50 research outputs found

    Design of power device sizing and integration for solar-powered aircraft application

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    The power device constitutes the PV cell, rechargeable battery, and maximum power point tracker. Solar aircraft lack proper power device sizing to provide adequate energy to sustain low and high altitude and long endurance flight. This paper conducts the power device sizing and integration for solar-powered aircraft applications (Unmanned Aerial Vehicle). The solar radiation model, the aerodynamic model, the energy and mass balance model, and the adopted aircraft configuration were used to determine the power device sizing, integration, and application. The input variables were aircraft mass 3 kg, wingspan 3.2 m, chord 0.3 m, aspect ratio 11.25, solar radiation 825 W/m2 , lift coefficient 0.913, total drag coefficient 0.047, day time 12 hour, night time 12 hours, respectively. The input variables were incorporated into the MS Excel program to determine the output variables. The output variables are; the power required 10.92 W, the total electrical power 19.47 W, the total electrical energy 465.5 Wh, the daily solar energy 578.33 Wh, the solar cell area 0.62 m, the number of PV cell 32, and the number of the Rechargeable battery 74 respectively. The power device was developed with the PV cell Maxeon Gen III for high efficiency, the rechargeable battery sulfur-lithium battery for high energy density, and the Maximum power point tracker neural network algorithm for smart and efficient response. The PD sizing was validated with three existing designs. The validation results show that 20% reduction of the required number of PV cells and RB and a 30% increase in flight durations

    Automatic blush detection in ‘concealed information’ test using visual stimuli

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    Blushing has been identified as an indicator of deception, shame, anxiety and embarrassment. Although normally associated with the skin coloration of the face, a blush response also affects skin surface temperature. In this paper, an approach to detect a blush response automatically is presented using the Argus P7225 thermal camera from e2v. The algorithm was tested on a sample population of 51 subjects, while using visual stimuli to elicit a response, and achieved recognition rates of ~77% TPR and ~60% TNR, indicating a thermal image sensor is the prospective device to pick up subtle temperature change synchronised with stimuli

    Non-invasive assessment of affective states on individual with autism spectrum disorder: a review

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    Individuals with Autism Spectrum Disorder (ASD) are identified as a group of people who have social interaction and communication impairment. They have difficulty in producing speech and explaining what they meant. They also suffer from emotional or cognitive states requirement that stance challenges to their interest in communicating and socializing. Hence, it is vital to know their emotion to help them develop better skills in social interaction. Emotion can be derived from affective states and can be detected through physical reaction and physiological signals. There are numerous known modalities available to detect the affective states either through invasive and non-invasive methods. In order to evaluate the affective states of individuals with ASD, amongst the methods used are through electrodermal activity (EDA), electromyographic (EMG) activity, and cardiovascular activity (ECG) and blood flow analyses. Though considered non invasive, these methods require sensor to be patched on to the skin causing discomfort to the subjects and might distract their true emotion. We propose non-invasive methods which is also contactless to address the problem to detect emotion of individual with ASD that is through thermal imaging. Through the impact of cutaneous temperature in blood flow, thermal imprint is radiated and can be detected in this method. To date, no research has been reported of the use of thermal imaging analysis of facial skin temperature on the individuals with ASD. In this paper we will justify the method and also discuss the merits and demerits of other methods

    Extracting Physiological Measurements from Thermal Images

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    Multiple techniques are used to extract physiological signals from the human body. These signals provide a reliable method to identify the physical and mental state of a person at any given point in time. However, these techniques require contact and cooperation of the individual as well as human effort for connecting the devices and collecting the needed measurement. Moreover, these methods can be invasive, timeconsuming, and infeasible in many cases. Recent efforts have been made in order to find alternatives to extract these measurements using noncontact and efficient techniques. One of these alternatives is the use of thermal cameras for health monitoring. Our work explores reliable methods for extracting respiration rate, skin temperature and heart rate from thermal video. These methods leverage a combination of image processing and signal processing techniques in order to extract and filter physiological signals from the thermal domain. Finally, we review the use of thermal imaging in several applications, such as deception detection, stress detection and emotion recognition.Master of ScienceComputer and Information Science, College of Engineering & Computer ScienceUniversity of Michigan-Dearbornhttp://deepblue.lib.umich.edu/bitstream/2027.42/167385/1/Christian Hessler Final Thesis.pdfDescription of Christian Hessler Final Thesis.pdf : Thesi

    Proximity and gaze influences facial temperature:a thermal infrared imaging study

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    Direct gaze and interpersonal proximity are known to lead to changes in psycho-physiology, behaviour and brain function. We know little, however, about subtler facial reactions such as rise and fall in temperature, which may be sensitive to contextual effects and functional in social interactions. Using thermal infrared imaging cameras 18 female adult participants were filmed at two interpersonal distances (intimate and social) and two gaze conditions (averted and direct). The order of variation in distance was counterbalanced: half the participants experienced a female experimenter’s gaze at the social distance first before the intimate distance (a socially ‘normal’ order) and half experienced the intimate distance first and then the social distance (an odd social order). At both distances averted gaze always preceded direct gaze. We found strong correlations in thermal changes between six areas of the face (forehead, chin, cheeks, nose, maxilliary and periorbital regions) for all experimental conditions and developed a composite measure of thermal shifts for all analyses. Interpersonal proximity led to a thermal rise, but only in the ‘normal’ social order. Direct gaze, compared to averted gaze, led to a thermal increase at both distances with a stronger effect at intimate distance, in both orders of distance variation. Participants reported direct gaze as more intrusive than averted gaze, especially at the intimate distance. These results demonstrate the powerful effects of another person’s gaze on psycho-physiological responses, even at a distance and independent of context

    Infrared thermal imaging in affective neuroscience: insights to the self from the peripheral nervous system.

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    Changes in peripheral physiology lay in the unconscious and occur as a response to external challenges, whether is to fight a virus (e.g. fever) a predator (e.g Fight or Flight) or even to face a social challenge. Autonomic adaptation carries its own physiological print and by harnessing the power given by homeostatic balance, distinctions can be made between arousal and parasympathetic restoration. Conventional physiological methods restrict the way in which experimental designs can be performed. Functional Infrared Thermal Imaging (fITI) provides an alternative for physiological monitoring that enables experimental paradigms that resemble real life situations. With the use of thermal imaging the following studies were set to examine self-conscious emotions in a naturalistic experimental setting while advancing methodologically the technique of fITI. In the following chapters the potentialities and limits of fITI are illustrated (Chapter 2) and three studies are presented where fITI has been applied to investigate the autonomic signature of guilt in children (Chapter 3); the facial imprints of autonomic contagion in mother and child (Chapter 4); the role of social proximity and gaze in modulating facial temperature (Chapter 5). FITI has managed to reliably and systematically collect physiological thermal changes between affective states illustrating a new pathway for contact-free autonomic monitoring in the arena of self-conscious emotions

    Thermal Imaging As A Biometrics Approach To Facial Signature Authentication

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    This dissertation develops an image processing framework with unique feature extraction and similarity measurements for human face recognition in the mid-wave infrared portion of the electromagnetic spectrum. The goal is to design specialized algorithms that would extract vasculature information, create a thermal facial signature and identify the individual. The objective is to use such findings in support of a biometrics system for human identification with a high degree of accuracy and a high degree of reliability. This last assertion is due to the minimal to no risk for potential alteration of the intrinsic physiological characteristics seen through thermal imaging. Thermal facial signature authentication is fully integrated and consolidates the main and critical steps of feature extraction, registration, matching through similarity measures, and validation through the principal component analysis. Feature extraction was accomplished by first registering the images to a reference image using the functional MRI of the Brain’s (FMRIB’s) Linear Image Registration Tool (FLIRT) modified to suit thermal images. This was followed by segmentation of the facial region using an advanced localized contouring algorithm applied on anisotropically diffused thermal images. Thermal feature extraction from facial images was attained by performing morphological operations such as opening and top-hat segmentation to yield thermal signatures for each subject. Four thermal images taken over a period of six months were used to generate a thermal signature template for each subject to contain only the most prevalent and consistent features. Finally a similarity measure technique was used to match images to the signature templates and the Principal Component Analysis (PCA) was used to validating the results of the matching process. Thirteen subjects were used for testing the developed technique on an in-house thermal imaging system. The matching using the similarity measures showed 88% accuracy in case of skeletonized feature signatures and 90% accuracy for anisotropically diffused feature signatures. The highly accurate results obtained in the matching process along with the generalized design process clearly demonstrate the ability of the developed thermal infrared system to be used on other thermal imaging based systems and related databases

    UNOBTRUSIVE Technique Based On Infrared Thermal Imaging For Emotion Recognition In Children- With-asd- Robot Interaction

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    Emoções são relevantes para as relações sociais, e indivíduos com Transtorno do Espectro Autista (TEA) possuem compreensão e expressão de emoções prejudicadas. Esta tese consiste em estudos sobre a análise de emoções em crianças com desenvolvimento típico e crianças com TEA (idade entre 7 e 12 anos), por meio do imageamento térmico infravermelho (ITIV), uma técnica segura e não obtrusiva (isenta de contato), usada para registrar variações de temperatura em regiões de interesse (RIs) da face, tais como testa, nariz, bochechas, queixo e regiões periorbital e perinasal. Um robô social chamado N-MARIA (Novo-Robô Autônomo Móvel para Interação com Autistas) foi usado como estímulo emocional e mediador de tarefas sociais e pedagógicas. O primeiro estudo avaliou a variação térmica facial para cinco emoções (alegria, tristeza, medo, nojo e surpresa), desencadeadas por estímulos audiovisuais afetivos, em crianças com desenvolvimento típico. O segundo estudo avaliou a variação térmica facial para três emoções (alegria, surpresa e medo), desencadeadas pelo robô social N-MARIA, em crianças com desenvolvimento típico. No terceiro estudo, duas sessões foram realizadas com crianças com TEA, nas quais tarefas sociais e pedagógicas foram avaliadas tendo o robô N-MARIA como ferramenta e mediador da interação com as crianças. Uma análise emocional por variação térmica da face foi possível na segunda sessão, na qual o robô foi o estímulo para desencadear alegria, surpresa ou medo. Além disso, profissionais (professores, terapeuta ocupacional e psicóloga) avaliaram a usabilidade do robô social. Em geral, os resultados mostraram que o ITIV foi uma técnica eficiente para avaliar as emoções por meio de variações térmicas. No primeiro estudo, predominantes decréscimos térmicos foram observados na maioria das RIs, com as maiores variações de emissividade induzidas pelo nojo, felicidade e surpresa, e uma precisão maior que 85% para a classificação das cinco emoções. No segundo estudo, as maiores probabilidades de emoções detectadas pelo sistema de classificação foram para surpresa e alegria, e um aumento significativo de temperatura foi predominante no queixo e nariz. O terceiro estudo realizado com crianças com TEA encontrou aumentos térmicos significativos em todas as RIs e uma classificação com a maior probabilidade para surpresa. N-MARIA foi um estímulo promissor capaz de desencadear emoções positivas em crianças. A interação criança-com-TEA-e-robô foi positiva, com habilidades sociais e tarefas pedagógicas desempenhadas com sucesso pelas crianças. Além disso, a usabilidade do robô avaliada por profissionais alcançou pontuação satisfatória, indicando a N-MARIA como uma potencial ferramenta para terapias
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