The primary aim of this dissertation was to develop and validate a methodology for identifying spatial clusters (hotspots) of various paediatric cancers within South Africa by using GIS software. The Hotspot Analysis (Getis-Ord Gi*) Tool was used for this purpose. A series of spatial clusters (hotspots) were identified by the tool for each cancer type and these clusters were compared with the exiting literature regarding known environmental and other carcinogens. The quality of the cancer data used in the dissertation was however found to be questionable and significantly underreported. This caused the results of the tool to also be questionable. The dissertation therefore concluded that the tool could be successfully used to identify spatial clusters of cancer in principle. It was however found that the results of the tool needed to be viewed without caution in this dissertation due to the low quality of the cancer data used. / MSc (Geography and Environmental Management), North-West University, Potchefstroom Campus, 2014

The primary aim of this dissertation was to develop and validate a methodology for identifying spatial clusters (hotspots) of various paediatric cancers within South Africa by using GIS software. The Hotspot Analysis (Getis-Ord Gi*) Tool was used for this purpose. A series of spatial clusters (hotspots) were identified by the tool for each cancer type and these clusters were compared with the exiting literature regarding known environmental and other carcinogens. The quality of the cancer data used in the dissertation was however found to be questionable and significantly underreported. This caused the results of the tool to also be questionable. The dissertation therefore concluded that the tool could be successfully used to identify spatial clusters of cancer in principle. It was however found that the results of the tool needed to be viewed without caution in this dissertation due to the low quality of the cancer data used. / MSc (Geography and Environmental Management), North-West University, Potchefstroom Campus, 2014

One of the defining characteristics of hotspot volcanism is the presence of a long-lived, linear chain of age-progressive volcanoes created by the movement of the lithosphere over a stationary melting anomaly. However, the spatial distribution of volcanism at hotspots is often complex and highly variable suggesting that the relationship between magma generation and magma transport at hotspots is poorly understood. Here, I present the results of the first systematic quantitative characterization of the spatial distribution of volcanism at oceanic hotspots. In the first study I develop a novel methodology to characterize the across-strike distribution of volcanism at hotspots and apply it to a catalog of 40 oceanic hotpots. I find that only 25% (10/40) of hotspots exhibit the simple single-peak profile predicted by geodynamic models of melt generation in mantle plumes. The remaining 75% (30/40) of hotspots exhibit a dual- or multi-peak pattern. In the second study, I focus on the across-strike distribution of volcanism at the oceanic hotspots that are sourced by a deep-rooted mantle plume. 14 out of the 15 consensus plume-fed hotspots exhibit a dual-peaked across-strike profile. The spacing between these peaks display a strong negative correlation with lithospheric age, in direct contrast to models of inter-volcanic spacing controlled by elastic plate thickness. This relation suggests a different mechanism controls volcanic spacing at plume-fed hotspots. In the third chapter, I investigate variations in the average topographic profiles over time along the two longest and best-constrained oceanic hotspot tracks: Hawaii and Louisville. I find that the dual-peak across-strike profile of volcanism is a persistent feature at the Louisville hotspot over the entire length of the track examined (spanning a period of more than 65 Myr). In contrast, the dual-peak profile of volcanism at Hawaii is only evident along the most recent portion of the track (i.e., over the last 5 Myr). In total, this thesis represents a significant step foreword in the collective understanding of hotspot volcanism, and introduces a new diagnostic tool for analysis of hotspot influenced seafloor topography.

Die Eifel ist eines der jüngsten vulkanischen Gebiete Mitteleuropas. Die letzte Eruption ereignete sich vor ungefähr 11000 Jahren. Bisher ist relativ wenig bekannt über die tieferen Mechanismen, die für den Vulkanismus in der Eifel verantwortlich sind. Erdbebenaktivität deutet ebenso darauf hin, dass die Eifel eines der geodynamisch aktivsten Gebiete Mitteleuropas ist. In dieser Arbeit wird die Receiver Function Methode verwendet, um die Strukturen des oberen Mantels zu untersuchen. 96 teleseismische Beben (mb > 5.2) wurden ausgewertet, welche von permanenten und mobilen breitbandigen und kurzperiodischen Stationen aufgezeichnet wurden. Das temporäre Netzwerk registrierte von November 1997 bis Juni 1998 und überdeckte eine Fläche von ungefähr 400x250 km². Das Zentrum des Netzwerkes befand sich in der Vulkaneifel. <br /> Die Auswertung der Receiver Function Analyse ergab klare Konversionen von der Moho und den beiden Manteldiskontinuitäten in 410 km und 660 km Tiefe, sowie Hinweise auf einen Mantel-Plume in der Region der Eifel. Die Moho wurde bei ungefähr 30 km Tiefe beobachtet und zeigt nur geringe Variationen im Bereich des Netzwerkes. Die beobachteten Variationen der konvertierten Phasen der Moho können mit lateralen Schwankungen in der Kruste zu tun haben, die mit den Receiver Functions nicht aufgelöst werden können. Die Ergebnisse der Receiver Function Methode deuten auf eine Niedriggeschwindigkeitszone zwischen 60 km bis 90 km in der westlichen Eifel hin. In etwa 200 km Tiefe werden im Bereich der Eifel amplitudenstarke positive Phasen von Konversionen beobachtet. Als Ursache hierfür wird eine Hochgeschwindigkeitszone vorgeschlagen, welche durch mögliches aufsteigendes, dehydrierendes Mantel-Material verursacht wird. Die P zu S Konversionen an der 410 km Diskontinuität zeigen einen späteren Einsatz als nach dem IASP91-Modell erwartet wird. Die migrierten Daten weisen eine Absenkung der 410 km Diskontinuität um bis zu 20 km Tiefe auf, was einer Erhöhung der Temperatur von bis zu etwa 140° Celsius entspricht. Die 660 km Diskontinuität weist keine Aufwölbung auf. Dies deutet darauf hin, dass kein Mantelmaterial direkt von unterhalb der 660 km Diskontinuität in der Eifel-Region aufsteigt oder, dass der Ursprung des Eifel-Plumes innerhalb der Übergangszone liegt. / The upper mantle in the region of the Eifel, Germany, analyzed with the <i>receiver function</i> method: <br /> The Eifel is the youngest volcanic area of Central Europe. The last eruption occurred approximately 11000 years ago. Little is known about the deep origin and the mechanism responsible for the Eifel volcanic activity. Earthquake activity indicates that the Eifel is one of the most geodynamically active areas of Central Europe. <br /> In this work the <i>receiver function</i> method is used to investigate the upper mantle structure beneath the Eifel. Data from 96 teleseismic events (mb > 5.2) that were recorded by both permanent stations and a temporary network of 33 broadband and 129 short period stations had been analyzed. The temporary network was operating from November 1997 till June 1998 and covered an area of approximately 400x250 km² centered on the Eifel volcanic fields. <br /> The <i>receiver function</i> analysis reveals a clear image of the Moho and the mantle discontinuities at 410 km and 660 km depth. Average Moho depth is approximately 30 km and it shows little variation over the extent of the network. The observed variations of converted waveforms are possibly caused by lateral variations in crustal structure, which could not resolved by it <i>receiver functions</i>. Inversions of data and migrated it receiver functions from stations of the central Eifel array suggest that a low velocity zone is present at about 60 to 90 km depth in the western Eifel region. There are also indications for a high velocity zone around 200 km depth, perhaps caused by dehydration of the rising plume material. The results suggest that P-to-S conversions from the 410-km discontinuity arrive later than in the IASP91 reference model. The migrated data show a depression of the 410 km discontinuity of about 20 km, which correspond to an increase of temperature of about 140° Celsius. The 660 km discontinuity seems to be unaffected. This indicates that no mantel material rises up from directly below the 660 km discontinuity in the Eifel region or the Eifel-Plume has its origin within the transition zone.

<p>Internet Service Providers (ISP) har på senare år etablerat ett ökat antal Wi-Fi Hotspots på publika platser för att erbjuda Internettjänster så som e-post, Web och andra Internet-baserade program, till resande användare. Exempel på dessa platser är flygplatser, skolor, parker och städer. Växjö universitet har valt att bygga etttrådlöst nätverk på campus som man ska påbörja under sommaren 2005. Uppsatsen tar upp detta som fallstudie för diskussion av ämnet.</p> / <p>Lately Internet Service Providers (ISP) have established an increased amount of Wi-Fi Hotspots at public places to offer Internet based services like e-mail, web surfing etc to roaming users. Example of places like this are airports, schools, parks and cities. Växjö University has decided to implement a wireless network covering the university campus. This project is planned to start during summer of 2005. This project is the unicase for discussion in this bachelor thesis</p>

Java est à ce jour l'un des langages, si ce n'est le langage, le plus utilisé toutes catégories de programmation confondues et sa popularité concernant le développement d'applications scientifiques n'est plus à démontrer. Néanmoins son utilisation dans le domaine du Calcul Haute Performance (HPC) reste marginale même si elle s'inscrit au cœur de la stratégie de certaine entreprise comme Aselta Nanographics, éditeur de l'application Inscale pour la modélisation des processus de lithographie par faisceaux d'électron, instigateur et partenaire industriel de cette thèse.Et pour cause, sa définition haut-niveau et machine-indépendante, reposant sur un environnement d'exécution, parait peu compatible avec le besoin de contrôle bas-niveau nécessaire pour exploiter de manière optimale des architectures de microprocesseurs de plus en plus complexes comme les architectures Intel64 (implémentation Intel de l'architecture x86-64).Cette responsabilité est entièrement déléguée à l'environnement d'exécution, notamment par le biais de la compilation dynamique, chargée de générer du code binaire applicatif à la volée. C'est le cas de la JVM HotSpot, au centre de cette étude, qui s'est imposée comme l'environnement de référence pour l'exécution d'applications Java en production.Cette thèse propose, dans ce contexte, de répondre à la problématique suivante : comment optimiser les performances de code séquentiel Java plus particulièrement dans un environnement HotSpot/Intel64 ?Pour tenter d'y répondre, trois axes principaux ont été explorés. Le premier axe est l'analyse des performances du polymorphisme, mécanisme Java haut-niveau omniprésent dans les applications, dans le lequel on tente de mesurer l'impact du polymorphisme sur les performances du code et d'évaluer des alternatives possibles. Le second axe est l'intégration de code natif au sein des applications - afin de bénéficier d'optimisations natives - avec prise en compte du compromis coût d'intégration/qualité du code. Enfin le troisième axe est l'extension du compilateur dynamique pour des méthodes applicatives afin, là encore, de bénéficier d'optimisations natives tout en s'affranchissant du surcout inhérent à l'intégration de code natif.Ces trois axes couvrent différentes pistes exploitables dans un contexte de production qui doit intégrer certaines contraintes comme le temps de développement ou encore la maintenabilité du code. Ces pistes ont permis d'obtenir des gains de performances significatifs sur des sections de code applicatif qui demeuraient jusqu'alors très critiques. / L'auteur n'a pas fourni de résumé en anglais

<p>Detta examensarbete är gjort på uppdrag av Fiber Optik Valley. Huvuduppdraget i projektet var att skapa ett fungerande betalningssystem för en hotspot och att utveckla företagets webbsida. Hotspotsystemet som baserades på en gratistjänst från Public IP, är tänkt att kunna fungera delvis autonomt utan ägarens ingripande. Företagets webbsida skapades i en Flex2-utvecklingsmiljö och produkten blev en Adobe Flash-applikation. För att få ett dynamiskt och konfigurerbart system skapades även en kontrollpanel till webbsidan åt företagets webbadministratörer, så att innehållet på sidan ska kunna förändras utan att behöva kompilera om koden. Kontrollpanelen säkrades också med en inloggningsprocess.</p><p>Som underliggande motor och som ersättning för brister i Flash-funktionaliteten, användes Simple PHP-tjänster mellan Flash-applikationen och PHP-skripten på servern. Betalningssystemet utvecklades med hjälp av PHP, MySQL och JavaScript. I systemet ingår PayPal’s IPN-tjänster för penningtransaktioner och validering av transaktioner. En självständig AMP-server, Apache2, MySQL och PHP5.0, lades till hotspotsystemet för att minska behovet av att ha en webbsida på ett externt webbhotell.</p> / <p>This graduation work was done as a assignment from Fiber Optic City company based in Hudiksvall Sweden. The base assignment was to create an automated payment system for a Hotspot network and a company web page. The hotspot system should work as a standalone service. The company has already a working free-of-charge service that is offered to its customers and is based on Public IP system.</p><p>The company webpage was done with the help of a development suite called Flex2 and the result was an Adobe Flash application. To increase webpage dynamics a second page was developed for the company to have the ability to change and configure the main company webpage. An authentication service was deployed to configuration page to increase its security. As an engine and a substitute for lack of functionality and security in Adobe Flash simplePHP web service was used to connect Flash with a PHP script on its server.</p><p>The payment system was developed with the help of PHP, MySQL and JavaScript. The system uses Paypal IPN service for money transaction and transaction validation</p><p>A standalone web server with Apache2, PHP 5.0 and MySQL was deployed to the hotspot system to reduce the need of having an authentication system on a commercial Internet based web hotel.</p>

In recent years, mobile hotspots have been getting much attention of the researchers. They are implemented on moving platforms. Research interests in mobile hotspots are motivated by the demand of seamless mobility. The IEEE 802.16e or mobile WiMAX opens a new door of possibility of mobile broadband. It provides extended mobility support and larger cell coverage. In this thesis we propose a simple link adaptation (LA) algorithm for the mobile hotspots, which are supported by (mobile) WiMAX network. The role of link adaptation (LA) is very important because it controls the physical layer throughput. Therefore, all the higher layers are affected by LA. The main function of an LA algorithm is to select an appropriate burst profile. We consider downlink scenarios of WiMAX supported mobile hotspot. We formulate a discrete value optimization problem for LA, whose objective is throughput maximization. We choose forward error correction block rate (FBER) as constraint. The proposed LA algorithm comes as solution of the optimization problem. The proposed algorithm adapt with MAC layer performance. We develop a downlink channel estimation technique, propose an intra subchannel power allocation strategy, and propose an adaptive automatic repeat request (ARQ) mechanism as part of LA technique. We estimate SNR using channel estimation and intra subchannel power allocation. Then the estimated SNR is adjusted based on velocity of mobile hotspot. Adjusted SNR is used to select optimum burst profile. The performances of the proposed LA algorithm are evaluated through numerical results obtained from link level simulations. According to numerical results, the proposed LA algorithm is able to maintain a certain level quality of service (QoS).

In recent years, mobile hotspots have been getting much attention of the researchers. They are implemented on moving platforms. Research interests in mobile hotspots are motivated by the demand of seamless mobility. The IEEE 802.16e or mobile WiMAX opens a new door of possibility of mobile broadband. It provides extended mobility support and larger cell coverage. In this thesis we propose a simple link adaptation (LA) algorithm for the mobile hotspots, which are supported by (mobile) WiMAX network. The role of link adaptation (LA) is very important because it controls the physical layer throughput. Therefore, all the higher layers are affected by LA. The main function of an LA algorithm is to select an appropriate burst profile. We consider downlink scenarios of WiMAX supported mobile hotspot. We formulate a discrete value optimization problem for LA, whose objective is throughput maximization. We choose forward error correction block rate (FBER) as constraint. The proposed LA algorithm comes as solution of the optimization problem. The proposed algorithm adapt with MAC layer performance. We develop a downlink channel estimation technique, propose an intra subchannel power allocation strategy, and propose an adaptive automatic repeat request (ARQ) mechanism as part of LA technique. We estimate SNR using channel estimation and intra subchannel power allocation. Then the estimated SNR is adjusted based on velocity of mobile hotspot. Adjusted SNR is used to select optimum burst profile. The performances of the proposed LA algorithm are evaluated through numerical results obtained from link level simulations. According to numerical results, the proposed LA algorithm is able to maintain a certain level quality of service (QoS).

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