Special Issue on the Economics of Security and Privacy: Guest Editors’ Introduction

This editorial introduces the special issue on the economics of security and privacy. The global adoption of the Internet has transformed economies and societies. However, Internet technologies have also resulted in heightened societal concerns about information security and privacy. Insufficient safeguards—actual or perceived—have become a barrier to certain economic activity, and a source of downside risk to growth and sustainability, with possible systemic impact. Scholars have long realized that choices pertaining to security and privacy affect the world in ways that are not captured within the narrow modeling of engineering systems. In essence, these choices are strategic decisions. Thus, the analysis that is performed should incorporate the models and methods developed in economics and, where applicable, in the behavioral sciences

Исследование динамических режимов бортового авиационного выпрямителя

Объектом исследования является бортовой авиационный выпрямитель на основе преобразователя с высокочастотным звеном. Цель работы – разработать имитационную модель бортового авиационного выпрямителя, провести проверку на адекватность полученной системы и исследовать динамические режимы выпрямителя.The object of research is an on-board aircraft rectifier based on a high-frequency converter. The purpose of the work is to develop a simulation model of an on-board aviation rectifier, to check the adequacy of the resulting system and explore the dynamic modes of the rectifier

The Security Cost of Cheap User Interaction

Human attention is a scarce resource, and lack thereof can cause severe security breaches. As most security techniques rely on considerate human intervention in one way or another, this resource should be consumed economically. In this context, we postulate the view that every false alarm or unnecessary user interaction imposes a negative externality on all other potential consumers of this chunk of attention. The paper identifies incentive problems that stimulate overconsumption of human attention in security applications. It further outlines a lump-of-attention model, devised against the backdrop of established theories in the behavioral sciences, and discusses incentive mechanisms to fix the misallocation problem in security notification, for instance the idea of a Pigovian tax on attention consumption. Categories and Subject Descriptors H.1.2 [Models and Principles]: Human/Machine Systems—human factors, human information processing; C.2.

Rooted Minors and Locally Spanning Subgraphs

Results on the existence of various types of spanning subgraphs of graphs are milestones in structural graph theory and have been diversified in several directions. In the present paper, we consider "local" versions of such statements. In 1966, for instance, D. W. Barnette proved that a $3$-connected planar graph contains a spanning tree of maximum degree at most $3$. A local translation of this statement is that if $G$ is a planar graph, $X$ is a subset of specified vertices of $G$ such that $X$ cannot be separated in $G$ by removing $2$ or fewer vertices of $G$, then $G$ has a tree of maximum degree at most $3$ containing all vertices of $X$. Our results constitute a general machinery for strengthening statements about $k$-connected graphs (for $1 \leq k \leq 4$) to locally spanning versions, i.e. subgraphs containing a set $X\subseteq V(G)$ of a (not necessarily planar) graph $G$ in which only $X$ has high connectedness. Given a graph $G$ and $X\subseteq V(G)$, we say $M$ is a minor of $G$ rooted at $X$, if $M$ is a minor of $G$ such that each bag of $M$ contains at most one vertex of $X$ and $X$ is a subset of the union of all bags. We show that $G$ has a highly connected minor rooted at $X$ if $X\subseteq V(G)$ cannot be separated in $G$ by removing a few vertices of $G$. Combining these investigations and the theory of Tutte paths in the planar case yield to locally spanning versions of six well-known results about degree-bounded trees, hamiltonian paths and cycles, and $2$-connected subgraphs of graphs

Preliminary Biomechanical Evaluation of a Novel Exoskeleton Robotic System to Assist Stair Climbing

A novel exoskeleton robotic system was developed to assist stair climbing. This active demonstrator consists of a motor with a cable system, various sensors, and a control system with a power supply. The objective of this preliminary study is a biomechanical evaluation of the novel system to determine its effectiveness in use. For this purpose, three test persons were biomechanically investigated, who performed stair ascents and descents with and without the exoskeleton. Kinematics, kinetics, and muscle activity of the knee extensors were measured. The measured data were biomechanically simulated in order to evaluate the characteristics of joint angles, moments, and reaction forces. The results show that the new exoskeleton assists both the ascent and the descent according to the measured surface electromyography (sEMG) signals, as the knee extensors are relieved by an average of 19.3%. In addition, differences in the interaction between the test persons and the system were found. This could be due to a slightly different operation of the assisting force or to the different influence of the system on the kinematics of the users

Preliminary Biomechanical Evaluation of a Novel Exoskeleton Robotic System to Assist Stair Climbing

A novel exoskeleton robotic system was developed to assist stair climbing. This active demonstrator consists of a motor with a cable system, various sensors, and a control system with a power supply. The objective of this preliminary study is a biomechanical evaluation of the novel system to determine its effectiveness in use. For this purpose, three test persons were biomechan- ically investigated, who performed stair ascents and descents with and without the exoskeleton. Kinematics, kinetics, and muscle activity of the knee extensors were measured. The measured data were biomechanically simulated in order to evaluate the characteristics of joint angles, moments, and reaction forces. The results show that the new exoskeleton assists both the ascent and the descent according to the measured surface electromyography (sEMG) signals, as the knee extensors are relieved by an average of 19.3%. In addition, differences in the interaction between the test persons and the system were found. This could be due to a slightly different operation of the assisting force or to the different influence of the system on the kinematics of the users