Electronic & Electrical Eng: Recent submissions
Now showing items 701-720 of 750
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A method for source-microphone range estimation in reverberant environments, using an array of microphones of unknown relative position
(IEEE, 2006)Estimating the range between an acoustic source and a microphone is a central problem in microphone-array processing. Although many approaches have been proposed in the literature, these tend to require knowledge of the ... -
Automatic location of IC design errors using an e-beam system
(IEEE, 1988)The ADVICE system discussed is an enhanced CAD (computer-aided design) linked E-beam tester to locate automatically design errors on custom VLSI devices. The goal is met by building a set of procedures to drive the interactive ... -
Independent brain computer interfacing control using visual spatial attention-dependent modulations of parieto-occipital alpha
(2005)Parieto-occipital alpha band (8-14 Hz) EEG activity was examined daring a spatial attention-based brain computer interface paradigm for its potential use as a feature for left/right spatial attention classification. In ... -
A spectrum of colors: investigating the temporal frequency characteristics of the human visual system using a system identification approach
(IEEE, 2006)Noise input signals are commonly used in both linear and nonlinear system identification of physiological systems. This method can be applied to electrophysiological analysis of the human visual system by controlling the ... -
A comparison of covert and overt attention as a control option in a steady-state visual evoked potential-based brain computer interface
(IEEE, 2004)EEG data were recorded from occipital scalp regions of subjects who attended to an alternating checkerboard stimulus in one visual field while ignoring a similar stimulus of a different frequency in the opposite visual ... -
Self-assembled uniaxial and biaxial multilayer structures in chiral smectic liquid crystals frustrated between ferro- and antiferroelectricity
(2004)With a view to obtain a molecular model for the subphases produced by the frustration between ferro- and antiferroelectricity in chiral smectic liquid crystals, we report results on two compounds and observe (i) the staircase ... -
Line registration of jittered video
(1997)With the imminent widespread availability of digital video broadcasts and the subsequent increase in the demand for broadcast material, image sequence restoration is an increasing source of concern for both archivists and ... -
Discrete flexoelectric polarizations and biaxial subphases with periodicities other than 3- and 4-layers in chiral smectic liquid crystals frustrated between ferroelectricity and antiferroelectricity
(2005)The subphase for the temperature range that lies in between Sm-CA* and the three-layer Sm-CA*(1 3) subphase has been confirmed to exist using the measurements of electric-field-induced birefringence, optical rotation, and ... -
Self-assembly of biaxial ordering and molecular tilt angle of chiral smectic liquid crystals in hometropically aligned cells investigated using Fourier transform infrared spectroscopy
(American Physics Society, 2005)Temperature dependences of the infrared absorbance have been measured for the four chiral liquid crystal samples in the homeotropic cell configuration. It is shown that the values of the orientational order parameter S ... -
Surface-induced multiple re-entrant transitions
(2006)We have studied tilted surface layers in the bulk SmA temperature window of one liquid crystal using null transmission ellipsometry. Five distinct nonplanar surface structures were observed. We present analyses of the tilt ... -
Investigations of nano-scale helical pitch in SmCá* and SmC* phases of a chiral smectic liquid crystal using differential optical reflectivity measurements
(2006)Differential optical reflectivity (DOR) was used to study the temperature dependence of the short helical pitch in freestanding films of a liquid crystal compound. The experimentally measured DOR signal was fitted using ... -
Orientation polarization from faster motions in the ultraviscous and glassy diethyl phthalate and its entropy
(2006)Dielectric spectra of the relaxation in glassy and ultraviscous liquid diethyl phthalate show that its relaxation strength , the distribution of times, and the relaxation rate are more sensitive to temperature T in the ... -
Exponential kinetics of spontaneous change in the localized motions of D-sorbitol glass
(2006)The dielectric relaxation spectra of D -sorbitol glass have been studied in real time during annealing at 221.1 K, which is 47 K below its Tg of 268 K. As the glass structurally relaxes during annealing, features of the ... -
The orientational order and the dynamics of the dendritic liquid crystal organo-siloxane tetrapodes determined using dielectric spectroscopy
(2006)The dielectric measurements have been carried out on the two zeroth generation dendrimers with four branched arms (called tetrapodes) based on the siloxane cores. The results are analyzed in the framework of the molecular ... -
Investigations of nanoscale helical pitch in smectic-C and smectic-C* phases of a chiral smectic liquid crystal using differential optical reflectivity measurements
(2006)Differential optical reflectivity DOR was used to study the temperature dependence of the short helical pitch in freestanding films of a liquid crystal compound. The experimentally measured DOR signal was fitted using ... -
Theory of the intermediate tilted smectic phases and their helical rotation
(2006)A molecular-statistical theory for the entire sequence of the chiral tilted smectic phases is derived. Uniaxial and biaxial subphases were found to be stable in different temperature ranges depending on the molecular parameters. ... -
Experimental demonstration, using polarized Raman and infrared spectroscopy that both conventional and de Vries smectic_A phase may exist in smectic liquid crystals with a first-order A-C* transition
(2006)Two models exist for the orientational distribution of the long molecular axes in smectic-A liquid crystals: the conventional unimodal distribution and the ?cone-shaped? de Vries distribution. The de Vries hypothesis provides ... -
Relaxations and nano-phase-separation in ultraviscous heptanol-alkyl halide mixture
(2007)To gain insight into the effects of liquid-liquid phase separation on molecular relaxation behavior we have studied an apparently homogeneous mixture of 5-methyl-2-hexanol and isoamylbromide by dielectric spectroscopy over ... -
Discontinuous change in the smectic layer thickness in ferrielectric liquid crystals
(2007)The temperature dependence of the thickness of thick free-standing films is studied using a high-resolution film thickness measurement technique. A small discontinuity in the temperature dependence of the smectic layer ...
