Variational description of Gibbs-non-Gibbs dynamical transitions for the Curie-Weiss model

Article / Letter to editorMathematisch Instituu

Self-aware trader: a new approach to safer trading

Traders are required to work in the financial market with highly complex information and to perform efficiently under high levels of psychological pressure. Multiple disciplines, from programs with artificial intelligence to complex mathematical functions, are used to help traders in their effort to maximize profits. However, an essential problem not yet considered in this rapidly evolving environment is that traders are not supported to adequately manage how stress influences their decisions. This paper takes into consideration the negative influences of stress on individuals and proposes a system designed to support traders by providing them with information that can reduce the likelihood of poor decision-making. The system has been designed considering both technical and physiological aspects to make information available in a suitable way. Biometric sensors are used to collect data associated with stress, a software platform then analyses this information and displays it to the trader. The resulting system is capable of making individual traders, as well as teams of traders, self-aware of their levels of stress. The system has been tested in real environments and the results provide evidence that self-aware traders benefit from the system by reducing risky decision-making

Recovering the real-space correlation function from photometric redshift surveys

Measurements of clustering in large-scale imaging surveys that make use of photometric redshifts depend on the uncertainties in the redshift determination. We have used light-cone simulations to show how the deprojection method successfully recovers the real space correlation function when applied to mock photometric redshift surveys. We study how the errors in the redshift determination affect the quality of the recovered two-point correlation function. Considering the expected errors associated to the planned photometric redshift surveys, we conclude that this method provides information on the clustering of matter useful for the estimation of cosmological parameters that depend on the large scale distribution of galaxies.Comment: 11 pages, 8 figures. Accepted for publication in MNRA

Macroscopic CNT fibres inducing non-epitaxial nucleation and orientation of semicrystalline polymers

In the presence of macroscopic fibres of carbon nanotubes (CNT), various semicrystalline polymers are shown to present accelerated crystallisation through the formation of a transcrystalline (TC) layer perpendicular to the fibre axis. From differential scanning calorimetry, polarized optical microscopy and X-ray diffraction we establish this to be due to much faster nucleation rates at the fibre surface. The formation of a TC layers is demonstrated for polyvinyldene fluoride, isotactic polypropylene and poly(lactic acid) in spite of the large differences in their chemistry and structure unit cells, suggesting that epitaxy in terms of lattice type or size matching is not a prerequisite. For the three polymers as well as poly(ether ether ketone), the TC layer is identically oriented with the chain axis in the lamella parallel to the CNTs, as observed by wide and small angle X-ray scattering. These results point to polymer chain orientation at the point of adsorption and the formation of a mesomorphic layer as possible steps in the fast nucleation of oriented lamella, with wetting of the CNT fibre surface by the molten semi-crystalline polymer a key condition for heterogeneous nucleation to take place

A detailed study of the gate/drain voltage dependence of RTN in bulk pMOS transistors

Random Telegraph Noise (RTN)has attracted increasing interest in the last years. This phenomenon introduces variability in the electrical properties of transistors, in particular in deeply-scaled CMOS technologies, which can cause performance degradation in circuits. In this work, the dependence of RTN parameters, namely current jump amplitude and emission and capture time constants, on the bias conditions, both VG and VD, has been studied on a set of devices, with a high granularity in a broad voltage range. The results obtained for the VG dependences corroborate previous works, but suggest a unique trend for all the devices in a VG range that goes from the near-threshold region up to voltages over the nominal operation bias. However, different trends have been observed in the parameters dependence for the case of VD. From the experimental data, the probabilities of occupation of the associated defects have been evaluated, pointing out large device-to-device dispersion in the VD dependences.Ministerio de Ciencia, Innovación y Universidades TEC2016-75151-C3-R, BES-2017-08016

Effect of reactive ion beam etching on the photoluminescence of CdTe epitaxial layers

We demonstrated the effect of reactive ion beam etching (RIBE) process on the PL properties of CdTe/sapphire metal organic vapor phase epitaxy layers. At optimum conditions, the RIBE attack does not make significant morphological changes but it results in an increase of the concentration of acceptor impurities. This was revealed by an increase of the overall photoluminescence (PL) intensity and, simultaneously, a decrease of the PL decay time, more important on the low energy side of PL spectrum due to the recombination of carriers in acceptor [email protected]

Is contact with birth parents beneficial to children in non-kinship foster care? A scoping review of the evidence

Many children in non-kinship foster care maintain contact with their birth parents, although debate continues about whether or not, or under what circumstances, it is beneficial to the child. In this scoping review we analyze the findings of studies conducted over the past two decades that have specifically examined face-to-face contact with birth parents for children in non-kinship foster care, our aim being to determine more clearly when it may contribute positively to the child’s well-being. The review was conducted in accordance with PRISMA-ScR guidelines and involved a search of nine electronic databases. A total of 21 studies met the criteria for inclu- sion in the review, namely primary studies analyzing one or more aspects of these contact visits, written in English or Spanish, and published during the period 1997–2022. In analyzing these studies we grouped their findings according to four broad areas of interest: characteristics of contact visits, appraisal of visits by families and professionals, relationship between contact and fostering outcomes, and impact of contact on children. The four main conclusions we draw from the review are: a) surprisingly few studies have specifically examined the effects of face-to-face contact with birth parents in non-kinship foster care; b) the findings to date are neither conclusive nor generalizable, although they are not generally encouraging; c) under the right circumstances (e.g., adequate supervision, conducted in a context of emotional security for the child), contact can contribute to the child’s well-being and increase the likelihood of family reunification; and d) more robust research is needed to guide the development of interventions that can improve parent–child relationships and the quality of contact visitsAndalusian Plan for Research, Development and Innovation (PAIDI) Research Group SEJ-466. Funding for open access charge: Universidad de M ́alaga / CBU

Jet quenching in a strongly coupled anisotropic plasma

The jet quenching parameter of an anisotropic plasma depends on the relative orientation between the anisotropic direction, the direction of motion of the parton, and the direction along which the momentum broadening is measured. We calculate the jet quenching parameter of an anisotropic, strongly coupled N=4 plasma by means of its gravity dual. We present the results for arbitrary orientations and arbitrary values of the anisotropy. The anisotropic value can be larger or smaller than the isotropic one, and this depends on whether the comparison is made at equal temperatures or at equal entropy densities. We compare our results to analogous calculations for the real-world quark-gluon plasma and find agreement in some cases and disagreement in others.Comment: 22 pages, 10 figures; v2: minor changes, added reference. Extends arXiv:1202.369

A General-Purpose Architecture to Control Mobile Robots

This paper at: 15th Workshop of Physical Agent. at took place, June 12 and 13, 2014 in León (Spain)Complex robotic tasks require the coordination of a considerable amount of skills. This is generally achieved generating and executing action plans that fulfill the preconditions of the given objective. These tasks can be highly dynamic, since the appearance of new objects or unexpected situations is a constant during the plan execution. In this context, robot control systems require the capability of managing a suitable world model (creating, removing or retyping dynamically objects as a result of the plan execution), and the capability of monitoring and replanning when unexpected situations are detected. In this paper we introduce a general-purpose architecture for autonomous mobile robots providing these features. The architecture allows to generate planning applications since it integrates planning, re-planning, monitoring and learning capabilities, and, at the same time, manages a consistent graph-like world model. Finally, we present some preliminary results of the deployment of such architecture in an advertisement promoting robot domain.This paper has been partially supported by the Spanish Ministerio de Economía y Competitividad TIN2012-TIN2012-38079 and FEDER funds, and by the Innterconecta Programme 2011 project ITC-20111030 ADAPTA.Publicad