47,194 research outputs found

    On the general governing equations of electromagnetic acoustic transducers

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    In this paper, we present the general governing equations of electrodynamics and continuum mechanics that need to be considered while mathematically modelling the behaviour of electromagnetic acoustic transducers (EMATs). We consider the existence of finite deformations for soft materials and the possibility of electric currents, temperature gradients, and internal heat generation due to dissipation. Starting with Maxwell's equations of electromagnetism and balance laws of nonlinear elasticity, we present the governing equations and boundary conditions in incremental form in order to solve wave propagation problems of boundary value type.Comment: Version 2: Added reference [16] and corrected grammar at a couple of place

    Progress on Polynomial Identity Testing - II

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    We survey the area of algebraic complexity theory; with the focus being on the problem of polynomial identity testing (PIT). We discuss the key ideas that have gone into the results of the last few years.Comment: 17 pages, 1 figure, surve

    A Compact CMOS Memristor Emulator Circuit and its Applications

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    Conceptual memristors have recently gathered wider interest due to their diverse application in non-von Neumann computing, machine learning, neuromorphic computing, and chaotic circuits. We introduce a compact CMOS circuit that emulates idealized memristor characteristics and can bridge the gap between concepts to chip-scale realization by transcending device challenges. The CMOS memristor circuit embodies a two-terminal variable resistor whose resistance is controlled by the voltage applied across its terminals. The memristor 'state' is held in a capacitor that controls the resistor value. This work presents the design and simulation of the memristor emulation circuit, and applies it to a memcomputing application of maze solving using analog parallelism. Furthermore, the memristor emulator circuit can be designed and fabricated using standard commercial CMOS technologies and opens doors to interesting applications in neuromorphic and machine learning circuits.Comment: Submitted to International Symposium of Circuits and Systems (ISCAS) 201

    An Alternative Method for Solving a Certain Class of Fractional Kinetic Equations

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    An alternative method for solving the fractional kinetic equations solved earlier by Haubold and Mathai (2000) and Saxena et al. (2002, 2004a, 2004b) is recently given by Saxena and Kalla (2007). This method can also be applied in solving more general fractional kinetic equations than the ones solved by the aforesaid authors. In view of the usefulness and importance of the kinetic equation in certain physical problems governing reaction-diffusion in complex systems and anomalous diffusion, the authors present an alternative simple method for deriving the solution of the generalized forms of the fractional kinetic equations solved by the aforesaid authors and Nonnenmacher and Metzler (1995). The method depends on the use of the Riemann-Liouville fractional calculus operators. It has been shown by the application of Riemann-Liouville fractional integral operator and its interesting properties, that the solution of the given fractional kinetic equation can be obtained in a straight-forward manner. This method does not make use of the Laplace transform.Comment: 7 pages, LaTe

    Community Self-Organisation from a Social-Ecological Perspective: ‘Burlang Yatra’ and Revival of Millets in Odisha (India)

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    In this paper, I focus on the revival of an Indigenous community seed festival known locally as Burlang Yatra (‘Indigenous Biodiversity Festival’) in the district of Kandhamal in Odisha (India). This annual event brings together millet farmers to share knowledge and practices, including exchange of Indigenous heirloom seeds. Such community seed festivals remain largely underappreciated (and underexplored). Investigating Burlang Yatra through a social-ecological lens allowed for a greater understanding of its capacity to build and strengthen relationships, adaptation, and responsibility, three key principles that together link the social and the ecological in a dynamic sense. These principles, driven by intergenerational participation and interaction as well as social learning, can be seen as fostering ‘social-ecological memory’ of millet-based biodiverse farming. The festival’s persistence and revival illustrate a form of grassroots self-organising that draws on values of an Indigenous knowledge system. Within a restorative context, it has the capacity to repair and restore cultural and ecological relationships that the community has with their own foods and practices. This paper offers a new understanding of community self-organising from a social-ecological perspective and particularly in a marginalised context as supporting the revitalisation of Indigenous food systems
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