Towards Model-Driven Development of Access Control Policies for Web Applications

We introduce a UML-based notation for graphically modeling systems’ security aspects in a simple and intuitive way and a model-driven process that transforms graphical specifications of access control policies in XACML. These XACML policies are then translated in FACPL, a policy language with a formal semantics, and the resulting policies are evaluated by means of a Java-based software tool

An Arabidopsis introgression zone studied at high spatio-temporal resolution: interglacial and multiple genetic contact exemplified using whole nuclear and plastid genomes

Background: Gene flow between species, across ploidal levels, and even between evolutionary lineages is a common phenomenon in the genus Arabidopsis. However, apart from two genetically fully stabilized allotetraploid species that have been investigated in detail, the extent and temporal dynamics of hybridization are not well understood. An introgression zone, with tetraploid A. arenosa introgressing into A. lyrata subsp. petraea in the Eastern Austrian Forealps and subsequent expansion towards pannonical lowlands, was described previously based on morphological observations as well as molecular data using microsatellite and plastid DNA markers. Here we investigate the spatio-temporal context of this suture zone, making use of the potential of next-generation sequencing and whole-genome data. By utilizing a combination of nuclear and plastid genomic data, the extent, direction and temporal dynamics of gene flow are elucidated in detail and Late Pleistocene evolutionary processes are resolved. Results: Analysis of nuclear genomic data significantly recognizes the clinal structure of the introgression zone, but also reveals that hybridization and introgression is more common and substantial than previously thought. Also tetraploid A. lyrata and A. arenosa subsp. borbasii from outside the previously defined suture zone show genomic signals of past introgression. A. lyrata is shown to serve usually as the maternal parent in these hybridizations, but one exception is identified from plastome-based phylogenetic reconstruction. Using plastid phylogenomics with secondary time calibration, the origin of A. lyrata and A. arenosa lineages is pre-dating the last three glaciation complexes (approx. 550,000 years ago). Hybridization and introgression followed during the last two glacial-interglacial periods (since approx. 300,000 years ago) with later secondary contact at the northern and southern border of the introgression zone during the Holocene. Conclusions: Footprints of adaptive introgression in the Northeastern Forealps are older than expected and predate the Last Glaciation Maximum. This correlates well with high genetic diversity found within areas that served as refuge area multiple times. Our data also provide some first hints that early introgressed and presumably preadapted populations account for successful and rapid postglacial re-colonization and range expansion

Requirements Engineering for Web Applications: A Comparative Study

The requirements engineering discipline has become more and more important in the last years. Tasks such as the requirements elicitation, the specification of requirements or the requirements validation are essential to assure the quality of the resulting software. The development of Web systems usually involves more heterogeneous stakeholders than the construction of traditional software. In addition, Web systems have additional requirements for the navigational and multimedia aspects as well as for the usability as no training is possible. Therefore a thoroughly requirements analysis is even more relevant. In contrast, most of the methodologies that have been proposed for the development of Web applications focus on the design paying less attention to the requirements engineering. This paper is a comparative study of the requirements handling in Web methodologies showing trends in the use of techniques for capturing, specifying and validating Web requirements

Model Transformations from Requirements to Web System Design

Requirements models are used to specify system functionalities from the customer viewpoint and are the starting point of software development. However, most Web engineering approaches do not provide a systematic method to build design models from requirements specification. We propose an approach using model transformations to close this gap. Our transformation rules are defined in the QVT language – a forthcoming OMG standard, which makes automatic model generation possible. This way design is kept consistent with the customer requirements.Deutsche Forschungsgemeinschaft (DFG) WI841/7-1EC 6th Framework project SENSORIA IST 01600

Don’t Throw your Software Prototypes Away. Reuse them!

The mechanism of prototype development is considered by the research and industrial software communities as a key tool for user-developer communication. In software development, prototypes are used in requirements engineering to help elicit and validate users’ needs. Software prototypes like mockups are frequently considered throwaway artefacts and therefore they are often developed very fast, or with very few resources and discarded. In this paper we propose to change this idea, and to create prototypes that can be reused in any model-driven engineering (MDE) process. The paper presents an approach for an automatic mechanism for translating prototype models into requirements models and its implementation in a suitable tool case. This way, software developer teams will be able to dedicate resources to improving communication with users using prototypes because the knowledge acquired will be automatically transferred to the requirements phase of the development process

Lean requirements traceability automation enabled by model-driven engineering

Background: The benefits of requirements traceability, such as improvements in software product and process quality, early testing, and software maintenance, are widely described in the literature. Requirements traceability is a critical, widely accepted practice. However, very often it is not applied for fear of the additional costs associated with manual efforts or the use of additional tools. Methods: This article presents a “low-cost” mechanism for automating requirements traceability based on the model-driven paradigm and formalized by a metamodel for the creation and monitoring of traces and an integration process for traceability management. This approach can also be useful for information fusion in industry insofar that it facilitates data traceability. Results: This article extends an existing model-driven development methodology to incorporate traceability as part of its development tool. The tool has been used successfully by several companies in real software development projects, helping developers to manage ongoing changes in functional requirements. One of those projects is cited as an example in the paper. The authors’ current work leads them to conclude that a model-driven engineering approach, traditionally used only for the automatic generation of code in a software development process, can also be used to successfully automate and integrate traceability management without additional costs. The systematic evaluation of traceability management in industrial projects constitutes a promising area for future work.Junta de Andalucía AT17-5904-USEJunta de Andalucía US-1251532Ministerio de Ciencia, Innovación y Universidades PID2019-105455GB-C3

A Modeling Language for Agile Requirements Engineering

Agile methodologies have an impact on how organizations carry out Requirements Engineering (RE). In this context, organizations use different kind of agile techniques like artifacts, meetings, methods or roles, but there is a lack of specific guidelines for agile RE. The aim of this paper is to present a modeling language for supporting organizational aspects of agile RE. It allows the visualization of agile RE concepts and their relationships, which can be used to define guidelines for a specific organization, project or domain. The modeling language for agile RE is used in projects in industry and our experiences reveal that it supports organizations in detecting problems and visualizing internal conflicts during the agile requirements phase, among other benefits

A Quantitative SWOT-TOWS Analysis for the Adoption of Model-Based Software Engineering

Enterprises’ trend to low-code development revives model-based software engineering (MBSE) since several low-code platforms are based on the principles of model-based design, automatic code generation, and visual programming. Changes in an enterprise’s software development process, however, always require strategic planning. To find an appropriate strategy, we present an analytical tool for identifying and evaluating strengths, weaknesses, opportunities and threats factors for the adoption of MBSE. This tool provides a SWOT-TOWS analysis supplemented by a quantitative evaluation of strategies based on a multiple-criteria decision technique drawing on the knowledge of industry experts. Our analytical tool is general so it can be used in the industrial context for making other strategic decisions.Fil: Escalona, María José. Universidad de Sevilla; EspañaFil: de Koch, Nora Parcus. Universidad de Sevilla; EspañaFil: Rossi, Gustavo Héctor. Universidad Nacional de La Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Guest Editorial to the Theme Section on Model-Driven Web Engineering

Model-Driven Engineering (MDE) is becoming a widely accepted paradigm for the design and development of complex distributed applications. MDE advocates the use of models and model transformations as key artefacts in all phases of the software process, from system specification and analysis, to design, development and testing. Each model usually addresses one concern, independently from the rest of the issues involved in the construction of the system. Thus, the basic functionality of the system can be separated from its final implementation, and the business logic can be separated from the underlying platform technology, etc. Transformations between models enable the automated implementation of a system from the different models defined for it.Facultad de Informátic

Correction to: An Arabidopsis introgression zone studied at high spatio-temporal resolution: interglacial and multiple genetic contact exemplified using whole nuclear and plastid genomes

Upon publication of the original article [1], the authors had flagged that there was an error in Fig. 1c, as the key in this figure was displaying incorrectly. The colours had not displayed in the key in the final published article, and instead appear as plain white