Rensselaer Polytechnic Institute

About: Rensselaer Polytechnic Institute is a education organization based out in Troy, New York, United States. It is known for research contribution in the topics: Terahertz radiation & Population. The organization has 19024 authors who have published 39922 publications receiving 1414699 citations. The organization is also known as: RPI & Rensselaer Institute.

Multiway analysis of epilepsy tensors

Abstract: Motivation: The success or failure of an epilepsy surgery depends greatly on the localization of epileptic focus (origin of a seizure). We address the problem of identification of a seizure origin through an analysis of ictal electroencephalogram (EEG), which is proven to be an effective standard in epileptic focus localization. Summary: With a goal of developing an automated and robust way of visual analysis of large amounts of EEG data, we propose a novel approach based on multiway models to study epilepsy seizure structure. Our contributions are 3-fold. First, we construct an Epilepsy Tensor with three modes, i.e. time samples, scales and electrodes, through wavelet analysis of multi-channel ictal EEG. Second, we demonstrate that multiway analysis techniques, in particular parallel factor analysis (PARAFAC), provide promising results in modeling the complex structure of an epilepsy seizure, localizing a seizure origin and extracting artifacts. Third, we introduce an approach for removing artifacts using multilinear subspace analysis and discuss its merits and drawbacks. Results: Ictal EEG analysis of 10 seizures from 7 patients are included in this study. Our results for 8 seizures match with clinical observations in terms of seizure origin and extracted artifacts. On the other hand, for 2 of the seizures, seizure localization is not achieved using an initial trial of PARAFAC modeling. In these cases, first, we apply an artifact removal method and subsequently apply the PARAFAC model on the epilepsy tensor from which potential artifacts have been removed. This method successfully identifies the seizure origin in both cases. Contact: [email protected]

Robust attitude stabilization of spacecraft using nonlinear quaternion feedback

Abstract: This paper considers the problem of three-axis attitude stabilization of a rigid spacecraft. A nonlinear control law which uses the feedback of the unit quaternion and the measured angular velocities is proposed and is shown to provide global asymptotic stability. The control law does not require the knowledge of the system parameters and is, therefore, robust to modeling errors. The significance of the control law is that it can be used for large-angle maneuvers with guaranteed stability. >

Role of Granular Activated Carbon Surface Chemistry on the Adsorption of Organic Compounds. 1. Priority Pollutants

Abstract: Uptake of two synthetic organic contaminants (SOCs), trichloroethylene and trichlorobenzene, by one coal-based and one wood-based granular activated carbon (GAC), modified using liquid-phase oxidation (HNO3) and heat treatment in an inert atmosphere (N2), and by several different as-received GACs was compared. Carbons were characterized by elemental analysis, surface area and pore size distribution, water vapor adsorption, acid−base adsorption characteristics measured using the Boehm technique, and a mass titration/pH equilibration method to determine the pHpzc. The results of isotherm experiments with the surface-treated coal- and wood-based carbons indicated that carbon surface acidity played an important role on the adsorption of hydrophobic SOCs. It was found that increasing surface acidity increased the polarity of the surface and reduced adsorption of hydrophobic SOCs by GAC. However, no significant trend was evident for as-received carbons; their behavior differed significantly from surface-treated...