Flow speed describes general traffic operation conditions on a segment of roadway. It is also used to diagnose special conditions such as congestion and incidents. Accurate speed estimation plays a critical role in traffic management or traveler information systems. Data from loop detectors have been primary sources for traffic information, and single loop are the predominant loop detector type in many places. However, single loop detectors do not produce speed output. Therefore, speed estimation using single loop outputs has been an important issue for decades. This dissertation research presents two methodologies for speed estimation using single loop outputs. Based on findings from past studies and examinations in this research, it is verified that speed estimation is a nonlinear system under various traffic conditions. Thus, a methodology of using Unscented Kalman Filter (UKF) is first proposed for such a system. The UKF is a parametric filtering technique that is suitable for nonlinear problems. Through an Unscented Transformation (UT), the UKF is able to capture the posterior mean and covariance of a Gaussian random variable accurately for a nonlinear system without linearization. This research further shows that speed estimation is a nonlinear non-Gaussian system. However, Kalman filters including the UKF are established based on the Gaussian assumption. Thus, another nonlinear filtering technique for non-Gaussian systems, the Particle Filter (PF), is introduced. By combining the strengths of both the PF and the UKF, the second speed estimation methodology - Unscented Particle Filter (UPF) is proposed for speed estimation. The use of the UPF avoids the limitations of the UKF and the PF. Detector data are collected from multiple freeway locations and the microscopic traffic simulation program CORSIM. The developed methods are applied to the collected data for speed estimation. The results show that both proposed methods have high accuracies of speed estimation. Between the UKF and the UPF, the UPF has better performance but has higher computation cost. The improvement of speed estimation will benefit real-time traffic operations by improving the performance of applications such as travel time estimation using a series of single loops in the network, incident detection, and large truck volume estimation. Therefore, the work enables traffic analysts to use single loop outputs in a more cost-effective way.

<p>This thesis deals with the development of high speed InPmesa HBT’s with power gain cut—off frequencies up toand above 300 GHz, with high current density and low collectordischarging times.</p><p>Key developments are Pd—based base ohmics yielding basecontact resistances as low as 10 Ωµm², base—collector grades to enable to use ofInP in the collector, and an increase in the maximum currentdensity through collector design and thermal optimization.HBT’s with a linear doping gradient in the base are forthe first time reported and compared to HBT’s with abandgap graded base. The effect of degenerate base doping issimulated, as well as the base transit time.</p><p>Key results include a DHBT with a 215 nm thick collector andan f_τ= 280GHz, and f_max=400 GHz. This represents the highest f_maxreported for a mesa HBT. Results also include aDHBT with a 150 nm thick collector and an f_τ= 300 GHz, and f_max=280 GHz. The maximum operating current densityhas been increased to above 10 mAµm while maintaining f_τand f_max≥ 200 GHz.</p><p>A mesa DHBT process with and as much yield and simplicity aspossible has been developed, while maintaining or pushingworld—class performance.</p>

Thesis (Civil Engineering)--École polytechnique fédérale de Lausanne, 2002. / PDF document ; contains 333 pages, with illustrations and charts (some col.). "Thèse no. 2568 (2002)." Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains x, 100 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 82-84).

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Volumetric modulated arc therapy (VMAT) is an efficient and conformal radiation therapy technique. It accomplishes this by dynamically varying multi-leaf collimator (MLC) positions, dose rates and gantry velocity. This work investigated the effect of varying the maximum MLC speed and maximum dose rate on the quality, efficiency and accuracy of treatment plans. The Pinnacle3 SmartArc treatment planning software was used to generate plans on prostate and head and neck (H&N) sites. A range of maximum MLC leaf speeds (0.55 cm/s to 2.20 cm/s) and maximum dose rates (200 MU/min to 600 MU/min) restrictions were applied to each plan to investigate their effect on the treatment quality, efficiency and accuracy. Each plan had their monitor units (MU) per fraction, delivery time, mean dose rate and leaf speed analysed. The dose volume histogram (DVH) data was used in the assessment of the conformity, homogeneity and plan quality. The treatments were delivered on Varian iX accelerator equipped with 120-leaf millennium MLC. Quality assurance measurements were performed using the ArcCHECK™ 3D diode array and results were assessed based on gamma analysis of dose fluence maps, beam delivery statistics and Dynalog data. The number of VMAT fields was found to be a key factor in how significant the maximum MLC leaf speed affected the plan parameters investigated. Single arc treatments were shown to have lower MU, dose rate and plan quality, while also exhibiting a slight increase in estimated delivery time. For dual arc treatments, MU, delivery time, dose rate and plan quality were largely independent of the maximum MLC speed allowed. The QA showed that higher MLC leaf speeds were prone to an increase in the discrepancy between planned and delivered control point (CP) fluence and higher MLC positioning errors. None of these were at a clinically significant level, and the overall fluence distribution and point dose comparisons were independent of maximum MLC leaf speed. The only clinically significant effect that modulation of the maximum dose rate had was on the delivery time. Lower maximum dose rates resulted in longer treatment delivery, which is an important consideration in minimising the intra-fractional motion during treatment. The results of the MLC leaf speed evaluation showed that the lower the maximum leaf speed the more accurate the delivered treatment, -however the quality of the plan is reduced. This indicates that there could be an optimum maximum MLC leaf speed which produces high quality plans that can be accurately delivered. Based on this work a maximum MLC leaf speed of 1.38 cm/s was shown to have no reduction in plan quality however it showed improvement in delivery accuracy. There was no justification found for reducing the maximum dose rate below the recommended 600 MU/min.

Abstract Previous studies have shown that wild smolt have 2.5-4.5 times higher survival rate than smolt grown in culture and that starved reared smolt behave more like wild born smolt. The purpose of this project was to study whether there are differences in migration patterns and survival during migration to the coast between wild and reared smolt and between different types of reared smolt. In 2009, 25 smolts in three different groups were tagged with acoustic transmitters: Wild Born, conventionally reared 2-year and 1 –year old smolt. For the 2010 trial there was also added a group of reared 2 –year old smolt that were starved before release. Receivers were placed in the river and in a line outside the estuary. The receivers recorded when the tagged fish passed and which fish it was. Based on information from the receivers the survival rate and migration speed could be calculated for each group and be compared to the smolts amount of body fat. In this study the condition factor (weight/length3 *100000) was used as an indicator of the smolts body fat levels. The study was conducted in river Dalälven. The results provide some indications that the wild born smolt in accordance with previous studies had a slightly higher (not significant) survival rate than the other groups. No major signs of differences in survival were seen between the groups of the conventionally reared and the starved reared smolt. The annual smolt seemed to have a slightly higher survival rate than these two groups. Unlike the results in earlier studies the wild born smolt did not migrate significantly faster than any of the other groups. No significant difference was observed between the conventionally reared and the starved smolt. The group that migrated fastest was the 1 –year old smolt. It was the group of 1 –year old smolt that was most similar to the wild born smolt in regard to the condition factor. But the wild born smolt were still considerably leaner. There was a significant difference in the condition factor between the starved smolt and those grown conventionally. But the difference was probably too small to show any differences in migration behavior when they still were much larger than the wild born smolt. There also tended to be a negative correlation between low condition factor and higher survival. In this study the starved smolt behaved more like the conventionally reared than the wild hatched. They were not starved for a sufficient amount of time to reach as low levels of body fat as the wild hatched smolt. It would require studies in which smolt were starved for longer period to evaluate whether the condition factor is crucial for if reared smolt in river Dalälven possibly can behave as wild smolt.