Survey on deep learning methods in human action recognition

A study on one of the most important issues in a human action recognition task, i.e. how to create proper data representations with a high‐level abstraction from large dimensional noisy video data, is carried out. Most of the recent successful studies in this area are mainly focused on deep learning. Deep learning methods have gained superiority to other approaches in the field of image recognition. In this survey, the authors first investigate the role of deep learning in both image and video processing and recognition. Owing to the variety and plenty of deep learning methods, the authors discuss them in a comparative form. For this purpose, the authors present an analytical framework to classify and to evaluate these methods based on some important functional measures. Furthermore, a categorisation of the state‐of‐the‐art approaches in deep learning for human action recognition is presented. The authors summarise the significantly related works in each approach and discuss their performance

An Experimental Study on Transient Pressure Changes in a Horizontal Two-Phase Slug Flow

Transient flow in a conduit is an unsteady flow, followed by the change in the flow rate. Transient flow analysis is commonly based on the assumption of no air entrainment in the liquid phase. However, air entrainment in the liquid flow frequently occurs in the pipelines. Experimental study has been carried out to investigate the characteristics of transient pressure in a two-phase, air-water slug flow inside a rectangular, horizontal pipeline. Pressure surges propagating the pipeline that results transient pressure changes have been studied by rapidly closing a sluice gate inside the pipeline. The pressure variations have been recorded by installing different pressure transducers to the pipe. The results showed that increasing the air/water discharge ratio affects the transient pressure distribution in pipeline significantly. In the downstream 10% of pipeline length, pressure variation is considerably sharp, fast damping, and with higher peak. In other sections of conduit, low-frequency pressure changes were observed which were damped slowly