Junhong Park

With the rapid progress in the deep learning technology, it is being used for vibration-based structural health monitoring. When the vibration is used for extracting features for system diagnosis, it is important to correlate the measured signal to the current status of the structure. The measured vibration responses show large deviation in spectral and transient characteristics for systems to be monitored. Consequently, the diagnosis using vibration requires complete understanding of the extrac

Despite the strengthening of vehicle emissions standards and test methods, nitrogen oxide (NOx) emissions from on-road mobile sources are not being notably reduced. The introduction of real driving emission (RDE) regulations is expected to reduce the discrepancy between emission regulations and actual air pollution. To analyze the effects of RDE regulations on heavy-duty diesel vehicles, pollutants emitted while driving were measured using a portable emission measurement system (PEMS) for Euro 5

The dynamic properties of inkjet-printed thin films on flexible polyimide (PI) substrates were investigated using the vibration analysis adopting wave approach. In order to fabricate the test specimens, the Ag nanoparticle suspension was inkjet printed on the plasma-treated PI substrate and sintered at different temperatures. The beam-shaped Ag-printed PI specimens with 30 mm length and 0.6 mm width were prepared by pico-second laser pulse cutting and were used as the cantilever beam in the vibr

Sound radiation from electric motor‐driven vehicles is negligibly small compared to sound radiation from internal combustion engine automobiles. When running on a local road, an artificial sound is required as a warning signal for the safety of pedestrians. In this study, an engine sound was synthesized by combining artificial mechanical and combustion sounds. The mechanical sounds were made by summing harmonic components representing sounds from rotating engine cranks. The harmonic components,