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Séparation des activités cérébrales phasiques et oscillatoires en MEG, EEG et EEG intracérébralJmail, Nawel 04 June 2012 (has links)
Les oscillations jouent un rôle de premier plan dans la mise en place des réseaux cérébraux sains et pathologiques. En particulier, au niveau clinique, les activités oscillatoires sont d'une grande importance diagnostique en épilepsie. Par ailleurs, les méthodes non-invasives d'électrophysiologie sont particulièrement adaptées pour la compréhension des réseaux cérébraux à grande échelle. Cependant, la majorité des études en épilepsie a été dirigée vers les pointes intercritiques, qui sont des activités transitoires. Une question qui reste donc en suspens est le lien entre les pointes épileptiques et les activités oscillatoires épileptiques. Cette thèse a visé à résoudre deux problématiques complémentaires autour de cette question. La première problématique est la séparation adéquate entre les activités oscillatoires et transitoires. Il s'agit d'une tâche difficile surtout lors d'un grand chevauchement temporel, qui peut résulter en la contamination d'une activité par l'autre. Nous avons évaluée trois méthodes de filtrage : le filtre FIR (méthode classique), la transformé d'ondelette stationnaire et le filtrage parcimonieux par matching pursuit (MP, basé sur un dictionnaire). Sur des simulations, la SWT a donné de très bons résultats pour la reconstruction des transitoires et le MP pour les oscillations ; de plus, les deux méthodes ont donné un faible taux de faux positifs en détection automatique des oscillations. La SWT et le FIR ont donné les meilleurs résultats de filtrage sur les signaux réels, en particulier lors de la localisation de source. / The Oscillatory activities play a leading role in the development of healthy and pathological brain networks. In particular, at the clinical level, the oscillatory activities are of great importance in the diagnostic of epilepsy. In addition, the non-invasive electrophysiology methods are particularly suitable for understanding the large-scale brain networks. However, most studies in epilepsy have been directed to the interictal spikes, which are transitional activities. One issue that remains unresolved is the relationship between epileptic spikes and epileptic oscillatory activities. This thesis resolves two complementary problems. The first one is the suitable separation between the oscillatory and transitory activity, which is quite sensitive to the presence of the overlap in the time-frequency domain. This can lead to a contamination between the activities. We did evaluate three filtering methods: the FIR (classic methods), the stationary wavelet SWT and the parsimonious filter with the matching pursuit MP. The SWT gave good results in the reconstruction of transient activity and the MP in the reconstruction of oscillatory activity both for simulated data; also they provide a low false positive in automatic detection of oscillatory activity. The SWT and FIR gave the best results on real signals especially for source localization. In the simulated data, the MP is optimal since the atoms of the dictionary resembles to the simulated signals, which isn't guaranteed for real signals. The second problem is the comparison between network connectivity of transient and oscillatory activity, as measured in surface recordings (MEG) and invasive recordings SEEG.
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Effects of Mean Stress and Stress Concentration on Fatigue Behavior of Ductile IronMeyer, Nicholas January 2014 (has links)
No description available.
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Dynamic and Static Approaches for Glyph-Based Visualization of Software MetricsMajid, Raja January 2008 (has links)
<p>This project presents the research on software visualization techniques. We will introduce the concepts of software visualization, software metrics and our proposed visualization techniques: Static Visualization (glyphs object with static texture) and Dynamic Visualization (glyphs object with moving object). Our intent to study the existing visualization techniques for visualization of software</p><p>metrics and then proposed the new visualization approach that is more time efficient and easy to perceive by viewer. In this project, we focus on the practical aspects of visualization of multivariate dataset. This project also gives an implementation of proposed visualization techniques of software metrics. In this research based work, we have to compare practically the proposed visualization approaches. We will discuss the software development life cycle of our proposed visualization system, and we will also describe the complete software implementation of implemented software.</p>
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Dynamic and Static Approaches for Glyph-Based Visualization of Software MetricsMajid, Raja January 2008 (has links)
This project presents the research on software visualization techniques. We will introduce the concepts of software visualization, software metrics and our proposed visualization techniques: Static Visualization (glyphs object with static texture) and Dynamic Visualization (glyphs object with moving object). Our intent to study the existing visualization techniques for visualization of software metrics and then proposed the new visualization approach that is more time efficient and easy to perceive by viewer. In this project, we focus on the practical aspects of visualization of multivariate dataset. This project also gives an implementation of proposed visualization techniques of software metrics. In this research based work, we have to compare practically the proposed visualization approaches. We will discuss the software development life cycle of our proposed visualization system, and we will also describe the complete software implementation of implemented software.
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An Empirical Study of How Novice Programmers Use the WebTula, Naveen 05 1900 (has links)
Students often use the web as a source of help for problems that they encounter on programming assignments.In this work, we seek to understand how students use the web to search for help on their assignments.We used a mixed methods approach with 344 students who complete a survey and 41 students who participate in a focus group meetings and helped in recording data about their search habits.The survey reveals data about student reported search habits while the focus group uses a web browser plug-in to record actual search patterns.We examine the results collectively and as broken down by class year.Survey results show that at least 2/3 of the students from each class year rely on search engines to locate resources for help with their programming bugs in at least half of their assignments;search habits vary by class year;and the value of different types of resources such as tutorials and forums varies by class year.Focus group results exposes the high frequency web sites used by the students in solving their programming assignments.
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Managing iron deficiency chlorosis (IDC) in soybean through a cropping system approachWaldrep, Katelin Savannah 12 May 2023 (has links) (PDF)
Iron deficiency chlorosis (IDC) is a frequent problem throughout many areas of the United States where soils are high in calcium carbonate (CaCO3), including the Blackland Prairie regions of Mississippi. The main objectives of this study were to 1) determine the effects of seven different cropping systems on IDC visual symptomology and grain yield in rainfed soybeans grown in calcareous soils, and 2) evaluate the effects of soil water tension (SWT) on IDC. Rotating soybeans with corn produced significantly higher yields for both tolerant and susceptible soybean varieties. IDC symptomology was worse, and yields were lower in cropping systems with lower average SWT, or wetter soils, throughout the growing season. Last, this study evaluated the use of multispectral imagery and apparent soil electrical conductivity (ECa) to identify IDC-prone areas of a field for the site-specific implementation of management strategies that produced higher yields in the plot-scale study.
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Demand Side Management Through Integrated Water Distribution Systems and Smart Irrigation ControllersLunstad, Nathan T. 12 August 2024 (has links) (PDF)
The innovation of electrical utilities in creating smart electrical grids has superseded that of water utilities in analogous efforts. While many water utilities are now using smart water technologies, they lack the virtual command center that allows for two-way communication for more effective forecasting, load balancing, preventive methods, emergency and master planning, and level of service delivery while ensuring environmental justice and enhancing the responsible use of resources. In this dissertation, I propose the idea of the Integrated Water Distribution System (IWDS) to overcome this challenge. IWDS coordinates management of water supply and demand in a way that benefits both the water utility and the customer. IWDS also allows for greater control over monitoring, operation and maintenance, security, asset management, artificial intelligence, and delivery of water in order to maximize economic, environmental, and social welfare. To provide a way forward for IWDS and bring water services onto a technological level equal to that of other infrastructure systems, I call for greater coordination and integration of smart water technology and data, including environmental justice evaluations, and improved customer engagement. As a demand side management (DSM) tool and smart water technology component of IWDS, smart irrigation controllers (SICs) have the potential to ensure water utilities are resilient to growth and can manage peak day demands. SICs, which interface with soil moisture, evapotranspiration, or weather sensors, have been promoted as a demand-side management tool for this purpose. I review the body of research on residential smart irrigation controllers and their effectiveness. I find that smart irrigation controllers consistently reduce water demand by 15% among general users and more than 40% among indulgent users. A hydraulic model simulation using EPANET demonstrates the effectiveness of residential SICs in shifting and shaving peak demands associated with outdoor irrigation. The pressurized irrigation system for Highland, Utah, USA, is modeled with irrigation demands on a baseline scenario compared to an intervention scenario. By employing the intervention, the water system experiences many positive impacts. Without the peak shifting and shaving adjustments, costly additional capital facility improvements would be needed to maintain the same level of service. The model indicates that the SICs, if providing a 30% conservation effect (intervention scenario with SIC conservation), would shave the peak demand allowing for greater optimization and efficiency. This is the first hydraulic model analysis to demonstrate the DSM effectiveness of SICs.
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Aplikace waveletové transformace v software Mathematica a Sage / Applications of wavelet transform in Mathematica and SageNovotný, Radek January 2013 (has links)
This thesis focuses on image processing using wavelet transform. The usage of wavelet transform is analysed especially for image compression and image noise reduction purposes. The analysis describes in detail aspects and application of the following wavelet transform methods: CWT, DWT, DTWT, 2D DWT. The thesis further explains the meaning of the mother wavelet and studies certain specific kinds of wavelets, kinds of thresholding and its purposes and also touches on the JPEG2000 standard. Mathematica and Sage software packages were used to design algorithms for image compression and image noise reduction, utilising relevant wavelet transform findings. The concluding part of the thesis compares the two software packages and results obtained using different algorithms.
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Aplikace waveletové transformace v software Mathematica a Sage / Applications of wavelet transform in Mathematica and SageNovotný, Radek January 2013 (has links)
This thesis focuses on image processing using wavelet transform. The usage of wavelet transform is analysed especially for image compression and image noise reduction purposes. The analysis describes in detail aspects and application of the following wavelet transform methods: CWT, DWT, DTWT, 2D DWT. The thesis further explains the meaning of the mother wavelet and studies certain specific kinds of wavelets, kinds of thresholding and its purposes and also touches on the JPEG2000 standard. Mathematica and Sage software packages were used to design algorithms for image compression and image noise reduction, utilising relevant wavelet transform findings. The concluding part of the thesis compares the two software packages and results obtained using different algorithms.
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