Model-Based Control Using Koopman Operators

This paper explores the application of Koopman operator theory to the control of robotic systems. The operator is introduced as a method to generate data-driven models that have utility for model-based control methods. We then motivate the use of the Koopman operator towards augmenting model-based control. Specifically, we illustrate how the operator can be used to obtain a linearizable data-driven model for an unknown dynamical process that is useful for model-based control synthesis. Simulated results show that with increasing complexity in the choice of the basis functions, a closed-loop controller is able to invert and stabilize a cart- and VTOL-pendulum systems. Furthermore, the specification of the basis function are shown to be of importance when generating a Koopman operator for specific robotic systems. Experimental results with the Sphero SPRK robot explore the utility of the Koopman operator in a reduced state representation setting where increased complexity in the basis function improve open- and closed-loop controller performance in various terrains, including sand.Comment: 8 page

Differentiating signals to make biological sense – a guide through databases for MS-based non-targeted metabolomics

Metabolite identification is one of the most challenging steps in metabolomics studies and reflects one of the greatest bottlenecks in the entire workflow. The success of this step determines the success of the entire research, therefore the quality at which annotations are given requires special attention. A variety of tools and resources are available to aid metabolite identification or annotation, offering different and often complementary functionalities. In preparation for this article, almost 50 databases were reviewed, from which 17 were selected for discussion, chosen for their on-line ESI-MS functionality. The general characteristics and functions of each database is discussed in turn, considering the advantages and limitations of each along with recommendations for optimal use of each tool, as derived from experiences encountered at the Centre for Metabolomics and Bioanalysis (CEMBIO) in Madrid. These databases were evaluated considering their utility in non-targeted metabolomics, including aspects such as ID assignment, structural assignment and interpretation of results

Nuevo reglamento para el canje de billetes y monedas

Explica las bondades del nuevo reglamento como un mecanismo eficaz para la gestión del circulante.

The effects of short-term omission of daily medication on the pathophysiology of heart failure

Aims Pharmacological therapies for heart failure (HF) aim to improve congestion, symptoms, and prognosis. Failing to take medication is a potential cause of worsening HF. Characterizing the effects of short-term medication omission could inform the development of better technologies and strategies to detect and interpret the reasons for worsening HF. We examined the effect of planned HF medication omission for 48 h on weight, echocardiograms, transthoracic bio-impedance, and plasma concentrations of NT-proBNP. Methods and results Outpatients with stable HF and an LVEF <45% were assigned to take or omit their HF medication for 48 h in a randomized, crossover trial. Twenty patients (16 men, LVEF 32 ± 9%, median NT-proBNP 962 ng/L) were included. Compared with regular medication, omission led to an increase in NT-proBNP by 99% (from 962 to 1883 ng/L, P < 0.001), systolic blood pressure by 16% (from 131 to 152 mmHg, P < 0.001), and left atrial volume by 21% (from 69 to 80 mL, P = 0.001), and reductions in transthoracic bio-impedance by 10% (from 33 to 30 Σ, P = 0.001) and serum creatinine by 8% (from 135 to 118 µmol/L, P = 0.012). No significant changes in body weight, heart rate, or LVEF were observed. Conclusions The characteristic pattern of response to short-term medication omission is of increasing congestion but, in contrast to the pattern reported for disease progression, with a rise in blood pressure and improved renal function. In stable HF, weight is not a sensitive marker of short-term diuretic omission

Switching dynamics of spatial solitary wave pixels

Separatrices and scaling laws in the switching dynamics of spatial solitary wave pixels are investigated. We show that the dynamics in the full model are similar to those in the plane-wave limit. Switching features may be indicated and explained by the motion of the (complex) solitary wave amplitude in the phase plane. We report generalization, into the domain of transverse effects, of the pulse area theorem for the switching process and a logarithmic law for the transient dynamics. We also consider, for what is the first time to our knowledge, phase-encoded address of solitary pixels and find that a near-square-wave temporal switching pattern is permitted without (transverse) cross switching

Nibiru, un nuevo mundo que depende de ti

L'història principal tracta sobre una societat del futur que en 2012 marxa cap a un nou planeta del sistema solar anomenat Nibiru. En aquest nou món, la societat evoluciona molt ràpidament aixecant grans ciutats i creant màquines intel·ligents anomenades cyborgs. Degut a que aquestes posseeixen sentiments, posteriorment s'enfrontaran als humans provocant una gran guerra entre ambdues espècies. Aquest projecte pot considerar-se una bíblia transmedia que guiarà als diferents professionals implicats en la realització d'aquesta experiència.La historia principal trata sobre una sociedad futura que en 2012 parte hacia un nuevo planeta del sistema solar llamado Nibiru. En este nuevo mundo la sociedad evoluciona de una manera muy rápida levantando grandes ciudades y creando máquinas inteligentes llamadas cyborgs. Debido a que éstas poseen sentimientos posteriormente se revelarán a los humanos provocando una gran guerra entre ambas especies. Este proyecto puede considerarse una biblia transmedia que guiará a los diferentes profesionales implicados en la realización de esta experiencia.The main story is about a future society that in 2012 travel to Nibiru, a new planet in the solar system. In this new world, the progress of the society grows up very quickly; they build big cities and create intelligent machines, named the cyborgs. Because these machines get feelings, it is caused a revolution, creating a big war between humans & robots. This project can be considered as a transmedia bible to guide all the different professionals involved in the realization of this experience