Resistance partial factor and reliability of cast ball-and-socket support joint

Considering the uncertainty of material performance, geometric characteristic and analysis method, the analysis of statistical parameters of the resistance of cast ball-and-socket support joints and the reliability analysis are carried out by JC method (improved first-order second-moment method) based on the relevant experimental data. Results show that the resistance partial factor of the joint increases with the increase of the reliability index. The resistance partial factors are suggested corresponding to the reliability index under different load combinations. Moreover, the suggested resistance partial factor is adopted in reliability design, and it is found that the reliability index of the joint is larger than the target reliability index. The optimal load combination is the one in which live load plays an important control role. Finally, based on the suggested resistance partial factors, the reliability analysis of cast ball-and-socket support joints of a project is conducted.     

基于MATLAB的结构可靠度分析方法研究

基于结构可靠度分析方法—JC法、蒙特卡罗法和响应面法的基本原理,利用MATLAB软件对算例编制了相应计算程序,并对计算结果进行了比较.计算结果表明,利用MATLAB可以编制结构可靠度分析程序,计算结果较快,数据合理,并为复杂结构的可靠性分析提供参考.     

PETS一3口语测试评分方法对信度的影响

全国公共英语等级考试包括笔试和口试两大部分,分为五级。PETS-3口语测试评分方法既有优点,也存在不足之处。该口试评分方法对测试的信度产生了一定影响。评分的信度取决于评分标准、评分依据以及评分人三方面的共同作用．最终确保评分信度的真实、可靠。     

Consistently inconsistent: An examination of the variability in the identification of emotional disturbance

The federal definition of emotional disturbance (ED) has been heavily criticized as vaguely defined and poorly operationalized yet there has not been a formal analysis of the reliability of the ED criteria. This study examined the reliability of the federal criteria for a special education designation of ED. A total of 179 school psychologists reviewed a mock special education report, made an eligibility determination, and provided information about their eligibility decision. In all, 56 participants found the student met ED eligibility criteria using 16 different combinations of the five criteria. Krippendorff’s α, a statistic preferred for content analysis, was calculated as a measure of criterion reliability. Results indicated extremely poor reliability (α = 0.2011). These findings demonstrate the importance of redefining the existing criteria.     

The Teacher Behavior Inventory: validation of teacher behavior in an interactive lecture environment

Students’ rating of teacher behaviors provides valuable information on teaching improvement and instructional quality. Unfortunately, there is a lack of new validated instruments for measuring teacher behaviors. The Teacher Behaviors Inventory is an old inventory that was initially developed to measure teaching behaviors as regards lecture-based instructions, which is effected through the use of low-inference items. The aim of this study was to assess its continued suitability in the present educational setting by examining its construct validity and internal consistency through the lens of one lecturer’s teaching behaviors, as rated by 527 students after six interactive lectures. The variables evaluated, as mentioned above, were achieved after an items removal process, which resulted in a 32-item version. Apart from being valid and reliable, this condensed version allows for immediate assessment of teaching behaviors after an instruction session as the rating procedure is now more straightforward and less time-consuming, and also enables a reduction in rating errors. Therefore, the 32-item format serves as a practical diagnostic feedback tool in the present educational arena, permitting a longitudinal teaching behavior assessment to enhance teachers’ professional development.     

一种装置点火单元可靠性评估方法研究

针对一种装置点火单元的组成特点及工作特性,对影响其可靠工作的主要性能参数进行了分析,依据该性能参数的不同分布特性,提出了相应的可靠性评估方法并建立了可靠性计算模型;同时对计数法在点火单元可靠性评估中的应用特点及计算模型进行了分析;最后对不同评估方法之间的关联性和各种评估方法的适用范围进行了研究.     

从语言测试学角度试析改革后的CET考试

大学英语考试是全国性的用于评估和指导大学英语教学的标准相关常模参照性考试。它对英语的教与学既有积极的促进作用,也有着严重的负面影响。改革后的CET考试在效度、信度、难度以及可操作性上仍然存在着不可忽视的问题。CET考试不仅应信度、效度并重,还应注重考试的可操作性。此外,CET考试中,应该增设口语考试的内容,尽量做到听说读写译加权相当。     

项目无回答的成因与降低其水平的途径

本文基于两个全国概率抽样调查的实证数据,采用序列变量逻辑斯蒂回归和稳健回归的分析方法,探讨了在中国社会科学概率抽样调查中影响项目无回答的主要因素,结果发现受访人的受教育水平、城乡、地域属性和年龄是对无回答水平最稳定、最关键的影响因素。在控制了这些人群特征和题目的难度类型之后,测量指标的信度水平对无回答也具有显著的影响。根据分析结果,本文从实践的角度提出了有关降低项目无回答水平的建议。     

Validity and reliability of a linear positional transducer across commonly practised resistance training exercises

This study investigated the validity and reliability of the GymAware PowerTool (GPT). Thirteen resistance trained participants completed three visits, consisting of three repetitions of free-weight back squat, bench press, deadlift (80% one repetition maximum), and countermovement jump. Bar displacement, peak and mean velocity, peak and mean force, and jump height were calculated using the GPT, a three-dimensional motion capture system (Motion Analysis Corporation; 150 Hz), and a force plate (Kistler; 1500 Hz). Least products regression were used to compare agreeability between devices. A within-trial one-way ANOVA, typical error (TE; %), and smallest worthwhile change (SWC) were used to assess reliability. Regression analysis resulted in R² values of >0.85 for all variables excluding deadlift mean velocity (R² = 0.54–0.69). Significant differences were observed between visits 3-2 for bench press bar displacement (0.395 ± 0.055 m; 0.383 ± 0.053 m), and deadlift bar displacement (0.557 ± 0.034 m; 0.568 ± 0.034 m). No other significant differences were found. Low to moderate TE (0.6–8.8%) were found for all variables, with SWC ranging 1.7–7.4%. The data provides evidence that the GPT can be used to measure kinetic and kinematic outputs, however, care should be taken when monitoring deadlift performance.     

Can sit-to-stand muscle power explain the ability to perform functional tasks in adults with severe obesity?

This study examined the relationship between sit-to-stand (STS) power and physical function in adults with severe obesity. Thirty-eight adults (age: 44 ± 12 years; body mass index [BMI]: 45.2 ± 7.8 kg/m²) completed evaluations of STS power, strength and functional performance. STS power was measured with a wearable inertial sensor, strength was assessed with the isometric mid-thigh pull, and function was measured with the timed up-and-go (TUG), six-minute walk test (6MWT) and 30-s chair STS. Power and strength (normalised to body mass) entered regression models in addition to age, gender, BMI and physical activity (daily step count). Power displayed large univariate associations with TUG (r = 0.50) and 30-s chair STS (r = 0.67), and a moderate association with 6MWT (r = 0.49). Forward stepwise regression revealed that power independently contributed to TUG (β = ?0.40, p = 0.010), 30-s chair STS (β = 0.67, p < 0.001) and 6MWT performance (β = 0.27, p = 0.007). Power also appeared to be a superior determinant of function compared with strength. Power generated via the STS transfer largely underpins the ability to perform functional tasks in adults with severe obesity, although intervention studies are required to investigate a potentially causal relationship.