Two Applications of High Order Methods: Wave Propagation and Accelerator Physics

Numerical simulations of partial differential equations (PDE) are used to predict the behavior of complex physics phenomena when the real life experiments are expensive. Discretization of a PDE is the representation of the continuous problem as a discrete problem that can be solved on a computer. The discretization always introduces a certain inaccuracy caused by the numerical approximation. By increasing the computational cost of the numerical algorithm the solution can be computed more accurately. In the theory of numerical analysis this fact is called the convergence of the numerical algorithm. The idea behind high order methods is to improve the rate of convergence so a slight increase of numerical work will lead to a significant increase of accuracy. We consider the wave equation on the domain around the body of a complex shape. This problem is challenging since because of the geometrical complexity. In this work we propose the Hybrid Hermite-Discontinuous Galerkin method of the overset grids for the wave equation. It combines highly efficient Hermite methods acting on Cartesian grids with the Discontinuous Galerkin method acting on a curvilinear grid around the body. The results of long time simulation will be presented to demonstrate the high order accuracy and stability of the proposed method. High energy particle physicists would like polarized electron beams in the next generation of circular particle accelerators. The so-called DK formulas predict well the level of polarization at current energies but they may not be valid at the higher energies of the next generation machines. We aim the check the validity of the formulas and extend them if needed by numerically integrating the so-called full Bloch equation. This is a system of PDEs which is more fundamental than the DK formulas and is believed to contain all the relevant physics. The full Bloch equations can be classified as an advection-diffusion problem in 3 degrees of freedom which is an enormous problem to solve on the computer. Our idea is to use the fast Fourier transform for the angular dimensions and introduce the parallel in Fourier modes numerical algorithm. The results of numerical simulation for a one degree of freedom and a two degrees of freedom model circular accelerator will be presented

Android Permissions Remystified: A Field Study on Contextual Integrity

Due to the amount of data that smartphone applications can potentially access, platforms enforce permission systems that allow users to regulate how applications access protected resources. If users are asked to make security decisions too frequently and in benign situations, they may become habituated and approve all future requests without regard for the consequences. If they are asked to make too few security decisions, they may become concerned that the platform is revealing too much sensitive information. To explore this tradeoff, we instrumented the Android platform to collect data regarding how often and under what circumstances smartphone applications are accessing protected resources regulated by permissions. We performed a 36-person field study to explore the notion of "contextual integrity," that is, how often are applications accessing protected resources when users are not expecting it? Based on our collection of 27 million data points and exit interviews with participants, we examine the situations in which users would like the ability to deny applications access to protected resources. We found out that at least 80% of our participants would have preferred to prevent at least one permission request, and overall, they thought that over a third of requests were invasive and desired a mechanism to block them

The Feasibility of Dynamically Granted Permissions: Aligning Mobile Privacy with User Preferences

Current smartphone operating systems regulate application permissions by prompting users on an ask-on-first-use basis. Prior research has shown that this method is ineffective because it fails to account for context: the circumstances under which an application first requests access to data may be vastly different than the circumstances under which it subsequently requests access. We performed a longitudinal 131-person field study to analyze the contextuality behind user privacy decisions to regulate access to sensitive resources. We built a classifier to make privacy decisions on the user's behalf by detecting when context has changed and, when necessary, inferring privacy preferences based on the user's past decisions and behavior. Our goal is to automatically grant appropriate resource requests without further user intervention, deny inappropriate requests, and only prompt the user when the system is uncertain of the user's preferences. We show that our approach can accurately predict users' privacy decisions 96.8% of the time, which is a four-fold reduction in error rate compared to current systems.Comment: 17 pages, 4 figure

Подвійна природа політичних ринків: чи підриває це демократію?

This article is an attempt to analyze the contradictions of political marketing as a theory and technology. Various aspects of scholarly debate analyzed and various problems associated with application of political marketing are highlighted. У статті проаналізовано суперечливу природу політичного маркетингу як теорії та технології. Також розглянуто різні аспекти цих суперечностей і різні проблеми, пов’язані із застосуванням політичного маркетингу

American Government (UWG)

This Grants Collection for American Government was created under a Round Four ALG Textbook Transformation Grant. Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process. Documents are in .pdf format, with a separate .docx (Word) version available for download. Each collection contains the following materials: Linked Syllabus Initial Proposal Final Reporthttps://oer.galileo.usg.edu/polisci-collections/1001/thumbnail.jp

Peculiarities of cryogenic pipelines insulation selection at small scale liquefied natural gas production and consumption facilities

The article analyzes the typical design and materials of thermal insulation of cryogenic pipelines, compares them on the basis of thermal conductivity, and considers the key differences in the regulatory and technical documents of the Russian Federation, the People's Republic of China and the European Union, which should be taken into account in the design of thermal insulation of pipelines at low-tonnage LNG facilities. A number of regulatory requirements in the Russian Federation restrict the use of commonly used materials such as polyisocyanurate and pouleorethane foam without the development of a safety case or the use of additional compensating measures. Thermal insulation structures based on aerogels or foam glass are acceptable, but have a number of shortcomings