149 research outputs found
Transmedia Strategies for Participatory Politics in Russia: Alexey Navalny’s Grassroots Campaign
Transmedia storytelling scholarship has been progressing rapidly over recent decades. Yet, a question that remains open is the lack of analysis of political transmedia campaigns. This political communication thesis contributes to filling that gap. Its goal is to develop a flexible and locally-specific approach to analysing transmedia political campaigning. To understand the context that affects the destinies of transmedia grassroots campaigns, the study turns to social movement and grassroots activism scholarships. In particular, it employs the idea of political opportunity structures to conceptualise those external opportunities and threats that affects transmedia campaigns in politics. To mitigate the negative aspects of a political climate, reduce the costs of political participation for active citizens and make their political change efforts more efficient, political organisers can mobilise valuable resources through transmedia campaigning, the thesis argues. Thus, the thesis incorporates the analysis of opportunity structures and mobilising resources to propose a new analytical approach to the study of political transmedia campaigns. Because this analytical approach reinterprets transmedia strategies through the lens of opportunity structures and resource mobilisation, I will refer to it in the thesis as the opportunity structures and mobilising resources (OSMR) analytical approach. The thesis tests it with the case study of Alexey Navalny\u27s 2013 mayoral campaign for Moscow. The case study outlines the opportunity structures of modern Russia and discusses the transmedia strategies Navalny’s campaign used to overcome some of their negative aspects. In doing so, the thesis enriches transmedia storytelling scholarship with insights from other disciplines and offers a flexible and locally specific approach to analysing political transmedia campaigns
New extended thin-sheet approximation for geodynamic applications—I. Model formulation
Thin-sheet approximations are widely used in geodynamics because of their potential for fast computation of 3-D lithospheric deformations using simple numerical techniques. However, this simplicity imposes limits to boundary conditions, rheological settings and accuracy of results. This paper presents a new approach to reduce these restrictions. The mathematical formulation of the model involves the construction of the depth distributions of stress and velocity fields using asymptotic approximations of 3-D force balance and rheological relations. The asymptotic treatment is performed on the basis of a small geometry parameter É› (thickness to width ratio of the thin sheet) with a high accuracy while keeping terms which are capable of generating strong singularities due to possible large variations in material properties in layered systems The depth profiles are verified by a condition of exact equilibrium in the depth-integrated force balance and by an asymptotic approach to the boundary conditions. The set of analytical depth profiles of velocities and stresses, together with the 2-D equations representing the integrated force balance, result in an extended thin-sheet approximation (ETSA). The potential of the ETSA is demonstrated by applications to problems with different types of boundary conditions and consideration of the types of systems of equations governing each case. These studies have not found any strong limitations to the boundary conditions considered and demonstrate the greater generality and higher accuracy of ETSA in comparison with the previous generation of thin-sheet approximations. The accompanying paper demonstrates the results of 2-D experiments based on ETS
New extended thin-sheet approximation for geodynamic applications—II. Two-dimensional examples
The potential of the new extended thin-sheet approximation (ETSA) has been investigated by application to a representative range of 2-D problems. The system of governing equations presented by Medvedev & Podladchikov (1999) for 3-D modelling was reduced to two dimensions and tested on problems involving one- and two-layer systems of Newtonian viscous materials. The application of ETSA in each case included (1) setting boundary conditions, (2) completion of equations by evaluation of coefficients, (3) comparison of equations with governing equations of existing thin-sheet approximations, and (4) linear analysis of small perturbations and determination of their dominant wavelengths. It is shown that most previous approaches can be derived by simplification of an extended system under specified boundary conditions. Linear analyses compare well with exact analytical solutions over a wide range of wavelengths for modelling isostatic adjustment, Rayleigh-Taylor instabilities and the development of instabilities due to lateral compression and extension. These problems cannot be described by the previous generation of thin-sheet approximations. Our results suggest that the new extended thin-sheet approximation (ETSA) will be a powerful tool for the realistic modelling of complicated 2- and 3-D geodynamic structure
The features of the Cosmic Web unveiled by the flip-flop field
Currently the dark matter environment is widely accepted as a framework for understanding of the observed structure in the universe. N-body simulations are indispensable for the analysis of the formation and evolution of the dark matter web. Two primary fields – density and velocity fields – are used in most of studies. Dark matter provides two additional fields that are unique for collisionless media only. They are the multistream field in Eulerian space and flip-flop field in Lagrangian space. The flip-flop field represents the number of sign reversals of an elementary volume of each collisionless fluid element. This field can be estimated by counting the sign reversals of the Jacobian at each particle at every time step of the simulation. The Jacobian is evaluated by numerical differentiation of the Lagrangian submanifold, i.e. the three-dimensional dark matter sheet in the six-dimensional space formed by three Lagrangian and three Eulerian coordinates. We present the results of the statistical study of the evolution of the flip-flop field from z = 50 to the present time z = 0. A number of statistical characteristics show that the pattern of the flip-flop field remains remarkably stable from z ≈ 30 to the present time. As a result the flip-flop field evaluated at z = 0 stores a wealth of information about the dynamical history of the dark matter web. In particular one of the most intriguing properties of the flip-flop is a unique capability to preserve the information about the merging history of haloes
The features of the Cosmic Web unveiled by the flip-flop field
Currently the dark matter environment is widely accepted as a framework for understanding of the observed structure in the universe. N-body simulations are indispensable for the analysis of the formation and evolution of the dark matter web. Two primary fields – density and velocity fields – are used in most of studies. Dark matter provides two additional fields that are unique for collisionless media only. They are the multistream field in Eulerian space and flip-flop field in Lagrangian space. The flip-flop field represents the number of sign reversals of an elementary volume of each collisionless fluid element. This field can be estimated by counting the sign reversals of the Jacobian at each particle at every time step of the simulation. The Jacobian is evaluated by numerical differentiation of the Lagrangian submanifold, i.e. the three-dimensional dark matter sheet in the six-dimensional space formed by three Lagrangian and three Eulerian coordinates. We present the results of the statistical study of the evolution of the flip-flop field from z = 50 to the present time z = 0. A number of statistical characteristics show that the pattern of the flip-flop field remains remarkably stable from z ≈ 30 to the present time. As a result the flip-flop field evaluated at z = 0 stores a wealth of information about the dynamical history of the dark matter web. In particular one of the most intriguing properties of the flip-flop is a unique capability to preserve the information about the merging history of haloes
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