This paper presents a method to estimate the yield and analyze the performance of a grid-connected photovoltaic (PV) power plant including a rooftop PV system and a solar farm. The yield model was developed based on a commercial PV model in a MATLAB/Simulink environment. A simulation model is built to connect with the PV rooftop system and the solar farm in which their total installed capacities are 0.986 and 30.7 MW, respectively. The simulated and measured final yield results of a rooftop PV system in Vietnam are compared. Additionally, this paper provides a function of reducing the final yield corresponding to different PV operation temperature values. Furthermore, the performance of both a rooftop PV system and a solar farm, in Vietnam, are evaluated as the rated power of 0.986 and 30.7 MWp, respectively. The results also show that their performance is satisfactory, in which the value of the performance ratio (PR) average reaches 70% for the rooftop PV system and 80.45% for the solar farm within a six-month period, in 2019. The PR is also compared with a global PR average from 70% to 80% for a sufficiently well-performed solar system.

This paper proposes an evaluating, monitoring, and warning system for water quality for taking care of fish that includes an Arduino Mega2560 board and a sensor system with wireless communication technologies based on IoT technology. Not only the temperature but also the pH and dissolved oxygen (DO) content of water are acquired through the Arduino Mega2560 board. These measurement data are transferred to the server through ESP8266 and SIM800A modules integrated on the board. The stored temperature, pH, and DO values are displayed on a ThingSpeak server. Furthermore, the fault detection of water quality under real working conditions is handled and displayed on the platform or a cellphone-based web service and short messaging service (SMS). The accuracy and reliability of the system for the functions of monitoring, evaluation, and fault detection were demonstrated. Compared with established systems, the proposed system has the advantages of (1) reduced cable use for the monitoring system, (2) a warning system via a cellphone-based SMS cellphone or web service, (3) costeffectiveness, and (4) portability.

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A The proposed system developed an omnidirectional algorithm to control autonomous mobile robots with three wheels. The implementation system consists of three Planet DC motors with rated power of 80 W for three wheels, three encoders for speed feedback, one encoder for distance feedback, and one digital compass sensor for angle feedback. The main system with an STM32F407 microcontroller is designed for directional control of wheels based the signal received from compass sensor and encoder and then controls three subsystems to adjust the steering speed of each wheel. The sub-system is built to control only one DC motor for each wheel with the built-in proportional integral derivative controller (PID) algorithm by an STM32F103 microcontroller.  Furthermore, the directional control algorithm is developed for three omnidirectional wheels and a PID algorithm is designed to control the speed of DC motor for each wheel. From the results the proposed system has the advantages: (1) to auto adjust the angle and position; (2) to erase the sensor for tracking line of the automobile robot; (3) cost-effectiveness and high accuracy

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