Extracting the Electric Network Frequency (ENF) fluctuations from an audio recording and comparing it to a reference database is a new technology intended to perform forensic digital audio authentication. The objective of this thesis is to implement and design a range of programs and algorithms for capturing and extracting ENF signals. The developed C-program combined with a probe can be used to build the reference database. Our implementation of the Short-Time Fourier Transform method is intended for the ENF extraction of longer signals while our novel proposed use of the Autoregressive parametric method and our implementation of the zero-crossing approach tackle the case of shorter recordings. A Graphical User Interface (GUI) was developed to facilitate the process of extracting the ENF fluctuations. The whole process is tested and evaluated for various scenarios ranging from long to short recordings.

There is a lot of applications for DSPs (Digital Signal Processor) in the most rapidly growing areas in the industry right now as wireless communication along with audio and video products are getting more and more popular. In this report, a DSP, developed at the division of Computer Engineering at the University of Linköping, is optimized and verified. Register Forwarding was implemented on a general architecture level to avoiddata hazards that may arise when implementing instruction pipelining in a processor. The very common FFT algorithm is also optimized but on instruction setlevel. That means the algorithm is carefully analyzed to find operations that mayexecute in parallel and then create new instructions for these parallel operations.The optimization is concentrated on the butterfly operation as it is such a majorpart of the FFT computation. Comparing the accelerated butterfly with the unaccelerated gives an improvement of 30% in terms of clock cycles needed for thecomputation. In the report there are also some discussions about the benefits and drawbacksof changing from a hardware to a software stack, mostly in terms of interrupts andthe return instruction. Another important property of the processor is scalability. That is, it is possibleto attach extra peripherals to the core, which accelerates certain tasks. Aninterface towards these peripherals is developed along with two template designsthat may be used to develop other peripherals. After all these modifications, a new test bench is developed to verify the functionality.

Abstract Cognitive Radio (CR) improves the efficiency of spectrum utilization by allowing non- licensed users to utilize bands when not occupied by licensed users. In this thesis, we address several challenges currently limiting the wide use of cognitive radios. These challenges include identification of unoccupied bands, energy consumption and other technical challenges. Improved accuracy edge detection techniques are developed for CR to mitigate both noise and estimation error variance effects. Next, a reduced complexity Simplified DFT (SDFT) is proposed for use in CR. Then, a sub-Nyquist rate A to D converter is introduced to reduce energy consumption. Finally, a novel multi-resolution PSD estimation based on expectation-maximization algorithm is introduced that can obtain a more accurate PSD within a specified sensing time.

Extracting the Electric Network Frequency (ENF) fluctuations from an audio recording and comparing it to a reference database is a new technology intended to perform forensic digital audio authentication. The objective of this thesis is to implement and design a range of programs and algorithms for capturing and extracting ENF signals. The developed C-program combined with a probe can be used to build the reference database. Our implementation of the Short-Time Fourier Transform method is intended for the ENF extraction of longer signals while our novel proposed use of the Autoregressive parametric method and our implementation of the zero-crossing approach tackle the case of shorter recordings. A Graphical User Interface (GUI) was developed to facilitate the process of extracting the ENF fluctuations. The whole process is tested and evaluated for various scenarios ranging from long to short recordings.

The choice of the topic addressed in this thesis aims to improve the service and maintenance on ceramic ball bearings in a specific test dynamometer and through an engineering approach develop tools for condition monitoring. The company connected to this thesis, AVL, is the world's largest privately owned company for development, simulation and testing technology of powertrains for passenger cars, trucks and large engines. Engine testing is a critical part of the business at AVL Sweden and unexpected bearing failure can result in long repair times and great economic losses due to loss of the testing time. In short terms, the methodological approach followed the following steps; first a thorough information retrieval regarding bearings and analysis was conducted. The search was deepened around areas such as hybrid ball bearings, bearing failure mechanisms, bearing defect frequencies, signal analysis and condition monitoring. After this a table for bearing damage detection was developed and a “step by step” guidance for condition monitoring. The tools where afterwards verified by simple testing to detect complications within the chosen system. The existing condition monitoring system that is used today revealed weaknesses as it lacked the feature of taking preventive measures. The system that is based on temperature measurements isn’t satisfactory enough, especially when it’s missing visual clarity. Service and maintenance according to specifications from the manufacturer should be scheduled to ensure operational and guarantees. Currently mounted accelerometers on the housing of the Dynas3 engine should be connected for collecting data and the total sum of energy should be calculated for simple monitoring of historical progression. This should be done by following the guidance in order to ensure proper data acquisition. The best way to implement condition monitoring showed to be by performing multi-parameter monitoring. The design of the condition monitoring system is highly connected to what to monitor and at what stage. One main consideration to keep in mind is that it’s very rare that manufacturing defects are the reason for bearing failure. Instead it derives from improper storage, transport, handling or dimensional errors and even in some cases by improperly implemented force analysis prior to bearing selection. / Huvudämnet som behandlas i detta examensarbete syftar till att förbättra service och underhåll på keramiska kullager i en viss testdynamometer och genom ett ingenjörsmässigt tillvägagångsätt utveckla verktyg för tillståndsövervakning. Företaget som är ansluten till detta examensarbete är AVL som är världens största privatägda företag för utveckling, simulering och testteknik för drivlinor för personbilar, lastbilar och stora motorer. Motorprovning är en viktig del av verksamheten vid AVL Sverige, och ett oväntat lagerhaveri kan leda till långa reparationstider och stora ekonomiska förluster på grund av utebliven test tid. I korta termer följde den metod som använts följande steg, först genomfördes en grundlig informationssökning om lager och tillhörande analyser. Efter det fördjupades sökande kring områden som hybrida kullager, lagerskademekanismer, frekvenser kopplade till lagerskador, signalanalys och tillståndsövervakning. Efter detta framställdes en tabell för detektering av lagerskador, samt en ”steg för steg” guide för tillståndsövervakning. Verktygen för tillståndsövervakning kontrolleras efteråt, genom att enkla tester genomfördes för att upptäcka komplikationer inom det valda systemet. Det övervakningssystem som används idag avslöjade svagheter genom att sakna funktionen att vidta förebyggande åtgärder. System som är baserat på temperaturmätningar är inte tillräckligt tillfredsställande, speciellt när det saknar en visuell tydlighet. Den service och underhåll som enligt tillverkarens föreskrifter påvisas bör planeras för att säkerställa drift och garantier. Nuvarande monterade accelerometrar fästa vid motorhöljet bör anslutas för att insamla data, och den totala summan av energin bör beräknas för en enkel övervakning av det historiska utvecklingsförloppet. Detta bör göras genom att följa de riktlinjer som framställts för att säkerställa korrekt datainsamling. Det bäst passande sättet att genomföra tillståndsövervakning på i detta fall visade sig vara att utföra multiparameterövervakning. Framställningen av tillståndsövervakningssystemet är starkt förknippat med vad som skall övervakas och i vilket skede. En huvudsaklig bidragande faktor att komma ihåg är att det är mycket ovanligt att fabrikationsfel är orsaken till lagerhaveri. Istället härstammar haveriet från felaktig förvaring, transportering, hantering eller dimensioneringsfel och i vissa fall av felaktigt genomförd kraftanalys inför lagerval.

Many people experience discomfort during movement when using a knee prosthesis. As a result, a study is being conducted to see if biomedical models can be used to produce an optimal prosthetic socket to reduce discomfort. This has previously been accomplished using pressure sensors embedded in the sleeve to measure leg pressure at various stages of the gait cycle. To gather more information, an EEG should be performed to find where discomfort occurs throughout a gait cycle. The purpose of the EEG is to perform measurements for a certain time during walking to then be able to analyze the signals that occur from the brain's motor cortex. The signal analysis is performed by applying the Fast Fourier transform to convert EEG data from the time domain to the frequency domain. By examining frequency differences, it is demonstrated that additional measurements with more individuals are required to ensure that the results reflect discomfort, and that the EEG is useful in the applied field of use. / Vid användning av knäproteser upplever ett stort antal personer obehag vid rörelse. På grund av detta utförs det en studie där man genom biomedicinska modeller kan producera den optimala proteshylsan för att minska obehag. Detta har tidigare gjorts med trycksensorer placerade i hylsan, för att kunna mäta tryck från benet vid olika faser av en gångcykel. EEG ska användas för att få mer information var det uppstår obehag under en gångcykel. Syftet med EEG är att genomföra mätningar under en viss tid vid gång, för att sedan kunna analysera signalerna från hjärnans motoriska cortex. Signalanalysen sker genom att transformera EEG-data från tidsdomänen till frekvensdomänen med hjälp av Snabb Fourier transform. Genom att undersöka frekvensskillnader påvisas att ytterligare mätningar med fler individer krävs för att säkerställa att resultaten återspeglar obehag och att EEG är användbart inom det tillämpade användningsområdet. / This work was supported by the research project SocketSense (https://www.socketsense.eu/), funded by the European Union’s Horizon 2020 research and innovation programme under grant agreement No 825429

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Paperboard is produced in a large and complex process where many parameters can affect its quality. The common methods of analysing paperboard quality are through traversing point-like sensors that only measure a very small fraction of the produced paperboard. Holmen Iggesund Paperboard has installed an IR-camera that measures the entire paperboard web and is looking for a tool to assess paperboard quality variation based on these measurements. The purpose of this thesis work is to develop such a tool. This was done through developing a user-friendly computer application (app) IR-measurement Analysis (IRMA). The app is designed to help the process engineers of Iggesunds mill assess the paperboard variability, which strongly correlates with its quality. The quality improvements of paperboard mainly concern eliminating irregularities in thickness, grammage, and moisture. In IRMA, theuser can prepare data, perform statistical analyses, execute a frequency analysis through Fast Fourier Transform and then compare the frequency peaks with the frequencies of possible sources for periodic process variation, for example rolls. Correlating frequency peaks and roll frequencies can indicate issues with rolls and make process engineers at the mill aware of maintenance needs. IRMA have been tested at the mill and these tests have indicated that IRMA can be beneficial in the process engineer’s daily quality control measures. Furthermore, a manual has been written and the process engineers will be thoroughly educated in the use of IRMA.

Master of Veterinary Bioscience / Department of Diagnostic Medicine/Pathobiology / Deon Van Der Merwe / Every year thousands of domestic animals are poisoned by ethylene glycol. Exposure is normally orally, but may be dermal, and poisonings are usually accidental and not malicious. Antifreeze, overwhelmingly the source of the ethylene glycol poisoning, is responsible for over 99% of reported cases. Storage, handling and proper disposal of ethylene glycol is extremely important in limiting access to this deadly product. Ethylene glycol exposures were involved in 1737 calls made to the American Society for the Prevention of Cruelty to Animals call center between 2006 and 2011. Dogs were involved in approximately 87% of exposures and cats in 13%. There were no seasonal or breed patterns. The most common clinical signs reported were neurological and gastrointestinal for both cats and dogs. Urinary calcium oxalate crystals were reported in 28.6% of exposed cats, and 21% of dogs. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) was used to detect calcium oxalate crystals in wax-mounted kidneys from twenty total cases, ten of which were suspected ethylene glycol poisoning submitted to the Kansas State Veterinary Diagnostic Laboratory, and ten samples deemed negative by a pathologist using light microscopy. Pure calcium oxalate monohydrate was used as a reference, and a unique absorption peak was detected between wavenumbers 1290 cm[superscript]-1 and 1320 cm[superscript]-1. The drying of kidney tissues resulted in increased sensitivity for calcium oxalate. Crystal detection by the ATR-FTIR was compared to light microscopy. Bi-fringence of crystals allowed microscopic detection, but the ATR-FTIR specificity for the test was 100%, and sensitivity was 80% compared to traditional microscopy for ca-oxalate crystal identification. ATR-FTIR was also used to detect un-metabolized ethylene glycol in vomitus using wavenumbers 1084 cm[superscript]−1, 1039 cm[superscript]−1, and 882 cm[superscript]−1, but ethylene glycol was not detectable. Ethylene glycol concentrations in samples were much too low to be detected as ethylene glycol on the ATR-FTIR, as the limit of detection was not distinguishable until 5000 ppm using a serial dilution. These methods presented simple, reliable, quick, sensitive, stable, and highly adaptable tests for detection, diagnosis and treatment of ethylene glycol poisoning.

International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / Because modern data acquisition systems use digital backplanes, it is logical for more and more data processing to be done in each Data Acquisition Unit (DAU) or even in each module. The processing related to an analog acquisition module typically takes the form of digital signal conditioning for range adjust, linearization and filtering. Some of the advantages of this are discussed in this paper. The next stage is powerful processing boards within DAUs for data reduction and third-party algorithm development. Once data is being written to and from powerful processing modules an obvious next step is networking and decom-less access to data. This paper discusses some of the issues related to these types of processing.