Thesis (MA(VA))--Stellenbosch University, 2014. / ENGLISH ABSTRACT: This thesis examines the extent to which the cuff and the collar as semiotic entities played a significant role in the symbolic expression of power and oppression in the seventeenth century Cape of Good Hope. These entities were visually naturalised by the Eurocentric imperialist hegemony at the Cape and offered as undisputed ‘truth’. These symbols permeated the collective consciousness of the society at the Cape on both a physical and cognitive level. The white ruff and cuffs, and the shackles of the slaves represented physical restraints, whilst mentally the slaves were confronted with identity construction and deconstruction. ‘The self’ was pitted against ‘the Other’, and these European values and hierarchies were enforced on the society at the Cape by creating dualistic relationships. An identity implies a certain amount of power. For this reason, the Europeans stripped the slaves of their identities in order to gain control over them. This theory, together with the investigation into the hybrid characteristic of culture as a product of colonialism and slavery at the Cape, will be established concurrently with the aim of my practical work — The Ruff/Rough Collection, The Shackle Collection, and The Soft Steel Collection. This body of work aims to deconstruct the boundaries and hierarchies established by the cuff and the collar (as symbols of the power and oppression paradigm) at the Cape. / AFRIKAANSE OPSOMMING: Hierdie tesis ondersoek die mate waarin die mouboordjie (‘cuff’) en die kraag (‘collar’) as semiotiese entiteite ’n beduidende rol gespeel het in die simboliese uitdrukking van mag en onderdrukking aan die Kaap de Goede Hoop in die sewentiende eeu. Hierdie simbole is visueel deur die Eurosentriese imperialistiese leierskap ingevoer en as onbetwisbare waarheid van hul mag en heerskappy voorgehou. Dié simbole het die kollektiewe bewussyn van die samelewing aan die Kaap op ’n fisieke en geestelike vlak geïnfiltreer. Die wit plooikraag (‘ruff’) wat die Europeërs gedra het om hulself as ‘meesters’ te vestig, en die boeie van die slawe het fisieke beperkings verteenwoordig, terwyl die slawe geestelik gekonfronteer is met die opbou en afbreek van hulle identiteit. ‘Die ek’ is teen ‘die Ander’gestel en Europese waardes is op grond van die Eurosentriese ingesteldheid van die ‘meesters’ op die samelewing afgedwing as ‘n dualistiese verhouding. ’n Identiteit impliseer ’n sekere graad van mag. Daarom het die Europeërs die slawe van hulle identiteit gestroop om sodoende mag oor hulle te verkry. Hierdie teorie, asook die ondersoek na die hibridiese eienskap van kultuur as ’n produk van kolonialisme en slawerny aan die Kaap, sal konkurrent met die doel van my praktiese werk — The Ruff/Rough Collection, The Shackle Collection en The Soft Steel Collection — gevestig word. Die doel van hierdie versameling kontemporêre juweliersware is om die grense en hiërargieë te dekonstrueer, wat deur die mouboordjie (‘cuff’) en die kraag (‘collar’) (as simbole van die mag- en onderdrukkingsparadigma) tot stand gebring is aan die Kaap de Goede Hoop.

Cette thèse porte sur la modélisation et vérification des signatures en ligne. La première partie a pour thème principal la modélisation biomécanique des mouvements de la main. Un modèle basé sur le critère de Minimum de Secousse (MS) a été choisi parmi plusieurs théories du contrôle moteur. Ensuite, le problème de la segmentation des trajectoires en traits qui correspondent au modèle cinématique choisi a été étudié, ce qui a conduit à la mise au point d'une méthode de segmentation itérative. Le choix du modèle et de la méthode de segmentation sont basé sur le compromis entre la qualité de reconstruction et la compression. Dans la deuxième partie, le modèle polynomial issu du critère de MS est volontairement dégradé. Les zéros non-Réels des polynômes sont jetés et les effets de cette dégradation sont étudiés dans une perspective de vérification biométrique. Cette dégradation est équivalente à la technique connue sous le nom d’Infinity Clipping, initialement appliqué à des signaux de parole. Pour les signatures en ligne, comme pour la parole, la préservation de l'information essentielle a été observée sur des tâches de vérification de signature. En fait, en utilisant seulement la distance de Levenshtein sur la représentation dégradée, un taux d'erreur comparable à ceux des méthodes plus élaborées a été obtenu. En outre, la représentation symbolique issue de l’Infinity Clipping permet d’établir une relation conceptuelle entre le nombre de segments obtenus par la segmentation itératif basée sur le MS et la complexité de Lempel-Ziv. Cette relation est potentiellement utile pour l'analyse des signatures en ligne et pour l’amélioration des systèmes de reconnaissance / This thesis deals with the modelling and verification of online signatures. The first part has as main theme the biomechanical modelling of hand movements associated to the signing gesture. A model based on the Minimum Jerk (MJ) criterion was chosen amongst the several available motor control theories. Next, the problem of signature trajectory segmentation into strokes that better fit the chosen kinematic model is studied, leading to the development of an iterative segmentation method. Both the choice of the model and the segmentation method are strongly based on the tradeoff between reconstruction quality and compression. On the second part, the polynomial model provided by the MJ criterion is intentionally degraded. The non-Real zeroes of the polynomials are discarded and the effects of this degradation are studied from a biometric verification perspective. This degradation is equivalent to the signal processing technique known as Infinity Clipping, originally applied to speech signals. On signatures, as for speech, the preservation of essential information was observed on signature verification tasks. As a matter of fact, using only the Levenshtein distance over the infinitely clipped representation, verification error rates comparable to those of more elaborate methods were obtained. Furthermore, the symbolic representation yielded by the infinity clipping technique allows for a conceptual relationship between the number of polynomial segments obtained through the Minimum Jerk-Based iterative segmentation and the Lempel-Ziv complexity. This relationship is potentially useful for the analysis of online signature signals and the improvement of recognition systems

This thesis studies the properties of finite automata recognizing sets of real vectors encoded in positional notation using an integer base. We consider both general infinite-word automata, and the restricted class of weak deterministic automata, used, in particular, as symbolic data structures for representing the sets of vectors definable in the first order additive theory of real and integer numbers. <br><br> In previous work, it has been established that all sets definable in the additive theory of reals and integers can be handled by weak deterministic automata regardless of the chosen numeration base. In this thesis, we address the reciprocal property, proving that the sets of vectors that are simultaneously recognizable in all bases, by either weak deterministic or Muller automata, are those definable in the additive theory of reals and integers. <br><br> Precisely, for weak deterministic automata, we establish that the sets of real vectors simultaneously recognizable in two multiplicatively independent bases are necessarily definable in the additive theory of reals and integers. For general automata, we show that the multiplicative independence is not sufficient, and we prove that, in this context, the sets of real vectors that are recognizable in two bases that do not share the same set of prime factors are exactly those definable in the additive theory of reals and integers. <br><br> Those results lead to a precise characterization of the sets of real vectors that are recognizable in multiple bases, and provide a theoretical justification to the use of weak automata as symbolic representations of sets. <br><br> As additional contribution, we also obtain valuable insight into the internal structure of automata recognizing sets of vectors definable in the additive theory of reals and integers.