Global controllability tests for geometric hybrid control systems

Hybrid systems are characterized by having an interaction between continuous dynamics and discrete events. The contribution of this paper is to provide hybrid systems with a novel geometric formulation so that controls can be added. Using this framework we describe some new global controllability tests for hybrid control systems exploiting the geometry and the topology of the set of jump points, where the instantaneous change of dynamics take place. Controllability is understood as the existence of a feasible trajectory for the system joining any two given points. As a result we describe examples where none of the continuous control systems are controllable, but the associated hybrid system is controllable because of the characteristics of the jump set.Comment: 27 pages, 5 figure

Estrategias utilizadas por estudiantes de distintos niveles educativos ante problemas de proporcionalidad compuesta

En este trabajo se analizan las actuaciones de alumnos desde 6.º de Educación Primaria hasta 2.º de Educación Secundaria Obligatoria (11-14 años) con distintos grados de instrucción en proporcionalidad al resolver ciertos problemas de proporcionalidad compuesta. En particular, observamos la tasa de éxito y las distintas estrategias empleadas, tanto correctas como incorrectas. Los resultados muestran un aumento progresivo de la tasa de éxito y una evolución en las estrategias utilizadas desde aquellas que hacen referencia a aspectos de razonamiento proporcional, hacia aquellas en las que prima el componente algorítmico

Hamiltonian engineering via invariants and dynamical algebra

We use the dynamical algebra of a quantum system and its dynamical invariants to inverse engineer feasible Hamiltonians for implementing shortcuts to adiabaticity. These are speeded up processes that end up with the same populations as slow, adiabatic ones. As application examples, we design families of shortcut Hamiltonians that drive two- and three-level systems between initial and final configurations, imposing physically motivated constraints on the terms (generators) allowed in the Hamiltonian.We are grateful to K. Takahashi and R. Kosloff for stimulating discussions. We acknowledge funding by Grants No. IT472-10 and No. FIS2009-12773-C02-01, and theUPV/EHU Program No. UFI 11/55. E.T. is supported by the Basque Government postdoctoral program. S.M.-G. acknowledges support from a UPV/EHU fellowship.Publicad

Relationships between depth and age, and recruitment indexes of hake on Galicia and Portugal shelf

In this paper it is studied the relations between the depth and the ages of the hake caugth in the six surveys done between 1974 and 1979 in the Divisions Vlllc and IXa, as soon as the recruitment levels in those years. It is observed a clear stratification of the ages and a significant bathimetric tendency to increase the mean age with the depth (1'=0.81). On the other hand, it is noticed a serious decrease in the following years over the recruitment level detected in 1974.Dans ce papier on a studie les relations entre l'âge et la profundeur du merlu capturée pendant six campagns realisées entre 1974 et 1979 dans subaire Vlllc et Division IXa du CIEM ainsi que les nivenux du recruitment durant ces annees. On observe une claire stratification entre la bathymetrie et l'âge et une tendence significatif a augmenter l'âge moyenne avec la profunder (r=0.81). D'antre coté, on constante une grave chute dans 1es anneés suivantes un relation avec le niveaux de recruitement detecté en 1974

A search for evidence of irradiation in Centaurus X-4 during quiescence

We present a study of the neutron star X-Ray Transient Cen X-4. Our aim is to look for any evidence of irradiation of the companion with a detailed analysis of its radial velocity curve, relative contribution of the donor star and Doppler tomography of the main emission lines. To improve our study all our data are compared with a set of simulations that consider different physical parameters of the system, like the disc aperture angle and the mass ratio. We conclude that neither the radial velocity curve nor the orbital variation of the relative donor's contribution to the total flux are affected by irradiation. On the other hand, we do see emission from the donor star at H${\alpha}$ and HeI 5876 which we tentatively attribute to irradiation effects. In particular, the H${\alpha}$ emission from the companion is clearly asymmetric and we suggest is produced by irradiation from the hot-spot. Finally, from the velocity of the HeI 5876 spot we constrain the disc opening angle to alpha=7-14 deg.Comment: 4 pages, 5 figures, accepted for publication in A&A as a R

Experimental Evaluation of Dynamic Resource Orchestration in Multi-Layer (Packet over Flexi-Grid Optical) Networks?

This paper has been presented at : ONDM 2019 23rd Conference on Optical Network Design and ModellingIn future 5G infrastructures, network services will be de- ployed through sets of Virtual Network Functions (VNFs) leveraging the advantages of both Software Defined Networking (SDN) and Net- work Function Virtualization (NFV). A network service is composed of an ordered sequence of VNFs, i.e., VNF Forwarding Graph (VNFFG), deployed across distributed data centers (DCs). Herein, we present a Cloud/Network Orchestrator which dynamically processes and accom- modates VNFFG requests over a pool of DCs interconnected by a multi- layer (packet/flexi-grid optical) transport network infrastructure. We propose two different cloud and network resource allocation algorithms aiming at: i) minimizing the distance between the selected DCs, and ii) minimizing the load (i.e., consumed cloud resources) of the chosen DCs. Both algorithms run on a Cloud/Network Orchestrator and are ex- perimentally validated and benchmarked on the CTTC ADRENALINE testbed.This work is partially funded by the EU H2020 5G TRANSFORMER project (761536) and the Spanish AURORAS project (RTI2018-099178