Innovations in optical communication are expected to transform the landscape of global communications, internet and datacenter networks. This dissertation investigates several important issues in optical communication such as fairness, throughput, blocking probability and differentiated quality of service (QoS). Novel algorithms and new approaches have been presented to improve the performance of optical circuit switching (OCS) and optical burst switching (OBS) for long haul, and datacenter networks. Extensive simulations tests have been conducted to evaluate the effectiveness of the proposed algorithms. These simulation tests were performed over a number of network topologies such as ring, mesh and U.S. Long-Haul, some high processing computing (HPC) topologies such as 2D and 6D mesh torus topologies and modern datacenter topologies such as FatTree and BCube. Two new schemes are proposed for long haul networks to improve throughput and hop count fairness in OBS networks. The idea is motivated by the observation that providing a slightly more priority to longer bursts over short bursts can significantly improve the throughput of the OBS networks without adversely affecting hop-count fairness. The results of extensive performance tests have shown that proposed schemes improve the throughput of optical OBS networks and enhance the hop-count fairness. Another contribution of this dissertation is the research work on developing routing and wavelength assignment schemes in multimode fiber networks. Two additional schemes for long haul networks are presented and evaluated over multimode fiber networks. First for alleviating the fairness problem in OBS networks using wavelength-division multiplexing as well as mode-division multiplexing while the second scheme for achieving higher throughput without sacrificing hop count fairness. We have also shown the significant benefits of using both mode division multiplexing and wavelength division multiplexing in real-life short-distance optical networks such as the optical circuit switching networks used in the hybrid electronic-optical switching architectures for datacenters. We evaluated four mode and wavelength assignment heuristics and compared their throughput performance. We also included preliminary results of impact of the cascaded mode conversion constraint on network throughput. Datacenter and high performance computing networks share a number of common performance goals. Another highly efficient adaptive mode wavelength- routing algorithm is presented over OBS networks to improve throughput of these networks. The effectiveness of the proposed model has been validated by extensive simulation results. In order to optimize bandwidth and maximize throughput of datacenters, an extension of TCP called multipath-TCP (MPTCP) has been evaluated over an OBS network using dense interconnect datacenter topologies. We have proposed a service differentiation scheme using MPTCP over OBS for datacenter traffic. The scheme is evaluated over mixed workload traffic model of datacenters and is shown to provide tangible service differentiation between flows of different priority levels. An adaptive QoS differentiation architecture is proposed for software defined optical datacenter networks using MPTCP over OBS. This scheme prioritizes flows based on current network state.

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Professional development (PD) of teachers is part of the Department of Basic Education‘s (DBE) initiative to encourage school communities to use of information and communication technology (ICT) to improve the quality of Mathematics teaching and learning. The South African Council of Educators stipulates that PD programmes should align with system-wide needs, strengthen learning area content and outcomes, and promote system transformation. Imbedded in this system-wide criterion is The White Paper on e-Education to employ a fully ICT integrated system at all levels of education: management, teaching and learning, and administration by 2013. Mathematics teachers require PD that develops their technological pedagogical and content knowledge (TPACK) and their social professional identity (SPI). The PD of Mathematics teachers for ICT integration can assist the DBE to achieve the aims of The White Paper on e-Education and bridge the technology gap between South Africa and international education systems. Open distance learning (ODL) could be a viable method to deliver PD to Mathematics teachers to address their zone of proximal development, develop their TPACK, and establish and maintain their SPI. This study made use of a fully mixed sequential equal status multi-mode research design and methodologies to develop guidelines for the PD of Mathematics teachers in the pedagogical use of ICT in ODL. The qualitative phase (Phase I) was rooted in the interpretivist paradigm. Through an adjustable exploration of a systematic literature review, the researcher identified 23 core documents, analysed them with Atlas.ti™, and conceptualised four themes according to Engeström‘s third generation activity theory (AT). Phase II (radical exploration phase) of the research design was rooted in the radical structuralist paradigm. In the context of transformation, it developed, validated, and standardised a research instrument for the measurement of Mathematics teachers‘ PD requirements. The instrument was distributed to 300 senior phase (grades 7-9) Mathematics teachers in eight education management district centres of the WCED. The analyses of the quantitative data conceptualised a fifth activity system. The five activity systems from the adjustable and radical exploration phases were symbiotic, and co-dependent. Expansive learning was used for boundary crossing and network building during six phases of this study. The findings from the six phases of the expansive learning cycle indicated that PD of Mathematics teachers in ODL for Phase III implementation of the e-Education policy should be a joint initiative. Fundamentally ICT integration and implementation should start with Department of Basic Education (DBE) initiatives. The DBE and Provincial Departments of Education (PDEs) should conduct a needs analysis of ICT implementation, evaluate previous ICT PD programmes, plan ICT PD strategies aligned with the ICT development plan, as well as with the requirements of the Mathematics teachers. The DBE and PDE should invest in the provision of ICT equipment, afford human capital, reinstate the laptop initiative for teachers, and supply schools with networked-computer facilities to explore online platforms for PD. Mathematics teachers should assess their professional knowledge to construct new philosophies, create a subject network group, and interact as participants and members within their social environments. The standardised instrument could be used to determine and compare the PD of Mathematics teachers in other provinces and contexts. / PhD (Training and development), North-West University, Potchefstroom Campus, 2014

Professional development (PD) of teachers is part of the Department of Basic Education‘s (DBE) initiative to encourage school communities to use of information and communication technology (ICT) to improve the quality of Mathematics teaching and learning. The South African Council of Educators stipulates that PD programmes should align with system-wide needs, strengthen learning area content and outcomes, and promote system transformation. Imbedded in this system-wide criterion is The White Paper on e-Education to employ a fully ICT integrated system at all levels of education: management, teaching and learning, and administration by 2013. Mathematics teachers require PD that develops their technological pedagogical and content knowledge (TPACK) and their social professional identity (SPI). The PD of Mathematics teachers for ICT integration can assist the DBE to achieve the aims of The White Paper on e-Education and bridge the technology gap between South Africa and international education systems. Open distance learning (ODL) could be a viable method to deliver PD to Mathematics teachers to address their zone of proximal development, develop their TPACK, and establish and maintain their SPI. This study made use of a fully mixed sequential equal status multi-mode research design and methodologies to develop guidelines for the PD of Mathematics teachers in the pedagogical use of ICT in ODL. The qualitative phase (Phase I) was rooted in the interpretivist paradigm. Through an adjustable exploration of a systematic literature review, the researcher identified 23 core documents, analysed them with Atlas.ti™, and conceptualised four themes according to Engeström‘s third generation activity theory (AT). Phase II (radical exploration phase) of the research design was rooted in the radical structuralist paradigm. In the context of transformation, it developed, validated, and standardised a research instrument for the measurement of Mathematics teachers‘ PD requirements. The instrument was distributed to 300 senior phase (grades 7-9) Mathematics teachers in eight education management district centres of the WCED. The analyses of the quantitative data conceptualised a fifth activity system. The five activity systems from the adjustable and radical exploration phases were symbiotic, and co-dependent. Expansive learning was used for boundary crossing and network building during six phases of this study. The findings from the six phases of the expansive learning cycle indicated that PD of Mathematics teachers in ODL for Phase III implementation of the e-Education policy should be a joint initiative. Fundamentally ICT integration and implementation should start with Department of Basic Education (DBE) initiatives. The DBE and Provincial Departments of Education (PDEs) should conduct a needs analysis of ICT implementation, evaluate previous ICT PD programmes, plan ICT PD strategies aligned with the ICT development plan, as well as with the requirements of the Mathematics teachers. The DBE and PDE should invest in the provision of ICT equipment, afford human capital, reinstate the laptop initiative for teachers, and supply schools with networked-computer facilities to explore online platforms for PD. Mathematics teachers should assess their professional knowledge to construct new philosophies, create a subject network group, and interact as participants and members within their social environments. The standardised instrument could be used to determine and compare the PD of Mathematics teachers in other provinces and contexts. / PhD (Training and development), North-West University, Potchefstroom Campus, 2014

Les applications du traitement du signal (TDSI) sont maintenant largement utilisées dans des domaines variés allant de l'automobile aux communications sans fils, en passant par les applications multimédias et les télécommunications. La complexité croissante des algorithmes implémentés, et l'augmentation continue des volumes de données et des débits applicatifs, requièrent souvent la conception d'accélérateurs matériels dédiés. Typiquement l'architecture d'un composant complexe du TDSI utilise des éléments de calculs de plus en plus complexes, des mémoires et des modules de brassage de données (entrelaceur/désentrelaceur pour les Turbo-Codes, blocs de redondance spatiotemporelle dans les systèmes OFDM/MIMO, ...), privilégie des connexions point à point pour la communication inter éléments de calcul et demande d'intégrer dans une même architecture plusieurs configurations et/ou algorithmes (systèmes (re)configurables). Aujourd'hui, le coût de ces systèmes en terme d'éléments mémorisant est très élevé; les concepteurs cherchent donc à minimiser la taille de ces tampons afin de réduire la consommation et la surface total du circuit, tout en cherchant à en optimiser les performances. Sur cette problématique globale, nous nous intéressons à l'optimisation des interfaces de communication entre composants. On peut voir ce problème comme la synthèse (1) d'interfaces pour l'intégration de composants virtuels (IP cores), (2) de composants de brassage de données (type entrelaceur) pouvant avoir plusieurs modes de fonctionnements, et (3) de chemins de données, potentiellement configurables, dans des flots de synthèse de haut niveau. Nous proposons une méthodologie de conception permettant de générer automatiquement un adaptateur de communication (interface) nommé Space-Time AdapteR (STAR). Notre flot de conception prend en entrée (1) des diagrammes temporels (fichier de contraintes) ou (2) une description en langage C de la règle de brassage des données (par exemple une règle d'entrelacement pour Turbo-Codes) et des contraintes utilisateur (débit, latence, parallélisme...) ou (3) en ensemble de CDFGs ordonnés et assignés. Ce flot formalise ensuite ces contraintes de communication sous la forme d'un Graphe de Compatibilité des Ressources Multi-Modes (MMRCG) qui permet une exploration efficace de l'espace des solutions architecturales afin de générer un composant STAR en VHDL de niveau transfert de registre (RTL) utilisé pour la synthèse logique. L'architecture STAR se compose d'un chemin de données (utilisant des FIFOs, des LIFOs et/ou des registres) et de machines d'état finis permettant de contrôler le système. L'adaptation spatiale (une donnée en peut être transmise de n'importe quel port d'entrée vers un ou plusieurs ports de sortie) est effectuée par un réseau d'interconnexion adapté et optimisé. L'adaptation temporelle est réalisée par les éléments de mémorisation, en exploitant leur sémantique de fonctionnement (FIFO, LIFO). Le composant STAR exploite une interface LIS (Latency Insensitive System) offrant un mécanisme de gel d'horloge qui permet l'asservissement par les données. Le flot de conception proposé génère des architectures pouvant intégrer plusieurs modes de fonctionnement (par exemple, plusieurs longueurs de trames pour un entrelaceur, ou bien plusieurs configurations dans une architecture multi-modes). Le flot de conception est basé sur quatre outils : - StarTor prend en entrée la description en langage C de l'algorithme d'entrelacement, et les contraintes de l'utilisateur (latence, débit, interface de communication, parallélisme d'entréesortie...). Il en extrait l'ordre des données d'entrée-sortie en produisant d'une trace à partir de la description fonctionnelle. Ensuite, l'outil génère le fichier de contraintes de communication qui sera utilisé par l'outil STARGene. - StarDFG prend en entrée un ensemble de CDFGs générés par un outil de synthèse de haut niveau. Ces CDFGs doivent être ordonnancés et les éléments de calculs doivent avoir été assignés. L'outil en extrait ensuite l'ordre des échanges de données. Enfin, il génère le fichier de contraintes de communication qui sera utilisé par l'outil STARGene. - STARGene, basé sur un flot à cinq étapes, génère l'architecture STAR : (1) construction des graphes de compatibilité des ressources MMRCG, à partir du fichier de contraintes, correspondant à chacun des modes de fonctionnement du design, (2) fusion des modes de fonctionnement, (3) assignation des structures de mémorisation (FIFO, LIFO ou Registre) sur le MMRCG (4) optimisation de l'architecture et (5) génération du VHDL niveau transfert de registre (RTL) intégrant les différents modes de communication. Le fichier de contraintes utilisé dans la première étape peut provenir de l'outil StarTor, comme nous l'avons indiqué, ou peut être généré par un outil de synthèse de haut niveau tel que l'outil GAUT développé au laboratoire LESTER. - StarBench génère un test-bench basé sur les contraintes de communication et permet de valider les architectures générées en comparant les résultats de simulation de l'architecture avec la spécification fonctionnelle. Les expérimentations que nous présentons dans le manuscrit ont été réalisées pour trois cas d'utilisation du flot STAR. En premier lieu, nous avons utilisé l'approche STAR dans le cadre de l'intégration et l'interconnexion de blocs IPs au sein d'une même architecture. Cette première expérience pédagogique permet de démontrer la validité de l'approche retenue et de mettre en avant les possibilités offertes en terme d'exploration de l'espace des solutions architecturales. Dans une seconde expérience, le flot STAR a été utilisé pour générer une architecture de type entrelaceur Ultra-Wide Band. Il s'agit là d'un cas d'étude industriel dans le cadre d'une collaboration avec la société STMicroelectronics. En utilisant notre flot, nous avons prouvé que nous pouvions réduire le nombre de points mémoires utilisés et diminuer la latence, par rapport aux approches classiques basées sur des bancs mémoires. De plus, lorsque nous utilisons notre flot, le nombre de structures à piloter est plus petit que dans l'architecture de référence, qui a été obtenue à l'aide d'un outil de synthèse de haut niveau du commerce. Actuellement, la surface totale de notre architecture d'entrelacement est environ 14% plus petite que l'architecture de référence STMicrolectronics. Enfin, dans une troisième série d'expériences, nous avons utilisé le modèle STAR dans un flot de synthèse de haut niveau ciblant la génération d'architectures reconfigurables. Cette approche a été expérimentée pour générer des architectures multi-débits (FFT 64 à 8 points, FIR 64 à 16 points...) et multi-modes (FFT et IFFT, DCT et produit de matrices...). Ces expériences nous ont permis de montrer la pertinence de l'association de l'approche STAR, pour l'optimisation et la génération de l'architecture de multiplexage et de mémorisation, à des algorithmes d'ordonnancement et d'assignation multi-configurations à l'étude dans GAUT (Thèse Caaliph Andriamissaina). Nous avons notamment obtenu des gains pouvant aller jusqu'à 75% en terme de surface par rapport à une architecture naïve et des gains pouvant aller jusqu'à 40% par rapport aux surfaces obtenues avec des méthodologies centrées sur la réutilisation d'opérateur (SPACT-MR).

The effect of microwave radiation on the prepared 0.5Fe/ZSM-5 catalysts as a post-synthesis modification step was studied in the methanol-to-hydrocarbons process using the temperature-programmed surface reaction (TPSR) technique. This was achieved by preparing a series of 0.5Fe/ZSM-5 based catalysts under varying microwave power levels (0–700 W) and over a 10 s period, after iron impregnating the HZSM-5 zeolite (Si/Al = 30 and 80). Physicochemical properties were determined by XRD, SEM, BET, FT-IR, C3H9N-TPSR, and TGA techniques. It was found that microwave radiation induced few changes in the bulk properties of the 0.5Fe/ZSM-5 catalysts, but their surface and catalytic behavior were distinctly changed. Microwave radiation enhanced crystallinity and mesoporous growth, decreased coke and methane formation, decreased the concentration of Brønsted acidic sites, and decreased surface area and micropore volume as the microwave power level was increased from 0 to 700 W. From the TPSR profiles, it was observed that microwave radiation affects the peak intensities of the produced hydrocarbons. Application of microwave radiation shifted the desorption temperatures of the MTH process products over the HZSM-5(30) and HZSM-5(80) based catalysts to lower and higher values respectively. The MeOH-TPSR profiles showed that methanol was converted to DME and subsequently converted to aliphatic and aromatic hydrocarbons. It is reasonable to suggest that microwave radiation would be an essential post-synthesis modification step to mitigate coke formation and methane formation and increase catalyst activity and selectivity. / Chemical Engineering / M. Tech. (Chemical Engineering)

The purpose of this master’s thesis is foremost to provide a simple guide how to build elements of optical metropolitan area network. The basic model consists to sequence of construction, network topology, passive and active parts. The collection contains examples of alternative technology such as Wireless LAN with different frequency. The optical network construction based on optical cable, fibres, splices, trays, adapters, connectors and active parts for example a lot of media convertor models. After that there are demonstrating type of wavelength division multiplexer used in metropolitan area network – passive planar PCL splitter. One of the passive planar splitter are used to increase optical fibre channel. At the end of the collection a simplified examples of used measurements – optical time domain reflectometry and optical fibre transmission. Contains standard protocols or reflectogram. The conclusion of this thesis summarizes costs of FTTb (Fibre To The Building) model of optical metropolitan area network in Czech republic and future contribution for society.