Nowadays, outsourcing as a strategic goal is becoming a critical success factor used by different organizations in order to provide high quality, and low price products for their customers. In this context, supplier s...
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In electromagnetic dosimetry, anatomical human models are commonly obtained by segmentation of magnetic resonance imaging (MRI) or computed tomography (CT) scans. In this paper, a human head model extracted from therm...
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Purpose - The purpose of this paper is to create a model to calculate the high frequency (HF) complex impedance of common low-voltage DC motors from construction parameters to predict their electromagnetic compatibili...
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Purpose - The purpose of this paper is to create a model to calculate the high frequency (HF) complex impedance of common low-voltage DC motors from construction parameters to predict their electromagnetic compatibility (EMC) emission behaviour and perform sensitivity analyses, and an optimization routine is developed to find combinations of construction parameters which best match a desired impedance curve. Design/methodology/approach - The motor is divided into components. For each component, its electrical behaviour including parasitics is derived from material and geometry, and the electromagnetic interactions between components are defined. These results are then reproduced using inductances, capacitances, and resistors where applicable. mathematical expressions are given to calculate their value from the material and geometrical parameters. Findings - The complex impedance of DC motors can be accurately constructed from geometry and material parameters within a small range. The optimization routine successfully finds parameters to match a desired curve within specified parameter ranges. This can help finding a motor with lower conducted electromagnetic interference. Originality/value - This analytically parameterized model constitutes a new way to describe electrical motors from an EMC perspective and define critical parameters.
Pepper berries classification has been performed manually by human vision. Hence the procedure consumes a lot of manpower and time. This research discusses an application of computer vision to classify the peppercorn ...
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Purpose - In order to assess the performance of an induction generator in standalone wind power application, it is imperative that mathematical models are developed that accurately represent the system and take into a...
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Purpose - In order to assess the performance of an induction generator in standalone wind power application, it is imperative that mathematical models are developed that accurately represent the system and take into account various electromagnetic influences such as skin effect. The purpose of this paper is to utilize mathematical models to study the transient and steady-state behaviour of the self-excited induction generator (SEIG), in one case with an aluminum rotor, in another case, with a copper rotor, under various load conditions while taking the above factor into account. Design/methodology/approach - mathematical models of a SEIG in the d-q axis frame have been developed based on the generalized machine theory. A relationship between the mutual inductance and the magnetizing current of the machine has been presented. The rotor impedances have been customized to include skin effect. Using these relations, the model has been extended to include the saturation and skin effects. In order to verify the accuracy of the models, numerical and experimental investigations have been carried out on two 7.5 hp aluminum-rotor and copper-rotor SEIGs. Findings - It was found that the model that takes into account the saturation and skin effects produces numerical results that closely match experimental values for both the machines. Originality/value - This paper describes how a model of an SEIG considering saturation and skin effect has been developed and applied to aluminum- and copper-rotor machines of similar power ratings to analyze their performance.
The paper deals with mechanical tests of the human abdominal fascia, identification of its material parameters and some numerical simulation of the tissue behaviour. Since mechanical properties of human fascia are not...
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In non-air-conditioned buildings, occupants are able to interact with their surrounding environment using various adaptive opportunities such as opening a window. The availability of these opportunities may make occup...
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In non-air-conditioned buildings, occupants are able to interact with their surrounding environment using various adaptive opportunities such as opening a window. The availability of these opportunities may make occupants feel thermally comfortable across a wider range of conditions than in air-conditioned buildings. Therefore, a good understanding of human adaptive behaviour is required to generate a realistic simulation of the thermal performance for non-air-conditioned buildings. From a field survey carried out in four non-air-conditioned buildings in the summer of 2009, in Loughborough University, UK, it was found that occupants have different preferences when using adaptive opportunities to adjust their surrounding thermal environment. This paper presents a new approach that attempts to model human adaptive behaviour captured from occupant survey data. In addition, an adaptive preference model, which is a key part of the approach, is introduced in this paper.
Although head injuries in football having approximately the same incidence as in American football and ice hockey, head protectors are barely used for prophylaxis. A detailed human head-neck model including force elem...
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Although head injuries in football having approximately the same incidence as in American football and ice hockey, head protectors are barely used for prophylaxis. A detailed human head-neck model including force elements describing the material behaviour of human soft tissue structures such as ligaments, tendons, cartilage layers, intervertebral discs and muscles has been developed using multi-body system (MBS) modelling techniques to investigate the effectiveness of commercial headgear. For ball-head impacts at ball velocity of about v = 20 m/s the simulations calculate a Head Impact Power (HIP) index of 4.1 kW resulting in a five percent injury risk for concussion. When using headgear the resulting HIP-value comes to 3.91 kW meaning that the reduction of the injury risk is very small. (C) 2010 Published by Elsevier Ltd.
This paper highlights and addresses some of the modelling and computational challenges associated with predicting the creep buckling behaviour of thinwalled concrete shells. Three creep mathematical models are examine...
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ISBN:
(纸本)9780937040904
This paper highlights and addresses some of the modelling and computational challenges associated with predicting the creep buckling behaviour of thinwalled concrete shells. Three creep mathematical models are examined, and the effects of shrinkage, aging, gradual loading, and geometric imperfection are outlined through numerical studies. A shallow concrete dome is considered for the numerical examples. The results show that the predicted nonlinear behaviour is affected significantly by the adopted creep model, the shrinkage strains and the geometric imperfection. These parameters may therefore significantly affect the design life of concrete shells.
This paper presents the study of sound frequency characteristic based on Electroencephalography (EEG) signals. The study includes feature extraction of the EEG signals with respect to different sound frequencies, cove...
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