302 research outputs found

    Energigräsutveckling i USA

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    Force/Vision Based Active Damping Control of Contact Transition in Dynamic Environments

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    When a manipulator interacts with objects with poorly damped oscillatory modes, undesired oscillations and bouncing may result. In this paper, we present a method for observer-based control of a rigid manipulator interacting with an environment with linear dynamics.The controller injects a desired damping into the environment dynamics, using both visual-and force sensing for stable control of the contact transition.Stability of the system is shown using an observer-based backstepping design method, and simulations are performed in order to validate the chosen approach

    Flexible Force-Vision Control for Surface Following using Multiple Cameras

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    A flexible method for six-degree-of-freedom combined vision/force control for interaction with a stiff uncalibrated environment is presented. An edge-based rigidbody tracker is used in an observer-based controller, and combined with a six-degree-of-freedom force- or impedance controller. The effect of error sources such as image space measurement noise and calibration errors are considered. Finally, the method is validated in simulations and a surface following experiment using an industrial robot

    Visual Position Tracking using Dual Quaternions with Hand-Eye Motion Constraints

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    In this paper a method for contour-based rigid body tracking with simultaneouscamera calibration is developed. The method works for a singleeye-in-hand camera with unknown hand-eye transformation,viewing a stationary object with unknown position. The method usesdual quaternions to express the relationship between the camera- andend-effector screws. It is shown how using the measured motion of therobot end-effector can improve the accuracy of theestimation, even if the relative position and orientation between sensorand actuator is completely unknown.The method is evaluated in simulations on images from a real-time 3D renderingsystem. The system is shown to be able to track the pose of rigid objects and changes in intrinsic camera parameters, using only rough initial values for the parameters. The method is finally validated in anexperiment using real images from a camera mounted on an industrial robot

    Persons or aliens? Making normative sense of non-citizens' legal standing in the U.S. and Germany.

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    This thesis aims to analyse the normative rationales behind non-citizens' legal standing in two liberal nation-states. The thesis takes the cosmopolitan and communitarian rationales as its theoretical starting point. Specific attention is given to the possibility of coherently combining the cosmopolitan and the communitarian rationales. The thesis analyses the actual legal standing of non-citizens in the U.S. and Germany and so links the political theoretical discourse to alienage jurisprudence. The conclusions drawn are that both the cosmopolitan and the communitarian rationales underlie non-citizens' legal standing. The treatment of noncitizens is fairly normatively coherent and in line with a weak cosmopolitan perspective. The thesis, however, identifies limited but important normative contradictions in the treatment of non-citizens and outlines, on a practical level, what is required to remedy this situation

    Posterior laryngitis: a disease with different aetiologies affecting health-related quality of life:a prospective case–control study

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    Background: Laryngo-pharyngeal reflux (LPR) is assumed to be the most common cause of posterior laryngitis (PL). Since LPR is found in healthy subjects, and PL patients are not improved by acid-reducing therapy, other aetiologies to PL must be considered. The aims of this study in PL were to investigate the prevalence of acid reflux in the proximal oesophagus and functional gastrointestinal symptoms, to analyse motilin levels in plasma, and to assess health-related quality of life (HRQOL) before and after treatment. Methods: Forty-six patients (26 women), with verified PL, median age 55 (IQR 41–68) years, were referred to oesophago-gastro-duodenoscopy and 24-h pH monitoring. Plasma motilin was analysed. The 36-item Short-Form questionnaire was completed at inclusion and at follow-up after 43±14 months, when also the Visual Analogue Scale for Irritable Bowel Syndrome was completed. Values were compared to controls. Treatment and relief of symptoms were noted from medical records. Results: Thirty-four percent had proximal acid reflux and 40% showed signs of distal reflux. Ninety-four percent received acid-reducing treatment, with total relief of symptoms in 17%. Patients with reflux symptoms had lower plasma motilin levels compared to patients without reflux symptoms (p = 0.021). The HRQOL was impaired at inclusion, but improved over time. Patients, especially men, had more functional gastrointestinal symptoms than controls. Conclusions: This study indicates that a minority of patients with PL has LPR and is cured by acid-reducing therapy. Disturbed plasma motilin levels and presence of functional gastrointestinal symptoms are found in PL. The impaired HRQOL improves over time

    Malmbanan Diaries

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    This booklet is a report for a case study visit during four day field trip, a group of nine PhD students and their supervisors – all part of the National Research School for Architecture and Planning in the Urban Landscape, APULA – set out to explore what may be considered the outback of Western Europe’s conurbations, the transnational region of Kiruna -Narvik.Both “remote” and “resourceful”, “threatened” and “thriving” (equally relative notions), this region seemed to offer possibilities to reflect upon many of the current tendencies influencing contemporary planning practice and research

    Impact of perioperative RSV or influenza infection on length of stay and risk of unplanned ICU admission in children: a case-control study

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    <p>Abstract</p> <p>Background</p> <p>Children with viral respiratory infections who undergo general anesthesia are at increased risk of respiratory complications. We investigated the impact of RSV and influenza infection on perioperative outcomes in children undergoing general anesthesia.</p> <p>Methods</p> <p>We performed a retrospective case-control study. All patients under the age of 18 years who underwent general anesthesia at our institution with confirmed RSV or influenza infection diagnosed within 24 hours following induction between October 2002 and September 2008 were identified. Controls were randomly selected and were matched by surgical procedure, age, and time of year in a ratio of three controls per case. The primary outcome was postoperative length of stay (LOS).</p> <p>Results</p> <p>Twenty-four patients with laboratory-confirmed RSV or influenza who underwent general anesthesia prior to diagnosis of viral infection were identified and matched to 72 controls. Thirteen cases had RSV and 11 had influenza. The median postoperative LOS was three days (intra-quartile range 1 to 8 days) for cases and two days (intra-quartile range 1 to 5 days) for controls. Patients with influenza had a longer postoperative LOS (p < 0.001) and patients with RSV or influenza were at increased risk of unplanned admission to the PICU (p = 0.04) than matched controls.</p> <p>Conclusions</p> <p>Our results suggest that children with evidence of influenza infection undergoing general anesthesia, even in the absence of symptoms previously thought to be associated with a high risk of complications, may have a longer postoperative hospital LOS when compared to matched controls. RSV and influenza infection was associated with an increased risk of unplanned PICU admission.</p

    Conditions for transformative learning for sustainable development: a theoretical review and approach

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    Continued unsustainability and surpassed planetary boundaries require not only scientific and technological advances, but deep and enduring social and cultural changes. The purpose of this article is to contribute a theoretical approach to understand conditions and constraints for societal change towards sustainable development. In order to break with unsustainable norms, habits, practices, and structures, there is a need for learning for transformation, not only adaption. Based on a critical literature review within the field of learning for sustainable development, our approach is a development of the concept of transformative learning, by integrating three additional dimensions—Institutional Structures, Social Practices, and Conflict Perspectives. This approach acknowledges conflicts on macro, meso, and micro levels, as well as structural and cultural constraints. It contends that transformative learning is processual, interactional, long-term, and cumbersome. It takes place within existing institutions and social practices, while also transcending them. The article adopts an interdisciplinary social science perspective that acknowledges the importance of transformative learning in order for communities, organizations, and individuals to be able to deal with global sustainability problems, acknowledging the societal and personal conflicts involved in such transformation
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