3,455 research outputs found

    Scalable Compression of Deep Neural Networks

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    Deep neural networks generally involve some layers with mil- lions of parameters, making them difficult to be deployed and updated on devices with limited resources such as mobile phones and other smart embedded systems. In this paper, we propose a scalable representation of the network parameters, so that different applications can select the most suitable bit rate of the network based on their own storage constraints. Moreover, when a device needs to upgrade to a high-rate network, the existing low-rate network can be reused, and only some incremental data are needed to be downloaded. We first hierarchically quantize the weights of a pre-trained deep neural network to enforce weight sharing. Next, we adaptively select the bits assigned to each layer given the total bit budget. After that, we retrain the network to fine-tune the quantized centroids. Experimental results show that our method can achieve scalable compression with graceful degradation in the performance.Comment: 5 pages, 4 figures, ACM Multimedia 201

    Preparations for Independence and Financial Security in Later Life: A Conceptual Framework and Application to Canada

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    In this paper, we develop a conceptual framework to describe an individual's preparations for later life. Situated in the life course perspective, this provides a framework that invites a more comprehensive and systematic study of preparations for later life. It describes a dynamic process that portrays the interplay between social structure and human agency. Through its consideration of collective preparations (the public protection programs offered by the state), individual preparations (financial and non- financial), and the interplay between the two, this framework provides fresh insight into the existing literature on retirement planning, the timing of retirement, savings, and consumption behaviour in later life. Moreover, the model may be used to structure research questions, to guide policy decision making and to point the direction for the design and content of future research studies. While the purpose of this paper is primarily the development of a conceptual model, we draw on empirical examples from the 1991 Survey of Aging and Independence (SAI) to illustrate some aspects of the model to Canada. We conclude by suggesting a number of research and questions that may be generated from the model.retirement planning; savings; SAI

    Charge Renormalization, Effective Interactions, and Thermodynamics of Deionized Colloidal Suspensions

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    Thermodynamic properties of charge-stabilised colloidal suspensions depend sensitively on the effective charge of the macroions, which can be substantially lower than the bare charge in the case of strong counterion-macroion association. A theory of charge renormalization is proposed, combining an effective one-component model of charged colloids with a thermal criterion for distinguishing between free and associated counterions. The theory predicts, with minimal computational effort, osmotic pressures of deionized suspensions of highly charged colloids in close agreement with large-scale simulations of the primitive model.Comment: 15 pages, 7 figure

    STAT3 controls COL1A2 enhancer activation cooperatively with JunB, regulates type I collagen synthesis post-transcriptionally and is essential for lung myofibroblast differentiation

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    Fibroblast differentiation is key cellular process that underlies the process of fibrosis, a deadly complication of fibrotic diseases like Scleroderma (SSc). This transition coincides with the overproduction of Collagen type I (COL1) and other extracellular matrix proteins. High level expression of the collagen type 1α2 subunit (COL1A2), requires the engagement of a far upstream enhancer, whose activation is strongly dependent on the AP1 factor JunB. We now report that STAT3 also binds the COL1A2 enhancer and is essential for RNA polymerase recruitment, without affecting JunB binding. STAT3 is required for the increased COL1A2 expression observed in myofibroblasts.We also report that TGFβ partially activates STAT3 and show that inhibiting STAT3 potently blocks TGFβ signalling, matrix remodelling and TGFβ-induced myofibroblast differentiation. Activation of STAT3 with IL6 trans-signalling alone however only increased COL1A2 protein expression, leaving COL1A2 mRNA levels unchanged. Our results suggest that activated STAT3 is not the limiting factor for collagen enhancer activation in human lung fibroblasts. Yet, a certain threshold level of STAT3 38 activity is essential to support activation of the COL1A2 enhancer and TGFβ signalling in fibroblasts. We propose that STAT3 operates at the post-transcriptional as well as the transcriptional level

    Density-Functional Theory of Quantum Freezing: Sensitivity to Liquid-State Structure and Statistics

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    Density-functional theory is applied to compute the ground-state energies of quantum hard-sphere solids. The modified weighted-density approximation is used to map both the Bose and the Fermi solid onto a corresponding uniform Bose liquid, assuming negligible exchange for the Fermi solid. The required liquid-state input data are obtained from a paired phonon analysis and the Feynman approximation, connecting the static structure factor and the linear response function. The Fermi liquid is treated by the Wu-Feenberg cluster expansion, which approximately accounts for the effects of antisymmetry. Liquid-solid transitions for both systems are obtained with no adjustment of input data. Limited quantitative agreement with simulation indicates a need for further improvement of the liquid-state input through practical alternatives to the Feynman approximation.Comment: IOP-TeX, 21 pages + 7 figures, to appear, J. Phys.: Condens. Matte

    Stability of Colloidal Quasicrystals

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    Freezing of charge-stabilized colloidal suspensions and relative stabilities of crystals and quasicrystals are studied using thermodynamic perturbation theory. Macroion interactions are modelled by effective pair potentials combining electrostatic repulsion with polymer-depletion or van der Waals attraction. Comparing free energies -- counterion terms included -- for elementary crystals and rational approximants to icosahedral quasicrystals, parameters are identified for which one-component quasicrystals are stabilized by a compromise between packing entropy and cohesive energy.Comment: 6 pages, 4 figure

    Paramagnetic Breakdown of Superconductivity in Ultrasmall Metallic Grains

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    We study the magnetic-field-induced breakdown of superconductivity in nm-scale metal grains having a mean electron level spacing d≃Δ~d \simeq \tilde\Delta (bulk gap). Using a generalized variational BCS approach that yields good qualitative agreement with measured spectra, we argue that Pauli paramagnetism dominates orbital diamagnetism, as in the case of thin films in a parallel magnetic field. However, the first-order transition observed for the latter can be made continuous by finite size effects. The mean-field procedure of describing the system by a single pairing parameter Δ\Delta breaks down for d≃Δ~d \simeq \tilde\Delta.Comment: 4 pages of revtex, 3 postscript figures, uses psfrag.sty, epsfig.sty. Slightly revised and improved version, matching published versio
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