A Practical Approach to Protect IoT Devices against Attacks and Compile Security Incident Datasets

open access articleThe Internet of Things (IoT) introduced the opportunity of remotely manipulating home appliances (such as heating systems, ovens, blinds, etc.) using computers and mobile devices. This idea fascinated people and originated a boom of IoT devices together with an increasing demand that was difficult to support. Many manufacturers quickly created hundreds of devices implementing functionalities but neglected some critical issues pertaining to device security. This oversight gave rise to the current situation where thousands of devices remain unpatched having many security issues that manufacturers cannot address after the devices have been produced and deployed. This article presents our novel research protecting IOT devices using Berkeley Packet Filters (BPFs) and evaluates our findings with the aid of our Filter.tlk tool, which is able to facilitate the development of BPF expressions that can be executed by GNU/Linux systems with a low impact on network packet throughput

Variationally consistent homogenization of electrochemical ion transport in a porous structural battery electrolyte

In this paper, we develop a multi-scale modeling framework for a multiphysics problem characterized by electro-chemically coupled ion transport in a Structural Battery Electrolyte (SBE). The governing equations of the problem are established by coupling Gauss law with mass conservation for each mobile species. By utilizing variationally consistent homogenization, we are able to establish a two-scale model where both the macro-scale and sub-scale equations are deduced from a single-scale problem. Investigations of the sub-scale RVE problem show that the transient effects are negligible for the length scales relevant to the studied application, which motivates the assumption of micro-stationarity. In the special case of linear constitutive response, we get a numerically efficient solution scheme for the macro-scale problem that is based on a priori upscaling. As a final step, we demonstrate the numerically efficient solution scheme by solving a 2D macro-scale problem using upscaled constitutive quantities based on a 3D RVE

Numerical Model Reduction with error estimation for computational homogenization of non-linear consolidation

Numerical Model Reduction (NMR) is adopted for solving the non-linear microscale problem that arises from computational homogenization of a model problem of porous media with displacement and pressure as unknown fields. A reduced basis is obtained for the pressure field using Proper Orthogonal Decomposition and the pertinent displacement basis is obtained using Nonuniform Transformation Field Analysis. An explicit, fully computable, a posteriori error estimator is derived based on the linearized error equation for quantification of the NMR error in terms of a suitably chosen energy norm. The performance of the error estimates is demonstrated via a set of numerical examples with varying load amplitudes

Variationally consistent computational homogenization of chemomechanical problems with stabilized weakly periodic boundary conditions

A variationally consistent model-based computational homogenization approach for transient chemomechanically coupled problems is developed based on the classical assumption of first-order prolongation of the displacement, chemical potential, and (ion) concentration fields within a representative volume element (RVE). The presence of the chemical potential and the concentration as primary global fields represents a mixed formulation, which has definite advantages. Nonstandard diffusion, governed by a Cahn–Hilliard type of gradient model, is considered under the restriction of miscibility. Weakly periodic boundary conditions on the pertinent fields provide the general variational setting for the uniquely solvable RVE-problem(s). These boundary conditions are introduced with a novel approach in order to control the stability of the boundary discretization, thereby circumventing the need to satisfy the LBB-condition: the penalty stabilized Lagrange multiplier formulation, which enforces stability at the cost of an additional Lagrange multiplier for each weakly periodic field (three fields for the current problem). In particular, a neat result is that the classical Neumann boundary condition is obtained when the penalty becomes very large. In the numerical examples, we investigate the following characteristics: the mesh convergence for different boundary approximations, the sensitivity for the choice of penalty parameter, and the influence of RVE-size on the macroscopic response

Loading of a Bose-Einstein condensate in the boson-accumulation regime

We study the optical loading of a trapped Bose-Einstein condensate by spontaneous emission of atoms in excited electronic state in the Boson-Accumulation Regime. We generalize the previous simplified analysis of ref. [Phys. Rev. A 53, 2466 (1996)], to a 3D case in which more than one trap level of the excited state trap is considered. By solving the corresponding quantum many-body master equation, we demonstrate that also for this general situation the photon reabsorption can help to increase the condensate fraction. Such effect could be employed to realize a continuous atom laser, and to overcome condensate losses.Comment: 7 pages, 5 eps figures, uses epl.st

Continuous optical loading of a Bose-Einstein Condensate in the Thomas-Fermi regime

We discuss the optical loading of a Bose-Einstein condensate in the Thomas-Fermi regime. The condensate is loaded via spontaneous emission from a reservoir of excited-state atoms. By means of a master equation formalism, we discuss the modification of the condensate temperature during the loading. We identify the threshold temperature, $T_{th}$, above (below) which the loading process leads to cooling (heating), respectively. The consequences of our analysis for the continuous loading of an atom laser are discussed.Comment: 7 pages, 3 figure

Model of Inspiring Media

Scholars have increasingly explored the ways that media content can touch, move, and inspire audiences, leading to numerous beneficial outcomes including increased feelings of connectedness to and heightened motivations for doing good for others. Although this line of inquiry is relatively new, sufficient evidence and patterns of results have emerged such that a clearer picture of the inspiring media experience is coming into focus. This article has two primary goals. First, we seek to synthesize the existing research into a working and evolving model of inspiring media experiences reflecting five interrelated and symbiotic elements: exposure, message factors, responses, outcomes, and personal/situational factors. The model also identifies theoretical mechanisms underlying the previously observed positive effects. Secondly, the article explores situations in which, and precipitating factors present, when these hoped-for outcomes either fail to materialize or result in negative or maladaptive responses and outcomes. Ultimately, the model is proposed as a heuristic roadmap for future scholarship and as an invitation for critique and collaboration in the emerging field of positive media psychology

Profiling the Audience for Self-Transcendent Media: A National Survey

This article reports the findings from a national survey of self-transcendent (or inspiring) media audience members in the United States. Exposure to self-transcendent content is socially significant because, theoretically, it can orient users towards matters beyond themselves, ultimately promoting connections with others and altruistic behaviors. However, to date, little is known about the daily audiences for such fare. Four primary questions guided the investigation: (1) What are the media sources and contents identified as “inspiring” by the audience?, (2) Who makes up the current U.S. audience for self-transcendent media content?, (3) What personality traits and viewer characteristics are associated with self-transcendent media consumption?, and (4) What prosocial and altruistic behaviors are associated with self-transcendent media consumption? To address these questions, a nationally representative survey (n = 3,006) was conducted. The findings are discussed in relation to the growing body of scholarship on positive media psychology

High resolution amplitude and phase gratings in atom optics

An atom-field geometry is chosen in which an atomic beam traverses a field interaction zone consisting of three fields, one having frequency $\Omega =c/\lambda$ propagating in the $\hat{z}$ direction and the other two having frequencies $\Omega +\delta_{1}$ and $\Omega +\delta_{2}$ propagating in the -$\hat{z}$ direction. For $n_{1}\delta_{1}+n_{2}\delta_{2}=0$ and $|\delta_{1}| T,|\delta_{2}| T\gg 1$, where $n_{1}$ and $n_{2}$ are positive integers and $T$ is the pulse duration in the atomic rest frame, the atom-field interaction results in the creation of atom amplitude and phase gratings having period $\lambda /[2(n_{1}+n_{2})]$. In this manner, one can use optical fields having wavelength $\lambda$ to produce atom gratings having periodicity much less than $\lambda$.Comment: 11 pages, 14 figure

Exploring the Spirit in U.S. Audiences: The Role of the Virtue of Transcendence in Inspiring Media Consumption

Little is yet known about audiences who routinely seek out media content that is inspirational in nature. The current study expands the research on inspirational media by utilizing a nationally representative sample of U.S. audiences (n = 2,016) to explore relationships between inspiring media exposure, trait transcendence, and self-transcendent emotions. Results show that media content is a reliable source for everyday self-transcendent emotional experiences in U.S. audiences. These experiences are most frequently encountered by persons with high levels of trait spirituality and gratitude. The profile of U.S. audiences that seek out inspiring media is discussed