In my opinion, compactness is the most important concept in mathematics. We 'll track it from the one-dimensional real line in calculus to infinite dimensional spaces of functions and surfaces and see what it can do.

Unlike encryption, steganography hides the very existence of secret information rather than hiding its meaning only. Image based steganography is the most common system used since digital images are widely used over the Internet and Web. However, the capacity is mostly limited and restricted by the size of cover images. In addition, there is a tradeoff between both steganographic capacity and stego image quality. Therefore, increasing steganographic capacity and enhancing stego image quality are still challenges, and this is exactly our research main aim. Related to this, we also investigate hiding secret information in communication protocols, namely Simple Object Access Protocol (SOAP) message, rather than in conventional digital files. To get a high steganographic capacity, two novel steganography methods were proposed. The first method was based on using 16x16 non-overlapping blocks and quantisation table for Joint Photographic Experts Group (JPEG) compression instead of 8x8. Then, the quality of JPEG stego images was enhanced by using optimised quantisation tables instead of the default tables. The second method, the hybrid method, was based on using optimised quantisation tables and two hiding techniques: JSteg along with our first proposed method. To increase the steganographic capacity, the impact of hiding data within image chrominance was investigated and explained. Since peak signal-to-noise ratio (PSNR) is extensively used as a quality measure of stego images, the reliability of PSNR for stego images was also evaluated in the work described in this thesis. Finally, to eliminate any detectable traces that traditional steganography may leave in stego files, a novel and undetectable steganography method based on SOAP messages was proposed. All methods proposed have been empirically validated as to indicate their utility and value. The results revealed that our methods and suggestions improved the main aspects of image steganography. Nevertheless, PSNR was found not to be a reliable quality evaluation measure to be used with stego image. On the other hand, information hiding in SOAP messages represented a distinctive way for undetectable and secret communication.

The aim of this study is to analyse selected episodes of the locally produced television programme Generations, in order to identify specific ways in which the programme seeks to forge a South African identity, and in so doing, 'flag' our nationhood as South Africans. These elements of 'South Africanness' are broadly defined as connections to a South African way of life, context, values and experiences. Generations is a programme produced under South African broadcasting local content provisions. These provisions arise out of the need, inter alia, to reflect the identity and multi-cultural nature of South Africa in order to foster 'national identity' and 'national culture'. These elements of 'South Africanness' are extracted through a genre and ideological analysis of selected sample episodes, taking into consideration the theoretical frameworks of the politics of representation and identity. The production context of, and representations made, in Generations, are found to be situated largely within the context of the South African discourses of the ‘rainbow nation', 'African renaissance' and 'black economic empowerment'. The analysis concludes that through the various categories of representations of 'South Africanness' in the selected episodes of Generations, specific instances of identity, that of national culture and national identity are formed.

Web Services is one of the latest golden concepts that promise flexibility and unlimited potential for interconnection between systems of the same or different type. The communication is based on SOAP ? Simple Object Access Protocol, which is founded on XML (eXtended Markup Language). We have made experiments with SOAP in a Web Service Environment to find out the performance in response time using SOAP compared to CORBA. Unsurprisingly CORBA (Common Object Request Broker Architecture) is significantly faster but with the improvements that we implemented and an intelligent choice of XML parser the response times for SOAP was drastically lowered.

Denna studie jämför Api-teknologierna WCF, ASMX web services och ASP.NET Web API som kan användas för att bygga tjänsteorienterade arkitekturer med användning av webbtjänster. För att hantera interaktionen för maskiner över ett nätverk och skicka data används SOAP/Rest. Frågan är vilken teknologi som är snabbast? Samma typ av applikation byggdes tillsammans med en applikation som kan använda tjänsterna hos webbtjänsten, svarstider beräknas från det att data efterfrågas från klient till webbtjänst och sedan tillbaka till klient. Totalt så testades varje teknologie på skickande av data från dess webbtjänst 100 gånger, där databasraderna var 10, 100 och 1000 stycken.  Enligt analysen som utfördes på den data som tagits fram genom experimentet går det att konstatera att REST är snabbare än SOAP-protokollet och att ASP.NET Web API bör väljas för att få de snabbaste svarstiderna vid utveckling av en webbtjänst inom ASP.NET, detta resultat stödjer även hypotesen som tagits fram före den påbörjade studien. Som ett framtida arbete skulle det vara bra att göra tester där en internetanslutning är till hands och inte bara lokalt nätverk.

This thesis is situated within the context of post-apartheid, post-1994 South Africa. Considering that South Africa only recently entered its second decade of democracy, it is not surprising that, within the context of the “New South Africa”, new identities and myths are continuously being constructed. It thus follows that the construction of identities is a contentious issue within South Africa today. The premise that serves as point of departure for this thesis is that narratives contribute to the construction of identities. It is argued that there exists no single, absolute or static identity and that both personal and collective identities are endlessly being negotiated and renegotiated. Within the context of the “New South-Africa” a variety of new voices are being heard and a variety of new narratives are being voiced. Consider as a case in point the far-reaching stories told in the hearings of the Truth and Reconciliation Commission. The far-reaching political, economic and cultural paradigm shifts South Africa has undergone in the recent past also manifest in the production of meaning in popular visual culture and, more specifically, in the undeniably popular South African soap opera. In the scope of this thesis it is argued that South African soap opera constitute one possible South African narrative and consequently that South African soap opera may be instrumental in the construction of the new identities referred to earlier. The first section of this thesis is devoted to a literature overview comprising an overview of seminal sources on Cultural Studies, the South African context, narrative, identity, soap opera, gender and the other. This is done in order to situate the thesis within the context of Cultural Studies and also to achieve an awareness of the literature and research relevant to this study. Initially the thesis focuses broadly on narrative, its characteristics and the role narrative plays in the construction of identities. Here the theories of Paul Ricouer serve as a basis on which narrative is defined and analysed. Important concepts that come to bear in the relationship between narrative and identity include time, story, history and imagination. In examining narrative I come to the conclusion that narrative can be embodied and that a narrative body implies gender. It is argued that narrative may be gendered as feminine, and consequently that it constitutes some kind of other – in this case, other to the masculine. Although Edward Said’s Orientalism is acknowledged as the unofficial origin of the concept of the Other, and mention is made of Simoné de Beauvoir, it is essentially the concept of the other as theorized by Luce Irigaray that is seminal to this thesis. The focus is narrowed down to soap opera narrative which is again argued to be a feminine, but also female, narrative for a variety of reasons. Soap opera narrative is othered to various hegemonic orders the most important of which is western masculine narrative. An argument is made for the potential of this narrative of the other to give a voice to the other and consequently pose a site where dominant identities and hegemonic orders may be (re)negotiated. The final part of this thesis is devoted to applying all of the above to South African soap opera narrative. Concrete examples from four South African soap operas (Egoli – Plek van Goud/Place of Gold, Isidingo – the need, Generations and 7de Laan) are used to substantiate the argument that South African soap opera may be regarded as other and consequently that it creates a site where new South African identities are created and old identities are being negotiated. / Dissertation (MA (Afrikaans))--University of Pretoria, 2008. / Afrikaans / unrestricted

The work presented in this thesis is an investigation of the dynamics of unconfined hydrogen-air flames in the presence of buoyant effects and the determination of an ignition criterion for flame propagation between adjacent pockets of reactive gas separated by air. The experimental work was conducted using the soap bubble technique and visualized with high speed schlieren or large scale shadowgraph systems. A study was first conducted to determine the most suitable soap solution additive among glycerol, guar and polyethylene oxide for conducting the experiments, isolating guar as the best candidate. The soap solution was then used to study the dynamics of flames in single or multiple soap bubbles filled with reactive mixtures of different compositions. The soap bubble method was also further improved by designing a soap dispenser that can maintain a bubble indefinitely and a method to burst the soap solution prior to an experiment using timed heated wires. In the experiments with single bubbles, it was found that for sufficiently lean hydrogen-air mixtures, buoyancy effects become important at small scales. The critical radius of hemispherical flames that will rise due to buoyancy was measured and estimated using a model comparing the characteristic burning speed and the rise speed of the flame kernel. Excellent agreement was found between the model predictions and the measured critical flame radii. The experiments with multiple bubbles provided the scaling rules for flame transition between neighboring pockets of hemispherical or spherical shape separated by an inert gas. The test results demonstrated that the separation distance between the bubbles is mainly determined by the expansion ratio when the buoyancy effects are negligible, corresponding to near stoichiometric mixtures. For leaner mixtures with stronger buoyant effects, the critical separation distance was no longer governed by the expansion ratio alone, as buoyancy forces render the flame propagation across the inert gas more difficult. Visualization of the ignition dynamics confirmed that buoyancy forces tend to accelerate the first kernel up before ignition of the second kernel can be achieved.

The Internet became a standard way of exchanging business data between B2B and B2C applications and with this came the need for providing various services on the web instead of just static text and images. Web services are a new type of services offered via the web that aid in the creation of globally distributed applications. Web services are enhanced e-business applications that are easier to advertise and easier to discover on the Internet because of their flexibility and uniformity. In a real life scenario it is highly difficult to decide which J2EE application server to go for when deploying a enterprise web service. This thesis analyzes the various ways by which web services can be developed & deployed. Underlying protocols and crucial issues like EAI (enterprise application integration), asynchronous messaging, Registry tModel architecture etc have been considered in this research. This paper presents a report by analyzing what various J2EE application servers provide by doing a case study and by developing applications to test functionality.

Please read abstract in the main document / Dissertation (MArch(Prof))--University of Pretoria, 2015. / Architecture / MArch(Prof) / Unrestricted

Im Rahmen dieser Arbeit werden zunächst die Grundlagen, die Unterschiede und die Features der beiden Service Technologien, SOAP und REST, erarbeitet. Anschließend werden die Web Service Frameworks Apache Axis 1, Apache Axis 2 und Metro 2.0 genauer betrachtet. Der letzte Teil dieser Arbeit beschäftigt sich mit der Verarbeitung von XML-Dokumenten. Hier spielen die verschiedenen Techniken, XML-Dokumente mittels DOM und StAX zu erstellen eine primäre Rolle. Dabei werden verschiedene Referenzimplementierungen der Standards sowie Frameworks betrachtet. Zusätzlich wird untersucht wie sich die Generierung von XML im Inline- und Stand Off-Markup auf die Performance auswirkt. Dazu werden die Standards der Text Encoding Initiative zur Textkodierung und -formatierung hinzugezogen. Am Schluß jedes Kapitels werden die Details zu den Durchführungen der Tests, deren Resultate und die daraus gewonnenen Schlussfolgerungen präsentiert. Dabei wird der Fokus auf die Linguistik gelegt.