Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

The objective of this work is to determine the bistatic angle from which independent random samples can be obtained. It also investigates the degree of correlation of the backscattered signals as a function of the spatial distribution of the receiving points and their time difference of arrival when using a multistatic radar system. Obtaining large, independent random samples is a crucial requirement for applying and developing the DRACEC method, which is used for detection in moment space based on a Gaussian distribution. This requirement is challenging to meet due to the prohibitively long acquisition and processing times involved. However, it becomes feasible through the use of multiple receivers, which enable the simultaneous acquisition of large, independent random samples. Furthermore, this work develops a simulation of the secondary emission correlation as a function of the bistatic angle, considering the baseline length between the transmitter and receiver and the angle between them. An exhaustive analysis is also performed of the spatial and temporal correlation function of the signal fluctuations from a radar target in a Multistatic Radar System (MRCS) comprising one transmitter and two receivers. Finally, this work derives approximate expressions for determining the correlation coefficient, as well as the approximate conditions for high and low spatial and temporal correlation of the echo fluctuations at the input of the MRCS receivers. INDEX TERMS: Bistatic radar, bistatic angle, multistatic radar system.

In Cuba, ETECSA has implemented VoIP in mobile and fixed networks (Nauta-Hogar and Public Wi-Fi Zones). However, the quality levels offered have not yet been evaluated adequately, a process essential for their commercialization and improvement. This article develops a procedure for measuring and evaluating VoIP QoS, applicable to fixed and mobile networks. The authors identified and established Key parameters such as delay, jitter, packet loss, and measurement methods for each type of network. Also, it validated the procedure through its application in real scenarios within ETECSA's network, demonstrating its effectiveness in providing an accurate evaluation of QoS and enabling the provider to improve service quality in both environments continuously.   index terms: Quality of Service (QoS), Voice Over IP (VoIP), Mobile Network, Nauta-Hogar, Public Wi-Fi, Measurement, Evaluation, Parameters.

Traditional IP network architecture has supported Internet development for decades, but it faces increasing limitations in the face of emerging application demands such as massive IoT, vehicular networks, and 6G services. This article presents a comparative analysis, based on scientific literature, between IP network management models and information-centric architectures, which are emerging as an alternative for a more efficient and flexible Internet. Fundamental aspects such as addressing, routing, traffic control, monitoring, security, scalability, and deployment strategies are addressed. The study identifies the main management challenges in both paradigms, highlighting how the ICN model enables native content management, greater distribution efficiency, data-level security, and mobility support. In addition, use cases in dynamic environments such as IoT and IoV are analyzed, as well as hybrid IP-ICN integration scenarios using technologies such as SDN. This work provides a clear overview of the state of the art and highlights the opportunities and challenges that must be addressed for an effective transition to content-centric networks.   INDEX TERMS: Network management, Information-Centric Networks (ICN), IP networks, Internet of Things (IoT), Internet of Vehicles (IoV).  

Rising energy consumption in data centers underscores the need for precise energy efficiency evaluation. This article critically examines current metrics for assessing data center energy performance, with particular attention to the limitations of the Power Usage Effectiveness (PUE). Additional metrics are examined to enable a general assessment that links energy consumption to service quality. Commercial and open-source tools for estimating PUE are compared based on their accuracy, usability, and cost-effectiveness. A layered integration architecture is introduced to measure energy efficiency metrics. This approach addresses the heterogeneity of energy data and supports accurate, near real-time presentation measurements for analysis of data center efficiency.   KEYWORDS: energy efficiency, PUE, data centers, evaluation tools, energy management.

One of the targets of signal processing is the feature identification of signal under test in such a way that it allows the measurement of important parameters related to the analyzed waveform. In this sense  the so called noticeable or fiducial points are considered, i.e. maxima, minima, onsets and offsets and other ones of interest. Still in ideal conditions to get some of these points might be relatively involved. In the presence of noise such process is even more complicated. The authors of this paper have developed a tool called "curvature filters" which makes possible to  capture, in an one-dimensional array, on the presence of noise, the more highlighting changes in a signal, getting  the onsets, offsets and local  peaks, with a taskforce easier in comparison with current methods. These issues has been reported by the authors in previous published works.  In the present report emphasis is targeted in the behavior in face to noise of the proposed process, summarizing application examples in the characterization of electrocardiographic signals. The procedure is simulated in Matlab and GNU Octave by using test signals from the MIT medical database, Cardiosim II equipment patterns and synthetic signals developed by the authors.

Carrying out maintenance in industrial sectors is essential and if this can be done in a predictive way, that is, it is possible to carry out preventive actions on the equipment before failures occur that leave them out of service, which is known as predictive maintenance, the downtimes and will be earned on availability. With the integration of Industry 4.0 technologies (Internet of things, cloud computing, cloud computing, Big Data, artificial intelligence, cybersecurity and cyber-physical systems, virtual reality, among others) to predictive maintenance, it is achieved that this is more efficient, consumes less time and allows better decisions to be made, however, carrying out such integration can be complex. To facilitate the performance of predictive maintenance, this project proposes a procedure that implements it, using Industry 4.0 technologies. This procedure consists of four stages: general requirements, data collection, data processing and maintenance execution and it was validated with its application to the use case of a thermoelectric plant.

The present article proposes to highlight forms of didactic approaches that seek to problematize the Teaching of History in contemporary times and its relationship with social and ethnic-racial issues that excel in a progressive education, marked by diversity and cultural plurality. The aim is to make a critical reading of its conservative axis that has gained strength in recent years, highlighting its exclusionary and Eurocentric bias, in favor of a non-discriminatory and anti-racist education. Therefore, we will approach the relevance and ways of applicability of heritage education, transdisciplinarity and decolonial epistemology in History Teaching, highlighting the important role of such practices for the construction of citizenship, social identity and the formation of collective subjectivities.

The integration of Network Function Virtualization (NFV) and Software-Defined Networking (SDN) technologies in the 5G Core (5GC) represents a crucial advancement in the telecommunications sector. These innovations offer significant improvements in flexibility, scalability, and operational efficiency. Through virtualization, an effective separation between hardware and software is achieved, which maximizes performance and minimizes dependence on specialized equipment. Despite their advantages, the development of these technologies has mainly been run by large corporations, creating challenges such as high acquisition costs and technological dependence. However, open-source initiatives that allow greater access and encourage innovation and collaboration within the sector have emerged. This article aims to conduct a literature review on the implementation of SDN and NFV in the 5GC and an evaluation of open-source technical solutions for its implementation. The combination of SDN and NFV optimizes available resources and enables the creation of advanced services that benefit various economic sectors. Ultimately, integrating these technologies in 5GC becomes a fundamental step towards a more efficient and adaptable future for telecommunications.

The accelerated technological development, with increasingly exponential growth in the first decades of the 21st century and its widespread use in all economic and social spheres in the world, imposes challenges to society and also to professional training. The latter implies the need to introduce modifications in both pre- and post-graduate professional training, which includes not only changes in contents, but also essential changes in the pedagogical approaches used in the teaching-learning process.  One of the new contents introduced in professional training is that of Sensor Networks, both in undergraduate and master courses. At the Technological University of Havana CUJAE, this subject is part of an optional undergraduate course and of the compulsory course Sensors and Sensor Networks, of the Electronics profile of the Master's Degree. It was proposed as a paradigm to place the student at the center of the learning process and guide his thinking to achieve the individual development of professional capacities and competences - taking into account affective, social and cognitive factors - and to lay the foundations for his self-preparation and creative performance. The article presents the results of the application of a teaching-learning methodology for the design of sensor networks (previously elaborated and published) applicable at different levels of education. The results obtained in elective and Master's courses, using new pedagogical approaches, show its efficiency and effectiveness. The evaluation of teachers and students of both courses is also presented.

The management of networks and services in the field of Information and Communication Technologies (ICT) requires a set of activities, methods, procedures and tools to ensure the proper functioning of a networked system. In this context, computer tools and information visualization techniques are essential to facilitate the monitoring and maintenance tasks of network administrators in their daily tasks. This article provides a systematic review of the literature on information visualization concepts, types, tools and techniques applied to network and service management. Through a historical analysis, the evolution and importance of these techniques as a tool to support the network and service management process is discussed. Finally, practical use cases are presented and future trends are explored, such as the integration of artificial intelligence and advanced analytics, which promise to transform the way information is visualized and managed in networks. This work seeks to provide a comprehensive and up-to-date view of the subject, serving as a reference for professionals and researchers in the ICT field.