1,101 research outputs found
A stable and accurate control-volume technique based on integrated radial basis function networks for fluid-flow problems
Radial basis function networks (RBFNs) have been widely used in solving partial differential equations as they
are able to provide fast convergence. Integrated RBFNs have the ability to avoid the problem of reduced convergence-rate caused by differentiation. This paper is concerned with the use of integrated RBFNs in the context of control-volume discretisations for the simulation of fluid-flow problems. Special attention is given to (i) the development of a stable high-order upwind scheme for the convection term and (ii) the development of a local high-order approximation scheme for the diffusion term. Benchmark
problems including the lid-driven triangular-cavity flow are
employed to validate the present technique. Accurate results at high values of the Reynolds number are obtained using relatively-coarse grids
Improvement of DHRA-DMDC Physical Access Software DBIDS Using Cloud Computing Technology: a Case Study
The U.S government has created and been executing an Identity and Management (IdM) vision to support a global, robust, trusted and interoperable identity management capability that provides the ability to correctly identify individuals and non-person entities in support of DoD mission operations. Many Directives and Instructions have been issued to standardize the process to design, re-designed new and old systems with latest available technologies to meet the visions requirements. In this thesis we introduce a cloud-based architecture for the Defense Biometric Identification System (DBIDS), along with a set of DBIDS Cloud Services that supports the proposed architecture. This cloud-based architecture will move DBIDS in the right direction to meet Dod IdM visions and goals by decoupling current DBIDS functions into DBIDS core services to create interoperability and flexibility to expand future DBIDS with new requirements. The thesis will show its readers how DBIDS Cloud Services will help Defense Manpower Data Center (DMDC) easily expanding DBIDS functionalities such as connecting to other DMDC services or federated services for vetting purposes. This thesis will also serve as a recommendation of a blue-print for DBIDS architecture to support new generation of DBIDS application. This is a step closer in moving DMDC Identity Enterprise Solution toward DoD IdM realizing vision and goals. The thesis also includes a discussion of how to utilize virtualized DBIDS workstations to address software-deployment and maintenance issues to resolve configuration and deployment issues which have been costly problems for DMDC over the years.http://archive.org/details/improvementofdhr109457379Civilian, Department of Defens
Investigation of Higgs boson anomalous FCNC interactions in the simple 3-3-1 model
We study phenomenological constraints on a simple model with flavor
violating Yukawa couplings. Both triplets Higgs couple to leptons and quarks,
which generates flavor violating signals in both lepton and quark sectors. We
have shown that this model can allow for large Higgs lepton flavor-violating
rate decay and also can be reached to perfect
agreements with other experimental constraints such as and . The contributions of flavor-changing neutral current
(FCNC) couplings, Higgs-quark-quark couplings, to the mesons mixing are
investigated. Br can be enhanced with keeping from
the measurements of meson mixing. The branching ratio for
can reach up to , but it could be as low as .Comment: 21 pages, 8 figure
Addressing Food Insecurity Among Undocumented Immigrants in California – An Expansion and Outreach Approach
A challenge that undocumented immigrants in California face with is the insecurity of food. The experience of food insecurity for undocumented immigrants is more than just a shortage of food, but rather it is the limited access and poor quality of food. Having accessibility to food is important for one’s wellbeing and in lowering the rate of other health disparities that is a public health problem. This paper will discuss the prevalence of food insecurity among undocumented immigrants in California and the barriers that they face with food assistance programs. Further discussion will focus on current interventions that are being made and will be explained through policy, organizational, interpersonal, and individual levels. Recommendations will then be made to improve food accessibility to undocumented immigrants in expansion and outreach. The aim is to improve the improve the challenge of food insecurity through creating more food programs that can be accessible to undocumented regardless of age of status
A continuum-microscopic method based on IRBFs and control volume scheme for viscoelastic fluid flows
A numerical computation of continuum-microscopic model for visco-elastic flows based on the Integrated Radial Basis Function (IRBF) Control Volume and the Stochastic Simulation Techniques (SST) is reported in this paper. The macroscopic flow equations are closed by a stochastic equation for the extra stress at the microscopic level. The former are discretised by a 1D-IRBF-CV method while the latter is integrated with Euler explicit or Predictor-Corrector schemes. Modelling is very efficient as it is based on Cartesian grid, while the integrated RBF approach enhances both the stability of the procedure and the accuracy of the solution. The proposed method is demonstrated with the solution of the start-up Couette flow of the Hookean and FENE dumbbell model fluids
Nanotechnology companies in the United States:a web-based content analysis of companies and products for poverty alleviation
This study analyzes the goals, nanotechnology experience, corporate social responsibility and products of 50 USA-based companies working with nanotechnology to see if they are developing products that help low-income populations. Out of the top 50 R&D companies that publish and patent nanotechnology research in agri-food, energy and water sectors, 18 of them do not mention nanotechnology on their websites. The other 32 companies discuss nanotechnology in varying degrees. However, only two of the companies relate their nanotechnology R&D to poverty alleviation. Even though few companies refer to poverty alleviation, 30 firms of the sample have some type of corporate social responsibility programs. From the study, we cannot definitively conclude that nanotechnology is a technology only for wealthy consumers, but we do find that the companies analyzed do not give much attention to pro-poor nanotechnology
Joint Resource Optimization for Multicell Networks with Wireless Energy Harvesting Relays
This paper first considers a multicell network deployment where the base
station (BS) of each cell communicates with its cell-edge user with the
assistance of an amplify-and-forward (AF) relay node. Equipped with a power
splitter and a wireless energy harvester, the self-sustaining relay scavenges
radio frequency (RF) energy from the received signals to process and forward
the information. Our aim is to develop a resource allocation scheme that
jointly optimizes (i) BS transmit powers, (ii) received power splitting factors
for energy harvesting and information processing at the relays, and (iii) relay
transmit powers. In the face of strong intercell interference and limited radio
resources, we formulate three highly-nonconvex problems with the objectives of
sum-rate maximization, max-min throughput fairness and sum-power minimization.
To solve such challenging problems, we propose to apply the successive convex
approximation (SCA) approach and devise iterative algorithms based on geometric
programming and difference-of-convex-functions programming. The proposed
algorithms transform the nonconvex problems into a sequence of convex problems,
each of which is solved very efficiently by the interior-point method. We prove
that our algorithms converge to the locally optimal solutions that satisfy the
Karush-Kuhn-Tucker conditions of the original nonconvex problems. We then
extend our results to the case of decode-and-forward (DF) relaying with
variable timeslot durations. We show that our resource allocation solutions in
this case offer better throughput than that of the AF counterpart with equal
timeslot durations, albeit at a higher computational complexity. Numerical
results confirm that the proposed joint optimization solutions substantially
improve the network performance, compared with cases where the radio resource
parameters are individually optimized
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