Around the world, managing and classifying solid waste is one of the most important challenges to sustaining economic growth and preserving the environment. The objective of this paper is to propose the use of Smart Ecological Points as a strategy to address the problem of solid waste management systems at the source, which has become one of the biggest problems globally, and Colombia is no exception. This article describes the current state of the problem in the country and presents a prototype of a low-cost Smart Ecological Point supported by the use of an experimental capacitive sensor and machine learning algorithms, which will reduce the time necessary for the classification of recyclable and non-recyclable waste, increasing the percentage of waste that can be reused and minimizing health risks by reducing the probability of being contaminated at the source, an aspect that is very common when waste is sorted manually. According to the results obtained, it is evident that the proposed prototype made an adequate classification of waste, generating the possibility of it being manufactured with existing technology in order to promote adequate waste classification at the source.

The excessive use of fossil fuels and the increasing generation of solid waste, driven by population growth, industrialization, and economic development, have led to serious environmental, energy, and public health issues. In light of this problem, it is crucial to adopt sustainable solutions that promote the transition to renewable energy sources, such as biogas. Although progress has been made in optimizing biogas production, there is still no adaptable model for various environments that allows for the determination of optimal quantities of different organic wastes, simultaneously considering their composition, moisture content, and control of critical factors for biogas production, as well as the biodigester’s capacity and other relevant elements. In practice, the dosing of waste is conducted empirically, leading to inefficiencies that limit the potential for biogas production in real scenarios. The objective of this article is to propose a linear optimization model with nonlinear constraints that maximizes biogas production, considering fundamental parameters such as the moisture percentage, pH, carbon/nitrogen ratio (C/N), substrate volume, organic matter, volatile solids (VS), and biogas production potential from different wastes. The model estimates the optimal waste composition based on the biodigester capacity to ensure balanced substrates. The results for the proposed scenarios demonstrate its effectiveness: Scenario 1 achieved 3.42 m³ (3418.67 L) of biogas, while Scenario 2, with a greater diversity of waste, reached 8.06 m³ (8061.43 L). The model maintained pH (6.49–6.50), C/N ratio (20.00), and moisture (60.00%) within optimal ranges. Additionally, a Monte Carlo sensitivity analysis (1000 simulations) validated its robustness with a 95% confidence level. This model provides an efficient tool for optimizing biogas production and waste dosing in rural contexts, promoting clean and sustainable technologies for renewable energy generation.

Las redes BPL (Broadband Power Line) operan bajo el estándar HomePlug AV (HPAV) el cual utiliza las tecnologías CSMA/CA y TDMA como mecanismo de acceso al medio, donde CSMA/CA está destinado para la transmisión de paquetes de datos y TDMA se utiliza para la transmisión de paquetes de voz y video, con el fin de ofrecer adecuados niveles de QoS. Sin embargo, pese a que el HPAV puede alcanzar altas tasas de transmisión, no cuenta con un adecuado mecanismo de asignación de ancho de banda (AB), lo cual afecta considerablemente el rendimiento de la red a medida que aumenta el número de usuarios debido a que únicamente un nodo puede transmitir a la vez. De acuerdo a lo planteado y, considerando que una red BPL puede ser representada como un juego cooperativo de utilidad transferible (UT), en el presente artículo se propone el uso de dos técnicas para la asignación equitativa de ancho de banda: nucleolus y max-min fairness, las cuales forman parte de la teoría de juegos cooperativos. Al realizar el comparativo de las técnicas nucleolus y max-min fairness como estrategia para la asignación de recursos, se encontró que esta última genera los mejores resultados. Además, se pudo evidenciar que la teoría de juegos puede ser considerada como una novedosa estrategia para la optimización de recursos en una red LAN sobre BPL.

The management and classification of solid waste is one of the most important challenges worldwide. The objective is to design a basic waste classification system at the source using a low-cost experimental capacitive sensor and machine learning algorithms. For this, two types of sensor models were established (Traditional Model (MT) and Non-Traditional Model (MNT)), which were built with recyclable material and tested with different types of materials, in order to evaluate their behavior and sensitivity level. The results obtained demonstrated that the two sensors responded with acceptable sensitivity levels for each of the materials used as a test; however, the MNT was the one that generated the values with the greatest variability, an aspect that is deemed highly significant, because, thanks to this type of response to various types of materials, it facilitates the classification processes through the use of machine learning algorithms. Finally, the two prototypes of sensors manufactured can be considered of significant relevance for the development of more complex solutions, related to the classification and possible characterization of materials, when compared to the capacitive sensors found on the market, which only then allow us to identify if there is a presence or not of some object through adjustment by potentiometer, generating as a result a digital output. This aspect largely limits the use of commercial capacitive sensors to applications exclusively related to presence or level detection.

Diversas organizaciones han expresado la necesidad de contar con un sistema de base tecnológica para monitorear y gestionar la trazabilidad del cacao durante el proceso de fabricación del chocolate. Por lo anterior, el objetivo del presente estudio fue desarrollar un sistema rfid (Radio Frequency IDentification) bajo la arquitectura del IoT, que realiza la trazabilidad de los bultos de cacao dentro del proceso de producción de chocolate mediante el uso de series de tiempo. Para ello, se diseñó un dispositivo capaz de realizar registros y consultas en un servidor donde se puede verificar la información de cada bulto de cacao, al momento de ser recibido y almacenado en el centro de acopio, mediante una arquitectura cliente/servidor y una tecnología rfid. Adicionalmente, se incorpora un desarrollo web con capacidad de realizar el proceso de análisis y modelamiento de las condiciones ambientales durante el almacenamiento del cacao, soportado en el uso del modelo de Holt-Winters. El sistema desarrollado de bajo costo realiza el registro, el control y el monitoreo de los procesos relacionados con la trazabilidad del cacao en la gestión del almacenamiento de manera eficiente, en términos de: contenido de humedad, peso, impurezas, granos defectuosos, granos bien fermentados, entre otros. Este modelo de Holt-Winters propuesto puede ser considerado como una herramienta de predicción para la temperatura y la humedad relativa, para mejorar la trazabilidad del cacao a un nivel de ajuste superior a 0,9; bajo error estándar de estimación y un nivel de confianza del 95 %.

The hybrid in-band on-channel (IBOC) transmission system, which serves as a digital audio radio scheme, facilitates the simultaneous transmission of analog FM and digital audio. In IBOC systems, broadcasters transmit signals within allocated channel bands, posing a challenge in bandwidth allocation for digital audio transmission. To address this, cooperative game theory, supported by the bankruptcy game and Shapley’s value, is proposed as a strategy to optimize bandwidth allocation at each node or station. This approach considers service demand, the number of stations, and radio channel conditions in the FM band. The paper presents a scenario under saturated traffic conditions to evaluate the degree of optimization achievable using the Shapley value under clearly defined traffic and channel conditions. The results indicate that cooperative game theory, with the support of the Shapley value, offers an excellent alternative for optimizing bandwidth in digital broadcasting over IBOC in FM, with potential applicability in other digital radio broadcasting systems.