We present a new algorithm for computing the straight skeleton of a polygon. For a polygon with n vertices, among which r are reflex vertices, we give a deterministic algorithm that reduces the straight skeleton computation to a motorcycle graph computation in O(n (log n) log r) time. It improves on the previously best known algorithm for this reduction, which is randomised, and runs in expected O(n √(h+1) log² n) time for a polygon with h holes. Using known motorcycle graph algorithms, our result yields improved time bounds for computing straight skeletons. In particular, we can compute the straight skeleton of a non-degenerate polygon in O(n (log n) log r + r^(4/3 + ε)) time for any ε > 0. On degenerate input, our time bound increases to O(n (log n) log r + r^(17/11 + ε))

Neste trabalho foi proposto um método e desenvolvido um protótipo para analisar imagens de microscopia de fluorescência obtidas a partir do teste FTA-ABS. Este teste é utilizado como comprovação do diagnóstico da sífilis por meio da identificação da bactéria causadora da doença. Um problema considerável na análise de tais imagens é a subjetividade na interpretação da intensidade de fluorescência apresentada, pois não existe uma descrição formal desse valor, outra dificuldade encontrada trata do baixo contraste entre o objeto de estudo e o fundo da imagem e finalmente a distribuição da fluorescência sobre as bactérias não é uniforme. O método proposto para auxiliar no diagnóstico por meio de análise de imagem consiste de três etapas. A primeira etapa é a de processamento das imagens. Para tal são utilizados algoritmos para aumentar o contraste entre o fundo da imagem e o objeto em estudo. Segue-se a realização da segmentação da imagem, utilizando-se algoritmos de binarização e crescimento de regiões. A segunda etapa realizada é a de classificação de pixels em grupos de cores pré- definidas por meio da utilização de Redes Neurais Artificiais treinadas com o algoritmo Backpropagation. Nesta etapa são treinadas e testadas diversas redes. De posse de todos os pixels classificados realiza-se a interpretação do diagnóstico por meio de técnicas fuzzy. / In this work we have developed a prototype to analyze fluorescence microscopy images obtained from the FTA-ABS. This test is used as confirmation of the diagnosis of syphilis by identifying the bacteria causing the disease. A considerable problem in the analysis of such images is the subjectivity in the interpretation of fluorescence intensity shown, because there is not a formal description of this value, another difficulty is the low contrast between the object of study and the background and finally the distribution of fluorescence on bacteria is not uniform. The proposed methodology for the diagnosis by means of image analysis consists of three stages. The first step is to image processing. For such algorithms are used to increase the contrast between the background image and the object under study. It follows the completion of the segmentation of the image, using algorithms for binarization and region growing. The second step is performed for the classification of pixels into color groups predefined by using Artificial Neural Networks trained with the Backpropagation algorithm. At this stage several neural networks are trained and tested to classify pixels into five classes of different colors. The interpretation of these colors in the third step is accomplished through the use of fuzzy techniques.

Neste trabalho foi proposto um método e desenvolvido um protótipo para analisar imagens de microscopia de fluorescência obtidas a partir do teste FTA-ABS. Este teste é utilizado como comprovação do diagnóstico da sífilis por meio da identificação da bactéria causadora da doença. Um problema considerável na análise de tais imagens é a subjetividade na interpretação da intensidade de fluorescência apresentada, pois não existe uma descrição formal desse valor, outra dificuldade encontrada trata do baixo contraste entre o objeto de estudo e o fundo da imagem e finalmente a distribuição da fluorescência sobre as bactérias não é uniforme. O método proposto para auxiliar no diagnóstico por meio de análise de imagem consiste de três etapas. A primeira etapa é a de processamento das imagens. Para tal são utilizados algoritmos para aumentar o contraste entre o fundo da imagem e o objeto em estudo. Segue-se a realização da segmentação da imagem, utilizando-se algoritmos de binarização e crescimento de regiões. A segunda etapa realizada é a de classificação de pixels em grupos de cores pré- definidas por meio da utilização de Redes Neurais Artificiais treinadas com o algoritmo Backpropagation. Nesta etapa são treinadas e testadas diversas redes. De posse de todos os pixels classificados realiza-se a interpretação do diagnóstico por meio de técnicas fuzzy. / In this work we have developed a prototype to analyze fluorescence microscopy images obtained from the FTA-ABS. This test is used as confirmation of the diagnosis of syphilis by identifying the bacteria causing the disease. A considerable problem in the analysis of such images is the subjectivity in the interpretation of fluorescence intensity shown, because there is not a formal description of this value, another difficulty is the low contrast between the object of study and the background and finally the distribution of fluorescence on bacteria is not uniform. The proposed methodology for the diagnosis by means of image analysis consists of three stages. The first step is to image processing. For such algorithms are used to increase the contrast between the background image and the object under study. It follows the completion of the segmentation of the image, using algorithms for binarization and region growing. The second step is performed for the classification of pixels into color groups predefined by using Artificial Neural Networks trained with the Backpropagation algorithm. At this stage several neural networks are trained and tested to classify pixels into five classes of different colors. The interpretation of these colors in the third step is accomplished through the use of fuzzy techniques.

No description available.

Cavitation has been known for a long time to cause damages in spillways athydropower plants, aerators are therefore often implemented to prevent this.The majority of the hydropower plants in Sweden are installed in the northernpart of the country. In this environment, construction details like vents areexposed to rain, snow, leaves, and other difficult nature conditions for a majorpart of the year. It is therefore of interest to see what will happen if the ventsare sealed.Similar experiments have earlier been investigated at Vattenfall AB, oneof the largest energy companies in Sweden. The investigation consists ofcase studies with multiple variables, closed and open vents, low and highwater levels. The calculations are done with help from computational fluiddynamics and the goal is to see how parameters such as pressure, spreading,and horizontal length change when the aerator is sealed compared to open.The calculations were also carried out in a way so tests in the future can bedone by Vattenfall to validate the results from the computational simulations.The geometry of the hydropower plant is taken from a plant in Skellefteälvenin northern Sweden.

In this thesis, computational aerodynamics, structural and aeroelastic analyses of the composite tactical unmanned air vehicle which is designed and manufactured in the Department of Aerospace Engineering are performed. Verification of the structural integrity of the air vehicle is shown at the minimum maneuvering and the dive speeds at the static limit loads which are calculated by the computational aerodynamics analysis of the full aircraft model. In the current work, aerodynamic loads are re-calculated for more accurately determined dive speed angle of attack in an effort to match the overall vertical pressure load more closely to the half of the aircraft weight at the positive load factor. Finite element models of the fuselage, wing and the vertical-horizontal tail plane are prepared including the filament wound boom connecting the wing and the tail plane. Structural analyses of the composite wing, vertical and horizontal tail plane are performed under the limit aerodynamic loads calculated at the corner points of the V-N diagram using the structural finite element model of the wing-tail plane combination only. Global finite element analysis of the wing-tail plane combination showed that composite and isotropic materials of the wing-tail plane combination have positive margins of safety. Woven carbon and E-glass fabric that was procured to be used for the serial production version of the airplane are characterized for the tensile properties by the tests. Comprehensive aeroelastic stability analyses of the airplane are conducted by adding one sub-structure at a time to the aeroelastic model. Specifically, aeroelastic models which are used are the wing only, wing-tail plane combination, complete air vehicle with and without wing control surfaces. With such a study it is intended to address the effect each sub-structure adds to the aeroelastic model on the critical aeroelastic stability modes and speeds, and to see how sensitive the aeroelastic stability modes and speeds are to model fidelity. Detailed structural and aeroelastic analyses showed that the airplane has sufficient structural integrity under the action of static limit loads, and no aeroelastic instability is expected to occur within the flight envelope of the airplane.

Ce travail de thèse est consacré à l'étude numérique de la forme instationnaire des équations de Navier--Stokes incompressibles en dimension trois d'espace. Ces équations sont étudiées dans leur formulation classique mais aussi dans leur formulation hydrostatique. Le schéma en temps est résolu à l'aide d'une méthode de projection, la méthode de projection incrémentale standard qui sert de référence à l'étude numérique des nouvelles méthodes proposées: la méthode de projection hydrostatique et la méthode de projection dynamique étendue. Ces méthodes sont combinées à la méthode de pénalisation de volume qui permet de tenir compte de la présence d'obstacles de forme quelconque dans le domaine de simulation en utilisant un maillage cartésien. Une nouvelle expression des équations de Navier--Stokes hydrostatiques issue de l'application de la méthode de pénalisation de volume est obtenue et étudiée. La discrétisation en espace s'effectue en utilisant la méthode des volumes finis sur une maillage décalé de type MAC. Un nouveau code de calcul baptisé VivAn'O a été conçu et validé durant ce travail. Il a permis l'étude numérique des différentes méthodes proposées et a également permis de réaliser des simulations dans la zone portuaire de Pointe-à-Pitre à partir de données bathymétriques réelles. / The present work is about the numerical study of the three dimensional form of the unstationnary Navier--Stokesequations. These equations are studied under their classical form but also under their hydrostatic one. Thetime--dependent problem is solved using a projection method called the standard incremental projection method which isused as the reference to the numerical study of the new projection methods we proposed : the hydrostatic projectionmethod and the extended dynamical projection method. These methods are combined with a volume penalization methodto take into account obstacles of any shape in the simulation domain using cartesian meshes. A new formulation of the hydrostatic Navier--Stokes equations is obtained from the use of the penalization method and studied. The space isdiscretized using the finite volume method on a staggered MAC mesh.A new computational fluid dynamic code nammed VivAn'O have been developped during this work. It had permitted thenumerical study of the proposed methods. It was also used to carry out simulations in the harbour area of Pointe--à--Pitre usine real bathvmetric data.

FAD * for Stadsgårdskajen Re-introduction of some of the knowledge from the master builder to the contemporary architect. This project investigates the interaction between designing architecture and building architecture in a computer controlled context. Algorithms have been developed to simulate and control an automated in situ brick stacking process. Brick laying is a well researched topic for robotic processes. It is an ideal material for building with robots (in Stockholm) since it is a generic building block that is cheap and easy to produce locally. Corbeled vaults, instead of keystone vaults, can be built without support and with all identical elements and are therefore also suitable for robotic fabrication.  The algorithms have been incorporated in a parametric model that have been used to develop public building at Stadsgårdskajen, Stockholm. FAD is about creating and explore a different architectural expression as well as reintroducing the brick as a relevant construction material for Stockholm. / FAD* för Stadsgårdskajen Återinförande av några av byggmästarens förmågor till den samtida arkitekten I detta examensarbete undersöks förhållandet mellan att designa arkitektur och att bygga arkitektur i en datorkontrollerad miljö. Algoritmer har utarbetats för att simulera och styra en automatiserad in situ murningsprocess. Inom fabrikation och automatisering med industrirobotar är tegelband ett välundersökt ämne. Tegel är ett idealiskt material vid byggande med robotar. Det är enkelt och billigt att framställa och tegel som byggkloss är en lämplig typologi för addativ fabrikation med robotar. Valv byggda genom utkragning istället för traditionella valvbågar kan byggas utan stöd och med identiska element. Därför är denna byggnadsteknik även lämplig för additiv fabrikation med robotoar. Algoritmerna har intergrerats i en parametrisk modell som har använts för att formge en offentlig byggnad på Stadsgårdskajen i Stockholm. FAD handlar såväl om skapande och utforskande av ett nytt arkitekturspråk som av återinförande av tegel som ett betydelsefullt konstruktionsmaterial i Stockholm.

Intresset för datajournalistik har ökat både på redaktionerna och inom forskningen det senaste decenniet i takt med att tillgången på data har ökat och därmed behovet av att kunna hitta nyheter och berätta med hjälp av data. De flesta tidigare studier om datajournalistik har utgjorts av intervjuer med verksamma datajournalister och bland annat undersökt olika ideal. Men det finns få kvantitativa studier av vad datajournalisterna faktiskt gör, och av svensk datajournalistik. Den här uppsatsen syftar till att med innehållsanalytiska metoder beskriva och analysera datajournalistik som publicerats i svenska medier de senaste fem åren, och som journalister själva lyfter fram som exempel på datajournalistik. Urvalet är 91 datajournalistiska projekt som lämnats in som bidrag till NODA (Nordic Data Journalism Awards) eller som publicerats i Facebookgruppen Datajournalistik mellan 2013 och 2017. Ur en genomgång av tidigare forskning om datajournalistik har fyra olika ideal identifierats: ett undersökande, ett vetenskapligt, ett entreprenöriellt och ett från hackerkulturen, vilka utgör grunden för en analysmodell. Dessutom undersöks vilka producenterna är, vilka ämnen som är vanligast, vilka metoder och datakällor som används och hur publiken inbjuds att ta del av data och att vara delaktiga utifrån teorier om interaktivitet. Resultatet visar att datajournalistiken i denna undersökning ofta bygger på unika data, det vill säga självständig research, och att det undersökande idealet är relativt starkt. Trots att datajournalistik sägs präglas av hackerkulturens ideal om samarbete och deltagande är det ofta få producenter och yrkesroller bakom varje publicering och publiken bjuds sällan in att delta i processen.

Efeitos de solventes tem sido um tema de grande interesse científco. Em particular, o estudo dos efeitos de solventes no espectro eletrônico de absorção tem sua própria motivação e complexidade. Neste trabalho, nós estudamos os efeitos da solução aquosa na estabilidade conformacional e no espectro eletrônico de absorção da molécula Óxido Mesitil (OM). Essa molécula pertence a família das cetonas ,-insaturadas e, semelhantemente aos outros membros da família, ela apresenta transições eletrônicas sensíveis ao solvente. Inicialmente, estudamos os isômeros syn e anti do OM isoladamente usando cálculos quânticos para determinar a energia livre relativa, a barreira de rotação, os momentos de dipolo e as transições eletrônicas de absorção. Nosso melhor resultado mostra que o isômero syn do OM é a conformação mais estável, por cerca de 1.3 kcal/- mol calculado com nível MP2/aug-cc-pVDZ. Com o mesmo nível de cálculo, obtivemos os momentos de dipolo de 2.80 e 3.97 D para os isômeros syn e anti respectivamente, que estão em boa concordância com os valores experimentais de 2.8 e 3.7 D. Para o espectro eletrônico de absorção, analisamos a banda mais intensa, -*, com diferentes funcionais de densidade e funções base. Obtivemos o comprimento de transição de 229 nm calculado com nível TD-B3LYP/6-311++G** para o isômero syn em muito boa concordância com o valor experimental de 231 nm medido em solução de iso-octano (solvente de baixa polaridade). Para realizar os estudos em solução, geramos estruturas supermoleculares dos isômeros do OM em solução aquosa usando simulações computacionais com o método Monte Carlo. Usamos os potenciais Lennard-Jones e Coulomb para descrever as interações intermoleculares com os parâmetros do campo de força OPLS. Verifcamos que as cargas atômicas OPLS não descrevem bem o potencial eletrostático do OM. Portanto, realizamos um processo iterativo para incluir a polarização do soluto na presença do solvente para descrever melhor as interações entre o OM e as moléculas de água. Assim, obtivemos um aumento de cerca de 80% nos momentos de dipolo dos isômeros isolados. Adicionalmente, calculamos a energia livre relativa entre os isômeros em solução aquosa usando teoria de perturbação termodinâmica. Obtivemos que o isômero anti do OM é a conformação mais estável, por cerca de 2.8 kcal/mol. Examinando os efeitos de solvente no espectro eletrônico de absorção do OM, identificamos que existem duas contribuições competindo para o deslocamento da banda -*. Uma contribuição vem da mudança conformacional syn anti do OM devido a mudança de polaridade, baixa alta, do solvente. Essa mudança conformacional provoca um deslocamento para o azul de 1210 cm-1 na transição -*. A outra contribuição vem do efeito do solvente na estrutura eletrônica do OM, que provoca um deslocamento para o vermelho de - 4460 cm-1 nessa transição. Adicionando essas duas contribuições, temos o efeito do solvente total no espectro eletrônico de absorção do OM em solução aquosa. Nosso melhor resultado é um valor médio de 248 nm obtido com 75 cálculos TD-B3LYP/6-311++G** de estruturas supermoleculares estatisticamente descorrelacionadas compostas por um anti-OM rodeado por 14 moléculas de água explícitas embebidas no campo eletrostático de 236 moléculas de água tratadas como cargas pontuais simples. Esse resultado está em muito boa concordância com o resultado experimental de 243 nm em solução aquosa. Sendo assim, este trabalho demonstra que a mudança conformacional syn anti é essencial para entender o deslocamento espectral da transição -* do OM em água. / Solvent effects have been the subject of considerable scientifc interest. In particular, the study of solvent effects in electronic absorption spectroscopy has its own motivation and complexities. In this work we study the effects of the aqueous solution in the conformational stability and the electronic absorption spectrum of the Mesityl Oxide (OM) molecule. This molecule belongs to the family of the ,-unsaturated ketones and, like other members of the family, presents sensitivity to solvent in the absorption transitions. Initially we studied the isolated syn and anti isomers of OM by performing quantum mechanical calculations to obtain the relative free energy, the rotational barrier, the dipole moments and the electronic absorption transitions. Our best result showed that the OM syn isomer is the most stable conformer, by approximately 1.3 kcal/mol calculated with the MP2/aug-cc-pVDZ level. With the same level of calculation, we obtained the dipole moments of 2.80 and 3.97 D for the syn and anti isomers respectively, which are in good agreement with the experimental values of 2.8 and 3.7 D. For the electronic absorption spectrum, we analyzed the most intense band, -*, with different density functional and basis sets. We obtained a transition wavelength of 229 nm calculated with TD-B3LYP/6-311++G** level for the syn isomer in good agreement with the experimental value of 231 nm measured in iso-octane (solvent of low polarity). For performing the in-solution studies, we generated supermolecular structures of the OM isomers in aqueous solution using computer simulations with the Monte Carlo method. We used the Lennard-Jones and Coulomb potentials to describe the intermolecular interactions with the OPLS force field parameters. We found that the OPLS atomic charges do not describe well the electrostatic potential of OM. Therefore we performed an iterative process for including the solute polarization in the presence of the solvent to better describe the interactions between the OM and the water molecules. We obtained an increase of about 80% in the dipole moments of the isolated isomers. Additionally, we calculated the relative free energy between the isomers in aqueous solution using thermodynamic perturbation theory. We found that the anti isomer is the most stable conformer in aqueous solution, by about 2.8 kcal/mol. Examining the solvent effects in the electronic absorption spectrum of OM, we found that there are two competing contributions to the -* band shift. One contribution is due to the syn anti conformational change of OM caused by the low high polarity change of the solvent. This conformational change led to a blue shift of 1210 cm-1 in the * band. The remaining contribution is due to the solvent effect in the electronic structure of OM, which led to a red shift of -4460 cm-1. Adding these two contributions, we obtained the total solvent effect in the electronic absorption spectrum of OM in aqueous solution. Our best result was an average wavelength transition of 248 nm obtained using 75 TD-B3LYP/6-311++G** quantum calculations on statistically uncorrelated supermolecular structures composed by one anti-OM surrounded by 14 explicit water molecules in the electrostatic embedding composed of 236 water molecules described as simple point charges. This result is in very good agreement with the experimental result of 243 nm in aqueous solution. Thus, this work demonstrates that the syn anti conformational change is the essential ingredient to understand the spectral shift of the - * absorption transition of OM in water.