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The quality of similar sample data determines the accuracy of photovoltaic (PV) power forecasting. However, under different time and space scales, the main meteorological characteristics affecting PV power and their mechanisms are different, which seriously affects the quality of similar samples. An adaptive classification strategy is proposed to filter historical similar samples. Firstly, path analysis (PA) adaptation is utilized to determine the main meteorological characteristics affecting PV power at different spatial and temporal scales, as well as the determining coefficient of each meteorological characteristic on PV power. Secondly, a negative feedback strategy based on the distribution factor and fitness function value of the forecasting model is claimed, which can adaptive adjust the selection time range of the historical similar samples until the forecasting model with higher fitting degree obtained based on the hybrid optimization support vector regression (HO-SVR) algorithm training. Finally, the validity and practicability of the forecasting model are verified by historical measured meteorological data and power data of a PV power plant.

The existing studies have shown that parapets have great influence on the girder distribution factor (GDF) of bridges. However, there is no method in the design guide to estimate the GDF considering the effect of parapets. This research aims to develop a simplified method for estimating the GDF by considering the effect of parapets. First, a simply supported steel-concrete composite girder bridge was tested to investigate the effect of parapets on the GDF. Then, finite-element (FE) model was established and verified by the field test data of strain and deflection. In addition, error study showed that the bending stiffness of the bridge was increased by about 92% and 19.1%, respectively, due to the effects of parapet and continuous layer. As the effect of the continuous layer on each girder was relatively uniform, the simplified method was optimized only considering the effect of the parapet. Finally, the effect of the parapet on the GDF was compared and discussed. Considering the effect of the parapet, the GDF of the exterior girder calculated by the simplified method and FE analysis decreased by about 26.92% and 23.53%, respectively, and the adjacent interior girder decreased by about 15.22% and 12.77%, respectively. Comparing the GDF calculated by the AASHTO LRFD specifications, the GDF calculated by the simplified method decreased by about 30.77% in the exterior girder and 41.30% in the interior girder, respectively. The results indicate that the method of calculating the GDF without considering the effect of the parapet in AASHTO LRFD specifications is conservative. The GDF calculated by the simplified method was basically close to the field test results, meaning that the proposed simplified method considering the effect of the parapet was relatively accurate.

A series of 3D finite element (FE) analyses were performed to estimate the peak penetration resistance of spudcan foundations in sand over clay soil profiles. Elasto-perfectly plastic models following Mohr&ndash, Coulomb and Tresca failure criteria were used for sand and clay layers, respectively. The coupled Eulerian&ndash, Lagrangian (CEL) approach was used to simulate the large deformation in soil that occurs during the spudcan penetration. The performance of the numerical model was validated against centrifuge test results. A parametric study with a broad range of strength parameters for sand and clay was performed. The numerical results were used to assess the influence of sand thickness (Hs), the diameter of spudcan (D), friction angle of sand, and undrained shear strength of clay (su). A wide range of su was utilized to predict the resistance both of the soft and stiff clays. The calculated peak resistances are compared with a published analytical model. It is demonstrated that the model highly overestimates the peak resistance for stiff clays, most likely because it was developed specifically for soft clays and, therefore, does not account for the influence of su. One of the parameters of the model is revised to account both for su. Comparisons highlight that the modified model is able to capture the simulated peak penetration resistance for both soft and stiff clays.

Purpose: To analyse the temporal resolution (TR) of modern computed tomography (CT) scanners using the impulse method, and assess the actual maximum TR at respective helical acquisition modes. Methods: To assess the actual TR of helical acquisition modes of a 128-slice dual source CT (DSCT) scanner and a 320-row area detector CT (ADCT) scanner, we assessed the TRs of various acquisition combinations of a pitch factor (P) and gantry rotation time (R). Results: The TR of the helical acquisition modes for the 128-slice DSCT scanner continuously improved with a shorter gantry rotation time and greater pitch factor. However, for the 320-row ADCT scanner, the TR with a pitch factor of 1.0, it was approximately one half of the gantry rotation time. The maximum TR values of single- and dual-source helical acquisition modes for the 128-slice DSCT scanner were 0.138 (R/. P = 0.285/1.5) and 0.074. s (R/. P = 0.285/3.2), and the maximum TR values of the 64. ×. 0.5- and 160. ×. 0.5-mm detector configurations of the helical acquisition modes for the 320-row ADCT scanner were 0.120 (R/. P = 0.275/1.375) and 0.195. s (R/. P = 0.3/0.6), respectively. Conclusion: Because the TR of a CT scanner is not accurately depicted in the specifications of the individual scanner, appropriate acquisition conditions should be determined based on the actual TR measurement. © 2016 Associazione Italiana di Fisica Medica.

Aims and objectives Methods and materials Results Conclusion Personal information References, Aims and objectives: Different parameters on CT can be used to reduce the patient radiation dose. One of these parameters is pitch, which is defined as the table movement per 360 degrees rotation time divided by the beam width (1). The use of a high pitch can reduce the...

We investigate numerically that a finite Airy-Gaussian (AiG) beam varies its trajectory and shape in the defected photonic lattices. The propagation properties and beam self-bending are controlled with modulation depth and period of the photonic lattices, positive and negative defects, beam distribution factor and nonlinearity change. For positive defects, the pseudo-period oscillation and localization of the AiG beam may be formed under a certain condition, while the beam is diffused for negative defects. Moreover, the solitons may appear during the propagation process when the self-focusing nonlinearity is introduced., 15 pages, 8 figures

This paper contributes to the understanding of gender aspects in the intra-household sharing of income. I estimate models of differences in financial satisfaction between household partners using panel data from the German Socio-Economic Panel Study, which allows one to account for household-level fixed effects. The paper adds to the literature a further convincing rejection of the equal sharing hypothesis. What is more and novel, the results imply that unequal income sharing is asymmetric and triggered by the relative employment statuses of the partners: in male breadwinner households, the women’s well-being is affected by the distribution factor; in double full-time couples, it is the man’s well-being.

Pierre Gy's equation is widely used in ore sampling. This equation is based in four parameters: shape factor, size distribution factor, mineralogical factor and liberation factor. The usual practice is to consider fixed values for the shape and size distribution factors. This practice does not represent well several important ores. The mineralogical factor considers only one specie of interest and the gangue, leaving out other cases such as polymetalic ores where there are more than one specie of interest. A sensibility analysis to the Gy's equation factors was done and a procedure to determine specific values for them was developed and presented in this work. Mean ore characteristics, associated with an insecure use of the actual procedure, were determined. Finally, for a case study, the effects of using each alternative were evaluated.La ecuación de Pierre Gy es la más utilizada en el muestreo de minerales. Esta ecuación está basada en cuatro parámetros: factor de forma, factor de granulometría, factor de mineralogía y factor de liberación. La práctica usual es considerar valores fijos para los factores de forma y granulometría, dejando fuera a una gama importante de minerales que no son bien representados por dichos valores. Con respecto al factor de mineralogía, se consideran, solamente, una especie mineralógica de interés y la ganga, no considerando otros casos, como los minerales polimetálicos donde hay más de una especie de interés. En este trabajo se sensibilizó la ecuación de Gy con respecto a sus factores y se han desarrollado algunos procedimientos para determinar valores específicos para éstos. Se han determinado las características principales de los minerales asociadas con un uso inseguro del procedimiento utilizado actualmente. Finalmente, para un caso en estudio, se evaluó el efecto de utilizar una u otra alternativa.

The present paper develops a theoretical model of labor supply with domestic production. It is shown that the structural components of the model can be identified without using a distribution factor, thereby generalizing the initial results of Apps and Rees (1997) and Chiappori (1997). The theoretical model is then estimated using the ATUS data. The empirical results are compared to those obtained from a similar model without domestic production.

The occurrence of cascading failure in electric power system due to the brittle sources of the system was excited by the brittleness theory, so how to find the brittle source of the system is the key to avoid the brittle risk occurring. This text forwards the method of the brittle source identification based on the combination of DC flow and distribution factor and proves its effectiveness and practicality through the IEEE-5 node system.