Test Case Generation Using Visual Contracts

Visual contracts provide a diagrammatic notation for pre- and postconditionsas alternative to the Object-Constraint Language (OCL) or code-levelcontract languages. Using visual contracts for testing, we benefit from their executabilityand formal background in graph transformation to provide model-basedtest oracles and coverage criteria. Based on a static analysis of their dependenciesand conflicts, in this paper we use visual contracts to generate test cases accordingto these coverage criteria.Together with previous work, this adds up to a comprehensive approach aiming toautomate the three major challenges of testing through the use of models

Detecting Structural Refactoring Conflicts Using Critical Pair Analysis

AbstractRefactorings are program transformations that improve the software structure while preserving the external behaviour. In spite of this very useful property, refactorings can still give rise to structural conflicts when parallel evolutions to the same software are made by different developers. This paper explores this problem of structural evolution conflicts in a formal way by using graph transformation and critical pair analysis. Based on experiments carried out in the graph transformation tool AGG, we show how this formalism can be exploited to detect and resolve refactoring conflicts

Visual Contracts as Test Oracle in AGG 2.0

A test oracle predicts expected outcomes for a set of test cases, often based on a formal, executable specification. Visual contracts are graph transformation rules describing pre- and post-conditions of a service’s operations. To obtain an oracle based on visual contracts, we use the Attributed Graph Grammar System (AGG) to execute the rules, creating a simulation of the behaviour expected of the system under test.The paper discusses the basic idea, illustrates it by an example, describes the challenges and solutions of its implementation and draws conclusions for the use of graph transformation and AGG in test oracles

Modeling and Analysis of Self-Adaptive Systems Based on Graph Transformation

Software systems nowadays require continuous operation despite changes both in user needs and in their operational environments. Self-adaptive systems are typically instrumented with tools to autonomously perform adaptation to these changes while maintaining some desired properties. In this paper we model and analyze self-adaptive systems by means of typed, attributed graph grammars. The interplay of different grammars representing the application and the adaptation logic is realized by an adaption manager. Within this formal framework we define consistency and operational properties that are maintained despite adaptations and we give static conditions for their verification. The overall approach is supported by the AGG tool that offers the features for modeling, simulating, and analyzing graph transformation systems. A case study modeling a business process that adapts to changing environment conditions is used to demonstrate and validate the formal framework

Formal Analysis and Verication of Self-Healing Systems: Long Version

Self-healing (SH-)systems are characterized by an automatic discovery of system failures, and techniques how to recover from these situations. In this paper, we show how to model SH-systems using algebraic graph transformation. These systems are modeled as typed graph grammars enriched with graph constraints. This allows not only for formal modeling of consistency and operational properties, but also for their analysis and verification using the tool AGG. We present sufficient static conditions for self-healing properties, deadlock-freeness and liveness of SH-systems. The overall approach is applied to a traffic light system case study, where the corresponding properties are verified

Sufficient Criteria for Consistent Behavior Modeling with Refined Activity Diagrams: Long Version

In use case-driven approaches to requirements modeling, UML activity diagrams are a wide-spread means for refining the functional view of use cases. Early consistency validation of activity diagrams is therefore desirable but difficult due to the semi-formal nature of activity diagrams. In this paper, we specify well-structured activity diagrams and define activities more precisely by pre- and post- conditions. They can be modeled by interrelated pairs of object diagrams based on a domain class diagram. This activity refinement is based on the theory of graph transformation and paves the ground for a consistency analysis of the required system behavior. A formal semantics for activity diagrams refined by pre- and post-conditions allows us to establish sufficient criteria for consistency. The semi-automatic checking of these criteria is supported by a tool for graph transformation

Molecular diagnostic tests for thrombophilia in patients referred to genetic counseling clinic because due to recurrent pregnancy failure. One center’s experience.

The loss of three or more subsequent pregnancies before the end of the 22nd week is observed in 0.4–1% of women. Despite great advances in medicine, the causes of pregnancy failure (miscarriages, missed abortions and stillbirths), and the birth of a child or children with congenital abnormalities, are still not determined precisely. The aim: The purpose of the research was to determine the association of polymorphisms and mutations of coagulation factors II and V genes, as well as methylenetethrahydrofolate reductase (MTHFR) gene polymorphism, with the course of pregnancy and the type of reproductive failure. Methods: The research was performed in a group of 116 women referred to the Genetic Outpatient Clinic of the NCU SM in Bydgoszcz between 2009–2010 due to reproductive failures. The molecular tests for thrombophilia, i.e. mutation of the factor V Leiden, prothrombin gene mutation 20210G>A, and MTHFR polymorphism 677C>T were done in all patients. Results: The Leiden mutation was found in 8 women (homozygotic in 2 of them) and prothrombin gene mutation in 3. 85 women had the heterozygotic MTHFR polymorphism, while 24 the homozygotic one. Coexistence of the Leiden mutation and the MTHFR polymorphism was found in 3 patients with history of miscarriages. Conclusions: 1. The presence of the mutations that promote thrombophilia in the genes responsible for the foliate metabolism and for the plasma coagulation is often associated with pregnancy failures and may be their basic cause in some cases. 2. The percentage of women with pregnancy failures being heterozygotes (73.3%), homozygotes (20.7%) or both (94%) of the MTHFR gene 677C>T polymorphism is statistically significantly higher than the highest prevalence of these changes in the general population (55, 13%, and 68%, respectively). 3. The factor V gene Leiden mutation is associated mainly with recurrent spontaneous abortions. In the present study it was found only in the group of women with both early and late miscarriages

Association Between Body Mass Index and Clinical and Endoscopic Features of Eosinophilic Esophagitis

Because eosinophilic esophagitis (EoE) causes dysphagia, esophageal narrowing, and strictures, it could result in low body mass index (BMI), but there are few data assessing this

Wavelet-Based Linear-Response Time-Dependent Density-Functional Theory

Linear-response time-dependent (TD) density-functional theory (DFT) has been implemented in the pseudopotential wavelet-based electronic structure program BigDFT and results are compared against those obtained with the all-electron Gaussian-type orbital program deMon2k for the calculation of electronic absorption spectra of N2 using the TD local density approximation (LDA). The two programs give comparable excitation energies and absorption spectra once suitably extensive basis sets are used. Convergence of LDA density orbitals and orbital energies to the basis-set limit is significantly faster for BigDFT than for deMon2k. However the number of virtual orbitals used in TD-DFT calculations is a parameter in BigDFT, while all virtual orbitals are included in TD-DFT calculations in deMon2k. As a reality check, we report the x-ray crystal structure and the measured and calculated absorption spectrum (excitation energies and oscillator strengths) of the small organic molecule N-cyclohexyl-2-(4-methoxyphenyl)imidazo[1,2-a]pyridin-3-amine

Cost Effectiveness of Internet Interventions: Review and Recommendations

10.1007/s12160-009-9131-6Annals of Behavioral Medicine38140-45ABME