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Stability assessment of nonlinear systems using the lyapunov exponentBest, Eric A. January 2003 (has links)
No description available.
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Residual Crashes and Injured Occupants with Lane Departure Prevention SystemsRiexinger, Luke E. 19 April 2021 (has links)
Every year, approximately 34,000 individuals are fatally injured in crashes on US roads [1]. These fatalities occur across many types of crash scenarios, each with its own causation factors. One way to prioritize research on a preventive technology is to compare the number of occupant fatalities relative to the total number of occupants involved in a crash scenario. Four crash modes are overrepresented among fatalities: single vehicle road departure crashes, control loss crashes, cross-centerline head-on crashes, and pedestrian/cyclist crashes [2]. Interestingly, three of these crash scenarios require the subject vehicle to depart from the initial lane of travel. Lane departure warning (LDW) systems track the vehicle lane position and can alert the driver through audible and haptic feedback before the vehicle crosses the lane line. Lane departure prevention (LDP) systems can perform an automatic steering maneuver to prevent the departure.
Another method of prioritizing research is to determine factors common among the fatal crashes. In 2017, 30.4% of passenger vehicle crash fatalities involved a vehicle rollover [1]. Half of all fatal single vehicle road departure crashes resulted in a rollover yet only 12% of fatal multi-vehicle crashes involved a rollover [1]. These often occur after the driver has lost control of the vehicle and departed the road. Electronic stability control (ESC) can provide different braking to each wheel and allow the vehicle to maintain heading. While ESC is a promising technology, some rollover crashes still occur. Passive safety systems such as seat belts, side curtain airbags, and stronger roofs work to protect occupants during rollover crashes. Seat belts prevent occupants from moving inside the occupant compartment during the rollover and both seat belts and side curtain airbags can prevent occupants from being ejected from the vehicle. Stronger roofs ensure that the roof is not displaced during the rollover and the integrity of the occupant compartment is maintained to prevent occupant ejection.
The focus of this dissertation is to evaluate the effectiveness of vehicle-based countermeasures, such as lane departure warning and electronic stability control, for preventing or mitigating single vehicle road departure crashes, cross-centerline head-on crashes, and single vehicle rollover crashes. This was accomplished by understanding how drivers respond to both road departure and cross-centerline events in real-world crashes. These driver models were used to simulate real crash scenarios with LDW/LDP systems to quantify their potential crash reduction. The residual crashes, which are not avoided with LDW/LDP systems or ESC, were analyzed to estimate the occupant injury outcome. For rollover crashes, a novel injury model was constructed that includes modern passive safety countermeasures such as seat belts, side curtain airbags, and stronger roofs. The results for road departure, head-on, and control loss rollover crashes were used to predict the number of crashes and injured occupants in the future. This work is important for identifying the residual crashes that require further research to reduce the number of injured crash occupants. / Doctor of Philosophy / Every year in the US, approximately 34,000 individuals are fatally injured in many different types of crashes. However, some crash types are more dangerous than other crash types. Drift-out-of-lane (DrOOL) road departure crashes, control loss road departure crashes, head-on crashes, and pedestrian crashes are more likely to result in an occupant fatality than other crash modes. In three of these more dangerous crash types, the vehicle departs from the lane before the crash occurs. Lane departure warning (LDW) systems can detect when the vehicle is about to cross the lane line and notify the driver with beeping or vibrating the steering wheel. A different system, called lane departure prevention (LDP), can provide automatic steering to prevent the vehicle from leaving the lane or return lane. In control loss crashes, the vehicle's motion is in a different direction than the vehicle's heading. During control loss, it is easier for the vehicle to roll over which is very dangerous. Electronic stability control (ESC) can prevent control loss by applying selective braking to each tire to keep the vehicle's motion in the same direction as the vehicle's heading. If a rollover still occurs, vehicles are equipped with passive safety systems and designs such as seat belts, side curtain airbags, and stronger roofs to protect the people inside. Seat belts can prevent occupants from striking the vehicle interior during the rollover and both seat belts and side curtain airbags can prevent occupants from being ejected from the vehicle. Stronger roofs ensure that the roof is not displaced during the rollover to prevent occupants from being ejected from the vehicle.
The focus of this dissertation is to estimate how many crashes LDW, LDP, and ESC systems could prevent. This was accomplished by understanding how drivers respond after leaving their lane in real crashes. Then, these real crash scenarios were simulated with an LDW or LDP system to estimate how many crashes were prevented. The occupants of residual crashes, which were not prevented by the simulated systems, were analyzed to estimate the number of occupants with at least one moderate injury. Understanding which crashes and injuries that were not prevented with this technology can be used to decide where future research should occur to prevent more fatalities in road departure, head-on and control loss crashes.
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Teorie fikčních světů. Analýza a interpretace vývoje teorie fikčních světů v posledních desetiletích. / Fictional Worlds Theories. An Analysis and Interpretation of the Recent Development of the Theories of Fictional Worlds.Zima, Martin January 2013 (has links)
The thesis analyzes the possibilities of application of the fictional worlds theory as a possible basis for a different literary-theoretical approach to the study of literary texts. Not being a mere literature research, the thesis inquires into issues which are necessarily connected with the fictional worlds theory and which have been so far rarely dealt with, if discussed at all. It contributes to the discussion on advantages and drawbacks of the mimetic approach and of the fiction theory, it analyzes the possible applicability of the fictional worlds theory in literary history, it attempts to determine the correlation between the Seymour Chatman's textual types and the fiction theory nomenclature, and last but not least the thesis deals with the possibilities of this theory in the fictional worlds of lyrical poetry. Powered by TCPDF (www.tcpdf.org)
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Stopover Ecology of Mallards : Where, when and how to do what?Bengtsson, Daniel January 2016 (has links)
The mallard (Anas platyrhynchos) is the most numerous and widespread duck in the northern hemisphere and a model species in ecology and harvest management. Migration is a crucial life stage for many birds and understanding the drivers of migration has important implications for conservation biology and assessment of animal population responses to global changes. Furthermore, mallard migration is a fundamental determinant of the epidemiology of many diseases of major relevance for both animal and human health. For example, it is the reservoir host for influenza A viruses (IAV), a widespread zoonosis causing mortality and economic damage. Improved knowledge of mallard behaviour during migration and the impacts of infection in mallards is needed to determine the role of wild birds in global IAV dynamics. This thesis focuses on mallard stopover ecology, an explicitly important part of the annual life cycle that is not well understood. The study area was southern Öland, SE Sweden, where mallard stopover behaviour was scrutinized by a combination of telemetry and ringing data analyses. Specifically, habitat preferences, movements, and emigration decisions were studied in-depth. Potential effects of low pathogenic avian influenza (LPAIV) infection on movement parameters were also investigated. Radio-tracking revealed that stopover mallards adhered to a strict diel pattern, in which they spent the days resting along the coast, visited crop fields at dawn and dusk, and foraged on inland water bodies during the darkest night hours. Notably, the importance of residual maize, as well as small ephemeral wetlands on the unique alvar steppe habitat that predominates on Öland, was previously unknown. LPAIV infection status did not affect movement behaviour, highlighting the possible risk of spread of IAV from wild mallards to poultry along the migratory flyway. Through capture-mark-recapture modelling, it was confirmed that weather, particularly wind direction, was the most important determinant of departure from the stopover site. In contrast, the body condition of departing mallards was less crucial. Taken together, the research presented in this thesis contributes to improved knowledge about mallard stopover ecology and its role in LPAIV disease dynamics.
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Mutual implications: otherness in theory and John Berryman's poetry of lossSchwieler, Elias January 2003 (has links)
<p>This thesis examines John Berryman’s poetry of loss together with four different theoretical perspectives. It is the purpose of the study to involve Berryman’s poetry and critical theory in a dialogue which attempts to break down the hierarchy that positions theory as the subject and literature or poetry as the object of study. Instead, by focusing on the otherness of each discourse, that is, what could be called the unconscious of Berryman’s poetry of loss and the language of theory, poetry and theory can be seen to presuppose and mutually imply each other. Those of Berryman’s poems mainly analyzed in the thesis, and which could be called his poetry of loss are “The Ball Poem,” Homage to Mistress Bradstreet, and The Dream Songs. The four theoretical perspectives consist of Martin Heidegger’s thinking concerning the word and concept departure, David S. Reynolds’s notion of the subversive in the American Renaissance, Nicolas Abraham’s psychoanalytical concept anasemia, and Maurice Blanchot’s theory of death and poetry in his book The Space of Literature. The theoretical base of the thesis is developed primarily from Shoshana Felman’s “To open the question,” an editorial introduction to a special issue of Yale French Studies entitled Literature and Psychoanalysis. The Question of Reading: Otherwise and Timothy Clark’s study Derrida, Heidegger, Blanchot.</p>
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Mutual implications: otherness in theory and John Berryman's poetry of lossSchwieler, Elias January 2003 (has links)
This thesis examines John Berryman’s poetry of loss together with four different theoretical perspectives. It is the purpose of the study to involve Berryman’s poetry and critical theory in a dialogue which attempts to break down the hierarchy that positions theory as the subject and literature or poetry as the object of study. Instead, by focusing on the otherness of each discourse, that is, what could be called the unconscious of Berryman’s poetry of loss and the language of theory, poetry and theory can be seen to presuppose and mutually imply each other. Those of Berryman’s poems mainly analyzed in the thesis, and which could be called his poetry of loss are “The Ball Poem,” Homage to Mistress Bradstreet, and The Dream Songs. The four theoretical perspectives consist of Martin Heidegger’s thinking concerning the word and concept departure, David S. Reynolds’s notion of the subversive in the American Renaissance, Nicolas Abraham’s psychoanalytical concept anasemia, and Maurice Blanchot’s theory of death and poetry in his book The Space of Literature. The theoretical base of the thesis is developed primarily from Shoshana Felman’s “To open the question,” an editorial introduction to a special issue of Yale French Studies entitled Literature and Psychoanalysis. The Question of Reading: Otherwise and Timothy Clark’s study Derrida, Heidegger, Blanchot.
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On the control of airport departure operations.Burgain, Pierrick Antoine 15 November 2010 (has links)
This thesis is focused on airport departure operations; its objective is to assign a value to surface surveillance information within a collaborative framework.
The research develops a cooperative concept that improves the control of departure operations at busy airports and evaluates its merit using a classical and widely accepted airport departure model. The research then assumes departure operations are collaboratively controlled and develops a stochastic model of taxi operations on the airport surface. Finally, this study investigates the effect of feeding back different levels of surface surveillance information to the departure control process. More specifically, it examines the environmental and operational impact of aircraft surface location information on the taxi clearance process. Benefits are evaluated by measuring and comparing engine emissions for given runway utilization rates.
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Multi-viewpoint lane detection with applications in driver safety systemsBorkar, Amol 19 December 2011 (has links)
The objective of this dissertation is to develop a Multi-Camera Lane Departure Warning (MCLDW) system and a framework to evaluate it. A Lane Departure Warning (LDW) system is a safety feature that is included in a few luxury automobiles. Using a single camera, it performs the task of informing the driver if a lane change is imminent. The core component of an LDW system is a lane detector, whose objective is to find lane markers on the road. Therefore, we start this dissertation by explaining the requirements of an ideal lane detector, and then present several algorithmic implementations that meet these requirements. After selecting the best implementation, we present the MCLDW methodology. Using a multi-camera setup, MCLDW system combines the detected lane marker information from each camera's view to estimate the immediate distance between the vehicle and the lane marker, and signals a warning if this distance is under a certain threshold. Next, we introduce a procedure to create ground truth and a database of videos which serve as the framework for evaluation. Ground truth is created using an efficient procedure called Time-Slicing that allows the user to quickly annotate the true locations of the lane markers in each frame of the videos. Subsequently, we describe the details of a database of driving videos that has been put together to help establish a benchmark for evaluating existing lane detectors and LDW systems. Finally, we conclude the dissertation by citing the contributions of the research and discussing the avenues for future work.
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Spatiotemporal characterization of indoor wireless channelsGurrieri, Luis 29 October 2010 (has links)
The continuous advancement in wireless communications technology demands new approaches to improving the capacity of existing radio links. The high data throughput required can be achieved by the complete utilization of space, time and polarization diversities inherent in any propagation environment. Among the different propagation scenarios, the indoor channels represent a particularly challenging problem given the number and complexity of interactions between the transmitted signal and the environment. This dissertation explores the interrelation between propagation physics and space-time-polarization diversity based on a novel high resolution channel sounding and reconstruction technique. First, a method to reconstruct the indoor complex channel response based on a limited set of samples and the elimination of the interference using deconvolution techniques is presented. Then, the results for the joint angle-of-arrival, delay characterization and depolarization of electromagnetic waves are presented. Finally, a novel approach to using depolarized multipath signals to boost the receiver signal-to-noise performance is presented. The current study shows that full utilization of the diversities of channel novel wireless systems can be proposed with significant improvement in capacity.
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Spatiotemporal characterization of indoor wireless channelsGurrieri, Luis 29 October 2010 (has links)
The continuous advancement in wireless communications technology demands new approaches to improving the capacity of existing radio links. The high data throughput required can be achieved by the complete utilization of space, time and polarization diversities inherent in any propagation environment. Among the different propagation scenarios, the indoor channels represent a particularly challenging problem given the number and complexity of interactions between the transmitted signal and the environment. This dissertation explores the interrelation between propagation physics and space-time-polarization diversity based on a novel high resolution channel sounding and reconstruction technique. First, a method to reconstruct the indoor complex channel response based on a limited set of samples and the elimination of the interference using deconvolution techniques is presented. Then, the results for the joint angle-of-arrival, delay characterization and depolarization of electromagnetic waves are presented. Finally, a novel approach to using depolarized multipath signals to boost the receiver signal-to-noise performance is presented. The current study shows that full utilization of the diversities of channel novel wireless systems can be proposed with significant improvement in capacity.
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