1,489 research outputs found
Discomfort luminance level of head-mounted displays depending on the adapting luminance
The Images in an immersive head-mounted display (HMD) for virtual reality provide the sole source for visual adaptation. Thus, significant, near-instantaneous increases in luminance while viewing an HMD can result in visual discomfort. Therefore, the current study investigated the luminance change necessary to induce this discomfort. Based on the psychophysical experiment data collected from 10 subjects, a prediction model was derived using four complex images and one neutral image, with four to six levels of average scene luminance. Result showed that maximum area luminance has a significant correlation with the discomfort luminance level than average, median, or maximum pixel luminance. According to the prediction model, the discomfort luminance level of a head-mounted display was represented as a positive linear function in log(10) units using the previous adaptation luminance when luminance is calculated as maximum area luminance
A Study of IEEE 802.15.4 Security Framework for Wireless Body Area Network
A Wireless Body Area Network (WBAN) is a collection of low-power and
lightweight wireless sensor nodes that are used to monitor the human body
functions and the surrounding environment. It supports a number of innovative
and interesting applications, including ubiquitous healthcare and Consumer
Electronics (CE) applications. Since WBAN nodes are used to collect sensitive
(life-critical) information and may operate in hostile environments, they
require strict security mechanisms to prevent malicious interaction with the
system. In this paper, we first highlight major security requirements and
Denial of Service (DoS) attacks in WBAN at Physical, Medium Access Control
(MAC), Network, and Transport layers. Then we discuss the IEEE 802.15.4
security framework and identify the security vulnerabilities and major attacks
in the context of WBAN. Different types of attacks on the Contention Access
Period (CAP) and Contention Free Period (CFP) parts of the superframe are
analyzed and discussed. It is observed that a smart attacker can successfully
corrupt an increasing number of GTS slots in the CFP period and can
considerably affect the Quality of Service (QoS) in WBAN (since most of the
data is carried in CFP period). As we increase the number of smart attackers
the corrupted GTS slots are eventually increased, which prevents the legitimate
nodes to utilize the bandwidth efficiently. This means that the direct
adaptation of IEEE 802.15.4 security framework for WBAN is not totally secure
for certain WBAN applications. New solutions are required to integrate high
level security in WBAN.Comment: 14 pages, 7 figures, 2 table
Multi-Signal Reconstruction Using Masked Autoencoder From EEG During Polysomnography
Polysomnography (PSG) is an indispensable diagnostic tool in sleep medicine,
essential for identifying various sleep disorders. By capturing physiological
signals, including EEG, EOG, EMG, and cardiorespiratory metrics, PSG presents a
patient's sleep architecture. However, its dependency on complex equipment and
expertise confines its use to specialized clinical settings. Addressing these
limitations, our study aims to perform PSG by developing a system that requires
only a single EEG measurement. We propose a novel system capable of
reconstructing multi-signal PSG from a single-channel EEG based on a masked
autoencoder. The masked autoencoder was trained and evaluated using the
Sleep-EDF-20 dataset, with mean squared error as the metric for assessing the
similarity between original and reconstructed signals. The model demonstrated
proficiency in reconstructing multi-signal data. Our results present promise
for the development of more accessible and long-term sleep monitoring systems.
This suggests the expansion of PSG's applicability, enabling its use beyond the
confines of clinics.Comment: Proc. 12th IEEE International Winter Conference on Brain-Computer
Interfac
Impact of Nap on Performance in Different Working Memory Tasks Using EEG
Electroencephalography (EEG) has been widely used to study the relationship
between naps and working memory, yet the effects of naps on distinct working
memory tasks remain unclear. Here, participants performed word-pair and
visuospatial working memory tasks pre- and post-nap sessions. We found marked
differences in accuracy and reaction time between tasks performed pre- and
post-nap. In order to identify the impact of naps on performance in each
working memory task, we employed clustering to classify participants as high-
or low-performers. Analysis of sleep architecture revealed significant
variations in sleep onset latency and rapid eye movement (REM) proportion. In
addition, the two groups exhibited prominent differences, especially in the
delta power of the Non-REM 3 stage linked to memory. Our results emphasize the
interplay between nap-related neural activity and working memory, underlining
specific EEG markers associated with cognitive performance.Comment: Submitted to 2024 12th IEEE International Winter Conference on
Brain-Computer Interfac
Relationship Between Mood, Sleepiness, and EEG Functional Connectivity by 40 Hz Monaural Beats
The monaural beat is known that it can modulate brain and personal states.
However, which changes in brain waves are related to changes in state is still
unclear. Therefore, we aimed to investigate the effects of monaural beats and
find the relationship between them. Ten participants took part in five separate
random sessions, which included a baseline session and four sessions with
monaural beats stimulation: one audible session and three inaudible sessions.
Electroencephalogram (EEG) were recorded and participants completed pre- and
post-stimulation questionnaires assessing mood and sleepiness. As a result,
audible session led to increased arousal and positive mood compared to other
conditions. From the neurophysiological analysis, statistical differences in
frontal-central, central-central, and central-parietal connectivity were
observed only in the audible session. Furthermore, a significant correlation
was identified between sleepiness and EEG power in the temporal and occipital
regions. These results suggested a more detailed correlation for stimulation to
change its personal state. These findings have implications for applications in
areas such as cognitive enhancement, mood regulation, and sleep management
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