This article presents a system for controlling the angle of sound and rapidly changing the radiation patterns of WiFi and Bluetooth antennas by modifying the phase shift in a patch antenna array. The system incorporates a phase shifting process to achieve beamforming, which improves signal strength in desired locations and reduces noise in undesired areas. This involves designing patch antennas with precise measurements, installing a control unit to adjust the phase shift, and testing their operation in both real and simulated environments. Measurements were made in a circular pattern, covering a 180- degree area with 30 points, at 6-degree intervals, in an anechoic chamber. A voltage of 3 V was used to determine the phase shift between measurements without a phase shifter. The results showed that without a phase shifter, a minimum value of -25.25 dB was found, while with the different voltages, a value of -25.29 dB was obtained at 3 V, indicating an approximate phase shift of 12 degrees compared to measurements without a phase shifter. The data show significant changes in signal coverage, power utilization, and an improvement in system performance. The findings highlight the potential of this approach for use in smart homes, IoT devices, and other wireless communication systems that require flexible radiation patterns.
This work addresses the generation of virtual environments based on data obtained by a mobile ground robot. The system uses a Raspberry Pi equipped with an 8-megapixel V2 camera and an MPU6050 inertial sensor (IMU) to record the route and environmental conditions. With this information, a processing methodology is proposed that allows the terrain traveled to be virtually reconstructed, showing changes recorded by the accelerometer and camera in real time. In addition, it proposes the creation of a custom database to facilitate the preparation and training of the system for future routes.
This work presents the design, implementation, and experimental validation of an open-loop three-phase inverter prototype. The experimental campaign was carried out with a regulated 48 V DC bus, while the bus-monitoring circuit was dimensioned for a wider voltage range. Control was implemented on an STM32 using digital SPWM, with a 120° phase shift and an adjustable output frequency between 60 and 80 Hz. To reduce the risk of cross-conduction in the MOSFETs, dead-time insertion was configured in both hardware and firmware. Tests with resistive loads verified three-phase operation in star and delta configurations, with balanced line voltages under laboratory conditions. The efficiency close to 92% corresponds to the tested low-load condition. Characterization at higher power levels and harmonic-distortion measurements are proposed as the next validation stage.
Reading comprehension of academic texts in English represents a significant challenge for Mechanical Engineering students, restricting access to specialized technical knowledge. This study aimed to develop and evaluate a mobile application based on active learning strategies to enhance academic reading comprehension among students of the Faculty of Mechanical Engineering at ESPOCH. The application was developed following the Scrum agile methodology in collaboration with the RITESP and GRIISOFT research groups, integrating pedagogical approaches for English for Specific Purposes (ESP) and software engineering standards. The evaluation assessed the application's technical quality using the ISO/IEC 25010 standard, focusing on usability, functionality, and efficiency, while its educational impact was measured through reading comprehension indicators and user-based evaluations. The results demonstrated improvements in academic reading comprehension and high user acceptance, contributing to the achievement of Sustainable Development Goal 4 (Quality Education).
This article analyzes the variability of the estimated voltage stability margin under load uncertainty in the IEEE 14-bus system. For this purpose, Monte Carlo scenarios were generated using random factors applied to active and reactive power demands, and power flows were solved using the Newton-Raphson method. In each scenario, λmax was estimated through feasibility assessment and bisection refinement within a defined interval; discrete P-V curves were also generated to identify the critical bus and analyze the evolution of the minimum voltage at PQ buses. The results show that load uncertainty produces noticeable variations in the estimated margin, although a significant portion of the scenarios reaches the upper limit of the exploration interval. Therefore, these cases are interpreted as censored scenarios and not as exact collapse points. The relationship between total active load and λmax showed an inverse trend, indicating a reduction in the margin associated with higher demand levels. In addition, criticality was mainly concentrated at buses 5 and 14, while the representative P-V curves made it possible to link the statistical dispersion with the electrical response of the system. The proposed approach enables the voltage stability margin to be characterized from a probabilistic and reproducible perspective.
