System Identification of multi-rotor UAVs using echo state networks

Controller design for aircraft with unusual configurations presents unique challenges, particularly in extracting valid mathematical models of the MRUAVs behaviour. System Identification is a collection of techniques for extracting an accurate mathematical model of a dynamic system from experimental input-output data. This can entail parameter identification only (known as grey-box modelling) or more generally full parameter/structural identification of the nonlinear mapping (known as black-box). In this paper we propose a new method for black-box identification of the non-linear dynamic model of a small MRUAV using Echo State Networks (ESN), a novel approach to train Recurrent Neural Networks (RNN)

Two-Layered Superposition of Broadcast/Multicast and Unicast Signals in Multiuser OFDMA Systems

We study optimal delivery strategies of one common and $K$ independent messages from a source to multiple users in wireless environments. In particular, two-layered superposition of broadcast/multicast and unicast signals is considered in a downlink multiuser OFDMA system. In the literature and industry, the two-layer superposition is often considered as a pragmatic approach to make a compromise between the simple but suboptimal orthogonal multiplexing (OM) and the optimal but complex fully-layered non-orthogonal multiplexing. In this work, we show that only two-layers are necessary to achieve the maximum sum-rate when the common message has higher priority than the $K$ individual unicast messages, and OM cannot be sum-rate optimal in general. We develop an algorithm that finds the optimal power allocation over the two-layers and across the OFDMA radio resources in static channels and a class of fading channels. Two main use-cases are considered: i) Multicast and unicast multiplexing when $K$ users with uplink capabilities request both common and independent messages, and ii) broadcast and unicast multiplexing when the common message targets receive-only devices and $K$ users with uplink capabilities additionally request independent messages. Finally, we develop a transceiver design for broadcast/multicast and unicast superposition transmission based on LTE-A-Pro physical layer and show with numerical evaluations in mobile environments with multipath propagation that the capacity improvements can be translated into significant practical performance gains compared to the orthogonal schemes in the 3GPP specifications. We also analyze the impact of real channel estimation and show that significant gains in terms of spectral efficiency or coverage area are still available even with estimation errors and imperfect interference cancellation for the two-layered superposition system

Liouville Quantum Gravity on the Riemann sphere

In this paper, we rigorously construct $2d$ Liouville Quantum Field Theory on the Riemann sphere introduced in the 1981 seminal work by Polyakov "Quantum Geometry of bosonic strings". We also establish some of its fundamental properties like conformal covariance under PSL$_2(\mathbb{C})$-action, Seiberg bounds, KPZ scaling laws, KPZ formula and the Weyl anomaly (Polyakov-Ray-Singer) formula for Liouville Quantum Gravity.Comment: Added conjectures relating Liouville quantum field theory to random planar map and optimal conditions in order to ensure existence of the unit volume Liouville measur

Renormalizability of Liouville Quantum Gravity at the Seiberg bound

Liouville Quantum Field Theory can be seen as a probabilistic theory of 2d Riemannian metrics $e^{\phi(z)}dz^2$, conjecturally describing scaling limits of discrete $2d$-random surfaces. The law of the random field $\phi$ in LQFT depends on weights $\alpha\in \mathbb{R}$ that in classical Riemannian geometry parametrize power law singularities in the metric. A rigorous construction of LQFT has been carried out in \cite{DKRV} in the case when the weights are below the so called Seiberg bound: $\alpha<Q$ where $Q$ parametrizes the random surface model in question. These correspond to conical singularities in the classical setup. In this paper, we construct LQFT in the case when the Seiberg bound is saturated which can be seen as the probabilistic version of Riemann surfaces with cusp singularities. Their construction involves methods from Gaussian Multiplicative Chaos theory at criticality

Chemistry of Plants From the Helianteae (Asteraceae) and Molluscicidal Activity and Phosphofructokinase Inhibition by Sesquiterpene Lactones (Calea, Squamopappus, Podachaenium, Biomphalaria Glabrata).

As part of a biochemical systematic investigation of the tribe Helianteae (Compositae) for their secondary metabolites, Calea deltophylla Cowan from the subtribe Galinsoginae, Squamopappus skutchii (S. F. Blake) Jansen, Harriman and Urbatsch, from the Ecliptinae, and Podachaenium eminens (Lagasca) Shultz-Bip. from the Verbesininae were chemically investigated. Calea deltophylla provided the known compounds ageratochromene and eupatarone and three new compounds, 3-methoxy-4-hydroxyseneciophenone, caldeltophyllide and deltophyllin. Squamopappus skutchii yielded the known sesquiterpenoid (beta)-eudesmol, two new guaianolides, skutchiolides A and B, and the new eudesmanolide chapinolin. P. eminens provided three known guaianolides. The structures of the compounds were established by chemical and spectroscopic methods including MS, IR, CD, (\u271)H NMR and (\u2713)C NMR techniques and single crystal X-ray diffraction analysis. The chemical data support the taxonomical classification of C. deltophylla and P. eminens and justify the removal of S. skutchii from the genera Calea and Podachaenium, and its placement into the subtribe Ecliptinae. Terpenoid extracts of thirty plants from the Composite family were tested for their molluscicidal activity against Biomphalaria glabrata snails. Nearly 50% of the extracts exhibited molluscicidal activity, the most active being those of Podachaenium eminens from Mexico and Ambrosia confertiflora from Nuevo Leon, Mexico, and Texas, with LC(,100) (24 hrs) of 50, 100 and 100ppm, respectively. Confertiflorin from A. confertiflora DC provided upon treatment with p-toluensulfonic acid a mixture of desacetylconfertiflorin and allodesacetylconfertiflorin. Treatment of confertiflorin with phenylselenyl chloride followed by hydrogen peroxide oxidation yielded a mixture of 8(alpha)-acetoxyambrosin and 2,3-dehydro-8(alpha)-acetoxypsilostachin C. The structures of the new compounds were inferred from spectral data. Forty sesquiterpene lactones were tested for their molluscicidal activity against B. glabrata snails. The most active of the compounds was 7(alpha)-hydroxy-3-desoxyzaluzanin C with an LC(,100) (24 hrs) = 1.0 ppm. Ten sesquiterpene lactones, four guaianolides and six pseudoguaianolides, were tested for their inhibitory activity toward the enzyme phosphofructokinase. All compounds were found to be active as inhibitors. The most active of the guaianolides was 7(alpha)-hydroxy-3-desoxyzaluzanin C and allodesacetylconfertiflorin the most active pseudoguaianolide with apparent K(,i) values of 0.07 and 3.24 mM, respectively

Incorporating variable viscosity in vorticity-based formulations for Brinkman equations

In this brief note, we introduce a non-symmetric mixed finite element formulation for Brinkman equations written in terms of velocity, vorticity and pressure with non-constant viscosity. The analysis is performed by the classical Babu\v{s}ka-Brezzi theory, and we state that any inf-sup stable finite element pair for Stokes approximating velocity and pressure can be coupled with a generic discrete space of arbitrary order for the vorticity. We establish optimal a priori error estimates which are further confirmed through computational example

De la situation financière des unions de fait dans le système juridique espagnol

La ruptura de los convivientes puede plantear diversas reclamaciones, que pueden ser por la liquidación del régimen de bienes existentes entre ellos, o por las pretensiones compensatorias por la prestación de servicios realizados por uno en beneficio del otro durante la convivencia. En este trabajo se analizan las diversas soluciones que la doctrina y la jurisprudencia española han desarrollado, frente a la multiplicidad de problemas por la falta de regulación estatal en la disolución de las uniones de hecho, aspiración que también es compartida por las crecientes leyes autonómicas y forales.A broken partnership may be surrounded by several complaints by the former partners. They could be caused by the liquidation or final settlement of the goods and values acquired by the former partners during the partnership, or by the compensatory allowances due between the former partners which are based on the services that they gave to each other during the partnership. On this article, we analyze the variety of solutions developed by the spanish higher courts through their decisions and by the Spanish jurisprudence, in order to solve the multiplicity of problems caused by the lack of state regulation over the dissolution of unregistered partnerships.Le rupture de cohabitation peut soulever diverses réclamations, qui peuvent être à la liquidation des biens entre eux, ou les demandes d’indemnisation pour la fourniture de services au profit de l’autre lors de la coexistence. Dans cet article, nous analysons les différentes solutions de la doctrine et de la jurisprudence espagnole –inclus les lois régionales et des Conseils– ont développés devant la multiplicité des problèmes dus au manque de régulation étatique dans la dissolution de l’union civile