On the Performance of Multiple Antenna Cooperative Spectrum Sharing Protocol under Nakagami-m Fading

In a cooperative spectrum sharing (CSS) protocol, two wireless systems operate over the same frequency band albeit with different priorities. The secondary (or cognitive) system which has a lower priority, helps the higher priority primary system to achieve its target rate by acting as a relay and allocating a fraction of its power to forward the primary signal. The secondary system in return is benefited by transmitting its own data on primary system's spectrum. In this paper, we have analyzed the performance of multiple antenna cooperative spectrum sharing protocol under Nakagami-m Fading. Closed form expressions for outage probability have been obtained by varying the parameters m and Omega of the Nakagami-m fading channels. Apart from above, we have shown the impact of power allocation factor (alpha) and parameter m on the region of secondary spectrum access, conventionally defined as critical radius for the secondary system. A comparison between theoretical and simulated results is also presented to corroborate the theoretical results obtained in this paperComment: Accepted in the proceedings of IEEE PIMRC 2015 Hong Kong, Chin

Characterizing Multiscale Geometry, Anisotropic Behaviors, Bulk Properties, and Wettability of the Woodford Shale

Overview: I am Pratap Bohara--a fourth year PhD student in the Department of Geology and Geological Engineering at the University of Mississippi. I define myself as a dedicated research fellow with more than seven years of experience in the field of Geology and Geological Engineering. The proposed study will integrate geology, geochemistry, and surface chemistry to advance understanding of oil and gas behavior within the Woodford Shale of Oklahoma. Intellectual Merit: Although this unit has abundant kerogen, total organic carbon (TOC), a high hydrogen index (HI), a low oxygen index (OI), and is thermally mature seemingly making reservoir economic but natural variability in lithology, fabric and thickness has limited detailed evaluation of its economic potential. As the flow and storage of shale oil are both scale and time dependent, the results from conventional laboratory techniques may not be enough to characterize the Woodford play in a reliable manner. Shale heterogeneity directly influences its wettability –which is the preference of a solid to interact with fluid in the surface. This study will examine the effects of heterogeneity on dynamic wettability and correlates results to lithologic, geochemical, and surface chemical data to build a unified model. External Opportunities: Most of the fund for the project will come from American Association for Petroleum Geologists (AAPG) in the name of Grants-in-Aid whose deadline to apply was 2nd Dec 2019. AAPG each year provides grants ranging from $500 -$ 3000 to cover expenses directly related to the student’s field and laboratory works. The AAPG Grants-in-Aid provides financial assistance to graduate student research which has application to the search for and development of petroleum and energy-mineral resources. The objectives of the proposed research perfectly fits the criteria of AAPG Grants-in-Aid program

Visualization of Time-Varying Data from Atomistic Simulations and Computational Fluid Dynamics

Time-varying data from simulations of dynamical systems are rich in spatio-temporal information. A key challenge is how to analyze such data for extracting useful information from the data and displaying spatially evolving features in the space-time domain of interest. We develop/implement multiple approaches toward visualization-based analysis of time-varying data obtained from two common types of dynamical simulations: molecular dynamics (MD) and computational fluid dynamics (CFD). We also make application case studies. Parallel first-principles molecular dynamics simulations produce massive amounts of time-varying three-dimensional scattered data representing atomic (molecular) configurations for material system being simulated. Rendering the atomic position-time series along with the extracted additional information helps us understand the microscopic processes in complex material system at atomic length and time scales. Radial distribution functions, coordination environments, and clusters are computed and rendered for visualizing structural behavior of the simulated material systems. Atom (particle) trajectories and displacement data are extracted and rendered for visualizing dynamical behavior of the system. While improving our atomistic visualization system to make it versatile, stable and scalable, we focus mainly on atomic trajectories. Trajectory rendering can represent complete simulation information in a single display; however, trajectories get crowded and the associated clutter/occlusion problem becomes serious for even moderate data size. We present and assess various approaches for clutter reduction including constrained rendering, basic and adaptive position merging, and information encoding. Data model with HDF5 and partial I/O, and GLSL shading are adopted to enhance the rendering speed and quality of the trajectories. For applications, a detailed visualization-based analysis is carried out for simulated silicate melts such as model basalt systems. On the other hand, CFD produces temporally and spatially resolved numerical data for fluid systems consisting of a million to tens of millions of cells (mesh points). We implement time surfaces (in particular, evolving surfaces of spheres) for visualizing the vector (flow) field to study the simulated mixing of fluids in the stirred tank