6,065 research outputs found

    Methodological Flaws in Cognitive Animat Research

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    In the field of convergence between research in autonomous machine construction and biological systems understanding it is usually argued that building robots for research on auton- omy by replicating extant animals is a valuable strategy for engineering autonomous intelligent systems. In this paper we will address the very issue of animat construction, the ratio- nale behind this, their current implementations and the value they are producing. It will be shown that current activity, as it is done today, is deeply flawed and useless as research in the science and engineering of autonomy

    The MMO problem

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    We consider a two polynomials analogue of the polynomial interpolation problem. Namely, we consider the Mixing Modular Operations (MMO) problem of recovering two polynomials fZp[x]f\in \Z_p[x] and gZq[x]g\in \Z_q[x] of known degree, where pp and qq are two (un)known positive integers, from the values of f(t)modp+g(t)modqf(t)\bmod p + g(t)\bmod q at polynomially many points tZt \in \Z. We show that if pp and qq are known, the MMO problem is equivalent to computing a close vector in a lattice with respect to the infinity norm. We also implemented in the SAGE system a heuristic polynomial-time algorithm. If pp and qq are kept secret, we do not know how to solve this problem. This problem is motivated by several potential cryptographic applications.Comment: Submitted to Interantaional Symposium on Symbolic and Algebraic Computation (ISSAC) 201

    Coherent absorption and enhanced photoluminescence in thin layers of nanorods

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    We demonstrate a large light absorptance (80%) in a nanometric layer of quantum dots in rods (QRs) with a thickness of 23 nm. This behavior is explained in terms of the coherent absorption by interference of the light incident at a certain angle onto the very thin QR layer. We exploit this coherent light absorption to enhance the photoluminescent emission from the QRs. Up to a seven- and fivefold enhancement of the photoluminescence is observed for p- and s-polarized incident light, respectively.Comment: Physical Review B 201

    Algorithm for efficient 3D reconstruction of outdoor environments using mobile robots

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    In this paper, an algorithm for the reconstruction of an outdoor environment using a mobile robot is presented. The focus of this algorithm is making the mapping process efficient by capturing the greatest amount of information on every scan, ensuring at the same time that the overall quality of the resulting 3D model of the environment complies with the specified standards. With respect to existing approaches, the proposed approach is an innovation since there are very few information based methods for outdoor reconstruction that use resulting model quality and trajectory cost estimation as criteria for view planning

    Aerodynamic shape optimization of a 3D wing via volumetric B-Splines

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    This paper shows a gradient-based aerodynamic shape optimization of a threedimensional wing using volumetric B-Splines. The wing is enclosed in a volumetric parallelepiped, commonly referred as control box, which can be seen as a rubber box that deforms the enclosed space. The deformation of the wing is provided by the manipulation of the control points, where the gradients are calculated using the continuous adjoint solution. This technique can be applied to arbitrary three dimensional complex designs and provides some advantages over other traditional geometry parameterization methods, such as deformation locality and the ability to handle some geometric constraints

    Interaction and coherence of a plasmon-exciton polariton condensate

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    Polaritons are quasiparticles arising from the strong coupling of electromagnetic waves in cavities and dipolar oscillations in a material medium. In this framework, localized surface plasmon in metallic nanoparticles defining optical nanocavities have attracted increasing interests in the last decade. This interest results from their sub-diffraction mode volume, which offers access to extremely high photonic densities by exploiting strong scattering cross-sections. However, high absorption losses in metals have hindered the observation of collective coherent phenomena, such as condensation. In this work we demonstrate the formation of a non-equilibrium room temperature plasmon-exciton-polariton condensate with a long range spatial coherence, extending a hundred of microns, well over the excitation area, by coupling Frenkel excitons in organic molecules to a multipolar mode in a lattice of plasmonic nanoparticles. Time-resolved experiments evidence the picosecond dynamics of the condensate and a sizeable blueshift, thus measuring for the first time the effect of polariton interactions in plasmonic cavities. Our results pave the way to the observation of room temperature superfluidity and novel nonlinear phenomena in plasmonic systems, challenging the common belief that absorption losses in metals prevent the realization of macroscopic quantum states.Comment: 23 pages, 5 figures, SI 7 pages, 5 figure
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