Satellite-map position estimation for the Mars rover

A method for locating the Mars rover using an elevation map generated from satellite data is described. In exploring its environment, the rover is assumed to generate a local rover-centered elevation map that can be used to extract information about the relative position and orientation of landmarks corresponding to local maxima. These landmarks are integrated into a stochastic map which is then matched with the satellite map to obtain an estimate of the robot's current location. The landmarks are not explicitly represented in the satellite map. The results of the matching algorithm correspond to a probabilistic assessment of whether or not the robot is located within a given region of the satellite map. By assigning a probabilistic interpretation to the information stored in the satellite map, researchers are able to provide a precise characterization of the results computed by the matching algorithm

Improvement of piezoresistance properties of silicon carbide ceramics through co-doping of aluminum nitride and nitrogen

The piezoresistance coefficient was measured on co-doped silicon carbide ceramics. Evaluation samples of alpha-silicon carbide ceramics were first fabricated by glass capsule HIP method using powder mixture of silicon carbide and aluminum nitride with various ratios. The resultant aluminum nitride added silicon carbide ceramics were doped with nitrogen by changing the post-HIP nitrogen gas pressure. The lattice parameter increased with the amount of adding aluminum nitride indicating that the incorporated aluminum substituted smaller silicon atoms. After post-HIP treatment, lattice parameter then decreased with nitrogen gas pressure. The piezoresistive coefficient increased with the addition of aluminum nitride, it further increased with the nitrogen doping pressure

Integrating Mathematical Models of Behavior and Infectious Disease: Applications to Outbreak Dynamics and Control

This dissertation applies mathematical models from several disciplines to represent the complex interaction between human behavior and infectious disease transmission. We first use game theory and evolutionary dynamics to capture contact and risk behaviors such that they can be coupled to compartmental transmission models. We use this behavior-disease approach to model adaptive prophylaxis use during sexually transmitted infeciton (STI) outbreaks as well as burial practices during the 2014 Ebola outbreak using this framework. We then link rational decision theory and quantitative microbial risk assessment (QMRA) to investigate incomplete compliance with household water treatment (HWT) due to usability/efficacy trade-offs. Our analyses of these systems address theoretical and practical consequences of relaxing simplifying assumptions about behavior. We find that feedback between adaptive behavior and disease prevalence in our STI model lead to a range of dynamic outcomes including damped and sustained oscillations as well as complicating the interpretation of the basic reproductive number. For Ebola, our behavior-disease model gives both a superior fit to surveillance data and more accurate final-size forecasts than a reduced model without behavior change. In addition, our model predicts a shift to sanitary burial practices that corresponds to a change in the estimated reporting rate/population at risk and appears to have reduced the force of infection in the later phases of the outbreak. Finally, simulations and optimal risk-reduction solutions from our decision theoretic QMRA model suggest that current efficacy-focused HWT recommendations may be less effective at reducing the burden of diarrheal disease than interventions that prioritize usability and acceptance by the target population. Together, these results demonstrate the potential to improve infectious disease surveillance and control by modeling human behavioral factors that are often simplified or omitted. Such elements can explain the temporal patterns of outbreaks on short and long term scales while behavioral modeling can identify feedbacks that could be exploited to improve the uptake and sustainability of intervention policies.PhDEpidemiological ScienceUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/133434/1/mhayash_1.pd

Sub-harmonic Oscillations in Power Circuits with Series Capacitors

A method based on the dual-input describing function is presented for the analysis of the sub-harmonic resonance of the order 1/3 in the electric circuits containing one saturable reactor. The paper describes the use of this method to analyse the 1/3-harmonic resonance which may be encountered in the application of series capacitors to power circuits, and presents the conditions on the circuit parameters to ensure the absence of the 1/3-harmonic resonance. An analog computer study on this problem is included

Transient Voltages across Series Capacitors on Three-Phase Transmission Line due to Non-Simultaneous Switching

Series capacitors have been utilized recently in order to increase the capacity of transmission systems by compensating the detrimental effects of inductance. In such cases, these capacitors have to be switched in or off according to the variation in load. This is necessarilly accompanied by power disturbances, abnormal voltage rises etc.. In order to insert the capacitors, the circuit breakers that are installed in parallel with them are opened, in which case it is scarcely possible to open all three poles of the breakers simultaneously. The present paper deals analytically the abnormal transient voltages across the capacitors arising due to non-simultaneous tripping of the poles, and the validity of the analytical results are affirmed by comparing with many experiments recently executed

On Local Symmetric Order Parameters of Vortex Lattice States

This paper gives a new refined definition of local symmetric order parameters (OPs)(s-wave, d-wave and p-wave order parameters) of vortex lattice states for singlet superconductivity. s-wave, d-wave and p-wave OPs at a site (m,n) are defined as A, B and E representations of the four fold rotation C_4 at the site (m,n) of nearest neighbor OPs etc. The new OPs have a well defined nature such that an OP(e.g. d-wave) at the site obtained under translation by a lattice vector (of the vortex lattice) from a site (m,n) is expressed by the corresponding OP (e.g. d-wave) at the site (m,n) times a phase factor. The winding numbers of s-wave and d-wave OPs are given.Comment: RevTeX v3.1, 5 pages with 3 figures, uses epsf.sty. to appear in Prog. Theor. Phys. Vol.101 No.3. (1999

Demonstration of deterministic and high fidelity squeezing of quantum information

By employing at recent proposal (R. Filip, P. Marek and U.L. Andersen, Phys. Rev. A {\bf 71}, 042308 (2005) \cite{Filip05.pra}), we experimentally demonstrate a universal, deterministic and high-fidelity squeezing transformation of an optical field. It relies only on linear optics, homodyne detection, feedforward and an ancillary squeezed vacuum state, thus direct interaction between a strong pump and the quantum state is circumvented. We demonstrate three different squeezing levels for a coherent state input. This scheme is highly suitable for the fault-tolerant squeezing transformation in a continuous variable quantum computer.Comment: 5 pages, 4 figure