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3118 Uppsatser om Engine control - Sida 5 av 208

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.

Konceptframtagning av inspektionspluggar till flygmotorer

This report describes the results of the project "Concept development of jet engine inspection plugs" carried out in the spring of 2008. The work was done at the department of product definition at the company Volvo Aero in Trollhättan. The objective of the work was to develop concepts for a "Volvo-unique" inspection plug. The work is part of Volvo Aero's focus on proprietary (self-developed) technologies. Inspection plugs can be found on virtually all aircraft engines and gas turbines.

Verksamhetsstyrning: Utrikesdepartementets personalbostäder

The purpose of this thesis is to find means of control that secure cost efficiency regarding the accommodation for the employees on missions abroad of the Swedish Ministry for Foreign Affairs. Today the ministry?s cost for the employees? rented housing is 100 million SEK and there is a need of improvement in the control of these costs. A work method for organizational development will be used in order to reach the findings presented in the thesis. First we study the strengths and weaknesses in today?s control system.

Locus of control, syskonplacering och kön : Finns det några samband?

The purpose of this study was to examine if there was a relation between birth order, gender and locus of control. There where 162 participants in the study, 44 men, 115 women. Birth order was coded into three levels. There where no significant differences between birth order and locus of control. The result showed that female participants where more external when it came to locus of control.

Personlighet och Health Locus of Control : en korrelationsstudie med deltagare från Sverige och Tyskland

I denna studie har undersökts personlighet och Health Locus of Control hos 56 kvinnor och män i åldrarna 18 till 65 år, där 30 var svenskar och 26 var tyskar. Undersökningens frågeställning var: Är en eller fler personlighetsdimensioner i Fem-Faktor-modellen relaterade till i vilken utsträckning en individ har Internality, Powerful others eller Chance Health Locus of Control. En NEO-PI enkät och ett Multi dimensionella Health Locus of Control-skalan-formulär administrerades. Resultatet från undersökningen kunde påvisa en signifikant korrelation mellan Openess to Experience och Powerful Others Health Locus of Control samt Conscientiousness och Powerful Others Health Locus of Control. En signifikant skillnad mellan svenskar och tyskar beträffande Powerful Others kunde också påvisas.

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.

Robotstyrning med metoden Sliding Mode Control

The task in this thesis is the steering of one of Saab Bofors Dynamics robots using Sliding Mode Control, a method they never used before. The robot constitutes a system which in addition to perturbations and uncertainties due to modeling imprecision, hold the difficulty of being highly time variant. In order to be able to keep required performance with uncertainties and modeling imprecision present, the use of robust control methods like Sliding Mode Control is necessary. SMC is based on the states of the system being forced to stay on or in the direct vicinity of a hyper plane in the state space which is chosen in a way that gives the system dynamics desired properties. Other advantages with sliding mode are reduced order dynamics on the switching surface and total insensitivity to some uncertainties and perturbations.

Chef över Erik men inte över Anna : påverkas företags styrning då inhyrd personal ingår i personalstyrkan?

The use of temporary workers gives companies the opportunity to be flexible, by avoiding hiring and dismissing workers because of economic conditions and trends in demand. The management control in use at the company has the purpose of influencing employees? behaviour to act in the company?s best interest and towards its goals. The management control should also influence the behaviour of the temporary worker. The companies have to create motivation and commitment among the temporary workers although they are employed by a staffing agency.

Halvledare för höga strömmar i fordon

Mechanical relays are more and more being replaced with semiconductortechnology. In this thesis it is investigated if and how the larger loads couldbe controlled by transistors. The main part of this work aims to create andverify a solution that can control the starter motor, as well as protect it incase of any failure. The different malfunctions that the solution protectsagainst is high current, too high peak current, low current, maximum cranktime and minimum cool off time. The timers also protect indirectly againstoverheating of the starter engine.The transistors used are BTS555, from Infineon.

Riskkapitalbolags påverkan på styrning i sina portföljbolag: En studie om utveckling av styrsystem i svenska Venture Capital finansierade företag.

The aim of this study is to investigate which management control mechanisms evolve in companies that receive funding from Venture Capital companies and why the management control systems evolve in the way that they do. A case study was performed on three Swedish high technology companies, that all received funding from Venture Capital companies for the first time in 2006. Merchant?s framework, defining all management control mechanisms as either, results control, action control or personnel control, was used to structure the study. Results show that the companies that received Venture Capital all increased the use of management control mechanisms within results control, action control and personnel control.

Traditionell ekonomistyrning vs modern verksamhetsstyrning : en fallstudie av ett växande företagsstyrfilosofi

The purpose with this paper is that trough a description of the management control at Jitech AB find out if traditional management control have been abandoned for benefit for modern management control and in which extent the transition have happened. Further is the second purpose with this paper to find out which decisions that lies behind the design of the management control and how these are in opposition to with the theory..

Health Locus of Control och impulsivitet i relation till träning : en studie om universitetsstudenters träningsbeteende

There are many aspects which must be taken into consideration when studying individuals? need of exercise. The study investigates if impulsivity and Health Locus of Control affect the continuity of physical practise. The main presumption was that individuals with high impulsivity, high Powerful Others and high Chance Health Locus of Control, would have a significantly harder time to maintain a continuous physical activity. The survey used two standardized tests to measure impulsivity and Health Locus of Control and in order to be able to measure the insensitivity and the periodicity of physical exercise, a test was developed by the authors.

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.

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