Multi-target tracking using appearance models for identity maintenance

This thesis considers perception systems for urban environments. It focuses on the task of tracking dynamic objects and in particular on methods that can maintain the identities of targets through periods of ambiguity. Examples of such ambiguous situations occur when targets interact with each other, or when they are occluded by other objects or the environment. With the development of self driving cars, the push for autonomous delivery of packages, and an increasing use of technology for security, surveillance and public-safety applications, robust perception in crowded urban spaces is more important than ever before. A critical part of perception systems is the ability to understand the motion of objects in a scene. Tracking strategies that merge closely-spaced targets together into groups have been shown to offer improved robustness, but in doing so sacrifice the concept of target identity. Additionally, the primary sensor used for the tracking task may not provide the information required to reason about the identity of individual objects. There are three primary contributions in this work. The first is the development of 3D lidar tracking methods with improved ability to track closely-spaced targets and that can determine when target identities have become ambiguous. Secondly, this thesis defines appearance models suitable for the task of determining the identities of previously-observed targets, which may include the use of data from additional sensing modalities. The final contribution of this work is the combination of lidar tracking and appearance modelling, to enable the clarification of target identities in the presence of ambiguities caused by scene complexity. The algorithms presented in this work are validated on both carefully controlled and unconstrained datasets. The experiments show that in complex dynamic scenes with interacting targets, the proposed methods achieve significant improvements in tracking performance

Cooperation and conflict: a case study in harmony and discord in Cleveland County, Oklahoma, 1889-1959

Thesis (M.A.)--University of Oklahoma

Silicosis In The Gold Mining Industry In Rhodesia

A CAJM article on silicosis induced by dusty gold mining environments

Remote capacitive sensing in two-dimension quantum-dot arrays

We investigate gate-defined quantum dots in silicon on insulator nanowire field-effect transistors fabricated using a foundry-compatible fully-depleted silicon-on-insulator (FD-SOI) process. A series of split gates wrapped over the silicon nanowire naturally produces a $2\times n$ bilinear array of quantum dots along a single nanowire. We begin by studying the capacitive coupling of quantum dots within such a 2$\times$2 array, and then show how such couplings can be extended across two parallel silicon nanowires coupled together by shared, electrically isolated, 'floating' electrodes. With one quantum dot operating as a single-electron-box sensor, the floating gate serves to enhance the charge sensitivity range, enabling it to detect charge state transitions in a separate silicon nanowire. By comparing measurements from multiple devices we illustrate the impact of the floating gate by quantifying both the charge sensitivity decay as a function of dot-sensor separation and configuration within the dual-nanowire structure.Comment: 9 pages, 3 figures, 35 cites and supplementar

Equilibrium distribution studies of dysprosium nitrate-erbium nitrate-nitric acid-tributyl phosphate systems

\u27!be equilibrium distribution of dysprosium nitrate, erbium nitrate, and nitric acid between water and tributyl phosphate was studied in this research. Separate equilibrium data were obtained for the distribution of dysprosium nitrate-nitric acid, erbium nitrate-nitric acid, and dysprosium nitrate-erbium nitrate-nitric acid mixtures. The equilibrium data were obtained by making single stage extractions from aqueous feed solutions using commercial grade tributyl phosphate. Equilibrium distribution of solutes was determined by analysis of each phase from the single stage extractions

A Silicon Surface Code Architecture Resilient Against Leakage Errors

Spin qubits in silicon quantum dots are one of the most promising building blocks for large scale quantum computers thanks to their high qubit density and compatibility with the existing semiconductor technologies. High fidelity single-qubit gates exceeding the threshold of error correction codes like the surface code have been demonstrated, while two-qubit gates have reached 98\% fidelity and are improving rapidly. However, there are other types of error --- such as charge leakage and propagation --- that may occur in quantum dot arrays and which cannot be corrected by quantum error correction codes, making them potentially damaging even when their probability is small. We propose a surface code architecture for silicon quantum dot spin qubits that is robust against leakage errors by incorporating multi-electron mediator dots. Charge leakage in the qubit dots is transferred to the mediator dots via charge relaxation processes and then removed using charge reservoirs attached to the mediators. A stabiliser-check cycle, optimised for our hardware, then removes the correlations between the residual physical errors. Through simulations we obtain the surface code threshold for the charge leakage errors and show that in our architecture the damage due to charge leakage errors is reduced to a similar level to that of the usual depolarising gate noise. Spin leakage errors in our architecture are constrained to only ancilla qubits and can be removed during quantum error correction via reinitialisations of ancillae, which ensure the robustness of our architecture against spin leakage as well. Our use of an elongated mediator dots creates spaces throughout the quantum dot array for charge reservoirs, measuring devices and control gates, providing the scalability in the design

Institutional abuse – characteristics of victims, perpetrators and organsations: a systematic review

Abuse of vulnerable adults in institutional settings has been reported from various countries; however, there has been no systematic review of the characteristics of the victims and their Q3 abusers. Our aim was to identify and synthesise the literature on victims and perpetrators of abuse in institutions and the characteristics of the institutions where abuse occurs in order to inform interventions to prevent such abuse. Methods: Searches of MEDLINE (OVID), CINHAL (EBSCO), EMBASE (OVID) and PsychINFO (OVID) databases identified 4279 references. After screening of titles and abstracts, 123 citations merited closer inspection. After applying inclusion and exclusion criteria, 22 articles were included in the review. Results: Our review suggested that the evidence available on risk factors is not extensive but some conclusions can be drawn. Clients, staff, institutional and environmental factors appear to play a role in increasing the risk of abuse. Cases of abuse may be underreported. Conclusions: Vulnerable clients need closer monitoring. Clients and staff may lack the awareness and knowledge to identify and report abuse. Institutions should take proactive steps to monitor clients, train staff and devise systems that allow for the identification and reporting of incidents of abuse and take steps to prevent such incidents. Staff need education and awareness of institutional policies to identify and report abuse. There is a need for further research into the association between the individual client, staff and institutional characteristics and abuse. Such information may be useful in quantifying risk to individual clients and planning their care

The Occurrence Rate of Earth Analog Planets Orbiting Sunlike Stars

Kepler is a space telescope that searches Sun-like stars for planets. Its major goal is to determine {\eta}_Earth, the fraction of Sunlike stars that have planets like Earth. When a planet 'transits' or moves in front of a star, Kepler can measure the concomitant dimming of the starlight. From analysis of the first four months of those measurements for over 150,000 stars, Kepler's science team has determined sizes, surface temperatures, orbit sizes and periods for over a thousand new planet candidates. In this paper, we characterize the period probability distribution function of the super-Earth and Neptune planet candidates with periods up to 132 days, and find three distinct period regimes. For candidates with periods below 3 days the density increases sharply with increasing period; for periods between 3 and 30 days the density rises more gradually with increasing period, and for periods longer than 30 days, the density drops gradually with increasing period. We estimate that 1% to 3% of stars like the Sun are expected to have Earth analog planets, based on the Kepler data release of Feb 2011. This estimate of is based on extrapolation from a fiducial subsample of the Kepler planet candidates that we chose to be nominally 'complete' (i.e., no missed detections) to the realm of the Earth-like planets, by means of simple power law models. The accuracy of the extrapolation will improve as more data from the Kepler mission is folded in. Accurate knowledge of {\eta}_Earth is essential for the planning of future missions that will image and take spectra of Earthlike planets. Our result that Earths are relatively scarce means that a substantial effort will be needed to identify suitable target stars prior to these future missions.Comment: Accepted for publication in the Astrophysical Journal. 19 pages, 8 figures. Minor text revisions, as requested by the scientific editor. Included an additional figure. No changes in the scientific result

Global Journalist: The future of space exploration: United States, Russia, and China

On this February 12, 2004 program of Global Journalist, science journalists discuss the ambitions of space programs between the United States, Russia, China, and how they all occupy in the same realm of space exploration. Host: Stuart Loory. Guests: Christopher Bodeen, Michael Cabbage, Oliver Morton, Simon Saradzhyan. Producers: Renata Johnson, Pareetha George (?), Unta Kon (?). Directors: Pat Akers