8,292 research outputs found

    A computer architecture for intelligent machines

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    The Theory of Intelligent Machines proposes a hierarchical organization for the functions of an autonomous robot based on the Principle of Increasing Precision With Decreasing Intelligence. An analytic formulation of this theory using information-theoretic measures of uncertainty for each level of the intelligent machine has been developed in recent years. A computer architecture that implements the lower two levels of the intelligent machine is presented. The architecture supports an event-driven programming paradigm that is independent of the underlying computer architecture and operating system. Details of Execution Level controllers for motion and vision systems are addressed, as well as the Petri net transducer software used to implement Coordination Level functions. Extensions to UNIX and VxWorks operating systems which enable the development of a heterogeneous, distributed application are described. A case study illustrates how this computer architecture integrates real-time and higher-level control of manipulator and vision systems

    Introduction aux Études critiques en autisme (ÉCA) issues de la recherche anglophone

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    Within the historic context of a distinct lack of autistic people’s representation in research, a body of emancipatory research is emerging under the banner of critical autism studies (CAS). The focus of CAS is the co-creation of scientific knowledge to produce research by and for the autistic community. Most CAS research emanates from the United Kingdom and Australia (e.g., Chown et al., 2017; Pellicano et al., 2014), with little present within Francophone academia in French as emancipatory design in disability research has only emerged since the 2010s. This paper aims to introduce CAS from the Anglophone academia. We begin by stating the fundamental principles of the neurodiversity movement in which CAS has taken root (Chamak, 2010; et al.; Nicolaidis, 2012). Next, we contrast the predominant medical model with the social model of disability (Chamak, 2010, Rosqvist et al., 2020). We then discuss CAS principles such as acknowledgement of power imbalances, recognition of autistic people’s meaningful input to research, and inclusiveness through adapting the research environment (Waltz 2009; Fletcher-Watson et al. 2019; Pickard et al., 2021; Rosqvist et al., 2019). We consider potential obstacles to CAS within the academic culture, such as lack of trusting relationships, practical and systemic barriers, and limited investment to support collaborative research (Pickard et al., 2021; Rosqvist et al., 2019). This paper concludes by discussing the need for a change in the language used to refer to autism (Fletcher-Watson et al., 2019; Woods, 2017) and environmental modifications to facilitate fair and socially just inclusion of neurodivergent people (Fletcher-Watson et al., 2019), within research and wider society

    Optimal Alignment Sensing of a Readout Mode Cleaner Cavity

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    Critically coupled resonant optical cavities are often used as mode cleaners in optical systems to improve the signal to noise ratio (SNR) of a signal that is encoded as an amplitude modulation of a laser beam. Achieving the best SNR requires maintaining the alignment of the mode cleaner relative to the laser beam on which the signal is encoded. An automatic alignment system which is primarily sensitive to the carrier field component of the beam will not, in general, provide optimal SNR. We present an approach that modifies traditional dither alignment sensing by applying a large amplitude modulation on the signal field, thereby producing error signals that are sensitive to the signal sideband field alignment. When used in conjunction with alignment actuators, this approach can improve the detected SNR; we demonstrate a factor of 3 improvement in the SNR of a kilometer-scale detector of the Laser Interferometer Gravitational-wave Observatory. This approach can be generalized to other types of alignment sensors

    Zero kinetic energy-pulsed field ionization and resonance enhanced multiphoton ionization photoelectron spectroscopy: Ionization dynamics of Rydberg states in HBr

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    The results of rotationally resolved resonance enhanced multiphoton ionization photoelectron spectroscopy and zero kinetic energy‐pulsed field ionization studies on HBr via various rotational levels of the F^ 1Δ_2 and f^ 3Δ_2 Rydberg states are reported. These studies lead to an accurate determination of the lowest ionization threshold as 94 098.9±1 cm^(−1). Observed rotational and spin–orbit branching ratios are compared to the results of ab initio calculations. The differences between theory and experiment highlight the dominant role of rotational and spin–orbit interactions for the dynamic properties of the high‐n Rydberg states involved in the pulsed field ionization process

    High-resolution Fourier-transform XUV photoabsorption spectroscopy of 14N15N

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    The first comprehensive high-resolution photoabsorption spectrum of 14N15N has been recorded using the Fourier-transform spectrometer attached to the Desirs beamline at the Soleil synchrotron. Observations are made in the extreme ultraviolet (XUV) and span 100,000-109,000 cm-1 (100-91.7 nm). The observed absorption lines have been assigned to 25 bands and reduced to a set of transition energies, f values, and linewidths. This analysis has verified the predictions of a theoretical model of N2 that simulates its photoabsorption and photodissociation cross section by solution of an isotopomer independent formulation of the coupled-channel Schroedinger equation. The mass dependence of predissociation linewidths and oscillator strengths is clearly evident and many local perturbations of transition energies, strengths, and widths within individual rotational series have been observed.Comment: 14 pages, 8 figures, one data archiv

    The Urban Political Ecology of Post-industrial Scottish Towns: Examining Greengairs and Ravenscraig

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    Urban ecological politics is shaped by both moments of concerted action and more silent perceptions and responses. Instead of only being evident in situations of organised protest, the politics of urban ecology is also manifested, in material and symbolic terms, in the daily life of the residents. The fragmentation of urban political ecology turns out to be an important element in the affirmation of post-political forms of urban governance. Those issues were the object of fieldwork research carried out in Greengairs and Ravenscraig, two towns in North Lanarkshire, near Glasgow, with the goal of unravelling the understanding and the coping mechanisms of environmentally deprived residents. The towns are permeated by a widespread, often dissimulated, political ecology that is nonetheless always present. Empirical results demonstrate that a more comprehensive handling of the political ecology of the urban is crucial in order to halt the sources of marginalisation and ecological degradation

    The spin-forbidden vacuum-ultraviolet absorption spectrum of <sup>14</sup>N<sup>15</sup>N

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    Photoabsorption spectra of 14N15N{}^{14}{\rm N}{}^{15}{\rm N} were recorded at high resolution with a vacuum-ultraviolet Fourier-Transform spectrometer fed by synchrotron radiation in the range 81 to 100 nm. The combination of high column density (3×10173\times 10^{17} cm2^{-2}) and low temperature (98 K) allowed for the recording of weak spin-forbidden absorption bands exciting levels of triplet character. The triplet states borrow intensity from 1Πu{}^1\Pi_u states of Rydberg and valence character while causing their predissociation. New predissociation linewidths and molecular constants are obtained for the states C3Πu(v=7,8,14,15,16,21)C\,{}^3\Pi_u(v=7,8,14,15,16,21), G3Πu(v=0,1,4)G\,{}^3\Pi_u(v=0,1,4), and F3Πu(v=0)F\,{}^3\Pi_u(v=0). The positions and widths of these levels are shown to be well-predicted by a coupled-Schroedinger equation model with empirical parameters based on experimental data on 14N2{}^{14}{\rm N}_2 and 15N2{}^{15}{\rm N}_2 triplet levels.Comment: 16 pages, 16 figure
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