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Les systèmes de transport intelligents coopératifs permettent la communication des véhicules entre eux ainsi qu'avec l'infrastructure, afin d'assurer la disponibilité des informations d'une manière plus fiable sur les véhicules, leurs positions et les conditions de la route. Cet échange d'informations pertinentes permet d'améliorer la sécurité routière, réduire les incidents du trafic et d'assurer l'efficacité de la mobilité des véhicules. IEEE 802.11p est standardisé comme la technologie par défaut pour les communications des véhicules. Dans ce contexte, le standard européen ETSI s'attaque en particulier aux applications de la sécurité routière. Pour ce faire, il standardise plusieurs types de messages comme CAM (Cooperative Awareness Message) et DENM (Decentralised Event Notification Message). Les CAMs sont des messages de diffusion à un seul-saut, envoyés par chaque véhicule contenant des informations sur sa position, sa vitesse, sa direction, etc., afin d'assurer une coopération lucide entre les autres usagers de la route (y compris les véhicules). Les DENMs sont envoyés à la détection d'un événement sur la route, comme le cas d'un accident, embouteillages, etc. Si nécessaire, une communication multi-saut, exploitant des algorithmes de routage standardisés, est mise en {oe}uvre pour disséminer ces messages au-delà de la portée du transmetteur. La faiblesse de 802.11p réside dans la congestion du canal radio due à la bande passante limitée (5.9 GHz). Afin de pallier à cela, ETSI a proposé un cadre pour le contrôle de la congestion appelé DCC (Distributed Congestion Control). Celui-ci permet l'échange d'informations, en particulier l'état du canal radio, entre les couches de la pile protocolaire. Ainsi, chaque protocole de communication contrôle ses propres paramètres pour éviter la congestion du canal. Par ailleurs beaucoup d'approches de contrôle de la congestion DCC existent pour les messages CAM tel que le contrôle de la période de génération des CAMs sur la couche Facilities. La puissance de transmission ou le débit sur la couche Accès, etc. En revanche, peu de travaux ont été faits sur DENMs. A cet égard, nous avons proposé une approche DCC sur la couche GeoNetworking qui contrôle les paramètres de routage en se basant sur l'état du canal radio. Une évaluation du dual-DCC, à savoir CAM sur Facilities et DENM sur GeoNet, a démontré l'efficacité de l'approche proposée. En outre, certaines applications tel que la gestion d'une flotte de véhicules, ont besoin d'un centre de contrôle localisé sur Internet qui communique avec la flotte. Pour ce type d'échange, une communication hybride (IP et Géo) est nécessaire. De plus pour assurer la fluidité de la communication, la gestion de la mobilité est primordiale. Tout en restant dans le cadre de l'architecture Mobile IP, nous proposons notre approche d'adressage qui constitue une adresse IP routable avec une adresse GeoNetworking, ce qui permet de traiter le problème d'accessibilité des véhicules en mouvement sur la route à partir d'une entité située sur Internet. Contrairement à Mobile IP, notre approche permet de réduire la surcharge de la signalisation. Et cela grâce au partitionnement de la route en zones de routage (RA) de telle sorte que l'accès à Internet se fait via une passerelle RSU-FA qui contrôle la RA. Chaque RA regroupe un certain nombre de RSUs. / Cooperative intelligent transport systems allow vehicles to communicate with each other as well as with the infrastructure in order to ensure the availability of information more reliably on vehicles, their positions and road conditions. This exchange of relevant information improves road safety, reduces traffic incidents and ensures efficient mobility of vehicles. IEEE 802.11p is standardized as the default technology for vehicle communications. In this context, the European ETSI standard addresses in particular road safety applications. To do this, it standardizes several types of messages such as CAM (Cooperative Awareness Message) and DENM (Decentralized Event Notification Message). CAMs are single-hop broadcast messages, sent by each vehicle containing information on its position, speed, direction, etc., in order to ensure lucid cooperation between other road users (including vehicles). The DENMs are sent when there is a detection of an event on the road, as in the case of an accident, traffic jams, etc. If necessary, multi-hop communication, using standardized routing algorithms, is implemented to disseminate these messages beyond the scope of the transmitter. The weakness of 802.11p lies in congestion of the radio channel due to the limited bandwidth (5.9 GHz). In order to compensate for this, ETSI proposed a framework for congestion control called DCC (Distributed Congestion Control). This allows the exchange of information, in particular the state of the radio channel, between the layers of the protocol stack. Thus, each communication protocol controls its own parameters to avoid congestion of the channel. In addition, many DCC congestion control approaches exist for CAM messages such as the control of the CAM generation period on the Facilities layer. Transmission power or data rate on the Access layer, etc. On the other hand, little works have been done on DENMs. In this regard, we proposed a DCC approach on the GeoNetworking layer which controls the routing parameters based on the state of the radio channel. An evaluation of the dual-DCC, namely CAM on Facilities and DENM on GeoNet, demonstrated the effectiveness of the proposed approach. In addition, some applications such as managing a fleet of vehicles require a localized control center that communicates with the fleet. For this type of exchange, a hybrid communication (IP and Geo) is necessary. Moreover, to ensure the fluidity of communication, the management of mobility is paramount. While remaining within the framework of the Mobile IP architecture, we propose our approach of addressing which constitutes a routable IP address with a geonetworking address, which makes it possible to deal with the problem of accessibility of vehicles moving on the road from of an entity on the Internet. Unlike Mobile IP, our approach reduces the overhead of signaling. This is done by partitioning the road into routing area (RA) in such a way that the access to the Internet is via a RSU-FA gateway that controls the RA. Each RA regroups a number of RSUs.

This essay aims to establish a marxist perspective upon a phenomena that could be seen as typical neoliberal–femvertising. I have noticed an expanding trend in fashion; the use of feminism as branding. Fashion brands such as Dior and H&M have lately profiled themselves with feminism, framing it as radical as well as feminist. Meanwhile, the theory of reification by Georg Lukács claims that capitalism fools us to believe that we may acccomplish human aims and characteristics through commodities. I will investigate if it is possible to look upon this phenomena as an example of reification? The attempt brings the capitalistic dimension of femvertising into daylight and questions it´s feminist pretense.

Cette thèse a pour but d'évaluer la performance théorique des approches coopératives pour la fiabilisation des transmissions dans les réseaux autour du corps humain. Ces réseaux sont formés d'un nombre limité de capteurs communicants disposés sur et dans le corps. Les techniques de coopération dans les réseaux de cette taille sont extrêmement dépendantes de l'information disponible quand à la qualité des canaux de communication au moment de la transmission. Sous une hypothèse de connaissance de la valeur moyenne à moyen et long terme de l'affaiblissement de ces canaux, nous dérivons une approximation du taux d'erreur paquet de bout en bout pour des techniques de relayage. Nous présentons également, pour certains de ces modèles, une allocation de puissance asymptotiquement optimale, fournissant un gain sur une large plage des puissances d'émission. En supposant ensuite que les noeuds ont une connaissance parfaite de l'état du réseau, nous étudions la capacité de Shannon sur des canaux à relais, et des canaux comprenant deux émetteurs coopérant entre eux. Pour ces deux modèles, nous montrons que lorsque l'on cherche à optimiser la répartition de puissance totale disponible à l'émission, l'étude se réduit à celle d'un modèle de canal équivalent simplifiant grandement l'analyse de la capacité et fournissant des solutions analytiques aux problèmes d'allocation de ressources. Nous présentons enfin une plate-forme de mesures pour les réseaux autour du corps humain, permettant de relever de manière quasi-simultanée l'intégralité des affaiblissements des liens entre les nœuds du réseau. Cette plateforme nous permet de traiter de la stabilité de ces liens et de la validité de l'hypothèse de réciprocité. Nous évaluons également la corrélation spatiale de l'affaiblissement des liens et nous montrons en particulier que celle-ci varie fortement au cours du mouvement, mais de façon suffisamment lente pour être estimée au fil de l'eau. / This thesis aimed at studying the theoretical performance bounds of cooperative techniques in Body Area Networks (BAN). These networks are sensor networks, with a small number of nodes located on and inside the human body. Cooperative techniques are extremely dependent on the channel side information available at the time of transmission. Considering statistical information about the channel fading and the short-term mean of the signal, we derive an asymptotic approximation of the packet error rate under the so-called block fading channel model. Using this approximation, we can express in closed-form asymptotically optimal power allocation among transmitting nodesfor various models of relay channels. Under a complete channel knowledge hypothesis, we then study the Shannon capacity of small-scale cooperative networks, namely relay channels and cooperative multiple access channels. We show that for these networks, when you aim at optimizing the global power allocation of the whole network, the problem is equivalent to a simpler problem on an equivalent channel model. Using this equivalence, we are able to derive a number of closed-form resource allocation for relay channels and cooperative multiple access channels. In the last part of the manuscript, we present a measurement platform for BAN where the quality of every link in the network is gathered in a quasi-simultaneous manner. This platform allows us to discuss results and assess hypotheses on the stability and reciprocity of BAN links. We also evaluate the variation of the spatial correlation of the links during a walking scenario, and show that although the correlation matrix may vary a lot during the movement, it does so sufficiently slowly to be estimated on-line by an adequate protocole, paving the way to more precise resource allocation techniques and relay selection protocols.

Master´s thesis analyses modern methods of communication in company management. The objective is to discover out the crucial defects of this issue and to outline possible solutions which would improve the weaknesses – of internal communication. The master´s thesis consists of three parts: The theoretical part is concerned about communicational instruments which have been used by the operational company ČEPRO, a.s. The analytical part describes implementation of communicational instruments in the company. (external communication, internal communication, crisis communication and communication during the new product implementation) The proposal part recommends appropriate elements for efficient communication within the current communication system in the company.

[pt] A necessidade de transmitir energia e dados através de barreiras metálicas tem sido cada vez maior em aplicações industriais, onde não é possível a penetração de cabos elétricos, ou o uso de ondas eletromagnéticas, tais como, por exemplo, em sistemas de sensoriamento de cimentação em poços de petróleo. Ondas acústicas podem ser uma solução para esse problema, porque não são afetadas pelo efeito gaiola de Faraday, além de possuírem baixa atenuação ao atravessarem metais. Diversos esforços foram feitos para realizar a transmissão de dados através de camadas metálicas, com abordagens que variam em composição do canal acústico, taxa de transmissão, transmissão simultânea de dados e energia e complexidade dos circuitos empregados; existe, porém, carência de trabalhos que envolvam camadas metal-fluído-metal. Este trabalho apresenta uma possível solução utilizando ondas acústicas como meio de transportar energia e dados em um canal composto de barreiras com duas camadas metálicas e uma de fluído. Aqui propõe-se uma inovadora técnica de controle automático de ganho e um melhor aproveitamento da largura de banda do canal acústico, que permite maior taxa de transmissão de dados. É ainda proposta uma técnica para controle dinâmico da portadora enviada ao lado passivo do sistema. Inicialmente, foi feita uma análise de um modelo numérico, baseado em trabalhos anteriores, fundamentado na propagação de ondas acústicas e baseado na analogia acustoelétrica. Em seguida, desenvolveu-se um sistema eletrônico para receber / transmitir energia e dados digitais, modulados em frequência, de um lado ao outro do sistema. Por fim, análises experimentais foram feitas utilizando como canal acústico, um conjunto de duas placas planas de aço (de 5 mm) separadas por uma camada de fluído (de 100 mm) e dois transdutores alinhados axialmente, realizando a transferência de energia e dados digitais modulados em frequência. O sistema foi capaz de realizar a transferência de dados a uma taxa de 19200 bps e simultaneamente uma transferência de energia de 66 mW, com essa energia foi possível alimentar o modulo eletrônico e um sensor de pressão e temperatura. Durante os testes foi constatado um aproveitamento de 5,5 por cento da energia aplicada ao canal, e foi possível atingir uma taxa de erro de bit de 5 por cento em um teste com 2 h e 30 min de duração, utilizando o canal acústico com camadas de múltiplos materiais propostos. O sistema de controle de portadora funcionou adequadamente, permitindo uma redução de consumo de até 53 por cento. O controle automático de ganho permitiu uma redução de 50 por cento na taxa de erro de decodificação. Demonstra-se, então, a viabilidade de tais sistemas de controle propostos, os quais podem ser úteis em casos onde existam variações nas características acústicas do canal em questão que, em conjunto com a transferência não intrusiva, pode prover solução para sistemas de sensoriamento. / [en] The need for energy and data transmission through metallic barriers is increasing in industrial applications, where the penetration of electrical waves or the use of electrical waves is not possible. An example of such a scenario is the monitoring of cementing in wellbore applications. Acoustic waves are promising to solve this problem, since they are not affected by the Faraday cage effect, in addition, they present low attenuation when propagating in metals. Several efforts have been made to carry out data transmission through metallic layers, with approaches that vary in composition of the acoustic channel, transmission speed, simultaneous transmission of data and energy and the complexity of the circuits used, but there is a lack of works involving metal-fluid-metal layers. This work presents a possible solution using acoustic waves as a mean of transporting energy and data in a channel composed of barriers with two metallic layers and one fluid layer. Here, it is proposed a novel technique for automatic gain control and better use of the available bandwidth of the acoustic channel, which allows higher data transmission speed. Also, a technique for dynamic control of the carrier sent to the passive side of the system is proposed. Initially, an analysis with a numerical model was made, following previous works, which is based on the propagation of acoustic waves and relying on the acoustoelectric analogy. Then, an electronic system was developed to receive/transmit power and digital data, frequency modulated, from one side of the system to the other. Finally, experimental analyzes were performed using as an acoustic channel, a set of two flat steel plates (5 mm) separated by a fluid layer (100 mm) and a pairs of axially aligned transducers, performing the energy transfer and frequency modulated digital data. The system was able to transfer data at a rate of 19200 bps and simultaneously a transfer of energy of 66 mW, with this energy it was possible to feed the inside block module and a pressure and temperature sensor. During the tests, it was verified that 5.5 per cent of the energy applied to the channel was used, and it a bit error rate down to of 5 per cent was reached in a test with 2 h and 30 min of duration, using the multi-layered acoustic. The automatic carrier control system worked as expected and allowed one to reduce energy consumption in 53 per cent. The automatic gain control allowed one to reduce the error rate in 50 per cent. These control systems prove the feasibility of the proposed system and further show the usefulness of the system in scenarios that are subject to variations in the acoustic characteristics of the channel.