Trace Diagnostics for Signal-based Temporal Properties

in IEEE Transactions on Software Engineering (in press)

Trace checking is a verification technique widely used in Cyber-physical system (CPS) development, to verify whether execution traces satisfy or violate properties expressing system requirements. Often ... [more ▼]

Trace checking is a verification technique widely used in Cyber-physical system (CPS) development, to verify whether execution traces satisfy or violate properties expressing system requirements. Often these properties characterize complex signal behaviors and are defined using domain-specific languages, such as SB-TemPsy-DSL, a pattern-based specification language for signal-based temporal properties. Most of the trace-checking tools only yield a Boolean verdict. However, when a property is violated by a trace, engineers usually inspect the trace to understand the cause of the violation; such manual diagnostic is time-consuming and error-prone. Existing approaches that complement trace-checking tools with diagnostic capabilities either produce low-level explanations that are hardly comprehensible by engineers or do not support complex signal-based temporal properties. In this paper, we propose TD-SB-TemPsy, a trace-diagnostic approach for properties expressed using SB-TemPsy-DSL. Given a property and a trace that violates the property, TD-SB-TemPsy determines the root cause of the property violation. TD-SB-TemPsy relies on the concepts of violation cause, which characterizes one of the behaviors of the system that may lead to a property violation, and diagnoses, which are associated with violation causes and provide additional information to help engineers understand the violation cause. As part of TD-SB-TemPsy, we propose a language-agnostic methodology to define violation causes and diagnoses. In our context, its application resulted in a catalog of 34 violation causes, each associated with one diagnosis, tailored to properties expressed in SB-TemPsy-DSL. We assessed the applicability of TD-SB-TemPsy on two datasets, including one based on a complex industrial case study. The results show that TD-SB-TemPsy could finish within a timeout of 1 min for ≈ 83.66% of the trace-property combinations in the industrial dataset, yielding a diagnosis in ≈ 99.84% of these cases; moreover, it also yielded a diagnosis for all the trace-property combinations in the other dataset. These results suggest that our tool is applicable and efficient in most cases. [less ▲]

Metamorphic Testing for Web System Security

in IEEE Transactions on Software Engineering (in press)

Security testing aims at verifying that the software meets its security properties. In modern Web systems, however, this often entails the verification of the outputs generated when exercising the system ... [more ▼]

Security testing aims at verifying that the software meets its security properties. In modern Web systems, however, this often entails the verification of the outputs generated when exercising the system with a very large set of inputs. Full automation is thus required to lower costs and increase the effectiveness of security testing. Unfortunately, to achieve such automation, in addition to strategies for automatically deriving test inputs, we need to address the oracle problem, which refers to the challenge, given an input for a system, of distinguishing correct from incorrect behavior (e.g., the response to be received after a specific HTTP GET request). In this paper, we propose Metamorphic Security Testing for Web-interactions (MST-wi), a metamorphic testing approach that integrates test input generation strategies inspired by mutational fuzzing and alleviates the oracle problem in security testing. It enables engineers to specify metamorphic relations (MRs) that capture many security properties of Web systems. To facilitate the specification of such MRs, we provide a domain-specific language accompanied by an Eclipse editor. MST-wi automatically collects the input data and transforms the MRs into executable Java code to automatically perform security testing. It automatically tests Web systems to detect vulnerabilities based on the relations and collected data. We provide a catalog of 76 system-agnostic MRs to automate security testing in Web systems. It covers 39% of the OWASP security testing activities not automated by state-of-the-art techniques; further, our MRs can automatically discover 102 different types of vulnerabilities, which correspond to 45% of the vulnerabilities due to violations of security design principles according to the MITRE CWE database. We also define guidelines that enable test engineers to improve the testability of the system under test with respect to our approach. We evaluated MST-wi effectiveness and scalability with two well-known Web systems (i.e., Jenkins and Joomla). It automatically detected 85% of their vulnerabilities and showed a high specificity (99.81% of the generated inputs do not lead to a false positive); our findings include a new security vulnerability detected in Jenkins. Finally, our results demonstrate that the approach scale, thus enabling automated security testing overnight. [less ▲]

Simulator-based explanation and debugging of hazard-triggering events in DNN-based safety-critical systems

in ACM Transactions on Software Engineering and Methodology (in press)

When Deep Neural Networks (DNNs) are used in safety-critical systems, engineers should determine the safety risks associated with failures (i.e., erroneous outputs) observed during testing. For DNNs ... [more ▼]

When Deep Neural Networks (DNNs) are used in safety-critical systems, engineers should determine the safety risks associated with failures (i.e., erroneous outputs) observed during testing. For DNNs processing images, engineers visually inspect all failure-inducing images to determine common characteristics among them. Such characteristics correspond to hazard-triggering events (e.g., low illumination) that are essential inputs for safety analysis. Though informative, such activity is expensive and error-prone. To support such safety analysis practices, we propose SEDE, a technique that generates readable descriptions for commonalities in failure-inducing, real-world images and improves the DNN through effective retraining. SEDE leverages the availability of simulators, which are commonly used for cyber-physical systems. It relies on genetic algorithms to drive simulators towards the generation of images that are similar to failure-inducing, real-world images in the test set; it then employs rule learning algorithms to derive expressions that capture commonalities in terms of simulator parameter values. The derived expressions are then used to generate additional images to retrain and improve the DNN. With DNNs performing in-car sensing tasks, SEDE successfully characterized hazard-triggering events leading to a DNN accuracy drop. Also, SEDE enabled retraining leading to significant improvements in DNN accuracy, up to 18 percentage points. [less ▲]

L'hagiographie à l'aune du numérique. Nouvelles perspectives d'étude des légendiers latins

in In Monte Artium (in press)

Die Hausarbeit im Kontext von Deutsch als Fach- und Fremdsprache

in Szurawitzki, Michael; Wolf-Farré, Patrick (Eds.) Handbuch Deutsch als Fach- und Fremdsprache (in press)

In diesem Beitrag wird der Entwicklungsgeschichte der studentischen Hausarbeit und ihrer Funktionen nachgegangen, die sie heutzutage in der deutschsprachigen Hochschullandschaft erfüllt. Zunächst werden ... [more ▼]

In diesem Beitrag wird der Entwicklungsgeschichte der studentischen Hausarbeit und ihrer Funktionen nachgegangen, die sie heutzutage in der deutschsprachigen Hochschullandschaft erfüllt. Zunächst werden die wichtigsten Ansätze zur Erforschung der Textsorte Hausarbeit und zum wissenschaftlichen Schreiben von Studierenden im deutschsprachigen Raum skizziert. Dabei werden allgemeine schreibdidaktische Herausforderungen beim Lehren und Lernen wissenschaftlichen Schreibens besprochen, bevor im Speziellen auf fach- und fremdsprachliche Aspekte beim Verfassen von Hausarbeiten eingegangen wird. Zum Abschluss zeigt der Beitrag gegenwärtige Problemfelder und Forschungstrends auf. [less ▲]

Gender, Loneliness and Happiness during COVID-19

in Journal of Behavioral and Experimental Economics (in press)

We analyse a measure of loneliness from a representative sample of German individuals interviewed in both 2017 and at the beginning of the COVID-19 pandemic in 2020. Both men and women felt lonelier ... [more ▼]

We analyse a measure of loneliness from a representative sample of German individuals interviewed in both 2017 and at the beginning of the COVID-19 pandemic in 2020. Both men and women felt lonelier during the COVID-19 pandemic than they did in 2017. The pandemic more than doubled the gender loneliness gap: women were lonelier than men in 2017, and the 2017-2020 rise in loneliness was far larger for women. This rise is mirrored in life-satisfaction scores. Men’s life satisfaction changed only little between 2017 and 2020; yet that of women fell dramatically, and sufficiently so to produce a female penalty in life satisfaction. We estimate that almost all of this female penalty is explained by the disproportionate rise in loneliness for women during the COVID-19 pandemic. [less ▲]

Schumpeterian entrepreneurial digital identity and funding from venture capital firms

in Journal of Technology Transfer (in press)

Schumpeterian entrepreneurs are considered agents of innovation and technology transfer. However, to fulfill this role, they need entrepreneurial finance. From the perspective of digital identity, we ... [more ▼]

Schumpeterian entrepreneurs are considered agents of innovation and technology transfer. However, to fulfill this role, they need entrepreneurial finance. From the perspective of digital identity, we examine the relationship between a Schumpeterian digital identity and venture capital (VC) funding. Because the VC industry celebrates innovative and visionary entrepreneurship, we posit that a founder’s digital identity as a Schumpeterian-type entrepreneur influences the venture’s chances of receiving VC funding. A quantitative analysis of the language used by 3313 founders in a large sample of Twitter messages, however, provides a mixed picture. While some dimensions of Schumpeterian entrepreneurship have a positive relationship with the acquisition of resources from VC firms (entrepreneurial vision and optimism), other dimensions seem to have no (uncertainty tolerance and rationality) or even a decreasing (achievement motivation) effect. The negative relationships observed can be explained by the particularities of the VC business model, which does not align with Schumpeterian entrepreneurship in all respects. Our study contributes to research on Schumpeterian entrepreneurship, the financing of technology transfer, and the link between entrepreneurial digital identity and entrepreneurial finance. From a practical perspective, the results of our study demonstrate the limits of VC with regard to the financing of technology transfer and highlight the need for public funding through governmental VC or agencies for (disruptive) innovation. [less ▲]

Children’s internalizing behavior development is heterogeneously associated with the pace of epigenetic aging

in Biological Psychology (in press)

Background: Internalizing behaviors are an indicator of children’s psychological and emotional development, predicting future mental disorders. Recent studies have identified associations between DNA ... [more ▼]

Background: Internalizing behaviors are an indicator of children’s psychological and emotional development, predicting future mental disorders. Recent studies have identified associations between DNA methylation (DNAm) and internalizing behaviors. This prospective study aimed at exploring the associations between pace of biological aging and the developmental trajectories of internalizing behaviors. Methods: Participants were children from the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort (N=974). Measures of DNA methylation were collected at birth, age 7 and ages 15-17. The pace of aging was estimated using the DunedinPoAm algorithm (PoAm). Internalizing behaviors reported by caregivers between ages 4 and 16 using the Strengths and Difficulties Questionnaire. To explore heterogeneity in the association between PoAm and internalizing behaviors we use Poisson quantile regression in cross-section heterogeneity and longitudinal latent class analysis over the childhood and adolescence. Results: Internalizing behavior trajectories were identified: low-risk, childhood limited, late onset and early onset (persistent). Accelerated aging at birth was negatively associated with internalizing behaviors in early childhood but positively correlated during adolescence. Higher PoAm at birth increased chance of low-risk profile, while decreasing likelihood of childhood limited trajectory. PoAm at age 15 was negatively associated with childhood limited profile and positively linked to late onset trajectories. Associations were larger at higher values of internalizing symptoms. Conclusions: The heterogeneity in the association between biological age acceleration and internalizing behaviors suggests a complex dynamic relationship, particularly in children with high or increased risk of adverse mental health outcomes. [less ▲]

I Want to Start My Own Business. Can I Ask Our Firm or Family for Help?

in Jaskiewicz, Peter; Rau, Sabine (Eds.) Enabling Next Generation Legacies”: 35 Questions that Next Generation Members in Enterprising Families Ask (in press)

It is often said that the entrepreneurs of today are the family businesses of tomorrow. This assertion is supported by findings in a Global Entrepreneurship Monitor (2019-20) Report on ‘Family ... [more ▼]

It is often said that the entrepreneurs of today are the family businesses of tomorrow. This assertion is supported by findings in a Global Entrepreneurship Monitor (2019-20) Report on ‘Family Entrepreneurship’ which cites that 75% of respondent entrepreneurs across 48 economies indicate that their family was actively involved in either starting or developing a new business . In spite of this, and the fact that it is becoming more popular for family firms to encourage entrepreneurialism within the younger generation, it is often challenging for Next Gens to ‘carve out’ an entrepreneurial identity for themselves. This is even more so the case if the intention is to pursue new ideas that are not central to the core business and which might disturb long-planned succession strategies, or expectations held by senior family members. Making the decision to get on board the entrepreneur(ship) is an important career decision that has huge implications, not only for the Next Gens who are planning this, but also for current members of the family business who might have to adjust their expectations. [less ▲]

Gegenstand, Entwicklungen und Forschungsfelder der Trans Studies

in Gradinari, Irina (Ed.) (Re-)Visionen: Epistemologien, Ontologien und Methodologien der Geschlechterforschung (in press)

The article introduces the reader to the dynamic and interdisciplinary field of Trans Studies with a focus on the development of the field in Germany. For this purpose, the article addresses socio ... [more ▼]

The article introduces the reader to the dynamic and interdisciplinary field of Trans Studies with a focus on the development of the field in Germany. For this purpose, the article addresses socio-political and theoretical contexts from which Trans Studies emerged, the impact of these intellectual influences as well as the methodological orientation and realization in individual studies, and it contains an overview of central fields of Trans Studies research as they have developed until 2021. [less ▲]