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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.
1

END-TO-END TIMING ANALYSIS OF TASK-CHAINS

Jin, Zhiqun, Zhu, Shijie January 2017 (has links)
Many automotive systems are real-time systems, which means that not only correct operationsbut also appropriate timings are their main requirements. Considering the in uence that end-to-end delay might have on the performance of the systems, the calculation of it is of necessity.Abundant techniques have actually been proposed, and some of them have already been applied intopractical systems. In spite of this, some further work still needs to be done. The target of thisthesis is to evaluate and compare two end-to-end timing analysis methods from dierent aspectssuch as data age, consumption time, and then decide which method is a prior choice for end-to-end timing analysis. The experiments can be divided into three blocks, system generation andend-to-end delay calculation by two methods respectively. The experiments focus on two kinds ofperformance parameters, data age and the consumption time that these two methods cost duringtheir execution. By changing the system generating parameters like task number and periods, thechanges of performances of the two methods are analyzed. The performances of the two dierentmethods are also compared when they are applied into the same automotive systems. According tothe results of the experiments, the second method can calculate more accurate data age and consumeless time than the rst method does.
2

Harmonic Losses in Windings of Inverter-Fed High-Speed PM Motors / Förluster i lindningar av högvarviga PM maskiner med växelriktare

Yang, Yang January 2015 (has links)
This master thesis focuses on the estimation of losses in windings of a high-speed PermanentMagnet (PM) motor. The PM motor studied in this thesis is applied to a nut-runner systemwith specic characteristics such as operating at a high speed (30000 rpm), relatively smallsize and being slot-less. Previously published analytical models for calculation the losses inwindings are discussed in the literature study along with related background theory. Finiteelement method (FEM) 2D is applied in the simulations using FLUX v12. Simulations beginwith several conductors and bundles. Meanwhile, the analytical estimation of those caseswas carried out. The comparisons between results from both sources are discussed. Beforefurther investigations, the way of connection of bundles and conductors and the applicationof symmetrical conditions for following simulations are discussed. Furthermore, the wholewindings with a iron ring and the rotor are simulated step by step in FLUX. Eect of ironmaterial, lamination thickness and base value are investigated. Finally, losses in windingswith various situations are calculated and compared at 10 kHz and 20 kHz. / Detta examensarbete behandlar uppskattning av forluster i lindningarna hos en permanentmagnet(PM) hoghastighets-motor. PM-motorn som studerats i denna avhandling tillhor ettmutterdragarsystem avsett for industriellt bruk. Utmarkande egenskaper for denna ar hoghastighet (30000 rpm), relativt liten storlek och avsaknad av statorspar. Tidigare publiceradeanalysmodeller for forlustberakningar i lindningar diskuteras i litteraturstudien tillsammansmed tillhorande bakgrundsteori. Finita Element Metoden (FEM) 2D anvands i simuleringarna.FEM-studierna har utforts i FLUX v12. Studierna utfors initialt pa era ledareoch buntar parallellt med analytiska uppskattningar for dessa. Resultaten fran bada kallornajamfors och diskuteras. Vidare diskuteras olika mojligheter till anslutning av era ledare ochledarvarv, samt tillampning av symmetriska villkor for vidare simuleringar. Lindningarnasimuleras darefter stegvis tillsammans med en jarnring och rotor. Paverkan av jarnmaterial,laminat-tjocklek och basvarde utreds. Slutligen utfors forlustjamforelser i lindningarna forolika kongurationer vid 10 kHz och 20 kHz. / Buntade, ledare, FEM 2D, forluster, PM motor, yteekt och narhetseekt, vridna, lindningarna
3

CheckMate : Remote Arduino powered chess / Trådlöst Arduino drivet schack

ERICSON, JOAKIM, WESTERMARK, ADAM January 2020 (has links)
Board games are on the rise and chess is no exception. However, in an increasingly digitalized world these board games lack something in comparison to digitalized games, being able to play with anyone anywhere. This project aimed to combine these two worlds by being a physical game of chess where one could play against an opponent from far away. CheckMate is a robot consisting of an acrylic frame and various electronic components, such as an electromagnet, two stepper motors, a Hall eect sensor and a WiFi module. The electromagnet and Hall eect sensor were able to move using a belt and pulley system. This allowed magnetic pieces to be identified and dragged across the board. The board then communicated the location of all the pieces on the board, using Wifi, to an website that also kept track on whose turn it was. The result of this project was a robot that was able to perform all the moves necessary on the chessboard as well as communicating to the website. When moving a piece from one location to another the piece repelled other pieces on its way. However, this was deemed to be acceptable since the pieces were not moved too large of a distance for the electromagnet to attract them when moved into its square. One move that the robot was not able to perform was castling. The results can therefore bee seen as a starting point toward further developments. / Brädspels popularitet stiger och schack är inget undantag. Dock saknar brädspel de digitala spelens möjlighet att spela med vem som helst varsomhelst. Detta projekt ville bygga över klyftorna mellan dessa två världar genom att vara ett fysiskt schackspel med de digitala spelens möjligheter. CheckMate är en robot byggd av akrylplast och diverse elektroniska komponenter sådan som en elektromagnet, två stegmotorer, en halleektsensor och en WiFi-modul. Elektromagneten och halleektsensorn förflyttades via ett system av kuggremmar drivet av stegmotorerna. Elektromagneten användes för att flytta pjäserna på brädet medan halleektsensorn användes vid kartläggning av pjäsernas position på brädet. Brädet kommunicerade, via trådlöst nätverk, till en hemsida som användes för att spara och överföra pjäsernas positioner. Projektet resulterade i en robot som kunde göra alla motsvarande drag hämtat från hemsidan. Dock så repellerade en flyttande pjäs på de stationära pjäserna när den passerade. Detta ansågs dock vara acceptabelt då elektromagneten kunde föra tillbaka pjäserna när den befann sig i dess ruta. Något som projektet ej lyckades utföra var draget rockad. Resultatet av detta projekt kan ses som en startpunkt i en vidareutveckling eller en färdig produkt vid obesvärad spelning.
4

Dynamics of quarks and leptons : theoretical Studies of Baryons and Neutrinos

Ohlsson, Tommy January 2000 (has links)
The Standard Model of Elementary Particle Physics (SM) is the present theoryfor the elementary particles and their interactions and is a well-established theorywithin the physics community. The SM is a combination of Quantum Chromodynamics(QCD) and the Glashow{Weinberg{Salam (GWS) electroweak model. QCDis a theory for the strong force, whereas the GWS electroweak model is a theoryfor the weak and electromagnetic forces. This means that the SM describes allfundamental forces in Nature, except for the gravitational force. However, the SMis not a nal theory and some of its problems will be discussed in this thesis.In the rst part of this thesis, several properties of baryons are studied suchas spin structure, spin polarizations, magnetic moments, weak form factors, andnucleon quark sea isospin asymmetries, using the chiral quark model (QM). TheQM is an eective chiral eld theory developed to describe low energy phenomena of baryons, since perturbative QCD is not applicable at low energies. The resultsof the QM are in good agreement with experimental data.The second part of the thesis is devoted to the concept of quantum mechanicalneutrino oscillations. Neutrino oscillations can, however, not occur within the GWSelectroweak model. Thus, this model has to be extended in some way. All studiesincluding neutrino oscillation are done within three avor neutrino oscillationmodels. Both vacuum and matter neutrino oscillations are considered. Especially,global ts to all data of candidates for neutrino oscillations are presented and alsoan analytical formalism for matter enhanced three avor neutrino oscillations usingtime evolution operators is derived. Furthermore, investigations of matter eectswhen neutrinos traverse the Earth are included.The thesis begins with an introductory review of the QM and neutrino oscillationsand ends with the research results, which are given in the nine accompanyingscientic articles. / QC 20100616

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