943 resultados para Weighted average power tests
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Pós-graduação em Agronomia (Energia na Agricultura) - FCA
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Pós-graduação em Agronomia (Energia na Agricultura) - FCA
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Pós-graduação em Agronomia (Ciência do Solo) - FCAV
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The Numerical INJection Analysis (NINJA) project is a collaborative effort between members of the numerical relativity and gravitational-wave (GW) astrophysics communities. The purpose of NINJA is to study the ability to detect GWs emitted from merging binary black holes (BBH) and recover their parameters with next-generation GW observatories. We report here on the results of the second NINJA project, NINJA-2, which employs 60 complete BBH hybrid waveforms consisting of a numerical portion modelling the late inspiral, merger, and ringdown stitched to a post-Newtonian portion modelling the early inspiral. In a 'blind injection challenge' similar to that conducted in recent Laser Interferometer Gravitational Wave Observatory (LIGO) and Virgo science runs, we added seven hybrid waveforms to two months of data recoloured to predictions of Advanced LIGO (aLIGO) and Advanced Virgo (AdV) sensitivity curves during their first observing runs. The resulting data was analysed by GW detection algorithms and 6 of the waveforms were recovered with false alarm rates smaller than 1 in a thousand years. Parameter-estimation algorithms were run on each of these waveforms to explore the ability to constrain the masses, component angular momenta and sky position of these waveforms. We find that the strong degeneracy between the mass ratio and the BHs' angular momenta will make it difficult to precisely estimate these parameters with aLIGO and AdV. We also perform a large-scale Monte Carlo study to assess the ability to recover each of the 60 hybrid waveforms with early aLIGO and AdV sensitivity curves. Our results predict that early aLIGO and AdV will have a volume-weighted average sensitive distance of 300 Mpc (1 Gpc) for 10M circle dot + 10M circle dot (50M circle dot + 50M circle dot) BBH coalescences. We demonstrate that neglecting the component angular momenta in the waveform models used in matched-filtering will result in a reduction in sensitivity for systems with large component angular momenta. This reduction is estimated to be up to similar to 15% for 50M circle dot + 50M circle dot BBH coalescences with almost maximal angular momenta aligned with the orbit when using early aLIGO and AdV sensitivity curves.
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This work aims at presenting a no-break system for microcomputers using ultracapacitors in replacement of the conventional chemical batteries. We analyzed the most relevant data about average power consumption of microcomputers, electrical and mechanical characteristics of ultracapacitors and operation of no-break power circuits, to propose a configuration capable of working properly with a microcomputer switching mode power supply. Our solution was a sixteen-component ultracapacitor bank, with a total capacitance of 350 F and voltage of 10.8 V, adequate to integrate a low-capacity no-break system, capable of feeding a load of 180 Wh, during 75 s. Our proposed no-break increases the reliability of microcomputers by reducing the probability of user data losses, in case of a power grid failure, offering, so, a high benefit-cost ratio. The replacement of the battery by ultracapacitors allows a quick no-break recharge and low maintenance costs, since these modern components have a lifetime longer than the batteries. Moreover, this solution reduces the environmental impact and eliminates the constant recharge of the energy storage device.
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We consider model selection uncertainty in linear regression. We study theoretically and by simulation the approach of Buckland and co-workers, who proposed estimating a parameter common to all models under study by taking a weighted average over the models, using weights obtained from information criteria or the bootstrap. This approach is compared with the usual approach in which the 'best' model is used, and with Bayesian model averaging. The weighted predictor behaves similarly to model averaging, with generally more realistic mean-squared errors than the usual model-selection-based estimator.
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The objective of this work is to analyze the viability of incorporation in a microcomputer box of a nobreak with an ultracapacitor as energy storage device, substituting the conventional chemical battery. An advantage of this inclusion is cost reduction because a specific metallic or plastic frame won’t be necessary to protect the components of the nobreak; the microcomputer metallic frame offers the necessary protection for both equipments. Moreover, a large quantity of internal space of microcomputers box isn’t used, and is possible to use it to wrap up the nobreak. This work uses data about average power consumption of microcomputers; operation of switching mode power supplies for microcomputers; electrical and mechanical characteristics of ultracapacitors and operation of power circuits of nobreaks, with the purpose of present a study of energy storage capacity that an ultracapacitor should have to allow a safe switching off of a microcomputer in case of electrical network fail. It was noticed that the use of ultracapacitors is feasible to feed an 180 W load for 75 s, using a capacitive bank with sixteen ultracapacitors, with a total capacitance of 350 F and voltage of 10,8 V. The use of the proposed nobreak increases the reliability of the microcomputer by reducing the probability of user data losses in case of an electrical network fail, offering a high cost/benefit product. The substitution of the battery by an ultracapacitor allows a quick nobreak recharge, with low maintenance costs, since ultracapacitors have a lifetime bigger than batteries; beyond reducing the environmental impact, because they don’t use potentially toxic chemical compounds
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Given the intense expansion of the industries in Brazil and the discovery of hydrocarbons in the pre-salt layer of the Santos and Campos Basin, there is a need to expand the distribution of oil and gas network in the country. The present work aims to present the development of susceptibility map by two distinct methods of two events (debris flows and full wave), applied to the establishment of pipelines on Ribeirão da Prata Basin. The research area covers two municipalities: São João da Boa Vista and Águas da Prata, in total 145 km2. In the paper was used the methodology proposed by Zaine (2011) for the physiographic subdivision method, which uses geological maps, geomorphological maps, digital terrain models and aerial photographs, used to extract the main elements of the physical environment, as rivers, lines, ridges, tops forms and valley forms and historical processes. Thus, the basin was divided into 11 physiographic zones, considering the following elements: thickness of soil, rock type, geomorphology, amplitude, ridges orientation, erosion occurences and mass movements. Were subsequently performed location maps of dams, that had as main purpose to localize major dams in the study area along with their area and perimeter of the reservoir, and land use map that subdivided the area in woody vegetation, permanent culture, temporary culture and urban area. Along with the preparation of the auxiliar maps was conducted a field campaign with three days and approximately 2 points per km2, which aimed to better understand the physical environment and check the main peculiarities of the study area. Criteria have been established for susceptibility maps physiographic subdivision and land use, and a survey of criteria weights used in each map for both processes under study. For the preparation of susceptibility maps were adopted two different methods, which treat the weighted average and the multiplicand. The weighted average method it is...
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Pós-graduação em Agronomia (Ciência do Solo) - FCAV
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The photon statistics of the random laser emission of a Rhodamine B doped di-ureasil hybrid powder is investigated to evaluate its degree of coherence above threshold. Although the random laser emission is a weighted average of spatially uncorrelated radiation emitted at different positions in the sample, a spatial coherence control was achieved due to an improved detection configuration based on spatial filtering. By using this experimental approach, which also allows for fine mode discrimination and timeresolved analysis of uncoupled modes from mode competition, an area not larger than the expected coherence size of the random laser is probed. Once the spectral and temporal behavior of nonoverlapping modes is characterized, an assessment of the photon-number probability distribution and the resulting second-order correlation coefficient as a function of time delay and wavelength was performed. The outcome of our single photon counting measurements revealed a high degree of temporal coherence at the time of maximum pump intensity and at wavelengths around the Rhodamine B gain maximum.
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The aim of this study was to evaluate the effects of a Gallium Arsenide (GaAs) laser, using a high final energy of 4.8J, during muscle regeneration after cryoinjury. Thirty Wistar rats were divided into three groups: Control (C, n=10); Injured (I, n=10) and Injured and laser treated (Injured/LLLT, n=10). The cryoinjury was induced in the central region of the tibialis anterior muscle (TA). The applications of the laser (904nm, 50mW average power) were initiated 24h after injury, at energy density of 69Jcm(-1) for 48s, for 5days, to two points of the lesion. Twenty-four hours after the final application, the TA muscle was removed and frozen in liquid nitrogen to assess the general muscle morphology and the gene expression of TNF-, TGF-, MyoD, and Myogenin. The Injured/LLLT group presented a higher number of regenerating fibers and fewer degenerating fibers (P<0.05) without changes in the collagen remodeling. In addition, the Injured/LLLT group presented a significant decrease in the expression of TNF- and myogenin compared to the injured group (P<0.05). The results suggest that the GaAs laser, using a high final energy after cryoinjury, promotes muscle recovery without changing the collagen remodeling in the muscle extracellular matrix.
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Linear resonant harvesters have been the most common type of generators used to scavenge energy from mechanical vibrations. When subject to harmonic excitation, good performance is achieved once the device is tuned so that its natural frequency coincides with the excitation frequency. In such a situation, the average power harvested in a cycle is proportional to the cube of the excitation frequency and inversely proportional to the suspension damping, which is sought to be very low. However, a very low damping involves a relatively long transient in the system response, where the classical formulation adopted for steady-state regimes do not hold. This paper presents an investigation into the design of a linear resonant harvester to scavenge energy from time-limited harmonic excitations involving a transient response, which could be more likely in some practical situations. An application is presented considering train-induced vibrations.
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Pós-graduação em Bases Gerais da Cirurgia - FMB
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Pós-graduação em Engenharia Civil e Ambiental - FEB
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This article discusses an ergonomic analysis of the controls used by tractor operators, covering their positions in relation to the casing of your job. Was performed an assessment of the controls of the job of a model NH 7630 tractor average power of 74 kW (100 CV), using the norms of the ABNT. With this screening could detect the positive and negative. Then was accomplished an analytical study of the controls. Evaluation results show that some controls of tractors have errors evaluated in relation to NBR/ ISO 6682.