An Efficient NVoD Scheme Using Implicit Error Correction and Subchannels for Wireless Networks

Implicit Error Correction (IEC) is a near Video-on-Demand (nVoD) scheme that trades bandwidth utilization for initial playback delay to potentially support an infinite number of users. Additionally, it provides error protection without any further bandwidth increase by exploiting the implicit redundancy of nVoD protocols, using linear combinations of the segments transmitted in a given time slot. However, IEC packet loss protection is weaker at the beginning of the playback due to the lack of implicit redundancy and lower decoding efficiency, resulting in worse subjective playback quality. In tackling this issue, this paper contributes with an extension of the original nVoD architecture, enhancing its performance by adding a new element namely, subchannels. These subdivisions of the original channels do not provide further packet loss protection but significantly improve the decoding efficiency, which in turn increases playback quality, especially at the beginning. Even for very high packet loss probabilities, subchannels are designed to obtain higher decoding efficiency which results in greater packet loss protection than that provided by IEC. The proposed scheme is especially useful in wireless cooperative networks using techniques such as network coding, as content transmissions can be split into different subchannels in order to maximize network efficiency.This work was supported by the AEI/FEDER, UE Project AIM under Grant TEC2016-76465-C2-1-R

Simone: a dynamic monitoring simulator for the evacuation of navy ships

In this paper, the automation of the evacuation process of a military ship is studied in real time. For this purpose, a scenario is reconfigured to produce a failure or damage. Then, an optimal network of alternative escape routes is computed. The resulting escape route map can be indicated by lighting the appropriate corridors on the ship. Through these corridors, the members of the embarked population and the entire process is monitored so that the crew can reach their lifeboats in the shortest possible time. To undertake this automated process, the dynamic ship evacuation monitoring system (SIMONE, from its acronym in Spanish: Sistema de Monitorización Dinámica de Evacuación de Buques) has been developed. This system integrates a communication gateway with the integrated platform control system (IPCS) and integrated lighting system that will be installed in new Spanish naval constructions.This research was funded by MCIN/AEI/10.13039/501100011033 grant number PID2020-116329GB-C22 and grant number TED2021-129336B-I00. This work is also a result of an internship funded by the Autonomous Community of the Region of Murcia through the Fundación Séneca-Agencia de Ciencia y Tecnología de la Región de Murcia (Seneca Foundation—Agency for Science and Technology in the Region of Murcia) and European Union NextGenerationEU program

Characterization of a piezoelectric acoustic sensor fabricated for low-frequency applications: a comparative study of three methods

Piezoelectric transducers are widely used for generating acoustic energy, and choosing the right radiating element is crucial for efficient energy conversion. In recent decades, numerous studies have been conducted to characterize ceramics based on their elastic, dielectric, and electromechanical properties, which have improved our understanding of their vibrational behavior and aided in the manufacturing of piezoelectric transducers for ultrasonic applications. However, most of these studies have focused on the characterization of ceramics and transducers using electrical impedance to obtain resonance and anti-resonance frequencies. Few studies have explored other important quantities such as acoustic sensitivity using the direct comparison method. In this work, we present a comprehensive study that covers the design, manufacturing, and experimental validation of a small-sized, easy-to-assemble piezoelectric acoustic sensor for low-frequency applications, using a soft ceramic PIC255 from PI Ceramic with a diameter of 10 mm and a thickness of 5 mm. We present two methods, analytical and numerical, for sensor design, followed by experimental validation, allowing for a direct comparison of measurements with simulated results. This work provides a useful evaluation and characterization tool for future applications of ultrasonic measurement systems.This workwas supported by the grants PID2020-116329GB-C22 and TED2021-129336B-I00 funded by MCIN/AEI/10.13039/501100011033 and by the European Union NextGenerationEU/PRTR. This work is also a result of an internship funded by the Autonomous Community of the Región of Murcia through the Fundación Séneca—Agencia de Ciencia y Tecnología de la Región de Murcia (Seneca Foundation—Agency for Science and Technology in the Region of Murcia) and the European Union’s NextGenerationEU program

Nanorouter awareness in flow-guided nanocommunication networks

Flow-guided electromagnetic nanonetworks will enable innovative medical applications for monitoring, information gathering, and data transmission inside the human body. These nanonetworks will have to operate under extreme computational and powering-related constraints, and in very hostile environments inside human vascular systems. Under these circumstances, successful transmissions between in-body nanonodes and an on-body nanorouter rarely occur, thus requiring new approaches to improve the network throughput in this scenario. Along this view, in classical flow-guided nanonetworks the nanonodes are envisioned to transmit packets if they have enough energy for the transmission, regardless of their vicinity to the nanorouter. In this paper, we propose a nanorouter awareness model that can provide significant throughput gains compared to the baseline based on blind transmissions, facilitating the roll-out of nanocommunication-supported medical applications.This work was supported by project “AriSe2: Future IoT Networks and Nano-networks (FINe)”, ref. PID2020-116329GB-C22 (AEI/FEDER, UE). This work was supported in part by the Fundación Séneca, Región de Murcia, through the ATENTO Project, under Grant 20889/PI/18, and in part by the LIFE project (Fondo SUPERA Covid-19 funded by the Agencia Estatal Consejo Superior de Investigaciones Científicas CSIC, Universidades Españolas, and Banco Santander). The author Filip Lemic was supported by the EU Marie Curie Actions Individual Fellowship project entitiled “Scalable Localization-enabled In-body Terahertz Nanonetwork” (ScaLeITN), grant nr. 893760

Understanding the applicability of terahertz flow-guided nano-networksfor medical applications

Terahertz-based nano-networks are emerging as a groundbreaking technology able to play a decisive role in future medical applications owing to their ability to precisely quantify figures, such as the viral load in a patient or to predict sepsis shock or heart attacks before they occur. Due to the extremely limited size of the devices composing these nano-networks, the use of the Terahertz (THz) band has emerged as the enabling technology for their communication. However, the characteristics of the THz band, which strictly reduce the communication range inside the human body, together with the energy limitations of nano-nodes make the in-body deployment of nano-nodes a challenging task. To overcome these problems, we propose a novel in-body flow-guided nano-network architecture consisting of three different devices: i) nano-node, ii) nano-router, and iii) bio-sensor. As the performance of this type of nano-network has not been previously explored, a theoretical framework capturing all its particularities is derived to properly model its behavior and evaluate its feasibility in real medical applications. Employing this analytical model, a thorough sensitivity study of its key parameters is accomplished. Finally, we analyze the terahertz flow-guided nano-network design to satisfy the requirements of several medical applications of interest

Co-creación, Arte Digital y Agencia: Experiencias de un proyecto de co-creación de obras de arte digital en Colombia

Este artículo analiza el proceso de co-creación de una obra de arte digital en el contexto del conflicto armado colombiano. El artículo sitúa este proceso dentro de un panorama más amplio de experiencias artísticas dedicadas a para transformar, testimoniar o bien generar memoria sobre el conflicto. Todas estas prácticas son parte del actual “boom de la memoria” que se vive en Colombia y se involucran con la teorización sobre victimización y sobrevivencia. A continuación, este artículo establece un dialogo con debates recientes de las Humanidades digitales que han exigido una ampliación de esta disciplina indicando cuestiones clave de representación artística digital. El articulo entonces hipotetiza sobre el potencial que los métodos artísticos digitales pueden tener para formas alternativas de compromiso y representación de experiencias traumáticas. A continuación, el artículo expone la conceptualización del enfoque artístico que sustenta la obra de arte digital en cuestión: Voces invisibles: Mujeres Víctimas del Conflicto Colombiano, con una descripción de las metodologías de co-creación seguidas de una presentación de la obra de arte resultante. El artículo reflexiona sobre el uso de métodos digitales y la transcreación a través de prácticas multimodales y multimedia para fomentar el intercambio de temas personales, sociales y colectivos, involucrando a los participantes en la exploración de prácticas artísticas en talleres físicos de co-creación con metodologías y enfoques adaptados. </jats:p