Reversible logic computing is a rapidly developing research area. Both reversible logic synthesis and testing reversible logic circuits are very important issues in this area. In this thesis, we present our work in these two aspects. We consider a new fault model, namely the crosspoint fault, for reversible circuits. The effects of this kind of fault on the behaviour of the circuits are studied. A randomized test pattern generation algorithm targeting this kind of fault is introduced and analyzed. The relationship between the crosspoint faults and stuck-at faults is also investigated. The crosspoint fault model is then studied for possible applications in reversible logic synthesis. One type of redundancy exists in Toffoli networks in the form of undetectable multiple crosspoint faults. So redundant circuits can be simplified by deleting those undetectable faults. The testability of multiple crosspoint faults is analyzed in detail. Several important properties are proved and integrated into the simplifying algorithm so as to speed up the process. We also provide an optimized implementation of a Reed-Muller spectra based reversible logic synthesis algorithm. This new implementation uses a compact form of the Reed-Muller spectra table of the specified reversible function to save memory during execution. Experimental results are presented to illustrate the significant improvement of this new implementation.

Reversible axial flow fans are used as emergency ventilation fans to discharge the smoke generated on the probable fires occurring in the underground transportation systems and mines as quickly as possible, without causing any harm to people exposed to it. The fans which are placed in different configurations according to the location of fire must be able to work bi-directionally, namely reversible. Due to this fact, the blade profiles of the fan must possess the same aerodynamic performance while working on either discharge or suction condition of the fan, dictated by direction of the rotation. This manuscript consists of the computation of the aerodynamic performances of symmetrical blade profiles of fully reversible axial fans by computational fluid mechanics (CFD) methods, developing a methodology for the design of reversible axial fans and analysis of the designed fan with CFD methods. The aerodynamic performances of the blade cascades are evaluated using FLUENT 6.0 software for different Reynolds numbers, solidities and angle of attacks of the cascade. The results of these computations are embedded into the developed methodology. Performance analysis of the reversible axial flow fan, which is designed with the developed methodology, is done with CFD techniques.

"Multi-functionalized Side-chain Supramolecular Polymers:A Methodology Towards Tunable Functional Materials". Even as we see a significant growth in the field of side-chain supramolecular polymers in the last ten years, systems employing multiple non-covalent interactions have been scarcely studied. Non-covalent multi-functionalization provides unique advantages such as rapid optimization via reversible functionalization as well as for the tuning of materials properties by exploiting the differences in the nature of these reversible interactions. This thesis involves the design principles, synthesis & methodology of side-chain multi-functionalized polymers. The combination of the principles of a functionally tolerant & a controlled polymerization technique such as ROMP with multiple noncovalent interactions such as hydrogen bonding, metal coordination & Coulombic self-assembly has been used to synthesize multi-functionalized polymers. Furthermore, the orthogonality between hydrogen bonding, metal coordination & ionic self-assembly in random/block copolymers has been studied in detail. In order to validate the viability of this multi-functionalization methodology towards materials design non-covalent crosslinking of polymers was used as a potential application. Three classes of crosslinked networks have been studied: complementary multiple-hydrogen bonded networks, multiple-metal crosslinked networks, & multi-functionalized hydrogen bonded & metal coordinated networks. By using non-covalent multi-functionalization, important materials properties & its responsiveness towards chemical agents have been tuned & controlled to yield novel materials which would be difficult to be obtained via traditional covalent techniques or by using single non-covalent interactions.

This thesis investigates the design, synthesis and biological assay of cysteine protease inhibitors within the papain superfamily of cysteine proteases. This is achieved by examining the effect of inhibitor design, especially warheads, on IC₅₀ values and structureactivity relationships between cysteine protease inhibitors of the papain superfamily. The representative proteases used are m-calpain, μ-calpain, cathepsin B and papain. Chapter One is an introductory chapter; Chapters Two-Four describe the design and synthesis of cysteine protease inhibitors; Chapter Five discusses assay protocol; and Chapter Six contains the assay results and structure-activity relationships of the synthesised inhibitors. Chapter One introduces cysteine proteases of the papain family and examines the structure, physiology and role in disease of papain, cathepsin B, m-calpain and μ-calpain. The close structural homology that exists between these members of the papain superfamily is identified, as well characteristics unique to each protease. Covalent reversible, covalent irreversible and non-covalent warheads are defined. The generic inhibitor scaffold of address region, recognition and warhead, upon which the inhibitors synthesised in this thesis are based, is also introduced. Chapter Two introduces reversible cysteine protease inhibitors found in the literature and that little is known about the effect of inhibitor warhead on selectivity within the papain superfamily. Oxidation of the dipeptidyl alcohols 2.6, 2.26, 2.29, 2.30, 2.35 and 2.36 utilising the sulfur trioxide-pyridine complex gave the aldehydes 2.3, 2.27, 2.19, 2.2, 2.21 and 2.22. Semicarbazones 2.37-2.40 were synthesised by a condensation reaction between the alcohol 2.3 and four available semicarbazides. The amidoximes 2.48 and 2.49 separately underwent thermal intramolecular cyclodehydration to give the 3-methyl-1,2,4- oxadiazoles 2.41 and 2.50. The aldehydes 2.3 and 2.27 were reacted with potassium cyanide to give the cyanohydrins 2.51 and 2.52. The cyanohydrins 2.51 and 2.52 were separately reacted to give 1) the α-ketotetrazoles 2.43 and 2.55; 2) the α-ketooxazolines 2.42 and 2.58; 3) the esterified cyanohydrins 2.60 and 2.61. A two step SN2 displacement reaction of the alcohol 2.6 to give the azide 2.62, an example of a non-covalent cysteine protease inhibitor. Chapter Three introduces inhibitors with irreversible warheads. The well-known examples of epoxysuccinic acids 3.1 and 3.5 are discussed in detail, highlighting the lack of irreversible cysteine protease specific inhibitors. The aldehydes 2.3 and 2.27 were reacted under Wittig conditions to give the α,β-unsaturated carbonyls 3.14-3.18. Horner- Emmons-Wadsworth methodology was utilised for the synthesis of the vinyl sulfones 3.20- 3.23. The dipeptidyl acids 2.24 and 2.28 were separately reacted with diazomethane to give the diazoketones 3.25 and 3.26. The diazoketones 3.25 and 3.26 were separately reacted with hydrogen bromide in acetic acid (33%) to give the α-bromomethyl ketones 3.27 and 3.28, which were subsequently reduced to give the α-bromomethyl alcohols 3.29-3.32. Under basic conditions the α-bromomethyl alcohols 3.29-3.32 ring-closed to form the peptidyl epoxides 3.33-3.36. Chapter Four introduces the disadvantages of peptide-based inhibitors. A discussion is given on the benefits of constraining inhibitors into the extended bioactive conformation known as a β-strand. Ring closing metathesis is utilised in the synthesis of the macrocyclic aldehyde 4.4, macrocyclic semicarbazone 4.15, the macrocyclic cyanohydrin 4.16, the macrocyclic α-ketotetrazole 4.18 and the macrocyclic azide 4.19. Chapter Five introduces enzyme inhibition studies. The BODIPY-casein fluorogenic assay used for establishing inhibitor potency against m-calpain and μ-calpain is validated. Assay protocols are also established and validated for cathepsin B, papain, pepsin and α- chymotrypsin. A discussion of the effect of solvent on enzyme activity is also included as part of this study. Chapter Six presents the assay results for all the inhibitors synthesised throughout this thesis and an extensive structure-activity relationship study between inhibitors is included. The alcohols 2.26 and 2.30 are unprecedented examples of non-covalent, potent, cathepsin B inhibitors (IC₅₀ = 0.075 μM selectivity 80-fold and 1.1 μM, selectivity 18-fold). The macrocyclic semicarbazone 4.15 is an unprecedented example of a potent macrocyclic cysteine protease inhibitor (m-calpain: IC₅₀ = 0.16 μM, selectivity 8-fold). The cyanohydrin 2.51 contains an unprecedented cysteine protease warhead and is a potent and selective inhibitor of papain (IC₅₀ = 0.030 μM, selectivity 3-fold). The O-protected cyanohydrin 2.61 is a potent and selective inhibitor of pepsin (IC₅₀ = 1.6 μM, selectivity 1.5-fold). The top ten warheads for potent, selective cathepsin B inhibition are: carboxylic acid, methyl ester, diazoketone, esterified cyanohydrin, α-bromomethyl ketone, α,β- unsaturated aldehyde, vinyl sulfones, α-bromomethyl-C₃-S,R-alcohol, alcohol and α,β- unsaturated ethyl ester. The selectivity of these warheads was between 5- and 130-fold for cathepsin B. The best inhibitors for cathepsin B were the α-bromomethyl ketone 3.26 (IC₅₀ = 0.075 μM, selectivity 16-fold), the α,β-unsaturated aldehyde 3.18 (IC₅₀ = 0.13 μM, selectivity 13-fold) and the esterified cyanohydrin 3.59 (IC₅₀ = 0.35 μM, selectivity 22- fold). Chapter Seven outlines the experimental details and synthesis of the compounds prepared in this thesis.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Depression and chronic pain coexist in several patients and may be modulated by the same neurotransmitter systems. In this context, various studies have demonstrated that antidepressants from the class of the inhibitors of monoamine oxidase-A (MAO-A) enzyme presented antinociceptive effect in different pain models in experimental animals, as well as analgesic action in clinic studies. Thus, in the present study were evaluated the MAO-A inhibitory properties, as well as the antidepressant and antinociceptive potential of the novel imidazoline compound 2-(3,4-dimethoxy-phenyl)-4,5-dihydro-1H-imidazole (2-DMPI) in mice. 2-DMPI showed to be a mixed, reversible and preferential MAO-A inhibitor. The treatment with 2-DMPI (100-1000 μmol/kg, s.c.) produced an antidepressant-like effect in the tail suspension test without affecting motor activity of the animals. The mice treated with 2-DMPI showed a decrease in serotonin and dopamine turnover in specific brain regions, suggesting that the antidepressant-like effect of this compound was mediated by serotonergic and dopaminergic systems. This was confirmed by experiments showing that the antidepressant-like effect of 2-DMPI was abolished by pretreatment with serotonergic and dopaminergic receptor antagonists. In order to evaluate a possible antinociceptive action of 2-DMPI, a mice model of neuropathic pain, induced by chronic constriction injury (CCI) of the sciatic nerve was used. It was observed that mice submitted to CCI presented an increase in MAO-A activity in lumbar spinal cord compared with sham-submitted mice and that the treatment with 2-DMPI (30-300 μmol/kg, s.c.) reversed the CCI-induced mechanical hyperalgesia. Furthermore, the antihyperalgesic effect of 2-DMPI was reversed by intrathecal injection of the serotonergic 5-HT3 receptor antagonist ondansetron (10 μg/site). These results suggest that 2-DMPI, due to its ability to modulate MAO-A activity and, consequently, the monoaminergic systems, could be a promising prototype to the development of new drugs with antidepressant and analgesic properties. / A depressão e a dor coexistem em muitos pacientes e podem ser moduladas pelos mesmos sistemas de neurotransmissores. Nesse contexto, diversos estudos têm demonstrado que antidepressivos da classe dos inibidores da enzima monoamina oxidase-A (MAO-A) apresentam efeito antinociceptivo em diferentes modelos de dor em animais experimentais, assim como ação analgésica em estudos clínicos. Em vista disso, no presente estudo foram avaliadas as propriedades inibitórias sobre a atividade da MAO-A, assim como os potenciais antidepressivo e antinociceptivo do novo composto imidazolínico 2-(3,4-dimetoxi-fenil)-4,5-diidro-1H-imidazol (2-DMPI) em camundongos. Foi observado que o 2-DMPI é um inibidor misto, reversível e preferencial da MAO-A. O tratamento com 2-DMPI (100-1000 μmol/kg, s.c.) produziu um efeito tipo-antidepressivo no teste de suspensão da cauda, sem afetar a atividade motora dos animais. Os camundongos tratados com 2-DMPI (300 μmol/kg, s.c.) apresentaram uma diminuição na taxa de renovação da serotonina e da dopamina em regiões cerebrais específicas, sugerindo que o efeito tipo-antidepressivo desse composto foi mediado pelos sistemas serotoninérgico e dopaminérgico. Isto foi confirmado por experimentos que mostraram que o efeito tipo-antidepressivo do 2-DMPI foi abolido pelo pré-tratamento com antagonistas de receptores serotoninérgicos e dopaminérgicos. A fim de avaliar um possível efeito antinociceptivo do 2-DMPI, foi utilizado um modelo de dor neuropática, induzida pela injúria por constrição crônica (CCI) do nervo ciático, em camundongos. Observou-se que os camundongos submetidos à CCI apresentaram um aumento na atividade da MAO-A na medula espinhal lombar comparado com os animais falso-operados e que o tratamento com 2-DMPI (30-300 μmol/kg, s.c.) reverteu a hiperalgesia mecânica induzida pela CCI. Além disso, o efeito antinociceptivo do 2-DMPI foi revertido pela administração intratecal do antagonista do receptor serotoninérgico 5-HT3, ondansetrona (10 μg/sítio). Esses resultados sugerem que o 2-DMPI, devido à sua capacidade de modular a atividade da MAO-A e, consequentemente, os sistemas monoaminérgicos, parece ser um protótipo promissor para o desenvolvimento de novos fármacos com propriedades antidepressiva e analgésica.

Face au problème des micropolluants émergents trouvés dans l’eau, l’utilisation de carbones activés est un moyen de réduire cette pollution à la source. Le but de ce travail est de mieux comprendre les mécanismes d’adsorption de certains micropolluants sur des tissus et feutres de carbones activés.Neuf molécules ont été étudiées dont des médicaments : la carbamazépine (CBZ), le diclofénac (DFN), l’ibuprofène (IBP) et l’ofloxacine (OFX), un produit anticorrosion : le benzotriazole (BZT), un perturbateur endocrinien : le bisphénol-A (BPA), deux herbicides : le mécoprop (MCP) et le pentachlorophénol (PCP) et une molécule utilisée comme indicateur de pollution des eaux usées : la caféine (CAF). Les adsorbants ultramicroporeux (tissu KIP1200 et feutre CSV4) et l’adsorbant mésoporeux (tissu BBV 800) (fournis par Dacarb, France) ont été caractérisés par adsorption d'azote à 77K et de CO2 à 273K, titrages acido-basiques (méthode de Boehm), mesure du pHpzc (point isoélectrique). Les cinétiques et isothermes d'adsorption ont été étudiées à 25°C à pH=7,5 dans un tampon phosphate NaHPO4/KH2PO4 (à 0,04M). La concentration résiduelle est analysée par HPLC.Les cinétiques d'adsorption ont été étudiées pour les 9 molécules à différentes concentrations initiales. Le temps pour atteindre l’équilibre d’adsorption dépend du volume des molécules ainsi que de leur affinité avec l’adsorbant. La quantité maximale adsorbable dépend du volume microporeux ainsi que de la surface spécifique de l’adsorbant, la quantité adsorbable est donc plus importante sur le tissu KIP 1200 que sur le feutre CSV 4. La vitesse de diffusion est la plus lente pour les adsorbants possédant un volume microporeux important, le tissu mésoporeux BBV 800 permet donc une adsorption rapide grâce à de plus larges pores qui permettent un accès plus rapide à la porosité.Des analyses en mélanges binaires et multi composés ont alors été réalisées pour connaître les paramètres clés gouvernant les cinétiques d’adsorption. Une compétition existe entre molécules dans certains cas (BZT et MCP par exemple) avec une première phase gouvernée par la cinétique d’adsorption liée à la diffusion dans les pores et la deuxième phase gouvernée par des phénomènes thermodynamiques entre le système soluté/solvant/carbone.Les isothermes d'adsorption ont été réalisés à 3 températures différentes et modélisées par des équations de Langmuir-Freundlich pour tous les micropolluants. Des paramètres thermodynamiques (enthalpie d’adsorption et enthalpie libre) ont alors été calculés et corrélés aux propriétés physico-chimiques des molécules. Une corrélation est mise en évidence entre l’enthalpie libre et la polarisabilité des molécules ainsi que les forces de Van der Waals déterminées avec le logiciel COSMO-RS mettant en évidence l’importance des forces non polaires dans le phénomène d’adsorption. Des mesures par calorimétrie d’adsorption à très faibles quantités adsorbées ont permis de mettre en évidence que l’entropie est le paramètre thermodynamique qui contrôle l’adsorption de molécules (BZT, PCP, CAF et OFX) sur le tissu KIP 1200. De fortes énergies d’interaction ont été mis en évidence entre les molécules (BZT, CAF et OFX) et les sites d’adsorption.Une étude d’adsorption-désorption de N2 et de CO2 sur des tissus KIP 1200 chargés en PCP, BZT, CAF et OFX a permis de mieux localiser le lieu de l’adsorption dans la porosité montrant une adsorption prioritairement dans les ultramicropores puis dans les supermicropores. Il a été montré également par cette méthode et par des mesures thermiques que l’eau est fortement adsorbée dans la porosité. / A lot of studies have revealed that some organic molecules such as pharmaceutical molecules, solvents, pesticides, etc.. are frequently found in water, at concentrations below µg/L, even after treatment at the exhaust of wastewater treatment plants. These molecules are highly toxic when accumulated in environment. One of the possibility for removing these micropollutants is the adsorption on activated carbons. Thus the aim of this work is to better understand the adsorption mechanism of some micropollutants onto activated carbon (ACs) in felt or fabric form.Nine micropollutants were studied, such as some pharmaceuticals: Carbamazepine (CBZ), Diclofenac (DFN), Ibuprofen (IBP), and Ofloxacin (OFX); one anti-corrosion compound : Benzotriazol (BZT); two herbicides : Mecoprop (MCP) and Pentachlorophenol (PCP) and an endocrine disruptor : Bisphenol A (BPA). Adsorption of Caffeine (CAF) which is an anthropic indicator of pollution in waste water, was also studied. The ACs (microporous KIP1200 fabric and CSV4 felt and mesoporous BBV 800 fabric, from Dacarb, France) were characterized by N2 adsorption-desorption at 77 K and CO2 adsorption at 273 K, pHpzc (point of zero charge) measurements and acido-basic titrations (Boehm method). The adsorption kinetics and isotherms were studied at pH 7.4 at 25°C in NaHPO4/KH2PO4 buffered solutions (about 0.04 M) using UV spectrometry and HPLC for the analysis of organic molecules in the remaining solution.Kinetics have been studied for 9 molecules at different initial concentrations. Time to reach adsorption equilibrium depends of the volume of the molecule and its affinity with the activated carbon. The maximum adsorbed quantity depends of the microporous volume and the specific area of the adsorbent, the adsorbed quantity is then bigger for KIP 1200 fabric than for CSV 4 felt. The speed of diffusion is slower for the adsorbent with high microporous volume, the mesoporous BBV 800 fabric gives place to a quick adsorption kinetics thanks to its large pores that gives an easy access to porosity.Binary and multi components kinetics have been done in order to understand key processes that drive kinetics adsorption. Competition between molecules have been shown (for BZT and MCP for example). Adsorption kinetics can be divided into two phases: the first one is driven by pore diffusion and the second one by thermodynamic phenomenon between the solute, the solvent and the AC.The adsorption isotherms of the molecules were studied at 13, 25 and 40°C; and the thermodynamic parameters (isoteric enthalpies and entropies Gibbs free energies) were determined. A correlation between Gibbs free energy and polarizability of molecules as well as Van der Waals energy calculated with Cosmotherm software shows the importance of non polar forces on adsorption phenomenon. Adsorption calorimetry experiments showed that entropy is the thermodynamic parameter that drives adsorption of molecules (BZT, PCP, CAF and OFX) onto KIP 1200 fabric.The pore size distributions of the carbons loaded with micropollutants were determined by DFT simulation from CO2 and N2 adsorption isotherms, to investigate the porosity accessible to the adsorbate. The accessible pore are firstly the ultramicropores and then supermicropores. With this technique and thermal experiments, it has been shown that water is highly bonded inside the porosity.

The production and consumption of today generates huge amounts of waste, and due to the increasing living standards the amount will continue to increase. The waste leads to large environmental impacts due to pollution and emissions of greenhouse gases, as well as the depletion of raw materials. This study aimed to investigate how sustainability through circular economy can drive the development towards reducing the packaging waste in a company. The ambition was to identify possible actions that could be implemented in order to decrease the amount of combustible waste and the entailed environmental impact. A case study was performed at Volvo Group Trucks Operations assembly plant in Tuve in Gothenburg. The initial part of the study consisted of a literature review and was followed by the empirical study where interviews and observations were conducted in order to investigate what actions that could reduce the packaging waste. The data was analysed and one action was selected to be further investigated, and calculations of its environmental and economic aspects are performed. Three different types of inner packaging of LDPE (Low Density Polyethelen) plastics were selected, and the calculations showed that the reduction of CO2-emissions amounts to as much as 6.3 tonnes per year and cost savings of 11 000 SEK per year when reusing the inner packaging. These savings indicate that it is profitable to return the packaging to the supplier if it is located closer than 10 200 - 16 600 km to the site. The managerial implications of implementing a returnable packaging system are the cost savings and the reduction of environmental impacts. / Produktioner och konsumtion genererar idag stora mängder avfall och på grund av den ökande levnadsstandarden fortsätter mängden avfall att öka. Avfallet leder till stor miljöpåverkan på grund av föroreningar och växthusgasutsläpp, liksom uttömning av råmaterial. Denna studien syftade till att undersöka hur hållbarhet genom cirkulär ekonomi kan driva utvecklingen mot att minska förpackningsavfallet i ett företag. Ambitionen var att identifiera möjliga förslag som skulle kunna implementeras för att minska mängden av brännbart avfall och därmed den miljöpåverkan som följer. En fallstudie utfördes på Volvo Group Trucks Operations monteringsanläggning i Tuve i Göteborg. Den inledande delen i arbetet bestod av en litteraturstudie som följdes av en empirisk studie, där intervjuer och observationer utfördes för att undersöka vilka förslag som skulle kunna minska förpackningsavfall. Datan analyserades och ett förslag valdes ut för att undersökas vidare genom beräkningar för dess miljömässiga och ekonomiska aspekter. Tre olika typer av inneremballage av LDPE-plast valdes ut och beräkningarna visade att reduceringen av CO2-utsläpp uppgick till 6,3 ton per år och kostnadsbesparingarna till 11 000 SEK per år då inneremballage återanvänds. Dessa besparingar indikerar att det är lönsamt att returnera förpackningar till leverantören om den är belägen närmare än 10 200- 16 600 km från fabriken. Incitament för företag att implementera ett retursystem är de minskade kostnaderna samt den minskade miljöpåverkan.

Cette thèse se situe à l'interface entre l'analyse d'images, dont l'objectif est la description automatique du contenu visuel, et la géométrie discrète, qui est l'un des domaines dédiés au traitement des images numériques. Pour être stocké et manipulé sur un ordinateur, un signal observé est régulièrement échantillonné. L'image numérique, qui est le résultat de ce processus d'acquisition, est donc constituée d'un ensemble fini d'éléments distincts. La géométrie discrète se propose d'étudier les propriétés géométriques d'un tel espace dépourvu de continuité. Dans ce cadre, nous avons considéré les régions homogènes et porteuses de sens d'une image, avec l'objectif de représenter leur contour au moyen de modèles géométriques ou de les décrire à l'aide de mesures. L'étendue des applications de ce travail en analyse d'images est vaste, que ce soit au cours du processus de segmentation, ou en vue de la reconnaissance d'un objet. Nous nous sommes concentrés sur trois modèles géométriques discrets définis par la discrétisation de Gauss : la partie convexe ou concave, l'arc de cercle discret et le segment de droite discrète. Nous avons élaboré des algorithmes dynamiques (mise à jour à la volée de la décision et du paramétrage), exacts (calculs en nombres entiers sans erreur d'approximation) et rapides (calculs simplifiés par l'exploitation de propriétés arithmétiques et complexité en temps linéaire) qui détectent ces modèles sur un contour. L'exécution de ces algorithmes le long d'un contour aboutit à des décompositions ou à des polygonalisations réversibles. De plus, nous avons défini des mesures de convexité, linéarité et circularité, qui vérifient un ensemble de propriétés fondamentales : elles sont robustes aux transformations rigides, elles s'appliquent à des parties de contour et leur valeur maximale est atteinte pour le modèle de forme qui sert de comparaison et uniquement sur celui-ci. Ces mesures servent à l'introduction de nouveaux modèles dotés d'un paramètre variant entre 0 et 1. Le paramètre est fixé à 1 quand on est sûr de la position du contour, mais fixé à une valeur inférieure quand le contour est susceptible d'avoir été déplacé par un bruit d'acquisition. Cette approche pragmatique permet de décomposer de manière robuste un contour en segments de droite ou en parties convexes et concaves. / The work presented in this thesis concerns the fields of image analysis and discrete geometry. Image analysis aims at automatically describing the visual content of a digital image and discrete geometry provides tools devoted to digital image processing. A two-dimensional analog signal is regularly sampled in order to be handled on computers. This acquisition process results in a digital image, which is made up of a finite set of discrete elements. The topic of discrete geometry is to study the geometric properties of such kind of discrete spaces. In this work, we consider homogeneous regions of an image having a meaning for a user. The objective is to represent their digital contour by means of geometric patterns and compute measures. The scope of applications is wide in image analysis. For instance, our results would be of great interest for segmentation or object recognition. We focus on three discrete geometric patterns defined by Gauss digitization: the convex or concave part, the digital straight segment and the digital circular arc. We present several algorithms that detect or recognize these patterns on a digital contour. These algorithms are on-line, exact (integer-only computations without any approximation error) and fast (simplified computations thanks to arithmetic properties and linear-time complexity). They provide a way for segmenting a digital contour or for representing a digital contour by a reversible polygon. Moreover, we define a measure of convexity, a measure of straightness and a measure of circularity. These measures fulfil the following important properties: they are robust to rigid transformations, they may be applied on any part of a digital contour, they reach their maximal value for the template with which the data are compared to. From these measures, we introduce new patterns having a parameter that ranges from 0 to 1. The parameter is set to 1 when the localisation of the digital contour is reliable, but is set to a lower value when the digital contour is expected to have been shifted because of some acquisition noise. This measure-based approach provides a way for robustly decomposing a digital contour into convex, concave or straight parts.

Le concept de réversibilité est ancien, mais il soulève de nos jours beaucoup d'intérêt. Il est en effet exploité dans de nombreux domaines tels que la conception de circuits, le débogage et le test de programmes, la simulation et l'informatique quantique. L'idée d'un modèle de programmation réversible peut se montrer particulièrement intéressante pour la construction de systèmes sûrs de fonctionnement, ne serait-ce que parce que plusieurs techniques connues pour la construction de tels systèmes exploitent une forme ou une autre de retour en arrière ou de reprise. Nous poursuivons dans cette thèse l'étude entreprise avec CCS réversible par Vincent Danos et Jean Krivine, en définissant un pi-calcul d'ordre supérieur réversible (rhopi). Nous prouvons que le modèle obtenu est causalement cohérent, et que l'on peut encoder fidèlement rhopi dans une variante du pi-calcul d'ordre supérieur. Nous définissons également une primitive de reprise à grain fin qui permet de contrôler le retour en arrière dans une exécution concurrente. Nous spécifions formellement la sémantique de cette primitive, et nous montrons qu'elle possède de bonnes propriétés, y compris en présence d'opérations de reprise concurrentes. Enfin nous définissons un algorithme concurrent implantant cette primitive de reprise et ous montrons que cet algorithme respecte la sémantique définie. / Reversible computing has a long history. Nowadays, reversible computing is attracting increasing interest because of its potential applications in diverse fields, including hardware design, biological modelling, program debugging and testing and quantum computing. Of particular interest is the application of reversible computation notions to the study of programming abstractions for dependable systems, because several techniques used to build dependable systems rely on some forms of undo or rollback. We continue, in this thesis, the study undertaken on reversible CCS by Vincent Danos and Jean Krivine, by defining a reversible higher-order pi-calculus (rhopi). We prove that reversibility in our calculus is causally consistent and that one can encode faithfully rhopi into a variant of HOpi. Moreover we design a fine-grained rollback primitive able to control the rollback of a concurrent execution. We give a formal specification of this primitive and show that it enjoys good properties, even in presence of concurrent conflicting rollbacks. We then devise a concurrent algorithm implementing such primitive and show that the algorithm respects the defined semantics.

Orientador: Claudio Aguinaldo Buzzi / Banca: João Carlos da Rocha Medrado / Banca: Luciana de Fátima Martins / Resumo: Nesse trabalho são apresentados alguns resultados importantes sobre bifurcações de codimensão dois de campos de vetores. O resultado principal dessa dissertação e o teorema que d a o diagrama de bifurcação e os retratos de fase da Bifurcação de Bogdanov-Takens. Para a demonstracão são usadas algumas técnicas basicas de Sistemas Dinâmicos e Teoria das Singularidades, tais como Integrais Abelianas, desdobramentos de Sistemas Hamiltonianos, desdobramentos versais, Teorema de Preparação de Malgrange, entre outros. Outra importante bifurcação clássica apresentada e a Bifurca cão do tipo Hopf-Zero, quando a matriz Jacobiana possui um autovalor simples nulo e um par de autovalores imagin arios puros. Foram usadas algumas hipóteses que garantem propriedades de simetria do sistema, dentre elas, assumiuse que o sistema era revers vel. Assim como na Bifurcação de Bogdanov-Takens, foram apresentados o diagrama de bifurcao e os retratos de fase da Bifurcação Hopf-zero bifurcação reversível. As técnicas usadas para esse estudo foram a forma normal de Belitskii e o método do Blow-up polar. / Abstract: In this work is presented some important results about codimension two bifurcations of vector elds. The main result of this work is the theorem that gives the local bifurcation diagram and the phase portraits of the Bogdanov-Takens bifurcation. In order to give the proof, some classic tools in Dynamical System and Singularities Theory are used, such as Abelian Integral, versal deformation, Hamiltonian Systems, Malgrange Preparation Theorem, etc. Another classic bifurcation phenomena, known as the Hopf-Zero bifurcation, when the Jacobian matrix has a simple zero and a pair of purely imaginary eigenvalues, is presented. In here, is added the hypothesis that the system is reversible, which gives some symmetry in the problem. Like in Bogdanov-Takens bifurcation, the bifurcation diagram and the local phase portraits of the reversible Hopf-zero bifurcation were presented. The main techniques used are the Belitskii theory to nd a normal forms and the polar Blow-up method. / Mestre