I apply the GMTS approach to graphical modelling of time series to data sets from economics, ecology and environmental science. This approach improves on traditional approaches to modelling insofar as it selects the most parsimonius model. I improve on this approach by removing some redundancies in the GMTS approach. However, a bias in terms of which links are selected means that it is unlikely that this model will select the best causal model.

Automatic Repeat-reQuest (ARQ) schemes are extensively used in communication systems and computer networks to achieve reliable transmission. Using space-time codes (STCs) with multiple input multiple output (MIMO) or multiple input single output (MISO) systems is an effective way to combat multipath fading, which is the most severe impairment for wireless communication systems. STCs are designed to use the rich scattering multipath environment provided by using multiple transmit antennas. The work done in this thesis focuses on the use of ARQ schemes with non-orthogonal space-time block codes (NOSTBCs) based on Reed Solomon codes. The truncated-selective ARQ (TS-ARQ) scheme is considered and three novel hybrid ARQ (HARQ) schemes are proposed. Simulation results reveal that, compared to using TS-ARQ with orthogonal space-time block codes (OSTBCs), using NOSTBCs with any of the three proposed HARQ schemes can provide significant gains in terms of dropped packet rate and spectral efficiency at the cost of increased decoding complexity. The performance can be further improved by using the water filling principle to adaptively allocate transmit power among transmit antennas.

This is a final bachelor degree project for mechanical engineering. TM Design & Installation AB company needs to reduce the setup time for one end-forming machine by 50%. After some discussion and analysis, the group decides to subdivide the main problem into six sub problems. By aiming at each small problem and figure out several solutions, the group finally have concepts for the problem. The Project contains of the achievement of a design process which thanks to the theories treated in Product Development Through System Engineering and thanks to our previous knowledge and experience. By following all the steps in the books, the project leads us to the selection of final concept.

Avdelningen för klinisk kemi vid Länssjukhuset i Kalmar analyserar läkemedel och alkoholer med BD Vacutainer® Plus Plastic Serum Tube (Serum Tube), som kräver en koagulationstid i upp till 60 minuter. BD Vacutainer® Rapid Serum Tube (RST™) innehåller trombin och kräver en koagulationstid på endast 5 minuter. Syftet med studien var att undersöka möjligheten att förkorta den preanalytiska väntetiden före centrifugering vid intoxikationsanalyser i serumrör från akutmottagningen. Studien utfördes genom att jämföra RST™ med Serum Tube vid analys av S-Paracetamol och S-Etanol. Totalt analyserades 70 prover för S-Paracetamol, varav 35 RST™ och 35 Serum Tube från 35 patienter. Analys av S-Etanol utfördes på 60 prover, varav 30 RST™ och 30 Serum Tube från 30 patienter. RST™ centrifugerades efter 5 minuter och Serum Tube efter 50 minuter, före kolorimetrisk analys på analysinstrumentet VITROS® 5,1 FS. Resultaten för S-Paracetamol var inom intervallet 74,9 – 198,7 µmol/L för RST™ och inom 76,6 – 195,3 µmol/L för Serum Tube. Resultaten för S-Etanol var inom intervallet 7,5 – 74,5 mmol/L för RST™ och inom 7,5 – 74,8 mmol/L för Serum Tube. Pearsons korrelationskoefficient var 0,9977 för S-Paracetamol och 0,9980 för S-Etanol och det fanns en liten positiv bias vid analys med RST™ för båda analyterna, men ingen signifikant skillnad (p>0,05) mellan provrören påvisades. Användning av RST™ på akutmottagningen medför en förkortad preanalytisk väntetid och en snabbare turnaround time (TAT). Hypotesen att S-Paracetamol och S-Etanol kan analyseras med RST™ på VITROS® 5,1 FS stämmer, med undantag för höga koncentrationer av S-Paracetamol som inte kunde utvärderas. För att RST™ ska kunna användas rutinmässigt bör därför ytterligare studier utföras.

Market based generation dispatch is becoming the industry norm in advanced electrical jurisdictions. Due to the continuous evolution of markets and their potential impacts on system operation, studies are performed from economic and social perspectives in order to gauge the effects of any changes before implementation into live systems. In addition, it is essential to verify the effect of changes in market design on power systems from a technical perspective. The main objective of this thesis is to develop a real-time power system simulator for use in the investigation of market designs and automatic generation control schemes. The scope of this thesis is the mathematical algorithms used in the simulator, hardware and software implementation, and validation of the implemented simulator. The simulator is based on a modified version of the power flow calculation using an innovative combination of a standard numerical technique implemented on a readily available computing hardware platform. The result is a significant decrease in computation time. The power flow is performed repeatedly, with frequency being calculated between time steps to provide system dynamics. Frequency is calculated using a modified version of the generic generator swing equation. Generator and load models and their respective control systems are provided for the purposes of simulator validation and testing, although do not fall within the scope of the simulator itself.

The Volvo Trucks plant in Umeå is a highy complex manufacturing facility where the same production line handles a variety of different models. This require flexible and agile processes with high quality standards. This thesis studies the flow of material through a production line and how Volvo can use their existing manufacturing monitoring system to optimize the flow of materials. The goal with the thesis is to identify eventual problems with the flow of materials and to deliver a few proposals on how the production line can improve its productivity. The theory of LEAN, Just-In-Time and Supply Chain Management serves as the scientific reference to this project. By analyzing the flow of material, performing interviews and observing the processes a few problems are identified. The problems are analyzed and some improvements are proposed along with recommendations for further investigation.

This thesis considers an approach to evaluate the effectiveness of risk communications for prescription drugs by performing interrupted time series analysis of prescription drug volumes prior to and after the risk communication date. The paper presents methods for detecting change in the presence of autocorrelation and techniques to reduce bias in estimation. Statistical results and data plots are presented for 63 data series. Size and power of the statistical techniques are considered, and a correspondence analysis between these statistical techniques and a small group of physicians is performed. The methods considered in this thesis correspond weakly with physician sentiment, and exhibit inflated type I errors in the presence of significant autocorrelation.

This thesis focuses on various aspects of community mobility and lifespace. Mobility is of particular interest to those working with the elderly population or patients affected by neurological diseases, such as Alzheimer's and Parkinson's diseases. One aspect of mobility is the number of “hotspots" in a person's daily (or weekly) trajectory, which represent the locations at which an individual remains for a minimum predetermined length of time. The individual demonstrates potential limited mobility if there is only one identified hotspot; the individual is more mobile if there are multiple identified hotspots. Based on GPS time series, we can use cluster analysis to identify hotspots. However, existing clustering algorithms such as k-means and trimmed k-means do not take into account the time dependencies between the location points in the series, and require knowing the number of clusters ahead of time. Thus, the resulting clusters do not represent the subjects' activity centres well. In this thesis we have developed a robust time-dependent clustering criterion that works very well to find clusters. Another aspect of mobility is the total distance travelled. The total distance computed from the original GPS data is inflated as there is noise in the data. Due to the particular characteristics of noise specific to GPS time series, we have investigated the identification of noisy segments of data as well as smoothing techniques. The average amplitude of acceleration is proposed as an appropriate method to identify the large noise that occurs in GPS data. A multi-level trimmed means smoother is proposed as an appropriate method to filter the identified large noise. Three methods were investigated to determine an ellipse that identifies the spatial area an individual purposely moves through in daily life. The classical and robust 95% ellipses contain 95% of the points, but do not necessarily capture the distinct shape of the data. The minimum spanning ellipse over the series with all points in each identified cluster reduced to each cluster's central value captures the shape of the data very well and is proposed as the most appropriate lifespace ellipse. Results are obtained and presented for the subjects available in the mobility study for the total distance travelled and a meaningful lower bound, the number of hotspots, the proportion of time spent in the hotspots, as well as the area of the classical 95% ellipse, robust 95% ellipse and minimum spanning ellipse. In the processing of the data, other problems that had to be addressed include obtaining appropriate estimates for the missing values and translating time series from degrees of longitude and latitude to metres in the Cartesian (x,y) plane. / Graduate / 0463 / lauramor@uvic.ca

This thesis is concerned with an investigation of twistorial structures present in curved Lorentzian space-times. Chapter 1 introduces the basic definitions and some theorems that will be used later in the text. Chapter 2 investigates generalised connections that arise in twister theory. First the Cartan con-formal connection is studied, and some of the geometry underlying it is shown to be that used by Fefferman and Graham C133. Also a condition that a space-time is conformal to vacuum is given. Secondly the theory of the Chern connection associated to a C.R. manifold is developed in such a way as to make the calculation of the connection associated to a twistor C.R. manifold straight forward. A new proof of the Chern theorem of existence and uniqueness is given. The Chern connection of a twistor C.R. manifold is then calculated, and discussed. In particular S-dimensionai C.R. manifolds arising as twistor C.R. manifolds are characterised. Canonical structures peculiar to the twister case are discussed. Applications of C.R. manifold theory to algebraically special space-times are suggested. Chapter three analyses how various twistorial structures behave in linearised general relativity. First, deformations of the space of complex null geodesies corresponding to variations of the conformal structure of space-time are shown to be generated by hami1tonians. Those that correspond to variations in the metric satisfying the field equations are given, along with hamiltonians corresponding to different fields and field equations. Beneralisations to nonlinear equations are discussed. These ideas are applied to hypersurface twisters in linearised theory, using fiat hypersurfaces and Cech cohoeology. Expressions are obtained for the deformation of the complex structure of the spaces and their evolution. The results are generalised to non flat hypersurfaces using Dolbeault cohomolcgy. It is shown that certain canonically defined forms on the spin bundle are preferred Dolbeault representatives for derivatives of the twister cohomology classes corresponding to the linearised field. In chapter four I generalise the results of chapter three to curved space using the Chern connection. In particular twistorial formulations of the constraint equations are given, and a formula for the evolution that satisfies the the vacuum evolution equations is given in terms of an "infinity" twistor and a "time" twister. This is then discussed. In chapter five I make some comments on the interpretation of a three form on the spin bundle discovered by B.A.J. Sparling as the gravitational hami1tonian. I then use this to show that one can give an interpretation of Penrose's quasi-local angular momentum twistor in terms of the canonical formalism.

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