28 research outputs found

    Auscultación de presas y su aplicación al estudio de gradientes hidráulicos

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    Las características morfológicas de la Presa de Las Fitas, presa de materiales sueltos con núcleo de arcilla. Así como las propias del terreno en que se ubica (compuesto por un sustrato terciario dominado por argilitas y limolitas con paquetes intercalados de arenisca de pequeño espesor), obliga a tener controladas en todo momento las filtraciones de agua a través del cimiento de la presa. Para ello se disponen de una serie de elementos de auscultación que de modo continuo están recogiendo información, tanto del cuerpo de presa como de sus interacciones con distintos elementos del contorno. En base a los datos de necesario control para prevenir y salvaguardar la integridad de la presa, se diseñaron unas secciones tipo con la distinta instrumentación que se requería. Del mismo modo, aguas abajo y fuera del cuerpo de presa, se disponen aforadores que permiten controlar las filtraciones a través de la cerrada. Con el análisis de los datos de esta instrumentación, especialmente en la fase de puesta en carga, se obtienen una serie de conclusiones que van a condicionar la futura explotación del embalse

    Sostenibilidad del proyecto de regulación y modernización del canal de Terreu

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    El sistema de Riegos del Alto Aragón, con fuentes de suministro muy distantes de la zona regable, obliga a largas conducciones que dificultan el suministro de agua a las demandas reales de las zonas, tanto en lo referente al caudal como a la regulación del mismo. El Canal de Terreu con una longitud total de 49,220 Km pertenece al Sistema de Riegos del Alto Aragón, tiene su origen en el Canal del Cinca del que deriva su caudal actual, dominando una superficie de 25.101 hectáreas de regadío con una dotación de 0,67 l/s/Ha. En la gestión interna del Sistema de Riegos del Alto Aragón es común la regulación con embalses de los principales canales, tal y como sucede en la cola del canal del Cinca (Embalse de Valdabra) o en el Canal del Flumen (Embalse del Torrollón

    Early detection of peritoneal dialysis complications through convolutional neural networks

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    La diálisis peritoneal es una alternativa para pacientes con insuficiencia renal crónica, que requiere el análisis periódico del líquido resultante para la detección precoz de complicaciones. Dicho análisis implica la evaluación directa del líquido bajo microscopio y una posterior prueba bioquímica. Como alternativa, el líquido podría analizarse a través de una fotografía (evaluación indirecta) lo que permitiría detectar precozmente una posible complicación, sin que el paciente deba acercarse a un centro de nefrología, mejorando sustancialmente su calidad de vida. En [Comas et al., XX Congreso Argentino de Bioingeniería, pp. 477–486 (2015)] se estudió preliminarmente la detección de muestras patológicas del líquido a partir de fotografías, utilizando descriptores de color y el clasificador k-vecinos más próximos. En el presente trabajo, se presenta un método basado en redes neuronales convolucionales, partiendo de la Alexnet y utilizando transfer learning. La fase de clasificación se implementó con un perceptrón multicapa, clasificando las fotografías entre “normal” y “patológica”, con el resultado de la prueba bioquímica como Gold-standard. Se obtuvo una tasa de error de 5,79%, una FPR de 4,21% y una FNR de 7,37%, con gran estabilidad, reflejada en bajas desviaciones estándar en la estimación de las medidas de error. El método propuesto es más robusto que el enfoque previo, sin requerir ningún tipo de preprocesamiento, ni extracción de características, siendo un buen punto de partida para el desarrollo de una herramienta automática con adecuada capacidad de soporte al diagnóstico.Peritoneal dialysis is an alternative for patients with chronic renal failure requiring periodic analysis of the resulting liquid for the early detection of complications, which involves a direct evaluation of the liquid under a microscope and a biochemical test. Alternatively, the liquid could be analyzed through a photograph (indirect evaluation), enabling the early detection of complications, without requiring the patient going to a nephrology center, improving their life quality. In [Comas et al., XX Congreso Argentino de Bioingeniería, pp. 477–486 (2015)], detection of pathological samples of the liquid from photographs was preliminary studied using color descriptors and k-nearest neighbors as classifier. In the present paper, a method based on convolutional neural networks is presented, starting from Alexnet and using transfer learning. The classification phase was implemented with a multilayer perceptron, classifying the photographs between “normal” and “pathological”, using the biochemical test as Gold-standard. An error rate of 5.79%, a FPR of 4.21% and a FNR of 7.37% were obtained with great stability, reflected in low standard deviations in the estimation of the error measures. The proposed method is more robust than the previous approach, without requiring any preprocessing or feature extraction, being a good starting point for the development of an automatic tool with adequate diagnostic capacity.Fil: Comas, Diego Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Científicas y Tecnológicas en Electrónica. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones Científicas y Tecnológicas en Electrónica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Meschino, Gustavo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Científicas y Tecnológicas en Electrónica. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones Científicas y Tecnológicas en Electrónica; ArgentinaFil: Ballarin, Virginia Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Científicas y Tecnológicas en Electrónica. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones Científicas y Tecnológicas en Electrónica; ArgentinaFil: Jerónimo Aguilera Díaz. Hospital Italiano; ArgentinaFil: Musso, Carlos. Hospital Italiano; ArgentinaFil: Rivera, Héctor. Hospital Italiano; ArgentinaFil: Plazzotta, Fernando. Hospital Italiano; ArgentinaFil: Algranati, Luis. Hospital Italiano; ArgentinaFil: Luna, Daniel. Hospital Italiano; Argentin

    Impact of the implementation of best practice guidelines on nurse's evidence-based practice and on nurses' work environment: research protocol

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    Abstract Aim: To determine the impact of the Best Practice Spotlight Organization® initia- tive on nurses' perception of their work environment and their attitudes to evidence- based practice. Design: Quasi-experimental, multicentre study. The intervention is the participation in Best Prectice Spotilight Organizations to implement Best Practice Guidelines. Methods: The study will include seven centres in the interventional group and 10 in the non-equivalent control group, all of them belonging to the Spanish national health system. The Practice Environment Scale of the Nursing Work Index, and the Health Sciences Evidence-Based Practice Questionnaire will be administered to a sample of 1,572 nurses at the beginning of the programme and at 1 year. This 3-year study started in April 2018 and will continue until December 2021. Statistical analy- ses will be carried out using the SPSS 25.0. This project was approved by the Drug Research Ethics Committee of the Parc de Salut Mar and registered in Clinical Trials. Discussion: The study findings will show the current state of nurses' perception of their work environment and attitudes to evidence-based practice, and possible changes in these parameters due to the programme. Impact: The findings could provide a strong argument for health policymakers to scale up the Best Practice Spotlight Organization® initiative in the Spanish national health system

    Aligned ovine diaphragmatic myoblasts overexpressing human connexin-43 seeded on poly (L-lactic acid) scaffolds for potential use in cardiac regeneration

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    Diaphragmatic myoblasts (DMs) are precursors of type-1 muscle cells displaying high exhaustion threshold on account that they contract and relax 20 times/min over a lifespan, making them potentially useful in cardiac regeneration strategies. Besides, it has been shown that biomaterials for stem cell delivery improve cell retention and viability in the target organ. In the present study, we aimed at developing a novel approach based on the use of poly (L-lactic acid) (PLLA) scaffolds seeded with DMs overexpressing connexin-43 (cx43), a gap junction protein that promotes inter-cell connectivity. DMs isolated from ovine diaphragm biopsies were characterized by immunohistochemistry and ability to differentiate into myotubes (MTs) and transduced with a lentiviral vector encoding cx43. After confirming cx43 expression (RT-qPCR and Western blot) and its effect on inter-cell connectivity (fluorescence recovery after photobleaching), DMs were grown on fiberaligned or random PLLA scaffolds. DMs were successfully isolated and characterized. Cx43 mRNA and protein were overexpressed and favored inter-cell connectivity. Alignment of the scaffold fibers not only aligned but also elongated the cells, increasing the contact surface between them. This novel approach is feasible and combines the advantages of bioresorbable scaffolds as delivery method and a cell type that on account of its features may be suitable for cardiac regeneration. Future studies on animal models of myocardial infarction are needed to establish its usefulness on scar reduction and cardiac function.Centro de Investigaciones Cardiovasculare

    On the influence of model fragment properties on a machine learning-based approach for feature location

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    [EN] Context: Leveraging machine learning techniques to address feature location on models has been gaining attention. Machine learning techniques empower software product companies to take advantage of the knowledge and the experience to improve the performance of the feature location process. Most of the machine learning-based works for feature location on models report the machine learning techniques and the tuning parameters in detail. However, these works focus on the size and the distribution of the data sets, neglecting the properties of their contents. Objective: In this paper, we analyze the influence of three model fragment properties (density, multiplicity, and dispersion) on a machine learning-based approach for feature location. Method: The analysis of these properties is based on an industrial case provided by CAF, a worldwide provider of railway solutions. The test cases were evaluated through a machine learning technique that uses different subsets of a knowledge base to learn how to locate unknown features. Results: Results show that the density and dispersion properties have a direct impact on the results. In our case study, the model fragments with extra-small density values achieve results with up to 43% more precision, 41% more recall, 42% more F-measure, and 0.53 more Matthews Correlation Coefficient (MCC) than the model fragments with other density values. On the other hand, the model fragments with extra-small and small dispersion values achieve results with up to 53% more precision, 52% more recall, 52% more F-measure, and 0.57 more MCC than the model fragments with other dispersion values. Conclusions: The analysis of the results shows that both density and dispersion properties significantly influence the results. These results can serve not only to improve the reports by means of the model fragment properties, but also to be able to compare machine learning-based feature location approaches fairly improving the feature location results.This work has been partially supported by the Ministry of Economy and Competitiveness (MINECO), Spain through the Spanish National R+D+i Plan and ERDF funds under the Project ALPS (RTI2018096411-B-I00). We also thank the ITEA3 15010 REVaMP2 Project and ACIF/2018/171.Ballarin, M.; Marcén, AC.; Pelechano Ferragud, V.; Cetina, C. (2021). On the influence of model fragment properties on a machine learning-based approach for feature location. Information and Software Technology. 129:1-19. https://doi.org/10.1016/j.infsof.2020.106430S119129Marcén, A. C., Lapeña, R., Pastor, Ó., & Cetina, C. (2020). Traceability Link Recovery between Requirements and Models using an Evolutionary Algorithm Guided by a Learning to Rank Algorithm: Train control and management case. Journal of Systems and Software, 163, 110519. doi:10.1016/j.jss.2020.110519Pérez, F., Font, J., Arcega, L., & Cetina, C. (2019). Collaborative feature location in models through automatic query expansion. Automated Software Engineering, 26(1), 161-202. doi:10.1007/s10515-019-00251-9ZHUANG, X., ENGEL, B. A., LOZANO-GARCIA, D. F., FERNÁNDEZ, R. N., & JOHANNSEN, C. J. (1994). Optimization of training data required for neuro-classification. International Journal of Remote Sensing, 15(16), 3271-3277. doi:10.1080/01431169408954326Foody, G. M., & Mathur, A. (2004). A relative evaluation of multiclass image classification by support vector machines. IEEE Transactions on Geoscience and Remote Sensing, 42(6), 1335-1343. doi:10.1109/tgrs.2004.827257Foody, G. M., Mathur, A., Sanchez-Hernandez, C., & Boyd, D. S. (2006). Training set size requirements for the classification of a specific class. Remote Sensing of Environment, 104(1), 1-14. doi:10.1016/j.rse.2006.03.004Weiss, G. M., & Provost, F. (2003). Learning When Training Data are Costly: The Effect of Class Distribution on Tree Induction. Journal of Artificial Intelligence Research, 19, 315-354. doi:10.1613/jair.1199Buda, M., Maki, A., & Mazurowski, M. A. (2018). A systematic study of the class imbalance problem in convolutional neural networks. Neural Networks, 106, 249-259. doi:10.1016/j.neunet.2018.07.011Arcuri, A., & Fraser, G. (2013). Parameter tuning or default values? An empirical investigation in search-based software engineering. Empirical Software Engineering, 18(3), 594-623. doi:10.1007/s10664-013-9249-9Lapeña, R., Font, J., Pastor, Ó., & Cetina, C. (2017). Analyzing the impact of natural language processing over feature location in models. ACM SIGPLAN Notices, 52(12), 63-76. doi:10.1145/3170492.3136052Shabtai, A., Moskovitch, R., Elovici, Y., & Glezer, C. (2009). Detection of malicious code by applying machine learning classifiers on static features: A state-of-the-art survey. Information Security Technical Report, 14(1), 16-29. doi:10.1016/j.istr.2009.03.003Song, Q., Jia, Z., Shepperd, M., Ying, S., & Liu, J. (2011). A General Software Defect-Proneness Prediction Framework. IEEE Transactions on Software Engineering, 37(3), 356-370. doi:10.1109/tse.2010.90Cao, Z., Tian, Y., Le, T.-D. B., & Lo, D. (2018). Rule-based specification mining leveraging learning to rank. Automated Software Engineering, 25(3), 501-530. doi:10.1007/s10515-018-0231-zArcuri, A., & Briand, L. (2012). A Hitchhiker’s guide to statistical tests for assessing randomized algorithms in software engineering. Software Testing, Verification and Reliability, 24(3), 219-250. doi:10.1002/stvr.1486García, S., Fernández, A., Luengo, J., & Herrera, F. (2010). Advanced nonparametric tests for multiple comparisons in the design of experiments in computational intelligence and data mining: Experimental analysis of power. 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    Interval type-2 fuzzy predicates for brain magnetic resonance image segmentation

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    The analysis of structural changes in the brain through Magnetic Resonance Imaging (MRI) provides useful information for diagnosis and clinical treatment of patients with pathologies like Alzheimer disease and dementia. While complexity achieved by the MRI equipment is high, quantification of structures and tissues has not been entirely solved. In the present paper, MRI segmentation is discussed using a new classification method called Type-2 Label-based Fuzzy Predicate Classification (T2-LFPC). From labeled data (pixels of different tissues selected by medical experts) a random partition is defined and the obtained subsets are analyzed discovering groups with similar properties called class prototypes. Using theses prototypes, interval type-2 membership functions and fuzzy predicates are defined. Parameters regarding the fuzzy predicates are optimized. Fuzzy predicates are applied on unlabeled pixels performing the segmentation and volumes occupied for the tissues into the intracranial cavity are computed. Results are compared to those of known methods. A method of measuring the progressive atrophy and possible changes compared to a therapeutic effect should be essentially automatic and therefore independent of the radiologist. Results show that the performance of the proposed method is highly acceptable as a contribution for this requirement. Advantages of this approach are presented throughout this paper.The analysis of structural changes in the brain through Magnetic Resonance Imaging (MRI) provides useful information for diagnosis and clinical treatment of patients with pathologies like Alzheimer disease and dementia. While complexity achieved by the MRI equipment is high, quantification of structures and tissues has not been entirely solved. In the present paper, MRI segmentation is discussed using a new classification method called Type-2 Label-based Fuzzy Predicate Classification (T2-LFPC). From labeled data (pixels of different tissues selected by medical experts) a random partition is defined and the obtained subsets are analyzed discovering groups with similar properties called class prototypes. Using theses prototypes, interval type-2 membership functions and fuzzy predicates are defined. Parameters regarding the fuzzy predicates are optimized. Fuzzy predicates are applied on unlabeled pixels performing the segmentation and volumes occupied for the tissues into the intracranial cavity are computed. Results are compared to those of known methods. A method of measuring the progressive atrophy and possible changes compared to a therapeutic effect should be essentially automatic and therefore independent of the radiologist. Results show that the performance of the proposed method is highly acceptable as a contribution for this requirement. Advantages of this approach are presented throughout this paper.Fil: Comas, Diego Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Científicas y Tecnológicas En Electronica. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones Científicas y Tecnológicas En Electronica.; ArgentinaFil: Meschino, Gustavo Javier. Universidad FASTA ; ArgentinaFil: Costantino, Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Científicas y Tecnológicas En Electronica. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones Científicas y Tecnológicas En Electronica.; ArgentinaFil: Capiel, Carlos. Instituto Radiologico Mar del Plata; Argentina. Universidad FASTA ; ArgentinaFil: Ballarin, Virginia Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Científicas y Tecnológicas En Electronica. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones Científicas y Tecnológicas En Electronica.; Argentina. Universidad FASTA ; Argentin

    Physical-mechanical wood properties of Myracrodruon urundeuva in homogeneous planting. Propriedades físico-mecânicas da madeira de Myracrodruon urundeuva em plantio homogêneo.

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    As a result of its high density and durability, wood of Myracrodruon urundeuva (aroeira) is highly valued, and its exploitation in Brazilian primary forests has been prohibited by law since 1991. One way to maintain this status and, at the same time, supply the increased demand for this wood is through the establishment of plantations. Therefore, the knowledge of M. urundeuva wood properties in plantations with young trees is essential. Thus, we evaluated we evaluated some physical and mechanical properties of wood from 20-year-old M. urundeuva (aroeira) twelve trees in a homogenous plantation. Basic density was 770 kg m-3 and apparent density was 984 kg m-3. The anisotropy coefficient of 1.69 is considered regular, indicating that wood can be used in the manufacture of fine furniture, frames, boats, musical instruments, sports equipment or flooring. The wood presented good mechanical behavior, with an average strength for parallel compression of 53.84 MPa, MOE of 12632 MPa and MOR of 123.58 MPa. The wood was identified as class 40, thus showing potential for use in medium-sized structures and construction. Basic density and apparent density correlated positively with compression parallel to the grain and MOR. Wood quality, a positive characteristic, added to good technology, even in young trees, shows that values of physical and mechanical properties are suitable for various uses when compared to the same values of older trees based on specialized literature. Our results confirmed that this homogeneous planting was adequate to obtain M. urundeuva wood with such quality. Devido à alta densidade e durabilidade, a madeira de Myracrodruon urundeuva (aroeira) é muito valorizada, e sua exploração em florestas nativas brasileiras é proibida desde 1991. O estabelecimento de plantações é uma maneira de manter essa situação e, ao mesmo tempo, fornecer o aumento da demanda por essa madeira. Assim, o conhecimento das propriedades da madeira de M. urundeuva em plantações com árvores jovens é essencial. Portanto, avaliamos algumas propriedades físicas e mecânicas da madeira em árvores de M. urundeuva com 20 anos em uma plantação homogênea. A densidade básica foi 770 kg m-3 e a densidade aparente foi 984 kg m-3. O coeficiente de anisotropia de 1,69 é considerado normal, indicando que a madeira pode ser utilizada na fabricação de móveis finos, quadros, barcos, instrumentos musicais, equipamentos esportivos, pisos etc. A madeira apresentou bom comportamento mecânico, com uma resistência média à compressão paralela de 53,84 MPa, MOE de 12632 MPa e MOR de 123,58 MPa. A madeira foi classificada na classe C40, apresentando potencial para uso em estruturas e na construção civil. A densidade básica e densidade aparente se relacionaram positivamente com a compressão paralela às fibras e com o MOR. Um aspecto positivo é a qualificação de madeira, com bom potencial tecnológico, mesmo em árvores jovens, mostrando que os valores das propriedades físicas e mecânicas foram adequados para vários usos, quando comparados com os valores de árvores mais velhas com base na literatura. O plantio homogêneo foi adequado para obter madeira M. urundeuva com qualidade
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