Made available in DSpace on 2016-12-06T17:07:21Z (GMT). No. of bitstreams: 1 Luciana Segato.pdf: 866229 bytes, checksum: 3c21b41ea1cc15261e43c75a047baf90 (MD5) Previous issue date: 2009-06-01 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The aim of this study was to investigate the relationship between nutritional profile, stress and mood states of elite sailors in a competition. From a field descriptive research, co relational cross type, participated 31 sailors high level sport that competed in the Pre-Olympic Sailing selected by a non-probabilistic intentional. The athletes answered a Questionnaire of Athlete s Characterization, the brazilian version of the Brunel Mood States (BRUMS), Brazilian Mood Scale - BRAMS (ROLFHS, 2006), the Perceived Stress Scale (COHEN and WILLIAMSON, 1988), the Recall of 24 hours and the Frequency of Food Intake Questionnaire, all those before or after the races. Data were analyzed by descriptive and inferential statistics (Pearson's and Spearman s correlation, t test and Mann-Whitney). The results showed that the sailors are young athletes, from an elite sailing group and have high level of education, which have a good self-evaluation health, quality of sleep and rest. Was observed in competition a poor food intake in calories and carbohydrates, but adequate in protein and lipids. The mood profile of the sailors showed high levels of depression, anger and fatigue and low vigour both athletes, evaluated before and after the races. The lipid intake had correlation with levels of anger before the race, and fatigue after the races, in sailors of two crew members classes. It also noted positive correlation between the carbohydrate intake and fatigue levels, and reverse between protein intake and tension, depression and anger after the races. The levels of stress displayed by the athletes were low to moderate, becoming from intrinsic sources of the competitive context (problems with the boat, disorganization of the team) and extrinsic (study, combining work and sport, family and financial problemsl). After the races, levels of stress were inversely related to protein intake and, in sailors of individual classes, the calories intake and carbohydrate. Athletes refer to have a good coping with stress using cognitive strategies (isolate itself) and somatic (listening music, rest/sleep, talk with friends) in competition. Among the psychological variables, stress was correlated to depression and anger, before and after the races, and inversely to vigor. These results support the hypothesis that exist a significant relationship between nutritional profile, mood states and stress in sailors in a competition. / O estudo teve por objetivo investigar a relação entre perfil nutricional, estados de humor e estresse de atletas de vela em competição. A partir de uma pesquisa descritiva de campo, do tipo correlacional transversal, participaram do estudo 31 velejadores de alto nível esportivo que competiram na Pré-olímpica de vela, selecionados de maneira não-probabilística intencional. Os atletas responderam o Questionário de Caracterização do Atleta, a Escala Brasileira de Humor (ROLFHS, 2006), a Escala de Estresse Percebido (COHEN e WILLIAMSON, 1988), o Recordatório de 24 horas e o Questionário de Freqüência de Consumo Alimentar antes ou depois das regatas. Os dados foram analisados através de estatística descritiva e inferencial (Correlação de Pearson e Spearman, Teste t e U de Mann-Whitney). Os resultados indicaram que os velejadores são atletas jovens, de alto nível de rendimento esportivo e elevado grau de instrução, que possuem uma boa auto-avaliação de saúde, qualidade de sono e descanso. Foi verificado um consumo alimentar em competição baixo em calorias e carboidratos, mas adequado em proteínas e lipídios. O perfil de humor dos velejadores mostrou elevados níveis de depressão, raiva e fadiga e baixos de vigor tanto em atletas avaliados antes, quanto após as regatas. O consumo lipídico foi correlacionado aos níveis de raiva antes das regatas, e à fadiga depois das regatas, em velejadores de classes com dois tripulantes. Também se observou correlação positiva entre o consumo de carboidrato e os níveis de fadiga, e inversa entre o consumo protéico e tensão, depressão e raiva depois das regatas. Os níveis de estresse apresentado pelos atletas variaram de baixo a moderado, sendo estes oriundos de fontes intrínsecas ao ambiente competitivo (problemas com o barco, desorganização da equipe) e extrínsecas (estudo, conciliar o trabalho com a vela, problemas familiares e financeiros). Depois das regatas, os níveis de estresse foram relacionados inversamente ao consumo protéico e, em velejadores de classes individuais, ao consumo de calorias e de carboidrato. Os atletas referem possuir um bom controle do estresse utilizando estratégias cognitivas (isolar-se) e somáticas (escutar música, descansar/dormir, conversar com os amigos) em competição. Entre as variáveis psicológicas, o estresse foi correlacionado à depressão e à raiva, antes e depois das regatas, e inversamente ao vigor. Estes resultados apóiam a hipótese de que existe relação significativa entre o perfil nutricional, estados de humor e estresse de atletas da vela em competição.

Orbital debris poses a serious threat to ongoing operations in space.  Recognising this threat, the European Commission has funded the three-year Technology for Self Removal (TeSeR) project with the goal of developing a standard scalable Post Mission Disposal (PMD) module to remove satellites from orbit following the completion of their mission.  As the project coordinator and key member of the TeSeR Project, Airbus Defence and Space Germany will invest significant resources in achieving this goal over the course of the project. This thesis details the initial analysis of potential PMD module designs conducted by the author during an internship within the AOCS/GNC department of Airbus Defence and Space Friedrichshafen between 1 April 2016 and 31 August 2016.  Three main concepts, drag sails, drag balloons and Electrodynamic Tethers (EDTs), were evaluated during this time with an emphasis on determining the ability of each design to permit passive attitude stabilisation of the satellite during PMD.  Following the required modification of a pre-existing MATLAB/Simulink model, several key findings were made for each device concept.  It was found that no drag sail designs investigated permitted passive aerodynamic attitude stabilisation at orbit heights above 550 km.  When deorbiting from 800 km, however, the lack of the desired and stable attitude was not found to have a significant increase on the deorbit time or the area‑time product. Drag balloon designs were predicted to be comparatively unstable and less mass efficient for deorbiting purposes, with area‑time products up to approximately 50 per cent higher than the equivalent mass drag sail designs.  In spite of this, unstable drag balloons were found to provide shorter deorbit times than stable balloons due to the contribution of the satellite body and solar array to the total frontal area of the satellite.  This indicated that attitude stabilisation is not required for satellites equipped with drag balloon devices. Modelling of bare EDTs suggested that tethers with lengths of 1000 metres or more would not permit passive attitude stabilisation at an orbit height of 800 km.  Simulation of a 500 metre EDT, however, indicated that passive attitude stabilisation can be achieved with EDT devices and proved that EDTs can generate significantly higher drag forces than aerodynamic devices while possessing a significantly lower device mass.  Following the analysis of these results, a recommendation was made for future work to be aimed at improving the EDT model used in this investigation.

De maneira geral, o mercado náutico brasileiro ainda é muito restrito, principalmente o de pequenas embarcações. Nos últimos anos, porém, devido a uma maior exposição na mídia dos bons resultados internacionais de velejadores e exploradores brasileiros, a vela tem se popularizado. Esta dissertação descreve o projeto de um veleiro de pequeno porte para esporte/lazer fabricado em polietileno linear de média densidade (PEMD) pelo método da rotomoldagem. Este método tem se difundido rapidamente no exterior para a fabricação de equipamentos náuticos de pequeno porte, como veleiros e caiaques, proporcionando redução de custos e vantagens ambientais relacionadas ao processo de construção. A embarcação projetada é voltada para uma tripulação de duas pessoas adultas (ou um adulto e duas crianças) e foi dimensionada para um fácil transporte, possibilitando carregá-la sobre o bagageiro de um automóvel. O foco deste trabalho está no projeto naval. Desta forma, foram percorridas todas as etapas pertinentes de um projeto de veleiro, desde o projeto do casco, passando pelo projeto do plano vélico, projeto dos apêndices (bolina e leme), análise estrutural do casco em elementos finitos e verificação de desempenho comparativo com um veleiro bem conhecido no ramo da vela. Destaca-se o projeto do plano vélico, no qual, de forma otimizada, se obteve um conjunto de velas (mestra e buja) de bom desempenho, sem, contudo, comprometer a estabilidade do veleiro. Uma análise econômica preliminar indicou a possibilidade de se fabricar o veleiro rotomoldado com custo reduzido, abaixo do preço de mercado de veleiros do mesmo porte disponíveis no mercado nacional. Complementarmente, verificou-se também a possibilidade de se utilizar material reciclado na construção da embarcação, o que, além de ser uma alternativa para diminuir custos, proporciona benefícios ambientais ao minimizar sobras de produção. / In a general way, the Brazilian nautical market is still very restricted, specially the one of small dinghies. In the last years, however, mainly due to a greater exposure on the media based on good international results of Brazilian sailors and explorers, sailing has being popularized. This Msc. Thesis describes the design of a small sail dinghy, for sport or leisure use, made with medium density linear polyethylene using the method of rotomolding. This method has been spreading rapidly worldwide as a process of fabrication of small nautical crafts like sailboats and kayaks, since it results in cost reductions and environmental gains related to the construction process. The designed sailboat is directed for a crew of two adults (or an adult and two children), and was dimensioned for an easy transport, even on the top of a car. This work is focused on the development of the naval design. Therefore, it goes through all the design steps of a sailboat, starting with the design of the hull, and then going through the design of the sails, appendices (rudder and dagger board), hull structural analysis by Finite Elements Method (FEM) and verification of performance of the sailboat in comparison with a well known sailing dinghy. It should be highlighted, also, the sails designing process, which, in an optimized way, generated a set of sails (main and jib) of good performance, without, however, jeopardizing the stability of the sailboat. Through a preliminary economical analysis, it was verified that it is possible to produce a rotomolded sailboat with reduced cost, even below the market prices of national sailboats of this size. As a complement, the possibility of employing recycled material in the construction of the boat has been studied. Besides being an alternative to diminish costs, it can bring environmental benefits, as it minimizes production scraps.

Thesis (MEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Throughout its lifetime in space, a spacecraft is exposed to risk of collision with orbital debris or operational satellites. This risk is especially high within the Low Earth Orbit (LEO) region where the highest density of space debris is accumulated. This study investigates orbital decay of some LEO micro-satellites and accelerating orbit decay by using a deorbitsail. The Semi-Analytical Liu Theory (SALT) and the Satellite Toolkit was employed to determine the mean elements and expressions for the time rates of change. Test cases of observed decayed satellites (Iridium-85 and Starshine-1) are used to evaluate the predicted theory. Results for the test cases indicated that the theory tted observational data well within acceptable limits. Orbit decay progress of the SUNSAT micro-satellite was analysed using relevant orbital parameters derived from historic Two Line Element (TLE) sets and comparing with decay and lifetime prediction models. The study also explored the deorbit date and time for a 1U CubeSat (ZACUBE-01). A proposed orbital debris solution or technology known as deorbitsail was also investigated to gain insight in sail technology to reduce the orbit life of spacecraft with regards to de- orbiting using aerodynamic drag. The deorbitsail technique signi cantly increases the e ective cross-sectional area of a satellite, subsequently increasing atmospheric drag and accelerating orbit decay. The concept proposed in this work introduces a very useful technique of orbit decay as well as deorbiting of spacecraft. / AFRIKAANSE OPSOMMING: Gedurende sy leeftyd in die ruimte word 'n ruimtetuig blootgestel aan die risiko van 'n botsing met ruimterommel of met funksionele satelliete. Hierdie risiko is veral hoog in die lae-aardbaan gebied waar die hoogste digtheid ruimterommel voorkom. Hierdie studie ondersoek die wentelbaanverval van sommige Lae-aardbaan mikrosatelliete asook die versnelde baanverval wanneer van 'n deorbitaal meganisme gebruik gemaak word. Die Semi-Analitiese Liu Teorie en die Satellite Toolkit sagtewarepakket is gebruik om die gemiddelde baan-elemente en uitdrukkings vir hul tyd-afhanlike tempo van verandering te bepaal. Toetsgevalle van waargenome vervalde satelliete (Iridium-85 en Starshine-1) is gebruik om die verloop van die voorspelde teoretiese verval te evalueer. Resultate vir die toetsgevalle toon dat die teorie binne aanvaarbare perke met die waarnemings ooreenstem. Die verloop van die SUNSAT mikrosatelliet se wentelbaanverval is ook ontleed deur gebruik te maak van historiese Tweelyn Elemente datastelle en dit te vergelyk met voorspelde baan- elemente. Die studie het ook ondersoek ingestel na die voorspelde baan-verbyval van 'n 1-eenheid cubesat (ZACUBE-01). Die impak op wentelbaanverval deur 'n voorgestelde oplossing vir die beperking van ruimterommel, 'n deorbitaalseil, is ook ondersoek. So seil verkort 'n satelliet se ruimte- leeftyd deur sy e ektiewe deursnee-area te vergroot en dan van verhoogde atmosferiese sleur en sonstralingsdruk gebruik te maak om die vervalproses te versnel. Hierdie voorgestelde konsep is 'n moontlike nuttige tegniek vir versnelde baanverval en beheerde deorbitalering van ruimtetuie om ruimterommel te verminder.

De maneira geral, o mercado náutico brasileiro ainda é muito restrito, principalmente o de pequenas embarcações. Nos últimos anos, porém, devido a uma maior exposição na mídia dos bons resultados internacionais de velejadores e exploradores brasileiros, a vela tem se popularizado. Esta dissertação descreve o projeto de um veleiro de pequeno porte para esporte/lazer fabricado em polietileno linear de média densidade (PEMD) pelo método da rotomoldagem. Este método tem se difundido rapidamente no exterior para a fabricação de equipamentos náuticos de pequeno porte, como veleiros e caiaques, proporcionando redução de custos e vantagens ambientais relacionadas ao processo de construção. A embarcação projetada é voltada para uma tripulação de duas pessoas adultas (ou um adulto e duas crianças) e foi dimensionada para um fácil transporte, possibilitando carregá-la sobre o bagageiro de um automóvel. O foco deste trabalho está no projeto naval. Desta forma, foram percorridas todas as etapas pertinentes de um projeto de veleiro, desde o projeto do casco, passando pelo projeto do plano vélico, projeto dos apêndices (bolina e leme), análise estrutural do casco em elementos finitos e verificação de desempenho comparativo com um veleiro bem conhecido no ramo da vela. Destaca-se o projeto do plano vélico, no qual, de forma otimizada, se obteve um conjunto de velas (mestra e buja) de bom desempenho, sem, contudo, comprometer a estabilidade do veleiro. Uma análise econômica preliminar indicou a possibilidade de se fabricar o veleiro rotomoldado com custo reduzido, abaixo do preço de mercado de veleiros do mesmo porte disponíveis no mercado nacional. Complementarmente, verificou-se também a possibilidade de se utilizar material reciclado na construção da embarcação, o que, além de ser uma alternativa para diminuir custos, proporciona benefícios ambientais ao minimizar sobras de produção. / In a general way, the Brazilian nautical market is still very restricted, specially the one of small dinghies. In the last years, however, mainly due to a greater exposure on the media based on good international results of Brazilian sailors and explorers, sailing has being popularized. This Msc. Thesis describes the design of a small sail dinghy, for sport or leisure use, made with medium density linear polyethylene using the method of rotomolding. This method has been spreading rapidly worldwide as a process of fabrication of small nautical crafts like sailboats and kayaks, since it results in cost reductions and environmental gains related to the construction process. The designed sailboat is directed for a crew of two adults (or an adult and two children), and was dimensioned for an easy transport, even on the top of a car. This work is focused on the development of the naval design. Therefore, it goes through all the design steps of a sailboat, starting with the design of the hull, and then going through the design of the sails, appendices (rudder and dagger board), hull structural analysis by Finite Elements Method (FEM) and verification of performance of the sailboat in comparison with a well known sailing dinghy. It should be highlighted, also, the sails designing process, which, in an optimized way, generated a set of sails (main and jib) of good performance, without, however, jeopardizing the stability of the sailboat. Through a preliminary economical analysis, it was verified that it is possible to produce a rotomolded sailboat with reduced cost, even below the market prices of national sailboats of this size. As a complement, the possibility of employing recycled material in the construction of the boat has been studied. Besides being an alternative to diminish costs, it can bring environmental benefits, as it minimizes production scraps.

Linjett Segelbåtar konstruerar och producerar högkvalitativa  segelbåtar på Rosättravarvet. Detta arbete syftar till att presentera en bättre mekanisk lösning till den nedgångslucka som Linjett har idag. Förbättringen består i att sänka produktionskostnaderna, underlätta montering och service men framförallt öka livslängden på mekanismen. Nedgångsluckan är den vertikala ”dörr” som skiljer utsidan från insidan på en segelbåt. I Linjett’s befintliga lösning så skjuts luckan ned i en balja under durken och försvinner undan på ett väldigt smidigt sätt. Tack vare en gasfjäder görs den annars ganska tunga luckan viktlös och kan lämnas halvöppen vilket kan vara väldigt praktiskt, det är en typ av funktion som den nya lösningen måste bibehålla. Arbetet har följt en generisk utvecklingsprocess. Koncept från en idégenerering har ställts mot varandra med hjälp av en pughmatris och en multiomröstning. Det vinnande konceptet har sedan förbättrats i en iterativ process för att uppfylla målen i så hög utsträckning som möjligt. Under vidareutvecklingen har fokus legat på att minimera antal komponenter genom DFA (Design For Assembley). För att motivera lösningen har monteringsscheman ställts upp och kompletterats med en självkostnadskalkyl. Dessa detaljstuderas och utvärderas för att agera beslutsunderlag till Linjett. Den presenterade lösningen använder konstantkraftsfjädrar för att bära upp luckans vikt. Dessa fjädrar ger lång livslängd i dessa utsatta miljöer och har ett förhållandevis lågt inköpspris. / Linjett Segelbåtar constructs and produces high quality sailing yachts at Rosättravarvet. This rapport aims to enhance the mechanical solution of the companionway door that Linjett is using. The enhancement consists in lowering production costs, simplify the mounting and service but most important, raise the lifetime of the mechanism. The companionway door is what separates the outside from the inside on a sailing yacht. Linjett has a special solution were the companionway door slides in under the cockpit floor and disappears in a clever way. Thanks to a gas spring the otherwise heavy door becomes weightless and can be left at any desired height which can come in handy. This is one of the function that the new solution must maintain. The work has followed a generic developmentprocess. Concepts from a brainstormingsession have been evaluated and compared in a pughmatris and a multivote. The winning concept has then been improved in a iterative process to fulfill the goals in the best way possible. During the enhancement of the concept there has been a strive to minimize the number of components throughout DFA (Deisgn for Assembley) To motivate the solution a mounting schedule was produced which in turn were complemented by a cost price calculation. These were studied in detail and evaluated to create a basis for decision making to Linjett. The presented solution uses constant force springs to carry the weight of the companionway door. Springs of these type provide long lifetime in these harsh conditions and is reasonably priced.

Wallenius Marine, KTH and SSPA are working together on a wind powered car carrier, that will ship cars over the atlatic. KTH has a small scale prototype of this vessel, and uses this prototype to test performance and new sensor systems, that can be used on the full scale vessel. The KTH research group wanted to add a sensor system that measured the pressure on the sails of the prototype ship. This thesis is about the design, construction and implementation of this sensor system. The system was first designed. The pressure measuring system would be divided into blocks where one block would measure one part of the sail. Each block would be connected to a common communication bus. This bus was then connected to the current control system of the ship. The pressure was going to be measured through pressure taps in the sail. After the design was done, the construction began. Here the choice of components was made. The sensors were from Honeywell, the microcontroller was a Teensy 4.1, communication was done using a RS-422 transceiver from Digilent and the power components were a 24 to 3.3V regulator and a 24 to 5V regulator. A circuit board was designed and created to fit all the components. The system was tested in a wind tunnel to verify that it worked as it should. The next step was the implementation. Three segments of the sail surface was removed. A support structure and fittings was added to the removed parts, so that they can be removed and attached. The taps was added and the system blocks were fitted. The measuring system was tested on the ship out on the sea. The results were that the system was able to measure the pressure distribution over the sail surface. The resulting measurements matched what was expected from viewing the tell tales on the sail. The system worked as specified, but more testing is required to see how the measurements are affected by factors such as the other sails and the hull. This system will continue to be used by the KTH research team in their future research projects. / Wallenius Marine, KTH och SSPA jobbar tillsammans för att konstruera et vinddrivet fraktfartyg för bilar, som ska skeppa bilar över Atlanten. KTH har en nedskalad version av det färdiga fartyget, som används för testning av prestanda och test av potentiella system som kan implementeras på det färdiga skeppet. Forsknings gruppen på KTH ville ha ett tryckmätningssystem som mäter trycket på seglena. Detta masterarbetet går ut på att designa, konstruera och implementera detta tryckmätningssystem. Första steget var design, detta gick ut på att i stora drag definiera systemets utseende. Systemet skulle byggas i block, där ett block innehöll ett antal trycksensorer, mikrokontroller och kommunikations hårdvara. Ett block mätte en horisontallinje över seglet och det var multipla block på ett segel. Varje block var ihopkopplat genom en kommunikationsbus, som sen kopplades till det nuvarande kontrollsystemet på båten. Andra steget var construktion, detta steget var att välja komponenter, bygga och testa systemet. Trycksensorerna som valdes var från Honeywell, mikrokontrollern var en Teensy 4.1 och kommunikations hårdvaran var en RS- 422 transceiver från Digilent. När komponenterna var valda, designades och gjordes ett kretskort för att koppla samman komponenterna. Efter komponenterna var fästa i kretskortet, testades systemet i en vindtunnel. Detta gjordes för att verifiera funktionaliteten av systemet och se om värdena som sensorerna gav var rimliga. Efter systemet var verifierat, så börjades implementationen av systemet. Tre segment av seglet yta togs bort, på tre olika höjder. En stöd struktur adderades till de borttagna segmenten, så de skulle fortsätta hålla sin form, och ett sätt att ta bort och fästa segmenten till seglet gjordes. Pressure taps fästes på ytan och plasttuber drogs från dessa till trycksensorerna. Kretskorten fästes på insidan av seglet och segmenten stängdes. Nästa steg var att testa systemet till havs, och resultaten var lovande. Systemet fungerade som det skulle. Det kunde mäta trycket både i vindtunnel och på havs. I vindtunneln matcha trycken det som förväntades, och ute till havs visade trycket det som förväntades när man kollade på tell talesen på ytan. Mer testning behövs för att se hur olika faktorer påverkar tryckmätningarna, och tryckmätning till alla segeln ska läggas till. Forskningsgruppen på KTH kommer fortsätta använda systemet i forskningen de driver.

This thesis provides insights to what is peculiar about a solar sail attitude and orbit control system and provides the assessment, in the form of a feasibility study, of the effectiveness of sail tip vanes as a control hardware to escape the Earth sphere of influence. The demonstrator aims to prove the technology for the Sunshade project, a constellation of solar sails located at the Lagrangian point L1 to obscure part of the solar radiation directed towards earth. Solar sailing poses a few fundamental challenges to spaceflight and it is a yet-to-be-proven branch of space engineering. Other tentative design exist but there is no standard to follow or off-the-shelf component that can be straightforward used. Moreover the scalability to the final project has to be accounted for in every step of the project.</p><p>The project is divided in a preliminary dimensioning, followed by a Simulink® based simulation which tests preliminary decisions. The simulation, performed on an orbit on the ecliptic plane, integrates models of Earth’s eclipse and environmental disturbance torques.  The escape time for a 100 m solar sail is found to be 1215 days, with a nonlinear PD control algorithm and sail tip vanes as the only control hardware. Attention is also posed on the consequence of a simplified sail film deformation in terms of centre of pressure to centre of mass off-set. / I detta examensarbete studeras vad som är speciellt med solsegels system för attityd- och bankontroll och ger en bedömning, i form av en möjlighetsstudie, av effektiviteten hos flöjlar som sätts på seglets hörn som kontrollhårdvara för att lämna jordens inflytelsesfär. Demonstratorn syftar till att bevisa tekniken för Sunshade-projektet, en konstellation av solsegel belägen vid lagrangepunkten L1 för att skugga en del av solstrålningen riktad mot jorden. Solsegling innebär några grundläggande utmaningar för rymdfärden och det är en ännu inte bevisad gren av rymdteknik. Annan preliminär design finns, men det finns ingen standard att följa eller standardkomponenter som enkelt kan användas. Dessutom måste skalbarheten till det slutliga projektet redovisas i varje steg i projektet.Projektet är uppdelat i en preliminär dimensionering, följt av en Simulink-baserad simulering som testar preliminära beslut. Simuleringen, utförd på en omloppsbana påekliptikan, integrerar modeller av jordens skugga och störningar av vridmoment från ett antal källor.Flykttiden för ett 100m solsegel blir 1215 dagar, med en icke-linjär PD kontrollalgoritm och segelhörnsflöjlar som den enda styrhårdvaran. Dessutom studeras förskjutningen av tryckcentrum i förhållande till masscentrum under en förenklad modell av segeldeformation.

Urbanisierungsprozesse beeinflussen die Funktionen natürlicher Ökosysteme signifikant. Bereitgestellte ökosystemare Leistungen unterliegen Veränderungen, die direkt die Lebensbedingungen des Menschen beeinflussen. Funktionale Freiflächen mit Baum- und Gehölzbeständen sind wichtige Bestandteile urbaner Ökosysteme und lindern lokal Einflüsse der Urbanisierung. Die Umweltbedingungen in der Stadt weichen von den natürlichen ab und mindern die Funktionsfähigkeit der Bäume. Gegenüber etablierten, terrestrischen Untersuchungen des Baumzustands ermöglicht die Fernerkundung räumlich und zeitlich flexible Vitalitätscharakterisierungen. In dieser Dissertation wird ein fernerkundlicher Ansatz zur Baumzustandserhebung erarbeitet. Bei Nutzung hyperspektraler Bilddaten werden biophysikalische und strukturelle Baumparameter mit dem quantitativen Ansatz der Strahlungstransfermodellierung (RTM) abgeleitet. Schwerpunkt dieser Arbeit war die Adaption der RTM auf einzelne Bäume. Hierzu wurden drei Anpassungen vorgenommen: die Korrektur höhenbedingter Bildpunktversätze, die Selektion von Bildelementen und die Nutzung eines geometrisch-optischen Modells, um Einflüsse der Kronentopographie zu korrigieren. Eine Validierung der Modelle und abgeleiteter Parameter basierte auf umfangreichen Geländeerhebungen. Beispielhaft wurde die weißblühende Rosskastanie, eine Hauptbaumart Berlins, untersucht. Ein Modelltest zeigte die Eignung der modifizierten RTM, die optischen Eigenschaften von Kastanien zu modellieren. Mit einer Sensitivitätsanalyse wurde der Einfluss spezifischer Baumeigenschaften auf die Modellergebnisse quantifiziert, was die Optimierung des Verfahrens ermöglichte. Durch Invertierung der Modelle konnten die vitalitätsrelevanten Parameter Chlorophyll- und Wassergehalt realistisch abgeleitet und in ein Baumkataster eingebunden werden. Damit leistet diese Dissertation einen Beitrag, das thematische Spektrum verfügbarer Biogeodaten zur Untersuchung stadtökologische Prozesse zu erweitern. / Urbanisation affects natural ecosystems functions significantly. This leads to changes in ecosystem services which are directly linked to human living conditions. Functional open spaces, especially when covered with wood and trees, are a major component of urban ecosystems and lessen the impact of urbanisation. Environmental conditions of urban areas are fare away from non urban, natural ones. The functionality of trees decreases as a consequence of these unfavourable conditions. In comparison to terrestrial surveys, remote sensing enables spatially and temporally flexible descriptions of tree vitality. In the present work a remote sensing based approach to investigate conditions of urban trees was developed. Radiative transfer models (RTM) were used to derive biophysical and structural parameters from hyperspectral data. In order to adapt the modelling approach to single trees three modifications were made: a) the correction of pixel shifts due to the height of trees and non-nadir view angles of the sensor; b) the selection of spectrally pure pixels; c) the correction of albedo effects induced by crown geometry. A detailed validation of the models and the estimated parameters is performed based on data of an extensive ground survey. Being one of Berlin’s main tree species, the horse chestnut (lat. Aesculus hippocastanum) was exemplary investigated. An Evaluation of the modified RTM showed that they are able to model the optical properties of chestnut canopies. A sensitivity analysis was performed to quantify the impact of tree specific effects on the results of the modelling approach. The findings allowed an optimization of the method. Vitality parameters such as chlorophyll and water content could be realistically estimated by model inversion. Results were finally linked to an existing cadastral system. Results from this work help widen the thematic spectrum of environmental biogeodata applications and investigating multiple processes of urban ecology.

Cette thèse vise à une meilleure compréhension de la dynamique du voilier et à la validation des outils numériques de prédiction de performances et d’optimisation par l'étude expérimentale in situ du problème aéro-élastique d'un gréement. Une instrumentation est développée sur un voilier de 8m de type J80 pour la mesure dynamique des efforts dans le gréement, de la forme des voiles en navigation, du vent et des attitudes du bateau. Un effort particulier est apporté à la mesure des caractéristiques géométriques et mécaniques des éléments du gréement, la calibration des capteurs et au système d'acquisition des données. Les principaux résultats montrent que le voilier instrumenté est un outil adapté pour les mesures instationnaires et soulignent l'amplitude de variation d'effort rencontrée en mer (20 à 50% de l'effort moyen dans une houle modérée). En outre, les variations du signal d'effort sont déphasées avec l'angle d'assiette, créant un phénomène d'hystérésis. Le comportement dynamique d'un voilier en mouvement diffère ainsi de l'approche quasi-statique. Les simulations numériques proviennent du code ARAVANTI, couplage implicite d’un code structure éléments finis ARA et d’un code fluide parfait, limitant son domaine de validité aux allures de près Les résultats de simulation sont très proches des cas stationnaires et concordent bien avec les mesures en instationnaire dans une houle de face. L'expérimentation numérique d'un gréement soumis à des oscillations harmoniques en tangage souligne l'importance de l'approche Interaction Fluide Structure (IFS) et montre que l’énergie échangée par le système avec la houle est reliée à la fréquence réduite et l'amplitude du mouvement. Certaines informations n'étant pas disponibles sur le voilier instrumenté, une expérience contrôlée en laboratoire est développée. Elle consiste en un carré de tissu tenu par deux lattes en oscillation forcée. Les mesures sur cette « voile oscillante » permettent d'étudier les phénomènes IFS avec décollement et sont utilisées pour la validation du couplage ARA-ISIS entre un code fluide Navier-Stokes (RANS) et le même code structure. / This work presents a full scale experimental study on the aero-elastic wind/sails/rig interaction in real navigation condition with the aim to give a reliable database of unsteady measurement. This database is used for the investigation of the dynamic behavior and loads in the rigging and for an experimental validation of an unsteady Fluid Structure Interaction (FSI) model. An inboard instrumentation system has been developed on a 8 meter yacht (J80 class) to simultaneously and dynamically measure the navigation parameters, yacht's motion, sails flying shape, wind and loads in the rigging. A special effort is made on mechanical and geometrical characteristics measurement, sensors calibration and data acquisition system synchronization. Results show that the instrumented boat is a reliable tool to measure the unsteady phenomena in navigation. Dynamic measurements at sea underline the load variation encountered, which represent 20 to 50% of the mean value in a moderate sea state. Oscillations of loads exhibit phase shift with the trim angle, reason for an hysteresis phenomenon, which shows that the dynamic behavior of a sail plan subject to yacht motion clearly deviates from the quasi-steady theory. Simulations are made with ARAVANTI, an implicit coupling of a Finite Element Method structural model ARA and an inviscid fluid model which restricts the simulation domain to upwind conditions. The simulation results compare very well with the experimental data for steady sailing conditions and show a good agreement in unsteady conditions (head swell). Numerical investigation of a sail plan submitted to harmonic pitching motion underlines the importance of FSI modeling and shows that the energy exchanged by the system with the swell increases with the motion reduced frequency and amplitude. Some information is not accessible on the instrumented boat and requires developing a controlled test case in laboratory. The experiment consists of a spinnaker fabric square mounted on two carbon battens moved in forced oscillation. This test case is used to study FSI phenomena with a separated flow and gives experimental results for the validation of the coupling ARA-ISIS of a RANS fluid model with the same structure model.