Piecewise-type nonlinearities, such as clutch dampers in a torsional system, induce complex nonlinear dynamic behaviors that resemble super- and sub-harmonic responses.This study focuses on investigating the sub-harmonic responses induced by piecewise-type nonlinearities in the middle of various dynamic behaviors in a torsional vibratory system.To

To solve the problems 3D Wooden Puzzle Night Light of untimely and low accuracy of tunnel project collapse risk prediction, this study proposes a method of multi-source information fusion.The method uses the PSO-SVM model to predict the surrounding rock displacement.With the prediction index as the benchmark, the Cloud Model (CM) is used to calcula

Achalasia is a disorder of the primary motility of the esophagus characterized by insufficient relaxation of the lower part esophageal sphincter and absence of esophageal peristalsis, clinically it presents dysphagia for solids and liquids and "bird-beak" appearance on endoscopic and radiological studies.A 77-year-old man presented at our emergency