394 research outputs found

    A Comparison of Inverse Simulation-Based Fault Detection in a Simple Robotic Rover with a Traditional Model-Based Method

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    Robotic rovers which are designed to work in extra-terrestrial environments present a unique challenge in terms of the reliability and availability of systems throughout the mission. Should some fault occur, with the nearest human potentially millions of kilometres away, detection and identification of the fault must be performed solely by the robot and its subsystems. Faults in the system sensors are relatively straightforward to detect, through the residuals produced by comparison of the system output with that of a simple model. However, faults in the input, that is, the actuators of the system, are harder to detect. A step change in the input signal, caused potentially by the loss of an actuator, can propagate through the system, resulting in complex residuals in multiple outputs. These residuals can be difficult to isolate or distinguish from residuals caused by environmental disturbances. While a more complex fault detection method or additional sensors could be used to solve these issues, an alternative is presented here. Using inverse simulation (InvSim), the inputs and outputs of the mathematical model of the rover system are reversed. Thus, for a desired trajectory, the corresponding actuator inputs are obtained. A step fault near the input then manifests itself as a step change in the residual between the system inputs and the input trajectory obtained through inverse simulation. This approach avoids the need for additional hardware on a mass- and power-critical system such as the rover. The InvSim fault detection method is applied to a simple four-wheeled rover in simulation. Additive system faults and an external disturbance force and are applied to the vehicle in turn, such that the dynamic response and sensor output of the rover are impacted. Basic model-based fault detection is then employed to provide output residuals which may be analysed to provide information on the fault/disturbance. InvSim-based fault detection is then employed, similarly providing \textit{input} residuals which provide further information on the fault/disturbance. The input residuals are shown to provide clearer information on the location and magnitude of an input fault than the output residuals. Additionally, they can allow faults to be more clearly discriminated from environmental disturbances

    Clarification of Governance Relevant to the Sustainable Management of Marine Species and Habitats within the United Kingdom: An Overview of Regional, National and International Authorities, Advisories, Legislation and Designation Types with Summary Schematic Tool

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    Marine management developments are occurring across the United Kingdom with the major aim to ensure economic growth and security of marine resources via the provision of legislative guidelines for sustainable management of activities within the marine environment. Many of these directives also provide guidance for maintaining ecologically valuable and/or endangered species and habitats that exist alongside, and may also support, marine activities/use. Marine governance is largely guided by several key directives laid out and implemented by governing authorities of Europe, the United Kingdom and those countries comprising the United Kingdom, and in line with several international conventions. The directives set out by each authority or convention may act discretely but more often tend to overlap, which can lead to confusion about the relevant marine conservation requirements and objectives that must be fulfilled for a given region, site or feature. Additionally, management objectives driven by the same legislation may oppose one another, adding further complexity to the matter. This article aims to provide an overview of governance that holds relevance to managing marine habitats and species, especially those deemed sensitive, ecologically valuable and/or endangered. A general overview and summary schematic tool of the marine governance, legislation and designations within each level of authority for the United Kingdom are provided. Additional consideration of the implications for legislation upon the United Kingdom leaving the EU is briefly discussed and a comparative case study of two marine habitats of high conservation value is provided to demonstrate how different sites/features may have considerably different management requirements

    Understanding Intermolecular Attraction: Fundamental Science and Environmental Applications

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    University of Minnesota Ph.D. dissertation. October 2016. Major: Chemistry. Advisor: Kenneth Leopold. 1 computer file (PDF); viii, 207 pages.Our world is shaped by the mutual attraction of molecules. Studying small clusters of 2-3 molecules yields a wealth of detailed information on the forces that hold them, and thus, most of the world, together. For my doctoral work, I used microwave spectroscopy to study the structure of molecular complexes to provide insight into the ways molecules adhere to each other. My work has focused on the fundamental science of these clusters, particularly the large amplitude motion they undergo, as well as their applications to atmospheric chemistry

    Inverse Simulation as a Tool for Fault Detection and Isolation in Planetary Rovers

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    With manned expeditions to planetary bodies beyond our own and the Moon currently intractable, the onus falls upon robotic systems to explore and analyse extraterrestrial environments such as Mars. These systems typically take the form of wheeled rovers, designed to navigate the difficult terrain of other worlds. Rovers have been used in this role since Lunokhod 1 landed on the Moon in 1970. While early rovers were remote controlled, communication latency with bodies beyond the Moon and the desire to improve mission effectiveness have resulted in increasing autonomy in planetary rovers. With an increase in autonomy, however, comes an increase in complexity. This can have a negative impact on the reliability of the rover system. With a fault-free system an unlikely prospect and human assistance millions of miles away, the rover must have a robust fault detection, isolation and recovery (FDIR) system. The need for comprehensive FDIR is demonstrated by the recent Chinese lunar rover, Yutu (or “Jade Rabbit”). Yutu was rendered immobile 42 days after landing and remained so for the duration of its operational life: 31 months. While its lifespan far exceeded its expected value, Yutu's inability to move severely impaired its ability to perform its mission. This clearly highlights the need for robust FDIR. A common approach to FDIR is through the generation and analysis of residuals. Output residuals may be obtained by comparing the outputs of the system with predictions of those outputs, obtained from a mathematical model of the system which is supplied with the system inputs. Output residuals allow simple detection and isolation of faults at the output of the system. Faults in earlier stages of the system, however, propagate through the system dynamics and can disperse amongst several of the outputs. This problem is exemplified by faults at the input, which can potentially excite every system state and thus manifest in every output residual. Methods exist for decoupling and analysing output residuals such that input faults may be isolated, however, these methods are complex and require comprehensive development and testing. A conceptually simpler approach is presented in this paper. Inverse simulation (InvSim) is a numerical method by which the inputs of a system are obtained for a desired output. It does so by using a Newton-Raphson algorithm to solve a non-linear model of the system for the input. When supplied with the outputs of a fault-afflicted system, InvSim produces the input required to drive a fault-free system to this output. The fault therefore manifests itself in this generated input signal. The InvSim-generated input may then be compared to the true system input to generate input residuals. Just as a fault at an output manifests itself in the residual for that output alone, a fault at an input similarly manifests itself only in the residual for that input. InvSim may also be used to generate residuals at other locations in the system, by considering distinct subsystems with their own inputs and outputs. This ability is tested comprehensively in this paper. Faults are applied to a simulated rover at a variety of locations within the system structure and residuals generated using both InvSim and conventional forward simulation. Residuals generated using InvSim are shown to facilitate detection and isolation of faults in several locations using simple analyses. By contrast, forward simulation requires the use of complex analytical methods such as structured residuals or adaptive thresholds

    RecycMe: The Ohio State University Recycling Phone Application

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    ENR 2367This paper is the blueprints for a recycling phone application for Ohio State called RecycMe. RecycMe is a mobile application that spreads knowledge about the environment and recycling through scanning QR codes. There is an element of competition that arises once the QR code is scanned as well to encourage the apps use. The goal is to spread awareness and increase environmentally friendly behaviors such as recycling.Academic Major: Environment, Economy, Development, and SustainabilityAcademic Major: Environmental ScienceAcademic Major: Geological SciencesAcademic Major: Natural Resources Managemen

    Non-structural protein-1 is required for West Nile virus replication complex formation and viral RNA synthesis

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    BACKGROUND: Flavivirus NS1 is a non-structural glycoprotein that is expressed on the cell surface and secreted into the extracellular space, where it acts as an antagonist of complement pathway activation. Despite its transit through the secretory pathway and intracellular localization in the lumen of the endoplasmic reticulum and Golgi vesicles, NS1 is as an essential gene for flavivirus replication. How NS1 modulates infection remains uncertain given that the viral RNA replication complex localizes to the cytosolic face of the endoplasmic reticulum. METHODS AND RESULTS: Using a trans-complementation assay, we show that viruses deleted for NS1 (∆-NS1) can be rescued by transgenic expression of NS1 from West Nile virus (WNV) or heterologous flaviviruses in the absence of adaptive mutations. In viral lifecycle experiments, we demonstrate that WNV NS1 was not required for virus attachment or input strand translation of the infectious viral RNA, but was necessary for negative and positive strand RNA synthesis and formation of the endoplasmic reticulum-associated replication complex. CONCLUSIONS: WNV RNA lacking intact NS1 genes was efficiently translated but failed to form canonical replication complexes at early times after infection, which resulted in an inability to replicate viral RNA. These results expand on prior studies with yellow fever and Kunjin viruses to show that flavivirus NS1 has an essential co-factor role in regulating replication complex formation and viral RNA synthesis

    Differential Requirements for COPI Coats in Formation of Replication Complexes among Three Genera of Picornaviridae

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    Picornavirus RNA replication requires the formation of replication complexes (RCs) consisting of virus-induced vesicles associated with viral nonstructural proteins and RNA. Brefeldin A (BFA) has been shown to strongly inhibit RNA replication of poliovirus but not of encephalomyocarditis virus (EMCV). Here, we demonstrate that the replication of parechovirus 1 (ParV1) is partly resistant to BFA, whereas echovirus 11 (EV11) replication is strongly inhibited. Since BFA inhibits COPI-dependent steps in endoplasmic reticulum (ER)-Golgi transport, we tested a hypothesis that different picornaviruses may have differential requirements for COPI in the formation of their RCs. Using immunofluorescence and cryo-immunoelectron microscopy we examined the association of a COPI component, ß-COP, with the RCs of EMCV, ParV1, and EV11. EMCV RCs did not contain ß-COP. In contrast, ß-COP appeared to be specifically distributed to the RCs of EV11. In ParV1-infected cells ß-COP was largely dispersed throughout the cytoplasm, with some being present in the RCs. These results suggest that there are differences in the involvement of COPI in the formation of the RCs of various picornaviruses, corresponding to their differential sensitivity to BFA. EMCV RCs are likely to be formed immediately after vesicle budding from the ER, prior to COPI association with membranes. ParV1 RCs are formed from COPI-containing membranes but COPI is unlikely to be directly involved in their formation, whereas formation of EV11 RCs appears to be dependent on COPI association with membranes

    Comparison of Long-Term Oral Anticoagulation Therapies Including Newly Approved Reversal Agent for Dabigatran

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    Anticoagulants are a well-known class of agents essential for the prevention of blood clots, which may further develop into deep vein thrombosis, pulmonary embolism or stroke. Individuals at a high risk of clotting, such as those with atrial fibrillation, multiple risk factors or recent hip/knee surgery, are in need of long-term anticoagulation therapy. The purpose of this review is to highlight the pros and cons for each available anticoagulant as well as discuss pivotal clinical trials that evaluated the safety and efficacy of these agents. Warfarin, the oldest anticoagulant, requires the patient to attend frequent appointments with a health care professional in order to test their international normalized ratio (INR). Newer anticoagulants, including dabigatran, rivaroxaban and apixaban, do not require frequent INR testing and have a quicker onset of action than warfarin, providing convenience for the patient. However, many health care professionals prefer warfarin because the INR may indicate its efficacy, its dosages can be easily changed and it is typically more affordable. Additionally, dabigatran may be chosen because it is the only one of these drugs that has a reversal agent, which can be utilized in the case of major bleeding or emergent surgery. There are many opportunities for pharmacists to impact patient outcomes in the anticoagulation therapy setting. From clinics to the community pharmacy setting, the pharmacist\u27s role in patient counseling and education is crucial in reducing mortality. Additionally, drug development is a growing market as reversal agents are needed for many of these newer anticoagulation therapies

    C43: Telehealth in the Emergency Department: Impact on Wait Times

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    Undergraduate nursing students investigated if implementing telehealth in the Emergency Department (ED) can help reduce wait times
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