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Développement d'un injecteur pour l'accélération laser plasma multi-étages / Design of an electron injector for multi-stages laser wakefield accelerationAudet, Thomas 10 November 2016 (has links)
L’accélération laser plasma (ALP) est un mécanisme d’accélération de particules reposant sur l’interaction d’impulsions laser ultra-intenses, de l’ordre de quelques 10^{18} W/cm², avec un plasma. L’onde plasma générée dans le sillage de l’impulsion laser est associée à des champs électriques de grande amplitude (1 − 100 GV/m). Ces champs électriques de trois ordres de grandeurs supérieurs aux champs maximums supportés dans les cavités radiofréquences des accélérateurs conventionnels constituent le principal point fort de l’ALP, permettant d’envisager des accélérateurs de particules plus compacts. Un important travail pour améliorer les propriétés des paquets d’électrons générés par ALP, leur stabilité et la cadence de tir est cependant nécessaire pour rendre l’ALP compétitive en termes d’applications.Un moyen d’améliorer les propriétés des faisceaux d’électrons consiste à les accélérer dans un régime faiblement non linéaire en plusieurs étapes successives : l’ALP multi-étages. La source laser-plasma d’électrons, ou injecteur, doit générer des paquets d’électrons d’énergie modeste (50 − 100 MeV), de charge la plus importante possible, de faible dimension et de faible divergence. Les électrons doivent alors être injectés dans un second étage purement accélérateur dont l’objectif est d’augmenter leur énergie cinétique.L’objet de cette thèse est le développement d’un injecteur laser plasma pour l’ALP multi-étages. Dans le cadre d’une collaboration autour de l’equipex CILEX et du programme d’ALP à deux étages, un prototype d’injecteur a été construit, ELISA, reposant sur une cellule de gaz de longueur variable. La densité électronique du plasma, qui est un paramètre crucial pour le contrôle du faisceau d’électrons, a été caractérisée à la fois expérimentalement et numériquement. ELISA a été utilisée sur deux installations laser différentes, et les mécanismes physiques déterminant les paramètres des paquets d’électrons produits par ELISA ont été étudiés en fonction des nombreux paramètres expérimentaux. Une gamme de paramètres pertinents pour un injecteur laser plasma a été déterminée.Une ligne de transport et diagnostic magnétique a également été construite, implantée et testée sur l’installation UHI100 du CEA Saclay, permettant à la fois de caractériser plus finement les propriétés des paquets d’électrons générés par ELISA, mais aussi d’évaluer la qualité des paquets d’électrons transportés pour l’injection dans un second étage. / Laser wakefield acceleration (LWFA) is a particle acceleration process relying on the interaction between high intensity laser pulses, of the order of 10^{18} W/cm² and a plasma. The plasma wave generated in the laser wake sustain high amplitude electric fields (1-100 GV/m). Those electric fields are three orders of magnitude higher than maximum electric fields in radio frequency cavities and represent the main benefit of LWFA, allowing more compact acceleration. However improvements of the LWFA-produced electron bunches properties, stability and repetition rate are mandatory for LWFA to be usable for applications.A scheme to improve electron bunches properties and to potentially increase the repetition rate is multi-stage LWFA. The laser plasma electron source, called the injector, has to produce relatively low energy (50-100 MeV), but high charge, small size and low divergence electron bunches. Produced electron bunches then have to be transported and injected into a second stage to increase electron kinetic energy.The subject of this thesis is to study and design a laser wakefield electron injector for multi-stage LWFA. In the frame of CILEX and the two-stages LWFA program, a prototype of the injector was built : ELISA consisting in a variable length gas cell. The plasma electronic density, which is a critical parameter for the control of the electron bunches properties, was characterized both experimentally and numerically. ELISA was used at two different laser facilities and physical mechanisms linked to electron bunches properties were studied in function of experimental parameters. A range of experimental parameters suitable for an laser wakefield injector was determined.A magnetic transport and diagnostic line was also built, implemented and tested at the UHI100 laser facility of the CEA Saclay. It allowed a more precise characterization of electron bunches generated with ELISA as well as an estimation of the quality of transported electron bunches for their injection in a second laser wakefield stage.
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VITAMIN B12 DEFICIENCY ANEMIA-ASSOCIATED MALIGNANCY ACCELERATED BY SUPPLEMENTATIONVedantam, Venkata Sri Harsha, Nair, Neethu, MOORE, CHRISTINE, Gorman-Nunley, Diana 05 April 2018 (has links)
Vitamin B12 and folate are necessary for bone marrow progenitor growth and division. Deficiencies are common in lymphoproliferative disorders due to increased demands of rapidly growing malignant cells. Isolated vitamin B12 deficiency is seen in 13% of these patients and may be their only manifestation. We present the case of vitamin B12 deficiency anemia due to an underlying malignancy that was discovered following supplementation.
A 77-year-old nonsmoker female with chronic kidney disease and hypothyroidism presented to her internist with dyspnea, tachycardia and unintentional 7-pound weight loss. Age-appropriate cancer screenings were up-to-date. Physical exam was notable for an overweight female with tachycardia and trace ankle edema bilaterally. Electrocardiogram demonstrated sinus tachycardia. Labs were remarkable for hemoglobin 10.3 mg/dL (12.1 mg/dL one year ago) and serum B12/mL. She was started on intramuscular vitamin B12 supplementation. At her one-month follow-up, she reported debilitating gastrointestinal distress, rash, and fatigue lasting 5-6 days with every vitamin B12 injection. Physical exam was notable for 20-pound weight loss. Labs revealed hemoglobin 9.9 mg/dL despite serum B12 750 pg/mL and worsening kidney function with marked proteinuria. Additional work-up by primary team and subsequent Hematology & Oncology referral demonstrated elevated M-spike on urine protein electrophoresis and abnormal bone marrow biopsy suspicious for lymphoid malignancy. CT abdomen and whole body PET scan revealed increased uptake in the T12 vertebrae and multiple nodal basins consistent with stage IV lymphoma. Biopsy of vertebral body confirmed diffuse large B-cell lymphoma. The patient received one cycle of chemotherapy with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone). Her course was complicated by pathologic hip fracture requiring hospitalization and surgical repair. The patient died following cardiac arrest in the setting of septic shock from sigmoid colon perforation 7 months from initial presentation.
Vitamin B12 and folate play critical roles in nucleic acid synthesis for bone marrow progenitors. Vitamin B12 deficiency arrests cell growth and division, leading to macrocytic anemia and various neuropsychiatric manifestations. It is a common diagnosis with numerous causes: autoantibodies to digestive proteins, poor dietary intake, small bowel malabsorption, etc. Diagnose with low hemoglobin (/dL or 13 mg/dL in non-pregnant women or men, respectively) and mean corpuscular volume >100 fL plus low serum B12 or elevated homocysteine and methyl-malonic acid levels. Replacement is given orally or intramuscularly. Vitamin B12 and folate deficiencies are found in lymphoproliferative disorders due to increased demands of rapidly growing malignant cells. Isolated vitamin B12 deficiency is seen in 13% of patients and may be the only clue. Replacement will not resolve their anemia. Physicians should monitor patients receiving supplementation. If anemia fails to improve or patients experience systemic symptoms, further investigation for lymphoid malignancies is warranted. This patient had dramatic deterioration with acceleration of underlying malignancy following vitamin B12 replacement. We believe supplementation enabled malignant lymphoid precursors to resume cell cycle growth and division. Only one report of vitamin B12 supplementation associated with unmasking a lymphoid malignancy exists in literature. Further research is needed to support whether supplementation can accelerate lymphoid malignancies.
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Gräva på djupet eller bredda horisonten? : Lärares syn på matematikundervisningens utformning för begåvade eleverJakobsson, Cornelia, Mattsson, Eva-Pia January 2020 (has links)
Syftet med denna undersökning var att undersöka om undervisningen för de begåvade eller högpresterande eleverna dels var meningsfull, men också att undersöka om undervisningen antog en accelererande eller berikande karaktär. Utöver detta undersöktes lärarnas uppfattning om vilka kringliggande faktorer som påverkade deras undervisning. Detta var av intresse då alla elever i den svenska skolan, enligt skollagen, har rätt till att nå så långt som möjligt i sitt lärande. Metoden som valdes var kvalitativa intervjuer. Totalt nio lärare, vilka var behöriga att undervisa i matematikämnet i årskurs 4-6, intervjuades. De analysverktyg som användes var begreppen acceleration och berikning samt en modell för vilka matematiska färdigheter som alla elever skall utveckla för att analysera undervisningens natur samt meningsfullhet. Ramfaktorteorin användes vid analysen av bakomliggande faktorer till matematikundervisningens utformning. Resultatet visar att de flesta undervisningsmetoder lärarna använder sig av är, enligt den modell som används, meningsfull. De allra flesta undervisningsmetoder är av berikande karaktär, dock förekom även undervisningsmetoder av accelererande typ. De bakomliggande faktorerna för matematikundervisningens upplägg visar sig vara variationsrik där flera olika typer av faktorer påverkar undervisningens utformning. Slutsatsen är att de begåvade eller högpresterande elever ges undervisning som är meningsfull och mestadels berikande och att matematikundervisningens upplägg inte beror på en enskild faktor, utan att flera bakomliggande faktorer påverkar undervisningens utformning. Nyckelord: Acceleration, berikning, begåvade elever, matematiska färdigheter, ramfaktorer.
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FPGA Acceleration of CNNs Using OpenCLJanuary 2020 (has links)
abstract: Convolutional Neural Network (CNN) has achieved state-of-the-art performance in numerous applications like computer vision, natural language processing, robotics etc. The advancement of High-Performance Computing systems equipped with dedicated hardware accelerators has also paved the way towards the success of compute intensive CNNs. Graphics Processing Units (GPUs), with massive processing capability, have been of general interest for the acceleration of CNNs. Recently, Field Programmable Gate Arrays (FPGAs) have been promising in CNN acceleration since they offer high performance while also being re-configurable to support the evolution of CNNs. This work focuses on a design methodology to accelerate CNNs on FPGA with low inference latency and high-throughput which are crucial for scenarios like self-driving cars, video surveillance etc. It also includes optimizations which reduce the resource utilization by a large margin with a small degradation in performance thus making the design suitable for low-end FPGA devices as well.
FPGA accelerators often suffer due to the limited main memory bandwidth. Also, highly parallel designs with large resource utilization often end up achieving low operating frequency due to poor routing. This work employs data fetch and buffer mechanisms, designed specifically for the memory access pattern of CNNs, that overlap computation with memory access. This work proposes a novel arrangement of the systolic processing element array to achieve high frequency and consume less resources than the existing works. Also, support has been extended to more complicated CNNs to do video processing. On Intel Arria 10 GX1150, the design operates at a frequency as high as 258MHz and performs single inference of VGG-16 and C3D in 23.5ms and 45.6ms respectively. For VGG-16 and C3D the design offers a throughput of 66.1 and 23.98 inferences/s respectively. This design can outperform other FPGA 2D CNN accelerators by up to 9.7 times and 3D CNN accelerators by up to 2.7 times. / Dissertation/Thesis / Masters Thesis Computer Science 2020
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En skola för alla? Att utmana högpresterande elever genom differentierad undervisningLiss, Helena, Tjernström, Josefin January 2021 (has links)
Forskning och egna erfarenheter tyder på att högpresterande elever inte utmanas tillräckligt. Syftet är att undersöka hur lärare differentierar svenskundervisningen med högpresterande elever i åtanke, och vilka förutsättningar som krävs för att genomföra en sådan undervisning. Frågeställningarna är: 1) Hur beskriver lärare i årskurs 4–6 att de differentierar svenskundervisningen med högpresterande elever i åtanke? och 2) Vilka förutsättningar anser lärare i årskurs 4–6 är viktiga för att de ska kunna differentiera svenskundervisningen med högpresterande elever i åtanke? Studiens inriktning är kvalitativ med kvantitativa inslag. En enkätundersökning gav resultat som analyserades utifrån begreppen berikning, acceleration, scaffolding och proximal utvecklingszon respektive ramfaktorteorin. Resultatet visar att lärarna använder olika differentieringsstrategier, framför allt berikning, och flertalet differentieringsmetoder, såsom att erbjuda valfrihet eller utmana genom fördjupning eller svårighetsgrader. Därtill är framför allt tillräckligt mycket tid och lärarkompetens förutsättningar för att kunna differentiera undervisningen för högpresterande elever.
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Vliv fenoménu post-aktivační potenciace na ukazatele výkonu při krátkém sprintu z nízkého startu / The influence of PAP phenomenon on performance indicators in sprint from crouch startHorák, Jan January 2021 (has links)
Title: Evaluation of post-activation potentiation effect on performance indicators of sprint following crouch start Objectives: The main objective of this thesis is to evaluate the influence of post- activation potentiation phenomenon on sprinter step performance indicators following crouch start by using Optojump system. Secondary objectives are firstly - to complile systematic up-to-date review based on recently published evidence, and secondly - to compare acquired results with current trends described in this review. Methods: Fifteen (n = 15) moderate to well trained male athletes completed the experimental procol of controlled sprints (20 m), activation of post-activation potentiation / post-activation performance enhancement elicited by series of squats (3 series, 5 repetition, load of 75 % of 1RM, resting interval 2 mins). Following the activation, all participants completed 1x20 m of sprinting performance from crouch start at 5 min, 10 min, 20 min and 40 min. All measurments were made by using the Optojump system. Acquired measurments were further analyzed and statistically evaluated. Results: Evaluation of acquired data did not result in significant positive effect of activation protocol on measured variables. Furthemore, series of squats were associated with decreased peak velocity and...
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Akcelerace algoritmů pro hledání triplexů v DNA sekvencích / Acceleration of Algorithms for Triplex Detection in DNA SequencesWeiser, Michal January 2012 (has links)
Triplex forms of DNA act as main factors of some important cell functions. However, their positions within genome and their effect on cell functions are not known well. Triplex search algorithms often don't consider many of triplexs features and the possibility of occurrence of errors. In the other hand the complexity of full featured algorithms is extremely high. This paper shows the way to speed up the algorithm that considers all known triplex features. Parallel aproach allows due to CUDA technology acceleration up to 50.
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Hardwarová akcelerace šifrování síťového provozu / Hardware Accelerated Encryption of Network TrafficNovotňák, Jiří January 2010 (has links)
The aim of this thesis is to draft and implement high-speed encryptor of network trafic with throughput 10Gb/s in one way. It has been implementated for FPGA Xilinx Virtex5vlx155t placed on card COMBOv2-LXT. The encryption is based on AES algorithm using 128 bit key length. The security protokol is ESP in version for protokol IPv4. Design is fully synthesizable with tool Xilinx ISE 11.3, however it is not tested on real hardware. Tests in simulation works fine.
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Accelerating sustainability goals through digitalization : How the consumer industry maximizes their SDG through digitalizationChristian, Thomas, Marechal, Dennis January 2022 (has links)
The purpose of this paper is to understand how supermarkets are able to meet their sustainability goals and accelerate them through digitized efforts. Qualitative research through case studies and primary data collected with interviews were conducted. It can be concluded that sustainability efforts get accelerated with the aid of digitalization. The participants of the interview showed on numerous levels that digitalization goes hand in hand with sustainability and helps expedite these efforts. The model brought forward by the authors seems to be rather relevant, additionally, it explains the phenomena concrete and accurately.
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Utmaningen med att utmana - Lärares undervisningsmetoder och förutsättningar för att utveckla högpresterande elever inom matematikGabrielsson, Linnéa, Norberg, Madeleine January 2022 (has links)
Denna kvalitativa intervjustudie syftar till att undersöka vilka undervisningsmetoder klasslärare använder för att utveckla högpresterande elever inom matematik i lågstadiet samt vilka förutsättningar läraren upplever att de har för att kunna utföra arbetet. Åtta lärare har fått beskriva hur de arbetar utifrån elevernas olika kunskapsnivåer med fokus på de högpresterande eleverna samt vilka möjligheter och hinder de upplever med undervisningen. Resultatet visar att samtliga deltagande lärare använder undervisningsmetoder för att hjälpa högpresterande elever framåt i sin utveckling, både kopplat till ämneskunskaper och till motivation. Enligt de flesta lärarna finns det dock brister som gör att det fattas förutsättningar att kunna utmana högpresterande elever i den uträckning som lärarna skulle vilja. Framför allt kunde utvecklingsområden identifieras kopplat till tillgång på personal, lokaler och utmanande material. Dessutom visade resultatet att det råder en brist på stöd från skolledning kopplat till undervisningen av högpresterande elever.
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