Juan Miguel Hernández Ontiveros

Profiling and parallel computing techniques in a cluster of six embedded systems with multiprocessors are introduced herein to implement a chaotic cryptosystem for digital color images. The proposed encryption method is based on stream encryption using a pseudo-random number generator with high-precision arithmetic and data processing in parallel with collective communication. The profiling and parallel computing techniques allow discovery of the optimal number of processors that are necessary to improve the efficiency of the cryptosystem. That is, the processing speed improves the time for generating chaotic sequences and execution of the encryption algorithm. In addition, the high numerical precision reduces the digital degradation in a chaotic system and increases the security levels of the cryptosystem. The security analysis confirms that the proposed cryptosystem is secure and robust against different attacks that have been widely reported in the literature. Accordingly, we highlight that the proposed encryption method is potentially feasible to be implemented in practical applications, such as modern telecommunication devices employing multiprocessors, e.g., smart phones, tablets, and in any embedded system with multi-core hardware.

This article presents the development of a personal computer-based AM/FM radio station operating on the AM/FM commercial band. Developing the graphical user interface for the software and the interconnection with an RF function generator by means of a GPIB is presented. Computer users can enter the desired transmission frequency within the commercial band as well as the transmission potency. En este trabajo se presenta el desarrollo de una estación de radio AM/FM basada en computadora personal, que opera en la banda comercial de AM y FM. Se presenta la evolución de la interfaz gráfica con el usuario del software y la interconexión por medio del ducto GPIB con un generador de funciones de RF. El usuario de la computadora tiene la opción de introducir la frecuencia deseada de transmisión dentro de la banda comercial, así como la potencia de transmisión, entre otros parámetros.

This work focused on the problem of finding a suitable medium access control protocol so that the nodes of a given cluster could communicate efficiently within their respective activity window. The nodes thus saved energy by turning off their transceivers during the time that they did not have to exchange information. This works main objective was to ensure that the nodes were mainly focused on energy efficiency and delivering packages, taking quality of service (QoS) requirements into account and comparing their performance to an existing protocol called sensor medium access control (S-MAC). The parameters being compared were the time that the nodes were asleep, energy consumption and average delay. This work was completed by using the OPNET simulator tool (OPNET Modeler, version 11.5.A PL3, OPNET Technologies Company Inc). This approach greatly improved the "PCF + Sleep” performance proposed in this work over the earlier S-MAC. Este trabajo se enfoca al problema de encontrar un protocolo de acceso al medio para que los nodos de un mismo grupo puedan comunicarse eficientemente dentro de la ventana de actividad que les corresponde. De esta manera, los nodos ahorran energía mediante el apagado de su subsistema de comunicaciones durante el tiempo en que no tienen que intercambiar información. El objetivo principal de este trabajo es el de que los nodos se enfoquen principalmente en la eficiencia de energía y la entrega de paquetes que toman en cuenta requerimientos de calidad de servicio, comparando su rendimiento contra un protocolo llamado SMAC; los parámetros comparados son: el tiempo que duran dormidos los nodos, su consumo de energía y su retardo promedio. La realización de este trabajo se hizo con la herramienta de simulación OPNET Modeler versión 11.5.A PL3, de la compañía OPNET Technologies Inc. Esta técnica mejora ampliamente el desempeño "PCF + Dormir" propuesto en este trabajo, al anterior, nombrado SMAC.