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1
Swe-Hee, Kwet Kon Kian Yen. "Detection of changes in times series". Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.279569.
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Braganza, Karl 1971. "Climate change detection and attribution using simple global indices". Monash University, School of Mathematical Sciences, 2002. http://arrow.monash.edu.au/hdl/1959.1/7783.
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Malhotra, Ashish. "Detection of abrupt changes and industrial applications". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0005/MQ59842.pdf.
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Aviv, David. "Detection of abrupt changes in statistical models". Thesis, Monterey, California. Naval Postgraduate School, 1991. http://hdl.handle.net/10945/43764.
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This dissertation investigates different types of disorder problems by using sequential procedures for on-line implementation. The problem is considered within the framework of detecting abrupt changes in an observed random process when the disorder can occur at unknown times. The focus of this work is on quickest detection methods for cumsum procedures implemented for different parametric and nonparametric nonlinearities and their performance evaluation. Both the non-Bayesian (Maximum-Likelihood) and the Bayesian frameworks are presented but the focus is mainly on non-Bayesian methods for which detailed analysis is provided. The use of Brownian motion approximations is also included and provides an additional viewpoint of analyzing the performance for both the non-Bayesian and Bayesian methods.
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Konstantinidis, Dimitrios. "Building detection for monitoring of urban changes". Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/57036.
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This thesis addresses the problem of monitoring urban changes by decomposing it to building and change detection. HOG features, in combination with several other discriminative features, such as NDVI, FAST and LBP features, are employed in a search for the development of a robust and accurate building detector. Furthermore, a novel cosine-based distance function is introduced for the computation of distances between the SVM feature vectors in order to suppress the sensitivity of the SVM classifier to the presence of noise and outliers. Moreover, the transformation of SVM scores to probabilities and the definition of a better threshold that differentiates positive from negative feature vectors are proposed. To allow the transition from the object-based building detection to the pixel-based building delineation, a set of novel region refinement processes that includes an unsupervised image segmentation technique and the construction of building candidates by employing the most probable to correspond to buildings image regions based on a novel scoring procedure is proposed. Taking advantage of the ability of the CNNs to automatically generate discriminative features, another approach to the problem of building detection involves the introduction of a Modular-CNN architecture. Two novel layers are proposed and added to the Modular-CNN architecture in order to improve its generalisation power and robustness. The change detection task is approached by a top-down approach that employs the computed building masks in order to identify building changes and a bottom-up approach that initially detects changes prior to their modelling using the computed building masks. In the change detection framework, we propose a novel change amplification algorithm that enhances the differences between the compared images in order to be more easily recognised and extracted. Finally, we propose a new robust change detector based on CNNs with the ability to automatically detect building changes, while discarding all other changes.
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Tavakkol, Behnam. "Real-time detection of wave profile changes". Thesis, Kansas State University, 2012. http://hdl.handle.net/2097/14135.
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Master of ScienceDepartment of Industrial and Manufacturing Systems Engineering
Shing I. Chang
This research studies a few methodologies for real-time detection of wave profile changes. In regular profile monitoring, change detection takes place at the end of time period when a complete profile is available. In real-time change detection of profiles, a potential profile change takes place between the beginning and the end of the time period. The decision involves the identification whether a process is in control or out of control before the entire profile is generated. In this regard, five proposed methodologies were developed and tested in this thesis. Earthquake waves, manufacturing processes, and heart beat rate are a few examples of profiles with different natures that the proposed methodologies can be applied to. Water temperature profiles generated during a curing process are considered as an example in this study. Successful implementation of the proposed work on these profiles would cause saving great amounts of time and money. Five methods are studied for monitoring the water control process of a curing process. The first four proposed methodologies are based on an univariate approach where the statistic used for process monitoring is the enclosed area between the profiles and their fitted cutting lines. A multivariate approach is also proposed. A simulation study is also conducted when the best method is chosen based on it performance and simplicity of operations. Various types of acceptable and unacceptable profiles are simulated for the best proposed method identified in the preliminary study. The best method has a satisfactory performance in detecting the changes in the unacceptable profiles. In addition, the false alarm rate in identifying acceptable profiles as bad profiles is lower than 10%.
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Graham, Neil. "Automatic detection of authorship changes within single documents". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0017/MQ49736.pdf.
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Bustamante, Mariana. "Detection and Quantification of Small Changes in MRI Volumes". Thesis, Uppsala universitet, Institutionen för informationsteknologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-219487.
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The focus of this research is to attempt to solve the problem of comparing two MRI brain volumes of the same subject taken at different times, and detect the location and size of the differences between them, especially when such differences are too small to be perceived with the naked eye. The research focuses on a combination of registration and morphometry techniques in order to create two different possible solutions: A voxel-based method and a tensor-based method. The first method uses Affine or B-Spline registration combined with voxel-by-voxel subtraction of the volumes; the second method uses Demons registration and analysis of the Jacobian determinants at each point of the deformation field obtained. The methods are implemented as modules for 3D Slicer, a software for medical image analysis and visualization. Both methods are tested on two types of experiments: Artificial experiments, in which made-up differences of distinct sizes are added to volumes of healthy subjects; and real experiments, in which MRIs of real patients are compared. The results obtained from the voxel-based method are very useful, since it was able to detect with almost complete accuracy all of the artificial differences and expected real differences during the experiments. The tensor-based method’s results are not as accurate in location or size of the detected differences, and it usually includes more areas of differences where there seems to be none; even though it behaves adequately when the differences are large. Most of the results obtained are useful for the diagnostic of patients with non-severe trauma to the head; especially when using the voxel-based method. However, the results from both methods are just a suggestion of the size and location of injuries; and as a consequence, the procedure requires the presence of a medical practitioner.
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Morak, Simone. "Impact of externally forced changes on temperature extremes". Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/8246.
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This thesis investigates changes in temperature extremes between 1950-2005, analysing gridded data sets of observations and climate model simulations. It focuses on changes in the frequency of extreme temperatures occurring in single days or over periods of six or more consecutive days. The study aims to quantify the significance of changes in extreme temperature events and answer the following questions. Are external or human-induced forcings together with natural forcings responsible for the observed change in temperature extremes or can these changes be explained due to natural climate variability alone? Are the observed changes consistent with those from climate model simulations? And are the changes in extremes linked only to changes in the mean climate, or only to those in climate variability or both? The analysis concentrates on changes from global to regional scale and from annual mean to seasonal scale. A detection method is applied to assess if changes are significantly different with respect to the internal climate variability. Results show that there has been a significant increase in warm daily extremes and a decrease in cold ones, both on large and small spatial scales. The increase in warm extremes has been found to be highly correlated with the increase in mean temperature. The changes in daily extremes are well represented in climate model simulations. Changes in the persistent extremes show a detectable increase in the frequency of warm and a decrease in cold events and are reproducible by models.
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Vellekoop, Michel Henri. "Rapid detection and estimation of abrupt changes by nonlinear filtering". Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286757.
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Coutinho, Ricardo Cesar. "High sensitivity optical detection using temporal coherence interferogram phase changes". Thesis, University College London (University of London), 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.406131.
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ALBUQUERQUE, FABIO DA COSTA. "ENVIRONMENT CHANGES DETECTION: A PROACTIVE SYSTEM TO MONITOR MOVING OBJECTS". PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2012. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=29127@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROSistemas de posicionamento, combinados com tecnologias de comunicação de baixo custo, abrem possibilidades interessantes para implementar aplicações em tempo real que monitoram objetos móveis e que apoiam sistemas de tomada de decisão. Inicialmente, esta dissertação discute requisitos básicos para aplicações proativas de monitoramento em tempo real. Em seguida, propõe uma arquitetura para aplicações proativas que monitoram objetos móveis, explorando a semântica da trajetória e a dinâmica do ambiente. Por fim, fornece um exemplo sobre como uma aplicação que monitora uma frota de caminhões pode se tornar proativa, utilizando notícias sobre condições da malha viária, a partir da publicação de dados em texto não estruturado através da Internet. A dissertação descreve como estruturar e georreferenciar as notícias, utilizando serviços de geocodificação.
Positioning systems, combined with inexpensive communication technologies, open interesting possibilities to implement real-time applications that monitor moving objects and that support decision making. This dissertation first discusses basic requirements for proactive real-time monitoring applications. Then, it proposes an architecture to deploy applications that monitor moving objects, are pro-active, explore trajectory semantics and are sensitive to environment dynamics. Lastly, this dissertation provides an example of how an application that monitors a fleet of trucks can become proactive, using unstructured text information available on Internet focused on road conditions change. The dissertation describes how to structure and geo-reference the text, using available geocoding services.
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Rittenhouse, Scott A. "Diagnosis of operational changes in microelectromechanical systems via fault detection". Morgantown, W. Va. : [West Virginia University Libraries], 2004. https://etd.wvu.edu/etd/controller.jsp?moduleName=documentdata&jsp%5FetdId=3632.
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Thesis (M.S.)--West Virginia University, 2004.Title from document title page. Document formatted into pages; contains v, 141 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 137-141).
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Ek, Edgar. "Monitoring Land Use and Land Cover Changes in Belize, 1993-2003: A Digital Change Detection Approach". Ohio University / OhioLINK, 2004. http://www.ohiolink.edu/etd/view.cgi?ohiou1102520727.
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Watson, Alfred. "The analysis and detection of shape changes in non-rigid objects". Thesis, University of Sunderland, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314795.
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Szyszka, Ollie. "The detection of disease in beef cattle through changes in behaviour". Thesis, University of Newcastle Upon Tyne, 2012. http://hdl.handle.net/10443/1785.
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Health challenges that lead to subclinical or clinical diseases can increase treatment costs, reduce performance and affect animal welfare. These impacts can be reduced by starting treatment early. Since behaviour is known to be affected by the health status of an animal, an early diagnosis by monitoring changes in behaviour is a possibility. The objective of this thesis was to quantify the changes in behaviour that take place as a consequence of health challenges and to asses them for their suitability to be used for the early detection of (sub) clinical disease. The behaviours looked at were: feeding; drinking; activity; and posture. In two experiments an acute health challenge was used, in the form of either a vaccination or a lipopolysaccharide bolus. These acute challenges, due to their transient nature, did not manifest as substantial changes in behaviour. A gastro-intestinal parasite (Ostertagia ostertagi) was used as a chronic challenge in three experiments. This health challenge affected several aspects of the behaviours measured. Due to its prolonged nature these effects increased over time, but were reversed after the challenge had been removed. The challenge also showed a dose dependency, demonstrating a threshold, rather than a gradient, when affecting behaviour for different levels of parasitic infection. From the overall results it was concluded that activity, posture and in some cases feeding behaviour, were affected by the parasitic (O. ostertagi) health challenge. From these, activity and posture were found to have the greatest magnitude of change and to be the most consistently affected across experiments. These behavioural changes, however, started at the same time as a rise in faecal egg counts and pepsinogen levels. Nonetheless, due to the magnitude of the behavioural changes, behaviour could still be used as an indicator of health status, predominantly in animals that receive little visual monitoring.
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Karoglou, Michail. "On the detection of structural changes in volatility dynamics with applications". Thesis, University of Leicester, 2006. http://hdl.handle.net/2381/30150.
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This study aimed to address a series of issues regarding both the CUSUM-type tests that have been developed to detect a potentially existing break in the conditional variance of an economic process, and their corresponding breakdate estimators that are used to identify the time of occurrence of that break. The approach taken has been based on an extensive Monte-Carlo simulation to evaluate the size, power and accuracy of the corresponding breakdate estimator of a set of 27 test variants for approximately 450 data generating processes, some homoskedastic but most conditionally heteroskedastic. The first set of issues is concerned with the finite sample properties of the tests, while the second one focuses on the choice of the appropriate test which depends on the assumptions made regarding the conditional variance of the underlying process. A third set of issues concerns the ability of the tests to detect breaks in the conditional mean of the process as well as the conditional variance. In addition to investigating the theoretical properties of the tests, four applications are included amongst which are a note on the work of Andreou and Ghyssels (2002), who perform a Monte-Carlo analysis with features common to those of this study, albeit with some discrepancies in the results, and three empirical studies that signify the importance of testing for structural changes in processes prior to any further analysis and provide suggestions about robustifying results obtained by the use of the CUSUM-type tests.
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Rodríguez, Borjabad Cèlia. "Familial Hypercholesterolemia in children. From detection and characterization to lifestyle changes". Doctoral thesis, Universitat Rovira i Virgili, 2021. http://hdl.handle.net/10803/672773.
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La Hipercolesterolèmia Familiar (HF) és una malaltia autosòmica dominant que cursa amb nivells elevats de
lipoproteïnes de baixa densitat (LDL) des del naixement. Aquesta malaltia sovint està infradiagnostica e infratractada.
La infantesa és un període òptim per la detecció i per començar amb el tractament (canvis d’estil de vida (CEV) i en
alguns casos, estatines). Si aquests nens són detectats i tractats de forma precoç, s’ha observat que milloren el seu
pronòstic.
Per aquest motiu, la present tesi doctoral té com objectiu millorar la detecció, el diagnòstic i el tractament dels nens
amb HF. Aquest objectiu general s’aconsegueix mitjançant tres accions: 1. Establint una estratègia de detecció precoç
per detectar nens amb HF; 2. Explorant nous biomarcadors i analitzant amb més profunditat el perfil de lipoproteïnes
per ressonància magnètica nuclear (RMN); i 3. Implementant un tractament primerenc basat en activitats educatives
destinades a establir CEV.
Respecte al objectiu 1, gràcies a estratègies de cribratge actiu basats en la cascada directa e indirecta, amb l’ajuda
dels pediatres dels centres d’atenció primària, s’han detectat 87 nens i 41 familiars amb HF en dos anys. Respecte al
objectiu 2, hem observat que els nens amb HF presenten més IDOL i PCSK9, així com un major nombre de partícules
LDL petites (les més aterogèniques).La Hipercolesterolemia Familiar (HF) es una enfermedad autosómica dominante que cursa con niveles elevados de lipoproteínas de baja densidad (LDL) desde el nacimiento. Esta enfermedad a menudo está infradiagnosticado e infratratada. La infancia es un periodo óptimo para la detección y para comenzar con el tratamiento (cambios de estilo de vida (CEV) y en algunos casos, estatinas). Si estos niños son detectados y tratados de forma precoz, se ha observado que mejoran su pronóstico. Por este motivo, la presente tesis doctoral tiene como objetivo mejorar la detección, el diagnóstico y el tratamiento de los niños con HF. Este objetivo general se consigue mediante tres acciones: 1. Estableciendo una estrategia de detección precoz para detectar niños con HF; 2. Explorando nuevos biomarcadores y analizando con más profundidad el perfil de lipoproteínas por resonancia magnética nuclear (RMN); y 3. Implementando un tratamiento temprano basado en actividades educativas destinadas a establecer CEV. Respecto al objetivo 1, gracias a estrategias de cribado activo basados en la cascada directa e indirecta, con la ayuda de los pediatras de los centros de atención primaria, se han detectado 87 niños y 41 familiares con HF en dos años. Respecto al objetivo 2, hemos observado que los niños con HF presentan más IDOL y PCSK9, así como un mayor número de partículas LDL pequeñas (las más aterogénicas).
Familial hypercholesterolemia (FH) is an autosomal dominant disease with high levels of low-density lipoprotein (LDL) from birth. This disease is usually underdiagnosed and undertreated. Childhood is an optimal time for detection and initiation of treatment (lifestyle changes (LSC), and in some cases, statins). If these children are found and treated early, they have been shown to improve their prognosis. For this reason, the present doctoral thesis aims to improve the detection, diagnosis and treatment of children with FH. This general objective is achieved through three actions: 1. Establish an early detection strategy to detect children with FH; 2. Explore new biomarkers and analyse in greater depth the lipoprotein profile assessed by nuclear magnetic resonance (NMR); and 3. Implement early treatment based on educational activities aimed at establishing LSC. With respect to Objective 1, thanks to active screening strategies based on direct and indirect cascade, with the help of pediatricians from primary care centers, 87 children and 41 relatives with FH have been detected in two years. Regarding target 2, we observed that children with FH present more IDOL and PCSK9, as well as a greater number of small LDL particles (the most atherogenic). And finally, to answer objective 3, we study how diet affects the entire lipid and lipoprotein profile. We have observed that although elevated LDL levels in children with FH are genetically determined, LSC are capable of reducing their values.
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Henshaw, Katie(Katherine A. ). "Optical detection of finger pressure through utilization of nailbed color changes". Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/127927.
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Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, May, 2020Cataloged from the official PDF of thesis.
Includes bibliographical references (pages 14-15).
This thesis presents the theory and design of a sensor that detects a when a finger is pressed by visually examining a user's fingernail coloration. Unlike other finger-based controllers that primarily depend on covering the finger pad, this method of sensing allows for accurate measurements without impairing a user's tactile sense. First the color change of a fingernail is examined based on the underlying biological mechanisms of the finger. Then the hue, saturation, and value (HSV) coordinates of videos of the fingernails are analyzed in three different locations; the entire image, a segment of the rear of the fingernail, and a segment of the tip of the fingernail. The front of the fingernail, where a white band develops when pressure is applied to the finger, proved to have statistically significant increases in saturation and value for all test subjects. With these results a simple sensor was designed and tested that accurately sensed finger presses, however with a significant time lag. Finally, the mechanical design of such a sensor was proposed, leaving room for further study and development.
by Katie Henshaw.
S.B.
S.B. Massachusetts Institute of Technology, Department of Mechanical Engineering
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Anderson, James. "A comparison of four change detection techniques for two urban areas in the United States". Morgantown, W. Va. : [West Virginia University Libraries], 2002. http://etd.wvu.edu/templates/showETD.cfm?recnum=2371.
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Thesis (M.A.)--West Virginia University, 2002.Title from document title page. Document formatted into pages; contains ix, 61 p. : col. ill., col. maps. Includes abstract. Includes bibliographical references (p. 40-42).
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Makarov, Aleksej. "Non parametric data qualification : detection and separation of cyclic and acyclic changes /". Lausanne : EPFL, 1997. http://library.epfl.ch/theses/?nr=1715.
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Weitzman, Robert C. "Statistical monitoring of police force for rapid detection of changes in frequency". Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1999. http://handle.dtic.mil/100.2/ADA374321.
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Thesis (M.S. in Operations Research) Naval Postgraduate School, December 1999."December 1999". Thesis advisor(s): David H. Olwell. Includes bibliographical references (p. 79-80). Also available online.
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Abbasova, Tahira. "Detection and analysis of changes in desertification in the Caspian Sea Region". Thesis, Stockholms universitet, Institutionen för naturgeografi och kvartärgeologi (INK), 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-43241.
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The Caspian Region includes the Caspian Sea and five littoral states: Azerbaijan, Iran, Turkmenistan, Kazakhstan and Russian. 40% of the Caspian coastal zone is arid, 69% of this territory undergone desertification according to international reports. Among the reasons are soil erosion caused by water, wind and irrigation, the salinization of soil, intense bioresources usage, and soil pollution due to oil extraction and production. Desertification is a serious problem, at global, national and local scales. It is important to know what should be sustained or developed in order to protect land from desertification. The generalization of data over desertification processes in Caspian countries, studying the dynamics of this process in space and time could help facilitate measures to counter regional desertification. To understand Caspian Region coastal desertification phenomenon, vegetation cover satellite images for the years 1982 – 2006 were investigated to give map vegetation changes over time. The Normalized Difference Vegetation Index (NDVI) data for this study was derived from the Global Inventory Modeling and Mapping Studies (GIMMS) dataset, with the spatial resolution of 8 km. A coastal strip 160 km from the coast, divided by countries, was investigated. Theanalyses were focused on extent and severity of vegetation cover degradation, and possible causes such as landscape, land use history and culture, climatic changes and policies. The aim was to address questions related to desertification phenomenon, by focusing on Caspian Region time-series of vegetation cover data and investigation patterns of desertification in the region. In this study evidence of land degradation in the Caspian Region countries was found to occur on local scales or sub-national scales rather than across the regional as a whole. Changes in vegetation cover revealed by AVHRR NDVI appeared to be reversible in character and were dependent on the climate conditions, and anthropogenic impact in approximately equal proportions.
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Yoonessi, Ali. "The role of natural image structure in visual detection of photometric changes". Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=21997.
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Traditionally, human visual sensitivity changes in luminance and chromatic contrast, collectively termed photometric changes, have been measured using simple laboratory stimuli such as disks or gratings. The results of experiments using such stimuli have generally been accounted for in terms of relatively low-level mechanisms such as quasi-linear filters in the visual cortex. Therefore, one might not expect the higher-order structure of natural scenes to influence sensitivity to uniform photometric changes. On the other hand, it is believed that the visual system is optimized for analyzing visual information in natural scenes, which leads to the alternative hypothesis that the unique structure of natural scenes will influence sensitivity to photometric changes. We tested between these two hypotheses by comparing sensitivity to uniform photometric changes in natural scenes with sensitivity to uniform photometric changes in the same scenes with the structure removed through phase scrambling. Sensitivity was found to be higher in the natural compared to phase-scrambled scenes. Additional experiments ruled out the possibility that the higher sensitivity in the natural scenes was due to one's familiarity with their colors, or that the lower sensitivity in the phase-scrambled scenes was due to the increase in color variability introduced by phase scrambling. In another series of experiments sensitivity to uniform photometric transformations in both natural and phase-scrambled scene was measured in dichoptic image-pairs that were transformed in equal and opposite directions. The results suggested that the superiority in sensitivity in natural scenes resulted from mechanisms operating at or after the point of binocular combination. Finally we considered whether the superiority in sensitivity in natural compared to phase-scrambled scenes was underpinned by one of the defining characteristics of natural scenes: the presence of uniform areas separated by edges. This requireLe rôle de la structure des images naturelles dans la sensibilité visuelle aux changements photométriques uniformes Chez l'être humain, les changements dans la sensibilité visuelle aux contrastes chromatiques et achromatiques, appelés changements photométriques, sont traditionnellement mesurés à l'aide de stimuli simples tels que des disques ou des réseaux de bars. Les résultats de ces études reposent généralement sur des mécanismes de bas-niveau tels que les filtres quasi-linéaires du cortex visuel, qui prédisent que la structure des scènes naturelles ne devrait pas influencer la sensibilité aux changements photométriques. D'un autre coté a été émise l'hypothèse selon laquelle le système visuel est optimisé pour l'analyse de l'information présente dans les scènes naturelles, ce qui suggère que la structure unique des scènes naturelles pourrait influencer la sensibilité aux changements photométriques. Nous avons donc testé ces deux hypothèses en comparant la sensibilité aux changements photométriques uniformes pour des scènes naturelles dont la structure est soit restée intacte, soit éliminée par l'intermédiaire d'un brouillage de leur information de phase. Les résultats de cette étude démontrent que la sensibilité est plus grande pour les scènes naturelles intactes que leurs versions ‘brouillées'. Des expériences complémentaires excluent la possibilité que la sensibilité plus élevée pour les scènes naturelles soit due à une familiarisation à leurs couleurs, ou la possibilité que la sensibilité plus faible pour leurs versions brouillées soit due à l'augmentation de la variabilité chromatique induite par le brouillage de phase. Dans une autre série d'expériences, la sensibilité aux changements photométriques uniformes pour les scènes intactes et brouillées a été mesurée pour des paires d'images présentées dichoptiquement et pour lesquelles les changements photométriques ont été appliqu
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Zhang, Xiaohu, e 张啸虎. "Automatic detection of land cover changes using multi-temporal polarimetric SAR imagery". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/193496.
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Dramatic land-cover changes have occurred in a broad range of spatial and temporal scales over the last decades. Satellite remote sensing, which can observe the earth's surface in a consistent manner, has been playing an important role in monitoring and evaluating land-cover changes. Meanwhile, optical remote sensing, a common approach to acquiring land-cover information, is limited by weather conditions and thus is greatly constrained in areas with frequent cloud cover and rainfall. Recent advances in polarimetric SAR (PolSAR) provide a promising means to extract timely information of land-cover changes regardless of weather conditions.
SAR satellite can pass through an area from different orbits, namely ascending orbit and descending orbit. The PolSAR images from the same orbit will have similar backscattering even with different incident angles. But if images are acquired from different orbits, the backscattering will vary greatly, which causes many difficulties to land cover change detection. The proposed algorithms in this study can perform land cover change detection in three situations: 1) repeat-pass images (image from the same orbit and with same incident angle, 2) images from the same orbit but with different incident angle, and 3) images from different orbits. Using images from different orbits will largely reduce the monitoring interval which is important in the surveillance of natural disasters.
The present study proposes 1) a sub-pixel automatic registration technique, 2) an automatic change detection technique and 3) an iterative framework to process a time series of PolSAR images that can be applied to the PolSAR images from different orbits. Firstly, automatic registration is crucial to the change detection task because a small positional error will largely degrade the accuracy of change detection. The automatic registration technique is based on the multi-scale Harris corner detector. To improve the efficiency and robustness, the orientation angle differencing method is proposed to reject outliers. This differencing method has been proved effective even in the experiment of using PolSAR images from different orbits when less than 5% of the feature point matches are correct. Secondly, the change detection technique can automatically detect land-cover conversions and classify the newly input image. Hierarchical segmentation has been applied in the change detection which generates objects within the constraint of the previous classification map. Multivariate kernel density estimation is applied to classify newly input PolSAR image. The experiments show that the proposed change detection technique can mitigate the effect of polarimetric orientation shift when the PolSAR images are from different orbits, and it can achieve high accuracy even when complex local deformation is appeared. Lastly, the iterative framework, which integrates the automatic registration and automatic change detection techniques, is proposed to process a time series of PolSAR images. In the iterative process, no obvious decrease of classification accuracy is observed. Therefore, the proposed framework provides a potential treatment to derive land-cover dynamics from a time series of PolSAR images from different orbits.published_or_final_version
Urban Planning and Design
Doctoral
Doctor of Philosophy
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Nama, Ernest Ekodo. "Detection of landscape changes arising from tectonism and volcanism on Mount Cameroon". Thesis, University of Salford, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.395921.
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Cosgrove, Paul. "Detection of frequency and intensity changes using synthetic vowels and other sounds". Thesis, Keele University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329556.
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Larsson, Daniel. "Large scale congurable text matching for detection of log changes and anomalies". Thesis, Karlstads universitet, Institutionen för matematik och datavetenskap (from 2013), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-72931.
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Manually analysing logfiles is a very time consuming and error-prone effort. By developing a system to automatically analysing the logfiles it is possible to both increase the speed and accuracy of the analysis. This thesis presents a method for automatic anomaly detection in logfiles using statistical analysis and threshold based classification. The presented method uses five different threshold based approaches to identify anomalous entries within a logfile. Each of the five approaches was successful in identifying and reporting perceived anomalies within 805 logfiles provided by Sandvine, it was however not possible to do a formal evaluation of the results due to a lack of a ground truth.
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Liang, Chun Ph D. "Cortical Representation of Frequency Changes in Cochlear Implant Users". University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1504796317530661.
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Cockerton, Helen Elizabeth. "Late-glacial and Holocene variations in the Si cycle in the Nile Basin : multi-isotope evidence from modern waters and lake sediments". Thesis, Swansea University, 2012. https://cronfa.swan.ac.uk/Record/cronfa42906.
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Nori, Wafa. "Detection of land cover changes in El Rawashda forest, Sudan: A systematic comparison". Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-95618.
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The primary objective of this research was to evaluate the potential for monitoring forest change using Landsat ETM and Aster data. This was accomplished by performing eight change detection algorithms: pixel post-classification comparison (PCC), image differencing Normalized Difference Vegetation Index (NDVI), Soil-Adjusted Vegetation Index (SAVI), Transformed Difference Vegetation Index (TDVI), principal component analysis (PCA), multivariate alteration detection (MAD), change vector analysis (CVA) and tasseled cap analysis (TCA). Methods, Post-Classification Comparison and vegetation indices are straightforward techniques and easy to apply. In this study the simplified classification with only 4 forest classes namely close forest, open forest, bare land and grass land was used The overall classification accuracy obtained were 88.4%, 91.9% and 92.1% for the years 2000, 2003 and 2006 respectively. The Tasseled Cap green layer (GTC) composite of the three images was proposed to detect the change in vegetation of the study area. We found that the RBG-TCG worked better than RGBNDVI. For instance, the RBG-TCG detected some areas of changes that RGB-NDVI failed to detect them, moreover RBG-TCG displayed different changed areas with more strong colours. Change vector analysis (CVA) based on Tasseled Cap transformation (TCT) was also applied for detecting and characterizing land cover change. The results support the CVA approach to change detection. The calculated date to date change vectors contained useful information, both in their magnitude and their direction. A powerful tool for time series analysis is the principal components analysis (PCA). This method was tested for change detection in the study area by two ways: Multitemporal PCA and Selective PCA. Both methods found to offer the potential for monitoring forest change detection. A recently proposed approach, the multivariate alteration detection (MAD), in combination with a posterior maximum autocorrelation factor transformation (MAF) was used to demonstrate visualization of vegetation changes in the study area. The MAD transformation provides a way of combining different data types that found to be useful in change detection. Accuracy assessment is an important final step addressed in the study to evaluate the different change detection techniques. A quantitative accuracy assessment at level of change/no change pixels was performed to determine the threshold value with the highest accuracy. Among the various accuracy assessment methods presented the highest accuracy was obtained using the post-classification comparison based on supervised classification of each two time periods (2000 -2003 and 2003-2006), which were 90.6% and 87% consequently.
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Mancero, Gabriela. "Detection of changes through visual alerts and comparisons using a multi-layered display". Thesis, Middlesex University, 2010. http://eprints.mdx.ac.uk/7327/.
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The Multi-Layered Displays (MLD) comprise two LCD screens mounted one in front of the other, allowing the presentation of information on both screens. This physical separation produces depth without requiring glasses. This research evaluated the utility of the MLD for change detection tasks, particularly in operational environments. Change Blindness refers to the failure to detect changes when the change happens during a visual disruption. The literature equates these visual disruptions with the types of interruptions that occur regularly in work situations. Change blindness is more likely to occur when operators monitor dynamic situations spread over several screens, when there are popup messages, and when there are frequent interruptions which are likely to block the visual transients that signal a change. Four laboratory experiments were conducted to evaluate the utility of the MLD for change detection tasks. The results from the experiments revealed that, when depth is used as a visual cue, the depth of the MLD has a different effect on the detection of expected changes and unexpected events. When the depth of the MLD is used as a comparison tool, the detection of differences is limited to translation differences in simple stimuli with a white background. These results call into question previous claims made for the MLD regarding operational change detection. In addition, observations and interviews were used to explore whether change blindness occurred in an operational command room. The results suggested that operators develop strategies to recover from interruptions and multitasking. These results call into doubt the wisdom of applying change detection theories to real world operational settings. More importantly, the research serves as a reminder that cognitive limitations found in the laboratory are not always found in real world environments.
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Planinc, Ana. "Detection of changes in n-glycosylation profiles of therapeutic glycoproteins using LC-MS". Doctoral thesis, Universite Libre de Bruxelles, 2016. https://dipot.ulb.ac.be/dspace/bitstream/2013/241427/4/Table.pdf.
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Biopharmaceuticals are becoming one of the most promising drugs on the market mainly due to their successful treatment of a vast array of serious diseases, such as cancers, immune disorders, and infections. Structurally, biopharmaceuticals are proteins and it is important to mention that more than 60 % of biopharmaceuticals are glycosylated. Glycosylation is one of the most common posttranslational modifications. It is also the most demanding and the most complex posttranslational modification. The research showed that glycosylation can significantly impact on the safety, efficiency, and quality of the therapeutic glycoproteins. In the first part of the introduction of the present thesis, the development of the therapeutic glycoproteins and their classification were reviewed. Glycosylation process and nomenclature were also discussed. The second part of the introduction revealed current issues in the field of the production and the characterization of the therapeutic glycoproteins. In the context of the doctoral thesis, we introduced new approach, namely hydrophilic interaction liquid chromatography coupled to a high-resolution mass spectrometer (HILIC-HR-MS) combined with Principal Component Analysis (PCA) and classification through Soft Independent Modelling by Class Analogy (SIMCA) data treatment. Accordingly, N-glycans were first enzymatically released using peptide-N-glycosidase F (PNGase F) and reduced using sodium borohydride. Then those N-glycans were separated by HILIC and detected by HR-MS. PCA and SIMCA simplified interpretation of the MS data collected in the huge tables. PCA was applied to test whether it is possible to visualize N-glycosylation differences between samples and to help identifying within which N-glycans changes occurred. SIMCA, which is a more complex data analysis technique, was applied to build and validate a classification models. SIMCA was also applied to verify whether it is possible to use built models to classify real samples. Described approach enabled us to detect small changes in N-glycosylation of the therapeutic glycoproteins (a change of only 1% in relative glycan abundance). It was applied to assess changes in N-glycosylation of therapeutic glycoproteins. Accordingly, we tested N-glycosylation consistency between batches of infliximab, trastuzumab, and bevacizumab and monitored the N-glycosylation of bevacizumab over storage time in plastic syringes.Furthermore, we worked on the faster sample preparation technique, where online-solid-phase extraction (SPE)-LC was combined to the previously mentioned HILIC-MS-PCA/SIMCA method. Online-SPE-LC allowed us to faster the sample preparation in terms of avoiding time-consuming cleaning steps.Doctorat en Sciences
info:eu-repo/semantics/nonPublished
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Ericson, Mark Anders. "Monaural detection of doppler frequency shifts and intensity changes in simulated moving sounds /". The Ohio State University, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=osu1486400446373743.
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Gunsolley, John C. "False positive rates encountered in the detection of changes in periodontal attachment level". VCU Scholars Compass, 1987. http://scholarscompass.vcu.edu/etd/4684.
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This thesis demonstrates that the assumption of normality used by Goodson results in the underestimation of the type I error rate of the tolerance method by a factor of 10. This underestimation is due to the positive kurtosis demonstrated in the distribution of replicate differences. Therefore, the assumption of normality does not seem warranted. It is shown here that a resampling technique more accurately estimates the type I error rate.
The estimates of false positive rates have important implications in the field of periodontics. When diagnostic decisions are based on single measurements, false positive rates are high. Even when thresholds as high as 3 mm. are used, over 3 out of 10 sites identified as "changed" have not changed. Unfortunately, in the clinical practice of periodontics, single measurements are commonly used. Therefore, clinicians who make treatment decisions based on attachment level measurements, may be treating a large percentage of sites that have not undergone destructive periodontal disease. Clinical periodontists generally regard a loss of attachment of 3 mm. or more as evidence of progressively worsening disease requiring additional therapy. The consequences of treating areas that are erroneously concluded as having progressed have to be compared to the consequences of not treating areas that are progressing. If a clinician treats sites when a change of 3 mm. in attachment level is detected, it is likely that as many as 32% of the sites may not have progressed. However, if the change in attachment level is real and the site is not treated, a significant proportion of the attachment may be lost. Changes of 3 mm. are large compared to the length of the root of the tooth. Weine (1982, p. 208-209), using Black's (1902) description of tooth anatomy, presents average root length of 13 categories of teeth. Average root lengths range from 12 to 16.5 mm. for the 13 categories. If a tooth with a root of 14 mm. (near the middle of the range of average tooth length) has a change in attachment level measurements of 3 mm., the clinician is faced with a dilemma as to whether the site should be treated. The dilemma is increased if prior to the change of 3 mm., the site had already lost 50% of its attachment. In this situation the 3 mm. change represents nearly half of the remaining attachment. For these reasons, better measurement techniques would be beneficial in the clinical practice of periodontics.
A controversy exists in the periodontal literature on the ability of single attachment level measurements to find actual change in attachment level. Two recent reports are in general agreement with this study. Imrey (1986) evaluates the ability of single measurements of attachment level to find change in attachment level. He concludes: "If true disease is uncommon and sensitivity to it is not high, these false positives may exceed in number the true positives detected" (p. 521). Ralls and Cohen (1986) reach similar conclusions: "the major issue is that 'bursts' of change can be explained by chance events which arise from measurement error and which occur at low but theoretically expected levels" (p. 751). The results of the present research demonstrate that a large percentage of the perceived change in attachment level is due to measurement error, but not to the degree that Imrey (1986) and Ralls and Cohen (1986) suggest. These researchers attribute almost all the attachment level changes to measurement error. In contrast, Aeppli, D. M., Boen, J. R., and Bandt, C. L. (1984) reach a different conclusion: "using an observed increase of greater than 1 mm. as a diagnostic rule leads to high sensitivity and yet satisfactorily high specificity" (p. 264).
All three of the above referenced studies base their conclusions on estimates of sensitivity and specificity. The methods of obtaining estimates of sensitivity and specificity vary between the studies. Aeppli, D. M., Boen, J. R., and Bandt, C. L. base their estimates of specificity and sensitivity on a calibration study involving 34 patients and 3 examiners. Their distribution of differences in replicated measurements is similar to the distribution that Goodson (1986) reports. Irnrey (1986) and Ralls and Cohen ( 1986), instead of using actual data, simulate the distribution of differences by using a normal approximation with standard deviations of 1.125 mm. and 1 mm. respectively. Even though the methods of obtaining data vary, all the reports obtain high values of specificity (Table 6). However, estimates of sensitivity vary both within and among the three studies. Table 6 demonstrates that for similar thresholds the studies obtain a wide range of estimates of sensitivity. Within each study estimates of sensitivity are shown to be highly dependent on the assumed magnitude of actual change and the threshold used to detect the change. As the threshold decreases or the assumed attachment level change increases, sensitivity increases. The possible wide range of estimates that can be obtained within a study is demonstrated by Ralls and Cohen (1986). Their estimates of sensitivity range from .0668 to .9772. As discussed in chapter 1, the broad range of estimates of sensitivity and those estimates' basis on arbitrary assumptions brings to question their value.
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Udugbezi, Emmanuel. "Evaluating interferometric synthetic aperture radar coherence for coastal geomorphological changes". Thesis, University of Dundee, 2018. https://discovery.dundee.ac.uk/en/studentTheses/b127af25-c290-4fdf-ac44-96c77449fb59.
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Interferometric Synthetic Aperture Radar (InSAR) is an established technique which has been applied to Earth surface displacement analysis and topographic reconstruction. Two complex coherent SAR acquisitions of the same scene are combined to form an interferogram from which surface displacement or terrain measurements are made. The similarities between both SAR signals is captured in the coherence and its magnitude is determined by the spatial separation between acquiring antennas and the changes (if any) to the physical characteristics of the scattering target in the duration between both SAR acquisitions. Both of these products derivable from the interferometric process have been applied in this study with the aim of enhancing monitoring and assessing changes in the coastal environment, with emphasis on the coastal geomorphology. A combination of remote sensing data acquired for Montrose Bay, NE Scotland, has been used to analyze changes to the geomorphology of the beach and dune system in terms of sediment volume analysis, erosion and accretion processes and shoreline changes over a short-term period of 4 years. The interferometric coherence was applied to detect changes to the dune morphology, which have been actively eroding at the southern flank of the Bay. The interferometric analysis presented in this thesis was based on SAR data acquired by the Sentinel-1 SAR antenna and the results demonstrated the limitations of the sensor for terrain mapping and DEM reconstruction. In addition, the significance of the vegetation on the interferometric coherence was demonstrated. However, the results have shown that temporal baseline remained a significant consideration in the application of interferometric coherence in highly dynamic environments such as the coastal environment.
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Lynch, James Andrew. "A study of smoke aging examining changes in smoke particulate size". Link to electronic thesis, 2004. http://www.wpi.edu/Pubs/ETD/Available/etd-0510104-194400/.
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Feng, Yuanjian. "Detection and Characterization of Multilevel Genomic Patterns". Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/38577.
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DNA microarray has become a powerful tool in genetics, molecular biology, and biomedical research. DNA microarray can be used for measuring the genotypes, structural changes, and gene expressions of human genomes. Detection and characterization of multilevel, high-throughput microarray genomic data pose new challenges to statistical pattern recognition and machine learning research. In this dissertation, we propose novel computational methods for analyzing DNA copy number changes and learning the trees of phenotypes using DNA microarray data.
DNA copy number change is an important form of structural variations in human genomes. The copy number signals measured by high-density DNA microarrays usually have low signal-to-noise ratios and complex patterns due to inhomogeneous composition of tissue samples. We propose a robust detection method for extracting copy number changes in a single signal profile and consensus copy number changes in the signal profiles of a population. We adapt a solution-path algorithm to efficiently solve the optimization problems associated with the proposed method. We tested the proposed method on both simulation and real CGH and SNP microarray datasets, and observed competitively improved performance as compared to several widely-adopted copy number change detection methods. We also propose a chromosome instability measure to summarize the extracted copy number changes for assessing chromosomal instabilities of tumor genomes. The proposed measure demonstrates distinct patterns between different subtypes of ovarian serous carcinomas and normal samples.
Among active research on complex human diseases using genomic data, little effort and progress have been made in discovering the relational structural information embedded in the molecular data. We propose two stability analysis based methods to learn stable and highly resolved trees of phenotypes using microarray gene expression data of heterogeneous diseases. In the first method, we use a hierarchical, divisive visualization approach to explore the tree of phenotypes and a leave-one-out cross validation to select stable tree structures. In the second method, we propose a node bandwidth constraint to construct stable trees that can balance the descriptive power and reproducibility of tree structures. Using a top-down merging procedure, we modify the binary tree structures learned by hierarchical group clustering methods to achieve a given node bandwidth. We use a bootstrap based stability analysis to select stable tree structures under different node bandwidth constraints. The experimental results on two microarray gene expression datasets of human diseases show that the proposed methods can discover stable trees of phenotypes that reveal the relationships between multiple diseases with biological plausibility.Ph. D.
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Flick, Hunter James. "Detection of Environmental Contaminants in Water Utilizing Raman Scanning for E. coli Phenotype Changes". Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/89651.
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Raman spectroscopy and its counterpart surface-enhanced Raman scattering (SERS) have proven to be effective methods for detecting miniscule changes in the phenotypes of E. coli and other single-celled organisms to aid in the detection of new strains for industrial use and discovery of new antibiotics. The purpose of this study is to develop a method to quickly and accurately detect contaminants in water samples through phenotype changes in E. coli measured through SERS. Contaminated Luria-Bertani (LB) media was inoculated with LB with an OD600 of 1, grown for two hours, and then dried on a flat piece of aluminum foil. These samples were then Raman scanned and processed to determine contaminant-induced changes to the phenotypes of the E. coli. Three types of tests were run to show the effectiveness of this method: single-component, multicomponent, and impure water sources. In single-component tests, it was found that differences due to NaCl contamination could be detected to 5.0E-9 weight percent (wt %), ethanol (EtOH) to 5.0E-7 volumetric percent (% v/v), citric acid (CA) to 2.8E-4 wt %, acetic acid (AA) to 2.6E-4 wt %, kanamycin to 2.5E-11 wt %, ampicillin to 2.5E-10 wt %, CoCl2 to trace amounts, and silver nanoparticles (AgNP) to 5.2E-7 wt %. Many of these are below the detection limits of analytical instrumentation, but their effects on E. coli phenotypes were detectable by Raman spectroscopy. Multicomponent tests showed that in a mixture, the most toxic or most concentrated contaminants have the most effect on cell phenotype. However, it was shown that similar concentrations of similar contaminants may be difficult to discern with current methods. This behavior was also seen in the impure water samples, showing that tap water behaves the closest to a DI control, followed by running water, and finally stagnant bodies. This new method of monitoring E. coli phenotypes with Raman spectroscopy as a biosensor shows promise for the fast, portable, and accurate determination of environmental contaminants with a broad-spectrum and very low detection limits.Master of Science
Recently, Raman spectroscopy and an enhanced version called surface-enhanced Raman scattering (SERS) have shown promise in showing the effects of a cell’s environment on how it expresses genes and what chemical compounds it produces to survive. It does this through reading the chemical signature it gives off due to these changes, and these readings have been used for showing the effects of antibiotics, finding varieties that are resistant to toxic byproducts of their activities, and as biosensors. The study outlined in this thesis aims to develop a test utilizing SERS to see the reactions of a non-pathogenic strain of E. coli to contaminants in their media and determine their identity. This test was run for three types of contaminated samples: one contaminant, three contaminants, and tests using impure water from a sink tap, a pond, and a stream. For the single contaminants, eight types were tested; NaCl, ethanol, citric acid, acetic acid (AA), kanamycin, ampicillin, CoCl2, and silver nanoparticles. Detection limits for all contaminants were found, with the lowest detectable concentrations all falling below or matching detection limits of common methods. The lowest detectable concentrations came from kanamycin and CoCl2, at 2.5E-11 weight percent and in amounts which are considered beneficial to the environment, respectively. The three-contaminant test shows that it is possible to pinpoint which contaminants are having the highest effect, though if contaminants are similar in nature and in similar concentrations, it may be difficult to pinpoint which is causing the effect. In the final test, similarity of water sources to pure water were found, with tap water being closest, followed by stream water and the most different being pond water. It was also found that pond water and stream water were closest in behavior, showing the power of this method in differentiating sources from each other.
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Arendt, Joseph T. "Detection of early cancerous changes and cancer in bladder tissue by autofluorescence and reflectance /". The Ohio State University, 1999. http://rave.ohiolink.edu/etdc/view?acc_num=osu148818776384652.
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Hallinan, Jennifer Susan. "Detection of malignancy associated changes in cervical cells using statistical and evolutionary computation techniques /". St. Lucia, Qld, 1999. http://adt.library.uq.edu.au/public/adt-QU2000.0037/index.html.
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EMVALOMENOS, Gaelle. "Quantitative Methods For Detection of Transient Changes in Endogenous Dopamine For Preclinical PET Studies". Thesis, The University of Sydney, 2021. https://hdl.handle.net/2123/25710.
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This thesis investigates quantitative methods for the characterisation of dopamine (DA) release in preclinical PET. The goal was to develop methodologies that improve quantification of the PET signal and test to what extent these techniques can reliably detect subtle DA fluctuations. Ultimately, reliable quantification could help to better understand the role of DA in human brain conditions.
The focus of this work is kinetic modelling, whose accuracy depends on different factors, from the quality of the measured imaging data to the interpretation of parameter estimates. An investigation of the model, linear parametric neurotransmitter PET (lp-ntPET), that enables the description of time-varying DA changes, was performed in 3 contexts.
First, its performance was tested in a Bayesian framework, the PET-ABC method. Second, it was evaluated in 1D-simulations by varying the activations and the priors, to study their effects on uncertainty in the estimates. Third, a [11C]raclopride study was performed in monkeys using the high sensitivity MiniExplorer, where different amphetamine doses were injected to induce variable DA releases. Finally, towards exploiting the synergies of PET/fMRI data in the future, a preclinical PET insert was evaluated in 3 configurations: as a standalone unit, in the MR bore and with the MR pulsing.
In conclusion, the results of the studies showed that the lp-ntPET model used in conjunction with PET-ABC is a robust quantitative method that not only provides parameter estimates and their uncertainties but also statistically sound inferences about model preference. Further, PET-ABC is able to reliably estimate parameters describing transient DA release in preclinical studies. The PET insert presented good performance in all configurations, enabling future investigation of parallel analysis of fMRI and PET data for improved parameter estimation.
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Tebaldi, Toma. "Computational and experimental detection of uncoupling between transcriptome and translatome changes of gene expression". Doctoral thesis, Università degli studi di Trento, 2010. https://hdl.handle.net/11572/369224.
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Transcriptome analysis by total mRNA profiling provides a measurement of the degree of variation for the amount of each single mRNA species after a physiological or pathological transition of cell state. It has become a general notion that variations in protein levels do not necessarily correlate with variations in total mRNA levels, for the presence of post-transcriptional controls which influence the fate of cytoplasmic mRNAs and affect their translational fitness. Nevertheless, the extent of this phenomenon and the rules, if any, governing it are still generally unknown.
To address this issue we took advantage of a number of studies performed using polysomal mRNA profiling in combination with classical total mRNA profiling in different mammalian and yeast systems. A normalization of the raw data coming from these datasets and a statistical meta-analysis aimed at maximizing uniformity in data processing have been performed. From the comparison of the results an extensive uncoupling between transcriptome and translatome variations of mRNA levels emerges, measured by a significant difference between steady state and polysomal fold changes induced by a cellular physiological or pathological transition.
It seems clear that virtually the majority of significant changes in cytoplasmic mRNA steady-state levels are subjected to a further elaboration by a post-transcriptional decision program, leading either to a widespread buffering of the cytoplasmic changes which transfers only a small fraction of them to translation, either to the creation of new changes which cannot be detected at the transcriptional level, yet capable of heavily influencing protein synthesis rates.
An explanatory model characterized by a cytoplasmic mRNA storage compartments is proposed and the involvement of P-bodies and the miRNA pathway in post-transcriptional reprogramming of gene expression has been experimentally tested in the biological model of EGF induction, in order to explain how a change in translational fitness can counteract or magnify a parallel change in citoplasmic mRNA availability. To investigate the role of specific cellular mechanism in generating uncoupling between transcriptome and translatome changes, the experimental model has been altered through silencing of three key genes involved in post-transcriptional regulation pathways: 4E-T, Xrn1 and Dicer.
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Tebaldi, Toma. "Computational and experimental detection of uncoupling between transcriptome and translatome changes of gene expression". Doctoral thesis, University of Trento, 2010. http://eprints-phd.biblio.unitn.it/300/1/PhD-Thesis.pdf.
Texto completo da fonteResumo:
Transcriptome analysis by total mRNA profiling provides a measurement of the degree of variation for the amount of each single mRNA species after a physiological or pathological transition of cell state. It has become a general notion that variations in protein levels do not necessarily correlate with variations in total mRNA levels, for the presence of post-transcriptional controls which influence the fate of cytoplasmic mRNAs and affect their translational fitness. Nevertheless, the extent of this phenomenon and the rules, if any, governing it are still generally unknown.
To address this issue we took advantage of a number of studies performed using polysomal mRNA profiling in combination with classical total mRNA profiling in different mammalian and yeast systems. A normalization of the raw data coming from these datasets and a statistical meta-analysis aimed at maximizing uniformity in data processing have been performed. From the comparison of the results an extensive uncoupling between transcriptome and translatome variations of mRNA levels emerges, measured by a significant difference between steady state and polysomal fold changes induced by a cellular physiological or pathological transition.
It seems clear that virtually the majority of significant changes in cytoplasmic mRNA steady-state levels are subjected to a further elaboration by a post-transcriptional decision program, leading either to a widespread buffering of the cytoplasmic changes which transfers only a small fraction of them to translation, either to the creation of new changes which cannot be detected at the transcriptional level, yet capable of heavily influencing protein synthesis rates.
An explanatory model characterized by a cytoplasmic mRNA storage compartments is proposed and the involvement of P-bodies and the miRNA pathway in post-transcriptional reprogramming of gene expression has been experimentally tested in the biological model of EGF induction, in order to explain how a change in translational fitness can counteract or magnify a parallel change in citoplasmic mRNA availability. To investigate the role of specific cellular mechanism in generating uncoupling between transcriptome and translatome changes, the experimental model has been altered through silencing of three key genes involved in post-transcriptional regulation pathways: 4E-T, Xrn1 and Dicer.
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Stöhr, Christina [Verfasser], e Claudia [Gutachter] Kirch. "Sequential change point procedures based on U-statistics and the detection of covariance changes in functional data / Christina Stöhr ; Gutachter: Claudia Kirch". Magdeburg : Universitätsbibliothek Otto-von-Guericke-Universität, 2019. http://d-nb.info/1219966282/34.
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Grecchi, Rosana Cristina. "Land-use and environmental changes in the Cerrados of South-Eastern Mato Grosso - Brazil". Thèse, Université de Sherbrooke, 2011. http://savoirs.usherbrooke.ca/handle/11143/2833.
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The human-induced changes of the Earth's land surfaces have been unprecedented, with outcomes often indicating degradation and loss of environmental quality. Mato Grosso State in Brazil, location of the study area, underwent extensive land-use and land-cover changes in recent decades with the rates, patterns and consequences poorly documented until now. In this context, the aim of the present research is to propose a multidisciplinary approach for quantifying historical land-use and environmental changes in the southeast part of this State, where the Cerrado biome (Brazilian savannas) has been intensively converted into agricultural lands. The methodology includes three parts: remote sensing change detection, land vulnerability mapping, and identification of key environmental indicators. Land-use/cover information was extracted from a temporal remote sensing dataset using an object-oriented classification approach, and the changes quantified employing a post-classification method. In addition, the study area was assessed for its vulnerabilities, focusing mainly on erosion risks, wetlands, and areas with limited or no suitability for crops. Finally, key environmental indicators were identified from the preceding steps and analyzed within the Organisation for Economic Co-operation and Development (OECD) Pressure-State-Response (PSR) framework. The results provided an improved mapping of the Cerrados natural vegetation conversion into crops and pastures, and indicate that the Cerrado vegetation was intensively converted and also became more fragmented in the time frame studied. Between 1985 and 2005 the area lost approximately 6491 km 2 of Cerrados (42 %). Modeling based on the Universal Soil Loss Equation indicated significant increase in erosion risk from 1985 to 2005 mainly related to the increase in crop areas and the crops' encroachment into more fragile lands.The identification of environmental indicators rendered complex environmental information more generally accessible by structuring it within the PSR framework.The indicators captured key information about land-use and environmental changes in the area, showing that agricultural expansion is the major human activity exerting pressure on natural resources at a landscape scale, and that the pattern of change included high rates of crop expansion and the use of fragile environments such as wetlands and sandy erodable soils.
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Resman, Daniel. "Using Alignment Methods to Reduce Translation of Changes in Structured Information". Thesis, Linköpings universitet, Interaktiva och kognitiva system, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-79363.
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In this thesis I present an unsupervised approach that can be made supervised in order to reducetranslation of changes in structured information, stored in XML-documents. By combining a sentenceboundary detection algorithm and a sentence alignment algorithm, a translation memory is createdfrom the old version of the information in different languages. This translation memory can then beused to translate sentences that are not changed. The structure of the XML is used to improve theperformance. Two implementations were made and evaluated in three steps: sentence boundary detection,sentence alignment and correspondence. The last step evaluates the using of the translation memoryon a new version in the source language. The second implementation was an improvement, using theresults of the evaluation of the first implementation. The evaluation was done using 100 XML-documents in English, German and Swedish. There was a significant difference between the results ofthe implementations in the first two steps. The errors were reduced by each step and in the last stepthere were only three errors by first implementation and no errors by the second implementation. The evaluation of the implementations showed that it was possible to reduce text that requires re-translation by about 80%. Similar information can and is used by the translators to achieve higherproductivity, but this thesis shows that it is possible to reduce translation even before the textsreaches the translators.
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Bengtsson, Staffan. "Detection and prediction of lane-changes: A study to infer driver intent using support vector machine". Thesis, KTH, Maskinkonstruktion (Inst.), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-99289.
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Examensarbetet som behandlas i rapporten har utförts i samarbete med Scania CV AB i Södertälje och institutionen för maskinkonstruktion på KTH i Stockholm. Scania CV AB är en ledande tillverkare av tunga lastbilar, bussar samt industri- och marinmotorer. Med allt tuffare krav på trafiksäkerhet för fordon under utveckling har en ny generationen av säkerhetssystem växt fram, Advanced Driver Assistance Systems (ADAS). De här nya systemen försöker inte bara att minska effekterna av en olycka utan även förhindra dess uppkomst. Det ställer stora krav på att systemen enbart ingriper när det behövs och inte motarbetar föraren under normal körning. Därför är det av intresse att undersöka hur en förares handlingar och intentioner avspeglas i sensorvärden för att i slutändan kunna förbättra säkerhetssystemens beslutsförmåga i olika situationer. I projektet har en studie gjorts för att se om det finns tydliga mönster i sensorvärden utöver blinkers, inför och under ett filbyte på motorväg med en lastbil. Syftet med studien var att undersöka hur den här typen av problem kan lösas, estimera vilka noggrannheter som kan uppnås samt ta reda på vilken uppsättning sensorer som behövs för att lösa problemet. Utifrån den konceptevaluering som gjordes valdes metoden support vector machine (SVM) för detta mönsterigenkänningsproblem. För att träna upp och testa algoritmen användes riktig fordonsdata insamlad under motorvägskörning. Algoritmen kunde utifrån datat med 82% noggrannhet korrekt detektera om föraren utförde en filhållnings- eller filbytesmanöver. Algoritmen kunde också snabbt detektera en filbytesmanöver innan det första hjulet korsade filmarkeringen. Med tillgängliga sensorer i testfordonet kunde inga mönster hittas i förarrelaterade sensorvärden inför ett filbyte som skulle avspegla dennes intentioner. Därför föreslogs en ny metod för att istället avgöra vad föraren borde vilja göra givet en situation genom att titta på omvärldsdata. Med hjälp av denna information kunde antalet felklassificeringar mellan filbytes- och filhållningsmanövrar minskas med 8 procentenheter.The master thesis in this report has been made in cooperation between Scania CV AB in Södertälje and the department of machine design at KTH in Stockholm. Scania CV AB is a leading manufacturer of heavy trucks, buses and coaches, and industrial- and marine engines. Increasing road safety demands for vehicles in development has resulted in a new generation of safety systems, called Advanced Driver Assistance Systems (ADAS). These new systems do not only try to mitigate the effects of a crash, they also try to prevent them from happening. To avoid that ADAS will interfere during controlled maneuvers by a driver, it is necessary to determine the intent and current actions of the driver from sensor measurements. This important information will help to improve the decision-making for safety systems of when to engage in assistive actions. In this study, the possibilities to detect and predict lane-changes from patterns in sensor measurements have been made using a truck. The main objectives were to decide how to approach this type of problem without using turn signals, estimate the accuracies that can be achieved and determine which sensors that are required to solve the task. From the concept evaluation it was determined to use the pattern recognition technique support vector machine (SVM) for the task. To train and test the algorithm real vehicle data was used, recorded from a truck during motorway driving. From this data the algorithm was able to correctly classify, with accuracy of 82%, between lane-keep and lane-change actions. The algorithm could also quickly detect a lane-change before the first wheel crossed the lane marking. With the set-up of sensors available in the test vehicle, no significant patterns were found in driver actions prior to a lane-change (the intent). Therefore, an alternative approach was suggested that aimed to determine what the driver should prefer to do in a specific situation from contextual data. This additional information helped to reduce the number of false positives with 8 percentage points when classifying between lane-change and lane-keep actions.
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Donovan, Tim. "Performance changes in wrist fracture detection and lung nodule perception following the perceptual feedback ot eye movements". Thesis, Lancaster University, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.524759.
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Goodnough, Candida Laura. "EARLY DETECTION OF PHYSIOLOGIC AND FUNCTIONAL CHANGES OF COMMON STRUCTURAL PROTEIN MUTATIONS UNDERLYING HUMAN DISEASES BY MRI". Case Western Reserve University School of Graduate Studies / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=case1428476431.
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