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.

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.

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 %.

Performance Evaluation under an AFR Scheme CSMA/CA for HomePlug AV Supported in Bianchi’s Model

Background/Objectives: In PLC networks, the Home Plug for Audio-Video (HPAV) protocol lacks a mechanism that allows optimizing the order of access of the nodes to the channel. The objective of this paper is to propose the use of Power Indexes as a strategy to solve the problem stated before. Methods/Statistical Analysis: This paper proposes two independent scenarios, formed by communications equipment (nodes) in clearly established traffic and channel conditions. The solution to that problem is obtained by using three methods applying Power indexes: Banzhaf, Shapley- Shubik and Deegan-Packel. A comparison of the obtained result is carried out and a Dunnett's test is applied in order to determine which method has a better performance to solve the problem stated before. Findings: The usage of the Game Theory, specially the Power Indexes, is an innovative strategy for the optimization of the order of access to the PLC channel. It is important to state the relevance that the Game theory has acquired as a tool used to analyze complex optimization situations within the communication networks. Furthermore, it is fair to say that no other similar paper has been found in the diverse bibliographic sources consulted. Based on the results obtained by means of the Dunnet test, it was possible to provide evidence that any of the three methods can be considered as a strategy for establishing the order for the nodes to access the channel. Such order will eventually improve the performance of the PLC network (with a 95% confidence). Nonetheless, the optimization method proposed by Shapley-Shubik can be considered as the best method out of the three because it presents the greatest average, and plus, it is the only method in which the difference Di is greater than 0 (Di ≥ 0). Application/Improvements: It is recommended to investigate on alternative methods to calculate Power Indexes that can offer a reduced computational complexity, in order to facilitate its implementation in low-cost embedded systems.

Background/Objectives: HPAV uses Time Division Multiple Access (TDMA) for the voice and video package transmission, in order to offer properQoS levels. The main goal of this paper is to propose a model Mm/M/1/B that allows assessing the performance of a Power Line Communication network (PLC) under TDMA, during the transmission of multimedia packages, using a AFR package (Aggregation with Fragment Retransmission). Methods/Statistic Analysis: In this paper, the throughput saturation concept for a finite Number N of stations. For that reason, it will be assumed that the package size is fixed of L bits to a rate of C Mbps. In order to analyze the performance of the network supported in TDMA, a model Mm/M/1/B is proposed; such model is based on a Round Robin Scheduler (RR) scheme, according to the MAC structure hybrid for HPAV. Subject Relevance: AFR is a scheme that was proposed to reach a high efficiency rate in the layer of Media Access Control (MAC) and that, to date, has only been considered in Wireless networks supported in 802.11n. Additionally, up to date, no models to assess the performance over TDMA applied to HPVA in different bibliographic sources have been found. Results: Based on the obtained results, it was possible to observe that the model permits to assess the probability of loss packages, the efficiency MAC over TDMA, the throughput and the levels of delay on a PLC network during a transmission of video and voice under a AFR scheme, according to the number of stations, the size of the containment window and the available bandwidth in the channel. Application/Improvements: The model proposed can be considered as a tool in future research papers, for the transmission of Voice and video over HPVA, to assess aspects related to QoS.