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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Gerenciamento de handovers em next generation networks com agregação de contexto / Handovers management with context aggregation in next generation networks

Roberto Sadao Yokoyama 23 July 2009 (has links)
Em NGN (Next Generation Networks), os usuários podem se conectar em diferentes tecnologias de rede e desejam, além de uma comunicação transparente, novos serviços personalizados. Neste sentido, este trabalho explora informações de contexto em NGN. O principal objetivo é capturar as informações de contexto envolvidas no momento da utilização da rede sem fio, na escolha do novo ponto de acesso e no procedimento do handover. Este contexto capturado é aplicado para serviços cientes de contexto. A proposta é validada por meio de dois cenários, o primeiro é um mashup que exibe as redes sem fio disponíveis de um determinado local e o segundo um protótipo gerenciador de conexões para atender as preferências do usuário. Adicionalmente, são realizadas duas avaliações do impacto do uso de contexto em handovers. Para tanto, foi implantado um testbed NGN com o protocolo Mobile IP / In the NGN (Next Generation Networks) users can connect their Internet devices to different network technologies. In addition to a seamless communication, users desire new and personalized services. In this sense, this thesis exploits the context-aware information in NGN environments. The main propose is to capture the context information about the time involved by the use of wireless link for selecting the target access point and on the handover procedure. This context information is applied to the context-aware services. The propose is validated through two scenarios: the first is a mashup that shows the availability of wireless networks in a particular location, and the second is a prototype of a connection manager to attend user´s preferences. In addition, two evaluations are accomplished on the impact by the use of context information over handovers. Thus, an NGN testbed is deployed with Mobile IP protocol
42

Διερεύνηση στοιχείων διαλειτουργικότητας μεταξύ δικτύων κινητής τηλεφωνίας και ασυρμάτων δικτύων δεδομένων

Βαφείδης, Παναγιώτης 27 August 2009 (has links)
Στην εν λόγω εργασία, έγινε μια προσπάθεια καταγραφής του τεχνολογικού τοπίου της τηλεπικοινωνιακής αγοράς, με έμφαση την διαλειτουργικότητα μεταξύ των Δικτύων Κινητής Τηλεφωνίας και των Ασύρματων Δικτύων Δεδομένων και των σχετικών αλλαγών που έχει επιφέρει αυτή η διαλειτουργικότητα, τόσο στις παρεχόμενες υπηρεσίες, όσο και στα εφαρμοζόμενα επιχειρηματικά μοντέλα από πλευράς εταιρειών της συγκεκριμένης αγοράς. Στα πλαίσια αυτής της προσπάθειας, χρειάστηκε να πραγματοποιηθεί μια λεπτομερής καταγραφή των τεχνολογικών εξελίξεων, σε επίπεδο τεχνικών προδιαγραφών και προτύπων, στις παραπάνω δύο κατηγορίες δικτύων, ώστε να καταλήξουμε σε εκείνα τα πρότυπα που πλέον μπορούν να οδηγήσουν στην υλοποίηση δικτύων τα οποία θα χαρακτηρίζονται από τα παρακάτω: • θα είναι ενοποιημένα ώστε οι διαφορετικές τεχνολογικές πλατφόρμες των εταιρειών να λειτουργούν απρόσκοπτα, • θα χαρακτηρίζονται από χαμηλό κόστος, • ο τελικός χρήστης θα μπορεί να είναι συνεχώς συνδεδεμένος με κάποιο δίκτυο ασύρματης πρόσβασης και να απολαμβάνει τις υπηρεσίες που επιθυμεί, οποτεδήποτε και οπουδήποτε. Η δομή της διπλωματικής εργασίας ακολουθεί τον προαναφερθέντα τρόπο σκέψης. Στο 1ο Κεφάλαιο γίνεται μια σύντομη παρουσίαση του στόχου σε επίπεδο τεχνολογιών αλλά και υπηρεσιών, δηλαδή των αναμενόμενων αποτελεσμάτων αυτών των δικτύων νέας γενιάς, στα οποία έχουμε συνηθίσει να αναφερόμαστε ως δίκτυα 4G (4th Generation) ή δίκτυα B3G (Beyond 3G) ή τέλος ως All – IP ασύρματα δίκτυα. Στο 2ο Κεφάλαιο, γίνεται μια λεπτομερής παρουσίαση των Δικτύων Κινητής Τηλεφωνίας από τις πρώτες τους εκδοχές (1G) έως τις πλέον σύγχρονες (3.5G) που έχουν εμφανιστεί μέχρι σήμερα. Αναλύονται τόσο οι γενιές των δικτύων όσο και τα χρησιμοποιούμενα πρότυπα, σε επίπεδο αρχιτεκτονικής όσο και σε επίπεδο πρωτοκόλλων. Στη συνέχεια του κεφαλαίου υπάρχει η τεχνική περιγραφή των επικρατέστερων δικτύων κινητής τηλεφωνίας, σήμερα, δηλαδή των GSM, GPRS και UMTS, ενώ στο τέλος του κεφαλαίου υπάρχει μια σύντομη περιγραφή της διαδικασίας intersystem handover μεταξύ των GSM και UMTS. Στο 3ο Κεφάλαιο, περνάμε πλέον στα Ασύρματα Δίκτυα Δεδομένων. Γίνεται μια εκτενής περιγραφή των προτύπων που έχουν καθοριστεί και συγκεκριμένα στα πρότυπα IEEE 802.15 Wireless Personal Area Networks (WPANs) με κυριότερους εκφραστές τα δίκτυα βασιζόμενα σε Bluetooth και IrDA, το πρότυπο IEEE 802.11 Wireless Local Area Networks (WLANs) με σημαντικότερος εκπροσώπους τα WiFi και HyperLan/2, το πρότυπο IEEE 802.16 Wireless Metropolitan Area Networks (WMANs) ή αλλιώς γνωστότερο ως WiMAX και τέλος το πρότυπο IEEE 802.20 Wireless Wide Area Networks (WWANs) ή διαφορετικά Mobile Broadband Wireless Access (MWBA) το οποίο είναι υπό διερεύνηση ακόμα και φιλοδοξεί να αποτελέσει το ασύρματο ανάλογο της τεχνολογίας xDSL, καθώς θα προσφέρει ασύρματες ευρυζωνικές υπηρεσίες. Στο 4ο Κεφάλαιο παρουσιάζονται μεθοδολογίες υλοποίησης του integration μεταξύ δικτύων των δύο κατηγοριών και συγκεκριμένα παραδείγματα διαλειτουργικότητας, όπως μεταξύ GPRS ή UMTS και WLANs ή μεταξύ UMTS και WiMAX. Γίνεται εκτενής συζήτηση γύρω από τα προβλήματα που θα πρέπει να αντιμετωπιστούν, όπως η εξασφάλιση ανεκτού επιπέδου QoS, οι μηχανισμοί για handover μεταξύ των δικτύων, η διαχείριση της κινητικότητας των χρηστών και των τερματικών και δίνονται παραδείγματα δημιουργίας ενοποιημένων δικτύων, τόσο με τη τεχνική της χαλαρής όσο και με την τεχνική της ισχυρής ζεύξης. Στο τελευταίο τμήμα του Κεφαλαίου, γίνεται μια εκτενής αναφορά στις αρχιτεκτονικές διασύνδεσης ετερογενών δικτύων με IP δίκτυα κορμού, τα γνωστά All – IP networks. Ιδιαίτερη έμφαση δίνεται στους μηχανισμούς πραγματοποίησης των handovers βάσει πολιτικών (policy based) και η χρήση τεχνικών για micromobility και macromobility σε σχέση με την κινητικότητα των τερματικών. Το 5ο Κεφάλαιο αφορά τις εφαρμογές και υλοποιήσεις ασυρμάτων δικτύων δεδομένων στον Ελληνικό χώρο, στα πλαίσια του Επιχειρησιακού Προγράμματος «Κοινωνία της Πληροφορίας» και πιο συγκεκριμένα τα «Εξοπλισμός και δικτύωση σε όλες τις βαθμίδες της εκπαίδευσης», «Ασύρματα Ευρυζωνικά Δίκτυα ΟΤΑ»και «Μητροπολιτικά Ευρυζωνικά Δίκτυα Οπτικών Ινών ΟΤΑ» και ουσιαστικά αποτελούν παραδείγματα και υλοποιήσεις διασύνδεσης WiFi, WiMAX και IP backbone δικτύων όπως το ΣΥΖΕΥΞΙΣ με δυνατότητες για παροχή VoIP. / In this thesis, an effort of presenting the technological landscape of the telecommunication market takes place, with focus on the interoperability between the Mobile Telephony Networks and the Wireless Data Networks and the relative changes that have evolved through this interoperability, both regarding the provided services and the applied business models by the enterprises of the specific market. Within the frames of this effort, a detailed recording of technological developments is realised, in terms of technical specifications and standards, in the two aforementioned categories of networks, so as to conclude to those standards that are utilized by the next generation networks (4G) which will be: • Networks that will be unified so as the different technological platforms will function smoothly. • Networks that will be characterized by low cost of deployment. • The end user will be continuously connected with a wireless access network, enjoying the preferred services anywhere and anytime. The master thesis structure follows the aforementioned methodology. The 1st Chapter includes a short presentation of expected results, both in terms of technologies and services for next generation networks, which we usually refer to as 4G networks (4th Generation) or B3G networks (Beyond 3G) or finally as All - IP wireless networks (AIPN). In the 2nd Chapter, a detailed presentation of Mobile Telephony Networks takes place, from their first versions (1G) until the most modern (3.5G) that have been presented up to today. The analysis includes both the various generations of networks and the used standards, in terms of modulation and multiplexing techniques. The rest of the chapter focuses on the technical description of the prevailing networks, GSM, GPRS and UMTS, while the chapter ends with a short description of intersystem handover processes between GSM and UMTS. Τhe 3rd Chapter, includes an extensive description of the Wireless Data Networks standards such as: IEEE 802.15 Wireless Personal Area Networks (WPANs) with main representatives networks based on Bluetooth and IrDA, standard IEEE 802.11 Wireless Local Area Networks (WLANs) mainly represented by WiFi and HyperLan/2, IEEE 802.16 Wireless Metropolitan Area Networks (WMANs) standard, widely known as WiMax and finally the IEEE 802.20 Wireless Wide Area Networks (WWANs) standard, namely Mobile Broadband Wireless Access (MWBA) that is still under development and aspires to constitutes the wireless version of the xDSL technology, since it aims to provide wireless broadband services. In the 4th Chapter methodologies for integrating the two types of networks, are presented along with examples of interoperability between GPRS / UMTS and WLANs or between UMTS and WiMAX. Extensive discussion around the problems that should be faced, as the guarantee of bearable QoS level, the mechanisms for handover between the networks and the management of mobility of users and terminals, is held. Moreover, examples of integrated networks with both loose and tight coupling methodologies are presented. The last section of the chapter concerns a detailed description of architectures for interconnecting heterogeneous wireless networks over IP – based backhaul networks, namely All – IP networks, with special focus on policy based handover mechanisms and techniques for managing micromobility and macromobility issues. The 5th Chapter concerns the changes taking place in the telecommunications market deriving from the technological progress in the subject of heterogeneous wireless networks interconnection. New service packets are created, as a result of new business plans that are drawn up by the big telecommunications organizations. Finally, we present the developments in the Greek market and subsidised projects from Information Society AE, via which wireless networks have been materialised, with aim to promote Broadband Services.
43

Interactions inter-couches et liens à long délai / Cross-layer interactions and long delay links

Kuhn, Nicolas 21 November 2013 (has links)
La demande accrue de services en temps rel, comme la vidéo streaming, justifie le besoin d'études qui visent à optimiser le délai de transmission de données. En plus du délai de transmission au niveau physique, les délais nécessaires à l'accès à la ressource et à la récupération de données venant des couches basses peuvent avoir un impact important sur les performances et ne doivent pas être négligés. Aussi, des études cross-layer doivent être menées pour minimiser le délai de transmission de l'information. Comprendre l'impact des mécanismes des couches basses sur les performances de bout-en-bout permet un meilleur dimensionnement du réseau, une adaptation du trafic transmis, ou l'introduction de service à faible priorité. Dans cette thèse, nous avons mesuré l'impact des mécanismes des couches liaison et réseau sur les performances de divers protocols de congestion de la couche transport.Dans le contexte des liens 4G par satellite, nous proposons un ensemble d'outils, Trace Manager Tool (TMT) et Cross Layer InFormation Tool (CLIFT), pour simuler de manière réaliste l'ensemble de la couche OSI dans le simulateur de réseau NS-2. Nous avons montré que, pour l'ensemble des variantes de TCP considérées, quand le débit au niveau transport est proche de la capacité de canal, utiliser ARQ au niveau liaison est optimal. Dans le cas où le taux d'erreur au niveau de la couche physique est plus élevé, H-ARQ permet d'obtenir un meilleur débit au niveau transport.Les dernières spécifications concernant l'accès au lien satellite DVB-RCS2 présentent deux méthodes d'accès (aléatoire et dédié) qui peuvent être implémentées pour permettre aux utilisateurs des services proposés par DVB d'aller sur Internet ou de transmettre des données. Nous avons développé un module pour NS-2, Physical Channel Access (PCA), qui modèle l'accès au canal pour chacune de ces méthodes afin de comparer leur impact sur les performances de bout-en-bout. Nous avons mesuré que les méthodes d'accès dédié permettent un débit plus important et les méthodes d'accès aléatoire une transmission rapide des flots courts. Nous avons donc proposé de mixer ces méthodes d'accès, en fonction de l'évolution dynamique de la charge du réseau et de la taille du flot de données transmis.Finalement, nous avons étudié s'il était possible d'exploiter les données de la gateway du satellite pour introduire un trafic à priorité basse. Nous avons montré qu'il était possible avec Low Ewtra Delay Background Transport (LEDBAT) comme protocole de la couche transport d'introduire un trafic en tâche de fond. Cependant, en fonction de la variation de la charge du réseau, paramétrer correctement des paramètres internes à ce protocole sont nécessaires. / Network providers offer services in line with users’ requests, even though the challengesintroduced by their mobility and the download of large content are crucial. Mobile videostreaming applications are delay sensitive and the increasing demand for this service legitimateextensive studies evaluating transmission delays. On top of physical transmissiondelays, accessing a resource or recovering data from lower layers should not be neglected.Indeed, recovery schemes or channel access strategies variously introduce end-to-end delays.This document argues that those cross-layer effects should be explored to minimizethe transmission delays and optimize the use of network resources. Also, understandingthe impacts of low layers protocols on the end-to-end transmission will enable betterdimensioning of the network and adapt the traffic carried on.In the context of satellite 4G links, we measure the impact of link layer retransmissionschemes on the performance of various transport layer protocols. We develop Trace ManagerTool (TMT) and Cross Layer InFormation Tool (CLIFT) to lead realistic cross layersimulations in NS-2. We show that, for all target TCP variants, when the throughput ofthe transport protocol is close to the channel capacity, using the ARQ mechanism is mostbeneficial for TCP performance improvement. In conditions where the physical channelerror rate is high, Hybrid-ARQ results in better performance.In the last specifications for DVB-RCS2, two access schemes (random and dedicated)are presented and can be implemented to manage the way home users access to the satellitelink for Web browsing or data transmission. We developed Physical Channel Access (PCA)that models in NS-2 the behaviour of those link layer level access methods. We measurethat, even though dedicated access methods can transmit more information data, randomaccess methods enable a faster transmission of short flows. Based on these results, wepropose to mix random and dedicated access methods depending on the dynamic load ofthe network and the sequence number of the TCP segments.As a potential exploitation of cross layer information, we explore the feasibility to introducelow priority traffic on long delay path. The rationale is to grab the unused 4G satellitelinks’ capacity to carry non-commercial traffic. We show that this is achievable with LEDBAT.However, depending on the fluctuation of the load, performance improvements couldbe obtained by properly setting the target value.
44

FPGA-Based Acceleration of LTE Protocol Decoding

Thelin, William January 2021 (has links)
This work investigates the possibility to accelerate a procedure in 4G/LTE systems, known as control channel analysis. The aim is to perform the procedure in real-time on cheap and accessible hardware.An LTE decoder implemented in software is modified to perform the procedure.The modified software is analyzed and profiled. The most time-consuming decoding steps are identified and implemented in hardware description language.The results show an acceleration of the most time-consuming steps of almost 50 times faster compared to implementation in software only. Furthermore, the resource utilization of the hardware design scales linearly with respect to faster decode time, if necessary the acceleration can be increased. However, the results from the profiling and time measurements of the software show that the time requirement is violated by other decoding steps.The thesis concludes that an acceleration in hardware of the most time-consuming steps is possible. However, to satisfy the time requirement further decode steps are required to be accelerated and/or a faster processor can be used.
45

Analýza uživatelské roviny mobilních sítí 4. generace / User plane analysis in 4th generation mobile networks

Velsh, Ilya January 2014 (has links)
The thesis describes the 2G, 3G and 4G mobile systems with a focus on the user plane. It decipt the problem of key performance indicators focusing on the characteristics of the user plane. It contains analysis of the basic data transmission services and requirements for their quality. The thesis also describes the user plane protocol stacks.
46

台灣推動第四代行動通訊WiMAX的行動者網絡分析 / An Actor-Network Analysis of the promotion of semi-4G WiMAX in Taiwan

邱鈞彥, Theodre, Chiu Unknown Date (has links)
摘要 台灣產官學研自2005年起推動被稱為準4G(第四代行動通訊)的WiMAX技術,然而今日WiMAX不但未成為國際通用的4G技術,在台灣市場也無法做大。本文以「行動者網絡理論」作為主要分析工具,輔以「後進技術框架」為鉅觀視野,還原台灣推動WiMAX的行動歷程。透過檢閱期刊文獻、官方資料、媒體報導,以及訪談科技法人、營運商、官員、技術專家、使用者、環運人士,研究結果如下: 2005年在代工困境及PC產業成長趨緩的背景下,台灣產官學研持續尋求解套辦法。產官人士發現,技術專利有助於刺激產業升級,而通訊技術則能帶動硬體裝置銷售成長,市場潛力大。當時恰逢電機電子工程師學會(IEEE)正在研發WiMAX,有許多技術專利可供搶佔,加上IEEE對外較開放,因此轉譯了台灣產官人士的興趣,促使WiMAX技術網絡在台灣萌生。 然而受到傳統電信商不支持、執照分區及載具限制等因素影響,WiMAX在台灣的用戶數始終停滯不前。為了解決市場限制,營運商透過命名、訊號轉換及體驗行銷等方式,力圖擴大市場。本研究也發現,WiMAX在使用者與訊號轉換器的共同運作之下,多被用成解決Wi-Fi覆蓋死角的網路技術,而未被當成行動網路來使用。傳統電信業者所慣用的綁約機制,則是影響使用者選擇進用WiMAX的關鍵因素。 承接前述脈絡,本文發現台灣推動WiMAX乃後進技術國家追尋現代性的顯著案例,我國治理組織推動WiMAX的主要目的並非佈局4G,而是為了取得專利、帶動產業升級、刺激產業典範轉移。在WiMAX網絡的萌生過程中,南韓則因為擁有成功的CDMA經驗,取代了歐美先進技術國家,成為台灣苦苦追趕的對象。 / Abstract From 2005, the Government-industry-university-research collaboration started to promote WiMAX, as the so called semi-4G, in Taiwan. However, WiMAX didn’t become the globally used standard, nor developed very well in Taiwan. The analytical frame of this paper is based on actor-network-theory(ANT), while applying the post technological frame. The research data are collected from Journal articles, formal informations, media reports and 8 actors. The results are as follower: The dilemma that OEMs are facing and the down of PC market shake off economics downturn in Taiwan. The Government-industry-university-research collaboration continued to find the solution to change the manufacturing paradigm. Around 2005 they found out the IPR and wireless broadband are having much market potential. At that time the IEEE was developing WiMAX standard. WiMAX and its IPR translate the Government-industry-university-research collaboration’s interests. Due to the lack of telecom operator’s support, license arrangement, and limitations of device capabilities the subscribers of WiMAX didn’t grow massively. For expanding the market, operators used naming, signal device, and experiential marketing to promote WiMAX. However, WiMAX was used as a Wi-fi not a Mobile broadband by the users and signal devices. The contract tied with 3G and Wi-fi impacted the subscribing of WiMAX. The promotion of WiMAX in Taiwan was a significant case of post technological country. The aim of promoting WiMAX was not for 4G, but for the paradigm shifting. In the promoting process, South-Korea played an important role as advanced technological country for Taiwan to chase up.
47

Conception d’un amplificateur de puissance reconfigurable en CMOS nanométrique pour les applications LTE dans les drones / Design of a reconfigurable power amplifier on 65nm CMOS for LTE applications in drones

Luong, Giap 20 July 2018 (has links)
Les véhicules aériens sans pilote (UAV), souvent appelés drones, trouvent de nombreuses applications dans la vie. Les applications de drones nécessitent plusieurs indicateurs de performance essentiels tels que la couverture, la force du signal, la latence et la mobilité dans des scénarios. Par conséquent, l'utilisation des communications sans fil dans les drones est essentielle pour répondre à toutes les exigences. En raison des connexions au haut débit entre les drones et les utilisateurs pour transférer des données de haut volume à haute résolution, les dernières générations sans fil, comme la norme LTE, sont privilégiées. Il est évident que l'intégration de blocs de radiofréquence (RF) est essentielle pour construire un système sur puce et réduire la taille des drones. Dans ce contexte, cette thèse vise à développer un amplificateur de puissance (PA) innovant avec haute performance reconfigurable entièrement intégré qui adresse les différents besoins imposés par le standard LTE à utiliser dans les applications des UAV. Le PA entièrement intégré en CMOS 65 nm a pour objectif de fournir une puissance de sortie élevée et résoudre le compromis entre la linéarité et l’efficacité. Un transformateur à quatre enroulements est implémenté pour configurer le fonctionnement en multi modes du PA. La technique « segmented bias » permet au PA d’améliorer la linéarité. Le PA obtient non seulement des performances élevées en RF, mais démontre également un potentiel pour l'adopter dans la bande 5G inférieure. / Unmanned aerial vehicles (UAVs), often known as drones, have been finding numerous applications in life. Drones applications need several essential performance indicators such as coverage, signal strength, latency, and mobility under scenarios. Therefore, the use of wireless communications in drones is critical to address all requirements. Because of high-speed connections between drones and users to transfer high-resolution high-volume data, latest wireless generations, namely the LTE standard, are privileged. It is straightforward that the integration of RF blocks is essential to build a system-on-chip and shrink the size of drones. To answer the above question, this thesis aims to develop a fully integrated reconfigurable high-performance innovated PA that supports 4G LTE standard to be used in UAVs’ applications. The fully integrated 65-nm CMOS power amplifier (PA) provides a watt-level output power, addresses the linearity/efficiency trade-off. A four-winding transformer is implemented to configure the multi-mode operation of the PA. The “segmented bias” technique allows the PA to increase the linearity. The PA not only obtains high radiofrequency performances but also demonstrates a potential to adopt it design in the lower 5G band.
48

Adsor??o do corante amarelo reativo BF-4G 200% por argila esmectita / Adsorption of the dye reactive yellow BF-4G 200% by smectite clay

Rodrigues Filho, Geraldo Martins 28 September 2012 (has links)
Made available in DSpace on 2014-12-17T15:01:30Z (GMT). No. of bitstreams: 1 GeraldoMRF_TESE.pdf: 3870711 bytes, checksum: 6a5339896637d234e88f58bd692fe8cf (MD5) Previous issue date: 2012-09-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This study aimed to evaluate the potential use of smectite clays for color removal of textile effluents. The experiments were performed by testing exploratory/planning method factorial and fractional factorial where the factors and levels are predetermined. The smectite clays were used originating from gypsum hub of the region Araripe-PE, and the dye used was Reactive Yellow BF-4G 200%. The smectite clay was collected and transported to the Laboratory of Soil Physics of UFRPE, where it held its preparation through air drying, lump breaking and classification in sieve to then submit it to the adsorption process. Upon completion of 22 complete factorial design it was concluded that the values of (96, 96,5 and 95,8%) corresponding to the percentage of of removal for "in-kind", chemically and thermally activated, respectively and adsorbed amounts of (4,80, 4,61 and 4,74 mg/g) for three clays. Showed that the activation processes used did not increase the adsorption capacity of smectite clay. The kinetic data were best fitted to the Freundlich isotherm, with an exponential distribution of active sites and that shows above the Langmuir equation for adsorption of cations and anions by clays. The kinetic model that best adapted to the results was the pseudosecond order model. In the factorial design study 24-1, at concentrations up to 500 mg/L obtains high percentage of color removal (92,37, 90,92 and 93,40%) and adsorbed amount (230,94, 227,31 and 233,50 mg/g) for three clays. The kinetic data fitted well to Langmuir and Freundlich isotherms. The kinetic model that best adapted to the results was the pseudosecond order model / Este trabalho teve como objetivo avaliar o potencial de utiliza??o das argilas esmectitas, para remo??o de cor de efluentes t?xteis. Os experimentos foram realizados atrav?s de ensaios explorat?rios/m?todo de planejamento fatorial e fatorial fracion?rio, em que os fatores e os n?veis s?o pr?-determinados. As argilas esmectitas usadas foram origin?rias do p?lo gesseiro da regi?o do Araripe-PE, e o corante utilizado foi o Amarelo Reativo BF-4G 200%. A argila esmectita foi coletada e transportada para o Laborat?rio de F?sica de Solos da UFRPE, onde se realizou a sua prepara??o atrav?s de secagem ao ar, destorroamento e classifica??o em peneiras para, em seguida, submet?-la ao processo de adsor??o. A partir da realiza??o do planejamento fatorial 22 concluiu-se que os valores de 96, 96,5 e 95,8%, correspondentes aos percentuais de remo??o para as argilas esmectitas innatura , quimicamente e termicamente ativadas, respectivamente, e com quantidades adsorvidas de 4,80, 4,61 e 4,74 mg/g, para as tr?s argilas, mostraram que os processos de ativa??o utilizados n?o aumentaram o poder de adsor??o da argila esmectita. Os dados cin?ticos ajustaram-se melhor ? isoterma de Freundlich, com uma distribui??o exponencial de s?tios ativos e que se mostra superior ? equa??o de Langmuir para adsor??o de c?tions e ?nions pelas argilas. O modelo cin?tico que melhor se adequou aos resultados foi o modelo pseudo-segunda ordem. No estudo do planejamento fatorial 24-1, em concentra??es de at? 500 mg/L se obt?m elevados percentuais de remo??o de cor (92,37, 90,92 e 93,40 %) e quantidade adsorvida (230,94, 227,31 e 233,50 mg/g) para as tr?s argilas. Os dados cin?ticos ajustaram-se bem ?s isotermas de Langmuir e Freundlich. O modelo cin?tico que melhor se adequou aos resultados foi o modelo pseudo-segunda ordem
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Holografický modul pro světelnou mikroskopii / Holographic module for a light microscopy

Škrabalová, Denisa January 2019 (has links)
The new arrangement of the off-axis holographic module, which is using polarizationactive diffraction grating divides signal into reference and subject wave of an interferometer based on their polarization. However, current design of the module does not have a possibility to tune a length of the optical paths. Thus the inability to tune optical paths leads to a reduced quality of interference structure during observation of biological samples. The current module is only suitable for technical applicating due to this limitation. Possibility of tuning branches is key step in biological applications. Therefore a new computer-controlled module is created in order to enable use for biological samples.
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Antenner för bussmarknaden : EN FÖRSTUDIE FÖR EN NY ANTENNPLATTFORM

Bitar, Michel, Engström, Victor January 2015 (has links)
Världsmarknaden för bussar växer ständigt och under 2012 har fler än 500 000 bussar producerats globalt. Utöver den växande bussmarknaden så drivs efterfrågan av internet ombord, fleetmanegment tjänster, TV, GPS, olika typer av radio och behovet av robusta tillförlitliga antenner för trådlös dataöverföring till och från bussar. Tillverkarna av bussar vill kunna erbjuda sina kunder dessa funktioner och bussoperatörerna satsar mer och mer på att kunna erbjuda trådlösa tjänster till sina kunder. Antennföretaget Smarteq Wireless ser en stor potential i denna marknad eftersom det idag inte finns något företag som uttalat satsar på antenner specifikt framtagen för bussar som kan möta kundernas krav på funktionalitet och robusthet. Utöver den potentiella marknaden så existerar också en eftermarknad som består av bussar som ständigt behöver uppdatera deras antenner. Smarteq ser här en möjlighet att utveckla en unik antennplattform anpassad till bussindustrin. Syftet med examensarbetet är att förse Smarteq med ett underlag som kan användas inför utvecklingen av den nya antennplattformen. Underlaget består av en omfattande marknadsundersökning, kravspecifikationer och en konkurrentanalys. Undersökningen syftar till att besvara vilka tekniska funktionaliteter en antennplattform för bussar bör innehålla för att attrahera tillverkare och operatörer på bussmarknaden. Arbetet har visat att det finns goda möjligheter på bussmarknaden för en ny antennplattform. Antennplattormen bör ha stöd för 4G, WiFi och GPS eftersom det har visat sig att dessa funktioner är mest efterfrågade. Den mest uppenbara delen av marknaden att fokusera på utifrån undersökningen är telematikleverantörerna. Detta eftersom de har en stark koppling till bussmarknaden där de flesta av deras system säljs dit. Att sälja en antenn tillsammans som del av ett system är enklare än att sälja antennenseparat. / The global market for buses is constantly growing and in 2012, more than 500,000 buses were produced globally. In addition to the growing bus market, the demand is driven by the Internet on board, fleetmanegment services, TV, GPS, various types of radio and the need for robust reliable antennas for wireless data transfer to and from buses. Bus manufacturers want to provide their customers with these functions and bus operators are investing more and more in order to offer wireless services to their customers. The antenna company Smarteq Wireless sees a great potential in this market because there are currently no other companies that produces antennas specifically designed for buses that can meet customer requirements for functionality and robustness. In addition to the potential market there is also an existing aftermarket consisting of buses that constantly need to update their antennas. Smarteq sees an opportunity to develop a unique antenna platform adapted to the bus industry. The aim of the project is to provide Smarteq with a theoretical basis that can be used for the development of the new antenna platform. The theoretical basis consists of an extensive market research, antenna specifications and competitor analysis. The study aims to answer which technical functionalities an antenna platform for buses should contain in order to attract manufacturers and operators in the bus market. The work has shown that there is great potential in the bus market with a new antenna platform. The antenna platform should have support for 4G, WiFi and GPS because it has been shown that these functionalities are the most requested ones. The most obvious part of the market to focus on, based on the survey is via suppliers of telematics. This is because they have a strong connection to the bus market, where most of their systems are sold. To sell an antenna together as part of a system is easier than selling an antenna individually.

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