• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 34
  • 5
  • 5
  • 5
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 63
  • 9
  • 9
  • 8
  • 7
  • 6
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • 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.
41

Data Collection, Analysis, and Classification for the Development of a Sailing Performance Evaluation System

Sammon, Ryan January 2013 (has links)
The work described in this thesis contributes to the development of a system to evaluate sailing performance. This work was motivated by the lack of tools available to evaluate sailing performance. The goal of the work presented is to detect and classify the turns of a sailing yacht. Data was collected using a BlackBerry PlayBook affixed to a J/24 sailing yacht. This data was manually annotated with three types of turn: tack, gybe, and mark rounding. This manually annotated data was used to train classification methods. Classification methods tested were multi-layer perceptrons (MLPs) of two sizes in various committees and nearest- neighbour search. Pre-processing algorithms tested were Kalman filtering, categorization using quantiles, and residual normalization. The best solution was found to be an averaged answer committee of small MLPs, with Kalman filtering and residual normalization performed on the input as pre-processing.
42

Attitude control using ion thrusters for solar sailing from Low Earth Orbit to sub-L1

Holm, Celeste, Ygland, Ida January 2022 (has links)
The purpose of the study is to evaluate the possibility of using gridded ion thrusters as a means of attitude control for a solar sail as a part of the sunshade project, which aims to place 10^8 solar sail sunshade spacecraft, each with an area of about 10 000 m^2, at the Sun-Earth Lagrangian point L1 in order to reduce Earth's global temperature. Two types of solar sail sunshade spacecraft were studied. The first type, referred to as the sunshade demonstrator, had an area of 100 m^2 and a mass of 10 kg, and the second type, referred to as the full-sized sunshade, had an area of 10 000 m^2 and a mass of 90 kg. To determine the significance of using ion thrusters for the attitude control system, the mass of the required fuel, as well as the total mass that had to be added to the spacecraft to implement the attitude control system, was calculated. Two types of journeys were studied for each spacecraft type: starting from Low Earth Orbit (LEO) to L1 and from Geostationary Orbit (GEO) to L1, respectively. The results showed that the duration of the journey of the full-sized spacecraft was about 570 days from LEO to L1 and 370 from GEO to L1, respectively. The required amounts of fuel for the respective journeys were 580 g and 15 g, respectively, and resulted in a total additional mass of 7.8 kg and 7.2 kg, respectively.
43

Engine Idle Sailing with Driver Assistant Systems For Fuel Consumption Minimization

Chandramouli, Nitish 15 August 2018 (has links)
No description available.
44

Towards sustainable shipping: Recommendations for the telescopic mast design of a sailing cargo vessel / Mot hållbar sjöfart: Rekommendationer för en teleskopisk mastdesign för ett segelfraktfartyg

Blau, Lukas January 2021 (has links)
A comparative study is carried out to investigate the most promising route towardsthe lightweight construction of a retractable mast for a sailing cargo vessel.Four design families are developed and compared. The primary criteria forjudgment are the structural mass, strength, and stiffness in relation to a providedbenchmark design. Additional evaluation criteria are the capital costsfor raw materials and manufacturing.The design space includes isotropic materials as well as fiber-reinforced polymer(FRP) solutions and is navigated by employing analytical evaluation methodssupported by finite element analysis (FEA). Restrictions to the designspace are given by a general arrangement of the benchmark design. This includesthe limitation to the ULS loads and the overall mast geometry.A review of relevant Det Norske Veritas (DNV) rules for classification is performedand the guidelines for wind turbine blades and wind-powered units(WPU) are judged most suitable to the design challenge. Relevant design principlesare implemented in the structural analysis.It is concluded that pure metal constructions imply an unreasonably large weightpenalty. Local buckling is found to disqualify FRP single-skin solutions as successfulcandidates. Secondary to that, strength concerns are the major driversfor the structural mass.The report presents two designs that are judged fit for the purpose, one is ahybrid truss structure from high strength low alloy steel (HSLA steel) and carbonfiber-reinforced polymer (CFRP). The second design is a sandwich constructionwith CFRP face sheets, a PVC foam core, and additional stiffeningmembers in steel. / A comparative study is carried out to investigate the most promising route towardsthe lightweight construction of a retractable mast for a sailing cargo vessel.Four design families are developed and compared. The primary criteria forjudgment are the structural mass, strength, and stiffness in relation to a providedbenchmark design. Additional evaluation criteria are the capital costsfor raw materials and manufacturing.The design space includes isotropic materials as well as fiber-reinforced polymer(FRP) solutions and is navigated by employing analytical evaluation methodssupported by finite element analysis (FEA). Restrictions to the designspace are given by a general arrangement of the benchmark design. This includesthe limitation to the ULS loads and the overall mast geometry.A review of relevant Det Norske Veritas (DNV) rules for classification is performedand the guidelines for wind turbine blades and wind-powered units(WPU) are judged most suitable to the design challenge. Relevant design principlesare implemented in the structural analysis.It is concluded that pure metal constructions imply an unreasonably large weightpenalty. Local buckling is found to disqualify FRP single-skin solutions as successfulcandidates. Secondary to that, strength concerns are the major driversfor the structural mass.The report presents two designs that are judged fit for the purpose, one is ahybrid truss structure from high strength low alloy steel (HSLA steel) and carbonfiber-reinforced polymer (CFRP). The second design is a sandwich constructionwith CFRP face sheets, a PVC foam core, and additional stiffeningmembers in steel.
45

The relationship between interorganisational behaviour and innovation within sport clusters / La relation entre le comportement interorganisationnel et l'innovation au sein des clusters de sport

Gerke, Anna Christina 08 September 2014 (has links)
Ce projet de thèse étudie la relation entre le comportement inter-organisationnel et l’innovation au sein des clusters de sport. L’objectif est de répondre à deux questions centrales de recherche. La première question concerne les composantes d’un cluster de sport. La deuxième examine l’influence du comportement inter-organisationnel citoyen sur l’innovation de produit au sein des clusters de sport. Cette recherche utilise la méthode de l’étude de cas en étudiant quatre cas, dans deux secteurs sportifs et trois pays. La collecte des données consiste en des entretiens semi-directifs et formels (103), des entretiens exploratoires et informels (14), des observations non-participatifs (17), et d’un ensemble de données secondaires, telles que des informations organisationnelles et des données issues d’archives. La collecte et l’analyse des données proposent une approche combinant des méthodes inductives et déductives; ainsi, le travail utilise une démarche abductive. Les questions de recherche sont déduites de la littérature. Toutefois, l’analyse des données inclut des éléments emprunts à la méthode inductive. L’analyse inclut le codage des données avec NVivo 10, dont découlent des tableaux de fréquences, des rapports, et des analyses intra-cas et inter-cas.Les résultats montrent que les clusters de sport dépendent fortement de facteurs locaux spécifiques. Dans le cadre du développement et de la durabilité des clusters de sport, les principaux facteurs sont géoéconomiques, socio-économiques, et ceux liés au sport. Les facteurs politiques, géographiques, et historiques sont moins importants. Ces clusters regroupent un ensemble d’organisations sous forme de typologies, qui inclut le fabricant de l’équipement principal, les équipementiers associés, les fabricants d’accessoires, les prestataires de services liés au produit, les media, les concepteurs, les organisations relatives au sport professionnel et amateur, les institutions de l’éducation et de la recherche, et les organismes de gouvernance. Les organisations relatives au cluster sont liées entre elles, au travers de relations et réseaux formels et informels. Les comportements les plus courants dans ces liaisons sont l’avancement, l’altruisme, la loyauté, et la collaboration. Ces comportements favorisent l’innovation au sein des clusters. Les liens externes entre les organisations du cluster sont facilités par la citoyenneté inter-organisationnelle et encouragent l’innovation pendant tout le processus d’innovation, surtout par rapport à l’innovation relative au matériel, ainsi que celle liée au design ou à l’usage. Ce projet de thèse propose de réaliser davantage de recherches sur les clusters de sport, ainsi que sur le comportement inter-organisationnel citoyen et ses conséquences. / This thesis investigates the relationship between interorganisational behaviour and innovation in sport clusters. Two central research questions are addressed. The first research question asks what constitutes a sport cluster. The second research question investigates the influence of interorganisational citizenship behaviour on product innovation in sport clusters.This thesis employs a multiple case study research design, investigating four cases in two sport sectors and three countries. The data collection consists of formal semi-structured interviews (103), explorative informal interviews (14), non-participatory observations (17), and secondary data (i.e. organisational information and archival data). The data collection and analysis is a combination of deduction and induction, hence an abductive approach. The research questions are informed by literature. However, data analysis includes inductive tactics. Data analysis processing consists of interview transcribing and report writing. Data was analysed with data coding in NVivo 10, frequency counts, report writing, within-case analysis, and cross-case analysis. Results reveal that sport clusters depend heavily on location-specific factors. Most important for sport cluster development and sustainability are geo-economic, socio-economic, and sport-related factors. Less important are political, geographical, and historical location-specific factors. These clusters comprise typical cluster organisations as members which include core equipment manufacturers, system suppliers, accessory suppliers, services providers, media, designers, professional and amateur sport, education/research institutions, and governing bodies. These cluster organisations are connected via formal and informal relationships and networks. The most common interorganisational behaviours within those linkages are advancement, altruism, loyalty, and collaboration. These behaviours enhance innovation in clusters. External links between cluster organisations are facilitated through interorganisational citizenship. These links foster innovation throughout the entire innovation process, particularly material innovation but also design and use innovation. This thesis suggests further research of sport clusters as well as the study of interorganisational citizenship behaviour and its outcomes.
46

Análise cinemática da dinâmica postural do tronco do velejador durante simulação da posição de escora / Biomechanical analysis of spine movements in simulated hiking on sailing

Menezes, Fábio Sprada de 02 July 2007 (has links)
Made available in DSpace on 2016-12-06T17:07:13Z (GMT). No. of bitstreams: 1 Dissertacao - Fabio.pdf: 2269771 bytes, checksum: 8ff775f5d92ce2397baa5a139a979e97 (MD5) Previous issue date: 2007-07-02 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The main objective of this study was to evaluate the movement and positioning of the vertebral spineof the sailor during the hiking position. This research was characterized as descriptive and exploratory and the sample was of the intentional type. This was composed for 3 sailors selected through contacts with clubs of sailing of the city, the Santa Catarina Sailing Federation and the Brazilian Sailing and Motor Federation. The research is part of the Project Human Performance of Sailing and had approval in the Ethics Committee in Research with Human beings of the UDESC. For the acquisition of the images four cameras of video of the System Peak Motus® of 60 Hz had been used. To this research, a Laser Standard boat was used, and was raised to 1,20m of height to allow the visualization of the markers of the spine. Marking reflexives of 7mm had been used, applied in 21 anatomical points of the body for the three-dimensional reconstruction through DLT. For the evaluation of the spine the spinal processes of C7, T7, L1, L3 and L5 had been used, beyond the Temporomandibular joints and trochanters of the hips. The other reflexives had been used for the calculation of the CG. For the processing of videos APAS-XP® was used to make the digitalization of pictures. The gotten data had been filtered through the cubic spline interpolation filter of APAS system. Principles of descriptive statistics with calculation of: maximum angles and moments of shoring, average, absolute standard deviation (in each execution), average standard deviation (between the executions) and minimum angles and moments of shoring. In the antropometrical values we can observe an disparity in subjects and one of the athletes was demonstrated low weight. In the calculation of the hiking moment an average value of 796,54±28,58 N.m was gotten. In the flexion angle of head 113,56±2,70º and in the thoracic kyphosis angle 154,15±2,92º. For data of lumbar lordosis the average values had 170,15±2,98º, for angle of rotation of trunk - 3,08±4,05º and for inclination of trunk -1,00±3,78º. This study identified the movements and adjustments realized by the sailor s trunk in hiking position. It was demonstrated that hiking is not a static posture. The body micro-movements executed to control and adjust the boat on water during this posture should be considered. So, to study the hiking position considering trunk as a fixed segment is not the better choice. / O objetivo principal deste estudo foi avaliar a movimentação e posicionamento da coluna vertebral do velejador durante a postura de escora. Esta pesquisa foi caracterizada como descritiva, exploratória, multicaso e a amostra foi do tipo intencional. Essa foi composta por 3 velejadores selecionados através de contatos com clubes de vela da cidade, a Federação Catarinense de Vela e a Federação Brasileira de Vela e Motor. A pesquisa faz parte do Projeto Performance Humana no Iatismo e teve aprovação no Comitê de Ética em Pesquisas com Seres Humanos da UDESC. Para a aquisição das imagens foram utilizadas quatro câmeras de vídeo do Sistema Peak Motus® com freqüência de aquisição de 60 hz. Para coleta, foi utilizado um barco Laser Standard, que foi elevado à 1,20m de altura para permitir a visualização dos marcadores da coluna. Foram utilizados marcadores reflexivos de 7mm, aplicados em 21 pontos anatômicos do corpo para a reconstrução tridimensional através de DLT. Para a avaliação da coluna foram usados os processos espinhosos de C7, T7, L1, L3 e L5, além das articulações temporomandibulares e trocânteres maiores dos quadris, sendo que os outros reflexivos foram usados para o cálculo do CG. Para o processamento dos vídeos foi utilizado o sistema de digitalização quadro a quadro APASXP ®. Os dados obtidos foram filtrados através do filtro de interpolação cubic spline do próprio sistema. Foram utilizados princípios da estatística descritiva com cálculo de: ângulos e momentos de escora máximos, média, desvio padrão absoluto (em cada execução), desvio padrão médio (entre as execuções) e ângulos e momentos de escora mínimos. Quanto aos valores antropométricos observou-se uma disparidade entre os sujeitos sendo um dos atletas demonstrou-se muito leve. No cálculo do momento de escora obteve-se um valor médio de 796,54±28,58 N.m. No ângulo de flexão da cabeça obteve-se 113,56±2,70º e no ângulo de cifose torácica 154,15±2,92º. Para os dados da lordose lombar os valores médios foram de 170,15±2,98º, para o ângulo de rotação do tronco -3,08±4,05º e para a inclinação do tronco -1,00±3,78º. Por fim, observou-se que o velejador realiza, nos três eixos, uma soma de pequenos ajustes posturais e movimentos durante a escora e que estes podem influenciar na performance do gesto. Com isso demonstra-se que a escora não é uma postura estática, e que estudar esse gesto usando o tronco como um segmento ou haste fixa pode não ser a melhor escolha
47

Territorialisation des espaces océaniques hauturiers. L'apport de la navigation à voile dans l'Océan Atlantique / Territorialization of the high seas : the contribution of sailing in the Atlantic Ocean

Parrain, Camille 01 July 2010 (has links)
Espace mythique et peuplé de légendes, espace physique complexe changeant, l’océan est soumis aux enjeux géopolitiques et à une extension progressive de l’homme à la manière d’un front pionnier (en surface et en profondeur). La territorialisation croissante des espaces maritimes, déjà prouvée sur les mers côtières, prend un angle particulier sur le domaine hauturier du fait de son immensité et de son éphémérité. Pour analyser ce processus, nous nous sommes intéressés à la navigation à voile, pratique de loisir et professionnelle, dans l’océan Atlantique. Cette pratique offre une vision intéressante du fait de la relation particulière entretenue entre l’homme, le voilier et l’océan et de la dualité entre tradition et technologie. La fin du XXème et le XXIème siècle constituent une époque charnière où les regards sur l’océan risquent d’être modifiés. Elle s’inscrit de plus dans le phénomène de mobilité croissante des sociétés, en quête ou non de rapidité, et démontre la réticularité croissante de cet espace, également liée à la mondialisation. Nous tâcherons de définir la notion de territoire en haute mer et de distinguer l’existence de « merritoires ». La connaissance des routes transatlantiques permet de dégager des centralités, périphéries et marges atlantiques. Elles constituent des réseaux territorialisés mettant en relation différents lieux où se révèle l’identité des navigateurs. Le long de ces trajets se greffent des paysages marins « itinérants », des repères, des discontinuités spatio-temporelles, des rites et représentations dégageant des disparités spatiales et une structuration de l’Océan Atlantique. / Mythical space filled with legends, complex changing physical space, the ocean is subject to geopolitical issues and a gradual extension of use by men pioneering both on the surface and the great depths. The increasing territorialisation of maritime areas, more and more common in coastal seas, takes a particular perspective on the offshore seas because of its vastness and its ephemerality. To analyze this regionalization process, we focus on sailing in the Atlantic Ocean, both a leisure and professional practice. This practice offers an interesting aspect due to the special relationship between human beings, their boat and the ocean and due to the duality between tradition and technology. The late twentieth and the twenty-first century is a turning point where the way we look at the ocean is likely to change.Moreover, it lies within an increasing mobility phenomenon of societies, searching or not for speed, and demonstrates the increasing reticularity (networkness) of this space, also linked to globalisation. We will try to define the concept of territory in the high seas and to distinguish the existence of « maritories ». The knowledge of the transatlantic routes allows to define Atlantic centralities, peripheries and margins. They represent territorialised network putting into relation the different places where the identity of the sailors can be revealed. Along these routes some « itinerant »seascape, marks, spatial and temporal discontinuities, rituals and représentations are built, creating a possibility to structure the Atlantic Ocean.
48

Traditional sailing ships in international waters : -A transnational cultural heritage / Traditionella segelfartyg i internationella farvatten : -Ett nationsöverskridande kulturarv

Swärd, Elin Synnøve K. January 2023 (has links)
Traditional sailing ships, as opposed to vernacular boats, evolved to consist of certain types of vessels that couldbe produced in the same way in different countries and were also sold between countries. They were usuallyengaged in longer voyages which often resulted in an international crew. The traditional sailing ships that sailinternationally today are still characterised by international crews. In my thesis I argue that traditional Westernsailing ships are part of a historically transnational maritime culture, and that their significance as transnationalcultural heritage lives on today. At the same time, traditional sailing ships have much to contribute to todays andfuture society. They are kind to maritime life, while proving to be useful instruments for achieving better mentalhealth, teamwork, and learning seamanship. Unfortunately, the great potential and importance of traditional shipsas transnational cultural heritage is rarely acknowledged, as today's heritage discourse is still strongly influencedby the hegemonic cultural discourse that author Laurajane Smith calls Authorised heritage discourse.Furthermore, today's maritime rules create both practical and economic difficulties for traditional sailing ships,as today's maritime rules are written for modern motorised ships that have completely different physical andeconomic conditions. Through interviews with primarily employees on the ships Götheborg and Tres Hombres,it appears that the greatest challenges are linked to the national regulations, and that there is a great need forpoliticians and officials to get involved in creating rules that are adapted to traditional ships. In addition, moremaritime officials with knowledge of sailing vessels are needed to achieve better safety when handling traditionalsailing vessels.Since traditional sailing ships often sail internationally, it is important that the regulations in different countriesare harmonised. One conclusion is that this is something that should be dealt with by the EU as the activities ofsailing ships are a common transnational cultural heritage that can contribute to more cooperation between theirmember countries and to strengthen international relations. / Traditionella segelfartyg till skillnad från allmogebåtar, utvecklades till att bestå av vissa fartygstyper som kundeproduceras på samma sätt i olika länder och även säljas mellan länder. De var oftast engagerade i längreseglingar vilket gärna ledde till en internationell besättning. De traditionella segelfartyg som seglar internationelltidag är fortfarande präglade av internationella besättningar. I min uppsats argumenterar jag för att traditionellavästerländska segelfartyg är del av en historiskt nationsöverskridande maritim kultur, och att deras betydelsesom nationsöverskridande kulturarv lever vidare än idag. Traditionella segelfartyg har samtidigt mycket att bidramed till dagens och framtidens samhälle. De är skonsamma mot havsmiljön, samtidigt som de har visat sig varaanvändbara instrument för att uppnå bättre psykisk hälsa, samarbetsförmåga, och att lära sig sjömanskap.Tyvärr uppmärksammas sällan traditionsfartygens stora potential och vikt som nationsöverskridande kulturarv,eftersom dagens kulturarvsdiskurs fortfarande är starkt präglad av den hegemoniska kulturdiskurs som forskarenLaurajane Smith kallar för Authorised heritage discourse.Samtidigt skapar, dagens regler för sjöfarten både praktiska och ekonomiska svårigheter för de traditionellasegelfartygen eftersom dagens sjöfartslagstiftning är skriven för moderna motordrivna fartyg som har helt andrafysiska och ekonomiska förutsättningar. Genom intervjuer med i första hand anställda på fartygen Götheborgoch Tres Hombres, framkommer att de största utmaningarna är kopplade till de nationella regelverken, och attdet finns ett stort behov av att politiker och tjänstemän engagerar sig i att skapa regler som är anpassadetraditionella fartyg. Samtidigt behövs det fler maritima tjänstemän med kunskap om segelfartyg för att kunnauppnå bättre säkerhet vid hantering av traditionella segelfartyg.Eftersom traditionella segelfartyg ofta seglar internationellt är det viktigt att regelverken i olika länderöverensstämmer. En slutsats är att detta är något som borde behandlas av EU då segelfartygen är ettnationsöverskridande kulturarv som kan bidra till mer samarbete mellan deras medlemsländer och styrkainternationella relationer.
49

Strength assessment of rig foundations for a sailing car carrier / Utvärdering av styrkan hos riggfundament för ett seglande biltransportfartyg

Rapaport, Alfred January 2020 (has links)
The wPCC project (wind powered car carrier) is carried out by Wallenius Marine, KTH Royal Institute of Technology and SSPA Sweden. By developing a car carrier mainly propelled by the wind, the emissions are estimated to be reduced by up to 90 %. This thesis deals with the structural aspects of the design. Specifically, the interface between the sail rigs and hull is considered. Different rig foundation concepts should be developed and compared to each other. The objective is to focus on characteristics such as stress levels, relevant failure mechanisms and cargo capacity. Scantling of merchant vessels is to a large extent governed by rules issued by classification societies such as DNV-GL and Lloyd’s Register. While traditional car carriers are covered to a great extent in terms of scantling loads and structural requirements, there exists a regulatory gap for vessels powered by the wind. Four different concepts for the rig foundations are developed. They are all using transverse and longitudinal bulkheads for transferring loads from the rigs to adjacent hull structure. The foundation concepts are then evaluated by creating a finite element model representing the midship section of the ship. The model includes three rig foundations and generally follows the preliminary scantlings of the wPCC. For reference, a model without rigs is also created. The bow and stern of the vessel are excluded in the model and some other model simplifications are also made. The accuracy of stress levels is thus not sufficient for final sizing of the conceptual solutions but the qualitative differences should be valid. The focus of the study is thus how the four concepts compare with respect to each other. The main strength of the chosen approach is that it allows for comparison of multiple concepts. Had a more advanced approach been chosen, the results would likely prove to be of a higher accuracy but then at the expense of modeling effort and time. The transverse strength is deemed being critical for multiple deck car carriers such as the wPCC. Racking, the transverse shearing of the ship, is a common problem which is covered in detail by class guidelines. These loads, based on rule calculations, are therefore included in the analysis. The rig loads are in turn based on assumptions regarding parameters such as the wing geometry and rig weight. The results of the finite element models are evaluated at several critical areas, chosen as to represent different aspects of the structural response. Results from buckling analyses as well as characteristics such as cargo capacity are also recorded as to broaden the comparison. The different results represent criteria which the evaluation process is based on. Each criterion is given a weight to account for its importance. The Pugh method is then applied, yielding a score for each of the evaluated concepts. The total score consequently depends on the chosen weights. Regardless, the study clearly presents which concepts that are interesting and which should be discarded. Interestingly, the best performing concept turns out to be highly unconventional compared to supporting structures used in traditional shipbuilding. For the future, the rig loads as well as additional load cases should be addressed. Failure mechanisms such as fatigue will likely pose a problem, and at some stage a thorough, full scale finite element model should be created in order to accurately predict the response of the entire hull structure. However, the author believes that the presented study serves as a draft in identifying key aspects to consider when introducing wind propulsion in commercial shipping. / wPCC-projektet (wind powered car carrier) bedrivs gemensamt av Wallenius Marine, Kungliga Tekniska Högskolan och SSPA Sweden. Genom att utveckla ett vinddrivet biltransportfartyg beräknas utsläppen minska med upp till 90 %. Detta examensarbete avhandlar delar av fartygsstrukturen med fokus på hållfasthet. Mer specifikt undersöks gränssnittet mellan segelriggarna och skrovet. Olika koncept för riggfundament utvecklas och jämförs med fokus på karaktäristika så som spänningar, brottmekanismer och lastkapacitet. Dimensionering av kommersiella fartyg styrs till stor del av regler utfärdade av klassällskap som DNV-GL och Lloyd’s Register. Medan traditionella biltransportfartyg omfattas av ett antal krav på dimensionerande laster och strukturkrav saknas det ordentliga regelverk för vinddrivna fartyg. Fyra olika koncept för riggfundamenten utvecklas. Samtliga använder sig av transversella och longitudinella skott för lastöverföring från riggarna till omgivande skrovstruktur. Koncepten utvärderas sedan genom att skapa en finita element-modell som representerar midskeppssektionen av fartyget. Modellen inkluderar tre riggfundament och följer till stor del preliminära ritningar av wPCC-fartyget. Som referens skapas även en modell utan riggar. Fören och aktern exkluderas i modellen utöver ett antal andra förenklingar. Precisionen på spänningsnivåer är därmed inte tillräcklig för att bestämma slutgiltiga dimensioner på koncepten men de kvalitativa skillnaderna koncepten emellan bör vara välgrundade. Studiens fokus är därför hur de fyra koncepten jämförs mot varandra. Den främsta fördelen med det valda tillvägagångssättet är att det möjliggör jämförandet av flera koncept. Om ett mer avancerat tillvägagångssätt använts skulle sannolikt resultaten vara mer precisa, men då till en högre kostnad i form av modelleringsarbete och tidsåtgång. Tvärskeppsstyrkan bedöms vara kritisk för biltransportfartyg med flera däck som wPCC-fartyget. Så kallad racking, transversell skjuvning av fartyget, är ett vanligt problem som avhandlas i detalj av klassregler. Rackinglaster baserade på klassregler inkluderas därför i analysen. Rigglasterna är i sin tur baserade på antaganden om parametrar som vinggeometri och riggvikt. Resultaten från finita element-modellerna utvärderas vid ett flertal kritiska områden valda för att representera olika aspekter av hur strukturen svarar på belastningarna. Resultat från bucklingsanalyser såväl som karaktäristika så som lastförmåga inkluderas också för att bredda jämförelserna. De olika resultaten representerar kriterier som utvärderingsprocessen baseras på. Varje kriterium ges en vikt för att ta hänsyn till dess betydelse. Pugh-metoden används sedan, vilket ger en poängsumma för varje koncept. Varje poängsumma beror därmed på valda vikter. Oavsett visar studien tydligt vilka koncept som är av intresse och vilka som kan förkastas. Intressant nog visar studien att konceptet med högst poäng är högst okonventionellt jämfört med bärande strukturer som används inom traditionell skeppsbyggnad. Inför framtiden bör riggbelastningarna såväl som ytterligare lastfall beaktas. Brottmekanismer som utmattning kommer sannolikt att utgöra problem och vid något tillfälle bör en stor, fullskalig finita element-modell skapas för att med högre precision förutse hur hela skrovstrukturen svarar på belastningarna. Författaren bedömer oavsett att denna studie fungerar som ett utkast till att identifiera nyckelaspekter vid introduktion av vind som framdrivning för kommersiell sjöfart.
50

Life at the Extreme: An investigation into the experiences of professional sailors competing in a fully crewed around the world race

Guthrie, Colin C. January 2008 (has links)
Participants were 15 professional sailors, ranging in age from 23-49 years (M age = 35.9 years; SD = 7.4), who competed in the 2005/06 VOR. After receiving approval from the Temple University Institutional Review Board, the researcher recruited participants who were subsequently required to provide informed consent to participate in the study. Using a semi-structured interview format, face-to-face interviews were completed with three sailors in Miami, FL, and with nine sailors in Valencia, Spain (three interviews with individual participants, one interview with two participants, and a focus group with four participants). Three interviews were completed via telephone. All interviews were transcribed verbatim. Each transcript was then analysed through an inductive open coding process. Data analysis revealed nine major themes (Background, Skiffs on Steroids, Boat Breakdowns, Managing Self, Pressure, Tragedy, Extreme, Team, and Reflecting) with associated subthemes, and three dimensions (Resonance, Edgework, and Performance Capacities) with associated subdimensions. A framework for understanding the experiences of the sailors was conceived in the form of a model depicting the dimensions of resonance (a passion for adventure and the VOR in particular), edgework (a desire and ability to perform in high-risk, life threatening situations), and performance capacities (team, individual, and boat). The model suggests an interplay between the dimensions of edgework and resonance, against which is set the performance dimension. This study is the first to take a glimpse inside the experiences of professional ocean racing sailors who compete in fully crewed around-the-world races. Findings confirm the widely held belief that the VOR is an extreme and unique event in the world of sport. / Kinesiology

Page generated in 0.4664 seconds