A Microcontroller-Based Measurement System for Human Response to Visual and Hearing Stimulations

Abstract

The present study is aimed to analyse the relationships of human responses to sudden changes in visual or hearing stimulations with respect to the age. As the accuracy of measurement of the time interval is significant in the study of human response, a microcontroller‐based time measurement system is designed and developed with a resolution of 1 µs. The hardware of the device takes care of the generation and management of the clock through I/O ports of the microcontroller, while software captures and computes the response time. The effect of age on human responses to both visual and hearing stimuli was studied, and the natures of both the responses were compared. The results were analysed to determine the characteristics of human responses and the relationship between human response, type of stimulus, and age. It was shown that the human visual and hearing response‐times increase with age, and the hearing response is faster than visual response.

Effect of on-line ultrasonic treatment on the properties of carbon fiber reinforced plastic composites

“…It included a vibrating system, which consists of a piezoelectricity transducer and amplitude-transformer, and an ultrasonic generator with functions of tracking, velocity stabilizing, current overload protection, and power adjusting. The frequency and output amplitude of the ultrasonic treatment system were calibrated using some experiments to ensure the performance stability of ultrasound, which was reported in our previous literature [26,27].…”

“…Thus, ultrasonic treatment is widely used in chemical synthesis, depolymerization, extraction, food engineering, materials processing, etc. [20][21][22][23][24][25][26][27][28][29]. The cavitation and agitation action in the liquid induced by ultrasound improve the adsorption, diffusion, and wetting of resin on the surface of carbon fibers, enhance the mechanical properties, and finally use fully the outstanding property of CFRP composites [30][31][32][33][34].…”

“…CFRP composites have many superior properties including low density (lower than aluminum); high strength (as strong as high-strength steel); high stiffness (stiffer than titanium); good toughness; good fatigue, creep, wear, and corrosion resistance; low friction coefficient; good dimensional stability; and high vibration damping ability [4][5][6][7][8][9][10][11][12]. But the surface of carbon fiber is smooth and inert, and the interfacial bond between the fiber and resin matrix is not strong; strong adhesion at their interface is needed for an effective transfer of stress and bond distribution throughout an interface, or that will affect the performances of CFRP composites and limit their applications [13][14][15][16][17][18][19]27].…”