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1.
J Acoust Soc Am ; 149(1): 508, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33514128

RESUMO

The goal of this research is to find a way of highlighting the acoustic differences between consonant phonemes of the Polish and Lithuanian languages. For this purpose, similarity matrices are employed based on speech acoustic parameters combined with a convolutional neural network (CNN). In the first experiment, we compare the effectiveness of the similarity matrices applied to discerning acoustic differences between consonant phonemes of the Polish and Lithuanian languages. The similarity matrices built on both an extensive set of parameters and a reduced set after removing high-correlated parameters are used. The results show that higher accuracy is obtained by the similarity matrices without discarding high-correlated parameters. In the second experiment, the averaged accuracies of the similarity matrices obtained are compared with the results provided by spectrograms combined with CNN, as well as the results of the vectors containing acoustic parameters and two baseline classifiers, namely k-nearest neighbors and support vector machine. The performance of the similarity matrix approach demonstrates its superiority over the methods used for comparison.


Assuntos
Idioma , Redes Neurais de Computação , Máquina de Vetores de Suporte , Acústica , Fonética
2.
Sensors (Basel) ; 19(17)2019 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-31480449

RESUMO

The automated identification system of vessel movements receives a huge amount of multivariate, heterogeneous sensor data, which should be analyzed to make a proper and timely decision on vessel movements. The large number of vessels makes it difficult and time-consuming to detect abnormalities, thus rapid response algorithms should be developed for a decision support system to identify abnormal movements of vessels in areas of heavy traffic. This paper extends the previous study on a self-organizing map application for processing of sensor stream data received by the maritime automated identification system. The more data about the vessel's movement is registered and submitted to the algorithm, the higher the accuracy of the algorithm should be. However, the task cannot be guaranteed without using an effective retraining strategy with respect to precision and data processing time. In addition, retraining ensures the integration of the latest vessel movement data, which reflects the actual conditions and context. With a view to maintaining the quality of the results of the algorithm, data batching strategies for the neural network retraining to detect anomalies in streaming maritime traffic data were investigated. The effectiveness of strategies in terms of modeling precision and the data processing time were estimated on real sensor data. The obtained results show that the neural network retraining time can be shortened by half while the sensitivity and precision only change slightly.

3.
Sci Rep ; 11(1): 15474, 2021 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-34326378

RESUMO

Within the tumor microenvironment, specifically aligned collagen has been shown to stimulate tumor progression by directing the migration of metastatic cells along its structural framework. Tumor-associated collagen signatures (TACS) have been linked to breast cancer patient outcome. Robust and affordable methods for assessing biological information contained in collagen architecture need to be developed. We have developed a novel artificial neural network (ANN) based approach for tumor collagen segmentation from bright-field histology images and have tested it on a set of tissue microarray sections from early hormone receptor-positive invasive ductal breast carcinoma stained with Sirius Red (1 core per patient, n = 92). We designed and trained ANNs on sets of differently annotated image patches to segment collagen fibers and extracted 37 features of collagen fiber morphometry, density, orientation, texture, and fractal characteristics in the entire cohort. Independent instances of ANN models trained on highly differing annotations produced reasonably concordant collagen segmentation masks and allowed reliable prognostic Cox regression models (with likelihood ratios 14.11-22.99, at p-value < 0.05) superior to conventional clinical parameters (size of the primary tumor (T), regional lymph node status (N), histological grade (G), and patient age). Additionally, we noted statistically significant differences of collagen features between tumor grade groups, and the factor analysis revealed features resembling the TACS concept. Our proposed method offers collagen framework segmentation from bright-field histology images and provides novel image-based features for better breast cancer patient prognostication.


Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/mortalidade , Carcinoma Ductal de Mama/metabolismo , Carcinoma Ductal de Mama/mortalidade , Colágeno/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/metabolismo , Mama/patologia , Colágeno/química , Diagnóstico por Imagem , Matriz Extracelular/patologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Pessoa de Meia-Idade , Neoplasias/metabolismo , Redes Neurais de Computação , Prognóstico , Modelos de Riscos Proporcionais , Resultado do Tratamento , Microambiente Tumoral
4.
Medicina (Kaunas) ; 45(3): 221-5, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19357452

RESUMO

Thermography is a relatively new contact-free method used in experimental and clinical studies and in cardiovascular surgery to investigate the myocardium and coronary artery function. Objects of complex study included mongrel dogs and patients with coronary artery disease who underwent cardiac surgery. For active dynamic thermography, we used a thermovision camera "A20V" (FLIR Systems, USA). Our data indicate that both experimental and clinical study performed on beating hearts could be an important approach to interoperation inspection of autovenous graft function. An infrared camera also can be successfully used to determine the extent of ischemic damage to the myocardium, heart, and blood vessels during surgery as a significant prognostic tool for evaluating outcome after cardiac operation.


Assuntos
Temperatura Corporal , Procedimentos Cirúrgicos Cardíacos , Ponte de Artéria Coronária , Vasos Coronários/cirurgia , Isquemia Miocárdica/diagnóstico , Termografia , Animais , Ponte Cardiopulmonar , Ponte de Artéria Coronária/métodos , Cães , Feminino , Parada Cardíaca Induzida , Humanos , Ligadura , Masculino , Prognóstico , Transplante Autólogo , Resultado do Tratamento , Veias/transplante
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