Introduction to Spectral Analysis and Frequency Sampling

Every physical phenomenon in our universe—from the sound of a cello and the rumble of an industrial turbine to the radio waves carrying mobile data—manifests as an analog signal. These signals are continuous in both time and amplitude, flowing in an unbroken stream of physical reality. However, to analyze, process, or store these signals using … Read more

Signal Processing in Vibration Testing

Vibration testing is a important subject of mechanical engineering, automotive design, aerospace safety, and structural health monitoring. It allows engineers to evaluate how materials, components, and systems respond to dynamic loads. However, raw vibration data is often complex, noisy, and difficult to interpret. This is where signal processing becomes indispensable: it transforms raw sensor outputs … Read more

The Effect of Preload, Density and Thickness on Seat Dynamic Stiffness

Abstract The vibration transferred to the car floor transmits to the human body through the seat structure, and the typical design of the seat structure consists of several components such as seat frame and seat cushion. The material widely used as seat cushion is open-cell polyurethane (PUR) foam; when under vibration, it will behave dynamically. … Read more