Effortless Fault Localisation:Conformance Testing of Real-Time Systems in Ecdar

Model checking of real-time systems has evolved throughout the years. Recently, the model checker Ecdar, using timed I/O automata, was used to perform compositional verification. However, in order to fully integrate model checking of real-time systems into industrial development, we need a productive and reliable way to test if such a system conforms to its corresponding model. Hence, we present an extension of Ecdar that integrates conformance testing into a new IDE that now features modelling, verification, and testing. The new tool uses model-based mutation testing, requiring only the model and the system under test, to locate faults and to prove the absence of certain types of faults. It supports testing using either real-time or simulated time. It parallelises test-case generation and test execution to provide a significant speed-up. We also introduce new mutation operators that improve the ability to detect and locate faults. Finally, we conduct a case study with 140 faulty systems, where Ecdar detects all faults.Comment: In Proceedings GandALF 2018, arXiv:1809.0241

COST Action IC 1402 ArVI: Runtime Verification Beyond Monitoring -- Activity Report of Working Group 1

This report presents the activities of the first working group of the COST Action ArVI, Runtime Verification beyond Monitoring. The report aims to provide an overview of some of the major core aspects involved in Runtime Verification. Runtime Verification is the field of research dedicated to the analysis of system executions. It is often seen as a discipline that studies how a system run satisfies or violates correctness properties. The report exposes a taxonomy of Runtime Verification (RV) presenting the terminology involved with the main concepts of the field. The report also develops the concept of instrumentation, the various ways to instrument systems, and the fundamental role of instrumentation in designing an RV framework. We also discuss how RV interplays with other verification techniques such as model-checking, deductive verification, model learning, testing, and runtime assertion checking. Finally, we propose challenges in monitoring quantitative and statistical data beyond detecting property violation

Shielded Reinforcement Learning for Hybrid Systems

Safe and optimal controller synthesis for switched-controlled hybrid systems, which combine differential equations and discrete changes of the system's state, is known to be intricately hard. Reinforcement learning has been leveraged to construct near-optimal controllers, but their behavior is not guaranteed to be safe, even when it is encouraged by reward engineering. One way of imposing safety to a learned controller is to use a shield, which is correct by design. However, obtaining a shield for non-linear and hybrid environments is itself intractable. In this paper, we propose the construction of a shield using the so-called barbaric method, where an approximate finite representation of an underlying partition-based two-player safety game is extracted via systematically picked samples of the true transition function. While hard safety guarantees are out of reach, we experimentally demonstrate strong statistical safety guarantees with a prototype implementation and UPPAAL STRATEGO. Furthermore, we study the impact of the synthesized shield when applied as either a pre-shield (applied before learning a controller) or a post-shield (only applied after learning a controller). We experimentally demonstrate superiority of the pre-shielding approach. We apply our technique on a range of case studies, including two industrial examples, and further study post-optimization of the post-shielding approach.Safe and optimal controller synthesis for switched-controlled hybrid systems, which combine differential equations and discrete changes of the system’s state, is known to be intricately hard. Reinforcement learning has been leveraged to construct near-optimal controllers, but their behavior is not guaranteed to be safe, even when it is encouraged by reward engineering. One way of imposing safety to a learned controller is to use a shield, which is correct by design. However, obtaining a shield for non-linear and hybrid environments is itself intractable. In this paper, we propose the construction of a shield using the so-called barbaric method, where an approximate finite representation of an underlying partition-based two-player safety game is extracted via systematically picked samples of the true transition function. While hard safety guarantees are out of reach, we experimentally demonstrate strong statistical safety guarantees with a prototype implementation and Uppaal Stratego. Furthermore, we study the impact of the synthesized shield when applied as either a pre-shield (applied before learning a controller) or a post-shield (only applied after learning a controller). We experimentally demonstrate superiority of the pre-shielding approach. We apply our technique on a range of case studies, including two industrial examples, and further study post-optimization of the post-shielding approach.</p

Metallomimetic C–F Activation Catalysis by Simple Phosphines

Delivering metallomimetic reactivity from simple p-block compounds is highly desirable in the search to replace expensive, scarce precious metals by cheap and abundant elements in catalysis. This contribution demonstrates that metallomimetic catalysis, involving facile redox cycling between the P(III) and P(V) oxidation states, is possible using only simple, cheap, and readily available trialkylphosphines without the need to enforce unusual geometries at phosphorus or use external oxidizing/reducing agents. Hydrodefluorination and aminodefluorination of a range of fluoroarenes was realized with good to very good yields under mild conditions. Experimental and computational mechanistic studies show that the phosphines undergo oxidative addition of the fluoroaromatic substrate via a Meisenheimer-like transition state to form a fluorophosphorane. This undergoes a pseudotransmetalation step with a silane, via initial fluoride transfer from P to Si, to give experimentally observed phosphonium ions. Hydride transfer from a hydridosilicate counterion then leads to a hydridophosphorane, which undergoes reductive elimination of the product to reform the phosphine catalyst. This behavior is analogous to many classical transition-metal-catalyzed reactions and so is a rare example of both functional and mechanistically metallomimetic behavior in catalysis by a main-group element system. Crucially, the reagents used are cheap, readily available commercially, and easy to handle, making these reactions a realistic prospect in a wide range of academic and industrial settings

Discovery of Sexual Dimorphisms in Metabolic and Genetic Biomarkers

Metabolomic profiling and the integration of whole-genome genetic association data has proven to be a powerful tool to comprehensively explore gene regulatory networks and to investigate the effects of genetic variation at the molecular level. Serum metabolite concentrations allow a direct readout of biological processes, and association of specific metabolomic signatures with complex diseases such as Alzheimer's disease and cardiovascular and metabolic disorders has been shown. There are well-known correlations between sex and the incidence, prevalence, age of onset, symptoms, and severity of a disease, as well as the reaction to drugs. However, most of the studies published so far did not consider the role of sexual dimorphism and did not analyse their data stratified by gender. This study investigated sex-specific differences of serum metabolite concentrations and their underlying genetic determination. For discovery and replication we used more than 3,300 independent individuals from KORA F3 and F4 with metabolite measurements of 131 metabolites, including amino acids, phosphatidylcholines, sphingomyelins, acylcarnitines, and C6-sugars. A linear regression approach revealed significant concentration differences between males and females for 102 out of 131 metabolites (p-values<3.8 x 10(-4); Bonferroni-corrected threshold). Sex-specific genome-wide association studies (GWAS) showed genome-wide significant differences in beta-estimates for SNPs in the CPS1 locus (carbamoyl-phosphate synthase 1, significance level: p<3.8 x 10(-10); Bonferroni-corrected threshold) for glycine. We showed that the metabolite profiles of males and females are significantly different and, furthermore, that specific genetic variants in metabolism-related genes depict sexual dimorphism. Our study provides new important insights into sex-specific differences of cell regulatory processes and underscores that studies should consider sex-specific effects in design and interpretation

3D inkjet printing of electronics using UV conversion

The production of electronic circuits and devices is limited by current manufacturing methods that limit both the form and potentially the performance of these systems. Additive Manufacturing (AM) is a technology that has been shown to provide cross sectoral manufacturing industries with significant geometrical freedom. A research domain known as Multi-Functional Additive Manufacturing (MFAM) in its infancy looks to couple the positive attributes of AM with application in the electronics sector could have a significant impact on the development of new products, however there are significant hurdles to overcome. This paper reports on the single step MFAM of three dimensional (3D) electronic circuitry within a polymeric structure using a combination of conductive and non-conductive materials within a single material jetting based AM system. The basis of this breakthrough is a study of the optical absorption regions of a silver nanoparticle (AgNP) conductive ink which lead to a novel method to rapidly process and sinter silver nanoparticle inks in ambient conditions using simple UV radiation contemporaneously with UV-curing of deposited polymeric structures

Game laboratory studies

Prof. Dr. Jens Schröter ist Herausgeber der Reihe und die Herausgeber der einzelnen Hefte sind renommierte Wissenschaftler und -innen aus dem In- und Ausland.Um die Analyse von Computerspielen aus produktionsästhetischer Perspektive zu erproben, lehnt sich der vorliegende Band an die Akteur-Netzwerk-Theorie (ANT) an. Mit ihr geht es ihm um die Frage nach den Aktanten des Game Design – etwa: Welche Hard- und Softwarekomponenten kommen wann und wofür zum Einsatz; wie und mittels welcher Medien notieren Level-Designer ihre Ideen, und wie werden die Aufzeichnungen später von Programmierern implementiert; und welche Rolle spielt eigentlich eine Action-Figur auf dem Schreibtisch eines Textur-Artists

Verbal, Facial and Autonomic Responses to Empathy-Eliciting Film Clips by Disruptive Male Adolescents with High Versus Low Callous-Unemotional Traits

This study examined empathy-related responding in male adolescents with disruptive behavior disorder (DBD), high or low on callous-unemotional (CU) traits. Facial electromyographic (EMG) and heart rate (HR) responses were monitored during exposure to empathy-inducing film clips portraying sadness, anger or happiness. Self-reports were assessed afterward. In agreement with expectations, DBD adolescents with high CU traits showed significantly lower levels of empathic sadness than healthy controls across all response systems. Between DBD subgroups significant differences emerged at the level of autonomic (not verbal or facial) reactions to sadness, with high CU respondents showing less HR change from baseline than low CU respondents. The study also examined basal patterns of autonomic function. Resting HR was not different between groups, but resting respiratory sinus arrhythmia (RSA) was significantly lower in DBD adolescents with high CU traits compared to controls. Results support the notion that CU traits designate a distinct subgroup of DBD individuals

Tight Encapsulation of a “Naked” Chloride in an Imidotitanium Hexanuclear Host

Treating the imidotitanium dimer [Ti­(μ-NAr)­(NMe₂)₂]₂ (Ar = 2,6-^<i>i</i>Pr₂C₆H₃) with excess Me₃SiCl affords the hexanuclear complex [{Ti­(NAr)­Cl₂}₆(Cl)]⁻[Q]⁺. The self-assembled hexameric cage arrangement encapsulates a chloride ion guest that provides evidence of new host–guest chemistry in this area, while the cationic part is composed of mixtures of the Q⁺ cations Me₂NHSiMe₃⁺ and Me₂N­(SiMe₃)₂⁺