From the article: Abstract Adjustment and testing of a combination of stochastic and nonstochastic observations is applied to the deformation analysis of a time series of 3D coordinates. Nonstochastic observations are constant values that are treated as if they were observations. They are used to formulate constraints on the unknown parameters of the adjustment problem. Thus they describe deformation patterns. If deformation is absent, the epochs of the time series are supposed to be related via affine, similarity or congruence transformations. S-basis invariant testing of deformation patterns is treated. The model is experimentally validated by showing the procedure for a point set of 3D coordinates, determined from total station measurements during five epochs. The modelling of two patterns, the movement of just one point in several epochs, and of several points, is shown. Full, rank deficient covariance matrices of the 3D coordinates, resulting from free network adjustments of the total station measurements of each epoch, are used in the analysis.
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Plant photosynthesis and biomass production are associated with the amount of intercepted light, especially the light distribution inside the canopy. Three virtual canopies (n = 80, 3.25 plants/m2) were constructed based on average leaf size of the digitized plant structures: ‘small leaf’ (98.1 cm2), ‘medium leaf’ (163.0 cm2) and ‘big leaf’ (241.6 cm2). The ratios of diffuse light were set in three gradients (27.8%, 48.7%, 89.6%). The simulations of light interception were conducted under different ratios of diffuse light, before and after the normalization of incident radiation. With 226.1% more diffuse light, the result of light interception could increase by 34.4%. However, the 56.8% of reduced radiation caused by the increased proportion of diffuse light inhibited the advantage of diffuse light in terms of a 26.8% reduction in light interception. The big-leaf canopy had more mutual shading effects, but its larger leaf area intercepted 56.2% more light than the small-leaf canopy under the same light conditions. The small-leaf canopy showed higher efficiency in light penetration and higher light interception per unit of leaf area. The study implied the 3D structural model, an effective tool for quantitative analysis of the interaction between light and plant canopy structure.
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Background: In clinical practice, nurses’ attitudes regarding older patients are important in relation to quality of care. The Older People in Acute Care Survey (OPACS) is an instrument measuring hospital nurses attitudes regarding older patients and is validated in Australia and the USA. The OPACS is translated in Dutch language and content validity of this translation is previously assessed, presenting questionable results. Measurement instruments, however, cannot be “validated” based on content validity evidence alone. Judgmental evidence and statistical analysis should be combined to fully evaluate content domain definition and representation and guide further development. Objective: Assess structural validity and reliability to fully evaluate the OPACS for use in the Netherlands, complementing previous conducted content validity results. Design: Cross-sectional. Setting: Three general hospitals in the Netherlands. Participants: 201 registered nurses. Methods: Confirmatory factor analysis was used to assess the structural validity. Reliability was assessed with Cronbach’s alpha. Results: OPACS Section A (measuring practice experiences) demonstrated to have acceptable structural validity- and good reliability outcomes after exclusion of two items (model fit: x² [df=537]=8475.40, p <0.001, CFI=0.96, TLI=0.96, RMSEA=0.21; Cronbach’s alpha=0.82). Section B (measuring general opinion) demonstrated to have inadequate structural validity outcomes (model fit: x² [df=1127]=9200.29, p<0.001, CFI=0.68, TLI=0.67, RMSEA=0.15). None of the items contributed significant to the factor and therefore no further analysis could be performed (range p(>|z|)= 0.551 -0 .788). Conclusion: Even though structural validity for section A was acceptable, content validity scores of a majority of items in this subscale were low, resulting in questionable use of this subscale for the Dutch context. The findings of this study, in relation to the earlier findings regarding content validity, justify the conclusion that use of the Dutch OPACS in clinical practice and research is not recommended. Given these findings, future research should pursue the development or (cross-cultural) validation of other instruments measuring hospital nurses attitudes towards older patients for the Dutch cultural context. Furthermore, this study demonstrated the influence of cultural differences on measurement instruments and the need for rigorous research before using a measurement instrument in a new culture or context.
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