Etude et réalisation d'un système de communications par lumière visible (VLC/LiFi). Application au domaine automobile.

The scientific problematic of this PhD is centered on the usage of Visible LightCommunications (VLC) in automotive applications. By enabling wireless communication amongvehicles and also with the traffic infrastructure, the safety and efficiency of the transportation canbe substantially increased. Considering the numerous advantages of the VLC technologyencouraged the study of its appropriateness for the envisioned automotive applications, as analternative and/or a complement for the traditional radio frequency based communications.In order to conduct this research, a low-cost VLC system for automotive application wasdeveloped. The proposed system aims to ensure a highly robust communication between a LEDbasedVLC emitter and an on-vehicle VLC receiver. For the study of vehicle to vehicle (V2V)communication, the emitter was developed based on a vehicle backlight whereas for the study ofinfrastructure to vehicle (I2V) communication, the emitter was developed based on a traffic light.Considering the VLC receiver, a central problem in this area is the design of a suitable sensorable to enhance the conditioning of the signal and to avoid disturbances due to the environmentalconditions, issues that are addressed in the thesis. The performances of a cooperative drivingsystem integrating the two components were evaluated as well.The experimental validation of the VLC system was performed in various conditions andscenarios. The results confirmed the performances of the proposed system and demonstrated thatVLC can be a viable technology for the considered applications. Furthermore, the results areencouraging towards the continuations of the work in this domain.La problématique scientifique de cette thèse est centrée sur le développement decommunications par lumière visible (Visible Light Communications - VLC) dans lesapplications automobiles. En permettant la communication sans fil entre les véhicules, ou entreles véhicules et l’infrastructure routière, la sécurité et l'efficacité du transport peuvent êtreconsidérablement améliorées. Compte tenu des nombreux avantages de la technologie VLC,cette solution se présente comme une excellente alternative ou un complément pour lescommunications actuelles plutôt basées sur les technologies radio-fréquences traditionnelles.Pour réaliser ces travaux de recherche, un système VLC à faible coût pour applicationautomobile a été développé. Le système proposé vise à assurer une communication très robusteentre un émetteur VLC à base de LED et un récepteur VLC monté sur un véhicule. Pour l'étudedes communications véhicule à véhicule (V2V), l'émetteur a été développé sur la base d’un pharearrière rouge de voiture, tandis que pour l'étude des communications de l'infrastructure auvéhicule (I2V), l'émetteur a été développé sur la base d'un feu de circulation. Considérant lerécepteur VLC, le problème principal réside autour d’un capteur approprié, en mesured'améliorer le conditionnement du signal et de limiter les perturbations dues des conditionsenvironnementales. Ces différents points sont abordés dans la thèse, d’un point de vue simulationmais également réalisation du prototype.La validation expérimentale du système VLC a été réalisée dans différentes conditions etscénarii. Les résultats démontrent que la VLC peut être une technologie viable pour lesapplications envisagées

A survey on acoustic positioning systems for location-based services

Positioning systems have become increasingly popular in the last decade for location-based services, such as navigation, and asset tracking and management. As opposed to outdoor positioning, where the global navigation satellite system became the standard technology, there is no consensus yet for indoor environments despite the availability of different technologies, such as radio frequency, magnetic field, visual light communications, or acoustics. Within these options, acoustics emerged as a promising alternative to obtain high-accuracy low-cost systems. Nevertheless, acoustic signals have to face very demanding propagation conditions, particularly in terms of multipath and Doppler effect. Therefore, even if many acoustic positioning systems have been proposed in the last decades, it remains an active and challenging topic. This article surveys the developed prototypes and commercial systems that have been presented since they first appeared around the 1980s to 2022. We classify these systems into different groups depending on the observable that they use to calculate the user position, such as the time-of-flight, the received signal strength, or the acoustic spectrum. Furthermore, we summarize the main properties of these systems in terms of accuracy, coverage area, and update rate, among others. Finally, we evaluate the limitations of these groups based on the link budget approach, which gives an overview of the system's coverage from parameters such as source and noise level, detection threshold, attenuation, and processing gain.Agencia Estatal de InvestigaciónResearch Council of Norwa

Mobile phones as medical devices in mental disorder treatment: an overview

Mental disorders can have a significant, negative impact on sufferers’ lives, as well as on their friends and family, healthcare systems and other parts of society. Approximately 25 % of all people in Europe and the USA experience a mental disorder at least once in their lifetime. Currently, monitoring mental disorders relies on subjective clinical self-reporting rating scales, which were developed more than 50 years ago. In this paper, we discuss how mobile phones can support the treatment of mental disorders by (1) implementing human–computer interfaces to support therapy and (2) collecting relevant data from patients’ daily lives to monitor the current state and development of their mental disorders. Concerning the first point, we review various systems that utilize mobile phones for the treatment of mental disorders. We also evaluate how their core design features and dimensions can be applied in other, similar systems. Concerning the second point, we highlight the feasibility of using mobile phones to collect comprehensive data including voice data, motion and location information. Data mining methods are also reviewed and discussed. Based on the presented studies, we summarize advantages and drawbacks of the most promising mobile phone technologies for detecting mood disorders like depression or bipolar disorder. Finally, we discuss practical implementation details, legal issues and business models for the introduction of mobile phones as medical devices

Visible Light Optical Camera Communication for Electroencephalography Applications

Due to the cable-free deployment and flexibility of wireless communications, the data transmission in the applications of home and healthcare has shown a trend of moving wired communications to wireless communications. One typical example is electroencephalography (EEG). Evolution in the radio frequency (RF) technology has made it is possible to transmit the EEG data without data cable bundles. However, presently, the RF-based wireless technology used in EEG suffers from electromagnetic interference and might also have adverse effects on the health of patient and other medical equipment used in hospitals or homes. This puts some limits in RF-based EEG solutions, which is particularly true in RF restricted zones like Intensive Care Units (ICUs). As a recently developed optical wireless communication (OWC) technology, visible light communication (VLC) using light-emitting diodes (LEDs) for both simultaneous illumination and data communication has shown its advantages of free from electromagnetic interference, potential huge unlicensed bandwidth and enhanced data privacy due to the line transmission of light. The most recent development of VLC is the optical camera communication (OCC), which is an extension of VLC IEEE standard 802.15.7, also referred to as visible light optical camera communication (VL-OCC). Different from the conventional VLC where traditional photodiodes are used to detect and receive the data, VL-OCC uses the imaging camera as the photodetector to receive the data in the form of visible light signals. The data rate requirement of EEG is dependent on the application; hence this thesis investigates a low cost, organic LED (OLED)-driven VL-OCC wireless data transmission system for EEG applications

Augmented reality applied to language translation

Being a tourist in a foreign country is an adventure full of memories and experiences, but it can be truly challenging when it comes to communication. Finding yourself in an unknown place, where all the road signs and guidelines have such different characters, may end up in a dead end or with some unexpected results. Then, what if we could use a smartphone to read that restaurant menu? Or even find the right department in a mall? The applications are so many and the market is ready to invest and give opportunities to creative and economic ideas. The dissertation intends to explore the field of Augmented Reality, while helping the user to enrich his view with information. Giving the ability to look around, detect the text in the surroundings and read its translation in our own dialect, is a great step to overcome language issues. Moreover, using smartphones at anyone’s reach, or wearing smartglasses that are even less intrusive, gives a chance to engage a complex matter in a daily routine. This technology requires flexible, accurate and fast Optical Character Recognition and Translation systems, in an Internet of Things scenery. Quality and precision is a must, yet to be further developed and improved. Entering in a realtime digital data environment, will support great causes and aid the progress and evolution of many intervention areas

Seeing the City Digitally

This book explores what's happening to ways of seeing urban spaces in the contemporary moment, when so many of the technologies through which cities are visualised are digital. Cities have always been pictured, in many media and for many different purposes. This edited collection explores how that picturing is changing in an era of digital visual culture. Analogue visual technologies like film cameras were understood as creating some sort of a trace of the real city. Digital visual technologies, in contrast, harvest and process digital data to create images that are constantly refreshed, modified and circulated. Each of the chapters in this volume examines a different example of this processual visuality is reconfiguring the spatial and temporal organisation of urban life

Virtualisation and Thin Client : A Survey of Virtual Desktop environments

This survey examines some of the leading commercial Virtualisation and Thin Client technologies. Reference is made to a number of academic research sources and to prominent industry specialists and commentators. A basic virtualisation Laboratory model is assembled to demonstrate fundamental Thin Client operations and to clarify potential problem areas

A MIXED-METHOD FEASIBILITY STUDY COMPARING THE OUTPATIENT ASSESSMENT OF BURN PATIENTS USING A TABLET DEVICE VERSUS THE USUAL FACE-TO-FACE ENCOUNTER

The number of verified burn centers across the U.S. has dramatically decreased, negatively impacting access to burn care. Telehealth is a solution for burn care, however there is minimal research evaluating burn care through telehealth. The primary purpose of this mixed method feasibility study was to examine the reliability of using a Motorola XOOM tablet to perform an outpatient standard burn assessment compared to the usual face-to-face examination. Qualitative information on patients’ perception of using the tablet was also evaluated. A convenience sample of 50 subjects, aged 19 to 76 years, with less than 10% total body surface area burned was recruited from an outpatient burn clinic. Descriptive statistics and the reliability of using a tablet device compared to a face-to-face encounter were measured between modalities, raters, and across raters and modalities using Cohen’s Kappa and the Spearman correlation. The reliability between two raters for the standard burn assessment showed substantial to near perfect agreement for skin graft take (Kappa = 0.892), burn depth (Kappa = 0.731), and cellulitis (Kappa = 0.847) when using a tablet device. The inter-modality reliability by rater showed substantial to perfect agreement for skin graft take (Kappa = 1.0), burn depth (Kappa = 0.848–1.0), and edema (Kappa = 0.876–0.958). The overall reliability of assessing a burn wound through a tablet device was similar to that obtained in face-to-face examination. Spearman correlations between the ratings made by the First Rater and the Second Rater when using a table device ranged from 0.531 to 0.852 and Spearman correlations from the face-to-face encounter ranged from 0.460 to 0.710. Results from this study provide support for the reliability of a tablet device to assess for burn depth and skin graft take. Findings suggest inconsistency in the reliability of a tablet device to assess the presence of cellulitis, edema and purulence. Tablet device use in burn care can augment the usual, standard face-to-face interaction between patient and provider. Continued research is necessary to further validate its use in early and accurate assessment of burn wounds, burn-related complications, the evaluation of graft take, and the development of hypertrophic scarring