Modelling Emergency Scenarios using Algebraic High Level Net Transformation Systems with Net Patterns

Emergency operations are a good case study for dynamic systems. Their size and high dynamicity make modelling them a challenging task. Algebraic high level net transformation systems are a well suited technique for modelling such dynamic systems. They consist of an algebraic high level net and a set of graph transformation rules. The net reflects the initial state of the operation and the transformation rules can be used to adapt this state to reflect the dynamicity of the operation. The applicability of graph transformation rules depends on the existence of a match morphism. While designing the algebraic high level net transformation system the designer has to ensure the existence of the right match morphisms for all reachable runtime states. This can be a tedious and error prone task for the designer. This paper uses a case study for modelling emergency operations with algebraic high level net transformation systems to show how the notion of net patterns can help the designer to cope with rule applicability

Erkennung von Adaptionskonflikten zur Laufzeit unter Benutzung von [email protected]

Selbstadaptive Softwaresysteme sind in der Lage, sich an die Heterogenität heutiger Computersysteme anzupassen. Adaptionen ermöglichen eine korrekte Funktionsweise trotz unterschiedlicher Computerplattformen, Fähigkeiten, Konfigurationen und Kontextsituationen. Hierfür muss das Softwaresystem trotz der Änderungen durch Adaptionen immer korrekt funktionieren. Um dieses Ziel zu erreichen kann Verifikation zur Designzeit mit einer Analyse zur Laufzeit kombiniert werden. Eine Verifikation zur Designzeit ermöglicht die frühzeitige Erkennung und Beseitigung von Problemen. Allerdings ist der Zustandsraum, welcher durch Adaption erreicht werden kann, oft sehr groß oder, in einigen Fällen, zur Designzeit nicht vollständig bekannt. Dies macht eine komplette Verifikation zur Designzeit unpraktisch oder sogar unmöglich. Analyse zur Laufzeit hat den Vorteil, dass ein großer Teil der zur Designzeit noch unbekannten Variablen feststeht. Statt einer Analyse des gesamten Zustandsraumes kann die Laufzeitanalyse auf dem aktuellen Zustand basieren. Das korrekte Verhalten der Adaptionen ist einer der Aspekte, die sichergestellt werden müssen. Adaptionen verursachen Änderungen im Softwaresystem. Diese Änderungen können miteinander in Konflikt stehen. Das laufende Softwaresystem muss diese Konflikte erkennen können, um auf sie zu reagieren. In dieser Doktorarbeit beschreiben wir den Trollmann Ansatz zur Erkennung von Adaptionskonflikten. Dieser Ansatz kann zwei Typen von Adaptionskonflikten erkennen: Adaption-Adaption Konflikte und Adaption-Konsistenz Konflikte. Adaption-Adaption Konflikte treten auf, wenn Adaptionen sich gegenseitig beeinflussen. Dies führt dazu, dass verschiedene Reihenfolgen der gleichen Adaptionen unterschiedliche Ergebnisse liefern. Es kann auch vorkommen, dass nach einer Adaption eine andere nicht mehr durchgeführt werden kann. Adaption-Konsistenz Konflikte sind Situationen, in denen die Adaptionen das System in einen inkonsistenten Zustand führen. Um Adaptionskonflikte zu lösen muss ein selbstadaptives Softwaresystem in der Lage sein, diese zu erkennen. Modellgetriebene Softwareentwicklung kann verwendet werden, um die Komplexität der Entwicklung und Handhabung von Softwaresystemen zu reduzieren. Bei einigen Ansätzen bleiben die Modelle zur Laufzeit erhalten und werden mit dem laufenden Softwaresystem synchronisiert. Der Trollmann Ansatz basiert auf einem solchen Ansatz. Adaptionen und Konsistenzbedingungen können auf diesen Modellen beschrieben werden. Als Formale Basis definieren wir einen Formalismus, der in der Lage ist, mehrere Modelle und deren Relation zu repräsentieren. Dieser Formalismus kann mit Graph Transformation und mit Nested Conditions kombiniert werden, um Adaptionen und Konsistenzbedingungen zu beschreiben. Basierend auf dieser Kombination von Formalismen definieren wir eine Analysemethode für Adaptionskonflikte. Die Analyse ermöglicht die Erkennung beider Konfliktarten. Für erkannte Konflikte werden die beteiligten Adaptionen, Modellelemente und elementaren Adaptionsoperationen (Erstellen und Löschen von Modellelementen) extrahiert. Das korrekte Verhalten des Trollmann Ansatzes wird durch Theoreme beschrieben und in der Arbeit bewiesen. Zusätzlich beschreiben wir die Implementierung des Trollmann Ansatzes im Rahmen des Eclipse Modeling Frameworks. Diese Implementierung wurde genutzt, um die Konflikterkennung im Rahmen eines Forschungsprojektes an der TU Berlin zu evaluieren.Self-adaptive software systems aim to cope with the heterogeneity of today’s computing environments by adjusting themselves. Adaptations enable the software system to function correctly despite different computing platforms, capabilities, configurations and context-of-use situations. Self-adaptive software systems need to assure correct behaviour despite the changes imposed by adaptations. To achieve this goal design time verification can be complemented with run time assurance. Design time verification enables the detection and resolution of problems at design time. However, due to its adaptations the state space of a self-adaptive software system is often very large or, in some cases, partially unknown at design. This makes a complete verification impractical or even impossible. Run time assurance methods profit from the fact that a lot of the variables that are free at design time are bound at run time. Instead of a verification of the complete state space such methods can concentrate on assuring that there are no failures in the current state of the software system. One aspect that needs to be assured at run time is the correct behaviour of the adaptation itself. Adaptations denote changes in the software system that can be in conflict with each other. The running software system needs to be able to detect these conflicts to resolve them. In this thesis we present the Trollmann approach to adaptation conflict detection. This approach is able to detect two types of adaptation conflicts: adaptation-adaptation and adaptation-consistency conflicts. Adaptation-adaptation conflicts are situations in which adaptations impact each other, leading to different results when applied in different order. The application of one adaptation can even disable another adaptation. Adaptation-consistency conflicts are situations in which adaptations leave the software system in an inconsistent state. The running software system needs to be able to detect and resolve these conflicts. Model driven engineering has been applied to tame the complexity of the development and management of software systems. The Trollmann approach assumes a model driven engineering approach in which the models are available at run time and reflect the current state of the software system, its adaptations and its consistency requirements. The detection of adaptation conflicts is based on these models. As formal foundation for the approach we define the formalism graph diagrams that can be used to represent multiple models and their relation. This formalism is combined with graph transformation and nested conditions to describe adaptations and consistency requirements. Based on this combination of formalisms we define analysis methods for adaptation conflicts. These analysis methods are able to detect both types of conflicts and to point out the adaptations, model elements and elementary adaptation actions (i.e., the creation and deletion of model elements) that are involved in the conflict. This information can be used by a conflict resolution mechanism. The correct behaviour of the Trollmann approach is described by a set of theorems that are proven in this thesis. In addition, we present an implementation of the Trollmann approach in the scope of the Eclipse Modeling Framework. This implementation has been used to evaluate the performance of the analysis algorithms and test the approach in the scope of a research project at the TU Berlin

A Search-Based and Fault-Tolerant Approach to Concurrent Model Synchronisation

In collaboration scenarios, we often encounter situations in which semantically interrelated models are changed concurrently. Concurrent model synchronization denotes the task of keeping these models consistent by propagating changes between them. This is challenging as changes can contradict each other and thus be in conflict. A problem with current synchronisation approaches is that they are often nondeterministic, i.e., the order in which changes are propagated is essential for the result. Furthermore, a common limitation is that the involved models must have been in a consistent state at some point, and that the applied changes are at least valid for the domain in which they were made. We propose a hybrid approach based on Triple Graph Grammars (TGGs) and Integer Linear Programming (ILP) to overcome these issues: TGGs are a grammar-based means that supplies us with a superset of possible synchronization solutions, forming a search space from which an optimum solution incorporating user-defined preferences can be chosen by ILP. Therefore, the proposed method combines configurability by comprising expert knowledge via TGGs with the flexible input handling of search-based techniques: By accepting arbitrary graph structures as input models, the approach is tolerant towards errors induced during the modelling process, i.e., it can cope with input models which do not conform to their metamodel or which cannot be generated by the TGG at hand. The approach is implemented in the model transformation tool eMoflon and evaluated regarding scalability for growing model sizes and an increasing number of changes

Age of epilepsy onset as modulating factor for naming deficit after epilepsy surgery: a voxel-based lesion-symptom mapping study

Abstract Age at onset of epilepsy is an important predictor of deterioration in naming ability following epilepsy surgery. In 141 patients with left hemispheric epilepsy and language dominance who received epilepsy surgery at the Epilepsy Centre Erlangen, naming of objects (Boston naming test, BNT) was assessed preoperatively and 6 months postoperatively. Surgical lesions were plotted on postoperative MRI and normalized for statistical analysis using voxel-based lesion-symptom mapping (VBLSM). The correlation between lesion and presence of postoperative naming deterioration was examined varying the considered age range of epilepsy onsets. The VBLSM analysis showed that volumes of cortex areas in the left temporal lobe, which were associated with postoperative decline of naming, increased with each year of later epilepsy onset. In patients with later onset, an increasing left posterior temporobasal area was significantly associated with a postoperative deficit when included in the resection. For late epilepsy onset, the temporomesial expansion also included the left hippocampus. The results underline that early onset of epilepsy is a good prognostic factor for unchanged postoperative naming ability following epilepsy surgery. For later age of epilepsy onset, the extent of the area at risk of postoperative naming deficit at 6 months after surgery included an increasing left temporobasal area which finally also comprised the hippocampus

First epileptic seizure and epilepsies in adulthood. Abridged version ofthe S2k guideline of the German Society for Neurology in cooperationwith the German Society for Epileptology

Holtkamp M, May T, Berkenfeld R, et al. Erster epileptischer Anfall und Epilepsien im Erwachsenenalter. Kurzfassung S2k-Leitlinie der Deutschen Gesellschaft für Neurologie in Zusammenarbeit mit der Deutschen Gesellschaft für Epileptologie. Clinical Epileptology. 2024.The new S2k guideline "First epileptic seizure and epilepsies in adulthood" provides recommendations on clinically relevant issues in five major topics: management of first epileptic seizures, pharmacotherapy, epilepsy surgery, complementary and supportive treatment, and psychosocial aspects. For the topic management of first epileptic seizures, the guideline provides recommendations on identifying the two major differential diagnoses, syncope and psychogenic non-epileptic seizure. The importance of additional examinations such as EEG, MRI and cerebrospinal fluid for syndromic classification and etiological allocation is discussed. Recommendations on neuropsychological and psychiatric screening tests are also given. The topic pharmacotherapy issues recommendations on antiseizure medication in monotherapy for focal, generalized and unclassified epilepsies; patient groups with special challenges such as the aged, women of childbearing potential and people with mental retardation are emphasized. Further issues are indications for measuring serum concentrations of antiseizure medication and possible risks of switching manufacturers. In the topic epilepsy surgery, indications for presurgical assessment and the multiple therapeutic approaches, such as resection, laser ablation, and neurostimulation are presented. Recommendations on postoperative management of patients, including rehabilitation and psychosocial counselling, are given. The topic complementary and supportive therapeutic approaches comprises recommendations on the diagnostics and treatment of common psychiatric comorbidities of epilepsy, such as anxiety disorder, depression and psychosis. Another important issue is the management of psychogenic non-epileptic seizures as a neuropsychiatric differential diagnosis or comorbidity of epileptic seizures. Furthermore, recommendations on the potential role of ketogenic diet and on acupuncture, homeopathy and other complementary approaches are made. The recommendations on psychosocial aspects comprise practical issues, such as fitness to drive a car, training and occupation, medical rehabilitation, sport, transition, patients' self-help, education programs for patients and next of kin, adherence, advise on SUDEP