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

A Conceptual Design of a Reliable Hard Docking System : Docking of an utonomous underwater vehicle to the new generation A26 submarine / En konceptuell design av ett pålitligt hårddockningssystem

EKSTRÖM, ELIN, SEVERINSSON, ELLEN January 2021 (has links)
In year 2024 and 2025 the Royal Swedish Navy is expected to launch two new submarines with new possibilities to dock underwater vehicles. The submarines are part of the new Blekinge Class (A26) and will aid the Swedish Armed Forces and the Swedish Defense Materiel Administration (FMV) in their aim to develop and use more autonomous systems, to increase staff efficiency and to face the technological challenges of tomorrow. This thesis was carried out at FMV, with the purpose of investigating the physical requirements put on the new submarines, when docking an autonomous underwater vehicle. These requirements were identified through an analysis of qualitative and quantitative research. The analysis resulted in ten key insights, which led to thirteen requirements. The requirements were combined with project specific data of the AUV62 system and A26 submarine, to develop three conceptual designs of hard docking systems. The concepts were verified through analysis of material, stress and deflection, and geometric constraints. The concepts were evaluated based on how well they were fulfilling each requirement. A hammock-alike concept was shown to have most potential in being the most reliable hard docking system. The thesis ended with concluding that its purpose had been fulfilled, followed with recommendations for continued work. / Under 2024 och 2025 förväntas Svenska Marinen sjösätta två nya ubåtar, med nya förmågor gällande dockning av undervattensfordon. Ubåtarna ingår i nya Blekingeklass (A26) och är en del av Försvarsmaktens och Försvarets Materielverks (FMV) målsättning om att utveckla och använda mer autonoma system, för att öka personaleffektivitet och för att kunna möta morgondagens tekniska utmaningar. Detta examensarbete utfördes på uppdrag av FMV, med syftet att undersöka vilka fysiska krav som ställs för att hårddocka ett autonomt undervattensfordon på de nya ubåtarna. Dessa krav identifierades genom analys av en kvalitativ och kvantitativ undersökning. Analysen uppdagade tio nyckelinsikter som gav upphov till tretton krav. Kraven kombinerades med projektspecifik data för AUV62-systemet och ubåt A26, för att utveckla tre konceptuella designförslag av hårddockningssystem. Koncepten verifierades genom analys gällande material, spänning och utböjning, samt geometriska begränsningar. Koncepten utvärderades baserat på hur väl de uppfyllde respektive krav. Ett hängmatteformat koncept visade sig ha störst potential för att bli ett pålitligt hårddockningssystem. Examensarbetet avslutades med att projektets syfte ansågs vara uppfyllt, följt av förslag på vidare arbete.
2

Utvecklingen av ubåt typ Blekinge : vilka drivkrafter har varit avgörande?

Ahlqvist, Erik January 2019 (has links)
Ubåtsvapnet har sedan dess instiftande utgjort en viktig del av det nationella försvaret av Sverige och har under lång tid ansetts vara flottans slagkraftigaste enheter. Genom utvecklingen som följde efter kalla kriget, där Europas stater närmade sig varandra genom EU och försvarssamarbeten, ominriktades Försvarsmakten mot ett insatsförsvar med internationellt fokus. Förband som inte kunde bidraga vid internationella insatser skulle avvecklas. För Ubåtsflottiljens del innebar detta att förbandet anpassade sig för att verka utanför Sveriges territorium och på så vis skapa legitimitet för sin fortsatta existens. Samtidigt påbörjades arbetet med att ta fram nästa generations ubåtar, som senare blev A26/Blekingeklassen. Då några direkta nationella hot inte längre förelåg designades dessa med färre torpedtuber och istället med en sluss för slussning av dykare och farkoster. Bakom ett beslut som detta finns flera aktörer, men på vilket sätt har dessa kunnat påverka designvalen för Blekinge? Genom att analysera projektet med hjälp av teorier kring beslutsfattande och drivkrafter har denna undersökning studerat vad som påverkat gjorda val. Undersökningens resultat visar att det funnits olika drivkrafter under projektets gång, men att de övergripande har varit rationellt aktörsagerande för att uppnå vinstsatisfiering både för Sverige som nation, men också för de enskilda aktörerna. Det har dock förekommit maktkamp mellan staten och försvarsindustrin samt stigberoende och byråkratiska inslag i form av handlande enligt tidigare uppgjorda rutiner.
3

Truster till förskeppet på NGU/A26 : Dimensionering och konceptgenerering / Thruster for NGU/A26 : Dimensioning and concept generation

Riddervold Sandberg, Emil, Lindblom, Markus January 2017 (has links)
This thesis work has been conducted on the behalf of the Swedish Defense Material Administration, which by directive from the Swedish Armed Forces has procured two new submarines of type A26 for delivery in 2024. For certain operations A26 will need to be able to be dynamically positioned in water currents of various speeds. For this, it is estimated that there is a need for some type of thruster in the ship’s forebody. Such a solution has never previously been implemented on a Swedish submarine, and it is therefore necessary to conduct preliminary studies to calculate the resulting forces, powers and dimensions, as well as generate conceptual suggestions for the design of such a system. The main objective of the project is to generate one or more conceptual proposals for the Swedish Defense Material Administration. The eligibility of the proposals should be based on the acquired specified requirements.   An initial wide-ranging study has been performed to identify the types, sizes and installation solutions of already existing thrusters and their principle function. During the initial study, the materials, machine elements and components suitable for the given application were also examined.   In order to determine for which flow angles and speeds the system is able to position the submarine, simplified power and torque calculations have been made. These should be seen as a valid basis for general approximations regarding the positioning ability of the concepts although further development of the concepts requires more detailed calculations to be made.   During the concept generation, it was determined which type of thruster is best suited for the application. Subsequently, a number of simple, function-modeled suggestions were generated to evaluate possible ways of integrations. Two of these proposals were later selected for final detail modeling. The final choices of both thruster type and concepts have been based on listed set of advantages and disadvantages, which were then, evaluated using decision matrices.   The results of the calculations that have been carried out shows that it is possible to dynamically position the submarine using a thruster system. This is under the presumption of the rudders being able to contribute with transverse force generation. A thruster is also found to be able to position the submarine with transverse forces only, implying that the only argument for using a, in the horizontal plane, rotatable thruster is the “limp-home” function.   Two particularly detailed conceptual proposals have been modeled; one that strictly complies with the specified volume requirement and one which, with certain adaptation to the internal geometry of the ships forebody, goes beyond the volume restriction. Both concepts are considered to be principally and technically feasible, with reservations of some specific solutions. The definitive concepts are meant to serve as a basis for possible further development of the systems.   The designed models and the calculations underlying these are all of a generic nature. They are fully adequate as a basis for this project but should not be seen as representative of the A26 in its entirety.
4

Embodied precarity : the biopolitics of AIDS biomedicine in South Africa

Mills, Elizabeth Anne January 2014 (has links)
This thesis centres on the lives of women who live in Khayelitsha and who receive AIDS biomedicines through South Africa's public health system. It is tiered across five ethnographic chapters to elucidate a single overarching argument: biopolitical precarity is networked into the permeable body. This argument is based on ethnographic research and seeks to challenge the discursive construction of distance that divorces women's lives and bodies from the governance of AIDS biomedicines as life-­giving technologies. The multi-­sited ethnography underpinning this thesis was configured to follow the networked threads that weave women's embodied precarity into the governance of technologies and the technologies of governance. To this end, fieldwork was conducted in South Africa from October 2010 – July 2011 in order to understand the embodied and political dimensions of access to AIDS biomedicine. Thereafter, fieldwork was conducted in Brazil from August 2011 – September 2011 to explore the networked connections spanning activist organisations, government coalitions and economic blocs to move out from the intimate spaces of women's lives and bodies to locate them in the regional and global spaces of biomedical developments and health policy dynamics. This thesis argues that although it is crucial to anchor technologies in people's lives, it is also analytically and politically necessary to link people's lives - and the technologies that sustain them - back into the global assemblage that is networked around the governance of medicine. Therefore, I locate biomedical technologies in social and political contexts of lives of the people with whom I worked in Khayelitsha, and I argue further that their lives also need to be understood as part of a complex network of actors (spanning international organisations, regional coalitions and national governments) and actants (HIV and ARVs) that assemble in dynamic configurations and that are woven into and through the body.

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