335 research outputs found

    Detailed CFD modelling of open refrigerated display cabinets

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    A comprehensive and detailed computational fluid dynamics (CFDs) modelling of air flow and heat transfer in an open refrigerated display cabinet (ORDC) is performed in this study. The physical-mathematical model considers the flow through the internal ducts, across fans and evaporator, and includes the thermal response of food products. The air humidity effect and thermal radiation heat transfer between surfaces are taken into account. Experimental tests were performed to characterize the phenomena near physical extremities and to validate the numerical predictions of air temperature, relative humidity, and velocity. Numerical and experimental results comparison reveals the predictive capabilities of the computational model for the optimized conception and development of this type of equipments. Numerical predictions are used to propose geometrical and functional parametric studies that improve thermal performance of the ORDC and consequently food safety.info:eu-repo/semantics/publishedVersio

    Digital signal processing mathematics

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    Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration

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    Problems related to the design and control of a mobile planetary vehicle to implement a systematic plan for the exploration of Mars are reported. Problem areas include: vehicle configuration, control, dynamics, systems and propulsion; systems analysis, terrain modeling and path selection; and chemical analysis of specimens. These tasks are summarized: vehicle model design, mathematical model of vehicle dynamics, experimental vehicle dynamics, obstacle negotiation, electrochemical controls, remote control, collapsibility and deployment, construction of a wheel tester, wheel analysis, payload design, system design optimization, effect of design assumptions, accessory optimal design, on-board computer subsystem, laser range measurement, discrete obstacle detection, obstacle detection systems, terrain modeling, path selection system simulation and evaluation, gas chromatograph/mass spectrometer system concepts, and chromatograph model evaluation and improvement

    Modeling, Analysis, and Optimization Issues for Large Space Structures

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    Topics concerning the modeling, analysis, and optimization of large space structures are discussed including structure-control interaction, structural and structural dynamics modeling, thermal analysis, testing, and design

    New Approach of Indoor and Outdoor Localization Systems

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    Accurate determination of the mobile position constitutes the basis of many new applications. This book provides a detailed account of wireless systems for positioning, signal processing, radio localization techniques (Time Difference Of Arrival), performances evaluation, and localization applications. The first section is dedicated to Satellite systems for positioning like GPS, GNSS. The second section addresses the localization applications using the wireless sensor networks. Some techniques are introduced for localization systems, especially for indoor positioning, such as Ultra Wide Band (UWB), WIFI. The last section is dedicated to Coupled GPS and other sensors. Some results of simulations, implementation and tests are given to help readers grasp the presented techniques. This is an ideal book for students, PhD students, academics and engineers in the field of Communication, localization & Signal Processing, especially in indoor and outdoor localization domains

    SMARTI - Sustainable Multi-functional Automated Resilient Transport Infrastructure

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    The world’s transport network has developed over thousands of years; emerging from the need of allowing more comfortable trips to roman soldiers to the modern smooth roads enabling modern vehicles to travel at high speed and to allow heavy airplanes to take off and land safely. However, in the last two decades the world is changing very fast in terms of population growth, mobility and business trades creating greater traffic volumes and demand for minimal disruption to users, but also challenges, such as climate change and more extreme weather events. At the same time, technology development to allow a more sustainable transport sector continue apace. It is within this environment and in close consultation with key stakeholders, that this consortium developed the vision to achieve the paradigm shift to Sustainable Multifunctional Automated and Resilient Transport Infrastructures. SMARTI ETN is a training-through-research programme that empowered Europe by forming a new generation of multi-disciplinary professionals able to conceive the future of transport infrastructures and this Special Issue is a collection of some of the scientific work carried out within this context. Enjoy the read

    Predictive analysis of auditory attention from physiological signals

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    In recent years, there has been considerable interest in recording physiological signals from the human body to investigate various responses. Attention is one of the key aspects that physiologists, neuroscientists, and engineers have been exploring. Many theories have been established on auditory and visual selective attention. To date, the number of studies investigating the physiological responses of the human body to auditory attention on natural speech is, surprisingly, very limited, and there is a lack of public datasets. Investigating such physiological responses can open the door to new opportunities, as auditory attention plays a key role in many cognitive functionalities, thus impacting on learning and general task performance. In this thesis, we investigated auditory attention on the natural speech by processing physiological signals such as Electroencephalogram (EEG), Galvanic Skin Response (GSR), and Photoplethysmogram (PPG). An experiment was designed based on the well established dichotic listening task. In the experiment, we presented an audio stimulus under different auditory conditions: background noise level, length, and semanticity of the audio message. The experiment was conducted with 25 healthy, non-native speakers. The attention score was computed by counting the number of correctly identified words in the transcribed text response. All the physiological signals were labeled with their auditory condition and attention score. We formulated four predictive tasks exploiting the collected signals: Attention score, Noise level, Semanticity, and LWR (Listening, Writing, Resting, i.e., the state of the participant). In the first part, we analysed all the user text responses collected in the experiment. The statistical analysis reveals a strong dependency of the attention level on the auditory conditions. By applying hierarchical clustering, we could identify the experimental conditions that have similar effects on attention score. Significantly, the effect of semanticity appeared to vanish under high background noise. Then, analysing the signals, we found that the-state-of-the-art algorithms for artifact removal were inefficient for large datasets, as they require manual intervention. Thus, we introduced an EEG artifact removal algorithm with tuning parameters based on Wavelet Packet Decomposition (WPD). The proposed algorithm operates with two tuning parameters and three modes of wavelet filtering: Elimination, Linear Attenuation, and Soft-thresholding. Evaluating the algorithm performance, we observed that it outperforms state-of-the-art algorithms based on Independent Component Analysis (ICA). The evaluation was based on the spectrum, correlation, and distribution of the signals along with the performance in predictive tasks. We also demonstrate that a proper tuning of the algorithm parameters allows achieving further better results. After applying the artifact removal algorithm on EEG, we analysed the signals in terms of correlation of spectral bands of each electrode and attention score, semanticity, noise level, and state of the participant LWR). Next, we analyse the Event-Related Potential (ERP) on Listening, Writing and Resting segments of EEG signal, in addition to spectral analysis of GSR and PPG. With this thesis, we release the collected experimental dataset in the public domain, in order for the scientific community to further investigate the various auditory processing phenomena and their relation with EEG, GSR and PPG responses. The dataset can be used also to improve predictive tasks or design novel Brain-Computer-Interface (BCI) systems based on auditory attention. We also use the deeplearning approach to exploit the spatial relationship of EEG electrodes and inter-subject dependency of a model. As a domain application, we finally discuss the implications of auditory attention assessment for serious games and propose a 3-dimensional difficulty model to design game levels and dynamically adapt the difficulty to the player status
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