Search results for "Simulation"
showing 10 items of 5095 documents
A mixed FES/EMG system for real time analysis of muscular fatigue
2010
International audience; In this article, we present a functional electrical stimulator allowing the extraction in real time of M-wave characteristics from resulting EMG recodings in order to quantify muscle fatigue. This system is composed of three parts. A Labview software managing the stimulation output and electromyogram (EMG) input signal, a hardware part amplifying the output and input signal and a link between the two previous parts which is made up from input/output module (NIdaq USB 6251). In order to characterize the fatigue level, the Continuous Wavelet Transform is applied yielding a local maxima detection. The fatigue is represented on a scale from 0 for a fine shaped muscle to …
Influence of correlations between stresses on calculated fatigue life of machine elements
1996
The correlation between components of the random stress tensor and its influence on the calculated fatigue life of machine elements were analysed. Three covariance matrices of components of biaxial stress state were considered. They were determined from measurements of strains in an element of a vibrating screen for aggregate, in the back wall of a bus, and in a welded element of excavator fittings. Calculations were made according to four criteria of multiaxial random fatigue. Cycles were counted with the rainflow method, and damage was cumulated with the Palmgren-Miner hypothesis. It was found that convariances of random stress state components strongly influence the calculated fatigue li…
Energy measurements at Skarpnes zero energy homes in Southern Norway: Do the loads match up with the on-site energy production?
2017
Five houses are designed as zero-energy homes in Skarpnes, Norway. The energy goal is to achieve net zero-energy balance on an annual basis. The houses have heat pumps and solar cells (PV). Energy use and delivered energy have been monitored from June 2015. Variations between calculations and measurements are explained by technical and non-technical reasons. For the first year, higher than expected energy loads result in a solar energy cover factor of 65–87% of delivered electricity. The PV generation performs satisfactorily, hence, it may be possible to achieve energy goals during later years provided technical adjustments or behavioral changes. Acknowledgements. This report has been writt…
Redesign of a Rural Building in a Heritage Site in Italy: Towards the Net Zero Energy Target
2017
In order to achieve the ambitious objective of decarbonising the economy, it is mandatory, especially in Europe and in Italy, to include the retrofitting of existing buildings. In a country where a large share of existing buildings have heritage value, it is important to design effective retrofit solutions also in historical buildings. In this context, the paper describes the experience of re-design of an existing rural building located in Sicily, inside the ancient Greeks' “Valley of the Temples”. An energy audit was performed on the building, and its energy uses were thoroughly investigated. A building model was developed in the TRNSYS environment and its performances validated. The valid…
An integrated simulation method for building energy performance assessment in urban environments
2012
a b s t r a c t The microclimate around a building, establishing through the interaction with other buildings or the natural environment, is a significant factor in the building energy consumption. This paper presents a method for the quantitative analysis of building energy performance under any given urban contexts by linking the microclimate model ENVI-met to the building energy simulation (BES) program EnergyPlus. The full microclimatic factors such as solar radiation, long wave radiation, air temperature, air humidity, and wind speed have been considered in the proposed scheme. A case study has been conducted to analyze the effects of different microclimatic factors on the energy balan…
Control of structural problems in cultural heritage monuments using close-range photogrammetry and computer methods
2005
This paper deals with the conservation of monumental buildings. Several methods used for the architectonic documentation are analysed in this study. Computers methods and close-range photogrammetry are proposed as a preventive method which allows to detect, measure and track the temporal evolution of some structural problems detected, and also to assess the degree of conservation of the materials employed. A group of monuments belonging to the Spanish historical heritage is analysed. In order to carry out the analysis a wire-frame model and a photo-realistic textured model were made. Work focused later on the area where structural problems were more acute.
Design of Wideband MIMO Car-to-Car Channel Models Based on the Geometrical Street Scattering Model
2012
Published version of an article in the journal: Modelling and Simulation in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2012/264213 Open access We propose a wideband multiple-input multiple-output (MIMO) car-to-car (C2C) channel model based on the geometrical street scattering model. Starting from the geometrical model, a MIMO reference channel model is derived under the assumption of single-bounce scattering in line-of-sight (LOS) and non-LOS (NLOS) propagation environments. The proposed channel model assumes an infinite number of scatterers, which are uniformly distributed in two rectangular areas located on both sides of the street. Analytical solutions a…
Peak Power Demand and Energy Consumption Reduction Strategies for Trains under Moving Block Signalling System
2013
Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2013/940936 Open Access In the moving block signalling (MBS) system where the tracking target point of the following train is moving forward with its leading train, overload of the substations occurs when a dense queue of trains starts (or restarts) in very close distance interval. This is the peak power demand problem. Several methods have been attempted in the literature to deal with this problem through changing train's operation strategies. However, most existing approaches reduce the service quality. In this paper, two novel approaches - …
H∞ fuzzy control of DC-DC converters with input constraint
2012
Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2012/973082 Open access This paper proposes a method for designing H∞ fuzzy control of DC-DC converters under actuator saturation. Because linear control design methods do not take into account the nonlinearity of the system, a T-S fuzzy model and a controller design approach is used. The designed control not only handles the external disturbance but also the saturation of duty cycle. The input constraint is first transformed into a symmetric saturation which is represented by a polytopic model. Stabilization conditions for the H∞ state feedba…
Integrated emitter local loss prediction using artificial neural networks.
2010
This paper describes an application of artificial neural networks (ANNs) to the prediction of local losses from integrated emitters. First, the optimum input-output combination was determined. Then, the mapping capability of ANNs and regression models was compared. Afterwards, a five-input ANN model, which considers pipe and emitter internal diameter, emitter length, emitter spacing, and pipe discharge, was used to develop a local losses predicting tool which was obtained from different training strategies while taking into account a completely independent test set. Finally, a performance index was evaluated for the test emitter models studied. Emitter data with low reliability were removed…