In this Ph.D. dissertation research, we lay the mathematical foundations of various fundamental concepts in convex mixed-integer programs (MIPs), that is, optimization problems where all the decision variables belong to a given convex set and, in addition, a subset of them are required to be integer. In particular, we study properties of their feasible region and properties of cutting planes. The main contribution of this work is the extension of several fundamental results from the theory of linear MIPs to the case of convex MIPs. In the first part, we study properties of general closed convex sets that determine the closedness and polyhedrality of their integer hulls. We first present necessary and sufficient conditions for the integer hull of a general convex set to be closed. This leads to useful results for special classes of convex sets such as pointed cones, strictly convex sets, and sets containing integer points in their interior. We then present a sufficient condition for the integer hulls of general convex sets to be polyhedra. This result generalizes the well-known result due to Meyer in the case of linear MIPs. Under a simple technical assumption, we show that these sufficient conditions are also necessary for the integer hull of general convex sets to be polyhedra. In the second part, we apply the previous results to mixed-integer second order conic programs (MISOCPs), a special case of nonlinear convex MIPs. We show that there exists a polynomial time algorithm to check the closedness of the mixed integer hulls of simple MISOCPs. Moreover, in the special case of pure integer problems, we present sufficient conditions for verifying the closedness of the integer hull of intersection of simple MISOCPs that can also be checked in polynomial time. In the third part, we present an extension of the duality theory for linear MIPs to the case of conic MIPs. In particular, we construct a subadditive dual to conic MIPs. Under a simple condition on the primal problem, we are able to prove strong duality. In the fourth part, we study properties of maximal S-free convex sets, where S is a subset of integers contained in an arbitrary convex set. An S-free convex set is a convex set not containing any points of S in its interior. In this part, we show that maximal S-free convex sets are polyhedra and discuss some properties of these sets. In the fifth part, we study some generalizations of the split closure in the case of linear MIPs. Split cuts form a well-known class of valid inequalities for linear MIPs. Cook et al. (1990) showed that the split closure of a rational polyhedron - that is, the set of points in the polyhedron satisfying all split cuts - is again a polyhedron. In this thesis, we extend this result from a single rational polyhedron to the union of a finite number of rational polyhedra. We also show how this result can be used to prove that some generalizations of split cuts, namely cross cuts, also yield closures that are rational polyhedra.

Du fait de l'augmentation de la demande de produits pour les applications grand public, industrielles et automobiles, des mémoires embarquées fiables et à faible coût de fabrication sont de plus en plus demandées. Dans ce contexte, les mémoires split-gate à piégeage discret sont proposées pour des microcontrôleurs. Elles combinent l'avantage d'une couche de stockage discrète et de la con guration split-gate. Durant ce travail de recherche, des mémoires split-gate à couche de piégeage discret ayant des longueurs de grille de 20nm sont présentées pour la première fois. Celles-ci on été réalisées avec des nanocristaux de silicium (Si-nc), du nitrure de silicium (SiN) ou un hybride Si-nc/SiN avec diélectrique de control de type SiO2 ou AlO et sont comparées en termes de performances lors des procédures d'eff acement et de rétention. Ensuite, la miniaturisation des mémoires split-gate à piégeage de charge est étudié, en particulier au travers de l'impact de la réduction de la longueur de grille sur la fenêtre de mémorisation, la rétention et la consommation. Le rôle des défauts dans le diélectrique de contrôle (alumine) utilisé dans les mémoires de type TANOS a été étudié. Des travaux ont été menés pour déterminer l'origine des pièges dans ce matériau, par le biais de la simulation atomistique ainsi que d'analyses physico-chimiques précises. Nous avons montré que la concentration de pièges dans AlO pouvait être réduite par ajustement des conditions de procédé de fabrication, débouchant ainsi sur l'amélioration de la rétention dans les mémoires à piégeage de charge. Ce résultat est convenable pour les applications de type embarqué

Traffic problems caused by congestion are increasing in cities all over the world. As a traffic management tool traffic predictions can be used in order to make prevention actions against traffic congestion. There is one software for traffic state estimations called Mobile Millennium Stockholm (MMS) that are a part of a project for estimate real-time traffic information.In this thesis a framework for running traffic predictions in the MMS software have been implemented and tested on a stretch north of Stockholm. The thesis is focusing on the implementation and evaluation of traffic prediction by running a cell transmission model (CTM) forward in time.This method gives reliable predictions for a prediction horizon of up to 5 minutes. In order to improve the results for traffic predictions, a framework for dynamic inputs of demand and sink capacity has been implemented in the MMS system. The third part of the master thesis presents a model which adjusts the split ratios in a macroscopic traffic model based on driver behavior during congestion.

Microwave near-field probes (MNPs) confine evanescent fields to regions that are substantially smaller than the wavelength at the operation frequency. Such probes are able to resolve subwavelength features, thus providing resolution much higher than the classical Abb?? limit. These abilities of MNPs are primarily due to the evanescent nature of the field generated at the tip of the probes. In the past, MNPs with ultra-high resolution were designed by tapering a resonant opening to provide high field concentration and high sensitivity. The limitations of these MNPs were subject to low surface roughness and practical realization challenges due to their geometrical features and vibration control constraints. Metamaterials with their ability to enhance evanescent fields, lead to the speculation that they could potentially increase the sensitivity of near-field probe. Periodically arranged metamaterial unit elements such as split-ring-resonators (SRRs) can create negative permeability media. Placing such material layer in the proximity of a probe leads to enhancement of the evanescent waves. Guided by this remarkable feature of metamaterials, I proposed an MNP consisting of a wire loop concentric with a single SRR. The evanescent field behavior of the probe is analyzed using Fourier analysis revealing substantial enhancement of the evanescent field consistent with metamaterial theory predictions. The resolution of the probe is studied to especially determine its ability for sub-surface detection of media buried in biological tissues. The underlying physics governing the probe is analyzed. Variations of the probe are developed by placement of lumped impedance loads. To further increase the field confinement to smaller region, a miniaturized probe design is proposed. This new probe consists of two printed loops whose resonance is tunable by a capacitor loaded in the inner loop. The sensing region is decreased from ??/20 to ??/55, where ?? is the wavelength of the probe???s unloaded frequency. The magnetic-sensitive nature of the new probe makes it suitable for sensing localized magnetostatic surface resonance (LMSR) occurring in electrically very small particles. Therefore, I proposed a sensing methodology for detecting localized magnetostatic surface (LMS) resonant particles. In this methodology, an LMS resonant sphere is placed concentrically with the loops. A circuit model is developed to predict the performance of the probe in the presence of a magnetic sphere having Lorentz dispersion. Full-wave simulations are carried out to verify the circuit model predictions, and preliminary experimental results are demonstrated. The Lorentzian fit in this work implies that the physical nature of LMSR may originate from spin movement of charged particle whose contribution to effective permeability may be analogous to that of bound electron movement to effective permittivity in electrostatic resonance. Detection of LMSR can have strong impact on marker-based sensing applications in biomedicine and bioengineering.

Cerebral blood flow dynamics is an essential component for preserving cerebral integrity. Cerebral blood flow abnormalities are often seen in patients with central nervous system pathologies such as epilepsy, migraine, Alzheimer's Disease, vascular dementia, stroke, and even HIV/AIDS. There is increasing clinical and experimental evidence implicating cerebral hypoperfusion during ageing. The determination of cerebral perfusion has therefore become an important objective in physiological, pathological, pharmacological, and clinical investigations. The knowledge of regional cerebral blood flow further provides useful diagnostic information and/or data for a better understanding of the complex clinical presentations in patients with neurological and psychiatric disorders. Several cerebrovasoactive drugs have found application in the clinical setting of cerebrovascular diseases such as migraine and dementia. Due to the similarities between humans and non-human primates with respect to their brains, both structurally and behaviourally, numerous studies have been conducted and several non-human primate models have been developed for physiological, pathological, pharmacological, and clinical studies, amongst others in Parkinson's disease and diabetes. The relatively large size of the Cape baboon Papio Ursinus with a weight of 27-30 kg for a large male, makes this primate especially suitable for in vivo brain studies using radiotracers and Single Photon Emission Computed Tomography (SPECT). The main aim of the current study was therefore to develop a suitable radiotracer (99m Tc-hexamethylpropylene amine oxime (HMPAO) or 99m Tc_ethyl_cysteinatedimer (ECD) or 123l-iodoamphetamine (IMP)) for adapted in vivo cerebral blood flow measurements in a non-human primate (Papio ursinus) as an investigative model. The model was to be validated and applied in various drug studies for the evaluation of pharmacological interventions. The study design made use of split-dose methodology, whereby the radiopharmaceutical (radiotracer) was administered twice during each study. The first administration was injected soon after the induction of the anaesthesia, and was followed by the first SPECT data acquisition. The second administration of the radioligand, a double dose of radioactivity with respect to the first radioligand injection, was done at a specific time during the study, which took into account the pharmacodynamics of the drug. A second SPECT data acquisition followed subsequently. The drugs that were included in the study were acetazolamide, a carbonic acid anhydrase inhibitor (often used in nuclear medicine to determine cerebral reserve); sumaptriptan, a 5-HT (serotonin) agonist used for treatment of migraine; sodium valproate (an anti-epileptic drug); nimodipine, a calcium channel blocker and nitro-glycerine, a vasodilator used for angina. Arterial blood pressures were recorded from a catheter in the femoral artery and heart rates were concurrently monitored. The split-dose method was successfully applied to develop a non-human primate cerebral blood flow model under anaesthesia. The model showed differences in cerebral perfusion of the different anaesthesia regimes. These anaesthesia data sets were suitable as control/baseline results for drug intervention studies. Acetazolamide evaluation through the split-dose method in the baboon confirmed the sensitivity of the model by presenting comparable perfusion. This result compared to those already familiar prompted the model to be applied in pharmacological intervention studies. Subsequent results of these investigations showed increases in perfusion for single drug nimodipine treatment (25%). However, nimodipine attenuated the increases in perfusion when administered in combination with acetazolamide. Sumatriptan was able to decrease and normalise the increased perfusion after long duration anaesthesia. Decreased cerebral blood flow was observed for combinations of nimodipine with sodium valproate suggesting drug-drug interaction with important clinical implications. Similar decreases were found also for sumatriptan and nitro-glycerine when administered in combination with nimodipine. Studies with the various tracers (99m Tc_HMPAO or 99m Tc_ECD or 123l_IMP) showed clear differences in the perfusion data, confirming variation in the biochemical performance of the tracers. These differences, if not taken into consideration, caution for inappropriate clinical conclusions and subsequent erroneous therapeutic decisions. Improvement of radiotracer efficacy was subsequently attempted through application of the cyclodextrine complexation approach. Although cyciodextrine technology did not markedly improve the brain disposition of the 99m Tc-ECD, protection of the tracer against degradation was demonstrated. This study encouraged further exploration of this method for protection of the tracer against chemical and metabolic degradation. The current study was aimed to develop and effectively apply a non-human primate model with nuclear medicine technology for cerebral blood flow determinations after pharmacological interventions. This was achieved through the split-dose method and dedicated computer programming, which yielded a successful model with the non-human primate under anaesthesia. The model was validated with the application of acetazolamide to confirm familiar cerebrovascular reserve results, indicating that the model is sensitive to CBF changes. The model was also effectively applied in several pharmacological intervention studies, whereby cerebropharmacodynamics of selected drugs were investigated and established. This unique model of a non-human primate, Papio ursinus for cerebral blood flow determinations has served pharmacological research successfully during the past 12 years and could do so in the future, with scope to investigate new frontiers with improved technologies. / Thesis (Ph.D. (Pharmacology))--North-West University, Potchefstroom Campus, 2004.

The Blended-Wing-Body is a conceptual aircraft design with rear-mounted, over wing engines. Turboelectric distributed propulsion system with boundary layer ingestion has been considered for this aircraft. It uses electricity to transmit power from the core turbine to the fans, therefore dramatically increases bypass ratio to reduce fuel consumption and noise. This dissertation presents methods on designing the TeDP system, evaluating effects of boundary layer ingestion, modelling engine performances, and estimating weights of the electric components. The method is first applied to model a turboshaft-driven TeDP system, which produces thrust only by the propulsors array. Results show that by distributing an array of propulsors that ingest a relatively large mass flow directly produces an 8% fuel burn saving relative to the commercial N+2 aircraft (such as the SAX-40 airplane). Ingesting boundary layer achieves a 7-8% fuel saving with a well-designed intake duct and the improved inlet flow control technologies. However, the value is sensitive to the duct losses and fan inlet distortion. Poor inlet performance can offset or even overwhelm this potential advantage. The total weight of the electric system would be around 5,000-7,000 kg. The large mass penalties further diminish benefits of the superconducting distributed propulsion system. The method is then applied to model a turbofan-driven TeDP system, which produces thrust by both the propulsors array and the core-engines. Results show that splitting the thrust between propulsors and core-engines could have a beneficial effect in fuel savings, when installation effects are neglected. The optimised thrust splitting ratio is between 60-90%, the final value depends on the propulsor intake pressure losses and the TeDP system bypass ratio. Moreover, splitting the thrust can reduce the weight of the electric system with the penalty of the increased core-engine weight. In short, if the power density of the superconducting system were high enough, turboshaft-driven TeDP would be preferable to power the N3-X aircraft

This thesis focuses upon the abilities of children with severe learning difficulties to contemplate the psychological states of other people, what is often referred to in the literature as 'mindreading' (Whiten and Perner, 1991). The first section contains a review of the literature on children's developing understanding of the mind and their conceptual representational abilities. This is followed by two studies investigating non-learning disabled children's abilities to attribute first-and second-order false belief. The first of these uses an adaptation of the Sally-Anne test (Baron-Cohen, et al., 1985). The second study uses an original false belief story scenario, which involves children in drama. The researcher uses a technique called 'split-briefing' to provide children with first-hand experience of first-and second-order false belief. Simplified versions of the two false belief story scenarios are then used with children with severe learning difficulties to investigate their abilities to represent first-and second-order false belief. The relationship between children's scores on belief attribution tasks and their scores on tests of non-verbal intellectual reasoning (Ravens Coloured Matrices) and receptive language ability (TROG) is also examined in this study. The third section outlines the findings of a questionnaire-based study examining parental reports of spontaneous internal state use by two groups of children: non-learning disabled children aged 1-5 years and pupils with Down's Syndrome aged 4-19 years with severe learning difficulties. 'Internal state language' is language which refers to intentions, cognitions and feeling states (Bretherton and Beeghly, 1981). This is followed by a further investigation of internal state language among a group of students with severe learning difficulties. This study uses a series of playlets written by the author to provide students with an interactive, participatory medium in which to draw their attention to people's internal states. The thesis concludes with a final statement on research into the social-cognitive development of children with severe learning difficulties, with recommendations for future research and intervention.

&ldquo / Dissociative Identity Disorder&rdquo / , also known as split or multiple personality disorder, made its appearance in literature in the form of &lsquo / the double&rsquo / , a projected dual personality. Ralph Tymms is believed to be the first to use the psychological provenance of the double as a literary device. To date, many publications have been made on Dissociative Identity Disorder, and many literary works dealing with &lsquo / the double&rsquo / have been published. However, the subject of the double, in all its literary and psychological manifestations, has not yet found the sufficient research and up-to-date study that it deserves. This paper ventures to study some of the links between Modern British Drama and Clinical and Social Psychology. It analyses the fact that although people adopting Dissociative Identity Disorder as a defence mechanism against social and personal constrictions are viewed outside the norms of personality structure, this practice allows them to create a personal space and a personal voice in the conditions they find themselves in. To this end, the characters Susan, Gareth, and Alan in the plays Woman in Mind, Philadelphia, Here I Come!, and Equus, written by Alan Ayckbourn, Brian Friel, and Peter Shaffer, respectively, will be studied.

The shareholder is supposed to be indifferent if one share costs 100 SEK, or 10 shares cost 10 SEK each. In an efficient market, shares should be valued directly to new expectations as a result of the announcement of the reverse split. We investigate whether abnormal returns incur surrounding reverse split and if owner structure change. One reason for the reverse share split is that most companies have plans to imple-ment other company’s specific events in order to survive rather than to change the price range to a more attractive level. We found a negative return in the ex-day at 8,1 per cent. When the ex-day is pure enough from other price driving information should the outcome be a reaction to how the market perceives changes in future divi-dends after the reverse split. In consideration of stock ownership of votes accounted for a reduction of individual owners, and increasing institutional owners, more in companies with low Market to Book. This may suggest that the institutional share-holders have increased their share of votes to increase their power in the companies.

Current theorising in the area of cognitive arithmetic suggests that simple arithmetic knowledge is stored in memory and accessed in the same way as word knowledge i.e., it is stored in a network of associations, with simple facts retrieved automatically from memory. However, to date, the main methodologies that have been employed to investigate automaticity in simple arithmetic processing (e.g., production and verification) have produced a wide variety of difficulties in interpretation. In an attempt to address this, the present series of investigations utilised a numerical variant of the well established single word semantic priming paradigm that involved the presentation of problems as primes (e.g., 2 + 3) and solutions as targets (e.g., 5), as they would occur in a natural setting. Adult university students were exposed to both addition and multiplication problems in each of three main prime target relationship conditions, including congruent (e.g., 2 + 3 and 5), incongruent (e.g., 2 + 3 and 13), and neutral conditions (X + Y and 5). When combined with a naming task and the use of short stimulus onset asynchronies (SOAs), this procedure enabled a more valid and reliable investigation into automaticity and the cognitive mechanisms underlying simple arithmetic processing. The first investigation in the present series addressed the question of automaticity in arithmetic fact retrieval, whilst the remaining investigations examined the main factors thought to influence simple arithmetic processing i.e., skill level, surface form, problem type and split. All factors, except for problem type, were found to influence processing in the arithmetic priming paradigm. For example, the results of all five investigations were consistent in revealing significant facilitation in naming congruent targets for skilled participants, following exposure to Arabic digit primes at the short SOA. Accordingly, the facilitation was explained in terms of the operation of an automatic spreading activation mechanism. Additionally, significant inhibitory effects in incongruent target naming were identified in skilled performance in all of the studies in the present series of investigations. Throughout the course of these investigations, these effects were found to vary with operation, surface form and SOA, and in the final investigation, the level of inhibition was found to vary with the split between the correct solution and the incongruent target. Consequently, a number of explanations were put forward to account for these effects. In the first two investigations, it was suggested that the inhibitory effects resulted from the use of a response validity checking mechanism, whilst in the final investigation, the results were more consistent with the activation of magnitude representations in memory (this can be likened to Dehaene’s, 1997, ‘number sense’). In contrast, the results of the third investigation led to the proposal that for number word primes, inhibition in processing results from the activation of phonological representations in memory, via a reading based mechanism. The present series of investigations demonstrated the utility of the numerical variant of the single word semantic priming paradigm for the investigation of simple arithmetic processing. Given its capacity to uncover the fundamental cognitive mechanisms at work in simple arithmetic operations, this methodology has many applications in future research.