Fledermaus is software where different kind of analysis with spatial data can be done. The main area where to use Fledermaus is related to hydrographical surveys. This study is aimed to test and analyse the way Swedish Maritime Administration (Sjöfartsverket) uses Fledermaus. Through step by step explaining how to do when measuring sea bed conditions from a vessel, this text is possible to use as a manual for the applications that are mentioned in this report. Another thing that is treated is the squat effect that belongs to vessel dynamic motions. Test of visualization that concerning squat in Fledermaus is done, but with a negative result when squat in a perspective to show motions in height that can be up to about a metre is very hard in a terrain model of thousands of metres. By further tests by arranging the input data, several interesting diagrams have been created through Microsoft Excel where graphs show that the depths are affecting the squat effect. This is showed in same diagram but with two different scales to show the relationship between how a point at the vessel moves in height compared to the depth under the vessel when the vessel is navigating in the sea. / Fledermaus är en programvara där olika analyser med rumsliga data kan genomföras. Största användningsområdet är att använda Fledermaus till mätningar som är relaterade till sjömätning. Den här studien är inriktad till att testa och analysera applikationer som Sjöfartsverket använder sig av i Fledermaus. Genom att steg för steg förklara hur Fledermaus ska användas när bottenförhållanden ska mätas sett från ett fartyg, så blir texten även möjlig att använda som en manual till de applikationer i Fledermaus som är nämnda i denna rapport. Det andra som behandlas är squateffekten som tillhör ett fartygs dynamiska rörelser. Test av visualisering som behandlar squat i Fledermaus är genomförd, dock med negativt resultat då squat i ett perspektiv med att visa rörelser i höjd som kan uppgå till runt en meter är väldigt svårt i en terrängmodell som sträcker sig tusentals meter. Dock genom vidare tester genom behandling av indata, har flertalet intressanta diagram skapats genom Microsoft Excel där kurvor visar att djupet inverkar på squateffekten. Detta visas genom att i samma diagram fast med två olika skalor visa förhållandet mellan hur en punkt på båten rör sig i höjd jämfört med att djupet under fartyget ändras då fartyget gör fart genom vattnet.

A system for vessel characterization aimed at detecting deep vein thrombosis (DVT) in the lower limbs has been developed and evaluated using ultrasound image processing, location and force sensors measurements, blood flow information and a protocol based on the current clinical standard, compression ultrasound. The goal is to provide an objective and repeatable system to measure DVT in a rapid and standardized manner, as this has been suggested in the literature as an approach to improve overall detection of the disease. The system uses a spatial Kalman filter-based algorithm with an elliptical model in the measurement equation to detect vessel contours in transverse ultrasound images and estimate ellipse parameters, and temporal constant velocity Kalman filters for tracking vessel location in real-time. The vessel characterization also comprises building a 3-D vessel model and performing compression and blood flow assessments to calculate measures that indicate the possibility of DVT in a vessel. A user interface designed for assessing a vessel for DVT was also developed. The system and components were implemented and tested in simulations, laboratory settings, and clinical settings. Contour detection results are good, with mean and rms errors ranging from 1.47-3.64 and 3.69-9.67 pixels, respectively, in simulated and patient images, and parameter estimation errors of 5%. Experiments showed errors of 3-5 pixels for the tracking approaches. The measures for DVT were evaluated, independently and integrated in the system. The complete system was evaluated, with sensitivity of 67-100% and specificity of 50-89.5%. System learnability and memorability were evaluated in a separate user study, with good results. Contributions include a segmentation approach using a full parameter ellipse model in an extended Kalman filter, incorporating multiple measurements, an alternate sampling method for faster parameter convergence and application-specific initialization, and a tracking approach that includes a sub-sampled sum of absolutes similarity calculation and a method to detect vessel bifurcations using flow data. Further contributions include an integrated system for DVT detection that can combine ultrasound B-mode, colour flow and elastography images for vessel characterization, a system interface design focusing on usability that was evaluated with medical professionals, and system evaluations through multiple patient studies.

Magistro baigiamojo darbo teorinėje dalyje analizuojami įvairūs virpesių lygio mažinimo būdai bei schemos laivuose. Aprašoma virpesių klasifikacija, pagrindiniai virpesių žadintojai laive, virpesių skaičiavimo būdai. Eksperimentinėje dalyje pateikiama kelto „Optima Seaways“ siurblio virpesių matavimo metodika. Nagrinėjami reiso Klaipėda-Karlshamnas-Klaipėda metu atliktų matavimų rezultatai bei nustatomos tiriamo siurblio padidinto virpesių lygio priežastys. Paskutinėje darbo dalyje pateikiamas racionalus sprendimas, reikalaujantis minimalių lėšų ir laiko sanaudų, tiriamo siurblio virpesių lygio sumažinimui. / The theoretical part of the Master’s thesis analyzes various vibration reduction systems and schemes in ships. Classification of vibrations on board, main vibration sources and vibration calculations are presented. The experimental part presents methodic for vibration measuring of ferry “Optima Seaways” pump. Vibration data, received during passage Klaipėda- Karlshamn- Klaipėda, is analyzed and reason of high pump vibration level is identified. Last part of thesis presents rational solution, with minimal cost and time expenses, for reduction of pump vibration level.

Image-guided therapies have the potential to improve the accuracy of treating liver cancer. In order to register intraoperative with preoperative liver images, joint segmentation and registration methods require fast segmentation of matching vessel centerlines. The algorithm presented in this thesis solves this problem by tracking the centerlines using ridge and cross-section information, and uses knowledge of the patient’s vasculature in the preoperative image to ensure correspondence. The algorithm was tested on three MR images of healthy volunteers and one CT image of a patient with liver cancer. Results show that in the context of join segmentation registration, if the registration error is less than 2.0mm, the average segmentation error is 0.73-1.68mm, with 88-100% of the vessels having an error less than a voxel length. For registration error less than 4.6mm, the average segmentation error is 1.17-2.11mm, with 79-98% of the vessels having an error less than a voxel length.

Image-guided therapies have the potential to improve the accuracy of treating liver cancer. In order to register intraoperative with preoperative liver images, joint segmentation and registration methods require fast segmentation of matching vessel centerlines. The algorithm presented in this thesis solves this problem by tracking the centerlines using ridge and cross-section information, and uses knowledge of the patient’s vasculature in the preoperative image to ensure correspondence. The algorithm was tested on three MR images of healthy volunteers and one CT image of a patient with liver cancer. Results show that in the context of join segmentation registration, if the registration error is less than 2.0mm, the average segmentation error is 0.73-1.68mm, with 88-100% of the vessels having an error less than a voxel length. For registration error less than 4.6mm, the average segmentation error is 1.17-2.11mm, with 79-98% of the vessels having an error less than a voxel length.

No description available.

No description available.

In this thesis a recently developed energy resolving x-ray detector (Medipix) is used to investigate potential medical applications of spectral x-ray imaging. Computed Tomography (CT) is one of the most important medical imaging modalities. Recent developments in CT techniques include dual-energy CT, where images are taken with two different x-ray spectra by either using two x-ray tubes operated at different voltages, or modulating the operating voltage of a single tube. These techniques provide spectral information in the CT dataset but are limited to what can be achieved by manipulating the x-ray source, since the detectors used in current CT systems are unable to provide spectral information about the detected x-rays. A preliminary investigation of the use of the Medipix detectors for two different medical applications is presented. The first, applications is imaging of blood vessels for diagnosis of vascular diseases, and the second, characterising and measuring the energy dependence of x-ray attenuation in fat and liver tissue using the Medipix2 detector. This second investigation is part of work towards (eventually) quantifying the fat content of liver tissue in vivo, which is important for the early diagnosis of fatty liver disease. While an early attempt to identify iron fluorescence x-rays in a Monte-Carlo simulation of blood vessel x-ray image was not successful, the potential for improving image contrast using the changes in x-ray attenuation at the iodine k-edge iodine have been investigated in a series of further simulations and appears to be feasible. The potential use of spectral imaging to differentiate and quantify tissues without the need for added contrast material has been investigated by using a Medipix2 detector to measure the energy dependence of x-ray absorption in fat and liver tissue. The results of this experimental work show significant differences in x-ray attenuation between these two tissues that suggest this form of spectral imaging may be useful in practice.

Keramikos studijos – informatyvus šaltinis archeologiniams paminklams pažinti. Pasirinkta šio darbo tema apima Kernavės viduramžių apžiestą keramiką. Pagrindinis darbo tikslas – pasekti Kernavės keramikos raidą viduramžių Kernavės miesto ir vėliau čia egzistavusio miestelio chronologinėse ribose. Didžiausias dėmesys skiriamas XIII-XIV a. puodininkystės raidos tendencijoms stebėti, tuo tarpu miestelio keramika naudojama daugiau kaip lyginamoji medžiaga pokyčių stebėjimui ir išryškinimui. Tikslo įgyvendinimui tyrinėti technologiniai, morfologiniai, puošybiniai keramikos požymiai, stebėtas jų stabilumas ar kaita laike ir erdvėje, įvertinta šių požymių reikšmė. Didžiąją dalį nagrinėjamos Kernavės keramikos sudaro įvairių dydžių puodai, kurie sąlygiškai suskirstyti į funkcines grupes: mažus puodelius, puodus, puodynes, galėjusius atlikti maisto gamybos, pernešimo, saugojimo funkcijas. Specializuotų apžiestos keramikos indų sutinkama retai - dauguma jų priklauso miestelio laikotarpiui Technologinių gamybos požymių kaita aptariamu laikotarpiu nėra žymi. XIII-XIV a. pokyčiai dažniau pastebima ne diachroninėje, o erdvinėje plotmėje. Molio liesinimui dažniausiai naudotas grūstas granitas, sienelės formuotos iš volelių, o XIV a. ir iš juostų, apžiedžiant puodui buvo suteikiama forma ir/ar nulyginamas paviršius. XIV a. II p. keramikoje pastebima kiek spartesnė gamybinių požymių kaita – smulkėja priemaišos, puodai apžiedžiami intensyviau, sienelių storis tolygesnis, jos kruopščiau... [toliau žr. visą tekstą] / The subject of this study is medieval wheel-turned pottery of Kernavė. The main goal of this work is to observe the development of pottery of medieval town and later settlement of Kernavė. Particular attention is paid to the pottery making traditions in 13th-14th centuries. Pottery from the later settlement meanwhile is used mainly as the comparative material in order to observe some changes through time. Technological, morphological and ornamental properties of pottery were identified for the study of their significance and evolution through time and space. The majority of pottery under consideration can be attributed to the pots of different sizes. These pots were differentiated into several functional groups: small pots, pots and jars. All these groups could be used for a variety of purposes such as cooking, transportation or storage. The amount of single-purpose vessels is very small and even these few belong to the settlement which was established in the 15th century in the place of earlier town. The evolution of technological attributes of Kernavė’s pottery in the Middle-ages is quite gradual. It is especially characteristic to the pottery of the 13th-14th centuries when most of discrepancies in pottery are influenced mainly by the individual peculiarities of every potter but not by the chronological differences. Crushed granite is typically used as a temper, the intensity of turning varies from the subtle surface smoothing to the partial forming of vessel. However... [to full text]

Ombord på fartyg är det inte önskvärt att få strömavbrott, en så kallad blackout. Examensarbetet har undersökt i vilken utsträckning det är möjligt att utföra jämförande och förebyggande studier med haverirapporter från europeiska flaggstater som underlag. Detta för att undersöka återkommande brister, på fartyg eller i arbetet ombord som har orsakat blackout. Dessutom har även möjligheterna till att kunna kategorisera fallen undersökts. Kategorierna var tekniskt fel, operativt fel och organisationsfel. I ungefär häften av fallen gick det inte att kategorisera en blackout till ett fel, eftersom det annars var en kombination av fel. Däremot finns återkommande fel där händelseförloppen är väldigt lika. Till exempel var heta ytor inte korrekt isolerade, vilket resulterade i brand vid bränsleläckage. Undersökningen visar att det finns en bristfällig symmetri i rapporteringen av haveri med avseende på språk, struktur, omfattning och publiceringsform. Brister fanns även på sökfunktionerna i databaserna. / On board vessels it is not desirable to have a power failure, a so-called blackout. The thesis has investigated to what extent it is feasible to perform comparative and preventive studies with the accident reports from European flag states as a basis. This in order to investigate recurring shortcomings, of the vessels or in the work on board that has caused the blackout. In addition the possibility to categorize the cases was investigated. The categories were technical errors, operational errors and organization errors. Roughly half of the cases show that a single category of fault could not be identified due to a combination of faults leading to the blackout. However there are recurring cases with almost identical scenarios. For example unsatisfactory insulation caused fires due to leaking fuel hitting the hot surfaces. The survey shows that there is a lack of symmetry regarding the language used, structure, scope and form of publication. It also showed faults in the search engines of the databases.