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Modelování, identifikace a řízení rotačního kyvadla / Modelling, identification and control of rotary pendulumKlusáček, Ondřej January 2009 (has links)
The diploma thesis deals with control of rotary inverted pendulum - Furuta pendulum. Solution for power electronics, sensors and coupling with PC is described, identification of parameters and nonlinear simulation model in Matlab/Simulink and SimMechanics toolbox is presented. Second type Lagrange equation is used for determination of equations of motion. Controll system based on state-space model of mechanism and LQR algorithm for design of state-space controller is used and switching between swing-up cotroller a stabilizing state-space control is achieved according to actual angular position of pendulum's angle. Input integrator eliminating steady state error was used with success.
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Inverted Organic Light Emitting Diodes: Optical and Electrical Device ImprovementThomschke, Michael 12 February 2013 (has links)
This study focuses on the investigation of the key parameters that determine the optical and electrical characteristics of inverted top-emitting organic light emitting diodes (OLED). A co-deposition of small molecules in vacuum is used to establish electrically doped films that are applied in n-i-p layered devices. The knowledge about the functionality of each layer and parameter is important to develop efficient strategies to reach outstanding device performances.
In the first part, the thin film optics of top-emitting OLEDs are investigated, focusing on light extraction via cavity tuning, external outcoupling layers (capping layer), and the application of microlens films. Optical simulations are performed to determine the layer configuration with the maximum light extraction efficiency for monochrome phosphorescent devices. The peak efficiency is found at 35%, while varying the thickness of the charge transport layers, the
semitransparent anode, and the capping layer simultaneously. Measurements of the spatial light distribution validate, that the capping layer influences the spectral width and the resonance wavelength of the extracted cavity mode, especially for TM polarization. Further, laminated microlens films are applied to benefit from strong microcavity effects in stacked OLEDs by spatial mixing of external and to some extend internal light modes. These findings are used to demonstrate white top-emitting OLEDs on opaque substrates showing power conversion efficiencies up to 30 lm/W and a color rendering index of 93, respectively.
In the second part, the charge carrier management of n-i-p layered diodes is investigated as it strongly deviates from that of the p-i-n layered counterparts. The influence of the bottom cathode material and the electron transport layer is found to be negligible in terms of driving voltage, which means that the assumption of an ohmic bottom contact is valid. The hole transport and the charge carrier injection at the anode is much more sensitive to the evaporation sequence, especially when using hole transport materials with a glass transition
temperature below 100°C. As a consequence, thermal annealing of fabricated inverted OLEDs is found to drastically improve the device electronics, resulting in lower driving voltages and an increased internal efficiency. The annealing effect on charge transport comes from a reduced charge accumulation due to an altered film morphology of the transport layers, which is proven for electrons and for holes independently. The thermal treatment can further lead to a device degradation. Finally, the thickness and the material of the blocking layers which usually control the charge confinement inside the OLED are found to influence the recombination much more effectively in inverted OLEDs compared to non-inverted ones.
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Towards stimuli-responsive functional nanocomposites: Smart tunable plasmonic nanostructures au-v02Kama Kama, Jean Bosco January 2010 (has links)
Magister Philosophiae - MPhil / The fascinating optical properties of metallic nanostructures, dominated by collective
oscillations of free electrons known as plasmons, open new opportunities for the
development of devices fabrication based on noble metal nanoparticle composite
materials. This thesis demonstrates a low-cost and versatile technique to produce
stimuli-responsive ultrafast plasmonic nanostructures with reversible tunable optical
properties. Albeit challenging, further control using thermal external stimuli to tune the
local environment of gold nanoparticles embedded in V02 host matrix would be ideal
for the design of responsive functional nanocomposites. We prepared Au-V02
nanocomposite thin films by the inverted cylindrical reactive magnetron sputtering
(ICMS) known as hollow cathode magnetron sputtering for the first time and report the
reversible tuning of surface plasmon resonance of Au nanoparticles by only adjusting
the external temperature stimuli. The structural, morphological, interfacial analysis and
optical properties of the optimized nanostructures have been studied. ICMS has been
attracting much attention for its enclosed geometry and its ability to deposit on large
area, uniform coating of smart nanocomposites at high deposition rate. Before
achieving the aforementioned goals, a systematic study and optimization process of
V02 host matrix has been done by studying the influence of deposition parameters on
the structural, morphological and optical switching properties of V02 thin films. A
reversible thermal tunability of the optical/dielectric constants of V02 thin films by
spectroscopic ellipsometry has been intensively also studied in order to bring more
insights about the shift of the plasmon of gold nanoparticles imbedded in V02 host
matrix.
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A scalable search engine for the Personal Cloud / Un moteur de recherche scalable pour le Personal CloudLallali, Saliha 28 January 2016 (has links)
Un nouveau moteur de recherche embarqué conçu pour les objets intelligents. Ces dispositifs sont généralement équipés d'extrêmement de faible quantité de RAM et une grande capacité de stockage Flash NANAD. Pour faire face à ces contraintes matérielles contradictoires, les moteurs de recherche classique privilégient soit la scalabilité en insertion ou la scalabilité en requête, et ne peut pas répondre à ces deux exigences en même temps. En outre, très peu de solutions prennent en charge les suppressions de documents et mises à jour dans ce contexte. nous avons introduit trois principes de conception, à savoir y Write-Once Partitioning, Linear Pipelining and Background Linear Merging, et montrent comment ils peuvent être combinés pour produire un moteur de recherche intégré concilier un niveau élevé d'insertion / de suppression / et des mises à jour. Nous avons mis en place notre moteur de recherche sur une Board de développement ayant un représentant de configuration matérielle pour les objets intelligents et avons mené de vastes expériences en utilisant deux ensembles de données représentatives. Le dispositif expérimental résultats démontrent la scalabilité de l'approche et sa supériorité par rapport à l'état des procédés de l'art. / A new embedded search engine designed for smart objects. Such devices are generally equipped with extremely low RAM and large Flash storage capacity. To tackle these conflicting hardware constraints, conventional search engines privilege either insertion or query scalability but cannot meet both requirements at the same time. Moreover, very few solutions support document deletions and updates in this context. we introduce three design principles, namely Write-Once Partitioning, Linear Pipelining and Background Linear Merging, and show how they can be combined to produce an embedded search engine reconciling high insert/delete/update rate and query scalability. We have implemented our search engine on a development board having a hardware configuration representative for smart objects and have conducted extensive experiments using two representative datasets. The experimental results demonstrate the scalability of the approach and its superiority compared to state of the art methods.
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Low slope roofs : Moisture transfer in inverted roofs constantly exposed to high moisture loads and drainage systems / Låglutande tak : Fuktvandring i omvända tak med konstant fuktigt tätskikt och takavvattningAntonopoulos, Charalampos January 2017 (has links)
Low slope roofs are roofs with an inclination between 1:16 and 1:4 and have been constructed and preferred for many years due to the benefits they present. The goal of the present work is to study the following problems of low slope roofs, as they are suggested by previous relevant theses and the current needs of the market. Moisture transfer in low slope roofs with constant exposure to high levels of relative humidity. Is protection against corrosion required for steel beams placed directly under the external membranes? If yes, what kind of protection is that? Roof drainage on low slope roofs The study of the first subject was based on simulations of this type of structures in order to see how external moisture affects the moisture level and the potential for corrosion on steel beams. The main goal was to conclude whether we can actually build inverted roofs with steel plates or beams lying right under the roof membrane and what kind of protection is more appropriate to apply, in case it is required. According to the literature review conducted on roof structures, corrosion and corrosion protection, as well as the results of the simulations, the main factor defining the corrosion potential is the indoor environment. Moreover, paint coating seems to be the indicated anticorrosive protection. Regarding drainage, the study focused on the literature review of the current situation, the solutions applied, the existing regulations and guidelines regarding the type of systems used (full flow or gravity, internal or external), the construction of drainage valleys (inclined or horizontal) and the placement and dimensioning of drains and overflows, in order to create a short handbook with issues to be considered by the roof engineer. The main conclusions are that drain valleys are suggested to be constructed completely horizontal, in order to facilitate the cooperation between drains, and that full-flow systems are more efficient than gravity ones and should be preferred, as long as the roof is not exposed to solid material and prone to its accumulation around drains (e.g. roofs covered with vegetation or stone ballast, with overhanging or nearby trees).
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The Sustainability Of Overconsumption? A Discursive Analysis Of Walmart's Sustainability CampaignAdams, Kathleen 01 January 2012 (has links)
This study inquires as to whether Walmart’s sustainability campaign represents a sincere and holistic change throughout the company’s global supply chain or if it is simply a public relations campaign which caters to the growing target market of “next-generation” consumers and justifies further expansion into “emerging markets”. A critical analysis of Walmart’s sustainability discourse is presented, using transcribed texts of various corporate and publicitygeared publications. Frequently utilized terms and themes are identified throughout the big-box retailer’s sustainability campaign which convey a distinctly Neoliberal ethos—a political economy which lies at the heart of current practices of institutional unsustainability—and emphasize the role of the atomized individual—who may purchase protection from environmental risks via green products. Other themes, which are commonly associated with sustainability research, are glaringly absent: subsidiarity; human rights; steady-state economics; economic inequity; the precautionary principle. This research aims to shed light on the prospects for the sustainability of green overconsumption, which Walmart is leading the way in promoting, and for the continuation of the modern economistic zeitgeist into the twenty-first century.
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Design, Modeling and Control of a Two-Wheel Balancing Robot Driven by BLDC MotorsRefvem, Charles T 01 December 2019 (has links) (PDF)
The focus of this document is on the design, modeling, and control of a self-balancing two wheel robot, hereafter referred to as the balance bot, driven by independent brushless DC (BLDC) motors. The balance bot frame is composed of stacked layers allowing a lightweight, modular, and rigid mechanical design. The robot is actuated by a pair of brushless DC motors equipped with Hall effect sensors and encoders allowing determination of the angle and angular velocity of each wheel. Absolute orientation measurement is accomplished using a full 9-axis IMU consisting of a 3-axis gyroscope, a 3-axis accelerometer, and a 3-axis magnetometer.
The control algorithm is designed to minimize deviations from a set point specified by an external radio remote control, which allows the remote operator to steer and drive the bot wirelessly while it remains balanced. Multiple dynamic models are proposed in this analysis, and the selected model is used to develop a linear-quadratic regulator based state-feedback controller to perform reference tracking. Controller tracking performance is improved by incorporating a prefilter stage between the setpoint command from the remote control and the state-feedback controller.
Modeling of the actuator dynamics is considered brie y and is discussed in relation to the control algorithm used to balance the robot. Electrical and software design implementations are also presented with a focus on effective implementation of the proposed control algorithms.
Simulated and physical testing results show that the proposed balance bot and controller design are not only feasible but effective as a means of achieving robust performance under dynamic tracking profiles provided by the remote control.
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A GENOME-WIDE ANALYSIS OF PERFECT INVERTED REPEATS IN <I>ARABIDOPSIS THALIANA</I>Sutharzan, Sreeskandarajan 12 December 2013 (has links)
No description available.
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Mechanisms of Inverted formin 2-mediated intracellular trafficking, invasion, and placentation in mouse and human pregnancyLamm, Katherine Young Bezold 07 June 2018 (has links)
No description available.
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The relationship between methane emissions and economic growth between High income and Low income countriesBjörk, Zackarias, Ahlm, Nathanael January 2022 (has links)
The Intergovernmental Panel on Climate Change 2018 highlights the importance of short-lived greenhouse gasses to combat global warming. This study explores the relationship between Gross Domestic Product per capita and methane per capita. The relationship is explored in relation to the Environmental Kuznets Curve theory where the subjects to examination used are High Income Countries and Low Income Countries based on United Nation classifications in 2019. In total 47 countries are examined where 30 countries are High Income Countries and 17 are Low Income Countries. The relationships are examined for the time periods 1970 to 2017 through Fixed Effect Models. To improve accuracy additional control variables are added: Population in agriculture (% of total employment), balance of payments and forest areas. With the added control variables, the time frame used in Fixed Effect Models changes to 1991 to 2017. The different Fixed Effect Models provide inverted U-shaped relationships for Low Income Countries and uncertain results for High Income Countries according to the Environmental Kuznets Curve.
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