A Hierarchy of Scheduler Classes for Stochastic Automata

Stochastic automata are a formal compositional model for concurrent stochastic timed systems, with general distributions and non-deterministic choices. Measures of interest are defined over schedulers that resolve the nondeterminism. In this paper we investigate the power of various theoretically and practically motivated classes of schedulers, considering the classic complete-information view and a restriction to non-prophetic schedulers. We prove a hierarchy of scheduler classes w.r.t. unbounded probabilistic reachability. We find that, unlike Markovian formalisms, stochastic automata distinguish most classes even in this basic setting. Verification and strategy synthesis methods thus face a tradeoff between powerful and efficient classes. Using lightweight scheduler sampling, we explore this tradeoff and demonstrate the concept of a useful approximative verification technique for stochastic automata

Behavioral types in programming languages

A recent trend in programming language research is to use behav- ioral type theory to ensure various correctness properties of large- scale, communication-intensive systems. Behavioral types encompass concepts such as interfaces, communication protocols, contracts, and choreography. The successful application of behavioral types requires a solid understanding of several practical aspects, from their represen- tation in a concrete programming language, to their integration with other programming constructs such as methods and functions, to de- sign and monitoring methodologies that take behaviors into account. This survey provides an overview of the state of the art of these aspects, which we summarize as the pragmatics of behavioral types

Choreography Rehearsal ⋆

Abstract. We propose a methodology for statically predicting the possible interaction patterns of services within a given choreography. We focus on choreographies exploiting the event notification paradigm to manage service interactions. Control Flow Analysis techniques statically approximate which events can be delivered to match the choreography constraints and how the multicast groups can be optimised to handle event notification within the service choreography.

Fair Subtyping for Multi-party Session Types

International audienceWe study a theory of session types in which we add a liveness property to the familiar safety one. In this setting, some subtype relations between session types that hold in other theories and that are commonly regarded as harmless become unsound. We present various equivalent definitions of the subtyping relation, we relate it with the standard ones, and we give algorithms for deciding it. Incidentally, we provide an original and remarkably simple coinductive characterization of the fair testing preorder for nondeterministic, sequential processes consisting of internal choices of outputs and external choices of inputs

Die Politische Ökonomie Beruflicher Weiterbildung: Der Einfluss von Tarifverträgen auf Arbeitgeberinvestitionen und Teilnahmequoten

Warum sind aber Arbeitgeber in einigen Ländern bereit, sich an Weiterbildungsmaßnahmen ihrer Mitarbeiter zu beteiligen, während dies in anderen Ländern nicht der Fall ist? In diesem Artikel wird die tarifvertragliche Abdeckung als zentraler Mechanismus hierfür herausgearbeitet: Einerseits intendiert, durch vertraglich geregelte Weiterbildungsmaßnahmen, und anderseits unintendiert, durch die Angleichung von Löhnen zwischen Firmen. Mithilfe von Mehrebenenregressionsanalysen auf Basis von Daten des European Social Survey kann gezeigt werden, dass Tarifverträge einen postiven Effekt auf die Finanzierungsbeteiligung von Arbeitgebern haben, sowie auf individuelle Teilnahmen. Diese Ergebnisse legen nahe, dass institutionelle Faktoren gewichtige Einflussgrößen in Erklärungen von Firmeninvestitionen und Weiterbildungsbeteiligung sind. In einer abschließenden Diskussion werden diese Funde im Kontext der internationalen Debatte um die Dezentralisierung korporatistischer Arrangements besprochen.Why are employers in some countries willing to pay for further training of their employees, but not in other countries. In this article, it is argued that the central mechanism for this is collective bargaining coverage. On the one hand, intentionally through contractual regulations regarding further training. On the other hand, unintentionally through equalization of wages between companies. Using multilevel-regression based on data from the European Social Survey, results indicate a positive effect of collective bargaining coverage on employer’s willingness to pay for further training, as well as on participation in further training. These results suggest institutions are significant factors in explanations of firm investments into skills and further training. In a concluding discussion, findings are reviewed in the context of the international debate about decentralization of corporatist arrangements

Functional impairment of systemic scleroderma patients with digital ulcerations: results from the DUO Registry

OBJECTIVES: Digital ulcers (DUs) are frequent manifestations of systemic scleroderma (SSc). This study assessed functional limitations due to DUs among patients enrolled in the Digital Ulcer Outcome (DUO) Registry, an international, multicentre, observational registry of SSc patients with DU disease. METHODS: Patients completed at enrolment a DU-specific functional assessment questionnaire with a 1-month recall period, measuring impairment in work and daily activities, and hours of help needed from others. Physician-reported clinical parameters were used to describe the population. For patients who completed at least part of the questionnaire, descriptive analyses were performed for overall results, and stratified by number of DUs at enrolment. RESULTS: This study included 2327 patients who completed at least part of the questionnaire. For patients with 0, 1–2, and ≥3 DUs at enrolment, mean overall work impairment during the prior month among employed/self-employed patients was 28%, 42%, and 48%, respectively. Across all included patients, ability to perform daily activities was impaired on average by 35%, 54%, and 63%, respectively. Patients required a mean of 2.0, 8.7, and 8.8 hours of paid help and 17.0, 35.9, and 63.7 hours of unpaid help, respectively, due to DUs in the prior month. Patients with DUs had more complications and medication use than patients with no DUs. CONCLUSIONS: With increasing number of DUs, SSc patients reported more impairment in work and daily activities and required more support from others