scholarly journals Smart Glasses-Based Personnel Proximity Warning System for Improving Pedestrian Safety in Construction and Mining Sites

2020 ◽  
Vol 17 (4) ◽  
pp. 1422 ◽  
Author(s):  
Jieun Baek ◽  
Yosoon Choi
Keyword(s):  
Warning System ◽  
Pedestrian Safety ◽  
Media Access Control ◽  
Media Access ◽  
Application Development ◽  
Detection Distance ◽  
Mining Sites ◽  
Task Load ◽  
Smart Glasses ◽  
Nasa Task Load Index

A smart glasses-based wearable personnel proximity warning system (PWS) was developed for pedestrian safety in construction and mining sites. The smart glasses receive signals transmitted by Bluetooth beacons attached to heavy equipment or vehicles, with the proximity determined by the signal strength. A visual alert is displayed to the wearer when in close proximity. The media access control address of the Bluetooth beacon provides information on the approaching equipment or vehicle, which is displayed to the wearer so that they can respond appropriately. There was a detection distance of at least 10 m regardless of the direction the pedestrian was looking and the alert was successful in all 40 trials at ≥10 meters. The subjective workload was evaluated using the NASA task load index on ten subjects, either without a personal PWS, with a smartphone-based PWS, or with the smart glasses-based PWS. The mental, temporal, and physical stresses were lowest when using the smart glasses-based PWS. Smart glasses-based PWSs can improve work efficiency by freeing both hands of the pedestrians, and various functions can be supported through application development. Therefore, they are particularly useful for pedestrian safety in construction and mining sites.

scholarly journals Smart Helmet-Based Personnel Proximity Warning System for Improving Underground Mine Safety

2021 ◽  
Vol 11 (10) ◽  
pp. 4342
Author(s):  
Yeanjae Kim ◽  
Jieun Baek ◽  
Yosoon Choi
Keyword(s):  
Signal Detection ◽  
Performance Test ◽  
Warning System ◽  
Mine Safety ◽  
Transmission Power ◽  
Detection Distance ◽  
Task Load ◽  
Smart Glasses ◽  
Heavy Equipment ◽  
Equipment Operator

A smart helmet-based wearable personnel proximity warning system was developed to prevent collisions between equipment and pedestrians in mines. The smart helmet worn by pedestrians receives signals transmitted by Bluetooth beacons attached to heavy equipment, light vehicles, or dangerous zones, and provides visual LED warnings to the pedestrians and operators simultaneously. A performance test of the proposed system was conducted in an underground limestone mine. It was confirmed that as the transmission power of the Bluetooth beacon increased, the Bluetooth low energy (BLE) signal detection distance of the system also increased. The average BLE signal detection distance was at least 10 m, regardless of the facing angle between the smart helmet and Bluetooth beacon. The subjective workload for the smartphone-, smart glasses-, and smart helmet-based proximity warning system (PWS) was evaluated using the National Aeronautics and Space Administration task load index. All six workload parameters were the lowest when using the smart helmet-based PWS. The smart helmet-based PWS can provide visual proximity warning alerts to both the equipment operator and the pedestrian, and it can be expanded to provide worker health monitoring and hazard awareness functions by adding sensors to the Arduino board.

IEEE 802.11 Tutorial

2018 ◽  
Author(s):  
Kiramat
Keyword(s):  
Access Control ◽  
Ieee 802.11 ◽  
Wireless Local Area Network ◽  
Local Area Network ◽  
Local Area ◽  
Physical Layer ◽  
Media Access Control ◽  
Area Network ◽  
Media Access ◽  
Computer Communications

IEEE 802.11 is a set of media access control (MAC) and physical layer (PHY) specifications for implementing wireless local area network (WLAN) computer communications. Maintained by the Institute of Electrical and Electronics Engineers (IEEE) LAN/MAN Standards Committee (IEEE 802). This document highlights the main features of IEEE 802.11n variant such as MIMO, frame aggregation and beamforming along with the problems in this variant and their solutions

Media Access Control Protocol with Differential Service in Aeronautical Frequency-Hopping Ad Hoc Networks

2014 ◽  
Vol 24 (8) ◽  
pp. 2214-2225 ◽  
Author(s):  
Ye-Qun WANG ◽  
Feng YANG ◽  
Guo-Ce HUANG ◽  
Heng-Yang ZHANG ◽  
Jian-Xin GUO
Keyword(s):  
Access Control ◽  
Ad Hoc Networks ◽  
Ad Hoc ◽  
Frequency Hopping ◽  
Media Access Control ◽  
Media Access ◽  
Control Protocol ◽  
Hoc Networks ◽  
Media Access Control Protocol

scholarly journals Performance Analysis of Synchronous Multi-Radio Multi-Link MAC Protocols in IEEE 802.11be Extremely High Throughput WLANs

2020 ◽  
Vol 11 (1) ◽  
pp. 317
Author(s):  
Taewon Song ◽  
Taeyoon Kim
Keyword(s):  
Ieee 802.11 ◽  
Markov Chain Model ◽  
Careful Consideration ◽  
Mac Protocols ◽  
Media Access Control ◽  
Chain Model ◽  
Distributed Coordination ◽  
Media Access ◽  
Medium Access ◽  
Coordination Function

The representative media access control (MAC) mechanism of IEEE 802.11 is a distributed coordination function (DCF), which operates based on carrier-sense multiple access with collision avoidance (CSMA/CA) with binary exponential backoff. The next amendment of IEEE 802.11 being developed for future Wi-Fi by the task group-be is called IEEE 802.11be, where the multi-link operation is mainly discussed when it comes to MAC layer operation. The multi-link operation discussed in IEEE 802.11be allows multi-link devices to establish multiple links and operate them simultaneously. Since the medium access on a link may affect the other links, and the conventional MAC mechanism has just taken account of a single link, the DCF should be used after careful consideration for multi-link operation. In this paper, we summarize the DCFs being reviewed to support the multi-radio multi-link operation in IEEE 802.11be and analyze their performance using the Markov chain model. Throughout the extensive performance evaluation, we summarize each MAC protocol’s pros and cons and discuss essential findings of the candidate MAC protocols.

scholarly journals Desktop lighting for comfortable use of a computer screen

Work ◽  
2021 ◽  
Vol 68 (s1) ◽  
pp. S209-S221
Author(s):  
Lu Han ◽  
Hechen Zhang ◽  
Zhongxia Xiang ◽  
Jinze Shang ◽  
Shabila Anjani ◽  
...  
Keyword(s):  
High Intensity ◽  
Motion Tracking ◽  
Tracking System ◽  
Computer User ◽  
Eye Tracker ◽  
Computer Screen ◽  
Task Load ◽  
Trunk Movements ◽  
Motion Tracking System ◽  
Nasa Task Load Index

BACKGROUND: The contrast between a bright computer screen and a dark ambient environment may influence comfort of the users, especially on their eyes. OBJECTIVE: The objective of this research is to identify the optimal desktop lighting for the comfortable use of the computer screen in a dark environment. METHODS: An experiment was designed where seven illumination setups were introduced for the users to perform their leisure tasks on a computer screen. Fifteen healthy subjects participated in the experiments. During each session, durations of the eye blinks, fixations and saccades of the user were recorded by an eye tracker. His/her neck and trunk movements were recorded by a motion tracking system as well. The comfort/discomfort questionnaire, localized postural discomfort questionnaire, NASA task load index and computer user questionnaire were used to record the overall comfort/discomfort, the local perceived physical discomfort, the cognitive workload, and general/eye health problems, respectively. RESULTS: Subjective and objective measurement results indicated that users felt more comfortable with high intensity warm lights using a computer screen. We also identified that the eye fixation durations, as well as the scores of two questions in the computer user questionnaire, have significant negative correlations with comfort. On the other side, the durations of blinks and the scores of three questions in the computer user questionnaire, were significantly correlated with discomfort. CONCLUSION: The warm (3000K) and high intensity (1500 lux) light reduced the visual and cognitive fatigue of the user and therefore improve the comfort of the user during the use of a computer screen.

Media access control manner with QoS for control network

2008 ◽  
Author(s):  
Lei Zhaoming ◽  
Sun Hexu ◽  
Liu Zuojun ◽  
Liang Tao
Keyword(s):  
Access Control ◽  
Media Access Control ◽  
Control Network ◽  
Media Access ◽  
Control Manner

Neural Correspondence to Human Cognition from Analysis to Intuition – Implications of Display Design for Cognition

2017 ◽  
Vol 61 (1) ◽  
pp. 51-55 ◽  
Author(s):  
Joseph K. Nuamah ◽  
Younho Seong
Keyword(s):  
Objective Measure ◽  
Mental Effort ◽  
Human Cognition ◽  
Behavioral Measures ◽  
Display Design ◽  
Percent Correct ◽  
Task Load ◽  
Frontal Midline Theta ◽  
General Difference ◽  
Nasa Task Load Index

Psychophysiological measures can be used to determine whether a particular display produces a general difference in brain function. Such information might be valuable in efforts to improve usability in display design. In this preliminary study, we aimed to use the electroencephalography (EEG) task load index (TLI), given by the ratio of mean frontal midline theta energy to mean parietal alpha energy, to provide insight into the mental effort required by participants performing intuition-inducing and analysis-inducing tasks. We employed behavioral measures (reaction time and percent correct), and a subjective measure (NASA-Task Load Index) to validate the objective measure (TLI). The results we obtained were consistent with our hypothesis that mental effort required for analysis-inducing tasks would be different from that required for intuition-inducing tasks. Although our sample size was small, we were able to obtain a significant positive correlation between NASA-Task Load Index and TLI.

Sign in / Sign up

Export Citation Format

Share Document