Indoor Positioning Using Acoustic Pseudo-Noise Based Time Difference of Arrival

The Global Positioning System (GPS) provides good precision on a global scale, but is not suitable for indoor applications. Indoor positioning systems (IPS) aim to provide high precision position information in an indoor environment. IPS has huge market opportunity with a growing number of commercial and consumer applications especially as Internet of Things (IoT) develops. This paper studies an IPS approach using audible sound and pseudo-noise (PN) based time difference of arrival (TDoA). The system’s infrastructure consists of synchronized speakers. The object to be located, or receiver, extracts TDoA information and uses multilateration to calculate its position. The proposed IPS utilizes sound waves since they travel much slower compared to electromagnetic waves, allowing for easier measurements. Additionally, the audible spectrum has a large availability of low directivity speakers and microphones allowing for a large coverage area compared to highly directive ultrasonic transceivers. This paper experimentally evaluates the feasibility of the proposed IPS

Adaptive EAGLE dynamic solution adaptation and grid quality enhancement

In the effort described here, the elliptic grid generation procedure in the EAGLE grid code was separated from the main code into a subroutine, and a new subroutine which evaluates several grid quality measures at each grid point was added. The elliptic grid routine can now be called, either by a computational fluid dynamics (CFD) code to generate a new adaptive grid based on flow variables and quality measures through multiple adaptation, or by the EAGLE main code to generate a grid based on quality measure variables through static adaptation. Arrays of flow variables can be read into the EAGLE grid code for use in static adaptation as well. These major changes in the EAGLE adaptive grid system make it easier to convert any CFD code that operates on a block-structured grid (or single-block grid) into a multiple adaptive code

Wave propagation through soils in centrifuge testing.

International audienceWave propagation phenomena in soils can be experimentally simulated using centrifuge scale models. An original excitation device (drop-ball arrangement) is proposed to generate short wave trains. Wave reflections on model boundaries are taken into account and removed by homomorphic filtering. Propagation is investigated through dispersion laws. For drop-ball experiments, spherical wave field analysis assuming linear viscoelasticity leads to a complete analytical description of wave propagation. Damping phenomena are examined and evaluated using this description

Mere Exposure Effects: Presence of parasitic mites induce a change in the metabolic rate of flies independent of infection

Parasites affect host physiology and populations in numerous ways including: increased mortality, decreased fecundity, and changes to host behavior. Many documented effects depend on infection to explain changes, for example: parasite blood feeding, tissue damage, and costs of immune responses. However, the effects that the mere presence of parasites have on their hosts is relatively unexplored. We study a fruit fly - mite model system. Macrocheles Domesticae is an ectoparasite that reversibly attaches to Drosophila Hydei as a means of transportation as well as feeding on host hemolymph. Since flies must move between resource patches, the effects of parasite infection on flight are significant. This system is can be used to illustrate host-parasite dynamics. We take an ecological physiology perspective and link physical changes in organisms to the larger scale processes of ecology; we deploy respirometry to compare energy consumption of flies under various conditions. Carbon Dioxide produced is measured as a flow, and linked to energy consumption by the cellular respiration equation. We hypothesize that host flight will be impaired by infection. Bioenergetic costs of infection imply this effect will be present even if mites are removed prior to flight. Results show that both flies carrying mites, and flies infected prior to flight, both hover for reduced lengths of time. Additionally, both actively resisting mites, as well as mere exposure to them, increases the Carbon Dioxide output of the host. These results have implications for host fitness and energy budgets in both the evolution and ecology of host-parasite interactions. *Indicates faculty mento

Microbial ecology of Thiobacillus ferrooxidans

FINAL TECHNICAL REPORT TO U.S. DEPARTMENT OF THE INTERIOR Geological Survey Washington. D.C.The contents of this report were developed in part under a grant from the Department of the Interior, U.S. Geological Survey. Grant number 14-08-0001-61313

Effects of Nuclear Structure on Quasi-fission

The quasi-fission mechanism hinders fusion of heavy systems because of a mass flow between the reactants, leading to a re-separation of more symmetric fragments in the exit channel. A good understanding of the competition between fusion and quasi-fission mechanisms is expected to be of great help to optimize the formation and study of heavy and superheavy nuclei. Quantum microscopic models, such as the time-dependent Hartree-Fock approach, allow for a treatment of all degrees of freedom associated to the dynamics of each nucleon. This provides a description of the complex reaction mechanisms, such as quasi-fission, with no parameter adjusted on reaction mechanisms. In particular, the role of the deformation and orientation of a heavy target, as well as the entrance channel magicity and isospin are investigated with theoretical and experimental approaches.Comment: Invited talk to NSRT12. To be published in Eur. Phys. J. Web of Con