Yu-Kai Wang

Dr. Yu-Kai Wang

University of Technology Sydney, Sydney, New South Wales, Australia
orcid

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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2 April 2015 in IEEE Transactions on Neural Systems and Rehabilitation Engineering
Verified
Journal Article
Closed access
YWYu-Kai Wang
Yu-Kai Wang
TJTzyy-Ping Jung
Tzyy-Ping Jung
CLChin-Teng Lin
Chin-Teng Lin
Distracted driving might lead to many catastrophic consequences. Developing a countermeasure to track drivers' focus of attention (FOA) and engagement of operators in dual (multi)-tasking conditions is thus imperative. Ten healthy volunteers participated in a dual-task experiment that comprised two tasks: a lane-keeping driving task and a mathematical problem-solving task (e.g., 24 + 15=37?) during which their electroencephalogram (EEG) and behaviors were concurrently recorded. Independent component analysis (ICA) was employed as a spatial filter to separate the contributions of independent sources from the recorded EEG data. The power spectra of six components (i.e., frontal, central, parietal, occipital, left motor, and right motor) extracted from single-task conditions were fed into support vector machine (SVM) based on the radial basis function (RBF) kernel to build an FOA assessment system. The system achieved 84.6 ± 5.8% and 86.2 ± 5.4% classification accuracies in detecting the participants' FOAs on the math versus driving tasks, respectively. This FOA assessment system was then applied to evaluate participants' FOAs during dual-task conditions. The detected FOAs revealed that participants' cognitive attention and strategies dynamically changed between tasks to optimize the overall performance, as attention was limited and competed. The empirical results of this study demonstrate the feasibility of a practical system to continuously estimating cognitive attention through EEG spectra.

24 October 2017 in IEEE Access
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Journal Article
Open access
CLChin-Teng Lin
Chin-Teng Lin
Mukesh PrasadMukesh Prasad
Mukesh Prasad
CCChia-Hsin Chung
Chia-Hsin Chung
Deepak PuthalDeepak Puthal
Deepak Puthal
HSHesham El Sayed
Hesham El Sayed
Arun Kumar SangaiahArun Kumar Sangaiah
Arun Kumar Sangaiah
Polysomnography (PSG) is considered the gold standard in the diagnosis of obstructive sleep apnea (OSA). The diagnosis of OSA requires an overnight sleep experiment in a laboratory. However, due to limitations in relation to the number of labs and beds available, patients often need to wait a long time before being diagnosed and eventually treated. In addition, the unfamiliar environment and restricted mobility when a patient is being tested with a polysomnogram may disturb their sleep, resulting in an incomplete or corrupted test. Therefore, it is posed that a PSG conducted in the patient's home would be more reliable and convenient. The Internet of Things (IoT) plays a vital role in the e-Health system. In this paper, we implement an IoT-based wireless polysomnography system for sleep monitoring, which utilizes a batterypowered, miniature, wireless, portable, and multipurpose recorder. A Java-based PSG recording program in the personal computer is designed to save several bio-signals and transfer them into the European data format. These PSG records can be used to determine a patient's sleep stages and diagnose OSA. This system is portable, lightweight, and has low power-consumption. To demonstrate the feasibility of the proposed PSG system, a comparison was made between the standard PSG-Alice 5 Diagnostic Sleep System and the proposed system. Several healthy volunteer patients participated in the PSG experiment and were monitored by both the standard PSG-Alice 5 Diagnostic Sleep System and the proposed system simultaneously, under the supervision of specialists at the Sleep Laboratory in Taipei Veteran General Hospital. A comparison of the results of the time-domain waveform and sleep stage of the two systems shows that the proposed system is reliable and can be applied in practice. The proposed system can facilitate the long-term tracing and research of personal sleep monitoring at home.

1 May 2020 in Neurocomputing
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Journal Article
Closed access
ZCZehong Cao
Zehong Cao
WDWeiping Ding
Weiping Ding
YWYu-Kai Wang
Yu-Kai Wang
FHFarookh Khadeer Hussain
Farookh Khadeer Hussain
Adel Al-jumailyAdel Al-jumaily
Adel Al-jumaily
CLChin-Teng Lin
Chin-Teng Lin

27 March 2018 in Frontiers in Neuroscience
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Journal Article
Open access
PDF file
CCChun-Hsiang Chuang
Chun-Hsiang Chuang
ZCZehong Cao
Zehong Cao
JKJung-Tai King
Jung-Tai King
BWBing-Syun Wu
Bing-Syun Wu
YWYu-Kai Wang
Yu-Kai Wang
CLChin-Teng Lin
Chin-Teng Lin
Fatigue is likely to be gradually cumulated in a prolonged and attention-demanding task that may adversely affect task performance. To address the brain dynamics during a driving task, this study recruited 16 subjects to participate in an event-related lane-departure driving experiment. Each subject was instructed to maintain attention and task performance throughout an hour-long driving experiment. The subjects' brain electrodynamics and hemodynamics were simultaneously recorded via 32-channel electroencephalography (EEG) and 8-source/16-detector functional near-infrared spectroscopy (fNIRS). The behavior performance demonstrated that all subjects were able to promptly respond to lane-deviation events, even if the sign of fatigue arose in the brain, which suggests that the subjects were fighting fatigue during the driving experiment. The EEG event-related analysis showed strengthening alpha suppression in the occipital cortex, a common brain region of fatigue. Furthermore, we noted increasing oxygenated hemoglobin (HbO) of the brain to fight driving fatigue in the frontal cortex, primary motor cortex, parieto-occipital cortex and supplementary motor area. In conclusion, the increasing neural activity and cortical activations were aimed at maintaining driving performance when fatigue emerged. The electrodynamic and hemodynamic signatures of fatigue fighting contribute to our understanding of the brain dynamics of driving fatigue and address driving safety issues through the maintenance of attention and behavioral performance.

27 April 2016 in International Journal of Neural Systems
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Journal Article
Closed access
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KHKuan-Chih Huang
Kuan-Chih Huang
THTeng-Yi Huang
Teng-Yi Huang
Chun-Hsiang (Michael) ChuangChun-Hsiang (Michael) Chuang
Chun-Hsiang (Michael) Chuang
JKJung-Tai King
Jung-Tai King
YWYu-Kai Wang
Yu-Kai Wang
TJTzyy-Ping Jung
Tzyy-Ping Jung

11 January 2019 in IEEE Computational Intelligence Magazine
Verified
Journal Article
Closed access
LKLi-Wei Ko
Li-Wei Ko
CLChin-Teng Lin
Chin-Teng Lin
YLYi-Chen Lu
Yi-Chen Lu
HBHumberto Bustince
Humberto Bustince
YCYu-Cheng Chang
Yu-Cheng Chang
GDGracaliz Pereira Dimuro
Gracaliz Pereira Dimuro
Brain-computer interface technologies, such as steady-state visually evoked potential, P300, and motor imagery are methods of communication between the human brain and the external devices. Motor imagery-based brain-computer interfaces are popular because they avoid unnecessary external stimuli. Although feature extraction methods have been illustrated in several machine intelligent systems in motor imagery-based brain-computer interface studies, the performance remains unsatisfactory. There is increasing interest in the use of the fuzzy integrals, the Choquet and Sugeno integrals, that are appropriate for use in applications in which fusion of data must consider possible data interactions. To enhance the classification accuracy of brain-computer interfaces, we adopted fuzzy integrals, after employing the classification method of traditional brain-computer interfaces, to consider possible links between the data. Subsequently, we proposed a novel classification framework called the multimodal fuzzy fusion-based brain-computer interface system. Ten volunteers performed a motor imagery-based brain-computer interface experiment, and we acquired electroencephalography signals simultaneously. The multimodal fuzzy fusion-based brain-computer interface system enhanced performance compared with traditional brain-computer interface systems. Furthermore, when using the motor imagery-relevant electroencephalography frequency alpha and beta bands for the input features, the system achieved the highest accuracy, up to 78.81% and 78.45% with the Choquet and Sugeno integrals, respectively. Herein, we present a novel concept for enhancing brain-computer interface systems that adopts fuzzy integrals, especially in the fusion for classifying brain-computer interface commands.