Zhu, Yujun
SitPose: Real-Time Detection of Sitting Posture and Sedentary Behavior Using Ensemble Learning With Depth Sensor
Jin, Hang, He, Xin, Wang, Lingyun, Zhu, Yujun, Jiang, Weiwei, Zhou, Xiaobo
Abstract-- Poor sitting posture can lead to various work-related musculoskeletal disorders (WMSDs). Office employees spend approximately 81.8% of their working time seated, and sedentary behavior can result in chronic diseases such as cervical spondylosis and cardiovascular diseases. Our results show that the ensemble learning model based on the soft voting mechanism achieves the highest F1 score of 98.1%. Finally, we deployed the SitPose system based on this ensemble model to encourage better sitting posture and to reduce sedentary habits. Office workers typically remain seated throughout their provided insights into the health implications of prolonged workday due to the nature of their tasks and various other sedentary lifestyles. Consequently, many experience backaches, primarily cohort of 360,047 participants from the UK Biobank, delved due to their poor sitting posture and prolonged sedentary into the relationship between sedentary behavior (exceeding 6 habits. Furthermore, prolonged sitting can aims to mitigate such risks by introducing a novel double the risk of developing diabetes, as well as contribute to sitting posture health detection system that utilizes visual the accumulation of abdominal fat, leading to health problems detection technology to provide interactive reminders. The RoSeFi [5] system between increased durations of sedentary behavior in adopted WiFi channel state information to monitor sedentary the workplace and a decline in self-reported general health status.
Real-Time Fall Detection Using Smartphone Accelerometers and WiFi Channel State Information
Wang, Lingyun, Su, Deqi, Zhang, Aohua, Zhu, Yujun, Jiang, Weiwei, He, Xin, Yang, Panlong
In recent years, as the population ages, falls have increasingly posed a significant threat to the health of the elderly. We propose a real-time fall detection system that integrates the inertial measurement unit (IMU) of a smartphone with optimized Wi-Fi channel state information (CSI) for secondary validation. Initially, the IMU distinguishes falls from routine daily activities with minimal computational demand. Subsequently, the CSI is employed for further assessment, which includes evaluating the individual's post-fall mobility. This methodology not only achieves high accuracy but also reduces energy consumption in the smartphone platform. An Android application developed specifically for the purpose issues an emergency alert if the user experiences a fall and is unable to move. Experimental results indicate that the CSI model, based on convolutional neural networks (CNN), achieves a detection accuracy of 99%, \revised{surpassing comparable IMU-only models, and demonstrating significant resilience in distinguishing between falls and non-fall activities.
NEARL: Non-Explicit Action Reinforcement Learning for Robotic Control
Lin, Nan, Li, Yuxuan, Zhu, Yujun, Wang, Ruolin, Zhang, Xiayu, Ji, Jianmin, Tang, Keke, Chen, Xiaoping, Zhang, Xinming
Traditionally, reinforcement learning methods predict the next action based on the current state. However, in many situations, directly applying actions to control systems or robots is dangerous and may lead to unexpected behaviors because action is rather low-level. In this paper, we propose a novel hierarchical reinforcement learning framework without explicit action. Our meta policy tries to manipulate the next optimal state and actual action is produced by the inverse dynamics model. To stabilize the training process, we integrate adversarial learning and information bottleneck into our framework. Under our framework, widely available state-only demonstrations can be exploited effectively for imitation learning. Also, prior knowledge and constraints can be applied to meta policy. We test our algorithm in simulation tasks and its combination with imitation learning. The experimental results show the reliability and robustness of our algorithms.