered. The proposed parallel algorithms exploit the parallelism associated with the possibility to simultaneously perform independent FE analyses. For the Line Sampling method a parallelization scheme is proposed both for the actual sampling process, and for the statistical gradient estimation method used to identify the so-called important direction of the Line Sampling scheme. Two parallelization strategies are investigated for the Subset Simulation method: the first one consists in the embarrassingly parallel advancement of distinct Markov chains; in this case the speedup is bounded by the number of chains advanced simultaneously. The second parallel Subset Simulation algorithm utilizes the concept of speculative computing. Speedup measurements in context with the FE model of a multistory building (24,000 DOFs) show the reduction of the wall-clock time to a very viable amount (<10 minutes for Line Sampling and ${\approx}$ 1 hour for Subset Simulation). The measurements, conducted on clusters of multi-core nodes, also indicate a strong sensitivity of the parallel performance to the load level of the nodes, in terms of the number of simultaneously used cores. This performance degradation is related to memory bottlenecks during the modal analysis required during each FE analysis.

Finite element and design code assessment of reinforced concrete haunched beams

  • Gulsan, Mehmet Eren;Albegmprli, Hasan M.;Cevik, Abdulkadir
    • Structural Engineering and Mechanics
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    • v.66 no.4
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    • pp.423-438
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    • 2018
  • This pioneer study focuses on finite element modeling and numerical modeling of three types of Reinforced Concrete Haunched Beams (RCHBs). Firstly, twenty RCHBs, consisting of three types, and four prismatic beams which had been tested experimentally were modeled via a nonlinear finite element method (NFEM) based software named as, ATENA. The modeling results were compared with experimental results including load capacity, deflection, crack pattern and mode of failure. The comparison showed a good agreement between the results and thus the model used can be effectively used for further studies of RCHB with high accuracy. Afterwards, new mechanism modes and design code equations were proposed to improve the shear design equation of ACI-318 and to predict the critical effective depth. These equations are the first comprehensive formulas in the literature involving all types of RCHBs. The statistical analysis showed the superiority of the proposed equation to their predecessors where the correlation coefficient, $R^2$ was found to be 0.89 for the proposed equation. Moreover, the new equation was validated using parametric and reliability analyses. The parametric analysis of both experimental and predicted results shows that the inclination angle and the compressive strength were the most influential parameters on the shear strength. The reliability analysis indicates that the accuracy of the new formulation is significantly higher as compared to available design equations and its reliability index is within acceptable limits.

Failure Probability Assessment of an API 5L X52 Gas Pipeline with a Wall-thinned Section

  • Lee Sang-Min;Yun Kang-Ok;Chang Yoon-Suk;Choi Jae-Boong;Kim Young-Jin
    • International Journal of Precision Engineering and Manufacturing
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    • v.7 no.3
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    • pp.24-29
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    • 2006
  • Pressurized gas pipelines are subject to harmful effects from both the surrounding environment and the materials passing through them. Reliable assessment procedures, including fracture mechanics analyses, are required to maintain their integrity. Currently, integrity assessments are performed using conventional deterministic approaches, even though there are many uncertainties to hinder rational evaluations. Therefore, in this study, a probabilistic approach was considered for gas pipeline evaluations. The objectives were to estimate the failure probability of a corroded pipeline in the gas and oil industries and to propose limited operating conditions for different types of loadings. To achieve these objectives, a probabilistic assessment program was developed using a reliability index and simulation techniques, and applied to evaluate the failure probabilities of a corroded API-5L-X52 gas pipeline subjected to internal pressures, bending moments, and combined loadings. The results demonstrated the potential of the probabilistic integrity assessment program.

Sensitivity Analysis of the 217PlusTM Component Models for Reliability Prediction of Electronic Systems (전자 시스템 신뢰도 예측을 위한 217PlusTM 부품모형의 민감도 분석)

  • Jeon, Tae-Bo
    • Journal of Korean Society for Quality Management
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    • v.39 no.4
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    • pp.507-515
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    • 2011
  • MIL-HDBK-217 has played a pivotal role in reliability prediction of electronic equipments for more than 30 years. Recently, RIAC developed a new methodology $217Plus^{TM}$which officially replaces MIL-HDBK-217. Sensitivity analysis of the 217Plus component models to various parameters has been performed and meaningful observations have been drawn in this study. We first briefly reviewed the $217Plus^{TM}$ methodolog and compared it with the conventional model, MIL-HDBK-217. We then performed sensitivity analysis $217Plus^{TM}$ component models to various parameters. Based on the six parameters and an orthogonal array selected, we have performed indepth analyses concerning parameter effects on the model. Our result indicates that, among various parameters, operating temperature and temperature rise during operation have the most significant impacts on the life of a component, and thus a design robust to high temperature is the most importantly required. Next, year of manufacture, duty cycle, and voltage stress are weaker but may be significant when they are in heavy load conditions. Although our study is restricted to a specific type of diodes, the results are still valid to other cases. The results in this study not only figure out the behavior of the predicted failure rate as a function of parameters but provide meaningful guidelines for practical applications.

The Validity and Reliability of a Lifestyle Evaluation Tool for Patients with Metabolic Syndrome (대사증후군 대상자의 생활습관 평가 도구 개발을 위한 타당도와 신뢰도 검증)

  • Kang, Se-Won
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.17 no.4
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    • pp.487-497
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    • 2010
  • Purpose: This study examined the validity and reliability to develop a lifestyle evaluation tool for metabolic syndrome patients. Methods: A methodological research design was used. The construct factors and preliminary items were identified by reviewing previous researches and tools related to lifestyle and reviewed by ten experts. It was tested with 195 patients with metabolic syndrome in a university hospital. The data were analyzed with SPSS/WIN 14.0. Results: To test the validity, principal component analyses were used and resulted in the extraction of six components. The convergent validity resulted r= .72 (p<.001) with Health Promotion Lifestyle Profile. The discriminant validity with Center for Epidemiologic Studies Depression Scale resulted r= -.15 (p=.004). The Internal consistency of the tool had an Cronbach's a of .92. The self-report format Lifestyle Evaluation Tool for the patients with metabolic syndrome was developed with 36 items and four-rating scales:'physical activity and weight control' eight items, 'dietary habits' sixteen items, 'drinking and smoking' three items, 'sleep and rest' two items, 'stress' three items, 'drug and health management' four items. Conclusion: This Tool will evaluate health behaviors in patients with metabolic syndrome. Also, it will contribute to the development of nursing intervention to improve the metabolic syndrome patients' lifestyle.