T-Ω formulation with higher order hierarchical basis functions for non simply connected conductors

This paper extends the T-\u3a9 formulation for eddy currents based on higher order hierarchical basis functions so that it can deal with conductors of arbitrary topology. To this aim we supplement the classical hierarchical basis functions with non-local basis functions spanning the first de Rham cohomology group of the insulating region. Such non-local basis functions may be efficiently found in negligible time with the recently introduced DS algorithm

Socializing One Health: an innovative strategy to investigate social and behavioral risks of emerging viral threats

In an effort to strengthen global capacity to prevent, detect, and control infectious diseases in animals and people, the United States Agency for International Development’s (USAID) Emerging Pandemic Threats (EPT) PREDICT project funded development of regional, national, and local One Health capacities for early disease detection, rapid response, disease control, and risk reduction. From the outset, the EPT approach was inclusive of social science research methods designed to understand the contexts and behaviors of communities living and working at human-animal-environment interfaces considered high-risk for virus emergence. Using qualitative and quantitative approaches, PREDICT behavioral research aimed to identify and assess a range of socio-cultural behaviors that could be influential in zoonotic disease emergence, amplification, and transmission. This broad approach to behavioral risk characterization enabled us to identify and characterize human activities that could be linked to the transmission dynamics of new and emerging viruses. This paper provides a discussion of implementation of a social science approach within a zoonotic surveillance framework. We conducted in-depth ethnographic interviews and focus groups to better understand the individual- and community-level knowledge, attitudes, and practices that potentially put participants at risk for zoonotic disease transmission from the animals they live and work with, across 6 interface domains. When we asked highly-exposed individuals (ie. bushmeat hunters, wildlife or guano farmers) about the risk they perceived in their occupational activities, most did not perceive it to be risky, whether because it was normalized by years (or generations) of doing such an activity, or due to lack of information about potential risks. Integrating the social sciences allows investigations of the specific human activities that are hypothesized to drive disease emergence, amplification, and transmission, in order to better substantiate behavioral disease drivers, along with the social dimensions of infection and transmission dynamics. Understanding these dynamics is critical to achieving health security--the protection from threats to health-- which requires investments in both collective and individual health security. Involving behavioral sciences into zoonotic disease surveillance allowed us to push toward fuller community integration and engagement and toward dialogue and implementation of recommendations for disease prevention and improved health security

Asymptotic and absorbing boundary conditions for finite element analysis of digital circuit and scattering problems

The finite element method (FEM) is very appealing for solving open regional digital circuit and scattering problems due to its simplicity in modeling complex-shaped structures and inhomogeneous dielectric scatterers. However, it must deal with the practical problems of mesh truncation and the introduction of an artificial outer boundary in order to limit the number of node points to a manageable size. Therefore, the major difficulty encountered when using FEM is how to find a boundary condition operator which when applied on the artificial outer boundary mimics the asymptotic behavior of the field at infinity and yields reasonably accurate results in the interior region without the need of an exorbitantly large number of mesh points.This thesis is an effort to provide some techniques to deal with the FEM mesh truncation, in an efficient manner, through the introduction of three new boundary condition concepts, viz., the boundary conditions for arbitrary outer boundaries, the asymptotic boundary condition for digital circuit applications, and the higher-order asymptotic and absorbing boundary conditions. The use of generalized boundary conditions or the boundary conditions for arbitrary outer boundaries enables one to reduce the number of node points significantly and to solve larger sized problems than had been possible in the past. The asymptotic boundary condition for digital circuit applications does not suffer from the complications associated with the infinite elements, and yet enables one to bring the outer boundary much closer to the structure than would be possible with a p.e.c. artificial outer boundary. The higher-order asymptotic and absorbing boundary conditions, unlike the available ABCs, e.g., the Bayliss, Gunzburger, and Turkel (BGT), which assume that in the far region the solution can adequately be represented by the first few terms of the series, require that the asymptotic representation be a combination of the lower- and higher-order terms. The higher-order boundary conditions help reduce the error in the finite element solution caused by the neglecting of the higher-order terms in other available ABC assumptions.Various investigations of scattering as well as two- and three-dimensional digital circuit problems are presented. Numerical examples are shown for a variety of scatterers and transmission line configurations. Results show that the boundary condition concepts introduced in this work yield good agreement with work published elsewhere and significant improvements in computation time and storage compared to other available methods.U of I OnlyETDs are only available to UIUC Users without author permissio

Asymptotic and Absorbing Boundary Conditions for Finite Element Analysis of Digital Circuit and Scattering Problems

Coordinated Science Laboratory was formerly known as Control Systems LaboratoryJoint Services Electronics Program / N00014-90-J-1270U of I OnlyRestricted to UIUC communit

Asymptotic and Absorbing Boundary Conditions for Finite Element Analysis of Digital Circuit and Scattering Problems

Coordinated Science Laboratory was formerly known as Control Systems LaboratoryJoint Services Electronics Program / N00014-90-J-1270U of I OnlyRestricted to UIUC communit