689 research outputs found
Comparison of Digital Watermarking Methods for an Id Authentication System
Current radio-frequency identification (RFID) card authentication systems are not secure enough to fight the latest and most novel hacking methods. Poor software implementations, outdated cryptography algorithms and faulty hardware are just some of the most common ways of exploiting these systems. Research in the field of image processing and cryptography suggests that an additional authentication layer based on digital watermarking could help improve the level of security of traditional RFID cards. Unfortunately, not all watermarking methods can be implemented in an embedded device, such as the one used for RFID card systems. The aim of this work is to provide a comparison among different digital watermarking techniques that can be used to add the extra security layer required by the basic RFID card authentication systems. In this work, two widely known methods proposed by Kang et al. in 2010 and 2003, were selected as the basis to create a comparison framework for their implementation in an embedded device. Important elements such as algorithm complexity and memory occupation were measured and analyzed in order to select the best candidate for an RFID card system. The method proposed by Kang et al. in 2010 represented the option with lowest algorithmic complexity and less memory footprint, indicating that this method is the most suitable for its implementation in an authentication system.Los métodos de autenticación basados en tarjetas con tecnología RFID (del inglés, radiofrequency identification) no son lo suficientemente seguros para contrarrestar las técnicas de hackeo más novedosas y actuales. Implementaciones deficientes, algoritmos de criptografía obsoletos y errores de hardware son solo algunas de las formas más comunes para vulnerar este tipo de sistemas. Investigaciones en el área de procesamiento digital de imágenes y criptografía sugieren que una capa adicional de autenticación basada en marcas de agua digitales podría ayudar a incrementar el nivel de seguridad de las tarjetas RFID tradicionales. Desafortunadamente, no todos los métodos de marca de agua digital pueden ser implementados en un sistema embebido como el usado en los sistemas de tarjetas RFID. El objetivo de este trabajo en proveer una comparación entre diversas técnicas de marcas de agua digital que pueden ser usadas para proveer una capa de seguridad extra a los sistemas de autenticación basados en RFID. En este trabajo, dos métodos ampliamente conocidos propuestos por Kang y Cols. en el 2010 y 2003, fueron seleccionados como base para crear un marco de comparación para su implementación en un sistema embebido. Elementos importantes como complejidad algorítmica y ocupación de memoria fueron medidos y analizados para elegir el mejor candidato para un sistema de tarjetas RFID. El método propuesto por Kang y Cols. en 2010 representó la opción con la complejidad algorítmica más baja y menor ocupación de memoria, con lo que indicó que este método es el más apto para su implementación en un sistema de autenticación como el deseado.Continental AutomotiveConsejo Nacional de Ciencia y Tecnologí
G\u3csub\u3emax\u3c/sub\u3e From Pressuremeter Tests: Theory; Chamber Tests; and Field Measurements
A method of analysis to predict the in situ maximum shear modulus Gmax,0 from self-boring pressuremeter unload tests is presented. The method considers both the stress and void ratio changes induced by pressuremeter loading and the nonlinear stress-strain response upon unloading. The results are presented in the form of a chart that allows Gmax,0 to be determined from the equivalent elastic unload modulus, G*, for a wide range of loading and unloading conditions. The analysis procedure is checked with chamber tests and field data and the results are found to be in good agreement provided factors to account for disturbance and anisotrophy are considered
Maternal and fetal risks of planned vaginal breech delivery vs planned caesarean section for term breech birth: A systematic review and meta-analysis
Background Breech presentation delivery approach is a controversial
issue in obstetrics. How to cope with breech delivery (vaginal or
C-section) has been discussed to find the safest in terms of morbidity.
The aim of this study was to assess the risks of foetal and maternal
mortality and perinatal morbidity associated with vaginal delivery
against elective caesarean in breech presentations, as reported in
observational studies.
Methods Studies assessing perinatal morbidity and mortality associated
with breech presentations births. Cochrane, Medline, Scopus,
Embase, Web of Science, and Cuiden databases were consulted. This
protocol was registered in PROSPERO CRD42020197598. Selection
criteria were: years between 2010 and 2020, in English language,
and full-term gestation (37-42 weeks). The methodological quality
of the eligible articles was assessed according to the Newcastle-Ottawa
scale. Meta-analyses were performed to study each parameter
related to neonatal mortality and maternal morbidity.
Results The meta-analysis included 94 285 births with breech presentation.
The relative risk of perinatal mortality was 5.48 (95%
confidence interval (CI) = 2.61-11.51) times higher in the vaginal
delivery group, 4.12 (95% CI = 2.46-6.89) for birth trauma and 3.33
(95% CI = 1.95-5.67) for Apgar results. Maternal morbidity showed
a relative risk 0.30 (95% CI = 0.13-0.67) times higher in the planned
caesarean group.
Conclusions An increment in the risk of perinatal mortality, birth
trauma, and Apgar lower than 7 was identified in planned vaginal
delivery. However, the risk of severe maternal morbidity because of
complications of a planned caesarean was slightly higher
A reliable criterion for the correct delimitation of the foveal avascular zone in diabetic patients
Background: Manual segmentation of the Foveal Avascular Zone (FAZ) has a high level of variability. Research into retinas needs coherent segmentation sets with low variability. Methods: Retinal optical coherence tomography angiography (OCTA) images from type-1 diabetes mellitus (DM1), type-2 diabetes mellitus (DM2) and healthy patients were included. Superficial (SCP) and deep (DCP) capillary plexus FAZs were manually segmented by different observers. After comparing the results, a new criterion was established to reduce variability in the segmentations. The FAZ area and acircularity were also studied. Results: The new segmentation criterion produces smaller areas (closer to the real FAZ) with lower variability than the different criteria of the explorers in both plexuses for the three groups. This was particularly noticeable for the DM2 group with damaged retinas. The acircularity values were also slightly reduced with the final criterion in all groups. The FAZ areas with lower values showed slightly higher acircularity values. We also have a consistent and coherent set of segmentations with which to continue our research. Conclusions: Manual segmentations of FAZ are generally carried out with little attention to the consistency of the measurements. A novel criterion for segmenting the FAZ allows segmentations made by different observers to be more similar
Combination of T-Gel chromatography and immunoaffinity and new protoco to removel immunoglobulins and albumin from serum samples: the case od rheumatoid arthritis
Comunicaciones a congreso
Sequential extraction of almond hull biomass with pulsed electric fields (PEF) and supercritical CO2 for the recovery of lipids, carbohydrates and antioxidants
This work reports the first example of combined sequential extraction by pulsed electric fields (PEF) (3 kV/cm, 100 kJ/kg, 2 Hz, 100 ms) and supercritical (SC) fluid extraction (SFE) (15 MPa, 25 mL/min, 50ºC, 60 min) with CO2 (SC-CO2) for the valorisation of almond hull (AH) biomass. PEF+SFE boosted the efficiency of the protocol up to 77% for total antioxidant capacity and 20% in terms of polyphenols recovery compared to the traditional soaking. Triple-TOF-LC-MS-MS analysis provided the phenolic profiles for the PEF and SC-CO2 extracts, observing significant differences in the polyphenol profile according to the technology applied. Additionally, NMR analysis detected the presence of the carbohydrate soluble (mainly glucose, fructose and sucrose) and lipidic fractions, both selectively extracted by PEF or SC-CO2, respectively. Finally, the post-extraction residual solid biomass was characterized by several techniques such as TGA, FT-IR and SEM. For the latter, the formation of surface pores after PEF and a high fibre compaction after SFE was observed. On the other hand, DTG curves allowed to firmly propose concurrent valorisation routes for this solid, in agreement with a zero-waste approach
Correction: Alfaro-Arnedo et al. IGF1R as a Potential Pharmacological Target in Allergic Asthma. Biomedicines 2021, 9, 912
Correction to Biomedicines 2021, 9(8), 912.Depto. de FisiologíaFac. de MedicinaTRUEpu
- …