Miguel A. Fernández

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Miguel verified their affiliation via an institutional email.

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• Ph.D. in Mathematics
• Catedrático de Universidad at University of Valladolid

The need for airtightness control is a reality given its impact on buildings’ energy use and IAQ. For the past few years, this fact has resulted in energy performance regulations being established in many countries in Europe and North America. However, compliance proof is not always required, and on-site testing is often avoided. In this sense, pre...

The need for airtightness control is a reality given its impact on buildings' energy use and Indoor Air Quality (IAQ). For the past few years, this fact has resulted in energy performance regulations establishment that involves airtightness requirements in many countries in Europe and North America. In this sense, efforts should not only be focused...

This paper examines how company board characteristics (directors’ quoted boards to date, quoted boards currently, board tenure and age) influence firm performance in a sample of Spanish listed companies for the period 2005–2015. Among the main contributions of the paper are that it analyses the boards of companies operating under a Continental, as...

This study aims to characterize locations on two-way rural roads where head-on crashes are more likely to occur, attending to geometric road design factors. For this purpose, a case-control study was carried out using multiple logistic regression models with variables related to road design parameters, considering several scenarios. The dataset cor...

A proper diagnosis of the state of an induction motor is of great interest to industry given the great importance of the extended use of this motor. Presently, the use of this motor driven by a frequency converter is very widespread. However, operation by means of an inverter introduces certain difficulties for a correct diagnosis, which results in...

In many real classification problems a monotone relation between some predictors and the classes may be assumed when higher (or lower) values of those predictors are related to higher levels of the response. In this paper, we propose new boosting algorithms, based on LogitBoost, that incorporate this isotonicity information, yielding more accurate...

Objective Single vehicle run-off crashes in urban areas constitute a growing problem that deserves more attention from authorities and researchers. This study aims to detect geometric road design risk factors characterizing places where urban run-off crashes might happen. Methods A case-control study was performed in the urban area of Valladolid (...

Purpose The purpose of this paper is to investigate the effect of board diversity on firm performance. Design/methodology/approach From different theories perspective and based on data collected about the composition of board of directors in Spanish non-financial firms, the paper determines statistically the relationship between board diversity an...

Data derived from microarray technologies are generally subject to various sources of noise and accordingly the raw data are pre-processed before formally analysed. Data normalization is a key pre-processing step when dealing with microarray experiments, such as circadian gene-expressions, since it removes systematic variations across arrays. A wid...

Objective Metal Road Safety Barriers (MRSB) are one of the devices implemented in roadsides to mitigate the consequences of run-off crashes. In Europe, they have to meet the requirements of the European Standard EN-1317-2. This article analyzes a set of run-off crashes against MRSB, for which an in-depth investigation has been performed, comparing...

S1 File contains the data on the real crashes considered in the paper. (PDF)

Motivation: Gene-expression data obtained from high throughput technologies are subject to various sources of noise and accordingly the raw data are pre-processed before formally analyzed. Normalization of the data is a key pre-processing step, since it removes systematic variations across arrays. There are numerous normalization methods available...

A considerable amount of papers have been published in recent years proposing supervised classifiers to diagnose the health of a machine. The usual procedure with these classifiers is to train them using data acquired through controlled experiments, expecting them to perform well on new data, classifying correctly the condition of a motor. But, obv...

Motivation Many biological processes, such as cell cycle, circadian clock, menstrual cycles, are governed by oscillatory systems consisting of numerous components that exhibit rhythmic patterns over time. It is not always easy to identify such rhythmic components. For example, it is a challenging problem to identify circadian genes in a given tissu...

Analyze the utility of a mobile health app named HeartKeeper in several groups of population and obtain conclusions to be applied to other similar apps. A questionnaire has been designed to evaluate the usage and utility of the HeartKeeper app. The questionnaire information was collected by collaborating cardiologists from 32 patients before and af...

The aim of circular order aggregation is to find a circular order on a set of n items using angular values from p heterogeneous data sets. This problem is new in the literature and has been motivated by the biological question of finding the order among the peak expression of a group of cell cycle genes. In this paper, two very different approaches...

Applications of circular regression models appear in many different fields such as evolutionary psychology, motor behavior, biology, and, in particular, in the analysis of gene expressions in oscillatory systems. Specifically, for the gene expression problem, a researcher may be interested in modeling the relationship among the phases of cell-cycle...

In recent years, mass spectrometry techniques have helped proteomics to become a powerful tool for the early diagnosis of cancer, as they help to discover protein profiles specific to each pathological state. One of the questions where proteomics is giving useful practical results is that of classifying patients into one of the possible severity le...

In this chapter, some problems related to oscillatory data are considered. We describe methodology to solve the problem of estimation of angular parameters under order constraints as well as how to make inferences under circular restrictions in von Mises models. Another interesting problem that is dealt in this chapter is the estimation of a common...

This paper proposes a methodology that provides a tool to support decisions in the monitoring of electrical energy consumption. The purpose is to help the manager of a set of non-residential buildings, such as, for example, factories, hospitals or university buildings, to objectively compare the energetic performance of all the installations under...

The incorporation of additional information into discriminant rules is receiving in- creasing attention as the rules including this information perform better than the usual rules. In this paper we introduce an R package called dawai, which provides the functions that allow to define the rules that take into account this additional information expr...

Oscillatory systems in biology are tightly regulated process where the individual components (e.g. genes) express in an orderly manner by virtue of their functions. The temporal order among the components of an oscillatory system may potentially be disrupted for various reasons (e.g. environmental factors). As a result some components of the system...

Abstract Classification rules that incorporate additional information usually present in discrimination problems are receiving certain attention during the last years as they perform better than the usual rules. Fernández, M. A., C. Rueda and B. Salvador (2006): "Incorporating additional information to normal linear discriminant rules," J. Am. Stat...

In many applications one may be interested in drawing inferences regarding the order of a collection of points on a unit circle. Due to the underlying geometry of the circle standard constrained inference procedures developed for Euclidean space data are not applicable. Recently, statistical inference for parameters under such order constraints on...

This paper presents a procedure for broken rotor bar diagnosis in induction motors based in data extracted from stator current, which is calculated in the time and frequency domains. Data comes from a tested motor fed by different types of supply: direct line and two different Voltage Source Inverters. Diagnosis is always difficult in Voltage Sourc...

In many applications, especially in cancer treatment and diagnosis, investigators are interested in classifying patients into various diagnosis groups on the basis of molecular data such as gene expression or proteomic data. Often, some of the diagnosis groups are known to be related to higher or lower values of some of the predictors. The standard...

A cell division cycle is a well-coordinated process in eukaryotes with cell cycle genes exhibiting a periodic expression over time. There is considerable interest among cell biologists to determine genes that are periodic in multiple organisms and whether such genes are also evolutionarily conserved in their relative order of time to peak expressio...

We propose and discuss improved classification rules when a subset of the predictors is known to be ordered. We compare the performance of the new rules with other standard rules in a restricted normal setting using simulation experiments and real data exposing their good performance.

Electricity demand forecasting is important for utilities and for some costumers. It allows to balance energy production and consumption. From the costumer point of view, it is essential for efficient operation, sizing of installation, maintenance scheduling, to name just a few. Load forecasting is a difficult task and there are many tools availabl...

This paper proposes a methodology to determine the optimum maintenance frequencies for the components of an electric railway overhead contact line system. This methodology is aimed at improving the reliability and availability of each component within its operational context and calculates the maintenance frequencies according to the criticality of...

In this article, a new methodology to determine the criticality of the components of the overhead contact line (OCL) system by means of a component criticality index is proposed. The methodology is based on classic failure mode and effects analysis (FMEA) but adapted to its application on this system, with characteristics far from industrial system...

We propose and discuss improved Bayes rules to discriminate between two populations using ordered predictors. To address the problem we propose an alternative formulation using a latent space that allows to introduce the information about the order in the theoretical rules. The rules are first defined when the marginal densities are fully known and...

Motivated by a problem encountered in the analysis of cell cycle gene expression data, this article deals with the estimation of parameters subject to order restrictions on a unit circle. A normal eukaryotic cell cycle has four major phases during cell division, and a cell cycle gene has its peak expression (phase angle) during the phase that may c...

Nowadays it is quite usual that systems are correctly maintained. This leads to a decreasing number of failures for the system. In this paper we discuss how to establish warning procedures that take into account features giving the chance of detecting eventual changes of trend in the systems and allowing taking measures before too much damage has a...

The discrimination problem for two normal populations with the same covariance matrix when additional information on the population is available is considered. A study of the robustness properties against training sample contamination of classification rules that incorporate this additional information is performed. These rules have received recent...

The most useful and broadly known rule in the classical two-group linear normal discriminant analysis is Anderson's rule. In this article we propose some alternative procedures that prove useful when prior constraints on the mean vectors are known. These rules are based on new estimators of the difference of means. We prove under mild conditions th...

In this paper, we consider classification procedures for exponential populations when an order on the populations parameters is known. We define and study the behavior of a classification rule which takes into account the additional information and outperforms the likelihood-ratio-based rule when two populations are considered. Moreover, we study t...

The Duane plot is a simple and widely used graphical technique in the analysis of repairable systems. The fitting of a straight line to points in that graph serves to determine the behavior of the system assuming a power law process. However, the classical least squares fitting suffer from lack of robustness and it is specially heavily affected by...

This study develops a systematic analysis of the concentration and inequality levels of 20 Spanish industries over the period 1990-2001. The methodology traced is based on the use of indices both for evaluating the inequality (Gini,MRD&Coefficient of Variation), and for studying the concentration (Herfindahl-Hirchman, Theil & Hannah-Kay). This arti...

The authors consider the estimation of linear functions of a multivariate parameter under orthant restrictions. These restrictions are considered both for location models and for the Poisson distribution. For these models, situations are characterized for which the restricted maximum likelihood estimator dominates the unrestricted one for the estim...

This article is motivated by the problem of estimating contrast in a one-way ANOVA model with restrictions in the parameter vector. We prove that when the restrictions are given by a tree order or a simple order the MLE of some contrast has greater MSE than the unrestricted estimator. A similar behaviour of the MLE is exhibited in a general restric...

We consider a random vector X with unimodal density, diagonal covariance matrix, Ω−1, and location parameter θ subject to order restrictions. For this model the maximum likelihood estimator (MLE) X∗ is the so-called isotonic regression. It is well known that, in certain situations, X∗ is not better than X when coordinate estimation is considered. W...

We consider a linear normal modelY=X[theta]+ewith[theta]verifying a linear restriction and the standard estimators [theta](unrestricted MLE) and[theta]* (restricted MLE). We prove that[theta]* is preferable to [theta]using a new and strong criterion which implies the domination under other usual criteria; in particular it is proven that the standar...

Summary We consider a normal model with known diagonal covariance matrix and a vector of means constrained to belong to a polyhedral cone. The standard estimatorsX (unrestricted MLE) andX * (restricted MLE) are compared for estimation of several components of the parameter simultaneously. We show thatX * is preferred toX under several conditions.

We consider random samples from independent uniform populations U(0, θ i ) where the parameters θ i follow a known partial order. The aim of this paper is to compare the restricted and the unrestricted MLE using the universal domination and the squared error criterions when linear functions of the parameter are estimated. We determine functions for...

Esta tesis se enmarca en la Inferencia Estadística bajo restricciones. Esta rama de la Estadística apareció en la mitad de los años 50 e incluye un conjunto de técnicas diseñadas para hacer frente a la información adicional que a menudo se tiene sobre los parámetros desconocidos relevantes de un modelo estadístico. Ha habido avances significativos...

Trabajo de investigación donde se analiza la relación entre el uso, diversificación e innovación tecnológica con el desarrollo económico regional de Castilla y León, España; para ello, los autores revisan asuntos de globalización, el papel de la universidad en el desarrollo tecnológico, el fenómeno de los parques tecnológicos, el sistema de innovac...