L'ultra large bande (UWB) est une nouvelle technologie à fort potentiel pour les futurs réseaux personnels WPAN (wireless personal area networks) à très haut débit et faible portée. L'objectif de cette thèse est de proposer un nouveau système UWB, de type LP-OFDM (linear precoded orthogonal frequency division multiplexing) pour les applications WPAN, visant à améliorer la solution MB-OFDM (multiband OFDM), supportée par l'Alliance WiMedia.<br />Dans un premier temps, une étude analytique est menée sur l'apport de la composante de précodage au système UWB, cette composante se réduisant en pratique à une simple addition d'une matrice d'étalement fréquentiel. La fonction de précodage est ensuite optimisée et différentes stratégies d'allocation dynamique des ressources sont étudiées. En considérant une approche classique tenant compte du taux d'erreur symbole (TES) ainsi qu'une nouvelle approche tenant compte du taux d'erreur binaire (TEB) moyen, différents algorithmes d'allocation dynamique visant à maximiser la portée ou le débit du système, ou à minimiser le TEB moyen du système, sont proposés. Les résultats analytiques montrent l'avantage d'utiliser une composante de précodage pour les applications UWB dont le canal est très sélectif en fréquence.<br />Dans un second temps, une étude système complémentaire à l'étude analytique est réalisée pour le système LP-OFDM UWB. Une composante MIMO est ajoutée au système, d'une part pour augmenter la portée du système à bas et moyen débit, et d'autre part pour augmenter le débit du système qui peut atteindre dans ce cas 1 gigabit/s. Les résultats de simulation sur le système proposé montrent que ce système est plus performant que le système MB-OFDM pour les débits déjà proposés dans la norme, et qu'il offre un débit deux fois plus important que ceux de la norme avec même une meilleure performance en terme de TEB.

We study inverse treatment planning approaches for stereotactic radiosurgery using Leksell Gamma Knife Perfexion (PFX, Elekta, Stockholm, Sweden) to treat brain cancer and tumour patients. PFX is a dedicated head-and-neck radiation delivery device that is commonly used in clinics. In a PFX treatment, the patient lies on a couch and the radiation beams are emitted from eight banks of radioactive sources around the patient's head that are focused at a single spot, called an isocentre. The radiation delivery in PFX follows a step-and-shoot manner, i.e., the couch is stationary while the radiation is delivered at an isocentre location, and only moves when no beam is being emitted. To find a set of well-positioned isocentres in tumour volumes, we explore fast geometry-based algorithms, including skeletonization and hybrid grassfire and sphere-packing approaches. For the selected set of isocentres, the optimal beam durations to deliver a high prescription dose to the tumour are later found using a penalty-based optimization model. We next extend our grassfire and sphere-packing isocentre selection method to treatments with homogenous dose distributions. Dose homogeneity is required in multi-session plans where a larger volume is treated to account for daily setup errors, and thus large overlaps with surrounding healthy tissue may exist. For multi-session plans, we explicitly consider the healthy tissue overlaps in our algorithms and strategically select many isocentres in adjacent volumes to avoid hotspots. There is also interest in treating patients with continuous couch motion to decrease the total treatment session and increase plan quality. We therefore investigate continuous dose delivery treatment plans for PFX. We present various path selection methods along which the dose is delivered using Hamiltonian paths techniques, and develop mixed-integer and linear approximation models to determine the configuration and duration of the radiation time along the paths. We consider several criteria in our optimization models, including machine speed constraints and movement accuracy, preference for single or multiple paths, and smoothness of movement. Our plans in all proposed approaches are tested on seven clinical cases and can meet or exceed clinical guidelines and usually outperform clinical treatments.

X–linked adrenoleukodystrophy (X–ALD) is the most common peroxisomal enzyme deficiency disorder, characterized by inborn mutations in the ABCD1 gene, an ATP–binding cassette (ABC) half–transporter. The ABCD1 gene encodes the adrenoleukodystrophy protein (ALDP), the transporter for the very–long–chain fatty acids (VLCFA; C > 22:0) from the cytosol into the peroxisomes to enter the peroxisomal B–oxidation pathway. The diagnostic disease marker is the elevated levels of VLCFAs which accumulate in different tissues and body fluids, leading to inflammatory demyelination, neuro–deterioration and adrenocortical insufficiency. At present, there is no satisfactory therapy for X–ALD available. However, another peroxisomal ABC half–transporter, ALDRP can compensate for the functional loss of ALDP and is encoded by the ABCD2 gene. This prompted a new approach to treatment strategies. Phenylbutyric acid (PBA) over–expresses the ABCD2 gene, leading to an increased expression of ALDRP and PBA decreases VLCFA levels by increasing peroxisomal B–oxidation. This study had a dual aim: to determine the antioxidant capacity of PBA and to verify known and identify new metabolites of PBA. In vitro, HeLa cells were cultivated and treated with 0.5 mM, 1 mM, 2 mM and 5 mM PBA for 48 hours. The ROS, lipid peroxidation, apoptosis and cell viability were determined using fluorescein–based flow cytometry. Images were taken to visualize the peroxisome proliferation. In vivo, a vervet monkey was given a single dose of 130 mg/kg PBA. Blood was collected before treatment and 15 minutes, 30 minutes, 1, 2 and 3 hours after treatment. ROS, apoptosis and lipid peroxidation were determined by fluorescein–based flow cytometry. Urine was collected before treatment and 15 minutes, 30 minutes, 1, 2, 3, 7 and 24 hours after PBA treatment. A standardised method, employing gas chromatography–mass spectrometry (GC/MS), was used to analyse the organic acids in the urine and fatty acids in the blood. In vitro results showed decreased levels of ROS and lipid peroxidation with increased concentrations of PBA. PBA showed a protective effect towards the HeLa cells with reduced apoptosis and a high number of viable cells. In vivo levels of ROS en lipid peroxidation decreased over time of treatment with PBA. The fluorescence microscope images confirmed an increased number of peroxisomes after PBA treatment. The short term effect of PBA showed an initial, but small decrease in the levels of the fatty acids, suggesting induction over a longer period rather than activation of peroxisomal B–oxidation. New metabolites of phenylbutyrate were identified in the urine of a vervet monkey. These new metabolites originated from monooxygenase, N–phenylacetyl–glutamine synthases and B–oxidation byproducts. Recently discovered metabolites in humans and rats were also verified and confirmed in the vervet monkey. We therefore propose that treatment with PBA, on account of its beneficial effects of restoring VLCFA levels and reducing oxidative stress, could be considered a novel approach for the treatment of X–ALD. / Thesis (M.Sc. (Pharmaceutical Chemistry))--North-West University, Potchefstroom Campus, 2011.

X–linked adrenoleukodystrophy (X–ALD) is the most common peroxisomal enzyme deficiency disorder, characterized by inborn mutations in the ABCD1 gene, an ATP–binding cassette (ABC) half–transporter. The ABCD1 gene encodes the adrenoleukodystrophy protein (ALDP), the transporter for the very–long–chain fatty acids (VLCFA; C > 22:0) from the cytosol into the peroxisomes to enter the peroxisomal B–oxidation pathway. The diagnostic disease marker is the elevated levels of VLCFAs which accumulate in different tissues and body fluids, leading to inflammatory demyelination, neuro–deterioration and adrenocortical insufficiency. At present, there is no satisfactory therapy for X–ALD available. However, another peroxisomal ABC half–transporter, ALDRP can compensate for the functional loss of ALDP and is encoded by the ABCD2 gene. This prompted a new approach to treatment strategies. Phenylbutyric acid (PBA) over–expresses the ABCD2 gene, leading to an increased expression of ALDRP and PBA decreases VLCFA levels by increasing peroxisomal B–oxidation. This study had a dual aim: to determine the antioxidant capacity of PBA and to verify known and identify new metabolites of PBA. In vitro, HeLa cells were cultivated and treated with 0.5 mM, 1 mM, 2 mM and 5 mM PBA for 48 hours. The ROS, lipid peroxidation, apoptosis and cell viability were determined using fluorescein–based flow cytometry. Images were taken to visualize the peroxisome proliferation. In vivo, a vervet monkey was given a single dose of 130 mg/kg PBA. Blood was collected before treatment and 15 minutes, 30 minutes, 1, 2 and 3 hours after treatment. ROS, apoptosis and lipid peroxidation were determined by fluorescein–based flow cytometry. Urine was collected before treatment and 15 minutes, 30 minutes, 1, 2, 3, 7 and 24 hours after PBA treatment. A standardised method, employing gas chromatography–mass spectrometry (GC/MS), was used to analyse the organic acids in the urine and fatty acids in the blood. In vitro results showed decreased levels of ROS and lipid peroxidation with increased concentrations of PBA. PBA showed a protective effect towards the HeLa cells with reduced apoptosis and a high number of viable cells. In vivo levels of ROS en lipid peroxidation decreased over time of treatment with PBA. The fluorescence microscope images confirmed an increased number of peroxisomes after PBA treatment. The short term effect of PBA showed an initial, but small decrease in the levels of the fatty acids, suggesting induction over a longer period rather than activation of peroxisomal B–oxidation. New metabolites of phenylbutyrate were identified in the urine of a vervet monkey. These new metabolites originated from monooxygenase, N–phenylacetyl–glutamine synthases and B–oxidation byproducts. Recently discovered metabolites in humans and rats were also verified and confirmed in the vervet monkey. We therefore propose that treatment with PBA, on account of its beneficial effects of restoring VLCFA levels and reducing oxidative stress, could be considered a novel approach for the treatment of X–ALD. / Thesis (M.Sc. (Pharmaceutical Chemistry))--North-West University, Potchefstroom Campus, 2011.

This thesis deals with the history records and charts its development through history to the present. It shows readers the first attempts of recording and reproducing apparatus , describes the history of the devices to play music and invented the phonograph . It outlines the creation of packaging design as a separate art disciplines and maps it over time to the present. The conclusion is devoted to contemporary music media. It outlines the emergence of followers technical revolution , cassettes and compact discs.

This thesis describes the design of a condensing steam turbine with reheating for fossil power plant. The turbine is a double parts. The first casing is formed by a simple HP casing. The second casing is combined MP-LP casing with axial outlet of steam into the water-cooled condenser. Feedwater regeneration system consists of two high-pressure heaters, the four low-pressure heaters and feed tank. In thesis is includes the calculation of heat balance and the draft of flow channel of HP and MP-LP casing. Next is a detailed calculation of MP-LP casing with includes calculation of flowing part, selection of blade´s profiles and its stress control. Rotor MP-LP casing is checked for torsion and computed size of the critical speed. Clutch is ispected by security check and draft radial bearings. Stress control casing is carried out according to the theory of thick shells. Work includes flow scheme for 100% and 75% performance. In the end is comparing the efficiency of the individual casing of the turbine with the work 3b together with the specific heat consumption. Work includes a longitudinal section of the MP-LP casing. This thesis has been developed in cooperation Škoda Power, Doosan.

The thesis deals with analysis and design of system for automatic localization and recognition of the license plate. The input images are from different sources, and contain large scenic and weather variations. The aim was to create a system able to find the licence plate on the image and recognize its alphanumeric figure. In this work, there is a focus on analysis and implementation of localization and optical character recognition methods. One own and four other localization methods are compared. There are also compared three classifiers for optical character recognition. Localization and OCR methods are tested on real data and evaluated in accordance with the calculated evaluation parameters. The work also contains sensitivity analysis of the proposed system.

<p><a></a><a>The visual system is capable of interpreting immense sensory complexity, allowing us to quickly identify behaviorally relevant stimuli in the environment. It performs this task with a hierarchical organization that works to detect, relay, and integrate visual stimulus features into an interpretable form. To understand the complexities of this system, visual neuroscientists have benefited from the many advantages of using mice as visual models. Despite their poor visual acuity, these animals possess surprisingly complex visual systems, and have been instrumental in understanding how visual features are processed in the primary visual cortex (V1). However, a growing body of literature has shown that primary sensory areas like V1 are capable of more than basic feature detection, but can express neural activity patterns related to learning, memory, categorization, and prediction. </a></p> <p>Visual experience fundamentally changes the encoding and perception of visual stimuli at many scales, and allows us to become familiar with environmental cues. However, the neural processes that govern visual familiarity are poorly understood. By exposing awake mice to repetitively presented visual stimuli over several days, we observed the emergence of low frequency oscillations in the primary visual cortex (V1). The oscillations emerged in population level responses known as visually evoked potentials (VEPs), as well as single-unit responses, and were not observed before the perceptual experience had occurred. They were also not evoked by novel visual stimuli, suggesting that they represent a new form of visual familiarity in the form of low frequency oscillations. The oscillations also required the muscarinic acetylcholine receptors (mAChRs) for their induction and expression, highlighting the importance of the cholinergic system in this learning and memory-based phenomenon. Ongoing visually evoked oscillations were also shown to increase the VEP amplitude of incoming visual stimuli if the stimuli were presented at the high excitability phase of the oscillations, demonstrating how neural activity with unique temporal dynamics can be used to influence visual processing.</p> <p>Given the necessity of perceptual experience for the strong expression of these oscillations and their dependence on the cholinergic system, it was clear we had discovered a phenomenon grounded in visual learning or memory. To further validate this, we characterized this response in a mouse model of Fragile X syndrome (FX), the most common inherited form of autism and a condition with known visual perceptual learning deficits. Using a multifaceted experimental approach, a number of neurophysiological differences were found in the oscillations displayed in FX mice. Extracellular recordings revealed shorter durations and lower power oscillatory activity in FX mice. Furthermore, we found that the frequency of peak oscillatory activity was significantly decreased in FX mice, demonstrating a unique temporal neural impairment not previously reported in FX. In collaboration with Dr. Christopher J. Quinn at Purdue, we performed functional connectivity analysis on the extracellularly recorded spikes from WT and FX mice. This analysis revealed significant impairments in functional connections from multiple layers in FX mice after the perceptual experience; some of which were validated by another graduate student (Qiuyu Wu) using Channelrhodopsin-2 assisted circuit mapping (CRACM). Together, these results shed new light on how visual stimulus familiarity is differentially encoded in FX via persistent oscillations, and allowed us to identify impairments in cross layer connectivity that may underlie these differences. </p> <p>Finally, we asked whether these oscillations are observable in other brain areas or are intrinsic to V1. Furthermore, we sought to determine if the oscillating unit populations in V1 possess uniform firing dynamics, or contribute differentially to the population level response. By performing paired recordings, we did not find prominent oscillatory activity in two visual thalamic nuclei (dLGN and LP) or a nonvisual area (RSC) connected to V1, suggesting the oscillations may not propagate with similar dynamics via cortico-thalamic connections or retrosplenial connections, <a>but may either be uniquely distributed across the visual hierarchy or predominantly</a> restricted to V1. Using K-means clustering on a large population of oscillating units in V1, we found unique temporal profiles of visually evoked responses, demonstrating distinct contributions of different unit sub-populations to the oscillation response dynamics.</p>

The thesis divided into four research topics dealt with an issue of the relation between silvicultural treatments and an amount of the bearing photosynthetically active assimilation apparatus quantified by leaf area index (LAI) in forest stands of an economically important tree species in the Czech Republic. In pure Norway spruce pole stands at the middle altitudinal zone, an effect of silvicultural treatments on the LAI and an efficiency of the photosynthetically active radiation (PAR; 380-720 nm) by foliage within the photosynthetic uptake was evaluated through both canopy production index (CPI) and leaf area effectivity (LAE), and the highest value of the LAI was achieved in a plot with the highest stand density. However, the highest efficiency of the PAR utilisation (CPI, LAE) was noted in the stand, which was tended by thinning from above. Thus, it was proved that not only the total LAI value but especially an efficacy of the leaf area reflecting sun and shade foliage ratio is the more relevant parameter for an evaluation of the effectivity of the thinning treatment. In a forest regeneration, the LAI can also be used for quantification of the regeneration process stage related to a growth dynamic of the natural regeneration. Besides that the newly developed device LaiPen LP 100 (PSI, ČR) for indirect optical LAI estimation was tested within this study. LAI values measured by LaiPen LP 100 showed almost same accuracy of the measurement and identical trends as world standard (LAI-2200 PCA; LI-COR, NE, USA); both at the stand level and the particular measurement point level. Within the study of the efficacy of the PAR utilisation by foliage in photosynthetic uptake expressed by radiation use efficiency (RUE) in pure, fully-stocked and not defoliated Norway spruce mature stands, it was found that mean air temperature most significantly affect annual and monthly values of the RUE with the significant linear relationship (R2 = 0.19; p < 0.05). In the spruce stands, the significant linear relationship (R2 = 0.85; p < 0.001) between an amount of the sequestrated carbon in the form of atmospheric CO2 molecules and the RUE was also proved. The research topic dealt with a seasonal dynamic of the LAI in selected pure and even-aged European beech and sycamore maple stands revealed findings that a culmination of the LAI is achieved within summer months (DOY 120-140) in the investigated stands. The period is the most suitable for estimation and mutual comparison of the LAI due to the stability of its values in investigated (but also in another deciduous) stands. In studied beech and maple stands, maximum LAI values were noted in the second half of June (DOY 170). General findings of underestimation of LAI values estimated by indirect optical methods compared to direct methods were also confirmed. In the last research topic, an effect of the stand age on the leaf area development was studied in pure, even-aged, and fully-leaved (not defoliated) forest stands of an economically important tree species (Norway spruce, Scots pine, silver fir, Douglas fir, European beech, pedunculate oak, and black walnut). Except for black walnut stands, significant linear relationships proving a decrease of the leaf area with increasing age of the stand were found. The relation between the leaf area expressed by effective plant area index (PAIe) and the age of stands was studied for monitoring of the leaf area dynamic within forest stands with a different age.

A MBS (Multi-port beamsplitter) for higher dimensional quantum communication has been designed and constructed and the theory and method for this is presented in this thesis. It uses optical fibers in a heterogeneous structure with a single-mode fiber spliced to a multi-mode fiber and then spliced to a few-mode fiber. Three MBS:s were constructed and tested to see if superpositions between spatial modes could be generated. One with 5.65cm multi-mode fiber, one with 9cm of multi-mode fiber and one with just the single-mode fiber spliced to the few-mode fiber. The optical modes that where focused on for the superposition were the linear polarized LP01, LP11a and LP11b modes. Simulations of superpositions between these modes were performed and experiments were done to see if these simulations could be realised. The shapes of these superpositions could be seen with a camera and the stability of the different modal powers and the stability of the phases between the modes where also tested. The last experiment tested the tunability of the modes by finding their maximum and minimum output power for each individual mode. The results of these experiments show that the stability of power and relative phases are high and testing of the tunability shows that the 9cm MBS is the most tunable, the 5.65cm MBS the second best and the SMF-FMF MBS the worst. Even though the shapes of the superpositions, the stability and tunability shows very positive results, the conclusion is that more experiments are required in order to identify the superpositions and for this to be used in a quantum communication system. / En Multi-port stråldelare (MSD) för kvantkommunikation med hjälp av rumsliga optiska moder har blivit designad och konstruerad. Teorin, metoden och resultatet av detta arbete presenteras i denna uppsats. Denna konstruktion använder sig av optiska fiber i heterogena strukturer med en single-mode fiber svetsad till en multi-mode fiber som i sin tur är svetsad till en few-mode fiber. Tre stycken MSD blev konstruerade och testade för att se om superpositioner mellan rumsliga moder kunde bli genererade, en med 5.65cm multi-mode fiber, en med 9cm multi-mode fiber och en med bara en single-mode fiber svetsad till en few-mode fiber. De moder som fokuserades på för superpositionerna var de linjärpolariserade moderna LP01, LP11a och LP11b. Superpositionerna simulerades och sen genomfördes experiment för att se ifall de kunde bli genererade. Formerna av dessa superpositioner kunde hittas och synliggöras med en kamera. Stabiliteten av modernas energi och stabiliteten av faserna mellan moderna testades också. Det sista experimentet som gjordes testade justerbarheten av moderna genom att hitta den minimala samt maximala intensiteten för varje mod. Experimenten visar att intensiteterna och de relativa faserna har hög stabilitet för alla konstruerade MSD, men i justerbarhets experimentet visar det sig att 9cm MSD:en presterar bäst, 5.65cm MSD:en presterar näst bäst och SMF-FMF strukturen presterar sämst. Trots att formerna av superpositionerna kunde hittas för alla tre konstruktioner, och att testen i stabiliteten visar goda resultat så krävs mer experiment för att identifiera superpositionerna mellan moderna och ifall denna konstruktion går att implementera i ett kvantkommunikationssystem.