Preferred Language
Articles
/
yWH6dZkBdMdGkNqjCye0
Efficient Bayesian modeling of large lattice data using spectral properties of Laplacian matrix
...Show More Authors

Spatial data observed on a group of areal units is common in scientific applications. The usual hierarchical approach for modeling this kind of dataset is to introduce a spatial random effect with an autoregressive prior. However, the usual Markov chain Monte Carlo scheme for this hierarchical framework requires the spatial effects to be sampled from their full conditional posteriors one-by-one resulting in poor mixing. More importantly, it makes the model computationally inefficient for datasets with large number of units. In this article, we propose a Bayesian approach that uses the spectral structure of the adjacency to construct a low-rank expansion for modeling spatial dependence. We propose a pair of computationally efficient estimation schemes that select the functions most important to capture the variation in response. Through simulation studies, we validate the computational efficiency as well as predictive accuracy of our method. Finally, we present an important real-world application of the proposed methodology on a massive plant abundance dataset from Cape Floristic Region in South Africa. © 2019 Elsevier B.V.

Scopus Clarivate Crossref
View Publication
Publication Date
Sat Oct 05 2019
Journal Name
Journal Of Engineering And Applied Sciences
Enhanced Dielectrically Properties of Up-Pistachio Peel Composites
...Show More Authors

View Publication
Crossref (2)
Crossref
Publication Date
Mon Mar 08 2021
Journal Name
Baghdad Science Journal
The structural and mechanical properties of ion beam
...Show More Authors

the structrual and mechanical properties of thin Ni films of different thicknesses deposited on coring glass substrate using lonbeam sputtering(IBS) technique under vacuum torr have been studied the TEM and electron

View Publication Preview PDF
Publication Date
Sat Oct 01 2011
Journal Name
Iraqi Journal Of Physics
Some gas sensing properties of PbS thin films
...Show More Authors

In this research PbS thin film have been prepared by chemical bath deposition technique (CBD).The PbS film with thickness of (1-1.5)μm was thermally treated at temperature of 100°C for 4 hours. Some Structural characteristics was studied by using X-ray diffraction (XRD)and optical microscope photograph some of chemical gas sensing measurements were carried out ,it shown that the sensitivity of (CO2) gas depend on the grain Size and deposition substrate. The grain size of PbS film deposited on on glass closed to 21.4 nm while 37.97nm for Si substrate. The result of current-voltage characterization shwon the sensitivity of prepared film deposited on Si better than film on glass.

View Publication Preview PDF
Publication Date
Wed Dec 13 2017
Journal Name
Al-khwarizmi Engineering Journal
Physical and Mechanical Properties of Synthesized Doped Nanoferrite
...Show More Authors

Nanoferrite materials have been synthesized by sol-gel auto combustion method. The effect of doping different percentages of Y2O3 (0.34 µm) on the physical and mechanical properties of selected mixed ferrite [(Li2.5Fe0.5) 0.9(Co4Fe2O4) 0.1] by adding 10% Cobalt ferrite was studied. Physical properties (i.e. .density, porosity and water absorption) were affected by the doping, where the density increased about 32% at 6 wt% Y2O3, while porosity has a drastically decreased about 80% at 6% Y2O3 and has a correlation effect on the mechanical properties(Splitting  tensile strength and Vicker

... Show More
View Publication Preview PDF
Publication Date
Tue Jul 01 2014
Journal Name
Journal Of Nanotechnology & Advanced Materials
Structural and optical properties of SnS thin films
...Show More Authors

Thin films of tin sulfide (SnS) were prepared by thermal evaporation technique on glass substrates, with thickness in the range of 100, 200 and 300nm and their physical properties were studied with appropriate techniques. The phase of the synthesized thin films was confirmed by X-ray diffraction analysis. Further, the crystallite size was calculated by Scherer formula and found to increase from 58 to 79 nm with increase of thickness. The obtained results were discussed in view of testing the suitability of SnS film as an absorber for the fabrication of low-cost and non toxic solar cell. For thickness, t=300nm, the films showed orthorhombic OR phase with a strong (111) preferred orientation. The films deposited with thickness < 200nm deviate

... Show More
Publication Date
Sun Jun 06 2010
Journal Name
Baghdad Science Journal
Manufacturing of flash lamp and studying its properties
...Show More Authors

This study presents the design of flash-lamps for pumped solid-state lasers. In this research have been study some of characters for flash lamp. The optimum pressure operation is found using different flash lamps about (600-4000) mbar. In conclusion, it was shown that the increase in pressure due to improve efficiency of radiation and decrease of temperature. Also this study illustrated the reason of decrease temperature is atomic number and due to increase of radiation efficiency.

View Publication Preview PDF
Crossref
Publication Date
Thu Nov 01 2001
Journal Name
Renewable Energy
Optoelectronic properties of a-Si1−xGex:H thin films
...Show More Authors

View Publication
Scopus (1)
Scopus Clarivate Crossref
Publication Date
Fri Oct 14 2016
Journal Name
Functional Pavement Design
Effect of different variables on asphalt mechanical properties
...Show More Authors

Permanent deformation (rutting) of asphalt mixtures is one of the major forms of distress. Aggregate gradation is one of the most important factors affecting the permanent deformation of asphalt mixtures. Other variables are also important to understand their effects on the mixture such as temperature, binder content and compaction level. For this purpose 6 different aggregate gradations have been chosen and each one of them has been manufactured / tested with different variables. The results showed that at relatively low temperature there is little effect of aggregate packing on the permanent deformation. However, as the temperature increases the effect of gradation becomes apparent, in that the better the packing the better the resistance

... Show More
View Publication Preview PDF
Scopus (1)
Crossref (3)
Scopus Crossref
Publication Date
Thu Dec 03 2020
Journal Name
Civileng
Evaluation of Concrete Material Properties at Early Age
...Show More Authors

This article investigates the development of the following material properties of concrete with time: compressive strength, tensile strength, modulus of elasticity, and fracture energy. These properties were determined at seven different hydration ages (18 h, 30 h, 48 h, 72 h, 7 days, 14 days, 28 days) for four pure cement concrete mixes totaling 336 specimens tested throughout the study. Experimental data obtained were used to assess the relationship of the above properties with the concrete compressive strength and how these relationships are affected with age. Further, this study investigates prediction models available in literature and recommendations are made for models that are found suitable for application to early age conc

... Show More
View Publication
Crossref (18)
Crossref
Publication Date
Fri Jan 01 2021
Journal Name
Aip Conference Proceedings
Optical properties of ZnS and PEDOT thin films
...Show More Authors

Vanadium dioxide nanofilms are one of the most essential materials in electronic applications like smart windows. Therefore, studying and understanding the optical properties of such films is crucial to modify the parameters that control these properties. To this end, this work focuses on investigating the opacity as a function of the energy directed at the nanofilms with different thicknesses(1–100) nm. Effective mediator theories(EMTs), which are considered as the application of Bruggeman’s formalism and the Looyenga mixing rule, have been used to estimate the dielectric constant of VO2 nanofilms. The results show different opacity behaviors at different wavelength ranges(ultraviolet, visible, and infrared). The results depict that th

... Show More
Scopus (3)
Scopus