Adaptable transition systems

We present an essential model of adaptable transition systems inspired by white-box approaches to adaptation and based on foundational models of component based systems. The key feature of adaptable transition systems are control propositions, imposing a clear separation between ordinary, functional behaviours and adaptive ones. We instantiate our approach on interface automata yielding adaptable interface automata, but it may be instantiated on other foundational models of component-based systems as well. We discuss how control propositions can be exploited in the specification and analysis of adaptive systems, focusing on various notions proposed in the literature, like adaptability, control loops, and control synthesis

Awareness and Control in Adaptable Transition Systems

The talk presents ATSs and some applications, and it introduces an explicit representation of awareness data, ideally intended as those “sensor” data that are exploited at the control level in order to possibly enforce an adaptation. Awareness and control data complement each other in answering the question regarding where and when adaptation takes places: A clear identification of awareness data helps selecting which artifacts indicate that it may be necessary to perform an adaptation, and precisely stating when that may occur

Adaptability Checking in Multi-Level Complex Systems

A hierarchical model for multi-level adaptive systems is built on two basic levels: a lower behavioural level B accounting for the actual behaviour of the system and an upper structural level S describing the adaptation dynamics of the system. The behavioural level is modelled as a state machine and the structural level as a higher-order system whose states have associated logical formulas (constraints) over observables of the behavioural level. S is used to capture the global and stable features of B, by a defining set of allowed behaviours. The adaptation semantics is such that the upper S level imposes constraints on the lower B level, which has to adapt whenever it no longer can satisfy them. In this context, we introduce weak and strong adaptabil- ity, i.e. the ability of a system to adapt for some evolution paths or for all possible evolutions, respectively. We provide a relational characterisation for these two notions and we show that adaptability checking, i.e. deciding if a system is weak or strong adaptable, can be reduced to a CTL model checking problem. We apply the model and the theoretical results to the case study of motion control of autonomous transport vehicles.Comment: 57 page, 10 figures, research papaer, submitte

Adaptable processes

We propose the concept of adaptable processes as a way of overcoming the limitations that process calculi have for describing patterns of dynamic process evolution. Such patterns rely on direct ways of controlling the behavior and location of running processes, and so they are at the heart of the adaptation capabilities present in many modern concurrent systems. Adaptable processes have a location and are sensible to actions of dynamic update at runtime; this allows to express a wide range of evolvability patterns for concurrent processes. We introduce a core calculus of adaptable processes and propose two verification problems for them: bounded and eventual adaptation. While the former ensures that the number of consecutive erroneous states that can be traversed during a computation is bound by some given number k, the latter ensures that if the system enters into a state with errors then a state without errors will be eventually reached. We study the (un)decidability of these two problems in several variants of the calculus, which result from considering dynamic and static topologies of adaptable processes as well as different evolvability patterns. Rather than a specification language, our calculus intends to be a basis for investigating the fundamental properties of evolvable processes and for developing richer languages with evolvability capabilities

Subordinating careers to market forces? A critical analysis of European career guidance policy

This study explores language regarding career and career development in European policy documents on career guidance in order to disclose underlying view(s) of these phenomena conveyed in the texts. Qualitative content analysis was used to approach the subject in the texts, followed by a sender-oriented interpretation. Sources for interpretation include several sociological and pedagogical approaches based upon social constructionism. These provide a framework for understanding how different views of career phenomena arise. The characterization of career phenomena in the documents falls into four categories: contextual change, environment-person correspondence, competence mobility, and empowerment. An economic perspective on career dominates, followed by learning and political science perspectives. Policy formulations convey contradictory messages and a form of career \u27contract\u27 that appears to subordinate individuals\u27 careers to global capitalism, while attributing sole responsibility for career to individuals. (DIPF/Orig.