9,065 research outputs found
E-business and Export Behaviour: Evidence from Indian Firms
E-business, international orientation, India
ID-based Ring Signature and Proxy Ring Signature Schemes from Bilinear Pairings
In 2001, Rivest et al. firstly introduced the concept of ring signatures. A
ring signature is a simplified group signature without any manager. It protects
the anonymity of a signer. The first scheme proposed by Rivest et al. was based
on RSA cryptosystem and certificate based public key setting. The first ring
signature scheme based on DLP was proposed by Abe, Ohkubo, and Suzuki. Their
scheme is also based on the general certificate-based public key setting too.
In 2002, Zhang and Kim proposed a new ID-based ring signature scheme using
pairings. Later Lin and Wu proposed a more efficient ID-based ring signature
scheme. Both these schemes have some inconsistency in computational aspect.
In this paper we propose a new ID-based ring signature scheme and a proxy
ring signature scheme. Both the schemes are more efficient than existing one.
These schemes also take care of the inconsistencies in above two schemes.Comment: Published with ePrint Archiv
Electronic structure study of vanadium spinels by using density functional theory and dynamical mean field theory
Theoretically, various physical properties of AVO (A=Zn, Cd and
Mg) spinels have been extensively studied for last 15 years. Besides of this,
no systematic comparative study has been done for these compounds, where the
material specific parameters are used. Here, we report the comparative
electronic behaviour of these spinels by using a combination of density
functional theory and dynamical mean-field theory, where the self-consistent
calculated Coulomb interaction and Hund's coupling (determined by
Yukawa screening ) are used. The main features, such as insulating
band gaps (), degree of itinerancy of V 3 electrons and position of
lower Hubbard band are observed for these parameters in these spinels. The
calculated values of for ZnVO, CdVO and
MgVO are found to be 0.9 eV, 0.95 eV and 1.15 eV,
respectively, where the values of are close to experiment for
ZnVO and MgVO. The position of lower Hubbard band are
observed around -1.05 eV, -1.25 eV and -1.15 eV for
ZnVO, CdVO and MgVO, respectively, which
are also in good agreement with the experimental data for ZnVO. The
order of average impurity hybridization function of V site are found to be
ZnVOMgVOCdVO. Hence, the degree of
localization of V 3 electrons is largest for CdVO and smallest
for ZnVO, which is in accordance with our earlier results. Hence,
present work shows the importance of material specific parameters to understand
the comparative electronic behaviour of these compounds.Comment: 7 pages, 5 figure
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