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Noise in a dynamic system is practically unavoidable. Today, such noise is commonly reduced using an active noise control (ANC) system with the filtered-x least mean square (FXLMS) algorithm. However, the performance of the ANC system with FXLMS algorithm is significantly impaired in nonlinear systems. Therefore, this paper develops an efficient nonlinear adaptive feedback neural controller (NAFNC) to eliminate narrowband noise for both linear and nonlinear ANC systems. The proposed controller is implemented to update its coefficients without prior offline training by neural network. Hence, the proposed method has rapid convergence rate as confirmed by simulation results. The proposed work also analyzes the stability and convergence of the proposed algorithm. Simulation results verify the effectiveness of the proposed method.

Radar is a type of wireless, noncontact sensor that does not need to be placed on or near a test object for detection. A key component of any radar sensor is the antenna. Among different types of antennas, the linear tapered slot antenna (LTSA) is a wideband antenna that has the advantages of small size, design simplicity, and easy adaptation to an array. This study examined and analyzed the 10 primary parameters that define the LTSA design when operated in the ultra-wideband (UWB) frequency range. The study method involved varying each of the 10 parameters to discern how the variations impact the three critical characteristics of an antenna, namely, (1) return loss, (2) the far field radiation pattern on the E-plane, and (3) the far field radiation pattern on the H-plane. By analyzing the changes in these critical characteristics, a set of design recommendations for the 10 parameters was developed for the LTSA.

Snake robots have come to represent a new subfield of bionic robot research in recent years. A snake robot comprises many modules and performs various movements in arranged connections. The structure of a snake body enables it to move smoothly in narrow spaces or pipes with high stability and reliability. This article studies the application of a snake robot on a large-scale nuclear power facility to sense in pipe components. Therefore, a snake robot must move in pipes in which high radiation is present to explore the surrounding environment and take samples. A simple but effective method of locomotion is developed and executed to confirm feasibility of motion, especially in narrow space. A sampling mechanism with a storage box is designed at the tail of the snake to take and keep the samples well at designated locations. We built a pipe system which has two right-angled turns to simulate the pipes of a large-scale nuclear power facility. A user interface helps operators to manipulate the snake robot.

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