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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Novel Front-end Electronics for Time Projection Chamber Detectors

García García, Eduardo José 03 September 2012 (has links)
Este trabajo ha sido realizado en la Organización Europea para la Investigación Nuclear (CERN) y forma parte del proyecto de investigación Europeo para futuros aceleradores lineales (EUDET). En física de partículas existen diferentes categorías de detectores de partículas. El diseño presentado esta centrado en un tipo particular de detector de trayectoria de partículas denominado TPC (Time Projection Chamber) que proporciona una imagen en tres dimensiones de las partículas eléctricamente cargadas que atraviesan su volumen gaseoso. La tesis incluye un estudio de los objetivos para futuros detectores, resumiendo los parámetros que un sistema de adquisición de datos debe cumplir en esos casos. Además, estos requisitos son comparados con los actuales sistemas de lectura utilizados en diferentes detectores TPC. Se concluye que ninguno de los sistemas cumple las restrictivas condiciones. Algunos de los principales objetivos para futuros detectores TPC son un altísimo nivel de integración, incremento del número de canales, electrónica más rápida y muy baja potencia. El principal inconveniente del estado del arte de los sistemas anteriores es la utilización de varios circuitos integrados en la cadena de adquisición. Este hecho hace imposible alcanzar el altísimo nivel de integración requerido para futuros detectores. Además, un aumento del número de canales y frecuencia de muestreo haría incrementar hasta valores no permitidos la potencia utilizada. Y en consecuencia, incrementar la refrigeración necesaria (en caso de ser posible). Una de las novedades presentadas es la integración de toda la cadena de adquisición (filtros analógicos de entrada, conversor analógico-digital (ADC) y procesado de señal digital) en un único circuito integrado en tecnología de 130nm. Este chip es el primero que realiza esta altísima integración para detectores TPC. Por otro lado, se presenta un análisis detallado de los filtros de procesado de señal. Los objetivos más importantes es la reducció / García García, EJ. (2012). Novel Front-end Electronics for Time Projection Chamber Detectors [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/16980 / Palancia
62

The Continuous Wavelet Transform and the Wave Front Set

Navarro, Jaime 12 1900 (has links)
In this paper I formulate an explicit wavelet transform that, applied to any distribution in S^1(R^2), yields a function on phase space whose high-frequency singularities coincide precisely with the wave front set of the distribution. This characterizes the wave front set of a distribution in terms of the singularities of its wavelet transform with respect to a suitably chosen basic wavelet.
63

Characterization of the Nature of Deformation and Metamorphic Gradient Across the Grenville Front Tectonic Zone in Carlyle Township, Ontario

O'Donnell, Lynn 09 1900 (has links)
<p> The last major episode of deformation occurred in the area studied during the Grenville orogeny (~1000 Ma ago). Deformation of this zone is characterized by a northeast trending penetrative foliation and southeast plunging mineral lineation which increase in intensity and decrease in inclination from northwest to southeast. The deformation was imposed during reverse fault movement in which the southeastern block (the Grenville province) was vertically displaced on the order of 20 kilometers above the adjacent block (the Southern province). The Killarney belt of granites, which separate the Grenville province from the Southern province in this area, are intrusive into the Huronian metasediments and predate the Grenville orogeny. These granites also show evidence of Grenvillian deformation. </p> <p> Paleopiezometry has shown that the differential stress during deformation increases from less than 1 Kbar to more than 6 Kbar from southeast to northwest. The microstructural strain features in quartz and felspar and the mineralogy indicate that a temperature change o£ 400 C is associated with this change in differential stress. Kinematic analysis of mylonites supports the reverse fault model o£ the Grenville Front. </p> / Thesis / Master of Science (MSc)
64

Structural Analysis along the Grenville Front near Sudbury, Ontario

Hsu, Mao-Yang 07 1900 (has links)
<p> Amphibolites and gneisses of the "Grenville province" and granitic rocks of the Chief Lake batholith near Sudbury show the effects of several phases of deformation. </p> <p> The first phase of deformation affected previously metamorphosed rocks of the "Grenville province" together with enclosed pegmatite sills, and formed congruous parasitic S- and Z-folds. The rocks were then subjected to faulting and local refolding. About 1, 750 m. y. ago, the Chief Lake batholith was intruded and truncated the previous folds. Finally, all the rocks were subjected to a simultaneous regional metamorphism and strong deformation. </p> <p> During this final deformation, all the previous linear structures were rotated to parallel the strongly-developed regional mineral lineations. The high-grade rocks of high amphibolite facies to the S. E. of the cataclastic zone flowed upwards from a greater depth than the rocks of greenschist facies to the N. E. of the cataclastic zone. The sharp increase in metamorphic grade occurs within the cataclastic zone which is about one mile wide. </p> <p> The final progressive deformation of the rocks is compared with the constant-volume deformation ellipsoid as initiated from the uniaxial prolate type through the constriction type to the plane- strain type; wherein the direction of maximum elongation plunges moderately to the S. S. E. and parallels the regional mineral lineations, the passive fold axes, the elongations of conical folds, and the original flow directions (shown by deformed mineral lineations) of slip folds; while the direction of maximum shortening generally plunges to the N. W. and is normal to the penetrative foliations and the active axial planes of slip folds. </p> / Thesis / Master of Science (MSc)
65

Side-Channel Attacks in RISC-V BOOM Front-end

Chavda, Rutvik Jayantbhai 29 June 2023 (has links)
The prevalence of side-channel attacks exploiting hardware vulnerabilities leads to the exfil- tration of secretive data such as secret keys, which poses a significant threat to the security of modern processors. The RISC-V BOOM core is an open-source modern processor design widely utilized in research and industry. It enables experimentation with microarchitec- tures and memory hierarchies for optimized performance in various workloads. The RISC-V BOOM core finds application in the IoT and Embedded systems sector, where addressing side-channel attacks becomes crucial due to the significant emphasis on security. While prior studies on BOOM mainly focus on the side channel in the memory hierarchy such as caches or physical attacks such as power side channel. Recently, the front-end of microprocessors, which is responsible for fetching and decoding instructions, is found to be another potential source of side-channel attacks on Intel Processors. In this study, I present four timing-based side-channel attacks that leverage components in the front-end of BOOM. I tested the effectiveness of the attacks using a simulator and Xilinx VCU118 FPGA board. Finally, I provided possible mitigation techniques for these types of attacks to improve the overall security of modern processors. Our findings underscore the importance of identifying and addressing vulnerabilities in the front-end of modern pro- cessors, such as the BOOM core, to mitigate the risk of side-channel attacks and enhance system security. / Master of Science / In today's digital landscape, the security of modern processors is threatened by the increasing prevalence of side-channel attacks that exploit hardware vulnerabilities. These attacks are a type of security threat that allows attackers to extract sensitive information from computer systems by analyzing the physical behavior. The risk of such attacks is further amplified when multiple users or applications share the same hardware resources. Attackers can ex- ploit the interactions and dependencies among shared resources to gather information and compromise the integrity and confidentiality of critical data. The RISC-V BOOM core, a widely utilized modern processor design, is not immune to these side-channel attacks. This issue demands urgent attention, especially considering its deploy- ment in data-sensitive domains such as IoT and embedded systems. Previous studies have focused on side-channel vulnerabilities in other areas of BOOM, ne- glecting the front-end. However, the front-end, responsible for processing initial information, has recently emerged as another potential target for side-channel attacks. To address this, I conducted a study on the vulnerability of the RISC-V BOOM core's front-end. By conduct- ing tests using both a software-based simulator and a physical board, I uncovered potential security threats and discussed potential techniques to mitigate these risks, thereby enhanc- ing the overall security of modern processors. These findings underscore the significance of addressing vulnerabilities in the front-end of processors to prevent side-channel attacks and safeguard against potential malicious activities.
66

Late Eocene paleoaltitude, paleoclimate, and paleogeography of the Front Range region, Colorado.

Gregory, Kathryn Mary. January 1992 (has links)
Erosion beveled the Laramide Front Range uplift in Colorado to a surface of low relief by the end of the Eocene. This study uses paleobotanic climate analysis techniques to determine the paleoelevation of this regional surface by examining the overlying 34.9 Ma Florissant flora. Multiple regression models explaining 93.4% of the variance in mean annual temperature (MAT), 86.1% of the variance in growing season precipitation (GSP) and 65.7% of the variance in rainfall distribution were derived from J. A. Wolfe's dataset of 31 leaf physiognomic character states from 86 modern vegetation sites. When applied to a new collection of 29 species from the Florissant flora, estimates of MAT = 10.7 ± 1.5°C, and GSP = 55.6 ± 12.5 cm, with precipitation occurring mostly during the growing season, are derived. This paleoclimate estimate is corroborated by data from late Eocene Sequoia affinis from Florissant. Higher mean ring width of the fossil trees as compared to modern counterparts can be explained by a climate with summer mean monthly temperatures ≥ 14°C and summer mean monthly rainfall >1.5 cm. The estimated MAT, when combined with coeval sea level MAT and terrestrial lapse rate, implies an elevation of 2.3-3.3 km for Florissant, which is indistinguishable from the modern elevation of 2.5 km. The elevation of Florissant is tied to that of the Great Plains by the Wall Mountain Tuff, so the Great Plains were also high. The elevation was created either by underplating and/or mass transfer in the Laramide, or by mantle uplift of crust thickened by pre-Laramide tectonics. This elevation estimate implies that: (1) Pliocene uplift is not required to explain the present elevation. Thus, late Tertiary plateau uplift in the western US was not a contributing factor to the marked global cooling since 15 Ma; and (2) in the late Eocene, regional surfaces of planation could be formed at elevations significantly above sea level but below tree line. The surface was possibly formed from a lack of storminess; a preponderance of small storm events will diffusively smooth topography.
67

La gauche française et la guerre d'Espagne (1936-1939) : entre idéalisme et pragmatisme

Vaillancourt, Johanne January 2007 (has links)
Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.
68

Fuzzy Front End de inovações sistêmicas: quadro conceitual e estudo de casos. / Fuzzy Front End of systemic innovation: conceptual framework and case studies.

Takey, Silvia Mayumi 08 June 2016 (has links)
Inovações sistêmicas são aquelas que requerem reajustes significativos em co-opetidores do ecossistema de inovação. A relevância de inovações sistêmicas tem crescido por diversos motivos, tais como o caráter sistêmico de inovações relacionadas ao desenvolvimento sustentável, o amadurecimento da sociedade em rede e a disseminação da inovação aberta. O fuzzy front end, ou seja, a etapa inicial e difusa do processo de inovação, tem sido explorado considerando-se principalmente relações díades empresa-consumidor. O objetivo desta dissertação é explorar como se diferencia o fuzzy front end em inovações sistêmicas, em ecossistemas de inovação complexos, que demandam a coordenação com diferentes entidades externas ao controle direto da empresa focal. Para tanto, a metodologia conta com três macroetapas: revisão sistemática da literatura de fuzzy front end e inovação sistêmica, estudo de caso piloto de caráter preliminar e estudos de caso exploratórios em empresas em diferentes posicionamentos do ecossistema de negócios de Redes Inteligentes (Smart Grid) com análises intra e inter casos. / Systemic innovations are those that require significant changes in co-opetitors within the innovation ecosystems in which they are inserted. The relevance of systemic innovations has grown due to several reasons, such as the systemic characteristic of sustainable development innovation projects, the higher maturity of the network society and the dissemination of open innovation practices. The fuzzy front end, the initial and diffuse phase of the innovation process, has been explored considering mainly dyadic relations between company and consumers. The goal of this dissertation is to explore how does the fuzzy front end differentiate in systemic innovations, in complex innovation ecosystems, considering the need for coordination with external entities outside the control of the focal company. Therefore, the methodology has three macro-steps: a systematic literature review of fuzzy front end and systemic innovation, a pilot case study and exploratory case study with intra and cross-case analysis in different positions in the Smart Grid business ecosystems.
69

Caractérisation des oxy-hydroxydes de fer et des éléments associés (S, Se, As, Mo, V, Zr) dans les environnements redox favorables aux gisements d’uranium / Iron oxi-hydroxides characterization and associated elements (S, Se, As, Mo, V, Zr) in the redox environments favorable for uranium deposits

Pons, Tony 22 September 2015 (has links)
Ce travail présente une étude multi-échelle et multi-technique sur la caractérisation des oxy-hydroxydes de fer dans trois types de gisements d’uranium et leur encaissant. Le choix des sites d’études s’est porté sur un gisement de type roll front : Zoovch Ovoo dans le bassin crétacé de East Gobi (Mongolie) ; un autre de type tectono-lithologique : Akola/Ebba dans le bassin de Tim Mersoï (Niger) et enfin un type discordance protérozoïque : Kiggavik en bordure du bassin du Thelon (Canada). Une nouvelle approche a été mise en œuvre pour caractériser les oxy-hydroxydes de fer sur échantillons macroscopiques : la spectroscopie infrarouge de terrain en utilisant le spectromètre ASD TerraSpec®. À partir d’indices originaux calculés sur les spectres, il a été possible à la fois de caractériser les oxy-hydroxydes de fer ; seules l’hématite et la goethite ont été identifiées dans les parties oxydées des différents fronts uranifères, et de visualiser les différentes zonations d’altération le long des fronts redox. De plus, la partie visible du spectre a été utilisée pour quantifier la couleur des échantillons à travers les paramètres des systèmes ITS (Intensité – Teinte – Saturation) et de Munsell. L’étude des paramètres de couleurs a permis d’identifier une teinte spécifique pour les échantillons minéralisés étudiés : un mélange de jaune et de rouge (2,5 à 10 YR en notation de Munsell). A l’échelle des cristaux, les oxy-hydroxydes de fer ont été caractérisés par la spectroscopie micro-Raman. Cette étude a permis de mettre en évidence une différence de cristallinité des cristaux d’hématite dans les différents gisements. D’un point de vue morphologique, les cristaux de goethite du gisement de Zoovch Ovoo, seul oxy-hydroxyde de fer authigène décrit dans ce front, sont maclés en forme d’étoile à six branches, ce qui témoigne d’une cristallisation de basse température, comparé aux gisements du Niger et de Kiggavik. Cette cristallisation est principalement contrôlée par la disponibilité des ions Feᴵᴵᴵ dans le fluide, libérés par la dissolution de la pyrite en milieu oxydant et le pH. D’un point de vue chimique, les oxy-hydroxydes de fer enregistrent le passage du fluide uranifère de part leur teneur eu uranium. Et d’autre part la composition en éléments en trace qui marque la typologie du gisement, par exemple de la teneur en zirconium dans les oxy-hydroxydes de fer provenant du gisement du Niger, source d’origine volcanique. Cette typicité de la mobilité du zirconium est particulièrement bien exprimée dans les fronts uranifères d’Ebba par la précipitation de cristaux authigènes de zircon contemporains de la pechblende. Les données minéralogiques et géochimiques obtenues dans ce travail sur le gisement de Zoovch Ovoo permettent de proposer un modèle original pour sa formation : l’uranium n’a pas précipité massivement en amont du front puisqu’il n’y a pas d’auréole d’irradiation observable en cathodoluminescence dans les minéraux détritiques dans la zone oxydée. L’uranium a précipité lorsque l’eau oxydante a rencontré un faciès sédimentaire ayant un pouvoir réducteur assez fort pour permettre la réduction de l’uranium. La précipitation a lieu dans un endroit particulier de la formation : un paléo-lac où la matière organique et la pyrite sont abondantes. / This work presents a multi-scale and a multi-technical study for the characterization of iron oxi-hydroxides in three uranium-type deposits and host rock. The choice of sites has focused on a roll front deposit: Zoovch Ovoo in a Cretaceous basin of East Gobi (Mongolia); a tectonic-lithological type: Akola/Ebba in Tim Mersoï basin (Niger) and a Proterozoic unconformity type: Kiggavik in Thelon basin (Canada). A new approach has been implemented to characterize the iron oxi-hydroxides on macroscopic samples: field infrared spectroscopy using the ASD TerraSpec® spectrometer. From the original indexes calculated on the spectra, it was possible both to characterize the iron oxi-hydroxides; only hematite and goethite were identified in the different parts of oxidized uranium fronts, and visualize the alteration zonation along the redox front. In addition, the visible part of spectrum was used to quantify the color of samples through the IHS system parameters (Intensity – Hue – Saturation) and the Munsell system. The color setting of the study identified a specific hue for mineralized samples studied: a mixture of yellow and red (2.5 to 10YR in Munsell notation). At the crystals scale, the iron-hydroxides were characterized by µ-Raman spectroscopy. The study highlighted a difference in crystallinity of hematite crystals in different fields. From a morphological point of view, the crystals of goethite in the Zoovch Ovoo deposit, is only authigenic iron oxi-hydroxides described in this uranium front, are twinned in the form of six-pointed star, reflecting a low crystallization temperature, compared to Niger and Kiggavik deposits. This crystallization is mainly controlled by the availability of Feᴵᴵᴵ ions in the fluid, released by pyrite dissolution in an oxidizing environment and pH. From a chemical point of view, iron oxi-hydroxides record the fluid passage owing their uranium content. Secondly, the composition in trace elements marks the type of deposit, for example zirconium content in oxi-hydroxides from Niger deposit, volcanic source. This typical mobility of zirconium is particularly expressed in the uranium front in Ebba deposit by the precipitation of authigenic crystals of zircon contemporary of pitchblende. The mineralogical and geochemical data obtained in this work on the Zoovch Ovoo deposit (Mongolia) allow us to propose an original model for its formation: uranium did not precipitate massively in upstream edge of front, because not radiation halo is visible in cathodoluminescence in detrital minerals in the oxidized area. Uranium precipitated when the oxidizing water met with sedimentary facies having a fairly strong reducing power to allow uranium reduction. The precipitation occurs in a particular location of the formation: paleo-lake where organic matter and pyrite are abundant.
70

Assessing the Maturity and Accuracy of Front End Engineering Design (FEED) for Large, Complex Industrial Projects

January 2019 (has links)
abstract: Planning efforts conducted during the early stages of a construction project, known as front end planning (FEP), have a large impact on project success and significant influence on the configuration of the final project. As a key component of FEP, front end engineering design (FEED) plays an essential role in the overall success of large industrial projects. The primary objective of this dissertation focuses on FEED maturity and accuracy and its impact on project performance. The author was a member of the Construction Industry Institute (CII) Research Team (RT) 331, which was tasked to develop the FEED Maturity and Accuracy Total Rating System (FEED MATRS), pronounced “feed matters.” This dissertation provides the motivation, methodology, data analysis, research findings (which include significant correlations between the maturity and accuracy of FEED and project performance), applicability and contributions to academia and industry. A scientific research methodology was employed in this dissertation that included a literature review, focus groups, an industry survey, data collection workshops, in-progress projects testing, and statistical analysis of project performance. The results presented in this dissertation are based on input from 128 experts in 57 organizations and a data sample of 33 completed and 11 on-going large industrial projects representing over $13.9 billion of total installed cost. The contributions of this work include: (1) developing a tested FEED definition for the large industrial projects sector, (2) determining the industry’s state of practice for measuring FEED deliverables, (3) developing an objective and scalable two-dimensional method to measure FEED maturity and accuracy, and (4) quantifying that projects with high FEED maturity and accuracy outperformed projects with low FEED maturity and accuracy by 24 percent in terms of cost growth, in relation to the approved budget. / Dissertation/Thesis / Doctoral Dissertation Construction Management 2019

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