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Johnson, Sandra. "En STARK specialtidskrift : Arbetet med att ta fram en grafisk mall till en specialtidskrift från STARK Magasin, samt en diskussion om hur båda tidskrifterna kan göras om till e-format." Thesis, Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:sh:diva-19183.
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The goal with this project was to develop a graphic template for a new magazine about running, STARK Löpning. Besides the looks of the graphic elements, sections in the magazine would be developed. Finally, a discussion is made about how the magazine can be remade into an electronic format. Content analyses has been made regarding magazines with both a main and a specific orientation, to review the graphic relationship between them. A content analysis regarding a competing magazine about running was also made. An unstructured interview was done with Art Director Petrus Iggström, to find out his way of working when he creates new graphic templates for magazines. The discussion concerning the electronic format was done based on previous research in the subject. The graphic relationship between main and specific magazines turned out to not be significant, they had few similarities. It was often showed that elements regarding the magazine s’identity had been changed, for example text fonts. This could be because the specific magazines are sighted towards a different target audience than the main magazine, and therefor wants an identity of its own. It’s an easy process to remake the magazines STARK Magasin and STARK Löpning into an electronic format, but none of the services that were looked closely upon in this essay were fitting for both passive and active readers. Nor did the services have a good enough browsing feature. For example, if the reader wants to read an article that was advertised on the cover page, it was not possible to go directly to the article from the cover.
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Wiman, Robin, and Alexander Persson. "Marknadseffektivitet och det systematiska felet : Finansanalytikers och Ekonomijournalisters marknadspåverkan." Thesis, Linnéuniversitetet, Institutionen för ekonomistyrning och logistik (ELO), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-44914.
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Forskningen kring effektiva marknader är uppdelad; ena sidan påstår att marknaden är fullständigt effektiv och det inte går att skapa någon form av överavkastning. Andra sidan hävdar tvärtemot att endast historisk information reflekteras i dagens priser. På kort sikt kan det finns en viss ineffektivitet och de flesta erkänner att marknaden innehåller anomalier Syftet med denna studie är att undersöka om det existerar systematiska fel beträffande informationsflöden som pekar mot att den svenska aktiemarknaden inte är av semi-stark form eller stark form av effektivitet Vi utgår från tre metodologiska ställningstaganden; utgångspunkt, forskningsansats samt kunskapssyn. En deduktivt kvantitativ metod tillämpas och vi applicerar metoden för event study. Vi finner stöd för att det finns systematiska fel i marknaden beträffande informationsflöden i form av aktierekommendationer. Resultaten antyder att den svenska aktiemarknaden inte är av starkt effektiv form och i ett fall av fyra finner vi att den inte heller besitter semi-stark form.Research concerning efficient markets are divided into two camps; the one hand, claims that the market is fully efficient and it is not possible to create any kind of excess returns. The other side argues the contrary that only historical information are reflected in today’s prices. Short term, there is some inefficiency and most recognize that the market contain anomalies The purpose is to investigate whether there exist indications regarding flows of information to the Swedish stock market suggesting a semi-strong form or strong form of efficiency. We start from three methodological statements; starting point, the research approach and epistemological beliefs. A deductive quantitative methodology is used, and we apply the method of event study. We find evidence for the existence of systematic errors in the market in terms of flows of information in the form of stock recommendations. The results suggest that the Swedish stock market is not of the strong efficient form and in one case out of four, we find that it does not possess the semi-strong form.
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Wingert, Daniel. "Evolutionsgleichungen und obere Abschätzungen an die Lösungen des Anfangswertproblems." Doctoral thesis, Universitätsbibliothek Chemnitz, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-107849.
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In dieser Arbeit werden die zu einem m-sektoriellen Operator assoziierten Halbgruppen betrachtet, die die Lösungen des Anfangswertproblems der zugehörigen Evolutionsgleichung beschreiben. Es wird eine 1987 von Davies veröffentlichte Methode zur Abschätzung dieser Halbgruppen verallgemeinert. Einen Schwerpunkt bilden die zu Dirichlet-Formen assoziierten Markov-Halbgruppen. Für diese werden die Resultate spezialisiert und der Zusammenhang zur intrinsischen Metrik dargelegt. Die Arbeit schließt mit verschiedenen Beispielen, die zeigen, wie mit diesen Verallgemeinerungen von Davies Methode neue Anwendungsgebiete erschlossen werden könnenThis thesis is about m-sectorial operators and their associated semigroups describing the solutions of the initial value problem of the corresponding evolution equation. We generalize a method published by Davies 1987 to estimate these semigroups. A focus is set on Markov semigroups associated with Dirchlet forms. The results are applied to them and the connection to the intrinsic metric is presented. The thesis ends with different examples showing how this generalization of Davies method can be applied into new fields of application
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Hellbratt, Douglas, and Anton Rosenberg. "En ineffektiv möjlighet : En kvantitativ studie på den svenska aktiemarknadens effektivitet utifrån nyckeltalen P/E och B/M." Thesis, Södertörns högskola, Institutionen för samhällsvetenskaper, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:sh:diva-45934.
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Statistics and public reports indicate that stock investment has developed to a popular and growing investment trend among individuals, where the underlying motivational factor is the possibility to generate a return on the investment, and therefore make money. A recurrent and controversial question in the financial context is how the individual investor should proceed to generate a return higher than the market. Although scientific research claims the market to be efficient, situations occur where individual performers manage to surpass the market, which is explained by deviations from the market’s efficiency. The deviations are known as market anomalies, and from the beginning of time several key ratio-anomalies have existed and disappeared. Despite their disappearance, some of these key ratios continue demonstrating the ability of forecasting returns. Therefore, the purpose of this essay is to use these key ratios to investigate the semi-strong form of market efficiency on the Swedish stock market during the period of 2013-2019. The execution will be done using key ratio-constructed stock portfolios based on the P/E-ratio, the B/M-ratio, and a combination of these. The portfolios will be compared both among themselves and towards a benchmark index with the intention to analyze if a significant return can be determined. According to the results, portfolios based on the P/E-ratio as well as the combination of the P/E-ratio and the B/M-ratio, can be used in portfolio construction to generate significantly risk-adjusted return on the Swedish stock market. This implicate that, during this investigation period, the Swedish stock market is not completely efficient according to the semi-strong form of market efficiency.
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Johnston, Katharine G. "Observational signatures of massive star formation : an investigation of the environments in which they form, and the applicability of the paradigm of low-mass star formation." Thesis, University of St Andrews, 2011. http://hdl.handle.net/10023/1895.
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This thesis presents both a study of the cluster-scale environments in which massive stars form, investigating in particular how the ionized gas in these regions relates to the molecular star-forming material, as well as detailed studies of two luminous forming stars, AFGL 2591 and IRAS 20126+4104, to determine whether they are forming similarly to their low-mass counterparts. The results of this work include the identification of 35 HII regions (20 newly discovered) via a radio continuum survey of ionized gas towards 31 molecular cluster-forming clumps. The observed ionized gas was found to be preferentially associated with the clumps, which were shown to have a range of evolutionary stages. The massive star formation efficiency was determined for the clumps with associated ionized gas, and a relationship was found between the mass of the clumps and the mass of their embedded massive stars. By modelling the SEDs and images of AFGL 2591 and IRAS 20126+4104, it was found that the geometry of their circumstellar material was generally consistent with an envelope plus disk, similar to that expected for low-mass protostars. However, within the central ~1800 AU, the mid-IR images of IRAS 20126+4104 were better described by only a flattened envelope, suggesting that the radiation from IRAS 20126+4104 may be affecting the regions closest to the star. Observations of the ionized and molecular gas towards AFGL 2591 were carried out, and a photoionization code was developed to interpret these observations. The results showed that the observed 3.6 cm emission is likely to be produced by both a shock-ionized jet and a hypercompact HII region that does not appear to have disrupted the jet or the large-scale circumstellar environment. In addition, the C¹⁸O(1-0) emission observed towards AFGL2591 traces the densest parts of the outflow, with the blue-shifted emission exhibiting many of the properties of the outflows from low-mass protostars.
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Queiroz, Anna Bárbara de Andrade. "Star horse : a Bayesian tool for determining masses, ages, distances and extinction for field stars." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2018. http://hdl.handle.net/10183/180515.
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Nos encontramos em uma localização vantajosa para o estudo da formação e evolução de galáxias espirais. Situados no disco da Via-Láctea, somos capazes de fazer observações detalhadas sobre as estrelas individuais que a compõem. Com o avanço tecnológico das últimas décadas, foi possível coletar um grande conjunto de informações, (e.g. composição química, cinemática, astrometria e parâmetros atmosféricos), com alta resolução para uma vasta parte do volume Galáctico. Com o objetivo de compreender melhor a nossa Galáxia, desenvolvemos uma ferramenta, chamada StarHorse, que estima parâmetros como distâncias, idades, massas e avermelhamento utilizando informação disponível em levantamentos espectroscópicos, fotométricos e astrométricos. O código StarHorse estima os parâmetros através de um método Bayesiano, que constrói uma distribuição de probabilidade a partir do cálculo de verossimilhança entre observações e modelos de evolução teórica e a partir de priores Galácticos bem conhecidos. Os parâmetros que o StarHorse estima são cruciais para estudos de arqueologia Galáctica. Com eles é possível investigar a estrutura, o histórico de formação estelar, a função de massa inicial, o mapa tridimensional da nossa Galáxia e também adicionar vínculos a modelos quemodinâmicos da Via Láctea Neste trabalho, focaremos na descrição e validação do método, testando sua aplicabilidade em levantamentos recentes de espectroscópica, astrometria e fotometria. Também disponibilizamos catálogos com distâncias e extinção para comunidade astronômica. As nossas distâncias e extinções se tornaram referência dentro da colaboração APOGEE e foram liberadas junto com o seu Data Release 14. Ademais, catálogos foram liberados para os surveys RAVE, Gaia-ESO e GALAH. Neste trabalho, exploramos os resultados do StarHorse, especialmente os resultados APOGEE, em um contexto amplo de arqueologia Galáctica.We are in an advantageous position to study the formation and evolution of disk galaxies. By being inside the Milky Way, we are able to make detailed observations about the individual stars that compose it. With the technological revolution of the latest years, it has been possible to collect a massive set of information, (e.g. chemical composition, kinematics, astrometry, and atmospheric parameters), with high resolution for a large portion of the Galactic volume. With the goal to understand better our Galaxy, we developed a tool, called StarHorse, that can estimate distances, ages, masses, and extinction from the available spectroscopic, astrometric, and photometric information. StarHorse makes these estimates through a Bayesian method, that builds a probability distribution over the models by calculating a likelihood function between observation and stellar evolution models, and by using common knowledge about our Galaxy as priors. The parameters that StarHorse estimates are crucial to Galactic archaeology studies. With them, we can investigate the structure, the star formation history, the initial mass function, the three-dimensional dust map of our Galaxy, and provide constraints to chemodynamical models of the Milky Way. In this work, we focus on the description and validation of the method, testing its applicability in recent spectroscopic and astrometric surveys. We also make available catalogs with distances and extinctions to the astronomy community. Our distances and extinctions became a reference inside the APOGEE-team and were released as part of the SDSS Data Release 14. Moreover, we made available catalogs also to other spectroscopic surveys such as Gaia-ESO, RAVE, and GALAH. In this work, we also explore these results, especially for APOGEE, in a broad Galactic archaeology context.
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Berkolaiko, Gregory. "Quantum star graphs and related systems." Thesis, University of Bristol, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340359.
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Popescu, Cristian D. "On a refined stark conjecture for function fields /." The Ohio State University, 1996. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487940308431494.
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Hubrig, S., K. Scholz, Wolf-Rainer Hamann, M. Schöller, Richard Ignace, I. Ilyin, K. G. Gayley, and Lidia M. Oskinova. "Searching for a Magnetic Field in Wolf-Rayet Stars Using FORS 2 Spectropolarimetry." Digital Commons @ East Tennessee State University, 2016. https://dc.etsu.edu/etsu-works/2694.
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To investigate if magnetic fields are present in Wolf–Rayet stars, we selected a few stars in the Galaxy and one in the Large Magellanic Cloud (LMC). We acquired low-resolution spectropolarimetric observations with the European Southern Observatory FORS 2 (FOcal Reducer low dispersion Spectrograph) instrument during two different observing runs. During the first run in visitor mode, we observed the LMC Wolf–Rayet star BAT99 7 and the stars WR 6, WR 7, WR 18, and WR 23 in our Galaxy. The second run in service mode was focused on monitoring the star WR 6. Linear polarization was recorded immediately after the observations of circular polarization. During our visitor observing run, the magnetic field for the cyclically variable star WR 6 was measured at a significance level of 3.3σ (〈Bz〉 = 258 ± 78 G). Among the other targets, the highest value for the longitudinal magnetic field, 〈Bz〉 = 327 ± 141 G, was measured in the LMC star BAT99 7. Spectropolarimetric monitoring of the star WR 6 revealed a sinusoidal nature of the 〈Bz〉 variations with the known rotation period of 3.77 d, significantly adding to the confidence in the detection. The presence of the rotation-modulated magnetic variability is also indicated in our frequency periodogram. The reported field magnitude suffers from significant systematic uncertainties at the factor of 2 level, in addition to the quoted statistical uncertainties, owing to the theoretical approach used to characterize it. Linear polarization measurements showed no line effect in the stars, apart from WR 6. BAT99 7, WR 7, and WR 23 do not show variability of the linear polarization over two nights.
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Mentz, Jacobus Johannes. "A search for pulsating B-type variable stars in the southern open clusters NGC 6204 and Hogg 22 / Jacobus Johannes (Jaco) Mentz." Thesis, North-West University, 2013. http://hdl.handle.net/10394/9520.
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The theory of stellar evolution and stellar structure relies on the observation of stars
in di erent phases of their evolutionary cycle. The relation between observations and
theory can be strengthened by obtaining observational data of a large sample of stars in a particular evolutionary phase. The search for Cephei stars, as conducted in this study,
can contribute to the sample of known Cephei stars, where these interesting stars are
massive non-supergiant early B-type stars, displaying pulsating behaviour which is not
well understood.
Stars tend to form in clusters where it can therefore be expected that young massive
stars can be found in open clusters. For this reason two young southern open clusters
were observed in order to search for B-type pulsating stars. The region of NGC 6204
and Hogg 22 was observed over a period of thirteen nights in Johnson B, V and I bands.
NGC 6204 is believed to be the oldest cluster of the two at a distance of 0.8 kpc while the
much younger Hogg 22 is more distant at 2.8 kpc. These two open clusters are located
6 arcminutes apart which made it possible to observe them simultaneously with a 12.8
12.8 arcminute eld of view. The observations were done with the newly installed 1600
telescope of the North-West University, South Africa.
In order to do a variability search, periodic stars need to be identi ed from the cluster
data, where a typical data set may contain thousands of scienti c images. In addition
to the main motivation for this study, a pipeline was created in order to automate the
photometry and data reduction processes. A Lomb-Scargle transform was applied to the
stellar light curves in order to identify periodic sources. 354 signi cantly periodic stars
were identi ed from the 3182 observed stars. Amongst them, two new possible Cephei
stars were found together with a possible slowly pulsating B star (SPB), and numerous
eclipsing binary systems.
By using photometry of this region obtained by Forbes & Short (1996), instrumental
magnitudes were transformed to a standard system in order to compare photometry
results. From the constructed colour magnitude diagram of the two clusters, it could be
seen that some stars, indicated by Forbes & Short (1996) to be cluster members, were
in fact eld stars belonging to neither cluster. The reduction and photometry pipeline was implemented successfully on the data set,
which also highlighted the importance of instrumentation and correct data analysis
procedures. Possible improvements were identi ed in order to overcome di culties experienced
during this study.Thesis (MSc (Space Physics))--North-West University, Potchefstroom Campus, 2013
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Day-Jones, A. C. "Searching for brown dwarf companions." Thesis, University of Hertfordshire, 2009. http://hdl.handle.net/2299/3475.
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In this thesis I present the search for ultracool dwarf companions to main sequence stars, subgiants and white dwarfs. The ultracool dwarfs identified here are benchmark objects, with known ages and distances. The online data archives, the two micron all sky survey (2MASS) and SuperCOSMOS were searched for ultracool companions to white dwarfs, where one M9 1 companion to a DA white dwarf is spectroscopically confirmed as the widest separated system of its kind known to date. The age of the M9 1 is constrained to a minium age of 1.94Gyrs, based on the estimated age of the white dwarf from a spectroscopically derived Teff and log g and an initial-final mass relation. This search was extended using the next generation surveys, the sloan digital sky survey (SDSS) and the UK infrared deep sky survey (UKIDSS), where potential white dwarf + ultracool dwarf binary systems from this search are presented. A handful of these candidate systems were followed-up with second epoch near infrared (NIR) imaging. A new white dwarf with a spectroscopic M4 companion and a possible wide tertiary ultracool component is here confirmed. Also undertaken was a pilot imaging survey in the NIR, to search for ultracool companions to subgiants in the southern hemisphere using the Anglo-Australian telescope. The candidates from that search, as well as the subsequent follow-up of systems through second epoch NIR/optical imaging and methane imaging are presented. No systems are confirmed from the current data but a number of good candidates remain to be followed-up and look encouraging. A search for widely separated ultracool objects selected from 2MASS as companions to Hipparcos main-sequence stars was also undertaken. 16 candidate systems were revealed, five of which had been previously identified and two new L0 2 companions are here confirmed, as companions to the F5V spectroscopic system HD120005 and the M dwarf GD 605. The properties of HD120005C were calculated using the DUSTY and COND models from the Lyon group, and the age of the systems were inferred from the primary members. For GD 605B no age constraint could be placed due to the lack of information available about the primary, but HD120005C has an estimated age of 2-4Gyr. In the final part of this thesis I investigate correlations with NIR broadband colours (J - H, H - K and J - K) with respect to properties, Teff , log g and [Fe/H] for the benchmark ultracool dwarfs, both confirmed from the searches undertaken in this work and those available from the literature. This resulted in an observed correlation with NIR colour and Teff, which is presented here. I find no correlation however with NIR colours and log g or [Fe/H], due in part to a lack of suitable benchmarks. I show that despite the current lack of good benchmark objects, this work has the potential to allow UCD properties to be measured from observable characteristics, and suggest that expanding this study should reveal many more benchmarks where true correlation between properties and observables can be better investigated.
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Campbell, Brian. "Type-based amortized stack memory prediction." Thesis, University of Edinburgh, 2008. http://hdl.handle.net/1842/3176.
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Controlling resource usage is important for the reliability, efficiency and security of software systems. Automated analyses for bounding resource usage can be invaluable tools for ensuring these properties. Hofmann and Jost have developed an automated static analysis for finding linear heap space bounds in terms of the input size for programs in a simple functional programming language. Memory requirements are amortized by representing them as a requirement for an abstract quantity, potential, which is supplied by assigning potential to data structures in proportion to their size. This assignment is represented by annotations on their types. The type system then ensures that all potential requirements can be met from the original input’s potential if a set of linear constraints can be solved. Linear programming can optimise this amount of potential subject to the constraints, yielding a upper bound on the memory requirements. However, obtaining bounds on the heap space requirements does not detect a faulty or malicious program which uses excessive stack space. In this thesis, we investigate extending Hofmann and Jost’s techniques to infer bounds on stack space usage, first by examining two approaches: using the Hofmann- Jost analysis unchanged by applying a CPS transformation to the program being analysed, then showing that this predicts the stack space requirements of the original program; and directly adapting the analysis itself, which we will show is more practical. We then consider how to deal with the different allocation patterns stack space usage presents. In particular, the temporary nature of stack allocation leads us to a system where we calculate the total potential after evaluating an expression in terms of assignments of potential to the variables appearing in the expression as well as the result. We also show that this analysis subsumes our previous systems, and improves upon them. We further increase the precision of the bounds inferred by noting the importance of expressing stack memory bounds in terms of the depth of data structures and by taking the maximum of the usage bounds of subexpressions. We develop an analysis which uses richer definitions of the potential calculation to allow depth and maxima to be used, albeit with a more subtle inference process.
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Bowe, Wendy. "Comparison of early literacy attitudes of Head Start teachers and the frequency of literacy activities in Wisconsin Head Start classrooms." Online version, 2002. http://www.uwstout.edu/lib/thesis/2002/2002bowew.pdf.
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Foley, Edward L. "A Rotating Aperture Mask for Small Telescopes." DigitalCommons@CalPoly, 2019. https://digitalcommons.calpoly.edu/theses/2105.
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Observing the dynamic interaction between stars and their close stellar neighbors is key to establishing the stars’ orbits, masses, and other properties. Our ability to visually discriminate nearby stars is limited by the power of our telescopes, posing a challenge to astronomers at small observatories that contribute to binary star surveys. Masks placed at the telescope aperture promise to augment the resolving power of telescopes of all sizes, but many of these masks must be manually and repetitively reoriented about the optical axis to achieve their full benefits. This paper introduces a design concept for a mask rotation mechanism that can be adapted to telescopes of different types and proportions, focusing on an implementation for a Celestron C11 Schmidt–Cassegrain optical tube assembly. Mask concepts were first evaluated using diffraction simulation programs, later manufactured, and finally tested on close double stars using a C11. An electronic rotation mechanism was designed, produced, and evaluated. Results show that applying a properly shaped and oriented mask to a C11 enhances contrast in images of double star systems relative to images captured with the unmasked telescope, and they show that the rotation mechanism accurately and repeatably places masks at target orientations with minimal manual effort. Detail drawings of the mask rotation mechanism and code for the software interface are included.
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Finch, Charlie T. "MINIMO a search for mini proper motion stars in the southern sky /." unrestricted, 2007. http://etd.gsu.edu/theses/available/etd-04202007-183626/.
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Thesis (M.S.)--Georgia State University, 2007.Title from file title page. Todd J. Henry, committee chair; Douglas R. Gies, Harold A. McAlister, committee members. Electronic text (110 p. : ill.) : digital, PDF file. Description based on contents viewed May 2, 2008. Includes bibliographical references (p. 66-69).
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Schilder, Dirk. "Smart Capital for Start-ups." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2009. http://nbn-resolving.de/urn:nbn:de:bsz:105-0846717.
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Unternehmensgründungen sind durch ein hohes Maß an Unsicherheit und durch eine häufige Notwendigkeit externer Beratung gekennzeichnet. Daher ist Smart Capital, als eine spezielle Finanzierungsform, die Kapital und Informationsflüsse in Form von Betreuung und Beratung verbindet, von besonderer Bedeutung für junge Unternehmen. Der empirische Teil der Dissertation analysiert die verschiedenen Typen von Finanziers, die als potentielle Anbieter von Smart Capital angesehen werden sowie regionale Einflüsse auf Finanzierungsbeziehungen im Rahmen von Smart Capital. Des Weiteren wird die Rolle der öffentlichen Hand auf dem Markt für Smart Capital untersucht. Die Analysen machen deutlich, dass viele verschiedene Typen von Finanziers als Anbieter von Smart Capital in Deutschland agieren. Regionale Nähe zwischen dem Investor und den finanzierten Unternehmen spielt dabei jedoch nur eine untergeordnete Rolle. Eine regionale Unterversorgung an Smart Capital für junge Unternehmen ist unter diesem Aspekt nicht zu befürchten. Des Weiteren zeigen die Ergebnisse, dass öffentlich geförderte Anbieter von Smart Capital ihre Förderfunktion im Wesentlichen erfüllen.
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Mellblom, Fredrik. "Start modelling for heavy trucks." Thesis, Linköping University, Department of Electrical Engineering, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2618.
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Modern heavy trucks tend to get more and more equipment demanding electric power. As a result, the electric power left for startingbecome more and more limited. If a complete view of the entire starting system-battery, starter and the combustion engine - is used, the total system can be investigated and optimized. This thesis is a study of the starting system and its components. Theories for each component are presented and models are derived for a complete starting system. Focus lies on the battery and starter motor. The purpose of the modelling work is to gain knowledge of the starting system. Some results can also be obtained from the simulations - it is very important to keep the electrical resistance as low as possible and the differences between battery types are surprisingly big.
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Vellala, Manoj. "Stack Composition for SILO Architecture." NCSU, 2008. http://www.lib.ncsu.edu/theses/available/etd-03212008-153547/.
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SILO is a new internetworking architecture that represents a significant departure from current philosophy and practice. The architecture consists of building blocks of fine-grain functionality, explicit support for combining elemental blocks to accomplish highly configurable complex communication tasks, and control elements to facilitate (what is currently referred to as) cross-layer interactions. It takes a holistic view of network design, allowing applications to work synergistically with the network architecture and physical layers so as to meet the application's needs within resource availability constraints. The SILO research advocates a non-layered architecture based on silos of services assembled on demand and specific to an application and network environment. With the goal to facilitate what in today's layered architecture is referred to as ``cross-laye' interactions, in a manner that meets the exact user requirements and optimizes performance, the main focus of this research work is on developing mechanisms to optimize the construction of SILOs (stack of services) in a manner that takes into account service specific constraints, current network conditions and user policies.
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Church, R. P. "Real stars for stellar clusters." Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.597692.
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This work first describes the creation of a rapid, reliable stellar evolution programme from the stellar evolution code STARS. The physics of stellar evolution and structure of the code are described. Modifications to the code, necessary for it to evolve single stars in a rapid and reliable manner, are detailed. The stellar evolution code has been combined with the stellar dynamics programme NBODY6 to model clusters containing 104 single stars. STARS has been extended to enable it to model binary star systems efficiently. The physics of binary stellar evolution is outlined and its implementation in the code discussed. The phenomenon of common envelope evolution is reviewed and a routine to model it is described. The extended code is used to model the binaries J1141-6545 and B2303+46, both of which contain a white dwarf and a neutron star in an eccentric orbit. The results are compared to those obtained with the synthetic binary evolution code BSE. It is shown that the process of common envelope evolution is critical to the evolution of this class of objects and models are produced that fit both systems from a single initial distribution. The extended code has been combined with NBODY6 to produce the first N-body code to contain live binary stellar evolution. Small proof-of-concept cluster models show that the code works although some challenging numerical problems remain. Full treatment of binary evolution is particularly important for blue stragglers formed by thermal-timescale mass transfer and close degenerate binaries formed via common envelope evolution.
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Cervantez, Brian. "Lone Star Booster: The Life of Amon G. Carter." Thesis, University of North Texas, 2011. https://digital.library.unt.edu/ark:/67531/metadc103297/.
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Abstract
Though a very influential Texan during the first half of the twentieth century, Amon Carter has yet to receive a full scholarly treatment, a problem which this dissertation attempts to rectify by investigating the narrative of Carter’s life to see how and why he was able to rise from humble beginnings to become a powerful publisher who symbolized boosterish trends within Texas and the New South. Publisher of the Fort Worth Star-Telegram, philanthropist, oilman, and aviation supporter, Carter used his power and influence to become a leading booster of his city and region seamlessly making the transition from being a business progressive to New Deal supporter to an Eisenhower Democrat. His connections with corporations like American Airlines and General Motors helped bring aviation and industry to his region, and his ability to work with public and private entities helped inspire his failed attempt to make the Trinity River navigable up to Fort Worth. His own success at building the Star-Telegram into the largest circulating newspaper in Texas encouraged him to expand his media empire into radio and television, while the wealth he gained from his oil activities enabled him to form a philanthropic foundation that would provide support for Fort Worth’s medical, cultural, and educational needs for the future. Possessing a life marked by both success and failure, it is clear throughout this dissertation that Carter embodied the idea of the New South civic booster, a figure who at once promoted his goals for his city and region while understanding how this fit within the larger national context.
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Manseau, P. M., P. Bergeron, and E. M. Green. "A SPECTROSCOPIC SEARCH FOR CHEMICALLY STRATIFIED WHITE DWARFS IN THE SLOAN DIGITAL SKY SURVEY." IOP PUBLISHING LTD, 2016. http://hdl.handle.net/10150/622679.
Full textAbstract:
We present a detailed search and analysis of chemically stratified hybrid (traces of helium and hydrogen) white dwarfs in the Sloan Digital Sky Survey (SDSS). Only one stratified white dwarf, PG 1305-017, was known prior to this analysis. The main objective is to confirm the existence of several new stratified objects. We first describe our new generation of stratified model atmospheres, where a thin hydrogen layer floats in diffusive equilibrium on top of a more massive helium layer. We then present the results of our search for hot (T-eff > 30,000 K) white dwarfs with a hybrid spectral type among the similar to 38,000 white dwarf spectra listed in the SDSS. A total of 51 spectra were retained in our final sample, which we analyze using spectroscopic fits to both chemically homogeneous and stratified model atmospheres. We identify 14 new stratified white dwarfs in the SDSS sample. From these results, we draw several conclusions regarding the physical processes that might explain the presence of helium in the atmospheres of all the stars in our sample.
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Olson, Ted. "Tennessee Ernie Ford: Bristol's Biggest Star." Digital Commons @ East Tennessee State University, 2015. https://dc.etsu.edu/etsu-works/1124.
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Brown, Misty Adana. "SLOWMO: A Search for Nearby Stars." Digital Archive @ GSU, 2007. http://digitalarchive.gsu.edu/phy_astr_theses/4.
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I report on suspected nearby stars with proper motions 1.0 arcsec > μ ≥ 0.5 arcsec/yr in the southern sky (DEC = −90° to 00°). This sample of slow-motion (SLOWMO) stars complements the work of Jao (2004), who reported on faster moving stars with μ ≥ 1.0 arcsec/yr in the entire sky for his doctoral dissertation, and the work of Finch (2007), who uncovered stars moving slower than 0.5 arcsec/yr between declinations −90° and −47°. Characterizations of SLOWMO systems include trigonometric parallaxes, optical and infrared photometry. For stars without trigonometric parallaxes, colors and apparent magnitudes are used to calculate photometric distance estimates and the statistics of this population of stars are analyzed. The SLOWMO sample is comprised of 1906 total stars − 560 estimated to be less than 25 parsecs away, and 245 stars without parallaxes estimated to be within 25 parsecs.
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Osley, Kristin R. Ellis Janet. "A head start on reading for children in a head start preschool program." [Denton, Tex.] : University of North Texas, 2009. http://digital.library.unt.edu/permalink/meta-dc-10985.
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Osley, Kristin R. "A head start on reading for children in a Head Start preschool program." Thesis, University of North Texas, 2009. https://digital.library.unt.edu/ark:/67531/metadc10985/.
Full textAbstract:
Literacy is a fundamental to all areas of learning. Early reading experiences prior to elementary school and kindergarten years are critical factors for later reading success. This study evaluated the effect Direct Instruction® reading procedures vs. Scholastic Early Childhood Program® reading procedures on the production of letter names, letter sounds, CV and CVC blends by preschool-aged students in a Head Start program. Results showed the intervention group improved in all areas, while the control group improved only in letter naming and letter sounds. This study discusses reading as a behavioral cusp as well as limitations, and recommendations for future research.
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Arias, Vidaurre Renato Andre, Oballe Valeria Escobar, Arrascue Mauricio Garcia, Janampa Sonia Angélica Gutiérrez, and Echegaray Alvaro Gonzalo Larrea. "Un nuevo negocio sobre ruedas Food Star." Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2020. http://hdl.handle.net/10757/654746.
Full textAbstract:
En el siguiente trabajo de investigación tiene como objetivo presentar la idea de negocio Food Star, emprendimiento de venta online de bocadillos a base de papa peruana en sus distintos tipos y posibles presentaciones. A través de métodos de investigación, como entrevistas y encuestas y el planteamiento de hipótesis para corroborar la viabilidad del negocio, se buscará analizar el entorno interno como fortalezas y debilidades y externo, como factores no controlables por parte de la empresa que tendrán repercusiones en las acciones que se tomen. Además, buscando comprender al mercado que lo rodeará (proveedores, clientes, competencia, etc.), se indagará en el que será el segmento al cual se dirigirán los esfuerzos de ventas, conociendo gustos y preferencias de usuarios en redes sociales para corroborar el óptimo funcionamiento en un futuro del negocio. De esta manera, conociendo la viabilidad que tendría en el contexto actual del país, analizando indicadores de rentabilidad y realizando las debidas proyecciones en miras al futuro confirmando su escalabilidad en el mercado y cumplimiento de estrategias tanto a corto, medio como largo alcance, asegurando un crecimiento sostenible a través de los años.In the following work of investigation it has the objective to present the idea of business Food Star, enterprise of sale online of sandwiches based on Peruvian potato in its different types and possible presentations. Through research methods, such as interviews and surveys and the development of hypotheses to corroborate the viability of the business, we will seek to analyze the internal environment as strengths and weaknesses and external, as factors not controllable by the company that will have an impact on the actions taken. In addition, seeking to understand the market that will surround it (suppliers, customers, competition, etc.), we will investigate in which segment will be the segment to which the sales efforts will be directed, knowing tastes and preferences of users in social networks to corroborate the optimal functioning of the business in the future. In this way, knowing the viability that would have in the current context of the country, analyzing profitability indicators and making the appropriate projections in view of the future to confirm its scalability in the market and compliance with strategies both short, medium and long range, ensuring sustainable growth over the years.
Trabajo de investigación
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Schmidt, Sarah J., Erika L. Wagoner, Jennifer A. Johnson, James R. A. Davenport, Keivan G. Stassun, Diogo Souto, and Jian Ge. "Examining the relationships between colour, T eff , and [M/H] for APOGEE K and M dwarfs." OXFORD UNIV PRESS, 2016. http://hdl.handle.net/10150/621724.
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We present the effective temperatures (T-eff), metallicities, and colours in Sloan Digital Sky Survey (SDSS), Two Micron All Sky Survey, and Wide-field Infrared Survey Explorer filters, of a sample of 3834 late-K and early-M dwarfs selected from the SDSS Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectroscopic survey ASPCAP (APOGEE Stellar Parameters and Chemical Abundances Pipeline) catalogue. We confirm that ASPCAP T-eff values between 3550 < T-eff < 4200 K are accurate to similar to 100 K compared to interferometric T-eff values. In that same T-eff range, ASPCAP metallicities are accurate to 0.18 dex between -1.0 <[M/H]< 0.2. For these cool dwarfs, nearly every colour is sensitive to both T-eff and metallicity. Notably, we find that g - r is not a good indicator of metallicity for near-solar metallicity early-M dwarfs. We confirm that J - K-S colour is strongly dependent on metallicity, and find that W1 - W2 colour is a promising metallicity indicator. Comparison of the late-K and early-M dwarf colours, metallicities, and T-eff to those from three different model grids shows reasonable agreement in r - z and J - K-S colours, but poor agreement in u - g, g - r, and W1 - W2. Comparison of the metallicities of the KM dwarf sample to those from previous colour-metallicity relations reveals a lack of consensus in photometric metallicity indicators for late-K and early-M dwarfs. We also present empirical relations for T-eff as a function of r - z colour combined with either [M/H] or W1 - W2 colour, and for [M/H] as a function of r - z and W1 - W2 colour. These relations yield T-eff to similar to 100 K and [M/H] to similar to 0.18 dex precision with colours alone, for T-eff in the range of 3550-4200 K and [M/H] in the range of -0.5-0.2.
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Hodder, Philip Jeremy Crichton. "A search for faint variable stars in the globular cluster M71." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/28830.
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A 67" x 104" area of the metal-rich globular cluster M71 was searched for variable stars using 73 CCD frames. Using mean B and V values a colour-magnitude diagram down to V ≈ 22 is constructed. Four variables were discovered, with two more stars classed as possible candidates for variability. Phase diagrams and real time light curves are presented for all variables. One variable blue straggler (or SX Phe star) has been discovered with a period of 0.d05181. Values for the mass depend on the pulsation mode assumed for this star - (0.90 ± 0.13)M. for the first overtone mode, and (1.57 ± 0.22)M. for the fundamental mode. A second variable, of similar period (0.d06053), but with a magnitude l.m75 below the main sequence turn off was also found but it may be a field star. Two candidate eclipsing binary systems were found. The most likely period of one is 0.d37244. This value, and the shape of the light curve, suggest it may be a W UMa type variable. Its position on the CMD suggests that it too may be a field star. No period was obtainable for the other candidate binary due to a lack of phase coverage. Further data is needed to confirm and strengthen these claims.Science, Faculty of
Physics and Astronomy, Department of
Graduate
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Lindsey, Christine M. (Christine Marie) 1977. "Critical process parameter determination during production start-up." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/34741.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering; and, (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management; in conjunction with the Leaders for Manufacturing Program at MIT, 2004.Includes bibliographical references (p. 83-84).
Production start-up data is consistently utilized in a reactive manner during the initial stages of a product's lifecycle. However, if proactive information systems are created before full scale production starts, ramp-up cycles can be shortened considerably. This project attempts to develop a framework for analyzing process data quickly and efficiently during a new product start-up in order to provide information for the short term goals relating to attaining stable processes as well as provide guidance on long term handles for process improvement. First, a summary of previous literature regarding start-up process data as well as typical stable process data usage will be presented. This will provide adequate background for evaluating typical gaps present during production ramp-up. Then, solutions to these gaps will be discussed in order to develop tools for better data analysis in shorter periods of time. These methods will then be applied to a case study involving the. new production of Kodak's DCS Pro 14N digital camera. The Kodak Professional DCS Pro 14N was an amazing leap in technology: a camera with double the resolution for roughly half the price of any product available. Unfortunately, it soon became apparent that the original demand estimates were grossly underestimated, straining original resource allocations. Manufacturing struggled to start and was already a year behind in backorders. With over 1.500 process attributes collected on each camera, the key drivers of quality had yet to be determined. The surrounding circumstances made the quick analysis of start-up data vital to effective resource management and yield improvement of the camera.
(cont.) After using the new process modeling framework and modified control techniques on the example Kodak case, two additional topics will be discussed. First, the many classifications of return on investment in proactive start-up data analysis will be presented. Ranging from waste minimization to higher customer satisfaction, these incentives justify early preparation for start- up data analysis. Finally, future areas of study will be recommended to augment the findings within the thesis.
by Christine M. Lindsey.
M.B.A.
S.M.
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Stark, Christoph [Verfasser]. "A Branch-and-Price Framework for Workforce Scheduling Problems / Christoph Stark." Aachen : Shaker, 2007. http://d-nb.info/1170528120/34.
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Huang, Wenjin. "Spectral Line Synthesis for Hot stars." Digital Archive @ GSU, 2005. http://digitalarchive.gsu.edu/phy_astr_diss/2.
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I developed a spectrum synthesis method to investigate the physical properties of hot OB main sequence (MS) stars, which are often rapid rotators. The code realistically simulates the surface conditions of rapidly rotating stars, considering the rotationally-deformed stellar shape and gravity darkening effect. Comparing the synthesized absorption line profiles with the observed spectra of the member stars of 19 young Galactic clusters, I determined the projected rotational velocities of 496 stars. The average surface temperature and gravity for most of these objects were then derived from H$\gamma$ line fits. The polar gravity of each star was estimated as a good indicator of the evolutionary status of the star. The derived parameters show that massive rotators spin down during their MS phase. The He abundance data (measured by fitting the He I lines) also favor the theoretical prediction that rotationally-induced mixing can gradually enrich the surface helium abundance through the MS phase. A quicker spin-down is evident in the lower mass star group where a large portion of helium peculiar stars are found. This correlation implies that strong stellar magnetic fields may exist on the surface of these lower mass stars. The same method is also applied to interferometric observations from the CHARA Array of a nearby rapid rotator, Regulus. By combining results from spectroscopic and interferometric analysis, the shape, space orientation, mass, and surface temperature distribution of Regulus are firmly determined. This analysis provides the first evidence of the gravity darkening phenomenon among stars that are not components of an eclipsing binary system. The surprisingly high luminosity determined for Regulus appears to agree with the theoretical prediction that rapid rotator can become more luminous as rotationally-induced mixing brings fresh hydrogen down to the core. Finally I present an extension of the model that simulates the shape, velocity, and temperature variations of a star experiencing nonradial pulsation. I simulated and analyzed the line profile variations in the spectra of $\epsilon$ Per, a B0.7~III star with strong evidence of nonradial pulsation (NRP). A comparison of the model simulations and observations indicates that the pulsations of $\epsilon$ Per have a corresponding local temperature variation that is out of phase with the radial oscillation (a non-adiabatic phase lag).
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Brown, Misty. "SLOWMO a search for nearby stars /." unrestricted, 2007. http://etd.gsu.edu/theses/available/etd-12032007-084403/.
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Thesis (M.S.)--Georgia State University, 2007.Title from file title page. Todd Henry, committee chair; David Wingert, Harold McAlister, committee members. Electronic text (156 p. : ill.) : digital, PDF file. Description based on contents viewed June 3, 2008. Includes bibliographical references (p. 92-97).
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Iglesias, Jennifer. "Searching Stars for a Moving Hider." Scholarship @ Claremont, 2012. https://scholarship.claremont.edu/hmc_theses/38.
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In a search game, a seeker searches for a hider in some space. The seeker wishes to find the hider as quickly as possible, and the hider wishes to avoid capture as long as possible. In this paper, I will focus on the case where the search space is a star, and the only information the seeker has is the speed of the hider. I will provide algorithms for some cases where the seeker is guaranteed to find the hider and prove optimality for some of these cases. Also, I will look at some cases where the hider can avoid capture indefinitely. I will also present some results for searching on trees.
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Hawkins, Keith A. "Searching for Solar-Type Hypervelocity Stars." Ohio University Honors Tutorial College / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ouhonors1367583430.
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Saffer, R. A., and J. Liebert. "Search for Close Binary Evolved Stars." Steward Observatory, The University of Arizona (Tucson, Arizona), 1988. http://hdl.handle.net/10150/623897.
Full textAbstract:
We report on a search for short -period binary systems composed of pairs of
evolved stars. The search is being carried out concurrently with a program to characterize
the kinematical properties of two different samples of stars. Each sample has produced one
close binary candidate for which further spectroscopic observations are planned. We also
recapitulate the discovery of a close detached binary system composed of two cool DA
white dwarfs, and we discuss the null results of Ha observations of the suspected white
dwarf /brown dwarf system G 29-38.
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Kirkpatrick, Joseph Davy. "Spectroscopic and photometric studies of main sequence M stars and a search for late-type dwarfs in the solar vicinity." Diss., The University of Arizona, 1992. http://hdl.handle.net/10150/185978.
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As any introductory astronomy student knows, M dwarfs are the most common stars in the Galaxy and are the faintest of the core hydrogen burners. A comprehensive study of these faint objects is crucial to our understanding of the stellar composition of the Galaxy and necessary for a more complete knowledge of the transition between main sequence M stars and their slightly less massive counterparts, the brown dwarfs, which never achieve hydrogen burning in their cores. In this thesis, a spectroscopic catalog of 125 K and M dwarfs is first presented. This catalog covers the wavelength range from 6300 to 9000 Å, near where these objects emit most of their light. Eight of these spectra, covering classes M2 through M9, are combined with infrared spectra from 0.9 to 1.5 μm to create a second catalog. The two sets of spectra are used to search for temperature-sensitive atomic lines and molecular bands, which are then used in fitting the observed spectra to a sequence of theoretical models. As a result, a new temperature scale for M dwarfs is determined, and this scale is more accurate than previous determinations which have depended on blackbody energy distributions. The sequence of spectra is also used to compare the spectrum of the brown dwarf candidate GD 165 B to known M dwarfs. Furthermore, the spectral catalog is used in an attempt to separate the spectra of faint companions from their M dwarf primaries in systems where the two objects are too close for conventional spectroscopy to resolve the individual components. A survey for faint M dwarfs is also launched using the data acquired through the CCD/Transit Instrument (CTI) on Kitt Peak, Arizona. Follow-up spectroscopy is presented for 133 of these objects, and several more very late M dwarfs are identified. This spectroscopy combined with photometric data from the CTI are used to construct a luminosity function for M dwarfs which is in excellent agreement with determinations from previous surveys. Finally, possible avenues for future work are discussed. These include spectroscopic follow-up of the reddest of Luyten's proper motion objects--the first results from which have uncovered, in just twelve observations, two objects of type M7 and one of type M8, among the coolest objects yet recognized. Future searches, such as an all-sky survey for objects of extremely high proper motion, are also outlined.
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Poulton, Christopher John. "The environments in which stars and circumstellar discs form." Thesis, St Andrews, 2008. http://hdl.handle.net/10023/700.
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Fialho, Márcio Afonso Arimura. "Improved star identification algorithms and techniques for monochrome and color star trackers." Instituto Nacional de Pesquisas Espaciais (INPE), 2017. http://urlib.net/sid.inpe.br/mtc-m21b/2017/08.10.22.44.
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This work presents modeling, implementation, testing and simulation of a real-time attitude estimator using extended Kalman filter (FKE), applied to a three-axis air-bearing platform controlled by gas jet actuators. The goal of this work is to obtain an attitude determination algorithm that can replace the attitude estimate from the embedded inertial unit, currently in use by the platform electronics. Two models of estimators were implemented in MATLAB environment: in the first one, the state vector is composed only by the quaternions of the attitude, and in the second, the state vector is composed by quaternions and biases of the three gyroscopes. These estimators were tested using data from the sensors of the platforms inertial unit, and the results were compared with the attitude estimation sent by the internal attitude solution of the inertial unit. Finally, tests of the two FKE algorithms were performed in the simulation model of the air-bearing platform. Both Kalman filter-based estimators were successful in the attitude determination process, both in the tests using real data and in the simulation of control of the air-bearing platform. The proposed bias estimation functioned in a degraded way for the cases tested. We then hypothesized the reasons for this performance, and the convenience of estimating them in the proposed application.Sensores de estrelas de cabeça-fixa modernos estão entre os sensores de atitude mais precisos disponíveis para uso em veículos espaciais. Seu princípio básico de operação consiste em adquirir imagens do céu e identificar as estrelas presentes nestas imagens, usando as estrelas identificadas como referências de atitude. Este processo engloba tarefas como pré-processamento de imagens, segmentação de imagens, cálculo de centroides, identificação de estrelas e determinação de atitude a partir de versores observados. Na tarefa de identificação de estrelas, este trabalho investiga como as informações de brilho (magnitudes) e cor (quando disponível) podem ser aproveitadas para melhorar a confiabilidade e a velocidade do processo de identificação de estrelas. Ao se incorporar verificações de magnitude e cor em um algoritmo de identificação de estrelas estado da arte, obteve-se uma redução na taxa de identificações incorretas maior que duas ordens de grandeza. Várias outras melhorias foram propostas e implementadas neste algoritmo de identificação de estrelas. Outras contribuições deste trabalho estão no uso de índices de cor (comum em astronomia, mas novo neste campo) na representação de cor em sensores de estrelas, com vantagens em relação à representação anteriormente usada na literatura, e no desenvolvimento de uma metodologia para avaliar a adequação de diferentes índices de cor no processo de identificação de estrelas. Uma investigação sobre tecnologias para imageamento a cores voltada para sensores de estrelas é realizada, na qual se verificou que sensores de imagem baseados em pixels empilhados apresentam potencial para aplicações futuras. Este trabalho também apresenta um algoritmo de pré-processamento de imagens simples para remoção da não uniformidade de coluna em sensores CMOS, desenvolvido para sensores de estrelas com pouca memória e baixo poder computacional. Uma estimativa do limite teórico para a precisão de sensores de estrelas é apresentada. Este limite representa, de certa forma, um limite fundamental para a precisão de sensores de estrelas que depende apenas da distribuição de estrelas na nossa vizinhança estelar, das dimensões físicas do sensor de estrelas e da duração da janela de tempo usada para observação das estrelas, sendo, portanto, completamente independente da tecnologia empregada. A utilidade desta estimativa é que ela provê uma referência ao qual se podem comparar diferentes sensores de estrelas. Esta estimativa foi calculada usando dados dos catálogos de estrelas Hipparcos, Tycho e 2MASS. Até onde o autor tenha conhecimento, o cálculo desta estimativa é uma contribuição original para esta área de pesquisa.
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Koch, Malina. "Tech Start-up Internationalisation : Development of an internationalisation model for born global web-based tech start-ups from European start-up hubs." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-211699.
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International entrepreneurship is a prominent phenomenon in contemporary research, because of the ease of internationalisation for companies. Start-up hubs in Europe are booming and especially web-based tech companies internationalise quickly. This new type of company, which internationalises almost immediately after foundation, is called born global. Research showed that despite the interest in born global tech start-ups, there is no representative model visualising the process of their internationalisation. Therefore, secondary research is conducted, as well as empirical research in the form of qualitative interviews with three representative, successfully internationalised tech start-ups from Europe. These companies are the music streaming service Spotify, social marketing SaaS Facelift and business management SaaS Ivy. The internationalisation factors resulting from this research can be divided into a preparation phase, possible strategy development and an implementation phase. Within these phases, factors are separated into company- internal and external influences. Based on these findings, a new model on the internationalisation process of web- based tech start-ups is developed.Internationell entreprenörskap är ett framstående fenomen inom modern forskning eftersom det blir enklare för företag att expandera över nationsgränserna. Startup-hubbar växer fram överallt i Europa och framförallt webbaserade techbolag är snabba med sin internationaliseringsprocess. Det handlar huvudsakligen om en viss typ av företag som kallas för born global, vilket innebär att bolaget börjar sälja sina produkter eller tjänster internationellt direkt efter grundandet. Forskning kring ämnet visar att det finns ett stort intresse för denna typ av företag men inga representativa modeller som visualiserar processen bakom deras internationalisering. Därför genomfördes sekundär forskning samt empirisk forskning i form av tre kvalitativa intervjuer med representanter från framgångsrika och internationella tech startups från Europa. Undersökningen ledde till upptäckten av olika faktorer som påverkar internationaliseringsprocessen. Dessa faktorer kategoriseras som interna eller externa påverkningar på företaget. Internationaliseringsfaktorerna kan delas in i tre faser - förberedelse, möjlig utveckling av strategi och implementering. Baserat på dessa resultat har en modell om internationaliseringsprocessen för born global tech startups utvecklats.
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Kumar, Rajnish. "Adaptable Protocol Stack for Future Sensor Networks." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/13931.
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The goal of this thesis is to provide an adaptable protocol stack
architecture for data fusion applications. Towards the goal, this
thesis presents the design of SensorStack, that addresses three key
issues. First, towards network-level adaptability, how to
dynamically adapt the placement of a fusion application task graph
on the network? We have designed a distributed role assignment
algorithm and implemented in the context of DFuse, a framework for
distributed data fusion. Second, towards node-level adaptability,
how to facilitate cross-layering on a node to foster agile
adaptation of a node's behavior commensurate with the network-level
changes? SensorStack provides information exchange service (IES) as
a framework for cross-module information exchange. Finally, towards
tying the network and node level adaptability together, control data
published in IES needs to be shared across the network. SensorStack
uses a probabilistic broadcast based dissemination service (IDS) for
control data. We implement SensorStack in TinyOS and Linux to
validate the SensorStack design, and use simulation experiments to
investigate its network performance. Experiments demonstrate the
utility of adaptability in SensorStack to increase application
longevity.
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Eroglu, Muammer. "A New Stack Architecture For Sensor Networks." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607590/index.pdf.
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In this thesis, a new stack architecture for sensor networks is proposed. The stack consists of the following layers: application, query, aggregation, network, MAC and physical. Various algorithms are implemented using this stack and it is
shown that this stack is modular.
Following an overview of sensor networks, the previous protocol stack suggestions for sensor networks are examined. Sensor network algorithms that can be classified as sensor data management systems are surveyed and compared with each other. Four of the surveyed algorithms, namely, TAG, Synopsis Diffusion, Tributary-Delta and Directed Diffusion are implemented using the introduced stack. The implementation is performed using a sensor network model developed with OMNeT++ simulator. The simulation results are compared to the original results of these algorithms. Obtaining similar results, the stack and algorithm implementations are validated, moreover, it is shown that the stack does not induce any performance degradation.
Using the implementation details of the algorithms, the modularity of the suggested stack is demonstrated. Finally, additional benefits of the stack are discussed.
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Holtmann, Angela. "The s-tame dimension vectors for stars." [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=967597013.
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Cappos, Justin. "Stork: Secure Package Management for VM Environments." Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/195385.
Full textAbstract:
Package managers are a common tool for installing, removing, and updating software on modern computer systems. Unfortunately existingpackage managers have two major problems. First, inadequate security leads to vulnerability to attack. Thereare nine feasible attacks against modern package managers, many of which are enabled by flaws in the underlying security architecture. Second, in Virtual Machine (VM) environments such as Xen, VMWare, and VServers,different VMs on the same physical machine are treated as separate systemsby package managers leading to redundant package downloads and installations.This dissertation focuses on the design, development, and evaluation ofa package manager called Stork that does not have these problems. Stork provides a security architecture that prevents the attacks other package managers are vulnerable to. Stork also is efficient in VM environments and reduces redundant package management actions. Stork is a real system thathas been in use for four years and has managed half a million VM instantiations.
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Liu, Kuangyi. "Start-up manufacturing firms : operations for survival." Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/5929.
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Start-up firms play an important role in the economy. Statistics show that a large percent of start-up firms fail after few years of establishment. Raising capital, which is crucial to success, is one of the difficulties start-up firms face. This Ph. D thesis aims to draw suggestions for start-up firm survival from mathematical models and numerical investigations. Instead of the commonly held profi t maximizing objective, this thesis assumes that a start-up firm aims to maximize its survival probability during the planning horizon. A firm fails if it runs out of capital at a solvency check. Inventory management in manufacturing start-up firms is discussed further with mathematical theories and numerical illustrations, to gain insight of the policies for start-up firms. These models consider specific inventory problems with total lost sales, partial backorders and joint inventory-advertising decisions. The models consider general cost functions and stochastic demand, with both lead time zero and one cases. The research in this thesis provides quantitative analysis on start-up firm survival, which is new to the literature. From the results, a threshold exists on the initial capital requirement to start-up firms, above which the increase of capital has little effect on survival probability. Start-up firms are often risk-averse and cautious about spending. Entering the right niche market increases their chance of survival, where the demand is more predictable, and start-ups can obtain higher backorder rates and product price. Sensitivity tests show that selling price, purchasing price and overhead cost have the most impact on survival probability. Lead time has a negative effect on start-up firms, which can be offset by increasing the order frequent. Advertising, as an investment in goodwill, can increase start-up firms' survival. The advertising strategies vary according to both goodwill and inventory levels, and the policy is more flexible in start-up firms. Externally, a slightly less frequency solvency check gives start-up firms more room for fund raising and/or operation adjustment, and can increase the survival probability. The problems are modelled using Markov decision processes, and numerical illustrations are implemented in Java.
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Magic, Zazralt. "Theoretical stellar atmosphere models for cool stars." Diss., Ludwig-Maximilians-Universität München, 2014. http://nbn-resolving.de/urn:nbn:de:bvb:19-173446.
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In kühlen Sternen wie der Sonne wird die nuklear erzeugte Energie aus dem Inneren an die Oberfläche transportiert. Diese kann dann in den freien Weltraum entfliehen, und so können wir das Sternenlicht letztlich beobachten. Die theoretische Modellierung des photosphärischen Übergangsbereiches – vom konvektiven zum radiativen Energietransport – ist aufgrund der inhärenten dreidimensionalen (3D) Natur der Konvektion und der komplexen, nicht-linearen und nicht-lokalen Interaktionen des Strahlungsfelds mit dem stellaren Plasma sehr anspruchsvoll. Theoretische Atmosphärenmodelle stellen die fundamentale Basis für die Untersuchung von Sternen dar, daher sind Astronomen für ihr Verständnis der Sterne auf diese letztlich angewiesen. Die üblicherweise verwendeten eindimensionalen (1D) Atmosphärenmodelle beinhalten verschiedene Vereinfachungen. Insbesondere wird die Konvektion für gewöhnlich mit der Mischungswegtheorie berechnet, trotz ihrer wohlbekannten Fehler, da derzeit keine deutlich besseren Alternativen vorhanden sind. Der einzige Ausweg, um dieses Problem zu überwinden ist, die zeitabhängigen, dreidimensionalen, hydrodynamischen Gleichungen, welche mit einem realistischen Strahlungstransport gekoppelt sind, zu lösen. Aufgrund der in den vergangenen Jahrzehnten rasch gestiegenen Rechenleistung wurden bedeutende Fortschritte mit Simulationen für 3D Strahlungshydrodynamik (RHD) von Atmosphären erzielt. Diese Modelle sind außerordentlich leistungsfähig, und besitzen eine enorme Vorhersagekraft, wie präzise Vergleiche mit Sonnenbeobachtungen wiederholt beweisen konnten.
Ausgestattet mit diesen ausgereiften Methoden möchte ich als Ziel meiner Dissertation die drei folgenden Fragen näher untersuchen: Was sind die Eigenschaften der Atmosphären von kühlen Sternen? Welche Unterschiede sind zwischen den 1D und 3D Modellen vorhanden? Wie verändern sich die Vorhersagen für die Sternstrukturen und Spektrallinien? Um mich dieser Aufgabenstellung systematisch anzunehmen, habe ich das Stagger-Gitter berechnet. Das Stagger-Gitter ist ein umfangreiches Gitter aus 3D RHD Atmosphärenmodellen von kühlen Sternen, welches einen großen stellaren Parameterbereich abdeckt. In der vorliegenden Dissertation beschreibe ich die Methoden, welche angewendet wurden, um die vielen Atmosphärenmodelle zu berechnen. Zudem werden die allgemeinen Eigenschaften der resultierenden 3D Modelle, auch deren zeitliche und räumliche Mittelwerte detailliert dargestellt und diskutiert. Die Unterschiede zwischen den 1D und 3D Schichtungen, sowie die Details der stellaren Granulation (die Manifestation der Konvektion unterhalb der Sternoberfläche) werden ebenfalls umfangreich erläutert und beschrieben. Des Weiteren habe ich folgende Anwendungen für die 3D Atmosphärenmodelle untersucht: Berechnung theoretischer Spektrallinien, wichtig für die Bestimmung von Sternparametern, Spektroskopie und Häufigkeiten-Analyse; die sogenannte Randverdunkelung, notwendig für die Analyse interferometrischer Beobachtungen und Suche nach extrasolaren Planeten; und die Kalibrierung der Mischungsweglänge, womit 1D-Sternmodelle verbessert werden können.
Die Qualität der hochauflösenden Beobachtungen hat inzwischen die der theoretischen 1D Atmosphärenmodelle aufgrund der technischen Entwicklungen in den vergangenen Jahren überschritten. Daher hat sich der Bedarf an besseren Simulationen für Atmosphärenmodelle erhöht. Durch die Bereitstellung eines umfangreichen Gitters aus 3D RHD Atmosphärenmodellen wurde dazu ein erheblicher Beitrag geleistet. Damit werden wir den Anforderungen an die Theorie für die derzeitigen und zukünftigen Beobachtungen gerecht werden, und können somit zu einem besseren Verständnis der kühlen Sterne beitragen.In cool stars, like the Sun, energy from the inside is transported to its surface by convection, which then can escape into space as radiation that we can observe. Modeling this photospheric transition region – from convective to radiative energy transport – is notoriously challenging due to the inherent three-dimensional (3D) nature of convection itself and the complex non-linear and non-local interaction of the radiation field with the stellar plasma. Astronomers rely on theoretical atmosphere models, which provide the fundamental basis to study and understand stars. The commonly employed one-dimensional (1D) atmosphere models make use of several simplifications, in particular, convection is usually treated with the mixing-length theory (MLT), despite its well-known wrongness simply due to the lack of a considerably improved alternative. Therefore, the only appropriate approach to overcome this issue, is to solve the time-dependent, 3D, hydrodynamic equations coupled a with the realistic treatment of radiative transfer. Due to the soaring computational power in the recent decades, significant progress has been established with the advent of 3D radiative hydrodynamic (RHD) atmosphere simulations. Nowadays, these perform exceedingly well and offer exceptional predictive potential as detailed comparisons with the Sun have repeatedly revealed. Equipped with this matured, powerful tool, I want to address the following three main questions as the aim of my thesis: What are the atmospheric properties of cool stars besides the Sun? Which differences are given between 1D and 3D models? How do the application-based predictions change? To attend to this matter in a systematical approach, I have computed the Stagger-grid, a comprehensive grid of 3D RHD model atmospheres of cool stars covering a wide range in stellar parameters. In this thesis I describe the methods I have applied for the computation of the grid models, and the general properties of the 3D models, as well as their temporal and spatial averages are presented and discussed in detail. Also, the differences between 1D and 3D stratifications are determined, and the details of stellar granulation, the manifestation of subsurface convection, is extensively depicted. Furthermore, I investigated with the Stagger-grid several applications for 3D atmosphere simulations including: spectral line profiles, important for stellar parameter determination, stellar spectroscopy and abundance analysis; limb darkening, necessary for interferometry and extrasolar planet search; and the calibration of the mixing length, which will improve stellar evolution models. The cumulative technical developments of high-resolution observations in the recent years have surpassed the standards of theoretical 1D atmosphere models, thereby, it has given rise to the enhanced demand of improved atmosphere simulations. By providing a comprehensive grid of 3D RHD atmosphere models to the astronomical community, a major contribution has been achieved to live up to the current and future high-precision observations, which ultimately will lead to a better understanding of cool stars.
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Marinos, Ilias. "Network and storage stack specialisation for performance." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/288228.
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In order to serve hundreds of millions of users, contemporary content providers employ tens of thousands of servers to scale their systems. The system software in these environments, however, is struggling to keep up with the increase in demand: contemporary network and storage stacks, as well as related APIs (e.g., BSD socket API) follow a `one-size-fits-all' design, heavily emphasising generality and feature richness at the cost of performance, leaving crucial hardware resources unexploited. Despite considerable prior research in improving I/O performance for conventional stacks, substantial hardware potential still remains unexploited because most of these proposals are fundamentally limited in their scope and effectiveness, as they still have to fit in a general-purpose design. In this dissertation, I argue that specialisation and microarchitectural awareness are necessary in system software design to effectively exploit hardware capabilities, and scale I/O performance. In particular, I argue that trading off generality and compatibility, allows us to radically re-architect the stack emphasising application-specific optimisations and efficient data movement throughout the hardware to improve performance. I first demonstrate that conventional general-purpose stacks fail to effectively utilise contemporary hardware while serving critical Internet workloads, and show why modern microarchitectural properties play a critical role in scaling I/O performance. I then identify core decisions in Operating Systems design that, although they were originally introduced to optimise performance, are now proven redundant or even detrimental. I propose clean-slate, specialised architectures for network and storage stacks designed to exploit modern hardware properties, and application domain-specific knowledge in order to sidestep historical bottlenecks in systems I/O performance, and achieve great scalability. With thorough evaluation of my systems, I illustrate how specialisation and greater microarchitectural awareness could lead to dramatic performance improvements, which could ultimately translate to improved scalability and reduced capital expenditure simultaneously.
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Hultquist, Adam. "Stellar atmosphere models for Population III stars." Thesis, Uppsala universitet, Observationell astrofysik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-432178.
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The rst stars to illuminate the universe are said to belong to a group called Population III. Having knowledge of their atmospheric conditions would be useful in many endeavours. The aimof this project was to compile and run the FORTRAN code TLUSTY (Hubeny and Lanz 2017) inorder to create stellar atmospheres for Pop III stars. With a working version of TLUSTY, severalcontrol runs were then performed to make sure that everything worked as intended with the final goal to create a large grid of calculated atmospheres in the parameter space of effective temperatureand surface gravity. Successful comparisons were made against earlier calculations made by Schaerer(2002) and Windhorst et al. (2019). Constructing such a grid required several codes to work togetherwith TLUSTY by constructing a shell script. The result is a grid lled with many points that werewell converged, as well as a few that did not appear to converge. Comparing the converged part ofthe grid with stellar evaluations tracks made by Yoon et al. (2012) showed that heavy, rotating PopIII stars fell almost within the grid. One problem that arose, however, was that as the grid did notfully converge all the way to the tracks some could not be uniquely mapped to di erent points on thegrid. Thus, some di erent tracks would become degenerate which should not be physically expected. However this may not be a fatal problem.
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You, Fenglong. "A Mirror Theorem for Toric Stack Bundles." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1494255385887568.
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Spruyt, Jon. "Gamified Individual Brainstorming : Reaching for the stars." Thesis, Umeå universitet, Institutionen för informatik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-133603.
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Ideation is a critical step in the creation of new solutions to problems. Brainstorming, being the most commonly known ideation method, is mostly done in groups. However, research points out that brainstorming individually is more effective than brainstorming in groups. This paper investigates if negative aspects (reduced enjoyment, motivation and self-rated performance) associated with brainstorming alone can be overcome by using a gamified approach to brainstorming. Gamified and non-gamified prototypes have been made and used in combination with a questionnaire to measure differences in these negative aspects. From the within-subject study including 20 participants, it appears that the implemented gamification approach was not different from the non-gamified approach for most of the negative aspects. Self-rated performance was however significantly higher in the non-gamified version. Using the gamified or non-gamified approach seems to largely come down to the preference of the user.
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Longa-Peña, Penélope Alejandra. "Orbital parameters estimation for compact binary stars." Thesis, University of Warwick, 2015. http://wrap.warwick.ac.uk/75554/.
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Most stars in the Galaxy are found in multiple systems of two or more stars orbiting together. Two stars orbiting around their centre of mass are called binary stars. In close binary stars, the evolution of one star affects its companion and evolutionary expansion of one star allows for mass exchange between the components. In most cases, the material from the less massive star forms an accretion disc around the heavier companion that has evolved into a compact stellar remnant, the final state of stellar evolution. We call these systems compact binary stars (CBs). The study of CBs is key to the development of two fundamental phenomena: accretion and evolution of binary stars. Statistical information on CBs can be deduced by extracting common properties and characteristic system parameter distributions from observed data. But, despite being fundamental for a wide range of astronomical phenomena, our comprehension of their formation and evolution is still poor, mainly because of the limited knowledge of crucial orbital parameters. This lack of reliable orbital parameters estimation is mainly due to observational handicaps, namely, the accretion disc outshines the system components. Astronomers have developed different techniques to overcome this, but are often very dependant of the signal to noise ratio of the data or are only able to obtain via target of opportunity programs (wait until the target is brighter). The focus of this work is to test and develop techniques, based on indirect imaging methods, that can overcome the main observational handicaps to estimate orbital parameters of CBs. We combine these techniques with the exploitation of more “exotic” emission lines that trace the irradiated face of the donor star, namely Ca II NIR triplet and the Bowen blend. We made use of empirical properties of Doppler tomography to estimate the values of the phase zero Á0 and the velocity of the irradiated face of the secondary star (Kem). We then used synthetic models accounting for an irradiated secondary to fit our measured Kem and perform a K-correction to derive the radial velocity of the secondary K2. To derive K1, we used the centre of symmetry technique, testing its validity among several emission lines and the stability of the results depending on the selected area. Having strong constraints for K1 and K2, we find estimates for the mass ratio q. Furthermore, we developed a variation from the Doppler tomography secondary emission method to constrain the value of the systemic velocity ƴ. We derive meaningful uncertainties of these parameters with the bootstrap technique. Using these techniques, we have successfully set dynamical constraints on the radial velocities of the binary components of CBs and derived fundamental orbital parameters, including the mass ratio, using basic properties of Doppler tomography.