María Dolores Esteban(University Miguel Hernández of Elche), María José Lombardía (University of A Coruña), Esther López-Vizcaíno ( Galician Institute of Statistics), Domingo Morales (University Miguel Hernández of Elche) and Agustín Pérez (University Miguel Hernández of Elche).
Abstract. This paper introduces area-level compositional mixed models by applying transformations to a multivariate Fay–Herriot model. Small area estimators of the proportions of the categories of a classification variable are derived from the new model, and the corresponding mean squared errors are estimated by parametric bootstrap. Several simulation experiments designed to analyse the behaviour of the introduced estimators are carried out. An application to real data from the Spanish Labour Force Survey of Galicia (north-west of Spain), in the first quarter of 2017, is given. The target is the estimation of domain proportions of people in the four categories of the variable labour status: under 16 years, employed, unemployed and inactive.
Keywords. Labour Force Survey; Area-level models; Compositional data; Bootstrap; Labour status,
Jenny Morales (Universidad Autónoma de Chile), Cristian Rusu (Universidad Católica de Valparaíso), Federico Botella (University Miguel Hernández of Elche) and Daniela Quiñones (Universidad Católica de Valparaíso)
Abstract. Programmers use various software development artifacts in their work, such as programming environments, design documents, and programming codes. These software artifacts can be studied and improved based on usability and User eXperience (UX) factors. In this paper, we consider programmers to be a specic case of users and analyze different elements that inuence their experience in this specic context. We conducted a systematic literature review of papers published over the last ten years related to 1) the denition of the Programmer eXperience (PX); 2) the PX, UX, and usability factors regarding the programming environments, design documents, and programming codes; and 3) sets of heuristics to evaluate the software development artifacts mentioned before.We analyzed 73 articles, and the results obtained show that: 1) the important elements that inuence the PX are the motivation of programmers and the choice of tools they use in their work, such as programming environments; 2) most of the identied studies (59%) aimed to evaluate the inuence of the PX, UX, and usability on programming environments; 3) the majority of the studies (70%) used methods such as usability tests and/or heuristic evaluation methods; and 4) four sets of heuristics are used to evaluate software development artifacts in relation to programming environments, programming languages, and application programming interfaces. The results suggest that further research in this area is necessary to better understand and evaluate the concept of the PX.
Keywords. Heuristic evaluation; Programmer eXperience; systematic literature review; User eXperience; usability.
Domingo Morales (University Miguel Hernández of Elche).
Tomás Caballero (The University of Sevilla), José A. Langa(University of Sevilla) and José Valero (University Miguel Hernández of Elche).
Abstract.In this paper we establish a strong comparison principle for a nonautonomous differential inclusion with a forcing term of Heaviside type. Using this principle, we study the structure of the global attractor in both the autonomous and nonautonomous cases. In particular, in the last case we prove that the pullback attractor is confined between two special bounded complete trajectories, which play the role of nonautonomous equilibria.
Keywords. Differential inclusions; Reaction–diffusion equations; Pullback attractors; Nonautonomous dynamical systems; Multivalued dynamical systems; Structure; Comparison of solutions.
Yoshito Hirata (The University of Tokyo and University of Tsukuba), Masanori Shiro (University National Institute of Advanced Industrial Science and Technology, Japan) and José M. Amigó (University Miguel Hernández of Elche).
Abstract. We propose a method for generating surrogate data that preserves all the properties of ordinal patterns up to a certain length, such as the numbers of allowed/forbidden ordinal patterns and transition likelihoods from ordinal patterns into others. The null hypothesis is that the details of the underlying dynamics do not matter beyond the refinements of ordinal patterns finer than a predefined length. The proposed surrogate data help construct a test of determinism that is free from the common linearity assumption for a null-hypothesis…
Keywords. Time series analysis; determinism; Museum pass games; stochasticity; permutations; hypothesis testing.
Javier Alcaraz (University Miguel Hernández of Elche), Mercedes Landete (University Miguel Hernández of Elche), Juan F. Monge (University Miguel Hernández of Elche) and José L. Sainz-Pardo (University Miguel Hernández of Elche).
Abstract. Some location problems with unreliable facilities present two different objectives, one consisting of minimizing the opening and transportation costs if none of the facilities fail and another consisting of minimizing the expected transportation costs. Usually, these different targets are combined in a single objective function and the decision maker can obtain some different solutions weighting both objectives. However, if the decision maker prefers to obtain a diverse set of non-dominated optimal solutions, then such procedure would not be effective. We have designed and implemented two multi-objective evolutionary algorithms for the realibility fixed-charge location problem by exploiting the peculiarities of this problem in order to obtain sets of solutions that are properly distributed along the Pareto-optimal frontier. The computational results demonstrate the outstanding efficiency of the proposed algorithms, although they present clear differences.
Keywords. Location; Multi-objective location problems; Reliability models; Pareto frontier; Multi-objective evolutionary algorithms; Metaheuristics.