Stochastic complexity measures for physiological signal analysis

Traditional feature extraction methods describe signals in terms of amplitude and frequency. This paper takes a paradigm shift and investigates four stochastic-complexity features. Their advantages are demonstrated on synthetic and physiological signals; the latter recorded during periods of Cheyne-Stokes respiration, anesthesia, sleep, and motor-cortex investigation     

Gas sensing properties of nanocrystalline diamond films

Toxic gas sensing device with metal electrodes built into nanocrystalline diamond (NCD) is investigated. The NCD morphology is controlled via seeding and/or deposition time. The surface properties and morphology of NCD are studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM). AFM measurements reveal increase in NCD surface area by up to 13%. Gas sensing properties of H-terminated NCD device show high sensitivity towards oxidizing species where the surface conductivity is increased by an order of magnitude for humid air and by three orders of magnitude for COCl₂. The surface conductivity exhibits a small decrease to reducing spices (CO₂, NH₃).     

Light-assisted adsorption processes in nanocrystalline diamond membranes studied by femtosecond laser spectroscopy

We report on femtosecond photoluminescence spectroscopy of nanocrystalline diamond membranes (thickness ～ 1000 nm) prepared by microwave plasma enhanced chemical vapour deposition (CVD) technique. The decay of photoluminescence excited by the blue femtosecond light pulses (405 nm) reflects the photoexcited charge carrier dynamics in the sub-band gap energy states. The photoluminescence is strongly influenced by ambient conditions and by the laser irradiation (405 nm, 70 fs pulses). Under lower ambient air pressure (5–300 Pa) the photoluminescence intensity increases and the photoluminescence decay gets faster. For higher air pressures (> 600 Pa) the photoluminescence intensity decreases and the photoluminescence decay rates do not evolve. We interpret the observed different behaviour of the photoluminescence in the two air pressure intervals in terms of a thin water layer condensed on the surface at higher air pressures. Due to a low coverage of the sample surface by water molecules under low pressure the air species can be adsorbed to NCD and influence the sub-band gap energy states.     

The electronic band structure of InN,InAs and InSb compounds

The electronic band structure of InN, InAs and InSb has been investigated by ETB. The ETB method has been formulated for sp³d² basis and nearest neighbor interactions of the compounds and its energy parameters have been derived from the results of the present first principles calculations carried on InN, InAs and InSb. It has been found that the present ETB parameters can produce the band structure of the compounds successfully.     

Stochastic complexity measures for physiological signal analysis

Traditional feature extraction methods describe signals in terms of amplitude and frequency. This paper takes a paradigm shift and investigates four stochastic-complexity features. Their advantages are demonstrated on synthetic and physiological signals; the latter recorded during periods of Cheyne-Stokes respiration, anesthesia, sleep, and motor-cortex investigation.