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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.
21

Modeling and Design of a Monolithic High Frequency Synchronous Buck with Fast Transient Response

Deng, Haifei 18 February 2005 (has links)
With the electronic equipments becoming more and more complicated, the requirements for the power management are more and more strict. Efficient performance, high functionality, small profile, fast transient and low cost are the most wanted features for modern power management ICs, especially for mobile power. In order to reduce profile, the number of external components should be as small as possible, which means that compensator, ramp compensation, current sensor, driver and even power devices should be all implemented on a single chip, i.e. monolithic integration. Comparing with discrete switching DC-DC converter, monolithic integration brings a number of benefits and new design challenges. Besides monolithic integration, high switching frequency is another trend for power management ICs due to its higher bandwidth and the ability to further reduce external passive component size. Comparing with low frequency counterparts, high frequency switching converter design is more difficult in terms of the stability modeling, high switching loss and difficult current sensing etc. The objective of this dissertation is to study the design issues for monolithic integration of high frequency switching DC-DC converter. For this purpose, a high frequency, wide input range monolithic buck converter ASIC with fast transient response is designed based on advanced trench BCD technology. Stability is the fundamental requirement in designing switching converter ASIC. Achieving this requires an accurate loop gain design, especially for monolithically integrated high frequency switching converter since compensator is fixed on silicon and loop delay is comparable with switching cycle. Since DC-DC switching converters are time-varying system, traditional small signal analysis in SPICE cannot be directly used to simulate the loop gain of this kind of system. A periodic small signal analysis based method is proposed to analyze and simulate DC-DC switching converter inside a SPICE like simulator without the need for averaging. This general method is suitable for any switching regulators. The results are accurate comparing with average modeling and experiment results even at high frequency part. A general procedure to design loop gain is proposed. Several novel design concepts are proposed for monolithic integration of high frequency switching DC-DC converter; a novel control scheme-Cotangent Control (Ctg control) is proposed for fast transient response; In order to realize on-chip implementation of the compensator, especially for low frequency zero, active feedback compensator is developed and a general design procedure is proposed. Adaptive compensation concept is proposed to stabilize the whole system for a wide application range. Multi-stage driver and multi-section device concepts are investigated for high efficiency and low noise power stage design. And finally, a new noise insensitive lossless RC sensor is proposed for high speed current sensing. At the end of this dissertation, the test results of the fabricated chip are presented to verify the correctness of these design concepts. / Ph. D.
22

Amélioration de l'incorporation d'indium dans zone active à base d'InGaN grâce à la croissance sur pseudo-substrat InGaN pour l'application à la DEL blanche monolithique / In incorporation improvement in InGaN based active region using InGaN pseudo substrate for monolithic white LED application

Even, Armelle 27 February 2018 (has links)
Les Diodes Electroluminescentes (DEL) à base de composés III-nitrures sont très efficaces pour les longueurs d’ondes correspondant à la couleur bleue. Ces DELs bleues sont très utilisées sur le marché car leur combinaison avec des phosphores produit une lumière blanche. Néanmoins, cette approche a plusieurs inconvénients tels que l’instabilité de la température de couleur ou les pertes liées à la conversion. Dans ce contexte la DEL blanche monolithique dont la lumière blanche est obtenue directement dans la zone active grâce à l’émission des puits quantiques à différentes longueurs d’ondes est envisagée.Pourtant, lorsque la longueur d’onde d’émission augmente, le rendement d’émission des puits quantiques InGaN/GaN diminue. Ceci est problématique pour l’application de la DEL blanche monolithique mais également pour l’application micro-display qui nécessite idéalement des DELs monochromatiques bleues, vertes et rouges fabriquées à partir de la même famille de matériaux. Ce problème est principalement du à la différence importante de paramètre de maille entre les puits quantiques InGaN et la couche GaN sur saphir utilisée comme substrat qui provoque une forte contrainte compressive. Cette contrainte est à l’origine d’un champ électrique interne dans les puits quantiques, préjudiciable au rendement d’émission, et d’un taux d’incorporation d’indium faible bien qu’originellement thermodynamiquement difficile.Cette thèse de doctorat propose de résoudre ce problème en réalisant la croissance de la DEL sur un pseudo-substrat InGaN appelé InGaNOS fabriqué par Soitec.Après avoir identifié les limitations des structures InGaN/GaN sur substrat GaN sur sapphire classique pour l’émission efficace à grande longueur d’onde, des structures « tout-InGaN » ont été crues par EPVOM sur substrats InGaNOS. Il a été démontré que la contrainte était partiellement relaxée et que l’incorporation d’indium était plus facile. Grâce à des caractérisations optiques et structurelles fines, les différentes étapes depuis la reprise de croissance InGaN jusqu’à la DEL complète ont été étudiées. En photoluminescence (PL), la longueur d’onde de 617 nm a été atteinte à température ambiante. Les performances optiques de ces structures de puits quantiques dans les régions spectrales correspondant au vert, jaune et ambre ont été mesurées et sont comparables aux meilleures valeurs de la littérature. Enfin, la croissance de la première DEL « tout InGaN » sur substrat InGaN a révélé les challenges restants qui nécessiteront des développements complémentaires. / Light emitting diodes (LEDs) based on nitride materials are very efficient in the blue range. These blue LEDs combined with phosphors are used to manufacture white LEDs widely used in the lighting market. Nonetheless, this converted approach presents some disadvantages , like an instability of the color temperature or conversion losses. In this context, the white monolithic LED which produces the white color thanks to different emission wavelengths produced from quantum wells (QWs) placed in the active region is one of the considered solution.However, as emission wavelength increases the quantum efficiency of the InGaN based QWs decreases. This is problematic for the white monolithic application but also for micro-display application which both ideally requires red, green and blue monochromatic LEDs grown in the same material system. This issue is mainly due to the great lattice mismatch between the InGaN QW and the GaN layer on sapphire substrate which induces an important compressive strain. This strain is responsible for a strong internal electric field in the QWs, which is detrimental for the quantum efficiency, and for low indium incorporation rate in GaN, originally thermodynamically difficult.This PhD thesis proposes to tackle this issue by growing the LED on an InGaN pseudo-substrate called InGaNOS manufactured by Soitec.After identifying the limitations of InGaN based structures grown on regular GaN on sapphire substrate for efficient long wavelength emission, full InGaN structures were grown by MOCVD on InGaNOS substrates. It was shown that the strain was partially released and the indium incorporation was made easier. Through fine structural, optical and electrical characterizations, the different steps leading from the InGaN buffer regrowth stage to the complete processed LED were studied. PL emission wavelengths up to 617 nm were reached at room temperature. The optical performances of these MQW structures in the green, yellow and amber range were measured to be comparable to the best ones achieved in the literature. Finally, the growth of the first full InGaN LED structure on InGaN substrate revealed the remaining challenges that will require some additional developments.
23

Stavebně technologický projekt výstavby centrální nabíjecí stanice v Púchově / Construction-technological project for the construction of a central charging station in Púchov

Stopka, Peter January 2019 (has links)
This diploma thesis focuses on the construction of a construction technological project for the construction of the Central Charging Station in Púchov. The building is located in the industrial area of Púchov and in the area of Continental Matador Rubber. In the thesis is elaborated technical report for building technological project, co-ordination situation of construction with wider transport routes, time and financial object plan, study of the realization of the main technological stages, construction site design, design of main building machines and mechanisms, time schedule of main building, securing material resources for the monolithic part of the building. In the thesis are made, technological rules for drilled pilots and ceiling structure above the first overground floor. Technological regulations follow control and test plans. Other assignments that have been made in this work, such as the occupational safety and health plan, the design and comparison of cranes and the item budget.
24

Mateřská škola Solivar / Kindergarten Solivar

Haršaníková, Veronika January 2019 (has links)
The goal of this diploma thesis is a design study and project documentation for a new-building of a kindergarten in a city of Prešov (city part Solivar), Slovakia. The kindergarten will be a institution for pre-school education for children from 3 to 6 years old. The projects of the kindergarten building consist of one classroom for children within the age from 3-4, one classroom, for children within the age from 4-5 and third classroom for children from 5-6 years old. The designed object also contains janitor’s room and closet, laundry room, director’s office and a community room for cultural happenings held by kindergarten. Parking spaces are designed outside, in front of the building next to the main entrance. The playground is placed on the south-west side. The building of a kindergarten is designed as monolithic reinforced concrete skeleton structure with longitudinal beams. The circumferential walls will be made of ceramic bricks with a contact thermal insulation ETICS system. Ceilings are designed as a monolithic reinforced concrete. Over the 2nd floor, there will be a saddle roof and the roof over the first floor will be flat, with a gravel layer. Foundings of the building are designed as a concrete strips which expand to pads under columns.
25

Stavebně technologický projekt pro Polyfunkční komplex Rudiny II. - Žilina, objekt Blok D / Construction-technological Project of the Polyfunctional complex Rudiny II. - Žilina, Blok D building

Papučík, Lukáš January 2020 (has links)
The aim of the thesis is to solve selected parts of the construction technology project for the building of the multifunctional complex Rudiny II, Žilina - building block D. The content of the thesis is a technical report to the construction technology project, studies of the implementation of the main technological stages of the building. technological regulation for horizontal and vertical monolithic structures, quality control and testing plan for the production of vertical and horizontal monolithic structures, OSH plan. In the appendix of my diploma thesis I processed drawings of construction equipment, itemized budget of the building, object budget according to THU, time plan of construction, dimensions of construction machines, laying plan for system formwork on standardized floor of multifunctional house.
26

Nosná konstrukce víceúčelové budovy / Load-bearing Structure of Multi-purpose Building

Hetmer, Jakub January 2015 (has links)
This master´s thesis“ Load-bearing Structure of Multi-purpose Building“ is processed in the form of project documentation according to applicable regulations. It deals with static solution of monolitic reinforced concrete construction of administrative building of Česká spořitelna. Subject of the solutions is reinforced concrete monolithic point – supported ceiling slab, columns and staircase.
27

Microservice Migration Patterns and how Continuous Integration and Continuous Delivery are affected : A Case study of Indicio’s journey towards microservice

Liu, Kasper January 2021 (has links)
Microservice is an architectural design that promises a more elastic system where a microservice can be allocated compute power according to demand. Through the separation of components, each microservice can have its own hardware or cloud setup. As a result, the code becomes more maintainable through smaller repositories. Development and Operations (DevOps) is a set of best practices to improve software development and operations. Two important components of DevOps are Continuous Integration (CI) and Continuous Delivery (CD). CI is a set of practices that aims to automate testing and increase development velocity through continuously integrate code changes. While CD aims to streamline the deployment process of the code, enabling a shorter time to market. When migrating a monolithic codebase towards a microservice architecture, one faces a lot of decisions that can have a deep impact on the whole organization. From a CI/CD perspective, some decisions can impact the efficiency of the CI/CD pipeline. This thesis investigated how Indicio’s CI/CD pipeline changed when going from a monolith towards a microservice architecture. It documents the decisions Indicio made along the way and investigates how the CI buildtime and CD deploy time were affected. The result showed that Indicio’s decision to keep the new microservice in the same repository added 44% to the median buildtime. The time increase was acceptable since it only resulted in an average of 20 seconds increase in median buildtime. Although, the decision to separate the CD into two independent CD pipelines, one for the old monolith and one for the new microservice didn’t affect the deploy time by any considerate margin. The new microservice was deployed to Microsoft Azure to be able to take advantage of the elastic compute power. The big advantage from a CD perspective by utilizing Azure was the blue-green deployment method resulting in zero downtime. / Mikrotjänster är en arkitektdesign som lovar ett mer flexibelt system där en mikrotjänst kan tilldelas den nödvändiga datakraften. Genom att dela upp komponenter kan varje mikrotjänst ha sin egen hårdvara eller molninställning. Det resulterar i mindre stycken kod som är lättare att underhålla. Development and Operations (DevOps) är en samling av bästa praxis för att förbättra mjukvaruutveckling och operationer. Två viktiga komponenter av DevOps är Continuous Integration (CI) och Continuous Delivery (CD). CI är en samling av verktyg som försöker automatisera tester och öka utvecklingshastigheten genom att kontinuerligt integrera kodändringar. Medan syftet med CD är att effektivisera distribution av kod, vilket möjliggör en kortare tid till marknaden. När man migrerar en monolitiskt kodbas mot en mikrotjänst arkitektur står man inför flera val som kan påverka hela organisationen. Utifrån ett CI/CD perspektiv så kan dessa val påverka effektiviteten av CI/CD processen. Denna uppsats undersöker hur Indicios CI/CD process förändras när dem går mot en mikrotjänstarkitektur från en monolit. Uppsatsen dokumenterar de val Indicio har gjort under migrationen och hur det påverkar CI byggnadstid och CD distribution tid. Resultaten visar att Indicios beslut att behålla den nya mikrotjänsten i samma förvar resulterade i 44% ökad medianbyggtid. Tidsökningen var acceptabel då det endast innebar en snittökning på 20 sekunder. Fastän Indicio beslutade att separera på CD processen till två nya, en för den nya mikrotjänsten och en för den nya monoliten så påverkades inte distribueringstiden särskilt mycket. Den nya mikrotjänsten distribuerades på Microsoft Azure för att kunna utnyttja den elastiska datakraften. Den stora fördelen från ett CD perspektiv med Azure var att man kunde utnyttja blågrön distributionsmetod, vilket gjorde att driftstopp tiden försvann.
28

A MONOLITHIC HIGH-G TELEMETRY TRANSMITTER

Ferguson, D., Meyers, D., Gemmill, P., Pereira, C. 11 1900 (has links)
International Telemetering Conference Proceedings / October 29-November 02, 1990 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Instrumentation for taking dynamic in-bore measurements during high accelerations typically has been limited to accelerations under 20,000 g’s. In munition development and testing, there is a need for telemetry instrumentation that can relay dynamic performance data at 100,000 g’s. This paper describes the development and testing of a stable, regulated, telemetry transmitter that has been successfully tested to 67,400 g’s.
29

The Development and Evaluation of a Fully-coupled Monolithic Approach to Aero-structural Analysis and Optimization

McCormick, Neil 05 December 2013 (has links)
A monolithic approach to aero-structural analysis and optimization has been developed and implemented. In contrast to a partitioned approach which uses individual fluid and structural solvers to solve their respective systems separately, the monolithic approach solves a fully-coupled system simultaneously, enforcing solution compatibility across the sub-system interfaces at each iteration. In this work, a three-field formulation is used, consisting of fluid, structural, and fluid mesh-movement sub-systems. The performance of the monolithic approach is characterized using 1-D unsteady and 2-D steady analysis problems, and compared with a partitioned approach. Four steady model aero-structural optimization problems are also investigated. Gradients of the objective function are computed using the discrete-adjoint and flow-sensitivity (direct) methods. In each case, the monolithic approach is shown to be a promising option for efficient aero-structural analysis and optimization, though the implementation requires additional development of coupling sub-matrices when compared to a partitioned approach.
30

Determinação de glifosato e ácido aminometilfosfônico em amostras ambientais por cromatografia a líquido em fase reversa controlada por injeção sequencial / Determination of glyphosate and aminomethylphosphonic acid in environmental samples by reversed-phase liquid chromatography controlled by sequential injection

Pereira, Erico Aparecido Oliveira 18 July 2018 (has links)
Introduzido na década de 1970, o glifosato figura entre os herbicidas mais consumidos em todo mundo. Devido a características como baixa toxicidade aguda a organismos não-alvo e alta eficiência na eliminação de plantas daninhas, o herbicida se tornou um sucesso de vendas, com um substancial incremento em sua utilização após o desenvolvimento de culturas geneticamente modificadas para tolerar o ingrediente ativo. O elevado consumo do glifosato vem se tornando uma preocupação para diferentes agências ambientais e de saúde. Consequentemente, métodos eficientes para a determinação e quantificação do herbicida se fazem necessários. Na presente dissertação, aprimorou-se um método que utiliza um sistema de análise de injeção sequencial por cromatografia líquida (SIC) com detecção por fluorescência para a determinação de glifosato e seu principal produto de degradação, o ácido aminometilfosfônico (AMPA), em amostras ambientais. Os limites de detecção (LD) e quantificação (LQ) para o glifosato foram 0,10 e 0,33 ԁmol L-1, respectivamente. Já para o AMPA, LD foi de 0,07 µmol L-1 e LQ de 0,22 µmol L-1. O método foi empregado na determinação das espécies em amostras de água fortificadas e gerou valores de recuperação entre 97,2 a 151,5% para o AMPA e 74,6 a 140,5% para o glifosato. Quando empregado em um estudo de adsorção-dessorção, o método foi capaz de produzir valores dos parâmetros de Freundlich e Langmuir comparáveis aos encontrados na literatura. Com qmax = 2,1 ± 0,1 µmol g-1 e KF = 0,53 ± 0,07 µmol1-1/n L1/n g-1, o Latossolo B se mostrou como o solo com maior capacidade de adsorver o glifosato. Em termos de dessorção, o percentual dessorvido ficou abaixo de 55% da quantidade inicialmente adsorvida para as concentrações trabalhadas. / Introduced in the 1970, glyphosate figures among the most used herbicides in the world. Due to characteristics such as low acute toxicity to non-target organisms and high efficiency regarding the elimination of weeds, the herbicide has experienced a huge success in terms of safes. Since genetically modified crops that tolerate the active ingredient have been developed, these safes have continued to increase. Glyphosate\'s high consumption has become a concern to different environmental and health agencies. As a result, efficient methods for the determination of glyphosate and its main metabolite, aminomethylphosphonic acid (AMPA), are necessary. This dissertation describes improvements in a sequential injection chromatography method for the determination of glyphosate and aminomethylphosphonic acid in environmental samples. The limits of detection (LOD) and quantification (LOQ) for glyphosate is 0.10 e 0.33 µmol L-1, respectively. LOD of 0.07 µmol L-1 and LOQ of 0,22 µmol L-1 is registered for AMPA. The method was employed for the determination of both species in spiked water samples and recovery values between 97.2 a 151.5% was obtained for AMPA and between 74.6 a 140.5% for glyphosate. When used in an adsorption-desorption study, the method was capable of generating values for the Freundlich and Langmuir parameters that are similar to those found in the scientific literature. With a qm\" of 2.1 ± 0.1 µmol g-1 and KF = 0.53 ± 0.07 µmol1-1/n L1/n g-1, Latossolo B was the soil sample with the largest glyphosate adsorption capacity. Regarding desorption, the percentages desorbed were beiow 55% of the initial mass of glyphosate adsorbed for the concentrations used.

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