I denna uppsats presenteras grundläggande delar av hyperbolisk geometri. Uppsatsen är indelad i två kapitel. I första kapitlet studeras Möbiusavbildningar på Riemannsfären. Andra kapitlet presenterar modellen av hyperbolisk geometri i övre halvplanet H, skapad av Poincaré på 1880-talet.Huvudresultatet i uppsatsen är Gauss ? Bonnét´s sats för hyperboliska trianglar..

Abstract CORDIC (Coordinate Rotation Digital Computer) is an iterative algorithm for the calculation of a two-dimensional vector in circular, linear or hyperbolic coordinate systems. This paper presents a survey of known CORDIC algorithms and architectures for the rotation and vectoring mode in the circular cordinate system. In addition an implementation of the differential CORDIC algorithm in VHDL has been done. The implementation is designed to keep the fast timing and throughput characteristic known for on-line redundant arithmetic..

This paper analyses the pricing on spare parts. Empirical studies have showed that manufacturers of durable goods make an unproportional large profit on its spare parts in relation to the revenue it generates. It is first showed that according to the standard economic model the price on spare part ought to be zero since the producer include an insurance in the price of the main good. Further it is showed that moral hazard alone do not explain the pricing found in the studies. Finally an analysis of whether consumers with present-biased preferences could be a possible explanation is made.

The use of spread spectrum signals has increased dramatically in military applications. Finding methods for detecting and positioning of these signals have become interesting research areas for signal intelligence purposes. One method is to measure the time difference of arrival (TDOA) that occurs when two receivers are synchronous and spatially separated. Based on the TDOA-technique an audio-demonstrator has been developed and implemented. This report describes the theory for how sound received in microphones can be used to extract information about the transmitter?s position from the measured time difference.