1,234 research outputs found

    A dynamical system approach to realtime obstacle avoidance

    Get PDF
    This paper presents a novel approach to real-time obstacle avoidance based on Dynamical Systems (DS) that ensures impenetrability of multiple convex shaped objects. The proposed method can be applied to perform obstacle avoidance in Cartesian and Joint spaces and using both autonomous and non-autonomous DS-based controllers. Obstacle avoidance proceeds by modulating the original dynamics of the controller. The modulation is parameterizable and allows to determine a safety margin and to increase the robot's reactiveness in the face of uncertainty in the localization of the obstacle. The method is validated in simulation on different types of DS including locally and globally asymptotically stable DS, autonomous and non-autonomous DS, limit cycles, and unstable DS. Further, we verify it in several robot experiments on the 7 degrees of freedom Barrett WAM ar

    Conceptual Modeling of the Impact of Smart Cities on Household Energy Consumption

    Get PDF
    AbstractSmart cities provide citizens with information on various urban services and allow them to track the impact of their resource consumption on the overall sustainability of their city. The premise of smart cities is that with improved access to information on resource consumption, residents make better use of those resources, resulting in increased sustainability of the city.This paper explores the influence of the smart city technologies on individuals’ resource consumption behavior, in particular on energy consumption, aiming at achieving environmentally sustainable development. This approach combines systems thinking with existing social science theories, such as cognitive and learning theories, to explore the impact of smart city information on individual decision-making and behavioral change. Using a CLIOS (complex, large-scale, interconnected, open, and sociotechnical) model, a conceptual soft systems model, the paper explores the impact of smart city technologies on behavioral change of households with regards to energy consumption

    Comparative evaluation of approaches in T.4.1-4.3 and working definition of adaptive module

    Get PDF
    The goal of this deliverable is two-fold: (1) to present and compare different approaches towards learning and encoding movements us- ing dynamical systems that have been developed by the AMARSi partners (in the past during the first 6 months of the project), and (2) to analyze their suitability to be used as adaptive modules, i.e. as building blocks for the complete architecture that will be devel- oped in the project. The document presents a total of eight approaches, in two groups: modules for discrete movements (i.e. with a clear goal where the movement stops) and for rhythmic movements (i.e. which exhibit periodicity). The basic formulation of each approach is presented together with some illustrative simulation results. Key character- istics such as the type of dynamical behavior, learning algorithm, generalization properties, stability analysis are then discussed for each approach. We then make a comparative analysis of the different approaches by comparing these characteristics and discussing their suitability for the AMARSi project

    Contribution of interleukin-11 and prostaglandin(s) in lipopolysaccharide-induced bone resorption in vivo

    Full text link
    Thesis (M.S.D.)--Boston University, Henry M. Goldman School of Dental Medicine, 2002 (Periodontology and Oral Biology).Includes bibliographical references (leaves 58-73).We previously demonstrated that interleukin- I (IL-1) and tumor necrosis factor (TNF) activities only partially account for calvarial bone resorption induced by local application of lipopolysaccharide (LPS) in mice. The present study was undertaken to determine the role and relative contribution of IL-11 and prostaglandin(s) (PGs) in LPS-induced bone resorption in vivo. One-time dose of LPS was injected into the subcutaneous tissue overlying the calvariae of IL-lRi- 1 - TNFRp5S-1--IL-1Rl _1 _ and wild-type mice. Mice were then treated with injections of anti-It -11 monoclonal antibody (mAb ), indomethacin or PBS and sacrificed 5 days later. Histological sections stained for TRAP were quantified by histomorphometric analysis. At low dose of LPS (100 μg/mouse), the percentage of bone surface covered by osteoclasts was found similar in three strains of mice. The increase was reduced by 50% with anti-IL-11 mAb and by 60% with indomethacin. At higher doses of LPS (500 μg/mouse), we found an 8-fold increase in wild type and 5-fold in IL-lRl _1 _ and TNFRp55-1--IL-1Rl _1 _ mice after normalizing with the value from saline+PBS control group in the same strain of mice. The increase was reduced by 63 and 78% in wildtype mice, and by about 73 and 84% in IL-lRi- 1 - and TNFRp5S-1--IL-1R1_1 _ mice treated with anti-IL-11 mAb or indomethacin respectively. Our findings suggest that in vivo at low-dose (100 μg/mouse), LPS-induced bone resorption is mediated ... [TRUNCATED

    Protective effects of gabapentin against the seizure susceptibility and comorbid behavioral abnormalities in the early socially isolated mice

    Get PDF
    Adolescence is a pivotal period of brain development during lifespan, which is sensitive to stress exposure. Early social isolation stress (SIS) is known to provoke a variety of psychiatric comorbidities as well as seizure risk. Psychiatric comorbidities present challenging dilemmas for treatment and management in people with seizure disorders. In this study, we aimed to investigate whether gabapentin (GBP) as an anti-epileptic drug is able to alleviate the seizure activity as well as comorbid behavioral abnormalities in socially isolated mice. Results showed that early SIS induced proconvulsant effects along with depressive, aggressive and anxiety-like behaviors. Whereas the administration of both acute and chronic GBP at sub-effective doses produced no alterations in the behavioral profile of socially conditioned counterparts the same treatments effectively reversed the seizure susceptibility to pentylenetetrazole and behavioral deficits in isolated mice. Results of the study indicate that 1) Early SIS could be considered as an animal model of psychosocial stress to investigate the psychiatric comorbidities in seizure disorders, 2) Chronic administration of low dose GBP prevented the shaping of behavioral abnormalities in adulthood, 3) Chronic administration of low dose GBP produced no negative behavioral effects in socially conditioned mice suggesting the safety of the drug, 4) Gabapentin at low doses may be considered as an agent for management of epilepsy in individuals with psychiatric comorbidities

    Neural Learning of Vector Fields for Encoding Stable Dynamical Systems

    Get PDF
    Lemme A, Reinhart F, Neumann K, Steil JJ. Neural Learning of Vector Fields for Encoding Stable Dynamical Systems. Neurocomputing. 2014;141:3-14

    Searching for the Perfect Solution: International Dispute Resolution and the New World Trade Organization

    Get PDF
    This Note discusses the effects of the Final Act Embodying the Results of the Uruguay Round on resolving international trade disputes. Through a comparison of the old GATT system of dispute resolution and the new system created by the World Trade Organization, this Note highlights some of GATT\u27s major flaws and analyzes the WTO\u27s attempts to fix these flaws. The creation of the Dispute Settlement Understanding, in particular, seeks to fix problems such as Contracting Parties\u27 lack of compliance by interjecting principles of legalism into an arena historically guided by principles of diplomacy and compromise. An analysis of this new dispute resolution mechanism as applied to the banana wars, however, concludes that while many changes have been made to improve the international dispute resolution process, little has been done to ensure just results

    NMDA RECEPTORS ARE INVOLVED IN THE ANTIDEPRESSANT-LIKE EFFECTS OF CAPSAICIN FOLLOWING AMPHETAMINE WITHDRAWAL IN MALE MICE

    Get PDF
    Abstract—Amphetamine withdrawal (AW) is accompanied by diminished pleasure and depression which plays a key role in drug relapse and addictive behaviors. There is no effi- cient treatment for AW-induced depression and underpinning mechanisms were not well determined. Considering both transient receptor potential cation channel, subfamily V, member 1 (TRPV1) and N-Methyl-D-aspartate (NMDA) receptors contribute to pathophysiology of mood and addictive disorders, in this study, we investigated the role of TRPV1 and NMDA receptors in mediating depressive-like behaviors following AW in male mice. Results revealed that administration of capsaicin, TRPV1 agonist, (100 lg/mouse, i.c.v.) and MK-801, NMDA receptor antagonist (0.005 mg/kg, i.p.) reversed AW-induced depressive-like behaviors in forced swimming test (FST) and splash test with no effect on animals’ locomotion. Co-administration of sub-effective doses of MK-801 (0.001 mg/kg, i.p.) and capsaicin (10 lg/mouse, i.c.v) exerted antidepressant-like effects in behavioral tests. Capsazepine, TRPV1 antagonist, (100 lg/mouse, i.c.v) and NMDA, NMDA receptor agonist (7.5 mg/kg, i.p.) abolished the effects of capsaicin and MK801, respectively. None of aforementioned treatments had any effect on behavior of control animals. Collectively, our findings showed that activation of TRPV1 and blockade of NMDA receptors produced antidepressant-like effects in male mice following AW, and these receptors are involved in AW-induced depressive-like behaviors. Further, we found that rapid antidepressant-like effects of capsaicin in FST and splash test are partly mediated by NMDA receptors. � 2016 Published by Elsevier Ltd on behalf of IBRO
    corecore