Forced quasi-periodic oscillations in strongly dissipative systems of any finite dimension

We consider a class of singular ordinary differential equations describing analytic systems of arbitrary finite dimension, subject to a quasi-periodic forcing term and in the presence of dissipation. We study the existence of response solutions, i.e. quasi-periodic solutions with the same frequency vector as the forcing term, in the case of large dissipation. We assume the system to be conservative in the absence dissipation, so that the forcing term is --- up to the sign --- the gradient of a potential energy, and both the mass and damping matrices to be symmetric and positive definite. Further, we assume a non-degeneracy condition on the forcing term, essentially that the time-average of the potential energy has a strict local minimum. On the contrary, no condition is assumed on the forcing frequency; in particular we do not require any Diophantine condition. We prove that, under the assumptions above, a response solution always exist provided the dissipation is strong enough. This extends results previously available in literature in the one-dimensional case.Comment: 20 pages. arXiv admin note: substantial text overlap with arXiv:1606.0687

Urban Governance of Employment Activation. The Case of Barcelona Activa (Spain) Governança urbana em ativação do emprego: o caso de Barcelona Activa (Espanha)

Within the framework of rescaling nation-State and improving new modes of governance, activation policieshave to be interpreted as qualified initiatives for economic growth and social integration at a subnationallevel and, specifically, in regional and urban contexts. Barcelona Activa is the local agency of theBarcelona City Council (Spain) designed for business improvement and employment quality through horizontalsubsidiary and public-private partnerships. This agency acts as a pivotal body of the municipaladministration in order to implement a variety of programs aimed at labour and professional empowerment,small and medium-sized companies creation and urban marketing. The paper focuses on BarcelonaActivas strategies, outcomes and criticisms in the current financial crisis, approaching its institutional rolefor the development of Barcelona as one of the main southern gateways to Europe

Construction of the Lyapunov spectrum in a chaotic system displaying phase synchronization

We consider a three-dimensional chaotic system consisting of the suspension of Arnold's cat map coupled with a clock via a weak dissipative interaction. We show that the coupled system displays a synchronization phenomenon, in the sense that the relative phase between the suspension flow and the clock locks to a special value, thus making the motion fall onto a lower dimensional attractor. More specifically, we construct the attractive invariant manifold, of dimension smaller than three, using a convergent perturbative expansion. Moreover, we compute via convergent series the Lyapunov exponents, including notably the central one. The result generalizes a previous construction of the attractive invariant manifold in a similar but simpler model. The main novelty of the current construction relies in the computation of the Lyapunov spectrum, which consists of non-trivial analytic exponents. Some conjectures about a possible smoothening transition of the attractor as the coupling is increased are also discussed.Comment: 24 pages, 10 figure

Cognitive Robots and the Conscious Mind: A Review of the Global Workspace Theory

Abstract Purpose of Review The theory of consciousness is a subject that has kept scholars and researchers challenged for centuries. Even today it is not possible to define what consciousness is. This has led to the theorization of different models of consciousness. Starting from Baars' Global Workspace Theory, this paper examines the models of cognitive architectures that are inspired by it and that can represent a reference point in the field of robot consciousness. Recent Findings Global Workspace Theory has recently been ranked as the most promising theory in its field. However, this is not reflected in the mathematical models of cognitive architectures inspired by it: they are few, and most of them are a decade old, which is too long compared to the speed at which artificial intelligence techniques are improving. Indeed, recent publications propose simple mathematical models that are well designed for computer implementation. Summary In this paper, we introduce an overview of consciousness and robot consciousness, with some interesting insights from the literature. Then we focus on Baars' Global Workspace Theory, presenting it briefly. Finally, we report on the most interesting and promising models of cognitive architectures that implement it, describing their peculiarities

A follower-centric approach to leadership in the newsroom: The case of El País

This article analyses leadership in the newsroom of the Spanish newspaper El País as well as its impact on the craft of journalism more generally. Through 23 in-depth interviews, we try to elucidate how the newsroom constructs its leaders (in the newsroom, what does it mean to be a leader?), paying particular attention to the main skills considered to be necessary. According to our newsroom findings, not all heads of section or editors-in-chief are leaders, a fact that questions formal authority relations and proclaims expertise and know-how as discriminatory skills. This study emphasizes that the collective recognition of a leader is not an ultimate disposition, but can vary over time: consequently leaders who do not achieve the professional requirements of the newsroom can be denied the status, despite their expertise and experience. Our findings indicate that leaders at El País are those journalists (no matter what their positions) with strong capacities and skills (fundamentally experience, expertise and creativity) to manage form (relationships) and substance (contents) in the daily work of the newsroom. In short, journalists seen as leaders combine reiterated and strong qualities and merit, graphically reflected in the texts they have published for years in the newspaper

Laparoscopic versus open radical prostatectomy in high prostate volume cases: impact on oncological and functional results

To prospectively compare the laparoscopic versus open approach to RP in cases with high prostate volume and to evaluate a possible diferente impact of prostate volume

Resonances within Chaos

A chaotic system under periodic forcing can develop a periodically visited strange attractor. We discuss simple models in which the phenomenon, quite easy to see in numerical simulations, can be completely studied analytically.Comment: 12 pages, 3 figure

Stand-alone wearable system for ubiquitous real-time monitoring of muscle activation potentials

Wearable technology is attracting most attention in healthcare for the acquisition of physiological signals. We propose a stand-alone wearable surface ElectroMyoGraphy (sEMG) system for monitoring the muscle activity in real time. With respect to other wearable sEMG devices, the proposed system includes circuits for detecting the muscle activation potentials and it embeds the complete real-time data processing, without using any external device. The system is optimized with respect to power consumption, with a measured battery life that allows for monitoring the activity during the day. Thanks to its compactness and energy autonomy, it can be used outdoor and it provides a pathway to valuable diagnostic data sets for patients during their own day-life. Our system has performances that are comparable to state-of-art wired equipment in the detection of muscle contractions with the advantage of being wearable, compact, and ubiquitous

A meta-analysis and systematic review of randomized controlled trials with degarelix versus gonadotropin-releasing hormone agonists for advanced prostate cancer

Our aim was to systematically evaluate the benefits of degarelix as antagonist versus agonists of gonadotropin-releasing hormones (GnRH) for the treatment of advanced prostate cancer (PC). This comparison was performed either in terms of biochemical or oncological or safety profiles. To this end we, carried out a systematic review and meta-analysis of the literature.We selected only studies directly and prospectively analyzing the two treatments in the same population (randomized phase III studies). We followed the Preferred Reporting Items for Systematic Reviews and meta-analyses process for reporting studies.After we eliminated studies according to the exclusion criteria, 9 publications were considered relevant to this review. These articles described 5 clinical trials that were eligible for inclusion. The follow-up duration in all trials did not exceed 364 days. This meta-analysis and review comprised a total of 1719 men, 1061 randomized to degarelix versus 658 to GnRH agonists treatment for advanced PC. Oncological results were evaluated only in 1 trial (CS21:408 cases) and they were not the primary endpoints of the study. Treatment emerging adverse events were reported in 61.4% and 58.8% of patients in the degarelix and GnRH agonists group, respectively (odds ratio, OR = 1.17; 95% confidence interval, 95% CI: 0.78-1.77, P > 0.1). Treatment related severe cardiovascular side effects were reported (trial CS21-30-35) in 1.6% and 3.6% of patients in the degarelix and GnRH agonists group, respectively (OR = 0.55, 95% CI: 0.26-1.14, P > 0.1).Our analysis evidences relevant limitations in particular for the comparative evaluation of the efficacy and the oncological results related to degarelix