Can coercive formulations lead to fast and accurate solution of the Helmholtz equation?

A new, coercive formulation of the Helmholtz equation was introduced in [Moiola, Spence, SIAM Rev. 2014]. In this paper we investigate $h$-version Galerkin discretisations of this formulation, and the iterative solution of the resulting linear systems. We find that the coercive formulation behaves similarly to the standard formulation in terms of the pollution effect (i.e. to maintain accuracy as $k\to\infty$, $h$ must decrease with $k$ at the same rate as for the standard formulation). We prove $k$-explicit bounds on the number of GMRES iterations required to solve the linear system of the new formulation when it is preconditioned with a prescribed symmetric positive-definite matrix. Even though the number of iterations grows with $k$, these are the first such rigorous bounds on the number of GMRES iterations for a preconditioned formulation of the Helmholtz equation, where the preconditioner is a symmetric positive-definite matrix.Comment: 27 pages, 7 figure

Understanding the role of social media in political corporate branding research in the context of Indian politics

This paper seeks to explore how political actors within the Bharatiya Janata Party (BJP) use social media in their communication campaigns and how these social media platforms are understood by citizens following the 2014 Indian General Election. This research attempts to address the limited understanding of social media in the context of politics (Barnard and Kreiss, 2013; Burton and Shea, 2010; Cogburn and Espinoza-Vasquez 2011; Ganz, 2009; Gulati and Williams, 2007; Kumar 2009; Owen and Davis 2008). Furthermore, the limited research on political branding and social media has predominantly focused a western context negating eastern perspectives including the republic of India. This study will use the adapted Kapferer’s (2008) brand identity prism developed by Pich et al. (2014) to a political setting. This framework will ground the study and offer the opportunity to examine the role of social media from an internal brand identity and external brand image perspective. The findings will have implications not only for political parties but also for politicians, candidates and other parties interested in social media. This study will offer organisations a mechanism that will allow them understand how their social media is projected and understood and allow them to investigate whether their projected brand identity is coherent with the understood external brand image

Uniform Stabilization of n-Dimensional Vibrating Equation Modeling ‘Standard Linear Model’ of Viscoelasticity

In this paper, we deal with the elastic vibrations of flexible structures modeled by the ‘standard linear model’ of viscoelasticity in n-dimensional space. We study the uniform exponential stabilization of such kind of vibrations after incorporating separately very small amount of passive viscous damping and internal material damping of Kelvin-Viogt type in the model. Explicit forms of exponential energy decay rates are obtained by a direct method, for the solution of such boundary value problems without having to introduce any boundary feedback

Radioprotective Potential of Plants and Herbs against the Effects of Ionizing Radiation

Ionizing radiations produce deleterious effects in the living organisms and the rapid technological advancement has increased human exposure to ionizing radiations enormously. There is a need to protect humans against such effects of ionizing radiation. Attempts to protect against the deleterious effects of ionizing radiations by pharmacological intervention were made as early as 1949 and efforts are continued to search radioprotectors, which may be of great help for human application. This review mainly dwells on the radioprotective potential of plant and herbal extracts. The results obtained from in vitro and in vivo studies indicate that several botanicals such as Gingko biloba, Centella asiatica, Hippophae rhamnoides, Ocimum sanctum, Panax ginseng, Podophyllum hexandrum, Amaranthus paniculatus, Emblica officinalis, Phyllanthus amarus, Piper longum, Tinospora cordifoila, Mentha arvensis, Mentha piperita, Syzygium cumini, Zingiber officinale, Ageratum conyzoides, Aegle marmelos and Aphanamixis polystachya protect against radiation-induced lethality, lipid peroxidation and DNA damage. The fractionation-guided evaluation may help to develop new radioprotectors of desired activities