Drivers overtaking cyclists on rural roads: How does visibility affect safety?: Results from a naturalistic study

Drivers overtaking cyclists on rural roads create a hazardous scenario due to the potentially high impact speeds and, therefore, severe consequences in case of a crash [1]. Díaz Fernández et al. analyzed crashes between cyclists and motorized vehicles from various data sources, including insurance reports and crash databases, and concluded that this scenario is particularly dangerous and new safety countermeasures are needed [2]. Other studies have shown that particularly the side-swipe risk through. aerodynamic forces due to low lateral clearance and high overtaking speed affects both the objective and subjective safety of the cyclist [3], [4]. Furthermore, recent work by Gildea et al. showed through a self-reported survey among cyclists that a significant amount of side-swipe crashes and near-crashes with lower severity of injuries remains unreported [ 5]. This underlines the importance of investigating further in what situations the side-swipe risk for cyclists increases and how it can be decreased effectively. Previous research investigated how driver behavior in overtaking is influenced by infrastructural elements such as lane widths [6], road markings [6], [7], parked cars [7], and the presence of road crossings. However, the effect of sight distance on driver behavior has not gained much attention yet. Therefore, this work analyzed the influence of sight distance on driver behavior and the resulting safety implications for the overtaken cyclist

Comparing autoencoder-based approaches for anomaly detection in highway driving scenario images

Autoencoder-based anomaly detection approaches can be used for precluding scope compliance failures of the automotive perception. However, the applicability of these approaches for the automotive domain should be thoroughly investigated. We study the capability of two autoencoder-based approaches using reconstruction errors and bottleneck-values for detecting semantic anomalies in automotive images. As a use-case, we consider a specific highway driving scenario identifying if there are any vehicles in the field of view of a front-looking camera. We conduct a series of experiments with two simulated driving scenario datasets and measure anomaly detection performance for different cases. We systematically test different autoencoders and training parameters, as well as the influence of image colors. We show that the autoencoder-based approaches demonstrate promising results for detecting semantic anomalies in highway driving scenario images in some cases. However, we also observe the variability of anomaly detection performance between different experiments. The autoencoder-based approaches are capable of detecting semantic anomalies in highway driving scenario images to some extent. However, further research with other use-cases and real datasets is needed before they can be safely applied in the automotive domain

Modeling Carbon Nanotube Field Effect Transistors with Fixed and Suspended Nanotube Gates

Carbon nanotubes (CNT) exhibit a range of properties that make them well suited for nanoelectronic and nanoelectromechanical devices. One-dimensional field effect transistors based on single-walled CNTs have demonstrated excellent electrical characteristics and are competitive with silicon-based solutions, and oscillators based on suspended CNTs have been shown to work at gigahertz frequencies with Q-factors exceeding 10$^3$. In this thesis, I present a theoretical model describing the operation of a carbon nanotube field-effect transistor (CNTFET) with a static or mechanically active CNT gate. Theoretical modeling gives a remarkably good agreementwith experimental measurements on CNT-gated CNTFETs, fabricated and characterised in the Atomic Physics group at University of Gothenburg, and provides an explanation for the steep sub-threshold slope and the short gate delay of the devices. With the help of the model it is demonstrated that a substantial improvement in gate delay time can be achieved by reducing the thickness of the gate dielectric.Furthermore, I show that utilizing the mechanical degree of freedom of a suspended gate CNT may lead to a sub-threshold slope smaller than the thermal 60 mV/decade limit. I present two designs of suspended CNTgated CNTFET, with doubly clamped or cantileved CNT gate. In the first design, the sub-threshold slope reaches 32 mV/decade, and in the secondas low as 15 mV/decade at room temperature. In the presented CNTFET designs, the instantaneous deflection of suspended CNT is mapped by transistor drain current. I show that the sensitivity of the CNTFETs towards the motion of suspended CNT surpasses that of the conventional nanoscale displacement detection methods

Modeling Carbon Nanotube Field Effect Transistors with Fixed and Suspended Nanotube Gates

Carbon nanotubes (CNT) exhibit a range of properties that make them well suited for nanoelectronic and nanoelectromechanical devices. One-dimensional field effect transistors based on single-walled CNTs have demonstrated excellent electrical characteristics and are competitive with silicon-based solutions, and oscillators based on suspended CNTs have been shown to work at gigahertz frequencies with Q-factors exceeding 10$^3$. In this thesis, I present a theoretical model describing the operation of a carbon nanotube field-effect transistor (CNTFET) with a static or mechanically active CNT gate. Theoretical modeling gives a remarkably good agreementwith experimental measurements on CNT-gated CNTFETs, fabricated and characterised in the Atomic Physics group at University of Gothenburg, and provides an explanation for the steep sub-threshold slope and the short gate delay of the devices. With the help of the model it is demonstrated that a substantial improvement in gate delay time can be achieved by reducing the thickness of the gate dielectric.Furthermore, I show that utilizing the mechanical degree of freedom of a suspended gate CNT may lead to a sub-threshold slope smaller than the thermal 60 mV/decade limit. I present two designs of suspended CNTgated CNTFET, with doubly clamped or cantileved CNT gate. In the first design, the sub-threshold slope reaches 32 mV/decade, and in the secondas low as 15 mV/decade at room temperature. In the presented CNTFET designs, the instantaneous deflection of suspended CNT is mapped by transistor drain current. I show that the sensitivity of the CNTFETs towards the motion of suspended CNT surpasses that of the conventional nanoscale displacement detection methods

Carbon nanotubes towards medicinal biochips

Carbon nanotubes (CNTs) exhibit a unique combination of biological and physical properties.(1-3) These properties make CNT-based devices, especially CNT field-effect transistors (FETs),(3,4) promising as a novel platform for chemical sensors,(5) biosensors,(6-8) and biochips.(9-11) The last ones seem to be especially promising for clinical diagnostics.(12) Namely, biochips permit the analysis of DNA, proteins, and other biological and chemical molecules in a massively parallel format.(13) They represent a multidisciplinary development unifying molecular biology, chemical and electronics engineering.(14) The emerging technologies of CNT biochips in medicine might provide further advantages relative to traditional biochip platforms including the cost and speed of medical tests.(12,15,16) Accordingly, our overview focuses on the recent advances in CNT-based biochips and tries to clarify their medicinal potential including lab-on-chips for molecular diagnostics,(17,18) drug screening,(19) and also novel strategies in molecular medicine.(20-22

Coupling Mechanics to Charge Transport in Carbon Nanotube Mechanical Resonators

4 pages, 4 figures.-- Printed version published Aug 28, 2009.-- Supporting information available at: www.sciencemag.org/cgi/content/full/1174290/DC1Nanoelectromechanical resonators have potential applications in sensing, cooling, and mechanical signal processing. An important parameter in these systems is the strength of coupling the resonator motion to charge transport through the device. We investigate the mechanical oscillations of a suspended single-walled carbon nanotube that also acts as a single-electron transistor. The coupling of the mechanical and the charge degrees of freedom is strikingly strong as well as widely tunable (the associated damping rate is ~ 5 · 10^5 Hz). In particular, the coupling is strong enough to drive the oscillations in the nonlinear regime.Peer reviewe