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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.
41

Offshore Wind Turbine Transportation & Installation Analyses Planning Optimal Marine Operations for Offshore Wind Projects

Uraz, Emre January 2011 (has links)
Transportation and installation of offshore wind turbines (Tower, Nacelle and Rotor) is a complete process conducted over several phases, usually in sequence. There are several factors that can turn this process into a challenge. These factors can either be due to offshore site conditions or the technical limitations of the installation vessels. Each project has its own characteristic parameters and requires a unique optimum solution. This paper identifies the dynamics of the installation process and analyzes the effects of each phase on the progression of events.The challenges in wind turbine installations due to offshore environment were investigated, the effects of each were explained and their significances were stressed. Special installation vessels were examined and their technical specifications were analyzed in terms of working conditions, dimensions, service performances, and crane capacities as well as projecting future design trends. Several offshore wind farm projects were analyzed; their installation methods were specified, and compared to each other to determine advantages and disadvantages of different pre-assembly concepts. The durations of the sub-phases of the process were defined in terms of different variables such as site conditions and individual vessel performance. These definitions were used for making time estimations, and conducting further analyses regarding the effects of different site specific parameters on the overall project duration.In conclusion, this study considered the main operation parameters in an offshore wind turbine installation context: the benefits and drawbacks of different pre-assembly methods were researched and evaluated resulting in new knowledge and a productive contribution for optimizing “the offshore turbine transportation and installation process”, based on actual time usage.
42

Análise Do Comportamento Dinâmico De Rotores Embarcados / Analysis of the Dynamic Behavior of Onboard Rotor

Sousa Júnior, Marcelo Samora 06 September 2017 (has links)
CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / FAPEMIG - Fundação de Amparo a Pesquisa do Estado de Minas Gerais / INCT-EIE - Instituto Nacional de Ciência e Tecnologia De Estruturas Inteligentes em Engenharia / UFU - Universidade Federal de Uberlândia / Este trabalho apresenta uma investigação numérica e experimental sobre o comportamento dinâmico de um sistema rotativo submetido a uma excitação pela base. Na área de aplicações aeronáuticas, o motor de uma aeronave é considerado um típico rotor embarcado, no qual seu comportamento dinâmico é afetado pela excitação da base. O modelo matemático do rotor é obtido a partir das equações de Lagrange e do método de elementos finitos, considerando as energias de deformação e cinética do eixo e as energias cinéticas do disco e da massa desbalanceada. A base do sistema rotativo é considerada rígida. As equações de movimento do sistema são utilizadas para determinar as respostas de vibração do rotor a partir das excitações devido ao desbalanceamento e ao movimento da base. Na análise numérica foi investigada uma máquina rotativa composta por um eixo horizontal flexível contendo dois discos e apoiada em suas extremidades. As diferenças entre o comportamento de rotores de base fixa e em movimento foram exploradas. Uma máquina rotativa composta por um eixo horizontal flexível apoiada em suas extremidades e um disco rígido foi utilizada na validação experimental do modelo adotado. As respostas de vibração do modelo matemático construído e medidas experimentalmente foram comparadas. Diferentes análises foram realizadas nos domínios de tempo e da frequência, onde foram obtidos funções de resposta em frequência, órbitas, respostas ao desbalanceamento e o diagrama de Campbell. Os resultados obtidos representam adequadamente o comportamento do sistema. / In the present work, a numerical and experimental investigation regarding the dynamic behavior of a rotating machine subjected to a base excitation is presented. Regarding the aeronautical applications, the aircraft engine is considered a typical onboard rotor which has its dynamic behavior influenced by base excitations. The mathematical model of the rotor is derived from the Lagrange’s equation and the finite element method, which is obtained by considering the strain and kinetic energies of the shaft, and the kinetic energy of the discs and mass unbalance. In this case, the base of the rotor system is considered as being rigid. The resulting differential equations are used to provide information about the vibration responses of the rotor under base and unbalance excitations simultaneously. In the numerical analysis a rotating machine composed by a horizontal flexible shaft containing two rigid discs and supported by two ball bearings was investigated. The differences between the dynamic behavior of a fixed base and onboard rotors were explored. A rotating machine is composed by a horizontal flexible shaft, one rigid disc, and two self-aligning ball bearings was used in the experimental validation of the adopted model. The vibration responses of the mathematical model and the experimental results were compared. Different analyses were performed both in the time and frequency domains, as generated by the orbits, unbalance response, and Campbell diagram. The obtained results adequately represent the behavior of the system. / Dissertação (Mestrado)
43

Middle manager's work for occupational health and safety in the shipping industry

Bågfeldt, Ted January 2021 (has links)
The middle manager situation is sometimes squeezed between requirements from different parties at the same time as they are crucial for the development of the organization. Masters, chief engineers and managers in the catering department onboard are middle managers squeezed between the office requirements and the working conditions of their crew. The purpose of this study was to look into the middle managers conditions with focus on the work for good working environment onboard ships in the commercial shipping industry. A study was made consisting of two main parts, first a literature review and secondly focus group interviews. The literature review looked for findings about the middle managers work for occupational health and safety, which were mostly about industries and organisations ashore. These findings were tested in the focus groups in order to find out if they applied also for the commercial shipping industry and if there are any special things to consider there. The focus group members were of both genders, from different management positions and companies within the Swedish commercial shipping industry. So what recommendations can be made in order to improve the middle managers work for a good working environment or occupational health and safety (OHS)? Recommendations are given about competence, staff engagement, policies, shared leadership and administrative workload. Three findings are suggested for further research, shared leadership, administrative workload and client pressure. It is interesting that the type of shared leadership that are found onboard seems to be rather unique for the commercial shipping industry.
44

Testing for verification and validation of an onboard orbit determination system exploiting GNSS : A nanosatellite application for HERMES-SP / Testning for verifikation och validering av ett ombord banbestämningssystem med GNSS : En applikation av nanosatelliter för HERMES-SP

Nermark, Clara January 2023 (has links)
When developing products for space, including nanosatellites, the verification and validation process is a mandatory part of any project conducted within the European space industry. Within such a process, testing is a method for verification and validation. In this degree project, the appropriate tests for verification and validation of a nanosatellite were investigated. The project was conducted at the Royal Institute of Technology and the Polytechnic of Milan, as part of a larger research project under the name HERMES-SP. The research project was, at the time at which the degree project was taking place, in its first phase of the verification process. Therefore, tests for verification and validation of the Orbit Determination System (ODS) had not yet been defined. HERMES-SP is developing a nanosatellite platform with a very precise and reliable ODS, combining both Inertial Navigation System (INS) and Global Navigation Satellite System (GNSS). This degree project was thus conducted with HERMES-SP as an applicative case to investigate tests for a ’nanosatellites onboard ODS focusing on the GNSS. The ODS developed for the nanosatellite platform was studied, along with the underlying theory for ODS and GNSS. The plan for verification defined within HERMES-SP was also examined, and the presented methodology for test development was followed. To fully answer the project’s research question, the appropriate tests had to be identified and defined. This was done by first determining the requirements related to the ODS, and then identifying the tests that were needed to verify the requirements. Lastly, the tests were defined in test specifications and procedures. It was found that the relevant tests in the verification process were a handful of tests on the Equipment Test (ET), Software Test (SWT), and Subsystem Integration Test (SSIT) test levels. The tests were needed for verification of individual components in the system, as well as integrated components and their interfaces. The defined tests were considered appropriate for verification and validation for the first phase of the verification process. The project contributed to the identification and definition of tests for a restricted part of the verification process, related to the specified system of the HERMES-SP nanosatellite. The findings could be used in other nanosatellite projects with similar ODS by following the process and the methodology for test development documented in this report. / Vid utvecklandet av produkter ämnade för rymden, såsom satelliter, är processen för verifiering och validering en obligatorisk del av projekt utförda inom den Europeiska rymdindustrin. Under en sådan process är testning en metod för verfiering och validering. I detta examensarbete undersöktes de lämpliga testerna för verifiering och validering av en nanosatellit. Arbetet utfördes på Kungliga Tekniska Högskolan (KTH) och Politecnico di Milano, som en del av ett större foskningsprojekt under namnet HERMES-SP. När detta examensarbete tog plats var forskningsprojektet i sin första verifieringsfas. Därför hade inte tester för verifiering och validering av systemet för ombord banbestämning ännu definerats. Inom HERMES-SP utvecklas en platform för nanosatelliter med ett precist och tillförlitligt banbestämmnings system. Systemet kombinerar därför både tröghetsnavigeringssystem och satellitnavigering (GNSS). Systemet för ombord banbestäming utvecklat för nanosatelliten studerades, tillsammans med underliggande teori för banbestäming och GNSS. HERMES-SPs plan för verifiering och validering studerades, och den presenterade metodiken för testning adapterades. För att besvara arbetets forskningsfråga behövdes de lämpliga testerna identifieras och sedan defineras. Detta gjorder genom att först bestämma krav på systemet för banbestämning, och därefter identifiera de tester som behövdes för att verifiera kraven. Sist definerades testen i form av test specifikationer och test procedurer. Arbetet resulterade i att en handfull at tester relevanta för verifieringsprocessen identifierades. Dessa tester tillhörde olika nivåer av testing, nämligen testning av komponenter, mjukvara, och integrering av delsystem. Dessa tester var nödvändiga för att utvärdera individuella komponenter i systemet, samt integrerade komponenter och deras gränssnitt. De tester som definerades i arbetet ansågs nödvändiga för verifiering och validering under den första fasen av processen för verifiering. Examensarbetet bidrog till identifiering och definering av tester tillhörande en begränsad fas av verifieringsprocessen, relaterade till det specifiecerade systemet av HERMES-SPs nanosatellit. Upptäckterna skulle kunna användas i andra projekt för nanosatelliter med liknande system för banbestämning, genom att följa metodiken för utveckling av tester dokumenterade i denna rapport.
45

Onboard Aircraft Traffic Tracking Algorithm to Support Conflict Detection and Resolution using Multi-sensor Data Integration and Integrity Monitoring

Bezawada, Rajesh January 2012 (has links)
No description available.
46

HAEC News

06 September 2013 (has links) (PDF)
No description available.
47

HAEC News

January 2013 (has links)
No description available.
48

Časomíra letu v ultralehkém letadle/vrtulníku / Flight Timer in Ultramicro Aircraft/Helicopter

Široký, Adam January 2015 (has links)
This thesis deals with the development of embedded system for ultra light airplanes and helicopters. The aim is to design a system which would allow to measure and record the length of individual flights. It is therefore an onboard electronic diary which should facilitate and streamline the administration associated with sport aircraft operation. The base of the system is created on microcontroller of the MSP430 family by Texas Instruments. A reader will be offered the used hardware, the system design, the way of function and the possibility of using of the suggested system.

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