Search results for "Classification methods"
showing 10 items of 15 documents
Bacteria classification using minimal absent words
2017
Bacteria classification has been deeply investigated with different tools for many purposes, such as early diagnosis, metagenomics, phylogenetics. Classification methods based on ribosomal DNA sequences are considered a reference in this area. We present a new classificatier for bacteria species based on a dissimilarity measure of purely combinatorial nature. This measure is based on the notion of Minimal Absent Words, a combinatorial definition that recently found applications in bioinformatics. We can therefore incorporate this measure into a probabilistic neural network in order to classify bacteria species. Our approach is motivated by the fact that there is a vast literature on the com…
Gabor frames for classification of paroxysmal and persistent atrial fibrillation episodes
2016
[EN] In this study, we propose a new classification method for early differentiation of paroxysmal and persistent atrial fibrillation episodes, i.e. those which spontaneously or with external intervention will return to sinus rhythm within 7 days of onset from the ones where the arrhythmia is sustained for more than 7 days. Today, clinicians provide patients classification once the course of the arrhythmia has been disclosed. This classification problem is dealt with in this study. We study a sparse representation of surface electrocardiogram signals by means of Gabor frames and afterwards we apply a linear discriminant analysis. Thus, we provide an early discrimination, obtaining promising…
Functional connectivity of major depression disorder using ongoing EEG during music perception
2020
Abstract Objective The functional connectivity (FC) of major depression disorder (MDD) has not been well studied under naturalistic and continuous stimuli conditions. In this study, we investigated the frequency-specific FC of MDD patients exposed to conditions of music perception using ongoing electroencephalogram (EEG). Methods First, we applied the phase lag index (PLI) method to calculate the connectivity matrices and graph theory-based methods to measure the topology of brain networks across different frequency bands. Then, classification methods were adopted to identify the most discriminate frequency band for the diagnosis of MDD. Results During music perception, MDD patients exhibit…
Evaluation of Record Linkage Methods for Iterative Insertions
2009
Summary Objectives: There have been many developments and applications of mathematical methods in the context of record linkage as one area of interdisciplinary research efforts. However, comparative evaluations of record linkage methods are still underrepresented. In this paper improvements of the Fellegi-Sunter model are compared with other elaborated classification methods in order to direct further research endeavors to the most promising methodologies. Methods: The task of linking records can be viewed as a special form of object identification. We consider several non-stochastic methods and procedures for the record linkage task in addition to the Fellegi-Sunter model and perform an e…
A kernel support vector machine based technique for Crohnâs disease classification in human patients
2017
In this paper a new technique for classification of patients affected by Crohnâs disease (CD) is proposed. The proposed technique is based on a Kernel Support Vector Machine (KSVM) and it adopts a Stratified K-Fold Cross-Validation strategy to enhance the KSVM classifier reliability. Traditional manual classification methods require radiological expertise and they usually are very time-consuming. Accordingly to three expert radiologists, a dataset composed of 300 patients has been selected for KSVM training and validation. Each patient was codified by 22 extracted qualitative features and classified as Positive or Negative as the related histological specimen result showed the CD. The eff…
A new shape-oriented classification method for UV/VIS-spectra
1996
A new shape-oriented classification method is described. It is shown, how shapes of UV/VIS-spectra can be classified and coded and how a classification technique can be used to improve database search operations for pre-selections or even shape-oriented identifications.
Clasificación de usos del suelo a partir de imágenes Sentinel-2
2017
[EN] Sentinel-2 (S2), a new ESA satellite for Earth observation, accounts with 13 bands which provide high-quality radiometric images with an excellent spatial resolution (10 and 20 m) ideal for classification purposes. In this paper, two objectives have been addressed: to determine the best classification method for S2, and to quantify its improve-ment with respect to the SPOT operational mission. To do so, four classifiers (LDA, RF, Decision Trees, K-NN) have been selected and applied to two different agricultural areas located in Valencia (Spain) and Buenos Aires (Argentina). All classifiers were tested using, on the one hand, all the S2 bands and, on the other hand, only selecting those…
Early detection of mechanical damage in mango using NIR hyperspectral images and machine learning
2014
Mango fruit are sensitive and can easily develop brown spots after suffering mechanical stress during postharvest handling, transport and marketing. The manual inspection of this fruit used today cannot detect the damage in very early stages of maturity and to date no automatic tool capable of such detection has been developed, since current systems based on machine vision only detect very visible damage. The application of hyperspectral imaging to the postharvest quality inspection of fruit is relatively recent and research is still underway to find a method of estimating internal properties or detecting invisible damage. This work describes a new system to evaluate mechanically induced da…
Embryo classification method based in time-lapse analysis is associated with blastocyst quality
2012
groups: 87.7%(10434/11893), 87.4%(2674/3060), 80.2%(1350/1683) and 81.0%(634/783). Abnormal fertilization rate was significantly lower in 9598% group(6.9%,54/783) than other groups(16.1%,1918/11893; 13.8%,421/ 3060; 11.4%,192/1683). Good embryo, pregnancy and implantation rates were no significant differences among four groups(48.9%,61.6%,43.5%; 48.9%,62.1%,43.5%; 50.0%,57.6%,42.3%; 53.1%,62.5%,45.7%). CONCLUSION: Sperm morphology does not affect normal fertilization, embryonic development and clinical outcome.
Teacher Talk Patterns in Science Lessons: Use in Teacher Education
2006
This paper presents an innovative and useful methodology to analyze instructional talk. In teacher education, there is a lack of practical methods that the tutor teacher can use to discuss and reflect on student teachers’ lessons. The student teacher cannot remember what actually happened during the lesson, and the feedback and discussions are based on memory and are, therefore, unstructured. The purpose of this explorative and descriptive case study was to characterize the teacher talk used in the process of a teacher’s guidance of secondary school students’ acquisition of knowledge about physics. First, a classification method for classroom talk was developed. Then, using this method, the…