Quadric reliability indices

1987 ◽  
Vol 17 (1) ◽  
pp. 23-36 ◽  
Author(s):  
D.B. Parkinson
Keyword(s):  
2012 ◽  
Vol 28 (4) ◽  
pp. 262-269 ◽  
Author(s):  
Matthias Johannes Müller ◽  
Suzan Kamcili-Kubach ◽  
Songül Strassheim ◽  
Eckhardt Koch

A 10-item instrument for the assessment of probable migration-related stressors was developed based on previous work (MIGSTR10) and interrater reliability was tested in a chart review study. The MIGSTR10 and nine nonspecific stressors of the DSM-IV Axis IV (DSMSTR9) were put into a questionnaire format with categorical and dimensional response options. Charts of 100 inpatients (50 Turkish migrants [MIG], 50 native German patients [CON]) with affective or anxiety disorder were reviewed by three independent raters and MIGSTR10, DSMSTR9, and Global Assessment of Functioning scale (GAF) scores were obtained. Interrater reliability indices (ICC) of items and sum scores were calculated. The prevalence of single migration-related stressors in MIG ranged from 15% to 100% (CON 0–92%). All items of the MIGSTR10 (ICC 0.58–0.92) and the DSMSTR9 (ICC 0.56–0.96) reached high to very high interrater agreement (p < .0005). The item analysis of the MIGSTR10 revealed sufficient internal consistency (Cronbach’s α = 0.68/0.69) and only one item (“family conflicts”) without substantial correlation with the remaining scale. Correlation analyses showed a significant overlap of dimensional MIGSTR10 scores (r² = 0.25; p < .01) and DSMSTR9 scores (r² = 9%; p < .05) with GAF scores in MIG indicating functional relevance. MIGSTR10 is considered a feasible, economic, and reliable instrument for the assessment of stressors potentially related to migration.


Author(s):  
Dr. Vikas Tantuway

Aim: To assess reliability indices of Air Bubble Test (ABT) for anatomical and functional success in external Dacryocystorhinostomy (DCR). Methods: Prospective case series of nasolacrimal duct obstruction underwent DCR. Functional success defined as Munk score 0 & 1 & anatomical success as free irrigation at followup.ABT performed by putting antibiotic drops into eye& asking patient to exhale while keeping nose & mouth closed. Formation of bubbles at punctum considered as positive test. Specificity, sensitivity, positive & negative predictive values calculated. Results: There were 103 DCR in 97 patients(23 male,74 female)with mean age 45.56 yr. Anatomical and functional success was 99.02% & 98.05%, respectively.ABT showed sensitivity 96.07%, specificity 100% for anatomical success after DCR. Sensitivity and specificity were 97.02% & 100% for functional success. Conclusion: As non-invasive procedure ABT is a good tool to assess success of DCR, though lacrimal syringing remains the gold standard. Keywords: Anatomical, Dacryocystorhinostomy & Air Bubble Test.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3956
Author(s):  
Khaled Guerraiche ◽  
Latifa Dekhici ◽  
Eric Chatelet ◽  
Abdelkader Zeblah

The design of energy systems is very important in order to reduce operating costs and guarantee the reliability of a system. This paper proposes a new algorithm to solve the design problem of optimal multi-objective redundancy of series-parallel power systems. The chosen algorithm is based on the hybridization of two metaheuristics, which are the bat algorithm (BA) and the generalized evolutionary walk algorithm (GEWA), also called BAG (bat algorithm with generalized flight). The approach is combined with the Ushakov method, the universal moment generating function (UMGF), to evaluate the reliability of the multi-state series-parallel system. The multi-objective design aims to minimize the design cost, and to maximize the reliability and the performance of the electric power generation system from solar and gas generators by taking into account the reliability indices. Power subsystem devices are labeled according to their reliabilities, costs and performances. Reliability hangs on an operational system, and implies likewise satisfying customer demand, so it depends on the amassed batch curve. Two different design allocation problems, commonly found in power systems planning, are solved to show the performance of the algorithm. The first is a bi-objective formulation that corresponds to the minimization of system investment cost and maximization of system availability. In the second, the multi-objective formulation seeks to maximize system availability, minimize system investment cost, and maximize the capacity of the system.


Author(s):  
Seyede Vahide Hashemi ◽  
Mahmoud Miri ◽  
Mohsen Rashki ◽  
Sadegh Etedali

This paper aims to carry out sensitivity analyses to study how the effect of each design variable on the performance of self-centering buckling restrained brace (SC-BRB) and the corresponding buckling restrained brace (BRB) without shape memory alloy (SMA) rods. Furthermore, the reliability analyses of BRB and SC-BRB are performed in this study. Considering the high computational cost of the simulation methods, three Meta-models including the Kriging, radial basis function (RBF), and polynomial response surface (PRSM) are utilized to construct the surrogate models. For this aim, the nonlinear dynamic analyses are conducted on both BRB and SC-BRB by using OpenSees software. The results showed that the SMA area, SMA length ratio, and BRB core area have the most effect on the failure probability of SC-BRB. It is concluded that Kriging-based Monte Carlo Simulation (MCS) gives the best performance to estimate the limit state function (LSF) of BRB and SC-BRB in the reliability analysis procedures. Considering the effects of changing the maximum cyclic loading on the failure probability computation and comparison of the failure probability for different LSFs, it is also found that the reliability indices of SC-BRB were always higher than the corresponding reliability indices determined for BRB which confirms the performance superiority of SC-BRB than BRB.


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