Requirement patterns: an approach for streamlining requirements engineering in software product families

Reusable structure is essential in all reuse-based software development processes. This provides a solid foundation for seamless management of reusable artefacts especially in software product line engineering (SPLE). One of the potential benefits provided by a well-defined structure is systematic reuse of these artefacts. Requirements pattern approach provides guidelines for requirement engineers to reuse and specify requirements. Although a plethora of research on requirements pattern have been reported in the literature, no research available focuses on requirement engineering (RE) activities of SPLE. In this paper, we present an anatomy of software requirement pattern (SRP) for SPLE with a structured example from e-learning domain. To enable practitioners, understand the concept of requirement pattern more, we present a meta-model for the SRP concepts and their relationships. In addition, we describe how the requirement pattern approach, streamlines RE activities, design for and with reuse in both domain and application engineering processes of SPLE. The requirement pattern approach thus helps in achieving systematic requirements reuse (RR) and generation of structured software requirement specification (SRS) for individual applications

Requirements patterns structure for specifying and reusing software product line requirements

A well-defined structure is essential in all software development, thus providing an avenue for smooth execution of the processes involved during various software development phases. One of the potential benefits provided by a well-defined structure is systematic reuse of software artifacts. Requirements pattern approach provides guidelines and modality that enables a systematic way of specifying and documenting requirements, which in turn supports a systematic reuse. Although there is a great deal of research concerning requirements pattern in the literature, the research focuses are not on requirement engineering (RE) activities of SPLE. In this paper, we proposed a software requirement pattern (SRP) structure based on RePa Requirements Pattern Template, which was adapted to best suit RE activities in SPLE. With this requirement pattern structure, RE activities such as elicitation and identification of common and variable requirements as well as the specification, documentation, and reuse in SPLE could be substantially improved

Advanced cutting pattern generation – Consideration of structural requirements in the optimization process

This paper presents extensions to optimized cutting pattern generation through inverse engineering regarding structural requirements. The optimized cutting pattern generation through inverse engineering is a general approach for the cutting pattern generation which is based on the description of the underlying mechanical problem. The three dimensional surface, which is defined through the form finding process, represents the final structure after manufacturing. For this surface the coordinates in three dimensional space Ω3D and the finally desired prestress state σprestress are known. The aim is to find a surface in a two dimensional space Ω2D which minimizes the difference between the elastic stresses σel,2D→3D arising through the manufacturing process and the final prestress σprestress. Thus the cutting pattern generation leads to an optimization problem, were the positions of the nodes in the two dimensional space Ω2D are the design variables. In this paper various improvements to the method will be shown. The influence of the seam lines to the stress distribution in the membrane is investigated. Additionally, the control of equal edge length for associated patterns is an example for important enhancement

A Local Radial Basis Function Method for the Numerical Solution of Partial Differential Equations

Most traditional numerical methods for approximating the solutions of problems in science, engineering, and mathematics require the data to be arranged in a structured pattern and to be contained in a simply shaped region, such as a rectangle or circle. In many important applications, this severe restriction on structure cannot be met, and traditional numerical methods cannot be applied. In the 1970s, radial basis function (RBF) methods were developed to overcome the structure requirements of existing numerical methods. RBF methods are applicable with scattered data locations. As a result, the shape of the domain may be determined by the application and not the numerical method. Radial basis function methods can be implemented both globally and locally. Comparisons between these two techniques are made in this work to illustrate how the local method can obtain very similar accuracy to the global method while only using a small subset of available points, and thus using substantially less computer memory. Finally, radial basis function methods are applied to solve systems of nonlinear partial differential equations (PDEs) that model pattern formation in mathematical biology. The local RBF method will be used to evaluate Turing pattern and chemotaxis models that are both modeled by advection-reaction-di↵usion type PDEs

Design and construction of a picosatellite’s primary structure by using 3D printing technologies

The viability of developing the design and manufacture of the structure of a small satellite CubeSat, at the School of Telecommunications and Aerospace Engineering of Castelldefels( EETAC), at the Polytechnical University of Catalonia (UPC), is analyzed. The design and detailed simulations of the most relevant mechanical tests have been performed by using the software SolidWorks. A honeycomb pattern monocoque structural design -called Hexagon- is proposed for a single unit CubeSat primary structure. Additionaly, Hexagon's mechanical behaviour is compared to that of the operational CubeSat structure Pumpkin. A preliminary viability study is developed, based on the results of structure simulations and theoretical studies. The resulting structure meets the corresponding CubeSat design requirements, both at the Qualification and at the Acceptance testing levels. Therefore Hexagon can be considered a viable design of a CubeSat's primary structure. After a process of research of manufacture techniques and appropriate materials, we propose to use laser sintering 3D-printing, and justify its convenience versus the use of traditional construction technologies. We suggest the material to use is a polyamide based (PA11) carbon fiber reinforced composite (PA11CF), provided by ADVANC3D Materials. We describe the construction and testing procedure and justify that the entire process can be completed by EETAC students, using equipment available to them. Finally, we propose the lines of future work to test PA11CF and, eventually, build and test the entire CubeSat structure

Efficient reverse-engineering of a developmental gene regulatory network

This is the final version of the article. Available from the publisher via the DOI in this record.Understanding the complex regulatory networks underlying development and evolution of multi-cellular organisms is a major problem in biology. Computational models can be used as tools to extract the regulatory structure and dynamics of such networks from gene expression data. This approach is called reverse engineering. It has been successfully applied to many gene networks in various biological systems. However, to reconstitute the structure and non-linear dynamics of a developmental gene network in its spatial context remains a considerable challenge. Here, we address this challenge using a case study: the gap gene network involved in segment determination during early development of Drosophila melanogaster. A major problem for reverse-engineering pattern-forming networks is the significant amount of time and effort required to acquire and quantify spatial gene expression data. We have developed a simplified data processing pipeline that considerably increases the throughput of the method, but results in data of reduced accuracy compared to those previously used for gap gene network inference. We demonstrate that we can infer the correct network structure using our reduced data set, and investigate minimal data requirements for successful reverse engineering. Our results show that timing and position of expression domain boundaries are the crucial features for determining regulatory network structure from data, while it is less important to precisely measure expression levels. Based on this, we define minimal data requirements for gap gene network inference. Our results demonstrate the feasibility of reverse-engineering with much reduced experimental effort. This enables more widespread use of the method in different developmental contexts and organisms. Such systematic application of data-driven models to real-world networks has enormous potential. Only the quantitative investigation of a large number of developmental gene regulatory networks will allow us to discover whether there are rules or regularities governing development and evolution of complex multi-cellular organisms.Funding: The laboratory of Johannes Jaeger and this study in particular was funded by the MEC-EMBL agreement for the EMBL/CRG Research Unit in Systems Biology, by Grant 153 (MOPDEV) of the ERANet: ComplexityNET program, by SGR Grant 406 from the Catalan funding agency AGAUR, by grant BFU2009-10184 from the Spanish Ministry of Science, and by European Commission grant FP7-KBBE-2011-5/289434 (BioPreDyn). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Multi-perspective requirements engineering for networked business systems: a framework for pattern composition

How business and software analysts explore, document, and negotiate requirements for enterprise systems is critical to the benefits their organizations will eventually derive. In this paper, we present a framework for analysis and redesign of networked business systems. It is based on libraries of patterns which are derived from existing Internet businesses. The framework includes three perspectives: Economic value, Business processes, and Application communication, each of which applies a goal-oriented method to compose patterns. By means of consistency relationships between perspectives, we demonstrate the usefulness of the patterns as a light-weight approach to exploration of business ideas