Dissertations / Theses: 'LMA TECHNIQUE'

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Adjei, Seth Akonor. "Refining Learning Maps with Data Fitting Techniques." Digital WPI, 2015. https://digitalcommons.wpi.edu/etd-theses/178.

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Learning maps have been used to represent student knowledge for many years. These maps are usually hand made by experts in a given domain. However, these hand-made maps have not been found to be predictive of student performance. Several methods have been proposed to find bet-ter fitting learning maps. These methods include the Learning Factors Analysis (LFA) model and the Rule-space method. In this thesis we report on the application of one of the proposed operations in the LFA method to a small section of a skill graph and develop a greedy search algorithm for finding better fitting models for this graph. Additionally an investigation of the factors that influence the search for better data fitting models using the proposed algorithm is reported. We also present an empirical study in which PLACEments, an adaptive testing system that employs a skill graph, is modified to test the strength of prerequisite skill links in a given learning map and propose a method for refining learning maps based on those findings. It was found that the proposed greedy search algorithm performs as well as an original skill graph but with a smaller set of skills in the graph. Additionally it was found that, among other factors, the number of unnecessary skills, the number of items in the graph, and the guess and slip rates of the items tagged with skills in the graph have an impact on the search. Further, the size of the evaluation data set impacts the search. The more data there is for the search, the more predictive the learned skill graph. Additionally, PLACEments, an adaptive testing feature of ASSISTments, has been found to be useful for refining skill graphs by detecting the strengths of prerequisite links between skills in a graph.

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Martínez, Brito Juan. "Characterization of Dielectric Samples at Microwave Frequencies Using Substrate Integrated Waveguide Techniques." Thesis, Universidad de las Américas Puebla, 2010. http://catarina.udlap.mx/u_dl_a/tales/documentos/lmt/martinez_b_j/.

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Complex permittivities of the materials are evaluated at microwave frequencies by using the Substrate Integrated Waveguide (SIW) cavity resonator and Epsilon Near Zero (ENZ) technology. Dielectric parameters such as dielectric constant and dielectric loss of solids samples, solvents and alcohols are determined by measuring the change in the resonant frequency and in the Q factor, due to the introduction of the samples in to these resonant structures. High Frequency Structure Simulator (HFSS) has been used to design and optimize the resonant structures. Simulations and measurements are performed with different substrates and different dielectric samples to validate the cavity perturbation theory using substrate integrated waveguide (SIW) cavity resonator. For ENZ structure, simulations are performed with various height ratios to choose an optimized ratio that allows higher sensitivity. Simulation and measurement results of cavity resonator and ENZ tunnel are in good agreement with theoretical values. Both structures present low profile, low cost, ease of fabrication and ease of integration, which adds important characteristics for portable material measurement systems.

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Kumar, Abhishek. "Convex Modeling Techniques for Aircraft Control." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/33530.

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The need to design a controller that self-schedules itself during the flight of an aircraft has been an active area of research. New methods have been developed beyond the traditional gain-scheduling approach. One such design method leads to a linear parameter varying (LPV) controller that changes based on the real-time variation of system dynamics. Before such a controller can be designed, the system has to also be represented as an LPV system. The current effort proposes a LPV modeling technique that is inspired by an affine LPV modeling techniques found in recent research. The properties of the proposed modeling method are investigated and compared to the affine modeling technique. It is shown that the proposed modeling technique represents the actual system behavior more closely than the existing affine modeling technique. To study the effect of the two LPV modeling techniques on controller design, a linear quadratic regulator (LQR) controller using linear matrix inequality (LMI) formulation is designed. This control design method provides a measure of conservatism that is used to compare the controllers based on the different modeling techniques. An F-16 short-period model is used to implement the modeling techniques and design the controllers. It was found that the controller based on the proposed LPV modeling method is less conservative than the controller based on the existing LPV method. Interesting features of LMI formulation for multiple plant models were also discovered during the exercise. A stability robustness analysis was also conducted as an additional comparison of the performance of the controllers designed using the two modeling methods. A scalar measure, called the probability of instability, is used as a measure of robustness. It was found that the controller based on the proposed modeling technique has the necessary robustness properties even though it is less conservative than the controller designed based on the existing modeling approach.
Master of Science

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Stenman, Jakob. "mRNA-expression-based classification of solid tumors : development of accurate amplification-based quantification techniques." Helsinki : University of Helsinki, 2002. http://ethesis.helsinki.fi/julkaisut/laa/kliin/vk/stenman/.

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Tutar, Özdarcan D., P. S. Smith, and V. Keskin. "Time-resolved spectropolarimetric observations of polars WX LMi and BY Cam." OXFORD UNIV PRESS, 2017. http://hdl.handle.net/10150/624423.

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Time-series spectropolarimetric observations of polar WX LMi and asynchronous polar BY Cam are presented. Magnetic field properties, radial velocities and optical polarization are investigated via consecutive observations with good phase sampling during a single orbital cycle. Both systems are found to have a decentred dipole magnetic field configuration. One of the poles of WX LMi has a field strength of 49 MG, while the other pole may have possible field strengths of 69, 104 or 207 MG, depending on the harmonic numbers of the cyclotron humps observed in the circularly polarized spectrum. For BY Cam, a field strength of 168 MG is found for one of the poles, while field strengths of 70, 160 or 212 MG are possible for the other pole.

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Halavaara, Juha. "Magnetic resonance imaging of focal liver lesions : characterization with the spin lock technique and detectability with tissue-specific contrast agents." Helsinki : University of Helsinki, 2002. http://ethesis.helsinki.fi/julkaisut/laa/kliin/vk/halavaara/.

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Estrada, Mariana. "A case study of cob earth based building technique in Matagalpa, Nicaragua – LCA perspective and rate of adoption." Thesis, Mittuniversitetet, Avdelningen för ekoteknik och hållbart byggande, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-21315.

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Cob is an earth based building technique that may be an alternative for the construction of new homes in developing countries. Earth based constructions techniques commonly used in the past, like adobe and wattle-and-daub, have increasingly been replaced by buildings using more processed materials commercially available such as bricks or concrete blocks. The cost of such commercial materials is often unreachable for a large part of the population in developing countries. Cob buildings could be an appropriate option in rural areas, where human labor is a less restricted resource compared to monetary capital, and most of the materials needed are locally available. The cob technique is based on a mixture of clay, sand, straw and water that enables the builder to combine different materials and to create a variety of shapes. A recently constructed cob building in Matagalpa, Nicaragua, was studied using screening LCA methodology applied to the construction phase, as well as by applying a diffusion of innovation framework (specifically the five perceived attributes of an innovation). Results regarding fossil CO2 emissions due to material production and material transportation were contrasted to an equivalent concrete block building. The highest contribution to CO2 emissions from the cob building was generated by paints and solvents, and bricks and tiles (cooked earth); whereas in the concrete building it was due to the concrete bricks and iron. According to this case study, cob building technique seems to have the potential to be an affordable option for rural housing in Nicaragua, and at the same time accountable for rather limited emissions of fossil CO2 emissions in its construction phase. At present, some obstacles to the use of cob technique are lack of examples for people to see and experience, and a general limited knowledge on how to work with cob technique.
Cob är en byggteknik med jord som främsta material som kan vara ett alternativ vid byggande av nya bostäder i utvecklingsländer. Några jordkonstruktionstekniker, som adobe och ”bajareque”, var vanligare förr, men har ersatts av byggande med förädlade material som tegel eller betongblock. Kostnaden för dessa material är oftast hög och blir oöverkomlig för en stor del av befolkningen. Cob hus skulle kunna vara ett alternativ på landsbygden, där arbetskraft är en mer tillgänglig resurs än kapital, och de flesta av de material som behövs finns lokalt. Cob tekniken är en blandning av lera, sand, halm och vatten som även kan kombineras med andra material för att skapa olika former. Byggnationsfasen för ett nyligen konstruerat cob hus i Matagalpa, Nicaragua, studerades med en screenande LCA. Valda delar av Rogers teori ”diffusion of innovation” användes (främst de fem attributen för innovationsspridning). Resultaten avseende CO2-utsläpp från produktion och transport av material jämfördes med ett hus i liknande storlek, byggt i betongblock. Det största bidraget till utsläpp av CO2 från cob huset genererades av färger och lösningsmedel, tegel och kakel (bränd jord), medan det i betongblockshuset berodde på betongblock och järn. Enligt denna fallstudie verkar cob byggteknik att ha potential att vara ett prisvärt alternativ för bostäder på landsbygden i Nicaragua, och resulterar i relativt små CO2-utsläpp under byggskedet. Några av de hinder för spridningen av cob tekniken som föreligger för närvarande är brist på exempel för människor att se och uppleva, samt dålig allmän kunskap om hur man arbetar med denna teknik.
Cob es una técnica de construcción en tierra que puede ser una alternativa para la construcción de nuevas viviendas en los países en vía de desarrollo. Algunas de las técnicas de construcciones en tierra como el adobe y el bahareque fueron comunes en el pasado, sin embargo han sido sustituidas por construcciones con materiales procesados como ladrillos o bloques de concreto. El costo de estos materiales suele ser alto volviéndose inasequibles para una gran parte de la población. Las construcciones en cob podrían ser una opción adecuada en las zonas rurales, donde la mano de obra es un recurso abundante a bajo costo, y la mayoría de los materiales necesarios están disponibles a nivel local. La técnica del cob se basa en una mezcla de arcilla, arena, paja y agua que puede ser combinada con otros materiales para crear una gran variedad de formas. La fase de construcción de una casa en cob en Matagalpa, Nicaragua; fue estudiada por medio de un LCA preliminar. Igualmente se utilizó el marco de difusión de la innovación propuesto por Rogers para evaluar los cinco atributos que hacen que esta técnica pueda o no ser difundida en Matagalpa. Los resultados en relación con las emisiones de CO2 por la producción de material y del transporte de material se contrastaron con una casa de dimensiones similares construida en bloque de concreto. La mayor contribución a las emisiones de CO2 de la casa de cob fue generada por las pinturas y solventes, y ladrillos y tejas (tierra cocida), mientras que en la casa de bloque de concreto las emisiones se debieron a los bloques de concreto y al hierro. De acuerdo con este caso de estudio, la técnica de construcción cob parece tener el potencial de ser una opción asequible para la vivienda rural en Nicaragua, generando emisiones de CO2 más bajas que las construcciones de bloque de concreto durante la fase de construcción. En la actualidad, algunos de los obstáculos para la difusión de la técnica del cob son la falta de ejemplos para que las personas puedan ver y experimentar, y un escaso conocimiento general sobre cómo trabajar con esta técnica.

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Yrigoyen, González Haydée Andrea. ""Environmental Diagnosis of Process Plants by Life Cycle Techniques"." Doctoral thesis, Universitat Rovira i Virgili, 2006. http://hdl.handle.net/10803/8559.

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Environmental Diagnosis of Process Plants by Life Cycle Techniques
Haydée A. Yrigoyen González
El objetivo de la investigación es desarrollar una herramienta que relacione aspectos de
simulación, evaluación ambiental y análisis de sensibilidad. Para lo cual se estableció una
metodología que consta de cinco niveles: Simulación de proceso, Inventario, evaluación de
impactos ambientales, análisis económico y análisis de sensibilidad.
La metodología describe las variables relacionadas con el proceso, así como los
impactos asociados a cada una de sus etapas y la viabilidad económica del proceso, e
identifica las etapas de proceso con el mayor impacto ambiental (mediante el análisis de
sensibilidad).
Para la simulación de procesos se empleó el simulador ASPEN Hysys®. El inventario,
la evaluación de impactos y el análisis económico se lleva a cabo en hojas de cálculo de forma
automática.
La obtención del inventario de efectos ambientales y la evaluación de los
correspondientes impactos se realizan siguiendo la metodología de ciclo de vida, por lo que se
consideran las cargas ambientales asociadas a las materias primas, la generación de
electricidad y utilidades. Para obtener el inventario se construyó una base de datos que
contiene la información ambiental asociada a varios procesos industriales que se relacionan
indirectamente al proceso bajo estudio. Similarmente, se incluyó una base de datos con los
factores de caracterización de las categorías de impacto más importantes.
La validación de la metodología y de la herramienta desarrollada se ha llevado a cabo
mediante tres procesos industriales: polietileno de baja densidad (LDPE), óxido de etileno (EO)
y biodiesel. Para cada proceso se han evaluado diferentes configuraciones para poder
determinar cual de ellas es la mejor opción desde el punto de vista ambiental y económico.
En el caso del LDPE, el cambio de configuración se ha enfocado en el origen de la
electricidad, la cual puede ser proveniente de la Red Nacional Española o de una unidad de
cogeneración. Los resultados indican que la mejor configuración corresponde al proceso que
emplea electricidad proveniente de la unidad de cogeneración, puesto que se obtiene vapor
como sub-producto y se evitan las emisiones asociadas a la generación de electricidad, lo que
se refleja en una importante reducción de los impactos ambientales asociados.
En el segundo proceso analizado, referente a la producción de oxido de etileno, se han
evaluado cuatro configuraciones, empleando aire u oxígeno como materia prima y electricidad
de la Red Española o produciéndola mediante cogeneración. En relación al origen de la
electricidad, al emplear la cogeneración, el comportamiento ambiental del proceso mejora
considerablemente. En cuanto a la importancia de la materia prima empleada, al utilizar
oxígeno se obtiene un mejor rendimiento en la etapa de reacción, con lo cual se compensa los
costes asociados a la materia prima con la productividad del proceso.
Finalmente, se ha llevado a cabo la evaluación del proceso de producción de biodiesel,
se comparó el comportamiento ambiental del proceso empleando un catalizador ácido y un
catalizador básico. En el proceso ácido se generan menores impactos ambientales. De forma
similar, ésta configuración tiene un mejor perfil económico ya que los costes asociados a la
producción son menores y no se requiere ninguna unidad de pretratamiento (necesaria en el
proceso alcalino).
Mediante la herramienta desarrollada, la información inicial puede modificarse en
cualquier momento con el fin de obtener los valores correspondientes a nuevas condiciones.
Uno de los aspectos más importantes es el que la herramienta se adapta fácilmente con el
mínimo de variaciones. Las bases de datos que se incluyen en las hojas de cálculo pueden ser
actualizadas por el usuario o ajustarse a las necesidades específicas de cada proceso. Todo el
análisis se lleva a cabo de forma automática, una vez introducida la información inicial del
proceso e información económica.

Environmental Diagnosis of Process Plants by Life Cycle Techniques
Haydée A. Yrigoyen González
The objective of this work is to develop a tool that integrates simulation, environmental
assessment and sensitivity analysis aspects. To support this tool, a methodology consisting of
five levels was established. These are: process simulation, Inventory, environmental impacts
assessment, economic analysis and sensitivity analysis.
The developed methodology describes the variables related to the process, as well as
the impacts associated to each stages, the economic viability of the process, and the process
stages with the highest environmental impact (by means of the sensitivity analysis).
ASPEN Hysys® is the chosen software for the simulation of processes. The inventory,
impact assessment and the economic analysis are automatically obtained in spreadsheets, by
means of macros execution.
The inventory and the impacts assessment are performed following the Life Cycle
methodology. Therefore, the environmental loads of the raw materials, electricity generation and
utilities are considered. In order to generate the inventory, a data base was constructed; it
contains the environmental information associated to industrial processes that are indirectly
related to the process under study. Similarly, a data base with the characterization factors of the
most important impact categories was included in the tool.
The validation of the methodology and the developed tool has been accomplished by
their application to three industrial processes: low density polyethylene (LDPE), ethylene oxide
(EO) and biodiesel production. Different configurations have been evaluated for each process to
determine the best option from the environmental and economic point of view.
For the LDPE process, the configuration change has focused in the origin of the
electricity, which can be supplied by the Spanish National Network or a cogeneration unit.
Based on our results, the best configuration corresponds to the process employing electricity by
cogeneration, since steam is obtained as by-product and the emissions associated to the
electricity generation are eliminated. These facts are reflected in an important reduction of the
overall impacts associated to this process.
In the second analyzed process, referring to the production of ethylene oxide, four
configurations have been evaluated: using air or oxygen as raw material and electricity from the
Spanish Network or produced by cogeneration. Related to the origin of the electricity, using
cogeneration, a better environmental profile is obtained. On the other hand, the oxygen as raw
material is better than air due to the best yield of ethylene oxide in the reaction stage. Due to
the better selectivity of the oxygen in the reaction, the costs of O2 as raw material are
compensated by high production.
Finally, the process evaluation of the biodiesel production has been carried out. In this
case, an acid and a basic catalyst were compared. The best configuration corresponds to the
process using an acid catalyst. In the acid process lower environmental impacts are generated.
Furthermore, this configuration has a better economical profile since the costs associated to the
production are smaller and a pre-treatment unit is not required, as in the alkaline process.
The initial information can be modified at any time to obtain the profile associated to the
new conditions by means of the developed tool. Also, the tool can be adapted to any process in
an easy way. The included database can be updated or adjusted by the user at any time to
personalize them to the specific necessities of each process. Once the initial information is
introduced, the analysis is executed automatically.
The developed tool is able to make the simulation, its environmental diagnosis,
economic evaluation and the sensitivity analysis of any industrial process, introducing the initial
operation conditions.

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Prunières, Luc. "L'étude du polymorphisme de l'A. D. N : base d'une nouvelle technique d'identification médico-judiciaire." Montpellier 1, 1990. http://www.theses.fr/1990MON11165.

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Wu, Hui. "Investigation of fluid flow in grinding using LDA techniques and CFD simulation." Thesis, Liverpool John Moores University, 2009. http://researchonline.ljmu.ac.uk/5944/.

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This research aimed to establish the requirements for effective fluid flow in grinding and to improve the efficiency of the fluid delivery system (fluid delivery optimization). Highly efficient fluid delivery will lower grinding temperatures, reduce the risk of thermal damage and reduce wheel wear. The thesis describes the work completed in the investigation of the complex fluid flow that occurs in the region close to the grinding contact zone between the wheel and workpiece and the boundary layer phenomena around the periphery of the rotating grinding wheel. Studies on air scraper and shoe nozzle application are also presented. Laser Doppler Anemometry (LDA) was employed to obtain a basic understanding of the flow velocity profile in the region close to the grinding contact zone in a low speed grinding system and key characteristics of the fluid flow under varying grinding conditions were identified. The mathematical formulae describing the air velocity distribution around the wheel have been derived from theory based on Newton's laws. Air boundary layer flow around the rotating grinding wheel was studied using LDA measurements and Computational Fluid Dynamics (CFD) simulation to get the air velocity distribution in varying conditions. The experimental results and the investigation made clear the contradictory knowledge relative to this issue and gave a full understanding of the air boundary layer flow. Air scrapers are used to reduce the effects of the air boundary layer. The effects of the size and position of the different scrapers on the air flow velocity and pressure distribution was investigated using CFD simulation. The research work provides a comprehensive assessment of the ability of the air scraper to reduce the intensity of the air boundary layer. The upper surface of the shoe nozzle can be regarded as an air scraper used to interrupt the air flow. Three different shoe nozzles were applied to investigate the fluid delivery situation using CFD simulation. Results from preliminary studies are presented for the shoe nozzle application. The effects of input fluid velocity, gap size and wheel speed on the pressure distribution along the arc of the gap are reported.

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Chuchón, Ayala Hilda. "Technological features of Lima fabrics associated with funerary contexts in Huaca Pucllana." Pontificia Universidad Católica del Perú, 2017. http://repositorio.pucp.edu.pe/index/handle/123456789/113357.

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A detailed description of the technological features of the textiles found in funerary contexts and architectural hills of the latest occupational phases of the Lima Culture is presented. These materials were found as part of the Huaca Pucllana research project established by the Municipality of Miraflores and the Ministry of Culture. Preliminary results indicate that in funerary contexts one or two simple plain weave cotton textiles were used to bundle the bodies. In some cases complete fabrics were used while in other the bundles were formed by many pieces put together, with some fragments with evidence of darning and mending. On the other hand, the textiles found in votive oerings in the architecture are of cotton and wool made by the ringed technique both simple and interconnected knotting. Geometric designs as well as intertwined ash were made using cactus spine needles which have been used to make nets. ere is also evidence of textiles made using a backstrap loom which are commonly the 1x1 plain weave, woven face fabric warp and warp faced list. is evidence suggests that there were diferent types of weavers in the Lima society dedicated to the production of domestic and ceremonial textiles.
Ofrecemos información sobre las particularidades tecnológicas de tejidos atribuidas a las últimas ocupaciones de la cultura Lima, encontrados en contextos funerarios y rellenos arquitectónicos durante las excavaciones efectuadas entre 1996 y 2000, como parte del «Proyecto de Investigación, Conservación y Puesta en Valor de Huaca Pucllana», convenio Instituto Nacional de Cultura-Municipalidad de Miraflores. La muestra textil estudiada indica que en los entierros funerarios Lima, se usaron como envoltorios de los cuerpos, tejidos llanos de algodón compuestos por una o dos telas completas y telas formadas por la unión de fragmentos, algunas de estas últimas con remiendos y zurcidos, a diferencia de los tejidos depositados como ofrendas que tienen tratamiento especial y son un solo elemento, elaborados en lana y algodónmediante la técnica del anillado interconectado simple y anudado, con diseños de figuras geométricas y de peces entrelazados, en cuya manufactura emplearon agujas de espina de cactus, utilizadas también para la elaboración de redes. Los tejidos confeccionados en telar de cintura se distinguen por técnicas comunes de: tejido llano 1x1, tejido cara de urdimbre y tejido listado cara de urdimbre, lo cual sirve de base para sostener que en la sociedad Lima había diferentes clases de artesanos dedicados a la producción de tejidos.

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Ranganathan, Raghuram. "NOVEL COMPLEX ADAPTIVE SIGNAL PROCESSING TECHNIQUES EMPLOYING OPTIMALLY DERIVED TIME-VARYING CONVERGENCE FACTORS WITH APPLICATIO." Doctoral diss., University of Central Florida, 2008. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4089.

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In digital signal processing in general, and wireless communications in particular, the increased usage of complex signal representations, and spectrally efficient complex modulation schemes such as QPSK and QAM has necessitated the need for efficient and fast-converging complex digital signal processing techniques. In this research, novel complex adaptive digital signal processing techniques are presented, which derive optimal convergence factors or step sizes for adjusting the adaptive system coefficients at each iteration. In addition, the real and imaginary components of the complex signal and complex adaptive filter coefficients are treated as separate entities, and are independently updated. As a result, the developed methods efficiently utilize the degrees of freedom of the adaptive system, thereby exhibiting improved convergence characteristics, even in dynamic environments. In wireless communications, acceptable co-channel, adjacent channel, and image interference rejection is often one of the most critical requirements for a receiver. In this regard, the fixed-point complex Independent Component Analysis (ICA) algorithm, called Complex FastICA, has been previously applied to realize digital blind interference suppression in stationary or slow fading environments. However, under dynamic flat fading channel conditions frequently encountered in practice, the performance of the Complex FastICA is significantly degraded. In this dissertation, novel complex block adaptive ICA algorithms employing optimal convergence factors are presented, which exhibit superior convergence speed and accuracy in time-varying flat fading channels, as compared to the Complex FastICA algorithm. The proposed algorithms are called Complex IA-ICA, Complex OBA-ICA, and Complex CBC-ICA. For adaptive filtering applications, the Complex Least Mean Square algorithm (Complex LMS) has been widely used in both block and sequential form, due to its computational simplicity. However, the main drawback of the Complex LMS algorithm is its slow convergence and dependence on the choice of the convergence factor. In this research, novel block and sequential based algorithms for complex adaptive digital filtering are presented, which overcome the inherent limitations of the existing Complex LMS. The block adaptive algorithms are called Complex OBA-LMS and Complex OBAI-LMS, and their sequential versions are named Complex HA-LMS and Complex IA-LMS, respectively. The performance of the developed techniques is tested in various adaptive filtering applications, such as channel estimation, and adaptive beamforming. The combination of Orthogonal Frequency Division Multiplexing (OFDM) and the Multiple-Input-Multiple-Output (MIMO) technique is being increasingly employed for broadband wireless systems operating in frequency selective channels. However, MIMO-OFDM systems are extremely sensitive to Intercarrier Interference (ICI), caused by Carrier Frequency Offset (CFO) between local oscillators in the transmitter and the receiver. This results in crosstalk between the various OFDM subcarriers resulting in severe deterioration in performance. In order to mitigate this problem, the previously proposed Complex OBA-ICA algorithm is employed to recover user signals in the presence of ICI and channel induced mixing. The effectiveness of the Complex OBA-ICA method in performing ICI mitigation and signal separation is tested for various values of CFO, rate of channel variation, and Signal to Noise Ratio (SNR).
Ph.D.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering PhD

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Durand, Jean-Pierre. "Contribution a l'etude du groupe des proteines nucleaires de faible mobilite electrophoretique (lmg)." Nantes, 1988. http://www.theses.fr/1988NANT2010.

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Swales, Christopher. "Advance LDA techniques for measurement of 3D boundary layer velocity profiles on a helicopter rotor." Thesis, University of Bristol, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327721.

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Dupree, A. K., A. Dotter, C. I. Johnson, A. F. Marino, A. P. Milone, J. I. Bailey, J. D. Crane, M. Mateo, and E. W. Olszewski. "NGC 1866: First Spectroscopic Detection of Fast-rotating Stars in a Young LMC Cluster." IOP PUBLISHING LTD, 2017. http://hdl.handle.net/10150/625815.

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High-resolution spectroscopic observations were taken of 29 extended main-sequence turnoff (eMSTO) stars in the young (similar to 200 Myr) Large Magellanic Cloud (LMC) cluster, NGC 1866, using the Michigan/Magellan Fiber System and MSpec spectrograph on the Magellan-Clay 6.5 m telescope. These spectra reveal the first direct detection of rapidly rotating stars whose presence has only been inferred from photometric studies. The eMSTO stars exhibit Ha emission (indicative of Be-star decretion disks), others have shallow broad H alpha absorption (consistent with rotation. greater than or similar to 150 km s(-1)), or deep Ha core absorption signaling lower rotation velocities (less than or similar to 150 km s(-1)). The spectra appear consistent with two populations of stars-one rapidly rotating, and the other, younger and slowly rotating.

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Cook, Casey Lee. "Seeding rate and seed size as management techniques for ryegrass (Lolium Multiflorum, Lam) in winter wheat." Texas A&M University, 2002. http://hdl.handle.net/1969.1/2284.

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Higher seeding rates and larger seed sizes could enhance the competitiveness of wheat with ryegrass. Growth room and field research evaluated the effects of wheat seeding rates and seed size in competition with Italian ryegrass. Winter wheat seeds cultivar “Ogallala” were divided into three seed sizes: small seed passed through a sieve with 2.08mm round holes, large seed which did not pass through a sieve with 3.18mm round holes, and bulk seed directly from a commercial seed bag. These wheat seed and seed of the Italian ryegrass cultivar AGulf@ were planted in plastic pots containing fritted clay. A replacement series design with 12 plants per pot compared the relative growth in pure culture and competitiveness in mixtures of the two species. The planting proportions of each wheat seed group and ryegrass were 100% and 0%, 50% and 50%, and 0% and 100%, respectively. Wheat seed size did not affect the growth of the wheat plants in pure culture. Wheat seed size did not affect competitiveness with ryegrass. There were no differences related to seed size among the pure or mixed cultures of wheat. The failure of increased wheat seed size to affect competition with ryegrass may be the result of the relative seed size difference between the two species. Even the small wheat seed in this study were almost 9-fold greater inweight than the ryegrass seed. Field experiments conducted for two years from fall 2002 through spring 2004 at the Texas A&M University Agronomy Farm measured wheat yields at the same three wheat seed sizes, two wheat densities of 250 plants m-2 and 400 plants m-2, and three ryegrass densities of 0, 100 and 200 plants m-2. Small, bulk, and large wheat seed produced similar yields in both years: one season favorable (2003) for growth and the other (2004) unfavorable. Thus, seed size in the field under favorable or unfavorable conditions or in the growth room experiment did not affect the competitiveness of wheat in the presence of ryegrass. Increasing the wheat plant population from 250 to 400 plants m-2 in the field also failed to enhance the competitiveness of wheat in either year.

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Manceaux-Cumer, Christelle. "Techniques de commande robuste : approche par multiplicateurs et approche stochastique." Toulouse, ENSAE, 1998. http://www.theses.fr/1998ESAE0003.

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Cette thèse concerne l'analyse et la synthèse de commandes, capables de stabiliser des systèmes linéaires en dépit d'incertitudes fréquentielles et paramétriques. Les travaux sont essentiellement axés sur la mise en œuvre pratique des méthodes de commande robuste. Mais, la prise en compte de la nature et de la structure de l'incertitude ainsi que le niveau de suffisance du critère de stabilité choisi rendent ce problème difficile à résoudre. Les méthodes couramment utilisées sont récapitulées mais ne répondent que partiellement au problème d'analyse. En particulier, les critères de stabilité mis sous forme de tests fréquentiels souffrent de l'échantillonnage fréquentiel et ne peuvent qu'induire des erreurs lors de la synthèse (μ-analyse et μ-synthèse). L'obtention de critères de stabilité pratiques pour la synthèse a donc orienté les travaux dans deux directions complémentaires. Le premier axe de recherche élabore des algorithmes fondés sur la théorie des multiplicateurs pour traiter des problèmes de type μ-synthèse (ou synthèse H₂ robuste) dans lesquels les incertitudes peuvent être mixtes. Là encore, nous utilisons une heuristique classique qui alterne entre analyse, à correcteur fixé, et synthèse, à multiplicateur fixé mais qui présente l'avantage d'éviter l'échantillonnage en fréquences. Au préalable, les multiplicateurs sont choisis dans une base soit polynômiale soit rationnelle. Ces approches se formulent par des problèmes d'optimisation convexe, de type LMI. Le scond axe de recherche utilise une technqiue hybride identification / commande pour le calcul des marges paramétriques d'un système commandé (PRABI), fondée sur la qualité d'identification paramétrique. Cette technique est exploitée pour l'obtention d'un nouvel algotithme de désensibilisation. On robustifie itérativement un compensateur à structure donnée, tout en assurant un compromis performance / robustesse paramétrique. Cela nous amène à travailler successivement dans l'espace des paramètres définissant le correcteur, puis dans l'espace des paramètres inhérents au modèle. En fin, on propose une généralisation de la méthode d'analyse PRABI, nécessitant le calcul d'un correcteur LQG équivalent. Toutes ces techniques sont validées sur des cas tests et des problèmes réalistes de l'aéronautique (missile, satellite de télécommunication).

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Cunha, Bianca Barino. "Qualidade do debridamento obtido pela técnica de instrumentação da lima única de NiTi em canais ovais e circulares." Universidade do Estado do Rio de Janeiro, 2010. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=6691.

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O presente avalia a qualidade da remoção de tecido pulpar após o preparo químico-cirúrgico realizado com a técnica da lima única, descrita por Ghassan Yared. Ainda não há publicado pesquisa sobre os resultados desta técnica. Este estudo compara o percentual de tecido pulpar remanescente em canais radiculares ovais e circulares de incisivos inferiores recém-extraídos que possuíssem polpa viva e armazenados em formol a 10%. Foram comparadas duas técnicas: ProTaper Universal e a técnica da lima única F2. Após uma rigorosa seleção, quarenta e oito dentes com polpa viva que possuíam indicação de extração, foram preparados, classificados em canais ovais e circulares, separados aleatoriamente em 4 grupos e instrumentados com as duas técnicas. O grupo controle, com 12 espécimes, não recebeu nenhum tipo de intervenção. G1 (n=12), canais ovais, instrumentados com a técnica ProTaper Universal; G2 (n=12), canais ovais instrumentados com a técnica da lima única F2; G3 (n=12), canais circulares instrumentados com a técnica ProTaper Universal; G4 (n=12), canais circulares instrumentados com a técnica da lima única F2. Então, seções transversais foram preparadas para avaliação histológica. A análise da quantidade de tecido pulpar remanescente foi avaliada digitalmente. A análise preliminar dos dados brutos em conjunto de todos os grupos experimentais revelou um padrão de distribuição normal por meio do uso do teste Kolmogorov-Smirnov. A análise foi realizada, e os dados brutos foram avaliados através de métodos não-paramétricos: Teste H Kruskal-Wallis. O valor percentual mínimo de tecido remanescente foi de 0% e o máximo de 37,78% entre todos os grupos. Os valores relativos a quantidade de tecido pulpar remanescente variaram entre 0 a 43.47% m2. Os resultados do Teste H Kruskal-Wallis não revelaram diferenças entre as seções mais apicais (p > 0.05). Entretanto, foi encontrada diferença significante entre as seções mais apicais e a seção do terço médio (p < 0.05). Também foram encontradas diferenças significantes quando canais circulares foram comparados com canais ovais independente da técnica de instrumentação utilizada (p < 0.05). Porém, entre as duas técnicas de instrumentação estudadas, tanto nos canais ovais quanto para os os canais circulares, não houve diferença estatística significante (p > 0.05). A proposta deste estudo é a de fazer uma reflexão sobre a real necessidade de um grande número de instrumentos para o total preparo de canais radiculares, uma vez que nenhuma das técnicas foi capaz de debridar por completo o espaço do canal radicular.
The present study evaluates the quality of the pulp tissue removal after chemical and surgical preparation performed with the single file technique, described by Ghassan Yared. This study compares the percentage of remaining pulp tissue in root canals, oval and circular incisors freshly extracted possessing vital pulp and stored in formaldehyde 10%. Two techniques were compared: ProTaper Universal and the single file F2 technique. After careful selection, forty-eight teeth with vital pulp that were likely to extraction, were prepared and divided into oval and circular root canals, divided into 4 groups and instrumented with both techniques. The control group, with 12 specimens, received no intervention. G1 (n = 12), oval canals instrumented with the ProTaper Universal technique G2 (n = 12), oval canals instrumented using the single file F2 technique, G3 (n = 12), the circular canals instrumented with ProTaper Universal, G4 (n = 12), the circular canals instrumented with the single file F2 technique. After biomechanical preparation, cross sections were prepared for histological evaluation. The analysis of the amount of remaining pulp tissue was assessed digitally. Preliminary analysis of the raw data set of all experimental groups revealed a normal distribution pattern by using the Kolmogorov-Smirnov test. The statistical analysis was performed, and the raw data were evaluated by non-parametric methods: H Test Kruskal-Wallis. The minimum percentage was 0% and maximum of 37.78% among all groups. The images for the amount of remaining pulp tissue ranged from 0 to 43.47% m 2. H Test Kruskal-Wallis results revealed no differences among the most apical sections (p> 0.05). However, a significant difference was found at most apical section of the middle third (p <0.05). Significant differences were also found when the circular root canals were compared with oval canals, independent of instrumentation technique used (p <0.05). Neither these techniques studied, on oval or circular root canals had significant statistic difference (p> 0.05). The aim of this study is to reflect about the real need for a large number of files for the preparation of the total root area, since no technique was able to completely debride the root canal space.

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Gonzales, Oscar Guillermo Osorio. "Tranferts techniques et artistiques entre le Perou et l' Europe. Les architectes péruviens élèves de l' Ecole des Beaux-arts et les architectes européenes actifs à Lima (1888-1930)." Master's thesis, Universidade de Évora, 2019. http://hdl.handle.net/10174/27326.

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Introduction: Ce mémoire porte sur les transferts artistiques et techniques entre la France et le Pérou, au tournant des XIXᵉ et XXᵉ siècles. Il s‟intéresse plus particulièrement à la trajectoire de sept architectes, anciens élèves de l‟École des Beaux-Arts en France, qui ont travaillé à Lima entre 1888 et 1930. Les dates des études de ces praticiens se répartissent sur quatre décennies. D‟autres architectes ayant fait des études en Italie, en Espagne, aux États-Unis et en Allemagne, ont travaillé à Lima à cette période, mais l‟étude de ces derniers n‟a pas été possible dans le cadre limité de ce mémoire. Le parcours académique de ces architectes élèves de l‟Ecole des Beaux-arts a joué un rôle décisif dans leur production architecturale ; pourtant, il n‟existe pas de travaux académiques approfondis sur cette question au Pérou. Les raisons de ce manque sont multiples : les documents sur les parcours professionnels et universitaires de ces architectes ne se trouvent pas au Pérou, mais en France ; ils ne sont pour la plupart pas accessibles sur Internet, même si la mise en ligne de base de données et la numérisation des archives progressent. La professionnalisation de ces élèves péruviens et européens s‟est consolidée en Europe et elle est essentielle pour comprendre les choix techniques et stylistiques appliqués à leurs édifices construits à Lima, commandés par des clients ou des entreprises privées, ainsi que par l‟État. L‟une des raisons de ce travail est de mieux comprendre le patrimoine architectural de Lima, formé par un ensemble de bâtiments hétérogènes. Ce mélange architectural, propre aux villes de l‟Amérique Latine, ne reflète pas seulement l‟histoire indépendante du pays, mais aussi l‟incapacité des gouvernements à homogénéiser la ville et à mener à bien des projets de « modernisation »...

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Matos, Inês Alexandra dos Ramos Moreno Viegas. "Relatório de Estágio na Pierre Fabre Portugal, Lda." Master's thesis, Instituto Superior de Economia e Gestão, 2009. http://hdl.handle.net/10400.5/1669.

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Mestrado em Ciências Empresariais
O sucesso num ambiente competitivo de negócios, tal como hoje acontece, é uma possível consequência de uma, cada vez maior, administração eficaz dos Recursos Humanos. Estrutura, tecnologia, recursos financeiros e materiais são, apenas, aspectos físicos e ineficazes que precisam de ser aplicados de forma racional, através das pessoas que compõem a organização. Deste modo, o factor que, efectivamente, constitui a dinâmica das organizações são as pessoas. A Gestão de Recursos Humanos assume, assim, cada vez mais uma maior importância no desenvolvimento de uma cultura organizacional direccionada para a inovação e aprendizagem contínua (Chiavenato, 2004). Este trabalho é a etapa final de um longo percurso académico orientado para a obtenção do grau de mestre em Ciências Empresariais. O seu objectivo consiste em explanar tudo o que pude aprender durante o meu estágio curricular na Pierre Fabre Portugal, Lda. No Capítulo I, será apresentada a componente teórica do trabalho, onde será explanada a evolução da função Recursos Humanos ao longo dos tempos, bem como a relação que pode existir entre a estratégia das organizações e a estratégia da Gestão de Recursos Humanos, de acordo com as características de cada organização. Por fim, serão descritas algumas das técnicas e práticas utilizadas na Gestão de Recursos Humanos. No Capítulo II, será abordada a componente prática, consequência da aprendizagem obtida em tempo de estágio, para que, finalmente, no Capítulo III, se desenvolvam conclusões, fruto do confronto do enquadramento teórico com a componente prática.
Nowadays, the success in a competitive business environment is probably due to the increasing Human Resources effective management. Structures, technologies, financial resources and materials are just physical and ineffective aspects that need to be used in a rational way by the people who make the organization. Therefore, the factor that truly makes up the dynamic of organizations is people. The administration of Human Resources is gradually becoming more important in the development of an organizational culture moving towards innovation and continuous learning (Chiavenato, 2004). This report is the final stage of a long academic path for the title of Master in Management Sciences. Its main purpose is to fully explain everything I learned during my internship at Pierre Fabre Portugal, Lda. Chapter One contains the theory of the evolution of Human Resources through history and the possible connection between the strategies of an organization and the ones in Human Resources Management according to the main characteristics of each organization. Lastly, there is a description of some of the techniques and procedures used in Human Resources Management. In turn, Chapter Two is an approach to the practical elements that were learned during the internship culminating in Chapter Three in the form of conclusions stemming from the comparison between the theoretical and the practical aspects.

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Knoth, Stefanie. "Topic Explorer Dashboard : A Visual Analytics Tool for an Innovation Management System enhanced by Machine Learning Techniques." Thesis, Linnéuniversitetet, Institutionen för datavetenskap och medieteknik (DM), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-105981.

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Innovation Management Software contains complex data with many different variables. This data is usually presented in tabular form or with isolated graphs that visualize a single independent aspect of a dataset. However, displaying this data with interconnected, interactive charts provide much more flexibility and opportunities for working with and understanding the data. Charts that show multiple aspects of the data at once can help in uncovering hidden relationships between different aspects of the data and in finding new insights that might be difficult to see with the traditional way of displaying data. The size and complexity of the available data also invites analyzing it with machine learning techniques. In this thesis it is first explored how machine learning techniques can be used to gain additional insight from the data and then the results of this investigation are used together with the original data in order to build a prototypical dashboard for exploratory visual data analysis. This dashboard is then evaluated by means of ICE-T heuristics and the results and findings are discussed.

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22

Carvalho, Maira de Souza. "Análise da capacidade de limpeza promovida por dois sistemas de lima única em movimento reciprocante." Universidade Federal do Amazonas, 2014. http://tede.ufam.edu.br/handle/tede/4061.

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FAPEAM - Fundação de Amparo à Pesquisa do Estado do Amazonas
The purpose of this study was to evaluate hystologically the cleaning capacity promoted by two reciprocating single-file systems the root canal system. To perform the experiment, 25 mandibular molars were selected, with mesial root canal curvature degree between 20º and 40º and radius of canal curvature ≤10 mm. Using K-type files, it was evaluated the presence of independent foramens with anatomical diameters compatible with #15 instrument. To standardize the size of the teeth in 16 mm crowns were partially sectioned. The selected specimens were divided in two experimental groups of 10 teeth each, Reciproc Group and WaveOne Group, and a Control Group, formed by 5 teeth. Then silicone blocks were prepared, which to be posted in a vise-grip, enabled the standardization of instrumentation position. The working length of the mesiobuccal canals was determined subtracting 0,5mm from apical foramen; Reciproc Group was prepared only with a R25 file in three peck motions towards the apex. The WaveOne Group used the Primary instrument, the same way formerly described. 2,5% sodium hypochlorite was used as irrigant solution, 1ml being used at each insertion of the instrument. The Control Group was uninstrumented and unirrigated. After canal preparation, the apical thirds were submitted to histological processing to obtain 15 serial transverse cross sections (5 μm), stained with hematoxylin and eosin. Histological analysis was performed by analysis of the cross-sections with 230x magnification and quantification of debris through the superposition of a grid. Data were submitted to Kruskal-Wallis test and Dunn's Multiple Comparisons Test (P = 005). The results showed no differences (P>0,05) between Reciproc (286,38) and WaveOne (325,20) Groups. In comparing the experimental groups with the Control Group (654,36), a statistically significant difference was found (P <0.001). Based on the methodology used and the results obtained, it may be concluded that there was no statistically significant difference between the the single-file and reciprocating motion systems.
O objetivo do presente estudo foi avaliar, por meio da análise histológica, a capacidade de limpeza do sistema de canais radiculares promovida por dois sistemas de lima única em movimento reciprocante. Para realização do experimento foram selecionados 25 molares inferiores com grau de curvatura da raiz mesial entre 20° e 40° e raio de curvatura ≤10 mm. Com a utilização de limas tipo K, avaliou-se a presença de forames independentes com diâmetros anatômicos compatíveis com um instrumento #15. Para padronização do tamanho dos dentes em 16 mm as coroas foram parcialmente seccionadas. Os espécimes selecionados foram divididos em dois grupos experimentais com 10 dentes cada, Grupo Reciproc e Grupo WaveOne, e um Grupo Controle, composto por 5 dentes. A seguir, foi confeccionado um bloco de silicone, que ao ser afixado em uma morsa de bancada, possibilitou a padronização da posição de instrumentação. O comprimento de trabalho dos canais mesiais foi definido a 0,5 mm aquém ao ápice, sendo o Grupo Reciproc preparado apenas com a lima R25 em três movimentos de entrada e saída em direção apical, no Grupo WaveOne utilizou-se o instrumento Primary com a mesma cinemática. Hipoclorito de sódio a 2,5% foi a solução irrigante empregada, sendo utilizado 1 ml a cada inserção do instrumento. O Grupo Controle não passou por preparo químico-mecânico e protocolo de irrigação. Após a instrumentação, o terço apical de cada espécime foi submetido ao processamento histológico de rotina para obtenção de 15 cortes com 5 μm de espessura, corados com hematoxilina e eosina. A análise histológica se deu pela avaliação das lâminas com aumento de 230x e determinação do percentual de debris por meio da superposição de uma grade de integração. Os dados obtidos foram submetidos ao teste de Kruskall-Wallis e teste de Múltiplas Comparações de Dunn (P=0,05). Os resultados mostraram não haver diferenças (P>0,05) entre Grupo Reciproc (286,38) e Grupo WaveOne (325,20). Na comparação dos grupos experimentais com o Grupo Controle (654,36), diferença estatística significante foi encontrada (P<0,001). Com base na metodologia empregada e nos resultados obtidos, conclui-se que não houve diferença estatisticamente significante entre os dois sistemas de instrumentação que empregam lima única e movimento reciprocante.

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23

Rickards, Jeremy. "Effect of suction on the evolution of laminar boundary layers, including the development of acoustic and LDA transition detection techniques." Thesis, University of Bristol, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.259447.

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24

Yameogo, Yvon Sosthène. "Etudes de nouvelles techniques d'estimation et d'égalisation de canal adaptées au systéme SC-FDMA." Phd thesis, Université Rennes 1, 2011. http://tel.archives-ouvertes.fr/tel-00657895.

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Le SC-FDMA " Single-Carrier Frequency Division Multiple Acces ", est une technique d'accès multiple à répartition fréquentielle, permettant d'allouer efficacement aux différents mobiles, les ressources de communication. Cette technique a suscité un intérêt particulier lors des conventions de normalisation du standard 3GPP LTE " Long Term Evolution ". Le regain de considération pour cette technique, est lié au fait qu'elle engendre des signaux temporels à faible variation d'amplitude caractérisée par un faible PAPR ou " Peak to Average Power Ratio ". Cet avantage majeur, rend possible l'utilisation de l'amplificateur de puissance du système dans sa zone proche du point de compression, maximisant ainsi son rendement sans toutefois risquer l'apparition des distorsions. C'est pourquoi, ce système a été adopté dans la norme 3GPP LTE comme technique d'accès multiple pour la voix montante. Cependant, dans les spécifications du 3GPP LTE un symbole sur sept est systématiquement réservé pour l'estimation de canal sur toutes les porteuses du système engendrant ainsi une réduction importante du débit utile du signal transmis. L'objectif de cette thèse est de proposer des techniques d'estimation et d'égalisation de canal adaptées pour le SC-FDMA afin d'éviter tant que possible cette perte de débit. Nous avons pu analyser, quelques techniques d'égalisation comme celle basée sur des références fantômes, mais également quelques techniques d'estimation de canal comme celle basée sur un " Ajout de Signal "dans la bande passante du signal utile.

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Wheeler, Sonya. "A structured technique for applying risk based internal auditing in information technology environments : (with specific reference to llA RBIA, King Report and CobiT) /." Link to the online version, 2005. http://hdl.handle.net/10019/1310.

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Norsten, Theodor. "Exploring the Potential of Twitter Data and Natural Language Processing Techniques to Understand the Usage of Parks in Stockholm." Thesis, KTH, Geoinformatik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-278532.

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Traditional methods used to investigate the usage of parks consists of questionnaire which is both a very time- and- resource consuming method. Today more than four billion people daily use some form of social media platform. This has led to the creation of huge amount of data being generated every day through various social media platforms and has created a potential new source for retrieving large amounts of data. This report will investigate a modern approach, using Natural Language Processing on Twitter data to understand how parks in Stockholm being used. Natural Language Processing (NLP) is an area within artificial intelligence and is referred to the process to read, analyze, and understand large amount of text data and is considered to be the future for understanding unstructured text. Twitter data were obtained through Twitters open API. Data from three parks in Stockholm were collected between the periods 2015-2019. Three analysis were then performed, temporal, sentiment, and topic modeling analysis. The results from the above analysis show that it is possible to understand what attitudes and activities are associated with visiting parks using NLP on social media data. It is clear that sentiment analysis is a difficult task for computers to solve and it is still in an early stage of development. The results from the sentiment analysis indicate some uncertainties. To achieve more reliable results, the analysis would consist of much more data, more thorough cleaning methods and be based on English tweets. One significant conclusion given the results is that people’s attitudes and activities linked to each park are clearly correlated with the different attributes each park consists of. Another clear pattern is that the usage of parks significantly peaks during holiday celebrations and positive sentiments are the most strongly linked emotion with park visits. Findings suggest future studies to focus on combining the approach in this report with geospatial data based on a social media platform were users share their geolocation to a greater extent.
Traditionella metoder använda för att förstå hur människor använder parker består av frågeformulär, en mycket tids -och- resurskrävande metod. Idag använder mer en fyra miljarder människor någon form av social medieplattform dagligen. Det har inneburit att enorma datamängder genereras dagligen via olika sociala media plattformar och har skapat potential för en ny källa att erhålla stora mängder data. Denna undersöker ett modernt tillvägagångssätt, genom användandet av Natural Language Processing av Twitter data för att förstå hur parker i Stockholm används. Natural Language Processing (NLP) är ett område inom artificiell intelligens och syftar till processen att läsa, analysera och förstå stora mängder textdata och anses vara framtiden för att förstå ostrukturerad text. Data från Twitter inhämtades via Twitters öppna API. Data från tre parker i Stockholm erhölls mellan perioden 2015–2019. Tre analyser genomfördes därefter, temporal, sentiment och topic modeling. Resultaten från ovanstående analyser visar att det är möjligt att förstå vilka attityder och aktiviteter som är associerade med att besöka parker genom användandet av NLP baserat på data från sociala medier. Det är tydligt att sentiment analys är ett svårt problem för datorer att lösa och är fortfarande i ett tidigt skede i utvecklingen. Resultaten från sentiment analysen indikerar några osäkerheter. För att uppnå mer tillförlitliga resultat skulle analysen bestått av mycket mer data, mer exakta metoder för data rensning samt baserats på tweets skrivna på engelska. En tydlig slutsats från resultaten är att människors attityder och aktiviteter kopplade till varje park är tydligt korrelerat med de olika attributen respektive park består av. Ytterligare ett tydligt mönster är att användandet av parker är som högst under högtider och att positiva känslor är starkast kopplat till park-besök. Resultaten föreslår att framtida studier fokuserar på att kombinera metoden i denna rapport med geospatial data baserat på en social medieplattform där användare delar sin platsinfo i större utsträckning.

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Thévenet, Jean-Baptiste. "Techniques d'optimisation avancées pour la synthèse de lois de commande." Toulouse 3, 2005. http://www.theses.fr/2005TOU30125.

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La résolution de nombreux problèmes d'automatique n'est pas couverte par les techniques disponibles actuellement. Elle nécessite des développements algorithmiques importants en optimisation, dans le domaine des inégalités matricielles non-convexes. Cette thèse met en oeuvre plusieurs approches complémentaires dans ce contexte. En premier lieu, les méthodes "spectral SDP", baseés sur l'utilisation de Lagrangiens augmentés, nous conduisent à la conception d'un logiciel, specSDP, et à la résolution d'un grand nombre de problèmes en commande : synthèse multimodèle ou structurée, contrôle d'ordre réduit. Une étude de convergence locale est également menée pour le cas classique, présageant d'évolutions positives. La deuxième approche proposée s'inspire d'une formulation non-lisse des problèmes BMI et des techniques associées. Nous exhibons, pour cette méthode, des résultats numériques probants, obtenus sur des exemples de grande dimension, qui mettent en échec les rares méthodes existantes
This thesis research area belongs to the class of nonlinear semidefinite programming, an emerging and challenging domain in optimization which is of central importance in robust control and relaxation of hard decision problems. Our contribution addresses convergence of algorithms, practical implementations and testing on applications in the field of reduced-order output feedback control. Firstly, our augmented Lagrangian-type "spectral SDP" method has shown to be extremely efficient on a variety of middle-scale BMI programs, including simultaneous, structured, or mixed H2/Hinf synthesis problems. Local convergence properties of the algorithm were studied as well, as far as classical nonlinear programs are concerned. On the other hand, we then focused on nonsmooth strategies for large bilinear matrix inequalities. Problems with up to a few thousand variables were successfully handled through this method, where alternative approaches usually give failure

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Saldaña, García Wilson Andrés. "Técnicas de valorización para medir el crecimiento empresarial en el proceso de fusión de la empresa financiera S.A. de Lima Metropolitana, Distrito de Surco, año 2016." Bachelor's thesis, Universidad Ricardo Palma, 2016. http://cybertesis.urp.edu.pe/handle/urp/1379.

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El objetivo principal de la presente tesis es aplicar técnicas de valorización con información que permitan determinar el valor de la empresa financiera S.A. la cual se fusionó absorbiendo a la entidad financiera Caja provincia en el año 2015 y sus implicancias para el mejoramiento y crecimiento competitivo entre empresas del mismo rubro además del crecimiento patrimonial .El método que fue aplicado en el presente trabajo es de matematización y diseño de Investigación - Acción, además de mostrar este diseño se utilizaron instrumentos que son las técnicas de valorización, entrevista al gerente de finanzas de la Financiera S.A., cuestionario a trabajadores de cada área de la Financiera S.A. con las cuales se obtuvo importantes informaciones necesarias para el desarrollo del trabajo de investigación, la fusión por absorción de la Financiera S.A. y caja Provincia significó que Caja Provincia entregó sus activos y pasivos para repotenciar a la empresa Financiera S.A. ocasionando inmediatamente un aumento patrimonial y un mayor capital de trabajo que le ha permitido ir creciendo de manera progresiva, en el trabajo de campo efectuado se observa que la fusión que se realizó de la Financiera S.A. absorbiendo a Caja provincia, según se muestra en los resultados de las técnicas aplicadas efectivamente está dando resultados positivos en el transcurso del tiempo por cuanto el valor de la empresa está creciendo y continuará creciendo significativamente. El resultado de la investigación demuestra que se ha cumplido con la hipótesis: Las técnicas de valorización permiten medir el crecimiento empresarial en un proceso de fusión de las empresas Financiera S.A. y Caja Provincia buscando el crecimiento a través de la obtención de activos estratégicos y mejorando su plan de trabajo para el periodo 2016-2018. Por último la Financiera S.A. al fusionarse, podrá competir en el mercado financiero con entidades de alto nivel, lo que la hará más atractiva al público que se encuentre buscando nuevas opciones donde colocar o invertir su dinero. The main objective of this thesis is to apply valuation technics with information that will allow us determine the value of Financiera S.A. which merged by absorption with the financial entity known as Caja Provincia in the year 2015 and its implications for the betterment and competitive growth between companies of the same category as well as their patrimonial growth. The method applied in the present paper is the mathematizing technique and the design of research – action. In addition to this design, valuation technics and interviews to the financial manager of Financiera S.A. as well as to the workers of every area of the financial department were used. This provided us with important information to the development of this research. The merger by absorption of Financiera S.A. and Caja Provincia meant that Caja Provincia gave its assets and liabilities to the company Financiera S.A. in order to potentiate it and consequently this action translated in an increase in the patrimony and the working capital which has allowed its progressive growth. In the field work done we can observe that the merger made by Financiera S.A. absorbing Caja Provincia, according to the results of the applied technics has, effectively, been giving positive results in the period of time lapsed and we can see that reflected in the company’s sustained growth. The result of the research shows that the hypothesis has been proved: the valuation techniques allow us measure the company’s growth during a merger process such as the one that Financiera S.A. and Caja Provincia underwent, in their search to improve themselves by acquiring strategic assets and upgrading their working plan for the period 2016-2018. Finally, after this merger, Financiera S.A. will be able to compete in the financial market with other entities of high profile, which in case will make it a more attractive option to the public’s eye and people who might be looking for new options or places to invest their money or savings.

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Grinover, Marina Mange. "Laboratório de projeto e construção: prática da arquitetura na obra de Renzo Piano e João Filgueiras Lima." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/16/16133/tde-09062015-120201/.

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Esta investigação desenvolveu-se a partir do questionamento da prática da arquitetura em relação a elaboração do projeto arquitetônico e a construção da obra. A escolha do estudo de caso da obra de Renzo Piano (1937 -), arquiteto italiano e João Filgueiras Lima, (1934 - 2014) arquiteto brasileiro, o Lelé, definiu-se por apresentarem, ambos, soluções de interesse estético e técnico que pareciam ter se extinguido. A documentação motivou um esforço teórico e histórico para ampliar os conceitos usados na analise da arquitetura. A partir da escolha de um recorte histórico, qual seja as décadas de 1960 a 90, período de debates sobre a validade dos preceitos modernos na arquitetura e de uma produção plural ligada à economia pós-industrial e à cultura de massa, analisou-se um conjunto selecionado de obras e seu diálogo, pela prática, com este debate. Sem a pretensão de fazer um trabalho comparativo, deu-se ênfase à análise de cada arquiteto em seu contexto sociotécnico particular, consolidando um modo de análise de obra que se desprende dos fatos documentados e se debruça sobre as motivações mais profundas do fabricar arquitetura. Ao compreender a poética que nasce deste processo orgânico entre pensar e fazer, definem-se valores técnicos e sociais fundamentais para o entendimento da dimensão cultural do trabalho do arquiteto. Nesta edição, a primeira parte do texto, assim, aborda os conceitos de arte, técnica e trabalho prático frente a cultura arquitetônica destes anos entre 1960 e 1990. E a segunda parte é a análise de obra, propriamente dita, com um capítulo destinado a cada arquiteto. O exame da inter-relação de processos criativos e técnicos da arquitetura teve o propósito de definir o conceito de Laboratório de Projeto e Construção.
This investigation was developed from architecture practice questioning in relation to the elaboration of architectural design and work construction. The case study choice of the work from Renzo Piano (1937 -), Italian architect, and João Filgueiras Lima, (1934 - 2014) Brazilian architect, also known as Lelé, was defined due to the fact that both feature solutions of aesthetic and technical interest which seemed to have been extinguished. The documentation motivated a theoretical and historical effort to broaden concepts used in architecture analysis. Taking as a reference the historical view from the 1960s to the 1990s, period of debates about the validity of modern precepts in architecture and of an intense production linked to post-industrial economy and mass culture, a selection of works and their dialogue, through practice, with this very debate, was analyzed. With no pretension of preparing a comparative thesis, the analysis of each architect in their own social technical context was emphasized, consolidating a work analysis mode which detaches itself from documented facts, rather leaning over deeper motivations to produce architecture. Through the understanding of the poetry which is born from this organic process between thinking and doing, fundamental technical and social values are defined for the understanding of the social dimension of the architects work. In this edition, the first part of the text addresses the art concepts, technique and practical work in comparison to the architectural culture during these years between 1960 and 1990. The second part is the work analysis itself, with a chapter dedicated to each architect. The study of the interrelation between architecture creative and technical processes had the goal of defining the concept of Project and Construction Lab.

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Ramos, Fernandez Julio Cesar. "Intégration de techniques floues pour la modélisation, l'identification et la commande de systèmes non linéaires." Phd thesis, Université du Sud Toulon Var, 2008. http://tel.archives-ouvertes.fr/tel-00276811.

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La modélisation et l'identification floues de systèmes avec de multiples entrées et une seule sortie (MISO), non linéaires, non stationnâmes et avec perturbations sont présentés. A cet effet, des techniques d'apprentissage floues sont utilisées. C'est ainsi qu'un modèle est mis en place à partir des mesures d'un système bio-climatique, qui concerne l'étude d'une serre expérimentale de l'Université du Sud Toulon Var (USTV) en France. L'analyse multi-modèles est utilisée, avec la structure de règles floues proposée par Takagi-Sugeno-Kang (TS), où les prémisses des règles sont identifiées au moyen de l'algorithme flou de C-Means. La démarche d'apprentissage local et global est introduite pour identifier les paramètres linéaires des conséquences des règles floues. Ainsi, des modèles flous TS sont obtenus avec une démarche pluri-objectif. Dans le cadre de la technique de la modélisation et de F identification floues TS, le développement d'un algorithme est détaillé, pour modéliser des systèmes SISO, pour lesquels l'algorithme flou de Gustafson-Kessel (G-K) sera mis en oeuvre afin d'identifier les prémisses des règles floues. L'innovation réside dans le fait que les conséquences des règles floues sont des polynômes d'ordre cubique. Enfin, avec la technique LMI et avec un modèle développé pour un système bio-climatique, la synthèse d'un contrôleur stable avec l'approche de Lyapunov qui régule le chauffage de la serre, est réalisée pour maintenir le paramètre VPD dans un domaine fiable pour la plantation.

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Danès, Patrick. "Techniques d'automatique et de traitement du signal pour l'asservissement visuel et la perception auditive en robotique." Habilitation à diriger des recherches, Université Paul Sabatier - Toulouse III, 2010. http://tel.archives-ouvertes.fr/tel-00604522.

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Les travaux présentés dans ce manuscrit d'Habilitation à Diriger des Recherches concernent essentiellement un ensemble de primitives du niveau fonctionnel de la Robotique, dont les fondements scientifiques sont ancrés dans l'Automatique et le Traitement du Signal. Bien plus qu'un domaine d'application de théories développées par ailleurs, la Robotique, par ses spécificités ou ses contraintes, " questionne " souvent l'état de l'art en Automatique et Signal, voire exige des extensions méthodologiques non triviales. C'est la richesse du dialogue entre ces trois disciplines qui a constitué le fil conducteur principal de nos recherches. Un premier volet de nos travaux vise à développer un cadre générique pour l'analyse et la synthèse "multicritères" de commandes référencées vision, i.e. qui prennent en compte l'ensemble des contraintes (visibilité, saturations d'actionneurs, contraintes 3D pendant le déplacement, etc.). Ces problèmes sont ramenés à l'analyse en stabilité / la stabilisation de systèmes non linéaires incertains rationnels sous contraintes rationnelles. Le support théorique est la théorie de Lyapunov et l'optimisation LMI. Par dualité, la localisation visuelle est abordée par des techniques de filtrage ensembliste robuste de systèmes rationnels. Une deuxième contribution s'inscrit dans la thématique relativement récente de l'Audition en Robotique. Nous proposons des fonctions auditives bas-niveau pour la détection de sources sonores, leur localisation et leur extraction. Un capteur auditif intégré original conçu au LAAS-CNRS permet leur implémentation. Le support théorique est le traitement d'antenne (formation de voie, méthodes à haute résolution) et l'optimisation LMI. Plus récemment, nous avons posé les fondements d'une nouvelle approche pour la détection d'activité vocale, sur la base du filtrage adapté stochastique. En parallèle à ces développements ciblés, un travail de fond dans les thématiques du filtrage stochastique et de la détection de ruptures s'est matérialisé par des collaborations scientifiques dans des domaines d'application ciblés : méthodes séquentielles de Monte Carlo et Quasi Monte Carlo pour le suivi visuel de personnes, de gestes, et la capture de mouvement par vision ; détection de ruptures et filtrage IMM entre modèles d'état d'ordres hétérogènes pour la surveillance de scènes dynamiques et la localisation ARGOS. Certaines des thématiques exposées ci-dessus se " rejoignent " au sein des axes structurants de nos développements futurs. Un effort particulier concernera la perception active (i.e. exploitant la proprioception et le mouvement), déclinée dans le cadre de l'audition binaurale, ainsi que la fusion de données auditives embarquées et déportées dans des lieux intelligents.

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Gul, Ahmet Bahtiyar. "Holistic Face Recognition By Dimension Reduction." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/1056738/index.pdf.

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Face recognition is a popular research area where there are different approaches studied in the literature. In this thesis, a holistic Principal Component Analysis (PCA) based method, namely Eigenface method is studied in detail and three of the methods based on the Eigenface method are compared. These are the Bayesian PCA where Bayesian classifier is applied after dimension reduction with PCA, the Subspace Linear Discriminant Analysis (LDA) where LDA is applied after PCA and Eigenface where Nearest Mean Classifier applied after PCA. All the three methods are implemented on the Olivetti Research Laboratory (ORL) face database, the Face Recognition Technology (FERET) database and the CNN-TURK Speakers face database. The results are compared with respect to the effects of changes in illumination, pose and aging. Simulation results show that Subspace LDA and Bayesian PCA perform slightly well with respect to PCA under changes in pose
however, even Subspace LDA and Bayesian PCA do not perform well under changes in illumination and aging although they perform better than PCA.

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Zanchin, Volnei Tonin. "Projetos de controladores para sistemas de potência utilizando LMI'S." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2003. http://hdl.handle.net/10183/6000.

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A presente dissertação tem como objetivo estudar e aprimorar métodos de projetos de controladores para sistemas de potência, sendo que esse trabalho trata da estabilidade dinâmica de sistemas de potência e, portanto, do projeto de controladores amortecedores de oscilações eletromecânicas para esses sistemas. A escolha dos métodos aqui estudados foi orientada pelos requisitos que um estabilizador de sistemas de potência (ESP) deve ter, que são robustez, descentralização e coordenação. Sendo que alguns deles tiveram suas características aprimoradas para atender a esses requisitos. A abordagem dos métodos estudados foi restringida à análise no domínio tempo, pois a abordagem temporal facilita a modelagem das incertezas paramétricas, para atender ao requisito da robustez, e também permite a formulação do controle descentralizado de maneira simples. Além disso, a abordagem temporal permite a formulação do problema de projeto utilizando desigualdades matriciais lineares (LMI’s), as quais possuem como vantagem o fato do conjunto solução ser sempre convexo e a existência de algoritmos eficientes para o cálculo de sua solução. De fato, existem diversos pacotes computacionais desenvolvidos no mercado para o cálculo da solução de um problema de inequações matriciais lineares. Por esse motivo, os métodos de projeto para controladores de saída buscam sempre colocar o problema na forma de LMI’s, tendo em vista que ela garante a obtenção de solução, caso essa solução exista.
The current work aims to study and improve the power system controllers design methods. And we are interested in the dynamic stability of power systems, and thus, in the design of electromechanical oscillations damping controllers. The design methods studied here were chosen to fill the requirements that a power system stabilizer (PSS) must obey, that are robustness, decentralization and coordination. And the characteristics of some of these methods were improved and extended in order to meet these requirements. The approach of the studied methods is restricted to the time domain analysis because of the easiness to model the parametric uncertainties, to meet the robustness requirement, and because it also simplifies the formulation of the decentralized control problem. Moreover the time domain approach allows one to use linear matrix inequalities (LMI’s) to formulate the design problem, which has the advantages that the solution set is always convex, and that there exists efficient algorithms to compute its solution. There are several software packages developed, in the market, to solve the problem of linear matrix inequality. So that the design methods using output controllers always try to formulate this problem in the form of an LMI, because it guarantees that one can obtain a solution for the problem, in the case that this solution exists.

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Itani, Lama [Verfasser], and Christof [Akademischer Betreuer] Schulz. "Development and application of optical diagnostic techniques for assessing the effects of preferential evaporation of multi-component fuels under engine-relevant conditions / Lama Itani ; Betreuer: Christof Schulz." Duisburg, 2018. http://d-nb.info/1154385892/34.

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Balavoine, Aurele. "Mathematical analysis of a dynamical system for sparse recovery." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/51882.

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This thesis presents the mathematical analysis of a continuous-times system for sparse signal recovery. Sparse recovery arises in Compressed Sensing (CS), where signals of large dimension must be recovered from a small number of linear measurements, and can be accomplished by solving a complex optimization program. While many solvers have been proposed and analyzed to solve such programs in digital, their high complexity currently prevents their use in real-time applications. On the contrary, a continuous-time neural network implemented in analog VLSI could lead to significant gains in both time and power consumption. The contributions of this thesis are threefold. First, convergence results for neural networks that solve a large class of nonsmooth optimization programs are presented. These results extend previous analysis by allowing the interconnection matrix to be singular and the activation function to have many constant regions and grow unbounded. The exponential convergence rate of the networks is demonstrated and an analytic expression for the convergence speed is given. Second, these results are specialized to the L1-minimization problem, which is the most famous approach to solving the sparse recovery problem. The analysis relies on standard techniques in CS and proves that the network takes an efficient path toward the solution for parameters that match results obtained for digital solvers. Third, the convergence rate and accuracy of both the continuous-time system and its discrete-time equivalent are derived in the case where the underlying sparse signal is time-varying and the measurements are streaming. Such a study is of great interest for practical applications that need to operate in real-time, when the data are streaming at high rates or the computational resources are limited. As a conclusion, while existing analysis was concentrated on discrete-time algorithms for the recovery of static signals, this thesis provides convergence rate and accuracy results for the recovery of static signals using a continuous-time solver, and for the recovery of time-varying signals with both a discrete-time and a continuous-time solver.

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López, Viena Karen Gabriela, and Avendaño Nicolás Málaga. "Immediate complications in post-mastectomy breast reconstruction: comparison between different surgical techniques in patients with breast cancer at the National Institute of Neoplastic Diseases in Lima, Peru 2014-2018." Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2021. http://hdl.handle.net/10757/656154.

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Introduction: The number of breast reconstructions after breast cancer is increasing over the years. This study evaluates complications in the first 30 days after breast reconstruction post mastectomy in different surgical techniques for patients with non-metastatic breast cancer. Methods: Retrospective cohort including patients who underwent breast reconstruction post mastectomy at the National Institute of Neoplastic Diseases (INEN) 2014-2018. Outcomes were immediate complications (first 30 days after surgery). Cumulative incidences were obtained. Association with clinical and demographic factors was evaluated using adjusted relative risk (aRR) obtained via Poisson Regression with robust variances. Results: 2092 patients had mastectomy at INEN during the study period, but only 271 underwent breast reconstruction. From them, 148 had complete data and fulfilled the selection criteria. Median age was 45 years old, 62.16% had overweight/obesity, and 35.85% had clinical stage III. 28.38% had immediate autologous reconstruction, 33.11% immediate prosthetic reconstruction, and 38.51% delayed reconstruction of any type. 48.65% had some surgical complication in the first 30 days, being the most frequent dehiscence (20.27%) and superficial infection (18.92%). Overweight/Obesity (aRR 1.96; 1.24-3.10) and having immediate reconstruction (aRR 1.54; 1.04-2.27) were associated to complications. Prosthetic technique use was protective (aRR 0.59; 0.40-0.85), as well as Neoadjuvant Chemotherapy (aRR 0.65; 0.42-0.99). Conclusions: The prosthetic surgical technique had less early complication incidence than the autologous one. On the other hand, immediate surgery after mastectomy was more likely to present complications compared with delaying. Variables as obesity, neoadjuvant therapy and ECOG intervened in the incidence of complications.
Introducción: El número de reconstrucciones mamarias post cáncer de mama ha ido en aumento. Este estudio evalúa las complicaciones en los primeros 30 días luego de reconstrucción mamaria post mastectomía para cáncer de mama no metastásico en sus diferentes técnicas quirúrgicas. Métodos: Cohorte retrospectiva de pacientes con reconstrucción mamaria post mastectomía en el Instituto Nacional de Enfermedades Neoplásicas (INEN) entre 2014-2018. Los desenlaces fueron las complicaciones quirúrgicas en los 30 días siguientes a la cirugía. Se obtuvieron incidencias acumuladas, y se evaluó su asociación con diversos factores clínico-demográficos mediante riesgos relativos crudos y ajustados (aRR) obtenidos vía Regresión de Poisson con varianza robusta. Resultados: De 2092 pacientes que tuvieron mastectomía en el INEN entre 2014-2018, solo 271 tuvieron reconstrucción mamaria. De ellas 148 tuvieron datos completos y cumplieron los criterios de selección. La mediana de edad fue 45 años, 62.16% tuvieron sobrepeso/obesidad, y 35.85% tenían estadio clínico III. El 28.38% tuvieron reconstrucción inmediata autóloga, 33.11% reconstrucción inmediata usando prótesis, y 38.51% reconstrucción tardía. El 48.65% de los pacientes experimentó alguna complicación en el mes siguiente post cirugía, siendo las complicaciones más frecuentes dehiscencia de sutura (20.27%) e infección superficial (18.92%). Obesidad (RR 1.96; 1.24-3.10), y tener Técnica Inmediata (RR 1.54; 1.04-2.27) se asociaron a más complicaciones. Uso de Técnica Protésica fue protector (RR 0.59; 0.40-0.85), así como también Quimioterapia Neoadyuvante (RR 0.65; 0.42-0.99). Conclusiones: La técnica quirúrgica protésica tuvo menos probabilidades de presentar complicaciones que la autóloga. Asimismo, la cirugía inmediata presenta más probabilidades de presentar complicaciones que la diferida. Las variables como obesidad, terapia neoadyuvante y ECOG intervienen en la presentación de complicaciones.
Tesis

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Alkadee, Dareen. "Techniques de réduction et de traitement des émissions polluantes dans une machine thermique." Phd thesis, Conservatoire national des arts et metiers - CNAM, 2011. http://tel.archives-ouvertes.fr/tel-01005123.

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Cette thèse de doctorat, a consisté, dans une première partie, à introduire d'une part, la notion de l'analyse du cycle de vie " ACV " et celle des biocarburants. D'autre part, à présenter l'intérêt d'appliquer une ACV sur des biocarburants afin de valoriser leurs bilans énergétiques et analyser leurs impacts environnementaux face aux carburants conventionnels. Dans une deuxième partie, nous avons comparé, d'un point de vue énergétique et environnemental, 3 scénarios de production d'électricité : 2 scénarios de cogénération (turbine à vapeur et ORC) pour la production d'énergie électrique et thermique à partir de biomasse, et un scénario de cogénération par moteur diesel. Ces scénarios sont comparés à l'aide de deux méthodes orientées " analyse des dommages ": Eco-indicateur 99 (E) et IMPACT2002+Dans une troisième partie, on a abordé la valorisation du biogaz sous forme de carburant dans des moteurs "dual fuel" pour des engins agricoles dans le but de déterminer l'impact environnemental lié à l'utilisation de ce carburant alternatif au diesel par rapport aux autres biocarburants. Les méthodes Eco-indicateur 99 (E) et CML ont été utilisées ici. On a pu ainsi identifier les principaux polluants générés à chaque étape du cycle de vie de l'agrocarburant et les étapes qui ont les plus grands impacts environnementaux et on a identifié, selon nos critères et par rapport au contexte, le scénario énergétique le plus compatible avec le principe de développement durable.

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Cerrón, Vásquez Andrea Milagros, and Pucuhuayla Adamary Iriana Meza. "Association between preference of pediatric dentistry behavior management technique and parenting styles of parents of children aged 5 to 13 years cared for in a university health center of a private university in Lima, Peru." Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2021. http://hdl.handle.net/10757/656447.

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Aim: To assess the association between preference of pediatric management techniques and parenting styles of parents of children aged 5-13 years cared for in a university health center in Lima, Peru. Materials and methods: The total of the respondents were 160 parents (77 % are female and 78 % belong to the age range of 30 years and over). Parenting styles are assessed using the self-paced questionnaire Parenting Style Dimension Questionnaire (PSDQ). The preference of the behavior management techniques was evaluated by means of an informative sheet of own elaboration where six techniques are included according to the American Academy of Pediatric Dentistry (AAPD) of 2015. As father's age in intervals of years, sex of the father, educational level, number of children, sex of the children, age of the child in years and order of birth of the children. Chi Square and Fisher's Exact Test were analyzed for bivariate analysis and for the numerical variable used Kruskal Wallis. Results: There is no association between preference of behavior management technique and parenting styles. The prevalence of authoritative parenting style and a greater preference for communication techniques were determined, the latter regardless of the parenting style he manages at home. Conclusions: The preference of the behavior management technique is not associated with the parenting styles. However, the prevalence of communication techniques leads us to conclude that more studies should be carried out around it.
Objetivo: Evaluar la asociación que existe entre la preferencia de las técnicas de manejo en Odontopediatría y los estilos de crianza de los padres de niños con edades entre los 5 y 13 años que son atendidos en un Centro Universitario de Salud de la ciudad de Lima, Perú. Materiales y métodos: Se encuestó a un total de 160 padres de familia, de los cuales el 77 % era de sexo femenino y el 78 % pertenecía al grupo etario de 30 años a más. Los estilos de crianza se evaluaron por medio del cuestionario autoaplicado Parenting Style and Dimension Questionary (PSDQ); y la preferencia de las técnicas de manejo de conducta se evaluó por medio de una ficha informativa de elaboración propia, en la cual se incluyeron 6 de las 13 técnicas que se emplean de acuerdo con Behavior Guidance for the Pediatric Dental Patient de la American Academy of Pediatric Dentistry (AAPD) que fue publicada en el 2015. Las variables registradas fueron: edad del padre en intervalos de años, sexo del padre, nivel educativo, número de hijos, sexo de los hijos, edad del niño en años y orden de nacimiento de los hijos. Luego se utilizó la prueba Chi-cuadrado y la prueba exacta de Fisher para realizar el análisis bivariado, y se aplicó la prueba de Kruskal Wallis para la variable numérica. Resultados: No existe asociación entre la preferencia por una técnica de manejo de conducta y los estilos de crianza, puesto que en la investigación se observó una prevalencia del estilo de crianza autoritativo y una mayor preferencia por las técnicas de comunicación, indistintamente del estilo de crianza que se manejaba en las casas. Conclusiones: La preferencia de la técnica de manejo de conducta no está asociada a los estilos de crianza. Sin embargo, la prevalencia de las técnicas comunicativas permite concluir que deben realizarse más estudios en torno a esta.
Tesis

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Yoo, Heejong. "Low-Power Audio Input Enhancement for Portable Devices." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/6821.

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With the development of VLSI and wireless communication technology, portable devices such as personal digital assistants (PDAs), pocket PCs, and mobile phones have gained a lot of popularity. Many such devices incorporate a speech recognition engine, enabling users to interact with the devices using voice-driven commands and text-to-speech synthesis. The power consumption of DSP microprocessors has been consistently decreasing by half about every 18 months, following Gene's law. The capacity of signal processing, however, is still significantly constrained by the limited power budget of these portable devices. In addition, analog-to-digital (A/D) converters can also limit the signal processing of portable devices. Many systems require very high-resolution and high-performance A/D converters, which often consume a large fraction of the limited power budget of portable devices. The proposed research develops a low-power audio signal enhancement system that combines programmable analog signal processing and traditional digital signal processing. By utilizing analog signal processing based on floating-gate transistor technology, the power consumption of the overall system as well as the complexity of the A/D converters can be reduced significantly. The system can be used as a front end of portable devices in which enhancement of audio signal quality plays a critical role in automatic speech recognition systems on portable devices. The proposed system performs background audio noise suppression in a continuous-time domain using analog computing elements and acoustic echo cancellation in a discrete-time domain using an FPGA.

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Obrocki, Lea Marit [Verfasser]. "Advances in geoarchaeological site formation research by integrating geophysical methods, direct push sensing techniques and stratigraphic borehole data - case studies from central Europe and the western Peloponnese around ancient Olympia - / Lea Marit Obrocki." Mainz : Universitätsbibliothek Mainz, 2019. http://d-nb.info/118923730X/34.

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Gaye, Oumar. "Contrôle du profil de facteur de sécurité dans les plasmas de tokamak en dimension infinie." Angers, 2012. https://theses.hal.science/tel-00774718.

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Les besoins énergétiques croissants de la population mondiale requièrent le développement, la maîtrise et la fourniture de nouvelles formes d'énergie. Dans ce contexte, la fusion nucléaire est une piste de recherche extrêmement prometteuse. Le projet mondial ITER est destiné à démontrer la faisabilité scientifique et technique de la fusion nucléaire comme nouvelle source d'énergie. Un des nombreux verrous tient à la maîtrise de la distribution spatiale du profil de courant dans les plasmas de tokamak, paramètre clé pour la stabilité et la performance des expériences. L'évolution spatiotemporelle de ce courant est décrite par un ensemble d'équations aux dérivées partielles non linéaires. Ce document traite de la stabilisation par un contrôle robuste de la distribution spatiale du profil de courant en dimension infinie. Deux approches sont proposées : la première s'inspire d'une approche de type mode glissant et la seconde (de type proportionnelle et proportionnelle intégrale) est basée sur les fonctions de Lyapunov en dimension infinie. La conception des lois de contrôle est basée sur l'équation 1D de la diffusion résistive du flux magnétique. Les lois de contrôle sont calculées en dimension infinie sans discrétisation spatiale préalables
The increasing energy needs of the world population require the development, the control and the supply of new forms of energy. In this context, nuclear fusion is a track of extremely promising research. World project ITER is intended to prove the scientific and technical feasibility of nuclear fusion. One of the many key-goal is the control of the current profile spatial distribution in plasmas of tokamak, which is one of the main parameter for the stability and the performance of the experiments. The spatiotemporal evolution of this current is described by a set of nonlinear partial differential equations. In this document stabilization is proposed considering robust control of current profile spatial distribution in infinite dimension. Two approaches are proposed : the first one is based on sliding mode approach and the second one (of type proportional and proportional integral) is based on the Lyapunov functions in infinite dimension. The design of the control law is based on the 1D equation resistive diffusion of the magnetic flux. The control laws are calculated in infinite dimension without space discretization

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Hijazi, Hala. "Proposition d'une méthode spectrale combinée LDA et LLE pour la réduction non-linéaire de dimension : Application à la segmentation d'images couleurs." Thesis, Littoral, 2013. http://www.theses.fr/2013DUNK0516.

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Les méthodes d'analyse de données et d'apprentissage ont connu un développement très important ces dernières années. En effet, après les réseaux de neurones, les machines à noyaux (années 1990), les années 2000 ont vu l'apparition de méthodes spectrales qui ont fourni un cadre mathématique unifié pour développer des méthodes de classification originales. Parmi celles-ci ont peut citer la méthode LLE pour la réduction de dimension non linéaire et la méthode LDA pour la discrimination de classes. Une nouvelle méthode de classification est proposée dans cette thèse, méthode issue d'une combinaison des méthodes LLE et LDA. Cette méthode a donné des résultats intéressants sur des ensembles de données synthétiques. Elle permet une réduction de dimension non-linéaire suivie d'une discrimination efficace. Ensuite nous avons montré que cette méthode pouvait être étendue à l'apprentissage semi-supervisé. Les propriétés de réduction de dimension et de discrimination de cette nouvelle méthode, ainsi que la propriété de parcimonie inhérente à la méthode LLE nous ont permis de l'appliquer à la segmentation d'images couleur avec succès. La propriété d'apprentissage semi-supervisé nous a enfin permis de segmenter des images bruitées avec de bonnes performances. Ces résultats doivent être confortés mais nous pouvons d'ores et déjà dégager des perspectives de poursuite de travaux intéressantes
Data analysis and learning methods have known a huge development during these last years. Indeed, after neural networks, kernel methods in the 90', spectral methods appeared in the years 2000. Spectral methods provide an unified mathematical framework to expand new original classification methods. Among these new techniques, two methods can be highlighted : LLE for non-linear dimension reduction and LDA as discriminating classification method. In this thesis document a new classification technique is proposed combining LLE and LDA methods. This new method makes it possible to provide efficient non-linear dimension reduction and discrimination. Then an extension of the method to semi-supervised learning is proposed. Good properties of dimension reduction and discrimination associated with the sparsity property of the LLE technique make it possible to apply our method to color images segmentation with success. Semi-supervised version of our method leads to efficient segmentation of noisy color images. These results have to be extended and compared with other state-of-the-art methods. Nevertheless interesting perspectives of this work are proposed in conclusion for future developments

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Schneider, A. "Role of LCA concepts at the research and development phase of a new process for waste treatment : the Trefoil Kiln process subject to integrated pollution prevention and control (IPPC) and best available techniques (BAT) requirements." Darmstadt, 2002. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=010198953&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.

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Renaud-Gentié, Christel. "Eco-efficience des itinéraires techniques viticoles : intérêt et adaptations de l’analyse du cycle de vie pour la prise en compte des spécificités de la viticulture de qualité." Thesis, Angers, 2015. http://www.theses.fr/2015ANGE0002/document.

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Afin d’accompagner les acteurs des filières viticoles, notamment d’AOC, dans la nécessaire amélioration de l’éco-efficience de leurs produits, nous avons voulu identifier dans quelles conditions l’Analyse du Cycle de Vie est une méthode appropriée à l'évaluation environnementale des itinéraires techniques viticoles (ITKv) de production de raisins de qualité, à l’échelle parcellaire, afin de pouvoir choisir les plus performants. Pour établir et tester un cadre méthodologique de l’ACV, adapté à cet objectif, des ITKv réels et variés visant un même objectif qualitatif sont nécessaires. Nous proposons ici une chaîne de traitement d’enquête originale, Typ-iti, qui permet le choix de cas réels représentant chaque groupe. Cinq groupes ont ainsi été identifiés parmi les ITKv de production de raisins de Chenin blanc pour vins blancs secs d’AOC en Moyenne Vallée de la Loire, dont trois en viticulture conventionnelle et deux en viticulture biologique. Cinq cas réels ont été choisis pour les représenter. L’ACV est ici déclinée pour la viticulture sur la base de ces cinq cas, par l’établissement d’un cadre méthodologique qui comprend : i) la définition de limites du système incluant les phases non productives et productives, ii) le choix des modèles disponibles les plus pertinents, pour le calcul des émissions directes de polluants à la vigne, iii) l’adaptation fine du modèle d’émissions de pesticides organiques Pest LCI 2.0 aux spécificités viticoles, iv) la proposition et le test d’unités fonctionnelles basées sur un indicateur de qualité du raisin original permettant la prise en compte de la qualité dans les ACV de raisins destinés à la production de vins de qualité. L’ACV a révélé, à l’échelle parcellaire, i) des éco-efficiences contrastées pour les cinq ITKv contrastés, ii) les pratiques responsables de ces contrastes, iii) des solutions d’amélioration et leurs effets quantifiés sur les performances environnementales. La généricité des résultats de ces cas aux groupes qu’ils représentent varie selon l’homogénéité des groupes et avec les catégories d’impacts selon qu’elles sont, ou non, conditionnées par le milieu. L’effet important du millésime sur les résultats, mis en évidence ici sur un cas, mérite d’être pris en compte dans toute ACV viticole. De nombreuses perspectives d’améliorations méthodologiques sont discutées ici pour accroître la pertinence et la complétude des résultats ainsi que la généricité de la méthode et pour son application auprès d’acteurs du développement des filières viticoles
In order to contribute to the effort of eco-efficiency improvement of the wine sctor, especially in the Protected Denomination of Origin (PDO) contaxt, we worked to identify in which conditions Life Cycle Assessment (LCA) is an appropriate method for environmental assessment, at plot scale, of quality vineyard Technical Management Routes (TMRs), to permit the choice of the most eco-efficient technical operations and TMRs.A methodological framework for LCA suited to this objective was designed and tested on five real and contrasted TMRs, oriented towards a same qualitative objective. These cases were chosen thanks to an original statistical analysis chain, Typ-iti, on the basis of a survey, among the TMRs producing Chenin blanc grapes for PDO dry white wines in the Middle Lore Valley. Five groups were identified and characterized, threee in conventional viticulture, and two in organic viticulture.The methodological framework that was established includes i) the studied system definition including productive and non-productive phases, ii) the choice of the most suitable and available models for calculation of pollutant direct emissions in the vineyard, iii) the customization of the organic pesticide emision calculation model, Pest LCI 2.0, to viticulture specific needs iv) the inclusion of grape quality in the LCA by two functional units including an original grape quality index.LCA proves to be a method complex but powerful, usable at parcel scale for grape production TMRs choice. It revealed i) contrasted eco-efficiencies for the 5 contrasted TMRs, ii) the viticultural practices responsible for these contrasts, iii) solutions for eco-efficiency improvement and quantification of their eco-efficiency effects.The important effect of the production year on the results, highlighted here on one case, must be taken into account in any viticulture LCA. Numerous perspectives of methodological improvement are discussed here in order to increase relevance and completeness of the results as well as genericity of the method and its accessibility for viticulture development stakeholders

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Giorgi, Karina Andrade Di. "Avaliação do efeito de duas técnicas de instrumentação na zona de risco de molares inferiores curvos por microtomografia computadorizada e análise de imagens." Universidade do Estado do Rio de Janeiro, 2010. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=3078.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
O objetivo deste estudo foi avaliar a espessura mínima radicular remanescente e o desgaste porcentual do terço cervical em raízes mesiais de molares inferiores, após a instrumentação com as técnicas ProTaper Universal e Lima única F2. Foram obtidos 100 primeiros molares inferiores com raízes completamente separadas. Desse total, foram selecionados e incluídos no estudo somente 22 que possuíam dois canais distintos na raiz mesial, comprimento entre 20 e 22 mm e grau de curvatura da raiz mesial com angulação variando entre 10 e 20. Destes, 8 foram eliminados por possuírem uma anatomia muito discrepante, o que limitava o processamento e análise digital das imagens (PADI). Os dentes foram acessados e a patência apical foi realizada em todos os canais determinando o comprimento de trabalho. Em cada dente, cada canal mesial foi instrumentado por uma técnica diferente. As amostras foram posicionadas em um dispositivo de montagem e digitalizadas através de microtomografia computadorizada antes e depois de serem completamente instrumentadas. O volume de interesse, correspondente à região de zona de risco, com uma grande margem de tolerância, tanto em direção apical quanto em direção cervical, foi determinado por 234 fatias, totalizando um comprimento vertical de 3,5 mm, para avaliação quantitativa comparativa. Através de PADI mediu-se, de forma automática, a espessura mínima radicular nos dois canais mesiais, antes e após a instrumentação, para todas as fatias de todos os dentes. A partir destes dados foi calculado o desgaste porcentual. Após o tratamento estatístico das mais de 6500 medidas obtidas, pôde-se concluir que não existiu diferença no desgaste da zona de risco produzido pelas duas técnicas de instrumentação testadas. Em todos os casos a espessura radicular remanescente permaneceu dentro de uma margem de segurança, não havendo, portanto, nenhum caso de rasgo ou perfuração. Dessa forma, ambas as técnicas estudadas foram consideradas seguras quanto ao desgaste da zona de risco da raiz mesial dos molares inferiores.
The aim of the present study was to evaluate the minimal remaining root canal thickness and percentage of dentin removed of the cervical third of the mesial roots mandibular molars after instrumentation with the ProTaper Universal and Single File F2 Techniques. From a total of 100 teeth, only 22 were selected and included in the study by having two distinct canals in the mesial root with length between 20 and 22 mm and degree of curvature presenting angle between 10 and 20. Eight specimens were eliminated because they have a very disparate anatomy that limited the digital processing and analysis of the images (PADI). The teeth were accessed and patency was performed in all canals determining the working length. In each tooth, each mesial canal was instrumented by a different technique. The samples were placed in a mounting device and scanned by microcomputed tomography before and after instrumentation. The corresponding volume of interest to the region of the risk zone was determined by 234 slices, with a total vertical length of 3.5 mm, for quantitative comparative evaluation with a high degree of tolerance. The PADI performed the measures automatically of the minimal thickness of root in both mesial canals, before and after instrumentation for all slices of each tooth. From these data, the percentage of dentin removed was calculated. After statistical analysis of more than 6500 measurements, it was concluded that there was no difference in the wear of the risk zone produced by the two instrumentation techniques tested. In all instrumented specimens, the root thickness remained within a security margin, thus, no case of strip perforation was observed. Therefore, both techniques were considered safe to be used in mesial root of mandibular molars.

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Zhong, Xiao. "A study of several statistical methods for classification with application to microbial source tracking." Link to electronic thesis, 2004. http://www.wpi.edu/Pubs/ETD/Available/etd-0430104-155106/.

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Thesis (M.S.)--Worcester Polytechnic Institute.
Keywords: classification; k-nearest-neighbor (k-n-n); neural networks; linear discriminant analysis (LDA); support vector machines; microbial source tracking (MST); quadratic discriminant analysis (QDA); logistic regression. Includes bibliographical references (p. 59-61).

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Bensmaine, Fayçal. "Modélisation et commande d'un système de stockage d'énergie à base de supercondensateur pour l'hybridation des groupes électrogènes." Thesis, Poitiers, 2014. http://www.theses.fr/2014POIT2341.

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Les travaux de recherche dans ce mémoire s’inscrivent dans l'étude et la commande d'un nouveau concept du groupe électrogène hybride permettant de réduire la puissance du moteur diesel (downsizing) d’économiser du carburant et d’améliorer le comportement de la génératrice synchrone durant les régimes transitoires. La solution adoptée consiste à mettre en parallèle à la génératrice synchrone un système de stockage d'énergie. Ce système est composé d'un onduleur avec un supercondensateur du côté du bus continu. L’objectif de la thèse a été de dimensionner l’ensemble supercondensateur /convertisseur statique et de développer une commande ayant des performances optimales pour obtenir le meilleur compromis entre l’énergie échangée dans le supercondensateur et l’efficacité sur la vitesse du groupe et sur l’amplitude des tensions de l’alternateur. Une commande par retour d’état avec intégration de l’écart en utilisant l’approche LMIs a été mise en place pour la synthèse des régulateurs des boucles de courants de l'onduleur. Une deuxième commande a été développée pour réguler la tension variable aux bornes du supercondensateur. Un simulateur regroupant l’alternateur et le système de stockage a été développé pour la mise au point de ces commandes. Toutes les validations ont été faites sur une maquette expérimentale spécifiquement élaborée pour cette thèse. Les essais ont été menés avec un moteur d’entraînement électrique et sur un diesel. En conclusion, les essais expérimentaux ont mis en évidence l’apport important de cette hybridation sur les variations de vitesse du diesel et sur la tension aux bornes de l’alternateur lors d’important impact ou de délestage de la charge
The research in this thesis are part of study and control of a new concept of hybrid generator to reduce the power of the diesel engine (downsizing) in order to save fuel and improve the behavior of the synchronous generator during transients. The adopted solution is to place in parallel with the synchronous generator an energy storage system. The latter consists of an inverter with a super capacitor on the DC bus. The aim of the thesis was to scale the entire supercapacitor / static converter and to develop a control law having the best performance with the best compromise between the energy exchanged in the supercapacitor, efficiency, the group speed and voltage amplitude of the generator. A feedback control condition with integration of the deviation using LMI's approach has been established for the synthesis of loop current regulators from the inverter.A second control law was developed to regulate the variable voltage across the supercapacitor. A simulator combining generator and storage system has been developed to test these commands.All validations were made on an experimental test rig specifically developed for this thesis. The tests were conducted with an electric drive motor in the test platform of the LIAS and with a diesel in that of the Leroy Somer Motors company.Finally, experimental tests have highlighted the significant contribution of this hybridization on the diesel speed variationsand on the terminal voltage of the alternator during impact or load shedding

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Giorgianni, Giulia. "Analisi dei principi e dei metodi per la valutazione della sostenibilità dei prodotti e dei processi con un'applicazione ai componenti per l’edilizia." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016.

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Tale elaborato si pone l’obiettivo di analizzare una tematica oggigiorno molto discussa, ma tuttora per molti versi inesplorata: la sostenibilità. Esso è stato scritto con la volontà di rendere disponibile uno scritto di consultazione che fornisca una panoramica il più possibile completa sugli studi e le metodologie applicative elaborati fino ad ora connessi al tema della sostenibilità. La logica con cui lo scritto è articolato, prevede in primis un inquadramento generale sul tema della sostenibilità, fortemente connesso con il concetto di Life Cycle Thinking, e prosegue concentrando l’attenzione su aspetti via via più specifici. Il focus dell’analisi si concentra infatti sullo studio delle singole tecniche del ciclo di vita e successivamente sulle potenzialità di applicazione delle stesse ad uno specifico settore: quello edilizio. All’interno di questo settore è poi fornito un dettaglio in merito ai materiali ceramici per i quali si è intrapreso un serio percorso verso l’applicazione concreta dei principi dello sviluppo sostenibile. Per consolidare i temi trattati, l’elaborato si concentra infine sull’analisi di due studi applicativi: uno studio di Life Cycle Assessment e uno di Life Cycle Costing realizzati al fine di studiare i profili ambientale ed economico delle piastrelle ceramiche in contrapposizione a quelle in marmo.

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Song, Yingying. "Amélioration de la résolution spatiale d’une image hyperspectrale par déconvolution et séparation-déconvolution conjointes." Thesis, Université de Lorraine, 2018. http://www.theses.fr/2018LORR0207/document.

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Une image hyperspectrale est un cube de données 3D dont chaque pixel fournit des informations spectrales locales sur un grand nombre de bandes contiguës sur une scène d'intérêt. Les images observées peuvent subir une dégradation due à l'instrument de mesure, avec pour conséquence l'apparition d'un flou sur les images qui se modélise par une opération de convolution. La déconvolution d'image hyperspectrale (HID) consiste à enlever le flou pour améliorer au mieux la résolution spatiale des images. Un critère de HID du type Tikhonov avec contrainte de non-négativité est proposé dans la thèse de Simon Henrot. Cette méthode considère les termes de régularisations spatiale et spectrale dont la force est contrôlée par deux paramètres de régularisation. La première partie de cette thèse propose le critère de courbure maximale MCC et le critère de distance minimum MDC pour estimer automatiquement ces paramètres de régularisation en formulant le problème de déconvolution comme un problème d'optimisation multi-objectif. La seconde partie de cette thèse propose l'algorithme de LMS avec un bloc lisant régularisé (SBR-LMS) pour la déconvolution en ligne des images hyperspectrales fournies par les systèmes de whiskbroom et pushbroom. L'algorithme proposé prend en compte la non-causalité du noyau de convolution et inclut des termes de régularisation non quadratiques tout en maintenant une complexité linéaire compatible avec le traitement en temps réel dans les applications industrielles. La troisième partie de cette thèse propose des méthodes de séparation-déconvolution conjointes basés sur le critère de Tikhonov en contextes hors-ligne ou en-ligne. L'ajout d'une contrainte de non-négativité permet d’améliorer leurs performances
A hyperspectral image is a 3D data cube in which every pixel provides local spectral information about a scene of interest across a large number of contiguous bands. The observed images may suffer from degradation due to the measuring device, resulting in a convolution or blurring of the images. Hyperspectral image deconvolution (HID) consists in removing the blurring to improve the spatial resolution of images at best. A Tikhonov-like HID criterion with non-negativity constraint is considered here. This method considers separable spatial and spectral regularization terms whose strength are controlled by two regularization parameters. First part of this thesis proposes the maximum curvature criterion MCC and the minimum distance criterion MDC to automatically estimate these regularization parameters by formulating the deconvolution problem as a multi-objective optimization problem. The second part of this thesis proposes the sliding block regularized (SBR-LMS) algorithm for the online deconvolution of hypserspectral images as provided by whiskbroom and pushbroom scanning systems. The proposed algorithm accounts for the convolution kernel non-causality and including non-quadratic regularization terms while maintaining a linear complexity compatible with real-time processing in industrial applications. The third part of this thesis proposes joint unmixing-deconvolution methods based on the Tikhonov criterion in both offline and online contexts. The non-negativity constraint is added to improve their performances

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MEENA, DULI CHAND. "INVESTIGATIONS ON OPERATION AND CONTROL OF SELF-EXCITED INDUCTION GENERATOR." Thesis, 2022. http://dspace.dtu.ac.in:8080/jspui/handle/repository/19625.

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Growing concerns of carbon dioxide emission and environmental pollution motivated the mankind worldwide towards the utilization of green and clean energy. The various energy sources in the green energy domain are wind, solar, biomass, tidal, ocean waves etc. There is a lot of potential to tap the green energy utilizing for medium and low power applications at isolated places of the globe. Due to vast availability of medium and small generators such as self-excited induction generator, brushless DC generator, permanent magnet generators and switched reluctance generator etc., the possibility of power generation from said energy sources enhanced manifold. The basic problem associated with these energy sources are their intermittent power supply nature. However, the matured power electronics technology has provided the viable solution if its proper interface is provided with the main energy source and load. The self-excited induction generator (SEIG) is the natural choice over other generators for three phase medium power applications due to its better electrical and mechanical characteristics. However, the problem of voltage and frequency variation is the concern for researchers at variable loading even at constant power supply from the prime mover turbine. Moreover, due to extensive use of nonlinear circuits in load, power quality problems such as unacceptable level of harmonics in the supply current, load unbalance at the generator terminal, are an additional issue to address. Further, the power electronics devices like active power filters (VSC/ DSTATCOM) are useful to mitigate the aforementioned problems. The operation of these devices is greatly dependent on the feedback controllers working in the current and voltage loops. There are many pulse width modulation techniques available for generating the gate pulses. The controllers in loops are equipped with control algorithms which are getting various feedback electrical signals at its Analog to digital converter (ADC). The selection of v | P a g e these control algorithms is dependent on their accuracy, speed and capability to extract fundamental components under dynamic loading conditions. Therefore, this thesis deals with the implementation of a few adaptive control algorithms based on least mean square principle, for improving the performance of Self Excited Induction Generator. The SEIG under study is working in standalone mode to feed power at isolated places and connected to linear/nonlinear load. The major problems associated with such kind of standalone power system is regulation of its voltage and frequency under variable loads. Further, maintaining a purely sinusoidal supply current with improved power factor is also one of the major objectives towards power quality standards. A static compensator (STATCOM) is used along with load to compensate currents to maintain power quality of standalone generator under various operating conditions. The Leaky-Momentum Control Algorithm (LMA) is being used to generate switching signals. A voltage source converter (VSC) to enhance the performance of a three-phase self excited induction generator operating with varying loads is used. This LMA technique controls VSC to regulate voltage and frequency of SEIG within a permissible limit. The LMA control is implemented to reduce the higher demand of reactive power, eliminations of harmonics in source current and balancing of loads under different operating conditions. During the electrical and mechanical dynamical conditions, the LMA technique is maintaining a constant voltage and frequency at point of common interfacing (PCI). The proposed technique is a modified control technique of basic Leaky and Momentum Algorithms. This control has removed the drawbacks of Leaky and momentum algorithms. Moreover, it is observed that LMA performs better when there are uncertainties in input conditions. In the second case, a modified NLMS based control algorithm is designed to control the SEIG system feeding three-phase nonlinear loads. The control algorithm extracts the fundamental weight components with reduced oscillations from sensed load current. vi | P a g e Implementation of modified algorithm for control of voltage source converter (VSC) provides fast dynamic response, harmonic eliminations, active/reactive power compensation, load leveling, rapid convergence and enhances the power quality in an isolated distributed wind energy generation system under nonlinear load conditions. The battery energy storage (BES) is employed at DC Link of STATCOM to balance the power in the system during load perturbations and wind speed changes. The simulation study on the proposed system shows the improved steady state and dynamic performance of SEIG system under fixed/varying wind speed while feeding fixed/varying nonlinear load. The entire system comprising SEIG, nonlinear load, voltage source converter and battery storage system is implemented in MATLAB /SIMULINK. Also, the experimental validation of proposed control approach is carried out in the laboratory environment to study the effectiveness. It has shown promising performance under both dynamical state and steady state of the system.

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Dissertations / Theses on the topic 'LMA TECHNIQUE'

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