10,698 research outputs found

    COORDINATION OF LEADER-FOLLOWER MULTI-AGENT SYSTEM WITH TIME-VARYING OBJECTIVE FUNCTION

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    This thesis aims to introduce a new framework for the distributed control of multi-agent systems with adjustable swarm control objectives. Our goal is twofold: 1) to provide an overview to how time-varying objectives in the control of autonomous systems may be applied to the distributed control of multi-agent systems with variable autonomy level, and 2) to introduce a framework to incorporate the proposed concept to fundamental swarm behaviors such as aggregation and leader tracking. Leader-follower multi-agent systems are considered in this study, and a general form of time-dependent artificial potential function is proposed to describe the varying objectives of the system in the case of complete information exchange. Using Lyapunov methods, the stability and boundedness of the agents\u27 trajectories under single order and higher order dynamics are analyzed. Illustrative numerical simulations are presented to demonstrate the validity of our results. Then, we extend these results for multi-agent systems with limited information exchange and switching communication topology. The first steps of the realization of an experimental framework have been made with the ultimate goal of verifying the simulation results in practice

    Local Power to Tax and Devolution: An Empirical Assessment of the French Constitutional Reform

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    The article explores the content and consequences of the French constitutional reform of March 2003. Among the objectives of that reform, one is to preserve the tax autonomy for the local public sector; another is to ensure that the coming wave of devolution of competencies to decentralised levels of government will be adequately financed. These constitutional safeguards are assessed and they prove to be somewhat counterproductive, as if the recourse to the higher level of juridical norms could not replace the legislative level when reforms of local public finance, however difficult, have to be conducted.Central government, Constitutional reform, France, Local public sector, Local taxation, National grants.

    User-centered design of a dynamic-autonomy remote interaction concept for manipulation-capable robots to assist elderly people in the home

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    In this article, we describe the development of a human-robot interaction concept for service robots to assist elderly people in the home with physical tasks. Our approach is based on the insight that robots are not yet able to handle all tasks autonomously with sufficient reliability in the complex and heterogeneous environments of private homes. We therefore employ remote human operators to assist on tasks a robot cannot handle completely autonomously. Our development methodology was user-centric and iterative, with six user studies carried out at various stages involving a total of 241 participants. The concept is under implementation on the Care-O-bot 3 robotic platform. The main contributions of this article are (1) the results of a survey in form of a ranking of the demands of elderly people and informal caregivers for a range of 25 robot services, (2) the results of an ethnography investigating the suitability of emergency teleassistance and telemedical centers for incorporating robotic teleassistance, and (3) a user-validated human-robot interaction concept with three user roles and corresponding three user interfaces designed as a solution to the problem of engineering reliable service robots for home environments

    Recommender systems and their ethical challenges

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    This article presents the first, systematic analysis of the ethical challenges posed by recommender systems through a literature review. The article identifies six areas of concern, and maps them onto a proposed taxonomy of different kinds of ethical impact. The analysis uncovers a gap in the literature: currently user-centred approaches do not consider the interests of a variety of other stakeholders—as opposed to just the receivers of a recommendation—in assessing the ethical impacts of a recommender system

    Stairs Detection for Enhancing Wheelchair Capabilities Based on Radar Sensors

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    Powered wheelchair users encounter barriers to their mobility everyday. Entering a building with non barrier-free areas can massively impact the user mobility related activities. There are a few commercial devices and some experimental that can climb stairs using for instance adaptive wheels with joints or caterpillar drive. These systems rely on the use for sensing and control. For safe automated obstacle crossing, a robust and environment invariant detection of the surrounding is necessary. Radar may prove to be a suitable sensor for its capability to handle harsh outdoor environmental conditions. In this paper, we introduce a mirror based two dimensional Frequency-Modulated Continuous-Wave (FMCW) radar scanner for stair detection. A radar image based stair dimensioning approach is presented and tested under laboratory and realistic conditions.Comment: 5 pages, Accepted and presented in 2017 IEEE 6th Global Conference on Consumer Electronics (GCCE 2017

    Dual-band substrate integrated waveguide textile antenna with integrated solar harvester

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    A dual-band wearable textile antenna based on substrate integrated waveguide technology is presented for operation in the [2.4-2.4835]-GHz Industrial, Scientific and Medical band and the [2.5-2.69]-GHz 4G LTE band 7. The antenna features an integrated flexible solar harvesting system, consisting of a flexible solar cell, a power management system, and energy storage. All these components are judiciously positioned on the antenna platform in order not to affect its radiation performance. The measured reflection coefficients and radiation characteristics after bending and deploying the antenna on a human body prove that the antenna is well suited for on-body use. A measured on-body antenna gain and radiation efficiency of 5.0 dBi and 89% are realized. Measurements in a real-life situation have demonstrated the ability to scavenge a maximum of 53 mW by means of a single integrated flexible solar cell

    Time in the ontology of Cornelius Castoriadis

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    We can locate the problematic of time within three philosophical questions, which respectively designate three central areas of philosophical reflection and contemplation. These are: 1) The ontological question, i.e. 'what is being?' 2) The epistemological question, i.e. 'what can we know with certainty?' 3) The existential question, i.e. 'what is the meaning of existence?' These three questions, which are philosophical, but also scientific and political, as they underline the political and moral question of truth and justice, arise from the phenomenon of time, the irreversible constant flow of phenomena that undermines every claim to absolute knowledge. The purpose of this essay is to illuminate the importance of time for philosophical thought and, more generally, for human social and psychical life, in the context of the ontology of Cornelius Castoriadis. Castoriadis, who asserted that " being is time – and not in the horizon of time " , correlated history to society and being to temporality within the social-historical stratum, the ontological plane created by human existence, where " existence is signification ". Time is interpreted as the creation and destruction of forms in a magmatic, layered with a non-regular stratification, reality, where the social-historical manifests as the creation of collective human activity, in the manner of social imaginary significations. This notion of temporality is accompanied by a profound criticism of traditional rationalistic philosophy, to which Castoriadis assigns the name 'ensemblistic/identitary', that highlights the necessity of a new, magmatic ontology, based on the primacy of time

    Overcoming barriers and increasing independence: service robots for elderly and disabled people

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    This paper discusses the potential for service robots to overcome barriers and increase independence of elderly and disabled people. It includes a brief overview of the existing uses of service robots by disabled and elderly people and advances in technology which will make new uses possible and provides suggestions for some of these new applications. The paper also considers the design and other conditions to be met for user acceptance. It also discusses the complementarity of assistive service robots and personal assistance and considers the types of applications and users for which service robots are and are not suitable
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