Content
- Example: seismic reliability of four-substation power network
- Multi-scale reliability analysis of composite structures – Application to the Laroin footbridge
- Multi-scale Dynamic System Reliability Analysis of Actively-controlled Structures under Random Stationary Ground Motions
- Dataset & Variables
- Validity
The first case is that the whole intersection is located in the safe domain as shown in Figure 6a, while the second is that the intersection is divided by the limit state surface as shown in Figure 6b. Where Rk denotes the k-th critical contour ellipsoid, which can be determined according to the critical elliptical contour feature of the GMM to ensure that the samples of each cluster are entirely encircled by the ellipsoid. Finally, the multi-CEM of the uncertainties can be constructed as the following Equation . Concurrent validity examines how well one measure relates to other concrete criterion that is presumed to occur simultaneously.
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Posted: Fri, 24 Mar 2023 15:32:41 GMT [source]
Natskår A., Moan T. Structural reliability analysis of a sea fastening structure for sea transport of heavy objects. This article, along with other proposed blogs on research design and writing quality research papers, will assist students, research scholars and academicians in publishing research articles in good journals. The focus of this article will be to go through a step-by-step process to measure Cronbach Alpha using a survey based on a conceptual model detailed below. In split-half reliability, the items on the scale are divided into two halves and the resulting half scores are correlated. In alternative-forms reliability, two equivalent forms of the scale are constructed and the same respondents are measured at two different times, with a different form being used each time. Note that the different types of validity discussed here refer to the validity of the measurement procedures , which is distinct from the validity of hypotheses testing procedures , such as internal validity , external validity , or statistical conclusion validity.
Example: seismic reliability of four-substation power network
Example applications to connectivity problems of an electric power substation and a network demonstrate the methodologies developed in this paper. Many ordinal variables in the extremism dataset are classified as categorical. That said, Jamovi does recognise them as ordinal, as long as these are not text (e.g. the underlying level needs to be numbered). Wang C., Matthies H.G. A modified parallelepiped model for non-probabilistic uncertainty quantification and propagation analysis. Zhang D.Q., Han X., Jiang C., Liu J., Li Q. Time-dependent reliability analysis through response surface method.
Since summated scales are an assembly of interrelated items designed to measure underlying constructs, it is very important to know whether the same set of items would elicit the same responses if the same questions are recast and re-administered to the same respondents. Variables derived multi-scale analysis from test instruments are declared to be reliable only when they provide stable and reliable responses over a repeated administration of the test. According to the sample distribution of the uncertain variables, two typical situations can be considered for the constructed multi-CEM.
Multi-scale reliability analysis of composite structures – Application to the Laroin footbridge
Unlike random error, which may be positive negative, or zero, across observation in a sample, systematic errors tends to be consistently positive or negative across the entire sample. Hence, systematic error is sometimes considered to be “bias” in measurement and should be corrected. Inter-rater reliability, also called inter-observer reliability, is a measure of consistency between two or more independent raters of the same construct. Usually, this is assessed in a pilot study, and can be done in two ways, depending on the level of measurement of the construct.
For instance, the frequency of one’s attendance at religious services seems to make sense as an indication of a person’s religiosity without a lot of explanation. However, if we were to suggest how many books were checked out of an office library as a measure of employee morale, then such a measure would probably lack face validity because it does not seem to make much sense. Interestingly, some of the popular measures used in organizational research appears to lack face validity. For instance, absorptive capacity of an organization has often been measured as research and development intensity (i.e., R&D expenses divided by gross revenues)! If your research includes constructs that are highly abstract or constructs that are hard to conceptually separate from each other (e.g., compassion and empathy), it may be worthwhile to consider using a panel of experts to evaluate the face validity of your construct measures.
Multi-scale Dynamic System Reliability Analysis of Actively-controlled Structures under Random Stationary Ground Motions
The numerical example is also used to investigate the effect of using different sizes of LRVEs, compared with a single RVE. In future work, other problem-dependent surrogates such as Kriging will be used to allow predicting lower probability of failures with high accuracy. In this example, the limit state function of system is linear, therefore the FOAM and the HL-RF iteration are adopted to compute the NPR indexes. When the value of the limit state function is bigger than zero, it means that the design is reliable. Based on this, the reliability analysis results formulated by the multidimensional volume ratios of the safe domain to the whole uncertainty domain are computed under different thresholds, and are shown in Figure 8. It can be seen that as the threshold increases, the reliability of the structure becomes higher and higher.
This chapter presents a computational framework for probabilistic seismic performance assessment of the network of interdependent infrastructural systems that supports the functions of our society. An increasing number of large-scale failures , initiated by relatively small natural or man-made disturbances , have brought unforeseen disruption to infrastructures in recent years. The disproportion between causes and effects highlight an emergent chaotic behaviour, traceable in the infrastructure complexity and level of interconnectedness.
Dataset & Variables
In case of negatively worded questions, ensure to recode them prior to using the dataset in SPSS for any analysis. Use the blog “Data cleaning after survey collection” for more information on data cleaning activity. The conceptual model used in this article to measure Cronbach Alpha using a survey questionnaire is detailed below, an adapted scale from and . Internal consistency reliability determines the extent to which different parts of a summated scale are consistent in what they indicate about the characteristic being measured.
A parametric study is performed to determine the number of segments during the lower-scale MSR analysis of each pipeline based on the strength of the spatial correlation of seismic intensity. It is shown that the spatial correlation should be considered at both scales for accurate reliability evaluation. The proposed multi-scale analysis approach provides an effective framework of risk assessment and decision support for lifeline networks under earthquake hazards.
Cronbach’s Alpha: A Tool for Assessing the Reliability of Scales
In this paper, an enhanced probability density evolution method framework considering multiple failure modes and limit states is proposed for reliability analysis of structures. Firstly, the PDEM principle and the enhanced mechanism are illustrated, and during the process three typical combination types (i.e., https://wizardsdev.com/ circle, triangle, square ways) are introduced. Secondly, two case studies are given to verify the effectiveness of the enhanced PDEM-based framework and the necessity to consider multiple limit states. Meanwhile, the Monte Carlo simulation is also performed for both examples as a comparison and validation.
- Jiang C., Han X., Lu G.Y., Liu J., Zhang Z., Bai Y.C. Correlation analysis of non-probabilistic convex model and corresponding structural reliability technique.
- Compared to the traditional convex model, the constructed multi-CEM has a rigorous but understandable form, and is more effective for handling the uncertainty with complex distribution.
- In this example, the three-dimensional bounded uncertain variables x1, x2, and x3 are considered, which are all assumed to follow the normal distribution in theory with the median values 3.358, 3.064, and 3.800, respectively.
- If the observations have not changed substantially between the two tests, then the measure is reliable.
- For the situation that the limit state surface divides the whole uncertainty domain into two parts, two cases can be, respectively, researched as shown in Figure 6.
- The available samples of the uncertain variables are shown in Figure 7 and listed in Table 1.
- Data collected is tabulated and subjected to correlational analysis or exploratory factor analysis using a software program such as SAS or SPSS for assessment of convergent and discriminant validity.