Regular Language Distance and Entropy

This paper addresses the problem of determining the distance between two regular languages. It will show how to expand Jaccard distance, which works on finite sets, to potentially-infinite regular languages. The entropy of a regular language plays a large role in the extension. Much of the paper is spent investigating the entropy of a regular language. This includes addressing issues that have required previous authors to rely on the upper limit of Shannon\u27s traditional formulation of channel capacity, because its limit does not always exist. The paper also includes proposing a new limit based formulation for the entropy of a regular language and proves that formulation to both exist and be equivalent to Shannon\u27s original formulation (when it exists). Additionally, the proposed formulation is shown to equal an analogous but formally quite different notion of topological entropy from Symbolic Dynamics -- consequently also showing Shannon\u27s original formulation to be equivalent to topological entropy. Surprisingly, the natural Jaccard-like entropy distance is trivial in most cases. Instead, the entropy sum distance metric is suggested, and shown to be granular in certain situations

A Novel Concept for a Positron Emission Tomography Scanner

Positron Emission Tomography (PET) allows physicians and researchers to visualize metabolic data in the human body and is widely used in cancer and neurological imaging. Traditional PET scanners consist of a thin ring of scintillators coupled to photo detectors but these scanners often take long periods of time to acquire an image, are very costly, and are too complex to fit inside other machinery such as MRI. In response to this, we are building a novel PET detector that utilizes non-traditional scintillators and photo detectors in an attempt to significantly decrease cost, allow combined PET/MRI modalities and reduce scan time

Near-Optimal Budgeted Data Exchange for Distributed Loop Closure Detection

Inter-robot loop closure detection is a core problem in collaborative SLAM (CSLAM). Establishing inter-robot loop closures is a resource-demanding process, during which robots must consume a substantial amount of mission-critical resources (e.g., battery and bandwidth) to exchange sensory data. However, even with the most resource-efficient techniques, the resources available onboard may be insufficient for verifying every potential loop closure. This work addresses this critical challenge by proposing a resource-adaptive framework for distributed loop closure detection. We seek to maximize task-oriented objectives subject to a budget constraint on total data transmission. This problem is in general NP-hard. We approach this problem from different perspectives and leverage existing results on monotone submodular maximization to provide efficient approximation algorithms with performance guarantees. The proposed approach is extensively evaluated using the KITTI odometry benchmark dataset and synthetic Manhattan-like datasets.Comment: RSS 2018 Extended Versio

Using a virtual reality cricket simulator to explore the effects of pressure, competition anxiety on batting performance in cricket

Virtual reality (VR) has created opportunities to innovatively re-imagine the way we examine the relations between pressure, competition anxiety and performance. This study aimed to determine the efficacy of VR as a means of measuring the effects of competition anxiety when pressure manipulations are applied while participants bat in a cricket batting VR simulator. The twenty-eight male participants who took part in two experiments were divided into a high (14, mean age: 22.94, SD: 5.4) and a low skill group (14; mean age: 23.55, SD: 9.9). The aim of the first experiment was to validate the VR simulator as a tool that could capture differences in batting performance between a high and low skilled group. The results showed that high skill participants not only scored significantly higher run rates than low skill participants, but they outperformed the low skill group in all performance measures including higher incidences of correct foot placements that reflect better anticipatory responses. Having established the VR batting simulator as being a reliable tool for capturing batting dynamics, experiment 2 aimed to explore the effects of a pressure manipulation on competition anxiety and batting performance. All measures of competition anxiety were significantly greater for both groups in the high-pressure condition compared to the two low-pressure conditions (p &lt; 0.001). The magnitude of this effect was greater in the low skill group for cognitive (0.59) and somatic (0.794) anxiety. Despite anxiety levels significantly increasing in the high-pressure condition, no significant negative changes to batting performance were found for either group, with both groups actually demonstrating performance improvements. Overall, the findings show how a cricket batting virtual reality simulator can be used as a tool to measure the effects of pressure on competition anxiety and batting performance in tasks involving dynamic skill execution.</p

Coherence requirements for quantum communication from hybrid circuit dynamics

The coherent superposition of quantum states is an important resource for quantum information processing which distinguishes quantum dynamics and information from their classical counterparts. In this article we determine the coherence requirements to communicate quantum information in a broad setting encompassing monitored quantum dynamics and quantum error correction codes. We determine these requirements by considering hybrid circuits that are generated by a quantum information game played between two opponents, Alice and Eve, who compete by applying unitaries and measurements on a fixed number of qubits. Alice applies unitaries in an attempt to maintain quantum channel capacity, while Eve applies measurements in an attempt to destroy it. By limiting the coherence generating or destroying operations available to each opponent, we determine Alice's coherence requirements. When Alice plays a random strategy aimed at mimicking generic monitored quantum dynamics, we discover a coherence-tuned phase transitions in entanglement and quantum channel capacity. We then derive a theorem giving the minimum coherence required by Alice in any successful strategy, and conclude by proving that coherence sets an upper bound on the code distance in any stabelizer quantum error correction codes. Such bounds provide a rigorous quantification of the coherence resource requirements for quantum communication and error correction.Comment: 19 pages, 12 figure

‘Back to Life’—Using knowledge exchange processes to enhance lifestyle interventions for liver transplant recipients: A qualitative study

Interventions to prevent excessive weight gain after liver transplant are needed. The purpose of the present study was to enhance a specialist post-transplant well-being program through knowledge exchange with end-users.The study used an interactive process of knowledge exchange between researchers, clinicians and health system users. Data were collected as focus groups or telephone interviews and underwent applied thematic analysis.There were 28 participants (age 24-68 years; 64% male). The results identified experiences that may influence decisions around health behaviours during the course of transplant recovery. Three over-arching themes were identified that impact on liver transplant recipients post-transplant health behaviours. These include (i) Finding a coping mechanism which highlighted the need to acknowledge the significant emotional burden of transplant prior to addressing long-term physical wellness; (ii) Back to Life encompassing the desire to return to employment and prioritise family, while co-ordinating the burden of ongoing medical monitoring and self-management and (iii) Tailored, Personalised Care with a preference for health care delivery by transplant specialists via a range of flexible eHealth modalities.This person-centred process of knowledge exchange incorporated experiences of recipients into service design and identified life priorities most likely to influence health behaviours post-transplant. Patient co-creation of services has the potential to improve the integration of knowledge into health systems and future directions will require evaluation of effectiveness and sustainability of patient-centred multidisciplinary service development

Industrial Solid-State Energy Harvesting: Mechanisms and Examples

This paper explores the potential for solid-state energy harvesting in industrial applications. In contrast to traditional heat recovery, the output of solid-state devices is electricity, which can be readily used in virtually any plant. The progress in harvesting waste heat via thermoelectric and thermionic generators is described. With second law efficiencies now approaching 50% and 80% respectively, we show that these technologies are on the cusp of practical use. Finally, we present an example of energy harvesting using thermionic devices in an industrial application. The example considers energy harvesting from a furnace at a glass manufacturing facility where exhaust gases are discharged at about 2,400oF and where there are no viable uses for recoverable heat. An optimal configuration of thermionic devices is shown to be capable of recovering nearly 1/3 of the available exergy in the exhaust gases as electrical energy