Firm Performance and Modes of Innovation

It has been shown that firms tend to develop different modes of innovation, based on the relationship between the different types of underlying knowledge and learning processes. This paper seeks to identify different modes of business innovation, relating them to firms’ innovative and economic performance, and to analyze the relationship between the different innovation modes and the economic impact of the crisis on firms’ performance. These hypotheses are tested by regression and latent class models for the Portuguese population of firms, using a sample of 397 firms, classified according to technological intensity, firm size and region. Our results show three different modes of innovation in terms of the relationship between economic and innovative performance, with significant differences in terms of resilience in the face of the economic crisis. These findings lead to a reflection on innovation, competitiveness and regional policy.FC

Multidimensional continued fractions, dynamical renormalization and KAM theory

The disadvantage of `traditional' multidimensional continued fraction algorithms is that it is not known whether they provide simultaneous rational approximations for generic vectors. Following ideas of Dani, Lagarias and Kleinbock-Margulis we describe a simple algorithm based on the dynamics of flows on the homogeneous space SL(2,Z)\SL(2,R) (the space of lattices of covolume one) that indeed yields best possible approximations to any irrational vector. The algorithm is ideally suited for a number of dynamical applications that involve small divisor problems. We explicitely construct renormalization schemes for (a) the linearization of vector fields on tori of arbitrary dimension and (b) the construction of invariant tori for Hamiltonian systems.Comment: 51 page

Three and Four-Dimensional Visualization and Analysis Approaches to Study Vertebrate Axial Elongation and Segmentation

info:eu-repo/semantics/publishedVersio

Preparation of nano-hydroxyapatite/chitosan aqueous dispersions: from lab scale to continuous production using an innovative static mixer

Chitosan is widely used in the preparation of organic-inorganic composite materials, such as n-HAp/CS composites, which findapplication for bone regeneration. The methods for their preparation are various, and usually based on the preparation of intermediate n-HAp/CS dispersions, which can greatly influence the final properties of the resulting composites since it is expected that homogenous and stable dispersions lead to composite materials with improved final properties. This work hypothesizes that, additionally to process parameters such as pH, n-HAp/CS weight ratio, mixing conditions and the presence of salts, chitosan itself has a high impact on dispersions stability. Thus, the importance of properly control the preparation of the n-HAp/CS intermediate dispersions is highlighted by doing a systematic study where relevant processing parameters were studied at lab scale using ultrasonication, alone or in the presence of chitosan, namely on particle size and zeta potential. Furthermore, and based on the best laboratorial conditions, the production of n-HAp/CS nanocomposite dispersions in continuous mode was attempted through NETmix® technology,an innovative static mixer and reactor developed at the Associate Laboratory LSRE-LCM of the Faculty of Engineering of the University of Porto(FEUP).Financial support for this work was provided in part by project Project POCI-01-0145-FEDER-006984 – Associate Laboratory LSRELCM funded by FEDER through COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI) – and by national funds through FCT - Fundação para a Ciência e a Tecnologia, and by “AIProcMat@N2020 - Advanced Industrial Processes and Materials for a Sustainable Northern Region of Portugal 2020”, with reference NORTE-01-0145-FEDER-000006, supported by NORTE 2020 under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). FCT and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2013). G. Ruphuy thanks Universidad de Costa Rica (UCR) and Ministerio de Ciencia, Tecnología y Telecomunicaciones de Costa Rica (MICITT) for her scholarship. Authors thank Fluidinova S.A. for providing the HAp samples.info:eu-repo/semantics/publishedVersio

Renormalisation scheme for vector fields on T2 with a diophantine frequency

We construct a rigorous renormalisation scheme for analytic vector fields on the 2-torus of Poincare type. We show that iterating this procedure there is convergence to a limit set with a ``Gauss map'' dynamics on it, related to the continued fraction expansion of the slope of the frequencies. This is valid for diophantine frequency vectors.Comment: final versio