Browsing by Author "Azemi G."
Now showing items 1-15 of 15
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A review of time-frequency matched filter design with application to seizure detection in multichannel newborn EEG
Boashash B.; Azemi G. ( Elsevier Inc. , 2014 , Article)This paper presents a novel design of a time-frequency (t-f) matched filter as a solution to the problem of detecting a non-stationary signal in the presence of additive noise, for application to the detection of newborn ... -
Detection of perinatal hypoxia using time-frequency analysis of heart rate variability signals
Dong S.; Boashash B.; Azemi G.; Lingwood B.E.; Colditz P.B. (2013 , Conference Paper)This paper presents a time-frequency approach to detect perinatal hypoxia by characterizing the nonstationary nature of heart rate variability (HRV) signals. Quadratic time-frequency distributions (TFDs) are used to represent ... -
Detection, classification, and estimation in the (t, f ) domain
Sayeed, A.M.; Papandreou-Suppappola, A.; Suppappola, S.B.; Xia, X.-G.; Hlawatsch, F.; Matz, G.; Boashash, B.; Azemi, G.; Khan, N.A.... more authors ... less authors ( Elsevier Inc. , 2016 , Book chapter)Several studies involving real-life applications have shown that methods for the detection, estimation, and classification of nonstationary signals can be enhanced by utilizing the time-frequency ((t,f)) characteristics ... -
EEG amplitude and correlation spatial decay analysis for neonatal head modelling
Odabaee M.; Layeghy S.; Mesbah M.; Azemi G.; Boashash B.; Colditz P.; Vanhatalo S.... more authors ... less authors (2012 , Conference Paper)There is an increased need to better understand the relation between brain structures and functions in newborns by using EEG source localization techniques. This requires a realistic head model that would take into account ... -
Generalised phase synchrony within multivariate signals: An emerging concept in time-frequency analysis
Omidvarnia A.; Boashash B.; Azemi G.; Colditz P.; Vanhatalo S. (2012 , Conference Paper)This paper introduces the notion of the instantaneous frequency (IF) based generalized phase synchrony in time-frequency analysis based on the concept of cointegration. This phase synchrony is then quantified by investigating ... -
Generalized Mean Phase Coherence for asynchrony abnormality detection in multichannel newborn EEG
Omidvarnia A.; Vanhatalo S.; Mesbah M.; Azemi G.; Colditz P.; Boashash B.... more authors ... less authors (2012 , Conference Paper)Inter-hemispheric asynchrony within the multichannel recordings of newborn EEG is associated with abnormal functionality of the newborn brain. Mean Phase Coherence (MPC) as a bivariate phase synchrony measure is widely ... -
Improved characterization of HRV signals based on instantaneous frequency features estimated from quadratic time-frequency distributions with data-adapted kernels
Dong S.; Azemi G.; Boashash B. ( Elsevier Ltd , 2014 , Article)The analysis of heart rate variability (HRV) provides a non-invasive tool for assessing the autonomic regulation of cardiovascular system. Quadratic time-frequency distributions (TFDs) have been used to account for the ... -
Improving the classification of newborn EEG time-frequency representations using a combined time-frequency signal and image approach
Boashash B.; Boubchir L.; Azemi G. (2012 , Conference Paper)This paper presents new time-frequency (T-F) features to improve the classification of non-stationary signals such as EEG signals. Previous methods were based only on signal features that were derived from the instantaneous ... -
Non-invasivemonitoring of fetal movements using time-frequency features of accelerometry
Layeghy S.; Azemi G.; Colditz P.; Boashash B. ( Institute of Electrical and Electronics Engineers Inc. , 2014 , Conference Paper)This paper presents a time-frequency approach for fetal movement monitoring which is based on the instantaneous amplitude (IA) and instantaneous frequency (IF) of signals collected using 3axial accelerometers placed over ... -
Orthogonalized partial directed coherence for functional connectivity analysis of newborn EEG
Omidvarnia A.H.; Azemi G.; Boashash B.; O'Toole J.M.; Colditz P.; Vanhatalo S.... more authors ... less authors (2012 , Conference Paper)The aim of this study is to develop a time-frequency method and test its applicability to investigating directional cortical connectivity in the newborn brain considering the effect of volume conduction. We modified ... -
Performance evaluation of multi-component instantaneous frequency estimation techniques for heart rate variability analysis
Dong S.; Azemi G.; Lingwood B.; Colditz P.B.; Boashash B. (2012 , Conference Paper)Accurate instantaneous frequency (IF) estimation of the non-stationary heart rate signal is important in quantifying the heart rate variability (HRV) measures. This study compares the effectiveness of four IF estimation ... -
Principles of time-frequency feature extraction for change detection in non-stationary signals: Applications to newborn EEG abnormality detection
Boashash B.; Azemi G.; Ali Khan N. ( Elsevier Ltd , 2015 , Article)This paper considers the general problem of detecting change in non-stationary signals using features observed in the time-frequency (t,f) domain, obtained using a class of quadratic time-frequency distributions (QTFDs). ... -
Robust estimation of highly-varying nonlinear instantaneous frequency of monocomponent signals using a lower-order complex-time distribution
Omidvarnia, A.; Azemi, G.; O'Toole, J.M.; Boashash, B. ( Elsevier B.V. , 2013 , Article)This paper proposes an approach for robust estimation of highly-varying nonlinear instantaneous frequency (IF) in monocomponent nonstationary signals. The proposed method is based on a lower order complex-time distribution ... -
Time-frequency methodologies in neurosciences
Boashash, B.; Stevenson, N.J.; Rankine, L.J.; Stevenson, N.J.; Azemi, G.; Sejdić, E.; Aviyente, S.; Akan, A.; Mert, A.; Dong, S.; Omidvarnia, A.; Zarjam, P.; O'Toole, J.M.; Colditz, P.... more authors ... less authors ( Elsevier Inc. , 2016 , Book chapter)This chapter presents a number of time-frequency (t,f) techniques that can provide advanced solutions to several problems in neuro-sciences with focus on the monitoring of brain abnormalities using EEG and other physiological ... -
A time–frequency based approach for generalized phase synchrony assessment in nonstationary multivariate signals
Omidvarnia, A; Azemi, G; Colditz, P.B; Boashash, B ( Elsevier , 2013 , Article)This paper proposes a new approach to estimate the phase synchrony among nonstationary multivariate signals using the linear relationships between their instantaneous frequency (IF) laws. For cases where nonstationary ...