504 research outputs found

    Estudi comparatiu de sistemes de producció d'energia tèrmica per a una guarderia al Prat de Llogregat

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    Estudi comparatiu de diferents sistemes de producció d’energia tèrmica (calderes de gas, energia solar tèrmica, bomba de calor geotèrmica, caldera de biomassa i motor de cogeneració de gas) per a un sistema de calefacció i ACS d’una guarderia en el Prat de Llobregat

    Fuel cell on-site integrated energy system parametric analysis of a residential complex

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    A parametric energy-use analysis was performed for a large apartment complex served by a fuel cell on-site integrated energy system (OS/IES). The variables parameterized include operating characteristics for four phosphoric acid fuel cells, eight OS/IES energy recovery systems, and four climatic locations. The annual fuel consumption for selected parametric combinations are presented and a breakeven economic analysis is presented for one parametric combination. The results show fuel cell electrical efficiency and system component choice have the greatest effect on annual fuel consumption; fuel cell thermal efficiency and geographic location have less of an effect

    Tamagawa numbers of polarized algebraic varieties

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    Let L=(L,v){\cal L} = (L, \| \cdot \|_v) be an ample metrized invertible sheaf on a smooth quasi-projective algebraic variety VV defined over a number field. Denote by N(V,L,B)N(V,{\cal L},B) the number of rational points in VV having L{\cal L}-height B\leq B. We consider the problem of a geometric and arithmetic interpretation of the asymptotic for N(V,L,B)N(V,{\cal L},B) as BB \to \infty in connection with recent conjectures of Fujita concerning the Minimal Model Program for polarized algebraic varieties. We introduce the notions of L{\cal L}-primitive varieties and L{\cal L}-primitive fibrations. For L{\cal L}-primitive varieties VV over FF we propose a method to define an adelic Tamagawa number τL(V)\tau_{\cal L}(V) which is a generalization of the Tamagawa number τ(V)\tau(V) introduced by Peyre for smooth Fano varieties. Our method allows us to construct Tamagawa numbers for QQ-Fano varieties with at worst canonical singularities. In a series of examples of smooth polarized varieties and singular Fano varieties we show that our Tamagawa numbers express the dependence of the asymptotic of N(V,L,B)N(V,{\cal L},B) on the choice of vv-adic metrics on L{\cal L}.Comment: 54 pages, minor correction

    Improved seismic hazard model with application to probabilistic seismic demand analysis

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    An improved seismic hazard model for use in performance-based earthquake engineering is presented. The model is an improved approximation from the so-called 'power law' model, which is linear in log-log space. The mathematics of the model and uncertainty incorporation is briefly discussed. Various means of fitting the approximation to hazard data derived from probabilistic seismic hazard analysis are discussed, including the limitations of the model. Based on these 'exact' hazard data for major centres in New Zealand, the parameters for the proposed model are calibrated. To illustrate the significance of the proposed model, a performance-based assessment is conducted on a typical bridge, via probabilistic seismic demand analysis. The new hazard model is compared to the current power law relationship to illustrate its effects on the risk assessment. The propagation of epistemic uncertainty in the seismic hazard is also considered. To allow further use of the model in conceptual calculations, a semi-analytical method is proposed to calculate the demand hazard in closed form. For the case study shown, the resulting semi-analytical closed form solution is shown to be significantly more accurate than the analytical closed-form solution using the power law hazard model, capturing the 'exact' numerical integration solution to within 7% accuracy over the entire range of exceedance rat

    Dünaamiline kiiruse jaotamine interaktiivses mitmevaatelises video vaatevahetuse ennustamineses

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    In Interactive Multi-View Video (IMVV), the video has been captured by numbers of cameras positioned in array and transmitted those camera views to users. The user can interact with the transmitted video content by choosing viewpoints (views from different cameras in the array) with the expectation of minimum transmission delay while changing among various views. View switching delay is one of the primary concern that is dealt in this thesis work, where the contribution is to minimize the transmission delay of new view switch frame through a novel process of selection of the predicted view and compression considering the transmission efficiency. Mainly considered a realtime IMVV streaming, and the view switch is mapped as discrete Markov chain, where the transition probability is derived using Zipf distribution, which provides information regarding view switch prediction. To eliminate Round-Trip Time (RTT) transmission delay, Quantization Parameters (QP) are adaptively allocated to the remaining redundant transmitted frames to maintain view switching time minimum, trading off with the quality of the video till RTT time-span. The experimental results of the proposed method show superior performance on PSNR and view switching delay for better viewing quality over the existing methods

    Calculation of Weibull strength parameters, Batdorf flaw density constants and related statistical quantities using PC-CARES

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    This manual describes the operation and theory of the PC-CARES (Personal Computer-Ceramic Analysis and Reliability Evaluation of Structures) computer program for the IBM PC and compatibles running PC-DOS/MS-DOR OR IBM/MS-OS/2 (version 1.1 or higher) operating systems. The primary purpose of this code is to estimate Weibull material strength parameters, the Batdorf crack density coefficient, and other related statistical quantities. Included in the manual is the description of the calculation of shape and scale parameters of the two-parameter Weibull distribution using the least-squares analysis and maximum likelihood methods for volume- and surface-flaw-induced fracture in ceramics with complete and censored samples. The methods for detecting outliers and for calculating the Kolmogorov-Smirnov and the Anderson-Darling goodness-of-fit statistics and 90 percent confidence bands about the Weibull line, as well as the techniques for calculating the Batdorf flaw-density constants are also described

    A Syntactic Study of the -ING form

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    Interconnection of islanded DC microgrids

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    In this paper, the interconnection of islanded DC microgrids are discussed. The interconnection increases the power supply reliability since a power shortfall in one of the microgrids can be supplied by the others. The islanded DC microgrids are interconnected through a bi-directional DC-DC converter. A high frequency transformer isolation is used in the converter. For interconnecting more than two microgrids, a multiple winding transformer is used. The interconnected system is studied for both equal and unequal capacity DC microgrids. A detail description of the interconnection technique is provided with simulation results and illustrations
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