3,212 research outputs found

    Kinematic Basis of Emergent Energetics of Complex Dynamics

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    Stochastic kinematic description of a complex dynamics is shown to dictate an energetic and thermodynamic structure. An energy function φ(x)\varphi(x) emerges as the limit of the generalized, nonequilibrium free energy of a Markovian dynamics with vanishing fluctuations. In terms of the ∇φ\nabla\varphi and its orthogonal field γ(x)⊥∇φ\gamma(x)\perp\nabla\varphi, a general vector field b(x)b(x) can be decomposed into −D(x)∇φ+γ-D(x)\nabla\varphi+\gamma, where ∇⋅(ω(x)γ(x))=\nabla\cdot\big(\omega(x)\gamma(x)\big)= −∇ωD(x)∇φ-\nabla\omega D(x)\nabla\varphi. The matrix D(x)D(x) and scalar ω(x)\omega(x), two additional characteristics to the b(x)b(x) alone, represent the local geometry and density of states intrinsic to the statistical motion in the state space at xx. φ(x)\varphi(x) and ω(x)\omega(x) are interpreted as the emergent energy and degeneracy of the motion, with an energy balance equation dφ(x(t))/dt=γD−1γ−bD−1bd\varphi(x(t))/dt=\gamma D^{-1}\gamma-bD^{-1}b, reflecting the geometrical ∥D∇φ∥2+∥γ∥2=∥b∥2\|D\nabla\varphi\|^2+\|\gamma\|^2=\|b\|^2. The partition function employed in statistical mechanics and J. W. Gibbs' method of ensemble change naturally arise; a fluctuation-dissipation theorem is established via the two leading-order asymptotics of entropy production as ϵ→0\epsilon\to 0. The present theory provides a mathematical basis for P. W. Anderson's emergent behavior in the hierarchical structure of complexity science.Comment: 7 page

    Improved real-time imaging spectrometer

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    An improved AOTF-based imaging spectrometer that offers several advantages over prior art AOTF imaging spectrometers is presented. The ability to electronically set the bandpass wavelength provides observational flexibility. Various improvements in optical architecture provide simplified magnification variability, improved image resolution and light throughput efficiency and reduced sensitivity to ambient light. Two embodiments of the invention are: (1) operation in the visible/near-infrared domain of wavelength range 0.48 to 0.76 microns; and (2) infrared configuration which operates in the wavelength range of 1.2 to 2.5 microns

    Improved Antireflection Properties of an Optical Film Surface with Mixing Conical Subwavelength Structures

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    Based on finite difference time domain method, an optical film surface with mixing conical subwavelength structures is numerically investigated to improve antireflection property. The mixing conical subwavelength structure is combined with the pure periodic conical subwavelength structures and the added small conical structures in the gap between the pure periodic conical subwavelength structures. The antireflection properties of two types of subwavelength structures with different aspect ratios in spectral range of 400–800 nm are analyzed and compared. It is shown that, for the mixing type, the average reflectance is decreased and the variances of the reflectance are evidently smaller. When the added structure with a better aspect ratio exists, the average reflectance of the surface can be below 0.30%. Obviously, the antireflection properties of the optical film surface with mixing conical subwavelength structures can be improved

    Noninvasive prediction of Blood Lactate through a machine learning-based approach.

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    We hypothesized that blood lactate concentration([Lac]blood) is a function of cardiopulmonary variables, exercise intensity and some anthropometric elements during aerobic exercise. This investigation aimed to establish a mathematical model to estimate [Lac]blood noninvasively during constant work rate (CWR) exercise of various intensities. 31 healthy participants were recruited and each underwent 4 cardiopulmonary exercise tests: one incremental and three CWR tests (low: 35% of peak work rate for 15 min, moderate: 60% 10 min and high: 90% 4 min). At the end of each CWR test, venous blood was sampled to determine [Lac]blood. 31 trios of CWR tests were employed to construct the mathematical model, which utilized exponential regression combined with Taylor expansion. Good fitting was achieved when the conditions of low and moderate intensity were put in one model; high-intensity in another. Standard deviation of fitting error in the former condition is 0.52; in the latter is 1.82 mmol/liter. Weighting analysis demonstrated that, besides heart rate, respiratory variables are required in the estimation of [Lac]blood in the model of low/moderate intensity. In conclusion, by measuring noninvasive cardio-respiratory parameters, [Lac]blood during CWR exercise can be determined with good accuracy. This should have application in endurance training and future exercise industry
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