Bond graph model based control of robotic manipulators

The performance of robotic manipulators is critical to their widespread use in industry. As manipulators become faster, their potential productivity can rise thus improving the return on the investment required to purchase them. Improving accuracy, on the other hand, increases the range of tasks for which the manipulator is suitable. The speed and accuracy of a manipulator is partly determined by the capability of the algorithm used to control it. Whilst being a highly non-linear multiple input, multiple output device, however, most industrial controllers are derived on the basis that the robot is a series of independent, linear actuator+ link subsystems. The resulting independent joint controller is simple to design and implement but is limited in its performance as link interactions and the non-linear effects of centrifugal and Coriolis forces degrade the accuracy at high manipulator velocities. Improvements in the control of manipulators may be made by incorporating a mathematical model of the manipulator in the control algorithm. Control schemes such as `computed torque' incorporate an inverse model of the manipulator to calculate the input torques required to force the end-effector to follow a desired trajectory. The equations of motion required to implement these controllers are large and complex even for relatively simple manipulators. This thesis explores how bond graph representations of robotic manipulators may be used to automate the implementation of model based controllers. To provide a practical basis for this research the bond graph derived controllers are tested on an experimental rigid, planar, direct drive two-link manipulator. It is shown how the bondgraph for this manipulator, including d.c. motor actuators, can be constructed and used to derive the equations of motion of the manipulator automatically. The bond graph model is then validated by comparing simulations obtained using these equations of motion with experimental data

Clinical Sequencing Exploratory Research Consortium: Accelerating Evidence-Based Practice of Genomic Medicine

Despite rapid technical progress and demonstrable effectiveness for some types of diagnosis and therapy, much remains to be learned about clinical genome and exome sequencing (CGES) and its role within the practice of medicine. The Clinical Sequencing Exploratory Research (CSER) consortium includes 18 extramural research projects, one National Human Genome Research Institute (NHGRI) intramural project, and a coordinating center funded by the NHGRI and National Cancer Institute. The consortium is exploring analytic and clinical validity and utility, as well as the ethical, legal, and social implications of sequencing via multidisciplinary approaches; it has thus far recruited 5,577 participants across a spectrum of symptomatic and healthy children and adults by utilizing both germline and cancer sequencing. The CSER consortium is analyzing data and creating publically available procedures and tools related to participant preferences and consent, variant classification, disclosure and management of primary and secondary findings, health outcomes, and integration with electronic health records. Future research directions will refine measures of clinical utility of CGES in both germline and somatic testing, evaluate the use of CGES for screening in healthy individuals, explore the penetrance of pathogenic variants through extensive phenotyping, reduce discordances in public databases of genes and variants, examine social and ethnic disparities in the provision of genomics services, explore regulatory issues, and estimate the value and downstream costs of sequencing. The CSER consortium has established a shared community of research sites by using diverse approaches to pursue the evidence-based development of best practices in genomic medicine

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Comparing Notes: Recording and Criticism

This chapter charts the ways in which recording has changed the nature of music criticism. It both provides an overview of the history of recording and music criticism, from the advent of Edison’s Phonograph to the present day, and examines the issues arising from this new technology and the consequent transformation of critical thought and practice

Sedimentary processes and cold-water coral mini-mounds at the Ferrol canyon head, NW Iberian margin

The western Iberian margin has a complex morphology controlled by both geological and oceanographic processes. Compared to the submarine canyons in the southern part of this margin (e.g. Nazare and Setubal), the canyons in the northern part (e.g. Ferrol and A Corufia) have received little attention. This study maps the geomorphological features around the Ferrol canyon head and combines them with oceanographic observations to infer the sedimentary and oceanographic processes active in this area. Furthermore, the occurrence of a cold water coral (CWC) mini-mound province near the canyon head and the Ortegal Spur pockmark field is investigated with regard to seepage processes, oceanographic conditions and anthropogenic impact. The Ferrol canyon head and outer Ortegal Spur are characterized by erosional (erosional and abraded surfaces, contourite channels and furrows), depositional (contourite drifts and sediment waves) and mixed (contourite terrace) features, indicating a dominant control of bottom currents on the sedimentary processes. Bottom currents are related to the interaction of the canyon head topography with both the Mediterranean Outflow Water (MOW) slope current and with M2 internal tides associated to the interface (pycnocline) between Eastern North Atlantic Central Water (ENACW) and MOW. Due to this interaction, the Ferrol canyon head is subject to active sediment resuspension and forms a potential source area for the intermediate nepheloid layers along the NW Iberian upper slope. The CWC mini-mounds (1.9-2.7 m high and 75-141 m in diameter) occur between 400 and 560 m depth. Seismic facies signatures indicative of fluid-flow and morphometric analysis implies that larger CWC mini mounds adjacent to the pockmark field initiated by colonization of pre-existing pockmarks, while smaller more clustered mounds developed independently. The observed mini-mounds are relict features likely related to their position outside of the contemporary ENACW-MOW interface which favours CWC growth through (1) increased bottom currents, enhancing food supply and (2) the presence of a potential density envelope sigma(theta) = 27.35-27.65 kg/m(3), proposed to control coral larvae transport along the NE Atlantic margin. Alternatively, the lack of contemporary coral growth might be related to habitat destruction by bottom trawling. However, a preliminary age constraint reveals CWC growth occurred during the early Holocene, coeval to relict CWC mini mounds near canyon heads on the Armorican margin. Their existence suggests a regional shift in the NE Atlantic density profile where the ENACW-MOW interface occurred up to 200 m above its contemporary position

Proceedings of the Thirteenth International Society of Sports Nutrition (ISSN) Conference and Expo

Meeting Abstracts: Proceedings of the Thirteenth International Society of Sports Nutrition (ISSN) Conference and Expo Clearwater Beach, FL, USA. 9-11 June 201

Wider Still and Wider: British Music Criticism since the Second World War

This chapter provides the first historical examination of music criticism in Britain since the Second World War. In the process, it also challenges the simplistic prevailing view of this being a period of decline from a golden age in music criticism

Post-acute COVID-19 neuropsychiatric symptoms are not associated with ongoing nervous system injury

A proportion of patients infected with severe acute respiratory syndrome coronavirus 2 experience a range of neuropsychiatric symptoms months after infection, including cognitive deficits, depression and anxiety. The mechanisms underpinning such symptoms remain elusive. Recent research has demonstrated that nervous system injury can occur during COVID-19. Whether ongoing neural injury in the months after COVID-19 accounts for the ongoing or emergent neuropsychiatric symptoms is unclear. Within a large prospective cohort study of adult survivors who were hospitalized for severe acute respiratory syndrome coronavirus 2 infection, we analysed plasma markers of nervous system injury and astrocytic activation, measured 6 months post-infection: neurofilament light, glial fibrillary acidic protein and total tau protein. We assessed whether these markers were associated with the severity of the acute COVID-19 illness and with post-acute neuropsychiatric symptoms (as measured by the Patient Health Questionnaire for depression, the General Anxiety Disorder assessment for anxiety, the Montreal Cognitive Assessment for objective cognitive deficit and the cognitive items of the Patient Symptom Questionnaire for subjective cognitive deficit) at 6 months and 1 year post-hospital discharge from COVID-19. No robust associations were found between markers of nervous system injury and severity of acute COVID-19 (except for an association of small effect size between duration of admission and neurofilament light) nor with post-acute neuropsychiatric symptoms. These results suggest that ongoing neuropsychiatric symptoms are not due to ongoing neural injury