Impact of Mobility on Information Systems and Information System Design

The subject of this thesis is to analyse the impact of mobile hardware and software on information systems, to survey existing approaches for specifying mobile systems of computer science in general, and to provide suitable means for the formal design of information systems comprising such mobile units in particular. We consider a mobile unit to denote a mobile hardware or software entity, and a mobile system as a system comprising or being accessed by such mobile components. The various forms of mobile units occurring in computer science are explained and a taxonomy for them is developed, followed by a detailed discussion of their effects on computer and information systems. Several approaches for specifying mobile systems are presented and classified, with a particular emphasis on formal methods. As it turns out, these approaches do not allow to describe the set-up and release of communication links or to distinguish between the ever-mobile units of a compound system and those which provide the fixed subsystem as the context for the mobile entities, which are both important aspects to consider when developing information systems with mobile components. Therefore, corresponding constructs are then presented as an extension to the specification language Troll and its theoretical foundations, i.e. extended data signatures and the Module Distributed Temporal Logic Mdtl, both being interpreted over event structures. Finally, the application of the constructs is illustrated with the development of a system for accessing web services from mobile phones, which complements the ongoing example of information retrieval via mobile agents used to explain the constructs and concepts.Thema dieser Arbeit ist die Analyse der Auswirkungen von mobiler Hard- und Software auf Informationssysteme, die Untersuchung vorhandener Ansätze zur Spezifikation mobiler Systeme in der Informatik allgemein und für den formalen Entwurf von Informationssystemen mit mobilen Einheiten insbesondere. "Mobile Einheit" wird dabei als Oberbegriff für mobile Hardware- und Softwarekomponenten verwendet, und ein "mobiles System" ist ein System, das solche mobilen Komponenten beinhaltet oder auf das durch diese zugegriffen wird. Wir beschreiben die verschiedenen Formen, in denen mobile Einheiten in der Informatik auftreten, und entwickeln eine entsprechende Taxonomie, bevor wir deren Auswirkungen auf Computer- und Informationssysteme ausführlich diskutieren. Verschiedene Ansätze zur Spezifikation mobiler Systeme werden vorgestellt und eingeordnet, wobei das Augenmerk speziell auf formalen Methoden liegt. Es stellt sich heraus, dass es keiner dieser Ansätze ermöglicht, den Auf- und Abbau von Kommunikationsverbindungen zu beschreiben und zwischen den stets mobilen Einheiten und denjenigen zu unterscheiden, die das feste Teilsystem als Kontext für sie bilden. Beides sind aber wesentliche Aspekte, die in der Entwicklung von Informationssystemen mit mobilen Bestandteilen zu berücksichtigen sind. Daher stellen wir dann entsprechende Sprachkonstrukte als Erweiterung der Spezifikationssprache Troll inklusive der formalen Grundlagen vor. Diese Grundlagen beruhen auf erweiterten Datensignaturen und einer modularen verteilten temporalen Logik Mdtl, die beide über Ereignisstrukturen interpretiert werden. Schließlich wird die Verwendbarkeit der Sprachkonstrukte in der Entwicklung eines Systems zur Nutzung von Web-Diensten von Mobiltelefonen aus illustriert

Articulations of the media, migration and the urban in constructions of black African subjectivity in post-apartheid South Africa: a decolonial approach.

Doctoral Degree. University of KwaZulu-Natal, Pietermaritzburg.This study enacts a decolonial Media and Cultural Studies. Rather than think in terms of what the media as technologies of culture ideally ought to do, the thesis focuses on what the media have historically done in South Africa. This epistemic delinking from a Media and Cultural studies that proceed from liberal pluralist normative assumptions locates representation at the centre of what the media have historically done in colonised and postcolonial parts of the world. The study embraces the constructivist approach to representation. Here representation is seen as emerging out of modernity and playing a constitutive role in contemporary postcolonial culture (Lloyd, 2019; Webb, 2009; Colebrook, 2000; Hall, 1997). Culture then occupies a similar space to the economy and material conditions in shaping historical events and social subjectivities (Hall, 1997). Media and Cultural Studies emerged in South Africa in the 1960s as a terrain for conversations and debates between British and Afrikaner viewpoints (Tomaselli, 2002; De Beer and Tomaselli, 2000). Historically, in both media practice and media studies, the black African subject has always been represented, that is spoken about and spoken for (Webb, 2009; Alcoff, 1991; Spivak, 1988). Decolonising Media and Cultural studies, then, partly means exploring this ‘visible’ black absence. In the postapartheid moment, western theory and methods have continued to be hegemonic. To explore this coloniality, this thesis puts representation at the centre of Media and Cultural Studies historically tracing the media’s articulations to its broader context that includes migration, the border and urbanity. The study theoretically stages a conversation between postcolonial studies, decolonial studies, black studies, Marxism, and other variants of critical theory. Located in the debates between Cultural Studies and critical political economy approaches to the study of culture, this research combines ethnography and textual analysis. Texts include 18 news stories taken from the Independent On line (IOL), News24 and the isiZulu Ilanga newspaper and in-depth interviews are analysed through discourse and ideology analysis. Eleven images, including 5 photojournalism and 6 photographs taken during the ethnographic field work, are analysed through semiotics analysis. The black African subject who emerges tethered to global colonial capital as a racialised colonial labourer, serf and slave still emerges in the contemporary articulations of the media, border and urban discourses as a precarious colonial labourer, illegalised, violent, dead, a non-being and an ethnicised national subject

An Introduction to Population Geographies : Lives across space

Introduction to all dimesnions to all aspects of Population Geography using a an expanded life course framework. This has the book addressing many issues and themes largely neglected to date by the sub-discipline

Tools and Algorithms for the Construction and Analysis of Systems

This open access book constitutes the proceedings of the 28th International Conference on Tools and Algorithms for the Construction and Analysis of Systems, TACAS 2022, which was held during April 2-7, 2022, in Munich, Germany, as part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2022. The 46 full papers and 4 short papers presented in this volume were carefully reviewed and selected from 159 submissions. The proceedings also contain 16 tool papers of the affiliated competition SV-Comp and 1 paper consisting of the competition report. TACAS is a forum for researchers, developers, and users interested in rigorously based tools and algorithms for the construction and analysis of systems. The conference aims to bridge the gaps between different communities with this common interest and to support them in their quest to improve the utility, reliability, exibility, and efficiency of tools and algorithms for building computer-controlled systems