No description available.

No description available.

Anthropometric test devices (ATDs), commonly referred to as crash test dummies, are tools used to conduct aerospace and spaceflight safety evaluations. Finite element (FE) analysis provides an effective complement to these evaluations. In this work a FE model of the Test Device for Human Occupant Restraint (THOR) dummy was developed, calibrated, and validated for use in aerospace and spaceflight impact analysis. A previously developed THOR FE model was first evaluated under spinal loading. The FE model was then updated to reflect recent updates made to the THOR dummy. A novel calibration methodology was developed to improve both kinematic and kinetic responses of the updated model in various THOR dummy certification tests. The updated THOR FE model was then calibrated and validated under spaceflight loading conditions and used to asses THOR dummy biofidelity. Results demonstrate that the FE model performs well under spinal loading and predicts injury criteria values close to those recorded in testing. Material parameter optimization of the updated model was shown to greatly improve its response. The validated THOR-FE model indicated good dummy biofidelity relative to human volunteer data under spinal loading, but limited biofidelity under frontal loading. The calibration methodology developed in this work is proven as an effective tool for improving dummy model response. Results shown by the dummy model developed in this study recommends its use in future aerospace and spaceflight impact simulations. In addition the biofidelity analysis suggests future improvements to the THOR dummy for spaceflight and aerospace analysis. / Master of Science

In this Master Thesis there are summarized basic methods for modelling time series, such as linear regression with seasonal dummy variables, exponential smoothing and SARIMA processes. The thesis is aimed on modelling and forecasting seasonal time series using these methods. Goals of the Thesis are to introduce and compare these methods using a set of 2184 seasonal time series followed by evaluation their prediction abilities. The main benefit of this Master Thesis is understanding of different aspects of forecasting time series and empirical verification of advantages and disadvantages these methods in field of creating predictions.

Für die Fahrzeugsicherheit und die Bewertung von Fahrzeugstrukturen spielt die Entwicklung von Crashtest-Dummys eine zentrale Rolle. Diese menschenähnlichen Puppen werden bei Crashtests eingesetzt, um die Auswirkungen von Kollisionen auf den Körper zu untersuchen. Der Stand des Wissens zeigt, dass aktuelle Crashtest-Dummys nach dem Prinzip der Ermittlung von physikalischen Belastungsgrößen arbeiten. Die komplexe Verletzungsentstehung infolge von Verkehrsunfällen lässt sich damit nicht vollständig darstellen. Ziel dieser Arbeit ist die Entwicklung, Konstruktion und Erprobung eines neuartigen Dummys mit biofidelen Eigenschaften zur Darstellung komplexer Verletzungen. Es wird ein Konzept entwickelt, mit dem Verletzungen durch Materialschäden direkt am Dummy dargestellt werden können. Die Konstruktion des biofidelen Dummys orientiert sich an der menschlichen Anatomie und Trauma-Biomechanik. Mit der Auswahl unterschiedlicher Werkstoffe wird ein Dummy gefertigt, der viele komplexe Verletzungen direkt darstellt. Im Rahmen dieser Arbeit wurde der biofidele Dummy in Schlittenversuchen und Crashtests untersucht. Die erfolgreiche Validierung des biofidelen Dummys zeigt, dass es möglich ist, eine Korrelation zwischen Materialschäden am Dummy und menschlichen Verletzungen herzuleiten.

Este trabalho visa implementar o planejamento tridimensional (3D) para tratamentos de braquiterapia ginecológica. Para isto, foram realizados testes de aceite e comissionamento do equipamento de braquiterapia para verificação de suas funções e para estabelecer um programa de garantia da qualidade periódico, assegurando assim a segurança dos pacientes e dos colaboradores. Uma etapa importante de ser realizada foi procurar um material que pudesse ser utilizado como dummy, já que os aplicadores utilizados não possuem dummy específica. Entretanto, somente com o emprego de uma biblioteca de aplicadores foi possível a reconstrução em imagens de ressonância magnética (RM) com a mesma acurácia da obtida em imagens de tomografia computadorizada (TC). Tal ferramenta torna-se assim imprescindível para a utilização clinica da braquiterapia 3D baseada em imagens de RM. Para validar o planejamento 3D realizou-se comparação das doses recebidas em pontos de avaliação de dose (ICRUBexiga, ICRUReto, Ponto Sig) utilizados em planejamento bidimensional (2D) com doses volumétricas (D0,1cc e D2cc) recebidas por órgãos adjacentes ao tumor. A relação média entre D2cc e dose em ICRUBexiga foi 1,74, que é 22% maior que a relação encontrada na literatura. Esta diferença pode ser explicada devido à diferença de volume inserido na bexiga para o planejamento, 50 cc neste estudo contra 200 cc no estudo realizado na literatura. A relação média entre a D2cc e a dose no ponto de reto, 0,85, está de acordo com o valor encontrado na literatura. A dose D2cc foi 69% maior que a dose do ponto de sigmoide utilizado, porém, não foi possível confrontar este valor, pois o ponto de sigmoide utilizado nos procedimentos com planejamento 2D no serviço não é utilizado em outros serviços. O percentual de dose em 2 cc do sigmóide encontrado foi de 57% da dose de prescrição, mesmo valor encontrado na literatura. Este trabalho possibilitou a implementação de um protocolo de braquiterapia de planejamento 3D viável, utilizando-se imagens de RM para primeira fração e imagens de TC para as frações subsequentes. / This work aims to implement the Tridimensional (3D) planning for gynecological brachytherapy treatments. For this purpose, tests of acceptance and commissioning of brachytherapy equipment were performed to establish a quality and periodic assurance program. For this purpose, an important step was searching for a material to be used as a dummy source, since the applicators dont have any specific dummy. In addition, the validation of the use of applicators library was made for reconstruction in computed tomography (CT) and magnetic resonance imaging (MRI). In order to validate 3D planning, comparison of doses in dose assessment points used in bidimensional (2D) plans have been performed with volumetric doses to adjacent organs to the tumor. Finally, a protocol was established for 3D brachytherapy planning alternately using magnetic resonance image (MRI) and CT images, making evaluation of the dose in the tumor through the recording of MR and CT images. It was not possible to find a suitable material that could be used as dummy in MRI. However, the acquisition of the licenses library for the applicators made possible the 3D planning based on MRI. No correlation was found between volumetric and specific doses analyzed, showing the importance of the implementation of 3D planning. The average ratio between D2cc and ICRUBladder dose was 1,74, 22% higher than the ratio found by others authors. For the rectum, D2cc was less than dose point for 60% of fractions; the average difference was 12,5%. The average ratio between D2cc and point dose rectum, 0,85, is equivalent to the value showed by Kim et al, 0,91. The D2cc for sigmoid was 69% higher than point dose used, unless it was not possible compare this value, since the sigmoid point used in the 2D procedures is not used in others institutes. Relative dose in 2 cc of sigmoid was 57% of the prescription dose, the same value was found by in literature. This work enabled the implementation of a viable brachytherapy 3D protocol planning, using MRI for the first fraction of the treatment and CT images for the subsequent fractions.

Este trabalho visa implementar o planejamento tridimensional (3D) para tratamentos de braquiterapia ginecológica. Para isto, foram realizados testes de aceite e comissionamento do equipamento de braquiterapia para verificação de suas funções e para estabelecer um programa de garantia da qualidade periódico, assegurando assim a segurança dos pacientes e dos colaboradores. Uma etapa importante de ser realizada foi procurar um material que pudesse ser utilizado como dummy, já que os aplicadores utilizados não possuem dummy específica. Entretanto, somente com o emprego de uma biblioteca de aplicadores foi possível a reconstrução em imagens de ressonância magnética (RM) com a mesma acurácia da obtida em imagens de tomografia computadorizada (TC). Tal ferramenta torna-se assim imprescindível para a utilização clinica da braquiterapia 3D baseada em imagens de RM. Para validar o planejamento 3D realizou-se comparação das doses recebidas em pontos de avaliação de dose (ICRUBexiga, ICRUReto, Ponto Sig) utilizados em planejamento bidimensional (2D) com doses volumétricas (D0,1cc e D2cc) recebidas por órgãos adjacentes ao tumor. A relação média entre D2cc e dose em ICRUBexiga foi 1,74, que é 22% maior que a relação encontrada na literatura. Esta diferença pode ser explicada devido à diferença de volume inserido na bexiga para o planejamento, 50 cc neste estudo contra 200 cc no estudo realizado na literatura. A relação média entre a D2cc e a dose no ponto de reto, 0,85, está de acordo com o valor encontrado na literatura. A dose D2cc foi 69% maior que a dose do ponto de sigmoide utilizado, porém, não foi possível confrontar este valor, pois o ponto de sigmoide utilizado nos procedimentos com planejamento 2D no serviço não é utilizado em outros serviços. O percentual de dose em 2 cc do sigmóide encontrado foi de 57% da dose de prescrição, mesmo valor encontrado na literatura. Este trabalho possibilitou a implementação de um protocolo de braquiterapia de planejamento 3D viável, utilizando-se imagens de RM para primeira fração e imagens de TC para as frações subsequentes. / This work aims to implement the Tridimensional (3D) planning for gynecological brachytherapy treatments. For this purpose, tests of acceptance and commissioning of brachytherapy equipment were performed to establish a quality and periodic assurance program. For this purpose, an important step was searching for a material to be used as a dummy source, since the applicators dont have any specific dummy. In addition, the validation of the use of applicators library was made for reconstruction in computed tomography (CT) and magnetic resonance imaging (MRI). In order to validate 3D planning, comparison of doses in dose assessment points used in bidimensional (2D) plans have been performed with volumetric doses to adjacent organs to the tumor. Finally, a protocol was established for 3D brachytherapy planning alternately using magnetic resonance image (MRI) and CT images, making evaluation of the dose in the tumor through the recording of MR and CT images. It was not possible to find a suitable material that could be used as dummy in MRI. However, the acquisition of the licenses library for the applicators made possible the 3D planning based on MRI. No correlation was found between volumetric and specific doses analyzed, showing the importance of the implementation of 3D planning. The average ratio between D2cc and ICRUBladder dose was 1,74, 22% higher than the ratio found by others authors. For the rectum, D2cc was less than dose point for 60% of fractions; the average difference was 12,5%. The average ratio between D2cc and point dose rectum, 0,85, is equivalent to the value showed by Kim et al, 0,91. The D2cc for sigmoid was 69% higher than point dose used, unless it was not possible compare this value, since the sigmoid point used in the 2D procedures is not used in others institutes. Relative dose in 2 cc of sigmoid was 57% of the prescription dose, the same value was found by in literature. This work enabled the implementation of a viable brachytherapy 3D protocol planning, using MRI for the first fraction of the treatment and CT images for the subsequent fractions.

<p>Every tenth year a financial crisis tend to interfere with an economy. Price bubbles with an accompanying market plunge are therefore not a new phenomenon. Such market disruptions have been causing problems for centuries, as history has a tendency to repeat itself. The intention with this study is to learn more about the bubble phenomenon and increase the knowledge in this area in order to, if possible, prevent such a thing from happening again. The purpose of the essay is to identify factors that significantly affected the development of the so called IT-bubble in Sweden and Finland during the years of 1995-2000. The previous purpose can be divided into two sub-purposes, namely; to point out which financial theory/theories that succeeds the best to explain the development of the IT-bubble, and additionally; to detect factors that can help us foreseeing similar scenarios in the future.</p><p>The study concentrates on Sweden and Finland. Furthermore, only stock market bubbles are studied. As a consequence, other types of financial crises, for example bank crises, are excluded from this study. The method used to answer the first sub-purpose is an analysis of financial theories which enables us to find factors that according to theory could have caused the rise of the price bubble. In order to answer the second sub-purpose we take use of a statistical method. We have designed a statistical model based on the results of previous mentioned analysis. In this model we try the relevance of the detected factors from the theoretical analysis in order to investigate if theory manages to explain the birth of a stock market bubble.</p><p>The result of our study has generated four different factors; macro economic; institutional; psychological and asymmetric information. These four categories showed importance for the development of the IT-bubble in Sweden and Finland. Out of the four factors, the psychological factor is said to be the most important, but in the mean time the hardest one to predict. The statistical model indicates that the number of bankruptcies, the total amount of household’s borrowing and results from attitude surveys in the case of Sweden, and the number of bankruptcies, new registrations of cars and finally consumers attitude towards making a big purchase at present, in the case of Finland are variables to be aware of when looking out for a stock market bubble. The statistical model, as pointed out in the study, is not perfect. Additional studies are necessary to confirm the results presented in this report.</p> / <p>Finansiella kriser tenderar att drabba ekonomin med ungefär tio års intervaller. Prisbubblor med tillhörande djupdykning på marknaden är således inget nytt fenomen. Denna störning i marknadsharmonin har funnits under flertalet sekler och historien har en benägenhet att upprepa sig. Bakgrunden till studien är således att öka förståelsen för bubbelfenomenet och att, om det är möjligt, förhindra att det händer igen. Syftet med studien är att påvisa faktorer som har haft signifikant betydelse för den så kallade IT-bubblans utveckling i Sverige och Finland under åren 1995-2000. Det övergripande syftet kan vidare indelas i två delsyften, vars mål dels är att påvisa vilken eller vilka finansiella teorier som bäst förklarar IT-bubblans utveckling, dels hitta faktorer som kan hjälpa oss att förutse likartade scenarier i framtiden.</p><p>Studien fokuserar på länderna Sverige och Finland, och avgränsar sig därmed från övriga länder. Vidare studeras enbart börsbubblor och fall, varför övriga typer av finansiella kriser, så som exempelvis bankkriser utesluts. Metoden för att besvara det första delsyftet är att göra en analys av finansiella teorier för att lyfta fram faktorer som enligt dem kan ha haft avgörande betydelse för bubblans uppbyggnad. Metoden för det andra delsyftet är att bygga en statistisk modell med hjälp av de faktorer som resulterat av ovan nämnda analys, för att pröva deras relevans.</p><p>Resultatet av vår studie har genererat en grupp bestående av fyra olika faktorer; makroekonomiska, institutionella, psykologiska faktorer och asymmetrisk information som bäst förklarar IT-bubblans uppkomst. Av dessa är den psykologiska faktorn den viktigaste, och samtidigt också den svåraste att förutsäga. Det är framförallt teorierna inom ”behavioural finance” som fokuserar på psykologiska effekter, varför de bäst förklarar händelseförloppet under IT-bubblan. Den statistiska modellen indikerar att antalet konkurser, hushållens totala utlåning och resultatet av samhällsekonomiska attitydundersökningar i fallet Sverige, samt antalet konkurser, nyregistrering av bilar, och slutligen konsumenternas attityd till stora köp och till att ta lån för tillfället, i fallet Finland, är variabler som vi kan vara uppmärksamma på för att försöka förutse börsbubblor. Den statistiska modellen är, som poängteras i arbetet, inte fulländad utan ytterligare studier fordras för att belägga detta ytterligare.</p>

<p>Finansiella kriser tenderar att drabba ekonomin med ungefär tio års intervaller. Prisbubblor med tillhörande djupdykning på marknaden är således inget nytt fenomen. Denna störning i marknadsharmonin har funnits under flertalet sekler och historien har en benägenhet att upprepa sig. Bakgrunden till studien är således att öka förståelsen för bubbelfenomenet och att, om det är möjligt, förhindra att det händer igen. Syftet med studien är att påvisa faktorer som har haft signifikant betydelse för den så kallade IT-bubblans utveckling i Sverige och Finland under åren 1995-2000. Det övergripande syftet kan vidare indelas i två delsyften, vars mål dels är att påvisa vilken eller vilka finansiella teorier som bäst förklarar IT-bubblans utveckling, dels hitta faktorer som kan hjälpa oss att förutse likartade scenarier i framtiden.</p><p>Studien fokuserar på länderna Sverige och Finland, och avgränsar sig därmed från övriga länder. Vidare studeras enbart börsbubblor och fall, varför övriga typer av finansiella kriser, så som exempelvis bankkriser utesluts. Metoden för att besvara det första delsyftet är att göra en analys av finansiella teorier för att lyfta fram faktorer som enligt dem kan ha haft avgörande betydelse för bubblans uppbyggnad. Metoden för det andra delsyftet är att bygga en statistisk modell med hjälp av de faktorer som resulterat av ovan nämnda analys, för att pröva deras relevans.</p><p>Resultatet av vår studie har genererat en grupp bestående av fyra olika faktorer; makroekonomiska, institutionella, psykologiska faktorer och asymmetrisk information som bäst förklarar IT-bubblans uppkomst. Av dessa är den psykologiska faktorn den viktigaste, och samtidigt också den svåraste att förutsäga. Det är framförallt teorierna inom ”behavioural finance” som fokuserar på psykologiska effekter, varför de bäst förklarar händelseförloppet under IT-bubblan. Den statistiska modellen indikerar att antalet konkurser, hushållens totala utlåning och resultatet av samhällsekonomiska attitydundersökningar i fallet Sverige, samt antalet konkurser, nyregistrering av bilar, och slutligen konsumenternas attityd till stora köp och till att ta lån för tillfället, i fallet Finland, är variabler som vi kan vara uppmärksamma på för att försöka förutse börsbubblor. Den statistiska modellen är, som poängteras i arbetet, inte fulländad utan ytterligare studier fordras för att belägga detta ytterligare.</p> / <p>Every tenth year a financial crisis tend to interfere with an economy. Price bubbles with an accompanying market plunge are therefore not a new phenomenon. Such market disruptions have been causing problems for centuries, as history has a tendency to repeat itself. The intention with this study is to learn more about the bubble phenomenon and increase the knowledge in this area in order to, if possible, prevent such a thing from happening again. The purpose of the essay is to identify factors that significantly affected the development of the so called IT-bubble in Sweden and Finland during the years of 1995-2000. The previous purpose can be divided into two sub-purposes, namely; to point out which financial theory/theories that succeeds the best to explain the development of the IT-bubble, and additionally; to detect factors that can help us foreseeing similar scenarios in the future.</p><p>The study concentrates on Sweden and Finland. Furthermore, only stock market bubbles are studied. As a consequence, other types of financial crises, for example bank crises, are excluded from this study. The method used to answer the first sub-purpose is an analysis of financial theories which enables us to find factors that according to theory could have caused the rise of the price bubble. In order to answer the second sub-purpose we take use of a statistical method. We have designed a statistical model based on the results of previous mentioned analysis. In this model we try the relevance of the detected factors from the theoretical analysis in order to investigate if theory manages to explain the birth of a stock market bubble.</p><p>The result of our study has generated four different factors; macro economic; institutional; psychological and asymmetric information. These four categories showed importance for the development of the IT-bubble in Sweden and Finland. Out of the four factors, the psychological factor is said to be the most important, but in the mean time the hardest one to predict. The statistical model indicates that the number of bankruptcies, the total amount of household’s borrowing and results from attitude surveys in the case of Sweden, and the number of bankruptcies, new registrations of cars and finally consumers attitude towards making a big purchase at present, in the case of Finland are variables to be aware of when looking out for a stock market bubble. The statistical model, as pointed out in the study, is not perfect. Additional studies are necessary to confirm the results presented in this report.</p>

Every tenth year a financial crisis tend to interfere with an economy. Price bubbles with an accompanying market plunge are therefore not a new phenomenon. Such market disruptions have been causing problems for centuries, as history has a tendency to repeat itself. The intention with this study is to learn more about the bubble phenomenon and increase the knowledge in this area in order to, if possible, prevent such a thing from happening again. The purpose of the essay is to identify factors that significantly affected the development of the so called IT-bubble in Sweden and Finland during the years of 1995-2000. The previous purpose can be divided into two sub-purposes, namely; to point out which financial theory/theories that succeeds the best to explain the development of the IT-bubble, and additionally; to detect factors that can help us foreseeing similar scenarios in the future. The study concentrates on Sweden and Finland. Furthermore, only stock market bubbles are studied. As a consequence, other types of financial crises, for example bank crises, are excluded from this study. The method used to answer the first sub-purpose is an analysis of financial theories which enables us to find factors that according to theory could have caused the rise of the price bubble. In order to answer the second sub-purpose we take use of a statistical method. We have designed a statistical model based on the results of previous mentioned analysis. In this model we try the relevance of the detected factors from the theoretical analysis in order to investigate if theory manages to explain the birth of a stock market bubble. The result of our study has generated four different factors; macro economic; institutional; psychological and asymmetric information. These four categories showed importance for the development of the IT-bubble in Sweden and Finland. Out of the four factors, the psychological factor is said to be the most important, but in the mean time the hardest one to predict. The statistical model indicates that the number of bankruptcies, the total amount of household’s borrowing and results from attitude surveys in the case of Sweden, and the number of bankruptcies, new registrations of cars and finally consumers attitude towards making a big purchase at present, in the case of Finland are variables to be aware of when looking out for a stock market bubble. The statistical model, as pointed out in the study, is not perfect. Additional studies are necessary to confirm the results presented in this report. / Finansiella kriser tenderar att drabba ekonomin med ungefär tio års intervaller. Prisbubblor med tillhörande djupdykning på marknaden är således inget nytt fenomen. Denna störning i marknadsharmonin har funnits under flertalet sekler och historien har en benägenhet att upprepa sig. Bakgrunden till studien är således att öka förståelsen för bubbelfenomenet och att, om det är möjligt, förhindra att det händer igen. Syftet med studien är att påvisa faktorer som har haft signifikant betydelse för den så kallade IT-bubblans utveckling i Sverige och Finland under åren 1995-2000. Det övergripande syftet kan vidare indelas i två delsyften, vars mål dels är att påvisa vilken eller vilka finansiella teorier som bäst förklarar IT-bubblans utveckling, dels hitta faktorer som kan hjälpa oss att förutse likartade scenarier i framtiden. Studien fokuserar på länderna Sverige och Finland, och avgränsar sig därmed från övriga länder. Vidare studeras enbart börsbubblor och fall, varför övriga typer av finansiella kriser, så som exempelvis bankkriser utesluts. Metoden för att besvara det första delsyftet är att göra en analys av finansiella teorier för att lyfta fram faktorer som enligt dem kan ha haft avgörande betydelse för bubblans uppbyggnad. Metoden för det andra delsyftet är att bygga en statistisk modell med hjälp av de faktorer som resulterat av ovan nämnda analys, för att pröva deras relevans. Resultatet av vår studie har genererat en grupp bestående av fyra olika faktorer; makroekonomiska, institutionella, psykologiska faktorer och asymmetrisk information som bäst förklarar IT-bubblans uppkomst. Av dessa är den psykologiska faktorn den viktigaste, och samtidigt också den svåraste att förutsäga. Det är framförallt teorierna inom ”behavioural finance” som fokuserar på psykologiska effekter, varför de bäst förklarar händelseförloppet under IT-bubblan. Den statistiska modellen indikerar att antalet konkurser, hushållens totala utlåning och resultatet av samhällsekonomiska attitydundersökningar i fallet Sverige, samt antalet konkurser, nyregistrering av bilar, och slutligen konsumenternas attityd till stora köp och till att ta lån för tillfället, i fallet Finland, är variabler som vi kan vara uppmärksamma på för att försöka förutse börsbubblor. Den statistiska modellen är, som poängteras i arbetet, inte fulländad utan ytterligare studier fordras för att belägga detta ytterligare.