134,417 research outputs found
Parallel Algorithms for Certain Matrix Computations
No full textThe complexity of performing matrix computations, such as solving a linear system, inverting a nonsingular matrix or computing its rank, has received a lot of attention by both the theory and the scientific computing communities. In this paper we address some “nonclassical” matrix problems that find extensive applications, notably in control theory. More precisely, we studythe matrix equations AX +XA^T = C and AX - XB = C, the “inverse” of the eigenvalue problem (called pole assignment), and the problem of testing whether the matrix [B AB ... A^nB] has full row rank. For these problems we show two kinds of PRAM algorithms: on one side very fast, i.e. polylog time, algorithms and on the other side almost linear time and processorefficient algorithms. In the latter case, the algorithms rely on basic matrix computations that can be performed efficiently also on realistic machine models
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Constant disturbance rejection and zero steady state tracking error for nonlinear systems design
No full textS. W. Su, B. D. O. Anderson, and T. S. Brinsmead. Constant disturbance rejection and zero steady state tracking error for nonlinear systems design, In Biswa Datta, editor, Applied computational control, signals, and circuits 2001, Pages 1-30, KLUWER, BOSTON
LMI based Stability and Stabilization of Second-order Linear Repetitive Processes
No full textThis paper develops new results on the stability and control of a class of linear repetitive processes described by a second-order matrix discrete or differential equation. These are developed by transformation of the secondorder dynamics to those of an equivalent first-order descriptor state-space model, thus avoiding the need to invert a possibly ill-conditioned leading coefficient matrix in the original model
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Figures 21-24 from: Volynkin AV, Singh N, Kirti JS, Datta HS (2020) Description of a new Barsine Walker, 1854 from India and Nepal (Lepidoptera, Erebidae, Arctiinae, Lithosiini). ZooKeys 941: 107-120. https://doi.org/10.3897/zookeys.941.51344
No full textFigures 21-24 Barsine germana: male genitalia 21 northeastern India, slide MWM 33964 Volynkin 22 Nepal, slide MWM 33962 Volynkin 23 holotype of B. thomasi, northern India, prep. H.S. Datta 24 holotype of B. valvalis, northeastern India, prep. H.S. Datta
Virtual graviton exchanges at the Z pole in large extra dimensions
No full textIn the framework of quantum gravity propagating in large extra dimensions, the effects of virtual Kaluza-Klein gravitons on the imaginary part of the amplitude of the process e(+)e(-) --> f (f) over bar are analyzed at the Z pole. Notably, the interference of the almost-continuous spectrum of the KK gravitons with the standard model resonant amplitude is finite and predictable in terms of the fundamental D-dimensional Planck scale M-D. We find that, while the virtual-graviton effect on total cross sections vanishes at tree-level, both angular and polarization asymmetries are modified by terms whose relative effect is at most of order 10(-4) for M-D > 1 TeV. Possible shifts in M-Z, due to the changes in Breit-Wigner line shape are also discussed. (C) 2002 Elsevier Science B.V. All rights reserved
Conversion of neutron stars to strange stars as the central engine of gamma-ray bursts
No full textWe study the conversion of a neutron star to a strange star as a possible energy source for gamma-ray bursts. We use different recent models for the equation of state of neutron star matter and strange quark matter. We show that the total amount of energy liberated in the conversion is in the range of (1ndash4)×1053 ergs (1 order of magnitude larger than previous estimates) and is in agreement with the energy required to power gamma-ray burst sources at cosmological distances
Garh Stone Inscription of the time of Mahhipala, V. S. 979
No full textB. Datta and C. L. Suri, "Garh Stone Inscription of the time of Mahhipala, V. S. 979," Epigraphia Indica 39, part 4 (1972): 189-98. © 198
S.K. De Datta receives Clifton Garvin Fellowship
No full textS.K. De Datta, of Blacksburg, associate provost for international affairs at Virginia Tech, received the university's Clifton Garvin Fellowship Award. The award was conferred by the Virginia Tech Board of Visitors at its quarterly meeting Monday, Nov. 8
- …
