Transfer learning or design a custom CNN for tactile object recognition

International Workshop on Robotac: New Progress in Tactile Perception and Learning in RoboticsNovel tactile sensors allow treating pressure lectures as standard images due to its highresolution. Therefore, computer vision algorithms such as Convolutional Neural Networks (CNNs) can be used to identify objects in contact. In this work, a high-resolution tactile sensor has been attached to a robotic end-effector to identify objects in contact. Moreover, two CNNs-based approaches have been tested in an experiment of classification of pressure images. These methods include a transfer learning approach using a pre-trained CNN on an RGB images dataset and a custom-made CNN trained from scratch with tactile information. A comparative study of performance between them has been carried out.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Spanish project DPI2015-65186-R, the European Commission under grant agreement BES-2016-078237, the educational project PIE-118 of the University of Malag

Obstructive Sleep Apnea Detection Methods Based on Heart Rate Variability Analysis: Opportunities for a Future Cinc Challenge

[EN] The effects of sleep-related disorders, such as obstructive sleep apnea (OSA), can be devastating either in children or adults. Misdiagnosis may lead to severe cardiovascular diseases. Besides, OSA consequences are often related to bad job performance, and road accidents. Nowadays, polysomnography (PSG) is still considered the gold standard for OSA diagnosis, but the required facilities are extremely high, thus reducing availability worldwide. For this reason, simpler and cost-effective diagnosing methods have been proposed in the late years. In this regard, the heart rate variability (HRV) has been demonstrated to strongly reflect apnea episodes during sleep. Hence, this work reviews the latest advances in the evaluation of OSA from the HRV perspective to consider its potentialities for a future revisited CinC Challenge.This research has been supported by grants DPI201783952-C3 from MINECO/AEI/FEDER EU, SBPLY/17/180501/000411 from Junta de Comunidades de Castilla-la Mancha and AICO/2019/036 from Generalitat Valenciana. Moreover, Daniele Padovano has held graduate research scholarships from Escuela Polit ' ecnica de Cuenca and Instituto de Tecnolog ' ias Audiovisuales, University of CastillaLa ManchaPadovano, D.; Martinez-Rodrigo, A.; Pastor, JM.; Rieta, JJ.; Alcaraz, R. (2020). Obstructive Sleep Apnea Detection Methods Based on Heart Rate Variability Analysis: Opportunities for a Future Cinc Challenge. IEEE. 1-4. https://doi.org/10.22489/CinC.2020.400S1

Fracture micromechanisms and mechanical behavior of YBCO bulk superconductors at 77 and 300 K

In this study two YBa2Cu3O7−δ bulk superconductors were evaluated, with the aim of analyzing the influence of the processing method (TSMG and Bridgman) and the test temperature on their mechanical behavior. The relationship between their mechanical properties and fracture micromechanisms has also been studied. Both materials were tested at room and at service temperature. TPB tests were carried out to determine their mechanical behavior, strength and toughness. Moreover, one of the two materials, characterized by transversal microstructural anisotropy, was tested in two directions. Hardness of both materials at nano and micro scale was studied. The results show that the mechanical behavior of the materials is controlled by the defects and cracks that have been introduced during the processing of the materials. A good degree of agreement was found between the experimental crack defects detected by means of SEM and those gathered from the fracture mechanical analysis of the experimental dat

LES of a pressurized sooting aero-engine model burner using a computationally efficient discrete sectional method coupled to tabulated chemistry

This work is focused on the modeling and analysis of soot formation and oxidation in the pressurized ethylene-based model burner investigated at DLR. This burner features a dual swirler configuration for the primary air supply and includes secondary dilution jets inside the combustion chamber, showing reacting flow characteristics representative of the RQL combustor technology. Large-eddy simulations (LES) of the DLR burner are conduced here to assess a coupling approach between flamelet generated manifold (FGM) chemistry and discrete sectional method (DSM) based soot model with clustering method. First, a validation of the numerical results is conducted for the gas velocity and temperature fields, and good agreement is obtained for both mean and fluctuating quantities. The Soot Volume Fraction (SVF) computed from LES shows a satisfactory agreement with the experimental data in both SVF distribution and magnitude. The analysis also includes a numerical investigation of the soot production and the Particle Size Distributions (PSD). Finally, the configuration without secondary air is evaluated and an accurate prediction of the SVF field is also obtained. In this case, the absence of dilution air strongly influences the central region of the combustion chamber, and soot distribution and PSD are mainly affected by transport and dilution, not oxidation. It is finally concluded the proposed modeling framework is capable of predicting the soot field and particle size distributions inside the combustor for both operating conditions.</p

LES of a pressurized sooting aero-engine model burner using a computationally efficient discrete sectional method coupled to tabulated chemistry

This work is focused on the modeling and analysis of soot formation and oxidation in the pressurized ethylene-based model burner investigated at DLR. This burner features a dual swirler configuration for the primary air supply and includes secondary dilution jets inside the combustion chamber, showing reacting flow characteristics representative of the RQL combustor technology. Large-eddy simulations (LES) of the DLR burner are conduced here to assess a coupling approach between flamelet generated manifold (FGM) chemistry and discrete sectional method (DSM) based soot model with clustering method. First, a validation of the numerical results is conducted for the gas velocity and temperature fields, and good agreement is obtained for both mean and fluctuating quantities. The Soot Volume Fraction (SVF) computed from LES shows a satisfactory agreement with the experimental data in both SVF distribution and magnitude. The analysis also includes a numerical investigation of the soot production and the Particle Size Distributions (PSD). Finally, the configuration without secondary air is evaluated and an accurate prediction of the SVF field is also obtained. In this case, the absence of dilution air strongly influences the central region of the combustion chamber, and soot distribution and PSD are mainly affected by transport and dilution, not oxidation. It is finally concluded the proposed modeling framework is capable of predicting the soot field and particle size distributions inside the combustor for both operating conditions.</p

Designing the Didactic Strategy Modeling Language (DSML) From PoN: An Activity Oriented EML Proposal

[EN] This paper presents the design of the didactic strategy modeling language (DSML) according to the principles of Physics of Notations (PoN). The DSML is a visual and activity-oriented language for learning design characterized by the representation of different activities according to the nature of the task. Once the language is designed, a blind interpretation study is conducted to validate the semantic transparency of the learning activity iconography. The results of the paper allow to refine the icons. In addition to this, an authoring tool for DSML, which is integrated to an LMS, is presented. As a result, a model driven course was designed as a DSML pre-validation.Ruiz, A.; Panach Navarrete, JI.; Pastor López, O.; Giraldo-Velásquez, FD.; Arciniegas, JL.; Giraldo, WJ. (2018). Designing the Didactic Strategy Modeling Language (DSML) From PoN: An Activity Oriented EML Proposal. IEEE-RITA: Latin-American Learning Technologies Journal. 13(4):136-143. https://doi.org/10.1109/RITA.2018.2879262S13614313

TFAP2C regulates transcription in human naive pluripotency by opening enhancers.

Naive and primed pluripotent human embryonic stem cells bear transcriptional similarity to pre- and post-implantation epiblast and thus constitute a developmental model for understanding the pluripotent stages in human embryo development. To identify new transcription factors that differentially regulate the unique pluripotent stages, we mapped open chromatin using ATAC-seq and found enrichment of the activator protein-2 (AP2) transcription factor binding motif at naive-specific open chromatin. We determined that the AP2 family member TFAP2C is upregulated during primed to naive reversion and becomes widespread at naive-specific enhancers. TFAP2C functions to maintain pluripotency and repress neuroectodermal differentiation during the transition from primed to naive by facilitating the opening of enhancers proximal to pluripotency factors. Additionally, we identify a previously undiscovered naive-specific POU5F1 (OCT4) enhancer enriched for TFAP2C binding. Taken together, TFAP2C establishes and maintains naive human pluripotency and regulates OCT4 expression by mechanisms that are distinct from mouse

Effect of strain and magnetic field on the critical current and electric resistance of the joints between HTS coated conductors

Engineering of devices and systems such as magnets, fault current limiters or cables, based on High Temperature Superconducting wires requires a deep characterization of the possible degradation of their properties by handling at room temperature as well as during the service life thus establishing the limits for building up functional devices and systems. In the present work we report our study regarding the mechanical behavior of spliced joints between commercial HTS coated conductors based on YBCO at room temperature and service temperature, 77 K. Tensile tests under axial stress and the evolution of the critical current and the electric resistance of the joints have been measured. The complete strain contour for the tape and the joints has been obtained by using Digital Image Correlation. Also, tensile tests under external magnetic field have been performed and the effect of the applied field on the critical current and the electric resistance of the joints has been studied. Additionally, fatigue tests under constant cyclic stress and loading-unloading ramps have been carried out in order to evaluate the electromechanical behavior of the joints and the effect of maximum applied stress on the critical current. Finally, a preliminary numerical study by means of the Finite Element Method (FEM) of the electromechanical behavior of the joints between commercial HTS is presented

Surface modification of Al2O3–ZrO2(Y2O3) eutectic oxides by laser melting: processing and wear resistance

Surface coatings of pseudo-binary Al2O3–Zr2O3(Y2O3) eutectic oxides were produced by laser melting of the surface of conventionally sintered materials using a high-power diode laser. It was possible to obtain smooth, homogeneous, and crack-free coatings up to 50_7 mm2 in area by carefully controlling the processing conditions (laser power, traveling speed of the specimen, and substrate temperature). The surface treatment was aimed at creating a dense, wear-resistant coating based on the eutectic microstructure generated upon solidification. The microstructure of the coating was formed by elongated colonies, and was similar to that found in rods grown by the laser-heated floating zone method at the same growth rates. The laser-melted coating presented much higher hardness and wear resistance than the sintered materials, and the optimum mechanical properties were measured in samples treated at 500 mm/h with a laser line power of 65–80 W/cm. These samples presented a hardness and wear rate of 19.770.4 GPa and 3.8_10_6 mm3/N m, respectively, while those of the conventionally sintered materials were 14.37 0.2 GPa and 2.3_10_6 mm3/N m

Effect of strain and magnetic field on the critical current and electric resistance of the joints between HTS coated conductors

Engineering of devices and systems such as magnets, fault current limiters or cables, based on High Temperature Superconducting wires requires a deep characterization of the possible degradation of their properties by handling at room temperature as well as during the service life thus establishing the limits for building up functional devices and systems. In the present work we report our study regarding the mechanical behavior of spliced joints between commercial HTS coated conductors based on YBCO at room temperature and service temperature, 77 K. Tensile tests under axial stress and the evolution of the critical current and the electric resistance of the joints have been measured. The complete strain contour for the tape and the joint has been obtained by using Digital Image Correlation. Also, tensile tests under external magnetic field have been performed and the effect of the applied field on the critical current and the electric resistance of the joints has been studied. Finally, a preliminary numerical study by means of Finite Element Method (FEM) of the mechanical behavior of the joints between commercial HTS is presented