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351 Uppsatser om Electrical drives - Sida 10 av 24
Adaptiv katalysatormodell för reglering
This master?s thesis describes the development of a model of the catalystsystem aiming at control by an MPC. A well functioning model, which is suitable in control purpose, is important while emission legislation become more and more hard to fulfill for the car manufacturers. Much research has been done in the field of physical modeling of the system, but in this work a linear adaptive time discrete ARX-model is developed and validated.The systems tendency to change its dynamic during usage implies that the model must be adaptive. The developed model proved to be well functioning and shows promising conditions for the MPC design.
Canine S- and M/L- cone electroretinograms
Full-field flash electroretinography is an electrodiagnostic method used to examine the function of retinal cells. Light stimulation of the eye elicits electrical potentials in the retina. By aid of a corneal electrode and a reference electrode close to the back of the eye, the electrical potentials can be recorded and presented as an electroretinogram (ERG). ERGs driven by mainly one type of cones can be used to examine the function of a single cone class. In human beings, studies have shown the cone class sensitive to light of short wavelengths, the S-cones, to be more vulnerable to acquired damage than the other cone classes (Daley et al., 1987; Gouras et al., 1993; Greenstein et al., 1989).
Dogs have two cone classes, S-cones, and M/L-cones (most sensitive to medium to long wavelengths).
Kravspecifikation för en knapp till ett automatväxlingskoncept
This thesis deals with the development of a specification regarding a push-button, which will be used to control the gear-shifting function in an automobile. In addition to this the author will describe different techniques and theories that have been helpful in achieving data and results for the specification.Kongsberg Automotive AB, is located in Mullsjö, Sweden, the company supplies parts to the automotive industry. In the research and development department, R&D, there is a group that works with development of Shift-By-Wire systems. In an automobile with a Shift-By-Wire system the communication between the gear-shifter and the gear-box occurs electronically. The mechanical link is, in most cases, taken away and replaced by the digital system.
Arbetsgruppsrelationer - En studie av provisonsanställda på en mäklarbyrå
This study examines work relations on a real estate agency. My interest is to examine how real estate agents apprehend their work relations, and how a recession can affect these relations. Previous research shows that the occurrence of competition in groups decreases the motivation to cooperate. A different research illustrates that reward interdependence is important to performance, and that task interdependence drives observed cooperative behavior. The study contained six interviews with real estate agents working on commission.
Förskolepedagogers uppfattningar av sitt arbete kring energiomsättningen
The aim of this study is to examine the understanding, preschool teachers, have about their work related to energy conversion in the human body. Through individual interviews, answers have been sought to the following questions: What do the preschool teachers believe they need to know about the link between food and energy? What are the different methods preschool teachers use to workwith the area of energy conversion in the human body?The results show that preschool teachers have knowledge in terms of food and its nutrients as an energy source for the body to cope with. However the more thorough and detailed questions become all the more uncertainty there is about the topic. Preschool teachers on their own initiative do bring up the topic with the children and begin conversations as well as ask questions, perform experiments and demonstrations.
Skillnader och likheter mellan kvinnliga actionhja?ltar under 1970-, 1980- & 2010-talet : En analys av kvinnliga karakta?rer i actionfilmer
Laura Mulvey was the first to suggest that women and men have different positions on the screen; men drives the plot forward, and the women are objects of masculine desire and lust.The purpose of this report was to look at and compare the two characters from the 70?s - and 80's with two characters from the 00?s - and 2010?s to gain a deeper understanding and insight into how female action heroes are presented. This will be done with the help of the questions; How is the female action heroes that are analyzed in the paper?What are the differences and similarities between the past and the present-day action heroes? Just how stereotypical are the women in their genre? The four female action heroes that were analyzed were; Princess Leia Star Wars, Sarah Connor Terminator and Lisbeth Salander Men Who Hates Women and Katniss Everdeen The Hunger Games.The four female action heroes were analyzed based on Rikke Schubarts categories (Moderarketypen, Amazon, Dotterarketypen, Ha?mnerskan and Dominatrix), the character's personal development, the character's violence and the reason for the character's.Characters from the past were more often presented as more uncertain and fragile than the modern confident characters. The female action heroes of modern times was more independent, strong, and in no need of a man in comparison with contemporary female action heroes.
Elektrisk integrering och projektering av förnybar energi i svagt lokalt elnät
För att en kvalitativ och driftsäker kraftomvandling från vind till elkraft skall erhållas ställs krav på en mängd olika faktorer. Klimatologiska och tekniska faktorer kräver korrekt dimensionering och anpassning av omvandlingstekniken för att största möjliga energimängd skall kunna omvandlas på ett driftsäkert och energieffektivt vis som vindkraftsägare, nätägare kräver. Vinden är som bekant en oberäknelig kraftkälla. Variationerna i styrka och tid kan innebära en hel del driftoptimeringsproblematik med efterverkningar för vindkraftsverket, nätet och belastningen. Konsekvenserna kan bero på vilken typ av teknik som är installerad i de olika delarna av energisystemet och i områdets elnät.
Höghastighetståg - Är det framtiden?
AbstractConsider a ?uid being heated from below. The heating leads to an upward convectiveforce that is counteracted by the viscous forces of the ?uid. If the convectiveforce is large enough in comparison to the viscous forces the ?uid will be put in anunstable state.
Testbänk för motorbåtsdrev
Marinediesel has, to meet there customers needs for a suitable sterndrive to powerboats, developed a prototype. The prototype is currently in the testing phase. The opportunity to test the sterndrive under load inside the workshop has not previously been possible. Until now the drive has been tested in a test bench without any load on the propeller axle. The prototype has also been tested under real conditions mounted on a boat.The idea with my thesis was to create a test bench that can run around the clock in order to be able to test things like wear and service intervals and other things that require that the test interval is long.
Synen på ett kollektivt lärande i arbetslivet utifrån ett pedagogiskt perspektiv : En intervjustudie
In an environment, demanding both innovation and flexibility, higher requirements of competitiveness and productivity is a necessity. Changed conditions of today's working situations have resulted in an actualization of new ways and methods of working. This has contributed to a development of participating working processes in form of groups and teams. The purpose of these communal working processes is that they ought to result in an increased knowledge and understanding among the group members which in turns will generate positive results in the daily work. This drives the search for new knowledge and development possibilities to handle these changed working processes.
Modell av en synkronmaskin för PSCAD/EMTDC med magnetisk mättning i d-led och elektriskt gränssnitt för fältmatare
This report describes a synchronous machine model with magnetic saturation in d-axis, neutralconnection and electrical exciter interface for the transient simulator PSCAD/EMTDC. It hasbeen designed and verified in comparison to the regular machine model in EMTDC.The performance of the model is very good when incorporating a linear as well as a saturatedmagnetising inductance. The dynamic deviation is only thousandths to ten thousandths perunit. By using a cubic interpolation of the saturation curve, the model gives a good representationof the saturation effect. The open source code implementation of the synchronousmachine model gives the possibility to easily adapt the model to specific requirements.The derived model makes it possible to simulate a synchronous machine with its excitationsystems, e.g.
Rayleigh-Bénard konvektion.
AbstractConsider a ?uid being heated from below. The heating leads to an upward convectiveforce that is counteracted by the viscous forces of the ?uid. If the convectiveforce is large enough in comparison to the viscous forces the ?uid will be put in anunstable state.
Bland tidningsartiklar och kurslitteratur: en studie om journalistikstudenters informationsanvändning i samband med uppsatsskrivande
This study examines journalism student?s information use atSödertörn University during the writing process of theirbachelor thesis. The students are divided in two groupsfollowing the schools main bachelor programs majoring injournalism.The method used in this study has been a reference analysisof the student?s bibliographies along with five semistructuredinterviews. The study stems upon a socioculturalperspective and drives the thesis that information use is asituated activity.
Solvärme till Östersunds Rehabcentrums terapibad : Förstudie av förutsättningar för, - och lönsamhet med, solfångare för att värma terapibadet
This report treats whether it is viable to invest in solar heating to heat the therapy pool at Östersunds Rehabcentrum. The rehab center is owned by the county council of Jämtland and is located on Solliden in Östersund city. The solar heating where supposed to be a complement to the district heating that was heating the pool in the current situation. Later, it however showed that this was not the case. The pool is currently being heated by a radiator circuit that is being heated by the district heating.
Test och verifiering av en ny inkapslingsmetod för SiC BJT och MOSFET
The use of silicon carbide (SiC) as a base material in power electronics has manyadvantages, including high breakdown voltage and excellent temperature endurance.However, the packaging of such electronics presents major challenges and there is aneed for packaging that can operate in higher temperature. The purpose of this thesishas been to develop a test method and verify the functionality of SiC powertransistors prototypes with a new packaging technique developed by Swerea IVF AB.It includes setting up an electrical test-bed for power and high temperature cyclingand analysis of the results. Even though test confirmed functionality after thepackaging process, (at room temperature) the performance seemed to have been reduced. This could be a result of the measurement setup and the packaging process.In higher temperature the transistors failed to operate longer than a couple ofminutes which showed the weaknesses in the design and the challenges with this typeof packaging..