Probabilistic Shortest Time Queries Over Uncertain Road Networks

In many real applications such as location-based services (LBS), map utilities, trip planning, and transportation systems, it is very useful and important to provide query services over spatial road networks. Nowadays we can easily obtain rich traffic information such as the speeds of vehicles on roads. However, due to the inaccuracy of devices or integration in consistencies, the traffic data (i.e., speeds) are often imprecise and uncertain. In this paper, we model road networks by uncertain graphs, which contain edges that are associated with probabilistic velocities. We formalize the problem of probabilistic shortest time query, and we propose time bound pruning and probabilistic bound pruning to filter out false alarms. Moreover, we design offline pre-computation to facilitate PSTQ processing

Generating Component Designs for an Improved NVH Performance by Using an Artificial Neural Network as an Optimization Metamodel

In modern vehicle development, suspension components have to meet many boundary conditions. In noise, vibration, and harshness (NVH) development these are for example eigenfrequencies and frequency response function (FRF) amplitudes. Component geometry parameters, for example kinematic hard points, often affect multiple of these targets in a non intuitive way. In this article, we present a practical approach to find optimized parameters for a component design, which fulfills an FRF target curve. By morphing an initial component finite element model we create training data for an artificial neural network (ANN) which predicts FRFs from geometry parameter input. Then the ANN serves as a metamodel for an evolutionary algorithm optimizer which identifies fitting geometry parameter sets, meeting an FRF target curve. The methodology enables a component design which considers an FRF as a component target. In multiple simulation examples we demonstrate the capability of identifying component designs modifying specific eigenfrequency or amplitude features of the FRFs