Supporting the development of CAM/DAOP applications: an integrated development process

The increasing complexity of large‐scale distributed applications is driving the Software Engineering community to adopt new software technologies for the development of distributed systems. In this sense, the emergence of component‐based software engineering represents a significant advance towards assembling applications by plugging in pre‐fabricated components. Additionally, the principle of ‘advanced’ separation of concerns is nowadays widely applied to improve modularity, reusability and adaptability of software components. In this way, the aspect‐oriented software development paradigm separates into a new dimension, named aspect, those properties that crosscut the system ‘objects’ or ‘components’, reducing their dependencies. However, the development of software based on the composition of components and aspects is still in its early stages. Part of the reason for this is the lack of well‐defined development processes and tools that help software developers in the use of existing component and aspect‐based approaches. Therefore, the primary aim of this paper is to propose an integrated development process for deriving applications by the assembly of a set of prefabricated components and aspects. This process supports the development of Component‐Aspect Model/Dynamic Aspect‐Oriented Platform (CAM/DAOP) applications, where CAM/DAOP is a new model and platform based on components and aspects. Our intention is to show how, with the support of the integrated development process presented in this paper, it is possible to use CAM/DAOP as an alternative to current distributed platforms. Copyright © 2006 John Wiley & Sons, Ltd.     

Experiences with component‐oriented technologies in nuclear power plant simulators

This paper proposes the application of modern component‐oriented technologies to the development of nuclear power plant simulators. On the one hand, as a significant improvement on previous simulators, the new kernel is based on the Common Component Architecture (CCA). The use of such a high‐performance computing oriented component technology, together with a novel algorithm to automatically resolve simulation data dependencies, allows the efficient execution of both parallel and sequential simulation models. On the other hand, RT‐CORBA is employed in the development of the rest of the applications that comprise the simulator. This real‐time communication middleware not only makes the management of communications easier, but also provides the applications with real‐time capabilities. Software components used in these two ways, simulation models integrating the kernel and distributed applications from which the simulator is comprised, improve the evolution and maintenance of the entire system, as well as promoting code reusability in other projects. Copyright © 2006 John Wiley & Sons, Ltd.     

A Java framework for Web-based multimedia and collaborativeapplications

MultiTel is a compositional framework for developing collaborative multimedia applications, and also designates a Web-based distributed platform that supports intercomponent communication. This article shows how compositional and coordination paradigms can be successfully applied to design cooperative Java applications with multimedia data exchange. The focus is on multimedia and network architectures, which define generic and specific components coordinated by connectors for resolving the resource management needs of collaborative applications. The MultiTel platform composes application components dynamically, providing mechanisms for building services with plug-and-play transport and multimedia resources     

UM-RTCOM: An analyzable component model for real-time distributed systems

Component-based development is a key technology in the development of software for modern real-time systems. However, standard component models and tools are not suitable for this type of system, since they do not explicitly address real time, memory or cost constraints. This paper presents a new predictable component model for real-time systems (UM-RTCOM) together with a set of tools to support it. The environment allows new components to be developed which can then be assembled to build complete applications, including hardware interaction. The model includes support for real-time analysis at the component and application level. The analysis is achieved by combining component meta-information in the form of an abstract behaviour model and a method to measure worst-case execution times in the final platform. Additionally, we propose an implementation model based on RT-CORBA where the developer uses the UM-RTCOM components and a set of tools to map these elements to elements of the desired platform. In order to apply our proposals, we have used the model and tools in real applications specifically in the context of nuclear power plant simulators.     

Introduction to the theme section on Agile model-driven engineering

Software and Systems Modeling -     

A framework for secure execution of software

The protection of software applications is one of the most important problems to solve in information security because it has a crucial effect on other security issues. We can find in the literature many research initiatives that have tried to solve this problem, many of them based on the use of tamperproof hardware tokens. This type of solution depends on two basic premises: (i) increasing the physical security by using tamperproof devices and (ii) increasing the complexity of the analysis of the software. The first premise is reasonable. The second one is certainly related to the first one. In fact, its main goal is that the pirate user not be able to modify the software to bypass an operation that is crucial: checking the presence of the token. However, experience shows that the second premise is not realistic because analysis of the executable code is always possible. Moreover, the techniques used to obstruct the analysis process are not enough to discourage an attacker with average resources.In this paper, we review the most relevant works related to software protection, present a taxonomy of those works, and, most important, introduce a new and robust software protection scheme. This solution, called SmartProt, is based on the use of smart cards and cryptographic techniques, and its security relies only on the first of the premises given above; that is, SmartProt has been designed to avoid attacks based on code analysis and software modification. The entire system is described following a lifecycle approach, explaining in detail the card setup, production, authorization, and execution phases. We also present some interesting applications of SmartProt as well as the protocols developed to manage licences. Finally, we provide an analysis of its implementation details.     

Full contract verification for ATL using symbolic execution

The Atlas Transformation Language (ATL) is currently one of the most used model transformation languages and has become a de facto standard in model-driven engineering for implementing model transformations. At the same time, it is understood by the community that enhancing methods for exhaustively verifying such transformations allows for a more widespread adoption of model-driven engineering in industry. A variety of proposals for the verification of ATL transformations have arisen in the past few years. However, the majority of these techniques are either based on non-exhaustive testing or on proof methods that require human assistance and/or are not complete. In this paper, we describe our method for statically verifying the declarative subset of ATL model transformations. This verification is performed by translating the transformation (including features like filters, OCL expressions, and lazy rules) into our model transformation language DSLTrans. As we handle only the declarative portion of ATL, and DSLTrans is Turing-incomplete, this reduction in expressivity allows us to use a symbolic-execution approach to generate representations of all possible input models to the transformation. We then verify pre-/post-condition contracts on these representations, which in turn verifies the transformation itself. The technique we present in this paper is exhaustive for the subset of declarative ATL model transformations. This means that if the prover indicates a contract holds on a transformation, then the contract’s pre-/post-condition pair will be true for any input model for that transformation. We demonstrate and explore the applicability of our technique by studying several relatively large and complex ATL model transformations, including a model transformation developed in collaboration with our industrial partner. As well, we present our ‘slicing’ technique. This technique selects only those rules in the DSLTrans transformation needed for contract proof, thereby reducing proving time.     

Adaptive mesh refinement in stress-constrained topology optimization

We present a topology structural optimization framework with adaptive mesh refinement and stress-constraints. Finite element approximation and geometry representation benefit from such refinement by enabling more accurate stress field predictions and greater resolution of the optimal structural boundaries. We combine a volume fraction filter to impose a minimum design feature size, the RAMP penalization to generate “black-and-white designs” and a RAMP-like stress definition to resolve the “stress singularity problem.” Regions with stress concentrations dominate the optimized design. As such, rigorous simulations are required to accurately approximate the stress field. To achieve this goal, we invoke a threshold operation and mesh refinement during the optimization. We do so in an optimal fashion, by applying adaptive mesh refinement techniques that use error indicators to refine and coarsen the mesh as needed. In this way, we obtain more accurate simulations and greater resolution of the design domain. We present results in two dimensions to demonstrate the efficiency of our method.