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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Först maten, sedan moralen : Kultur- och bildningsideal inom tidningen Social-Demokraten 1886

Esbjörnson, Alfred January 2015 (has links)
In the autumn of 1886 the editor in chief of the Swedish social democratic newspaper Social-Demokraten August Palm resigns and Hjalmar Branting takes over as editor in chief. This will lead toa shift how the newspaper writes about culture and general education (bildning in Swedish, after theGerman term Bildung which lacks an English equivalent). August Palm’s resignation and the shift inthe content of the newspaper is in many ways the culmination of an internal struggle within the earlysocial democratic labour movement where one side claims that culture and general education shouldbe made available to all, including workers, and that doing so will lead to the eventual transformationof society. The other side claims that the working class should indeed be granted access to culture andgeneral education, but first an economic transformation must occur. The dispute is over causality, thetwo sides in the conflict have different opinions as to whether the economic transformation of societywill happen before or after culture and general education is made available to the working masses. Inthis study I have shown how these two positions were not as clearly defined or as clearly opposed toeach other as they have sometimes been portrayed in earlier research. As I have shown, there was infact agreement on the basic goal that culture and general education ought to be something thateveryone can enjoy despite there being differing opinions as to how society might get there.
2

Faktorers påverkan på bostadsbränder : En statistisk analys

Nyström, Felix, Humbla, Christian January 2018 (has links)
Sveriges räddningstjänster åker på cirka 6000 bostadsbränder varje år. Var och en av dessa 6000 insatser är unika och att veta vilken åtgärd som är effektivast vid respektive scenario är oavsett en gedigen kunskapsgrund väldigt svårt. Detta arbete vill genom statistisk analys, försöka kartlägga dessa åtgärder och dess effektivitet och därmed försöka besvara vilka åtgärder som är framgångsrika vid en räddningsinsats samt vilka taktiska upplägg som fungerat bäst i respektive scenario.     För att besvara frågeställningarna genomfördes en litteraturstudie av tidigare forskning inom området, vilket följdes av en utrensning och sammanställning av materialet utifrån några utvalda kriterier. Utfall för en insats kategoriserades enligt grönt, gult och rött. Fortsättningsvis genomfördes en indelning enligt bostadskategorierna villa, flerbostadshus, rad-/ par-/ kedjehus och fritidshus. Resultatet framställdes sedan genom ordinal regression med Stata, ett program för hantering av statistik.   Resultatet gav att samtliga variabler i de modeller som framställts hade en negativ påverkan på den genomsnittliga sannolikheten för att en insats ska få ett grönt utfall. Dessa variabler hade också en ökande påverkan av den genomsnittliga sannolikheten för en insats med gult eller rött utfall. För villor hade släckning från marken en markant påverkan på utfallen, medan åtgärden skärsläckare var den åtgärd som hade minst påverkan. För flerbostadshus gav åtgärderna dimspik, skärsläckare och håltagning en stor påverkan på de olika utfallen. I rad-/ par-/ kedjehus samt fritidshus hade ett fåtal variabler signifikans, vilket gav ett osäkert resultat.   Vid analys av resultatet visade sig skärsläckare ha den minsta negativa påverkan på utfallet och släckning från marken ha den största negativa påverkan på utfallet vid en räddningsinsats för bostadskategorin villor. De samband som kunde kartläggas gällande flerbostadshus var att de åtgärder som tillsattes vid en stor brandomfattning hade ett sämre utfall än de åtgärder som tillsattes i ett tidigare läge. För rad-/ par-/ kedjehus kunde ett osäkert samband dras där insatser med åtgärden dimspik hade ett marginellt bättre utfall än de insatser som använde åtgärden släckning från marken. Även för fritidshus gavs ett osäkert resultat med endast släckning från marken som förklarande variabel. För villa och flerbostadshus skiljer sig variablernas påverkan av utfallet tydligt och detta beror på att åtkomligheten för dessa bostäder kan variera. Vid flerbostadshus finns det svårigheter att angripa en brand på ett effektivt sätt. Den begränsade statistiken för rad-/ par-/ kedjehus och fritidshus är en förklaring varför signifikansen för majoriteten av variablerna var låg och inte kunde användas på samma sätt som de andra bostadskategorierna. För dessa kategorier kunde ingen säker slutsats dras.
3

Efficient sequential learning in structured and constrained environments / Apprentissage séquentiel efficace dans des environnements structurés avec contraintes

Calandriello, Daniele 18 December 2017 (has links)
L'avantage principal des méthodes d'apprentissage non-paramétriques réside dans le fait que la nombre de degrés de libertés du modèle appris s'adapte automatiquement au nombre d'échantillons. Ces méthodes sont cependant limitées par le "fléau de la kernelisation": apprendre le modèle requière dans un premier temps de construire une matrice de similitude entre tous les échantillons. La complexité est alors quadratique en temps et espace, ce qui s'avère rapidement trop coûteux pour les jeux de données de grande dimension. Cependant, la dimension "effective" d'un jeu de donnée est bien souvent beaucoup plus petite que le nombre d'échantillons lui-même. Il est alors possible de substituer le jeu de donnée réel par un jeu de données de taille réduite (appelé "dictionnaire") composé exclusivement d'échantillons informatifs. Malheureusement, les méthodes avec garanties théoriques utilisant des dictionnaires comme "Ridge Leverage Score" (RLS) ont aussi une complexité quadratique. Dans cette thèse nous présentons une nouvelle méthode d'échantillonage RLS qui met à jour le dictionnaire séquentiellement en ne comparant chaque nouvel échantillon qu'avec le dictionnaire actuel, et non avec l'ensemble des échantillons passés. Nous montrons que la taille de tous les dictionnaires ainsi construits est de l'ordre de la dimension effective du jeu de données final, garantissant ainsi une complexité en temps et espace à chaque étape indépendante du nombre total d'échantillons. Cette méthode présente l’avantage de pouvoir être parallélisée. Enfin, nous montrons que de nombreux problèmes d'apprentissage non-paramétriques peuvent être résolus de manière approchée grâce à notre méthode. / The main advantage of non-parametric models is that the accuracy of the model (degrees of freedom) adapts to the number of samples. The main drawback is the so-called "curse of kernelization": to learn the model we must first compute a similarity matrix among all samples, which requires quadratic space and time and is unfeasible for large datasets. Nonetheless the underlying effective dimension (effective d.o.f.) of the dataset is often much smaller than its size, and we can replace the dataset with a subset (dictionary) of highly informative samples. Unfortunately, fast data-oblivious selection methods (e.g., uniform sampling) almost always discard useful information, while data-adaptive methods that provably construct an accurate dictionary, such as ridge leverage score (RLS) sampling, have a quadratic time/space cost. In this thesis we introduce a new single-pass streaming RLS sampling approach that sequentially construct the dictionary, where each step compares a new sample only with the current intermediate dictionary and not all past samples. We prove that the size of all intermediate dictionaries scales only with the effective dimension of the dataset, and therefore guarantee a per-step time and space complexity independent from the number of samples. This reduces the overall time required to construct provably accurate dictionaries from quadratic to near-linear, or even logarithmic when parallelized. Finally, for many non-parametric learning problems (e.g., K-PCA, graph SSL, online kernel learning) we we show that we can can use the generated dictionaries to compute approximate solutions in near-linear that are both provably accurate and empirically competitive.
4

Formulation and Solution of Electromagnetic Integral Equations Using Constraint-Based Helmholtz Decompositions

Cheng, Jin 01 January 2012 (has links)
This dissertation develops surface integral equations using constraint-based Helmholtz decompositions for electromagnetic modeling. This new approach is applied to the electric field integral equation (EFIE), and it incorporates a Helmholtz decomposition (HD) of the current. For this reason, the new formulation is referred to as the EFIE-hd. The HD of the current is accomplished herein via appropriate surface integral constraints, and leads to a stable linear system. This strategy provides accurate solutions for the electric and magnetic fields at both high and low frequencies, it allows for the use of a locally corrected Nyström (LCN) discretization method for the resulting formulation, it is compatible with the local global solution framework, and it can be used with non-conformal meshes. To address large-scale and complex electromagnetic problems, an overlapped localizing local-global (OL-LOGOS) factorization is used to factorize the system matrix obtained from an LCN discretization of the augmented EFIE (AEFIE). The OL-LOGOS algorithm provides good asymptotic performance and error control when used with the AEFIE. This application is used to demonstrate the importance of using a well-conditioned formulation to obtain efficient performance from the factorization algorithm.
5

HIGH-ORDER INTEGRAL EQUATION METHODS FOR QUASI-MAGNETOSTATIC AND CORROSION-RELATED FIELD ANALYSIS WITH MARITIME APPLICATIONS

Pfeiffer, Robert 01 January 2018 (has links)
This dissertation presents techniques for high-order simulation of electromagnetic fields, particularly for problems involving ships with ferromagnetic hulls and active corrosion-protection systems. A set of numerically constrained hexahedral basis functions for volume integral equation discretization is presented in a method-of-moments context. Test simulations demonstrate the accuracy achievable with these functions as well as the improvement brought about in system conditioning when compared to other basis sets. A general method for converting between a locally-corrected Nyström discretization of an integral equation and a method-of-moments discretization is presented next. Several problems involving conducting and magnetic-conducting materials are solved to verify the accuracy of the method and to illustrate both the reduction in number of unknowns and the effect of the numerically constrained bases on the conditioning of the converted matrix. Finally, a surface integral equation derived from Laplace’s equation is discretized using the locally-corrected Nyström method in order to calculate the electric fields created by impressed-current corrosion protection systems. An iterative technique is presented for handling nonlinear boundary conditions. In addition we examine different approaches for calculating the magnetic field radiated by the corrosion protection system. Numerical tests show the accuracy achievable by higher-order discretizations, validate the iterative technique presented. Various methods for magnetic field calculation are also applied to basic test cases.
6

Numerické řešení Fredholmovy integrální rovnice druhého druhu související s indukčním ohřevem / Numerical Solution of a Fredholm Integral Equation of the Second Kind Related to Induction Heating

Rak, Josef January 2012 (has links)
This thesis deals with numerical solution of an integral equation of the second kind with special singular kernel function related to induction heating. The numerical solution is based on collocation and Nyström methods. The idea of collocation methods is to choose a finite-dimensional space of candidate solutions (usually polynomials up to a certain degree). The Nyström methods are based on approximation of the integral in equation by numerical integration rule. This thesis describes and gives error estimates of both methods. Error estimates are compared to the exact solutions in simple cases.
7

Utvärdering av processtyrning vid tillverkning av gasturbiner : En fallstudie på Siemens Industrial Turbomachinery AB, Finspång

Stenbäck Juhrich, Albert, Nyström, Daniel January 2020 (has links)
Denna rapport är ett resultat av utförd fallstudie på Siemens Industrial Turbomachinery AB. Studien utfördes som ett DMAIC-projekt i syfte att utvärdera befintlig processtyrning och ge förslag på nya styrparametrar för att styra och övervaka tillverkningsprocessen av rotorer. En rotor skapas genom montage av turbinmodul på kompressorrotor. För att säkerställa rotorns funktionalitet mäts rotorkast kontinuerligt under tillverkningprocessen. Stora rotorkast uppstår sporadiskt vid montaget varpå nuvarande avhjälpningsmetod  innefattar tids- och kostnadskrävande demontage och återmontage av turbinmodul på kompressorrotor.  Rekommendationer har utformats och baserats utifrån historiskt analyserad data, insamlad mellan åren 2013 och 2020, 19 intervjuer och 2 workshops. Rekommendationer innefattar implementering av statistisk processtyrning. Ett av argumenten till implementeringen är att börja utvärdera effekten av genomförda förbättringsprojekt. Denna studie identifierade ett förbättringsprojekt, genomfört år 2016, som ökade andelen defekter med 454%. Då förbättringsprojektet tros bidragit med en förbättring i ett annat processteg ges rekommendationen att utvärdera helheten av implementerad förbättringsåtgärd. Avslutningsvis rekommenderas att uppdatera dagens bristfälliga processtyrning genom beräknandet av nya toleranser baserat på önskad kvalitetsnivå och eliminera diskrepanserna mellan de idag använda toleranserna. / This report is a result of a case study carried out at Siemens Industrial Turbomachinery AB. The study was conducted as a DMAIC project with the aim of evaluating existing process control and proposing new control parameters for controlling and monitoring the manufacturing pro- cess of rotors. A rotor is created by the assembly of a turbine module on a compressor rotor. In order to ensure the functionality of the rotor, rotor-runout is continuously measured during the manufacturing process. Large rotor-runouts occur sporadically during assembly and the current method to fix the abnormalities includes time- and costly disassembly and re-assembly of the turbine module on the compressor rotor. Recommendations have been designed after analysis of historical data collected between 2013 and 2020, 19 interviews and 2 workshops. Recom- mendations include implementation of statistical process control. One of the arguments for the implementation is to start evaluating the effects of completed improvement projects. This study identified an improvement project, completed in 2016, which increased the proportion of defects by 454%. Since the improvement project is believed to have contributed to an enhancement in another part of the process, a more holistic way of evaluation is needed to follow up effects of improvements projects. Finally, it is recommended to update the tolerances by calculating new ones based on the desired quality level while also eliminating the discrepancies between the different tolerances used today.
8

A computational model for the diffusion coefficients of DNA with applications

Li, Jun, 1977- 07 October 2010 (has links)
The sequence-dependent curvature and flexibility of DNA is critical for many biochemically important processes. However, few experimental methods are available for directly probing these properties at the base-pair level. One promising way to predict these properties as a function of sequence is to model DNA with a set of base-pair parameters that describe the local stacking of the different possible base-pair step combinations. In this dissertation research, we develop and study a computational model for predicting the diffusion coefficients of short, relatively rigid DNA fragments from the sequence and the base-pair parameters. We focus on diffusion coefficients because various experimental methods have been developed to measure them. Moreover, these coefficients can also be computed numerically from the Stokes equations based on the three-dimensional shape of the macromolecule. By comparing the predicted diffusion coefficients with experimental measurements, we can potentially obtain refined estimates of various base-pair parameters for DNA. Our proposed model consists of three sub-models. First, we consider the geometric model of DNA, which is sequence-dependent and controlled by a set of base-pair parameters. We introduce a set of new base-pair parameters, which are convenient for computation and lead to a precise geometric interpretation. Initial estimates for these parameters are adapted from crystallographic data. With these parameters, we can translate a DNA sequence into a curved tube of uniform radius with hemispherical end caps, which approximates the effective hydrated surface of the molecule. Second, we consider the solvent model, which captures the hydrodynamic properties of DNA based on its geometric shape. We show that the Stokes equations are the leading-order, time-averaged equations in the particle body frame assuming that the Reynolds number is small. We propose an efficient boundary element method with a priori error estimates for the solution of the exterior Stokes equations. Lastly, we consider the diffusion model, which relates our computed results from the solvent model to relevant measurements from various experimental methods. We study the diffusive dynamics of rigid particles of arbitrary shape which often involves arbitrary cross- and self-coupling between translational and rotational degrees of freedom. We use scaling and perturbation analysis to characterize the dynamics at time scales relevant to different classic experimental methods and identify the corresponding diffusion coefficients. In the end, we give rigorous proofs for the convergence of our numerical scheme and show numerical evidence to support the validity of our proposed models by making comparisons with experimental data. / text
9

Técnicas secuenciales y paralelas para la resolución de problemas computacionales en electromagnetismo

Vidal Pantaleoni, Ana 08 July 2013 (has links)
La mejora en términos de e¿ciencia en problemas de análisis de dispositivos pasivos de microondas y la dispersión de objetos es un tema de creciente interés. Pese a que el avance de la tecnología de computadores permite la ejecución de programas muy complejos, la e¿ciencia computacional sigue siendo importante debido a la tendencia de aumentar la frecuencia de trabajo en los citados problemas electromagné- ticos. En esta tesis se recogen una serie de herramientas para la mejora de la e¿ciencia de técnicas de análisis electromagnético en espacio abierto y cerrado mediante una recopilación de artículos indexados en prensa cientí¿ca, que se presentan de forma razonada. En primer lugar se aplica la transformada Wavelet en al análisis de dispersores cilíndricos mediante la técnica de la Ecuación Integral. Posteriormente se introducen distintas técnicas de discretización, así como rutinas de solución de problemas de autovalores y autovectores adaptadas a la estructura matricial y al procesado en paralelo en el entorno del análisis de dispositivos cerrados. En concreto, dichas técnicas se han aplicado al método denominado Boundary Integral Resonant Mode Expansion (BI-RME) en el dominio bidimensional. Este método realiza una expansión modal de una guía de ondas arbitraria en función de los modos correspondientes a una guía canónica de referencia. Finalmente se han introducido mejoras en la técnica BI-RME aplicada en entornos tridimensionales para el análisis de cavidades con geometría arbitraria. El objetivo en todos los casos consiste en obtener una mejora del tiempo de cálculo y en la memoria requerida, sin perder precisión en gran medida. Todo este trabajo se ha integrado en un software comercial existente, que se emplea actualmente en el diseño y la caracterización de dispositivos pasivos de microondas utilizados en aplicaciones espaciales. / Vidal Pantaleoni, A. (2013). Técnicas secuenciales y paralelas para la resolución de problemas computacionales en electromagnetismo [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/30776 / TESIS
10

To portray the beautiful, exotic and feminine land of cheap export : How Sweden imagined Japan during Japonism, from 1858 to 1914

Ingemarsson, Hugo January 2021 (has links)
This master thesis explores the image of Japan in the artistic creations during Japonism in Sweden. Japan and Sweden first started trading in 1868 and knowledge about Japan in Sweden were limited at best. With the emergence of the Western art movement known as Japonism, ranging from 1858 to 1914, fascination for the unknown country grew in Europe. As the art movement Japonism became the first era of interest of Japan in Sweden, the portrayal and subsequent image of the country that emerged during this time is of interest to examine, as to better understand how Japan was imagined by Sweden. Herein, this study aims to analyse the portrayal of Japan in artworks from Swedish artists during Japonism in order to examine what components and ideas composed the image of Japan conveyed during Japonism. A collection of visual artworks depicting Japanese elements, based on Japonism associated artists and creators, have been collected using digital archives and databases to assess what is depicted and how by the creators. Japanese elements, such as objects, clothes, people and landscapes were subsequently analysed using a visual analysis based on researcher Jules David Prown’s three-step method of analysing historical objects. Using the concept of the image, as defined by scholar Torsten Burgman, as the basis of the analysis the depictions of Japanese elements are examined and categorised into several larger and smaller components. The examination is conducted within a framework of ethnocentrism and orientalism to contextualise the image of Japan with the thought structures in 19th century Sweden, as the creators portrayed Japan from both a Swedish and Western Eurocentric colonial perspective. As the source material is artistic depictions, an additional aesthetic framework was applied to contextualise the image of Japan with its artistic medium. Four major image components were found in the material: Japan presented as a commodity; Japanese things as something feminine; Japan as something faraway and exotic, contrasting the West; and Japan as a reference or commentary on the ongoing Japonism movement. The image of Japan found in these depictions of Swedish Japonism was a Eurocentric and ethnocentric understanding of the country. Japan and Japanese things, were imagined as something exotic and beautiful, and usually conveyed as exotic commercial flair for Western women.

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