IJEM Vol. 10, No. 3, Jun. 2020
Cover page and Table of Contents: PDF (size: 878KB)
REGULAR PAPERS
In this paper, we are reporting on the comprehensive model design for time-frequency analysis system using Short-Time Fourier Transform (STFT) and Wigner-Ville Distribution (WVD) methods. As a case study, both STFT and WVD based time-frequency transforms have been developed via MATLAB platform and applied for both Chirp and Sunspot signals. The developed model considers the use of hamming moving window of length L=50 with 90% overlapping between the current and previous window positions. The simulation results showed that WVD is more accurate method for time and frequency analysis than STFT since it can provide simultaneous localization in both time and frequency with higher resolution than STFT which can only provide localization in either time or frequency at the same time. Also, the applied techniques provide an adequate distribution of time-frequency analysis only if they used with a non-stationary signal such as Chirp signal.
[...] Read more.The evolving information technology abridges the hardship in the daily life of consumers all over the world, hence the application of this knowledge in the irrigation field is necessary nowadays. The exponential growth of demand in food is due to the ever-evolving population of the world, thus it becomes necessary to expand the present area of cultivation. Considering the present situation of weather change due to global warming as a result of industrial activities, farming via irrigation is the reliable process of food production. Water remains the only source for survival for crop production, thus optimal management and proper use of water become pertinent with the ever-increasing land for irrigation. Arduino based automatic plant irrigation control system; provides a simple approach to automated irrigation. This work makes use of the GSM module for the notification of the user about the situation in the farm, this project aims to design and implement an automatic plant irrigation control system using Arduino and GSM module. In this proposed system, there are two main parts hardware and software units. Mechanical units which are the hardware unit comprises of instrumentation systems and watering irrigation systems. The equipment system is based on microcontroller, flow meter, moisture sensor, LCD, and GSM module. The software part comprises of C++ code, this is to enable the linkage between various modules. The main control of this system is the microcontroller unit that serves as the brain for coordinating control for various modules of the system, it synchronizes and operates the watering system and notifies the user about the condition of the field and watering section via GSM module. Implementation of this project will significantly help in a water-saving of about 30 – 50% as compared to the conventional watering system like the sprinkler, improve growth and discourage weeds because water will only be served to the needed area, simple method and timer-based system for automatic watering can be incorporated for efficiency.
[...] Read more.Highway engineering standards are constantly improving. In this study, a design has been done for a horizontal and vertical alignment for the centerline of a federal highway. The construction cost and pavement design have been done according to the Malaysian public works department for the federal roads system (JKR). The results indicate that the designed highway has an adequate, accurate, and economical system based on the proposed data. Accordingly, the objective has been achieved since the reliability of the designed highway was 94%.
[...] Read more.Ceramic products produced depend not only on the over-all chemical composition but also on the individual compositions, its crystalline structures and particles sizes of the raw materials. It has also been revealed that the appropriateness of particle size of materials used and the crystalline formation is much desired in the production of high strength electrical porcelain insulator. There is virtually no study conducted locally in Nigeria reviewed by the author at the point of compiling this study gave credence to particle sizes of materials as a considerable factor in producing their porcelain insulator. However, the dielectric and mechanical properties of the electrical porcelain insulators produced still need to be improved upon in order to produce high strength electrical porcelain insulators. The study therefore experiments by varying particle sizes 75µm, 150µm, and 300µm at developing electrical porcelain insulator with quality mechanical and dielectric strength using locally sourced raw materials. The raw materials were mixed by adopting two varied formulations from previous study, while slip cast techniques was employed in producing test samples sintered at 1200oC at the rate of 5 oC per minute. The physio-mechanical properties and dielectric strength of the samples were carried out in accordance to American Standard for Testing and Materials (ASTM) C20-00, and ATSM D116 standards. Sample A1S of 75 µm particle size is the most acceptable of all the sample that met the required physio-mechanical and dielectric strength properties. However, this study suggests that 150µm particle sizes as a starting powder for production of electrical porcelain Insulator could also be used since its cost of processing is not much unlike 75 µm particle size and could easily be achieved locally in Nigeria.
[...] Read more.Linear Quadratic Regulator (LQR) is one of the optimal control methods that continue to gain popularity. This paper designed an optimal LQR controller to control the system of the ball-on-sphere. System equations were derived and due to the nonlinearity of the system, the equations were linearized. After that, the coefficient matrices of the system dynamics were derived. Given some initial conditions, the response was simulated and controlled close to the desired values. An improvement of about 87% was achieved and the performance of the controller was observed to be good based on the simulation results. The results showed that LQR controller is one of the best optimal control methods because of its high performance improvement.
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