8,063 research outputs found

    Decision Making for Inconsistent Expert Judgments Using Negative Probabilities

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    In this paper we provide a simple random-variable example of inconsistent information, and analyze it using three different approaches: Bayesian, quantum-like, and negative probabilities. We then show that, at least for this particular example, both the Bayesian and the quantum-like approaches have less normative power than the negative probabilities one.Comment: 14 pages, revised version to appear in the Proceedings of the QI2013 (Quantum Interactions) conferenc

    Intense CIII] 1907,1909 emission from a strong Lyman continuum emitting galaxy

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    We have obtained the first complete ultraviolet (UV) spectrum of a strong Lyman continuum(LyC) emitter at low redshift -- the compact, low-metallicity, star-forming galaxy J1154+2443 -- with a Lyman continuum escape fraction of 46% discovered recently. The Space Telescope Imaging Spectrograph spectrum shows strong Lya and CIII] 1909 emission, as well as OIII] 1666. Our observations show that strong LyC emitters can have UV emission lines with a high equivalent width (e.g. EW(CIII])=11.7±2.9A˚=11.7 \pm 2.9 \AA rest-frame), although their equivalent widths should be reduced due to the loss of ionizing photons. The intrinsic ionizing photon production efficiency of J1154+2443 is high, log(ξion0)=25.56\log(\xi_{\rm ion}^0)=25.56 erg1^{-1} Hz, comparable to that of other recently discovered z0.30.4z \sim 0.3-0.4 LyC emitters. Combining our measurements and earlier determinations from the literature, we find a trend of increasing ξion0\xi_{\rm ion}^0 with increasing CIII] 1909 equivalent width, which can be understood by a combination of decreasing stellar population age and metallicity. Simple ionization and density-bounded photoionization models can explain the main observational features including the UV spectrum of J1154+2443.Comment: 5 pages, 4 figures. Accepted for publication in A&A Letter

    Approaching equilibrium and the distribution of clusters

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    We investigate the approach to stable and metastable equilibrium in Ising models using a cluster representation. The distribution of nucleation times is determined using the Metropolis algorithm and the corresponding ϕ4\phi^{4} model using Langevin dynamics. We find that the nucleation rate is suppressed at early times even after global variables such as the magnetization and energy have apparently reached their time independent values. The mean number of clusters whose size is comparable to the size of the nucleating droplet becomes time independent at about the same time that the nucleation rate reaches its constant value. We also find subtle structural differences between the nucleating droplets formed before and after apparent metastable equilibrium has been established.Comment: 22 pages, 16 figure

    The GREATS Hβ\beta+[OIII] Luminosity Function and Galaxy Properties at z8\mathbf{z\sim8}: Walking the Way of JWST

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    The James Webb Space Telescope will allow to spectroscopically study an unprecedented number of galaxies deep into the reionization era, notably by detecting [OIII] and Hβ\beta nebular emission lines. To efficiently prepare such observations, we photometrically select a large sample of galaxies at z8z\sim8 and study their rest-frame optical emission lines. Combining data from the GOODS Re-ionization Era wide-Area Treasury from Spitzer (GREATS) survey and from HST, we perform spectral energy distribution (SED) fitting, using synthetic SEDs from a large grid of photoionization models. The deep Spitzer/IRAC data combined with our models exploring a large parameter space enables to constrain the [OIII]+Hβ\beta fluxes and equivalent widths for our sample, as well as the average physical properties of z8z\sim8 galaxies, such as the ionizing photon production efficiency with log(ξion/erg1Hz)25.77\log(\xi_\mathrm{ion}/\mathrm{erg}^{-1}\hspace{1mm}\mathrm{Hz})\geq25.77. We find a relatively tight correlation between the [OIII]+Hβ\beta and UV luminosity, which we use to derive for the first time the [OIII]+Hβ\beta luminosity function (LF) at z8z\sim8. The z8z\sim8 [OIII]+Hβ\beta LF is higher at all luminosities compared to lower redshift, as opposed to the UV LF, due to an increase of the [OIII]+Hβ\beta luminosity at a given UV luminosity from z3z\sim3 to z8z\sim8. Finally, using the [OIII]+Hβ\beta LF, we make predictions for JWST/NIRSpec number counts of z8z\sim8 galaxies. We find that the current wide-area extragalactic legacy fields are too shallow to use JWST at maximal efficiency for z8z\sim8 spectroscopy even at 1hr depth and JWST pre-imaging to 30\gtrsim30 mag will be required.Comment: 13 pages, 9 figures, accepted for publication in MNRA

    Economic Feasibility Study of Photovoltaic Panels Installation by PVsyst 6.73 Simulator

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    The increasing pursuit of industry modernization presenting efficiency gains, productivity and cost reduction raises the discussion about the use of new technologies that promote, simultaneously, business sustainability and productive and economic efficiency for offshore companies, which operates in the Campos Basin, located at the municipality of Macaé, Rio de Janeiro State, Brazil. This paper presents an economic feasibility evaluation to use photovoltaic panels in order to measure the project costs and highlight its benefits; to this end, a local supplier was contacted to estimate a budget. The author ran the PVsyst 6.73 simulator to calculate the energy produced by the photovoltaic system and other parameters. Taking into account the Minimum Attractive Rate (MAR) of 8,3 percent, established by the board of directors, the results, by the Simple Payback and Discounted Payback (SPDP); Profitability Index (PI); Return on Investment (ROI); Net Present Value (NPV); and Internal Rate of Return (IRR) methods applied, proved the project is economically feasible and that this company has physical structure to install the equipment. As such, it is possible to have a great medium-and long-term financial economy, contributing to produce clean energy in the country

    Efeito das temperaturas e substratos sobre a germinação de Parkia gigantocarpa Ducke (Leguminosae-Mimosoideae).

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    Parkia gigantocarpa Ducke, conhecida popularmente como Fava- Atanã é uma espécie de grande porte, que pode ser utilizada para produção de celulose, recomposição de áreas degradadas e construção em geral. O objetivo desse estudo foi verificar a influência de diferentes substratos e temperaturas sobre a germinação de sementes de P. gigantocarpa. Realizou-se um experimento inteiramente casualizado em esquema fatorial 5 x 5, com 4 repetições de 25 sementes, por um período de 12 dias. Foram utilizados diferentes substratos (rolo de papel, areia, areia + serragem (1:1), vermiculita e fibra de coco triturada) em função de diferentes temperaturas constantes (15, 20, 25, 30 e 35ºC). Nas temperaturas de 15 e 20ºC houve inibição no desenvolvimento normal das plântulas, ocorrendo germinação de plântulas normais somente nas temperaturas de 25, 30 e 35°C. No geral, a temperatura de 30°C foi a mais favorável para a germinação das sementes de P. gigantocarpa, tendo como melhores substratos a areia, areia + serragem (1:1) e fibra de coco

    Eigenlogic: a Quantum View for Multiple-Valued and Fuzzy Systems

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    We propose a matrix model for two- and many-valued logic using families of observables in Hilbert space, the eigenvalues give the truth values of logical propositions where the atomic input proposition cases are represented by the respective eigenvectors. For binary logic using the truth values {0,1} logical observables are pairwise commuting projectors. For the truth values {+1,-1} the operator system is formally equivalent to that of a composite spin 1/2 system, the logical observables being isometries belonging to the Pauli group. Also in this approach fuzzy logic arises naturally when considering non-eigenvectors. The fuzzy membership function is obtained by the quantum mean value of the logical projector observable and turns out to be a probability measure in agreement with recent quantum cognition models. The analogy of many-valued logic with quantum angular momentum is then established. Logical observables for three-value logic are formulated as functions of the Lz observable of the orbital angular momentum l=1. The representative 3-valued 2-argument logical observables for the Min and Max connectives are explicitly obtained.Comment: 11 pages, 2 table
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