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Jensen, Jonathan Andrew. "Robust discrete estimation of the space shuttle main engine." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/49608.
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Svientsitskiy, Vladyslav, Владислав Віталійович Свенцицкий, Denys Denysiuk, and Денис Олександрович Денисюк. "Main causes of engine failure: impact and preventive measures." Thesis, National Aviation University, 2021. https://er.nau.edu.ua/handle/NAU/50484.
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1. JET ENGINE FAILURES RARE, USUALLY NOT FATAL. URL:https://www.cbsnews.com/news/jet-engine-failures-rare-usually-not-fatal/
2. Federal Aviation Administration. Retrieved 31 December 2012. URL:"Technical Report on Propulsion System and APU-Related Aircraft Safety Hazards"(PDF).
3. Mike Berry is a 17,000-hour airline transport pilot, is type rated in the B727 and B757 interview. Retrieved 11 March 2013.<br>The work is devoted to engine failure main problems observing the impact of the leading causes and preventive methods to be useful in minimizing quantity such occurrences in order to increase the level of safety in air transportations.<br>Наукова праця присвячена основним причинам відмови двигуна та запобіжним заходам, які можуть бути корисними для мінімізації кількості таких випадків з метою підвищення рівня безпеки під час повітряних перевезень.
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Ho, Nhut Tan 1974. "Failure detection and isolation for the Space Shuttle Main Engine." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/9909.
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Miste', Gianluigi. "Variable speed rotor helicopters: optimization of main rotor-turboshaft engine integration." Doctoral thesis, Università degli studi di Padova, 2015. http://hdl.handle.net/11577/3424123.
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Variable speed rotors (VSRs) represent an innovative research field for the development of new rotorcraft designs. The possibility to change the rotational speed of a helicopter rotor, as a function of the specific flight condition, makes it possible to achieve optimum performance and relevant fuel consumption reductions. However, issues related to employing a main rotor variable speed are numerous and require an interdisciplinary approach. The present study represents the first effort in the open literature aimed at understanding the performance implications of coupling helicopter trim and turboshaft engine simulations for a VSR model.
A gas turbine simulation code, TSHAFT, and a helicopter performance tool, TCOPTER, have been implemented in order to be able to carry out the coupled analysis. Following this, the VSR concept has been tested on a real helicopter case: the models of a UH-60 Black Hawk helicopter and a GE T700 turboshaft engine have been implemented and validated against experimental data. Subsequently, an optimization routine has been employed to find the optimal main rotor speeds which minimize fuel consumption in different helicopter flight conditions.
Two different approaches to VSRs have been analyzed: the former employing a traditional fixed ratio transmission (FRT), the latter assuming a continuously variable transmission (CVT). In the FRT case, since the turbine and main rotor speeds are in a fixed ratio, the optimal speed has been calculated as the best compromise between optimal main rotor speed and optimal turbine speed. In the CVT case, the study has been carried out assuming that main rotor and turbine speeds were free to rotate at their optimal speeds.
Different simulation cases have been analyzed in order to quantify the benefits related to the optimal main rotor speed depending on flight conditions, altitude and helicopter gross weight. It has been found that coupling both the helicopter and engine model is important to adequately determine the correct rotational speed corresponding to minimum fuel consumption. More than 13% fuel saving has been shown to be feasible.
Finally, possible improvements to the VSR concept have been studied. In particular, a trial has been made to redesign the power turbine of the GE T700 in order to improve the efficiency of the engine in a wide speed variation range.<br>I rotori a velocità di rotazione variabile (Variable Speed Rotors, VSR) rappresentano un argomento di ricerca innovativo per lo sviluppo di nuove configurazioni di velivoli a decollo verticale, quali l’elicottero o il convertiplano. La possibilità di modificare la velocità di rotazione del rotore principale, in funzione della specifica condizione di volo, permette di ottenere prestazioni ottimali e significative riduzioni del consumo di carburante. Tuttavia, le problematiche connesse all’impiego di una velocità di rotazione variabile sono numerose e richiedono un approccio di analisi interdisciplinare. Il presente studio si configura come il primo esempio in letteratura di analisi prestazionale eseguita con simulazioni accoppiate rotore e motore turbo-albero per un modello di VSR.
Due strumenti di simulazione sono stati implementati al fine di effettuare la suddetta analisi accoppiata: un codice di simulazione di turbomotori a gas (TSHAFT) e un software per la stima dell’assetto e delle prestazioni di un elicottero (TCOPTER). La validità del concetto di rotore a velocità variabile è stata testata su un caso reale: a tale scopo i modelli di un elicottero UH-60 Black Hawk e di un motore turbo-albero GE T700 sono stati implementati e sottoposti a validazione su dati sperimentali. Successivamente, si è proceduto alla costruzione di una routine di ottimizzazione capace di individuare le velocità ottimali del rotore, in funzione delle diverse condizioni di volo dell’elicottero; tali velocità corrispondono alla condizione di minimo consumo di carburante.
Sono state analizzate a livello puramente prestazionale due differenti tipologie di VSR: la prima contempla l’utilizzo di una trasmissione tradizionale a rapporto di riduzione fisso (Fixed Ratio Transmission, FRT); la seconda prevede l’impiego un’ipotetica trasmissione a variazione continua (Continuously Variable Transmission, CVT). Nel caso FRT, poiché le velocità di rotazione della turbina e del rotore principale sono in un rapporto fisso, la velocità ottimale è stata calcolata come il miglior compromesso tra la velocità ottimale del rotore principale e quella della turbina. Nel caso CVT, invece, lo studio è stato effettuato assumendo che le velocità di rotore e turbina fossero libere di ruotare alle rispettive velocità ottimali.
Diversi casi di simulazione sono stati analizzati, al fine di quantificare i benefici legati alla possibilità di operare alla velocità ottimale del rotore in funzione delle condizioni di volo, dell’altitudine e del peso dell'elicottero. L'accoppiamento del modello dell'elicottero e del modello di motore turbo-albero è risultato determinante per un’adeguata individuazione della velocità corrispondente a consumo minimo. La massima riduzione nei consumi di carburante è stata stimata attorno al 13%.
Infine, sono state studiate possibili soluzioni progettuali in grado di apportare ulteriori margini di miglioramento a elicotteri operanti con VSR. In particolare, è stato effettuato un tentativo di riprogettazione preliminare della turbina di potenza del GE T700 con l’obiettivo di incrementarne l’intervallo di funzionamento a massima efficienza. In sostanza si è cercato di rendere le prestazioni della turbina meno sensibili alle variazioni nel numero di giri, cercando di estendere la zona di rendimento massimo attorno al punto di progetto.
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Brown, Joseph R. "Model Identification for the Space Shuttle Main Engine High Pressure Oxidizer Turbopump." Ohio University / OhioLINK, 1992. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1239733713.
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AUTORE, CLAUDIO. "Dynamic Models of the Main Sub-Assemblies of a High Performance Engine." Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2016. http://hdl.handle.net/2108/202263.
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Questo progetto di tesi focalizza la sua attenzione sulle metodologie di analisi sviluppate
per lo studio dinamico di sottoassiemi funzionali per un corretto design di motori a combustione
interna ad elevate prestazioni. La progettazione di un motopropulsore e frutto
di complesse attivita di concurrent engineering. Un motore e un insieme di sottosistemi
interconnessi, dove ciascuno di essi assolve una specica funzione e richiede competenze
speciche per essere progettato. Tuttavia non e possibile studiare un sottosistema isolato
dagli altri per via delle forti correlazioni. Il lavoro si articola in diverse sezioni, ciascuna
della quali volta a indagare nel dettaglio la metodologia di calcolo che di volta in volta si
rivela piu idonea.
Cuore dell'attivita e l'analisi della distribuzione condotta per mezzo di un modello
a parametri concentrati. L'indagine
esso-torsionale degli assi a camme sottolinea le
interrelazioni funzionali tra i diversi cinematismi. Ampliando il dominio di analisi il
modello a parametri concentrati e stato sviluppato per permettere lo studio dinamico del
comando distribuzione. La cinematica planare delle catene silent e delle catene a rulli
si e resa necessaria per analizzare la dinamica di ogni link delle catene. Forme modali
del comando e frequenze di risonanza dello stesso permettono di raggiungere un livello di
dettaglio non riscontrato in letteratura. Non solo la distribuzione benecia delle corrette
torsionali che vengono in tal modo calcolate, ma il comando stesso si rivela essere oggetto
di indagine scrupolosa per la dinamica dei tenditori idraulici e del moto di ogni link della
catena: angoli di ingranamento e velocita di impatto su guide e rocchetti possono essere
analizzate.
I sistemi ausiliari comandati da cinghie sono stati invece trattati per mezzo delle
equazioni del continuo. Si e evidenziato come solo un approccio statistico permette di individuare
la corretta dinamica se l'obiettivo e l'ottenimento delle forme modali trasversali
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dei rami di cinghia.
Non ultima la dinamica dell'albero motore e stata scandagliata nel dettaglio. Un
modello parametrico per lo studio della dinamica di motori pluricilindrici e stato sviluppato.
Importante in letteratura si e rivelato il contributo relativo all'analisi delle forze
di inerzia sbilanciate. Dierenti architetture motoristiche, tra le piu proposte sul mercato,
sono state oggetto di indagine. Una metodologia multibody per l'analisi dinamica
del motopropulsore rigido e stata inne sviluppata, beneciando delle forzanti di input
calcolate dall'indagine sull'albero motore.<br>This thesis focuses on the analytical methodologies developed for the dynamic study of
operational subsystems for the correct design of high performance internal combustion
engines. The engine design phase is a synthesis of several concurrent engineering activities.
An internal combustion engine is a highly complex system made by self-interacting
sub-assemblies, each of which requires very specic skills and detailed know-how to be
designed: it is nevertheless impossible to design each single component without considering
its proper function and how it works coupled with all the other sub-assemblies in
the complex engine system.
This thesis will explore dierent topics and for each will give a detailed explanation
of the analytical approach used to investigate and solve any specic task.
The main matter discussed in this work is how to approach and analyse a lumped
mass model both the single valve train and the complete chain drive system with a
bending-torsional deformable camshaft in order to consider the self-interaction of the
dierent valve train systems. In addition this lumped mass model approach is also used
to compute and analyse in detail the complex dynamic behaviour of the whole chain
drive system. A detailed 2D approach was also used to model the dynamic behaviour
for each single link of a roller or silent timing chain drive. As a result it was possible to
obtain a reliable and highly accurate model that can be used for calculating the timing
drive eigenvectors as well as to describe and analyse the complex dynamic behaviour of
hydraulic tensioners and for each chain link the capability to evaluate its tilt angle and
the contact impact with the guides.
In this thesis belt drive systems are also analysed. The dynamics and vibration of
axially moving continua have been extensively studied. The most important output of
the study conducted concerns the fact that to gain into the real dynamic behaviour of a
v
serpentine belt drive system it is necessary to use a statistical approach: a deterministic
approach is not sucient to detect the real dynamic response of such a complex dynamic
problem.
Lastly, the crankshaft dynamics has been in-depth analysed. A parametric model for
the multi-cylinder engines has been developed. The contribution of the inertia unbalanced
forces has been recognised as important. Various industrial case studies have been analysed.
The modelling of the crankshaft dynamics allows the denition of external forces
exerted on the engine and transmitted to the chassis through the engine mounts. The
theoretical bases for the development of a predictive multibody model of the powertrain
dynamics under the action of such external forces have been laid.
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Greco, Philip Andrew. "Turbine performance mapping of the space-shuttle main engine high-pressure fuel turbopump." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1995. http://handle.dtic.mil/100.2/ADA306473.
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Thesis (M.S. in Aeronautical Engineering) Naval Postgraduate School, September 1995.<br>Thesis advisor(s): Garth V. Hobson. "September 1995." Includes bibliographical references. Also available online.
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Southward, James D. "Laser doppler velocimetry in the space-shuttle main engine high-pressure fuel turbopump." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1998. http://handle.dtic.mil/100.2/ADA342224.
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Thesis (M.S. in Aeronautical Engineering) Naval Postgraduate School, March 1998.<br>Thesis advisor(s): Garth V. Hobson. "March 1998." Includes bibliographical references (p. 145-147). Also available online.
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Tosun, Mustafa G. "A methodology for multidisciplinary decision making for a surface combatant main engine selection problem." Thesis, Monterey, California: Naval Postgraduate School, 2014. http://hdl.handle.net/10945/42742.
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Approved for public release; distribution is unlimited<br>In the ship design process, delivering optimum performance while reducing development and construction costs are key considerations. A great amount of optimization effort should be done before progressing on a project. When it comes to the main engine selection phase that corresponds to the heart of the ship, the ultimate choice will affect the overall platform. However, the problem of main engine selection is, as is the overall ship design problem in general, basically a multidisciplinary and multicriterion optimization problem. In this project, we will focus on the multicriterion decision- making methodology for a surface combatant main engine selection problem. This study will consist of a collection of systematic approaches to the overall design optimization. The factors that need to be taken into consideration while selecting a main engine for a surface combatant will be discussed. We propose to develop and examine a mathematical model to analyze the main engine selection problem. The mathematical model will be comprehensively formulated, including both quantitative criteria as well as fuzzy systems, to establish an algorithm that will be able to create a unique solution or a set of Pareto solutions to the main engine selection problem.
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Foster, John D. "The application of Quality Function Deployment to the design and manufacture of engine main bearings." Master's thesis, This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-02022010-020218/.
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Pugh, Gareth Joseph. "The analysis of heat release in the investigation of split-main fuel injection in a diesel engine." Thesis, University of Nottingham, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.420356.
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Murugan, Ganesh. "Improving Knowledge Organizations Search Interface design by Evaluating Main-Stream Search Interface Design." Thesis, Högskolan i Borås, Institutionen Handels- och IT-högskolan, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-20835.
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Usage of search is very popular among all kinds of people to locate unknown information in websites. Mainstream search engines like Google work really hard to deliver a simple and effective search experience with the help of professionals and usability lab testing. Search interfaces often show a poor usability for the users who want to find information in differentknowledge organizations website. The purpose of this research is to create an understanding for some important characteristics of search interfaces, characteristics that may enhance the usability of knowledge organization search interface design. This Paper aim is to identify and discuss the specialized search interface design for knowledge organizations. This paper provides the detailed information about the search interface design and its improvement. This study gives the specialized wireframe standards for improving knowledge organization search interface design.<br>Program: Magisterutbildning i informatik
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Rutkowski, Richard J. "Cold flow simulation of the alternate turbopump development turbine of the space shuttle main engine high pressure fuel turbopump." Thesis, Monterey, California. Naval Postgraduate School, 1994. http://hdl.handle.net/10945/28034.
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Approved for public release; distribution is unlimited<br>Completion of the installation at the Naval Postgraduate School of a cold-flow test facility for the turbine of the Space Shuttle Main Engine High Pressure Fuel Turbopump is reported. The article to be tested is the first stage of the Alternate Turbopump Development model designed and manufactured by Pratt & Whitney. The purpose of the facility is to enable the development of non- intrusive flow measurements and comparison of those measurements with numerical simulations. Flow field characteristics of the turbine stator were predicted using a three-dimensional viscous flow code. A sensitivity study was conducted to determine the effect of inlet profile to flow field solution. Recommendations are made for future use of the test facility and validation of the numerical simulation scheme
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McKee, Joseph R. "Experimental and computational investigation of cold-flow through the turbine of the space-shuttle main engine high-pressure fuel turbopump." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1998. http://handle.dtic.mil/100.2/ADA356000.
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Thesis (M.S. in Aeronautical Engineering) Naval Postgraduate School, September 1998.<br>"September 1998." Thesis advisor(s): Garth V. Hobson. Includes bibliographical references (p. 115-116). Also available online.
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Studevan, Colin C. "Design of a cold-flow test facility for the high-pressure fuel turbopump turbine of the space-shuttle main engine." Thesis, Monterey, California. Naval Postgraduate School, 1993. http://hdl.handle.net/10945/19733.
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Approved for public release; distribution is unlimited<br>The design and installation at the Naval Postgraduate School of a cold-flow test facility for the turbine of the high-pressure fuel turbopump of the Space Shuttle Main Engine, is reported. The specific article to be tested is the 'Alternate Development Model' designed and manufactured by Pratt & Whitney. The design of individual components is documented. The installation of the facility subsystem is described in detail. A preliminary estimation of turbine performance is made.
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Koen, Peter-John. "An investigation into the main causes for poor OEE at the Struandale Engine Plant of Ford Motor Company of Southern Africa." Thesis, Nelson Mandela Metropolitan University, 2009. http://hdl.handle.net/10948/1172.
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The Struandale Engine Plant (SEP) was set up in 1924 and was the 16th Ford plant outside North America. The plant has since produced a variety of different components ranging from wheel hubs, to engine components such as crank shafts and cylinder blocks, to the assembly of engines. Manufacturing at this plant has predominantly been via the job-shop method, where mass production techniques were used. The RoCam programme preparation started in 1999. In 2001, SEP experienced a very steep ramp-up due to an unexpected surge in volume requirements. This forced the plant’s Human Resources team to embark on an “emergency” recruitment drive to cover the required human resources to support the programme. Due to this action being taken by the Human Resources department, the educational level of the employees was at a very basic level and had an adverse effect on productivity. The SEP operating committee made a decision in 2004 to focus on the implementation and maintenance of the Ford Production System (FPS). This initiative was important because ageing equipment needed to be maintained at predetermined intervals through continuous improvement techniques that form part of the FPS programme. If these techniques are not in place, the Overall Equipment Efficiency (OEE) suffers. This programme comprises a number of critical elements such as FTPM that requires a certain education and skill level in effort to completely comprehend the system. Evidently, education was an issue and an effort had to be made to upgrade the workforce skill’s level, specifically the team leaders. On the 30th January 2008, Ford Motor Company of Southern Africa (FMCSA) had announced plans to invest more than R1.5-billion to expand its operations in South Africa for the production of Ford's next-generation compact pick-up truck iv and Puma diesel engine. In an effort to secure and retain the Puma contract at SEP, the plant had to prove that it could compete globally; hence it had to improve OEE levels to the world-class standard. The Puma engine contract had been contracted to South America, Turkey, Thailand, and South Africa. This was a strategic move in order to retain flexibility within the supply chain i.e. if one supplier / plant cannot deliver, demand can be shifted to one of three alternative suppliers. The problem statement which will be addressed by this research is: What are the main causes for the poor Overall Equipment Efficiency level (OEE) at the Struandale Engine Plant of Ford Motor Company of Southern Africa? The Primary Objective of this research is to: Identify the main causes for the poor Overall Equipment Efficiency level (OEE) at the Struandale Engine Plant of Ford Motor Company of Southern Africa
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Farhang, Mehr Farzaneh. "An investigation of the efficacy of a water-cooled chill in improving the as-cast structure of the main bearing bulkhead in A319 engine blocks." Thesis, University of British Columbia, 2017. http://hdl.handle.net/2429/63809.
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In recent years, the automotive industry has been increasing the production of small, high-power gas engines as part of several strategies to achieve the new “Corporate Average Fuel Economy” (CAFE) standards, while at the same time meeting consumer demand for increased performance. This trend requires an improvement in the thermal and mechanical fatigue durability of the aluminium alloys used in the production of the cylinder heads and engine blocks in these engines. In the absence of modifying alloy chemistry, which potentially has significant implications for downstream operations such as heat treating and machining, one viable way to improve fatigue performance is to reduce the length-scales of the microstructural features arising from solidification that limit fatigue life. This, in turn, may be achieved by increasing the cooling rate during solidification (reducing the solidification time). Conventionally, solid chills are employed in industry to achieve this. A potential means of improving the efficacy of these chills is to incorporate water cooling. To assess the effectiveness of this method, a water-cooled chill was designed at UBC and installed in a bonded-sand engine block mould package (1/4 section). Twelve experiments were conducted with both a conventional solid chill and with a water-cooled chill (with and without a delay in water cooling). The moulds were instrumented with thermocouples to measure the evolution of temperature at key locations in the casting, and “Linear Variable Displacement Transducers” (LVDTs) to measure the gap size at the interface between the chill and the casting. A coupled thermal-stress mathematical model was developed in “ABAQUS 2016” to reproduce the experimental conditions and provide insight into interfacial heat transport and gap dynamics. Overall, the experimental and modelling results show the gap dynamics are complex and play a critical role in governing heat transport. If implemented carefully, the adoption of water-cooled chill technology has the potential to improve the cast microstructure, hence, increase the fatigue durability of the engine blocks.<br>Applied Science, Faculty of<br>Materials Engineering, Department of<br>Graduate
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Ujvari, Szerena Krisztina. "Journal Bearing Friction Optimization." Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-60669.
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Engine downsizing, improving fuel efficiency while satisfying the environmental legislations are one of the main driving forces in developing new solutions for passenger cars.Engine main bearings, are journal bearings which support the crankshaft and operate principally in full film lubrication. Defining the optimum design parameters of the bearings which can provide low friction and high durability for automobiles represents a multi-variable problem.Being the supporters of the main shaft driven by the internal combustion engine, main bearings are subjected to strenuous operating conditions. These include high loads and pressures amongst others. The trend in lubricant selection for these components is shifting towards choosing engine oils with lower viscosity to further reduce fuel consumption. Simultaneously with the shift in oil, new solutions for controlling the geometry and the topography on the micro-scale are becoming available. Three main bearing top layers plated on a conventional aluminum alloy containing tin and silicon were selected for the study. The top layers, one bismuth based and two newly developed polymer based, were investigated for their frictional and wear performance.In order to study experimentally the influence of different design parameters on bearing performance a test rig and a methodology was developed. The selected engine main bearings were tested in lubricated condition with two oils having different viscosity. Pre - and post test analysis of the shaft surface roughness was performed using white light interferometry. The wear performance of the bearings was measured both as mass loss and surface topography.The results suggest that the developed test rig can be used to simulate close to running condition testing. The measurement method and set up shows good consistency at a load of 2000 N, but indicates inconsistency in set up at 500 N.It is found that the newly developed engine main bearing top layers have promising frictional and wear performance, providing a reduction in friction by up to 20%.
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Tamatam, Lakshminarayana Reddy. "Tribological performance of different crankshaft bearings in conjunction with textured shaft surfaces." Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-65511.
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Improving vehicle efficiency and complying to stricter exhaust emission legislations are some of the driving factors to advancement in technology of engine components. The main bearings in an internal combustion engine contribute significant amount of friction. These bearings support engine loads and allow free rotation of the crankshaft. The bearings consist of a steel backing, a lining material and an optional overlay. The overlays help to minimize friction and enhance seizure resistance during adverse operating conditions. The aim of the thesis is to study the friction and wear performance of five multi-layered bearings with various overlays. A bi-metal bearing is used as the reference for comparison. Additionally, influence of two shaft surface textures are also studied comparing to the standard shaft surface finish. A modified twin-disc test rig is used to evaluate tribological performance of the bearing system. Forced misalignment tests were also performed to simulate edge contact conditions, which occur in an engine due to shaft deflection, asymmetrical loading and other factors. The bearing surface profiles were measured using an optical interferometer. The test setup showed good repeatability and consistent results. Relative friction and wear performance are compared and the bearings are ranked accordingly. One bearing type with a polymer and MoS2 overlay showed the best overall performance. This bearing combined with a plateau textured shaft further lowered the friction coefficient by 3 % in boundary and mixed lubrication regime.
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Hanson, Anton, and Emma Horck. "Arbetsskador som drabbar marin maskinpersonal : En kartläggning av skaderiskerna för marin maskinpersonal ombord på svenska fartyg, samt en jämförelse av skaderisken med liknande arbeten iland." Thesis, Linnéuniversitetet, Sjöfartshögskolan (SJÖ), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-25735.
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Syftet med undersökningen är att kartlägga skaderiskerna med att arbeta som marin maskinpersonal och jämföra skaderisken med anställda som har liknande arbeten iland. Undersökningen inbegriper även att kartlägga vilka typer av arbetsskador, som ger de mest allvarliga konsekvenserna för den anställde i förhållande till hur vanlig olyckan är. Undersökningen är en litteraturstudie där Arbetsmiljöverkets arbetsskadeanmälningar utgör grundmaterialet, där totalt 198 arbetsskador behandlades och kategoriserades. Transportstyrelsens statistik för ombordanställda jämfördes med Arbetsmiljöverket och Statistiska centralbyrån statistik över anställda iland. Detta för att se vilken yrkeskategori som hade högst skaderisk. Resultatet av undersökningen visar att arbetsolyckor under kategorierna ”Bära” och ”Halka/Snubbla/Trilla” och arbetssjukdomar under kategorin ”Tunga lyft/Arbetsställningar” är de arbetsskador, som ger de mest allvarliga konsekvenserna i förhållande till hur vanlig arbetsskadan är. Vid jämförelsen av skaderisken med liknande yrkeskategorier iland ligger maskinanställda till sjöss näst sämst till. Den yrkeskategori som är mest lik marin maskinpersonal har fyra gånger mindre skaderisk.<br>The aim with this thesis is to identify the risks of injury while working as marine engine staff and compare the risk of injury to employees who have similar jobs ashore. The thesis also includes identifying the types of work injuries, which leads to the most serious consequences for the employee in relation to how frequent the accident is. The thesis studied literature in which the Swedish Work Environment Authority's work injury reports are the base material, where a total of 198 injuries were treated and categorized. The Swedish Transport Agency’s statistics for employees at sea were compared with the Swedish Work Environment Authority’s and the Swedish Central Bureau of Statistics’ statistics for employees ashore. The result of the thesis show that work related accidents categorized as "Carry" and "Slip/Trip/Fall" and work related diseases categorized as "Heavy lifting/Working positions" are the injuries leading to the most serious consequences in relation to how frequent the accident is. When comparing the risk of injury with similar professions ashore, marine engine staff is the second worst. The profession most similar to marine engine staff has four times less risk of injury.
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Brooks, Thomas D. "Split-main fuel injection strategies for diesel engines and their influence on emissions and fuel consumption." Thesis, University of Nottingham, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.417186.
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Marin, Radovan [Verfasser]. "The influence of engine and vehicle constructions to fuel consumption and air pollution / Radovan Marin." München : GRIN Verlag, 2020. http://d-nb.info/1209545497/34.
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De, Césare Cédric. "Acquisition de mosaïques d'images complètes à l'aide d'un engin sous-marin autonome." Nice, 2009. http://www.theses.fr/2009NICE4055.
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Durant les dernières années, l’imagerie visuelle est de plus en plus utilisée dans le milieu sous-marin, aussi bien comme une aide à la navigation que comme un outil de cartographie permettant l’étude et la surveillance des fonds sous-marins. Ces opérations de surveillance consistent principalement en l’établissement de cartes des fonds sur de larges zones (plusieurs km2). Les contraintes du milieu (grandes profondeurs, faible absorption de la lumière, etc…) imposent comme systématique l’utilisation de robots autonomes (AUVs), et ce à une altitude proche du fond. La carte est alors réalisée en mettant en correspondance les images enregistrées et en les fusionnant : on parle de mosaïques d’images. Les méthodes actuelles de construction de larges mosaïques ne garantissent pas le recouvrement de celles-ci, permettant ainsi l’existence possible de trous. Pourtant, cet enjeu est primordial afin de permettre une observation complète de la zone de mission. C’est dans ce contexte que s’inscrit notre sujet : «Acquisition de mosaïques d’images complètes à l’aide d’un engin sous-marin autonome». Nous développons une stratégie adaptative qui assure le recouvrement de la mosaïque. Nous nous basons sur des trajectoires de type lawnmower et déterminons, à la fin de chaque segment observé, la distance avec le prochain segment. Cette distance dépend de l’incertitude de positionnement du robot. Celui-ci dérivant au cours du temps, il doit régulièrement se repositionner pour ne pas se perdre. En ce sens, les caractéristiques morphologiques de la zone observée vont définir des événements possibles de recalage, au cours desquels le robot va faire une mise à zéro de son erreur. Plus la région observée est texturée, plus le nombre d’événements est élevé, et plus le véhicule est mieux à même de se repositionner. La distance inter-segment sera alors grande. Au contraire, plus la région sera lisse, plus la distance de recouvrement sera faible. Dans notre souci d’optimisation de la distance inter-segment, nous risquons d’être confrontés à des situations de mises en correspondance d’images présentant un faible recouvrement. Les méthodes classiques échouent dans de telles situations car elles forcent les associations entre les localités des images (templates). Nous avons établit une méthode, basée sur la Théorie de l’Information, qui pallie ce problème et prend en compte ces ambiguïtés<br>During the last years, visual imagery has been more and more used in the underwater environment, as well as an help for navigation than as a tool for cartography allowing the study and survey of seafloors. These operations of survey consist principally in the establishment of maps of the seafloor on large zones (several km2). The constraints of the environment (depth, low absorption of light, etc…) impose as systematic the use of autonomous underwater vehicles (AUV), and this at an altitude close to the ground. The map (image mosaic) is then obtained by matching and fusing the recorded images. The current construction methods of large mosaics do not guarantee the overlap of these ones, leading to the possible existence of holes in the mosaics. However, this stake is high in order to allow the complete observation of the mission zone. It is in this context that we have developed our subject of research : “Acquisition of complete image mosaics with an autonomous underwater vehicle”. We develop an adaptive strategy that ensures the mosaic overlapping. We base our study on lawnmower trajectories and determine, at the end of each observed segment, the distance with the next segment. This distance depends on the robot relative positioning incertitude. This incertitude increasing with the time, the vehicle must recalculate its position frequently in order to not lose itself. The relief characteristics of the observed zone will define possible registration events, for which the vehicle will reset his positioning error. The more the textured region is, the higher the number of events is, and thus the vehicle can better position itself. The inter-track distance is then high. On the contrary, the less the region is informative, the lower the distance is. In our aim of inter-track distance optimisation, we risk to be confronted to low overlap image matching situations. The classical methods fail in such situations because they force the association between image localities (templates). We have established a method, based on Information Theory, that palliates this problem and take into account these ambiguities
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Pham, Hai Minh. "Computation of the vibration of a whole aero-engine model with nonlinear bearings." Thesis, University of Manchester, 2010. http://www.manchester.ac.uk/escholar/uk-ac-man-scw:128171.
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Aero-engine assemblies are complex structures typically involving two or three nested rotors mounted within a flexible casing via squeeze-film damper (SFD) bearings. The deployment of SFDs into such structures is highly cost-effective but requires careful calculation since they can be highly nonlinear in their performance, particularly if they are unsupported (i.e. without a retainer spring). The direct study of whole-engine models with nonlinear bearings has been severely limited by the fact that current nonlinear computational techniques are not well-suited for complex large-order systems. The main contributions of this thesis are: • A procedure for unbalance response computation, suitable for generic whole-engine models with nonlinear bearings, which significantly extends the capability of current finite element packages. This comprises two novel nonlinear computational techniques: an implicit time domain integator referred to as the Impulsive Receptance Method (IRM) that enables rapid computation in the time domain; a whole-engine Receptance Harmonic Balance Method (RHBM) for rapid calculation of the periodic response in the frequency domain. Both methods use modal data calculated from a one-off analysis of the linear part of the engine at zero speed.• First-ever analyses on real twin-spool and three-spool engines. These studies illustrate the practical use of these solvers, provide an insight into the nonlinear dynamics of whole-engines and correlate with a limited amount of industrial experimental data. Both IRM and RHBM are directly formulated in terms of the relative response at the terminals of the nonlinear bearings. This makes them practically immune to the number of modes that need to be included, which runs into several hundreds for a typical engine. The two solvers are extensively tested on two/three-shaft engine models (with 5-6 SFDs) provided by a leading engine manufacturer using an SFD model that is used in industry. The tests show the IRM to be many times faster than an established robust conventional implicit integrator while achieving a similar level of accuracy. It is also shown to be more reliable than another popular implicit algorithm. The RHBM enables, for the first time, the frequency domain computation of the nonlinear response of whole-engine models. Its use is illustrated for both Single-Frequency Unbalance (SFU) excitation (unbalance confined to only one shaft) and Multi-Frequency Unbalance (MFU) excitation (unbalance located on two or more shafts, rotating at different speeds). Excellent correlation is demonstrated between RHBM and IRM.The parametric studies compare and contrast the frequency spectra for SFU and MFU cases. They also reveal the varying degree of lift at the unsupported SFDs. The sensitivity of the response to end-sealing and bearing housing alignment is also illustrated. It is demonstrated that the use of suitably preloaded vertically oriented “bump-springs” at the SFDs of heavy rotors produces a significant improvement in journal lift. It is also shown that the consideration of a slight amount of distributed damping in the structure significantly affects the predicted casing vibration levels, bringing them closer to measured levels, while having little effect on the SFD orbits.
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Michalík, David. "Simulátor řízení vozidla." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2019. http://www.nusl.cz/ntk/nusl-400556.
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This master’s thesis is mainly focused on creating our own car driving simulator and basic data gathering from the driver’s input. To achieve this goal, the thesis includes introduction to man-machine systems and basic information about functions and runtime game engine employs. Research about commonly used open source game engines is also presented with a detailed focus on the engine we chose - Unreal Engine. In conclusion ofthis thesis, a full version of a car driving simulator is created with gathered data analysis.
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ZIANI, CHERIF SALIM. "Contribution a la modelisation, l'estimation des parametres dynamiques, et la commande d'un engin sous marin." Nantes, 1998. http://www.theses.fr/1998NANT2046.
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La maitrise du monde marin repose sur la mise en uvre en parallele de deux strategies distinctes : la connaissance de ses lois et le developpement d'outils pour son investigation. Les vehicules sous-marins sont des moyens qui repondent a cette double problematique. Le present travail s'adresse a une classe de ces vehicules. Dans un but de simulation et de commande, nous proposons une methodologie visant a identifier le comportement dynamique des engins teleoperes (rov) a six degres de liberte (ddls). Notre contribution se concretise d'abord dans une revue des methodes existantes, puis dans l'application d'une methodologie bien connue (pour les robots manipulateurs) mais jamais experimentee pour les engins sous-marins, et enfin dans sa mise en uvre experimentale sur un rov d'essai. L'approche adoptee peut etre caracterisee comme suit : nous cherchons a etablir d'abord un modele du comportement dynamique de l'engin. Celui-ci doit avoir un caractere de generalite sans pour autant etre complexe. Les parametres de ce modele sont ensuite estimes par l'algorithme des moindres carres ordinaires. En particulier, nous montrons quelles peuvent etre les contraintes pratiques de sa mise en uvre ainsi que les solutions que nous preconisons. En dernier, nous utilisons les parametres estimes pour la mise au point d'une commande dynamique modifiee. Afin d'evaluer cette methodologie d'identification et de commande, une mise en uvre experimentale est effectue pour le mouvement en cap (1ddl) du rov vortex de l'ifremer. Cette meme demarche est ensuite testee en simulation sur les 6ddls du vortex.
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Stirbys, Renatas. "Kelto "Optima Seaways" aušinimo siurblio sistemos virpesių tyrimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2013. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2013~D_20130626_141507-94096.
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Magistro baigiamojo darbo teorinėje dalyje analizuojami įvairūs virpesių lygio mažinimo būdai bei schemos laivuose. Aprašoma virpesių klasifikacija, pagrindiniai virpesių žadintojai laive, virpesių skaičiavimo būdai. Eksperimentinėje dalyje pateikiama kelto „Optima Seaways“ siurblio virpesių matavimo metodika. Nagrinėjami reiso Klaipėda-Karlshamnas-Klaipėda metu atliktų matavimų rezultatai bei nustatomos tiriamo siurblio padidinto virpesių lygio priežastys. Paskutinėje darbo dalyje pateikiamas racionalus sprendimas, reikalaujantis minimalių lėšų ir laiko sanaudų, tiriamo siurblio virpesių lygio sumažinimui.<br>The theoretical part of the Master’s thesis analyzes various vibration reduction systems and schemes in ships. Classification of vibrations on board, main vibration sources and vibration calculations are presented. The experimental part presents methodic for vibration measuring of ferry “Optima Seaways” pump. Vibration data, received during passage Klaipėda- Karlshamn- Klaipėda, is analyzed and reason of high pump vibration level is identified. Last part of thesis presents rational solution, with minimal cost and time expenses, for reduction of pump vibration level.
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ALAOUI, MYDRISS. "Etude theorique et numerique du comportement bidimensionnel et quasi-statique d'un cable de remorquage d'un engin sous-marin." Rennes 1, 1995. http://www.theses.fr/1995REN10173.
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Cette these porte sur la modelisation du comportement d'un cable de remorquage sous-marin flexible et inextensible, tracte par un bateau, auquel est attache a son extremite un engin de mesure (sonar,). Ce probleme a ete pose par l'i. F. R. E. M. E. R. En vue de mettre au point des methodes numeriques performantes et rapides pour determiner la trajectoire du cable et de l'engin en fonction de celle du bateau. Apres avoir modelise le probleme physique en faisant des hypotheses simplificatrices nous sommes conduits a la resolution d'un systeme d'equations d'evolution paraboliques quasi-lineaires integro-differentielles singulieres avec des conditions aux limites melees, dont l'inconnue est l'angle que fait la tangente au cable avec l'horizontale. Nous pouvons aussi prendre en compte la trainee de l'engin. Nous avons montre l'existence et l'unicite de la solution du probleme continu ; pour cela nous avons utilise des techniques de pseudo-monotonie et de compacite introduites par j. -l. Lions, ladyzenskaja, f. Murat pour les equations paraboliques quasi-lineaires. Mais les theoremes d'existence-unicite connus necessitent de la regularite sur le second membre. Pour cela nous avons regularise le probleme continu et nous avons montre que le probleme regularise admettait une solution et nous avons obtenu des estimations a priori pour cette solution. Mais ces estimations sont insuffisantes pour passer a la limite en utilisant des theoremes de compacite. Pour remedier a cela, nous avons donne des conditions suffisantes sur les donnees du probleme physique ; ces conditions qui sont raisonnables au point de vue physique nous ont permis d'avoir plus de regularite et de pouvoir passer a la limite. Pour l'unicite nous etions amenes a montrer quelques proprietes d'une solution telles que la negativite et la monotonie d'une solution par rapport a la variable d'espace. Nous avons discretise le probleme continu par la methode des elements finis p#1 et nous avons etabli des estimations d'erreurs dans des espaces appropries. Ensuite nous avons defini une discretisation complete en espace-temps ; ceci nous a amene a proposer des schemas d'integration numerique tels que euler explicite et euler semi-implicite ainsi que crank-nicolson extrapole et runge-kutta dont nous avons etudie la stabilite numerique. En dernier, nous avons valide par des exemples numeriques notre code de calcul qui adapte le pas de temps
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Joannides, Marc. "Navigation intégrée d'un engin sous-marin remorqué. Filtrage non-linéaire des systèmes sans bruit d'observation et/ou mesures parfaites." Aix-Marseille 1, 1997. http://www.theses.fr/1997AIX11005.
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Dans la premiere partie de cette these, nous considerons le probleme de l'estimation de la trajectoire d'un engin sous-marin remorque, en se basant sur deux sources d'information differentes: des mesures precises d'acceleration de l'engin (ins) et des mesures de position du navire de surface (gps). Les mesures ins restituent fidelement les hautes frequences du mouvement de l'engin, mais derivent avec le temps. Nous utilisons l'information gps, fiable a long terme, pour recaler le mouvement moyen de l'engin. Nous introduisons un modele numerique du systeme cable-engin pour transferer l'information de positionnement depuis la surface jusqu'a l'engin, et nous proposons un estimateur hybride de sa trajectoire. Nous nous interessons ensuite au probleme de filtrage des processus de diffusion, dans le cas ou l'on dispose d'observations non-bruitees, en temps discret. Ce probleme est singulier car la loi conditionnelle est supportee a chaque instant par un ensemble de niveau de la fonction d'observation, qui est en general de mesure nulle (pour la mesure de lebesgue) dans l'espace d'etat. Dans le cas ou la valeur observee est reguliere, nous obtenons une expression explicite pour la densite de la loi conditionnelle, par rapport a la mesure canonique sur l'ensemble de niveau. Ce resultat est d'abord obtenue par une approche directe. Nous introduisons ensuite une approche asymptotique qui permet d'aborder le cas des valeurs singulieres. La methode ainsi developpee peut etre adaptee pour resoudre un probleme voisin en statistique des processus: il s'agit de l'asymptotique petit bruit de l'estimateur bayesien dans le cas non identifiable, lorsque l'observation est un signal deterministe perturbe. Nous donnons une expression explicite pour la densite de la loi limite, lorsque l'ensemble des points minimum de l'information de kullback-leibler est une sous-variete de l'espace des parametres
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Dorée, Philippe. "Analyses atmosphériques et d'airs expirés : contribution à la connaissance des effets du confinement à bord d'un sous-marin nucléaire lance-engins." Aix-Marseille 3, 1998. http://www.theses.fr/1998AIX30111.
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Une campagne de prelevements atmospheriques et d'air expire a eu lieu a bord d'un sous-marin nucleaire lance-engins sur un groupe de 19 sujets et selon des modalites permettant d'apprecier la variabilite spatiale (points de prelevements multiples) et la variabilite temporelle (prelevements repetes au cours de la patrouille). Les echantillons ont ete analyses par cpg-fid et cpg-sm et les resultats soumis a un depouillement associant analyse de variance et analyse en composantes principales. Les enseignements tires de l'etude pour ce qui concerne des polluants de type industriel font etat d'une repartition homogene a bord et d'un respect avec une marge tres importante des valeurs-limites atmospheriques et des index biologiques d'exposition quand ils existent. Les variations de concentrations de produits d'origine metabolique comme le n-pentane, l'isoprene, le 1,1,1 trichloroethane sont egalement envisagees en rapport avec les donnees de la litterature (lipoperoxydation, stress, metabolisme des hydrocarbures halogenes).
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Olguín, Díaz Ernesto. "Modélisation et commande d'un système véhicule/manipulateur sous-marin." Grenoble INPG, 1999. http://www.theses.fr/1999INPG0012.
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Ce travail de these, en co-tutelle avec l'institut francais de recherche pour l'exploitation de la mer (ifremer) est consacre a un double but. Le premier est l'obtention d'un modele analytique du systeme vehicule/-manipulateur sous-marin (uvms, de l'anglais underwater vehicle/manipulator system), qui nous permettra plus tard de definir le second but : celui de la conception de la commande. La modelisation d'un uvms est realise en considerant les modeles lagrangiens du vehicule et du manipulateur a base libre plus les efforts hydrodynamiques et hydrostatiques qui s'exercent sur les differents corps du systeme. La modelisation des efforts hydrodynamiques est fait en decomposant les systemes en des differents corps rigides. Pour le cas du manipulateur, ceux-ci sont approches a des corps ellipsoides ou des corps cylindriques selon le type d'effort modelise : inertielle ou dissipative. Le modele est complete lorsqu'on ajoute les modeles des propulseurs du vehicule est des actionneurs du bras manipulateur. La commande de cette systeme est concue a partir de deux regulateurs lineaires pd. Les bandes passantes induites etant suffisamment differentes pour le vehicule et le manipulateur, cette boucle decouple partiellement le uvms, montre par une analyse sur la theorie des perturbations singulieres. Une commande non lineaire independante de la connaissance des parametres du systeme est concue a partir de une loi optimale. Cette deuxieme boucle, malgre la perte de optimalite, reste robuste et les performances du systeme en boucle fermee rivalisent avec les performances d'une commande linearisante.
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Ripa, Roberta. "Integrare Search Engine Optimization e Website usability al processo di localizzazione di un sito Web. Proposta di localizzazione dal francese all’italiano del sito del Parc de loisirs du Lac de Maine." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/10027/.
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Ce mémoire a comme objectif de montrer le processus de localisation en langue italienne d’un site Internet français, celui du Parc de loisir du Lac de Maine. En particulier, le but du mémoire est de démontrer que, lorsqu’on parle de localisation pour le Web, on doit tenir compte de deux facteurs essentiels, qui contribuent de manière exceptionnelle au succès du site sur le Réseau Internet. D’un côté, l’utilisabilité du site Web, dite également ergonomie du Web, qui a pour objectif de rendre les sites Web plus aisés d'utilisation pour l'utilisateur final, de manière que son rapprochement au site soit intuitif et simple. De l’autre côté, l’optimisation pour les moteurs de recherche, couramment appelée « SEO », acronyme de son appellation anglais, qui cherche à découvrir les meilleures techniques visant à optimiser la visibilité d'un site web dans les pages de résultats de recherche. En améliorant le positionnement d'une page web dans les pages de résultats de recherche des moteurs, le site a beaucoup plus de possibilités d’augmenter son trafic et, donc, son succès.
Le premier chapitre de ce mémoire introduit la localisation, avec une approche théorique qui en illustre les caractéristiques principales ; il contient aussi des références à la naissance et l’origine de la localisation. On introduit aussi le domaine du site qu’on va localiser, c’est-à-dire le domaine du tourisme, en soulignant l’importance de la langue spéciale du tourisme. Le deuxième chapitre est dédié à l’optimisation pour les moteurs de recherche et à l’ergonomie Web. Enfin, le dernier chapitre est consacré au travail de localisation sur le site du Parc : on analyse le site, ses problèmes d’optimisation et d’ergonomie, et on montre toutes les phases du processus de localisation, y compris l’intégration de plusieurs techniques visant à améliorer la facilité d’emploi par les utilisateurs finaux, ainsi que le positionnement du site dans les pages de résultats des moteurs de recherche.
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Gabriel, Vladislav. "Internet v marketingu." Master's thesis, Vysoká škola ekonomická v Praze, 2008. http://www.nusl.cz/ntk/nusl-16633.
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This project describes internet marketing and its components (search engine marketing, internet advertising, internet PR, e-mail marketing etc.). It also describes the possibilities of employing internet in marketing and depicts new ways of online communication. The expenses for internet advertising are constantly growing as well as the number of internet users. The number of universities is increasing and so is the competition. That's why it's vital that they should act as a part of the market and use marketing strategies. The objective of this project is to analyse and suggest communication strategies of the Faculty of Management at the University of Economics in Prague using the knowledge acquired from the theoretical part. The practical part specifies the target group, draws up a report and chooses the way of communication. Further on, we will consider the timing of every single activity and the overall budget.
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Sousselier, Thomas. "Conception et validation d'un algorithme de mise en formation d'essaim de micro-robots sous-marins auto-organisés : application à l'exploration de zone en guerre des mines." Lorient, 2013. https://hal.archives-ouvertes.fr/tel-01096431.
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La convergence des besoins en mission de guerre des mines et des avancées scientifiques dans le domaine de la robotique nous ont amenés à explorer une méthode innovante pour résoudre ce problème. Contrairement aux solutions de l'état de l'art, nous proposons de prendre en compte l'ensemble des contraintes opérationnelles de la mission et d'utiliser de nombreux UUV. Dans nos travaux, nous proposons une solution originale : le comportement d'essaim. Le comportement réactif des robots permet de faire émerger un comportement de groupe, effectuant la mission. Nous justifions l'approche en essaim de micro-robots par une étude technico-opérationnelle. Nous nous appuyons sur une méthode partant du général vers le particulier pour concevoir notre algorithme. Cet algorithme est capable d'aligner un essaim et de le faire progresser le long d'une trajectoire sans aucune communication. Nos résultats montrent que notre solution est robuste. L'essaim parvient à reconstituer la formation en cas de perte. La présence d'obstacles ne dégrade pas l'efficacité opérationnelle de l'essaim. L'application des méthodes en essaim à un domaine très contraint reste très peu explorée. Nous estimons que nos travaux montrent leurs capacités sur des missions complexes<br>Convergence of mine warfare needs and scientific advances in the field of robotics lead us to explore an innovative method to solve this issue. In our work, we propose a solution never applied to this specific area: the swarm behavior. The reactive behavior of robots leads to an emergent behavior, performing the mission. Our technical and operational study allows us to justify the micro-robots swarm approach. Before designing our algorithm by a method starting from the general to the particular, we specify the operational need. Our algorithm drives the swarm to form a line and to advance along a path without use any communication. We analyze the results of our algorithm to draw various conclusions. We demonstrate that our solution is robust. The swarm manages to reconstruct the formation in case of loss. The presence of obstacles does not decrease the operational efficiency of the swarm. Application of swarm methodologies to a very constrained environment remains largely unexplored. We believe that our research shows their capacity for complex missions
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Musilová, Veronika. "Elektronický obchod a jeho marketing." Master's thesis, Vysoké učení technické v Brně. Fakulta podnikatelská, 2009. http://www.nusl.cz/ntk/nusl-222011.
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I will attend to creation suitable model of e-marketing for e-shop with flowers in my diploma work. The aim will by join the possible instruments of online marketing in order that the company can succesfully work on the Internet. and ensure the betterposition before the competition. I will focus on e-marketing and its individua instruments. I will make some analysis of the company, by virtue of I will propose what kind of e-marketing can company use. Last but not least I will attend to the aims, which company should achieve and own potential which should valorize.
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Rosén, Carl-Johan. "Bricoleur, digitala varelser och brus." Thesis, Konstfack, Institutionen för Konst (K), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:konstfack:diva-3313.
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Bricoleur, digitala varelser och brus utgör tre viktiga noder, runt vilka mitt konstnärliga arbete rör sig. Parallellt med ett antal av mina verk beskrivs dessa begrepp kortfattat.<br>Bricoleur, digital beings and noise are three important nodes, making up cornerstones of my artistic work. These ideas are explained briefly parallel to a selection of my artworks.
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Cassagnabère, Christophe. "Etude et implémentation d'algorithmes d'illumination globale stochastiques accélérés par le matériel." Littoral, 2007. http://www.theses.fr/2007DUNK0167.
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Les méthodes stochastiques de Monte-Carlo représentent une solution élégante permettant de calculer des effets d'illumination globale de manière plus réaliste que d'autres algorithmes de rendus. Toutefois, le principal inconvénient de ces méthodes réside dans les temps de calcul conséquents qu'ils immpliquent la plupart du temps. Que ce soit par l'utilisation de structures de données hiérarchiques ou par la distribution des calculs sur un cluster d'ordinateurs personnels en passant par l'implémentation sur une architecture de type super-ordinateur, nombre de méthodes existent en vues d'améliorer les performances des algorithmes de Monte-Carlo en terme de temps de rendu. Nous apportons une contribution à ce domaine très actif en abordant la question sous plusieurs angles. D'une part nous proposons une étude approfondie d'un serveur de calcul commercial dédié au calcul de lancer de rayons, et nous proposons une méthode afin d'étendre le champ d'appliqations de ce serveur aux techniques de Monte-Carlo pour le rendu. D'autre part, nous présentons une méthode de classification des rayons au sein et une reconstruction des algorithmes de Monte-Carlo classiques, permettant ainsi une utilisation efficace des cartes graphiques programmables récentes pour l'accélération du calcul d'intersections intervenants dans le processus. Enfin nous proposons l'architecture logicielle modulable IGLOO, conçue dans le cadre de cette thèse afin de disposer au sein du Laboratoire d'Informatique du Littoral d'une plate-forme de développement et de comparaison des techniques de Monte-Carlo commune servant de base à de nombreux projets en cours dans le cadre d'autres travaux<br>Monte-Carlo methods are elegant and efficient solutions for computing realistic global illumination effects far better than most other algorithms. However the main drawback of these methods appears in the important rendering times involved by such techniques. By using adapted hierarchical data structures, distributing the main part of computations on a large personal computer cluster or even designing a specific dedicated software for a specific supercomputer architecture, many solutions exist, trying to improve Monte-Carlo algorithms performances from a rendering time point of view. In our work we contribute to this particularly active research topic and we approach it in several and complementary ways. First of all we propose a near complete study of ray-tracing dedicated server, and we propose to extend ots capabilities to the use of Monte-Carlo methods for rendering. Then, we present a specific method of our own in order to classify rays and an adapted rebuild of classical Monte-Carlo algorithms, so we can efficiently use modern programmable graphics cards to accelerate intersections tests involved in the rendering process. Last but not least, we present the IGLOO modular software architecture. It has been designed and implemented during this thesis in order to permit the whole LIL Laboratory to benefit from a commune development and benchmark platform for Monte-Carlo methods. This architecture is at the basis of many other thesis works actually in progress
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Gaškaitė, Giedrė. "Įmonės „Stoke Travel” internetinio marketingo priemonės." Bachelor's thesis, Lithuanian Academic Libraries Network (LABT), 2013. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2013~D_20130620_113443-95197.
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Bakalauro baigiamajame darbe nagrinėjamos įmonės „Stoke Travel” interentinio marketingo priemonės. Pagrindinis tyrimo tikslas, aptarus internetinio marketingo priemones teoriniu požiūriu ir atlikus anketinę apklausą, bei interviu, ištirti kaip respondentai vertina įmones naudojamas internetinio marketingo priemones, bei pasiūlyti įmonei tinkamiausias interentinio marketingo priemones.<br>In this Bachelor’s Degree Work companies “Stoke Travel” Internet marketing tools are analyzing. The main objective is after researching theoretical background of the subject to conduct a survey and interview to find out companies internet marketing tools dimension, their clients internet use peculiarity and clients evaluation to the companies used internet marketing tools.
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Rousselle, Denis. "Classification d’objets au moyen de machines à vecteurs supports dans les images de sonar de haute résolution du fond marin." Electronic Thesis or Diss., Rouen, INSA, 2016. http://www.theses.fr/2016ISAM0020.
Full textAbstract:
Cette thèse a pour objectif d'améliorer la classification d'objets sous-marins dans des images sonar haute résolution. En particulier, il s'agit de distinguer les mines des objets inoffensifs parmi une collection d'objets ressemblant à des mines. Nos recherches ont été dirigées par deux contraintes classiques en guerre de la mine : d'une part, le manque de données et d'autre part, le besoin de lisibilité des décisions. Nous avons donc constitué une base de données la plus représentative possible et simulé des objets dans le but de la compléter. Le manque d'exemples nous a mené à utiliser une représentation compacte, issue de la reconnaissance de visages : les Structural Binary Gradient Patterns (SBGP). Dans la même optique, nous avons dérivé une méthode d'adaptation de domaine semi-supervisée, basée sur le transport optimal, qui peut être facilement interprétable. Enfin, nous avons développé un nouvel algorithme de classification : les Ensemble of Exemplar-Maximum Excluding Ball (EE-MEB) qui sont à la fois adaptés à des petits jeux de données mais dont la décision est également aisément analysable<br>This thesis aims to improve the classification of underwater objects in high resolution sonar images. Especially, we seek to make the distinction between mines and harmless objects from a collection of mine-like objects. Our research was led by two classical constraints of the mine warfare : firstly, the lack of data and secondly, the need for readability of the classification. In this context, we built a database as much representative as possible and simulated objects in order to complete it. The lack of examples led us to use a compact representation, originally used by the face recognition community : the Structural Binary Gradient Patterns (SBGP). To the same end, we derived a method of semi-supervised domain adaptation, based on optimal transport, that can be easily interpreted. Finally, we developed a new classification algorithm : the Ensemble of Exemplar-Maximum Excluding Ball (EE-MEB) which is suitable for small datasets and with an easily interpretable decision function
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Rousselle, Denis. "Classification d’objets au moyen de machines à vecteurs supports dans les images de sonar de haute résolution du fond marin." Thesis, Rouen, INSA, 2016. http://www.theses.fr/2016ISAM0020.
Full textAbstract:
Cette thèse a pour objectif d'améliorer la classification d'objets sous-marins dans des images sonar haute résolution. En particulier, il s'agit de distinguer les mines des objets inoffensifs parmi une collection d'objets ressemblant à des mines. Nos recherches ont été dirigées par deux contraintes classiques en guerre de la mine : d'une part, le manque de données et d'autre part, le besoin de lisibilité des décisions. Nous avons donc constitué une base de données la plus représentative possible et simulé des objets dans le but de la compléter. Le manque d'exemples nous a mené à utiliser une représentation compacte, issue de la reconnaissance de visages : les Structural Binary Gradient Patterns (SBGP). Dans la même optique, nous avons dérivé une méthode d'adaptation de domaine semi-supervisée, basée sur le transport optimal, qui peut être facilement interprétable. Enfin, nous avons développé un nouvel algorithme de classification : les Ensemble of Exemplar-Maximum Excluding Ball (EE-MEB) qui sont à la fois adaptés à des petits jeux de données mais dont la décision est également aisément analysable<br>This thesis aims to improve the classification of underwater objects in high resolution sonar images. Especially, we seek to make the distinction between mines and harmless objects from a collection of mine-like objects. Our research was led by two classical constraints of the mine warfare : firstly, the lack of data and secondly, the need for readability of the classification. In this context, we built a database as much representative as possible and simulated objects in order to complete it. The lack of examples led us to use a compact representation, originally used by the face recognition community : the Structural Binary Gradient Patterns (SBGP). To the same end, we derived a method of semi-supervised domain adaptation, based on optimal transport, that can be easily interpreted. Finally, we developed a new classification algorithm : the Ensemble of Exemplar-Maximum Excluding Ball (EE-MEB) which is suitable for small datasets and with an easily interpretable decision function
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Nico, Thibaut. "Étude et développement de solutions de relocalisation d'objets sous-marins par des véhicules sous-marins hétérogènes." Thesis, Brest, École nationale supérieure de techniques avancées Bretagne, 2019. http://www.theses.fr/2019ENTA0005.
Full textAbstract:
Dans le contexte de guerre des mines (MCM), il est important de revisiter les objets potentiellement dangereux afin de les identifier et les neutraliser s’il s’agit effectivement de mines. Cette dangereuse tâche était habituellement réalisée par des plongeurs démineurs qui sont petit à petit remplacés par des drones sous-marins. Le design « low cost » des robots de revisite/destruction de mines ne permet en général pas de garantir la revisite d’une cible géolocalisée en allant droit dessus. De plus, le robot pourrait commencer sa mission sous-marine à une distance éloignée et l’absence de positionnement GPS en environnement sous-marin imposent l’élaboration d’une stratégie afin de garantir la revisite de la cible. En se basant sur des informations a priori de l’environnement et notamment la présence de points de repère (amers), le problème est résolu par la planification d’une stratégie à suivre en prenant en compte les incertitudes de déplacement inhérentes en milieu sous-marin. Dans un contexte d’erreurs bornées, une approche ensembliste est proposée. Premièrement, en se basant sur la position et la forme des amers, ainsi que la zone visible du capteur embarqué, les cartes de recalages sont construites afin de définir les poses du robot qui permettent de détecter les différents amers afin de réduire l’incertitude de position du robot.Deuxièmement, en se basant sur un modèle paramétrique de déplacement avec des paramètres incertains, une stratégie haut-niveau est proposée à travers l’optimisation d’un graphe. La stratégie consiste à naviguer entre les cartes de recalage afin de réduire l’incertitude de position du robot et finalement garantir la revisite de la cible souhaitée<br>In the Mine Counter Measure (MCM) context in the underwater environment, it is vital to revisit some potentially dangerous objects to identify and neutralize them if they are actually mines. This dangerous task was usually performed by humandivers but more and more it is conducted by unmanned underwater robots. Due to the low cost design of the revisit/mine-killer robot, going straightforward to the geolocalized suspicious object does not guarantee that the robot will redetect it.Moreover the robot may dive at a far position from the target and the lack of absolute positioning system in underwater environment demands a strategy to follow to guarantee the revisit of this target. Based on a priori information in the working area and especially the presence of geolocalized landmarks, the problem is solved as a motion planning problem considering uncertainties due to the increasing error when navigating underwater. In the context of bounded errors, the problem is solved in a set-membership manner. Firstly, based on the location and the shape of the landmarks, and on the visibility area of the sensor embedded, the registration maps are computed indicating the sets of robot poses to detect the different landmarks considered in order to reduce the uncertainty on the robot position. Secondly, based on a parametric motion model with uncertain parameters, an high level strategy is provided through a raph optimization. The strategy consists in navigating between the registration maps toreduce each times the uncertainty in position of therobot and finally to guarantee the reachability of agoal area corresponding to the redetection of the target
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Escudie, Marie-Pierre. "Gaston Berger, les sciences humaines et les sciences de l’ingénieur : Un projet de réforme de la société." Thesis, Lyon 2, 2013. http://www.theses.fr/2013LYO20094.
Full textAbstract:
Notre thèse étudie la pensée et l'action de Gaston Berger et plus particulièrement la philosophie en action qui était la sienne au sein d’un projet de réforme de la société. Par une démarche reconstructive de l’œuvre, nous questionnons chez l’auteur les liens entre philosophie et politique dont la mobilisation se veut une réponse à la crise spirituelle et morale présente en Europe au XXe siècle. En s’inspirant de la phénoménologie, Berger affirme la nécessité d’une métaphysique, seule à même de penser le monde social tel qu’il apparaît. Il construit cette recherche à partir de l’idée d’intentionnalité ainsi que de l’anthropologie prospective, sources d’un savoir sur l’esprit humain, qui lui permettent de penser la figure du « philosophe en action », lequel doit posséder un rôle décisif dans les réformes sociales et politiques. Le projet de réforme de la société, tel que Berger le met en œuvre au travers de l’éducation, concerne d’abord la formation des ingénieurs. Ainsi s’élabore une « politique de l’esprit », qui met en avant le rôle essentiel de la philosophie et des sciences humaines et sociales dans le renouvellement intellectuel et politique de la fonction de l’ingénieur. Elles permettent, selon Berger, de replacer science et technique dans la culture et de comprendre ce qui fait l’humanité de la pratique des ingénieurs et la distingue d’une simple activité technique. En cela, cette thèse étudie la création de l’INSA de Lyon en 1957 comme le témoignage exemplaire de cette politique<br>The present thesis explores the thought and action of Gaston Berger and especially his “philosophy in action” in a project to reform society. In a reconstructive process of his work, we question the author’s view of the relationship between philosophy and politics, which mobilization is seen as a response to the spiritual and moral crisis in Europe in the 20th century. Inspired by phenomenology, Berger claims the necessity of metaphysics as the only way to think the social world as it appears. He builds this research on the idea of intentionality and prospective anthropology, sources of knowledge about the human mind, which allows him to think the figure of the "philosopher in action" with a decisive role in the social and political reforms. The proposed reform of society, such as Berger implements through education, concerns at first the training of engineers. This is how a “politics of the spirit” is developed, which highlights the essential role of philosophy, human and social sciences in the intellectual and political renewal of the engineer’s function. They allow, according to Berger, to put science and technology back into culture and understand what makes the humanity of engineer’s practice and distinguishes it from a mere technical activity. In that respect, this thesis studies the creation of the INSA in Lyon in 1957 as the exemplary expression of this policy
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Pan, Wensen, and 潘文聖. "Mobility Analysis of Resilient Mounts for Main Engine." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/49598812849241327222.
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LIOU, JIA-WEI, and 劉嘉偉. "The Study on Availability Analysis of Ship Main Engine System." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/73xuuq.
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YANG, Chin-yuan, and 楊致遠. "Vibration Analysis of A SWATH Ship due to Main-Engine Excitations." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/93463262716265927091.
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Dai, Chih-Kun, and 戴志錕. "Application of Digital Signal Processing for Marine Main Engine Condition Monitoring." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/73572783657023647222.
Full textAbstract:
碩士<br>國立高雄海洋科技大學<br>輪機工程研究所<br>103<br>An effective condition monitoring method of the main engine is the main task for continuous ship sailing. In the past, the diagnosis of the level of mechanical damage was based on experience, thus uncertain mechanical error could affect the maintenance of machinery. This cost labor and time. In this thesis, we use the data acquisition card and acceleration sensors to measure vibration signals, then we plot time-frequency image to analyze the state of the main engine. By using the information of frequency intensity in time, the level of possible damage to the machine is detected. Finally, the vibration signals measured from the main engine of yacht is applied. The results show that the corresponding time and frequency analytical information can provides marine engineering to determine the state of main engine and do immediate repair to reduce labor costs and time.
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Chen, Chun-Sheng, and 陳俊盛. "Application of ship weather route planningon main engine fuel consumption analysis." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/03746480891991611914.
Full textAbstract:
碩士<br>國立臺灣海洋大學<br>輪機工程學系<br>104<br>Due to combustion petroleum produce of a great deal of carbon dioxide
have already exceeded a guarding area, the shipping company faces the fuel
cost the rising and carbon dioxide reduces of pressure. This thesis manages
the study to Taiwanese ships energy system, with reach effective economize
on energy and reduce cost and exaltation competence for study a purpose.
Reach to save the energy to need to be equipped and its method, Through fuel
consumption and the ship speed the trend line of ratio analyze, may find out
the reason of consuming the oil and improper voyage.
This thesis manages the study to the marine ship and energy management
under Yang Ming sea transportation company and makes use of a meteorol-
ogy to navigate and the ships host information data, provide the optimization
route the program to reach the effective economy energy and reduce cost and
exaltation competence. Make use of the AWT and WNI information analysis,
reach economical host fuel depletion’s optimization analysis the host opera-
tions, ships of filling water and route trace analysis. Showing to make use of
meteorology and walrus information system as a result can save the fuel de-
pletion,andthroughfuelconsumptionandtheshipspeedthetrendlineofratio
analyze, can find out the reason of consuming the oil and improper voyage.
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CHEN, CHIEN-CHANG, and 陳建璋. "The Study on Availability Analysis of Ship Main Engine Auxiliary System." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/3y5vma.
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YEH, CHARNG-KUEN, and 葉長坤. "A Study on Air Cut-Off Valve of the Main Diesel Engine." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/6h25um.
Full textAbstract:
碩士<br>國立高雄海洋科技大學<br>輪機工程研究所<br>105<br>With the internal components fret of a starting air cut-off valve, the main engine will
be unable to successfully and completely start-up. Thus, this research will propose
a technique to solve the foregoing problem. The starting air cut-off valve for starting
system of Sulzer RTA 52, 72 and 84C low-speed marine main diesel engine will be
used as examples in this research.Vessel crash and grounding accident will occur if
the main engine cannot appropriately start-up and continuously supply power during
the period of entering and leaving the harbor. In order to increase the efficiency of
navigation safety, this research will propose a plan with regular replacement of
internal components of starting air cut-off valve firstly. Then, in an urgent case, with
the demolition of solenoid valves and small piece of tubes of the starting air cut-off
valve, and the installation of a bulkhead of pipeline, the main diesel engine will be
able to start-up and run smoothly immediately.Because the research results present
in this thesis have been used on the large vessels of the shipping companies, it is
significant from the viewpoint of practical applications.
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Liao, Tzu-Hsiang, and 廖子翔. "The Study of Energy Efficiency Management for Electronic-controlled Main Diesel Engine." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/73kcyr.
Full textAbstract:
碩士<br>國立臺灣海洋大學<br>輪機工程學系<br>105<br>In facing of global climate change, the International Maritime Organization (IMO) has imposed more stringent regulations on emissions for Vessel. Because of more control parameters can be adjusted for electronic fuel injection engine and achieve better emission, we focus on this type of engine to study how to realize the energy efficiency management plan. In the study, we consider to measure the fuel consumption rate and the exhaust gas temperature. Fuel consumption rate is corresponding to the CO2 emission rate, and exhaust gas temperature is equivalent to the nitrogen oxides (NOx) emissions. When adjusting the fuel quality setting (FQS) of the actual vessel, the fuel consumption rate of the experimental ship can be reduced effectively by about 4 to 6%, whereas the exhaust temperature is slightly increased by 12 ° C only. With the TORQUE mode program to control the engine, the fuel consumption rate is reduced by about 3% and the exhaust temperature rises slightly by about 13 ° C. The above two tests are carried out under the wind and waves below level 7. Experimental results indicate that either by the proper adjustment of FQS, or through the choice of fixed torque mode, the electronic fuel injection engine can achieve the effect of reducing the carbon dioxide emissions and to save the cost of the fuel as well.