Interrelationships between human capital and social capital in small and medium sized firms: The effect of age and sector of activity

This study explores the interconnection between human factors and social factors and analyses the relations influenced by the specific activity and age of firms. A statistical approach is implemented which applies factor analysis techniques, based on a sample of small and medium sized firms from four sectors of activity which are between four and fifteen years old, and are split into three time periods. It is found that there are interconnected groups of human capital and social capital factors, although a sizeable proportion of the literature conceptually separates these factors and deals with them individually. It is also ascertained that this relationship is influenced by the field of activity and the age of the firms.Entrepreneurship, Factor analysis, Human capital, Management, Social capital

Nonequilibrium scaling explorations on a 2D Z(5)-symmetric model

We have investigated the dynamic critical behavior of the two-dimensional Z(5)-symmetric spin model by using short-time Monte Carlo (MC) simulations. We have obtained estimates of some critical points in its rich phase diagram and included, among the usual critical lines the study of first-order (weak) transition by looking into the order-disorder phase transition. Besides, we also investigated the soft-disorder phase transition by considering empiric methods. A study of the behavior of $\beta /\nu z$ along the self-dual critical line has been performed and special attention has been devoted to the critical bifurcation point, or FZ (Fateev-Zamolodchikov) point. Firstly, by using a refinement method and taking into account simulations out-of-equilibrium, we were able to localize parameters of this point. In a second part of our study, we turned our attention to the behavior of the model at the early stage of its time evolution in order to find the dynamic critical exponent z as well as the static critical exponents $\beta$ and $$ of the FZ-point on square lattices. The values of the static critical exponents and parameters are in good agreement with the exact results, and the dynamic critical exponent $z\approx 2.28$ very close of the 4-state Potts model ($z\approx 2.29$).Comment: 11 pages, 7 figure

A new look at the 2D Ising model from exact partition function zeros for large lattice sizes

A general numerical method is presented to locate the partition function zeros in the complex beta plane for large lattice sizes. We apply this method to the 2D Ising model and results are reported for square lattice sizes up tp L=64. We also propose an alternative method to evaluate corrections to scaling which relies only on the leading zeros. This method is illustrated with our data.Comment: 9 pages, Latex, 3 figures. To appear in Int. J. Mod. Phys.

A influência dos factores de caracterização dos portos no desempenho, medido por indicadores operacionais, financeiros e de eficiência

This paper aims to study the performance of ports by characterization factors and understand its importance. The methods used are data envelopment analysis (DEA), factor analysis and linear regression. The sample consists of 43 European ports. The results indicate the existence of a relationship between performance and several variables that characterize the port and confirm the impact of location, governance, size, infrastructure, port specialisation, logistics integration and maritime services in the operational and financial performance and efficiency of ports

Was the GLE on May 17, 2012 linked with the M5.1-class flare the first in the 24th solar cycle?

On May 17, 2012 an M5.1-class flare exploded from the sun. An O-type coronal mass ejection (CME) was also associated with this flare. There was an instant increase in proton flux with peak at $\geq 100$ MeV, leading to S2 solar radiation storm level. In about 20 minutes after the X-ray emission, the solar particles reached the Earth.It was the source of the first (since December 2006) ground level enhancement (GLE) of the current solar cycle 24. The GLE was detected by neutron monitors (NM) and other ground based detectors. Here we present an observation by the Tupi muon telescopes (Niteroi, Brazil, $22^{0}.9 S$, $43^{0}.2 W$, 3 m above sea level) of the enhancement of muons at ground level associated with this M5.1-class solar flare. The Tupi telescopes registered a muon excess over background $\sim 20\%$ in the 5-min binning time profile. The Tupi signal is studied in correlation with data obtained by space-borne detectors (GOES, ACE), ground based neutron monitors (Oulu) and air shower detectors (the IceTop surface component of the IceCube neutrino observatory). We also report the observation of the muon signal possibly associated with the CME/sheath striking the Earth magnetosphere on May 20, 2012. We show that the observed temporal correlation of the muon excess observed by the Tupi muon telescopes with solar transient events suggests a real physical connection between them. Our observation indicates that combination of two factors, the low energy threshold of the Tupi muon telescopes and the location of the Tupi experiment in the South Atlantic Anomaly region, can be favorable in the study and detection of the solar transient events. Our experiment provides new data complementary to other techniques (space and ground based) in the study of solar physics.Comment: 9 pages, 10 figure