Velázquez, Ramiro
Preferred name
Velázquez, Ramiro
Official Name
Velázquez Guerrero, Ramiro
Alternative Name
rvelazquez
Main Affiliation
ORCID
0000-0001-9966-9131
Scopus Author ID
7003505296
Researcher ID
GQW-6348-2022
179 results
Now showing 1 - 10 of 179
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Item type:Publication, Adaptive Jamming Mitigation for Clustered Energy-Efficient LoRa-BLE Hybrid Wireless Sensor Networks(MDPI AG, 2025-03-20); ; ; José Varela-AldásWireless sensor networks (WSNs) are fundamental for modern IoT applications, yet they remain highly vulnerable to jamming attacks, which significantly degrade communication reliability and energy efficiency. This paper proposes a novel adaptive cluster-based jamming mitigation algorithm designed for heterogeneous WSNs that integrate LoRa and Bluetooth Low Energy (BLE) technologies. The proposed strategy dynamically switches between communication protocols, optimizes energy consumption, and reduces retransmissions under interference conditions by leveraging real-time network topology adjustments and adaptive transmission power control. Through extensive experimental validation, we demonstrate that our mitigation mechanism reduces energy consumption by up to 38% and lowers packet retransmission rates by 47% compared to single-protocol networks under jamming conditions. Additionally, our results indicate that the hybrid LoRa-BLE approach outperforms standalone LoRa and BLE configurations in terms of network resilience, adaptability, and sustained data transmission under attack scenarios. This work advances the state-of-the-art by introducing a multi-protocol interference-resilient communication strategy, paving the way for more robust, energy-efficient, and secure WSN deployments in smart cities, industrial IoT, and critical infrastructure monitoring. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Real-Time Object Finding for the Visually Impaired Using an Image-to-Speech Wearable Device(Springer Nature Switzerland, 2025-11-18); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Dynamic Jamming Mitigation in Wireless Sensor Networks: A Comprehensive Algorithm for Resilience and Efficiency(Springer Nature Switzerland, 2025-11-18); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Editorial – Elsevier smart health special issue: Advancing ICT for health, accessibility, and wellbeing(Elsevier BV, 2025-06) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, On the Design of New Assistive Mobility Devices to Enhance Spatial Cognition(Springer Nature Switzerland, 2026) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Mechanical, Thermal, and Environmental Energy Harvesting Solutions in Fully Electric and Hybrid Vehicles: Innovative Approaches and Commercial Systems(MDPI AG, 2025-04-11); ; Roberto De FazioEnergy harvesting in the automotive sector is a rapidly growing field aimed at improving vehicle efficiency and sustainability by recovering wasted energy. Various technologies have been developed to convert mechanical, thermal, and environmental energy into electrical power, reducing dependency on traditional energy sources. This manuscript provides a comprehensive review of energy harvesting applications/methodologies, aiming to trace the research lines and future developments. This work identifies the main categories of harvesting solutions, namely mechanical, thermal, and hybrid/environmental solar–wind systems; each section includes a detailed review of the technical and scientific state of the art and a comparative analysis with detailed tables, allowing the state of the art to be mapped for identification of the strengths of each solution, as well as the challenges and future developments needed to enhance the technological level. These improvements focus on energy conversion efficiency, material innovation, vehicle integration, energy savings, and environmental sustainability. The mechanical harvesting section focuses on energy recovery from vehicle vibrations, with emphasis on regenerative suspensions and piezoelectric-based solutions. Specifically, solutions applied to suspensions with electric generators can achieve power outputs of around 1 kW, while piezoelectric-based suspension systems can generate up to tens of watts. The thermal harvesting section, instead, explores methods for converting waste heat from an internal combustion engine (ICE) into electrical power, including thermoelectric generators (TEGs) and organic Rankine cycle systems (ORC). Notably, ICEs with TEGs can recover above 1 kW of power, while ICE-based ORC systems can generate tens of watts. On the other hand, TEGs integrated into braking systems can harvest a few watts of power. Then, hybrid solutions are discussed, focusing on integrated mechanical and thermal energy recovery systems, as well as solar and wind energy harvesting. Hybrid solutions can achieve power outputs above 1 kW, with the main contribution from TEGs (≈1 kW), compared to piezoelectric systems (hundreds of W). Lastly, a section on commercial solutions highlights how current scientific research meets the automotive sector’s needs, providing significant insights for future development. For these reasons, the research results aim to be guidelines for a better understanding of where future studies should focus to improve the technological level and efficiency of energy harvesting solutions in the automotive sector. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Tecnología Funcional de Nariz Electrónica para el Monitoreo de Gases en el Aire(Escuela Politecnica Nacional, 2025-11-30); ; Roberto De FazioEn los últimos años, las narices electrónicas se han consolidado como herramientas innovadoras para el monitoreo ambiental, particularmente en la detección de contaminantes en el aire. En este trabajo, se presenta el diseño e implementación de una tecnología funcional, portátil y de bajo costo de nariz electrónica, capaz de identificar gases como el monóxido de carbono, el metano y varios compuestos volátiles. Esta tecnología integra un arreglo de sensores y un módulo de adquisición de datos junto con algoritmos avanzados de procesamiento de señales. Se propone la aplicación del Método de Filtrado y Diagonalización (FDM) para la extracción de características espectrales, combinado con Bosques Aleatorios (RF) para la clasificación de gases. Los resultados experimentales demuestran una precisión del 96.4 % en la identificación de compuestos gaseosos, validando la efectividad de la combinación FDM-RF. Este estudio contribuye al avance de tecnologías accesibles para el monitoreo de la calidad del aire y así como de nuevos métodos de detección y clasificación de gases ambientales. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, On Spatial Cognition and Mobility Strategies(Springer Nature Switzerland, 2026); Simon Gay - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Optimización del balanceo de un mecanismo plano mediante redistribución de masas(2022); ; ; 9 2 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A four-fingered robot hand with shape memory alloys(2009)Scopus© Citations 18 11 1