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40 Uppsatser om 64-slice computed - Sida 2 av 3
Dynamisk tredimensionell visualisering av fot med datortomografi
Projektets syfte var att med modern datortomografi (computed tomography, CT) skapa tidsupplösta tredimensionella sekvenser, även kallade 4D-sekvenser, med låg stråldos och tillräckligt bra upplösning samt att påbörja en implementering av denna metod på Karolinska Universitetssjukhuset i Huddinge. För att få ett så bra resultat som möjligt involverades ett antal personer med olika medicinsk yrkesbakgrund och olika kompetensområden.En fantomstudie utfördes genom att dra ett fantom med en konstant hastighet genom CT:n med hjälp av en motor. Efter detta utfördes en pilotstudie på två försökspersoners högerfötter som utförde en rörelse under olika lång tid under en CT-undersökning.Scanningen av fötterna genomfördes först efter att det visade sig att scanningen av fantomet gav adekvat resultat med avseende på bildkvalitet och stråldos. För att avgöra detta gjordes en analys av bilderna på fantomet och en dosberäkning.Scanningen av fötterna genererade tolkningsbara bilder med tillräckligt låg stråldos. Denna metod kommer därför säkerligen användas i undervisnings- och forskningssyfte.
Shopping Cart Support
This is a product development project which has developed a prototype in order to facilitate for people using mobility devices when they want to buy a larger quantity of groceries. The prototype is a shopping cart composed with the upper part of a walker.Today there are many different types of mobility devices used by elderly and people with physical impairment. According to Myndigheten för samhällsskydd och beredskap (MSB) are accidental falls the most common cause of accidents in Sweden.This project has been using Computer Aided Design (CAD) as a tool to create a visual image of the prototype. The advantage of this is to modify the functionality and performance of the prototype on the computer before the modification takes place in the real model. Using human manikins, the CAD model was rendered in natural surroundings to get as true a picture as possible.
Kvalitetskontroll av servicedatabasen Sisyla
Sisyla is a joint project between the counties of Skåne, Blekinge, Jönköping, Kronobergand Kalmar in Sweden. A geographic database has been built with the aim to study theservice situation of the area. The main purpose of this thesis is to find a method toinvestigate the quality of the Sisyla database and to apply it. The method is adjusted tothe standard ISO 19114. The agreement between the database and reality was studied ina test sample.
Optimering av slutfasstyrning
Modern missiles must meet higher and higher demands. They should be autonomous, have long range and still have a big effect on the target. To maximize effect on target some missiles not only minimize miss distance, but also try to hit with a certain angle; often perpendicular to the surface of the target. In this thesis a method to guide the missile in the terminal phase of its mission where both point of impact as angle of impact are specified. The method consist of two parts.
Microstrip Solutions for Innovative Microwave Feed Systems
This report is introduced with a presentation of fundamental electromagnetic theories, which have helped a lot in the achievement of methods for calculation and design of microstrip transmission lines and circulators. The used software for the work is also based on these theories. General considerations when designing microstrip solutions, such as different types of transmission lines and circulators, are then presented. Especially the design steps for microstrip lines, which have been used in this project, are described. Discontinuities, like bends of microstrip lines, are treated and simulated.
Support Vector Machines for Classification applied to Facial Expression Analysis and Remote Sensing
The subject of this thesis is the application of Support Vector Machines on two totally different applications, facial expressions recognition and remote sensing.The basic idea of kernel algorithms is to transpose input data in a higher dimensional space, the feature space, in which linear operations on the data can be processed more easily. These operations in the feature space can be expressed in terms of input data thanks to the kernel functions. Support Vector Machines is a classifier using this kernel method by computing, in the feature space and on basis of examples of the different classes, hyperplanes that separate the classes. The hyperplanes in the feature space correspond to non linear surfaces in the input space.Concerning facial expressions, the aim is to train and test a classifier able to recognise, on basis of some pictures of faces, which emotion (among these six ones: anger, disgust, fear, joy, sad, and surprise) that is expressed by the person in the picture. In this application, each picture has to be seen has a point in an N-dimensional space where N is the number of pixels in the image.The second application is the detection of camouflage nets hidden in vegetation using a hyperspectral image taken by an aircraft.
Uppskattning av Ytkurvatur och CFD-simuleringar i Mänskliga Bukaortor
By applying a segmentation procedure to two different sets of computed tomography scans, two geometrical models of the abdominal aorta, containing one inlet and two outlets have been constructed. One of these depicts a healthy blood vessel while the other displays one afflicted with a Abdominal Aortic Aneurysm. After inputting these geometries into the computational dynamics software FLUENT, six simulations of laminar, stationary flow of a fluid that was assumed to be Newtonian were performed. The mass flow rate across the model outlet boundaries was varied for the different simulations to produce a basis for a parameter analysis study. The segmentation data was also used as input data to a surface description procedure which produced not only the surface itself, but also the first and second directional derivatives in every one of its defining spatial data points.
En studie av retentionen i floden Oder och dess avrinningsområden, Polen.
Nutrient enrichment is the main cause of the increasing eutrophication process in the Baltic Sea during last century. A prerequisite counteract this process the load of nutrients to the Sea must be investigated. The large contribution of nutrients to the Sea is caused by emission from the rivers within the drainage basin. For the total emission of nutrient into the Sea the retention process in the rivers has big influence. This process in the river system has been assumed as a not important part of the nutrient cycle.
Utvärdering och uppdatering av typkurvor
The purpose of this thesis is to evaluate and update load curves for Fortum Distribution AB. Theload curve method is a tool used to forecast the strain of an electric grid. The method is based oncustomer annual energy consumption, outdoors temperature as well as customer category. Theload curve method was established by Svenska Elverksföreningen at the start of the nineties andfocus was put on standardizing annual energyconsumption, in order to make the method usableacross the nation. Present consumption patterns have changed since the original load curves wereproduced, which leads to a need to update the load curves.The work began with an update of present load curves according to recommendation taken fromanother earlier thesis.
Identifiering av gallringsbehov med hjälp av flygburen laserskanning :
Thinning is one of the most important silvicultural activities in middle aged forests, partly to minimize damages and partly because it leads to earlier harvesting revenues and increases the value of the remaining trees. There are many different indices used to describe stand density and thereby the need of thinning in forests today. Studies have shown that forest variables can be estimated with high accuracy using airborne laser scanning and it is likely that the method could also be used to estimate forest density indices. In this study, the possibility of using the forest density index ?H² to determine and map priorities for thinning operations for a forest area was examined.
Verifikation av verktyget aspect analyzer
Rising complexity in the development of real-time systems has made it crucial to have reusable components and a more flexible way of configuring these components into a coherent system. Aspect-oriented system development (AOSD) is a technique that allows one to put a system?s crosscutting concerns into"modules"that are called aspects. Applying AOSD in real-time and embedded system development one can expect reductions in the complexity of the system design and development. A problem with AOSD in its current form is that it does not support predictability in the time domain.
Noggrannhet vid målinmätning : Analys av ett eldledningsinstrument med förbättringsförslag
This Master Thesis has been conducted as an assignment of the Swedish Defence MaterialAdministration and the Swedish Armed Forces and aims to examine the Target Location Error(TLE) of a Forward Observer System. The targeting accuracy of the system is vital if the systemis to be used as a sensor for precision munitions. The analyzed system, EOI (FOI 2000), wasdelivered to the Swedish Armed Forces in 2007. The targeting sequence starts with deciding theposition of the system with a GPS-receiver, continues with methods where the north direction issettled and ends by measuring the distance, direction and elevation to the target. When allparameters have been measured the system calculates the position of the target.
PET-CT, en funktionell och anatomisk avbildningsteknik
Under 70-talet introducerades Positron Emissions Tomografi (PET) och på tidigt 90-tal påbörjades en planering av att kombinera PET och CT utrustning i samma hölje. PET är en metod som avbildar funktioner i människokroppen och CT, som står för computed tomografi (datortomografi) ger snittbilder av patientens anatomi. Detta ger på så vis en bild av både anatomin och funktionen. Det ger mycket viktigt information för diagnostik och planeringen av patientens behandling. Mycket förenklat kan man säga att en PET-CT undersökning går till så att det radioaktivt märkta ämnet, spårsubstansen, till exempel FDG injiceras intravenöst och sedan avläser kameran hur sockret tas upp i vävnaden.
Fördelar och nackdelar med vismutskydd över bröst vid datortomografiundersökning : En litteraturstudie
Sammanfattning Bakgrund Stråldosen vid en datortomografiundersökning (CT-undersökning) kan vara 100 gånger större än vid en konventionell röntgenundersökning [1]. På 10 år har antalet CT-undersökningar nästan fördubblats [2], vilket också innebär att stråldosen till patienterna ökar [1]. Bröstkörtlarna är ett av de mest strålkänsliga organen och är därför viktiga att skydda [3, 4]. Material som dämpar röntgenstrålning kraftigt och som lämpar sig för strålskydd är t.ex. bly och vismut [5].
Wobblerpump
The task was to design and manufacture a submersible displacement pump working with the wobble plate principle. The main task for the Wobble plate pump is to be used as a sewage pump for smaller households or dewatering pump in environments where small flows and high pressures are acquired. For these purposes ITT Flygt sell a screw pump, PC-Grinder 3068. The hydraulic part of the PC-Grinder is manufactured by a subcontractor. Therefore ITT Flygt wants to evaluate an alternative to their screwpump PC-Grinder, which can be entirely manufactured by them self.