44 research outputs found
A Machine Learning Approach to Reveal the NeuroPhenotypes of Autisms
This work was partly supported by the MINECO Under the TEC2015-64718-R Project, the Salvador de Madariaga Mobility Grants 2017 and the Consejería de Economía, Innovación, Ciencia y Empleo (Junta de Andalucía, Spain) under the Excellence Project P11-TIC-7103. The study was conducted in association with the National Institute for Health Research Collaborations for Leadership in Applied Health Research and Care (NIHR CLAHRC) East of England (EoE). The Project was supported by the UK Medical Research Council (Grant No. GO 400061) and European Autism Interventions — a Multicentre Study for Developing New Medications (EU-AIMS); EU-AIMS has received support from the Innovative Medicines Initiative Joint Undertaking Under Grant Agreement No. 115300, resources of which are composed of financial contribution from the European Union’s Seventh Framework Programme (FP7/2007–2013) and EFPIA companies’ in-kind contribution. During the period of this work, M-CL was supported by the OBrien Scholars Program in the Child and Youth Mental Health Collaborative at the Centre for Addiction and Mental Health (CAMH) and The Hospital for Sick Children, Toronto, the Academic Scholar Award from the Department of Psychiatry, University of Toronto, the Slaight Family Child and Youth Mental Health Innovation Fund, CAMH Foundation, and the Ontario Brain Institute via the Province of Ontario Neurodevelopmental Disorders (POND) Network; MVL was supported by the British Academy, Jesus College Cambridge, Wellcome Trust, and an ERC Starting Grant (ERC-2017-STG; 755816); SB-C was supported by the Autism Research Trust. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health, UK.Although much research has been undertaken, the spatial patterns, developmental course, and sexual dimorphism of brain structure associated with autism remains enigmatic. One of the difficulties in investigating differences between the sexes in autism is the small sample sizes of available imaging datasets with mixed sex. Thus, the majority of the investigations have involved male samples, with females somewhat overlooked. This paper deploys machine learning on partial least squares feature extraction to reveal differences in regional brain structure between individuals with autism and typically developing participants. A four-class classification problem (sex and condition) is specified, with theoretical restrictions based on the evaluation of a novel upper bound in the resubstitution estimate. These conditions were imposed on the classifier complexity and feature space dimension to assure generalizable results from the training set to test samples. Accuracies above 80% on gray and white matter tissues estimated from voxel-based morphometry (VBM) features are obtained in a sample of equal-sized high-functioning male and female adults with and without autism (N=120, n=30/group). The proposed learning machine revealed how autism is modulated by biological sex using a low-dimensional feature space extracted from VBM. In addition, a spatial overlap analysis on reference maps partially corroborated predictions of the “extreme male brain” theory of autism, in sexual dimorphic areas.This work was partly supported by the MINECO Under the TEC2015-64718-R Project, the Salvador de Madariaga Mobility Grants 2017 and the Consejería de Economía, Innovación, Ciencia y Empleo (Junta de Andalucía, Spain) under the Excellence Project P11-TIC-7103The Project was supported by the UK Medical Research Council (Grant No. GO 400061) and European Autism Interventions — a Multicentre Study for Developing New Medications (EU-AIMS)EU-AIMS has received support from the Innovative Medicines Initiative Joint Undertaking Under Grant Agreement No. 115300MVL was supported by the British Academy, Jesus College Cambridge, Wellcome Trust, and an ERC Starting Grant (ERC-2017-STG; 755816
Cortical and subcortical contributions to state- and strength-based perceptual judgments
peer reviewe
A Connection Between Pattern Classification by Machine Learning and Statistical Inference With the General Linear Model
A connection between the general linear
model (GLM) with frequentist statistical testing and machine
learning (MLE) inference is derived and illustrated.
Initially, the estimation of GLM parameters is expressed as
a Linear Regression Model (LRM) of an indicator matrix;
that is, in terms of the inverse problem of regressing the
observations. Both approaches, i.e. GLM and LRM, apply to
different domains, the observation and the label domains,
and are linked by a normalization value in the least-squares
solution. Subsequently, we derive a more refined predictive
statistical test: the linear Support Vector Machine (SVM),
that maximizes the class margin of separation within a
permutation analysis. This MLE-based inference employs
a residual score and associated upper bound to compute a
better estimation of the actual (real) error. Experimental results
demonstrate how parameter estimations derived from
each model result in different classification performance in
the equivalent inverse problem. Moreover, using real data,
the MLE-based inference including model-free estimators
demonstrates an efficient trade-off between type I errors
and statistical power.Ministerio de Ciencia e Innovacion (Espana)/FEDER RTI2018-098913B100Junta de AndaluciaEuropean Commission CV20-45250
A-TIC-080-UGR18
P20-00525National Health and Medical Research Council (NHMRC) of Australia 18/0490
Robust Ensemble Classification Methodology for I123-Ioflupane SPECT Images and Multiple Heterogeneous Biomarkers in the Diagnosis of Parkinson’s Disease
In last years, several approaches to develop an effective Computer-Aided-Diagnosis
(CAD) system for Parkinson’s Disease (PD) have been proposed. Most of these methods
have focused almost exclusively on brain images through the use of Machine-Learning
algorithms suitable to characterize structural or functional patterns. Those patterns
provide enough information about the status and/or the progression at intermediate
and advanced stages of Parkinson’s Disease. Nevertheless this information could be
insufficient at early stages of the pathology. The Parkinson’s ProgressionMarkers Initiative
(PPMI) database includes neurological images along with multiple biomedical tests.
This information opens up the possibility of comparing different biomarker classification
results. As data come from heterogeneous sources, it is expected that we could include
some of these biomarkers in order to obtain new information about the pathology. Based
on that idea, this work presents an Ensemble Classification model with Performance
Weighting. This proposal has been tested comparing Healthy Control subjects (HC)
vs. patients with PD (considering both PD and SWEDD labeled subjects as the same
class). This model combines several Support-Vector-Machine (SVM) with linear kernel
classifiers for different biomedical group of tests—including CerebroSpinal Fluid (CSF),
RNA, and Serum tests—and pre-processed neuroimages features (Voxels-As-Features
and a list of definedMorphological Features) fromPPMI database subjects. The proposed
methodology makes use of all data sources and selects the most discriminant features
(mainly from neuroimages). Using this performance-weighted ensemble classification
model, classification results up to 96% were obtained.This work was supported by the MINECO/FEDER under
the TEC2015-64718-R project and the Ministry of Economy,
Innovation, Science and Employment of the Junta de Andalucía
under the Excellence Project P11-TIC-7103
Aplicación del marco COBIT 2019 en procesos asociados a la generación de información financiera y cumplimientos tributarios y aduaneros de empresas distribuidoras de adhesivos y lubricantes automotrices del departamento de La Libertad.
El trabajo se concibe a través de la necesidad de mejoras continuas que desafían a las empresas con la utilización de herramientas tecnológicas, las cuales se han vuelto un recurso estratégico para toda organización, posicionándose en niveles de competencia más aceptados, encaminando sus procesos a mejorar la eficiencia con el objetivo de generar valor en el trabajo de gestión y gobierno de la empresa. El presente trabajo le apuesta a optimizar la mejora de los procesos en las áreas financiera, tributaria y aduanera, mediante la implementación de la metodología COBIT 2019. Con ello se busca mejorar en los procesos analíticos para el contador y la comunicación con los demás departamentos. La metodología utilizada en el estudio permitió obtener conocimiento sobre la estructura y la necesidad de mejora en los procesos de algunas áreas. La herramienta utilizada fue la entrevista mediante una guía de preguntas. Los resultados obtenidos se materializa en la optimización del tiempo, el cual se logra mediante la automatización de procesos recomendados en las actividades de COBIT 2019, en sus objetivos APO12 Gestionar el Riesgo y APO13 Gestionar la Seguridad. Se determinó que la metodología COBIT 2019 posee una serie de actividades que pueden aplicarse a una serie de procesos de un área específica. La ventaja de estas actividades es que se van actualizando a medida surgen oportunidades de mejora generadas por las nuevas tecnologías
Connected system for monitoring electrical power transformers using thermal imaging
The stable supply of electricity is essential for the industrial activity and economic development as well as for human
welfare. For this reason, electrical system devices are equipped with monitoring systems that facilitate their management and
ensure an uninterrupted operation. This is the case of electrical power transformers, which usually have monitoring systems that
allow early detection of anomalies in order to prevent potential malfunctions. These monitoring systems typically make use of
sensors that are in physical contact with the transformer devices and can therefore be affected by transformer problems.
In this work we demonstrate a monitoring system for electrical power transformers based on temperature measurements
obtained by means of thermal cameras. Properly positioned, the cameras provide thermal data of the transformer, the incoming and
outgoing lines and their surroundings. Subsequently, by appropriate image processing, it is possible to obtain temperature series
to monitor the transformer operation. In addition, the system stores and processes thermal data in external equipment (placed
in locations other than the transformers) and is equipped with a communications module that allows secure data transmission
independent of the power grid. This aspect, along with the fact that there is no need to have physical contact with the transformer,
make this approach safer and more reliable than standard approaches based on sensors. The proposed system has been evaluated in
14 stations belonging to the Spanish power grid, obtaining accurate and reliable temperature time seriesConsejería de
Economía, Innovación, Ciencia y Empleo (Junta de
Andalucía)FEDER under B-TIC-586-UGR20P20-00525 projects and by the University of GranadaEndesa Distribución under the PASTORA (ref.
EXP – 00111351/ITC-20181102)RESISTO (ref.
2021/C005/00144188) contract
Ensemble of random forests One vs. Rest classifiers for MCI and AD prediction using ANOVA cortical and subcortical feature selection and partial least squares.
Background: Alzheimer’s disease (AD) is the most common cause of dementia in the elderly and affects approximately 30 million individuals worldwide. Mild cognitive impairment (MCI) is very frequently a prodromal phase of AD, and existing studies have suggested that people with MCI tend to progress to AD at a rate of about 10 % to 15 % per year. However, the ability of clinicians and machine learning systems to predict AD based on MRI biomarkers at an early stage is still a challenging problem that can have a great impact in improving treatments. Method: The proposed system, developed by the SiPBA-UGR team for this challenge, is based on feature standardization, ANOVA feature selection, partial least squares feature dimension reduction and an ensemble of one vs. rest random forest classifiers. With the aim of improving its performance when discriminating healthy controls (HC) from MCI, a second binary classification level was introduced that reconsiders the HC and MCI predictions of the first level. Results: The system was trained and evaluated on an ADNI datasets that consist of T1-weighted MRI morphological measurements from HC, stable MCI, converter MCI and AD subjects. The proposed system yields a 56.25 % classification score on the test subset which consists of 160 real subjects. Comparison with Existing Method(s): The classifier yielded the best performance when compared to: i) One vs. One (OvO), One vs. Rest (OvR) and error correcting output codes (ECOC) as strategies for reducing the multiclass classification task to multiple binary classification problems, ii) support vector machines, gradient boosting classifier and random forest as base binary classifiers, and iii) bagging ensemble learning. Conclusions: A robust method has been proposed for the international challenge on MCI prediction based on MRI data.This work was supported by the MINECO/FEDER under TEC2015-64718-R project, the Consejería de Economía, Innovacion, Ciencia, y Empleo of the Junta de Andalucía under the P11-TIC-7103 Excellence Project and the Salvador de Madariaga Mobility Grants 2017
Assisted Diagnosis of Parkinsonism Based on the Striatal Morphology
Parkinsonism is a clinical syndrome characterized by the progressive loss of striatal dopamine. Its diagnosis
is usually corroborated by neuroimaging data such as DaTSCAN neuroimages that allow visualizing
the possible dopamine deficiency. During the last decade, a number of computer systems have been
proposed to automatically analyze DaTSCAN neuroimages, eliminating the subjectivity inherent to the
visual examination of the data. In this work, we propose a computer system based on machine learning
to separate Parkinsonian patients and control subjects using the size and shape of the striatal region,
modeled from DaTSCAN data. First, an algorithm based on adaptative thresholding is used to parcel
the striatum. This region is then divided into two according to the brain hemisphere division and characterized
with 152 measures, extracted from the volume and its three possible 2-dimensional projections.
Afterwards, the Bhattacharyya distance is used to discard the least discriminative measures and, finally,
the neuroimage category is estimated by means of a Support Vector Machine classifier. This method was
evaluated using a dataset with 189 DaTSCAN neuroimages, obtaining an accuracy rate over 94%. This
rate outperforms those obtained by previous approaches that use the intensity of each striatal voxel as
a feature.This work was supported by the MINECO/
FEDER under the TEC2015-64718-R project, the
Ministry of Economy, Innovation, Science and
Employment of the Junta de Andaluc´ıa under the
P11-TIC-7103 Excellence Project and the Vicerectorate
of Research and Knowledge Transfer of the
University of Granada
Using CT Data to Improve the Quantitative Analysis of 18F-FBB PET Neuroimages
18F-FBB PET is a neuroimaging modality that is been increasingly used to assess
brain amyloid deposits in potential patients with Alzheimer’s disease (AD). In this work,
we analyze the usefulness of these data to distinguish between AD and non-AD
patients. A dataset with 18F-FBB PET brain images from 94 subjects diagnosed with
AD and other disorders was evaluated by means of multiple analyses based on t-test,
ANOVA, Fisher Discriminant Analysis and Support Vector Machine (SVM) classification.
In addition, we propose to calculate amyloid standardized uptake values (SUVs) using
only gray-matter voxels, which can be estimated using Computed Tomography (CT)
images. This approach allows assessing potential brain amyloid deposits along with the
gray matter loss and takes advantage of the structural information provided by most of
the scanners used for PET examination, which allow simultaneous PET and CT data
acquisition. The results obtained in this work suggest that SUVs calculated according to
the proposed method allow AD and non-AD subjects to be more accurately differentiated
than using SUVs calculated with standard approaches.This work was supported by the MINECO/FEDER under
the TEC2012-34306 and TEC2015-64718-R projects and the
Ministry of Economy, Innovation, Science and Employment of
the Junta de Andalucía under the Excellence Project P11-TIC-
7103. The work was also supported by the Vicerectorate of
Research and Knowledge Transfer of the University of Granada
Granger Causality-based Information Fusion Applied to Electrical Measurements from Power Transformers.
In the immediate future, with the increasing presence of electrical vehicles and the large increase in the use of renewable energies, it will be crucial that distribution power networks are managed, supervised and exploited in a similar way as the transmission power systems were in previous decades. To achieve this, the underlying infrastructure requires automated monitoring and digitization, including smart-meters, wide-band communication systems, electronic device based-local controllers, and the Internet of Things. All of these technologies demand a huge amount of data to be curated, processed, interpreted and fused with the aim of real-time predictive control and supervision of medium/low voltage transformer substations. Wiener–Granger causality, a statistical notion of causal inference based on Information Fusion could help in the prediction of electrical behaviour arising from common causal dependencies. Originally developed in econometrics, it has successfully been applied to several fields of research such as the neurosciences and is applicable to time series data whereby cause precedes effect. In this paper, we demonstrate the potential of this methodology in the context of power measures for providing theoretical models of low/medium power transformers. Up to our knowledge, the proposed method in this context is the first attempt to build a data-driven power system model based on G-causality. In particular, we analysed directed functional connectivity of electrical measures providing a statistical description of observed responses, and identified the causal structure within data in an exploratory analysis. Pair-wise conditional G-causality of power transformers, their independent evolution in time, and the joint evolution in time and frequency are discussed and analysed in the experimental section.This work was partly supported by the MINECO/ FEDER under the RTI2018-
098913-B100 project. The authors would like to acknowledge the support of
370 CDTI (Centro para el Desarrollo Tecnologico Industrial, Ministerio de Cien cia, Innovacion y Universidades and FEDER, SPAIN) under the PASTORA
project (Ref.: ITC-20181102). and to thank the companies within the PAS TORA consortium: Endesa, Ayesa, Ormaz´abal and Ingelectus. We would like
to thank the reviewers for their thoughtful comments and efforts towards im 375 proving our manuscript. Finally, JM Gorriz would like to thank Dr G´omez Exp´osito for his helpful advice and comments