Synthesizing interpreted domain-specific models to manage smart microgrids

The increase in prominence of model-driven software development (MDSD) has placed emphasis on the use of domain-specific modeling languages (DSMLs) during the development process. DSMLs allow for domain concepts to be conceptualized and represented at a high level of abstraction. Currently, most DSML models are converted into high-level languages (HLLs) through a series of model-to-model and/or model-to-text transformations before they are executed. An alternative approach for model execution is the interpretation of models directly without converting them into an HLL. These models are created using interpreted DSMLs (i-DSMLs) and realized using a semantic-rich execution engine or domain-specific virtual machine (DSVM).In this article we present an approach for model synthesis, the first stage of model interpretation, that separates the domain-specific knowledge (DSK) from the model of execution (MoE). Previous work on model synthesis tightly couples the DSK and MoE reducing the ability for implementations of the DSVM to be easily reused in other domains. To illustrate how our approach to model synthesis works for i-DSMLs, we have created MGridML, an i-DSML for energy management in smart microgrids, and an MGridVM prototype, the DSVM for MGridML. We evaluated our approach by performing experiments on the model synthesis aspect of MGridVM and comparing the results to a DSVM from the user-centric communication domain.     

KALA: Kernel aspect language for advanced transactions

Transaction management is a known crosscutting concern. Previous research has been conducted to express this concern as an aspect. However, such work has used general-purpose aspect languages which lack a formal foundation, and most importantly are unable to express advanced models of transaction management. In this paper, we propose a domain-specific aspect language for advanced transaction management, called KALA, that overcomes these limitations. First, KALA is based on a recognized formalism for the domain of advanced transaction management, called ACTA. Second, as a consequence of being based on the ACTA formalism, KALA covers a wide variety of models for transaction management. Finally, being a domain-specific aspect language, KALA allows programmers to express their needs at a higher level of abstraction than what is achieved with general-purpose aspect languages. This paper reports on the design of KALA and its implementation over Java, based on the Reflex AOP kernel for domain-specific aspect languages.     

Automating the construction of domain-specific modeling languages for object-oriented frameworks

The extension of frameworks with domain-specific modeling languages (DSML) has proved to be an effective way of improving the productivity in software product-line engineering. However, developing and evolving a DSML is typically a difficult and time-consuming task because it requires to develop and maintain a code generator, which transforms application models into framework-based code. In this paper, we propose a new approach for extending object-oriented frameworks that aims to alleviate this problem. The approach is based on developing an additional aspect-oriented layer that encodes a DSML for building framework-based applications, eliminating the need of implementing a code generator. We further show how a language workbench is capable of automating the construction of DSMLs using the proposed layer.     

Dependability in open proof software with hardware virtualization—The railway control systems perspective

Using the openETCS initiative as a starting point, we describe how open software can be applied in combination with platform-specific, potentially closed-source extensions, in the development, verification, validation and certification of safety-critical railway control systems. To achieve certification credit for safety-critical system developments, evidence about numerous development, verification and validation artifacts has to be provided. Our focus is therefore on open models, and a model-driven development approach ensures that a large portion of the artifacts is automatically generated from the model. This strategy is illustrated by means of the ETCS standard, as far as applicable to the ETCS on-board computer managing train control and train protection. We show that a domain-specific language is suitable to cover all modeling aspects for this computer, starting from the ETCS standard itself and ending at supplier-specific adaptations extending the re-usable core model in concrete developments. In order to re-use certification credits once achieved for the re-usable core model, we suggest virtualization of run-time environments, so that suppliers can embed re-usable core components as binary code into their ETCS target platforms. A detailed analysis is provided, indicating how future changes in the standard and project-specific adaptations, extensions and restrictions, can be accounted for in a new ETCS development, while minimizing the re-certification effort. It is shown for all phases of the development life cycle how the peer-reviewing capacity of the openETCS community may contribute to the correctness of the phases’ outputs, thereby increasing overall system dependability, with special emphasis on safety and security.     

A pure embedding of attribute grammars

Attribute grammars are a powerful specification paradigm for many language processing tasks, particularly semantic analysis of programming languages. Recent attribute grammar systems use dynamic scheduling algorithms to evaluate attributes on demand. In this paper, we show how to remove the need for a generator, by embedding a dynamic approach in a modern, object-oriented and functional programming language. The result is a small, lightweight attribute grammar library that is part of our larger Kiama language processing library. Kiama’s attribute grammar library supports a range of advanced features including cached, uncached, higher order, parameterised and circular attributes. Forwarding is available to modularise higher order attributes and decorators abstract away from the details of attribute value propagation. Kiama also implements new techniques for dynamic extension and variation of attribute equations. We use the Scala programming language because of its support for domain-specific notations and emphasis on scalability. Unlike generators with specialised notation, Kiama attribute grammars use standard Scala notations such as pattern-matching functions for equations, traits and mixins for composition and implicit parameters for forwarding. A benchmarking exercise shows that our approach is practical for realistic language processing.     

A DSL for modeling application-specific functionalities of business applications

Models have been widely used in the information system development process. Models are not just means for system analysis and documentation. They may be also transformed into system implementation, primarily program code. Generated program code of screen forms and transaction programs mainly implements generic functionalities that can be expressed by simple retrieval, insertion, update, or deletion operations over database records. Besides the program code of generic functionalities, each application usually includes program code for specific business logic that represents application-specific functionalities, which may include complex calculations, as well as a series of database operations. There is a lack of domain-specific and tool-supported techniques for specification of such application-specific functionalities at the level of platform-independent models (PIMs). In this paper, we propose an approach and a domain-specific language (DSL), named IIS^⁎CFuncLang, aimed at enabling a complete specification of application-specific functionalities at the PIM level. We have developed algorithms for transformation of IIS^⁎CFuncLang specifications into executable program code, such as PL/SQL program code. In order to support specification of application-specific functionalities using IIS^⁎CFuncLang, we have also developed appropriate tree-based and textual editors. The language, editors, and the transformations are embedded into a Model-Driven Software Development tool, named Integrated Information Systems CASE (IIS^⁎Case). IIS^⁎Case supports platform-independent design and automated prototyping of information systems, which allows us to verify and test our approach in practice.     

Implementing collaborative learning activities in the classroom supported by one-to-one mobile computing: A design-based process

Mobile devices such as PDAs, smartphones and tablet computers are becoming increasingly popular, setting out opportunities for new ways of communicating and collaborating. Research initiatives have ascertained the potential of mobile devices in education, and particularly, the benefits of incorporating them in the classroom for eliciting collaborative learning and active student participation. However, the development of technology-supported learning environments poses challenges to education researchers, practitioners, and software technologists in creating educational tools that respond to real needs of instructors and learners, meet clearly defined didactic purposes, and are practical for the intended audience. This article reports on a technology for facilitating the implementation of collaborative learning environments in the classroom supported by one-to-one mobile computing. The approach encompasses a framework supporting the design and implementation of the mobile software, and a design-based process that guides interdisciplinary efforts utilizing the framework, towards creating effective pedagogical models based on collaborative learning. The proposed design-based process allowed us to develop pedagogical models that respond to real needs of learners and instructors, where development is grounded on rigorous scientific research, allowing to reuse both knowledge and software, and showing an improvement of the mobile software built based on continuous experimentation and evaluation. A case study illustrating the application of the technology is presented and plans for future research are discussed.     

MDE for SoC design

We employ the principles of model-driven engineering to assist the design of system-on-chip (SoC) architectures. As a concrete example, we look at the MICAS architecture, for which we propose a graphical specification language, defined via metamodeling techniques, that models the architecture at different abstraction levels. Model transformations are defined to support the refinement of MICAS specification towards implementation. In addition, several libraries are put in place, to enable reuse and automation throughout the design process. Tool support for editing the specifications, enforcing their consistency, and for running the transformations is provided via the Coral modeling framework. The approach shows that model-driven engineering can be seen as an enabler in providing computer-aided software engineering (CASE) tool support and automation for the development of SoC architectures.     

A type-safe embedding of SQL into Java using the extensible compiler framework J%

J% is an extension of the Java programming language that efficiently supports the integration of domain-specific languages. In particular, J% allows the embedding of domain-specific language code into Java programs in a syntax-checked and type-safe manner. This paper presents J%׳s support for the sql language. J% checks the syntax and semantics of sql statements at compile-time. It supports query validation against a database schema or through execution to a live database server. The J% compiler generates code that uses standard jdbc api calls, enhancing runtime efficiency and security against sql injection attacks.     

Statically safe program generation with SafeGen

SafeGen is a meta-programming language for writing statically safe generators of Java programs. If a program generator written in SafeGen passes the checks of the SafeGen compiler, then the generator will only generate well-formed Java programs, for any generator input. In other words, statically checking the generator guarantees the correctness of any generated program, with respect to static checks commonly performed by a conventional compiler (including type safety, existence of a superclass, etc.). To achieve this guarantee, SafeGen supports only language primitives for reflection over an existing well-formed Java program, primitives for creating program fragments, and a restricted set of constructs for iteration, conditional actions, and name generation. SafeGen’s static checking algorithm is a combination of traditional type checking for Java, and a series of calls to a theorem prover to check the validity of first-order logical sentences, constructed to represent well-formedness properties of the generated program under all inputs. The approach has worked quite well in our tests, providing proofs for correct generators or pointing out interesting bugs.