618 research outputs found

    Cloud Computing and Dependency: An ERA of Computing

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    Cloud Computing offers an entirely new way of looking at IT infrastructure. Cloud Computing system fundamentally provide access to large pools of data and computational resources through a variety of interfaces similar in spirit to existing grid and programming system. Cloud Computing eliminates an up-front commitment by users, thereby allowing agencies to start small and increases hardware resources only when there is an increase in their needs. Moreover,cloud computing provides the ability to pay for use of computing resources in a short term basis as needed and release them as needed. In this paper we focus on architecture, types of cloud services, characteristics, advantages & disadvantages and security of cloud computing

    Technique for Calculating Solution Derivatives With Respect to Geometry Parameters in a CFD Code

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    A solution has been developed to the challenges of computation of derivatives with respect to geometry, which is not straightforward because these are not typically direct inputs to the computational fluid dynamics (CFD) solver. To overcome these issues, a procedure has been devised that can be used without having access to the mesh generator, while still being applicable to all types of meshes. The basic approach is inspired by the mesh motion algorithms used to deform the interior mesh nodes in a smooth manner when the surface nodes, for example, are in a fluid structure interaction problem. The general idea is to model the mesh edges and nodes as constituting a spring-mass system. Changes to boundary node locations are propagated to interior nodes by allowing them to assume their new equilibrium positions, for instance, one where the forces on each node are in balance. The main advantage of the technique is that it is independent of the volumetric mesh generator, and can be applied to structured, unstructured, single- and multi-block meshes. It essentially reduces the problem down to defining the surface mesh node derivatives with respect to the geometry parameters of interest. For analytical geometries, this is quite straightforward. In the more general case, one would need to be able to interrogate the underlying parametric CAD (computer aided design) model and to evaluate the derivatives either analytically, or by a finite difference technique. Because the technique is based on a partial differential equation (PDE), it is applicable not only to forward mode problems (where derivatives of all the output quantities are computed with respect to a single input), but it could also be extended to the adjoint problem, either by using an analytical adjoint of the PDE or a discrete analog

    A solution adaptive structured-unstructured grid procedure for unsteady flows

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    A solution adaptive hybrid grid method for the computation of two-dimensional, unsteady flows is presented. The method is capable of handling multiple component, complex geometries in relative motion, such as those encountered in turbomachinery analysis. The numerical approach uses a hybrid structured-unstructured zonal grid topology along with modeling equations and solution techniques that are most appropriate in the individual domains, thus combining the advantages of both structured and unstructured grid methods. The viscous flow region in the immediate vicinity of the airfoils is resolved using a third-order accurate, implicit, upwind solution of the Navier-Stokes equations on structured, O-type grids. Explicit solutions of the Euler equations are obtained in the rest of the domain that consists of an unstructured mesh made up of triangular cells. The use of both central- and upwind-differenced flux schemes is investigated for the unstructured domains. Methodologies for accurate, conservative transfer of information at the interface between the structured and unstructured domains as well as that between two unstructured grids in relative motion are developed. An efficient and robust solution adaptation strategy is developed which incorporates both refinement and de-refinement capabilities for the unstructured grid regions. Both time-averaged and time-resolved results are presented for test cases and are compared with available experimental data. The quality of the results obtained by the present method is comparable with those obtained by methods based on fully structured grids. Calculations performed using the solution adaptation capabilities are also presented

    Extended 16x16 Play-Fair Algorithm for Secure Key Exchange Using RSA Algorithm

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    With the world entering in the 21st century rigorous efforts are being made to secure data and flow of information among the users. Though with the advancements are fast and efficient the third party intervention and security threats has also increased many folds. The algorithms being used to encrypt and decrypt data needs to be strong enough to secure the data but also simple enough for a user to handle the process. With this article a novel, practical approach is presented which not only makes the information more secured but also being based on RSA algorithm is easy enough for users to understand and implement into the systems

    Study of efficacy of oral ivermectin in comparison to commonly used topical antiscabetic drugs gamma benzene hexachloride and permethrin

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    Background: Scabies is an infectious disease, contagious in nature and caused by Sarcoptes Scabiei, is transmitted readily, often throughout an entire household, by prolonged skin-to-skin contact with an infected person. The objective was to know the efficacy of oral ivermectin in the treatment of scabies infection in comparison to commonly used topical antiscabetic drugs gamma benzene hexachloride and permethrin.Methods: Using prospective, longitudinal, comparative randomized design, study was conducted for a period of one year in 299 patients, in the age group of 5 to 60 years, belonging to both sexes, attending outpatient department of dermatology of J.L.N. Medical College and associated hospitals Ajmer (RAJ), India. Pregnant and lactating women, children below 5 years, elderly patients more than 60 year, patients not willing to come for follow-up and patients with any serious systemic illness were excluded. Data so collected, were analyzed as per the aims and objectives with the help of appropriate statistical software (primer statistical software version 6).Results: Efficacy of oral ivermectin therapy was comparable with topical permethrin therapy but more efficacious (statistically significant) than topical gama benzene hexachloride therapy.Conclusions: Ivermectin can be a very useful weapon in patients who do not show compliance with topical therapy

    Study of efficacy of oral ivermectin in comparison to commonly used topical antiscabetic drugs gamma benzene hexachloride and permethrin

    Get PDF
    Background: Scabies is an infectious disease, contagious in nature and caused by Sarcoptes Scabiei, is transmitted readily, often throughout an entire household, by prolonged skin-to-skin contact with an infected person. The objective was to know the efficacy of oral ivermectin in the treatment of scabies infection in comparison to commonly used topical antiscabetic drugs gamma benzene hexachloride and permethrin.Methods: Using prospective, longitudinal, comparative randomized design, study was conducted for a period of one year in 299 patients, in the age group of 5 to 60 years, belonging to both sexes, attending outpatient department of dermatology of J.L.N. Medical College and associated hospitals Ajmer (RAJ), India. Pregnant and lactating women, children below 5 years, elderly patients more than 60 year, patients not willing to come for follow-up and patients with any serious systemic illness were excluded. Data so collected, were analyzed as per the aims and objectives with the help of appropriate statistical software (primer statistical software version 6).Results: Efficacy of oral ivermectin therapy was comparable with topical permethrin therapy but more efficacious (statistically significant) than topical gama benzene hexachloride therapy.Conclusions: Ivermectin can be a very useful weapon in patients who do not show compliance with topical therapy

    Three dimensional analysis of a rotor in forward flight

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    Fast responding ephedrine detection with miniaturized surface ionization gas sensors

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    AbstractWe report on novel kinds of miniaturized gas sensors whose operation is based on the principle of surface ionization (SI). In SI gas sensing adsorbed analyte species are ionized at a heated solid surface and the formed ions are extracted towards an oppositely charged collector electrode positioned a short distance from the emitting surface. Here, we show that SI sensors allow for a fast, sensitive and selective detection of illicit drugs in the presence of large concentrations of solvent water
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