504 research outputs found
Estudi comparatiu de sistemes de producció d'energia tèrmica per a una guarderia al Prat de Llogregat
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
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
Let be an ample metrized invertible sheaf on
a smooth quasi-projective algebraic variety defined over a number field.
Denote by the number of rational points in having -height . We consider the problem of a geometric and arithmetic
interpretation of the asymptotic for as in
connection with recent conjectures of Fujita concerning the Minimal Model
Program for polarized algebraic varieties.
We introduce the notions of -primitive varieties and -primitive fibrations. For -primitive varieties over we
propose a method to define an adelic Tamagawa number which
is a generalization of the Tamagawa number introduced by Peyre for
smooth Fano varieties. Our method allows us to construct Tamagawa numbers for
-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 on the choice of -adic metrics on .Comment: 54 pages, minor correction
Improved seismic hazard model with application to probabilistic seismic demand analysis
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
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
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
Interconnection of islanded DC microgrids
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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