DSpace Community:
http://hdl.handle.net/10261/4
20160626T12:04:57Z

Inphase, outofphase and T/4 synchronization of square waves in delaycoupled nonidentical optoelectronic oscillators
http://hdl.handle.net/10261/134035
Title: Inphase, outofphase and T/4 synchronization of square waves in delaycoupled nonidentical optoelectronic oscillators
Authors: MartínezLlinàs, Jade; Colet, Pere
Abstract: © 2015 Optical Society of America. We model two nonidentical delayline optoelectronic oscillators mutually coupled through delayed crossfeedback. The system can generate multistable nanosecond periodic squarewave solutions which arise through a Hopf instability. We show that for suitable ratios between self and cross delay times, the two oscillators generate square waves with different amplitude but synchronized in phase, out of phase or with a dephasing of a quarter of the period. We also show that the synchronization is robust to small mismatches in the delay times.
20160624T09:18:57Z

Competitive function approximation for reinforcement learning
http://hdl.handle.net/10261/133994
Title: Competitive function approximation for reinforcement learning
Authors: Agostini, Alejandro; Celaya, Enric
Abstract: The application of reinforcement learning to problems with continuous domains requires representing
the value function by means of function approximation. We identify two aspects of reinforcement learning that make the function approximation process hard: nonstationarity of the target function and biased sampling. Nonstationarity is the result of the bootstrapping nature of dynamic programming where the value function is estimated using its current approximation. Biased sampling occurs when some regions of the state space are visited too often, causing a reiterated updating with similar values which fade out the occasional updates of infrequently sampled regions. We propose a competitive approach for function approximation where many different local approximators are available at a given input and the one with expectedly best approximation is selected by means of a relevance function. The local nature of the approximators allows their fast adaptation to nonstationary changes and mitigates the biased sampling problem. The coexistence of multiple approximators updated and tried in parallel permits obtaining a good estimation much faster than would be possible with a single approximator. Experiments in different benchmark problems show that the competitive strategy provides a faster and more stable learning than noncompetitive approaches.
20160623T10:58:07Z

Rigid and deformable pick and place algorithms
http://hdl.handle.net/10261/133992
Title: Rigid and deformable pick and place algorithms
Authors: Martí, Felip; Alenyà, Guillem
Abstract: This technical report explains the packages used in the WAM robot to pick and place cloth
or tableware objects. The goal was to check if the WAM arm robot could perform several
movements to fold and unfold deformables and manipulate some tableware objects. Eight different
nodes have been implemented following a generic and a modular design in order to allow
scalability and adaptability.
20160623T10:54:25Z

Temperature modelling and Model Predictive Control of a pilotscale batch reaction system
http://hdl.handle.net/10261/133990
Title: Temperature modelling and Model Predictive Control of a pilotscale batch reaction system
Authors: Sánchez, Javier; OcampoMartinez, Carlos
Abstract: The temperature control equipment on a pilot scale batch reaction system located at EAFIT
University in Medell´ın, Colombia, is modeled and a new controller is designed aiming at using it
in the reactor current PLCbased control system. Some mathematical models are developed from
experimental data to describe the system behavior and using them several model based predictive
controllers are designed. The simplest, yet reliable, model obtained is an ARX polynomial model
of order (1,1,1) that yields a four states affine model for which an explicit MPC was calculated.
This controller has a reduced mathematical complexity and can probably be used directly on
the existing control system.
20160623T10:50:26Z