Thesis (PhD (Biochemistry))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Metabolic Control Analysis (MCA) provides a powerful quantitative framework for understanding and explaining the control and regulation within a cellular system. MCA allows the global control of a steady-state system to be quantified in terms of control coeficients, which we can express in terms of the local properties referred to as elasticity coeficients. MCA relates elasticities to control coeficients through a matrix inversion, thus allowing scientists to predict and quantify how the kinetics of the individual enzymes affect the systemic behaviour of cellular systems. Traditionally we solved this problem numerically, while we used algebraic and symbolic control analysis techniques less frequently. By using symbolic algebraic computation we present a general implementation of the symbolic matrix inversion of MCA, known as SymCA, which requires only the description of any allosteric modifier interactions and the stoichiometry of a cellular system. The algebraic expressions generated allow an in-depth analysis of the distribution of the control within a system and also of the parameters which exhibit the greatest effect on this control distribution. This also applies when the exact values for the elasticities or control coeficients are unknown. We have demonstrated that by quantifying the control patterns, referred to as `routes of regulation', inherent in all control coeficient expressions, we can gain insight into how perturbations are propagated through a cellular system and which regulatory pathways are favoured under changing conditions. / AFRIKAANSE OPSOMMING: Metaboliese Kontrole-Analise (MKA) bied 'n kragtige kwantitatiewe raamwerk om die beheer en regulering binne sellulere sisteme te verstaan en te verduidelik. 'n Sleutelaspek van MKA is dat die globale beheer van 'n sisteem met 'n bestendige toestand gekwantifiseer kan word in terme van kontrole-koefisente en dat hierdie koefisente uitgedruk kan word in terme van die sisteem se lokale eienskappe, genaamd elastisiteitskoefisente. Deur van matriksinversie gebruik te maak kan MKA die verband tussen elastisiteitskoefisente en kontrole-koefisente aflei wat mens in staat stel om te sien hoe die kinetika van die individuele ensiemreaksies die sisteemgedrag op sellulere vlak beinvloed. Die probleem word tradisioneel hoofsaaklik op numeriese wyse bereken terwyl die gebruik van algebraiese en simboliese kontrole-analise minder gereeld gebruik word. In hierdie proefskrif verskaf ons, deur van simboliese algebraiese metodes gebruik te maak, 'n generiese implementasie van die simboliese matriksinversie van MKA, genaamd SymCA, wat slegs 'n beskrywing van 'n sellulere sisteem se allosetriese interaksies en die stoichiometrie benodig. Die algebraiese uitdrukkings sodanig gegenereer stel mens in staat om 'n in-diepte analise te doen om vas te stel waar die beheer binne 'n sisteem le, asook watter parameters die grootste effek op die kontrole-verspreiding het. Dit geld selfs in die geval waar die presiese waardes van die elastisiteitskoefisente of kontrole-koefisente onbekend is. Hierdie proefskrif demonstreer hoe die kwantifisering van kontrole-patrone, ook gesien as 'roetes van regulering', wat inherent is aan kontrole-koefisent vergelykings, mens in staat stel om te sien hoe perturbasies in 'n sellulere sisteem voortplant en watter regulatoriese paaie bevoordeel word onder veranderde kondisies.

The objective of this thesis is to generate a discrete alphabet of low-level robotic controllers rich enough to mimic the actions of high-level users using the robot for a specific task. This alphabet will be built through the analysis of various user data sets in a modified version of the motion description language, MDLe. It can then be used to mimic the actions of a future user attempting to perform the task by calling scaled versions of the controls in the alphabet, potentially reducing the amount of data required to be transmitted to the robot, with minimal error. In this thesis, theory is developed that will allow the construction of such an alphabet, as well as its use to mimic new actions. A MATLAB algorithm is then built to implement the theory. This is followed by an experiment in which various users drive a Khepera robot through different courses with a joystick. The thesis concludes by presenting results which suggest that a relatively small group of users can generate an alphabet capable of mimicking the actions of other users, while drastically reducing bandwidth.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-07-25T12:17:51Z No. of bitstreams: 1 igordesouzarodrigues.pdf: 2477010 bytes, checksum: 7b65c23ed5e7ae025ee01517b70d513d (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-07-25T16:33:51Z (GMT) No. of bitstreams: 1 igordesouzarodrigues.pdf: 2477010 bytes, checksum: 7b65c23ed5e7ae025ee01517b70d513d (MD5) / Made available in DSpace on 2016-07-25T16:33:51Z (GMT). No. of bitstreams: 1 igordesouzarodrigues.pdf: 2477010 bytes, checksum: 7b65c23ed5e7ae025ee01517b70d513d (MD5) Previous issue date: 2015-03-05 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este estudo tem como objetivo discutir a questão da identidade do morador de rua a partir da produção simbólica e de sua vinculação à estrutura social, demonstrando como essa constituição está incrustada nas ideologias neoliberais e nos processos de controle e dominação, por exemplo, na transformação da necessidade em escolha, denominada aqui “mito da escolha masoquista”. Nesse sentido, busca-se desconstruir algumas ideologias, que inclusive perpassam a constituição dessa identidade e da formação desses indivíduos, como a “invisibilidade” do morador de rua, a redução do problema a uma dimensão meramente econômica, expressa na classificação “sem-teto”, e a forma policialesca com que são percebidos. Discute-se também como a mão de obra do lumpem se transformou de exército reserva dos empregos fabris em um trabalho autônomo-dependente, não reconhecido sequer como trabalho. A questão principal é a de entender como ser “morador de rua” indica muito mais do que o local onde se dorme, assumindo uma localização em referência ao trabalho, familiar e moral do indivíduo, o que acaba se refletindo no meio acadêmico e em políticas institucionais, dentre elas as formas higienista, domesticadora e piedosa de perceber e atentar para os moradores de rua. / This study aims to discuss the question of the identity of the homeless from the symbolic production and their relation to the social structure, demonstrating how this constitution is embedded in the neoliberal ideologies and processes of control and domination, for example, the transformation of need for choice, called here the "myth of masochistic choice." In this sense, we seek to deconstruct some ideologies that permeate even the constitution of this identity and training of these individuals, as the "invisibility" of the homeless, reducing the problem to a purely economic dimension, expressed in the rating "homeless "policing and the way they are perceived. We also discuss how the hand labor of lumpem became army reserve of factory jobs in a selfdependent work, not even recognized as work. The main issue is to understand how to be "homeless" means much more than the place where you sleep, assuming a location in reference to the work, family and morality of the individual, which ends up being reflected in the academic and policy institutional, among them the hygienist forms, domesticating and pious to notice and pay attention to the homeless.

Από τα δεδομένα μιας ποιοτικής προσέγγισης του φαινομένου της εισαγωγής και πιθανής ενσωμάτωσης των Τεχνολογιών Πληροφορίας και Επικοινωνίας στο μάθημα της ιστορίας (σχολικό έτος 2009-2010) προκύπτει ότι η δευτεροβάθμια εκπαίδευση δεν ανταποκρίνεται στις τάσεις και προκλήσεις που σημειώθηκαν και σημειώνονται στο χώρο της παιδείας σε παγκόσμιο επίπεδο. Ανάγκες εκσυγχρονισμού και ευριζωνικότητας παραμένουν ανικανοποίητες. Έτσι, αναδεικνύονται παραδοσιακές μορφές συμβολικού ελέγχου που φαίνεται να κυριαρχούν στο σύγχρονο εκπαιδευτικό χώρο. Ακόμα και σημαντικές πρωτοβουλίες προώθησης της αλλαγής (net book) φαντάζουν στα μάτια των εκπαιδευτικών «αυθαίρετες» εκφράσεις εξουσίας χωρίς αποτέλεσμα. Όσοι εκπαιδευτικοί τόλμησαν την αλλαγή βίωσαν την ανάγκη ξεπαγώματος μιας ισχυρά δομημένης εκπαιδευτικής πρακτικής στο πλαίσιο ανέτοιμων εγκαταστάσεων και συνειδήσεων για την αποδοχή του εμβλήματος της εποχής. Συμπερασματικά λοιπόν, η παγίωση μιας εκπαιδευτικής καινοτομίας δεν εξασφαλίζει μαθησιακά αποτελέσματα με διχοτομήσεις του τύπου κλειστό/ανοικτό σχολείο αντίθετα απαιτείται συντονισμός και συλλογική δράση. / It can be elicited from the qualitative data that the quadric education doesn’t correspond to the tendencies and the challenges that take place in the field of education worldwide. The need for update remains unsatisfied. As a result traditional forms of symbolic control emerge and seem to dominate in the current educational area. Even important initiatives that promote change (net book) have been treated by the educators as arbitrary and ineffective expressions of authority. On the other hand some of those who presumed to launch this change they faced a deeply rooted educational practice underlined by the lack of facilities and the lack of consciousness which in turn discourage the need for change. Concluding, the consolidation of an educational novelty doesn’t provide learning outcomes with dichotomies such as open or close school but on the contrary coordination and collective action is needed.

Cette thèse porte sur le développement d'approches compositionnelles et efficaces de synthèse de contrôleurs pour les systèmes cyber-physiques (CPS). En effet, alors que les techniques de conception des CPS basées sur des modèles ont fait l'objet de nombreuses études au cours de la dernière décennie, leur scalabilité reste problématique. Dans cette thèse, nous contribuons à rendre de telles approches plus évolutives.La première partie est axée sur les approches compositionnelles. Un cadre général pour le raisonnement compositionnel en utilisant des contrats d’hypothèse-garantie est proposé. Ce cadre est ensuite combiné avec des techniques de contrôle symbolique et appliqué à un problème de synthèse de contrôleur pour des systèmes échantillonnés, distribués et multipériodiques, où l'approche symbolique est utilisé pour synthétiser un contrôleur imposant un contrat donné. Ensuite, une nouvelle approche de calcul compositionnel des abstractions symboliques est proposée, basée sur la notion de composition approchée et permettant de traiter des abstractions hétérogènes.La deuxième partie de la thèse porte sur des techniques efficaces d'abstraction et de synthèse de contrôleurs. Deux nouvelles techniques de calcul d’abstractions sont proposées pour les systèmes à commutation incrémentalement stables. La première approche est basée sur l'échantillonnage multi-niveaux où nous avons établi l'existence d'un paramètre optimal d'échantillonnage qui aboutit à un modèle symbolique avec un nombre minimal de transitions. La deuxième approche est basée sur un échantillonnage événementiel, où la durée des transitions dans le modèle symbolique est déterminée par un mécanisme déclencheur, ce qui permet de réduire le conservatisme par rapport au cas périodique. La combinaison avec des techniques de synthèse de contrôleurs paresseux est proposée permettant la synthèse à un coût de calcul réduit. Enfin, une nouvelle approche de synthèse paresseuse a été développée pour les systèmes de transition monotones et les spécifications de sécurité dirigées. Plusieurs études de cas sont considérées dans cette thèse, telles que la régulation de la température dans les bâtiments, le contrôle des convertisseurs de puissance, le pilotage des véhicules et le contrôle de la tension dans les micro-réseaux DC. / This thesis focus on the development of compositional and efficient controller synthesis approaches for cyber-physical systems (CPS). Indeed, while model-based techniques for CPS design have been the subject of a large amount of research in the last decade, scalability of these techniques remains an issue. In his thesis, we contribute to make such approaches more scalable.The focus of the first part is on compositional approaches. A general framework for compositional reasoning using assume-guarantee contracts is proposed. This framework is then combined with symbolic control techniques and applied to a controller synthesis problem for multiperiodic distributed sampled-data systems, where symbolic approaches have been used to synthesize controllers enforcing a given assume-guarantee contract. Then, a new approach to the compositional computation of symbolic abstractions is proposed based on the notion of approximate composition, allowing to deal with heterogeneous abstractions and arbitrary interconnections.The second part is about efficient abstraction and controller synthesis techniques. Two new abstractions schemes have been developed for incrementally stable switched systems. The first approach is based on multirate sampling where we established the existence of an optimal multirate sampling parameter that results in a symbolic model with a minimal number of transitions. The second approach is based on event-based sampling, where the duration of transitions in the symbolic model is determined by some triggering mechanism, which makes it possible to reduce the conservatism with respect to the periodic case. Combination with lazy controller synthesis techniques has been proposed allowing the synthesis at a reduced computational cost. Finally, a new lazy approach has been develop for monotone transition systems and directed safety specifications. Several case studies have been considered in this thesis such as temperature regulation in buildings, control of power converters, vehicle platooning and voltage control in DC micro-grids.