Ordered Navigation on Multi-attributed Data Words

We study temporal logics and automata on multi-attributed data words. Recently, BD-LTL was introduced as a temporal logic on data words extending LTL by navigation along positions of single data values. As allowing for navigation wrt. tuples of data values renders the logic undecidable, we introduce ND-LTL, an extension of BD-LTL by a restricted form of tuple-navigation. While complete ND-LTL is still undecidable, the two natural fragments allowing for either future or past navigation along data values are shown to be Ackermann-hard, yet decidability is obtained by reduction to nested multi-counter systems. To this end, we introduce and study nested variants of data automata as an intermediate model simplifying the constructions. To complement these results we show that imposing the same restrictions on BD-LTL yields two 2ExpSpace-complete fragments while satisfiability for the full logic is known to be as hard as reachability in Petri nets

Flat Model Checking for Counting LTL Using Quantifier-Free Presburger Arithmetic

This paper presents an approximation approach to verifying counter systems with respect to properties formulated in an expressive counting extension of linear temporal logic. It can express, e.g., that the number of acknowledgements never exceeds the number of requests to a service, by counting specific positions along a run and imposing arithmetic constraints. The addressed problem is undecidable and therefore solved on flat under-approximations of a system. This provides a flexibly adjustable trade-off between exhaustiveness and computational effort, similar to bounded model checking. Recent techniques and results for model-checking frequency properties over flat Kripke structures are lifted and employed to construct a parametrised encoding of the (approximated) problem in quantifier-free Presburger arithmetic. A prototype implementation based on the z3 SMT solver demonstrates the effectiveness of the approach based on problems from the RERS Challange

Temporal logic for properties with relative frequency

Inherently unreliable or fault-tolerant systems demand for a specification formalism that allows the user to express a required ratio of certain observations. Such a requirement can be, e.g. that deadlines in a real-time system must be met in at least 80% of all cases. Logics and in particular temporal logics provide powerful, flexible and well established specification formalisms. We therefore propose fLTL, an extension to linear-time temporal logic that allows for expressing relative frequencies by an intuitive generalization of the temporal operators. We develop a game theoretical methodology and a semantics for temporal logic with counters. For our novel logic, we establish an undecidability result regarding the satisfiability problem but identify a decidable fragment which strictly increases the expressiveness of linear-time temporal logic by allowing, e.g., to express non-context-free properties

Model-Checking Counting Temporal Logics on Flat Structures

We study several extensions of linear-time and computation-tree temporal logics with quantifiers that allow for counting how often certain properties hold. For most of these extensions, the model-checking problem is undecidable, but we show that decidability can be recovered by considering flat Kripke structures where each state belongs to at most one simple loop. Most decision procedures are based on results on (flat) counter systems where counters are used to implement the evaluation of counting operators

First international Competition on Runtime Verification: rules, benchmarks, tools, and final results of CRV 2014

The first international Competition on Runtime Verification (CRV) was held in September 2014, in Toronto, Canada, as a satellite event of the 14th international conference on Runtime Verification (RV’14). The event was organized in three tracks: (1) offline monitoring, (2) online monitoring of C programs, and (3) online monitoring of Java programs. In this paper, we report on the phases and rules, a description of the participating teams and their submitted benchmark, the (full) results, as well as the lessons learned from the competition.ICT COST ActionFFG HARMONIAAustrian Science Fund (FWF)31704

Frequency Linear-time Temporal Logic

We propose fLTL, an extension to linear-time temporal logic (LTL) that allows for expressing relative frequencies by a generalization of temporal operators. This facilitates the specification of requirements such as the deadlines in a realtime system must be met in at least 95 % of all cases. For our novel logic, we establish an undecidability result regarding the satisfiability problem but identify a decidable fragment which strictly increases the expressiveness of LTL by allowing, e.g., to express non-context-free properties

D.: Impartiality and anticipation for monitoring of visibly context-free properties

Abstract. We study monitoring of visibly context-free properties. These properties reflect the common concept of nesting which arises naturally in software systems. They can be expressed e.g. in the temporal logic CaRet which extends LTL by means of matching calls and returns. The future fragment of CaRet enables us to give a direct unfolding-based automaton construction, similar to LTL. We provide a four-valued, impartial semantics on finite words which is particularly suitable for monitoring. This allows us to synthesize monitors in terms of deterministic push-down Mealy machines. To go beyond impartiality, we develop a construction for anticipatory monitors from visibly push-down ω-automata by utilizing a decision procedure for emptiness

Familiy mediation within the counselling system

Familienmediation als Verfahren der sach- und handlungsorientierten Regelung von familiären Konflikten hat zunehmend einen Platz in der Beratung gefunden. Allerdings fehlten bisher genauere Kenntnisse über die tatsächliche Versorgungssituation mit Familienmediation in der institutionellen Beratung. In der vorliegenden Untersuchung, an der sich 726 Beratungsstellen beteiligten, wird das bundesweite Angebot an Familienmediation in der institutionellen Beratung evaluiert. Die Ergebnisse zeigen, dass fast ein Drittel (31,3 %) der Beratungsstellen Familienmediation im Rahmen ihrer Beratungskonzeption anbieten und dass mediative Techniken und Strategien in der Beratungspraxis relativ häufig eingesetzt werden. Stellen, die Mediation anbieten, unterscheiden sich von nicht anbietenden nur in wenigen Merkmalen, allerdings beschäftigen sie deutlich mehr Honorarkräfte. In der familienmediatorischen Klientel sind getrennt lebende, verheiratete oder unverheiratete Eltern mit zwei Kindern am häufigsten. Durchschnittlich führten die anbietenden Beratungsstellen im Bezugsjahr 2003 knapp 32 Mediationen mit einer Dauer von jeweils sieben Zeitstunden durch. Der inhaltliche Schwerpunkt liegt nach wie vor auf der Mediation von Trennungs-, Scheidungs- und Nachscheidungskonflikten, wobei Probleme im Zusammenhang mit der Eltern-Kind-Beziehung überwiegen. Kinder werden in den Mediationsprozess eher selten einbezogen. Insgesamt wird der Bedarf an Familienmediation deutlich höher eingeschätzt als die bestehende Nachfrage und ebenfalls höher als das bestehende Angebot. Aus den Ergebnissen werden wichtige Schlussfolgerungen für Praxis und Erforschung der Familienmediation in der Beratung gezogen, und zwar zur Verbesserung der Versorgungslage, für die Erweiterung des in der Mediation behandelten Themenspektrums sowie zur verstärkten Beteiligung von Kindern.(DIPF/Orig.)Family mediation has been established as a method of resolving family conflicts within the counselling system. Unfortunately there existed only rare information about the real presence and efficacy of family mediation services within this system. 726 counselling centres from all over the country participated at the present study, which was outlined to evaluate their supply of family mediation and the use of it. The results show that nearly one third of the centres are offering family mediation as a regular service to their clients, and that mediative skills are quite frequently used by the counselling professionals. Centres, which offer a regular service of mediation, have an obviously higher percentage of honorary staff, indicating that this service might have a more fragile status. Each centre, which conducted mediation, had an average mediation caseload of 32 in 2003, which means a percentage of 7 percent of all counselling cases treated in this year. These mediations needed an average treatment of 7 hours. Most frequent cases in mediation are separated married or separated non-married parents with 2 children. In most cases, family mediation was used to regulate conflicts in separation, divorce or post divorce, mainly concerned with issues of child custody. In contrast to the researchers’ expectations, children were introduced at the mediation process only rarely. The need for mediation in the local population was rated much higher than the factual demand for and the factual supply of mediation. Based on the outcomes of the study, some recommendations are made: for the improvement of the supply of family mediation, for the expansion of the issues to which mediation is offered, and for strengthening the approaches to include children into the mediation process.(DIPF/Orig.

Additional file 1 of ClonoCalc and ClonoPlot: immune repertoire analysis from raw files to publication figures with graphical user interface

Figure S1. Component diagram shows the software architecture of ClonoPlot. (PDF 22 kb