scholarly journals CIR-Based Device-Free People Counting via UWB Signals

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3296
Author(s):  
Mauro De Sanctis ◽  
Aleandro Conte ◽  
Tommaso Rossi ◽  
Simone Di Domenico ◽  
Ernestina Cianca

The outbreak of COVID-19 has resulted in many different policies being adopted across the world to reduce the spread of the virus. These policies include wearing surgical masks, hand hygiene practices, increased social distancing and full country-wide lockdown. Specifically, social distancing involves keeping a certain distance from others and avoiding gathering together in large groups. Automatic crowd density estimation is a technological solution that could help in guaranteeing social distancing by reducing the probability that two persons in a public area come in close proximity to each other while moving around. This paper proposes a novel low complexity RF sensing system for automatic people counting based on low cost UWB transceivers. The proposed system is based on an ordinary classifier that exploits features extracted from the channel impulse response of UWB communication signals. Specifically, features are extracted from the sorted list of singular values obtained from the singular value decomposition applied to the matrix of the channel impulse response vector differences. Experimental results achieved in two different environments show that the proposed system is a promising candidate for future automatic crowd density monitoring systems.

2012 ◽  
Vol 11 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Dustin Maas ◽  
Mohammad H. Firooz ◽  
Junxing Zhang ◽  
Neal Patwari ◽  
Sneha K. Kasera

2021 ◽  
Vol 21 (2) ◽  
pp. 112
Author(s):  
Vita Awalia Mardiana ◽  
Mochamad Mardi Martadinata ◽  
Galih Nugraha Nurkahfi ◽  
Arumjeni Mitayani ◽  
Dayat Kurniawan ◽  
...  

COVID-19, which has become a global pandemic since March 2020, has tremendously affected human life globally. The negative impact of COVID-19 affects societies in almost all aspects. Implementing quarantine monitoring, also social distancing, and contact tracing are a series of processes that can suppress the new infected COVID-19 cases in various countries. Prior works have proposed different monitoring systems to assist the monitoring of individuals in quarantines, as well as many methods are offered for social distancing and contact tracing. These methods focus on one function to provide a reliable system. In this paper, we propose IoT-based quarantine monitoring by implementing a geofence equipped with social distancing features to offer an integrated system that provides more benefits than one system carrying one particular function. We propose a system consisting of a low cost, low complexity, and reusable wristband design and mobile apps to support the quarantine monitoring system. For the geofencing, we propose a GPS-based geofence system that was developed by taking advantage of the convenience offered by the Traccar application. Meanwhile, we add the notification for social distancing feature with adaptive distance measurement RSSI-based set up in the android application. Based on the experiment we did to validate the system, in terms of wristband-to-smartphone communication, scanning interval in smartphone and advertising interval in wristband is best to set in 7 s for both. For social distancing notification and geofence, we measure the system performance through precision, recall, accuracy, and F-measure.


Electronics ◽  
2021 ◽  
Vol 10 (14) ◽  
pp. 1715
Author(s):  
Michele Alessandrini ◽  
Giorgio Biagetti ◽  
Paolo Crippa ◽  
Laura Falaschetti ◽  
Claudio Turchetti

Photoplethysmography (PPG) is a common and practical technique to detect human activity and other physiological parameters and is commonly implemented in wearable devices. However, the PPG signal is often severely corrupted by motion artifacts. The aim of this paper is to address the human activity recognition (HAR) task directly on the device, implementing a recurrent neural network (RNN) in a low cost, low power microcontroller, ensuring the required performance in terms of accuracy and low complexity. To reach this goal, (i) we first develop an RNN, which integrates PPG and tri-axial accelerometer data, where these data can be used to compensate motion artifacts in PPG in order to accurately detect human activity; (ii) then, we port the RNN to an embedded device, Cloud-JAM L4, based on an STM32 microcontroller, optimizing it to maintain an accuracy of over 95% while requiring modest computational power and memory resources. The experimental results show that such a system can be effectively implemented on a constrained-resource system, allowing the design of a fully autonomous wearable embedded system for human activity recognition and logging.


2020 ◽  
Vol 1651 ◽  
pp. 012060
Author(s):  
Fujian Feng ◽  
Shuang Liu ◽  
Yongzheng Pan ◽  
Xin He ◽  
Jiayin Wei ◽  
...  

Author(s):  
Xinghao Ding ◽  
Fujin He ◽  
Zhirui Lin ◽  
Yu Wang ◽  
Huimin Guo ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document