M. Thulasidas

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There has been an increase in research interest for brain-computer interface (BCI) technology as an alternate mode of communication and environmental control for the disabled, such as patients suffering from amyotrophic lateral sclerosis (ALS), brainstem stroke and spinal cord injury. Disabled patients with appropriate physical care and cognitive ability to(More)
We report the implementation of a text input application (speller) based on the P300 event related potential. We obtain high accuracies by using an SVM classifier and a novel feature. These techniques enable us to maintain fast performance without sacrificing the accuracy, thus making the speller usable in an online mode. In order to further improve the(More)
Improving classification accuracy is a key issue to advancing brain computer interface (BCI) research from laboratory to real world applications. This article presents a high accuracy EEG signal classification method using single trial EEG signal to detect left and right finger movement. We apply an optimal temporal filter to remove irrelevant signal and(More)
We report the effect of removing ocular artifacts on the performance of a word-processing application based on the event related potential P300. Various methods of removing artifacts have been reported. The efficiency of these algorithms are usually done by subjective visual comparisons. Noting that there is a direct correlation of artifact rectifying(More)
We report our studies on a Brain Computer Interface (BCI) speller application with an aim to optimize its performance and usability. We study the dependence of the spelling accuracy as a function of (a) the number of visual stimuli (repetitions) presented to the user, (b) the P300 segment length used, (c) the number of channels used, and (d) the amount of(More)
We report new measurements of the diierential and total branching ratios for inclusive B decay to D 0 , D + and D + and the rst measurement of the same quantities for inclusive B decay to D 0. Here B is the mixture of B d and Bu from (4S) decay. Furthermore, since more than one charm particle (or antiparticle) of the same kind can be produced in B decay,(More)
Gamma ray bursts (GRB) occur at random points in the sky at cosmological distances. They emit intense γ rays for a brief period. The spectrum then evolves through X–ray, optical region to possibly radio frequency. Though there are some models, the origin and time evolution of GRB are not well understood. Extragalactic radio sources also exhibit a baffling(More)
Searches for scalar top, scalar bottom and degenerate scalar quarks have been performed with data collected with the ALEPH detector at LEP. The data sample consists of 57 pb taken at √ s = 181–184 GeV. No evidence for scalar top, scalar bottom or degenerate scalar quarks was found in the channels t̃ → cχ, t̃ → blν̃, b̃ → bχ, and q̃ → qχ. From the channel t̃(More)