Interplay between security providers, consumers, and attackers: a weighted congestion game approach

Network users can choose among different security solutions to protect their data. Those solutions are offered by competing providers, with possibly different performance and price levels. In this paper, we model the interactions among users as a noncooperative game, with a negative externality coming from the fact that attackers target popular systems to maximize their expected gain. Using a nonatomic weighted congestion game model for user interactions, we prove the existence and uniqueness of a user equilibrium, compute the corresponding Price of Anarchy, that is the loss of efficiency due to user selfishness, and investigate some consequences for the (higher-level) pricing game played by security providers.Game theory;Weighted games; Security

Wi-Fi Offload: Tragedy of the Commons or Land of Milk and Honey?

Fueled by its recent success in provisioning on-site wireless Internet access, Wi-Fi is currently perceived as the best positioned technology for pervasive mobile macro network offloading. However, the broad transitions of multiple collocated operators towards this new paradigm may result in fierce competition for the common unlicensed spectrum at hand. In this light, our paper game-theoretically dissects market convergence scenarios by assessing the competition between providers in terms of network performance, capacity constraints, cost reductions, and revenue prospects. We will closely compare the prospects and strategic positioning of fixed line operators offering Wi-Fi services with respect to competing mobile network operators utilizing unlicensed spectrum. Our results highlight important dependencies upon inter-operator collaboration models, and more importantly, upon the ratio between backhaul and Wi-Fi access bit-rates. Furthermore, our investigation of medium- to long-term convergence scenarios indicates that a rethinking of control measures targeting the large-scale monetization of unlicensed spectrum may be required, as otherwise the used free bands may become subject to tragedy-of-commons type of problems.Comment: Workshop on Spectrum Sharing Strategies for Wireless Broadband Services, IEEE PIMRC'13, to appear 201

09192 Abstracts Collection -- From Quality of Service to Quality of Experience

From 05.05. to 08.05.2009, the Dagstuhl Seminar 09192 ``From Quality of Service to Quality of Experience\u27\u27 was held in Schloss Dagstuhl~--~Leibniz Center for Informatics. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available

09192 Executive Summary -- From Quality of Service to Quality of Experience

From May 05 to May 08, 2009, the Dagstuhl Seminar 09192 ``From Quality of Service to Quality of Experience \u27\u27 was held in Schloss Dagstuhl~--~Leibniz Center for Informatics. The notion of emph{Quality of Service} has served as a central research topic in communication networks for more than a decade, however, usually starting from a rather technical view on service quality. Therefore, recently the notion of emph{Quality of Experience} has emerged, redirecting the focus towards the end user and trying to quantify her subjective experience gained from using a service. The goal of this Dagstuhl seminar is to discuss this important paradigm shift in an interdisciplinary international community of key researchers, to investigate innovative research methodologies and to deepen the scientific understanding of this topic which is highly relevant for the economic success of future mobile and fixed communication services

Equilibrium free energy measurement of a confined electron driven out of equilibrium

We study out-of equilibrium properties of a quantum dot in a GaAs/AlGaAs two-dimensional electron gas. By means of single electron counting experiments, we measure the distribution of work and dissipated heat of the driven quantum dot and relate these quantities to the equilibrium free energy change, as it has been proposed by C. Jarzynski [Phys. Rev. Lett. {\bf78}, 2690 (1997)]. We discuss the influence of the degeneracy of the quantized energy state on the free energy change as well as its relation to the tunnel rates between the dot and the reservoir.Comment: 5 pages, 4 figure

Vom künstlichen Leben zur Lebenskunst: Was die Ethik digitaler Bildung von ökologischer Verantwortung lernen kann

Während die Digitalisierung weithin für diverse Ersetzungsphänomene menschlicher Kompetenzen bis hin zur Schaffung von künstlichen Superintelligenzen steht, handelt es sich im Kern doch vor allem um eine neue Form von Umwelt, der wir in unserer Leiblichkeit gegenüberstehen und mit ihr verschmelzen. In diesem Sinne betrachten wir soziale Netze, Robotik und KI als Kulturtechniken des Menschen, die selbst zu kultürlichen Umweltfaktoren humanen Sozialverhaltens werden. Vor dem Hintergrund komplexer Wechselwirkungen zwischen Mensch, Technik und Gesellschaft diskutieren wir die Frage der Verantwortung als Bedingungserhaltung menschlichen Handelns, die sich auch als ein Gradmesser digitaler Infrastrukturen, Ökologie und Bildung zu erweisen hat. Auf dem Weg in eine gewollte Zukunft plädieren wir für eine Ethik der Lebenskunst und Klugheit im Umgang mit natürlichen wie kultürlichen Umwelten, um schlussendlich soziale Innovation in Zeiten umfassender Digitalisierungsprozesse zu leben.While the Digital Transformation is widely perceived as a paradigm for replacing various human competencies up to the creation of an artificial superintelligence, in fact it represents a new form of environment to be encountered through human embodiment. Hence, we consider social networks, robotics and AI as cultural techniques that evolve into environmental factors of human social behavior. In this context of complex interdependencies between human, technology and society, we discuss the issue of responsibility as a matter of preserving the essential conditions for human agency, which at the same time serves as key indicator for digital infrastructures, ecology and education. On our way into technological futures which are truly desired we opt for ethics as a way of prudent living with and within natural and cultural environments in order to enable social innovation in a time of comprehensive digitization processes

Associations between depression and specific childhood experiences of abuse and neglect: a meta-analysis

Background Research documents a strong relationship between childhood maltreatment and depression. However, only few studies have examined the specific effects of various types of childhood abuse/neglect on depression. This meta-analysis estimated the associations between depression and different types of childhood maltreatment (antipathy, neglect, physical abuse, sexual abuse, and psychological abuse) assessed with the same measure, the Childhood Experience of Care and Abuse (CECA) interview. Method A systematic search in scientific databases included use of CECA interview and strict clinical assessment for major depression as criteria. Our meta-analysis utilized Cohen's d and relied on a random-effects model. Results The literature search yielded 12 primary studies (reduced from 44), with a total of 4372 participants and 34 coefficients. Separate meta-analyses for each type of maltreatment revealed that psychological abuse and neglect were most strongly associated with the outcome of depression. Sexual abuse, although significant, was less strongly related. Furthermore, the effects of specific types of childhood maltreatment differed across adult and adolescent samples. Limitations Our strict criteria for selecting the primary studies resulted in a small numbers of available studies. It restricted the analyses for various potential moderators. Conclusion This meta-analysis addressed the differential effects of type of childhood maltreatment on major depression, partially explaining between-study variance. The findings clearly highlight the potential impact of the more “silent” types of childhood maltreatment (other than physical and sexual abuse) on the development of depression

Das Netz als Basar?

Ein Basar hat viele Facetten: Er ist Ort der (Ver-)handlung und Ort der Suche, von Proust bis Indiana Jones, er bietet Raum für das Feilschen und Tauschen und erweist sich dabei allzu leicht als Netz eifriger Fischer*innen, in das wir gegangen sind. Gar manches landet hier in den Waagschalen, anderes fällt daneben, wenn orientalische Potentaten sich als platonische Philosophenkönige gerieren. Hinter jeder dieser Assoziationen verbirgt sich eine Facette kritischer Philosophie, wie wir mit besonderem Blick auf Anders und Arendt ergründen wollen. Das Netz als Basar wird so zum Topos des digitalen Humanismus, ein soziales Gewebe aus diversen Fasern, mal feiner und mal gröber versponnen. Können sie, so sie denn dicht genug greifen, als fliegender Teppich ins Bodenlose tragen? Und stell dir vor, es ist Teppich und keiner steht drauf..