Search results for "pattern"
showing 10 items of 4203 documents
Do Carbon Traders Behave as a Herd?
2017
Abstract This paper shows the existence of herding behavior in the European Carbon Futures Market and studies its possible causes and consequences. This market is characterized by leading the carbon price discovery process and by being highly dominated by professional traders. Both features make it an appropriate environment for the existence of herding. A patterns analysis indicates that the herding level increases in speculative periods, on those days on which the price and size clustering effect is stronger, and with the arrival of carbon-related news. Regarding possible market drivers, we find that herding behavior is positively related with the number of trades, the intraday volatility…
Survival causal patterns of social and commercial entrepreneurial initiatives in Spain
2021
This research aims at analysing the influence of a holistic configuration of factors related to industry and the characteristics of the entrepreneur and the business, on the survival of social and commercial entrepreneurial initiatives in both, new and consolidated companies. The sample ranges from 2,851 to 2,109 firms, according to the period considered, and has been obtained from the reports of the projects submitted to the Assistance Programme to Young Entrepreneurs, promoted by the Valencian Institute of Youth. Other sources of information have been the Institute’s own reports and the Chambers of Commerce. A configurational analysis is performed using the Fuzzy-Set Qualitative Comparati…
Nature in malls: Effects of a natural environment on the cognitive image, emotional response, and behaviors of visitors
2019
This study aims to assess the role of a natural environment and its effects on the following components of attitudes: cognitive image, affective response, and behavioral intentions. Using a survey conducted among 292 mall visitors, this study also examines how the perception of the atmosphere in a mall can indirectly affect behavioral intentions. The findings confirm that the components of cognitive image, namely, appealingly design features, may positively influence affective responses at malls. Affective response also positively impacts the behavioral intention of a mall visitor. Affective response features were found to be more powerful than the cognitive image and natural atmosphere att…
Eigenexpressions: Emotion Recognition Using Multiple Eigenspaces
2013
This paper presents an appearance-based holistic method for expression recognition. A two stage supervised learning approach is used. At the first stage, training images are used to compute one subspace per expression. At the second stage, the same images are used to train a classifier. In this step, Euclidean distances from each image to each particular subspace are used as the input to the classifier. The resulting system significantly outperforms the baseline eigenfaces method on the Cohn-Kanade data set, with performance gains in the range 10%-20%.
CNN based Gearbox Fault Diagnosis and Interpretation of Learning Features
2021
Machine learning based fault diagnosis schemes have been intensively proposed to deal with faults diagnosis of rotating machineries such as gearboxes, bearings, and electric motors. However, most of the machine learning algorithms used in fault diagnosis are pattern recognition tools, which can classify given data into two or more classes. The underlined physical phenomena in fault diagnosis are not directly interpretable in machine learning schemes, thus it is usually called black/gray box models. In this study, convolutional neural networks (CNN) machine learning algorithm is proposed to classify gearbox faults, and the learning features of the CNN filters are visualized to understand the…
Detection of Ventricular Fibrillation Using the Image from Time-Frequency Representation and Combined Classifiers without Feature Extraction
2018
Due the fact that the required therapy to treat Ventricular Fibrillation (V F) is aggressive (electric shock), the lack of a proper detection and recovering therapy could cause serious injuries to the patient or trigger a ventricular fibrillation, or even death. This work describes the development of an automatic diagnostic system for the detection of the occurrence of V F in real time by means of the time-frequency representation (T F R) image of the ECG. The main novelties are the use of the T F R image as input for a classification process, as well as the use of combined classifiers. The feature extraction stage is eliminated and, together with the use of specialized binary classifiers, …
Real-Time Localization of Epileptogenic Foci EEG Signals: An FPGA-Based Implementation
2020
The epileptogenic focus is a brain area that may be surgically removed to control of epileptic seizures. Locating it is an essential and crucial step prior to the surgical treatment. However, given the difficulty of determining the localization of this brain region responsible of the initial seizure discharge, many works have proposed machine learning methods for the automatic classification of focal and non-focal electroencephalographic (EEG) signals. These works use automatic classification as an analysis tool for helping neurosurgeons to identify focal areas off-line, out of surgery, during the processing of the huge amount of information collected during several days of patient monitori…
Computation of the field diffracted by a local surface defect: application to tip–sample interaction in the photon scanning tunneling microscope
1996
We use a method based on the Fourier transform of the electromagnetic field to compute the field diffracted by a local deformation of a plane boundary surface. We give a complete development of each step of the technique. To show the interaction that exists between the probe of a near-field optical microscope and the observed sample, we use the model of a truncated cone-shaped tip above a rectangular surface defect. We compute the electrical intensity along a line located between the tip and the local surface defect. We show the influence of the polarization of the incident wave and the effect of the position of the tip with respect to the position of the surface defect.
On the repeatability of the EMI for the monitoring of bonded joints
2015
We study the feasibility and the repeatability of the electromechanical impedance (EMI) method for the health monitoring of lightweight bonded joints. The EMI technique exploits the coupling between the displacement field and the potential field of a piezoelectric material, by attaching or embedding a piezoelectric transducer to the structure to be monitored. The sensor is excited by an external voltage and the electrical admittance which is the ratio between the electric current and the applied voltage is measured as it depends on the mechanical coupling between the transducer and the host structure. Owing to this interaction, the admittance may represent a signature for the health of the …
Size measuring techniques as tool to monitor pea proteins intramolecular crosslinking by transglutaminase treatment
2015
International audience; In this work, techniques for monitoring the intramolecular transglutaminase cross-links of pea proteins, based on protein size determination, were developed. Sodium dodecyl sulfate polyacrylamide gel electrophoresis profiles of transglutaminase-treated low concentration (0.01% w/w) pea albumin samples, compared to the untreated one (control), showed a higher electrophoretic migration of the major albumin fraction band (26 kDa), reflecting a decrease in protein size. This protein size decrease was confirmed, after DEAE column purification, by dynamic light scattering (DLS) where the hydrodynamic radius of treated samples appears to be reduced compared to the control o…