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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

Driving Behavior Analysis and Prediction for Safe Autonomous Vehicles

Nasr Azadani, Mozhgan 18 January 2024 (has links)
Driving Behavior Analysis (DBA) plays a pivotal role in designing intelligent transportation systems, enhancing road safety, and advancing Autonomous Vehicles (AVs). Driver identification, as a key aspect of DBA, has the potential to provide unprecedented opportunities for enhanced security and driver profiling. However, the current solutions for driver identification suffer from demanding extensive data collection, limited scalability, and inadequate generalization. Furthermore, DBA is also essential for training AVs, addressing the main challenges they face: accurately perceiving their surroundings to make informed decisions and to navigate safely, and effectively handling unforeseen scenarios. In the first part of this thesis, we concentrate on behavior analysis for driver identification and verification and design two novel schemes aiming to reduce data dependency and enhance the generalization ability of existing approaches. First, we propose a novel driver identification model, called DriverRep, which reduces data dependency by presenting a fully unsupervised triplet loss training. DriverRep is the first model that extracts the latent representations associated with each driver, called driver embeddings, in an unsupervised manner. In addition, we develop a novel model to tackle driver verification and impostor detection tasks based on DBA and extracted driver embeddings. In the second part, we focus on behavior prediction for AVs and their surrounding agents. First, we tackle behavior prediction in dynamic and complex scenarios by introducing three novel prediction models for forecasting drivers intentions and behaviors at unsignalized intersections. We then address social reasoning by proposing a novel prediction model that analyzes agent interactions using graph neural networks, making the scene understanding process more informative for AVs. Our proposed prediction model, called STAG, explicitly activates social modeling with a directed graph representation while considering spatial and temporal inter-agent correlations. We further design a novel prediction system, namely CAPHA, which conditions the future behavior of agents on grid-based plans modeled as a Markov decision process and solves the prediction task via inverse reinforcement learning to produce scene compliant behaviors. Moreover, we introduce a novel goal-based prediction model, called GMP, which encodes interactions between agents and dynamic and static context information to estimate the distribution of target goals, efficiently considering the inherent uncertainty in agents behavior. Extensive quantitative and qualitative comparisons have been conducted between the developed solutions and related benchmark schemes using various scenarios and environments. The obtained results demonstrate the potential of these solutions for the understudy tasks of DBA and real-world applications.
212

Analysis of Aircraft Emissions Based on Flight Trajectory : ATR 72-500 trajectory and emission study

Forsberg, Gustav, Sundberg, Carl-Michael January 2022 (has links)
Emissions related to aviation have during the last decades become an important topic of discussion. Besides carbon dioxide ($CO_2$) which is the major pollutant from air travel, other gas emissions such as hydrocarbons ($HC$), nitrogen oxides ($NO_x$), carbon monoxide ($CO$) and sulfur oxides ($SO_x$) also need to be investigated. The work within this field has traditionally been challenged by the fact that aircraft emission calculations often required engine proprietary data which usually is difficult to obtain. However, in recent years other methods have been developed and this report investigates one such method, namely The Boeing Fuel Flow Method 2. The analysis is carried out on an ATR 72-500 turboprop aircraft flying at $13000$ feet from Visby to Bromma, Sweden. The method uses continuous data of fuel flow and altitude together with estimated emission index data at sea level for the specific engine to estimate the amount of emissions emitted during the flight. From this it was possible to determine the levels of $HC$,$NO_x$,$CO$, $CO_2$ and $SO_x$ emitted during the different stages of flight. There was a clear trend that $HC$ and $CO$ emissions were the highest at low fuel flow levels, i.e. at low power, while $NO_x$ increased with increasing fuel flow. Emission levels of $CO_2$ and $SO_x$ were found to be proportional to fuel flow. In addition, two alternative trajectories at $10000$ and $24000$ feet were studied. When comparing the $10000$ feet route with the original $13000$ feet route the the level of $NO_x$, $CO_2$ and $SO_x$ were unaffected while $HC$ and $CO$ decreased as the period of high fuel flow were shortened. In the $24000$ feet route the levels of $HC$, $CO$ and $SO_x$ were unaffected while the level of $CO_2$ and $NO_x$ decreased. This decrease can be explained by the lowered fuel flow rate as air resistance is significantly lower at $24000$ feet compared to $13000$ feet.
213

ACOUSTICALLY AIDED COALESCENCE OF DROPLETS IN AQUEOUS EMULSIONS

Pangu, Gautam D. 27 February 2006 (has links)
No description available.
214

OPTIMISM/PESSIMISM AS A MEDIATOR OF SOCIAL STRUCTURAL DISPARITIES EFFECTS ON PHYSICAL HEALTH AND PSYCHOLOGICAL WELL-BEING: A LONGITUDINAL STUDY OF HOSPITALIZED ELDERS

Burant, Christopher J. 13 June 2006 (has links)
No description available.
215

Biomechanics of spore discharge in the Basidiomycota

Stolze-Rybczynski, Jessica L. 12 August 2009 (has links)
No description available.
216

Logarithmic and Exponential Transients in GNSS Trajectory Models as Indicators of Dominant Processes in Post-Seismic Deformation

Sobrero, Franco Sebastian 08 October 2018 (has links)
No description available.
217

Urban Transportation Analysis Using Taxi Trajectory and Weather Data

Tang, Hui 15 December 2016 (has links)
No description available.
218

Nonlinear Tracking by Trajectory Regulation Control using Backstepping Method

Cooper, David 07 October 2005 (has links)
No description available.
219

Robust control via higher order trajectory sensitivity minimization

Chopra, Avnish January 1994 (has links)
No description available.
220

Detection, location, and trajectory tracing of moving objects in the real world two-dimensional images

Reza, Hasnain January 1988 (has links)
No description available.

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