A multivariate semiparametric Bayesian spatial modeling framework for hurricane surface wind fields

Storm surge, the onshore rush of sea water caused by the high winds and low pressure associated with a hurricane, can compound the effects of inland flooding caused by rainfall, leading to loss of property and loss of life for residents of coastal areas. Numerical ocean models are essential for creating storm surge forecasts for coastal areas. These models are driven primarily by the surface wind forcings. Currently, the gridded wind fields used by ocean models are specified by deterministic formulas that are based on the central pressure and location of the storm center. While these equations incorporate important physical knowledge about the structure of hurricane surface wind fields, they cannot always capture the asymmetric and dynamic nature of a hurricane. A new Bayesian multivariate spatial statistical modeling framework is introduced combining data with physical knowledge about the wind fields to improve the estimation of the wind vectors. Many spatial models assume the data follow a Gaussian distribution. However, this may be overly-restrictive for wind fields data which often display erratic behavior, such as sudden changes in time or space. In this paper we develop a semiparametric multivariate spatial model for these data. Our model builds on the stick-breaking prior, which is frequently used in Bayesian modeling to capture uncertainty in the parametric form of an outcome. The stick-breaking prior is extended to the spatial setting by assigning each location a different, unknown distribution, and smoothing the distributions in space with a series of kernel functions. This semiparametric spatial model is shown to improve prediction compared to usual Bayesian Kriging methods for the wind field of Hurricane Ivan.Comment: Published at http://dx.doi.org/10.1214/07-AOAS108 in the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

An evaluation method for multiview surface reconstruction algorithms

We propose a new method...

Response-surface-model-based system sizing for nearly/net zero energy buildings under uncertainty

Properly treating uncertainty is critical for robust system sizing of nearly/net zero energy buildings (ZEBs). To treat uncertainty, the conventional method conducts Monte Carlo simulations for thousands of possible design options, which inevitably leads to computation load that is heavy or even impossible to handle. In order to reduce the number of Monte Carlo simulations, this study proposes a response-surface-model-based system sizing method. The response surface models of design criteria (i.e., the annual energy match ratio, self-consumption ratio and initial investment) are established based on Monte Carlo simulations for 29 specific design points which are determined by Box-Behnken design. With the response surface models, the overall performances (i.e., the weighted performance of the design criteria) of all design options (i.e., sizing combinations of photovoltaic, wind turbine and electric storage) are evaluated, and the design option with the maximal overall performance is finally selected. Cases studies with 1331 design options have validated the proposed method for 10,000 randomly produced decision scenarios (i.e., users’ preferences to the design criteria). The results show that the established response surface models reasonably predict the design criteria with errors no greater than 3.5% at a cumulative probability of 95%. The proposed method reduces the number of Monte Carlos simulations by 97.8%, and robustly sorts out top 1.1% design options in expectation. With the largely reduced Monte Carlo simulations and high overall performance of the selected design option, the proposed method provides a practical and efficient means for system sizing of nearly/net ZEBs under uncertainty

Assessment of Surface Downwelling Shortwave Radiation in 2021-2050 in Laayoune − Sakia El Hamra Region, Morocco

Morocco's energy system is highly dependent on external energy markets. According to the Ministry Energy, Mines and Sustainable Development today more than 93 % of energy resources are imported to Morocco. In 2008 the Moroccan Government has developed a National Energy Strategy, and one of its priority areas is to increase the share of renewable technologies in the country's energy sector. Morocco is rich in solar energy resources. Studies on the assessment of the Morocco's solar energy potential indicate, among other benefits, low additional costs when using solar installations compared to losses associated with the solution of future climate problems and lack of resources. The plan envisages the commissioning of solar power plants in Ouarzazate, Ain Ben Mathar, Boujdour, Tarfaya and Laayoune by 2020.The aim of this research is determination of the characteristics of the distribution of Surface Downwelling Shortwave Radiation in the area of the solar power Boujdour, Tarfaya and Laayoune, located in the Laayoune − Sakia El Hamra region in 2021−2050. The data from regional climate modeling with high spatial resolution of the CORDEX-Africa project are used in this research. The RCM modeling is carried out for the region of Africa, in a rectangular coordinate system with a spatial resolution of ~ 44 km. Then, from the modeling data, values are highlighted for the territory of Laayoune − Sakia El Hamra region. Model calculation is performed taking into account the greenhouse gas concentration trajectory of RCP 4.5 calculated using 11 regional climate models. As a result of the simulation for the period 2021−2050, average monthly values of the Surface Downwelling Shortwave Radiation "RSDS" (W/m2) are derived, on the basis of which the mean values for the period of time are calculated. For more detailed information, average monthly total cloud cover values "TC" (%) for the period under study are calculated.Analysis of the change in RSDS in 2021–2050 relative to the recent climatic period is shown that in the Laayoune − Sakia El Hamra region we can expect an increase or retention of its values. The annual run of the RSDS has one maximum in June and one minimum in December.In the future, the distribution of RSDS in the Laayoune − Sakia El Hamra region will have a significant impact on proximity to the Atlantic Ocean, where an increased amount of total cloud cover significantly reduces the amount of incoming radiation.In the location of solar power plants in the near future, the current RSDS values are expected to be maintained, which creates favorable conditions for the further development of the renewable energy industry in this area and increasing its productivity

Surface waves in orthotropic incompressible materials

The secular equation for surface acoustic waves propagating on an orthotropic incompressible half-space is derived in a direct manner, using the method of first integrals

Fermi Surface, Surface States, and Surface Reconstruction in Sr2RuO4

The electronic structure of Sr2RuO4 is investigated by high angular resolution ARPES at several incident photon energies. We address the controversial issues of the Fermi surface (FS) topology and of the van Hove singularity at the M point, showing that a surface state and the replica of the primary FS due to (sqrt2 x sqrt2) surface reconstruction are responsible for previous conflicting interpretations. The FS thus determined by ARPES is consistent with the de Haas-van Alphen results, and it provides additional information on the detailed shape of the alpha, beta and gamma sheets.Comment: Final version for Physical Review Letters. Revtex, 4 pages, 4 postscript pictures embedded in the tex

GENERAL DESCRIPTION PINNING SOT23 P-channel, enhancement mode, PIN DESCRIPTION

logic level, field-effect power transistor. This device has low 1 gate threshold voltage and extremely fast switching making it ideal for 2 source battery powered applications and high speed digital interfacing. 3 drain 3 Top view The BSH201 is supplied in the SOT23 subminiature surface mounting package

National Ambient Water Quality Criteria.................................................................... 7-9 Agricultural Water Quality Limits................................................................................. 7-9

US Geological Survey (USGS)........................................................................................ 7-1

Surface imaging of metallic material fractures using optical coherence tomography

We demonstrate the capability of optical coherence tomography (OCT) to perform topography of metallic surfaces after being subjected to ductile or brittle fracturing. Two steel samples, OL 37 and OL 52, and an antifriction Sn-Sb-Cu alloy were analyzed. Using an in-house-built swept source OCT system, height profiles were generated for the surfaces of the two samples. Based on such profiles, it can be concluded that the first two samples were subjected to ductile fracture, while the third one was subjected to brittle fracture. The OCT potential for assessing the surface state of materials after fracture was evaluated by comparing OCT images with images generated using an established method for such investigations, scanning electron microscopy (SEM). Analysis of cause of fracture is essential in response to damage of machinery parts during various accidents. Currently the analysis is performed using SEM, on samples removed from the metallic parts, while OCT would allow in situ imaging using mobile units. To the best of our knowledge, this is the first time that the OCT capability to replace SEM has been demonstrated. SEM is a more costly and time-consuming method to use in the investigation of surfaces of microstructures of metallic materials. © 2014 Optical Society of America