UbiqBIOPARC: A GPS and WIFI Based Context-Aware System for an Enhanced Guide Experience

This document discusses and evaluates the use of GPS, WIFI and iPhone SDK based technologies to develop UbiqBIOPARC, a context-aware system in a particular context: a new generation zoological park that has been created based on the zooimmersion concept, submersing the visitor totally in the savage habitats. It offers appropriate contextual information to users, depending on their preferences and the environment in which they are positioned. UbiqBIOPARC is a context-aware application that provides information to zoo visitors. It combines the flexibility of iPhone SDK with the connectivity provided by WIFI, the location capabilities of GPS and the orientation offered by a compass integrated in the device. In this document the overall architecture and the implementation steps followed to create this application are presented. We also demonstrate that a new approach to build context-aware applications with the aid of GPS and compass features is possible. Finally, several experiments have been carried out in order to evaluate performance and system behavior. In particular, system reaction time and data download time are under study. Besides power consumption in different modes such as GPS, local, WIFI and compass modes is evaluated.Sorribes Díaz, JV. (2010). UbiqBIOPARC: A GPS and WIFI Based Context-Aware System for an Enhanced Guide Experience. http://hdl.handle.net/10251/14544Archivo delegad

Autoconfiguración de redes ad hoc basadas en confianza.

[ES] En la presente tesis se aborda el problema del descubrimiento de vecinos en redes estáticas inalámbricas ad hoc, redes sin infraestructura. En estas redes los nodos deben descubrir los vecinos como un primer paso tras el despliegue. Además se aborda el problema de creación de redes espontáneas basadas en la confianza, y el de selección de vecinos. Se han presentado distintos algoritmos que solucionan el problema siguiendo unas premisas que se irán relajando a lo largo de la tesis. Se han implementado esos algoritmos en Castalia 3.2 para su validación y comparación con otros protocolos de referencia. Los protocolos determinísticos presentan mejores resultados de simulación, aunque requieren que sigan una planificación en la transmisión. En cuanto al protocolo aleatorio CDPRR (Collision Detection Probabilistic Round Robin) no sigue una planificación pero requiere el conocimiento del número de nodos de la red. El protocolo CDH (Collision Detection Hello) permite el desconocimiento del número de nodos. Ambos logran el descubrimiento de los vecinos con probabilidad 1 mediante la detección de colisiones. Ambas propuestas obtienen mejores prestaciones que los protocolos usados como referencia. Tanto para CDH como para CDPRR se ha realizado un modelo analítico de determinadas métricas. Se ha propuesto un protocolo aleatorio basado en líder que permite obtener buenas prestaciones y se puede usar de forma asíncrona aunque solo permite su uso en entornos one-hop. Finalmente, se presenta un protocolo aleatorio consciente de la energía que permite buenos resultados para altos duty cycles y redes compuestas de pocos nodos. En cuanto a la creación de redes espontáneas basadas en la confianza, se ha propuesto un modelo que usa el protocolo CDPRR como base. Este protocolo de creación de redes espontáneas basadas en la confianza permite premisas más realistas y mejora un protocolo determinístico de referencia. Finalmente, se propone un protocolo que combina el descubrimiento y la selección de vecinos con el objetivo de proporcionar nodos favoritos. Estos nodos permiten el envío de información al exterior de la red o en futuras operaciones como el encaminamiento.[CA] En la present tesi s'aborda el problema del descobriment de veïns en xarxes estàtiques sense fil ad hoc, xarxes sense infraestructura. En estes xarxes els nodes han de descobrir els veïns com un primer pas després del desplegament. A més s'aborda el problema de creació de xarxes espontànies basades en la confiança, i el de selecció de veïns. S'han presentat distints algoritmes que solucionen el problema seguint unes premisses que se n'aniran relaxant al llarg de la tesi. S'han implementat eixos algoritmes en Castalia 3.2 per a la seua validació i comparació amb altres protocols de referència. Els protocols determinístics presenten millors resultats de simulació, encara que requerixen que seguisquen una planificació en la transmissió. Quant al protocol aleatori CDPRR (Collision Detection Probabilistic Round Robin) no seguix una planificació però requerix el coneixement del nombre de nodes de la xarxa. El protocol CDH (Collision Detection Hello) permet el desconeixement del nombre de nodes. Ambdós aconseguixen el descobriment dels veïns amb probabilitat 1 per mitjà de la detecció de col·lisions. Ambdós propostes obtenen millors prestacions que els protocols usats com a referència. Tant per a CDH com per a CDPRR s'ha realitzat un model analític de determinades mètriques. S'ha proposat un protocol aleatori basat en líder que permet obtindre bones prestacions i es pot usar de forma asíncrona encara que només permet el seu ús en entorns onehop. Finalment, es presenta un protocol aleatori conscient de l'energia que permet bons resultats per a alts duty cycles i xarxes compostes de pocs nodes. Quant a la creació de xarxes espontànies basades en la confiança, s'ha proposat un model que usa el protocol CDPRR com a base. Este protocol de creació de xarxes espontànies basades en la confiança permet premisses més realistes i millora un protocol determinístic de referència. Finalment, es proposa un protocol que combina el descobriment i la selecció de veïns amb l'objectiu de proporcionar nodes favorits. Estos nodes permeten l'enviament d'informació a l'exterior de la xarxa o en futures operacions com l'encaminament.[EN] This thesis addresses the neighbor discovery problem in static wireless ad hoc networks, infrastructure-less networks. In these networks the nodes must discover the neighbors as a first step after the deployment. Furthermore, the thesis addresses the problem of creation of spontaneous networks based on trust, and the neighbor selection. Several algorithms have been presented that solve the problem following some assumptions that will be relaxed throughout the thesis. Those algorithms have been implemented in Castalia 3.2 for validation and comparison with other reference protocolos. The deterministic protocols provide better simulation results, although they require a transmission schedule. As for the randomized protocol CDPRR (Collision Detection Probabilistic Round Robin), it does not follow a schedule but it requires the knowledge of the number of nodes in the network. The CDH (Collision Detection Hello) protocol allows the ignorance of the number of nodes. They both achieve the discovery of the neighbors with probability 1 by detecting collisions. Both proposals achieve better performance than the protocols used as reference. For CDH and CDPRR an analytical model has been carried out regarding several metrics. A randomized protocol based on leader has been proposed that achieves a good performance and it can be used in an asynchronous way although it can only be used in one-hop environments. Finally, an energy-aware randomized protocol is proposed, which achieves good results for high duty cycles and networks composed of a small number of nodes. As for the creation of spontaneous networks based on trust, a model has been proposed which is based on the CDPRR protocol. This protocol for the creation of spontaneous networks based on trust allows more realistic assumptions and outperforms a determinsitic protocol used as reference. Finally, a protocol is proposed which combines the discovery and selection of neighbors aiming at providing favourite nodes. These nodes allow sending information towards outside the network or in future operations such as routing.Sorribes Díaz, JV. (2021). Autoconfiguración de redes ad hoc basadas en confianza [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/180283TESI

A Spontaneous Wireless Ad Hoc Trusted Neighbor Network Creation Protocol

[EN] Spontaneous networks lack an a priori communication infrastructure, the neighbors are unknown right after the deployment, and they are used during a period of time and in a certain location. In this paper, we present a new randomized creation model of a spontaneous wireless ad hoc network based on trusted neighbors. The idea is to manage the neighbor discovery with the exchange of identity cards, and the checking of a signature establishes a relationship based on trust of the neighbors. To asses the performance of our randomized trusted network proposal and compare it against an existing deterministic protocol used as reference, we relied on Castalia 3.2 simulator, regarding 4 metrics: time, energy consumption, throughput, and number of discoveries vs packet sent ratio. We found that our proposal outperforms the reference protocol in terms of time, energy, and discoveries vs packet sent ratio in a one-hop setting, while it outperforms the reference protocol regarding all 4 metrics in multihop environments. We also evaluated our proposal through simulations varying the transmission probability and proved that it does not require to know the number of nodes if a fixed transmission probability is set, providing reasonable results. Moreover, our proposal is based on collision detection, it knows when to terminate the process, it does not require a transmission schedule, and it follows more realistic assumptions. In addition, a qualitative comparison is carried out, comparing our proposal against existing protocols from the literature.This work has been partially supported by the "Ministerio de Economia y Competitividad" in the "Programa Estatal de Fomento de la Investigacion Cientifica y Tecnica de Excelencia, Subprograma Estatal de Generacion de Conocimiento" within the project under Grant TIN2017-84802-C2-1-P. This work has also been partially supported by European Union through the ERANETMED (Euromediterranean Cooperation through ERANET joint activities and beyond) project ERANETMED3-227 SMARTWATIR.Sorribes, JV.; Peñalver Herrero, ML.; Lloret, J. (2021). A Spontaneous Wireless Ad Hoc Trusted Neighbor Network Creation Protocol. Wireless Communications and Mobile Computing (Online). 2021:1-20. https://doi.org/10.1155/2021/5531923120202

Gain-Scheduled Predictive Extended State Observer for Time-varying Delays Systems with Mismatched Disturbances

[EN] In this paper, a novel control scheme for systems with input and output time-varying delays is provided in discrete-time domain. The control strategy combines predictor-like techniques with a delay-dependent gain-scheduled extended state observer. The main goal is twofold: (i) to minimize the negative effect of time-varying delays in the closed-loop performance and, (ii) to actively compensate the effect of mismatched disturbances in the controlled output. Moreover, a sufficient condition based on Linear Matrix Inequalities (LMI) is provided to obtain the maximum delay interval that ensures the stability of the closed-loop system. Finally, the achieved benefits of the proposal are shown by simulation in open-loop unstable plants, and experimentally validated in a test-bed quadrotor platform. (C) 2018 ISA. Published by Elsevier Ltd. All rights reserved.This work was supported in part by European Commission as part of Project H2020-SEC-2016-2017, Topic: SEC-20-BES-2016 Id: 740736 C2 Advanced Multi-domain Environment and Live Observation Technologies , in part by the Spanish Ministry of Economy, Industry, and Competition under Project TIN2017-86520-C3-1-R, in part by Universitat Politècnica de València under Project FPI-UPV 2017 PAID-01-17, and in part by Spanish Government/European Union Project DPI2015-69376-R (MINECO/FEDER).González Sorribes, A.; Balaguer Garín, V.; García Gil, PJ.; Cuenca, Á. (2019). Gain-Scheduled Predictive Extended State Observer for Time-varying Delays Systems with Mismatched Disturbances. ISA Transactions. 84:206-213. https://doi.org/10.1016/j.isatra.2018.09.024S2062138

Randomized neighbor discovery protocols with collision detection for static multi-hop wireless ad hoc networks

[EN] Neighbor discovery represents a first step after the deployment of wireless ad hoc networks, since the nodes that form them are equipped with limited-range radio transceivers, and they typically do not know their neighbors. In this paper two randomized neighbor discovery approaches, called CDH and CDPRR, based on collision detection for static multi-hop wireless ad hoc networks, are presented. Castalia 3.2 simulator has been used to compare our proposed protocols against two protocols chosen from the literature and used as reference: the PRR, and the Hello protocol. For the experiments, we chose five metrics: the neighbor discovery time, the number of discovered neighbors, the energy consumption, the throughput and the number of discovered neighbors versus packets sent ratio. According to the results obtained through simulation, we can conclude that our randomized proposals outperform both Hello and PRR protocols in the presence of collisions regarding all five metrics, for both one-hop and multi-hop scenarios. As novelty compared to the reference protocols, both proposals allow nodes to discover all their neighbors with probability 1, they are based on collision detection and know when to terminate the neighbor discovery process. Furthermore, qualitative comparisons of the existing protocols and the proposals are available in this paper. Moreover, CDPRR presents better results in terms of time, energy consumption and number of discovered neighbors versus packets sent ratio. We found that both proposals achieve to operate under more realistic assumptions. Furthermore, CDH does not need to know the number of nodes in the network.This work has been partially supported by the "Ministerio de Economia y Competitividad" in the "Programa Estatal de Fomento de la Investigacion Cientifica y Tecnica de Excelencia, Subprograma Estatal de Generacion de Conocimiento" within the project under Grant TIN2017-84802-C2-1-P. This work has also been partially supported by European Union through the ERANETMED (Euromediterranean Cooperation through ERANET joint activities and beyond) project ERANETMED3-227 SMARTWATIR.Sorribes, JV.; Peñalver Herrero, ML.; Tavares De Araujo Cesariny Calafate, CM.; Lloret, J. (2021). Randomized neighbor discovery protocols with collision detection for static multi-hop wireless ad hoc networks. Telecommunication Systems. 77(3):577-596. https://doi.org/10.1007/s11235-021-00763-457759677

Collision Avoidance Based Neighbor Discovery in Ad Hoc Wireless Networks

[EN] Neighbor discovery is an important first step after the deployment of ad hoc wireless networks since they are a type of network that do not provide a communications infrastructure right after their deployment, the devices have radio transceivers which provide a limited transmission range, and there is a lack of knowledge of the potential neighbors. In this work two proposals to overcome the neighbor discovery in static one-hop environments in the presence of collisions, are presented. We performed simulations through Castalia 3.2, to compare the performance of the proposals against that for two protocols from the literature, i.e. PRR and Hello, and evaluate them according to six metrics. According to simulation results, the Leader-based proposal (O(N)) outperforms the other protocols in terms of neighbor discovery time, throughput, discoveries vs packets sent ratio, and packets received vs sent ratio, and the TDMA-based proposal is the slowest (O(N-2)) and presents the worst results regarding energy consumption, and discoveries vs packets sent ratio. However, both proposals follow a predetermined transmission schedule that allows them to discover all the neighbors with probability 1, and use a feedback mechanism. We also performed an analytical study for both proposals according to several metrics. Moreover, the Leader-based solution can only properly operate in one-hop environments, whereas the TDMA-based proposal is appropriate for its use in multi-hop environments.This work has been partially supported by the "Ministerio de Economia y Competitividad" in the "Programa Estatal de Fomento de la Investigacion Cientifica y Tecnica de Excelencia, Subprograma Estatal de Generacion de Conocimiento" within the project under Grant TIN2017-84802-C2-1-P. This work has also been partially supported by European Union through the ERANETMED (Euromediterranean Cooperation through ERANET joint activities and beyond) project ERANETMED3-227 SMARTWATIR.Sorribes, JV.; Peñalver Herrero, ML.; Lloret, J.; Tavares De Araujo Cesariny Calafate, CM. (2022). Collision Avoidance Based Neighbor Discovery in Ad Hoc Wireless Networks. Wireless Personal Communications. 125(2):987-1011. https://doi.org/10.1007/s11277-021-09091-x9871011125

Severe manifestations of SARS-CoV-2 in children and adolescents: from COVID-19 pneumonia to multisystem inflammatory syndrome: a multicentre study in pediatric intensive care units in Spain

Background Multisystem inflammatory syndrome temporally associated with COVID-19 (MIS-C) has been described as a novel and often severe presentation of SARS-CoV-2 infection in children. We aimed to describe the characteristics of children admitted to Pediatric Intensive Care Units (PICUs) presenting with MIS-C in comparison with those admitted with SARS-CoV-2 infection with other features such as COVID-19 pneumonia. Methods A multicentric prospective national registry including 47 PICUs was carried out. Data from children admitted with confirmed SARS-CoV-2 infection or fulfilling MIS-C criteria (with or without SARS-CoV-2 PCR confirmation) were collected. Clinical, laboratory and therapeutic features between MIS-C and non-MIS-C patients were compared. Results Seventy-four children were recruited. Sixty-one percent met MIS-C definition. MIS-C patients were older than non-MIS-C patients (p = 0.002): 9.4 years (IQR 5.5-11.8) vs 3.4 years (IQR 0.4-9.4). A higher proportion of them had no previous medical history of interest (88.2% vs 51.7%, p = 0.005). Non-MIS-C patients presented more frequently with respiratory distress (60.7% vs 13.3%, p < 0.001). MIS-C patients showed higher prevalence of fever (95.6% vs 64.3%, p < 0.001), diarrhea (66.7% vs 11.5%, p < 0.001), vomits (71.1% vs 23.1%, p = 0.001), fatigue (65.9% vs 36%, p = 0.016), shock (84.4% vs 13.8%, p < 0.001) and cardiac dysfunction (53.3% vs 10.3%, p = 0.001). MIS-C group had a lower lymphocyte count (p < 0.001) and LDH (p = 0.001) but higher neutrophil count (p = 0.045), neutrophil/lymphocyte ratio (p < 0.001), C-reactive protein (p < 0.001) and procalcitonin (p < 0.001). Patients in the MIS-C group were less likely to receive invasive ventilation (13.3% vs 41.4%, p = 0.005) but were more often treated with vasoactive drugs (66.7% vs 24.1%, p < 0.001), corticosteroids (80% vs 44.8%, p = 0.003) and immunoglobulins (51.1% vs 6.9%, p < 0.001). Most patients were discharged from PICU by the end of data collection with a median length of stay of 5 days (IQR 2.5-8 days) in the MIS-C group. Three patients died, none of them belonged to the MIS-C group. Conclusions MIS-C seems to be the most frequent presentation among critically ill children with SARS-CoV-2 infection. MIS-C patients are older and usually healthy. They show a higher prevalence of gastrointestinal symptoms and shock and are more likely to receive vasoactive drugs and immunomodulators and less likely to need mechanical ventilation than non-MIS-C patients

Severe manifestations of SARS-CoV-2 in children and adolescents: from COVID-19 pneumonia to multisystem inflammatory syndrome: a multicentre study in pediatric intensive care units in Spain

Background Multisystem inflammatory syndrome temporally associated with COVID-19 (MIS-C) has been described as a novel and often severe presentation of SARS-CoV-2 infection in children. We aimed to describe the characteristics of children admitted to Pediatric Intensive Care Units (PICUs) presenting with MIS-C in comparison with those admitted with SARS-CoV-2 infection with other features such as COVID-19 pneumonia. Methods A multicentric prospective national registry including 47 PICUs was carried out. Data from children admitted with confirmed SARS-CoV-2 infection or fulfilling MIS-C criteria (with or without SARS-CoV-2 PCR confirmation) were collected. Clinical, laboratory and therapeutic features between MIS-C and non-MIS-C patients were compared. Results Seventy-four children were recruited. Sixty-one percent met MIS-C definition. MIS-C patients were older than non-MIS-C patients (p = 0.002): 9.4 years (IQR 5.5–11.8) vs 3.4 years (IQR 0.4–9.4). A higher proportion of them had no previous medical history of interest (88.2% vs 51.7%, p = 0.005). Non-MIS-C patients presented more frequently with respiratory distress (60.7% vs 13.3%, p < 0.001). MIS-C patients showed higher prevalence of fever (95.6% vs 64.3%, p < 0.001), diarrhea (66.7% vs 11.5%, p < 0.001), vomits (71.1% vs 23.1%, p = 0.001), fatigue (65.9% vs 36%, p = 0.016), shock (84.4% vs 13.8%, p < 0.001) and cardiac dysfunction (53.3% vs 10.3%, p = 0.001). MIS-C group had a lower lymphocyte count (p < 0.001) and LDH (p = 0.001) but higher neutrophil count (p = 0.045), neutrophil/lymphocyte ratio (p < 0.001), C-reactive protein (p < 0.001) and procalcitonin (p < 0.001). Patients in the MIS-C group were less likely to receive invasive ventilation (13.3% vs 41.4%, p = 0.005) but were more often treated with vasoactive drugs (66.7% vs 24.1%, p < 0.001), corticosteroids (80% vs 44.8%, p = 0.003) and immunoglobulins (51.1% vs 6.9%, p < 0.001). Most patients were discharged from PICU by the end of data collection with a median length of stay of 5 days (IQR 2.5–8 days) in the MIS-C group. Three patients died, none of them belonged to the MIS-C group. Conclusions MIS-C seems to be the most frequent presentation among critically ill children with SARS-CoV-2 infection. MIS-C patients are older and usually healthy. They show a higher prevalence of gastrointestinal symptoms and shock and are more likely to receive vasoactive drugs and immunomodulators and less likely to need mechanical ventilation than non-MIS-C patients

The Peripheral Arterial disease study (PERART/ARTPER): prevalence and risk factors in the general population

<p>Abstract</p> <p>Background</p> <p>The early diagnosis of atherosclerotic disease is essential for developing preventive strategies in populations at high risk and acting when the disease is still asymptomatic. A low ankle-arm index is a good marker of vascular events and may be diminished without presenting symptomatology (silent peripheral arterial disease). The aim of the study is to know the prevalence and associated risk factors of peripheral arterial disease in the general population.</p> <p>Methods</p> <p>We performed a cross-sectional, multicentre, population-based study in 3786 individuals >49 years, randomly selected in 28 primary care centres in Barcelona (Spain). Peripheral arterial disease was evaluated using the ankle-arm index. Values < 0.9 were considered as peripheral arterial disease.</p> <p>Results</p> <p>The prevalence (95% confidence interval) of peripheral arterial disease was 7.6% (6.7-8.4), (males 10.2% (9.2-11.2), females 5.3% (4.6-6.0); <it>p </it>< 0.001).</p> <p>Multivariate analysis showed the following risk factors: male sex [odds ratio (OR) 1.62; 95% confidence interval 1.01-2.59]; age OR 2.00 per 10 years (1.64-2.44); inability to perform physical activity [OR 1.77 (1.17-2.68) for mild limitation to OR 7.08 (2.61-19.16) for breathless performing any activity]; smoking [OR 2.19 (1.34-3.58) for former smokers and OR 3.83 (2.23-6.58) for current smokers]; hypertension OR 1.85 (1.29-2.65); diabetes OR 2.01 (1.42-2.83); previous cardiovascular disease OR 2.19 (1.52-3.15); hypercholesterolemia OR 1.55 (1.11-2.18); hypertriglyceridemia OR 1.55 (1.10-2.19). Body mass index ≥25 Kg/m²OR 0.57 (0.38-0.87) and walking >7 hours/week OR 0.67 (0.49-0.94) were found as protector factors.</p> <p>Conclusions</p> <p>The prevalence of peripheral arterial disease is low, higher in males and increases with age in both sexes. In addition to previously described risk factors we found a protector effect in physical exercise and overweight.</p

Analytical Models for Randomized Neighbor Discovery Protocols based on Collision Detection in Wireless Ad Hoc Networks

[EN] Neighbor discovery is a crucial first step after the deployment of wireless ad hoc networks, which do not have a communications infrastructure. In this paper we present analytical models of randomized neighbor discovery protocols for static one-hop environments: CDPRR (Collision Detection Probabilistic Round Robin) and CDH (Collision Detection Hello). For CDPRR we assumed a geometric distribution and a uniform distribution for CDH. For comparison purposes, we chose two protocols from the literature, i.e., Hello and PRR, to be used as reference. To assess the performance of the proposals we carried out a mathematical study regarding six metrics, i.e., neighbor discovery time, energy consumption, overhead (number of packets sent), packet delivery ratio, the CDF of discoveries, and percentage of idle slots, and presented graphical results obtained from the equations. According to the analytical results, CDH protocol outperforms the other solutions regarding the neighbor discovery time, energy consumption, number of packets sent, packet delivery ratio and CDF of discoveries, while CDPRR achieves good results and it is better than Hello and PRR in terms of neighbor discovery time, energy consumption, CDF of discoveries and the overhead (number of packets sent). Moreover, we found that CDPRR presents more percentage of idle slots than PRR, which is a clear advantage in terms of energy consumed and number of packets sent. In addition, as novelty compared to the reference protocols, we found that both CDH and CDPRR protocols manage to discover all the neighbors, know when to terminate the discovery process, and achieve to operate under more realistic assumptions. We also focused the study on the CDH protocol varying the slot width, and demonstrated that the number of nodes in the network can be unknown, still providing reasonable results.This work has been partially supported by the "Ministerio de Economia y Competitividad'' in the "Programa Estatal de Fomento de la Investigacion Cientifica y Tecnica de Excelencia, Subprograma Estatal de Generacion de Conocimiento'' within the project under Grant TIN2017-84802-C2-1-P. This work has also been partially supported by European Union through the ERANETMED (Euromediterranean Cooperation through ERANET joint activities and beyond) project ERANETMED3-227 SMARTWATIR.Sorribes, JV.; Lloret, J.; Peñalver Herrero, ML. (2022). Analytical Models for Randomized Neighbor Discovery Protocols based on Collision Detection in Wireless Ad Hoc Networks. Ad Hoc Networks. 126(102739):1-19. https://doi.org/10.1016/j.adhoc.2021.10273911912610273