Performance analysis with network-enhanced complexities: On fading measurements, event-triggered mechanisms, and cyber attacks

Copyright © 2014 Derui Ding et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Nowadays, the real-world systems are usually subject to various complexities such as parameter uncertainties, time-delays, and nonlinear disturbances. For networked systems, especially large-scale systems such as multiagent systems and systems over sensor networks, the complexities are inevitably enhanced in terms of their degrees or intensities because of the usage of the communication networks. Therefore, it would be interesting to (1) examine how this kind of network-enhanced complexities affects the control or filtering performance; and (2) develop some suitable approaches for controller/filter design problems. In this paper, we aim to survey some recent advances on the performance analysis and synthesis with three sorts of fashionable network-enhanced complexities, namely, fading measurements, event-triggered mechanisms, and attack behaviors of adversaries. First, these three kinds of complexities are introduced in detail according to their engineering backgrounds, dynamical characteristic, and modelling techniques. Then, the developments of the performance analysis and synthesis issues for various networked systems are systematically reviewed. Furthermore, some challenges are illustrated by using a thorough literature review and some possible future research directions are highlighted.This work was supported in part by the National Natural Science Foundation of China under Grants 61134009, 61329301, 61203139, 61374127, and 61374010, the Royal Society of the UK, and the Alexander von Humboldt Foundation of Germany

Event-based security control for discrete-time stochastic systems

This study is concerned with the event-based security control problem for a class of discrete-time stochastic systems with multiplicative noises subject to both randomly occurring denial-of-service (DoS) attacks and randomly occurring deception attacks. An event-triggered mechanism is adopted with hope to reduce the communication burden, where the measurement signal is transmitted only when a certain triggering condition is violated. A novel attack model is proposed to reflect the randomly occurring behaviours of the DoS attacks as well as the deception attacks within a unified framework via two sets of Bernoulli distributed white sequences with known conditional probabilities. A new concept of mean-square security domain is put forward to quantify the security degree. The authors aim to design an output feedback controller such that the closed-loop system achieves the desired security. By using the stochastic analysis techniques, some sufficient conditions are established to guarantee the desired security requirement and the control gain is obtained by solving some linear matrix inequalities with nonlinear constraints. A simulation example is utilised to illustrate the usefulness of the proposed controller design scheme.This work was supported in part by Royal Society of the UK, the National Natural Science Foundation of China under Grants 61329301, 61573246 and 61374039, the Shanghai Rising-Star Programme of China under Grant 16QA1403000, the Program for Capability Construction of Shanghai Provincial Universities under Grant 15550502500 and the Alexander von Humboldt Foundation of Germany

From distributed coordination to field calculus and aggregate computing

open6siThis work has been partially supported by: EU Horizon 2020 project HyVar (www.hyvar-project .eu), GA No. 644298; ICT COST Action IC1402 ARVI (www.cost -arvi .eu); Ateneo/CSP D16D15000360005 project RunVar (runvar-project.di.unito.it).Aggregate computing is an emerging approach to the engineering of complex coordination for distributed systems, based on viewing system interactions in terms of information propagating through collectives of devices, rather than in terms of individual devices and their interaction with their peers and environment. The foundation of this approach is the distillation of a number of prior approaches, both formal and pragmatic, proposed under the umbrella of field-based coordination, and culminating into the field calculus, a universal functional programming model for the specification and composition of collective behaviours with equivalent local and aggregate semantics. This foundation has been elaborated into a layered approach to engineering coordination of complex distributed systems, building up to pragmatic applications through intermediate layers encompassing reusable libraries of program components. Furthermore, some of these components are formally shown to satisfy formal properties like self-stabilisation, which transfer to whole application services by functional composition. In this survey, we trace the development and antecedents of field calculus, review the field calculus itself and the current state of aggregate computing theory and practice, and discuss a roadmap of current research directions with implications for the development of a broad range of distributed systems.embargoed_20210910Viroli, Mirko; Beal, Jacob; Damiani, Ferruccio; Audrito, Giorgio; Casadei, Roberto; Pianini, DaniloViroli, Mirko; Beal, Jacob; Damiani, Ferruccio; Audrito, Giorgio; Casadei, Roberto; Pianini, Danil

Precarious Positions: Toward a Theory and Analysis of Rhetorical Vulnerability

In this project, I develop a framework for treating rhetoric as a system for managing vulnerabilities to and through discourse. I contend that, through rhetoric, we are all put into a fundamentally precarious position, an unavoidable state of exposure to material, social, institutional, and rhetorical forces that work to condition us as both agents and audiences. Rhetoric is not simply something we use; it is also something that we respond to, something to which we are continuously exposed, whether we like it or not. There is, in other words, a necessary concern for vulnerability at the heart of rhetorical theory and praxis, which makes it possible to analyze rhetorical genres and situations in terms of how vulnerabilities are managed by rhetors, audiences, and others. In my first chapter, I examine current scholarship on vulnerability within and beyond rhetorical studies, ultimately arguing that vulnerability is both a universal condition and a unique position. I then apply this framework in my next chapter to the rhetoric of the Westboro Baptist Church (WBC), which I describe as “trolling rhetoric” designed to provoke responses rather than persuade audiences. In my third chapter, I examine how opponents of the WBC attempt to manage their rhetorical vulnerability through legal appeals to decorum. Finally, in my fourth chapter, I examine the citational composing methods of the God Loves Poetry movement, an online initiative that manages rhetorical vulnerability by redacting the WBC’s documents into poems

Un/Composing (Visual) Rhetorics: A (Strange) Comic(s) View of Writing in the Age of New Media

This dissertation finds its exigency in \u27The 9/11 Commission Report,\u27 and specifically its claim that \u27a failure of imagination\u27 that dismisses possibilities relates to the work currently in focus within rhetoric and composition studies as it relates to writing (with) new media. My argument relies on the underdeveloped concept of `imagination\u27 in composition as a way to argue for an alternate theoretical framework for addressing what writing (with) new media entails as a growing form of art. As such, I take up Geoff Sirc\u27s invitation to `remake\u27 his English Composition as a Happening with all of its references to avant-garde art as conceptualized in Allan Kaprow\u27s figure of the unartist and Dick Higgins calls for intermedia practices. Both of these concepts appear in the unart of comics - an `art\u27 for artists who have left their `homes\u27 in disciplinary iterations of art (unart) and for artists who are more concerned with working between media than they are within a specific medium (intermedia). Comics, as I use the term, does not refer to a specific medium, but works as a form of thought in the Deleuzian sense: a sort of intuition exercised by imagination engaged in the continuous discovery of possibilities. Building on `post-pedagogical\u27 theories of invention--Italo Calvino, Byron Hawk, Cynthia Haynes, Gregory Ulmer--avant-garde writing and art practices (as it relates to new media)--Maurice Blanchot, Andre Breton, Friedrich Kittler, Jean-Francois Lyotard--and institutional rhetorics--Giorgio Agamben, Jacques Derrida, Bill Readings, Thomas Rickert--I propose a `strange\u27 manner of writing that foregoes the demands of argumentative writing in favor of a playful writing that attunes itself to imaginative possibilities of discovery. To write strangely connotes an unconventional approach to composition that would offer us the opportunities to think about `the coming composition\u27 as we invent new forms and ways of thinking according to methods invented for the occasion. In inventing new forms by thinking in terms of intermedia, we can realize the goal of Lyotard\u27s postmodern writer: to present (allusions to) the unpresentable. If we are to address the `failure of imagination\u27 in institutional practice and in `the scene of teaching,\u27 we need to be willing to be nomadic as both artists AND writers. Comics `artists,\u27 or those who I refere to as unartists, are adept at demonstrating ways in which this work can proceed, especially if we think of comics in terms of Haynes\u27 slash-technology that cuts through the divisions between media. In this dissertation, comics function as a form of thought that extends `multimodal composition\u27 and `art\u27 to their limits in order to suggest a strangely imaginative composition capable of attending to the disast(e)rous `failure of imagination.\u2

Pedagogy and power relations in English studies ; insights from literary and rhetorical theory

In this dissertation, I examine, against a history of current literature and composition teaching, the question of teacher authority versus student freedom in four different sites: the writing conference, especially as it takes place in writing centers; the“open” class discussion, particularly the issue of whether it encourages dissent or defusesit; non authoritarian strategies such as teaching in a circle and all they signify about classroom hierarchies; and the use of networked computers in the reading and writing course, which has been both endorsed and excoriated by leaders in the discipline.Chapter two draws heavily on recent social constructionist theories of composition to interrogate tutoring practices, while chapter three employs critiques of Mikhail Bakhtin’s dialogism in questioning models of classroom conversation. Chapter three problematizes, through applications of Louis Althusser and Michel Foucault, what may be seen as utopian techniques rooted in Paulo Freire and his followers. Finally, chapter five uses the theorists of the preceding three chapters, and touches briefly upon JacquesDerrida, in the analysis of online class interactions. Each site reveals the paradox thatEnglish pedagogies that at first seem liberatory for both teachers and students often reveal themselves, under theoretical and empirical pressure, as conservative at best and oppressive at worst. In each chapter and an afterword, I propose a demystifying pedagogy for English studies that foregrounds asymmetrical power relations between teachers and students and allows instructors to proclaim their vision of social justice