Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The widespread use of virtual learning environment (VLE) has great potential for the development of applications that meet needs in education. U -Learning environments the goal is to seek information related to the needs and preferences of users to create their context and present adaptations in its content to suit the user's profile, as in most traditional VLEs, such as Moodle, this process is not generally considered. Given the importance of a dynamic application that can continually adapt to the levels of students' knowledge, this dissertation proposes a module called SistEX (A Dynamic System for Detecting Student Experience). The adaptations in the environment used the Adaptive Hypermedia, and the type of information collected was the level of user knowledge, which were obtained through questionnaires applications. Furthermore, it was used and adapted the algorithm Q -Learning, from the intelligent tutoring system (ITS), to contribute to the user's learning process. As a result, the Software and user testing demonstrated that the environment SistEX worked satisfactorily, based on the assessments made by users who tested the module and its operation. The questionnaire was the System Usability Scale (SUS) on the module developed, which gave a result within a range considered good, which includes the objectives proposed in this work, even though some limitations and difficulties have been identified during development. / A difusão do uso de ambiente virtual de aprendizagem (AVA) apresenta um grande potencial para o desenvolvimento de aplicações que atendam necessidades na área da educação. Em ambientes U-Learning o objetivo é buscar informações relacionadas às necessidades e preferências dos usuários para criar o seu contexto e apresentar adaptações no seu conteúdo para se adequar ao perfil do usuário, visto que na maioria dos AVAs tradicionais, como o Moodle, esse processo geralmente não é considerado. Tendo em vista a importância de uma aplicação mais dinâmica e que consiga se adaptar continuamente aos níveis de conhecimento dos alunos, esta dissertação propõe um módulo denominado de SistEX (Um Sistema Dinâmico para Detectar a Experiência do Aluno). As adaptações realizadas no ambiente utilizaram a Hipermídia Adaptativa, sendo que o tipo de informação coletada foi o nível de conhecimento do usuário, que foram obtidas por meio de aplicações de questionários. Além disso, foi utilizado e adaptado o algoritmo Q-Learning, proveniente do sistema tutor inteligente (STI), para contribuir no processo de aprendizagem do usuário. Como resultados, no teste de Software e com usuários demonstraram que o ambiente SistEX atuou de forma satisfatória, tendo como base as avaliações feitas por usuários que testaram o módulo e o seu funcionamento. O questionário aplicado foi o System Usability Scale (SUS) sobre o módulo desenvolvido, que apresentou resultado dentro de uma escala considerada como boa, o que contempla os objetivos propostos neste trabalho, mesmo que algumas limitações e dificuldades tenham sido identificados durante o desenvolvimento.

The Master thesis deals with the water-heater design for heat-exchange station with total power output 5,5 MW. The goal of the thesis is to make thermal and hydraulic calculation in the extent of the assignment and to develop a projection drawing of the heater along with a correct dimensioning of the shell and flanges. Thesis goals were met according to the assignment. The introductory part of the thesis briefly introduces to the heat-exchanger problematic and selected topics about heat-transfer. Following the basic mass and energy flows calculation inside the heater together with the thermal and hydraulic design determines the size of the heat transfer surface of pipes. After that the design calculations were made, whose results are used to determine the basic dimensions of selected parts and checking the accuracy of designed dimensions. In the last part of the work the design process is more described also with a more detailed description of selected parts.

L’objectif de ce travail consiste d’une part à étudier la plasticité dans le dioxyde d’uranium en décrivant à l’échelle atomique le mécanisme de glissement des dislocations, et d’autre part à étudier l’oxyde sur-stœchiométrique en déterminant les configurations atomiques et les relations structurales des phases se formant sur le diagramme en fonction de la stœchiométrie O/U et de la température. Nous réalisons pour cela des simulations à l’échelle atomique par minimisation d’énergie et par dynamique moléculaire à l’aide d’un potentiel empirique complexe à charges variables, autorisant des modifications de charges d’ions en fonction de leur environnement local. Cette étude nous a permis dans un premier temps de caractériser la plasticité dans les monocristaux d’UO₂ en montrant qu’elle est produite dans les plans de glissement principaux {100} par glissement thermiquement activé de dislocations coin à basse température par un procédé de germination et de croissance de paires de décrochements sur ces dislocations. Dans un second temps, le même potentiel empirique nous a permis de préciser à l’échelle atomique la structure de la phase désordonnée UO₂₊ₓ à haute température et l’évolution en fonction de la température de la structure de la phase ordonnée U₄O₉₋ᵧ. Nous donnons alors une description atomistique d’une partie du diagramme de phase. Ainsi, l’outil que nous utilisons, un potentiel à charges variables, nous a permis de mieux comprendre les propriétés de l’UO₂ et d’une façon plus générale, nous prouvons que ce type d’outil est prometteur complémentaire aux potentiels empiriques classiques et aux méthodes ab-initio pour modéliser des systèmes atomiques complexes. / The aim of this work is to study on the first hand plasticity in uranium dioxide by the mean of an atomic scale characterization of dislocations glide mechanisms, and on the other hand to study hyper-stoichiometric uranium dioxide by the determination of atomic configurations and their relations that appear on the phase diagram as a function of O/U ratio and temperature. To achieve this, we perform atomic scale simulations by energy minimization and molecular dynamics using a complex variable charge empirical potential, which let the ionic charges vary as the local atomic environment is modified. We firstly characterize plasticity in UO₂ single crystals and show that it is governed in the {100} main glide planes by thermally activated edge dislocations glide at low temperatures by a mechanism of nucleation and growth of kink pairs on these dislocations. Then, the same empirical potential let us derive at the atomic scale the structure of the high temperature disordered UO₂₊ₓ phase and the evolution with temperature of the ordered structure U₄O₉. This gives an atomistic description of part of the U-O phase diagram. So, the tool we use, a variable charge empirical potential, let us understand more precisely UO₂ properties, and more generally we prove that this kind of tool is a promising alternative to classical empirical potentials and ab-initio methods to model complex atomic systems.

Title: Cloud-top morphology of convective storms as observed by meteorological satellites Author: Michaela Radová Department: Department of Atmospheric Physics Supervisor: RNDr. Martin Setvák, CSc., Czech Hydrometeorological Institute Abstract: This work focuses on study of features occurring at tops of convective storms, namely embedded warm areas, cold rings, cold-U/Vs and overshooting tops (OTs), mainly from the perspective of satellite observations. We have assembled a database of 104 subjectively detected cold rings and cold-U/Vs from the area of Europe. We discuss relationship between satellite- observed brightness temperature and cloud top height determined from radar measurements for storms with distinct cold-rings. Our results support the hypothesis that the warm area is a consequence of presence of central elevated dome reaching warmer lower stratosphere. Moreover, a storm with transformation of cold ring into cold-U is studied and an elevated plume above storm anvil in the warmer lower stratosphere is found to be a likely explanation of the warm area inside the cold-U. Both analyses confirm that thermal inversion above the tropopause is a necessary prerequisite for occurrence of cold rings and cold-U/Vs. We also propose a method for automated objective determination of spatial characteristics of...

Title: Seasonal variabilityof speed and endurance skills of young elite soccer players. Objectives: Comparison of variability in speed and endurance capabilities of young elite soccer players during one season in the U-12 category based on the results of a test battery consisting of 4 tests (30 m sprint test, Agility 505 Test, Illinois test and Yo-yo intermittent recovery test level 1). Methods: Our thesis is characterized by using comparison and testing methods. We use the comparison method in the result section, in order to compare the performance of individual players by means of statistical methods. This is how we focus on each of our test exercises during all four testing phases included in seasonal macrocycle. The results: As the result of our thesis, we found out that the physical abilities of individual players and their demonstration in the performed tests improve or remain the same or statistically very similar throughout the season. We observe the highest variability in agility 505 test with a 6.96 % DL and 7.29 % NDL as well as a 25.86 % in Yo-Yo intermittent recovery level 1. According to our observations, deviations in the performance of soccer players are mainly caused by long-term and systematic training process, different training and match load of the players during the...

Cette thèse présente de nouveaux tests d’hypothèses statistiques efficaces pour la relative similarité et dépendance, et l’estimation de la matrice de précision. La principale méthodologie adoptée dans cette thèse est la classe des estimateurs U-statistiques.Le premier test statistique porte sur les tests de relative similarité appliqués au problème de la sélection de modèles. Les modèles génératifs probabilistes fournissent un cadre puissant pour représenter les données. La sélection de modèles dans ce contexte génératif peut être difficile. Pour résoudre ce problème, nous proposons un nouveau test d’hypothèse non paramétrique de relative similarité et testons si un premier modèle candidat génère un échantillon de données significativement plus proche d’un ensemble de validation de référence.La deuxième test d’hypothèse statistique non paramétrique est pour la relative dépendance. En présence de dépendances multiples, les méthodes existantes ne répondent qu’indirectement à la question de la relative dépendance. Or, savoir si une dépendance est plus forte qu’une autre est important pour la prise de décision. Nous présentons un test statistique qui détermine si une variable dépend beaucoup plus d’une première variable cible ou d’une seconde variable.Enfin, une nouvelle méthode de découverte de structure dans un modèle graphique est proposée. En partant du fait que les zéros d’une matrice de précision représentent les indépendances conditionnelles, nous développons un nouveau test statistique qui estime une borne pour une entrée de la matrice de précision. Les méthodes existantes de découverte de structure font généralement des hypothèses restrictives de distributions gaussiennes ou parcimonieuses qui ne correspondent pas forcément à l’étude de données réelles. Nous introduisons ici un nouveau test utilisant les propriétés des U-statistics appliqués à la matrice de covariance, et en déduisons une borne sur la matrice de précision. / The dissertation presents novel statistically and computationally efficient hypothesis tests for relative similarity and dependency, and precision matrix estimation. The key methodology adopted in this thesis is the class of U-statistic estimators. The class of U-statistics results in a minimum-variance unbiased estimation of a parameter.The first part of the thesis focuses on relative similarity tests applied to the problem of model selection. Probabilistic generative models provide a powerful framework for representing data. Model selection in this generative setting can be challenging. To address this issue, we provide a novel non-parametric hypothesis test of relative similarity and test whether a first candidate model generates a data sample significantly closer to a reference validation set.Subsequently, the second part of the thesis focuses on developing a novel non-parametric statistical hypothesis test for relative dependency. Tests of dependence are important tools in statistical analysis, and several canonical tests for the existence of dependence have been developed in the literature. However, the question of whether there exist dependencies is secondary. The determination of whether one dependence is stronger than another is frequently necessary for decision making. We present a statistical test which determine whether one variables is significantly more dependent on a first target variable or a second.Finally, a novel method for structure discovery in a graphical model is proposed. Making use of a result that zeros of a precision matrix can encode conditional independencies, we develop a test that estimates and bounds an entry of the precision matrix. Methods for structure discovery in the literature typically make restrictive distributional (e.g. Gaussian) or sparsity assumptions that may not apply to a data sample of interest. Consequently, we derive a new test that makes use of results for U-statistics and applies them to the covariance matrix, which then implies a bound on the precision matrix.

Ett fönsters värmeisolerande egenskaper är nödvändiga att känna till för den som köper fönstren eftersom det ställs krav på en byggnads energianvändning vid ny- och ombyggnation. Det är även en kostnadsfråga då energi för att värma eller kyla byggnader måste betalas för. Ett fönsters värmeisolerande egenskaper beskrivs med dess U-värde. För fönster som tillverkas i fasta mått kan ett U-värde antingen mätas eller beräknas enligt standarder och sedan uppges för beställaren av fönstret. När fönster inte tillverkas i fasta mått blir det en tidskrävande procedur att för varje nytt fönstermått beräkna eller mäta fönstrets U-värde. Syftet med detta arbete var att utifrån U-värdesberäkningar för flera olika måttkonfigurationer av fönstermodellen "A" som tillverkas på måttbeställning av "B" fastställa sambandet mellan dess geometri och dess U-värde. Fönstret är ett renoveringsfönster som monteras i en byggnads befintliga fönsterkarmar. Genom att fastställa sambandet mellan geometri och U-värde fastställs hur fönstrets totala U-värde påverkas av den karm som det monteras i. Tanken var att "B" skulle kunna använda resultaten för att ange fönstermodellens U-värde vid beställning av ett specifikt mått. Resultatet kan också vara intressant för andra fönstertillverkare, köpare av fönster, konsulter, ackrediteringsorgansitationer och fönsterbranschen i stort. Dels eftersom sambandet mellan fönstergeometri och U-värde fastställes, men även då arbetet ger en ingående beskrivning av hur aktuella standarder kan användas. Fönstrets U-värde beräknades enlig SS-EN ISO 10077-1 och karmens U-värde beräknades enligt SS-EN ISO 10077-2. Glaskassettens U-värde var känt sedan tidigare och beräknades inte i detta arbete. Mjukvara användes för att beräkna karmens U-värde.' Resultatet visade att fönstermodellens U-värde minskar då dess area ökar. Det visade också att rektangulära fönster fick ett lägre U-värde ju mer kvadratiska de blev till formen. Detta gällde oavsett om fönsterhöjden var större än fönsterbredden och vice versa. Höga fönster hade ett lägre U-värde än låga fönster på grund av att karmen hos denna fönstermodell hade olika U-värden på sidorna och upptill och nedtill. Diagram har tagits fram på fönstrets U-värde i olika geometrier, storlekar och utföranden. Det visade sig att standarderna som användes är bättre lämpad för att jämföra olika fönstermodellers U-värden snarare än att undersöka hur en enskild fönstermodells U-värde förändras med dess geometri då standarderna i vissa avseenden inte tar hänsyn till fysikaliska lagar. För att noggrannare undersöka hur ett fönsters storlek och geometri påverkar dess U-värde bör framtida studier fokusera på att utföra värmetekniska simuleringar, snarare än att räkna enligt standarderna som använts i detta arbete. / The thermal insulation properties of a window are essential to know for the purchaser since there are energy use regulations concerning construction of new buildings or those undergoing deep renovations. It’s also a matter of cost since energy for heating and cooling a building must be paid for. The thermal insulating properties of a window is described with its U-value. The thermal properties for windows produced in fixed sizes could be measured or calculated according to standards and be presented to the purchaser of the window. When windows are not manufactured in fixed sizes a great deal of work must be done to calculate or measure the U-value for each individual window size. The purpose of this report was to establish the relationship between the geometry and the U-value for the window model "A" which is manufactured in customer requested sizes by "B". The establishment of the relationship between U-value and geometry was accomplished through U-value calculations for different size configurations of the window. The window is a renovation window which is mounted onto a buildings already existing window frames. By establishing the relationship between the geometry and the U-value, it can be known how the U-value of the window is affected by the frame it is mounted on. The idea was that "B" would be able to use the results to be able to specify the U-value when receiving an order of a window of a specific size. The results could potentially be of interest to other window manufacturers, purchaser of windows, consultants, accreditation organizations and the window industry in general. Partly because the relationship between the window geometry and its U-value is established, and partly because the thesis gives an in depth explanation of how relevant standards can be used. The U-value of the window was calculated in accordance with SS-EN ISO 10077-1 and the U-value of the frame in accordance with SS-EN ISO 10077-2. The glazing part of the window was already known and therefore not calculated in this work. Software was used to calculate the U-value of the frame. Results showed that the U-value of the window model declined when its area increased. It also showed that rectangular windows got a lower U-value as it becomes more square shaped. This applied regardless of if the window height was greater than the window width or vice versa. Tall windows had a lower U-value than short windows because the upper, lower, and side members of this window models frame had different U-values. Diagrams have been produced showing the U-value of the window model in different geometries, sizes, and designs. It turned out the standards that was used is better suited to compare different window models U-values rather than to investigate how the U-value of a specific window varies with its geometry because the standards in some regards does not consider physical laws. To more accurately investigate how a windows size and geometry affects its U-value further studies should focus on performing heat transfer simulations, rather than calculate according to the standards that was used in this paper.

This pre-study investigates the possibility of U-value measurements through an acoustic method. A hypothesis about an acoustic model built on acoustic theories combined with U-value theories is presented to answer the questions:•Can U-value theory be combined with acoustic theories?•Can the coefficient of heat be affirmed trough an acoustic measurement?The idea for this dissertation begun with a logical idea in mathematical similarity, between the coefficient of heat transmission units and sound intensity units. The U-value theory is based on assumptions such as initial resistance for inner walls and initial resistance for outer walls. The resistance in the material is interpreted through sound intensity theory.The argument is built upon mass law theory, which means if the frequency or thickness of the material layer doubles it implies an increase of sound reduction by 6 dB. Six different materials; foam, glas fiber insulation, MDF, gypsum, concrete and glass are being investigated through Insul 7 simulations. A practical lab assessment with two glass fiber insulation boards with different density is presented. These fiberboards were received from Saint-Gobain Isover, with alredy measured density and lambda value.The conclusions are drawn from simulations, practical lab testing and different theories. This dissertation confirms that it´s possible to use an acoustic model for U-value measurements, but the hypothesis need a further investigation. That means that the hypothesis is based on mass law theory only and the second degree effects are not calculated in this model. In other words, the model will most probably work better for materials with low density and will be less reliable on materials with high density.

Den 1 september 2020 trädde den konsoliderade versionen av Boverkets Byggregler BBR 29 i kraft. En stor del av skillnaden från föregående version var det ökade kravet på energihushållning. Det nya kravet som fastställts innebär att U-medelvärdet är sänkt från 0,4 W/m2K till 0,3 W/m2K. Detta är ett mått på hur väl en byggnad är isolerad. Företaget Kontio expanderade till Sverige från Finland för snart fyra år sedan. De säljer framförallt fritidsboende och småhus byggda av egentillverkade timmerstockar med korslimmad arktisk furu i olika dimensioner. Deras hus säljs på den finska marknaden, men i Sverige har endast vissa timmerdimensioner klarat det gamla kravet från BBR 28. Med det nya kravet måste klimatskärmen anpassas till den nya kravbilden. Tak och golv är färdigprojekterade med låga U-värden, därför finns den största möjligheten för anpassning i väggkonstruktionerna. Med hjälp av givna förutsättningar togs ett antal väggkonstruktioner fram för beräkning av U-värdet. Dessa gav upphov till olika typlösningar som varierar med, förutom väggkonstruktionen, fönstertyper och minskade fönsterareor. Framräknat U-värde för väggkonstruktion låg till grund för beräkning av U-medelvärde tillsammans med U-värde för fönster, golv och tak. Ändringar i väggkonstruktioner kan resultera i en förekomst av fuktproblem. Därför testas dessa med hjälp av en Glaser-tabell som undersöker genom stationära beräkningar huruvida det föreligger någon risk i framtagna väggkonstruktioner. Detta projekt analyserar även för- och nackdelar med timmer i furu och dess värmelagrande funktion som beror på en hög värmekapacitet. Med utgångspunkt i litteraturstudien analyseras och utreds var i konstruktionen man med störst fördel placerar den massiva timmerstrukturen i förhållande till värmeisolering. Alla väggkonstruktioner behövde göras om utom 275 där endast fönstertyp ändrades till de med lägre U-värde. Vid anpassning av väggkonstruktioner med timmerdimension 135 och 205 krävdes mer omfattande åtgärder. Genom att isolera väggarna, ändra fönstertyper och minska fönsterareor kunde kravet på U-medelvärde nås på olika sätt. Ingen av dessa vägguppbyggnader uppvisade tecken på fukttekniska problem. / On September 1, 2020, the consolidated version of the National Board of Housing, Building and Planning's Building Rules BBR 29 took effect. A large part of the difference from the previous version was the increased demand for energy management. The new requirement that has been established means that the mean U-value has been reduced from 0.4 W/m2K to 0.3 W/m2K. This is a measurement of how well a building is insulated. Almost four years ago, the company Kontio expanded to Sweden from Finland. They mainly sell holiday homes and living houses built from self-made logs with cross-laminated arctic pine in various dimensions. Their houses are sold on the Finnish market, but in Sweden only certain timber dimensions have met the old requirement from BBR 28. With the new BBR 29, the building shell must be adapted to the new requirement. Ceilings and floors are pre-designed with low U-values and for this reason further improvements are best made in the wall construction. Using the given conditions, a number of wall constructions were developed for calculating the U-value. These gave rise to different type solutions that vary with, in addition to the wall construction, window types and reduced window areas. Calculated U-value for wall construction was the basis for calculating the mean U-value together with the U-value for windows, floors and ceilings. Changes in wall constructions can result in the occurrence of moisture problems, therefore these walls are tested using a Glaser-table which examines, by stationary calculations, whether there is any risk in the adapted constructions. This project also analyzes the advantages and disadvantages of pine timber and its heat storage function due to its high heat capacity. Based on the literature study, it is analyzed and investigated where in the construction the massive timber structure is placed with the greatest advantage in relation to the thermal insulation. All wall constructions needed to be adapted except 275 where only the window type was changed to those with a lower U-value. When adapting wall constructions with timber dimensions 135 and 205, more extensive measures were required. By insulating the walls, changing window types and reducing window areas, the requirement for the mean U-value could be achieved in various ways. None of these wall constructions showed signs of moisture technical problems.

This is a master thesis conducted at KTH Centre for Naval Architecture in collaboration with Wallenius Marine AB. Rolling motions is something that is undesired in all kinds of seafaring. In terms of propulsion resistance, comfort and route planning it would be desirable to reduce these motions. This thesis is an investigation on how different roll stabilising systems affect the performance of an 8000 unit PCTC vessel, special emphasis is put on investigating the performance of anti roll tanks. The ship in question has a recorded incidence of parametric rolling and the ability of the tanks to countervail this phenomenon is also investigated. The tank and fin stabilising systems are relatively equal when it comes to roll damping performance related to changes in the required forward propulsion power. The tanks however, have a higher potential for improvements, addition of features such as heeling systems and parametric roll prevention systems. The tank performance is also independent of the speed of the ship. The tanks are easier to retrofit and do not require the ship to be put in dry dock during installation. The conclusion of this thesis is that a combined anti roll and heeling system should be installed but that a further study has to be made on the performance of active rudder stabilisation. It is shown that passive tanks are efficient at preventing parametric rolling in some sea states. A proposal is made for a further study on a control system that could achieve the same performance for all sea states. / HTML clipboard Detta är ett examensarbete utfört på KTH Marina System i samarbete med Wallenius Marine AB. Rullningsrörelser är något som är oönskat i all form av sjöfart. Framsteg kan göras i både framdrivningsmotstånd, komfort och ruttplanering om dessa rörelser kunde minskas. Detta examensarbete består av en undersökning hur olika system för rulldämpning påverkar prestandan hos ett 8000 enheters PCTC-fartyg. Speciell vikt har lagts vid att undersöka prestandan hos antirulltankar. Det undersökta fartyget har en dokumenterad incident med parametrisk rullning och tankarnas förmåga att motverka detta fenomen undersöks. Tank- och fenstabilisatorer är i princip likvärdiga vad det gäller dämpningsprestanda relaterat till erforderliga ändringar i framdrivningseffekten. Tankarna har dock en större potential för förbättring och tillägg av ytterligare inslag som krängningshämmare och system för motverkan av parametrisk rullning. Tankarnas prestanda är också oberoende av fartygets fart. Tankarna är lättare att installera i efterhand och kräver inte att fartyget läggs i torrdocka under installationen. Slutsatsen av detta arbete är att en kombinerad antirull- och krängningshämmande tank bör installeras men att en vidare studie måste göras på prestandan hos aktiva roderstabiliseringssystem. Det visas att passiva tankar kan motverka parametrisk rullning i vissa sjötillstånd. Ett förslag om en vidare studie på reglersystem som skulle kunna ge samma prestanda vid alla sjötillstånd ges.