Sökresultat

In this report the motor side of a converter driven AC-locomotive is studied and modeled. The motor side consists of an asynchronous electrical engine, an indirect self controller, a voltage converter, a Pulse Width Modulator(PWM) and the train mechanics. The converter is supplied with voltage from a DC-link. The link is connected to a line converter which transfers energy from the railway net to

Modelica-TM is an object-oriented language for modeling physical systems that was designed in the last years with the goal to become a standardized multi-domain modeling language. This paper describes a robust model for homogenous and inhomogenous two phase flows with dynamic or static slip correlation. It was developed in the context of developing a Modelica base library for thermo-hydraulic appl

In the presence if poor excitation and abrupt changes of a time-varying system the Recursive least square (RLS) with forgetting factor is not able to track the parameters in a suitable way. The purpose of this thesis is to investigate different kinds of proposals of algorithms to deal with the phenomenons arising, such as estimator windup or too slow convergence of the estimations. Attention is al

The thesis consists of two parts. Registration of Digital Images: Registration of images is a fundamental task in image processing. This is to match two or more images taken, for example, at different times, from different sensors or from different points of view. The methods used to register images are striving for a similarity metric indicating when the images are correctly registered. A similar

Nowadays, multiple antennas are becoming widely used in small mobile terminals as they can significantly improve wireless communication performance in terms of link reliability and spectral efficiency. Also, pattern reconfiguration is another new trend for antenna design as it enables the antennas to adapt to different propagation and user scenarios. However, due to the limited space in the termin

This is a project that have been conduct at IKEA of Sweden in Älmhult. Due to the limitation of time for this project, the study has only been conduct for one several Home Furnisher Business (HFB) within IKEA. The purpose of the project was to provide suggestions on how to improve the Sales and Supply process in order to enhance balancing of demand and supply. Within the concerned HFB there are

Purpose: The aim of this study was to investigate a new methodology for brachytherapy of oesophageal cancer using magnetic resonance (MR) imaging for treatment planning. That includes finding a suitable oesophageal applicator that can be visualised on MR images and to create dose and fraction schedule that should be used brachytherapy treatments. Material and Methods: A total of six patients were

Purpose: This work examined the feasibility of flattening filter free (FFF) volumetric modulated arc therapy (VMAT) for extreme hypofractionation of prostate cancer. The aim was to investigate the potential gain in treatment time per fraction for extreme hypofractionation of prostate cancer, while preserving or improving the treatment plan quality and radiation delivery quality. The impact of intr

Syftet med denna undersökning var att se om det blev en tidsskillnad när man byggde LEGO efter tvådimensionella (2D) eller tredimensionella (3D) instruktioner samt ifall 3D instruktioner kan förbättra tiden för människor med lägre spatial förmåga jämfört med 2D instruktioner. Forskningsdesignen var inomindividsdesign och urvalet bestod av 33 deltagare i åldrarna 20-33 år, 11 var kvinnor och 22 var