16,329 research outputs found

    Distributed Deep Learning for Question Answering

    Full text link
    This paper is an empirical study of the distributed deep learning for question answering subtasks: answer selection and question classification. Comparison studies of SGD, MSGD, ADADELTA, ADAGRAD, ADAM/ADAMAX, RMSPROP, DOWNPOUR and EASGD/EAMSGD algorithms have been presented. Experimental results show that the distributed framework based on the message passing interface can accelerate the convergence speed at a sublinear scale. This paper demonstrates the importance of distributed training. For example, with 48 workers, a 24x speedup is achievable for the answer selection task and running time is decreased from 138.2 hours to 5.81 hours, which will increase the productivity significantly.Comment: This paper will appear in the Proceeding of The 25th ACM International Conference on Information and Knowledge Management (CIKM 2016), Indianapolis, US

    Effective diffusion constant in a two dimensional medium of charged point scatterers

    Full text link
    We obtain exact results for the effective diffusion constant of a two dimensional Langevin tracer particle in the force field generated by charged point scatterers with quenched positions. We show that if the point scatterers have a screened Coulomb (Yukawa) potential and are uniformly and independently distributed then the effective diffusion constant obeys the Volgel-Fulcher-Tammann law where it vanishes. Exact results are also obtained for pure Coulomb scatterers frozen in an equilibrium configuration of the same temperature as that of the tracer.Comment: 9 pages IOP LaTex, no figure

    A computationally efficacious free-energy functional for studies of inhomogeneous liquid water

    Full text link
    We present an accurate equation of state for water based on a simple microscopic Hamiltonian, with only four parameters that are well-constrained by bulk experimental data. With one additional parameter for the range of interaction, this model yields a computationally efficient free-energy functional for inhomogeneous water which captures short-ranged correlations, cavitation energies and, with suitable long-range corrections, the non-linear dielectric response of water, making it an excellent candidate for studies of mesoscale water and for use in ab initio solvation methods.Comment: 6 pages, 5 figure

    Dynamical transition for a particle in a squared Gaussian potential

    Full text link
    We study the problem of a Brownian particle diffusing in finite dimensions in a potential given by ψ=ϕ2/2\psi= \phi^2/2 where ϕ\phi is Gaussian random field. Exact results for the diffusion constant in the high temperature phase are given in one and two dimensions and it is shown to vanish in a power-law fashion at the dynamical transition temperature. Our results are confronted with numerical simulations where the Gaussian field is constructed, in a standard way, as a sum over random Fourier modes. We show that when the number of Fourier modes is finite the low temperature diffusion constant becomes non-zero and has an Arrhenius form. Thus we have a simple model with a fully understood finite size scaling theory for the dynamical transition. In addition we analyse the nature of the anomalous diffusion in the low temperature regime and show that the anomalous exponent agrees with that predicted by a trap model.Comment: 18 pages, 4 figures .eps, JPA styl

    Perturbation theory for the effective diffusion constant in a medium of random scatterer

    Full text link
    We develop perturbation theory and physically motivated resummations of the perturbation theory for the problem of a tracer particle diffusing in a random media. The random media contains point scatterers of density ρ\rho uniformly distributed through out the material. The tracer is a Langevin particle subjected to the quenched random force generated by the scatterers. Via our perturbative analysis we determine when the random potential can be approximated by a Gaussian random potential. We also develop a self-similar renormalisation group approach based on thinning out the scatterers, this scheme is similar to that used with success for diffusion in Gaussian random potentials and agrees with known exact results. To assess the accuracy of this approximation scheme its predictions are confronted with results obtained by numerical simulation.Comment: 22 pages, 6 figures, IOP (J. Phys. A. style

    Glycine supplementation to low protein, amino acid-supplemented diets supports optimal performance of broiler chicks

    Get PDF
    Six experiments were conducted to determine the effects of low CP in diets for broilers and to evaluate limiting essential and nonessential amino acids (AA) in these diets. All experiments were conducted with Ross x Ross broilers in brooder batteries from 0 to 17 or 18 d posthatch. Treatments were replicated with 6 pens of either 5 or 6 broilers each. In Experiment (Exp.) 1, corn-soybean meal diets were formulated to 16.18, 17.68, 19.18, 20.68, or 22.18% CP. The 22.18% CP diet provided 1.23% Lys and 0.89% TSAA, met or exceeded all nutrient requirements of young broilers, and served as the positive control (PC) diet in all experiments. Increasing dietary CP linearly increased final BW, daily gain (ADG), and gain:feed (G:F) (P \u3c 0.005). In Exp. 2, additions of crystalline essential (EAA) or nonessential AA (NEAA) were added to the low CP diet to simulate the AA profile of the PC. Daily gain, final BW, and G:F were decreased (P \u3c 0.01) when CP was reduced, but the addition of the NEAA increased final BW, ADG, and G:F (P \u3c 0.07) to the level of broilers fed the PC. Addition of EAA alone was without effect. In Exp. 3, chicks fed diets with supplemental Glu, Ala, Asp, or Pro had reduced daily feed intake (ADFI), ADG, and final BW (P \u3c 0.05) compared with the PC diet. Addition of Gly or the combination of Gly, Glu, Asp, Ala, and Pro to the low CP diet increased G:F (P \u3c 0.01) compared with chicks fed PC, and ADG was not different from that of broilers fed the PC diet. In Exp. 4, chicks were fed either the PC diet, the low CP diet with Gly + Ser concentrations of 1.23, 1.35, 1.47, 1.59, 1.71, 1.83, 1.95, or 2.07%, or a 10th diet that contained 1.23% Gly + Ser and with Glu to equal the N concentration of the 2.07% Gly + Ser diet. Final BW, ADG, and G:F were increased linearly (P \u3c 0.001) as the concentration of dietary Gly + Ser was increased. Chicks fed the low CP diet with 2.07% Gly + Ser had growth performance that was not different from that of chicks fed the PC. The addition of Glu to the low CP diet was without effect. In Exp. 5, chicks were fed the PC with additions of 0, 0.15, or 0.30% Gly or the low CP diet containing 1.60, 1.72, 1.84, 1.96, 2.08, 2.20, or 2.32% Gly + Ser. Glycine addition to the PC had no effect, but Gly addition to the low CP diet increased G:F linearly (P \u3c 0.001). Growth performance of chicks fed the low CP diet with 2.32% Gly + Ser was equal to that of chicks fed the PC diet. In Exp. 6, chicks were fed the PC or the low CP diet containing 1.80, 1.95, 2.10, 2.25, 2.40, 2.55, 2.70, 2.85, or 3.00% Gly + Ser. Glycine addition to the low CP diet increased G:F linearly (P \u3c 0.001). In summary, low CP diets result in optimal growth of broilers with Gly + Ser levels of 2.44%. ©2006 Poultry Science Association, Inc

    Effect of protein and energy sources and bulk density of diets on growth performance of chicks

    Get PDF
    Four completely randomized designed experiments (EXP) were conducted to determine the effect of energy, amino acid (AA) levels, and bulk density of diets on growth performance of chicks fed diets containing corn (C) or cornstarch:dextrose (CD) as energy sources and soybean meal (SBM) or soy protein isolate (SPI) as protein sources. The chicks were fed C-SBM diets 6 to 8 d posthatching before allotment to treatment, and the assay periods ranged from 7 to 14 d. Initial weights were 86, 93, 94, and 71 g in EXP 1 to 4, respectively. Treatments were replicated 6 to 8 times with 4, 5, or 6 chicks per replicate. In EXP 1, the treatments were 1) CSBM (1.26% Lys and 3,200 kcal of ME/kg); 2) CD-SPI (1.26% Lys and 3,460 kcal of ME/kg); 3) CD-SPI (1.36% Lys and 3,460 kcal of ME/kg); and 4) CD-SPI (1.26% Lys and 3,200 kcal of ME/kg). The AA in all diets were increased in proportion to Lys. In EXP 2, chicks were fed C or CD as the energy source and SBM or SPI as the protein source in a 2 x 2 factorial arrangement. In EXP 3, the treatments were 1) C-SBM (1.26% Lys and 3,200 kcal of ME/kg); 2) CD-SPI (1.26% Lys and 3,200 kcal of ME/kg); 3) Diet 1 limit-fed to chicks consuming 90% of Diet 2; 4) Diet 2 limit-fed to chicks consuming 90% of Diet 2. In EXP 4, Diets 1 and 2 were the same as Diets 1 and 2 in EXP 3, but fed in mash or pelleted form. In all EXP, chicks with access ad libitum to diets with SPI had decreased (P \u3c 0.02) average daily gain (ADG) and feed intake (ADFI) compared with those with access ad libitum to diets with SBM. In EXP 2, feeding C- or CD-dextrose as the energy source had no effect (P \u3e 0.05) on ADG, ADFI, or gain:feed. In EXP 3, ADG was decreased in chicks fed the diets with SPI relative to those fed diets with SBM, but the decrease was much greater in chicks that had access ad libitum to feed (protein source x feed intake, P \u3c 0.01) than in those limit-fed to the same feed intake. In EXP 4, ADG, ADFI, and gain:feed were decreased (P \u3c 0.01) in chicks fed diets with SPI as the protein source. Pelleting increased (P \u3c 0.01) ADG, ADFI, and gain:feed regardless of protein source, but the increase was much greater in chicks fed the diets with SPI (protein source x feed form, P \u3c 0.01). Results from these EXP indicate that diets with SPI compared with SBM do not result in maximum growth performance in commercial broilers, and the problem may be due somewhat to nutrient deficiency but more to the physical form of the diet. ©2005 Poultry Science Association, Inc

    Urban heat island research in phoenix, Arizona

    Get PDF
    Over the past 60 years, metropolitan Phoenix, Arizona, has been among the fastest-growing urban areas in the United States, and this rapid urbanization has resulted in an urban heat island (UHI) of substantial size and intensity. During this time, an uncommon amount of UHI-specific research, relative to other cities in North America, occurred within its boundaries. This review investigates the possible reasons and motivations underpinning the large body of work, as well as summarizing specific themes, approaches, and theoretical contributions arising from such study. It is argued that several factors intrinsic to Phoenix were responsible for the prodigious output: strong applied urban climate research partnerships between several agencies (such as the academy, the National Weather Service, private energy firms, and municipal governments); a high-quality, long-standing network of urban meteorological stations allowing for relatively fine spatial resolution of near-surface temperature data; and a high level of public and media interest in the UHI. Three major research themes can be discerned: 1) theoretical contributions from documenting, modeling, and analyzing the physical characteristics of the UHI; 2) interdisciplinary investigation into its biophysical and social consequences; and 3) assessment and evaluation of several UHI mitigation techniques. Also examined herein is the successful implementation of sustainable urban climate policies within the metropolitan area. The authors note the importance of understanding and applying local research results during the policy formation process.</jats:p
    corecore