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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.
371

Value creation in an Open Innovation relationship : Investigating the relational factors in an accelerator program

Badiale, Annalena, Jazeb, Parisa, Wik, Clara January 2022 (has links)
The mutual need between organizations and startups, from one side to stay competitive and the other to survive, leads to open innovation relationships. However, the actors are asymmetrical, leading to a risk that no value is created. Nevertheless, value needs to be created in the relationship to enable open innovation. This study identifies in literature four relational factors. The aim is to investigate how a startup and established organization perceive the relational factors of actor bonds, resource ties, activity links, network embeddedness, and their influence on value creation. Six semi-structured interviews are conducted. The main findings are: (I) all the relational factors influence value creation in this context. Thus, all are needed to enable an open innovation process (II) each theme that emerged in theory was confirmed (III) each actor􏰈s perceptions were found to be different, demonstrating that value is determined differently depending on the unique actor, their needs and context. Therefore, each actor needs to put more emphasis on the specific themes that actors in the relationship find valuable (IV) new themes are found to influence the relational factor of actor bonds (V) the level of value created depends on how the relational factors are managed by the actors.
372

A Study on Fault Tolerance of Object Detector Implemented on FPGA / En studie om feltolerans för objektdetektor Implementerad på FPGA

Yang, Tiancheng January 2023 (has links)
Objektdetektering har fått stort forskningsintresse de senaste åren, eftersom det är maskiners ögon och är en grundläggande uppgift inom datorseende som syftar till att identifiera och lokalisera föremål av intresse. Hårdvaruacceleratorer syftar vanligtvis till att öka genomströmningen för realtidskrav samtidigt som energiförbrukningen sänks. Studier av feltolerans säkerställer att algoritmen utförs korrekt även med felpresentation. Denna avhandling täcker dessa ämnen och tillhandahåller en Field-Programmable Gate Array (FPGA)-implementering av en objektdetekteringsalgoritm, You Only Look Once (YOLO), samtidigt som man undersöker implementeringens feltolerans. En baslinjeimplementering på FPGA tillhandahålls först och sedan tillämpas, implementeras och testas två feltoleranta implementeringar, en med trippelmodulär redundans och en med tidsredundans. Fastnade fel injiceras i implementeringarna för att studera feltoleransen. Vår FPGA-implementering av YOLO ger en höghastighets, låg strömförbrukning och mycket konfigurerbar hårdvaruaccelerator för objektdetektering. I detta examensarbete görs implementeringsdesignen med en kombination av egendesignade moduler med VHDL och Xilinx-försedd Intellectual Property (IP). Jämfört med andra forsknings- eller öppen källkodsversioner som använder High-Level Synthesis (HLS), är denna design mer konfigurerbar för framtida referenser och tar bort onödiga hårdvarusvarta lådor. Jämfört med andra studier om hårdvaruacceleratorer fokuserar denna avhandling på feltolerans. Detta examensarbete skapar utrymme för mer arbete med att utforska feltolerans, t.ex. skapa en mer feltolerant implementering eller undersöka hur vissa fel kan påverka resultatet. Det är också möjligt att använda implementeringen från denna avhandling som baslinje för andra forskningsändamål, eftersom implementeringen är fristående och mycket konfigurerbar. / Object detection gets great research interest in recent years, as it is the eyes of machines and is a fundamental task in computer vision that aims at identifying and locating objects of interest. Hardware accelerators usually aim at boosting the throughput for real-time requirements while lowering power consumption. Studies on fault tolerance ensure the algorithm to be performed correctly even with error presenting. This thesis covers these topics and provides a Field-Programmable Gate Array (FPGA) implementation of an object detection algorithm, You Only Look Once (YOLO), while investigating the fault tolerance of the implementation. A baseline implementation on FPGA is first provided and then two fault-tolerant implementations, one with triple-modular redundancy and one with time redundancy are applied, implemented, and tested. Stuck-at faults are injected into the implementations to study the fault tolerance. Our FPGA implementation of YOLO provides a high-speed, low-power-consumption, and highly-configurable hardware accelerator for object detection. In this thesis, the implementation design is done with a combination of self-designed modules with VHDL and Xilinx-provided Intellectual Property (IP). Compared to other research or open-source versions using High-Level Synthesis (HLS), this design is more configurable for future references and removes unnecessary hardware black boxes. Compared to other studies on hardware accelerators, this thesis focuses on fault tolerance. This thesis creates space for more work on exploring fault tolerance, e.g., creating a more fault-tolerant implementation or investigating how certain faults could affect the result. It is also possible to use the implementation from this thesis as a baseline for other research purposes, as the implementation is stand-alone and highly configurable.
373

Monitoring the electron beam position at the TESLA Test Facility Free Electron Laser

Kamps, Thorsten 14 June 2000 (has links)
Der Betrieb eines Freien Elektronen Lasers (FEL), bei dem die spontan emittierte Undulatorstrahlung ueber Wechselwirkung mit dem Elektronenstrahl selbst verstaerkt wird, setzt eine praezise Ausrichtung des Elektronenstrahls mit dem Photonenstrahl voraus. Um den Ueberlapp von Elektronen-und Photonenstrahl zu gewaehrleisten, wurde ein neuartiger Typ von Wellenleiter-Strahllagemonitor entwickelt, der in eine Vakuumkammer des Undulators des FELs der TESLA Test Facility (TTF) integriert ist. Vier um das Strahlrohr verteilte Wellenleiter koppeln ueber schmale Schlitze einen Bruchteil jenes elektromagnetischen Feldes aus, welches den Strahl begleitet. Die induzierten Signale haengen von der transversalen Strahlposition und der Strahlintensitaet ab. Mit vier Schlitz-Wellenleiter Paaren laesst sich ein lineares Signal ableiten, anhand dessen die Position des Elektronenstrahls bestimmt werden kann. Die induzierten Signale werden mittels eines stegbelasteten Wellenleiters in die erste Stufe eines bei 12 GHz arbeitenden Empfaengers zugefuehrt. Die vorliegende Arbeit beschreibt Design, Tests und Implementierung dieses neuartigen Typs von Strahllagemonitor. / The operation of a free electron laser working in the Self Amplified Spontaneous Emission mode (SASE FEL) requires the electron trajectory to be aligned with very high precision in overlap with the photon beam. In order to ensure this overlap, one module of the SASE FEL undulator at the TESLA Test Facility (TTF) is equipped with a new type of waveguide beam position monitor (BPM). Four waveguides are arranged symmetrically around the beam pipe, each channel couples through a small slot to the electromagnetic beam field. The induced signal depends on the beam intensity and on the transverse beam position in terms of beam--to--slot distance. With four slot--waveguide combinations a linear position sensitive signal can be achieved, which is independent of the beam intensity. The signals transduced by the slots are transferred by ridged waveguides through an impedance matching stage into a narrowband receiver tuned to 12 GHz. The present thesis describes design, tests, and implementation of this new type of BPM.
374

Demonstrating reliableinstrumentation in theATLAS Tile Calorimeter : Fault tolerance and redundancy in hardware and firmwarefor the Phase-II Demonstrator project in preparation forHigh Luminosity LHC at CERN

Åkerstedt, Henrik January 2024 (has links)
The Large Hadron Collider at CERN is scheduled to undergo upgrades in 2026-2028 to significantly increase its luminosity. These upgrades, while providing the experiments with a higher collision rate, pose a number of challenges to the design of the hardware and software in the detectors. The Tile Calorimeter (a scintillating sampling calorimeter read out by photomultiplier tubes) at the ATLAS experiment will have its read-out electronics completely replaced to enable performance and reliability improvements.  Advances in electronics, new requirements due to the luminosity upgrade as well as lessons learned from the current readout scheme drove development with the goals to partition the readout into small independent units with full granularity readout and a robust mitigation strategy for radiation induced errors. To verify the functionality of the new system while retaining backward compatibility a "Demonstrator'' has been developed to emulate the current functionality while using new and improved hardware. The board responsible for managing digitized calorimeter data and communicating with the off-detector electronics, called the DaughterBoard, is the main focus of this thesis. It has two electrically isolated sides for redundancy where each side consists of voltage regulators, two optical transceivers, a GigaBit transceiver chip (for clocking and configuration) and a Kintex FPGA for data processing. In addition to data management and transmission, the FPGA (and every other component) needs to be able to withstand the effects of radiation both in terms of total dose (ionization and displacement damage) and due to single event effects. The DaughterBoard was developed with this in mind and has undergone several radiation tests during its development to verify reliability and fault tolerance. / CERN
375

An advanced neuromorphic accelerator on FPGA for next-G spectrum sensing

Azmine, Muhammad Farhan 10 April 2024 (has links)
In modern communication systems, it’s important to detect and use available radio frequencies effectively. However, current methods face challenges with complexity and noise interference. We’ve developed a new approach using advanced artificial intelligence (AI) based computing techniques to improve efficiency and accuracy in this process. Our method shows promising results, requiring only minimal additional resources in exchange of improved performance compared to older techniques. / Master of Science / In modern communication systems, it’s important to detect and use available radio frequencies effectively. However, current methods face challenges with complexity and noise interference. We’ve developed a new approach using advanced artificial intelligence (AI) based computing techniques to improve efficiency and accuracy in this process. Our method shows promising results, requiring only minimal additional resources in exchange of improved performance compared to older techniques.
376

名古屋大学タンデトロンAMS14Cシステムの現状と利用(2012)

Tomiyama, Shinji, Hase, Kazuma, Soda, Aoi, Kato, Tomomi, Jyomori, Yuka, Ikemori, Kazufumi, Nishida, Masami, Ohta, Tomoko, Miyata, Yoshiki, Hakozaki, Masataka, Itoh, Kazumi, Hitoki, Eri, Ikeda, Akiko, Oda, Hirotaka, Minami, Masayo, Nakamura, Toshio, 冨山, 慎二, 長谷, 和磨, 早田, 葵, 加藤, ともみ, 城森, 由佳, 池盛, 文数, 西田, 真砂美, 太田, 友子, 箱崎, 真隆, 宮田, 佳樹, 伊藤, 一充, 一木, 絵理, 池田, 晃子, 小田, 寛貴, 南, 雅代, 中村, 俊夫 03 1900 (has links)
名古屋大学年代測定総合研究センターシンポジウム報告
377

Enterprise Computing

Spruth, Wilhelm G. 13 November 2013 (has links) (PDF)
Das vorliegende Buch entstand aus einer zweisemestrigen Vorlesung „Enterprise Computing“, die wir gemeinsam über viele Jahre als Teil des Bachelor- oder Master-Studienganges an der Universität Leipzig gehalten haben. Das Buch führt ein in die Welt des Mainframe und soll dem Leser einen einführenden Überblick geben. Band 1 ist der Einführung in z/OS gewidmet, während sich Band 2 mit der Internet Integration beschäftigt. Ergänzend werden in Band 3 praktische Übungen unter z/OS dargestellt.
378

Development of a compact test facility for SRF Photoelectron injectors

Völker, Jens 09 August 2018 (has links)
SHF Photoelektroneninjektoren sind eine vielversprechende Elektronquelle für hochbrillante Teichenbeschleuniger mit hohem mittlerem Strom und kurzen Teilchenpulsen, wie FELs und ERLs. Für das ERL Projekt bERLinPro wurde einer unabhängige Testanlage GunLab entwickelt um die Leistungsfähigkeit der Injektoren und die Strahlparameter zu überprüfen. Darüber hinaus können neue Komponenten zur Strahldiagnose getestet werden. Die Hauptaufgabe von GunLab ist die Beschreibung des vollständigen sechsdimensionalen Phasenraums der Elektronen in Abhängigkeit aller Injektorparameter. Die Anlage besteht aus einer kompakten Diagnosestrahlführungan dem SHF Photoelektroneninjektoren und einem Kathodenlasersystem. Im Rahmen dieser Arbeit wurden analytische und numerische Studien zu den SHF Photoelektroneninjektoren durchgeführt, um zu erwartende Strahlparameter zu detektieren und die Anforderungen an die Strahldiagnose festzulegen. Darüber hinaus wurden verschiedene Emittanzbeiträge der einzelnen Injektorkomponenten untersucht. Diesbezüglich wurde das Magnetfeld des aktuellen Solenoiden kartiert und auf Asymmetrien getestet, die ebenfalls zu Emittanzvergrößerungen beitragen können. Eine der wesentlichen Komponenten der Diagnosestrahlführung ist das (transversale) Phasenraummesssystem, für das eine besondere Magnetgeometrie entwickelt wurde. Weitere Diagnose Komponenten sind ein optimierter Spektrometerdipol und eine transversal ablenkende Kavität, durch die sich zusammen mit zwei Quadrupolmagneten die Scheibenemittanz bestimmen lässt. Für GunLab wurden unterschiedliche optische Messsysteme entwickelt und optimiert. Der herausforderndste Aufbau ist dabei das Strahl-Halo Messsystem. Es ermöglicht die Beobachtung der transversalen Ladungsverteilung über einen Dynamikbereich von bis zu 6 Größenordnungen. Die Leistungsfähigkeit und die Auflösung aller Messsysteme und Messroutinen wurden bestimmt, um die Visualisierung des kompletten Phasenraums durch GunLab sicher zu stellen. / SRF photoelectron injectors are promising electron sources for high brightness accelerators with high average current and short pulse duration like FELs and ERLs. For the ERL project bERLinPro an independent test facility called GunLab was developed and set up to optimize the operation performance of SRF photoinjectors and the electron beam parameters. Furthermore, GunLab allows to investigate the operation of different kinds of photocathodes in the environment of an SRF accelerator and to study new beam diagnostic concepts. Of outmost importance is the characterization of the full six dimensional phase space as a function of all injector parameters. GunLab consists of the compact diagnostic beam line, connected to the SRF photoinjetor module, and a drive laser. In the context of this thesis, analytical and numerical investigations of the SRF photoinjector were performed to estimate beam parameter ranges and to determine the diagnostics requirements. Furthermore, various emittance contributors of the injector were determined. Thereby the magnetic field of the final designed solenoid was measured to determine field asymmetries, which are one major source of emittance growth. One of the central diagnostic components of the beamline is the (horizontal) phase space scanner system. For this purpose, a dedicated air-coil magnet design was developed. Additional diagnostic components include an optimized spectrometer system, a transverse deflecting cavity (TCav) and two quadrupole magnets, to determine longitudinal and sliced emittance. For GunLab different optical measurement systems were developed and optimized, the most challenging setup is a beam halo measurement system. This device is able to observe the transverse charge density with a dynamic range of up to 6 orders of magnitude. The performance and the resolution of all measurement systems and routines for GunLab were determined to ensure the visualization of the electron beam phase space.
379

Experimental studies of radiation damage in uranium nitride / Experimentella studier av strålskador i urannitrid

Giamouridou, Maria January 2023 (has links)
The effect of proton (H+) irradiation on uranium mononitride (UN) and UN compositefuel with 10 at.% ZrN (UN10at%ZrN) was examined. Protons of 2 MeV with fluences of1E17, 1E18, 1E19 and 1E20 ions/cm2 were accelerated towards the fabricated samples in orderto investigate the evolution of the micro-structure. Stopping and Range of Ions in Matter(SRIM) calculations were performed to determine the displacements per atom associatedwith the depth of the highest damage, for each fluence.X-Ray diffraction (XRD) was used in both samples to identify the chemical composition ofeach pellet, which revealed the low presence of oxygen. Based on scanning electron microscopy(SEM), deterioration of the samples surface was observed, as the proton fluence increased.The applied stress due to the irradiation, led to the cracking of the pellets at the highestfluences. Blisters and craters appear to surround the cracked region, which might originatefrom the significant levels of hydrogen implantation within the samples.From Electron backscatter diffraction (EBSD) analysis, the grain size of the UN10at%ZrNcomposite was found to be smaller than in UN, due to the nano-particle nature of the ZrNpowder. The latter technique was also used to observe the elevated irradiated regions, whichwere further investigated by atomic force microscopy (AFM). Nano-indentation detectedirradiation hardening for both samples in the irradiated regions. Focused ion beam (FIB)milling was applied to remove lamellas from the cracked regions in both UN and compositesamples in order to be analyzed by transmission electron microscopy (TEM). The latter mightreveals the formation of dislocation loops in the irradiated areas. / Effekten av protonbestrålning på urannitrid (UN) och UN-kompositbränsle med 10 at.% ZrN (UN10at%ZrN) undersöktes. Protoner på 2 MeV med total dos på 1E17, 1E18, 1E19 och 1E20 joner/cm2 accelererades mot de tillverkade proverna för att undersöka utvecklingen av mikrostrukturen under bestrålning. SRIM-beräkningar (Stopping and Range of Ions in Matter) utfördes för att bestämma profilen på skadan och jonimplanteringen i förhållande till djupet, för varje dosnivå.  Röntgendiffraktion (XRD) användes på båda proverna för att identifiera den kemiska sammansättningen av varje kuts, vilket visade att syrehalten var låg. Med hjälp av svepelektronmikroskopi (SEM) observerades en försämring av provernas yta när protonflödet ökade. Den resulterande mekaniska spänningen överskred provets brottstyrka på djupet, eftersom nitriderna inte är så duktila, vilket ledde till sprickbildning i proverna som utsattes för de högsta doserna. Blåsor och kratrar omger det spruckna området, vilket beror på betydande väteimplantering i provet.  Genom electron backscatter diffraction analys (EBSD) konstaterades att kornstorleken hos UN10at%ZrN-kompositen var mindre än hos UN, på grund av ZrN-pulvrets nanopartikelnatur. Den sistnämnda tekniken användes för att observera de högt bestrålade områdena, som undersöktes ytterligare med Atomic force microscopy (AFM). Genom nano-indientation upptäcktes bestrålningshärdning för båda proverna i de bestrålade områdena. Fräsning med en fokuserad jonstråle (FIB) användes för att avlägsna lameller från de spruckna områdena i både UN- och kompositprovet för att kunna analyseras med transmission electron microscopy (TEM). Det senare visade att det bildades dislokationer i de bestrålade områdena.
380

Beam Dynamics and Limits for High Brightness, High Average Current Superconducting Radiofrequency (SRF) Photoinjectors

Panofski, Eva 05 June 2019 (has links)
Zukünftige Beschleunigerprojekte und Nutzerexperimente erfordern für ihren Betrieb einen hochbrillanten Elektronenstrahl mit hohem mittlerem Strom. Eine Elektronenquelle mit dem Potential die Anforderungen erfüllen, ist ein supraleitender Hochfrequenz (SHF) Photoinjektor im Dauerstrichbetrieb. Die Strahldynamik eines solchen Photoinjektor Systems bestimmt die maximal zu erreichende Strahlbrillanz und wird ihrerseits von den Design und Betriebsparametern des Photoinjektors beeinflusst. Ziel ist immer die entscheidenden Design- und Betriebsparameter der Elektronenquelle hinsichtlich einer maximalen Strahlbrillanz zu wählen. Diese Aufgabe verlangt ein detailliertes Verständnis der Strahldynamik-Prozesse. Ferner ist es notwendig, eine Optimierung des Photoinjektors als Ganzes, mit dem Ziel einer maximalen Strahlqualität bei hohem mittlerem Strom, vorzunehmen. Dieses ermöglicht auch, die physikalischen Grenzen eines gegebenen Designs zu ermitteln und im Betrieb vollständig auszunutzen. Diese Doktorarbeit befasst sich mit der Strahldynamik in einem SHF Photoinjektor, unter Berücksichtigung interner Raumladungseffekte. Die Erkenntnisse zur Strahldynamik werden für die Entwicklung eines Optimierungsprogramms verwendet, um die Leistung des Injektors hinsichtlich der Strahlbrillanz zu verbessern. Die entwickelte Methode basiert auf Pareto-Optimierung mehrerer Zielfunktionen, unter Verwendung eines generischen Algorithmus. Das zentrale Ergebnis dieser Arbeit umfasst ein universelles Optimierungsprogramm, das für Photoinjektoren unabhängig von ihrem Design und Anwendungsgebiet genutzt werden kann. Für den Betrieb mit hoher Strahlbrillanz ist es möglich aus den erhaltenen Pareto-optimalen Lösungen einen stabilen Satz an Einstellwerten für den Photoinjektor zu extrahieren. Durch die allgemeine Optimierungsstrategie lässt sich das entwickelte Programm auch für andere Beschleunigerabschnitte, oder die Optimierung einer ganzen Anlage mit erweiterter Zielsetzung anpassen. / An increasing number of future accelerator projects, light sources and user experiments require high brightness, high average current electron beams for operation. Superconducting radio-frequency (SRF) photoinjectors running in continuous-wave (cw) mode hold the potential to serve as an electron source that generates electron beams of high brightness. Different operation and design parameters of the SRF photoinjector impact the beam dynamics and, thus, the beam brightness. Therefore, an in-depth understanding of the beam dynamics processes in an SRF photoinjector and the dependency of the beam dynamics on the photoinjector set parameters is crucial. A high brightness beam operation requires a global optimization of the SRF photoinjector that allows to find suitable photoinjector settings and to figure out and extend the physical performance limits of the investigated injector design. The dissertation at hand offers a detailed analysis of the beam dynamics in an SRF photoinjector regarding internal space charge effects. Furthermore, the impact of the photoinjector elements on the electron beam is discussed. The lessons learned from this theoretical view are implemented in the development of an optimization tool to achieve a high brightness performance. A universal multi-objective optimization program based on a generic algorithm was developed to extract stable, optimum gun parameter from Pareto-optimum solutions. This universal tool is able to optimize and find the physical performance limit of any (S)RF photoinjector independent from the individual application of the electron source (energy recovery linac, free electron laser, ultra-fast electron diffraction). This thesis thereby verifies and complements existing theoretical considerations regarding photoinjector-beam interactions. The global optimization strategy can be introduced to variable optimization objectives as well as it can be extended to an optimization of further parts of the accelerator facility.

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