Automatic assessment of creativity in heuristic problem-solving based on query diversity

Indexación: Web of Science; Scopus.Research, development and innovation are the pillars on which companies rely to offer new products and services capable of attracting consumer demand. This is why creative problem-solving emerges as one of the most relevant skills of the 21st century. Fortunately, there are many creativity training programs that have proven effective. However, many of these programs and methods base on a previous measurement of creativity and require experienced reviewers, they consume time for being manual, and they are far from everyday activities. In this study, we propose a model to estimate the creative quality of users' solutions dealing with heuristic problems, based on the automatic analysis of query patterns issued during the information search to solve the problem. This model has been able to predict the creative quality of solutions produced by 226 users, reaching a sensitivity of 78.43%. Likewise, the level of agreement among reviewers in relation to the creative characteristics is evaluated through two rubrics, and thereby, observing the difficulties of the manual evaluation: subjectivity and effort. The proposed model could be used to foster prompt detection of non-creative solutions and it could be implemented in diverse industrial processes that can range from the recruitment of talent to the evaluation of performance in R&D&I processes.https://www.revistadyna.com/search/automatic-assessment-of-creativity-in-heuristic-problem-solving-based-on-query-diversit

Characterization of qubit chains by Feynman probes

We address the characterization of qubit chains and assess the performances of local measurements compared to those provided by Feynman probes, i.e. nonlocal measurements realized by coupling a single qubit regis- ter to the chain. We show that local measurements are suitable to estimate small values of the coupling and that a Bayesian strategy may be successfully exploited to achieve optimal precision. For larger values of the coupling Bayesian local strategies do not lead to a consistent estimate. In this regime, Feynman probes may be exploited to build a consistent Bayesian estimator that saturates the Cram\'er-Rao bound, thus providing an effective characterization of the chain. Finally, we show that ultimate bounds to precision, i.e. saturation of the quantum Cram\'er-Rao bound, may be achieved by a two-step scheme employing Feynman probes followed by local measurements.Comment: 8 pages, 5 figure

Giant planets around two intermediate-mass evolved stars and confirmation of the planetary nature of HIP67851 c

Precision radial velocities are required to discover and characterize planets orbiting nearby stars. Optical and near infrared spectra that exhibit many hundreds of absorption lines can allow the m/s precision levels required for such work. However, this means that studies have generally focused on solar-type dwarf stars. After the main-sequence, intermediate-mass stars (former A-F stars) expand and rotate slower than their progenitors, thus thousands of narrow absorption lines appear in the optical region, permitting the search for planetary Doppler signals in the data for these types of stars. We present the discovery of two giant planets around the intermediate-mass evolved star HIP65891 and HIP107773. The best Keplerian fit to the HIP65891 and HIP107773 radial velocities leads to the following orbital parameters: P=1084.5 d; m$_b$sin$i$ = 6.0 M$_{jup}$; $e$=0.13 and P=144.3 d; m$_b$sin$i$ = 2.0 M$_{jup}$; $e$=0.09, respectively. In addition, we confirm the planetary nature of the outer object orbiting the giant star HIP67851. The orbital parameters of HIP67851c are: P=2131.8 d, m$_c$sin$i$ = 6.0 M$_{jup}$ and $e$=0.17. With masses of 2.5 M$_\odot$ and 2.4 M$_\odot$ HIP65891 and HIP107773 are two of the most massive stars known to host planets. Additionally, HIP67851 is one of five giant stars that are known to host a planetary system having a close-in planet ($a <$ 0.7 AU). Based on the evolutionary states of those five stars, we conclude that close-in planets do exist in multiple systems around subgiants and slightly evolved giants stars, but probably they are subsequently destroyed by the stellar envelope during the ascent of the red giant branch phase. As a consequence, planetary systems with close-in objects are not found around horizontal branch stars.Comment: Accepted for publication in A&

Improving information/disturbance and estimation/distortion trade-offs with non universal protocols

We analyze in details a conditional measurement scheme based on linear optical components, feed-forward loop and homodyne detection. The scheme may be used to achieve two different tasks. On the one hand it allows the extraction of information with minimum disturbance about a set of coherent states. On the other hand, it represents a nondemolitive measurement scheme for the annihilation operator, i.e. an indirect measurement of the Q-function. We investigate the information/disturbance trade-off for state inference and introduce the estimation/distortion trade-off to assess estimation of the Q-function. For coherent states chosen from a Gaussian set we evaluate both information/disturbance and estimation/distortion trade-offs and found that non universal protocols may be optimized in order to achieve better performances than universal ones. For Fock number states we prove that universal protocols do not exist and evaluate the estimation/distortion trade-off for a thermal distribution.Comment: 10 pages, 6 figures; published versio

The Seven Sisters DANCe. I. Empirical isochrones, Luminosity and Mass Functions of the Pleiades cluster

The DANCe survey provides photometric and astrometric (position and proper motion) measurements for approximately 2 millions unique sources in a region encompassing $\approx$80deg$^{2}$ centered around the Pleiades cluster. We aim at deriving a complete census of the Pleiades, and measure the mass and luminosity function of the cluster. Using the probabilistic selection method described in Sarro+2014, we identify high probability members in the DANCe ($i\ge$14mag) and Tycho-2 ($V\lesssim$12mag) catalogues, and study the properties of the cluster over the corresponding luminosity range. We find a total of 2109 high probability members, of which 812 are new, making it the most extensive and complete census of the cluster to date. The luminosity and mass functions of the cluster are computed from the most massive members down to $\approx$0.025M$_{\odot}$. The size, sensitivity and quality of the sample result in the most precise luminosity and mass functions observed to date for a cluster. Our census supersedes previous studies of the Pleiades cluster populations, both in terms of sensitivity and accuracy.Comment: Language Edition Done. Final version to be published in A&A. Tables will be published at CDS. Meanwhile, they can be requested to H. Bouy (hbouy -at- cab . inta - csic . es

Incomplete quantum process tomography and principle of maximal entropy

The main goal of this paper is to extend and apply the principle of maximum entropy (MaxEnt) to incomplete quantum process estimation tasks. We will define a so-called process entropy function being the von Neumann entropy of the state associated with the quantum process via Choi-Jamiolkowski isomorphism. It will be shown that an arbitrary process estimation experiment can be reformulated in a unified framework and MaxEnt principle can be consistently exploited. We will argue that the suggested choice for the process entropy satisfies natural list of properties and it reduces to the state MaxEnt principle, if applied to preparator devices.Comment: 8 pages, comments welcome, references adde

Optimal estimation of entanglement

Entanglement does not correspond to any observable and its evaluation always corresponds to an estimation procedure where the amount of entanglement is inferred from the measurements of one or more proper observables. Here we address optimal estimation of entanglement in the framework of local quantum estimation theory and derive the optimal observable in terms of the symmetric logarithmic derivative. We evaluate the quantum Fisher information and, in turn, the ultimate bound to precision for several families of bipartite states, either for qubits or continuous variable systems, and for different measures of entanglement. We found that for discrete variables, entanglement may be efficiently estimated when it is large, whereas the estimation of weakly entangled states is an inherently inefficient procedure. For continuous variable Gaussian systems the effectiveness of entanglement estimation strongly depends on the chosen entanglement measure. Our analysis makes an important point of principle and may be relevant in the design of quantum information protocols based on the entanglement content of quantum states.Comment: 9 pages, 2 figures, v2: minor correction

Estimation of Aneurysm Wall Motion from 4D Computerized Tomographic Angiography Images

It is widely accepted that wall shear stressis associated to aneurysm formation, growthand rupture. Early identification of potential risk factors may contribute to decide the treatment and improve patient care. Previous studies have shown associations between high aneurysm wall shear stress values and both elevated risk of rupture and localization of regions of aneurysm progression. Based on the assumption that damaged regions of the endothelium have different mechanical properties, regions with differentiated wall displacement amplitudes are expected. A previous approach based on the analysis ofbidimensional dynamic tomographic angiography images at a limited number of points during the cardiac cycle showed only small displacements in some patients using that simplified and semi-automatic low resolution methodology. The purpose of this work is to overcome some of those limitations. High time and spatial resolution four dimensional computerized tomographic angiography images of cerebral aneurysms were acquired and analyzed in order to identify and characterize wall motion. Images were filtered andsegmented at nineteentime points during the cardiac cycle.An average image was computed to generate the vascular model. Anunstructured mesh of tetrahedral elements was generated using an advancing front technique. A finite element blood flow simulationwas carried out under personalized pulsatile flow conditions. A fuzzy c-means clustering algorithm was used to estimate regions that exhibit wall motion within the aneurysm sac. A good correlation between localization of regions of elevated wall shear stress and regionsexhibiting wall motion was found.Fil: Castro, Marcelo Adrian. Universidad Tecnológica Nacional. Facultad Regional Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ahumada Olivares, María C.. Universidad Favaloro; ArgentinaFil: Putman, Christopher M. . Inova Fairfax Hospital. Department of Interventional Neuroradiology; Estados UnidosFil: Cebral, Juan R.. George Mason University. Department of Computational and Data Sciences; Estados Unido

Optimization of nanopores generated by chemical etching of swift-ion irradiated LiNbO3.

The morphology of the nanopores obtained by chemical etching on ion-beam irradiated LiNbO3 has been investigated for a variety of ions (F, Br, Kr, Cu, Pb), energies (up to 2300 MeV), and stopping powers (up to 35 keV/nm) in the electronic energy loss regime. The role of etching time and etching agent on the pore morphology, diameter, depth, and shape has also been studied. The transversal and depth profiles of the pore have been found to be quite sensitive to both, irradiation and etching parameters. Moreover, two etching regimes with different morphologies and etching rates have been identified

On the order of BEC transition in weakly interacting gases predicted by mean-field theory

Predictions from Hartree-Fock (HF), Popov (P), Yukalov-Yukalova (YY) and $t$-matrix approximations regarding the thermodynamics from the normal to the BEC phase in weakly interacting Bose gases are considered. By analyzing the dependence of the chemical potential $\mu$ on temperature $T$ and particle density $\rho$ we show that none of them predicts a second-order phase transition as required by symmetry-breaking general considerations. In this work we find that the isothermal compressibility $\kappa_{T}$ predicted by these theories does not diverge at criticality as expected in a true second-order phase transition. Moreover the isotherms $\mu=\mu(\rho,T)$ typically exhibit a non-singled valued behavior in the vicinity of the BEC transition, a feature forbidden by general thermodynamic principles. This behavior can be avoided if a first order phase transition is appealed. The facts described above show that although these mean field approximations give correct results near zero temperature they are endowed with thermodynamic anomalies in the vicinity of the BEC transition. We address the implications of these results in the interpretation of current experiments with ultracold trapped alkali gases.Comment: 16 pages, 5 figure