5,727 research outputs found
Relationship Lending and Firm Innovativeness
This study investigates the effects of relationship lending on firm innovativeness using a panel of Italian manufacturing firms. In order to disentangle the impact of bank ties on the discovery phase from that in the introduction phase of new technologies, the analysis proceeds in two steps, estimating two distinct equations for each phase. As there are conflicting theoretical predictions on the effects of the various sources of funding in the different stages of the innovative process, this study provides results for small and high-tech firms, so as to control for firm heterogeneity, relying on both cross-section and panel data techniques. Results suggest that for small firms, banks do not carry out a sophisticated intervention at the stage of development of new technologies, playing their traditional role of financing investments of constrained firms. Differently, relationship banks do play an important role in both phases for high-tech firms.Credit relationship;external financing;bank competition
Unit Roots and the Dynamics of Market Shares:An Analysis Using Italian Banking Micro-Panel
The paper proposes the use of panel data unit root tests to assess market share instability in order to have (preliminary) indications of the industry dynamic. The idea is to consider the movements in market shares not only as element of the market structure but rather reflecting conduct that arise from that market. If shares are mean-reverting, the firm actions only have a temporary effect on shares. On the other hand, if they are evolving, as signaled by the presence of unit roots, the gain in shares respect with the competitors could be long-term. To illustrate the potential of unit roots tests, I consider an application to the Italian retail banking industry
Intensity of Competition and Market Structure in the Italian Banking Industry
This work tests the predictions of Sutton’s model of independent submarkets for the Italian retail banking industry. In the first part of this paper, I develop a model of endogenous mergers to evidence the relationship between firms’ conduct, market entry and market structure. In the second part, I identify the submarket dimension and estimate the relationship between market size and market structure using data on bank branches. The size of the submarkets turned out to be at most provincial whereas the limiting concentration index - as argued by Sutton for industries with exogenous sunk costs - goes to zero as the market becomes larger.Concentration;Truncated Poisson and Negative Binomial models;quantile regressions
Segmentation and generalisation for writing skills transfer from humans to robots
In this study, the authors present an enhanced generalised teaching by demonstration technique for a KUKA iiwa robot. Movements are recorded from a human operator, and then the recorded data are sent to be segmented via MATLAB by using the difference method (DV). The outputted trajectories data are used to model a non-linear system named dynamic movement primitive (DMP). For the purpose of learning from multiple demonstrations correctly and accurately, the Gaussian mixture model is employed for the evaluation of the DMP in order to modelling multiple trajectories by the teaching of demonstrator. Furthermore, a synthesised trajectory with smaller position errors in 3D space has been successfully generated by the usage of the Gaussian mixture regression algorithm. The proposed approach has been tested and demonstrated by performing a Chinese characters writing task with a KUKA iiwa robot
Analysis of unmitigated large break loss of coolant accidents using MELCOR code
In the framework of severe accident research activity developed by ENEA, a MELCOR nodalization of a generic Pressurized Water Reactor of 900 MWe has been developed. The aim of this paper is to present the analysis of MELCOR code calculations concerning two independent unmitigated large break loss of coolant accident transients, occurring in the cited type of reactor. In particular, the analysis and comparison between the transients initiated by an unmitigated double-ended cold leg rupture and an unmitigated double-ended hot leg rupture in the loop 1 of the primary cooling system is presented herein. This activity has been performed focusing specifically on the in-vessel phenomenology that characterizes this kind of accidents. The analysis of the thermal-hydraulic transient phenomena and the core degradation phenomena is therefore here presented. The analysis of the calculated data shows the capability of the code to reproduce the phenomena typical of these transients and permits their phenomenological study. A first sequence of main events is here presented and shows that the cold leg break transient results faster than the hot leg break transient because of the position of the break. Further analyses are in progress to quantitatively assess the results of the code nodalization for accident management strategy definition and fission product source term evaluation
Unveiling the inner morphology and gas kinematics of NGC 5135 with ALMA
The local Seyfert 2 galaxy NGC5135, thanks to its almost face-on appearance,
a bulge overdensity of stars, the presence of a large-scale bar, an AGN and a
Supernova Remnant, is an excellent target to investigate the dynamics of
inflows, outflows, star formation and AGN feedback. Here we present a
reconstruction of the gas morphology and kinematics in the inner regions of
this galaxy, based on the analysis of Atacama Large Millimeter Array (ALMA)
archival data. To our purpose, we combine the available 100 pc resolution
ALMA 1.3 and 0.45 mm observations of dust continuum emission, the spectroscopic
maps of two transitions of the CO molecule (tracer of molecular mass in star
forming and nuclear regions), and of the CS molecule (tracer of the dense star
forming regions) with the outcome of the SED decomposition. By applying the
BAROLO software (3D-Based Analysis of Rotating Object via Line
Observations), we have been able to fit the galaxy rotation curves
reconstructing a 3D tilted-ring model of the disk. Most of the observed
emitting features are described by our kinematic model. We also attempt an
interpretation for the emission in few regions that the axisymmetric model
fails to reproduce. The most relevant of these is a region at the northern edge
of the inner bar, where multiple velocity components overlap, as a possible
consequence of the expansion of a super-bubble.Comment: 15 pages, 13 figures, resubmitted to MNRAS after moderate revision
Three-dimensional flow instability in a lid-driven isosceles triangular cavity
Linear three-dimensional modal instability of steady laminar two-dimensional states developing in a lid-driven cavity of isosceles triangular cross-section is investigated theoretically and experimentally for the case in which the equal sides form a rectangular corner. An asymmetric steady two-dimensional motion is driven by the steady motion of one of the equal sides. If the side moves away from the rectangular corner, a stationary three-dimensional instability is found. If the motion is directed towards the corner, the instability is oscillatory. The respective critical Reynolds numbers are identified both theoretically and experimentally. The neutral curves pertinent to the two configurations and the properties of the respective leading eigenmodes are documented and analogies to instabilities in rectangular lid-driven cavities are discussed
Ab-initio calculation of all-optical time-resolved calorimetry of nanosized systems: Evidence of nanosecond-decoupling of electron and phonon temperatures
The thermal dynamics induced by ultrashort laser pulses in nanoscale systems,
i.e. all-optical time-resolved nanocalorimetry is theoretically investigated
from 300 to 1.5 K. We report ab-initio calculations describing the temperature
dependence of the electron-phonon interactions for Cu nanodisks supported on
Si. The electrons and phonons temperatures are found to decouple on the ns time
scale at 10 K, which is two orders of magnitude in excess with respect to that
found for standard low-temperature transport experiments. By accounting for the
physics behind our results we suggest an alternative route for overhauling the
present knowledge of the electron-phonon decoupling mechanism in nanoscale
systems by replacing the mK temperature requirements of conventional
experiments with experiments in the time-domain.Comment: 5 pages, 3 figures. Accepted on Physical Review B
ATLASGAL-selected massive clumps in the inner Galaxy: I. CO depletion and isotopic ratios
In the low-mass regime, it is found that the gas-phase abundances of
C-bearing molecules in cold starless cores rapidly decrease with increasing
density, as the molecules form mantles on dust grains. We study CO depletion in
102 massive clumps selected from the ATLASGAL 870 micron survey, and
investigate its correlation with evolutionary stage and with the physical
parameters of the sources. Moreover, we study the gradients in [12C]/[13C] and
[18O]/[17O] isotopic ratios across the inner Galaxy, and the virial stability
of the clumps. We use low-J emission lines of CO isotopologues and the dust
continuum emission to infer the depletion factor fD. RATRAN one-dimensional
models were also used to determine fD and to investigate the presence of
depletion above a density threshold. The isotopic ratios and optical depth were
derived with a Bayesian approach. We find a significant number of clumps with a
large fD, up to ~20. Larger values are found for colder clumps, thus for
earlier evolutionary phases. For massive clumps in the earliest stages of
evolution we estimate the radius of the region where CO depletion is important
to be a few tenths of a pc. Clumps are found with total masses derived from
dust continuum emission up to ~20 times higher than the virial mass, especially
among the less evolved sources. These large values may in part be explained by
the presence of depletion: if the CO emission comes mainly from the low-density
outer layers, the molecules may be subthermally excited, leading to an
overestimate of the dust masses. CO depletion in high-mass clumps seems to
behave as in the low-mass regime, with less evolved clumps showing larger
values for the depletion than their more evolved counterparts, and increasing
for denser sources. The C and O isotopic ratios are consistent with previous
determinations, and show a large intrinsic scatter.Comment: 20 pages, 17 figures, 38 pages of online material (tables and
figures
Preliminary neutron kinetic. Thermal hydraulic coupled analysis of the ALFRED reactor using PHISICS/RELAP5-3D
The development of a lead-cooled fast reactor (LFR) demonstrator was proposed, mainly in EU, to investigate the feasibility of an industrial size ELFR (European Lead-cooled Fast Reactor). The demonstrator, called ALFRED (Advanced Lead-cooled Fast Reactor European Demonstrator), consists of a pool-type lead-cooled fast reactor, with a nominal thermal power of 300 MWt. This paper aims to verify the capability of the PHISICS/RELAP5-3D coupled approach to simulate transients of such reactor and to evaluate the effects of accidental scenarios relevant for the safety analysis on the system thermal-hydraulics and on the core power spatial evolution. RELAP5-3D©, developed at Idaho National Laboratory (INL), is a thermal-hydraulic system code, validated for a wide range of transient simulations. The code provides the possibility to simulate innovative working fluids (such as lead and lead alloys) and to use a fully integrated multi-dimensional nodalization. In addition, the need to study complex neutronic systems recommended the development of a new kinetic model allowing the calculation with any number of energy groups and also considering the transport for the angular variations. At this purpose, INL developed PHISICS (Parallel and Highly Innovative Simulation for INL Code System) and its coupling methodology with RELAP5-3D. The simulation activity described in this paper has been focused on the safety analysis of ALFRED reactor assuming the occurrence of two unprotected transient scenarios: unprotected loss of flow (ULOF) and unprotected transient overpower (UTOP). At this purpose, a thermal-hydraulic geometrical scheme of the whole reactor has been developed. The models and the outcomes of the calculations are described and discussed in the paper, highlighting the capability of the coupling approach to obtain results consistent with the ones available in the literature
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