A Systematic Aspect-Oriented Refactoring and Testing Strategy, and its Application to JHotDraw

Aspect oriented programming aims at achieving better modularization for a system's crosscutting concerns in order to improve its key quality attributes, such as evolvability and reusability. Consequently, the adoption of aspect-oriented techniques in existing (legacy) software systems is of interest to remediate software aging. The refactoring of existing systems to employ aspect-orientation will be considerably eased by a systematic approach that will ensure a safe and consistent migration. In this paper, we propose a refactoring and testing strategy that supports such an approach and consider issues of behavior conservation and (incremental) integration of the aspect-oriented solution with the original system. The strategy is applied to the JHotDraw open source project and illustrated on a group of selected concerns. Finally, we abstract from the case study and present a number of generic refactorings which contribute to an incremental aspect-oriented refactoring process and associate particular types of crosscutting concerns to the model and features of the employed aspect language. The contributions of this paper are both in the area of supporting migration towards aspect-oriented solutions and supporting the development of aspect languages that are better suited for such migrations.Comment: 25 page

A Boxology of Design Patterns for Hybrid Learning and Reasoning Systems

We propose a set of compositional design patterns to describe a large variety of systems that combine statistical techniques from machine learning with symbolic techniques from knowledge representation. As in other areas of computer science (knowledge engineering, software engineering, ontology engineering, process mining and others), such design patterns help to systematize the literature, clarify which combinations of techniques serve which purposes, and encourage re-use of software components. We have validated our set of compositional design patterns against a large body of recent literature.Comment: 12 pages,55 reference

V3CMM: a 3-view component meta-model for model-driven robotic software development

There are many voices in the robotics community demanding a qualitative improvement in the robotics software development process and tools, in order to increase product flexibility, adaptability, and overall quality, while reducing its cost and time-to-market. This article describes a first step towards a model-driven approach to robotics software development, based on the definition of highly reusable and platform-independent component-based design models. The proposed approach revolves around the V3CMM modeling language and the definition of different model transformations for deriving both special purpose models (e.g., models suited for analysis or simulation purposes) and lower-level design models, in which platform-specific and application-dependent details can be progressively included. The article describes the tool-chain implemented to support the different stages of the proposed MDE process, including (1) the definition of component-based architectural models, defined using the V3CMM platform-independent modeling language, (2) the automatic transformation of the V3CMM component-based models into equivalent object-oriented designs, described in terms of the UML standard, and (3) the transformation of the UML models into an the Ada 2005 object-oriented programming language. In order to show the feasibility and the benefits of the proposal, a simple (yet complete) case study regarding the design of a Cartesian robot is presented.This research has been funded by the Spanish CICYT Project EXPLORE (ref. TIN2009-08572), the Fundación Séneca Regional Project COMPAS-R (ref. 11994/PI/09), and the Spanish Research Network on Model-Driven Software Development (ref. TIN2008-00889-E)

Colored model based testing for software product lines (CMBT-SWPL)

Over the last decade, the software product line domain has emerged as one of the mostpromising software development paradigms. The main benefits of a software product lineapproach are improvements in productivity, time to market, product quality, and customersatisfaction.Therefore, one topic that needs greater emphasis is testing of software product lines toachieve the required software quality assurance. Our concern is how to test a softwareproduct line as early as possible in order to detect errors, because the cost of error detectedIn early phases is much less compared to the cost of errors when detected later.The method suggested in this thesis is a model-based, reuse-oriented test technique calledColored Model Based Testing for Software Product Lines (CMBT-SWPL). CMBT-SWPLis a requirements-based approach for efficiently generating tests for products in a soft-ware product line. This testing approach is used for validation and verification of productlines. It is a novel approach to test product lines using a Colored State Chart (CSC), whichconsiders variability early in the product line development process. More precisely, the vari-ability will be introduced in the main components of the CSC. Accordingly, the variabilityis preserved in test cases, as they are generated from colored test models automatically.During domain engineering, the CSC is derived from the feature model. By coloring theState Chart, the behavior of several product line variants can be modeled simultaneouslyin a single diagram and thus address product line variability early. The CSC representsthe test model, from which test cases using statistical testing are derived.During application engineering, these colored test models are customized for a specificapplication of the product line. At the end of this test process, the test cases are generatedagain using statistical testing, executed and the test results are ready for evaluation. Inxaddition, the CSC will be transformed to a Colored Petri Net (CPN) for verification andsimulation purposes.The main gains of applying the CMBT-SWPL method are early detection of defects inrequirements, such as ambiguities incompleteness and redundancy which is then reflectedin saving the test effort, time, development and maintenance costs

Early aspects: aspect-oriented requirements engineering and architecture design

This paper reports on the third Early Aspects: Aspect-Oriented Requirements Engineering and Architecture Design Workshop, which has been held in Lancaster, UK, on March 21, 2004. The workshop included a presentation session and working sessions in which the particular topics on early aspects were discussed. The primary goal of the workshop was to focus on challenges to defining methodical software development processes for aspects from early on in the software life cycle and explore the potential of proposed methods and techniques to scale up to industrial applications

A systematic aspect-oriented refactoring and testing strategy, and its application to JHotDraw.

Aspect oriented programming aims at achieving better modularization for a system's crosscutting concerns in order to improve its key quality attributes, such as evolvability and reusability. Consequently, the adoption of aspect-oriented techniques in existing (legacy) software systems is of interest to remediate software aging. The refactoring of existing systems to employ aspect-orientation will be considerably eased by a systematic approach that will ensure a safe and consistent migration. In this paper, we propose a refactoring and testing strategy that supports such an approach and consider issues of behavior conservation and (incremental) integration of the aspect-oriented solution with the original system. The strategy is applied to the JHotDraw open source project and illustrated on a group of selected concerns. Finally, we abstract from the case study and present a number of generic refactorings which contribute to an incremental aspect-oriented refactoring process and associate particular types of crosscutting concerns to the model and features of the employed aspect language. The contributions of this paper are both in the area of supporting migration towards aspect-oriented solutions and supporting the development of aspect languages that are better suited for such migration

Space life sciences strategic plan

Over the last three decades the Life Sciences Program has significantly contributed to NASA's manned and unmanned exploration of space, while acquiring new knowledge in the fields of space biology and medicine. The national and international events which have led to the development and revision of NASA strategy will significantly affect the future of life sciences programs both in scope and pace. This document serves as the basis for synthesizing the options to be pursued during the next decade, based on the decisions, evolution, and guiding principles of the National Space Policy. The strategies detailed in this document are fully supportive of the Life Sciences Advisory Subcommittee's 'A Rationale for the Life Sciences,' and the recent Aerospace Medicine Advisory Committee report entitled 'Strategic Considerations for Support of Humans in Space and Moon/Mars Exploration Missions.' Information contained within this document is intended for internal NASA planning and is subject to policy decisions and direction, and to budgets allocated to NASA's Life Sciences Program

Safety analysis of software product lines using state-based modeling and compositional model checking

Software product lines are widely used due to their advantageous reuse of shared features while still allowing optional and alternative features in the individual products. In high-integrity product lines such as pacemakers, flight control systems, and medical imaging systems, ensuring that common and variable safety requirements hold as each new product is built or existing products are evolved is key to the safe operations of those systems. However, this goal is currently hampered by the complexity of identifying the interactions among common and variable features that may undermine system safety. This is largely due to (1) the fact that the available safety analysis techniques lack sufficient support for analyzing the combined effects of different features, and (2) existing techniques for identifying feature interactions do not adequately accommodate the presence of common features and results in repeated checking across different products. The work described here addresses the first problem by systematically exploring the relationships between behavioral variations and potential hazardous states through scenario guided executions of the state model over the variations. It contributes to a solution to the second problem by generating formal obligations at the interfaces between features, so that sequentially composed features can be verified in a way that allows reuse for subsequent products. The main contributions of this work are an approach to perform safety analysis on the variations in a product line using state-based modeling, a tool-supported technique that guides and manages the generation of model-checkable properties from product-line requirements, and a formal framework for model checking product-line features that removes restrictions on how the features can be sequentially composed. The techniques and their implementations are demonstrated in the context of a medical-device product line

Challenging the Computational Metaphor: Implications for How We Think

This paper explores the role of the traditional computational metaphor in our thinking as computer scientists, its influence on epistemological styles, and its implications for our understanding of cognition. It proposes to replace the conventional metaphor--a sequence of steps--with the notion of a community of interacting entities, and examines the ramifications of such a shift on these various ways in which we think