303 research outputs found
Position tracking of a varying number of sound sources with sliding permutation invariant training
Recent data- and learning-based sound source localization (SSL) methods have
shown strong performance in challenging acoustic scenarios. However, little
work has been done on adapting such methods to track consistently multiple
sources appearing and disappearing, as would occur in reality. In this paper,
we present a new training strategy for deep learning SSL models with a
straightforward implementation based on the mean squared error of the optimal
association between estimated and reference positions in the preceding time
frames. It optimizes the desired properties of a tracking system: handling a
time-varying number of sources and ordering localization estimates according to
their trajectories, minimizing identity switches (IDSs). Evaluation on
simulated data of multiple reverberant moving sources and on two model
architectures proves its effectiveness on reducing identity switches without
compromising frame-wise localization accuracy.Comment: Accepted for publication at the 31st European Signal Processing
Conference (EUSIPCO 2023
Music Boundary Detection using Convolutional Neural Networks: A comparative analysis of combined input features
The analysis of the structure of musical pieces is a task that remains a
challenge for Artificial Intelligence, especially in the field of Deep
Learning. It requires prior identification of structural boundaries of the
music pieces. This structural boundary analysis has recently been studied with
unsupervised methods and \textit{end-to-end} techniques such as Convolutional
Neural Networks (CNN) using Mel-Scaled Log-magnitude Spectograms features
(MLS), Self-Similarity Matrices (SSM) or Self-Similarity Lag Matrices (SSLM) as
inputs and trained with human annotations. Several studies have been published
divided into unsupervised and \textit{end-to-end} methods in which
pre-processing is done in different ways, using different distance metrics and
audio characteristics, so a generalized pre-processing method to compute model
inputs is missing. The objective of this work is to establish a general method
of pre-processing these inputs by comparing the inputs calculated from
different pooling strategies, distance metrics and audio characteristics, also
taking into account the computing time to obtain them. We also establish the
most effective combination of inputs to be delivered to the CNN in order to
establish the most efficient way to extract the limits of the structure of the
music pieces. With an adequate combination of input matrices and pooling
strategies we obtain a measurement accuracy of 0.411 that outperforms the
current one obtained under the same conditions
Direction of Arrival Estimation of Sound Sources Using Icosahedral CNNs
In this paper, we present a new model for Direction of Arrival (DOA)
estimation of sound sources based on an Icosahedral Convolutional Neural
Network (CNN) applied over SRP-PHAT power maps computed from the signals
received by a microphone array. This icosahedral CNN is equivariant to the 60
rotational symmetries of the icosahedron, which represent a good approximation
of the continuous space of spherical rotations, and can be implemented using
standard 2D convolutional layers, having a lower computational cost than most
of the spherical CNNs. In addition, instead of using fully connected layers
after the icosahedral convolutions, we propose a new soft-argmax function that
can be seen as a differentiable version of the argmax function and allows us to
solve the DOA estimation as a regression problem interpreting the output of the
convolutional layers as a probability distribution. We prove that using models
that fit the equivariances of the problem allows us to outperform other
state-of-the-art models with a lower computational cost and more robustness,
obtaining root mean square localization errors lower than 10{\deg} even in
scenarios with a reverberation time of 1.5 s.Comment: Submitted to IEEE/ACM Transactions on Audio Speech and Language
Processing. The code to reproduce this work can be found in our GitHub
repository: https://github.com/DavidDiazGuerra/icoDO
IDENTIFICACIÓN Y APROPIACIÓN DE LOS SIGNOS IDENTITARIOS DE LA MARCA BARRANQUILLA EN JÓVENES UNIVERSITARIOS
This study was born with the purpose of identifying in university students the most representative symbols of the city of Barranquilla. The communication method using the structured questionnaire technique is used, with which a perceptual map is constructed, using the multivariate multidimensional scaling technique with the support of the statistical software SPSS 25. It is observed that there are different patterns in the semiotics of the city that have an influence on the memories of young people, the foods, places and songs are an extension of the time with some cultural inheritances and with their own transformations. The signs identified form an inventory necessary for the construction of city brand communication policies focused on this segment.Este estudio nace con el propósito de identificar en jóvenes universitarios los símbolos más representativos de la ciudad de Barranquilla. Se emplea el método de comunicación mediante la técnica de cuestionario estructurado, con el cual, se construye un mapa perceptual, usando la técnica multivariada de escalamiento multidimensional con apoyo del software estadístico SPSS 25. Se observa que existen diferentes patrones en la semiótica de la ciudad que tienen injerencia en los recuerdos de los jóvenes, las comidas, lugares y canciones son una extensión de la época con algunas herencias culturales y con transformaciones propias. Los signos identificados forman un inventario necesario para la construcción de políticas de comunicación de marca ciudad enfocadas a este segmento
Differences in Respiratory Symptoms and Lung Structure Between Hispanic and Non-Hispanic White Smokers: A Comparative Study
Background: Prior studies have demonstrated that U.S. Hispanic
smokers have a lower risk of decline in lung function and
chronic obstructive pulmonary disease (COPD) compared with
non-Hispanic whites (NHW). This suggests there might be
racial-ethnic differences in susceptibility in cigarette
smoke-induced respiratory symptoms, lung parenchymal
destruction, and airway and vascular disease, as well as in
extra-pulmonary manifestations of COPD. Therefore, we aimed to
explore respiratory symptoms, lung function, and pulmonary and
extra-pulmonary structural changes in Hispanic and NHW smokers.
Methods: We compared respiratory symptoms, lung function, and
computed tomography (CT) measures of emphysema-like tissue,
airway disease, the branching generation number (BGN) to reach a
2-mm-lumen-diameter airway, and vascular pruning as well as
muscle and fat mass between 39 Hispanic and 39 sex-, age- and
smoking exposure-matched NHW smokers. Results: Hispanic smokers
had higher odds of dyspnea than NHW after adjustment for COPD
and asthma statuses (odds ratio[OR] = 2.96; 95% confidence
interval [CI] 1.09-8.04), but no significant differences were
found in lung function and CT measurements. Conclusions: While
lung function and CT measures of the lung structure were
similar, dyspnea is reported more frequently by Hispanic than
matched-NHW smokers. It seems to be an impossible puzzle but
it's easy to solve a Rubik' Cube using a few algorithms
The effect of intra-articular injection of autologous bone marrow stem cells on pain and knee function in patients with osteoarthritis
Abstract Aim: Management of osteoarthritis (OA) is basically symptomatic. Recently, stem cells (SC) have been used in the search for an optimum treatment. We decided to conduct a controlled clinical trial to determine if a single intra-articular injection of in vivo stimulated bone marrow SC could lead to an improvement in pain management and quality of life in patients with knee OA. Method: This was a prospective, open-label, phase I/II clinical trial to assess the safety and efficacy of a single intra-articular injection of autologous stimulated bone marrow stem cells (BM-SC) in patients with knee OA. Individuals of both genders older than 30 years with confirmed diagnosis of OA who signed informed consent were included in two groups: SC group received in vivo BM stimulation with subcutaneous administration of granulocyte colony stimulating factor (G-CSF). SC were obtained by BM aspiration and administered in a single intra-articular injection. The control group received exclusively oral acetaminophen. Visual analogue scale and Western Ontario and McMaster Universities Osteoarthritis Index scores were performed at 1 week, 1 month and 6 months in both groups. This trial was registered in ClinialTrials.gov NCT01485198. Results: A total of 61 patients were included. Socio-demographic characteristics, OA grades and initial scores were similar in both groups. The BM-SC group showed significant improvement in knee pain and quality of life during the 6-month follow-up. Conclusion: The study demonstrates feasibility and supports efficacy of a completely ambulatory procedure in treatment of knee OA. Key words: bone marrow, knee osteoarthritis, stem cells
Modelos de redes cristalográficas
En este trabajo se aborda el diseño y la construcción de modelos de las cinco redes planas (oblicua, rectangular, rómbica, cuadrada y hexagonal) sobre los que se pueden situar sus elementos de simetría (ejes de rotación, planos de simetría y planos de deslizamiento).
Estos modelos son desmontables, de tal modo que los profesores y estudiantes pueden construir paso a paso cada una de las cinco redes planas y localizar sus elementos de simetría. Estas redes, una vez montadas, pueden apilarse en la dirección vertical para construir las catorce Redes de Bravais
The sole DNA ligase in entamoeba histolytica is a high-fidelity DNA ligase involved in DNA damage repair
"The protozoan parasite Entamoeba histolytica is exposed to reactive oxygen and nitric oxide species that have the potential to damage its genome. E. histolytica harbors enzymes involved in DNA repair pathways like Base and Nucleotide Excision Repair. The majority of DNA repairs pathways converge in their final step in which a DNA ligase seals the DNA nicks. In contrast to other eukaryotes, the genome of E. histolyticaencodes only one DNA ligase (EhDNAligI), suggesting that this ligase is involved in both DNA replication and DNA repair. Therefore, the aim of this work was to characterize EhDNAligI, its ligation fidelity and its ability to ligate opposite DNA mismatches and oxidative DNA lesions, and to study its expression changes and localization during and after recovery from UV and H2O2 treatment. We found that EhDNAligI is a high-fidelity DNA ligase on canonical substrates and is able to discriminate erroneous base-pairing opposite DNA lesions. EhDNAligI expression decreases after DNA damage induced by UV and H2O2 treatments, but it was upregulated during recovery time. Upon oxidative DNA damage, EhDNAligI relocates into the nucleus where it co-localizes with EhPCNA and the 8-oxoG adduct. The appearance and disappearance of 8-oxoG during and after both treatments suggest that DNA damaged was efficiently repaired because the mainly NER and BER components are expressed in this parasite and some of them were modulated after DNA insults. All these data disclose the relevance of EhDNAligI as a specialized and unique ligase in E. histolytica that may be involved in DNA repair of the 8-oxoG lesions.
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