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253 Uppsatser om Aircraft engine - Sida 4 av 17

Automatisk indexering på webben - en studie av sökmotorn HotBot

The web has made an incredible amount of unorganized information available to anyone. There are search engines that help us structuring the information, but it is still difficult to find what you search for on the web. The purpose of this master's thesis is to investigate whether the already existing techniques for automatic indexing are suited for the new information retrieval context on the web and how the choice to support these techniques, or not, affects the search results. This is examined through a literature study on automatic indexing and other related concepts, such as information retrieval and information searching on the web in order to get a theoretical frame to the work and by an observation of the search engine HotBot to approach the purpose of the thesis. The observation is carried out by searching HotBot's database and investigating the search results in order to try to identify patterns that can reveal something about how HotBot's automatic indexing is done.

EKONOMISTYRNING I EN MOTORVERKSTAD: En analys av centralt ställda krav ur ett operationellt perspektiv

The purpose of this thesis is to analyze the design and function of an engine production management?s control system and its intended function, and to contrast it with the present management control systems in use on an operational level. Interviews conducted with employees from all levels of the engine production are the main source of this study?s empirical foundation. Information has also been gathered from relevant written material such as annual reports, internal documents etc.

Modellering av ett bränslesystem i Modelica : tillämpat på ett obemannat flygplan

Mathematical models possible to simulate are of great importance in order to make successful projects in the aircraft manufacturing industry. An aircraft fuel system is very complex, containing pipes, tanks, orifices, valves and pumps. The principal of this thesis is using the tool Easy5, which no longer is considered reliable enough in terms of development and support. This thesis tries to evaluate the Modelica language as a possible alternative to Easy5. To make this evaluation, the components concerned in the fuel library in Easy5 are implemented to the Modelica language.

Primär eller sekundär söktjänst? En effektivitetsstudie av söktjänsten Google och metasöktjänsten Dogpile

This thesis examines the retrieval effectiveness of two Web search engines. The two search engines are chosen to represent two different types Google as a broad general search engine and Dogpile as a broad general metasearcher. Twenty queries have been used and the first twenty hits for each query were evaluated for relevance. The queries were invented by the authors, based upon their interests and information needs. They were expressed in a general manner, by using one or several keywords, in accordance with the simple search mode available for each search engine.

Småskalig biobränsleeldad kraftvärmeproduktion : teknik och investeringsutrymme

To achieve the requirements to decrease emissions of greenhouse gases by 20 % by 2020, Swedenneeds to increase its use of bioenergy. In doing so it seems natural that those who already haveaccess to large amounts of biofuels in the form of by-products such as straw, wood chips anddigestible materials take advantage of these assets locally. By combining production of heat withpower production at the farm it may be possible to not only reduce the direct use of fossil fuel forheating but also reduce energy costs.The purpose was to simulate different cases of using a small scale biofueled combined heat andpower plant for farm-based systems. A MatLab-model was developed and used to draw conclusionsabout the costs for production of heat and electricity with different conversion technologies.The model uses climate data to simulate the variations in heat energy demand on a day-to-day basis.The given heat demand is the base of the simulation and from this the possible electric output iscalculated. This study has focused on the impact of the following properties: electric-, heat- andtotal efficiency, fuel, fuel price and specific fuel requirements.

Flygplanstillverkning : Fixturkoncept till robotgradning

Volvo Aeros flygmotortillverkning i Trollhättan har infört ett antal nya detaljvarianter i produktionen. Detta har medfört att den robotcell som är avsedd att utföra en avgradningsoperation är i behov av uppdatering av både hårdvara och mjukvara. Denna rapport följer framtagningen av fixturkoncept som möjliggör att robotcellen kan användas även till de nya detaljerna. De förslag som arbetats fram sträcker sig från enklast möjliga till mer avancerade och nytänkande funktioner. Samtliga funktioner och koncept har genomgått gallringar i ett flertal steg.

Höghöjdsflygning & strukturella batterier : En konceptstudie i flygteknik

This report is written in the purpose to investigate the mechanical forces and characteristics related to a propeller driven aircraft in the Earth?s atmosphere. It?s written as a thesis project during the spring semester of 2014 and graded accordingly.Thanks Arne Karlsson for fruitful discussions. Also thanks to Simon Leijonmarck for help with useful discussions concerning structural batteries..

Hastighets- och positionsinterface för motorer

The environmental requirements and laws on combustion engine emissions are very tough today andthey will become even more stringent in the future. To achieve these requirements there are highdemands on the control systems for these engines. An improved precision in the measurement of anengine's speed and position gives the electronic control system an even better timing when it comes tofuel injection and ignition. This makes the engine more fuel efficient, reducing the emissions. This thesisis part of a collaborative project between Hoerbiger Control Systems and subsidiaries.

Globala och lokala sökmotorer: en utvärdering av Google, MSNSearch och Svesök

The purpose of this thesis is to evaluate three search engines with regard to retrieval effectiveness of information specific to Swedish users. Coverage and the precision in result descriptions are also examined. The three selected search engines are Google, MSN Search and Svesök. 30 queries were tested against the search engines and the first 20 result descriptions and results were judged for relevancy. Relevancy was judged by a binary scale.

Evaluering av återvinningseffektiviteten i Svensk Medicin och Google Scholar med medicinska frågor ur Fråga doktorn.

The purpose of this thesis is to evaluate and compare the retrieval effectiveness of two search engines on the Internet: Svensk Medicin and Google Scholar. Svensk Medicin is a medicine-specific search engine and Google Scholar specialises in indexing scholarly material. A set of 20 questions in four categories were used to conduct the searches with the search engines. Genuine medical information needs were selected from a question collection provided by the television program Fråga doktorn. The relevance of the first 10 retrieved documents was judged by using a binary scale and the measure used was precision.

Utvärdering och rekommendation av uppföljningsprogram för flygplanunderhåll : för Täby Air Maintenance

By today?s date there are a lot of companies that are in great need of restructuring their paperwork in a more organized way. This can be excellent arranged with the help of properly constructed computer software. The aviation industry is no exception, but actually a good example of this. Täby Air Maintenance (TAM) is a company which is situated in Örebro.

Visualisering av Flight Recorder-data i Saab 2000 avionikrigg

The main purpose of a Flight Data Recorder (FDR) is to facilitate the investigation of incidents. In order to interpret the data that has been recorded in the FDR the data has to be visualized in some way. This can be done with software on a computer or with hardware that is specific for the model of aircraft that the data originates from.The aim of this project is to visualize data for six parameters from the FDR of Saab 2000 in an avionics rig. The avionics rig resembles the cockpit of Saab 2000 and the displays in it are identical to the ones found in the plane. All six parameters are shown on the same display.Due to safety regulation vital systems in aircraft are doubled, with one system on the left side and one on the right.

Utveckling av en Multi-Zonsmodell för NOx Bildning i Diesel Motorer

This thesis work is the last part of the Master of Science education inmechanical engineering at KTH, Stockholm.The aim of this project was the development of a Multi-zone modelfor NOxformation in Diesel engines. Because of the stringent emissionlegislations, great effort is made to decrease the fuel consumption and theharmful emissions of internal combustion engines. Computer simulationsplay a decisive role in this context because they substitute the expensiveand time-consuming laboratory tests.The model is based on a multi-zone approach and uses the wellknownExtended Zeldovich Mechanism which gives a relation to calculatethe NO formation rate using the concentration of different gas speciesinvolved in the process.All the most important phenomena involved in the Diesel combustionhave been modelled. A special attention is then paid to the equilibriumconcentration calculation; this is a significant part of the model whichstrongly influences the following steps.A Simulink model has also been developed. This second version isbased on the previous model and it is made especially to allow theconnection with other external softwares, GT-power in this case.

Design av en ejektorspädare samt ett system för partikelmassmätning av dieselavgaser

This master thesis was a subtask of a project called EMIR-1. The goal with the thesis was tobuild a system for particulate mass measurements in one of the engine test cells at KTH. Theparticulate mass measurements are planned to be measured with a TEOM.The exhaust gases must first be diluted with air before the sample is sent to the TEOM.Therefore an ejector diluter for this matter also was designed and evaluated in the thesis.Emissions measurements have been done both with and without dilution to determine thedilution ratio. Tests have been done for different speeds and loads.Problems with stability of the dilution ratio have been an issue throughout the process andpressure pulsations in the exhaust pipe are believed to be the cause. More tests have to be done tomake sure that this is the problem.One idea is to make the inner diameter of the diluter nozzle smaller and see if it changes thedilution ratio stability.

Utveckling och design av WiGID

The Center for Genomics and Bioinformatics (CGB) is an academic department at Karolinska Institute. Generally stated, the CGB department is committed to the generation and management of genetic information by approaches aiming at elucidating the connection between genes, protein and function.WiGID is a genome information database that is available through WAP (Wireless Application Protocol).Our version of WiGID is based on WML, PHP and PostgreSQL as a database server.One of the changes on the old WiGID application was the creation of a relational database with seven tables and one view, instead of the file that represented the database on the old version. We also changed the script language from python to PHP.The search engine ability has been extended with three new search alternatives for a user to choose from. Each choice leads to other, sometimes multiple choices.A GUI has been created for the administrator, to be able to insert information into the database.The structure of the search engine is primarily for narrowing down the search result on the phone display, thereby making the search efficient..

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