1,662 research outputs found

    Meromorphic Functions and the Topology of Giant Gravitons

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    Using Mikhailov's map from holomorphic functions to supersymmetric D3-brane solutions, we show how to construct giant gravitons in AdS5 x S5 with toroidal topologies. In the 1/4-BPS sector we show that these are always of the form #^K (S2 x S1), and in the limit in which this becomes a set of m+n perpendicular spherical giants re-connected near to their intersections, we find K in terms of m,n. In the 1/8-BPS sector we find a similar class of solutions.Comment: 10 pages, 8 figure

    DDoS Attack Detection in WSN using Modified Invasive Weed Optimization with Extreme Learning Machine

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    Wireless sensor networks (WSN) are the wide-spread methodology for its distribution of the vast amount of devoted sensor nodes (SNs) that is employed for sensing the atmosphere and gather information. The gathered information was transmitted to the sink nodes via intermediate nodes. Meanwhile, the SN data are prone to the internet, and they are vulnerable to diverse security risks, involving distributed denial of service (DDoS) outbreaks that might interrupt network operation and compromises data integrity. In recent times, developed machine learning (ML) approaches can be applied for the discovery of DDoS attacks and accomplish security in WSN. To achieve this, this study presents a modified invasive weed optimization with extreme learning machine (MIWO-ELM) model for DDoS outbreak recognition in the WSN atmosphere. In the presented MIWO-ELM technique, an initial stage of data pre-processing is conducted. The ELM model can be applied for precise DDoS attack detection and classification process. At last, the MIWO method can be exploited for the parameter tuning of the ELM model which leads to improved performance of the classification. The experimental analysis of the MIWO-ELM method takes place using WSN dataset. The comprehensive simulation outputs show the remarkable performance of the MIWO-ELM method compared to other recent approaches

    Multifarious transparent glass nanocrystal composites

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    Glasses comprising well known ferroelectric crystalline phases have been a subject of curious investigation from the point of view of exploiting these composites for dielectric, pyroelectric, ferroelectric, electro and non-linear optical devices. Transparent glass-ceramics containing ferroelectric crystallites at nano scale have been of much interest owing to their promising physical properties. The advantages that are associated with glass-ceramics include very low levels of porosity and hence high break down voltages. It is of our interest to nanocrystallize Aurivillius family of ferroelectric oxides and tetragonal tungsten bronzes on borate and tellurite based glass matrices and demonstrate their promising optical and nonlinear optical properties. Apart from the above, the nanocrystallites of well known ferroelectric material LiNbO3 was grown in a reactive glass matrix. These nanocrystals of LiNbO3 exhibited intense second harmonic signals in transmission mode when exposed to IR light at 1064 nm. The most interesting result was the demonstration of optical diffraction of the second harmonic signals which was attributed to the presence of self- organized sub-micrometer sized LiNbO3 crystallites that were indeed inscribed by the IR laser light which was used to probe in the NLO property of these materials

    Taxonomic notes on two endemic species of Oberonia Lindl. from Western Ghats, India

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    The genus Oberonia is known for its micro floral arrangement. Due to its minute structure, excess of new species are reported. The present paper reveals the synonymization of two recently described species of the genus Oberonia viz. O. saintberchmansii and O. wynadensis under O. anamalayana and O. josephi respectively. The original illustration and live dissected images of the species are provided for easy identification

    Comfort properties and dyeing behaviour of cotton/milkweed blended rotor yarn fabrics

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    Milkweed (M) fibres have been blended with cotton (C) fibres at three different proportions and the rotor-spun yarn fabrics are produced. The comfort properties of 100% cotton and C/M blended fabrics are analysed. The fabrics have been dyed with two types of reactive dyes, namely CI Reactive Yellow 3RS and CI Reactive Red 120, and the colour strength and other calorimetric parameters of the dyeing are analysed. From the comfort properties of the fabrics, it is noticed that the air and water vapour permeabilities of C/M blended fabrics are lower than the 100% cotton fabric and decrease with the increase in milkweed proportion. The thermal conductivity of C/M blended fabrics is lower than 100% cotton fabric and decreases with the increase in milkweed proportion. The reduction in inter-yarn space and higher yarn hairiness leads to reduction in air, water and thermal conductivity values with the increase in milkweed proportion. The wickability of C/M blended fabrics increases with milkweed proportion due to the open yarn structure and hollowness of milkweed fibres. From the dyeing behaviour of fibres, it is observed that the colour strength of C/M 80/20 is higher than 100% cotton and it decreases with the further increase in milkweed blend proportion. The low cellulose percentage, higher crystalline orientation index of milkweed fibres compared to cotton results in lower colour strength values with milkweed percentage greater than 20%

    T-Duality of Green-Schwarz Superstrings on AdS(d) x S(d) x M(10-2d)

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    We verify the self-duality of Green-Schwarz supercoset sigma models on AdSd×Sd_d \times S^d backgrounds (d=2,3,5) under combined bosonic and fermionic T-dualities without gauge fixing kappa symmetry. We also prove this property for superstrings on AdSd×Sd×Sd_d \times S^d \times S^d (d=2,3) described by supercoset sigma models with the isometries governed by the exceptional Lie supergroups D(2,1;α)D(2,1;\alpha) (d=2) and D(2,1;α)×D(2,1;α)D(2,1;\alpha)\times D(2,1;\alpha) (d=3), which requires an additional T-dualisation along one of the spheres. Then, by taking into account the contribution of non-supercoset fermionic modes (up to the second order), we provide evidence for the T-self-duality of the complete type IIA and IIB Green-Schwarz superstring theory on AdSd×Sd×T10−2d_d\times S^d \times T^{10-2d} (d=2,3) backgrounds with Ramond-Ramond fluxes. Finally, applying the Buscher-like rules to T-dualising supergravity fields, we prove the T-self-duality of the whole class of the AdSd×Sd×M10−2d_d\times S^d \times M^{10-2d} superbackgrounds with Ramond-Ramond fluxes in the context of supergravity.Comment: v2: 57 pages, 1 figure, typos fixed and clarifications added, version to appear in JHE

    Bacterial foraging optimization based adaptive neuro fuzzy inference system

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    Life of human being and animals depend on the environment which is surrounded by plants. Like human beings, plants also suffer from lot of diseases. Plant gets affected by completely including leaf, stem, root, fruit and flower; this affects the normal growth of the plant. Manual identification and diagnosis of plant diseases is very difficult. This method is costly as well as time-consuming so it is inefficient to be highly specific. Plant pathology deals with the progress in developing classification of plant diseases and their identification. This work clarifies the identification of plant diseases using leaf images caused by bacteria, viruses and fungus. By this method it can be identified and control the diseases. To identify the plant leaf disease Adaptive Neuro Fuzzy Inference System (ANFIS) was proposed. The proposed method shows more refined results than the existing works

    Scattering in AdS2/CFT1 and the BES phase

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    We study worldsheet scattering for the type IIA superstring in AdS 2 ×S 2 ×T 6. Using the Green-Schwarz action to quartic order in fermions we take the near-BMN limit, where as in the AdS3/CFT2 case there are both massive and massless excitations. For the massive excitations we compute all possible tree-level processes, and show that these agree with a truncated version of the exact AdS 5 × S 5 S-matrix. We also compute several S-matrix elements involving massless excitations. At one loop we find that the dressing phase is the same Hernándes-López phase appearing in AdS5/CFT4. We see the same phase when calculating this by semiclassical means using the PSU(1, 1 2)/U(1)2 coset sigma model, for which we can also study the scattering of fermions. This supports the conjecture that the all-loop dressing phase is again the BES phase, rather than a new phase like that seen in AdS3/CFT2
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