Simulations of simulink models using Kalman filters are often very time-consuming. This problem depends mainly on the fact that the Kalman correction has to be performed at each sample instance through the whole simulation. The goal for this thesis work is to reduce that time-consumption for the filtering part (the integration partis treated in a complementary report) of a simulation. Furthermore a Matlab routine to perform parameter tuning and finally a graphical user interface is developed.The filtering part of the simulation in this thesis is based on an Extended Kalman Filter (EKF). The time optimization of this filter considers searching for the possibility to replace the today?s existing Matlab functions that is used to perform the filtering calculations.

At Flight and Systems test Saab AB, a post-processing software is used to process GPS data. A new software by the name GrafNav has been purchased and the purpose of this master thesis therefore became, partly to make a judgment regarding GrafNav?s ability to estimate position, velocity and accuracy, partly to if needed improve the estimate and finally find one or several methods to estimate the position and velocity accuracy. The judgment of GrafNav was performed partly by a comparison to the former post-processing software (PNAV) and partly by a comparison to the airplane?s inertial navigation system (INS).

Simulation of different systems can be done using a graphical model description of the system based on block diagrams. The simulation software Matlab/Simulink offers a lot of possibilities to describe a huge number of systems, which can be linear as well as nonlinear. The simulation using Matlab/Simulink is done by integration based on different kinds of numerical methods.When nonlinear Simulink-models are simulated, it is often interesting to apply a Kalman filter to handle the noise that may occur within the process as well as corrupting the measurement. However, application of such a filter leads to an extensive time-consumption despite using fast computers. The reason is that the existing Matlab functions are not constructed for time optimal evaluation.

The aim of the Master?s Thesis work is to study and develop algorithms for autonomous travel of a UGV (Unmanned Ground Vehicle). A vehicle for the mounting of sensors has been constructed in order to perform the work. Since the UGV is to be used outdoor in urban areas, GPS can be used. To improve precision and robustness, inertial navigation is used in addition to GPS, since GPS reception is likely to be diminished in such areas.

The purpose of this report is to evaluate different methods for identifying states in robot models. Both linear and non-linear filters exist among these methods and are compared to each other. Advantages, disadvantages and problems that can occur during tuning and running are presented. Additional measurements from accelerometers are added and their use with above mentioned methods for state estimation is evaluated. The evaluation of methods in this report is mainly based on simulations in Matlab, even though some experiments have been performed on laboratory equipment.The conclusion indicates that simple non-linear models with few states can be more accurately estimated with a Kalman filter than with an extended Kalman filter, as long as only linear measurements are used.

This master thesis is a study on how a rategyro triad, an accelerometer triad, and a magnetometer triad can be integrated into a navigation system, estimating a vehicle?s attitude, i.e. its roll, tipp, and heading angles. When only a rategyro triad is used to estimate a vehicle?s attitude, a drift in the attitude occurs due to sensor errors.

The focus of this work is to study whether public libraries should offer their patrons unlimited access to the Internet, or restrict which sites they can visit. The most common tool used to limit Internet access is filtering software. The author has administered four interviews with public librarians working in libraries in Southern Sweden. All four librarians had different opinions about restricting Internet access. The most important question asked was if they had chosen to use filtering, and the reasons for their decision.

I den här rapporten utvärderas ett antal olika collaborative filtering algoritmer för att ta reda på vilken av dess som lämpar sig bäst för att implementera åt PlanEatSmile i en PHP/MySQL-miljö. Målet är att hitta en algoritm som klarar av att skapa rekommendationer i realtid och med hög precision. Därtill är det viktigt att algoritmen ska kunna skapa rekommendationer åt nya användare (cold-start-problemet) samt att algoritmen ska skala väl när sajten växer.De algoritmer som undersöks är user-based collaborative filtering, item-based collaborative filtering och tendencies collaborative filtering. Samtliga algoritmer undersöks i två versioner. En version som utgår ifrån receptbetyget och en version som omvandlar receptbetygen till  ingrediensbetyg.Algoritmerna testas på data insamlat genom en enkät för att avgöra deras precision.

Fler och fler spel öppnas upp för användargenererat innehåll, vilket ofta resulterar i större mängder material än vad en ensam spelare kan utnyttja. Den unika spelare vill ta del av det som passar just dennes smak.Studien genomfördes med designforskning som metodval och med hjälp av denna metod skapades en artefakt. Med hjälp av den utvecklade artefakten, ett plattformspel som är både enkelt att förstå och spela, kunde en datamängd samlas in ifrån olika spelare. Data byggdes upp av att användarna efter varje slutförd nivå, explicit fick lämna sitt betyg på nivån i en skala mellan 1 och 5.Genom att introducera collaborative filtering och där låta användarens tidigare betyg jämföras med övriga användare kan en predicering av kommande betyg ges. Vid jämförelser av olika collaborative filtering-algoritmer kunde den mest lämpliga upptäckas och senare även användas.Resultaten visar att mer precisa uppskattningar av kommande betyg kan göras av collaborative filteringen än genom att använda nivåns medelbetyg och resultaten leder därför till slutsatsen att collaborative filtering kan ge skräddarsydda spelupplevelser för en unik användare och således förhöja dennes spelupplevelse..

The global Positioning System (GPS) provides location and time information as long as there are unobstructed lines of sight to four or more GPS satellites. However, when this is not the case the signal may be inaccurate or sometimes even completely blocked. In these situations the Inertial Navigation System (INS) is an appropriate choice for positioning.  An INS has already been proposed in a previous thesis by Erik Andersson and the objective of this thesis is to fuse the GPS with the INS in a proper way. A part of this project is to decide the reliability of the GPS.Three methods for GPS reliability detection have been proposed. One method based on the statistical properties of each of the separate systems, and two methods based on the statistical properties of the residuals between the GPS and INS.

There has been a sharp increase in high-technology surveillance. Surveillance is almost alwaysproposed as a complete response on a wide variety of safety issues. At the same time, there has beenan increase in criminal activity online. There is therefore a considerable interest in using Internetfiltering to regulate the behavior of individuals on the Internet. In recent years, many countries havechosen to restrict content on the Internet, where child-abusive material is the content that moststates currently block access to.

WesDyne TRC AB is a fully owned subsidiary of the global WestinghouseElectric Corporation. WesDyne is a world leader in non-invasive methods for theinspection of nuclear power plants. One of the inspection platforms used to scanfor defects in and around the welds in the reactor vessel is called the T-crawler.The T-crawler operates under water in a radioactive environment by stepping onthe vessel (reactor tank) inner wall using suction cups. The environment is harshand many traditional positioning sensors are not suitable for implementation. Thisthesis investigates the possibility to use a gyroscope and a pressure sensor tocreate an alternative and independent positioning system.

When a helicopter is flying, the dynamics vary depending on, for example, speed and position. Hence, a time-invariant linear model cannot describe its properties under all flight conditions. It is therefore desirable to update the linear helicopter model continuously during the flight. In this thesis, two different recursive estimation methods are presented, LMS (Least Mean Square) and adaptation with a Kalman filter. The main purpose of the system estimation is to get a model which can be used for feedback control.

This paper is a research review in the realm of censorship systems andfiltering systems. It applies ethical considerations to the creation of censorshipsystems bringing forward discussion on the ethics of technology with thepurpose of limiting access to information.There is active research being done in the area of automatic content filteringand censorship systems. These are systems that can filter out undesiredmaterial, typically from the Internet, automatically. Used in some nations,many schools and even mandated in some libraries there are many ethicalquestions raised concerning censorship and access to information.Part of the review concerns the level of accuracy of these systems presentedby researchers in the field and the different approaches used. Reviewedarticles centre around automatic content classification and filtering ofpotentially harmful materials with regards to minors while some relate tocensorship technology in a wider sense.Results show a general lack of discussion concerning the ethics of thetechnology in the research reviewed.

Examensarbetet har genomförts med utveckling och undersökning av signalbehandlingsalgoritmer för MEMS-gyron. Idag används många MEMS-gyron i olika elektronikprodukter. Företaget Motion Control utvecklar elektronik och inbyggd programvara och de har bland annat tagit fram MultiPos, som är en huvudmus för rörelsehindrade. MultiPos är en MEMS-gyro-baserad datormus. MEMS-gyron används för att känna av huvudrörelser som användaren gör, men det är önskvärt med en bättre signalbehandling, d.v.s.