342 research outputs found

    Adaptive cancelation of self-generated sensory signals in a whisking robot

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    Sensory signals are often caused by one's own active movements. This raises a problem of discriminating between self-generated sensory signals and signals generated by the external world. Such discrimination is of general importance for robotic systems, where operational robustness is dependent on the correct interpretation of sensory signals. Here, we investigate this problem in the context of a whiskered robot. The whisker sensory signal comprises two components: one due to contact with an object (externally generated) and another due to active movement of the whisker (self-generated). We propose a solution to this discrimination problem based on adaptive noise cancelation, where the robot learns to predict the sensory consequences of its own movements using an adaptive filter. The filter inputs (copy of motor commands) are transformed by Laguerre functions instead of the often-used tapped-delay line, which reduces model order and, therefore, computational complexity. Results from a contact-detection task demonstrate that false positives are significantly reduced using the proposed scheme

    Justice-Forward Course Design

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    With shifting societal and learner needs, expectations, and experiences, course design must evolve to best support students in both adapting to and creating change. By incorporating the Toward a Liberated Learning Spirit (TALLS) model into backward course design, courses can be designed to encourage intellectual risk-taking and attend to diverse knowledge and ways of knowing that disrupt oppressive and colonizing practices in both content and structure. This article outlines the use of the TALLS model in the backward design of a Native Movement undergraduate course to showcase how courses can be developed for engagement, inclusivity, and active and justice-forward learning

    Structured smoking cessation training for health professionals on cardiology wards: a prospective study.

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    Background: Smoking is a major cardiovascular risk factor, and smoking cessation is imperative for patients hospitalised with a cardiovascular event. This study aimed to evaluate a systems-based approach to helping hospitalised smokers quit and to identify implementation barriers. Design: Prospective intervention study followed by qualitative analysis of staff interviews Methods: The prospective intervention study assessed the effects of implementing standard operating procedures (SOPs) for the provision of counselling and pharmacotherapy to smokers admitted to cardiology wards on counselling frequency. In addition, a qualitative analysis of staff interviews was undertaken to examine determinants of physician and nurse behaviour; this sought to understand barriers in terms of motivation, capability and/or opportunity. Results: A total of 150 smoking patients were included in the study (75 before and 75 after SOP implementation). Before the implementation of SOPs, the proportion of patients reporting to have received cessation counselling from physicians and nurses was 6.7% and 1.3%, respectively. Following SOP implementation, these proportions increased to 38.7% (p < 0.001) and 2.7% (p = 0.56), respectively. Qualitative analysis revealed that lack of motivation, e.g. role incongruence, appeared to be a major barrier. Conclusions: Introduction of a set of standard operating procedures for smoking cessation advice was effective with physicians but not nurses. Analysis of barriers to implementation highlighted lack of motivation rather than capability or opportunity as a major factor that would need to be addressed

    Hemophilia gene therapy knowledge and perceptions: Results of an international survey

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    Background Hemophilia gene therapy is a rapidly evolving therapeutic approach in which a number of programs are approaching clinical development completion. Objective The aim of this study was to evaluate knowledge and perceptions of a variety of health care practitioners and scientists about gene therapy for hemophilia. Methods This survey study was conducted February 1 to 18, 2019. Survey participants were members of the ISTH, European Hemophilia Consortium, European Hematology Association, or European Association for Hemophilia and Allied Disorders with valid email contacts. The online survey consisted of 36 questions covering demographic information, perceptions and knowledge of gene therapy for hemophilia, and educational preferences. Survey results were summarized using descriptive statistics. Results Of the 5117 survey recipients, 201 responded from 55 countries (4% response rate). Most respondents (66%) were physicians, and 59% were physicians directly involved in the care of people with hemophilia. Among physician respondents directly involved in hemophilia care, 35% lacked the ability to explain the science of adeno-associated viral gene therapy for hemophilia, and 40% indicated limited ability or lack of comfort answering patient questions about gene therapy for hemophilia based on clinical trial results to date. Overall, 75% of survey respondents answered 10 single-answer knowledge questions correctly, 13% incorrectly, and 12% were unsure of the correct answers. Conclusions This survey highlighted knowledge gaps and educational needs related to gene therapy for hemophilia and, along with other inputs, has informed the development of "Gene Therapy in Hemophilia: An ISTH Education Initiative.

    Engineering Temperature‐Dependent Carrier Concentration in Bulk Composite Materials via Temperature‐Dependent Fermi Level Offset

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    Precise control of carrier concentration in both bulk and thin‐film materials is crucial for many solid‐state devices, including photovoltaic cells, superconductors, and high mobility transistors. For applications that span a wide temperature range (thermoelectric power generation being a prime example) the optimal carrier concentration varies as a function of temperature. This work presents a modified modulation doping method to engineer the temperature dependence of the carrier concentration by incorporating a nanosize secondary phase that controls the temperature‐dependent doping in the bulk matrix. This study demonstrates this technique by de‐doping the heavily defect‐doped degenerate semiconductor GeTe, thereby enhancing its average power factor by 100% at low temperatures, with no deterioration at high temperatures. This can be a general method to improve the average thermoelectric performance of many other materials.Temperature‐dependent modulation doping is demonstrated in a GeTe–CuInTe2 composite material. Temperature‐dependent carrier concentration is achieved by controlling the temperature‐dependent Fermi level offset between the GeTe matrix and CuInTe2 inclusions. An enhanced average power factor over a wide temperature range is demonstrated.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141881/1/aenm201701623.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141881/2/aenm201701623-sup-0001-S1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141881/3/aenm201701623_am.pd

    Microdevices for extensional rheometry of low viscosity elastic liquids : a review

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    Extensional flows and the underlying stability/instability mechanisms are of extreme relevance to the efficient operation of inkjet printing, coating processes and drug delivery systems, as well as for the generation of micro droplets. The development of an extensional rheometer to characterize the extensional properties of low viscosity fluids has therefore stimulated great interest of researchers, particularly in the last decade. Microfluidics has proven to be an extraordinary working platform and different configurations of potential extensional microrheometers have been proposed. In this review, we present an overview of several successful designs, together with a critical assessment of their capabilities and limitations

    Foreign policy and political possibility

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    This article explores the relationship between foreign policy and political possibility in two parts. First, the relationship between foreign policy and political possibility is theorized around three analytical moments: political possibility is linked to the framing of conceivable, communicable and coercive foreign policy. Second, this framework is developed and demonstrated through a brief analysis of Coalition foreign policy in the War on Terror, considering American, British and Australian foreign policy between 2001 and 2003. This analysis dissects distinct and divergent Coalition foreign policies through a linked three-part conceptualization of political possibility. It enables an understanding of how the War on Terror was rendered possible through the construction of foreign policy in thinkable, resonant and ultimately dominant terms. The article concludes by looking to the wider analytical applicability of this particular theorization of the relationship between foreign policy and political possibility

    SABRE: A bio-inspired fault-tolerant electronic architecture

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    As electronic devices become increasingly complex, ensuring their reliable, fault-free operation is becoming correspondingly more challenging. It can be observed that, in spite of their complexity, biological systems are highly reliable and fault tolerant. Hence, we are motivated to take inspiration for biological systems in the design of electronic ones. In SABRE (self-healing cellular architectures for biologically inspired highly reliable electronic systems), we have designed a bio-inspired fault-tolerant hierarchical architecture for this purpose. As in biology, the foundation for the whole system is cellular in nature, with each cell able to detect faults in its operation and trigger intra-cellular or extra-cellular repair as required. At the next level in the hierarchy, arrays of cells are configured and controlled as function units in a transport triggered architecture (TTA), which is able to perform partial-dynamic reconfiguration to rectify problems that cannot be solved at the cellular level. Each TTA is, in turn, part of a larger multi-processor system which employs coarser grain reconfiguration to tolerate faults that cause a processor to fail. In this paper, we describe the details of operation of each layer of the SABRE hierarchy, and how these layers interact to provide a high systemic level of fault tolerance. © 2013 IOP Publishing Ltd

    Building safer robots: Safety driven control

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    In recent years there has been a concerted effort to address many of the safety issues associated with physical human-robot interaction (pHRI). However, a number of challenges remain. For personal robots, and those intended to operate in unstructured environments, the problem of safety is compounded. In this paper we argue that traditional system design techniques fail to capture the complexities associated with dynamic environments. We present an overview of our safety-driven control system and its implementation methodology. The methodology builds on traditional functional hazard analysis, with the addition of processes aimed at improving the safety of autonomous personal robots. This will be achieved with the use of a safety system developed during the hazard analysis stage. This safety system, called the safety protection system, will initially be used to verify that safety constraints, identified during hazard analysis, have been implemented appropriately. Subsequently it will serve as a high-level safety enforcer, by governing the actions of the robot and preventing the control layer from performing unsafe operations. To demonstrate the effectiveness of the design, a series of experiments have been conducted using a MobileRobots PeopleBot. Finally, results are presented demonstrating how faults injected into a controller can be consistently identified and handled by the safety protection system. © The Author(s) 2012
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