Electrical and Electronic Engineering - Research Publications

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    Jeeva: Enterprise Grid Enabled Web Portal for Protein Secondary Structure Prediction
    Jin, C ; Gubbi, J ; Buyya, R ; Palaniswami, M ; Thulasiram, R (IEEE, 2008)
    This paper presents a Grid portal for protein secondary structure prediction developed by using services of Aneka, a .NET-based enterprise Grid technology. The portal is used by research scientists to discover new prediction structures in a parallel manner. An SVM (Support Vector Machine)-based prediction algorithm is used with 64 sample protein sequences as a case study to demonstrate the potential of enterprise Grids.
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    Interaction between sleep EEG and ECG signals during and after obstructive sleep apnea events with or without arousals
    KHANDOKER, AHSAN ; KARMAKAR, CHANDAN ; PALANISWAMI, MARIMUTHU (IEEE - Institute of Electrical and Electronic Engineers, 2008)
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    Identification of onset, maximum and termination of obstructive sleep apnoea events in single lead ECG recordings
    Karmakar, CK ; Khandoker, AH ; Palaniswami, M (IEEE, 2008)
    Measuring the Apnoea Hypopnoea Index (AHI) is important for determining the severity of any apnoea patient. This study presents a method of screening each apnoea event separately based on the single lead Electrocardiogram (EGG) signal. The whole ECG of a subject was divided into Normal, Onset, OSA-maximum and Termination epochs with length of 5 seconds. PSD analysis was used for determining the features directly from the ECG. ROC area was calculated to determine the discrimination capability of each feature (or power in each frequency bin) found by PSD analysis. The maximum ROC area found between Normal vs. OSA-maximum was 0.81 in the frequency range of 52-72 Hz. The ROC area and significant frequency band for Normal vs. Onset and Normal vs. Termination were 0.78, 0.78 and 57-65 Hz, 52-66 Hz respectively.
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    Analysis of coherence between sleep EEG and ECG signals during and after obstructive sleep apnea events
    Khandoker, AH ; Karmakar, CK ; Palaniswami, M (IEEE, 2008)
    This study presents the first successful preliminary attempt to directly investigate the interactions of power spectra of sleep EEG and ECG signals of patients with obstructive sleep apnea syndrome (OSAS) by coherence analysis. ECG and EEG signals were collected from 8 OSAS patients and 3 healthy subjects. Coherence between two signals over different frequency bands(0-128 Hz) were calculated for normal breathing events, obstructive sleep apnea (OSA) events and events following OSA terminations (with/without arousals) in non-REM as well as REM sleep. Overall coherence of ECG and EEG in REM sleep is higher than that in non-REM sleep. A significant (p=0.0164) difference of coherence in the range of 10-5 Hz was found among normal, OSA and termination events in REM sleep. The results could be useful in detecting OSA events or OSA related arousals to characterize sleep fragmentation from ECG and EEG signals.
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    An Adaptive REM for Improving AQM Performance
    SUN, J ; ZUKERMAN, M ; PALANISWAMI, M (IEEE - Institute of Electrical and Electronic Engineers, 2008)
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    Risk-aware beacon scheduling for tree-based ZigBee/IEEE 802.15.4 wireless networks
    Yen, Li-Hsing ; Law,Yee Wei ; PALANISWAMI, MARIMUTHU (ICST, 2008)
    In a tree-based ZigBee network, ZigBee routers (ZRs) must schedule their beacon transmission times to avoid beacon collisions. The beacon schedule determines packet delivery latency from the end devices to the ZigBee coordinator at the root of the tree. Traditionally, beacon schedules are chosen such that a ZR does not reuse the beacon slots already claimed by its neighbors, or the neighbors of its neighbors. We observe however that beacon slots can be reused judiciously, especially when the risk of beacon collision caused by such reuse is low. The advantage of such reuse is that packet delivery latency can be reduced. We formalize our observation by proposing a node pair classification scheme, that classifies pairs of nodes that are at most two hops apart. Based on this scheme, we can easily assess the risk of slot reuse by a node pair. If the risk is high, slot reuse is disallowed; otherwise, slot reuse is allowed. This forms the essence of our ZigBee-compliant, distributed, risk- aware, probabilistic beacon scheduling algorithm. Simulation results confirm that our algorithm produces a lower latency compared to if a more conventional slot reuse rule is used.