New efficient constructive heuristics for the hybrid flowshop to minimise makespan: A computational evaluation of heuristics

This paper addresses the hybrid flow shop scheduling problem to minimise makespan, a well-known scheduling problem for which many constructive heuristics have been proposed in the literature. Nevertheless, the state of the art is not clear due to partial or non homogeneous comparisons. In this paper, we review these heuristics and perform a comprehensive computational evaluation to determine which are the most efficient ones. A total of 20 heuristics are implemented and compared in this study. In addition, we propose four new heuristics for the problem. Firstly, two memory-based constructive heuristics are proposed, where a sequence is constructed by inserting jobs one by one in a partial sequence. The most promising insertions tested are kept in a list. However, in contrast to the Tabu search, these insertions are repeated in future iterations instead of forbidding them. Secondly, we propose two constructive heuristics based on Johnson’s algorithm for the permutation flowshop scheduling problem. The computational results carried out on an extensive testbed show that the new proposals outperform the existing heuristics.Ministerio de Ciencia e Innovación DPI2016-80750-

Ciudadanía y gobiernos abiertos

Las instituciones públicas tienen la obligación de defender a la ciudadanía y apoyar sus demandas. Para ello se precisa un cambio en las relaciones de poder actual, unas instituciones más flexibles, transparentes, abiertas, participativas, que muestren una vocación por la práctica de la accountability y, sobre todo, por la rendición de cuentas periódica. A su vez se precisa eliminar el clientelismo, abrir los debates a todos los niveles y desligar la función pública de la política fortaleciendo unas estructuras abiertas en donde la capacidad y el mérito presida dicha función pública. Solo de este modo se conseguirá un incremento de la confianza de la sociedad civil hacia nuestras institucione

A general numerical solution of dispersion relations for the nuclear optical model

A general numerical solution of the dispersion integral relation between the real and the imaginary parts of the nuclear optical potential is presented. Fast convergence is achieved by means of the Gauss-Legendre integration method, which offers accuracy, easiness of implementation and generality for dispersive optical model calculations. The use of this numerical integration method in the optical-model parameter search codes allows for a fast and accurate dispersive analysis

Safety of permanent pacemaker implantation: a prospective study

Although pacemaker implantation is considered to be low risk, it is not exempt from complications and technical failures during the procedure, both in the short and long term, and the complications that such patients may present remain unknown. The aim has been to analyze the complication rates associated with permanent pacing and to identify if these differ between patients with or without previous antithrombotic therapy. We used a prospective, single center, observational study of 310 adult patients with indications of permanent pacing. They were hospitalized from 1 January to 31 December 2014 and followed up for 6 months after the pacemaker implant. The participants were distributed into two groups according to the antithrombotic therapy prior to the implant. The most frequent major complications were pneumothorax (3.87%) and lead dislodgement (8.39%), while superficial phlebitis (12.90%) and uncomplicated hematomas (22.58%) were presented as the most recurrent minor complications. Hematomas were the most frequent minor complication in the antithrombotic therapy cohort, and shoulder pain was reported as the most recurrent minor complication in the non-exposed group. Finding out about complications in pacemaker implants enables a complete view of the process, and hence the prioritization of actions aimed at improving safety and reducing associated risks

GEANT4 application for the simulation of the head of a siemens primus linac

The Monte Carlo simulation of the head of a Siemens Primus Linac used at Virgen Macarena Hospital (Sevilla, Spain) has been performed using the code GEANT4 [1-2], version 9.2. In this work, the main features of the application built by our group are presented. They are mainly focused in the optimization of the performance of the simulation. The geometry, including the water phantom, has been entirely wrapped by a shielding volume which discards all the particles escaping far away through its walls. With this, a factor of four in the time spent by the simulation can be saved. An interface to read and write phase-space files in IAEA format has been also developed to save CPU time in our simulations [3-4]. Finally, some calculations of the dose absorption in the water phantom have been done and compared with the results given by EGSnrc [5] and with experimental data obtained for the calibration of the machine

Analytical expressions for the dispersive contributions to the nucleon-nucleus optical potential

Analytical solutions of dispersion relations in the nucleon-nucleus optical model have been found for both volume and surface potentials. For the energy dependence a standard Brown-Rho function has been assumed for both the volume and surface imaginary contributions multiplied in this later case by a decreasing exponential function. The solutions are valid for any even value of the powers appearing in these functional forms.Junta de Andalucía y CICYT FPA2001-0144-C05-03 FPA2001-4960-EUnión Europea KIW-CT-2000-0010

Quality of Institutions, Technological Progress, and Pollution Havens in Latin America. An Analysis of the Environmental Kuznets Curve Hypothesis

A set of 17-year panel data (1996–2013) across a representative sample from eighteen Latin American countries is used to respond four research questions: Did Latin American Greenhouse Gas (GHG) emissions prove the Environmental Kuznets Curve (EKC) hypothesis? Did the quality of institutions play a compensating role for income on environmental stress? Did technological progress help decouple income from environmental stress? Has the Pollution Haven Hypothesis (PHH) been proven? In order to answer the research questions, the paper expands the traditional EKC approach by including an exclusive quality analysis of institutions, technological progress, and PHH as part of the model. This innovation is developed considering the most recent literature about EKC as a starting point. Major findings show that the relationship between income and GHG emissions is adjusted to the traditional EKC hypothesis for the analyzed period. They also show that the quality of institutions and technological progress improve environmental sustainability. However, the variables, Foreign Direct Investment and International Trade, provide a negative answer to the fourth question. The main methodological contribution of this paper is to use a threefold extended classic EKC model to conduct the feasible generalized least squares method. The paper also contributes to the growing body of PHH literature.Junta de Andalucía proyecto SEJ-132Cátedra de Economía de la Energía y del MedioUniversidad Autónoma de Chil

Collisions of Nucleons with Atoms: Calculated Cross Sections and Monte Carlo Simulation

After a summary description of the theory of elastic collisions of nucleons with atoms, we present the calculation of a generic database of differential and integrated cross sections for the simulation of multiple elastic collisions of protons and neutrons with kinetic energies larger than 100 keV. The relativistic plane-wave Born approximation, with binding and Coulomb-deflection corrections, has been used to calculate a database of proton-impact ionization of K-shell and L-, M-, and N-subshells of neutral atoms These databases cover the whole energy range of interest for all the elements in the periodic system, from hydrogen to einsteinium (Z = 1–99); they are provided as part of the penh distribution package. The Monte Carlo code system penh for the simulation of coupled electron-photon-proton transport is extended to account for the effect of the transport of neutrons (released in proton-induced nuclear reactions) in calculations of dose distributions from proton beams. A simplified description of neutron transport, in which neutron-induced nuclear reactions are described as a fractionally absorbing process, is shown to give simulated depth-dose distributions in good agreement with those generated by the Geant4 code. The proton-impact ionization database, combined with the description of atomic relaxation data and electron transport in penelope, allows the simulation of proton-induced x-ray emission spectra from targets with complex geometries.Ministerio de Ciencia, Innovación y Universidades RTI2018-098117-B-C21, RTI2018-098117-BC2

Learning sequences of rules using classifier systems with tags

IEEE International Conference on Systems, Man, and Cybernetics. Tokyo, 12-15 October 1999.The objective of this paper was to obtain an encoding structure that would allow the genetic evolution of rules in such a manner that the number of rules and relationship in a classifier system (CS) would be learnt in the evolution process. For this purpose, an area that allows the definition of rule groups has been entered into the condition and message part of the encoded rules. This area is called internal tag. This term was coined because the system has some similarities with natural processes that take place in certain animal species, where the existence of tags allows them to communicate and recognize each other. Such CS is called a tag classifier system (TCS). The TCS has been tested in the game of draughts and compared with the classical CS. The results show an improving of the CS performance