Tesis: "CO₂ detection"

1

Li, Yuan. "Multiuser Detection for Co-channel Interference Cancellation". 京都大学 (Kyoto University), 2000. http://hdl.handle.net/2433/180902.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

2

Hogan, Justin Allan. "Multi-spectral imaging of vegetation for COâ‚‚ leak detection". Thesis, Montana State University, 2011. http://etd.lib.montana.edu/etd/2011/hogan/HoganJ0511.pdf.

Texto completo

Resumen

Though its status as a crisis situation remains the subject of much debate [1,2] there does exist evidence that global warming is a real phenomenon [3] and that its processes are to some degree enhanced by anthropogenically introduced greenhouse gases, perhaps most notably carbon dioxide (COâ‚‚) [3]. This claim is backed by observations of increasing atmospheric COâ‚‚ concentrations from nearly 280-ppm around 1750 to 360 ppm in 1995 [4]. By the end of 2010, this number was up to approximately 390 ppm [5]. To reduce human influence on the global environment, carbon capture and sequestration (CCS) is proposed as a means of collecting COâ‚‚ generated through industrial and consumer processes and sequestering it so as not to release it into the atmosphere, thereby reducing atmospheric concentrations of the gas. Suggested methods of sequestration include direct deep-sea injection [6], soil sequestration through improved land use and management practices [7], and geological carbon sequestration in which captured carbon is injected into underground geological features. This research focuses primarily on development and testing of a leak detection technology for deployment to geological sequestration sites. A diverse technology portfolio will be required to implement safe and efficient sequestration solutions [8]. Included in this portfolio is technology capable of monitoring sequestration site integrity; detecting and signaling leakage, should it occur. Early leak detection is paramount to ensuring on-site safety and to minimize, or at least understand, potentially harmful environmental leak effects.

Los estilos APA, Harvard, Vancouver, ISO, etc.

3

Zavala, Martin. "Autonomous detection and characterization of nuclear materials using co-robots". Thesis, Georgia Institute of Technology, 2016. http://hdl.handle.net/1853/55052.

Texto completo

Resumen

Radiation safety is the biggest concern of the nuclear industry, and co-robots are a crucial component to insuring that safety. Currently, radiation mapping data is typically gathered using hand held detectors or other detection systems requiring constant human interaction. This results in direct exposure to radiation of the individual performing the survey. Co-robots can coordinate computer algorithms and human input to determine the most efficient and accurate methods of surveying these same regions while eliminating health hazards. These surveying methods can then be adapted for multiple uses in the industry including nonproliferation, maintenance, and accident response scenarios. This work describes the process by which two vehicles were modified to detect radiation with minimal human interaction. An algorithm was developed to control the robot and to navigate the area of interest while ensuring that all sources are found. A compact detector system was used to keep the vehicles as small and light as possible. The vehicles were constructed to satisfy the requirements of the detector system and relay the necessary information back to the control station. The process, which is nearly fully autonomous, can map an area of interest and proceed to characterize the radiation materials that are found using neutron and gamma spectroscopy. The vehicles were tested in several scenarios which included obstacles, multiple sources, and shielding of the sources to determine the practicality of these co-robots. The evaluation of these co-robots was critical, as the future of radiation safety lies in the research and construction of small autonomous radiation detection systems to minimize the risk that radiation exposure poses to humans.

Los estilos APA, Harvard, Vancouver, ISO, etc.

4

Chen, Yi-Ching. "Co-design of Fault-Tolerant Systems with Imperfect Fault Detection". Thesis, Linköpings universitet, Programvara och system, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-104942.

Texto completo

Resumen

In recent decades, transient faults have become a critical issue in modernelectronic devices. Therefore, many fault-tolerant techniques have been proposedto increase system reliability, such as active redundancy, which can beimplemented in both space and time dimensions. The main challenge of activeredundancy is to introduce the minimal overhead of redundancy and to schedulethe tasks. In many pervious works, perfect fault detectors are assumed to simplifythe problem. However, the induced resource and time overheads of suchfault detectors make them impractical to be implemented. In order to tacklethe problem, an alternative approach was proposed based on imperfect faultdetectors. So far, only software implementation is studied for the proposed imperfectfault detection approach. In this thesis, we take hardware-acceleration intoconsideration. Field-programmable gate array (FPGA) is used to accommodatetasks in hardware. In order to utilize the FPGA resources efficiently, themapping and the selection of fault detectors for each task replica have to be carefullydecided. In this work, we present two optimization approaches consideringtwo FPGA technologies, namely, statically reconfigurable FPGA and dynamicallyreconfigurable FPGA respectively. Both approaches are evaluated andcompared with the proposed software-only approach by extensive experiments.

Los estilos APA, Harvard, Vancouver, ISO, etc.

5

Sahin, Mustafa. "Baseband receiver algorithms for 4G co-channel femtocells". [Tampa, Fla] : University of South Florida, 2009. http://purl.fcla.edu/usf/dc/et/SFE0003283.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

6

Rosso, Kevin M. "Detection limits of CO₂in fluid inclusions using microthermometry and Raman spectroscopy and the spectroscopic characterization of CO₂". Thesis, Virginia Tech, 1994. http://hdl.handle.net/10919/40534.

Texto completo

Resumen

In many geologic environments, dominant1y aqueous solutions contain low concentrations of CO2. At ambient temperature, in fluid inclusions which trap these solutions, the typical phase assemblage consists of a CO2-rich vapor (where Pco2 = PintemaI) and an aqueous phase containing dissolved salts and CO2. In this study, the CO2 minimum detection limits (MDLs) using microthermometry and laser Raman spectroscopy are established in terms of Pco2 using synthetic H20-C02 inclusions. The purpose of the microthermometric experiments was to examine the diagnostic CO2 phase changes and determine the quantity of CO2 necessary to result in observable solid CO2 melting. The results of these experiments show that an observable solid CO2 melting event requires Pco2 ~ 45 bar at 25°C. The Raman spectroscopic detection limits were investigated using a multichannel Raman spectrometer. Because the Raman spectroscopic MDLs are a function of counts, the CO2 MDLs were determined by collecting signal-to-noise ratios for both the upper and lower V1-2V2 bands as a function of CO2 pressure (5-60 bars) and over a range of integration times and incident laser power to predict the optimal instrument settings. The resulting CO2 MDLs are on the 'order of 1 bar for our instrument. The band splitting of the v 1-2v2 diad as a function of CO2 pressure was measured up to 500 bar at ambient temperature. The CO2 pressures were converted to pc02 and the results are given in terms of the frequency separation between the upper and lower bands. These results are compared to those of previous studies. An analysis of the estimated errors indicates that the technique can be used to determine CO2 densities in fluid inclusions containing a homogenous, free CO2 phase to a precision of approximately ± 0.02 g/cm3• The temperature dependence of the intensity ratio of the hot bands to the v1-2v2 diad was measured from 270 to 315 K. The close agreement between the calculated and observed results indicate that laser induced sample heating is not significant. The intensity ratio can be used to estimate the CO2 temperature and, combined with the Raman density determination, allows calculation of the CO2 pressure.
Master of Science

Los estilos APA, Harvard, Vancouver, ISO, etc.

7

Rosso, Kevin Michael. "Detection limits of CO₂ in fluid inclusions using microthermometry and Raman spectroscopy and the spectroscopic characterization of CO₂ /". This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-01052009-091123/.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

8

Raisi, Elaheh. "Weakly Supervised Machine Learning for Cyberbullying Detection". Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/89100.

Texto completo

Resumen

The advent of social media has revolutionized human communication, significantly improving individuals' lives. It makes people closer to each other, provides access to enormous real-time information, and eases marketing and business. Despite its uncountable benefits, however, we must consider some of its negative implications such as online harassment and cyberbullying. Cyberbullying is becoming a serious, large-scale problem damaging people's online lives. This phenomenon is creating a need for automated, data-driven techniques for analyzing and detecting such behaviors. In this research, we aim to address the computational challenges associated with harassment-based cyberbullying detection in social media by developing machine-learning framework that only requires weak supervision. We propose a general framework that trains an ensemble of two learners in which each learner looks at the problem from a different perspective. One learner identifies bullying incidents by examining the language content in the message; another learner considers the social structure to discover bullying. Each learner is using different body of information, and the individual learner co-train one another to come to an agreement about the bullying concept. The models estimate whether each social interaction is bullying by optimizing an objective function that maximizes the consistency between these detectors. We first developed a model we referred to as participant-vocabulary consistency, which is an ensemble of two linear language-based and user-based models. The model is trained by providing a set of seed key-phrases that are indicative of bullying language. The results were promising, demonstrating its effectiveness and usefulness in recovering known bullying words, recognizing new bullying words, and discovering users involved in cyberbullying. We have extended this co-trained ensemble approach with two complementary goals: (1) using nonlinear embeddings as model families, (2) building a fair language-based detector. For the first goal, we incorporated the efficacy of distributed representations of words and nodes such as deep, nonlinear models. We represent words and users as low-dimensional vectors of real numbers as the input to language-based and user-based classifiers, respectively. The models are trained by optimizing an objective function that balances a co-training loss with a weak-supervision loss. Our experiments on Twitter, Ask.fm, and Instagram data show that deep ensembles outperform non-deep methods for weakly supervised harassment detection. For the second goal, we geared this research toward a very important topic in any online automated harassment detection: fairness against particular targeted groups including race, gender, religion, and sexual orientations. Our goal is to decrease the sensitivity of models to language describing particular social groups. We encourage the learning algorithm to avoid discrimination in the predictions by adding an unfairness penalty term to the objective function. We quantitatively and qualitatively evaluate the effectiveness of our proposed general framework on synthetic data and data from Twitter using post-hoc, crowdsourced annotation. In summary, this dissertation introduces a weakly supervised machine learning framework for harassment-based cyberbullying detection using both messages and user roles in social media.
Doctor of Philosophy
Social media has become an inevitable part of individuals social and business lives. Its benefits, however, come with various negative consequences such as online harassment, cyberbullying, hate speech, and online trolling especially among the younger population. According to the American Academy of Child and Adolescent Psychiatry,1 victims of bullying can suffer interference to social and emotional development and even be drawn to extreme behavior such as attempted suicide. Any widespread bullying enabled by technology represents a serious social health threat. In this research, we develop automated, data-driven methods for harassment-based cyberbullying detection. The availability of tools such as these can enable technologies that reduce the harm and toxicity created by these detrimental behaviors. Our general framework is based on consistency of two detectors that co-train one another. One learner identifies bullying incidents by examining the language content in the message; another learner considers social structure to discover bullying. When designing the general framework, we address three tasks: First, we use machine learning with weak supervision, which significantly alleviates the need for human experts to perform tedious data annotation. Second, we incorporate the efficacy of distributed representations of words and nodes such as deep, nonlinear models in the framework to improve the predictive power of models. Finally, we decrease the sensitivity of the framework to language describing particular social groups including race, gender, religion, and sexual orientation. This research represents important steps toward improving technological capability for automatic cyberbullying detection.

Los estilos APA, Harvard, Vancouver, ISO, etc.

9

Haddad, Lema. "New approaches to co-segregation studies and mutation detection in familial hypercholesterolaemia". Thesis, University College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286402.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

10

Doblas, Jiménez David. "Exploration and detection of ultra-traces of explosives by chip calorimetry". Thesis, Strasbourg, 2015. http://www.theses.fr/2015STRAE017/document.

Texto completo

Resumen

La détection de très faibles quantités de Matériaux Energétiques (ME) est un challenge important dans la lutte contre le terrorisme. En plus des méthodes de détection des ME par affinité chimique, il est aussi intéressant d'utiliser les variations enthalpiques dues à la décomposition des ME pour les détecter par analyse thermique. Cependant, la sensibilité des methodes classiques est insuffisante pour la détection des particules dont la masse se situe dans le domaine des nanogrammes. En revanche, la nanocalorimétrie est parfaitement adaptée pour la caractérisation de très faibles quantités d'échantillons et est de ce fait adaptée aux exigences de la détection. Afin d'explorer la possibilité de détecter et d'identifier des micro-particules solides de ME à l'aide de l'analyse thermique, nous avons élaboré des protocols optimisés pour la détection et l'identification de particules pures unitaires de quelques nanogrammes de ME ainsi que leurs mélanges. Les résultats montrent que la limite de détection se situe environ à quelques centaines de picrogrammes. Les expériences ont été complétées par de l'analyse structurale in-situ en utilisant sa combinaison avec de la DRX par faisceau nanofocus synchrotron
Being able to sense the minuscule amounts of energetic materials is crucial in the context of the fight against terrorism. Apart from the methods of detection of EM, which are specific to the chemical structure, one could use the enthalpy variations of the EM decomposition process for their detection by means of thermal analysis. However, the sensitivity of classical methods would be still insufficient to sense particles in the nanogram range. By contrast, the recently developed technique of chip calorimetry is perfectly suited for characterizing small amounts of samples and is therefore fully adequate for this task.In order to explore the possibilities of detection and identification of solid micro-particles of EM with thermal analysis, we discuss on the protocols optimized for the detection and identification of nanogram-size particles of EM and its mixtures with the chip calorimeter accessory. The results obtained on pure EM and its mixtures show that the detection threshold can be put at approximately several hundred picograms. The experiments were completed by the in-situ structural analysis using a combination with nanofocus synchrotron XRD

Los estilos APA, Harvard, Vancouver, ISO, etc.

11

Sánchez, Reátegui Rafael. "Porphyrins based detection of NH3 and CO, using field effect grid gate devices". Thesis, Linköping University, Applied Physics, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-56245.

Texto completo

Resumen

Porphyrins consist of twenty-atom rings containing four nitrogen atoms and can be used as sensor to detect odours and gases.

This thesis investigates whether or not porphyrins can be used as functional materials on grid gate devices. Drops of PVC embedded porphyrins were deposited on the surface of a grid gate which is a Metal Oxide Semiconductor (MOS) capacitor. In order to detect the gas sensing properties of the porphyrins a light addressable method called Scanning Light Pulse Technique (SLPT) has been used.

Drops of porphyrins were deposited with a stretched capillary tube (1 mm diameter).

The MOS capacitor has been exposed to nitrogen atmosphere as reference environment, while the target gases were carbon monoxide (100 ppm) and ammonia (500 ppm).

The result from the eight porphyrins is that one of them [Pt(II) TPP] has a response for both gases, ammonia induces a change in both the work function and surface resistance, while the carbon monoxide induces only a change in the surface resistance.

Los estilos APA, Harvard, Vancouver, ISO, etc.

12

Griffin, Ryan D. "MULTISPECTRAL CO-OCCURRENCE ANALYSIS FOR AUTOMATED TUMOR DETECTION IN METASTATIC MEDULLARY THYROID CARCINOMA". The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1285101309.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

13

Khelladi, Djamel Eddine. "Co-évolution des contraintes OCL suite à l'évolution des métamodèles". Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066335.

Texto completo

Resumen

Le paradigme ingénierie-dirigée par les modèles (Model-Driven Engine MDE) encourage l'utilisation des modèles et des langages de modélisation durant le processus de développement afin d'améliorer la qualité et la productivité. Les métamodèles sont des composants essentiels de tout écosystème de langage de modélisation afin de définir les aspects structurels d'un domaine d'activité. En complément, l'Object Constraint Language (OCL) est utilisé pour spécifier en détail les aspects du domaine d'activité, par exemple plus de 750 contraintes viennent avec le métamodèle UML. Malheureusement, les métamodèles sont constamment soumis aux changements et évolution qui affectent les contraintes OCL définies qui peuvent avoir besoin d'être co-évolué en conséquence. Bien que plusieurs approches aient été proposées pour détecter les changements de métamodèle lors de l'évolution et de les utiliser par la suite pour co-évoluer les contraintes OCL. Ils ne peuvent toujours pas détecter une trace d'évolution complète et correcte du métamodèle tout en proposant une résolution unique par contrainte OCL impactée alors que des résolutions multiples et alternatives peuvent être appliquées. Dans cette thèse, nous proposons une approche pour détecter les changements de métamodèle lors d'une évolution, tout en visant la complétude et une haute précision. Notre approche de détection considère les changements atomiques et complexes au cours de l'évolution. Par ailleurs, nous proposons une approche dédiée à la co-évolution des contraintes OCL tout en tenant compte des résolutions alternatives et à veiller à ce que seules les résolutions appropriées sont proposées à l'utilisateur pour chaque contrainte OCL impactée. Notre validation montre d'une part que le rappel (recall) de 100% est toujours atteint dans nos cas d'études avec une précision moyenne de 70,75%, qui est encore améliorée par nos heuristiques jusqu'à 91% et 100% dans certains cas. D'autre part, une moyenne de 92% et 93% respectivement syntaxiquement et sémantiquement correcte de co-évolution d'OCL sont atteintes dans nos études de cas. Les deux approches sont implémentées sous forme de plugins pour l'IDE Eclipse, un environnement de développement très répandu pour les développeurs de logiciels. Les plugins sont testés par nos partenaires industriels du projet ANR MoNoGe. Cette thèse a abouti à huit articles publiés et trois autres articles qui sont en cours de soumission / phase de révision
Model-Driven Engineering (MDE) paradigm promotes the use of models and modeling languages during the development process aiming at a better quality and productivity. Metamodels are core components of any modeling language ecosystem to define structural aspects of a business domain. As a complement, the Object Constraint Language (OCL) is used to specify detailed aspects of the business domain, e.g. more than 750 constraints come with the UML metamodel. Unfortunately, metamodels are subject to a constant change and evolution which impacts the defined OCL constraints that may need to be co-evolved as well. Although several approaches have been proposed to detect metamodel changes during evolution and to use them to co-evolve OCL constraints. They still cannot detect a complete and a correct evolution trace of the metamodel while proposing a unique resolution per impacted OCL constraint whereas multiple and alternative ones can be applied. In this thesis, we propose an approach to detect metamodel changes during evolution while aiming at completeness and high precision. Our detection approach considers both atomic and complex changes during evolution. In addition, we propose a dedicated approach to co-evolve OCL constraints while considering alternative resolutions and ensuring that only the appropriate resolutions are proposed to the user for each impacted OCL constraint. Our validation shows on the one hand that a 100% recall is always reached in our case studies with an average precision of 70.75%, which is improved by our heuristics up to 91% and 100% in some cases. On the other hand, an average of 92% and 93% of respectively syntactically and semantically correct OCL co-evolution are reached in our case studies. Both approaches are implemented as plugins for the Eclipse IDE a wide-spread development environment for software developers. The plugins are under test by our industrial partners in the ANR MoNoGe project. This PhD resulted in eight published papers and three other papers are currently under submission/revision phase

Los estilos APA, Harvard, Vancouver, ISO, etc.

14

Matra, L., M. A. MacGregor, P. Kalas, M. C. Wyatt, G. M. Kennedy, D. J. Wilner, G. Duchene et al. "Detection of Exocometary CO within the 440Myr Old Fomalhaut Belt: A Similar CO+ CO2 Ice Abundance in Exocomets and Solar System Comets". IOP PUBLISHING LTD, 2017. http://hdl.handle.net/10150/624435.

Texto completo

Resumen

Recent Atacama Large Millimeter/submillimeter Array observations present mounting evidence for the presence of exocometary gas released within Kuiper Belt analogs around nearby main-sequence stars. This represents a unique opportunity to study their ice reservoir at the younger ages when volatile delivery to planets is most likely to occur. We here present the detection of CO J=2-1 emission colocated with dust emission from the cometary belt in the 440 Myr old Fomalhaut system. Through spectrospatial filtering, we achieve a 5.4s detection and determine that the ring's sky-projected rotation axis matches that of the star. The CO mass derived (0.65-42) x10(-7) M-circle plus is the lowest of any circumstellar disk detected to date and must be of exocometary origin. Using a steady-state model, we estimate the CO+ CO2 mass fraction of exocomets around Fomalhaut to be between 4.6% and 76%, consistent with solar system comets and the two other belts known to host exocometary gas. This is the first indication of a similarity in cometary compositions across planetary systems that may be linked to their formation scenario and is consistent with direct interstellar medium inheritance. In addition, we find tentative evidence that(49 +/- 27)% of the detected flux originates from a region near the eccentric belt's pericenter. If confirmed, the latter may be explained through a recent impact event or CO pericenter glow due to exocometary release within a steady-state collisional cascade. In the latter scenario, we show how the azimuthal dependence of the CO release rate leads to asymmetries in gas observations of eccentric exocometary belts.

Los estilos APA, Harvard, Vancouver, ISO, etc.

15

Chureesampant, Kamolratn. "AUTOMATIC CO-REGISTRATION OF SAR IMAGES FOR LAND COVER CLASSIFICATION AND CHANGE DETECTION APPLICATIONS". 京都大学 (Kyoto University), 2012. http://hdl.handle.net/2433/165029.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

16

Cannizzaro, Vincenzo. "Determination of Co and Mn in marine waters using flow injection with chemiluminescence detection". Thesis, University of Plymouth, 2001. http://hdl.handle.net/10026.1/2815.

Texto completo

Resumen

This thesis describes the design, optimisation and shipboard deployment of a flow injection - chemiluminescence (FI-CL) technique for the determination of cobalt (Co) and manganese (Mn) in seawater. Chapter One presents an overview of the marine environment and the biogeochemistry of Co and Mn. Current analytical methods for the determination of Co and Mn in natural waters are also reviewed. Chapter Two reports reagent clean-up techniques and the synthesis of an 8- hydroxyquinoline resin used for in-line matrix elimination and preconcentration. The resin is also characterised in terms of its chelating ability for the transition metals and the earth alkaline metals. A new column design is also presented. Chapter Three details the optimisation of a FI-CL system for the determination of Co in seawater. The method described is based on a new chemistry whereby CL emission is produced by oxidation of pyrogallol with hydrogen peroxide in alkaline medium in the presence of CTAB and MeOH. Chapter Four details the optimisation of a FI-CL system for the determination of Mn in seawater. The method chosen involved the luminous oxidation of 7,7,8,8- tetracyanoquinodimethane (TCNQ) by dissolved O2. The weak chemiluminescence of TCNQ is effectively sensitised by Eosin Y in DDAB. In Chapter Five the application of the FI-CL method to the shipboard determination of Co in the western North Sea is presented together with results from the determination of Mn in the western North Sea samples after the cruise. Co and Mn profiles are shown for all the geographical area investigated. The data from an entire tidal cycle of the Humber are also shown. Chapter Six presents the results of an intercomparison exercise. Co and Mn have been measured with different analytical techniques: FI-CL, AdCSV, and ICP-MS. The method developed for Co has been adapted in order to measure the concentration of Co in samples from the Scheldt estuary with an integrated luminometer at the Universite Libre de Bruxelles.

Los estilos APA, Harvard, Vancouver, ISO, etc.

17

Marx, Anja. "Utilization of an under-actuated robot for co-manipulated guidance for breast cancer detection". Paris 6, 2013. http://www.theses.fr/2013PA066645.

Texto completo

Resumen

This research is situated in the emerging field of co-manipulation systems where robot and user perform a task in a collaborative way. It is applied to the medical context of breast cancer diagnosis where the standard procedure today is the succession of an initial mammography (MX) examination and a supplementary Ultrasound (U/S) scan. The surgeon's task is to localize the target lesion defined in the MX images using 2D U/S. One difficulty of this procedure results from the fact that breast geometry changes for both examinations due to different patient's positions. A second difficulty is the mental correlation of two different image types. MX provides a 3D view, whereas U/S only displays a cross section of the object. The proposed system facilitates this combined examination by keeping the breast geometry and by adding a U/S probe guidance robot to the mammography system. A 6DOF parallel co-manipulation system is set up where the robot and user simultaneously impact on the probe. A robot control is developed for active task assistance. Its relevance is evaluated in vitro and showed a significant increase in examination quality when using robot guidance compared to the standard examination. The novel aspect treated in this thesis is under-actuated co-manipulation, where the robot has less DOF than the task requires. The initial idea is that, although the robot cannot perform the task autonomously, it may bring partial assistance that still improves the movement. This involves adaptation in terms of robot control and system architecture. It is shown in this work that, in case of under-actuation, simple reduction from a fully-actuated robot control to the remaining robot DOF is not sufficient to guarantee system stability. System architecture needs to be adapted accordingly. To quantify examination improvements when using under-actuated guidance, different under-actuated robot controls have been compared. The main outcome of this thesis is that even an under-actuated robot system increases task precision significantly while decreasing execution time
Cette thèse s'inscrit dans le domaine de la co-manipulation. Dans les systèmes co-manipulés, le robot et l'utilisateur accomplissent une tâche d'une manière collaborative. Il existe trois types de co-manipulation. La co-manipulation orthodique est notamment utilisée pour la rééducation des membres où le robot et l'humain sont liés dans plus qu'un point. Dans un système de co-manipulation sérielle, le robot se situe entre l'utilisateur et l'outil qui est contrôlé par le robot. Cette thèse se situe dans le contexte de la co-manipulation parallèle. Dans cette classe, le robot et l'humain manient l'outil directement et en même temps. Ce principe de co-manipulation parallèle a été appliqué dans un contexte médical, plus précisément au diagnostic du cancer du sein. Aujourd'hui, la procédure standard pour ces examens est basée sur des imageries consécutives du sein utilisant d'abord la mammographie (MX) et puis l'échographie (U/S). Cette image U/S en 2D représente une coupe de l'objet. Les images MX peuvent être superposées comme des ``couches d'images'' afin d'obtenir un modèle 3D du sein. Ce fait relève la difficulté principale de cet examen d'imagerie. Pendant l'examen échographique, le radiologue doit localiser une zone d'intérêt précédemment définie dans les images MX en se servant seulement de la coupe 2D du sein. Il est à noter que la patiente doit adopter des positions différentes pour chaque examen. Elle est debout avec un sein comprimé entre une pelote de compression et le détecteur du système pour une mammographie. Cependant pour l'échographie, la patiente est couchée sur le dos. Cette différence de posture de la patiente représentent la deuxième difficulté de l'examen du sein. Le système proposé dans cette thèse facilite la procédure d'examens combinés en gardant la même géométrie du sein. De plus, un bras robotisé guidant la sonde échographique est rajouté au système de mammographie existant. Ainsi, un système de co-manipulation parallèle, qui permet la manipulation simultanée de la sonde échographique par le robot et l'utilisateur, a été mis en place. Jusqu'à présent, plusieurs systèmes de co-manipulation parallèle ont été présentés dans le domaine médical. Tous ont comme point commun d'avoir au moins autant de degrés de liberté (DDL) actionnés que la tâche à effectuer. Ceci implique un coût élevé du système entier ainsi qu'un possible encombrement causé par la structure robotisée. L'intérêt de ce travail est d'analyser des solutions alternatives permettant une amélioration significative du geste médical tout en réduisant l'encombrement dût au robot ainsi que son coût. D'un point de vue robotique, l'innovation consiste à proposer des guidages d'outils d'une manière sous-actionnée. Le robot ne fourni donc pas d'assistance couvrant tous les DDL de la tâche mais une aide partielle ayant comme but d'améliorer les gestes du radiologue. Des mesures comme la distance à la cible et le temps d’examen ont été choisies comme indicateur de performance. Les résultats d'une première série de tests ont démontré qu'un guidage complètement actionné améliore les performances des utilisateurs comparé à aucun guidage. Pour qualifier des améliorations des examens avec un guidage sous-actionné, différents modes de sous-actionnements ont été testés. Les résultats montrent que même un guidage partiel augmente d'une manière significative la qualité des examens échographiques. La précision a pu être augmentée en diminuant la durée de l'intervention. La réduction des DDL nécessite néanmoins une adaptation de la commande du robot à l'architecture du système. Il a été observé dans cette thèse qu'une simple réduction des DDL peut induire des instabilités reliées à l'architecture du système. Elle doit donc être adaptée en fonction du sous-actionnement de chaque cas

Los estilos APA, Harvard, Vancouver, ISO, etc.

18

Alhamwi, Ali. "Co-design hardware/software of real time vision system on FPGA for obstacle detection". Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30342/document.

Texto completo

Resumen

La détection, localisation d'obstacles et la reconstruction de carte d'occupation 2D sont des fonctions de base pour un robot navigant dans un environnement intérieure lorsque l'intervention avec les objets se fait dans un environnement encombré. Les solutions fondées sur la vision artificielle et couramment utilisées comme SLAM (simultaneous localization and mapping) ou le flux optique ont tendance a être des calculs intensifs. Ces solutions nécessitent des ressources de calcul puissantes pour répondre à faible vitesse en temps réel aux contraintes. Nous présentons une architecture matérielle pour la détection, localisation d'obstacles et la reconstruction de cartes d'occupation 2D en temps réel. Le système proposé est réalisé en utilisant une architecture de vision sur FPGA (field programmable gates array) et des capteurs d'odométrie pour la détection, localisation des obstacles et la cartographie. De la fusion de ces deux sources d'information complémentaires résulte un modèle amelioré de l'environnement autour des robots. L'architecture proposé est un système à faible coût avec un temps de calcul réduit, un débit d'images élevé, et une faible consommation d'énergie
Obstacle detection, localization and occupancy map reconstruction are essential abilities for a mobile robot to navigate in an environment. Solutions based on passive monocular vision such as simultaneous localization and mapping (SLAM) or optical flow (OF) require intensive computation. Systems based on these methods often rely on over-sized computation resources to meet real-time constraints. Inverse perspective mapping allows for obstacles detection at a low computational cost under the hypothesis of a flat ground observed during motion. It is thus possible to build an occupancy grid map by integrating obstacle detection over the course of the sensor. In this work we propose hardware/software system for obstacle detection, localization and 2D occupancy map reconstruction in real-time. The proposed system uses a FPGA-based design for vision and proprioceptive sensors for localization. Fusing this information allows for the construction of a simple environment model of the sensor surrounding. The resulting architecture is a low-cost, low-latency, high-throughput and low-power system

Los estilos APA, Harvard, Vancouver, ISO, etc.

19

Patel, Mehul Bhupendra. "Image Analysis Algorithms for Ovarian Cancer Detection Using Confocal Microendoscopy". Thesis, The University of Arizona, 2008. http://hdl.handle.net/10150/193311.

Texto completo

Resumen

Confocal microendoscopy is a promising new diagnostic imaging technique that is minimally invasive and provides in-vivo cellular-level images of tissue. In this study, we developed various image analysis techniques for ovarian cancer detection using the confocal microendoscope system. Firstly, we developed a technique for automatic classification of images based on focus, to prune out the out-of-focus images from the ovarian dataset. Secondly, we modified the texture analysis technique developed earlier to improve the stability of the textural features. The modified technique gives stable features and more consistent performance for ovarian cancer detection. Although confocal microendoscopy provides cellular-level resolution, it is limited by a small field of view. We present a fast technique for stitching the individual frames of the tissue to form a large mosaic. Such a mosaic will aid the physician in diagnosis, and also makes quantitative and statistical analysis possible on a larger field of view.

Los estilos APA, Harvard, Vancouver, ISO, etc.

20

Schöldström, Jens. "Thermal Radiation from Co-evaporated Cu(In,Ga)Se2 : End point detection and process control". Doctoral thesis, Uppsala universitet, Fasta tillståndets elektronik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-170437.

Texto completo

Resumen

The use of solar cells for energy production has indeed a bright future. Reduction of cost for fabrication along with increased efficiency are key features for a market boom, both achieved as a result of increased knowledge of the technology. Especially the thin film solar cell technology with absorbers made of Cu(In,Ga)Se2 (CIGS) is promising since it has proven high power conversion efficiency in combination with a true potential for low cost fabrication. In this thesis different recipes for fabrication of the Cu(In,Ga)Se2 absorber layer have been studied. The deposition technique used has been co-evaporation from elemental sources. For all depositions the substrate has been heated to a constant temperature of 500 ºC in order for the growing absorber to form a chalcopyrite phase, necessary for the photovoltaic functionality. The selenium has been evaporated such to always be in excess during depositions whereas the metal ratio Cu/(In+Ga) has been varied according to different recipes but always to be less than one at the end of the process. In the work emphasis has been on the radiative properties of the CIGS film during growth. The substrate heater has been temperature controlled to maintain the constant set temperature of the substrate, regardless of varying emitted power caused by changing surface emissivity. Depending on the growth conditions the emissivity of the growing film is changing, leading to a readable variation in the electrical power to the substrate heater. Since the thermal radiation from the substrate during growth has been of central focus, this has been studied in detail. For this reason the substrate has been treated as an optical stack composed of glass/Mo/Cu(In,Ga)Se2/CuxSe which determine the thermally radiated power by its emissivity. An optical model has been adopted to simulate the emissivity of the stack. In order to use the model, the optical constants for Cu(In,Ga)Se2 and CuxSe have been derived for the wavelength interval 2 μm to 20 μm. The simulation of the emissivity of the stack during CIGS growth agreed well with what has been seen for actual growth. Features of the OP-signal could hereby be explained as a result of film thickness of Cu(In,Ga)Se2 and CuxSe respectively. This is an important knowledge for an efficient fabrication in large scale.

Los estilos APA, Harvard, Vancouver, ISO, etc.

21

Khelladi, Djamel Eddine. "Co-évolution des contraintes OCL suite à l'évolution des métamodèles". Electronic Thesis or Diss., Paris 6, 2016. http://www.theses.fr/2016PA066335.

Texto completo

Resumen

Le paradigme ingénierie-dirigée par les modèles (Model-Driven Engine MDE) encourage l'utilisation des modèles et des langages de modélisation durant le processus de développement afin d'améliorer la qualité et la productivité. Les métamodèles sont des composants essentiels de tout écosystème de langage de modélisation afin de définir les aspects structurels d'un domaine d'activité. En complément, l'Object Constraint Language (OCL) est utilisé pour spécifier en détail les aspects du domaine d'activité, par exemple plus de 750 contraintes viennent avec le métamodèle UML. Malheureusement, les métamodèles sont constamment soumis aux changements et évolution qui affectent les contraintes OCL définies qui peuvent avoir besoin d'être co-évolué en conséquence. Bien que plusieurs approches aient été proposées pour détecter les changements de métamodèle lors de l'évolution et de les utiliser par la suite pour co-évoluer les contraintes OCL. Ils ne peuvent toujours pas détecter une trace d'évolution complète et correcte du métamodèle tout en proposant une résolution unique par contrainte OCL impactée alors que des résolutions multiples et alternatives peuvent être appliquées. Dans cette thèse, nous proposons une approche pour détecter les changements de métamodèle lors d'une évolution, tout en visant la complétude et une haute précision. Notre approche de détection considère les changements atomiques et complexes au cours de l'évolution. Par ailleurs, nous proposons une approche dédiée à la co-évolution des contraintes OCL tout en tenant compte des résolutions alternatives et à veiller à ce que seules les résolutions appropriées sont proposées à l'utilisateur pour chaque contrainte OCL impactée. Notre validation montre d'une part que le rappel (recall) de 100% est toujours atteint dans nos cas d'études avec une précision moyenne de 70,75%, qui est encore améliorée par nos heuristiques jusqu'à 91% et 100% dans certains cas. D'autre part, une moyenne de 92% et 93% respectivement syntaxiquement et sémantiquement correcte de co-évolution d'OCL sont atteintes dans nos études de cas. Les deux approches sont implémentées sous forme de plugins pour l'IDE Eclipse, un environnement de développement très répandu pour les développeurs de logiciels. Les plugins sont testés par nos partenaires industriels du projet ANR MoNoGe. Cette thèse a abouti à huit articles publiés et trois autres articles qui sont en cours de soumission / phase de révision
Model-Driven Engineering (MDE) paradigm promotes the use of models and modeling languages during the development process aiming at a better quality and productivity. Metamodels are core components of any modeling language ecosystem to define structural aspects of a business domain. As a complement, the Object Constraint Language (OCL) is used to specify detailed aspects of the business domain, e.g. more than 750 constraints come with the UML metamodel. Unfortunately, metamodels are subject to a constant change and evolution which impacts the defined OCL constraints that may need to be co-evolved as well. Although several approaches have been proposed to detect metamodel changes during evolution and to use them to co-evolve OCL constraints. They still cannot detect a complete and a correct evolution trace of the metamodel while proposing a unique resolution per impacted OCL constraint whereas multiple and alternative ones can be applied. In this thesis, we propose an approach to detect metamodel changes during evolution while aiming at completeness and high precision. Our detection approach considers both atomic and complex changes during evolution. In addition, we propose a dedicated approach to co-evolve OCL constraints while considering alternative resolutions and ensuring that only the appropriate resolutions are proposed to the user for each impacted OCL constraint. Our validation shows on the one hand that a 100% recall is always reached in our case studies with an average precision of 70.75%, which is improved by our heuristics up to 91% and 100% in some cases. On the other hand, an average of 92% and 93% of respectively syntactically and semantically correct OCL co-evolution are reached in our case studies. Both approaches are implemented as plugins for the Eclipse IDE a wide-spread development environment for software developers. The plugins are under test by our industrial partners in the ANR MoNoGe project. This PhD resulted in eight published papers and three other papers are currently under submission/revision phase

Los estilos APA, Harvard, Vancouver, ISO, etc.

22

RADHAKRISHNAN, RAJESH. "A STUDY OF THE RECEPTION OF CO-DIRECTIONAL USERS USING BEAMFORMING, SWITCHED BEAMS AND MULTIUSER DETECTION STATEGIES". University of Cincinnati / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1037812447.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

23

Baumeyer, Julien. "Co-manipulation sûre d’un robot de protonthérapie". Thesis, Orléans, 2017. http://www.theses.fr/2017ORLE2015/document.

Texto completo

Resumen

Cette thèse se place dans un contexte médical de traitements oncologiques, plus particulièrement en protonthérapie robotisée. L’objectif de cette thèse, réalisée sous contrat Cifre avec la société LEONI CIA Cable Systems, est le développement d’une commande en co-manipulation sûre dédiée à un robot médical sériel. Cette commande doit permettre à un opérateur de manipuler intuitivement et précisément un robot de grande inertie positionneur de patients. Les contributions portent sur deux axes, d’une part le développement et l’implémentation sur le robot Orion de l’entreprise LEONI CIA Cable Systems d’une commande en admittance ainsi que la comparaison de trois dispositifs haptiques, et d’autre part le développement d’un mécanisme de détection de collisions proprioceptif permettant l’amélioration de la sécurité de fonctionnement. À partir d’une revue de la littérature concernant les commandes compliantes, nous avons développé et implémenté une commande en admittance dédiée au robot Orion en tenant compte de la discrétisation de la commande par le contrôleur spécifique de ce robot. Une expérience de comparaison sur le robot nous a permis d’identifier le dispositif haptique le mieux adapté au cas clinique considéré. Après une étude de l’état de l’art des mécanismes de détection de collisions, une approche fréquentielle de la modélisation du couple axial prenant en compte les rapports de réduction élevés et de technologie différente du robot a été proposée. Elle permet de modéliser finement le couple théoriquement fourni par les moteurs ; celui-ci est ensuite comparé avec la mesure du couple réellement produit afin de détecter une éventuelle collision
This PhD thesis takes place in a medical context of oncological treatments, more particularly in robotised protontherapy. The objective of this thesis, carried out under a CIFRE contract with LEONI CIA Cable Systems, is the development of a safe comanipulation control dedicated to a serial medical robot. This control law should allow an operator to intuitively and precisely manipulate a robot of high inertia for accurate patients positioning. The contributions of this thesis focus on the development and implementation of an admittance-controlled Orion robot from LEONI CIA Cable Systems and the comparison of three haptic devices, and on the other hand, on the development of a proprioceptive collision detection mechanism allowing the improvement of operational safety. Based on a review of the literature on compliant controls, we have developed and implemented an admittance control approach dedicated to the Orion robot, taking into account the discretization of the control by the controller specific to this robot. A comparison experiment on the robot allowed us to identify the haptic device best suited to the clinical case considered. Based on a state of the art of collision detection mechanisms analysis, a frequency approach of the modeling of the axial torque taking into account the high reduction ratios and different robot technology has been proposed. It allows us to finely model the torque theoretically provided by the motors ; The latter is then compared with the measurement of the torque actually produced in order to detect a possible collision

Los estilos APA, Harvard, Vancouver, ISO, etc.

24

Yang, Ya-Mei. "Statistical Methods for Integrating Multiple CO₂ Leak Detection Techniques at Geologic Sequestration Sites". Research Showcase @ CMU, 2011. http://repository.cmu.edu/dissertations/25.

Texto completo

Resumen

Near-surface monitoring is an essential component of leak detection at geologic CO2 sequestration sites. With different strengths and weaknesses for every monitoring technique, an integrated system of leak detection monitoring methods is needed to combine the information provided by different techniques deployed at a site, and no current methodology exists that allows one to quantitatively combine the results from different monitoring technologies and optimize their design. More importantly, an evaluation that is able to provide the assessment of possible size of a leak based on the multiple monitoring results further helps the managers and decision makers to know whether the unexpected leakage event is smaller than the required annual seepage rate for effective long-term storage. The proposed methodology for this application is the development and use of a Bayesian belief network (BBN) for combining measurements from multiple leak detection technologies at a site. The Bayesian Belief Network for CO2 leak detection is built through an integrated application of a subsurface model for CO2 migration under different site conditions; field-generated background information on several monitoring techniques; and statistical methods for processing the field background data to infer the leak detection threshold for each monitoring technique and the conditional probability values used in the BBN. Several statistical methods are applied to estimate the detection thresholds and the conditional probabilities, including (1) Bayesian methods for characterizing the natural background (pre-injection) conditions of the techniques for leak detection, (2) the combination of the characterization of the background monitoring results and the simulated CO2 migration for estimating the probability of leak detection for each monitoring technique given the size of leak, (3) a probabilistic design of CO2 leak detection for estimating the detection probability of a monitoring technique under different site conditions and monitoring densities, (4) a Bayesian belief network for combining measurements from multiple leak detection technologies at an actual test site, with the site conditions and the probability distributions of leak detection and leakage rate estimated for the site. The BBN model is built for the Zero Emissions Research and Technology (ZERT) test site in Montana. The monitoring techniques considered in this dissertation include soil CO2 flux measurement and PFC tracer monitoring. The possible near-surface CO2 and PFC tracer flux rates as a function of distance from a leakage point are simulated by TOUGH2, given different leakage rates and permeabilities. The natural near-surface CO2 flux and background PFC tracer concentration measured at the ZERT site are used to determine critical values for leak inference and to calculate the probabilities of leak detection given a monitoring network. A BBN of leak detection is established by combing the TOUGH2 simulations and the background characterization of near-surface CO2 flux and PFC tracer at the sequestration site. The BBN model can be used as an integrated leak detection tool at a geologic sequestration site, increasing the predicted precision and inferring the possible leak distribution by combining the information from multiple leak detection techniques. Moreover, the BBN model can also be used for evaluating each monitoring technique deployed at a site and for determining the performance of a proposed monitoring network design by a single or multiple techniques.

Los estilos APA, Harvard, Vancouver, ISO, etc.

25

Cheng, Jennifer J. (Jennifer Jay) 1979. "The detection of immortal DNA strand co-segregation as a method of adult stem cell identification". Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/18042.

Texto completo

Resumen

Thesis (S.M.)--Massachusetts Institute of Technology, Biological Engineering Division, 2004.
Includes bibliographical references (leaves 35-40).
The study of stem cells is one of the most fascinating topics in biology. Adult stem cells (ASC), which play the prime role in the maintenance and restoration of tissues, are thought to hold great potential for the advancement of medicine. It has been postulated that adult stem cells are able to retain "immortal" DNA template strands over successive generations by non-random chromosome co-segregation, and in so doing, to protect the long-term genomic fidelity of whole tissue compartments. The investigation of this theory may yield insights into areas such as the development of cancer and the process of aging. In addition, it may lead to the discovery of an effective method for the unique identification of adult stem cells, the study of which has thus far suffered from the lack of unique identifiers. Thus, the goal of this research was to develop an assay for the detection of immortal DNA strand co-segregation that could be applied to the detection and analysis of adult stem cells. It is proposed that such an assay may in itself serve as a unique identification method for adult stem cells. In this thesis, the development of such an assay is described. This assay, referred to as the label release assay, has provided further evidence for the existence of immortal strand co-segregation in model cell lines, and will potentially be useful in the study of adult stem cells in tissues.
by Jennifer J. Cheng.
S.M.

Los estilos APA, Harvard, Vancouver, ISO, etc.

26

Daniel, Tertei. "Co-design of architectures and algorithms for mobile robot localization and model-based detection of obstacles". Phd thesis, Univerzitet u Novom Sadu, Fakultet tehničkih nauka u Novom Sadu, 2016. http://www.cris.uns.ac.rs/record.jsf?recordId=101781&source=NDLTD&language=en.

Texto completo

Resumen

This thesis proposes SoPC (System on a ProgrammableChip) architectures for efficient embedding of vison-basedlocalization and obstacle detection tasks in a navigationalpipeline on autonomous mobile robots. The obtainedresults are equivalent or better in comparison to state-ofthe-art. For localization, an efficient hardware architecturethat supports EKF-SLAM's local map management withseven-dimensional landmarks in real time is developed.For obstacle detection a novel method of objectrecognition is proposed - detection by identificationframework based on single detection window scale. Thisframework allows adequate algorithmic precision andexecution speeds on embedded hardware platforms.
Ova teza bavi se dizajnom SoPC (engl. System on aProgrammable Chip) arhitektura i algoritama za efikasnuimplementaciju zadataka lokalizacije i detekcije preprekabaziranih na viziji u kontekstu autonomne robotskenavigacije. Za lokalizaciju, razvijena je efikasnaračunarska arhitektura za EKF-SLAM algoritam, kojapodržava skladištenje i obradu sedmodimenzionalnihorijentira lokalne mape u realnom vremenu. Za detekcijuprepreka je predložena nova metoda prepoznavanjaobjekata u slici putem prozora detekcije fiksnedimenzije, koja omogućava veću brzinu izvršavanjaalgoritma detekcije na namenskim računarskimplatformama.

Los estilos APA, Harvard, Vancouver, ISO, etc.

27

Törtei, Dániel. "Co-design of architectures and algorithms for mobile robot localization and model-based detection of obstacles". Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30294/document.

Texto completo

Resumen

Un véhicule autonome ou un robot mobile est équipé d'un système de navigation qui doit comporter plusieurs briques fonctionnelles pour traiter de perception, localisation, planification de trajectoires et locomotion. Dès que ce robot ou ce véhicule se déplace dans un environnement humain dense, il exécute en boucle et en temps réel plusieurs fonctions pour envoyer des consignes aux moteurs, pour calculer sa position vis-à-vis d'un repère de référence connu, et pour détecter de potentiels obstacles sur sa trajectoire; du fait de la richesse sémantique des images et du faible coût des caméras, ces fonctions exploitent souvent la vision. Les systèmes embarqués sur ces machines doivent alors intégrer des cartes assez puissantes pour traiter des données visuelles en temps réel. Par ailleurs, les contraintes d'autonomie de ces plateformes imposent de très faibles consommations énergétiques. Cette thèse proposent des architectures de type SOPC (System on Programmable Chip) conçues par une méthodologie de co-design matériel/logiciel pour exécuter de manière efficace les fonctions de localisation et de détection des obstacles à partir de la vision. Les résultats obtenus sont équivalents ou meilleurs que l'état de l'art, concernant la gestion de la carte locale d'amers pour l'odométrie-visuelle par une approche EKF-SLAM, et le rapport vitesse d'exécution sur précision pour ce qui est de la détection d'obstacles par identification dans les images d'objets (piétons, voitures...) sur la base de modèles appris au préalable
An autonomous mobile platform is endowed with a navigational system which must contain multiple functional bricks: perception, localization, path planning and motion control. As soon as such a robot or vehicle moves in a crowded environment, it continously loops several tasks in real time: sending reference values to motors' actuators, calculating its position in respect to a known reference frame and detection of potential obstacles on its path. Thanks to semantic richness provided by images and to low cost of visual sensors, these tasks often exploit visual cues. Other embedded systems running on these mobile platforms thus demand for an additional integration of high-speed embeddable processing systems capable of treating abundant visual sensorial input in real-time. Moreover, constraints influencing the autonomy of the mobile platform impose low power consumption. This thesis proposes SOPC (System on a Programmable Chip) architectures for efficient embedding of vison-based localization and obstacle detection tasks in a navigational pipeline by making use of the software/hardware co-design methodology. The obtained results are equivalent or better in comparison to state-of-the-art for both EKF-SLAM based visual odometry: regarding the local map size management containing seven-dimensional landmarks and model-based detection-by-identification obstacle detection: algorithmic precision over execution speed metric

Los estilos APA, Harvard, Vancouver, ISO, etc.

28

Jalali, Jalal. "Artificial neural networks for reservoir level detection of CO₂ seepage location using permanent down-hole pressure data". Morgantown, W. Va. : [West Virginia University Libraries], 2010. http://hdl.handle.net/10450/11137.

Texto completo

Resumen

Thesis (Ph. D.)--West Virginia University, 2010.
Title from document title page. Document formatted into pages; contains xii, 140 p. : ill. (some col.), col. maps. Includes abstract. Includes bibliographical references (p. 99-104).

Los estilos APA, Harvard, Vancouver, ISO, etc.

29

Radhakrishnan, Rajesh. "A study of the reception of co-directional users using beamforming, switched beams and multiuser detection strategies". Cincinnati, Ohio : University of Cincinnati, 2002. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=ucin1037812447.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

30

Ižák, Tomáš. "Detection of Correlated Mutations". Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2013. http://www.nusl.cz/ntk/nusl-236417.

Texto completo

Resumen

Tato práce zkoumá existující možnosti a metody detekce korelovaných mutací v proteinech. Práce začíná teoretickým úvodem do zkoumané problematiky. Využití informací o korelovaných mutacích je především při predikci terciální struktury proteinu či hledání oblastí s významnou funkcí. Dále následuje přehled v současnosti používaných metod detekce a jejich výhody a nevýhody. V této práci jsou zkoumány zejména metody založené na statistice (například Pearsonově korelačním koeficientu nebo Pearsonově chi^2 testu), informační teorii (Mutual information - MI) a pravděpodobnosti (ELSC nebo Spidermonkey). Dále jsou popsány nejdůležitější nástroje s informací o tom, které metody používají a jakým způsobem. Také je diskutována možnost návrhu optimálního algoritmu. Jako optimální z hlediska úspěšnosti detekce je doporučeno využít více zmíněných metod. Také je doporučeno při detekci využít fyzikálně-chemických vlastností aminokyselin. V praktické části byla vyvinuta metoda využívající fyzikálně-chemických vlastností aminokyselin a fylogenetických stromů. Výsledky detekce byly porovnány s nástroji CAPS, CRASP a CMAT.

Los estilos APA, Harvard, Vancouver, ISO, etc.

31

TACCA, BERNARDO. "Implementation of iterative multiuser joint detection techniques in a dvb-rcs satellite scenario". Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2009. http://hdl.handle.net/2108/902.

Texto completo

Resumen

Con la crescita vertiginosa delle telecomunicazioni, è divenuto sempre più importante un uso efficiente dello spettro a disposizione: l’ottimizzazione del piano di riutilizzo delle frequenze è quindi fondamentale per le attuali reti satellitari, in quanto la banda è ormai una risorsa estremamente preziosa. Lo scopo del presente lavoro di Dottorato è quello di sviluppare una nuova metodologia per migliorare l’utilizzo della banda disponibile nel Return Link (RL) di un satellite multibeam. Il metodo proposto permette l’uso della stessa frequenza per beam adiacenti (mentre solitamente beam adiacenti utilizzano bande differenti per non interferire tra loro alle antenne del satellite) e mitiga l’Interferenza Co-Canale (CCI) risultante adottando un appropriato algoritmo Multiuser Joint Detection (MUD) alla gateway, ovvero, per sopprimere l’interferenza CCI, tutti i canali sono demodulati assieme. Lo scenario di riferimento è quello di un sistema satellitare in cui la gateway supporta una comunicazione bidirezionale verso terminali utente equipaggiati con antenne di apertura relativamente piccola e che trasmettono a bassa potenza. Il RL implementa uno standard DVB-RCS ottimizzato, operante con utenti TDMA a basso bit-rate (fino a qualche Mbit/s), essendo questo lo schema maggiormente in uso per lo scenario in esame. La tecnica MUD selezionata si basa sull’adattamento di strategie iterative (o turbo) di cancellazione d’interferenza già presenti in letteratura, ma analizzate principalmente per sistemi CDMA. Sono state effettuate simulazioni complete del demodulatore in scenari generali, rappresentativi di casi reali, le quali hanno dimostrato una ragionevole complessità dell’algoritmo di mitigazione proposto ed un’efficace riduzione dell’interferenza CCI. Linee guida dettagliate sono riportate alla fine della tesi.
With the explosive growth of telecommunications, the efficient use of available spectrum is becoming increasingly important: tightened frequency reuse planning is a pressing need in satellite networks, as the frequency spectrum has become an extremely precious resource. The purpose of this work is to develop a novel methodology for improving the bandwidth utilization on the Reverse Link (RL) of a multibeam satellite. The proposed method permits the frequency reuse for adjacent beams (usually adjacent beams employ different modulation bands so as not to interfere at the satellite antennas) and mitigates the resulting Co-Channel Interference (CCI) using a suitable Multiuser Joint Detection (MUD) algorithm at the gateway side, that is all the channels are demodulated together in order to suppress the CCI interference. The reference scenario will be a satellite system where the gateway station supports a two-way communication with several interactive user terminals equipped with a relatively small aperture antenna and transmitting low power. The RL implements an enhanced DVB-RCS standard operating with low-rate TDMA users (data rates up to few Mbit/s), as this scheme is currently the most popular for the considered scenario. The selected MUD technique is based on the adaption of iterative (turbo) interference cancellation strategies presented in literature for CDMA systems. Complete demodulator simulations were performed in general scenarios representative of real cases. The simulations have demonstrated the proposed interference mitigation algorithm reasonable complexity and an effective CCI reduction. Detailed guidelines have been finally reported in the thesis.

Los estilos APA, Harvard, Vancouver, ISO, etc.

32

Mekala, Priyanka. "Field Programmable Gate Array Based Target Detection and Gesture Recognition". FIU Digital Commons, 2012. http://digitalcommons.fiu.edu/etd/723.

Texto completo

Resumen

The move from Standard Definition (SD) to High Definition (HD) represents a six times increases in data, which needs to be processed. With expanding resolutions and evolving compression, there is a need for high performance with flexible architectures to allow for quick upgrade ability. The technology advances in image display resolutions, advanced compression techniques, and video intelligence. Software implementation of these systems can attain accuracy with tradeoffs among processing performance (to achieve specified frame rates, working on large image data sets), power and cost constraints. There is a need for new architectures to be in pace with the fast innovations in video and imaging. It contains dedicated hardware implementation of the pixel and frame rate processes on Field Programmable Gate Array (FPGA) to achieve the real-time performance. The following outlines the contributions of the dissertation. (1) We develop a target detection system by applying a novel running average mean threshold (RAMT) approach to globalize the threshold required for background subtraction. This approach adapts the threshold automatically to different environments (indoor and outdoor) and different targets (humans and vehicles). For low power consumption and better performance, we design the complete system on FPGA. (2) We introduce a safe distance factor and develop an algorithm for occlusion occurrence detection during target tracking. A novel mean-threshold is calculated by motion-position analysis. (3) A new strategy for gesture recognition is developed using Combinational Neural Networks (CNN) based on a tree structure. Analysis of the method is done on American Sign Language (ASL) gestures. We introduce novel point of interests approach to reduce the feature vector size and gradient threshold approach for accurate classification. (4) We design a gesture recognition system using a hardware/ software co-simulation neural network for high speed and low memory storage requirements provided by the FPGA. We develop an innovative maximum distant algorithm which uses only 0.39% of the image as the feature vector to train and test the system design. Database set gestures involved in different applications may vary. Therefore, it is highly essential to keep the feature vector as low as possible while maintaining the same accuracy and performance

Los estilos APA, Harvard, Vancouver, ISO, etc.

33

Vozny, A. A., Μ. Ο. Stetsenko, S. P. Rudenko, Володимир Володимирович Косяк, Владимир Владимирович Косяк, Volodymyr Volodymyrovych Kosiak, L. S. Maksimenko et al. "Detection of Structural Characteristics of Nanosized SnxSy Film by the Modulation-polarization Spectroscopy of Plasmon Resonance". Thesis, Sumy State University, 2015. http://essuir.sumdu.edu.ua/handle/123456789/42581.

Texto completo

Resumen

The present work deals with the study of the structural properties of nanosized SnS2 films deposited by the close-spaced vacuum sublimation (CSVS) method. Surface morphology of the obtained films was determined by the scanning electron microscope (SEM-102Е). Structural investigations of the films were performed with the Raman spectroscopy. The analysis of chemical composition of the layers was carried out by the scanning electron microscope by energy dispersive X-ray (ЕDS) spectroscopy. The structure features of SnxSy films were investigated by the modulation-polarization spectroscopy (MPS) technique of surface plasmon resonance.

Los estilos APA, Harvard, Vancouver, ISO, etc.

34

Cassel, Kevin William. "FACTORS INFLUENCING SITE OCCUPANCY OF BREEDING BIRDS, HERPTILES, MESOCARNIVORES, AND SMALL MAMMALS ON SUBURBAN FOREST PRESERVES IN THE CHICAGO METROPOLITAN AREA". OpenSIUC, 2014. https://opensiuc.lib.siu.edu/theses/1563.

Texto completo

Resumen

Wildlife in urban settings are a management challenge because wildlife populations and their habitats are often fragmented and degraded, but natural resource managers need information concerning their spatial distribution, spatial turnover, and spatial co-occurrence while accounting for imperfect detection. Based in the Chicago Metropolitan Area during 2009-2012, my study modeled 23 species across 5 wildlife taxa concerning patterns of site occupancy, spatial turnover (i.e., colonization and extinction), and/or spatial co-occurrence at 1-2 spatial scales. In detail, I investigated: (1) detection probabilities, site occupancy, and spatial turnover as affected by habitat and anthropogenic influences at 2 spatial scales for 6 species of songbirds: field sparrows (Spizella pusilla), great crested flycatchers (Myiarchus crinitus), willow flycatchers (Empidonax traillii), bobolinks (Dolichonyx oryzivorus), marsh wrens (Cistothorus palustris), and rose-breasted grosbeaks (Pheucticus ludovicianus); (2) detection probabilities, site occupancy, and spatial turnover as affected by habitat and anthropogenic influences at 2 spatial scales for 3 species of reptiles and 4 species of amphibians: common garter snakes (Thamnophis sirtalis), painted turtles (Chrysemys picta), snapping turtles (Chelydra serpentina), blue-spotted salamanders (Ambystoma laterale), tiger salamanders (Ambystoma tigrinum), green frogs (Rana clamitans), and northern leopard frogs (Rana pipiens); (3) habitat use and landscape site occupancy and spatial turnover as affected by habitat and anthropogenic influences for 4 species of mesocarnivores: coyotes (Canis latrans), raccoons (Procyon lotor), striped skunks (Mephitis mephitis), and Virginia opossums (Didelphis virginiana); and (4) detection probabilities and spatial distributions as affected by local habitat, an interacting species (dominant or subordinate), or both for 6 species of small mammals: short-tailed shrews (Blarina brevicauda), meadow voles (Microtus pennsylvanicus), white-footed mice (Peromyscus leucopus), gray squirrels (Sciurus carolinensis), masked shrews (Sorex cinereus), and eastern chipmunks (Tamias striatus). I elucidate how managers can improve or design their survey techniques that will aid their inference of the distribution of wildlife in the Midwest. This work also provides suburban natural resource managers in the Chicago Metropolitan Area with information concerning land management and land acquisition guidelines to best conserve, attract, or deter the aforementioned wildlife on their properties.

Los estilos APA, Harvard, Vancouver, ISO, etc.

35

Kitenge, Denis. "Optical detection of CO and H2 based on surface plasmon resonance with Ag-YSZ, Au and Ag-Cu nanoparticle films". Scholar Commons, 2009. http://scholarcommons.usf.edu/etd/2047.

Texto completo

Resumen

Silver, gold, and copper metallic nanoparticle films have been utilized in various MEMS devices due to not only their electrical but also their optical properties. The focus of this research is to study the detection at room temperature of carbon monoxide (CO) and hydrogen (H2) via Surface Plasmon Resonance (SPR) phenomenon of silver-embedded Yttrium Stabilized Zirconium (Ag-YSZ) nanocomposite film, gold (Au) nanoparticle film, and an alloy film of silver-copper (Ag-Cu) , grown by the Pulsed Laser Deposition (PLD). To determine the appropriate film materials for quick and accurate CO and H2 detection at room temperature with the PLD technique, the growth process was done repeatedly. Optical tools such as X-Ray Diffraction, Alpha Step 200 Profilometer, Atomic Force Microscopy, and Scanning Electron Microscopy were used to characterize thin films. The gas sensing performance was studied by monitoring the SPR band peak behavior via UV/vis spectrophotometer when the films were exposed to CO and H2 and estimating the percent change in wavelength. The metallic nanoparticle films were tested for concentration of CO (100 to 1000 ppm) and H2 (1 to 10%). Silver based sensors were tested for the cross-selectivity of the gases. Overall the sensors have a detection limit of 100 ppm for CO and show a noticeable signal for H2 in the concentration range as low as 1%. The metallic films show stable sensing over a one-hour period at room temperature. The SPR change by UV/vis spectrophotometer shows a significant shift of 623 nm wavelength between 100 ppm CO gas and dry air at room temperature for the alloy films of Ag-Cu with a wider curve as compared to silver and gold films upon their exposure to CO and H2 indicating an improvement in accuracy and quick response. The results indicate that in research of CO and H2 detection at room temperature, optical gas sensors rather than metal oxide sensors are believed to be effective due to not only the absence of chemical involvement in the process but also the sensitivity improvement and accuracy, much needed characteristics of sensors when dealing with such hazardous gases.

Los estilos APA, Harvard, Vancouver, ISO, etc.

36

Kitenge, Denis. "Optical detection of CO and H₂ based on surface plasmon resonance with Ag-YSZ, Au and Ag-Cu nanoparticle films". [Tampa, Fla] : University of South Florida, 2009. http://purl.fcla.edu/usf/dc/et/SFE0003296.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

37

Barty, Simon. "Statistical detection techniques to reduce confounding by association (co-medication) and confounding by indication in the Australian spontaneous reporting system". Thesis, University of Ballarat, 2005. http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/61443.

Texto completo

Resumen

This research is the incorporation and melding of classical and Bayesian statistical techniques into an iterative methodology aimed at reducing two major confounding issues in Adverse Drug Reactions (ADRs), confounding by association (drug therapy) and confounding by indication (medical condition) to assist in the detection of signals. [...] This study highlights the ability of the STATFILE algorithm to detect drugs that are potential signals. More importantly, it also flags those drugs that are considered to be bystander drugs or noise, consequently reducing confounding by association. [...] This work highlights the significance and viability of an automated signal detection system and its practical application for the Australian spontaneous reporting of ADRs scene and potentially the international scene.
Doctor of Philosophy

Los estilos APA, Harvard, Vancouver, ISO, etc.

38

Alamgir, Nyma. "Computer vision based smoke and fire detection for outdoor environments". Thesis, Queensland University of Technology, 2020. https://eprints.qut.edu.au/201654/1/Nyma_Alamgir_Thesis.pdf.

Texto completo

Resumen

Surveillance Video-based detection of outdoor smoke and fire has been a challenging task due to the chaotic variations of shapes, movement, colour, texture, and density. This thesis contributes to the advancement of the contemporary efforts of smoke and fire detection by proposing novel technical methods and their possible integration into a complete fire safety model. The novel contributions of this thesis include an efficient feature calculation method combining local and global texture properties, the development of deep learning-based models and a conceptual framework to incorporate weather information in the fire safety model for improved accuracy in fire prediction and detection.

Los estilos APA, Harvard, Vancouver, ISO, etc.

39

Sajid, Attique. "Detection of a low power communication signal in the presence of a strong co-channel TV broadcast interference using Kalman filter". Thesis, Monterey, California: Naval Postgraduate School, 2014. http://hdl.handle.net/10945/44663.

Texto completo

Resumen

Approved for public release; distribution is unlimited
This research focuses on the detection of a low power communication signal in the presence of a strong co-channel television broadcast interference signal. The presence of strong co-channel interference makes the recovery of the desired weak power signal impossible using conventional filtering techniques that are based on time and frequency characteristics of the signals. The second-generation digital video broadcasting terrestrial (DVB-T2) standard is employed as co-channel interference in an additive white Gaussian noise channel. The weak signal is assumed to have a considerably smaller bandwidth than the TV interference and negligible phase-shift due to multipath. By using two antennas at the receiver, channel diversity can be exploited, and the weak signal can be recovered using Kalman filter (KF), assuming the channels seen by the two antennas are independent and time-invariant. Moreover, the transmitted co-channel interference is modeled as the state of a dynamic system whose input is the signal received at one antenna and the output is the signal received at the second antenna. Within this framework, the state can be estimated by a KF. Channel estimation is performed using DVB-T2 pilots. Performance of the system is evaluated at different signal-to-noise ratio (SNR) and signal-to-interference ratio (SIR). Results show that the weak signal can be reconstructed with bit error ratio (BER) of 10-3 or less under most SNR and SIR conditions considered in the study.

Los estilos APA, Harvard, Vancouver, ISO, etc.

40

Nguyen, Anh-Minh Ngoc. "High-Quality Detection in Heavy-Traffic Avionic Communication System Using Interference Cancellation Techniques". Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/29069.

Texto completo

Resumen

This dissertation focuses on quantifying the effects of multi-user co-channel interference for an avionic communication system operating in a heavy-traffic aeronautical mobile environment and proposes advanced interference cancellation techniques to mitigate the interference. The dissertation consists of two parts. The first part of the work investigates the use of a visualization method to quantify and characterize the multi-user co-channel interference (multiple access interference) effects impinging on an avionic communication system. The interference is caused by complex interactions of thousands of RF signals transmitted from thousands of aircraft; each attempts to access a common communication channel, which is governed by a specific channel contention access protocol. The visualization method transforms the co-channel interference, which is specified in terms of signal-overlaps (signal collisions), from a visual representation to a matrix representation for further statistical analysis. It is found that the statistical Poisson and its cumulative distribution provide the best estimates of multi-user co-channel interference. It is shown, using Monte Carlo simulation, that the co-channel interference of a victim aircraft operating in the heavy-traffic environment could result in as high as eight signal-overlaps. This constitutes to approximately 83.4% of success rate in signal detection for the entire three thousand aircraft environment using conventional FSK receiver. One key finding shows that high-quality communications, up to 98.5% success rate, is achievable if only three overlapping signals can be decoded successfully. The interference results found in the first part set the stage for interference cancellation research in the second part. The second part of the work proposes the use of advanced interference cancellation techniques, namely sequential interference cancellation (SIC) and parallel interference cancellation (PIC), as potential solutions to mitigating the interference effects. These techniques can be implemented in radio receivers to perform multi-signal decoding functionality to remove the required interferers (three overlapping signals) so that high-quality communication, as described in the first part, can be achieved. Various performance graphs are shown for B-FSK and B-PSK for both SIC and PIC techniques. One key finding is that the system performance can be improved substantially to an additional 15% in signal reception success rate by using SIC or PIC. This means that critical information transmitted from 450 aircraft (out of approximately three thousand aircraft in the environment) is preserved and successfully decoded. Multi-signal decoding using these interference cancellation receivers comes at a small penalty of 2 - 4.5 dBs in Eb/No when sufficient signal-to-interference (SIR) ratio (7-12 dB) is provided.
Ph. D.

Los estilos APA, Harvard, Vancouver, ISO, etc.

41

Rashid, A. N. M. Bazlur. "Cooperative co-evolution-based feature selection for big data analytics". Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2021. https://ro.ecu.edu.au/theses/2428.

Texto completo

Resumen

The rapid progress of modern technologies generates a massive amount of highthroughput data, called Big Data, which provides opportunities to find new insights using machine learning (ML) algorithms. Big Data consist of many features (attributes). However, irrelevant features may degrade the classification performance of ML algorithms. Feature selection (FS) is a combinatorial optimisation technique used to select a subset of relevant features that represent the dataset. For example, FS is an effective preprocessing step of anomaly detection techniques in Big Cybersecurity Datasets. Evolutionary algorithms (EAs) are widely used search strategies for feature selection. A variant of EAs, called a cooperative co-evolutionary algorithm (CCEA) or simply cooperative co-evolution (CC), which uses a divide-and-conquer approach, is a good choice for large-scale optimisation problems. The goal of this thesis is to investigate and develop three key research issues related to feature selection in Big Data and anomaly detection using feature selection in Big Cybersecurity Data. The first research problem of this thesis is to investigate and develop a feature selection framework using CCEA. The objective of feature selection is twofold: selecting a suitable subset of features or in other words, reducing the number of features to decrease computations and improving classification accuracy, which are contradictory, but can be achieved using a single objective function. Using only classification accuracy as the objective function for FS, EAs, such as CCEA, achieves higher accuracy, even with a higher number of features. Hence, this thesis proposes a penalty-based wrapper single objective function. This function has been used to evaluate the FS process using CCEA, henceforth called Cooperative Co-Evolutionary Algorithm-Based Feature Selection (CCEAFS). Experimental analysis was performed using six widely used classifiers on six different datasets, with and without FS. The experimental results indicate that the proposed objective function is efficient at reducing the number of features in the final feature subset without significantly reducing classification accuracy. Furthermore, the performance results have been compared with four other state-of-the-art techniques. CC decomposes a large and complex problem into several subproblems, optimises each subproblem independently, and collaborates different subproblems only to build a complete solution of the problem. The existing decomposition solutions have poor performance because of some limitations, such as not considering feature interactions, dealing with only an even number of features, and decomposing the dataset statically. However, for real-world problems without any prior information about how the features in a dataset interact, it is difficult to find a suitable problem decomposition technique for feature selection. Hence, the second research problem of this thesis is to investigate and develop a decomposition method that can decompose Big Datasets dynamically, and can ensure the probability of grouping interacting features into the same subcomponent. Accordingly, this thesis proposes a random feature grouping (RFG) with three variants. RFG has been used in the CC-based FS process, hence called Cooperative Co-Evolution-Based Feature Selection with Random Feature Grouping (CCFSRFG). Experiment analysis performed using six widely used ML classifiers on seven different datasets, with and without FS, indicates that, in most cases, the proposed CCFSRFG-1 outperforms CCEAFS and CCFSRFG-2, and also does so when using all features. Furthermore, the performance results have been compared with five other state-of-theart techniques. Anomaly detection from Big Cybersecurity Datasets is very important; however, this is a very challenging and computationally expensive task. Feature selection in cybersecurity datasets may improve and quantify the accuracy and scalability of both supervised and unsupervised anomaly detection techniques. The third research problem of this thesis is to investigate and develop an anomaly detection approach using feature selection that can improve the anomaly detection performance, and also reduce the execution time. Accordingly, this thesis proposes an Anomaly Detection Using Feature Selection (ADUFS) to deal with this research problem. Experiments were performed on five different benchmark cybersecurity datasets, with and without feature selection, and the performance of both supervised and unsupervised anomaly detection techniques were investigated by ADUFS. The experimental results indicate that, instead of using the original dataset, a dataset with a reduced number of features yields better performance in terms of true positive rate (TPR) and false positive rate (FPR) than the existing techniques for anomaly detection. In addition, all anomaly detection techniques require less computational time when using datasets with a suitable subset of features rather than entire datasets. Furthermore, the performance results have been compared with six other state-of-the-art techniques.

Los estilos APA, Harvard, Vancouver, ISO, etc.

42

Chase, Tanya. "Greenhouse gas detection using cavity enhanced absorption spectroscopy and cavity ring-down spectroscopy : trace detection of CH₄, CO₂ and N₂0 in ambient air, standard gas samples and in the headspace of soils". Thesis, University of Bristol, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.686246.

Texto completo

Resumen

The work presented in this thesis is predicated upon the environmental applications of cavity enhanced absorption spectroscopy and cavity ring-down spectroscopy. These are related techniques that are highly useful for sensitive gas detection which is important in terms of anthropologically induced climate change and the detection of the changing levels of greenhouse gases. Sensitive gas detection techniques, specifically isotope ratio analysis, are useful for determining the sources and sinks of greenhouse gases and for distinguishing whether sources and sinks are natural or anthropogenic. The research involved gas detection using commercial near-infrared cavity ring-down spectrometers, made by Picarro, and highlights how well and to what environmental uses these instruments can be applied. Various gas mixtures containing methane and carbon dioxide were analysed by the CRDS instruments to try to determine the detection limits, and the effect that varying the concentrations would have upon the precision and accuracy of the measurements made. Headspace soil measurements of CH4 and C02 were also demonstrated to be made easily without processing of the gas stream.The main work described in this Thesis involved the implementation of a home-built optical feedback cavity enhanced absorption spectroscopy /cavity ring-down spectroscopy experiment which made use of a V-shaped optical cavity and a 7.8 υm quantum cascade laser for the detection of greenhouse gases in the mid-infrared. This comprised of the detection and analyses of spectral lines of methane and nitrous oxide isotopologues. Measurement in the mid-IR took advantage of the excitation of the stronger fundamental vibrational transitions occurring in this region and increased optical path lengths from the optical cavity and signal amplification from optical feedback are features that gave high signal to noise measurements. These techniques have the potential to be further developed for field usage by overcoming many of the limitations of alternative greenhouse gas detection techniques, such as instrument sensitivity and portability.

Los estilos APA, Harvard, Vancouver, ISO, etc.

43

Mathys, Sophie. "Development and application of real-time PCR tools for detection of Bifidobacterium thermophilum RBL67 and Pediococcus acidilactici UVA1, two bacteriocin-producing human faecal co-isolates". Zürich : ETH, 2008. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17735.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

44

Di, Maggio F. "AACVD synthesis and characterisation of Cr2O3, CTO and WCTO for the fabrication of gas sensing thin films and the detection of Co, H2 and H2S". Thesis, University College London (University of London), 2017. http://discovery.ucl.ac.uk/1542349/.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

45

Wilson, Lindsay. "Electrochemical immunosensor based on cyclodextrin supramolecular interactions for the detection of human chorionic gonadotropin". Thesis, University of the Western Cape, 2012. http://hdl.handle.net/11394/3995.

Texto completo

Resumen

>Magister Scientiae - MSc
Glucose oxidase (GOx) and horseradish peroxidase (HRP) are important enzymes for the development of amperometric enzyme linked immunosensors. The selectivity of each enzyme towards its analyte deepens its importance in determining the sensitivity of the resultant immunosensor. In designing immunosensors that have customized transducer surfaces, the incorporation with FAD and iron based enzymes ensures that electron kinetics remains optimal for electrochemical measurement. Various different immobilization strategies are used to produce response signals directly proportional to the concentration of analyte with minimal interferences. The combination of self-assembled monolayers and supramolecular chemistry affords stability and simplicity in immunosensor design. In this work, two electrochemical strategies for the detection of human chorionic gonadotropin(hCG) is presented. This involves the modification of a gold surface with a thiolated β-cyclodextrin epichlorohydrin polymer (βCDPSH) to form a supramolecular inclusion complex with ferrocene (Fc)-functionalised carboxymethyl cellulose polymer (CMC). Cyclic voltammetry indicated that ferrocene is in close proximity to the electrode surface due to the supramolecular complex formed with βCDPSH. Furthermore, strategy (a) for the detection of hCG used α-antihCG labelled (HRP) as reporter conjugate. Strategy (b) maintained the CMC bifunctionalised with Fc and recognition antibody for hCG hormone. However, the system was functionalised with a HRP enzyme and detection is done by using GOx reporter conjugates for in situ production of hydrogen peroxide. The reduction of H2O2 was used for the amperometric detection of hCG by applying a potential of 200 mV. The sensitivity and limit of detection of both strategies were calculated from calibration plots. For strategy (a) the LOD was found to be 3.7283 ng/mL corresponding to 33.56 mIU/mL and a sensitivity of 0.0914 nA ng-1 mL-1. The corresponding values for strategy (b) are 700 pg/mL (6.3 mIU/mL) and 0.94 nA ng-1 mL-1.

Los estilos APA, Harvard, Vancouver, ISO, etc.

46

Leleu, Adrien. "Dynamique des planètes coorbitales". Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066244/document.

Texto completo

Resumen

Ce travail porte principalement sur la dynamique et les méthodes de détection des exoplanètes coorbitales. Nous appelons "coorbitale" toute configuration pour laquelle deux planètes orbitent avec le même moyen mouvement moyen autour d'une même étoile. Dans un premier temps, nous revisitons les résultats du cas coplanaire circulaire. Nous rappelons également que les variétés des coorbitaux circulaires et celle des coorbitaux coplanaires sont toutes deux invariantes par le flot du Hamiltonien moyen. Nous nous intéressons donc à ces deux cas particuliers. L'accent est mis sur le cas coplanaire (excentrique), où nous étudions l'évolution de familles d'orbites quasi-périodiques de dimension non maximale en fonction de l'excentricité des planètes. Nous montrons que la géométrie des ces familles dépend fortement de l'excentricité, ce qui entraine des changements de topologie importants dans l'ensemble de l'espace des phases à mesure que celle-ci augmente. Un chapitre est dédié à la détection des exoplanètes coorbitales. On y rappelle les différentes méthodes de détection adaptées au cas coorbital. On développe particulièrement le cas des vitesses radiales, ainsi que leur combinaison avec des mesures de transit. Enfin, on décrit une méthode permettant d'étudier l'effet de perturbations orbitales sur les résonances spin-orbite d'un corps indéformable. Nous appliquons cette méthode dans deux cas: le cas coorbital excentrique, et le cas circumbinaire
This work focuses on the dynamics and the detection methods of co-orbital exoplanets. We call "co-orbital" any configuration in which two planets orbit with the same mean mean-motion around the same star. First, we revisit the results of the circular coplanar case. We also recall that the manifold associated to the coplanar case and the manifold corresponding to the circular case are both invariant by the flow of the averaged Hamiltonian. We hence study these two particular cases. We focus mainly on the coplanar case (eccentric), where we study the evolution of families of non-maximal quasi-periodic orbits parametrized by the eccentricity of the planets. We show that the geometry of these families is highly dependent on the eccentricity, which causes significant topology changes across the space of phases as the latter increases. A chapter is dedicated to the detection of co-orbital exoplanets. We recall the different detection methods adapted to the co-orbital case. We focus on the radial velocity technique, and the combination of radial velocity and transit measurements. Finally, we describe a method to study the effect of orbital perturbations on the spin-orbit resonances for a rigid body. We apply this method in two cases: the eccentric co-orbital case and the circumbinary case

Los estilos APA, Harvard, Vancouver, ISO, etc.

47

Hellman, Hanna. "Data Aggregation in Time Sensitive Multi-Sensor Systems : Study and Implementation of Wheel Data Aggregation for Slip Detection in an Autonomous Vehicle Convoy". Thesis, KTH, Mekatronik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-217857.

Texto completo

Resumen

En övergång till bilar utrustade med avancerade automatiska säkerhetssystem (ADAS) och även utvecklingen mot självkörande fordon innebär ökad trafik på den lokala databussen. Det finns således ett behov av att både minska den faktiska mängden data som överförs, samtidigt som värdet på datat ökas. Data aggregation tillämpas i dagsläget inom områden såsom trådlösasensornätverk och mindre mobila robotar (WMR’s) och skulle kunna vara en del av en lösning. Denna rapport avser undersöka aggregation av sensordata i ett tidskänsligt system. För ett användarfall gällande halka under konvojkörning testas en aggregationsstrategi genom implementation på en fysisk demonstrator. Demonstratorn består av ett autonomt fordon i mindre skala som befinner sig i en konvoj med ett annat identiskt fordon. Resultaten pekar mot att ett viktat medelvärde, som i realtid anpassar sin viktning baserat på specifika sensorers koherens, med fördel kan användas för att estimera fordonshastighet baserat på individuella hjuls sensordata. Därefter kan en slip ratio beräknas, vilket avgör om fordonet befinner sig i ett tillstånd av halka eller ej. Begränsningar för den undersökta strategin inkluderar antalet icke-halkande hjul som behövs för tillförlitliga resultat. Simulerade resultat antyder att extra hastighetsreferenser behövs för tillförlitliga resultat. Relaterat till användarfallet konvojkörning föreslås att andra fordon används som hastighetsreferens. Detta skulle innebära en ökad precision för estimeringen av fordonshastigheten samt utgöra en intressant sammanslagning av områdena samarbetande cyberfysiska system (CO-CPS) och dataaggregation.
With an impending shift to more advanced safety systems and driver assistance (ADAS) in the vehicles we drive, and also increased autonomousity, comes increased amounts of data on the internal vehicle data bus. There is a need to lessen the amount of data and at the same time increase its value. Data aggregation, often applied in the field of environmental sensing or small mobile robots (WMR’s), could be a partial solution. This thesis choses to investigate an aggregation strategy applied to a use case regarding slip detection in a vehicle convoy. The approach was implemented in a physical demonstrator in the shape of a small autonomousvehicle convoy to produce quantitative data. The results imply that a weighted adaptive average can be used for vehicle velocity estimation based on the input of four individual wheel velocities. There after a slip ratio can be calculated which is used to decide if slip exists or not. Limitations of the proposed approach is however the number of velocity references that is needed since the results currently apply to one-wheel slipon a four-wheel vehicle. A proposed future direction related to the use case of convoy driving could be to include platooning vehicles as extra velocity references for the vehicles in the convoy, thus increasing the accuracy of the slip detection and merging the areas of CO-CPS and data aggregation.

Los estilos APA, Harvard, Vancouver, ISO, etc.

48

Armour, Patricia. "Usefulness of the Captia Syphilis IgG EIA test method and reverse algorithm for detection of syphilis infection in a public health setting". VCU Scholars Compass, 2018. https://scholarscompass.vcu.edu/etd/5341.

Texto completo

Resumen

Syphilis, a systemic sexually transmitted disease, is on the rise in the US, with infection rates the highest recorded since 1994 according to the CDC. Useful laboratory testing is an important diagnostic tool for determining individual syphilis infection and preventing community-wide disease spread. The purpose of this study was to determine the usefulness of a specific automated treponemal test method, the CaptiaTM Syphilis IgG EIA, and the syphilis reverse algorithm interpretation for detecting syphilis infection among patients seeking care in a public health clinic. The study employed a retrospective, nonexperimental descriptive correlational design with data collected between 2012-2013 from 4,077 public health clinic patients with 21% of the patients diagnosed with syphilis infection. There was a statistically significant difference between the CaptiaTM Syphilis IgG and the Fujirebio Serodia TP-PA test results; between the CaptiaTM Syphilis IgG Signal to Cutoff (S/CO) and the MacroVue RPR titer continuous variables; and between the reverse and traditional syphilis interpretation algorithms. The reverse algorithm using the CaptiaTM Syphilis IgG test method provided more useful performance measures with a sensitivity of 82%; specificity of 99%; accuracy of 95%; positive likelihood ratio of 63.06 and negative likelihood of 0.18 than the traditional algorithm using the MacroVue RPR test method. Statistical comparison of the area under the curve (AUC) for the continuous variables, CaptiaTM Syphilis IgG S/CO and RPR titer, concluded that the Syphilis IgG AUC (0.9500) was higher than the RPR titer (0.8155) indicating greater accuracy for detecting syphilis infection. This was the first study to determine that the CaptiaTM Syphilis IgG, the S/CO value, and reverse algorithm are useful diagnostic predictors of syphilis infection among public health clinic patients. The data from this study can be utilized by future researchers and scientists who are developing or improving syphilis detection methods.

Los estilos APA, Harvard, Vancouver, ISO, etc.

49

Steinbeck, Lisa [Verfasser]. "Detection of muscle wasting in patients with chronic heart failure using C-terminal agrin fragment : results from the Studies Investigating Co-morbidities Aggravating Heart Failure (SICA-HF) / Lisa Steinbeck". Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2016. http://d-nb.info/1119803764/34.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

50

Boukhalfa, Noureddine. "Etude de la dissociation du co#2 par decharge couronne. Application a la detection et a la mesure des oxydes de carbone dans l'air ambiant par une methode simple". Paris 6, 1990. http://www.theses.fr/1990PA066051.

Texto completo

Resumen

L'objectif de la presente etude est double: etudier certains mecanismes de dissociation du co#2 par decharge couronne en milieu gazeux a pression atmospherique, dans le co#2 ou en melange avec l'azote, l'oxygene ou l'air synthetique; et puis elaborer un dispositif simple pour la detection et le dosage du co#2. Un faisceau d'experiences dans les melanges co#2-n#2, co#2o#2 et co#2-air a teneur variable de co#2, a mis en evidence l'effet catalytique de certains etats de n#2 excite. La simulation de la dissociation du co#2 montre en plus la necessite d'introduire le concept catalytique que joue n#2. Dans le second volet consacre a l'etude des caracteristiques electriques de la decharge, il apparait clairement qu'un role particulier est joue par les decharges filamentaires (streamers) d'une part et par les decharges proches a la transition a l'arc d'autre part, ou un emballement en terme de production de co se fait sentir. Il en est notamment ainsi de l'influence jouee, en polarite negative, par la transition decharge impulsionnelle/decharge continue. Quant au role joue par la distance interelectrode en decharge positive dans le co#2 pur, l'importance de metastables de co#2 y est soulignee. Cette etude est completee par la mise au point d'une methode de mesure et d'identification de co#2

Los estilos APA, Harvard, Vancouver, ISO, etc.

Tesis sobre el tema "CO₂ detection"

Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros