1,721,548 research outputs found
Underwater Acoustic Modems
Full text link© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Due to the growing interest using underwater acoustic networks, there are more and more research papers about underwater communications. These papers are mainly focused on deployments and studies about the constraints of the underwater medium. The underwater acoustic channel is highly variable and the signal transmission can change according to environmental factors such as the temperature, pressure or salinity of the water. For this reason, it is important to know how these devices are developed and the maximum distance and data transfer rates they can achieve. To this end, this paper presents an exhaustive study of existing underwater acoustic modems where their main features are highlighted. We also review the main features of their hardware. All presented proposals in the research literature are compared with commercial underwater acoustic modems. Finally, we analyze different programs and improvements of existing network simulators that are often used to simulate and estimate the behavior of underwater networks.This work was supported by the Ministerio de Ciencia e Innovacion through the Plan Nacional de I+D+i 2008-2011 within the Subprograma de Proyectos de Investigacion Fundamental under Project TEC2011-27516. The associate editor coordinating the review of this paper and approving it for publication was Dr. Lei Shu. (Corresponding author: Jaime Lloret.)Sendra, Sandra;Lloret, Jaime;Jimenez, Jose M.;Parra-Boronat, L. (2015). Underwater Acoustic Modems. IEEE Sensors Journal. 16(11):4063-4071. https://doi.org/10.1109/JSEN.2015.2434890S40634071161
Probabilistic Semantic Filtering and Uncertainty-Aware Compression for Energy-Efficient RF Communication
No full text[EN] We propose a novel approach to energy-efficient radio frequency (RF) communication based on uncertainty-aware semantic filtering and multitask learning. The framework utilizes a Bayesian neural network (BNN) with Monte Carlo Dropout to estimate predictive uncertainty and filter semantically redundant RF frames. This adaptive mechanism enables efficient data reduction based on confidence levels, optimizing bandwidth without sacrificing performance. The retained high-confidence frames are used for multiclass modulation classification and signal-to-noise ratio (SNR) prediction, supporting intelligent transmission under varying channel conditions while minimizing unnecessary processing. Experimental results show that entropy-based filtering achieves bandwidth savings of up to 40%, maintaining 90.80% classification accuracy, and reducing energy consumption by 10% compared to the baseline. uniform manifold approximation and projection (UMAP) visualizations confirm improved latent space separability after filtering. Energy consumption is tracked using CodeCarbon, showing a significant reduction in energy per transmitted frame. The proposed framework is lightweight, ideal for real-time inference in resource-constrained environments, and offers applications in edge artificial intelligence (AI), low-power Internet of Things (IoT), and vehicular networks (V2X), paving the way for energy-efficient communication in future 6G systems.Ciocan, AV.;Hamrioui, S.;Lorenz, P.;Lloret, Jaime (2025). Probabilistic Semantic Filtering and Uncertainty-Aware Compression for Energy-Efficient RF Communication. IEEE Internet of Things. 12(19):40628-40635. https://doi.org/10.1109/JIOT.2025.3589498S4062840635121
Cost-Effective Strategy for IIoT Security Based on Bi-Objective Optimization
No full text[EN] The Internet of Things (IoT) and its industrial counterpart, the industrial IoT (IIoT), have transformed sectors, such as home automation, healthcare, and manufacturing by enhancing data management through advanced networking. However, the rapid growth of IIoT has introduced significant cybersecurity challenges, necessitating a comprehensive approach to securing data across the TCP/IP model. This article presents a novel cybersecurity investment strategy formulated as a bi-objective optimization problem, validated through genetic and iterative algorithms. The strategy effectively balances security and cost, achieving nearly 50% efficiency in solution effectiveness. By utilizing these optimization techniques, the approach provides a practical and cost-effective solution to improve IIoT security within budget constraints, offering valuable insights for cybersecurity professionals seeking robust and economically viable solutions.This work was supported in part by the CERADE Laboratory at ESAIP School of Engineering as part of its projects on cybersecurity and IIoT, and in part by the Brazilian National Council for Scientific and Technological Development (CNPq) under Grant 306607/2023-9.Hamrioui, S.;Lorenz, P.;Lloret, Jaime;Rodrigues, JJ. (2025). Cost-Effective Strategy for IIoT Security Based on Bi-Objective Optimization. IEEE Internet of Things. 12(10):14577-14585. https://doi.org/10.1109/JIOT.2025.3525779S1457714585121
Simple Two-Wire Lead Compensation for Resistive Sensors Using Microcontroller ADCs
No full text[EN] This article introduces a simplified two-wire measurement system for accurate resistance measurement of resistive sensors, leveraging the Anderson current loop. The proposed configuration features a precision reference resistor ( R-ref ) and two diodes ( D-1 and D-2 ), directly interfaced with the analog-to-digital converter (ADC) and output pins of a microcontroller, eliminating the need for external stabilization resistors. Utilizing ratiometric voltage measurements and an adaptive tuning factor, the system effectively compensates for lead-wire resistance and diode mismatches. A prototype implemented with an ATmega2560 microcontroller demonstrates accurate resistance measurements in the range of 60- 320 Omega , corresponding to a Pt100 sensor, achieving an uncertainty error of less than 0.13% for a lead-wire resistance of 4.87 Omega and 0.15% for 10.0 Omega . Experimental results confirm the system's precision and reliability over long lead lengths, offering a cost effective and robust solution for industrial and remote sensing applications requiring accurate temperature measurements.This work was supported by Mahasarakham University.Aurasopon, A.;Khamsen, W.;Takeang, C.;Lloret, Jaime (2025). Simple Two-Wire Lead Compensation for Resistive Sensors Using Microcontroller ADCs. IEEE Sensors Journal. 25(9):15873-15881. https://doi.org/10.1109/JSEN.2025.3549778S158731588125
Optimizing IoT network lifetime through an enhanced hybrid energy harvesting system
No full text[EN] The growing need for sustainable and renewable energy sources has become critical with the Internet of Things (IoT) advancement. IoT relies on low-power, battery-operated devices, but the limited lifespan of these batteries requires frequent recharging or replacement, which is costly and time-consuming. Researchers have proposed energy harvesting systems that capture sustainable ambient energy from the environment to address this issue. This paper presents a hybrid system for harvesting sustainable energy from solar and wind sources. The system features a boost converter controlled by a novel hybrid method combining the Honey Badger Algorithm (HBA) and Harris Hawks Optimization (HHO). This method maximizes power extraction from solar and wind sources, enhancing overall system efficiency. Additionally, the system includes an innovative energy management algorithm that selects the most powerful input source while protecting the storage battery from overcharging or complete depletion, thereby extending its lifespan. The proposed design is validated through MATLAB/Simulink simulations. The HHO-HBA MPPT is compared with existing MPPT methods, evaluating efficiency, battery charge curves, and IoT network energy status. Simulation results show that the proposed approach significantly increases network longevity, offering a cost-effective and sustainable solution for the energy needs of Wireless Sensor Network (WSN)-IoT devices.Rabah, S.;Zaier, A.;Sendra, Sandra;Lloret, Jaime;Dahman, H. (2025). Optimizing IoT network lifetime through an enhanced hybrid energy harvesting system. Sustainable Computing: Informatics and Systems. 46. https://doi.org/10.1016/j.suscom.2025.101081S4
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
- …
