R. Monteiro, C. Bastos-Filho, M. Cerrada, Diego Cabrera, Réne-Vinicio Sánchez
{"title":"Using the Kullback-Leibler Divergence and Kolmogorov-Smirnov Test to Select Input Sizes to the Fault Diagnosis Problem Based on a CNN Model","authors":"R. Monteiro, C. Bastos-Filho, M. Cerrada, Diego Cabrera, Réne-Vinicio Sánchez","doi":"10.21528/LNLM-VOL18-NO2-ART2","DOIUrl":"https://doi.org/10.21528/LNLM-VOL18-NO2-ART2","url":null,"abstract":"Choosing a suitable size for signal representations, e.g., frequency spectra, in a given machine learning problem is not a trivial task. It may strongly affect the performance of the trained models. Many solutions have been proposed to solve this problem. Most of them rely on designing an optimized input or selecting the most suitable input according to an exhaustive search. In this work, we used the Kullback-Leibler Divergence and the Kolmogorov-Smirnov Test to measure the dissimilarity among signal representations belonging to equal and different classes, i.e., we measured the intraclass and interclass dissimilarities. Moreover, we analyzed how this information relates to the classifier performance. The results suggested that both the interclass and intraclass dissimilarities were related to the model accuracy since they indicate how easy a model can learn discriminative information from the input data. The highest ratios between the average interclass and intraclass dissimilarities were related to the most accurate classifiers. We can use this information to select a suitable input size to train the classification model. The approach was tested on two data sets related to the fault diagnosis of reciprocating compressors.","PeriodicalId":386768,"journal":{"name":"Learning and Nonlinear Models","volume":"1044 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113995608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lídio Mauro Lima de Campos, J. H. A. Pereira, Danilo Souza Duarte, R. C. L. Oliveira
{"title":"Evolving deep neural networks for Time Series Forecasting","authors":"Lídio Mauro Lima de Campos, J. H. A. Pereira, Danilo Souza Duarte, R. C. L. Oliveira","doi":"10.21528/LNLM-VOL18-NO2-ART4","DOIUrl":"https://doi.org/10.21528/LNLM-VOL18-NO2-ART4","url":null,"abstract":"The aim of this paper is to introduce a biologically inspired approach that can automatically generate Deep Neural networks with good prediction capacity, smaller error and large tolerance to noises. In order to do this, three biological paradigms were used: Genetic Algorithm (GA), Lindenmayer System and Neural Networks (DNNs). The final sections of the paper present some experiments aimed at investigating the possibilities of the method in the forecast the price of energy in the Brazilian market. The proposed model considers a multi-step ahead price prediction (12, 24, and 36 weeks ahead). The results for MLP and LSTM networks show a good ability to predict peaks and satisfactory accuracy according to error measures comparing with other methods.","PeriodicalId":386768,"journal":{"name":"Learning and Nonlinear Models","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122995184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Romero, M. Gutoski, L. T. Hattori, Manassés Ribeiro, H. S. Lopes
{"title":"A Study of the Influence of Data Complexity and Similarity on Soft Biometrics Classification Performance in a Transfer Learning Scenario","authors":"M. Romero, M. Gutoski, L. T. Hattori, Manassés Ribeiro, H. S. Lopes","doi":"10.21528/LNLM-VOL18-NO2-ART5","DOIUrl":"https://doi.org/10.21528/LNLM-VOL18-NO2-ART5","url":null,"abstract":"Transfer learning is a paradigm that consists in training and testing classifiers with datasets drawn from distinct distributions. This technique allows to solve a particular problem using a model that was trained for another purpose. In the recent years, this practice has become very popular due to the increase of public available pre-trained models that can be fine-tuned to be applied in different scenarios. However, the relationship between the datasets used for training the model and the test data is usually not addressed, specially where the fine-tuning process is done only for the fully connected layers of a Convolutional Neural Network with pre-trained weights. This work presents a study regarding the relationship between the datasets used in a transfer learning process in terms of the performance achieved by models complexities and similarities. For this purpose, we fine-tune the final layer of Convolutional Neural Networks with pre-trained weights using diverse soft biometrics datasets. An evaluation of the performances of the models, when tested with datasets that are different from the one used for training the model, is presented. Complexity and similarity metrics are also used to perform the evaluation.","PeriodicalId":386768,"journal":{"name":"Learning and Nonlinear Models","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134299758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Silva, L. Araújo, Victor F. Souza, Raimundo Matos Barros Neto, Adam Santos
{"title":"Comparative Analysis of Convolutional Neural Networks Applied in the Detection of Pneumonia Through X-Ray Images of Children","authors":"L. Silva, L. Araújo, Victor F. Souza, Raimundo Matos Barros Neto, Adam Santos","doi":"10.21528/LNLM-VOL18-NO2-ART1","DOIUrl":"https://doi.org/10.21528/LNLM-VOL18-NO2-ART1","url":null,"abstract":"Pneumonia is one of the most common medical problems in clinical practice and is the leading fatal infectious disease worldwide. According to the World Health Organization, pneumonia kills about 2 million children under the age of 5 and is constantly estimated to be the leading cause of infant mortality, killing more children than AIDS, malaria, and measles combined. A key element in the diagnosis is radiographic data, as chest x-rays are routinely obtained as a standard of care and can aid to differentiate the types of pneumonia. However, a rapid radiological interpretation of images is not always available, particularly in places with few resources, where childhood pneumonia has the highest incidence and mortality rates. As an alternative, the application of deep learning techniques for the classification of medical images has grown considerably in recent years. This study presents five implementations of convolutional neural networks (CNNs): ResNet50, VGG-16, InceptionV3, InceptionResNetV2, and ResNeXt50. To support the diagnosis of the disease, these CNNs were applied to solve the classification problem of medical radiographs from people with pneumonia. InceptionResNetV2 obtained the best recall and precision results for the Normal and Pneumonia classes, 93.95% and 97.52% respectively. ResNeXt50 achieved the best precision and f1-score results for the Normal class (94.62% and 94.25% respectively) and the recall and f1-score results for the Pneumonia class (97.80% and 97.65%, respectively).","PeriodicalId":386768,"journal":{"name":"Learning and Nonlinear Models","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122189230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Michel Costa, Vanessa Castro Rezende, Cledisson Martins, Adam Santos
{"title":"Methodology for Classifying Diseases in Plants Using Convolutional Neural Networks","authors":"Michel Costa, Vanessa Castro Rezende, Cledisson Martins, Adam Santos","doi":"10.21528/LNLM-VOL18-NO2-ART3","DOIUrl":"https://doi.org/10.21528/LNLM-VOL18-NO2-ART3","url":null,"abstract":"Convolutional neural networks (CNNs) are one of the deep learning techniques that, due to the computational advance of the last few years, have leveraged the area of computer vision, allowing substantial gains in the most varied classification problems, especially those involving digital images. In this context, this paper aims to propose a methodology for the classification of multiple pathologies related to different plant species. Initially, this methodology involved the image processing and the generation of ten new databases, varying between 50 and 66 classes with greater representation. After training the models (VGG16, RestNet101v1, ResNet101v2, ResNetXt50, and DenseNet169), a comparative study was conducted based on widely used classification metrics, such as test accuracy, f1-score, and area under the curve. To attest the significance of the results, Friedman’s nonparametric statistical test and two post-hoc procedures were performed, which demonstrated that ResNetXt50 and DenseNet169 obtained superior performances when compared with VGG16 and ResNets.","PeriodicalId":386768,"journal":{"name":"Learning and Nonlinear Models","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124618795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Improving Prototypes Representativeness by Internal Validity Index Analysis","authors":"Alexandre Szabo, Thomaz A. Ruckl","doi":"10.21528/lnlm-vol19-no1-art1","DOIUrl":"https://doi.org/10.21528/lnlm-vol19-no1-art1","url":null,"abstract":"Internal validity indexes are applied to evaluate the solution of a partition, which no equally reflects the same quality for all clusters, individually, in terms of prototypes representativeness. Thus, knowing their representativeness in respective clusters, it is possible adjust them to increase the confidence in analysis of found clusters. In this sense, this paper proposes a simple and effective method to obtain the internal validity index value in every cluster in a partition, identify those with low prototypes representativeness and improve them. Experiments were carried out by sum of the squared error index, which measures the compactness of clusters. The behavior of the method was illustrated by a synthetic dataset and performed for ten datasets from the literature with k-Means algorithm. The results demonstrated its effectiveness for all experiments.","PeriodicalId":386768,"journal":{"name":"Learning and Nonlinear Models","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125956281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Carteiras de Black Litterman com Análises Baseadas em Redes Neurais","authors":"Diego Guerreiro Bernardes, O. L. Costa","doi":"10.21528/LNLM-VOL18-NO1-ART5","DOIUrl":"https://doi.org/10.21528/LNLM-VOL18-NO1-ART5","url":null,"abstract":"This paper presents an autonomous portfolio management system. Autonomous investment systems consist of a series of buy and sell rules on financial markets, which can be executed by machines, oriented to maximizing investor gains. The system uses a Neural Network approach for monitoring the market and the Black-Litterman model for portfolio composition. The ten most traded assets from the Bovespa Index are analyzed, with dedicated neural networks, which suggests future return estimates using technical indicators as input. Those estimates are inserted in the Black-Litterman model which proposes daily portfolio composition using long and short positions. The results are compared to a second autonomous trading system without the Black-Litterman approach, referred to as Benchmark. The numerical results show a great performance compared to the Benchmark, especially the risk-return ratio, captured by the Sharpe Index. Such results suggest that the use of Bayesian inference models combined with neural networks may be a good alternative in portfolio management.","PeriodicalId":386768,"journal":{"name":"Learning and Nonlinear Models","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132774823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Aerial Human Activity Recognition Through a Cognitive Architecture and a New Automata Proposal","authors":"M. Pinto, Aurelio G. Melo, A. Marcato, C. Moraes","doi":"10.21528/lnlm-vol18-no1-art1","DOIUrl":"https://doi.org/10.21528/lnlm-vol18-no1-art1","url":null,"abstract":"Video surveillance often involves several actors in multiple interactions and modelling complex activities becomes a challenge, especially in real environments. When applying autonomous video surveillance, object recognition techniques are used to produce symbolic information related to the information present in a scene. An automaton is a specialized structure capable of accepting or rejecting those symbols producing an efficient computation structure for these types of data processing. This research work presents an innovative structure for the well-known Weighted Automata to organize the information from sensors, grouping these measurements into a symbolic representation of actions that are happening in the real world. This work also proposes a hierarchical architecture formed by a multilevel sensorial system comprised of low, middle and high levels to perceive the environment and to comprehend scenes. The proposed architecture is designed to operate in a decentralized way and onboard of the Unmanned Aerial Vehicles (UAVs). The experiments showed that this system updated effectively the semantic structure given the sequence of information and demonstrated the automaton and architecture effectiveness..","PeriodicalId":386768,"journal":{"name":"Learning and Nonlinear Models","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134310767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rafael M. Carmo, Luís Tarrataca, J. Colares, F. Henriques, D. B. Haddad, Raphael M. Guedes
{"title":"Distributed Adaptive Filtering on Wireless Sensor Networks with Shared Medium Competition","authors":"Rafael M. Carmo, Luís Tarrataca, J. Colares, F. Henriques, D. B. Haddad, Raphael M. Guedes","doi":"10.21528/lnlm-vol18-no1-art2","DOIUrl":"https://doi.org/10.21528/lnlm-vol18-no1-art2","url":null,"abstract":"Wireless Sensor Networks (WSN) are of significant importance with increasingly diverse and viable applications. They gained even more traction after the IEEE 802.15.4 standard was defined. Distributed adaptive filtering algorithms have added statistical inference to WSN applications, employing techniques that extract data from distributed devices. In contrast, most adaptive filtering contributions do not consider realistic features of the subjacent telecommunications network protocols. Similarly, the telecommunications area typically does not take into account interesting abilities of adaptive filtering algorithms. In this paper, we explore this gap between the two study areas, allowing the development of network-protocol-aware distributed adaptive filtering techniques. In order to explore network realistic behaviors, this paper focuses on distributed inference problems. More specifically, we propose two new diffuse adaptive algorithms, aware of the characteristics of the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol, namely: (i) Variant Reuse of Coefficients Least Mean Squares (VRCLMS) algorithm; and the (ii) Reuse of Coefficients Least Mean Squares (RC-LMS) algorithm in the Adapt-Then-Combine (ATC) modality. These two new algorithms will bring some advantages, specifically when information is delayed because of too much packet loss. Another advantage will be the addition of the spatial information diversity contribution in the VRC-LMS algorithm.","PeriodicalId":386768,"journal":{"name":"Learning and Nonlinear Models","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130136574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Romero, M. Gutoski, L. T. Hattori, Manassés Ribeiro, H. S. Lopes
{"title":"Soft Biometrics Classication in Videos Using Transfer Learning and Bidirectional Long Short-Term Memory Networks","authors":"M. Romero, M. Gutoski, L. T. Hattori, Manassés Ribeiro, H. S. Lopes","doi":"10.21528/lnlm-vol18-no1-art4","DOIUrl":"https://doi.org/10.21528/lnlm-vol18-no1-art4","url":null,"abstract":"","PeriodicalId":386768,"journal":{"name":"Learning and Nonlinear Models","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126793027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}