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Contribution à l'estimation des canaux relatifs aux signaux utile et interférent dans un système full-duplex dédié aux communications véhiculaires / Signal of interest and self interference channel estimate in a full-duplex system for vehicular communicationsBouallegue, Sélima 28 March 2019 (has links)
Dans ces travaux de thèse, nous proposons de nouvelles méthodes d’estimation de canal pour un système full-duplex dédié aux communications véhiculaires. Les deux canaux relatifs au signal utile (SOI) et au signal interférant (SI) sont estimés. Les méthodes que nous proposons sont classées selon si les pilotes des deux signaux sont envoyés séparément ou simultanément. Dans le cas de la transmission séparée des pilotes, nous proposons un algorithme se basant sur un positionnement dynamique des pilotes ainsi qu’une méthode hybride qui combine l’approche du changement de position des pilotes avec l’emploi des séquences d’apprentissage en début de trame. Nous proposons également une méthode visant à optimiser l’estimation classique qui se base sur un séquence d’apprentissage en amélioration l’estimation au niveau de chaque symbole préambule. Dans le contexte d’une transmission simultanée des pilotes, nous proposons deux algorithmes visant à améliorer les performances d’estimation par rapport aux méthodes existantes. Dans la première méthode proposée, les deux canaux SI et SOI sont estimés dans le domaine fréquentiel à l’aide des itérations de Landweber. La seconde proposition consiste à utiliser une matrice de projectionafin d’éviter le bruit engendré par les données inconnues du signal SOI lors de l’estimation. Finalement, nous proposons une méthode d’estimation de canal sélectif en temps et en fréquence pour des fréquences doppler faibles à modérées. Certaines méthodes proposées sont implémentées dans un système full-duplex expérimental qui a recours aux antennes reconfigurables pour réaliser l’annulation passive. / In this work of thesis, we propose new channel estimation approaches for a full-duplex system dédicated to vehicular communications. Both the self-interference (SI) and intended (SOI) channel are estimated. We propose different estimation méthods according to whether the pilots of the signals are transmitted jointly or separately. In the separate transmission, an estimation based on a new pilot configuration is proposed as well as a hybrid method which use both pilot configuration and training sequences.We also propose an optimisation of the conventional training-based method.It consists of improving the estimation of each training symbole. In the joint transmission, we propose two algorithms that aims to improve the estimation performances compared to the existing methods. In the first proposed method, the two channels are first estimated in the frequency domain using the Landweber iterations. The second proposition consists of using a projection matrix to manipulate only the pilots and avoid the noise that is caused by the SOI unknown datas. Finally, we propose a time and frequency-selective channel estimation for low and medium doppler frequency. Some of the proposed estimators are implemented on a real Full Duplex communication system which use Multi-reconfigurable antennas to perform the passive cancellation.
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Využívání dataloggerů ve výuce fyziky (se zaměřením na systém Vernier) / Using dataloggers in physics teaching (focused on Vernier experimental system)Kácovský, Petr January 2012 (has links)
Title: Using dataloggers in physics teaching (focused on Vernier experimental system) Author: Petr Kácovský Department: Department of Physics Education Supervisor: Mgr. Pavel Böhm Supervisor's e-mail address: pavel.bohm@mff.cuni.cz Abstract: Modernizing equipment enables schools to involve advanced computer- aided systems in physics teaching. This work especially focuses on systems capable of recording and storing measured data for later evaluation - the dataloggers. The introduction of this work is devoted to a survey among physics teachers that should investigate what form of instructions they prefer; then a brief search of existing ma- terials follows. The main part of the work consists of newly created instructions for experiments with dataloggers of the Vernier experimental system, primarily designed to serve tea- chers to implement physics experiments in their teaching. The instructions always include a description how to prepare and undertake the measurement, how to process the measured data and what questions and tasks for students can be connected with this part of physics. Experiments described in this work mainly focus on secondary school thermodynamics (or more precisely on molecular physics and thermals) and their thematic intersection is energy, its forms, transmission and conservation.
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Počítačem podporované experimenty ve výuce chemie na střední škole / Microcomputer-Based Laboratory in Secondary School Chemistry EducationStratilová Urválková, Eva January 2013 (has links)
Eva Stratilová Urválková; Dissertation Thesis Title: Microcomputer-Based Laboratory in Secondary School Chemistry Education Abstract School experimental practice should reflect the real laboratory practice so that school science keeps in touch with reality. Todays laboratories are fully equipped with instrumental devices that are often presented in media, so it is necessary that students have experience also with this way of experiments. For school purposes seem suitable probeware (school experimental systems), that combine modern technology with concept of student-centered learning (eg inquiry based science education) that should successfully prepare students for lifelong learning. During recent years probeware has become one of discussed topics in Czech science education, but there has been a lack of research examining whether both teachers and pupils are prepared to accept and implement probeware into school chemistry curriculum. Almost none research has been done in field search describing the way of using the probeware and microcomputer-based laboratory in Czech school curriculum. Presented mixed method research focuses on attitudes of chemistry teachers (N = 65), pre-service chemistry teachers (N = 38) and students (N = 50) regarding attitudes to general devices and measuring devices (or probeware) to...
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Neurostimulations-KulturKalmbach-Özdem, Monika 12 1900 (has links)
Die Medizintechnik Tiefe-Hirnstimulation ist nicht nur als naturwissenschaftlich-technisches Produkt zu sehen, sondern vor allem auch als kultur-technische Leistung mit historischen Wurzeln. Dieserart Schnittstellenhandlungen nehmen einen festen Platz in der Medizingeschichte ein und sind nicht losgelöst von dieser zu bestimmen. Ein- und zugreifende Praktiken wie Trepanationen und Schädelkulte sind vielfältig verankert und offenbaren einen menschheitsalten Wunsch nach Einflussnahme und Bemächtigung. Hierüber lässt sich der Mensch als verknüpf-, einstell- und gestaltbare Entität im Rahmen 'eutoper' Welt- und Technikbilder sowie deterministischer Menschenbilder darstellen. Mit der Integration aktiver, technischer Elemente in den menschlichen Körper verschieben wir die Grenzverläufe zwischen biologischen und artifiziellen Entitäten. Sowohl die Hardware-Software-Relationen als auch die Körper-Geist-Relationen unterliegen dabei Verknüpfungs- und Gestaltungsprozessen. Aus der Interaktion zwischen menschlichen und nicht-menschlichen Handlungsteilnehmern resultieren neuartige Wechselbeziehungen, welche unter Zuhilfenahme der Embodiment- und Embedded-Theorie nachgezeichnet werden. Den schwerwiegenden Aus- und Nebenwirkungen dieser Interkation wird mit einem empirischen Fallbeispiel nahegekommen. Dass diese Entwicklung hin zu einer konfigurierenden Gestaltungskultur risikobehaftet ist, wird unter Zuhilfenahme des Terminus 'Experimentalsystem' dargelegt. Dabei ist festzuhalten, dass die Tiefe-Hirnstimulation nicht trotz sondern wegen experimenteller Faktoren erfolgreich und faszinierend ist. Neurostimulationen in erster Linie als Konzept zu begreifen bedeutet, den Fokus auf kulturelle Anschichten und Handlungen zu lenken. In welchem Ausmaß wir zu ein- und zugreifenden Gestaltungen unserer Selbst bereit sind, hängt in letzter Konsequenz an unserem menschlichen Selbstverständnis. / Medical technology deep brain stimulation is not only a scientific and technical product, but also a cultural and technical achievement with historical roots. This kind of interface actions occupy a firm place in medical history and cannot be determined separately from it. Interfering practices such as trepanations and cults of the skull are rooted in many different ways and reveal an ancient human desire for influence and empowerment. In this way, man can be represented as a connectable, adjustable and configurable entity within the framework of 'eutoper' world and technology images as well as deterministic human images. By integrating active technical elements into the human body, we are shifting the boundaries between biological and artificial entities. Both the hardware-software-relations as well as the body-spirit-relations are subject to connection and design processes. The interaction between human and non-human action participants results in novel interrelationships, which are traced with the aid of the Embodiment and Embedded Theory. The serious side effects of this interaction are approached with an empirical case study. The fact that this development towards a configuring design culture entails risk is explained with the help of the term 'experimental system'. It should be noted that deep brain stimulation is successful and fascinating not despite but because of experimental factors. Understanding neurostimulation primarily as a concept means focusing on cultural strata and actions. The extent to which we are prepared to embrace and intervene in shaping ourselves depends ultimately on our human self-conception.
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Charakterizace vlastností fotovoltaického systému / Characteristic of photovoltaic systemPokorný, Marek January 2011 (has links)
The aim of this work is informed first about photovoltaics universally, works to inform the photovoltaic panels and complete plants. The work also includes instructions on how to implement PVP in accordance with law. Another part is the rough draft of the photovoltaic power 30 kWp, which can be placed on the house, computation and calculation of investment and them profitable investments to time. Design is made in two separate forms of the Fronius Solar and Sunny Design, their outputs are compared. The practical part of this work cooperates with the company SOLARTEC Ltd. for experimental measurements of the photovoltaic system and develop a methodology for setting the properties of real solar systems in operation from the measured data then stored in a database. These data further evaluate and compare the similar operating conditions. This data will show as the course of production of electricity during the typical day in percentage terms, depending on the incident irradiance, cell temperature, angle of incident radiation, etc. We can compare what it looks like an ideal day in terms of production of photovoltaic power, with the other days. Further are in work mentioned histograms achievement panel behind classical day and behind all - time investigation.
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