32,034 research outputs found
Making Transport Safer: V2V-Based Automated Emergency Braking System
An important goal in the field of intelligent transportation systems (ITS) is to provide driving aids aimed at preventing accidents and reducing the number of traffic victims. The commonest traffic accidents in urban areas are due to sudden braking that demands a very fast response on the part of drivers. Attempts to solve this problem have motivated many ITS advances including the detection of the intention of surrounding cars using lasers, radars or cameras. However, this might not be enough to increase safety when there is a danger of collision. Vehicle to vehicle communications are needed to ensure that the other intentions of cars are also available. The article describes the development of a controller to perform an emergency stop via an electro-hydraulic braking system employed on dry asphalt. An original V2V communication scheme based on WiFi cards has been used for broadcasting positioning information to other vehicles. The reliability of the scheme has been theoretically analyzed to estimate its performance when the number of vehicles involved is much higher. This controller has been incorporated into the AUTOPIA program control for automatic cars. The system has been implemented in Citroën C3 Pluriel, and various tests were performed to evaluate its operation
Goals and Plans in Protective Decision Making
Protective decisions are often puzzling. Among other anomalies, people insure against non-catastrophic events, underinsure against catastrophic risks, and allow extraneous factors to influence insurance purchases and other protective decisions. Neither expected utility theory nor prospect theory can explain these anomalies satisfactorily. We propose a constructed-choice model for general decision making. The model departs from utility theory and prospect theory in its treatment of multiple goals and it suggests several different ways in which context can affect choice. To apply this model to the above anomalies, we consider many different insurance-related goals, organized in a taxonomy, and we consider the effects of context on goals, resources, plans and decision rules. The paper concludes by suggesting some prescriptions for improving individual decision making with respect to protective measures.
Application of Biological Learning Theories to Mobile Robot Avoidance and Approach Behaviors
We present a neural network that learns to control approach and avoidance behaviors in a mobile robot using the mechanisms of classical and operant conditioning. Learning, which requires no supervision, takes place as the robot moves around an environment cluttered with obstacles and light sources. The neural network requires no knowledge of the geometry of the robot or of the quality, number or configuration of the robot's sensors. In this article we provide a detailed presentation of the model, and show our results with the Khepera and Pioneer 1 mobile robots.Office of Naval Research (N00014-96-1-0772, N00014-95-1-0409
Stationary-state electronic distribution in quantum dots
We wish to draw an attention to a non-gibbsian behavior of zero-dimensional
semiconductor nanostructures, which appears to be manifested in experiments by
an effect of incomplete depopulation from electronic excited states or by an
effect of up-conversion of electronic level occupation after preparing the
system in the ground state of electronic excitation. In the present work the
effect is interpreted with help of electron-LO-phonon interaction, which is
supposed to play a role in these structures in the form of multiple-scattering
of electron on the optical phonons. Quantum kinetic equation describing the
process of electronic ralaxation with the inclusion of electronic multiple
scattering on phonons is considered. The multiple electron scattering
interpretation of the effect is supported by pointing out a considerable degree
of agreement between the theoretical picture presented and a rather extensive
amount of existing experimental data.Comment: 8 pages, 3 figure
New Source Term for QGP Formation in the Background-Field Model
We consider pair production in a space-time-dependent background field and
derive a source term, i.e., production rate in the one-particle phase space.
Such a source term is required in Boltzmann-equation-based models of
quark-gluon plasma formation and evolution. We compare the source term derived
here with the one that has been used in the literature so far. Significant
differences are observed.Comment: 12 pages latex and 4 post-script figure
Future Evolution of CSMA Protocols for the IEEE 802.11 Standard
In this paper a candidate protocol to replace the prevalent CSMA/CA medium
access control in Wireless Local Area Networks is presented. The proposed
protocol can achieve higher throughput than CSMA/CA, while maintaining
fairness, and without additional implementation complexity. Under certain
circumstances, it is able to reach and maintain collision-free operation, even
when the number of contenders is variable and potentially large. It is backward
compatible, allowing for new and legacy stations to coexist without degrading
one another's performance, a property that can make the adoption process by
future versions of the standard smooth and inexpensive.Comment: This paper has been accepted in the Second IEEE ICC Workshop 2013 on
Telecommunication Standards: From Research to Standard
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