• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 53
  • 13
  • 10
  • 3
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 111
  • 27
  • 16
  • 11
  • 10
  • 10
  • 9
  • 9
  • 8
  • 8
  • 8
  • 7
  • 6
  • 6
  • 6
  • 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.
61

Hydrogen burning: Study of the 22Ne(p,gamma)23Na, 3He(alpha,gamma)7Be and 7Be(p, gamma)8B reactions at ultra-low energies

Takács, Marcell Péter 05 June 2018 (has links)
The neon-sodium cycle (NeNa cycle) of hydrogen burning is active in stars of the Asymptotic Giant Branch, in classical novae, and in supernovae of type Ia. The thermonuclear reaction rate of the 22Ne(p,γ)23Na reaction is determined by a large number of resonances, and it represents the most uncertain rate in the NeNa cycle. This PhD thesis reports on an experiment to study tentative 22Ne(p,γ)23Na resonances at Elab = 71 and 105 keV, as well as the direct capture component of the reaction rate for Elab ≤ 400 keV. The measurements were performed deep underground at the Laboratory for Un- derground Nuclear Astrophysics - LUNA (Gran Sasso, Italy), taking advantage of the strong reduction in the cosmic ray induced background. The LUNA-400-kV electrostatic accelerator and a differentially pumped, windowless gas target of iso- topically enriched 22Ne gas were used. The γ-rays from the reaction were detected with a 4π bismuth germanate scintillator. The data show upper limits on the strengths of the resonances at Elab = 71 and 105 keV of 5.8 × 10−11 and 7.0 × 10−11 eV respectively. The resonances at Elab = 156.2, 189.5 and 259.7 keV have been re-studied and show 20% higher strength than the literature. The present experiment did not show any evidence for the direct capture process at the low energies studied. In addition to the experimental work at LUNA, the 3He(α, γ)7Be and 7Be(p, γ)8B reactions were studied using the most recent solar neutrino data available. Based on the standard solar model and the experimentally measured fluxes of solar 7Be and 8B neutrinos, the astrophysical S-factors of both reactions were evaluated directly in the solar Gamow peak.
62

The Buddhist Worldview of Neon Genesis Evangelion: Positioning Neon Genesis Evangelion in a Japanese Cultural Context

Vaughan, Cassandra N. January 2009 (has links)
No description available.
63

Optimising IIR Filters Using ARM NEON

Bentmar Holgersson, Sebastian January 2012 (has links)
ARMs processorserie Cortex-A9 har stöd för SIMD-instruktioner med hjälp av NEON MPE. Detta innebär att processorn kan använda sig av vektor-instruktioner som kan utföra operationer på ett flertal element med varje instruktion. Målet med bruk av NEON MPE är att öka prestandan, men då man försöker optimera en speciell IIR-filtertyp som kallas för "biquads" kan man stöta på problem. Problemen med NEON-optimering av "biquads" beror på att endast fem operationer krävs för varje iteration och att behandling av IIR-filter kräver att man behandlar en sampel i taget eftersom varje behandlat sampels värde beror på tidigare behandlade samplar. Rapporten ger en kort beskrivning och genomgång av hur IIR-filter och NEON-optimering fungerar.För att analysera NEON-optimering av biquad-filter skapas fyra olika implementationer av en audioeffekt. De fyra implementationerna jämför prestandan hos flyttalsaritmetik, fixpunkts-aritmetik och NEON-optimering samt en version som implementerar både fixpunktsaritmetik och NEON-optimering. Problemen med optimering av biquad-filter med hjälp av NEON-instruktioner löses genom parallell behandling av ljudkanalerna. Eftersom kanalerna är självständiga kan man fördubbla prestanda genom att utföra varje operation på såväl höger- som vänsterkanal. Vidare prestandaförbättring ges även då effektiviteten hos minnesoperationer förbättras och med hjälp av fixpunkts-behandling.Resultaten visar att fixpunktsversionen som använder sig av NEON-instruktioner är snabbast, men flyttalsversionen med NEON-instruktioner är bara marginellt långsammare och dessutom enklare att implementera. Användandet av NEON-instruktioner förbättrar prestandan med mellan 1,7-2,8 gånger i de fall som testas. / The ARM Cortex-A9 CPU has a SIMD extension called NEON MPE. It allows for vector instructions that can perform operations on multiple elements in a single instruction. Whilst this usually improves performance, certain IIR filters called biquads pose problems as only five operations are necessary per sample and every iteration is dependent on the result of the previous result. A brief overview is given for IIR filters, the NEON extension and fixed-point processing.In order to analyse optimisation of biquad filters, an audio effect with four different implementations is produced, comparing results with/without fixed-point processing and with/without NEON optimisation. The problems introduced by the use of biquad filters are solved by running multiple channels in parallel. As the audio channels are independent, two samples can be calculated in parallel, which approximately doubles peformance. Further performance improvement is provided by improved memory operation efficiency and the use of fixed-point processing.The results show that the fixed-point NEON implementation is the fastest, however the floating-point NEON implementation is marginally slower but simpler to write. The use of NEON MPE improves performance by between 1.7 to 2.8 times in this case.
64

ENTRE O BOI E O NEON: Fragmentos de mem?rias, identidades, imagens e sons no filme de Gabriel Mascaro

Carvalho, Rodrigo Souza Fontanini de 27 February 2018 (has links)
Submitted by SBI Biblioteca Digital (sbi.bibliotecadigital@puc-campinas.edu.br) on 2018-05-09T13:24:45Z No. of bitstreams: 1 RODRIGO SOUZA FONTANINI DE CARVALHO.pdf: 2354621 bytes, checksum: 975ee9e02c911a156265b2ea01e872a7 (MD5) / Made available in DSpace on 2018-05-09T13:24:45Z (GMT). No. of bitstreams: 1 RODRIGO SOUZA FONTANINI DE CARVALHO.pdf: 2354621 bytes, checksum: 975ee9e02c911a156265b2ea01e872a7 (MD5) Previous issue date: 2018-02-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / This dissertation is the result of an interdisciplinary research in Languages, Media and Art. It is an interpretive analysis of the discourse of the Brazilian film Boi Neon (2016), by Gabriel Mascaro, and aims to develop reflections on the identities of the narrative characters and how their identities may be related to the formations of the contemporary subjects. Following an essayistic and rhizomatic model, the interlaced construction of the chapters from this text and the analysis of the corpus derive from statements collages ? based on the dialogues between authors of several areas of knowledge, such as Albuquerque, Deleuze and Guattari, Xavier, Zurian, and others ? to understand how the discourse of the film is able to (de)construct and (re)organize the multiple identities of its characters, by using descriptions of scenes, readings of images and interpretations of soundtracks. Scenes with potential for discussion and analysis of the identity formation of the characters were selected, trying to comprehend the relationships and social practices that implicate the constitution of the contemporary subject in the cinematographic discourse, as well as the way in which the film disrupts and reiterates social values from the collective imaginary ? especially those which define the Brazilian backlands ?, playing with the expectation of the public. / Esta disserta??o de mestrado ? resultado de uma pesquisa interdisciplinar do Programa de P?s-Gradua??o em Linguagens, M?dia e Arte, da PUC-Campinas. Trata-se da an?lise interpretativa do discurso do filme brasileiro Boi Neon (2016), de Gabriel Mascaro, buscando reflex?es a respeito da forma??o das identidades das personagens da narrativa e de como essas identidades podem estar relacionadas ? forma??o dos sujeitos contempor?neos. Seguindo um modelo ensa?stico e rizom?tico, a constru??o entrela?ada dos cap?tulos do texto e a an?lise do corpus derivam de colagens de enunciados capazes de ? alicer?ados nos di?logos entre/com autores de diversas ?reas do conhecimento, como Albuquerque, Deleuze e Guattari, Xavier, Zurian, entre outros ? entender como o discurso do filme expressa, (des)constr?i e (re)organiza as identidades m?ltiplas de suas personagens, a partir de descri??es de cenas, leituras de imagens e interpreta??es de trilhas sonoras. Foram selecionadas cenas com potencial para a discuss?o e a an?lise da forma??o identit?ria das personagens, tentando compreender as rela??es, os la?os e as pr?ticas sociais que implicam a constitui??o do sujeito contempor?neo no discurso cinematogr?fico, bem como a maneira com que o filme rompe e reitera valores sociais presentes no imagin?rio coletivo ? sobretudo o que marca o sertanejo nordestino brasileiro ?, brincando com a expectativa do p?blico.
65

Edelgase als Tracer für Wechselwirkungen von Krusten- und Mantelfluiden mit diamantführenden Gesteinen des östlichen Baltischen Schildes

Wiersberg, Thomas January 2001 (has links)
In der vorliegenden Arbeit werden anhand der Edelgaszusammensetzung von Kimberliten und Lamproiten sowie ihrer gesteinsbildenden Minerale die Wechselwirkungen dieser Gesteine mit Fluiden diskutiert. Die untersuchten Proben stammen vom östlichen Baltischen Schild, vom Kola-Kraton (Poria Guba und Kandalaksha) und vom karelischen Kraton (Kostamuksha). Edelgasanalysen nach thermischer oder mechanischer Gasextraktion von 23 Gesamtgesteinsproben und 15 Mineralseparaten ergeben folgendes Bild: Helium- und Neon-Isotopendaten der Fluideinschlüsse von Lamproiten aus Kostamuksha lassen auf den Einfluss einer fluiden Phase krustaler Herkunft schliessen. Diese Wechselwirkungen fanden wahrscheinlich schon während des Magmenaufstiegs statt, denn spätere Einflüsse krustaler Fluide auf die Lamproite und ihr Nebengestein (Quarzit) sind gering, wie anhand der C/<sup>36</sup>Ar-Zusammensetzung gezeigt wird. Auch sind die mit verschiedenen Datierungsmethoden (Rb-Sr, Sm-Nd, K-Ar) an Mineralseparaten und teilweise an Gesamtgestein ermittelten Alter konsistent und machen eine metamorphe Überprägung unwahrscheinlich. Aufgrund der Verteilung der primordialen Edelgasisotope zwischen Fluideinschlüssen und Gesteinsmatrix ist ein langsamer Magmenaufstieg anzunehmen, was die Möglichkeit der Kontamination mit einem krustalen Fluid während des Magmenaufstiegs erhöht.<br /> <br>Die Gasextraktion aus Mineralseparaten erfolgte thermisch, wodurch eine Freisetzung der Gase ausschließlich aus Fluideinschlüssen nicht möglich ist. Hierbei zeigen Amphibol und Klinopyroxen, separiert aus Kostamuksha-Lamproiten, in ihrer Neon-Isotopenzusammensetzung im Vergleich zur krustalen Zusammensetzung (Kennedy et al., 1990) ein leicht erhöhtes Verhältnis von <sup>20</sup>Ne/<sup>22</sup>Ne, was ein Hinweis auf Mantel-Neon sein könnte. Kalifeldspäte, Quarz und Karbonate enthalten dagegen nur Neon krustaler Zusammensetzung. Phlogopite haben sehr kleine Verhältnisse von <sup>20</sup>Ne/<sup>22</sup>Ne und <sup>21</sup>Ne/<sup>22</sup>Ne, zurückzuführen auf in-situ-Produktion von <sup>22</sup>Ne in Folge von U- und Th-Zerfallsprozessen.<br><br /> Wie unterschiedliche thermische Entgasungsmuster für <sup>40</sup>Ar und <sup>36</sup>Ar zeigen, ist <sup>36</sup>Ar in Fluideinschlüssen konzentriert. Das <sup>40</sup>Ar/<sup>36</sup>Ar-Isotopenverhältnis der Fluideinschlüsse von Lamproiten aus Kostamuksha ist antikorreliert mit der durch thermische Extraktion bestimmten Gesamtmenge an <sup>36</sup>Ar. Argon aus Fluideinschlüssen setzt sich daher aus zwei Komponenten zusammen: Einer Komponente mit atmosphärischer Argon-Isotopenzusammensetzung und einer krustalen Komponente mit einem Isotopenverhältnis <sup>40</sup>Ar/<sup>36</sup>Ar > 6000. Diffusion von radiogenem <sup>40</sup>Ar aus der Kristallmatrix in die Fluideinschlüsse spielt keine wesentliche Rolle.<br /> <br>Kimberlite aus Poria Guba und Kandalaksha zeigen anhand der Helium- und z. T. auch der Neon-Isotopenzusammensetzung eine Mantelkomponente in den Fluideinschlüssen an. Bei einem angenommenen <sup>20</sup>Ne/<sup>22</sup>Ne-Isotopenverhältnis von 12,5 in der Mantelquelle ergibt sich ein <sup>21</sup>Ne/<sup>22</sup>Ne-Isotopenverhältnis von 0,073 ± 0,011 sowie ein <sup>3</sup>He/<sup>4</sup>He-Isotopenverhältnis, welches im Vergleich zum subkontinentalem Mantel (Dunai und Baur, 1995) stärker radiogen geprägt ist. Solche Isotopensignaturen sind mit höheren Konzentrationen an Uran und Thorium in der Mantelquelle der Kimberlite zu erklären.<br /> <br>Rb-Sr- und Sm-Nd-Altersbestimmungen erfolgten von russischer Seite (Belyatskii et al., 1997; Nikitina et al., 1999) und ergeben ein Alter von 1,23 Ga für den Lamproitvulkanismus in Kostamuksha. Eigene K-Ar-Datierungen an Phlogopiten und Kalifeldspäten stimmen mit einem Alter von 1193 ± 20 Ma fast mit den Rb-Sr- und Sm-Nd-Altern überein. Die K-Ar-Datierung an einem Phlogopit aus Poria Guba, separiert aus dem Kimberlit PGK 12a, ergibt ein Alter von 396 Ma, ebenfalls in guter Übereinstimmung mit Rb-Sr-und Sm-Nd-Altern (ca. 400 Ma, Lokhov, pers. Mitteilung). K-Ar-Altersbestimmungen an Gesamtgestein aus Poria Guba erbrachten kein schlüssiges Alter. Die Rb-Sr- und Sm-Nd-Alter des Lamproitmagmatismus in Poria Guba betragen 1,72 Ga (Nikitina et al., 1999).<br /> <br>Vergleiche von gemessenen mit berechneten Edelgaskonzentrationen aus in-situ-Produktion zeigen weiterhin, dass in Abhängigkeit vom Alter der Probe Diffusionsprozesse stattgefunden haben, die zu unterschiedlichen und z. T. erheblichen Verlusten an Helium und Neon führten. Diffusionsverluste an Argon sind dagegen kaum signifikant. Unterschiedliche Diffusionsverluste in Abhängigkeit von Alter und betrachtetem Edelgas zeigen auch die primordialen Edelgase. / In the present thesis, interactions of kimberlites and lamproites as well as their constituent minerals with fluids are discussed based on noble gas compositions. The samples originate from the eastern Baltic Shield, more specifically from the Kola craton (Poria Guba and Kandalaksha) and the Karelia craton (Kostamuksha). Gas was extracted by stepwise heating and crushing from 23 whole rock samples and 15 mineral separates. These two techniques allow differential extraction of gas from fluid inclusions (crushing technique) and from the bulk sample (stepwise heating). The noble gas analyses provide the following information:</P> <P>Helium and neon isotopic compositions of fluid inclusions in lamproites reveal the presence of a crustal fluid phase. Fluid interaction probably ocurred already during the process of magma ascent. Interaction after lamproite emplacement seems unlikely. The lamproites and their host rock differ in the degree of fluid-rock interaction, as demonstrated by the C/<sup>36</sup>Ar composition. In addition, various dating methods (Rb-Sr, Sm-Nd, K-Ar) yield almost the same age within analytical error. Thus, a metamorphic overprint can be excluded. The distribution of primordial noble gases between fluid inclusions and crystal lattice suggests a relatively slow magma ascent, making an interaction of the lamproitic magma with crustal fluids even more likely. Since noble gases from mineral separates were extracted only by the stepwise heating method, gases stored in fluid inclusions could not be released separately.</P> <P>Amphibole and clinopyroxene separates yielded a higher <sup>20</sup>Ne/<sup>22</sup>Ne ratio in comparison to crustal composition (Kennedy et al., 1990). This presumably is an indication of a mantle derived fluid phase. On the other hand, neon isotopic composition of K-feldspar, quartz and carbonate separates are indistinguishable from the crustal composition. In comparison to other mineral separates, phlogopite yields very low ratios of <sup>20</sup>Ne/<sup>22</sup>Ne and <sup>21</sup>Ne/<sup>22</sup>Ne due to in situ production of <sup>22</sup>Ne, which is a result of nuclear reactions.</P> <P>The distinct thermal gas release patterns of <sup>40</sup>Ar and <sup>36</sup>Ar indicates that <sup>36</sup>Ar is concentrated in fluid inclusions. The <sup>40</sup>Ar/<sup>36</sup>Ar isotopic ratio in fluid inclusions shows a negative correlation with the total amount of <sup>36</sup>Ar released by thermal extraction. Therefore, argon from fluid inclusions is a simple 2-component mixture of air and a crustal component with an <sup>40</sup>Ar/<sup>36</sup>Ar ratio > 6000. It can be shown that diffusion of <sup>40</sup>Ar from the matrix into fluid inclusions is negligible.</P> <P>In contrast to lamproites, whole rock kimberlite samples from Poria Guba and Kandalaksha show clear evidence in helium and, to a certain extentalso in neon isotope ratios, of interaction with a mantle derived fluid phase. Assuming a <sup>20</sup>Ne/<sup>22</sup>Ne ratio of 12.5 for the mantle endmember, a <sup>21</sup>Ne/<sup>22</sup> Ne ratio of 0.073 ± 0.011 can be calculated. Likewise, the resulting <sup>3</sup>He/<sup>4</sup>He ratio is more strongly influenced by radiogenic helium in comparison to the mean subcontinental mantle (Dunai und Baur, 1995). Such behaviour reflects higher concentrations of uranium and thorium in the magma source of kimberlites than the subcontinental mantle.</P> <P>Rb-Sr and Sm-Nd age determinations (Belyatskii et al., 1997; Nikitina et al., 1999) yield 1.23 Ga for the lamproite magmatism in Kostamuksha. K-Ar dating of phlogopite and K-feldspar provides similar ages (1.19 Ga). K-Ar dating of a single phlogopite separate from the Kimberlite sample PGK12a from Poria Guba, yields an age of 396 Ma which corresponds well with Rb-Sr and Sm-Nd ages.</P> <P>Depending on sample age, distinct and partly extensive diffusive loss of helium and neon has occurred, as shown by comparison of measured and calculated concentrations of in situ produced isotopes. Diffusion loss is negligible for argon. This is also strongly supported by primordial noble gas composition.
66

Experimental Study of the 22Ne(p,γ)23Na Reaction and its Implications for Novae Scenarios

Menzel, Marie-Luise 22 May 2013 (has links) (PDF)
The 22Ne(p,γ)23Na reaction belongs to the catalytic neon-sodium cycle and has an important role in the explosive hydrogen burning. The neon-sodium cycle takes place at temperatures of T = 0:1 - 0:5GK and is assumed to occur in di erent astrophysical systems: e.g. in novae, in super novae of type Ia and during the shell-burning of red giant branch stars. The implications of 22Ne(p,γ)23Na and the neon-sodium cycle in a nova scenario have been studied by using the nuclear network code libnucnet at GSI in Darmstadt. A nova is an outburst of matter in a binary system consisting of a white dwarf and a red giant star. It is therefore a representative phenomenon for explosive hydrogen burning. For the calculation of the nucleosynthesis during the nova outburst, the code libnucnet requires the initial mass composition of the novae partners, the temperature and density pro les of the nova explosion and the thermonuclear reaction rates of the participating reactions. In the following, the code determined the ow and the nal atomic abundance in the neon-sodium cycle during the entire nova process. Additionally, the in uence of the temperature pro le of the novae outburst as well as the thermonuclear reaction rate of the 22Ne(p,γ)23Na reaction on the nal atomic abundance in the outburst has been studied. A characteristic measure for the reactions in astrophysical environments is the thermonuclear reaction rate. The reaction rate of 22Ne(p,γ)23Na has still strong uncertainties in the temperature range of T = 0:03-0:3 GK. These uncertainties are based on insu cient upper limits of the resonance strengths as well as the possible existence of tentative states that are populated in the energy range of Elabp = 30 - 300 keV. The research presented in this thesis is dedicated to the experimental study of the 22Ne(p,γ)23Na reaction for an improved determination of the thermonuclear reaction rate. Furthermore, the implications of 22Ne(p,γ)23Na and the neon-sodium-cycle in novae scenarios are discussed. The data taking has been performed at the Laboratori Nazionali del Gran Sasso, Italy. This laboratory provides the LUNA facility (Laboratory for Underground Nuclear Astrophysics) for the measurement of small reaction cross sections. The LUNA facility includes a 400 kV ion accelerator, a windowless gas target system and a HPGe-detector. Based on the measurements of the 22Ne(p,γ)23Na reaction at LUNA, upper limits for the strengths of ve isolated resonances in the energy range of Elabp = 150 - 340 keV have been determined. For the nuclear resonance at Elabres = 186 keV, a positive resonance strength has been measured for the rst time in literature.
67

Řeč světla ve veřejném prostoru / Language of light in the public space

Žaludová, Klára January 2011 (has links)
RESUME V diplomové práci, Řeč světla ve veřejném prostoru, zpracovávám otázku role světla a světelných reklam ve vztahu k architektuře a volnému umění na území dnešní České republiky. Zajímám se o celkovou estetiku, ale i dobové podmínky, které tuto oblast ovlivnily, ať již umělecky, nebo technologicky. Pokouším se situaci v tehdejším Československu uvést do celosvětového kontextu. První část je věnována období největšího rozkvětu světelné reklamy, tedy dvacátým a třicátým letům. Pokouším jsem se o zmapování celkového vývoje světelné techniky a osvětlování vůbec. V uvedené době byla světelná reklama úzce spjata s architekturou. Na konkrétních příkladech staveb poukazuji na roli denního i umělého světla. Zmiňuji zde také dobové příklady volné umělecké tvorby, související se světlem. V druhé, obsáhlejší části, se zabývám světelnými reklamami především v období padesátých a šedesátých let, s ohledem na tehdejší ekonomickou, hospodářskou a politickou situaci, která úzce souvisela s tímto uměleckoprůmyslovým odvětvím. V průběhu výzkumu jsem dospěla k tomu, že role světelných reklam v sedmdesátých a osmdesátých letech klesla na minimum. Popisuji zde, proč se tak stalo a jak v této době vypadaly a v jaké nové formy se přetransformovaly. Závěrem své práce ve stručnosti popisuji situaci devadesátých let, kdy...
68

Experimental Study of the 22Ne(p,γ)23Na Reaction and its Implications for Novae Scenarios

Menzel, Marie-Luise January 2013 (has links)
The 22Ne(p,γ)23Na reaction belongs to the catalytic neon-sodium cycle and has an important role in the explosive hydrogen burning. The neon-sodium cycle takes place at temperatures of T = 0:1 - 0:5GK and is assumed to occur in di erent astrophysical systems: e.g. in novae, in super novae of type Ia and during the shell-burning of red giant branch stars. The implications of 22Ne(p,γ)23Na and the neon-sodium cycle in a nova scenario have been studied by using the nuclear network code libnucnet at GSI in Darmstadt. A nova is an outburst of matter in a binary system consisting of a white dwarf and a red giant star. It is therefore a representative phenomenon for explosive hydrogen burning. For the calculation of the nucleosynthesis during the nova outburst, the code libnucnet requires the initial mass composition of the novae partners, the temperature and density pro les of the nova explosion and the thermonuclear reaction rates of the participating reactions. In the following, the code determined the ow and the nal atomic abundance in the neon-sodium cycle during the entire nova process. Additionally, the in uence of the temperature pro le of the novae outburst as well as the thermonuclear reaction rate of the 22Ne(p,γ)23Na reaction on the nal atomic abundance in the outburst has been studied. A characteristic measure for the reactions in astrophysical environments is the thermonuclear reaction rate. The reaction rate of 22Ne(p,γ)23Na has still strong uncertainties in the temperature range of T = 0:03-0:3 GK. These uncertainties are based on insu cient upper limits of the resonance strengths as well as the possible existence of tentative states that are populated in the energy range of Elabp = 30 - 300 keV. The research presented in this thesis is dedicated to the experimental study of the 22Ne(p,γ)23Na reaction for an improved determination of the thermonuclear reaction rate. Furthermore, the implications of 22Ne(p,γ)23Na and the neon-sodium-cycle in novae scenarios are discussed. The data taking has been performed at the Laboratori Nazionali del Gran Sasso, Italy. This laboratory provides the LUNA facility (Laboratory for Underground Nuclear Astrophysics) for the measurement of small reaction cross sections. The LUNA facility includes a 400 kV ion accelerator, a windowless gas target system and a HPGe-detector. Based on the measurements of the 22Ne(p,γ)23Na reaction at LUNA, upper limits for the strengths of ve isolated resonances in the energy range of Elabp = 150 - 340 keV have been determined. For the nuclear resonance at Elabres = 186 keV, a positive resonance strength has been measured for the rst time in literature.
69

Performance Optimization of Signal Processing Algorithms for SIMD Architectures

Yagneswar, Sharan January 2017 (has links)
Digital Signal Processing(DSP) algorithms are widely implemented in real time systems.In fields such as digital music technology, many of these said algorithms areimplemented, often in combination, to achieve the desired functionality. When itcomes to implementation, DSP algorithms are performance critical as they havetight deadlines. In this thesis, performance optimization using Single InstructionMultiple Data(SIMD) vectorization technique is performed on the ARM Cortex-A15 architecture for six commonly used DSP algorithms; Gain, Mix, Gain and Mix,Complex Number Multiplication, Envelope Detection and Cascaded IIR Filter. Toensure optimal performance, the instructions should be scheduled with minimalpipeline stalls. This requires execution time to be measured with fine time granularity.First, a technique of accurately measuring the execution time using thecycle counter of the processor’s Performance Management Unit(PMU) along withsynchronization barriers is developed. It was found that the execution time measuredby using the operating system calls have high variations and very low timegranularity, whereas the cycle counter method was accurate and produced reliableresults. The cost associated with the cycle counter method is 75 clock cycles. Usingthis technique, the contribution by each SIMD instruction towards the executiontime is measured and is used to schedule the instructions. This thesis also presentsa guideline on how to schedule instructions which have data dependencies usingthe cycle counter timing execution time measurement technique, to ensure that thepipeline stalls are minimized. The algorithms are also modified, if needed, to favorvectorization and are implemented using ARM architecture specific SIMD instructions.These implementations are then compared to that which are automaticallyproduced by the compiler’s auto-vectorization feature. The execution times of theSIMD implementations was much lower compared to that produced by the compilerand the speedup ranged from 2.47 to 5.11. Also, the performance increaseis significant when the instructions are scheduled in an optimal way. This thesisconcludes that the auto-vectorized code does poorly for complex algorithms andproduces code with a lot of data dependencies causing pipeline stalls, even with fulloptimizations enabled. Using the guidelines presented in this thesis for schedulingthe instructions, the performance of the DSP algorithms have significant improvementscompared to their auto-vectorized counterparts. / Digitala signalbehandlingsalgoritmer(DSP) implementeras ofta i realtidssystem. Inomfält som exempelvis digital musikteknik används dessa algoritmer, ofta i olika kombinationer,för att ge önskad funktionalitet. Implementationen av DSP-algoritmerär prestandakritisk eftersom systemen ofta har små tidsmarginaler. I det härexamensarbetet genomförs prestandaoptimering med Single Instruction MultipleData(SIMD)-vektorisering på en ARM A15-arkitektur för 6 vanliga DSP-algoritmer;volym, mix, volym och mix, multiplikation av komplexa tal, amplituddetektering,och seriekopplade IIR-filter. Maximal optimering av algoritmerna kräver ocksåatt antalet pipeline stalls i processorn minimeras. För att kunna observera dettakrävs att exekveringstiden kan mätas med hög tidsupplösning. I det här examensarbeteutvecklas först en teknik för att mäta exekveringstiden med hjälp aven klockcykelräknare i processorns Performance Management Unit(PMU) tillsammansmed synkroniseringsbarriärer. Tidsmätning med hjälp av operativsystemsfunktionervisade sig ha sämre noggrannhet och tidsupplösning än metoden medatt räkna klockcykler, som gav tillförlitliga resultat. Den extra exekveringstidenför klockcykelräkning uppmättes till 75 klockcykler. Med den här tekniken är detmöjligt att mäta hur mycket varje SIMD-instruktion bidrar till den totala exekveringstiden.Examensarbete presenterar också en metod att ordna instruktioner somhar databeroenden sinsemellan med hjälp av ovanstående tidsmätningsmetod, såatt antalet pipeline stalls minimeras. I de fall det behövdes, skrevs koden till algoritmernaom för att bättre kunna utnyttja ARM-arkitekturens specifika SIMDinstruktioner.Dessa jämfördes sedan med resultaten från kompilatorns automatgenereradevektoriseringkod. Exekveringstiden för SIMD-implementationerna varsignifikant kortare än för de kompilatorgenererade och visade på en förbättring påmellan 2,47 och 5,11 gånger, mätt i exekveringstid. Resultaten visade också på entydlig förbättring när instruktionerna exekveras i en optimal ordning. Resultatenvisar att automatgenererad vektorisering presterar sämre för komplexa algoritmeroch producerar maskinkod med signifikanta databeroenden som orsakar pipelinestalls, även med optimeringsflaggor påslagna. Med hjälp av metoder presenteradei det här examensarbete kan prestandan i DSP-algoritmer förbättras betydligt ijämförelse med automatgenererad vektorisering.
70

Aesthetics of Destruction: Music and the Worldview of Ikari Shinji in Neon Genesis Evangelion

Hoffer, Heike January 2012 (has links)
Director Anno Hideaki's series Neon Genesis Evangelion caused a sensation when it first aired on TV Tokyo in 1995 and has become one of the most influential anime ever made. Since its premiere, fans across the globe have debated the possible interpretations of the complex plot, but little has been said about how composer Sagisu Shiro's score might contribute to understanding the series. Anno's rehabilitation in a Jungian clinic and subsequent personal study of human psychology plays heavily into understanding the main character Ikari Shinji, and music has much to contribute to appreciating Shinji's view of the world. Shinji is an impressionable fourteen-year old boy, so his musical interpretations of the people and things around him do not always match reality. Sagisu's music gives the viewers welcome insight into Shinji's thoughts and feelings as he matures throughout the series.

Page generated in 0.0308 seconds