Traffic congestion has continued to grow as a result of urbanization, which is associated with an increase in car ownership. As a way to improve the efficiency of the transportation system, emerging technologies including Connected Automated Vehicles (CAVs), loop detectors, Advanced Traveler Information Systems (ATISs), and Advanced Public Transportation Systems (APTSs) are being deployed. One of the successful techniques that has demonstrated benefits for system users, operators and agencies is Transit Signal Priority (TSP). TSP favors transit vehicles in the allocation of green times at traffic signals. A successful deployment of TSP depends on different factors including the prediction of various components of transit vehicle travel times to predict when a vehicle would arrive at a traffic signal. Current TSP state-of-the-art and state-of-practice disregards the impact of bus stops, transit vehicle characteristics, driver, and the prevailing traffic conditions on the predicted arrival time of transit vehicles at traffic signals. Considering these factors is important the success of TSP hinges on the ability to predict transit vehicle arrival times at traffic signals in order to provide these vehicles with priority service. The main contribution of this research effort relates to the modeling of the various components of transit vehicle travel times. This model explicitly captures the impact of passengers, drivers and vehicle characteristics on transit vehicle travel times thus providing better models for use in various transit applications, including TSP. Furthermore, the thesis presents a comprehensive understanding of the determinants of each travel time component. In essence, the determinants of each component, the stochasticity in these determinants and the correlation between them are explicitly modeled and captured. To achieve its contribution, the study starts by improving the current state-of-the-art and state-of-practice transit vehicle boarding/alighting (BA) models by explicitly accounting for the different factors that impact BA times while ensuring a relatively generalized formulation. Current formulations are specific for the localities and bus configurations that they were developed for. Alternatively, the proposed BA time model is independent of the transit vehicle capacity and transit vehicle configuration (except for the fact that it is only valid for two-door buses – a separate door for alighting and boarding the bus) and accounts for the number of on-board passengers, boarding and alighting passengers. The model also captures the stochasticity and the correlation between the model coefficients with minimum computational requirements. Next the model was extended to capture the bus driver and vehicle impacts on the transit vehicle delay in the vicinity of bus stops, using a vehicle kinematics model with maximum speed and acceleration constraints to model the acceleration/deceleration delay. The validation of the model was done using field data that cover different driving conditions. Results of this work found that the proposed formulation successfully integrated the human and vehicle characteristics component in the model and that the new formulation improves the estimation of the total delay that transit vehicles experience near bus stops. Finally, the model was extended to estimate the time required to merge into the adjacent lane and the time required to traverse a queue upstream of a traffic signal. The final part of this study models the bus arrival time at traffic signal using shockwave and prediction model in a connected environment. This section aims to model the transit vehicle arrival time at traffic signal considering the impact of signal timing and the prevailing traffic conditions. In summary, the proposed model overcomes the current state-of-the-art models in the following ways: 1) it accounts for the vehicle capacity and the number of on-board passengers on bus BA times, 2) it captures the stochasticity in the bus stop demand and the associated BA times, 3) it captures the impact of the traffic in modeling the delay at a bus stop , 4) it incorporates the driver and vehicle impact by modeling the acceleration and deceleration time, and 5) it uses shockwave analysis to estimate bus arrival times through the use of emerging technology data. Through statistical modeling and evaluation using field and simulated data, the model overcomes the current state-of practice and state-of art transit vehicle arrival time models. / Doctor of Philosophy / Traffic congestion grows rapidly causing increment in travel time, reducing travel time reliability, and reducing the number of public transportation riders. Using the Advanced Public Transportation Systems (APTS) technology with Advanced Traveler Information Systems (ATISs) helps in improving transportation network travel time by providing real-time travel information. One of the successful techniques that has demonstrated benefits for system users, operators and agencies is Transit Signal Priority (TSP). A successful deployment of TSP depends on different factors including the prediction of various components of transit vehicle travel times to predict when a vehicle would arrive at a traffic signal. Current TSP state-of-the-art and state-of-practice disregards the impact of bus stops, transit vehicle characteristics, driver, and the prevailing traffic conditions on the predicted arrival time of transit vehicles at traffic signals. The difficulty of modeling the various determinants of the transit vehicle travel time as explicit variables rather than include some of them are implicitly modeled due to two main reasons. First, there are various significant factors affecting estimating the transit vehicle arrival time including; the passenger demand at bus stop, driver characteristics, vehicle characteristics and the adjacent prevailing traffic conditions. Second, the stochasticity and the fluctuation nature of each variables as they differ spatiotemporally. The research presented in this thesis provides a comprehensive investigation of the determinants of different transit vehicle travel time components of the transit vehicle arrival time at traffic signal leading to a better implementing of TSP. This study was initiated due to the noticeable overlooking of the different factors including human and vehicle behavior in the current state-of-practice and state-of-art which, as a result, fails to capture and incorporate the impact of these components on the implementing of TSP.

Werden zwei Aufgaben in einem Doppelaufgaben-Paradigma gleichzeitig bearbeitet, dann treten oft sogenannte Doppelaufgabenkosten auf (längere Reaktionszeiten und/oder höhere Fehlerzahlen). Diese Doppelaufgabenkosten werden durch einen zentralen “Flaschenhals” erklärt, der die gleichzeitige Verarbeitung der beiden Aufgaben an der zentralen Verarbeitungsstufe der Reaktionsauswahl verhindert. Das Ziel der vorliegenden Arbeit war es, einige mögliche Faktoren der Verarbeitungsreihenfolge an diesem Flaschenhals zu untersuchen. Die Studie zeigt, dass die Ankunftszeit am Flaschenhals ein wichtiger Faktor bei der Festlegung der Verarbeitungsreihenfolge ist. Zusätzlich ist der Einfluss der Ankunftszeit auf die Verarbeitungsreihenfolge unabhängig davon, welche der beiden Aufgaben manipuliert wurde um den Einfluss dieser Aufgabe zu untersuchen (visuelle oder auditorische Aufgabe). Ein zweiter Faktor der manipuliert wurde, ist die Instruktion an die Probanden. Die Ergebnisse zeigen, dass unter bestimmten Instruktionsbedingungen kognitive Kontrollprozesse aktiviert zu werden scheinen. Als dritten Faktor wurden Aufgabenanforderungen untersucht, indem eine Aufgabe mit zeitlicher Reihenfolge-Entscheidung mit einer Doppelaufgabe mit zufälliger Aufgabenreihenfolge, d.h.: Bestimmung der zeitlichen Reihenfolge mit der zusätzlichen Anforderung einer Reaktionswahl-Aufgabe, verglichen wurde. Die Ergebnisse dieser Experimente deuten darauf hin, dass die Entscheidung über die zeitliche Reihenfolge der beiden Aufgaben zwischen der Wahrnehmungsstufe und der Reaktionswahlstufe getroffen wird. / The simultaneous performance of two tasks in a dual-task paradigm is often accompanied by dual-task costs (longer reaction times and/or higher error rates). These dual-task costs have been explained by the existence of a central bottleneck which prohibits the simultaneous processing of the two tasks at the central response-selection stage of information processing. The aim of the present work was to investigate several of the possible factors which determine the task processing order at this central bottleneck. The study shows that the arrival time of the two tasks at the bottleneck plays an important role in the determination of task order. Additionally, the influence of the arrival time on processing order is independent of the component task which is manipulated to test the influence of that task (i.e., visual & auditory task). A second factor that was manipulated is the instruction given to the participants. The results show that cognitive control processes are activated under certain instruction conditions. As a third factor, task requirements were investigated by comparing a temporal order judgement task with a dual task with random task order (i.e., temporal order judgement with the additional requirement to do a choice-RT task). The results suggest that the decision about the temporal order of the two tasks is located between the perception stage and the response-selection stage of processing.

Waterflood optimization via rate control is receiving increased interest because of rapid developments in the smart well completions and I-field technology. The use of inflow control valves (ICV) allows us to optimize the production/injection rates of various segments along the wellbore, thereby maximizing sweep efficiency and delaying water breakthrough. It is well recognized that field scale rate optimization problems are difficult because they often involve highly complex reservoir models, production and facilities related constraints and a large number of unknowns. Some aspects of the optimization problem have been studied before using mainly optimal control theory. However, the applications to-date have been limited to rather small problems because of the computation time and the complexities associated with the formulation and solution of adjoint equations. Field-scale rate optimization for maximizing waterflood sweep efficiency under realistic field conditions has still remained largely unexplored. We propose a practical and efficient approach for computing optimal injection and production rates and thereby manage the waterflood front to maximize sweep efficiency and delay the arrival time to minimize water cycling. Our work relies on equalizing the arrival times of the waterfront at all producers within selected sub-regions of a water flood project. The arrival time optimization has favorable quasi-linear properties and the optimization proceeds smoothly even if our initial conditions are far from the solution. We account for geologic uncertainty using two optimization schemes. The first one is to formulate the objective function in a stochastic form which relies on a combination of expected value and standard deviation combined with a risk attitude coefficient. The second one is to minimize the worst case scenario using a min-max problem formulation. The optimization is performed under operational and facility constraints using a sequential quadratic programming approach. A major advantage of our approach is the analytical computation of the gradient and Hessian of the objective which makes it computationally efficient and suitable for large field cases. Multiple examples are presented to support the robustness and efficiency of the proposed optimization scheme. These include several 2D synthetic examples for validation purposes and 3D field applications.

In this thesis, the problem of Angle of Arrival estimation of radar signals with Time Difference of Arrival method in an outdoor land multipath environment with limited line of sight is analyzed. A system model is proposed. Effects of system, channel and radar parameters on the Angle of Arrival estimation performance are investigated through Monte Carlo simulations. Improving effect of utilization of diversity on the estimation performance is observed. Performances of the space diversity with noncoherent and selective combining are compared. Finally a realistic scenario is studied and performance of the proposed system is investigated.

Frontotemporal lobar degeneration (FTLD) is a heterogeneous group of illnesses which can be difficult to diagnose. Modern diagnostic criteria require the presence of imaging abnormalities, but these are not always seen in the early stages of the illness. Hence there is a need to consider the use of more advanced MR techniques. This thesis reports the results of a multimodal MRI study of patients with FTLD, and considers two things: how well data from the different modalities can classify patients, and how well the different modalities can identify affected tissue. FTLD is thought to involve alterations in cerebral blood flow, but it is possible that microvascular changes will alter additional perfusion parameters, such as the time taken for blood to reach the tissue (the arrival time). Multi-time point arterial spin labelling (ASL) measurements have the ability to extract the relevant parameters. I consider the parameters involved in modelling these data, and report the accuracy of cerebral blood flow (CBF) measurement achievable in a clinically acceptable time. FTLD patients have atrophy in the frontal and temporal lobes, regions problematic for MRI because of susceptibility artefacts caused by adjacent air spaces. I consider two ASL MR read-out sequences (gradient-echo and spin-echo)and show that spin-echo images give higher signal in frontal and temporal regions than gradient-echo. ASL, T1-weighted and diffusion-weighted images were collected for a group of 17 FTLD patients and 18 controls. I found decreased CBF in highly atrophied regions of cortical grey matter in patients, but this deficit was not seen when corrected for atrophy. An increased arrival time was seen in regions adjacent to the atrophied regions, but a decreased arrival time was seen in the atrophied regions; this is a novel finding. The diffusion metrics of fractional anisotropy (FA) and particularly mean diffusivity (MD) are found to be highly sensitive to differences in FTLD patients. I speculate that this is an increased sensitivity to atrophy because of the increased signal from cerebrospinal fluid. I combine the regional values of all the modalities in a classification method to distinguish patients from controls, and establish a combination of region and modality that classified 21/22 subjects correctly. This exploratory study is the first time all three modalities have been combined in a study of FTLD patients; it shows that combining MR modalities may lead to improved classification of FTLD patients and better identification of affected tissue.

Moderne Experimente in der Kurzzeitphysik erfordern eine hochpräzise Synchronisation der beteiligten Strahlungsquellen, um dynamische Prozesse und atomare Strukturen aufzulösen. Die Komplexität und räumliche Ausdehnung einer linearbeschleuniger-getriebenen Strahlungsquelle wie ELBE verlangt nach neuen Konzepten, um die anspruchsvollen Anforderungen zu erfüllen. Kernbestandteile der vorliegenden Arbeit sind die Konzeption, der Aufbau und die Inbetriebnahme eines gepulsten optischen Synchronisationssystems zur Verteilung eines Phasenreferenzsignals. Dieses System bildet eine wesentliche Grundvoraussetzung für wissenschaftliche Experimente mit einer Auflösung im Bereich von wenigen zehn Femtosekunden. Darüber hinaus wurde der Prototyp eines Ankunftszeitmonitors am ELBE-Beschleuniger entwickelt und charakterisiert. Mit diesem Diagnoseelement wurden erstmals Messungen der Elektronenpulsankunftszeit mit einer Auflösung von wenigen Femtosekunden am ELBE-Strahl möglich. Die implementierte Datenanalyse erlaubt einzelpulsaufgelöste Messzyklen mit bisher unerreichter spektraler Bandbreite am kontinuierlichen (CW) Elektronenstrahl. Ferner wurde eine Methode zur Datenerfassung entwickelt, die unter Verwendung der Lockin-Technik besonders rauscharme Messungen hervorbringen kann. Abschließend wurde der ELBE-Beschleuniger hinsichtlich Ankunftszeit und Energiestabilität umfassend untersucht. Dabei wurden die erweiterten Möglichkeiten, die ELBE als CW-Beschleuniger bietet, ausgeschöpft. Der Fokus lag besonders auf der spektralen Analyse der Störungen bei verschiedenen Kompressionszuständen der Elektronenpulse. Diese methodische Untersuchung wurde sowohl für den thermionischen Injektor als auch für die supraleitende Fotoelektronenquelle durchgeführt. Die präsentierten Messergebnisse ermöglichen ein erweitertes Verständnis für die wirkenden Störmechanismen während der Elektronenpulspropagation und stellen den Ausgangspunkt für systematische Verbesserungen der Strahlqualität dar. Ein beschriebener Grundlagenversuch belegt, wie der ELBE-Elektronenstrahl in Zukunft aktiv stabilisiert werden kann, um die erforderliche Zeitauflösung zu erreichen. Intrinsische Strahlinstabilitäten können dadurch signifikant reduziert werden.

Vasaloppet is a cross country ski event which has been held in Sweden for about 50 years. Now more than 50,000 people of different ages participate in various cross country ski races during the Vasaloppet winter week in Dalarna County. This increasing demand needs good traffic and transportation planning to avoid congestion and provide safe, on time and environmentally friendly transportation for participants and visitors to the area. The key for a good event traffic planning is reliable and up-to-date traffic data which is not available for the Vasaloppet winter week. This study is an attempt to collect traffic data in order to find the movement patterns in the area and estimate origin-destination matrices for the main event of Vasaloppet week. Based on resources and time limitation it was decided to use a web-base d participants’ survey in order to collect traffic data. The link to the survey was sent to email address of a sample of 5000 participants. About 64% of the participants drove from their home town to the area and about 31 percent travelled by bus. Train and airplane have a very small share in travel mode to the area. Malungsälen, Mora and Älvdalen are three municipalities in Dalarna County with the highest share in accommodating participants. On the day of the race, bus and car have approximately the same share in travel mode with 45% and 47% respectively.

The Arterial Spin Labelling (ASL) method is a Magnetic Resonance technique used toquantify the cerebral perfusion. It has the big advantage to be non-invasive so doesn’tneed the injection of any contrast agent. But due to a relatively low Signal-to-NoiseRatio (SNR) of the signal acquired (only approximately 1% of the image intensity), ithas been hampered to be widely used in a clinical setting so far.The primary objective of this project is to make the method more robust by improvingthe quality of the images, the SNR, and by reducing the acquisition time. DifferentASL protocols with different sets of parameters have been investigated. The modificationsperformed on the protocol have been investigated by analyzing images acquired onhealthy volunteers. An optimized protocol leading to a good trade-off between the differentaspects of the method, has been suggested. It is characterized by a 3:43:44:0mm3with a two-segment acquisition.A more advanced ASL method implies the acquisition of images at different inversiontimes (TI), which is called the mutli-TI method. The influence of the range of TI used inthe method has been explored. An optimized TI range (from 410ms to 3860ms, sampledevery 150ms) has been suggested to make the ASL method as performant as possible.A numerical model and a fitting algorithm have been used to extract the informationon the perfusion from the images acquired. Different models have been investigated aswell as their influence on the reliability of the results.Finally, a criterion has been implemented to evaluate the reliability of the results sothat the clinician or the user of the method can figure out how much he can count onthe results provided by the method.

Expanding the standard, single-well recording geometry used to monitor seismicity during hydro-fracture treatments could provide more accurate hypocenter locations and seismic velocities, improving general reservoir characterization. However, for the real, two-well data set obtained for this project, only S-wave picks were available, and testing resulted in anomalous hypocenter location behavior. This study uses a hypocenter location algorithm and both real and synthetic data sets to investigate how the accuracy of the velocity model, starting hypocenter location, recording geometry, and arrival-time picking error affect final hypocenter locations. Hypocenter locations improved using a velocity model that closely matched the observed sonic log rather than a smoothed version of this model. The starting hypocenter location did not affect the final location solution if both starting and final locations were between the wells. Two solutions were possible when the true solution was not directly between the wells. Adding realistic random picking errors to synthetic data closely modeled the dispersed hypocenter error pattern observed in the real data results. Adding data from a third well to synthetic tests dramatically reduced location error and removed horizontal geometric bias observed in the two-well case. Seismic event data recorded during hydro-fracture treatments could potentially be used for three-dimensional joint hypocenter-velocity tomography. This would require observation wells close enough to earthquakes to record P- and S-wave arrivals or wells at orientations sufficient to properly triangulate hypocenter locations. Simulating results with synthetic tests before drilling could optimize survey design to collect data more effectively and make analysis more useful. / Master of Science

Coronal mass ejections (CMEs) are some of the extraterrestrialevents most impactful to earth. Eorts to model and predict theireects have seen new possibilities in the two most recent decades dueto multiple new spacecrafts providing a wider range of data than everbefore. Models of these events suer from a number of inaccuracies,one of them being the density ratio between the CME and the ambientsolar wind. Since the arrival time for potentially harmful disturbancespredicted by models has been proved to be highly sensitive to thisparameter we therefore take care to set it as accurately as possible.Traditionally this value is either set to a default, justied by denitionand theory, or set to the density ratio between the bulk if the ejectedgas and the surrounding medium. A proposition has been made tomeasure density enhancement dierently, using a reference point at theshock wave preceding the CME for each event. This method strives toimprove arrival time predictions and was in this paper tested for onecoronal mass ejection event. Two runs if the model WSA-ENLIL+Conewas made; one with the default value of density enhancement, onewith a value determined through the revised method using coronographdata. Running the model with the revised value improved the predictedarrival time by moving it forwards in time by 4h, which was still tooearly. Other input data into the model run was then discussed as apossible cause of the remaining inaccuracy. / Koronamassutkastningar är ett av solfenomenen som påverkar jorden mest.Nya rymdfarkoster med instrument som satts i arbete de senaste två decenniernahar gett data som gjort det möjligt att modellera och förutse dessaevent till en högre precision än någonsin. Alla dessa modeller lider av någonform av felkälla, en av vilka är kvoten mellan densitet för massutkastningenoch den omgivande miljön. Eftersom förutsedda ankomsstider för potentielltskadliga störningar har visat sig vara särskilt känsliga för denna parameterså tar vi särskild hänsyn till att ange den så precist som möjligt. Vanligtvissätts detta värde till ett fast standardvärde, som anges av dess denitionoch bakomliggande teori, eller till kvoten mellan utkastningens bulk ochomgivningen. Ett förslag har dock lagts fram om att omdeniera parametern.Denna metod strävar efter att förbättra förutsedda ankomsttider ochhar i denna text testats för en koronamassutkastning. Två körningar avmodellen WSA-ENLIL+Cone gjordes; en med defaultvärdet för densitetsratiot,en med värdet satt genom mätning av empirisk cononagrafdata enligtden föreslagna metoden. Att köra modellen med den nya parametern förbättrade den förutsedda ankomsttiden genom att ytta den framåt i tidenmed 4 timmar, vilket fortfarande är för tidigt. Andra inputdata i modellendiskuterades då som möjliga orsaker till den återstående diskrepansen.