Gossip Codes for Fingerprinting: Construction, Erasure Analysis and Pirate Tracing

This work presents two new construction techniques for q-ary Gossip codes from tdesigns and Traceability schemes. These Gossip codes achieve the shortest code length specified in terms of code parameters and can withstand erasures in digital fingerprinting applications. This work presents the construction of embedded Gossip codes for extending an existing Gossip code into a bigger code. It discusses the construction of concatenated codes and realisation of erasure model through concatenated codes.Comment: 28 page

Evaluation of petroleum based horticulture oil for the management of the tea red spider mite, Oligonychus coffeae Neitner (Acarina: Tetranychidae)

The Servo agro spray oil (petroleum based horticulture oil) was evaluated in the laboratory against tea red spider mite, Oligonychus coffeae to determine its effect on adult mortality, viability of eggs, oviposition deterrence and repellent properties. The same was also evaluated in the field to determine its effect on mite population. Direct spray method was used in the laboratory at concentrations of 0.5, 1.0, and 1.5%. Mortality of O. coffeae was both concentration and time dependent. Deposition of eggs by adult mites on treated leaf surfaces decreased significantly and the viability of eggs was also significantly reduced. In addition, different concentrations of the Servo agro spray also exhibited repellent properties against adult mites. In the field Servo agro spray oil significantly reduced the mite population and its bio-efficacy was comparable to that of the synthetic pesticide (propargite 57 EC). No phytotoxic effect was observed when tea bushes were sprayed with different doses of Servo agro spray. Tea samples were taint free. Quality (appearance of liquor, flavour, taint and taste) of made tea was not adversely affected by treatments with Servo agro spray oil. Therefore Servo agro spray oil may be a potential agent to be used in the sustainable management of tea red spider mite

Density functional investigations of defect induced mid-gap states in graphane

We have carried out ab initio electronic structure calculations on graphane (hydrogenated graphene) with single and double vacancy defects. Our analysis of the density of states reveal that such vacancies induce the mid gap states and modify the band gap. The induced states are due to the unpaired electrons on carbon atoms. Interestingly the placement and the number of such states is found to be sensitive to the distance between the vacancies. Furthermore we also found that in most of the cases the vacancies induce a local magnetic moment.Comment: 15 page

The determinants of hotels' marketing managers' green marketing behaviour

Little is known about the factors underlying the pro-environmental behaviour of marketing managers. This paper explores the determinants of green marketing practices in the Red Sea hotel sector in Egypt. The research model assesses green marketing practices against the personal and organisational values of the marketing managers, together with a range of organisational and demographic variables expected to influence hotels' environmental behaviour. From a valid sample of 89 marketing managers responsible for 194 hotels, it was found that organisational contextual variables, and in particular targeting Western tourists, being affiliated to an international hotel chain and the marketers' own demographics, including age, academic subject studied and gender, were the best predictors of more proactive green marketing. Personal environmental values did not explain the pro-environmental behaviour of marketers, and the organisational environmental values that had explained part of their ethical behaviour had resulted from voluntarism rather than utilitarian or conformance-based values. Government policies also appeared to be ineffective determinants. The implications for green marketing practices are also discussed. © 2010 Taylor & Francis

Angular momentum transport in accretion disks

We reexamine arguments advanced by Hayashi & Matsuda (2001), who claim that several simple, physically motivated derivations based on mean free path theory for calculating the viscous torque in a quasi-Keplerian accretion disk yield results that are inconsistent with the generally accepted model. If correct, the ideas proposed by Hayashi & Matsuda would radically alter our understanding of the nature of the angular momentum transport in the disk, which is a central feature of accretion disk theory. However, in this paper we point out several fallacies in their arguments and show that there indeed exists a simple derivation based on mean free path theory that yields an expression for the viscous torque that is proportional to the radial derivative of the angular velocity in the accretion disk, as expected. The derivation is based on the analysis of the epicyclic motion of gas parcels in adjacent eddies in the disk.Comment: Matches published versio

Signatures of a spin-1/2 cooperative paramagnet in the diluted triangular lattice of Y2_2CuTiO6_6

We present a combination of thermodynamic and dynamic experimental signatures of a disorder driven dynamic cooperative paramagnet in a 50% site diluted triangular lattice spin-1/2 system, Y$_2$CuTiO$_6$. Magnetic ordering and spin freezing are absent down to 50 mK, far below the Curie Weiss scale of ~-134 K. We observe scaling collapses of the magnetic field- and temperature-dependent magnetic heat capacity and magnetisation data, respectively, in conformity with expectations from the random singlet physics. Our experiments establish the suppression of any freezing scale, if at all present, by more than three orders of magnitude, opening a plethora of interesting possibilities such as disorder-stabilized long range quantum entangled ground states.Comment: 18 pages, 9 figures, published in Physical Review Letter