A context-aware framework for dynamic composition of process fragments in the internet of services

Abstract In the last decade, many approaches to automated service composition have been proposed. However, most of them do not fully exploit the opportunities offered by the Internet of Services (IoS). In this article, we focus on the dynamicity of the execution environment, that is, any change occurring at run-time that might affect the system, such as changes in service availability, service behavior, or characteristics of the execution context. We indicate that any IoS-based application strongly requires a composition framework that supports for the automation of all the phases of the composition life cycle, from requirements derivation, to synthesis, deployment and execution. Our solution to this ambitious problem is an AI planning-based composition framework that features abstract composition requirements and context-awareness. In the proposed approach most human-dependent tasks can be accomplished at design time and the few human intervention required at run time do not affect the system execution. To demonstrate our approach in action and evaluate it, we exploit the ASTRO-CAptEvo framework, simulating the operation of a fully automated IoS-based car logistics scenario in the Bremerhaven harbor

Context Verification and Adaptation in Web Service Composition

Automatic web-service composition aims at automating the design of an appropriate combination of existing web services to achieve a global goal. Most proposed AWSC approaches only consider input/output parameters and quality features of services. However, most real-world web services have applicable conditions and require constraints to be considered according to the execution context of composite services. Constraint verification has a significant impact on the composition and execution of composite services. In particular, runtime verification of service constraints can result in the failure of the execution of composite services and eventually waste computational resources and may incur monetary costs. In addition, traditional adaptation approaches for web service composition consider recovery in case of failure when a service becomes unavailable. They do not take into account changes and limitations in service execution environment which potentially can affect the execution of a wide range of services. Externally-defined constraints are likely to be defined and become or cease to be applicable after the composite service has been deployed. In this thesis, we propose a novel approach to model and verify different types of constraints inside composite services. We not only consider input/output parameters but also the values that can be assigned to parameters during design and execution of composite services. In addition, we provide novel failure recovery and adaptation approaches for different types of constraints according to the execution context of composite services. In our solution, we develop a new structure including alternative composite services to recover broken composite services and adapt to external constraints. We finally propose a brokerage architecture including all proposed approaches for constraint-aware service composition and adaptation

A study of children learning multicolumn addition with microcomputer software support.

Three computer-aided tutoring procedures were devised to teach multicolumn addition according to the standard school algorithm, one procedure to each of three groups of 2nd-grade children. The key differences between groups were the demands placed on short term memory and the amount of conceptual understanding the procedures attempted to teach. Each child solved a sequence of two-digit problems on a computer screen by touching each digit with a light pen in the correct sequence. The control group did not receive on-screen number-fact assistance. One treatment ( assisted ) group did receive on-screen number-fact assistance, testing the hypothesis that the algorithm is learned more effectively when learned first as a sequence of procedural steps alone, without subjects\u27 need to recall number-facts. A second treatment ( simulation ) group received the same on-screen assistance along with an additional display of simulated blocks which, like concrete manipulative materials, represented symbol manipulations. The simulation group tested a second hypothesis that a concurrent display of the meaning of procedural steps contributes to even more effective algorithmic learning. T-tests (one-tailed, 5% level) applied pair-wise to pretest/posttest difference scores indicated support for the first hypothesis but not for the second, an indication that 2nd-grade children learn the addition algorithm more effectively if demand on short term memory is temporarily lifted. A descriptive framework called superposition of frames is proposed to account for anomalies in findings and for the rich diversity of errors generally manifested by children in multidigit addition. Drawing on current concepts in cognitive psychology and mathematics education, this description suggests that children\u27s mathematical knowledge is fragmented into isolated, unstable, and sometimes entrenched frames of knowledge. When a child finds appropriate correspondences between frames and initiates a superposition of frames, the child\u27s procedural and conceptual knowledge, previously in disarray, may then become integrated. Implications for elementary mathematics instruction are discussed

Algorithmic Reason

Are algorithms ruling the world today? Is artificial intelligence making life-and-death decisions? Are social media companies able to manipulate elections? As we are confronted with public and academic anxieties about unprecedented changes, this book offers a different analytical prism to investigate these transformations as more mundane and fraught. Aradau and Blanke develop conceptual and methodological tools to understand how algorithmic operations shape the government of self and other. While disperse and messy, these operations are held together by an ascendant algorithmic reason. Through a global perspective on algorithmic operations, the book helps us understand how algorithmic reason redraws boundaries and reconfigures differences. The book explores the emergence of algorithmic reason through rationalities, materializations, and interventions. It traces how algorithmic rationalities of decomposition, recomposition, and partitioning are materialized in the construction of dangerous others, the power of platforms, and the production of economic value. The book shows how political interventions to make algorithms governable encounter friction, refusal, and resistance. The theoretical perspective on algorithmic reason is developed through qualitative and digital methods to investigate scenes and controversies that range from mass surveillance and the Cambridge Analytica scandal in the UK to predictive policing in the US, and from the use of facial recognition in China and drone targeting in Pakistan to the regulation of hate speech in Germany. Algorithmic Reason offers an alternative to dystopia and despair through a transdisciplinary approach made possible by the authors’ backgrounds, which span the humanities, social sciences, and computer sciences

Algorithmic Reason

Are algorithms ruling the world today? Is artificial intelligence making life-and-death decisions? Are social media companies able to manipulate elections? As we are confronted with public and academic anxieties about unprecedented changes, this book offers a different analytical prism to investigate these transformations as more mundane and fraught. Aradau and Blanke develop conceptual and methodological tools to understand how algorithmic operations shape the government of self and other. While disperse and messy, these operations are held together by an ascendant algorithmic reason. Through a global perspective on algorithmic operations, the book helps us understand how algorithmic reason redraws boundaries and reconfigures differences. The book explores the emergence of algorithmic reason through rationalities, materializations, and interventions. It traces how algorithmic rationalities of decomposition, recomposition, and partitioning are materialized in the construction of dangerous others, the power of platforms, and the production of economic value. The book shows how political interventions to make algorithms governable encounter friction, refusal, and resistance. The theoretical perspective on algorithmic reason is developed through qualitative and digital methods to investigate scenes and controversies that range from mass surveillance and the Cambridge Analytica scandal in the UK to predictive policing in the US, and from the use of facial recognition in China and drone targeting in Pakistan to the regulation of hate speech in Germany. Algorithmic Reason offers an alternative to dystopia and despair through a transdisciplinary approach made possible by the authors’ backgrounds, which span the humanities, social sciences, and computer sciences

“What can’t be coded can be decorded” Reading Writing Performing Finnegans Wake

This thesis examines the ways in which performances of James Joyce’s Finnegans Wake (1939) navigate the boundary between reading and writing. I consider the extent to which performances enact alternative readings of Finnegans Wake, challenging notions of competence and understanding; and by viewing performance as a form of writing I ask whether Joyce’s composition process can be remembered by its recomposition into new performances. These perspectives raise questions about authority and archivisation, and I argue that performances of Finnegans Wake challenge hierarchical and institutional forms of interpretation. By appropriating Joyce’s text through different methodologies of reading and writing I argue that these performances come into contact with a community of ghosts and traces which haunt its composition. In chapter one I argue that performance played an important role in the composition and early critical reception of Finnegans Wake and conduct an overview of various performances which challenge the notion of a ‘Joycean competence’ or encounter the text through radical recompositions of its material. In chapter two I discuss Mary Manning’s The Voice of Shem (1955) and find that its theatrical reassembling of the text served as a competent reading of the Wake’s form as an alternative to contemporary studies of the book, and that its specific ‘redistribution’ of the text accessed affective and genetic elements that were yet to be explored in Joyce scholarship. In chapter three I consider several decompositions of the Wake by John Cage (1975-1983) and find that by paying attention to the materiality of the book rather than its ‘plot’ or ‘meaning’ his performances reencountered the work concealed in Finnegans Wake’s composition. In chapter four, I document and analyse my own performance, About That Original Hen (2014), a ‘research-as-performance’ lecture which re-enacts a visit to the James Joyce Archive. By reconfiguring Finnegans Wake in relation to a marginal figure from its composition process and a contemporary act of protest within the university, this performance explores how a diachronic re-animation of archival materials can engage with the ghosts which haunt its composition and enact a political reading of the text’s production and subsequent archivisation. I conclude the thesis by arguing that these performances repeat the contingencies, misreadings and appropriations and collective acts of reading and writing that were integral to the composition of Finnegans Wake

Disaster Anarchy

Due to the devastating effects of global warming, natural disasters have been increasing at a brutal pace all around the globe. Shockingly poor state-led relief efforts have been cause for much misery among those affected. In fact, the most successful disaster responses have come from anarchist-inspired social movements. These have been the target of both repression and intense curiosity on part of governmental entities looking to co-opt these autonomous movement practices.*BR**BR*In this groundbreaking and timely book, Rhiannon Firth provides a comprehensive anarchist approach to understanding and responding to natural disasters, drawing on historical and contemporary sources as well as empirical case studies. Offering a new framework to address one of the 21st century's most pressing problems, Firth introduces disaster anarchism as a powerful tool to provide a break from capitalism and the state even beyond the scope of disaster relief

Programming distributed and adaptable autonomous components--the GCM/ProActive framework

International audienceComponent-oriented software has become a useful tool to build larger and more complex systems by describing the application in terms of encapsulated, loosely coupled entities called components. At the same time, asynchronous programming patterns allow for the development of efficient distributed applications. While several component models and frameworks have been proposed, most of them tightly integrate the component model with the middleware they run upon. This intertwining is generally implicit and not discussed, leading to entangled, hard to maintain code. This article describes our efforts in the development of the GCM/ProActive framework for providing distributed and adaptable autonomous components. GCM/ProActive integrates a component model designed for execution on large-scale environments, with a programming model based on active objects allowing a high degree of distribution and concurrency. This new integrated model provides a more powerful development, composition, and execution environment than other distributed component frameworks. We illustrate that GCM/ProActive is particularly adapted to the programming of autonomic component systems, and to the integration into a service-oriented environment

Achieving Autonomic Web Service Compositions with Models at Runtime

Over the last years, Web services have become increasingly popular. It is because they allow businesses to share data and business process (BP) logic through a programmatic interface across networks. In order to reach the full potential of Web services, they can be combined to achieve specifi c functionalities. Web services run in complex contexts where arising events may compromise the quality of the system (e.g. a sudden security attack). As a result, it is desirable to count on mechanisms to adapt Web service compositions (or simply called service compositions) according to problematic events in the context. Since critical systems may require prompt responses, manual adaptations are unfeasible in large and intricate service compositions. Thus, it is suitable to have autonomic mechanisms to guide their self-adaptation. One way to achieve this is by implementing variability constructs at the language level. However, this approach may become tedious, difficult to manage, and error-prone as the number of con figurations for the service composition grows. The goal of this thesis is to provide a model-driven framework to guide autonomic adjustments of context-aware service compositions. This framework spans over design time and runtime to face arising known and unknown context events (i.e., foreseen and unforeseen at design time) in the close and open worlds respectively. At design time, we propose a methodology for creating the models that guide autonomic changes. Since Service-Oriented Architecture (SOA) lacks support for systematic reuse of service operations, we represent service operations as Software Product Line (SPL) features in a variability model. As a result, our approach can support the construction of service composition families in mass production-environments. In order to reach optimum adaptations, the variability model and its possible con figurations are verifi ed at design time using Constraint Programming (CP). At runtime, when problematic events arise in the context, the variability model is leveraged for guiding autonomic changes of the service composition. The activation and deactivation of features in the variability model result in changes in a composition model that abstracts the underlying service composition. Changes in the variability model are refl ected into the service composition by adding or removing fragments of Business Process Execution Language (WS-BPEL) code, which are deployed at runtime. Model-driven strategies guide the safe migration of running service composition instances. Under the closed-world assumption, the possible context events are fully known at design time. These events will eventually trigger the dynamic adaptation of the service composition. Nevertheless, it is diffi cult to foresee all the possible situations arising in uncertain contexts where service compositions run. Therefore, we extend our framework to cover the dynamic evolution of service compositions to deal with unexpected events in the open world. If model adaptations cannot solve uncertainty, the supporting models self-evolve according to abstract tactics that preserve expected requirements.Alférez Salinas, GH. (2013). Achieving Autonomic Web Service Compositions with Models at Runtime [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/34672TESI