Thesis (MSc)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Stepwise development of a program using refinement ensures that the program correctly implements its requirements. The specification of a system is “refined” incrementally to derive an implementable program. The programming space includes both specifications and implementable code, and is ordered with the refinement relation which obeys some mathematical laws. Morgan proposed a modification of this “classical” refinement for systems where the confidentiality of some information is critical. Programs distinguish between “hidden” and “visible” variables and refinement has to bear some security requirement. First, we review refinement for classical programs and present Morgan’s approach for ignorance pre- serving refinement. We introduce the Shadow Semantics, a programming model that captures essential properties of classical refinement while preserving the ignorance of hidden variables. The model invalidates some classical laws which do not preserve security while it satisfies new laws. Our approach will be algebraic, we propose algebraic laws to describe the properties of ignorance preserving refinement. Thus completing the laws proposed in. Moreover, we show that the laws are sound in the Shadow Semantics. Finally, following the approach of Hoare and He for classical programs, we give a completeness result for the program algebra of ignorance preserving refinement. / AFRIKAANSE OPSOMMING: Stapsgewyse ontwikkeling van ’n program met behulp van verfyning verseker dat die program voldoen aan die vereistes. Die spesifikasie van ’n stelsel word geleidelik ”verfyn” wat lei tot ’n implementeerbare kode, en word georden met ‘n verfyningsverhouding wat wiskundige wette gehoorsaam. Morgan stel ’n wysiging van hierdie klassieke verfyning voor vir stelsels waar die vertroulikheid van sekere inligting van kritieke belang is. Programme onderskei tussen ”verborgeën ”sigbare” veranderlikes en verfyning voldoen aan ’n paar sekuriteitsvereistes. Eers hersien ons verfyning vir klassieke programme en verduidelik Morgan se benadering tot onwetendheid behoud. Ons verduidelik die ”Shadow Semantics”, ’n programmeringsmodel wat die noodsaaklike eienskappe van klassieke verfyning omskryf terwyl dit die onwetendheid van verborge veranderlikes laat behoue bly. Die model voldoen nie aan n paar klassieke wette, wat nie sekuriteit laat behoue bly nie, en dit voldoen aan nuwe wette. Ons benadering sal algebraïese wees. Ons stel algebraïese wette voor om die eienskappe van onwetendheid behoudende verfyning te beskryf, wat dus die wette voorgestel in voltooi. Verder wys ons dat die wette konsekwent is in die ”Shadow Semantics”. Ten slotte, na aanleiding van die benadering in vir klassieke programme, gee ons ’n volledigheidsresultaat vir die program algebra van onwetendheid behoudende verfyning.

The title of this essay is ”A place forgotten by the world – the image of the Other and the Elsewhere in Forty Days Without Shadow by Oliver Truc”. Olivier Truc is a French-born journalist living in Stockholm, where he works as a correspondent for Le Monde and Le Point. He has also produced TV documentaries and non-fiction books. Forty Days Without Shadow is his first fictional work, a crime novel published in 2012. The story is settled in the Norwegian and Swedish parts of Lapland, and Sami people are in focus. In this essay, a postcolonial reading is used to interpret the novel, based mainly on the fact that the Sami are or were victims of Scandinavian colonization. The aim of the essay is therefore to examine whether the novel comprises colonialist or anti-colonialist attitudes, or perhaps both, and whether it contains exoticism and othering of the Sami. In particular it is examined how Lapland as a geographical place is described, and how Sami people are depicted compared to people of other origins in the novel. Another fact that is discussed, is how stereotypical characterisation is a common trait of crime novels, an aggravating circumstance for the analysis. The conclusion is that the novel has a strong anti-colonialist perspective, seen mainly in the treating of themes like the colonization of Lapland and its effects on some of the characters. At the same time, the physics of the Sami are described in recurring terms such as “high cheekbones”, whereas the faces of the normative Norwegian and Swedish characters are not described in the same way. In certain places in the novel there is a colonialist focalization which contributes to exoticism and othering of Sami people.

Viviane Sassen is a Dutch fashion photographer, whose personal work feature people from African descent. Through the employment of the equatorial light, her models’ personal identities and faces are left in the shadow, their dark skin rendered “just” black, depicting the sitters invisible and without personal recognition. In this thesis I offer an alternative to reading her work whose praise always stay on the surface; I examine her work in relation to the historical and geographical location, offer an analysis to the ontology of the shadow in photography, and examine the treatment of the surface of Sassen’s models.

A promising approach investigated here is to utilize thin film multilayer structures where the thickness of a catalyst layer at an exposed edge of photolithographically defined pattern determines the diameter of the nanotubes/nanowires grown from it. This can in turn be incorporated into photolithographically defined post structures resulting in an array of suspended nanowires for line-of-site shadow lithography. Success of the diameter control approach has been shown by selectively growing carbon nanotubes (CNTs) from narrow lines (12-60 nm) of SiO2, Fe, Ni, Co on micron-scale patterned substrates in a ferrocene or nonferrocene catalyzed CVD process. In addition, the concept has been extended to VS growth of CuO nanowires and VLS growth of ZnO nanowires from an exposed edge in a Al2O3/Cu(40-100 nm)/Al2O3 and Al2O3/Au(10 nm)/Al2O3 thin film multilayer structures. The exposed middle layer of patterned thin-film multilayer acts as a nm-scale wide selective growth area. The resultant CNT/nanowire diameter is directly related to the catalyst/catalyst support size. Growth kinetic studies of CuO nanowires from a thin film multilayer structure indicate diffusion controlled process. Dispersion of CNTs between lithographically defined trenches of width of 200 nm and depth of 500 nm when coupled with line-of-site deposition resulted in nm-scale line underneath the suspended CNT. The width of the resulting shadow is nearly a simple function of CNT/nanowire diameter, incident evaporation angle, and height of CNT above the substrate in a line-of-site evaporation geometry. Another promising approach to control the placement of nanotubes/nanowires is the selective functionalization of only their tips followed by selfassembly onto chemically patterned substrates. Towards this goal, arrays of aligned CNTs were impregnated with polystyrene to form aligned CNT membranes. These CNT membranes were also studied for gas and ionic transport studies. Different functionalization chemistry was performed on each side of the membrane. After dissolution of polymer matrix, a suspension of CNTs with different functionality at each tip was formed, allowing for sophisticated selfassembled architectures.

Le travail présenté dans ce mémoire a pour objectif le développement de nouvelles approches permettant d'introduire de manière robuste des marques dans une vidéo. Il s'agira tout d'abord de sélectionner les zones des images les plus appropriées à l'introduction du tatouage. Pour cela, plusieurs critères devront être pris en compte. Tout d'abord, lorsqu'une marque est introduite dans une zone de l'image, il est nécessaire d'introduire la même marque au même endroit sur toutes les images de la séquence. En effet, dans le cas contraire, un simple filtrage temporel dans le sens du mouvement permet de détruire la marque. Il sera également important de détecter les zones moins importantes visuellement dans lesquelles des modifications pourraient être introduites plus facilement sans qu'elles soient visibles. Il s'agit notamment des zones visibles dans peu d'images différentes, ou des zones ou l'œil humain est peu susceptible de détecter des différences, telles que les zones d'ombres en mouvement. Pour parvenir à une détection efficace de telles régions, une phase d'analyse permettant notamment la création d'images mosaïques (ou sprite dans le contexte MPEG-4) et la détection des ombres en mouvement devra être réalisée. / The work presented in this thesis aims to develop new approaches to introduce, in a robust way, a marks in a video. The areas of the images which are most appropriate to the introduction of the tattoo should be selected. For that, several criteria must be taken into account. Firstly, when a mark is introduced into an area of the image, it is necessary to introduce the same mark at the same location on all images in the sequence. It is also important to detect an invisible areas where changes could be introduced easily without being seen. These are areas where the human eye is less sensitive to changes, such as shadows region of moving objects. To achieve the e#ective detection of such regions, a phase of analysis including the creation of mosaic images and the detection of shadows of moving objects will be realized.

M.Comm / This dissertation comprises of four parts that attempt to explain the history and application of shadow pricing in South African water projects with reference to water resource development and water pricing reforms. Water is a precious resource and people simply cannot survive without fresh water. It becomes a vital function to then price water correctly and therefore revolutionise the way water is treated. The application of CBA has become increasingly important over recent years Governments often finance these projects, but there is a need for a consistent or standard framework to evaluate capital projects to minimise the risk and possible losses. As a result a manual and method to evaluate spending priorities was developed in the 1980’s in South Africa. CBA has found extensive applications in the field of water development. Important issues such as the opportunity cost of water and a method to calculate the economic value or the opportunity cost of water have been developed further in South Africa over the past few years. It emphasises that pricing water can be a complicated process affected by various forces, many of which are difficult to define and model. The History and Application of Shadow Pricing in South African Water Projects Page v This dissertation demonstrates that the strategies employed in each country are different variations of CBA, with the use of shadow pricing and are adapted to each countries varying circumstance. The political experiences in South Africa have placed strain on the countries scarce national resources. As a result there is a need for some kind of framework and method to evaluate spending and pricing of infrastructure and importantly the development of water pricing reforms and management thereof. The study concludes that there is limited literature that actually defines and explains how shadow prices are calculated in water resource management. Wrong policy or planning decisions can often be a result of price distortions. Therefore, countries are becoming more aware that external factors, such as social welfare and the environment need to be taken into consideration.

This thesis contains four stories of fantasy and science fiction. Four story lengths are represented: the short short ("Dragon Lovers"), the shorter short story ("Homecoming"), the longer short story ("Shadow Mistress"), and the novel ("Sword of Albruch," excerpted here).

Liability of shareholders and other persons for debts of the company (multinational included) This master thesis is devoted to the issue of the legal liability of shareholders and others for debts of the company in consequence of their influence on the company or in case of its insolvency. The former is not a wholly new institute in Czech law, however it raises many new questions especially because of its broader concept. The latter is an entirely new issue in the Czech legal system which was influenced by the English concept called wrongful trading. The thesis is composed of five chapters. Chapter one briefly presents the concept of limited liability of the shareholders, its development, significance and criticism, including certain means that are used by the legal systems and courts to break the limited liability under some specific circumstances. Chapter two points out certain legal devices that had provided protection for creditors and that were abandoned, which may leads to the higher importance of the legal liability of the shareholders and other persons connected with the company. Chapter three concerns the concept of influential and controlling person, and also explains the concept of shadow director and de facto director under English law. Subsequently it presents certain categories of...

What does it actually mean to be bored? According to media you most likely get the impression that it is a disease that needs to be cured. And the word certainly has a negative tone attached to it. To be “bored” is not a state of mind where most people want to be. Therefore we live in a world where we can find all kinds of distractions and tools to make things as effective and entertaining as possible.   In my essay “Upprepningar och tristess”, I explore the link between boredom, creativity and development. Through studies, books, essays and magazines I try to get under the skin of a hard definable topic. What has been written and what has been said? Is it overall just a bad thing that we should try to eliminate, or is it an important state of mind that we need to pay attention to and try to understand better? In the end, also my essay falls prey to the depths of boredom. / <p><em>My exam work consists of a written essay part and a formed/interpreted part.</em></p>

Notre étude répond a l'intitulé « La Dialectique ombre et lumière dans la poésie de Baudelaire et Senghor ». Elle s'attache à décrire la sémantique de ces deux métaphores de la condition humaine dans les œuvres de nos auteurs, sous l'autorité méthodologique de la stylistique de Spitzer et de la thématique richardienne. De fait, bien plus qu'un simple ornement, ombre et lumière traduisent au mieux leur pensée et décrivent la structure des œuvres. Ainsi, sont-elles une matrice génératrice d'une esthétique, d'une philosophie, et d'une religion parfois dissonante. Opportunément, le travail tente de mettre en lumière l'apport de Baudelaire dans la poésie senghorienne. Il établit que, contrairement à ce que certains critiques ont écrit, et à ce que Senghor à laisser entendre, sa poésie n'est pas influencée par celle du poète français. Ce dernier agit plutôt comme un révélateur, en lui faisant prendre conscience de la beauté de l'Afrique et de la femme noire, leur véritable point de rencontre / Our study answers to the title "The Dialectic shadow and light in Baudelaire and Senghor poetry". It strives to describe semantics of these two metaphors of the human condition in the work of our authors, under the methodological authority from Spitzer stylistics and from Richardřs themathic. Ac-tually, more than a simple ornament, a shadow and a light translate at best as possible their thought and describe the structure of the work. So, they are a generative matrix of aesthetics, a philosophy, and a sometimes dissonant religion. Conveniently, the work tries to highlight Baudelaire contribution in the Senghor poetry. It establishes that, in opposition to what some critics wrote, and in what Senghor let understand, his poetry is not influenced by that of the French poet. This last one acts rather as a revelation, by making him become aware of the beauty of Africa and black woman, their real meeting point