Detta examensarbete undersöker om ett skolprogram på Vetenskapens Hus har förmågan att skapa en bro mellan gymnasieelevers matematikkunskap, universitetsmatematik och dess praktiska tillämpning för att därmed öka deras intresse och motivation för inlärning av matematik- och fysikämnen. Skolprogrammets tema är fourieranalys och dess tillämpning inom ljudsyntes och digital ljudbehandling (DSP). Skolprogrammet har att göra med matematik, fysik och IT, vilket gör programmet tvärvetenskapligt. En viktig del av detta arbete är också att vidareutveckla detta skolprogram med avseende på resultaten från denna undersökning. Resultaten är baserade på kvalitativa data från enkäter och intervjuer med eleverna som deltog i testfallen av skolprogrammet och deras lärare samt på litteraturstudier. Information samlades också in under en iterativ process av programmets vidareutveckling. Denna rapport inleds med motivering till genomförandet av detta arbete, studiens syfte- och målsättning samt formulering av huvudfrågeställningar. Därefter beskrivs metoder som användes för att besvara frågeställningarna. I mitten av rapporten sammanfattas litteratur och forskningsstudier inom undervisning, intresse och motivation samt sammanfattas en vetenskaplig bas för innehållet i skolprogrammet inom fourieranalys. Därefter beskrivs utvecklingsprocessen av skolprogrammet. Detta följs av en presentation av resultaten från testning av skolprogrammet med gymnasieelever med avseende på hur deras intresse och motivation påverkas av det. Rapporten avslutas med diskussion av dessa resultat och dess trovärdighet. Resultaten visar att den sista versionen av den laborativa aktiviteten, som vidareutvecklades inom ramen av detta arbete, väcker elevernas intresse och motivation för temat av skolprogrammet. Resultaten visar också att vissa komplexa begrepp (både nya och de som eleverna lär sig i skolan) blir klarare för eleverna efter skolprogrammet, vilket potentiellt kan leda till ökning av deras motivation till att lära sig matematik och naturvetenskap generellt. Problemet är dock att skolprogrammet testades med för få gymnasieklasser för att kunna generalisera resultatet över hela målgruppen av gymnasieelever. / This thesis investigates the ability of a lab exercise in House of Science (Vetenskapens Hus),Stockholm, to create bridges between upper-secondary school students’ knowledge, university mathematics and practical application of that knowledge, thus increasing their motivation and interest to learn more mathematics and physics. The topic of the lab exercise is Fourier analysis and its practical application in Digital Sound Processing (DSP). The lab exercise deals with mathematics, physics and IT-technology thus making the activity interdisciplinary. An important part of the work is also to improve this lab exercise based on the results of this study. The result is based on qualitative data from interviews, questionnaires filled by students and their teachers and also on literature studies. Some data is also collected through an iterative process of improving the lab exercise. This report starts with justification for conducting this work, setting the goals and objectives and formulating main questions. Then the methods, which were used in order to answer these questions, are described. The middle part of the report summarizes literature and research studies in education, interest and motivation of students and also summarizes a scientific basis for the content of the school program in Fourier analysis. Next, the development process of the school program is described. This is followed by a presentationof the results of testing the school program with upper secondary school students with regard to how their interest and motivation are affected by it. The report ends with a discussion of these results and its credibility. The result shows that the final version of the lab exercise, that is modified within the framework of this study, wakes students’ interest and motivation towards the topic of the exercise. The result also shows that some complex concepts (both new and those which are learned in school) become clearer for the students after the exercise which could potentiallylead to an increase in their motivation for learning the mathematics and physics in general. The problem is that the lab exercise was tested on too few classes for being able to generalize the result over the whole target group of the upper-secondary school students.

A key goal of modern evolutionary biology is the identification of genes or genome regions that have been targeted by natural selection. Methods for detecting natural selection utilise the information sampled in contemporary gene sequences and test for deviation from the null hypothesis of neutrality. One such method is the McDonald Kreitman test (MK test), which detects the the molecular 'footprint' left by natural selection by considering the frequency of observed mutations within the sampled population. In this thesis I investigate the applicability of the MK test to viral populations and develop several new methods based on the original MK test. In chapter 2, I use a combination of simulation and methodological improvements to show that the MK test can have low error when applied to analysis of RNA virus populations. Then, in chapter 3, I develop an extension of the MK test with the purpose of estimating rates of adaptive fixation for all genes of the human influenza A virus subtypes H1N1 and H3N2. My results are consistent with previous studies on selection in influenza virus populations, and provide a new perspective on the evolutionary dynamics of human influenza virus. In chapter 4 I develop a formal statistical framework based, on the MK test, for calculating the number of non neutral sites at any frequency range in the site frequency spectrum. In this framework, I introduce a new method for reconstructing the site frequency spectrum that incorporates sampling error and allows for the inclusion of prior knowledge. Using this new framework I show that the majority of nucleotide sites in hepatitis C virus sequences sampled during chronic infection represent deleterious mutations. Finally, in chapter 5 I use the generalised framework introduced in chapter 4 to develop a statistic for evaluating the deleterious mutation load of a population. I apply this test sequences that represent 96 RNA virus genes and show that my approach has comparable power to equivalent phylogenetic methods. In this thesis I have developed computationally efficient methods for analysis of genetic data from virus populations. It is my hope that these methods will become useful given the explosion in sequence data that has accompanied recent improvements in sequencing technology.

Made available in DSpace on 2008-05-13T13:48:27Z (GMT). No. of bitstreams: 1 2142.pdf: 937600 bytes, checksum: 2ea39c80c8dbfa4f1a4c9e92d891f5f3 (MD5) Previous issue date: 2006-08-11 / A research was accomplished on the UMTS frequency spectrum licensing on Europe on the years 2000 and 2001. It was analyzed the bidders behaviors’, the auction rules’, the auction environment and each auction objective. After the European auction analysis was done a discussion on the specifics aspects of brazilian market for those types of auction. / Atualmente, o leilão de espectro tem sido evento de considerável relevância para o mercado de telecomunicações. As cifras alcançadas nos leilões, a oportunidade que eles representam para as empresas interessadas em explorar o mercado de telecomunicações, e o interesse do governo em alocar de forma eficiente este recurso, trouxeram notoriedade e magnitude para este mecanismo de seleção. Com o advento de novas tecnologias de comunicação móvel, detentoras de características inovadoras que permitem preencher cada vez mais a cesta de necessidades do consumidor, e a partir da alocação destas tecnologias a distintas faixas de espectro, tornou-se necessário, a determinação do mecanismo de escolha mais adequado daquele que será o gestor do recurso que permitirá a oferta desses serviços ao mercado: o espectro de freqüência. Com o intuito de se avaliar esse cenário, e os distintos papéis de seus participantes, busca-se nesse trabalho, através da análise do mais recente conjunto de leilões realizados para alocação deste recurso, o leilão das licenças 3G na Europa, compreender os pormenores envolvidos desde a elaboração até o desfecho deste processo. Objetiva-se, por fim, enriquecer o debate sobre esse tema ao discutir-se o cenário brasileiro. O trabalho ao analisar os leilões europeus nos permite identificar que as regras do leilão, como comentado por diversos autores, não são diretamente transplantáveis entre diferentes ambientes. Afinal dentro do ambiente homogêneo caracterizado pelo continente europeu, apesar da semelhança entre os diversos modelos de leilão utilizados, o sucesso obtido em países como Reino Unido e Alemanha, não foi repassado aos demais, ao compararmos o preço pago per capta. Entretanto, o espectro tem seu valor altamente conectado à disponibilidade tecnológica de sua utilização, logo, espectro sem tecnologia adequada para seu uso é observado como de valor privado aproximadamente zero pelos participantes. Esse fenômeno foi caracterizado pelo baixo valor atribuído ao espectro não pareado. Apesar de valor ser relativamente nulo, não é zero, pois a aquisição do direito de uso do espectro pode representar um 'hedge' para ser utilizado, senão hoje, quando a tecnologia estiver disponível. Porém sendo o espectro recurso escasso, a alocação deste para tecnologia ainda indisponível pode ser considerado ineficiente. Observa-se, também, que o 'incumbent' tende a valorizar mais uma licença, porém não se conseguiu determinar se isso ocorre devido a maior quantidade de informação que este detém sobre o mercado, ou devido à tentativa de manter o 'status quo' do oligopólio atual. Baseado no comentado anteriormente e nos resultados dos leilões torna-se evidente que caso o entrante não seja protegido, como o 'incumbent' valoriza mais a licença este sempre pagará mais por esta. E caso, o entrante tenha esta certeza, este não virá participar do leilão, o que na maior parte dos casos inviabilizaria o leilão pois haveriam tantas licenças quanto participantes. Ao analisar-se o caso brasileiro identifica-se a presença de um jogo nacional e um subjogo regional, onde os participantes podem ser simultaneamente 'incumbents' para uma região, porém entrantes em outra.

Cette thèse se place dans le cadre de l'analyse des forces évolutives qui génèrent les polymorphismes et les divergences entre les génomes d'une même espèce. Le cadre théorique utilisé dans la majorité des domaines de l'évolution moléculaire est la théorie neutraliste, proposée par Motoo Kimura en 1968. Ce modèle est caractérisé par les hypothèses de neutralité, de taille constante de la population étudiée, et de panmixie. Dans un premier temps nous avons cherché à comprendre comment ce cadre théorique est utilisé en pratique et quelles peuvent être les conséquences de ces hypothèses sur les inférences et les prédictions faites dans ce cadre théorique. Pour cela nous avons mené deux études confrontant des données à des méthodes existantes d'inférence démographique. Une première étude a montré que les méthodes utilisées fréquemment pour l'inférence démographique microbienne, basées sur la reconstruction d'un arbre phylogénétique unique, sont biaisées par la sélection, la recombinaison et les biais d'échantillonnage. Nous avons ensuite comparé plusieurs méthodes d'inférence démographique en les appliquant à une population humaine africaine, les Yoruba. Cette étude a montré les limites d'une méthode existante, et elle illustre le problème d'identifiabilité des histoires démographiques lorsque l'inférence est basée sur le spectre de fréquence. Enfin, dans un troisième temps nous avons analysé plusieurs jeux de données de polymorphisme génétique avec un modèle de référence alternatif à coalescences multiples avec démographie. Nous avons comparé comment le modèle de référence actuel et ce modèle alternatif pouvaient expliquer les données observées de diversité génétique. / The general setting of this thesis is the analysis of evolutionary forces that generate polymorphisms and divergence between genomes within a species. The theoretical framework used in the majority of disciplines of molecular evolution is the neutral theory, formulated by Motoo Kimura in 1968. This model is characterized by the hypotheses of neutrality, constant population size and panmixia. First, we investigated how this theoretical framework is used in practice and what are the consequences of these hypotheses on the inferences and predictions made in this framework. To this end, we carried out two studies confronting existing demographic inference methods with data. A first study demonstrated that methods frequently used for bacterial demographic inference, based on a single reconstructed phylogenetic tree, are biased by selection, recombination and sampling bias. We then compared several demographic inference methods, by applying them to an African human population, the Yoruba. This study showed the limits of an existing method, and illustrates the issue of identifiability of demographic histories, when the inference is based on the site frequency spectrum. Finally, in a third study we analyzed several genetic polymorphism datasets with an alternative reference model comprising multiple mergers and demography. We compared how the current reference model and this alternative model can explain the observed genetic diversity.

The public procurement draws a lot of attention in terms of treatment with public resources. Unfortunately this attention has mostly negative character. The aim of this Diploma Thesis is to bring an untraditional overview on the processing of public procurement and introduce one of the modern ways of using auction mechanisms. Combinatorial auctions can, as it already happened in other areas, open new possibilities for contracting authorities and bidders who participate in procurement conducted in accordance with Czech legislation. Also this Diploma Thesis can be the inspiration for thought if the current rules for public procurement are in accordance with the best interests of contracting authorities and bidders. In order to present the application of combinatorial auctions on public procurement the mathematical model based on partially real data was compiled in software Lingo. The results of such model were used as the source for the effectiveness analysis of discussed topic.

This master’s thesis deals with signal evaluation using Fourier transform. In the theoretical section, different methods of signal analysis with an emphasis on a Fast Fourier Transform are described. Theoretical section also contains description of common machinery faults and their diagnosis using frequency spectrum analysis. In the practical section, an algorithm for signal evaluation with an emphasis on coherence condition was designed in the Matlab environment. This algorithm was later used to evaluate submitted signals.

This dissertation thesis is focused on the problem of the noise measurement and construction of the noise test station what was also interest of my employer - company Kollmorgen,sr.o. This testing station should be located directly in the assembly line with target of the noise motor s identification. On base of these measured values and implemented intelligent testing procedures, we should be able to identify real root cause of the noise The noise of electrical machines is actual issue. There is a big pressure for low-noise driving system construction created by many end-customers. We can achieve these requirements with 100% quality of all parts of current product, implementation of noise testing station and also with design optimization of the current product. Basic testing procedures of induction motors were showed in first part of this work (chapter 4.1.). These procedures are able to provide good picture of the motor condition. For the motor noise measurements was constructed a workplace including noise box with acoustical absorption up to 30dB what allowed the workplace implementation directly into the motor assembly line. Testing techniques and frequency analysis procedures were implemented sequentially with the target of the test evaluation improvement. After the detailed analyze of the motor noise root causes was performed check of the current motor design with respect of the “noiselessness” motor construction principles. As next step was created the motor prototype with optimized construction with target of the motor noise reduction. This optimized motor was tested and compared with standard motor design.

Au début des années 2000, les instances aéronautiques ont exprimé le besoin de développer un nouveau système de radiocommunication aéronautique du fait de l'augmentation du trafic aérien et de la saturation croissante des capacités de communication radio entre les aéronefs et les stations de contrôle aérien. L'une des composantes de ce système, nommée L-DACS (« L-band Digital Aeronautical Communication System »), devrait opérer dans la bande L-aéronautique (960-1164 MHz), dans laquelle fonctionnent également de nombreux autres systèmes radioélectriques. La compatibilité radioélectrique (CRE) de L-DACS avec ces systèmes est un des facteurs principaux à prendre en considération dans le développement d'un tel système.L'objectif principal de cette thèse est d'identifier les principaux problèmes reliés à la CRE et d'en étudier les cas critiques. Ces travaux sont fondamentaux en aéronautique, puisque tout dysfonctionnement dans la communication ou dans les systèmes de radionavigation peut mettre en danger la sécurité du vol. Les conclusions de cette thèse contribueront à la normalisation du système L-DACS et à la finalisation de ses spécifications.Dans une première étape, on étudie l'état de l'art dans les communications aéronautiques et en CRE. On analyse en particulier les dernières spécifications des deux systèmes candidats L-DACS. Ensuite, on propose un algorithme de calcul de brouillage dans le but d'étudier la CRE dans le domaine fréquentiel, d'en identifier et d'en traiter les cas critiques. L'analyse fréquentielle étant insuffisante dans plusieurs cas, on propose alors une approche temporelle d'étude de CRE. Après en avoir présenté les avantages, on présente un exemple d'étude de l'effet d'un système L-DACS sur un récepteur DME (« Distance Measuring Equipment ») à l'aide d'un banc de test CRE aéronautique.Cette thèse a été réalisée en collaboration avec la Direction Générale de l'Aviation Civile (DGAC), qui est un acteur principal pour la réglementation des communications et un affectataire de fréquence pour le spectre aéronautique en France. La thèse contribue aux études menées par la DGAC à l'échelle nationale et internationale.Dans les perspectives, on propose la poursuite de cette étude par une approche temporelle plus générale pour étudier la CRE entre des systèmes radioélectriques quelconques en tenant compte de paramètres supplémentaires liés à la dynamique des systèmes et aux propriétés de leurs technologies. / In the beginning of the 21th century, the aeronautical authorities expressed their need to develop a new system for aeronautical radiocommunications, because the air-traffic is increasing and that current communication systems between pilots and air-controllers are reaching their capacity limits. The L-band Digital Aeronautical Communication System (L-DACS) is the part of the future system that will be operating in a part of the aeronautical L-band (960-1164 MHz), already occupied by a large number of radio-frequency legacy systems. Consequently, it is essential to consider its radio-frequency compatibility (RFC) for the development of the future L-DACS system. This thesis aims at identifying the principal issues related to RFC and studying its critical situations. Such topics are fundamental in aeronautics, as any communication or radionavigation dysfunction may endanger flight and passengers security. Some obtained results will be used for the L-DACS standardization and its specifications finalization. We first analyze the state-of-the-art in both aeronautical communications and RFC, focalizing on updated specifications of both preselected L-DACS candidate systems. We then propose a deterministic algorithm to compute the interference level in order to study the RFC in the frequency domain under identified critical scenarios. Since the frequency-domain analysis seems to be insufficient in several cases, we develop a different methodology, called the time-frequency approach, to analyze the RFC for such situations. We apply this new approach to analyze the effect of an L-DACS interferer on a Distance Measuring Equipment (DME) receiver, using an aeronautical RFC test-bed that we implemented at SUPELEC. This work has been performed in collaboration with the French Civil Aviation Authorities (DGAC), which are an important actor in aeronautical communication regulations and aeronautical spectrum management in France. The thesis contributes to DGAC studies at national as well as international levels. For further work, we suggest to generalize the proposed time-frequency approach to analyze the RFC between any two radio-frequency systems, taking into account additional parameters related to system dynamics and their technology properties.

Abstract Demographic history and natural selection are central forces shaping the genetic diversity of populations. Knowledge on these forces increases understanding of processes shaping genetic variability of populations. In this PhD thesis I investigated demographic history and selection in multiple populations of Arabidopsis lyrata, an outcrossing herbaceous plant species of the Brassicaceae family. Due to its wide distribution in the temperate and boreal regions, A. lyrata serves as a good model system to study population genetic consequences of colonization of northern latitudes. The first aim of this study was to characterize the demographic and colonization history of the species using site frequency spectra estimated from whole-genome diversity data. Another aim was to detect genetic loci targeted by recent selective sweeps at genome-wide scale as well as at candidate flowering time genes. Patterns of genome-wide selection at linked sites (linked selection) were also compared between populations of Capsella grandiflora and A. lyrata with contrasting demographic histories. Evidence for strong effective population size decline in the past few hundred thousand years was detected in A. lyrata populations species-wide. This study also suggests recent Scandinavian colonization from an unknown refugium, distinct from the Central European source population. Selection analyses revealed loci targeted by positive selection in two Scandinavian lineages after the recent population split as well as selective sweeps in flowering time genes in the colonizing populations. In comparison with the studied C. grandiflora population, the Norwegian A. lyrata population had weaker purifying selection and no evidence for reduction of diversity around genes was found. This thesis offers novel information on species colonization history and its genome-wide effects, which is important for understanding the framework of local adaptation. / Tiivistelmä Populaation demografinen historia ja luonnonvalinta ovat keskeisiä populaation perinnöllisen muuntelun muokkaajia. Näiden tekijöiden tutkimus on tärkeää eliöiden sopeutumisen ymmärtämiselle. Tässä väitöskirjassa tutkin demografista historiaa ja valintaa monivuotisen ristisiittoiseen ruohovartisen Brassicaceae-heimon kasvilajin idänpitkäpalon (Arabidopsis lyrata) useissa eri populaatioissa. Idänpitkäpalko on erinomainen mallilaji pohjoiseen ympäristöön sopeutumisen tutkimukseen, koska sen toisistaan eristäytyneet paikalliset populaatiot ovat levittäytyneet laajalle boreaalisella ja lauhkealla ilmastovyöhykkeellä. Tutkimuksen tarkoituksena oli luonnehtia populaatioiden demografista historiaa ja kolonisaatioreittejä käyttäen koko perimän laajuisesta muunteluaineistosta estimoituja alleelifrekvenssispektrejä. Lisäksi koko perimän laajuista aineistoa sekä kukkimisaikaa ohjaavien geenien sekvenssejä käytettiin positiivisen luonnonvalinnan merkkien tunnistukseen. Genominlaajuista kytkeytynyttä valintaa vertailtiin toiseen ristisiittoiseen Brassicaceae-heimon lajin Capsella grandifloran populaatioon, jonka demografinen historia poikkeaa huomattavasti tutkituista idänpitkäpalon populaatioista. Tutkimuksessa havaittiin, että kaikissa tutkituissa idänpitkäpalon populaatioissa tehollinen populaatiokoko oli pienentynyt viimeisen muutaman sadantuhannen vuoden aikana. Kolonisaatiohistorian tarkastelu osoitti, että idänpitkäpalon skandinaaviset populaatiot ovat todennäköisesti peräisin keskieurooppalaisesta refugiosta erillisestä läntisestä refugiosta. Skandinavian kolonisaation yhteydessä vaikuttaneen positiivisen luonnonvalinnan merkkejä havaittiin useissa eri genomin osissa sekä erityisesti valojaksoa mittaavissa geeneissä. Tämä kertoo erilaisiin valojaksoihin sopeutumisen tärkeydestä skandinaavisen kolonisaation yhteydessä. Verrattuna tutkittuun C. grandifloran populaatioon, idänpitkäpalolla puhdistavan valinnan havaittiin olevan heikompaa ja muuntelun vähenemistä geenien ympärillä ei havaittu. Tämä tutkimus tarjoaa uutta tietoa Skandinavian kolonisaatiohistoriasta ja sen genominlaajuisista vaikutuksista. Tutkimuksessa tuotettua tietoa voidaan hyödyntää paikallisen sopeutumisen ymmärtämisessä.

In mathematical population genetics a multiple merger <i>n</i>-coalescent process, or <i>Λ</i> <i>n</i>-coalescent process, {<i>Πⁿ(t) t</i> ≥ 0} models the genealogical tree of a sample of size <i>n</i> (e.g. of DNA sequences) drawn from a large population of haploid individuals. We study various properties of <i>Λ</i> coalescents. Novel in our approach is that we introduce the partition lattice as well as cumulants into the study of functionals of coalescent processes. We illustrate the success of this approach on several examples. Cumulants allow us to reveal the relation between the tree height, <i>T_n</i>, respectively the total branch length, <i>L_n</i>, of the genealogical tree of Kingman’s <i>n</i>-coalescent, arguably the most celebrated coalescent process, and the Riemann zeta function. Drawing on results from lattice theory, we give a spectral decomposition for the generator of both the Kingman and the Bolthausen-Sznitman <i>n</i>-coalescent, the latter of which emerges as a genealogy in models of populations undergoing selection. Taking mutations into account, let <i>M_j</i> count the number of mutations that are shared by <i>j</i> individuals in the sample. The random vector (<i>M₁</i>,...,<i>M_n-1</i>), known as the site frequency spectrum, can be measured from genetical data and is therefore an important statistic from the point of view of applications. Fu worked out the expected value, the variance and the covariance of the marginals of the site frequency spectrum. Using the partition lattice we derive a formula for the cumulants of arbitrary order of the marginals of the site frequency spectrum. Following another line of research, we provide a law of large numbers for a family of <i>Λ</i> coalescents. To be more specific, we show that the process {<i>#Πⁿ(t), t</i> ≥ 0} recording the number <i>#Πⁿ(t)</i> of individuals in the coalescent at time <i>t</i>, coverges, after a suitable rescaling, towards a deterministic limit as the sample size <i>n</i> grows without bound. In the statistical physics literature this limit is known as a hydrodynamic limit. Up to date the hydrodynamic limit was known for Kingman’s coalescent, but not for other <i>Λ</i> coalescents. We work out the hydrodynamic limit for beta coalescents that come down from infinity, which is an important subclass of the <i>Λ</i> coalescents.