Comparing Russian, French and UK television news: portrayals of the casualties of war

Focusing on the news value of compassion in war reporting, this article examines portrayals of victims in foreign conflict reporting by Russian, French and UK television news. It compares the reports of Russia's state-aligned news provider, Vremya; BBC's News at Ten; and France 2's 20 Heures and explores the extent to which they draw on, or sideline, this news value to maintain the newsworthiness of their items. The article investigates coverage of the intra-Palestinian fighting in June 2007 and discusses representations of two very different forms of victimhood to determine how the broadcasters perceive “victims”. The first concerns civilians caught up in the fighting and the emerging humanitarian crisis in Gaza and the second focuses on coverage of two hostage-takings

The role of mathematics for physics teaching and understanding

That mathematics is the “language of physics” implies that both areas are deeply interconnected, such that often no separation between “pure” mathematics and “pure” physics is possible. To clarify their interplay a technical and a structural role of mathematics can be distinguished. A thorough understanding of this twofold role in physics is also important for shaping physics education especially with respect to teaching the nature of physics. Herewith the teachers and their pedagogical content knowledge play an important role. Therefore we develop a model of PCK concerning the interplay of mathematics and physics in order to provide a theoretical framework for the views and teaching strategies of teachers. In an exploratory study four teachers from Germany and four teachers from Israel have been interviewed concerning their views and its transfer to teaching physics. Here we describe the results from Germany. Besides general views and knowledge held by all or nearly all teachers we also observe specific individual focus depending on the teachers’ background and experiences. The results fit well into the derived model of PCK

Properties of the value function in optimal control problems with infinite horizon

The article investigates properties of the value function of the optimal control problem on infinite horizon with an unlimited integrand index appearing in the quality functional with a discount factor. The estimate is derived for approximating the value function in a problem with the infinite horizon by levels of value functions in problems with lengthening finite horizons. The structure of the value function is identified basing on stationary value functions which depend only on phase variables. The description is given for the asymptotic growth of the value function generated by various types of the quality functional applied in economic and financial modeling: logarithmic, power, exponential, linear functions. The property of continuity is specified for the value function and estimates are deduced for the Holder parameters of continuity. These estimates are needed for the development of grid algorithms designed for construction of the value function in optimal control problems with infinite horizon

Hybrid membranes for blood-contacting surfaces: preliminary characterization

The hemocompatibility of any mechanical circulatory support device is mostly conditioned by the nature of the blood-contacting surface. Hybrid membranes as the inner surfaces of the artificial ventricle were produced by coupling a polymeric material (polycarbonate urethane) with decellularized biological tissues (animal pericardia). Physicochemical and mechanical characteristics of the hybrid membranes were carefully evaluated confirming satisfactory features in terms of composition and mechanical resistance

Numerical methods for construction of value functions in optimal control problems with infinite horizon

The article is devoted to the analysis of optimal control problems with infinite time horizon. These problems arise in economic growth models and in stabilization problems for dynamic systems. The problem peculiarity is a quality functional with an unbounded integrand which is discounted by an exponential index. The problem is reduced to an equivalent optimal control problem with the stationary value function. It is shown that the value function is the generalized minimax solution of the corresponding Hamilton-Jacobi equation. The boundary condition for the stationary value function is replaced by the property of the Hölder continuity and the sublinear growth condition. A backward procedure on infinite time horizon is proposed for construction of the value function. This procedure approximates the value function as the generalized minimax solution of the stationary Hamilton-Jacobi equation. Its convergence is based on the contraction mapping method defined on the family of uniformly bounded and Hölder continuous functions. After the special change of variables the procedure is realized in numerical finite difference schemes on strongly invariant compact sets for optimal control problems and differential games. Copyright © 2020 The Authors. This is an open access article under the CC BY-NC-ND licens

Numerical methods for construction of value functions in optimal control problems on an infinite horizon

This article deals with the optimal control problem on an infinite horizon, the quality functional of which is contained in the integrand index and the discounting factor. A special feature of this formulation of the problem is the assumption of the possible unboundedness of the integrand index. The problem reduces to an equivalent optimal control problem with a stationary value function as a generalized (minimax, viscosity) solution of the Hamilton–Jacobi equation satisfying the Hölder condition and the condition of linear growth. The article describes the backward procedure on an infinite horizon. It is the method of numerical approximation of the generalized solution of the Hamilton–Jacobi equation. The main result of the article is an estimate of the accuracy of approximation of a backward procedure for solving the original problem. Problems of the analyzed type are related to modeling processes of economic growth and to problems of stabilizing dynamic systems. The results obtained can be used to construct numerical finite-difference schemes for calculating the value function of optimal control problems or differential games. © 2019 Udmurt State University. All right reserved