In this thesis an algorithm for detecting leakages in the pneumatic system of heavy vehicles is developed. Besides a description of this algorithm, the thesis includes a description of the pneumatic system of heavy vehicles, a review of some basic statistics and change detection analysis, and a description and analysis of some validation tests. Heavy vehicles use compressed air for various applications, including brakes and suspensions. Leakages in the pneumatic system are quite common and results in an increase in fuel usage, since more compressed air has to be produced. This is of course both environmentally and economically damaging. In order to avoid this damage, leakages need to be fixed. The first step is to notice the presence of leakages. The leakage detecting algorithm is based on a statistical deviation analysis. Inputs used are pressure measurements from the different compressed air circuits and some state variables regarding the compressed air users. All this information is communicated aboard on the vehicles’ controller area network (CAN). The algorithm has been validated using real data measurements from test drives, some of them including a vehicle suffering from leakages. The results indicate that the algorithm manages to identify leakages, but also that there are some problems regarding incorrectly interpreting other events as leakages. The results also indicate that the algorithm fail in the ambition to locate the leakages. If this algorithm should be implemented in a real time system to be used aboard, it is suggested that some improvements are made. These improvements mainly concern avoiding false alarms.

The phenomenon of spontaneous growth of metallic filaments, known as whisker growth has been studied. Until now the problem that Sn whisker growth could cause in electronics by making shorts has been partially prohibited as Pb and Sn have been used together in solders and coating. Regulations restricting Pb use in electronics has made the need to understand Sn whisker growth more current. It is shown that whiskers are highly resilient towards vibrations and shocks. A Sn whisker is shown to withstand 55 mA. Results show that reflowing of the Sn plated surface does not prevent extensive whisker growth. Results show that intermetallic compound growth can not be the sole reason behind whisker growth. Nickel and silver underlayer have been shown not to prevent whisker growth, but perhaps restrain whisker growth. Heat treatment damped whisker growth considerably. It is judged that base material CuSn6 is less prone to show whisker growth than CuSn0.15 and E-Cu58.

<p>This report treats detection in IR-pictures taken from airplanes over the ground. The detection is divided in two parts. First there is a detection with filterkernels with the task to point on targets and objects that look like targets. The second part is a discriminator that demands more calculations and has the task to sort out the false alarms from the discriminator. Both the detector and the discriminator contain thresholds thats been trained from trainingsets of data. The results from the detector was better then expected hence it wasn’t possible to test the diskriminator properly.</p> / <p>Den här rapporten behandlar detektering i IR-bilder som är tagna från flygplan över marken. Detekteringen är i det här arbetet uppdelat i två delar. Först görs en detektering med filterkärnor som har till uppgift att peka ut mål och målliknande objekt. Den andra delen är en diskriminator som är något mer beräkningskrävande och har till uppgift att sortera bort de falskmål som detektorn fått med. Både detektorn och diskriminatorn innehåller trösklar som har tränats fram med träningsdata. Detektorn gav bättre resultat än väntat och diskriminatorn har därför inte kunnat testas ordentligt.</p>

The work presented in this thesis was undertaken to quantitatively determine the best place to sit on a roller coaster. Maximizing the time spent feeling weightless and the highest value of negative Z acceleration were used as criteria for the best seat. Acceleration values were measured on the California Screamin' roller coaster at Disney California Adventure Park using an iPhone and an application to record data from its accelerometers. After analyzing acceleration data, it was determined that the front row had the greatest negative acceleration in the z direction and was therefore the "best place" to sit.

Photonic crystals (PCs) and binary supergratings (BSGs) with large refractive index steps are promising structures for designing new compact optical devices. This thesis presents an inverse design tool in these two important areas of photonics. The tool consists of an optimization module and a simulation engine. Due to the binary nature of PCs and BSGs, Boolean particle swarm optimization (Boolean PSO), a recently proposed binary stochastic optimization algorithm, is used in the optimization module. The simulation engine, on the other hand, is chosen according to the structure to be modeled. The proposed inverse design tool has been used to design a very low F-number photonic crystal lens and compact BSG filters for applications such as wavelength-division multiplexing, tunable lasers and intrachip optical networks. The inverse design tool allows designing optical filters with almost arbitrary wavelength filtering, in addition the proposed filters are more compact than previous demonstrations of BSG. Furthermore, it is found that Boolean PSO outperforms Genetic Algorithm (GA) as an optimization technique for use in the inverse design tool developed in this thesis.

This thesis outlines the prospects for top quark mass measurement through the Fully Hadronic decay of top-antitop events with the ATLAS detector. Methods with and without b-tagging were explored. Without b-tagging the signal was hidden beneath the QCD multi-jet background and prospects for a mass measurement do not appear to be good. A standard and a pessimistic b-tagging likelihood significance value were explored. The standard value gives a S/B of 0.88 and the more pessimistic value gives a S/B of 0.79. For 1 fb−1 a significance of 36.8 and 32.0 can be obtained for the standard and pessimistic scenarios respectively. A selection efficiency of 1.4% and 1.1% can be achieved for the standard and pessimistic values respectively. Assuming a top mass of 174 GeV, a mass peak can clearly be seen for both b-tagging values. For the standard scenario, a top mass of 168.94 GeV with a statistical error of 0.33 GeV can be extracted. With the pessimistic scenario, the extracted mass is 169.11 GeV with a statistical error of 0.36 GeV. This is the first attempt with fully simulated events and therefore there are possibilities for improvement. This analysis did not include b-jet energy scale correction.

We present the first determination of the radial velocities and metallicities of 78 red giant stars in the isolated dwarf irregular galaxy WLM. Observations of the calcium II triplet in these stars were made with FORS2 at the VLT-UT2 in two separated fields of view in WLM, and the [Fe/H] values were conformed to the \cite{CG97} ([Fe/H]$_{CG97}$) metallicity scale. The mean metallicity is $\langle$[Fe/H]$\rangle = -1.27 \pm 0.04$ dex, with a standard deviation of $\sigma = 0.37$. We find that the stars in the inner field are more metal rich by $\Delta$[Fe/H]$=0.30 \pm 0.06$ dex. These results are in agreement with previous photometric studies that found a radial population gradient, as well as the expectation of higher metallicities in the central star forming regions. Ages are estimated using Victoria-Regina stellar models, and we find that the youngest stars in the sample ($< 6$ Gyr) are more metal rich by $\Delta$[Fe/H]$= 0.32 \pm 0.08$ dex. These stars also show a lower velocity dispersion at all elliptical radii compared to those of the metal-poor stars. Additionally, the stellar kinematics suggest a velocity gradient approximately half that of the gas rotation curve, with the stellar components occupying a thicker disk decoupled from the H\,I rotation plane. Taken together, the kinematics, metallicities, and ages in our sample suggest a young metal-rich, and kinematically cold stellar population in the central gas-rich regions of WLM, surrounded by a separate dynamically hot halo of older, metal poor stars.

We have obtained broad-band NIR-photometry for six Galactic star clusters, M92,M15,M13, NGC1851, M71 and NGC6791, as observed with the WIRCam wide-field imager on the Canada-France-Hawaii Telescope; supplemented by images taken with HAWK-I on VLT. From the resultant (V − J)-V and (V − K)-V colour-magnitude diagrams, fiducial sequences spanning the range in metallicity, −2.4 ≤ [Fe/H] ≤+0.3, have been defined which extend from the tip of the red-giant branch to ∼ 2.5 magnitudes below the main-sequence turnoff. These fiducials provide a valuable set of empirical isochrones for the interpretation of stellar population data in the 2MASS system. From the NIR data, the reddenings of M15, M71 and NGC6791 — which have been subject to considerable controversy — were found to be E(B−V)=0.075, 0.22 and 0.155 mag respectively. Comparisons of our CMDs to Victoria isochrones that have been transformed using the MARCS model colour-Teff relations reveal that the models reproduce the giant branches of clusters more metal-rich than [Fe/H] ≈ −1.3, but they become systematically redder than the observed RGBs as the cluster metallicity decreases. These discrepancies are seen consistently in the two colours and therefore may indicate that the temperature scale of the stellar evolutionary models for giant stars at low metallicity is too cool.MARCS colour transformations were also tested using the classic Population II subdwarfs. The MARCS colours show redward offsets of ∼ 0.03 mag when compared with the observed (V − K) and (J − K) colours (assuming best estimates of Teff, log g, and [Fe/H]), and a systematic blue offset relative to the isochrone temperatures. Together with the indications from the cluster (V − K) and (V − J) CMDs, these results suggest that there is a problem with the MARCS colour transformations involving J.

In preparations for the ATLAS experiment at the Large Hadron Collider at CERN, sections of the ATLAS Electromagnetic Endcap Calorimeter (EMEC) and Hadronic Endcap Calorimeter (HEC) were subjected to particle beams in the summer of 2002. The EMEC and HEC are non-compensating calorimeters with e/h > I: electromag¬netic showers will, on average; have a higher energy response than hadronic showers initiated by particles of the same energy. To reconstruct the energy of pions, the method of software compensation is investigated. Several beam energy dependent weighting schemes are studied, using calorimeter depth weights and cluster energy density weights. Finally, a beam energy independent cluster energy density weighting scheme is studied. Partial software compensation is achieved for pion energy recon¬struction, improving the energy resolution and response linearity of the calorimeters.

The precise determination of the CKM matrix element |Vub| is crucial in testing the Standard Model mechanism for CP violation. From a sample of 88 million BB pairs collected with the MBAR detector, charmless semileptonic B decays are selected using simultaneous requirements on the electron energy, Ee, and the invariant mass squared of the electron-neutrino pair, q2. The partial branching fraction, unfolded for detector effects, is determined in a region of the q2-Ee plane where the dominating semileptonic decays to charm mesons are highly suppressed. Theoretical calculations based on the Heavy Quark Expansion allows for a determination of |Vub| = (3.95 ± 0.27 +0.58 -0:42 ± 0.25) x 10 3, where the errors represent experimental, heavy quark parameters and theoretical uncertainties, respectively.