Detta examensarbete utröner möjligheten att aktivt släcka ut en amplitudstark frekvensmodulerad sinussignal digitalt. Detta skall göras utan förkunskap om signalen gällande fas, frekvens eller amplitud. Eventuellt övriga, men betydligt svagare, sinussignaler i den analoga signalen skall inte påverkas nämnvärt av utsläckningen. För att lösa problemet har olika teorier för att lösa delproblemen med att mäta amplitud, fas och frekvens studerats varefter en lämplig kombination valts för implementering i en FPGA. Prestandan som uppmätts har jämförts med vad som teoretiskt är möjligt och vi konstaterar att metoden löser problemet på ett adekvat sätt men är i behov av en del förbättringar som diskuteras i slutet..

The majority of all power cuts that affects individuals and communities are caused by earth faults on the power transmission lines at 10kV and 20kV level [1]. If these power cuts could be eliminated, less disturbances and interrupts would lead to large amounts of money savings.Swedish Neutral has developed such a protection system. When an earth fault occurs power is injected into the neutral point of the transformer. The RCC (Residual Current Compensation) protection calculates a compensation current exactly 180 degrees out of phase to the fault current. Doing this, the voltage at the fault location becomes very close to zero, without affecting the power transmission.The protection system can only compensate automatically for the fundamental frequency (50Hz), and manually for the 3rd, 5th, 7th and 9th harmonics.

This thesis is performed at Saab Bofors Dynamics in Karlskoga and investigates a technique for ranging with laser pulses. The investigated technique is called Constant Fraction Detection (CFD). Described briefly, the received laser pulse is split into two equal parts, where one part is delayed half the pulse width and inverted. This signal is added to the original pulse. The resulting curve has the shape of a laying S and the detection of the zero level is used to stop the time measurement.

The report descripbs how a diplexer for a hybrid analog/digital filterbank has been constructed and tested. A diplexer divides the frequency band into two different bands that do not who doesn't overlapp each other. The sampling rate for the two ADC:s is 80 Msps, and therefore it is advantage to have zero at 80 MHz. The reason for this is that a proposed class of hybrid filterbanks with very good quality requires a zero at or close the sampling frequency to work well. The diplexer was made in three versions.

The running of gas turbines with low emissions causes high pressure pulsations to arise in the combustion chamber. These pulsations are high amplitude sound vibrations. At some frequencies these are harmful to the gas turbine. Hence these pulsations are monitored to avoid operating conditions where pulsations are specifically harmful. It is necessary to expose the system of known pulsations to verify the functionality of the monitoring process.

This report discusses a method to detect divers in harbour environments usingpassive acoustic detection. The goal was to achieve as high detection as possiblewithout having too high false alarm rate. A short execution time was also desirable.By using the characteristic of an inhalation a band-pass filter was applied to the signalto improve the signal to noise ratio. After the filtering an energy estimation of thesignal was made. This energy estimation was later used in a frequency analysis, whichcould tell us if there were enough energy in the frequencies that correspond to adivers breathing frequency.

Harmonics are a well-known problem that has to be dealt with in the design of thegenerator. Internationally accepted standards limits the amount of harmonics allowedin the no-load voltage. These limits can be difficult to fulfill with integral slot winding,where the number of slots per pole and phase is an integer. The presence of thedamper winding often makes the problem with harmonics even worse and harmonicswith frequencies of order 6q±1 arise with significant amplitude. How the damperwinding is designed affect the content of harmonics in the no-load voltage and the aimwith these ? has been to investigate in which extent design of the damper windingaffects the contents of harmonics.Simulations with the 2-D finite element method have showed that if the damper barsis centered in the pole shoe, the amplitude of the harmonics of order 6q±1dependsboth on the ratio between the stator slot pitch and damper bars slot pitch and if thedamper bars are connected between the poles or not.If the damper bars is displaced with ¼ stator slot pitch alternately, the amplitude ofthe harmonics of order 6q±1 is reduced and the influence of the ratio between thestator slot pitch and the damper bars slot pitch will vanish.

This report discusses a method to detect divers in harbour environments usingpassive acoustic detection. The goal was to achieve as high detection as possiblewithout having too high false alarm rate. A short execution time was also desirable.By using the characteristic of an inhalation a band-pass filter was applied to the signalto improve the signal to noise ratio. After the filtering an energy estimation of thesignal was made. This energy estimation was later used in a frequency analysis, whichcould tell us if there were enough energy in the frequencies that correspond to adivers breathing frequency.

AbstractAim of this project was to analyse signals and try to localize the position of source of sound. It is donewith three microphones which have 90 degrees angle to each other. Each microphone detects one partof the sound wave. The microphones are connected toan ADC which turns signals from analogue todigital shape. After that the three signals are transformed to a computer.

AbstractParental participation is something that is included in school either we like it or not. Several studies have been done about this phenomena but not many of them have examined the pupils estimation about parental participation. Therefore did we get interested about the pupils situation because why haven?t almost anyone asked the pupils about this phenomena when it?s constructed fore them? To learn more about the pupils estimation did we a questionnaire in twelve different classes with children in the ages between 10-16 years. The results we got from the questionnaire concerning the pupils estimation about parental participation were both expected and unexpected.Keywords: Parental participationQuestionnairePupil estimation.

I denna uppsats behandlas de grammatiska fenomenen complete phase och incomplete phase i det austronesiska språket rotumanska. Min avsikt med uppsatsen är att ta reda på varför complete phase respektive incomplete phase används i en viss syntaktisk eller morfologisk kontext. Jag har baserat denna studie endast på litteratur, främst från C.M Churchwards Rotuman Grammar and Dictionary..

The purpose of this study is to examine in what extent primary school teachers, teaching children in the age of 6 to 9, choose to use digital tools in their teaching of mathematics. I also want to examine what these teachers think, in terms of advantages and disadvantages, about using digital tools on their mathematics lessons. Finally I want to examine what skills they possess about digital tools.I am using a quantitative method to collect my data. The quantitative survey consisted of a questionnaire survey of ten questions that 38 primary school teachers have answered.The results of my study show that the teachers to some extent use digital tools when they teach mathematics and that the availability of various digital tools are generally good. But it turns out that the availability of tools is not a guarantee that they are used in teaching of mathematics.

The thesis work of 15 credits has been performed to interest of Norrtälje ElektronikPartner AB (NEP) in Norrtälje. The aim of the thesis was to develop a prototype for an integrated digital multimeter, designed for one of NEP's proprietary test systems. A digital multimeter module according to NEP's requirement specification, such as physical size and accuracy should be constructed. The module should be able to measure current, voltage and resistance.The final circuit was based on the chosen analog to digital-converter, Maxim integrated´s Max134, which is the main component of the circuit for this instrument. A circuit diagram and PCB layout were made. The result of this project is a constructed DMM board.

This paper examines how debt cancellation, given under the HIPC-initiative, has affected corruption over the period 2000-2006. The examination is foremost interesting due to earlier research showing that high corruption leads to unequal distribution of economic resources. This, combined with the objective of the HIPC initiative to reduce poverty, indicates that combating corruption must be successful in order to fulfill the goals of the initiative. A linear regression shows that countries that have benefited from the HIPC-initiative indeed have a lower corruption than other countries. A panel-data analysis shows on the other hand that no effect on corruption due to debt cancellation or reforms undertaken in the program can be confirmed..

It is important that the language in textbooks for foreign language learners reflects the language that the learners would encounter in real life. For this reason, the presence of the thousand most common nouns in two Swedish textbooks in Spanish for upper secondary school is observed in this study. Furthermore, this study aims to examine how these nouns occur in order to determine if their pattern of occurence favours the learning and consolidation of words. The main materials that have been used are A Frequency Dictionary of Spanish by Davies (2006) and the word search program available in the digital versions of the textbooks. The results show that the presence of the thousand most common Spanish nouns does reflect the frequency information presented in the frequency dictionary but not all thousand nouns are included.