Adaptive neural network control of fes-induced cyclical lower leg movements

As a first step to the control of paraplegic gait by functional electrical stimulation (FES), the control of the swinging lower leg is being studied. This paper deals with a neural control system, that has been developed for this case. The control system has been tested for a model of the swinging lower leg using computer simulations. The neural controller was trained by supervised learning (SL) and by backpropagation through time (BTT). The performance of the controller with random initial weights was poor after training with BTT and fair after SL. BTT training of the neural controller with weights, which had been initialized by SL, resulted in good control. Training with BTT thus improved the performance of the controller that initially had been trained by SL. An adaptive neural control system based on BTT has been proposed and partially tested. The controller adapted relatively fast to the change of an important model parameter

Neuromuscular control of arm movements: A modelling approach

Mechanical Maritime and Materials Engineerin

Polarization bremsstrahlung by fast charge on atomic bound electrons—Analog of nuclear M¨ossbauer’s effect

Features of polarization bremsstrahlung radiation (PB) by a relativistic charge on medium electrons bound in atoms are discussed. PB is considered as a dispersion of virtual photons of an electromagnetic field of a fast charge on atomic bound electrons. In this case atomic electron can get dispersed at a recoil energy in only certain portions, as in the nuclear M¨ossbauer process. Because of this a spectrum of dispersed photons is degenerated in a series of narrow peaks

Modelling of potential hazards in agent-based safety risk analysis

Contains fulltext : 194308.pdf (publisher's version ) (Open Access)One of the key steps in safety risk assessment of an Air Traffic Management (ATM) operation is to identify as many potential hazards as is possible. All these potential hazards have to be analysed upon their possible contribution to safety risk of the operation considered. In an agent-based safety risk assessment of ATM operations there are two approaches towards the assessment of the safety risk impacts of hazards. The direct way is to incorporate the hazard in the agent-based model, and to assess this agent-based model on safety risk by conducting Monte Carlo simulations. The alternative is to avoid the modelling of a potential hazard in the agent-based model, and instead assess the impact of the hazard on safety risk through sensitivity analysis and bias and uncertainty assessment. Because agent-based modelling and simulation of hazards might reveal emergent behaviour that remains invisible through sensitivity analysis, there is a need to understand how to model various hazard types in an agent-based model. In order to comply with this need, this paper identifies 38 model constructs that are able to capture more than 97% of the potential ATM related hazards in an agent-based model. The paper also shows that four of the five main model constructs are related to four widely used modelling domains in aviation, i.e. system reliability, human performance simulation, human reliability analysis, and aircraft trajectory simulation. However, the model construct that captures the highest percentage of hazards (41%) is related to the more recent domain of multi-agent systems modelling.10th USA/Europe Air Traffic Management Research and Development Seminar (ATM2013), Chicago, US