1,747 research outputs found
Solving Sudoku with Membrane Computing
Sudoku is a very popular puzzle which consists on
placing several numbers in a squared grid according to some
simple rules. In this paper we present an efficient family of P
systems which solve sudokus of any order verifying a specific
property. The solution is searched by using a simple human-style
method. If the sudoku cannot be solved by using this strategy, the
P system detects this drawback and then the computations stops
and returns No. Otherwise, the P system encodes the solution
and returns Yes in the last computation step.Ministerio de Ciencia e Innovación TIN2008-04487-EMinisterio de Ciencia e Innovación TIN2009–13192Junta de Andalucía P08-TIC-0420
Investment option under CIR interest rates
We analyze extensively the characteristics of the solution to an irreversible investment decision when the only source of uncertainty comes from interest rates. They are assumed to be driven by the popular Cox–Ingersoll–Ross (CIR) stochastic process. Particular attention is paid to the impact that both CIR parameters and risk aversion have on the threshold rate.Financial support from the Spanish Ministry of Education and Science through the grant SEJ 2005-09372 (Leon) and SEJ 2004-05815 (Carmona) is gratefully acknowledged
Pandemic effects in the Solow growth model
We show how diseases can affect economic growth in a Solow growth model, with population growth and no technical progress, but modified to include a saving rate that depends on the individual health status. We successively insert this model into the SIS (susceptible–infected–susceptible) and SIR (susceptible–infected–recovered) models of disease spreading. In these two models, the spread of the infection proceeds according to the so-called basic reproductive number. This number determines in which of the two possible equilibria, the disease-free or the pandemic equilibrium, the economy ends. We show that output per capita is always lower in the pandemic steady state, which implies a contraction in the economy's production possibilities frontier.Julio Carmona acknowledges the financial support from the Spanish Ministerio de Economía y Competitividad, through the project ECO2016-77200-P. Ángel León acknowledges the financial support from the Spanish Ministerio de Economía y Competitividad, through grant PID2021-124860NB-I00
Robust people detection by fusion of evidence from multiple methods
Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. V. Fernández-Carbajales, M. A. García, and J. M. Martínez, "Robust People Detection by Fusion of Evidence from Multiple Methods", in Ninth International Workshop on Image Analysis for Multimedia Interactive Services, 2008. WIAMIS 2008, p. 55-58.This paper describes and evaluates an algorithm for real-time people detection in video sequences based on the fusion of evidence provided by three simple independent people detectors. Experiments with real video sequences show that the proposed integration-based approach is effective, robust and fast by combining simple algorithms.This work is supported by Cátedra Infoglobal-UAM
para “Nuevas tecnologías de vídeo aplicadas a la
seguridad”, the Spanish Government (TEC2007-
65400 SemanticVideo) and the Comunidad de Madrid
(S-050/TIC-0223 - ProMultiDis-CM)
El estado actual de la investigación sobre la congruencia persona-ambiente. Propuesta de aplicación de un diseño experimental
En el presente trabajo se hace una revisión del estado actual de la investigación sobre
la congruencia persona-ambiente, analizando los principales problemas conceptuales
y metodológicos que existen en esta línea de investigación, así como las críticas que
recibe uno de los modelos más representativos del momento: el modelo de la elección
vocacional de Holland. Según este autor, los individuos suelen elegir profesiones que
son congruentes con sus características personales, y este ajuste tiene repercusiones
positivas tanto para el rendimiento como para la satisfacción en el trabajo. Además,
existen otros modelos que han sido propuestos desde diferentes perspectivas (el estrés
laboral, socialización laboral, ajuste laboral...). Teniendo en cuenta los inconvenientes
que presentan la mayoría de los estudios empíricos realizados, se plantea la posibilidad
de abordar el tema desde el paradigma experimental sugiriendo un diseño que permite
solventar, o al menos minimizar, dichos problemas.The aim of this paper is to review the present state of the person-environment
congruence research. We analyze the main conceptual and methodological problems
that this research have and the cristicisms that one of the most representative model
receives: Holland’s vocational choices model. This author suggests that the individuals
tend to choose occupations that are congruent with their personal characteristics, and
that this fi t (or adjustment) has positive implications both for the performance and job satisfaction. On the other hand, models from other approaches have also been proposed
(work stress, work socialization, laboral fi t (or adjustment...). Taking into account the
inconvenients that most of these kind of studies have, the possibility of start on this
subject from an experimental paradigm suggesting a design that may solve or reduce
these problems is proposed
Long-Term Drug Misuse Increases the Risk of Cognitive Dysfunctions in Intimate Partner Violence Perpetrators: Key Intervention Targets for Reducing Dropout and Reoffending
Intimate partner violence against women (IPVAW) is a major public health problem, with an important mortality rate in women across the world. In this regard, it has been well-established that drug misuse explains (at least in part) an increased risk of IPVAW perpetration. Even though alcohol is the most widely studied drug underlying IPVAW, other drugs, such as cannabis and cocaine also seem to be significant indicators of this type of violence. Nonetheless, little is known about mediators, such as cognitive domains that facilitate proneness to violence after drug consumption. Therefore, the primary objective of the present study was to compare drug misuse patterns and cognitive performance in a carefully selected sample of IPVAW perpetrators (n = 63) and a group of non-violent men (control group; n = 39). Second, we also aimed to study the association between different patterns of drug misuse and cognitive performance and several facets of IPVAW perpetration (i.e., severity of injuries and type of aggression). Our results revealed that IPVAW perpetrators showed considerably higher levels of sustained drug misuse (alcohol, cannabis, cocaine, and heroin) for years and worse cognitive performance than controls. Moreover, the highest drug misuse sustained over time was related to the worst cognitive performance and the highest IPVAW severity. Finally, alcohol and cocaine seemed to be related to IPVAW and risk of reo ending. Whereas, cannabis, heroin, and MDMA were related to the existence of a previous criminal record (delinquency without violence). Hence, research in this field would help to develop coadjutant treatments and intervention packages to reduce drug misuse in the initial stages, which in turn would reduce cognitive impairments in IPVAW perpetrators. These expected improvements migh
Pricing executive stock optons under employment shocks
We obtain explicit expressions for the subjective, objective and market value of perpetual executive stock options (ESOs) under exogenous employment shocks driven by an independent Poisson process. Previously, we obtain the executive's optimal exercise policy from the subjective valuation that is necessary for the objective one, or fair value. The perpetual ESO is compared with the true finite maturity ESO finding that the approximation is reasonably good. To illustrate the usefulness of the objective valuation for accounting purposes, we analyze the statistical distribution of the fair value when there is uncertainty about the employment shock intensity. Finally, the role of ESOs in the design of executives’ incentives is also discussed.Spanish Ministry for Science and Innovation through the Grant SEJ 2004-05815; Spanish Ministry for Science and Innovation through the Grant ECO2008-02599/ECO; Spanish Ministry for Science and Innovation through the Grant ECO2010-18567
Enzymatic deinking of secondary fibers: cellulases/hemicellulases versus laccase-mediator system
The use of enzymes has been suggested as an environmentally-friendly alternative to complement conventional chemical deinking in the recycling of recovered paper. This study compares the use of carbohydrate hydrolases versus laccase-mediator system for deinking printed fibers from newspapers and magazines. For this purpose, two commercial enzyme preparations with endoglucanase and endoxylanase activities (Viscozyme Wheat from Aspergillus oryzae and Ultraflo L from Humicola insolens) and a commercial laccase NS51002 from Trametes villosa), the latter in the presence of synthetic or natural (lignin related) mediators, were evaluated. The enzymatic treatments were studied at laboratory scale, using a standard chemical deinking sequence consisting of pulping, alkaline deinking and peroxide bleaching stages. Then, handsheets were prepared and their brightness, residual ink concentration, and strength properties were measured. Among the different enzymatic treatments assayed, both carbohydrate hydrolases were found to deink the secondary fibers more efficiently. Brightness increased up to 3-4% ISO on newspaper fibers, being Ultraflo 20% more efficient in the ink removal. Up to 2.5% ISO brightness increase was obtained when magazine fibers were used, being Viscozyme 9% more efficient in the ink removal. As regards laccase-mediator system, alone or combined with carbohydrate hydrolases, it was ineffective deinking both newspaper and magazine fibers, resulting in pulps with worse brightness and residual ink concentration values. However, pulp deinking by laccase-mediator system was displayed when secondary fibers rich in lignin, i.e. printed cardboard, were used, obtaining up to 3% ISO brightness increase and lower residual ink concentrations
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