DOI: 10.3897/jucs.110894

Authors: Razieh Dehghani, Raman Ramsin

Abstract: Organizational processes have been recognized as valuable knowledge assets. Situational Method Engineering (SME) processes are particularly valuable as they are used for engineering other processes: SME processes help construct bespoke Software Development Methodologies (SDMs) for specific software-engineering project situations. Every SDM has a Software Development Process (SDP) at its heart, which specifies the activities that should be performed throughout the project, the products that should be produced, and the people that should be involved. Existing SME methods suffer from certain weaknesses that are rooted in loss of knowledge within their processes; for instance, the method engineers' experience, which is a kind of tacit knowledge, is not properly captured and utilized in these processes. Managing SME process knowledge helps alleviate these weaknesses through reusing the software developers' experience and maintaining the method engineers' knowledge. We propose an evaluation framework that can be used for assessing an SME method's ability to manage process knowledge. We also provide a model that guides the improvement of existing SME methods in their support for Knowledge Management (KM), and also helps engineer new SME methods that provide adequate KM support. We have assessed the applicability of the proposed evaluation framework and improvement model by using them to enhance eight prominent SME methods, and also by applying them to four industrial case studies.

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DOI: 10.3897/jucs.91311

Authors: Geovana Ramos Sousa Silva, Genaína Nunes Rodrigues, Edna Dias Canedo

Abstract: Verification of chatbot conversational flows is paramount to capturing and understanding chatbot behavior and predicting problems that would cause the entire flow to be restructured from scratch. The literature on chatbot testing is scarce, and the few works that approach this subject do not focus on verifying the communication sequences in tandem with the functional requirements of the conversational flow itself. However, covering all possible conversational flows of context-oriented chatbots through testing is not feasible in practice given the many ramifications that should be covered by test cases. Alternatively, model checking provides a model-based verification in a mathematically precise and unambiguous manner. Moreover, it can anticipate design flaws early in the software design phase that could lead to incompleteness, ambiguities, and inconsistencies. We postulate that finding design flaws in chatbot conversational flows via model checking early in the design phase may overcome quite a few verification gaps that are not feasible via current testing techniques for context-oriented chatbot conversational flows. Therefore, in this work, we propose a modeling strategy to design and verify chatbot conversational flows via the Uppaal model checking tool. Our strategy is materialized in the form of templates and a mapping of chatbot elements into Uppaal elements. To evaluate this strategy, we invited a few chatbot developers with different levels of expertise. The feedback from the participants revealed that the strategy is a great ally in the phases of conversational prototyping and design, as well as helping to refine requirements and revealing branching logic that can be reused in the implementation phase.

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DOI: 10.3897/jucs.76030

Authors: María Castañeda, Mercedes G. Merayo, Juan Boubeta-Puig, Iván Calvo

Abstract: There exist areas, such as the disease prevention or inclement weather protocols, in which the analysis of the information based on strict protocols require a high level of rigor and security. In this situation, it would be desirable to apply formal methodologies that provide these features. In this scope, recently, it has been proposed a formalism, fuzzy automaton, that captures two relevant aspects for fuzzy information analysis: imprecision and uncertainty. However, the models should be designed by domain experts, who have the required knowledge for the design of the processes, but do not have the necessary technical knowledge. To address this limitation, this paper proposes MODELFY, a novel model-driven solution for designing a decision-making process based on fuzzy automata that allows users to abstract from technical complexities. With this goal in mind, we have developed a framework for fuzzy automaton model design based on a Domain- Specific Modeling Language (DSML) and a graphical editor. To improve the interoperability and functionality of this framework, it also includes a model-to-text transformation that translates the models designed by using the graphical editor into a format that can be used by a tool for data anal- ysis. The practical value of this proposal is also evaluated through a non-trivial medical protocol for detecting potential heart problems. The results confirm that MODELFY is useful for defining such a protocol in a user-friendly and rigorous manner, bringing fuzzy automata closer to domain experts.

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DOI: 10.3897/jucs.71833

Authors: Damjan Ekert, Jürgen Dobaj, Alen Salamun

Abstract: The new generations of cars have a number of ECUs (Electronic Control Units) which are connected to a central gateway and need to pass cybersecurity integration tests to fulfil the homologation requirements of cars. Cars usually have a gateway server (few have additional domain servers) with Linux and a large number of ECUs which are real time control of actuators (ESP, EPS, ABS, etc. – usually they are multicore embedded controllers) connected by a real time automotive specific bus (CAN-FD) to the domain controller or gateway server. The norms (SAE J3061, ISO 21434) require cybersecurity related verification and validation. Fir the verification car manufacturers use a network test suite which runs > 2000 test cases and which have to be passed for homologation. These norms have impact on the way how car communication infrastructure is tested, and which cybersecurity attack patterns are checked before a road release of an ECU/car.This paper describes typical verification and validation approaches in modern vehicles and how such test cases are derived and developed.

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DOI: 10.3897/jucs.72367

Authors: Jürgen Dobaj, Damjan Ekert, Jakub Stolfa, Svatopluk Stolfa, Georg Macher, Richard Messnarz

Abstract: Cybersecurity has become a crucial challenge in the automotive sector. At the current stage, the framework described by the ISO/SAE 21434 is insufficient to derive concrete methods for the design of secure automotive networked embedded systems on the supplier level. This article describes a case study with actionable steps for designing secure systems and systematically eliciting traceable cybersecurity requirements to address this gap. The case study is aligned with the ISO/SAE 21434 standard and can provide the basis for integrating cybersecurity engineering into company-specific processes and practice specifications.

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DOI: 10.3897/jucs.72072

Authors: Richard Messnarz, Ricardo Colomo-Palacios, Georg Macher, Andreas Riel, Miklos Biro

Abstract: This is a special issue in cooperation with EuroSPI (www.eurospi.net). EuroSPI represents a large international network of renowned experts and annual European conference series running successfully since its foundation in 1994. From 2013 onwards, an international functional safety and from 2016 onwards a functional safety and cybersecurity workshop has been established, to which leading European and Asian industry and research have been actively contributing to.High-quality, original papers about best practices for implementing functional safety and cybersecurity in automotive, IT, and connected services have been selected for this special issue. They provide insights into the current state of the art implementations in automotive safety and cybersecurity, IT security, and safety in future highly autonomous self-learning vehicles.

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DOI: 10.3897/jucs.70369

Authors: Xabier Larrucea, Micha Moffie, Dan Mor

Abstract: Since the emergence of GDPR, several industries and sectors are setting informatics solutions for fulfilling these rules. The Health sector is considered a critical sector within the Industry 4.0 because it manages sensitive data, and National Health Services are responsible for managing patients’ data. European NHS are converging to a connected system allowing the exchange of sensitive information cross different countries. This paper defines and implements a set of tools for extending the reference architectural model industry 4.0 for the healthcare sector, which are used for enhancing GDPR compliance. These tools are dealing with data sensitivity and data hiding tools A case study illustrates the use of these tools and how they are integrated with the reference architectural model.

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DOI: 10.3897/jucs.2020.067

Authors: Ana Allian, Edson OliveiraJr, Rafael Capilla, Elisa Nakagawa

Abstract: For nearly 30 years, industry and researchers have proposed many software variability tools to cope with the complexity of modeling variability in software development, followed by a number of publications on variability techniques built upon theoretical foundations. After more than 25 years of the practice of software variability, there are not many studies investigating the impact of software variability tools in the industry and the perception of practitioners. For this reason, we investigate in this research work how existing software variability tools fulfill the needs of companies demanding this kind of tool support. We conducted a survey with practitioners from companies in eight different countries in order to analyze the missing capabilities of software variability management tools and we compared the results of the survey with the scientifoc literature through a systematic mapping study (SMS) to analyze if the proposed solutions cover the needs required by practitioners. Our major findings indicate that many tools lack important qualities such as interoperability, collaborative work, code generation, scalability, impact analysis, and test; while the results from the SMS showed these such capabilities are, to some extent, found in some of the existing tools.

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DOI: 10.3897/jucs.2020.064

Authors: Emilio Rodríguez-Priego, Francisco García-Izquierdo, Ángel Rubio

Abstract: Although modeling is used to address complex problems, it is difficult to study modeling itself with an easy to understand model. Many authors have proposed such a model of modeling, but a consensus on the meaning of the basic modeling concepts has yet to materialize. We claim that any proposal regarding the fundamentals of modeling should address several objectives, such as to focus on the concept of model and define what it is, how a model is created and how it relates to the entities it models or to explain the relationship between model and other basic concepts such as metamodel or (modeling-)language. In this paper, we present some of the most important elements of our proposal, named Scientific Method approach to Modeling (SMM). Our proposal uses the Scientific Method as a metaphor to explain the mechanisms of modeling, since it provides well-known mechanisms constantly utilized when developing or understanding models: validation, analysis, synthesis and analogy. Inspired by these mechanisms, our proposal addresses the notion of model by including several constructors that allow us to explain better several complex modeling mechanisms extensively discussed in the literature, such as the metamodel notion.

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DOI: 10.3897/jucs.2020.060

Authors: Tony Clark, Jens Gulden

Abstract: Model Driven Software Engineering aims to provide a quality assured process for designing and generating software. Modelling frameworks that offer technologies for domain specific language and associated tool construction are called language workbenches. Since modelling is itself a domain, there are benefits to applying a workbenchbased approach to the construction of modelling languages and tools. Such a framework is a meta-modelling tool and those that can generate themselves are reflective metatools. This article reviews the current state of the art for modelling tools and proposes a set of reflective meta-modelling tool requirements. The XTools framework has been designed as a reflective meta-tool and is used as a benchmark.

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DOI: 10.3897/jucs.2020.020

Authors: Jeppe Rasmussen, Lars Hvam, Katrin Kristjansdottir, Niels Mortensen

Abstract: Product configuration systems (PCSs) are increasingly being used in various industries to manage product knowledge and create the required specifications of customized products. Companies applying PCS face significant challenges in modelling, structuring and documenting the systems. Some of the main challenges related to PCSs are formalising product knowledge conceptually and structuring the product features. The modelling techniques predominantly used to visualise and structure PCSs are the Unified Modelling Language (UML) notations, Generic Bill of Materials (GBOM) and Product Variant Master (PVM), associated with class collaboration cards (CRC-cards). These methods are used to both analyse and model the products and create a basis for implementation to a PCS by using an object-oriented approach. However, the modelling techniques do not consider that most commercial PCSs are not fully object-oriented, but rather, they are expert systems with an inference engine and a knowledge base; therefore, the constructed product models require modifications before implementation in the configuration software. The consequences are that what is supposedly a feasible structure of the product model is not always appropriate for the implementation in standard PCS software. To address this challenge, this paper investigates the best practice in modelling and implementation techniques for PCSs in standard software and alternative structuring methods used in object-oriented software design. The paper proposes a method for a modular design of a PCS in not fully object-oriented standard PCS software using design patterns. The proposed method was tested in a case company that suffered from a poorly structured product model in a not fully object-oriented PCS. The results show that its maintainability can be improved by using design patterns in combination with an agile documentation approach.

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DOI: 10.3217/jucs-024-11-1627

Authors: Laura Po, Davide Malvezzi

Abstract: The Linked Open Data (LOD) Cloud has more than tripled its sources in just six years (from 295 sources in 2011 to 1163 datasets in 2017). The actual Web of Data contains more then 150 Billions of triples. We are assisting at a staggering growth in the production and consumption of LOD and the generation of increasingly large datasets. In this scenario, providing researchers, domain experts, but also businessmen and citizens with visual representations and intuitive interactions can significantly aid the exploration and understanding of the domains and knowledge represented by Linked Data. Various tools and web applications have been developed to enable the navigation, and browsing of the Web of Data. However, these tools lack in producing high level representations for large datasets, and in supporting users in the exploration and querying of these big sources. Following this trend, we devised a new method and a tool called H-BOLD (High level visualizations on Big Open Linked Data). H-BOLD enables the exploratory search and multilevel analysis of Linked Open Data. It offers different levels of abstraction on Big Linked Data. Through the user interaction and the dynamic adaptation of the graph representing the dataset, it will be possible to perform an effective exploration of the dataset, starting from a set of few classes and adding new ones. Performance and portability of H-BOLD have been evaluated on the SPARQL endpoint listed on SPARQL ENDPOINT STATUS. The effectiveness of H-BOLD as a visualization tool is described through a user study.

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DOI: 10.3217/jucs-024-02-0149

Authors: Roberto Munoz, Rodolfo Villarroel, Thiago Barcelos, Alexandra Souza, Erick Merino, Rodolfo Guiñez, Leandro Silva

Abstract: Learning Analytics is the intelligent use of data generated from students with the objective of understanding and improving the teaching and learning process. Currently, there is a lack of tools to measure the development of complex skills in real classroom environments that are flexible enough to add and process data from different sensors and oriented towards a massive public. Based on this finding, we developed a free software system that permits to capture and to visualize a set of 10 body postures using the Microsoft Kinect sensor, along with the ability to track custom body postures and data from other sensors. The developed tool was validated by means of precision and usability tests. Furthermore, with the goal of demonstrating the potential of incorporating this type of software into the classroom, the software was used as a tool to give feedback to the teacher and to the students at the moment of giving and evaluating oral presentations. Also, a clustering analysis of data gathered from 45 student presentations indicate that presentations on similar topics with also similar complexity levels can be successfully discriminated.

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DOI: 10.3217/jucs-023-12-1147

Authors: Edgar Marçal, Rossana Maria de Castro Andrade, Windson Viana

Abstract: While field trips promote the scientific spirit of students by increasing their ability of observation and discovery in various areas of knowledge, the introduction of ubiquitous technologies, such as sensors and actuators, during the field trips, improves students' motivation and learning. However, the development of systems for this purpose implies to deal with the seamless treatment of the devices heterogeneity, absence of fixed communication infrastructure, dynamics of the computational elements of the environment, and support for user mobility. This paper presents then the development and evaluation of a system, called Ubiquitous Field Classes Inventor (UFC-Inventor), which aims to promote the use of mobile and ubiquitous technologies in field trips. The UFC-Inventor evaluation is performed in two stages: first, with five teachers of natural sciences; and later, during a field trip with seventeen students. Two of the teachers were from higher education (Geology and Animal Science) and three of them from high school (two in Geography and one in Biology). The seventeen students who participated in the case study were undergraduate students in the third year of their Geology course. The results suggest a good acceptance of UFC-Inventor and indicate that its execution occurred correctly.

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DOI: 10.3217/jucs-023-08-0769

Authors: Arthur Pinto, Ricardo Terra, Eduardo Guerra

Abstract: As software evolves, developers usually introduce deviations from the planned architecture, due to unawareness, conflicting requirements, technical difficulties, deadlines, etc. This occurs in systems with an explicit division of responsibility between groups of classes, such as modules and layers. Although there are architectural conformance tools to identify architectural violations, these tools are underused and detected violations are rarely corrected. To address these shortcomings, this article introduces an architectural conformance process into continuous integration. Thus, the conformance process is triggered by every code integration and, when no violations are detected, the code is integrated into the repository. The implemented tool, called ArchCI, supports the proposed solution using DCL (Dependency Constraint Language) as underlying conformance technique and Jenkins as the Continuous Integration server. We also evaluated the applicability of our proposed solution in a real-world Java project where we incrementally introduced 44 constraints through six releases. As the result, our process was able to detect 42 violations, which have always been fixed before the ensuing release.

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DOI: 10.3217/jucs-021-13-1746

Authors: Nadia Bouassida, Salma Jamoussi, Ahmed Msaed, Hanêne Ben-Abdallah

Abstract: Any inexperienced designer may not take advantage of design patterns due to their high level of abstraction, on the one hand, and their overwhelming number, on the other hand. In this paper, we propose a new approach that first retrieves and recommends a design pattern that is adequate to a designer's modeling context, it then helps them in its instantiation. Our approach learns past pattern reuse cases and it interacts with the designer through a questionnaire to ensure that the retrieved pattern corresponds to their needs and intentions. It uses the text mining technique Principal Component Analysis on past experiences of design pattern reuses; the choice of this technique was based on an experimental evaluation we conducted to determine the most adequate text representation and mining technique for our problem. In a final assistance step, after retrieving the most appropriate design pattern, our approach transforms the design situation at hand into the pattern constituting the solution.

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DOI: 10.3217/jucs-020-08-1089

Authors: Dionysios Efstathiou, Peter Mcburney, Steffen Zschaler, Johann Bourcier

Abstract: Infrastructure-less Mobile Ad hoc NETworks (MANETs) and ServiceOriented Architecture (SOA) enable the development of pervasive applications. Based on SOA, we can abstract devices' resources as software services which can be combined into value-added composite services providing complex functionalities while exhibiting specified QoS properties. Configuring compositions with optimal QoS is challenging due to dynamic network topologies and availability of resources. Existing approaches seek to optimise the selection of which services to participate in a centralised orchestration without considering the overhead for estimating their combined QoS. QoS metrics can be used as fitness functions to guide the search for optimal compositions. When composing services offered by diverse devices, there is no trivial relationship between the composition's QoS and its component services. Measuring the fitness values of a candidate composition could be done either by monitoring its actual invocation or simulating it. However, both approaches are too expensive to be used within an optimisation process. In this paper, we propose a surrogate-based multi-objective optimisation approach for exploring trade-off compositions. The evaluation results show that by replacing the expensive fitness functions with lightweight surrogate models, we can vastly accelerate the optimisation algorithm while producing trade-off solutions of high quality.

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DOI: 10.3217/jucs-020-07-0944

Authors: Chiraz Hog, Raoudha Djemaa, Ikram Amous

Abstract: Web services are rapidly gaining acceptance as a fundamental technology in the web fields. They are becoming the cutting edge of communication between the different applications all over the web. Because of today's wide diversity of devices together with the variety of the user's preferences, context-aware web services are becoming a fundamental challenge that must be targeted. This issue is a part of the Human Computer Interaction (HCI) discipline and it aims at adapting the web service behavior according to the user's context such as his specific work environment, language, type of Internet connection, devices and preferences. Many solutions have been proposed in this area. Nevertheless, the adaptation was carried out only at the runtime and it partially covered the user's general context. In this paper, we introduce a new context-aware approach that provides adaptive web services. Our approach allows to express requirements by taking into account potential user's profile in addition to the functional one. While the latter ensures the description of the web service-functionalities, adaptation expresses the ability of a service to be self-adapted to runtime context changes. Our approach deals with adaptation from the very beginning of the modeling step of a web service. Furthermore, it upgrades description and publication usual methods in order to support profile specification.

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DOI: 10.3217/jucs-020-05-0720

Authors: Rafael De Mello, Eldanae Teixeira, Marcelo Schots, Cláudia Maria Lima Werner, Guilherme Travassos

Abstract: Software Product Line Engineering (SPL) should ensure the correctness, completeness and consistenc y of its artefacts and related domain to prevent the propagation of defects in derived products. Software inspection techniques are effective in detecting defects in software artefacts and avoiding their propagation throughout the software development process. However, the results of a quasi-systematic review of the technical literature reported in this paper pointed to a lack of such techniques to support the inspection of SPL artefacts, including techniques to support the inspection of feature models (FMs) that are largely used in domain modelling. Therefore, a checklist-based inspection technique (FMCheck) has been developed to support the detection of defects on FMs. FMCheck is configurable and can be applied to the original feature model notation (the F ODA approach) and its extensions, including the Odyssey-FEX notation. The inspection technique was empirically evaluated, having indicated its feasibility and effectiveness. It is possible to see that inspectors applying FMCheck to inspect F-s can be more effective than those applying ad-hoc techniques, regarding four distinct domains.

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DOI: 10.3217/jucs-020-05-0640

Authors: Mauricio Alférez, Roberto Lopez-Herrejón, Ana Moreira, Vasco Amaral, Alexander Egyed

Abstract: Software Product Line Engineering (SPLE) is a successful paradigm to produce a family of products for a specific domain. A challenge in SPLE is to check that different models used in early SPL specification do not contain inconsistent information that may be propagated and generate inconsistent products that do not conform to its requirements. This challenge is difficult to address due to the high number of possible combinations of product features and model fragments specifying those features. Variability Consistency Checking (VCC) offers automatic means to address that challenge. VCC relates information inferred from the relationships between features and from base models related to those features. Validating if all the products in an SPL satisfy user-defined consistency constraints is based on searching for a satisfying assignment of each formula generated by VCC. We validated VCC and its supporting tool on two case studies from different application domains, the results were encouraging as we did not observed significant performance penalties.

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DOI: 10.3217/jucs-020-04-0534

Authors: Patricia Matsumoto, Eduardo Guerra

Abstract: An Adaptive Object Model (AOM) is a common architectural style for systems in which classes, attributes, relationships and behaviors of applications are represented as metadata consumed at runtime. This allows them to be very flexible and changeable at runtime, enabling their modification by end users without source code modification. Nevertheless, this flexibility comes with a cost of a greater complexity when developing the system, and therefore one usually uses a bottom-up approach, adding flexibility only when it is needed. As a consequence, many AOM components are tied to the specific domain of a single application and this fact makes it difficult to develop and use generic and reusable AOM frameworks that properly handle specific requirements of the AOM architecture. This work presents an architectural model that aims to adapt domain-specific AOM core structures to a common core structure by identifying AOM roles played by each element through custom metadata configuration. By doing this, this model allows the integration of domain-specific AOM applications and AOM frameworks, making it feasible to develop reusable components for the AOM architecture. This model is evaluated by creating an AOM framework and a case study based on it, in which is performed a modularity and a performance analysis.

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DOI: 10.3217/jucs-020-03-0329

Authors: Jakub Malý, Martin Nečaský

Abstract: Complex applications can benefit greatly from using conceptual models and Model Driven Architecture during development, deployment and runtime. XML applications are not different. In this paper, we examine the possibility of using Object Constraint Language (OCL) for expressing constraints over a conceptual model for XML data. We go through the different classes of OCL expression and show how each class can be translated into XPath constructs. Subsequently we show how the constraints can be checked using Schematron. We introduce a function library OclX, which provides constructs necessary to translate those OCL constructs that have no counterpart in XPath. With our tool, it is possible to check validity of OCL constraints in XML data.

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DOI: 10.3217/jucs-020-03-0277

Authors: Jakub Klímek, Soběslav Benda, Martin Nečaský

Abstract: Today, XML (eXtensible Markup Language) is a standard for exchange inside and among IT infrastructures. For the exchange to work an XML format must be negotiated between the communicating parties. The format is often expressed as an XML schema. In our previous work, we introduced a conceptual model for XML, which utilizes modeling, evolution and maintenance of a set of XML schemas and allows schema designers to export modeled formats into grammar-based XML schema languages like DTD and XML Schema. However, there is another type of XML schema languages called rule-based languages with Schematron as their main representative. In our preceding conference paper [Benda et al.(2013)] we briefly introduced the process of translation from our conceptual model to Schematron. Expressing XML schemas in Schematron has advantages over grammar-based languages and in this paper, we describe the previously introduced translation in more detail with focus on structural constraints and how they are represented in Schematron. Also, we discuss the possibilities and limitations of translation from our grammar-based conceptual model to the rule-based Schematron.

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DOI: 10.3217/jucs-019-12-1703

Authors: Habib Fardoun, Abdulfattah Mashat, Sebastián López

Abstract: In a world where the most used sentences is: "I haven't got the time..." Information Technologies (IT) plays an important role in supporting our daily work, including in everyday educational settings. Such technologies can aid a complete educational system to function successfully so to help the whole school educational life. For this to prove, we present the "Coaching for Teacher" system, a personal technological conversational coach; it aims to provide solutions to overcome difficulties that teachers face during their teaching and learning process. In real time, a teacher can appeal and seek advice rapidly by comfortably talking to an agent. In this paper, we present the steps we followed to design and develop this agent-based application, and a case study conducted in an educational centre for proof that the concept works in an authentic educational environment.

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DOI: 10.3217/jucs-019-10-1433

Authors: Jennifer Pérez, Isidro Ramos, Jose Carsí, Cristóbal Costa-Soria

Abstract: The Model-Driven Development (MDD) paradigm has become widely spread in the last few years due to being based on models instead of source code, and using automatic generation techniques to obtain the final software product. Until now, the most mature methodologies that have been proposed to develop software following MDD are mainly based on functional requirements by following the Object-Oriented Paradigm. Therefore, mature MDD methodologies are required for supporting the code generation from models that specify non-functional requirements. The Aspect-Oriented Software Development (AOSD) approach was created to provide explicit mechanisms for developing non-functional requirements through reusable elements called aspects. Aspect-Oriented Software Architectures (AOSA) emerged to deal with the design of both, functional requirements and non-functional requirements, which opened an important challenge in the software engineering field: the definition of a methodology for supporting the development of AOSAs following the MDD paradigm. This new methodology should allow the code generation from models which specify functional and non-functional requirements. This paper presents a mature approach, called PRISMA, which deals with this challenge. Therefore, this contribution takes a step forward in the area presenting in detail the PRISMA MDD process, which has been applied to generate the code of several real applications of the tele-operated robotics domain. PRISMA MDD approach provides complete support for the development of technology-independent AOSAs, which can be compiled from high-level, aspect-oriented architectural models into different technology platforms and languages following an MDD process. This contribution illustrates how to apply the PRISMA MDD approach through the modelling framework that has been developed to support it, and a case study of a tele-operated robot that has been completely developed using this approach. Finally, the results obtained from the application of PRISMA MDD process to develop applications of the tele-operation domain are analyzed in terms of code generation.

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DOI: 10.3217/jucs-019-07-0950

Authors: Habib Fardoun, Bassam Zafar, Abdulrahman Altalhi, Antonio Paules

Abstract: The design of an educational system involves a good understanding of the whole school environment in order to find the correct approach to develop a comprehensive educational system that will meet real educational needs in their operation. This article describes a design model for an educational system based on the teaching methods applied in the Spanish classrooms, which takes into account new advances in technology, while preserving the current teaching methods in the classroom to ensure a quality teaching and learning process. This development has been achieved by combining technological components such as Cloud Computing, Web Services and Distributed User Interfaces. The proposed system is based on a systematic approach where different phases are implemented, containing workflows and stages.

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DOI: 10.3217/jucs-019-07-0873

Authors: Diogo Azevedo, Benjamim Fonseca, Hugo Paredes, Stephan Lukosch, Jordan Janeiro, Robert Briggs

Abstract: The need for computer-supported collaboration has grown over the last years and made collaboration an important factor within organizations. This trend has resulted in the development of a variety of tools and technologies to support the various forms of collaboration. Many collaborative processes, e.g. strategy building, scenario analysis, root cause analysis and requirements engineering, require various collaboration support tools. Data flow, fishbone and brainstorming diagrams, play an important role within these synchronous collaborative applications to create, evaluate, elaborate, discuss, and revise graphical models. Currently, the necessary tools are not integrated and flexible enough to support such processes. In this paper, a synchronous collaborative brainstorming diagram editor integrated in a flexible group support system is described. This approach goes beyond the current state of the art as it can be seamlessly integrated with other collaboration support tools such as text-based brainstorming or voting. The usability of the taken approach is evaluated within a case study on collaborative learning.

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DOI: 10.3217/jucs-019-01-0110

Authors: Matias Urbieta, Gustavo Rossi, Silvia Gordillo, Armanda Rodrigues, Joao Araujo, Ana Moreira

Abstract: The growing availability of on-line geographical information, since the advent of open map servers in the 2000s, originated a new generation of Web applications, those which combine "conventional" Web functionality with typical features of traditional Geographic Application System (GIS). The rapid growth in number and complexity of Web applications with geo-referenced data together with the need to support fast requirements change, demands for increased modularity. The volatility of some of these changing requirements, both in the scope of their geographic nature or in the period of time in which they are valid, stresses the importance of the applications" modularity. A solution is to take into consideration the crosscutting nature of these requirements and decouple their realization from "conventional" requirements in separate software modules. This paper proposes an end-to-end Aspect-Oriented approach to deal with spatial requirements from the early stages of applications development throughout to implementation. A significant contribution of this approach is the characterization of the most common spatial requirements in Web-GIS applications. The result is the improvement of

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DOI: 10.3217/jucs-018-20-2920

Authors: Anton Uzunov, Eduardo Fernandez, Katrina Falkner

Abstract: Rapid technological advances in recent years have precipitated a general shift towards software distribution as a central computing paradigm. This has been accompanied by a corresponding increase in the dangers of security breaches, often causing security attributes to become an inhibiting factor for use and adoption. Despite the acknowledged importance of security, especially in the context of open and collaborative environments, there is a growing gap in the survey literature relating to systematic approaches (methodologies) for engineering secure distributed systems. In this paper, we attempt to fill the aforementioned gap by surveying and critically analyzing the state-of-the-art in security methodologies based on some form of abstract modeling (i.e. model-based methodologies) for, or applicable to, distributed systems. Our detailed reviews can be seen as a step towards increasing awareness and appreciation of a range of methodologies, allowing researchers and industry stakeholders to gain a comprehensive view of the field and make informed decisions. Following the comprehensive survey we propose a number of criteria reflecting the characteristics security methodologies should possess to be adopted in real-life industry scenarios, and evaluate each methodology accordingly. Our results highlight a number of areas for improvement, help to qualify adoption risks, and indicate future research directions.

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DOI: 10.3217/jucs-018-19-2731

Authors: Deepti Mishra, Alok Mishra

Abstract: Globally distributed software development is an established trend towards delivering high-quality software to global users at lower costs. The main expected benefits from distributed software development are improvements in development time efficiency, being close to the customers and having flexible access to greater and less costly resources. Organizations require to use their existing resources as effectively as possible, and also need to employ resources on a global scale from different sites within the organization and from partner organization throughout the world. However, distributed software development particularly face communication and coordination problems due to spatial, temporal and cultural separation between team members. Ensuring quality issues in such projects is a significant issue. This paper presents global software inspection process in the distributed software development environment towards quality assurance and management.

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DOI: 10.3217/jucs-018-19-2602

Authors: José Hernández, Aurora Vizcaíno, Ismael Caballero, Gabriela Aranda

Abstract: The Distributed Software Development involves various challenges, many of which are related to the lack of trust experienced by team members since they often do not know each other personally. Other problems which are already considered to be classic are related to communication, coordination and collaboration. Bearing in mind that providing information about co-workers may increase both the team spirit and the team members' confidence in each other, we have carried out surveys to discover what information might be useful in attaining this objective, and to reduce those problems related to the three 'c's. The results of the questionnaires have been analyzed from different points of view, first by differentiating the respondents' roles and then by analyzing their specific use in communication, coordination and control activities. The results of this analysis have allowed us to obtain the requirements needed to design a tool with which to support global software development. The implementation of this tool is also described in this paper.

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DOI: 10.3217/jucs-018-17-2474

Authors: Valeria De Castro, Juan Vara, Esperanza Marcos

Abstract: During the last years, Web Information Systems have evolved from simple information sources to systems offering services to end-users. The development of this kind of systems presents different challenges, such as the alignment between business services and their implementation, and the way business processes are placed in the system. To address this type of challenges this paper presents a methodological and technical proposal for Service-Oriented development of Web Information Systems. It follows a model-driven approach, defining a set of models at different levels of abstraction and the model transformations needed to connect them. Besides, the development of a conference management system is used as case study to illustrate the proposal.

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DOI: 10.3217/jucs-018-17-2383

Authors: Jorge Roa, Pablo Villarreal, Omar Chiotti

Abstract: The representation of process and service choreographies has been recognized as an important requirement in service-oriented methodologies. The guarantee of alignment between process and service choreographies and the verification of the behavior of choreographies represent an important improvement for such methodologies, since they enable the automatic generation of choreography service specifications from well-defined choreography process models. To deal with these issues, we propose a transformation pattern that guarantees behavior alignment between process and service choreographies, and a verification method for the control flow of choreographies, which can be applied to any choreography language. These approaches make use of the Global Interaction Nets (GI-Nets) language to formalize the behavior of process and service choreographies. This formal representation can then be used to conclude on the behavioral aspects of choreographies. In addition, we present a tool for the modeling, automatic generation and verification of GI-Nets, and apply the proposed approaches to the UP-ColBPIP and WS-CDL choreography languages.

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DOI: 10.3217/jucs-018-17-2364

Authors: Juan Vara, Vasilios Andrikopoulos, Michael Papazoglou, Esperanza Marcos

Abstract: In the field of Service-Oriented Architecture (SOA) evolution is a key issue given the non-trivial nature of updating widely distributed and heterogeneous systems. With this in mind, in this work we used some of the technologies developed in the context of the Eclipse Modeling Framework (EMF) to provide a proof of concept of the possible synergy between Model-Driven Engineering (MDE) and Service Orientation. In particular, we present a DSL toolkit for modeling the structural part of Abstract Service Descriptions (ASDs) and the reasoning mechanism that assesses whether two versions of a service are compatible with respect to its consumers.

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DOI: 10.3217/jucs-018-12-1679

Authors: Reijo Savola, Christian Frühwirth, Ari Pietikäinen

Abstract: The need for effective and efficient information security solutions is steadily increasing in the software industry. Software and system developers require practical and systematic approaches to obtain sufficient and credible evidence of the security level in the system under development in order to guide their efforts and ensure the efficient use of resources. We present experiences of developing and using hierarchical security metrics and measurements in an industrial pilot study at Ericsson Finland. The pilot focused on risk-driven security design and implementation in the context of an Agile software development process. The pilot target was a well-established telecommunications product of Ericsson and a core component in modern mobile networks. The results of the study demonstrate the practical potential of risk-driven security metrics, particularly in offering some early visibility of security effectiveness and efficiency. Hierarchical metrics models enable the linking of security objectives with detailed measurements. Security metrics visualization was found to play a crucial role in increasing the manageability of metrics. We also found that the practical means of managing larger collections of metrics and measurements are more essential than individual security metrics. A major challenge in the use of risk-driven security metrics is the lack of evidence for security effectiveness evidence in the early phases of product development and Risk Analysis, when the needs for it are at their greatest.

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DOI: 10.3217/jucs-018-12-1608

Authors: Haralambos Mouratidis, Christos Kalloniatis, Shareeful Islam, Marc-Philippe Huget, Stefanos Gritzalis

Abstract: The increasing dependency on information systems to process and manage sensitive information requires the usage of development methods that support the development of secure and private information systems. The literature provides examples of methods that focus on security and privacy individually but fail to provide evidence of information systems development methods that consider security and privacy in a unified framework. Security and privacy are very much related, in particular certain security properties and mechanisms support the achievement of privacy goals. Without a development framework to support developers to explicitly model that relationship, conflicts and vulnerabilities can be introduced to a system design that might endanger its security. In this paper, we present our work in developing a framework that supports the unified analysis of privacy and security. In particular, we present a meta-model that combines concepts from security and privacy requirements methods, such as security and privacy goals, properties, constraints, and actor and process patterns within a social context. A real case study is employed to demonstrate the applicability of our work.

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DOI: 10.3217/jucs-018-11-1483

Authors: Marc Forment, María Casany, Enric Mayol, Jordi Piguillem, Nikolas Galanis, Francisco García-Peñalvo, Miguel Conde

Abstract: Google Docs is a well-known suite of online collaborative tools for document processing, spreadsheets, online presentations, drawing and even forms. The last versions of the major open source LMS Moodle, offers weak integrations with Google Docs treating it as a content repository. But these integrations are neglecting the collaborative qualities of the Google Docs suite and its potential as a learning activity within the LMS course. This paper presents an integration proposal that using the IMS Basic Learning Tools Interoperability (IMS BLTI) standard turns Google Docs into an engine that powers collaborative learning activities within the LMS Moodle.

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DOI: 10.3217/jucs-018-06-0816

Authors: Raimundas Matulevičius, Haralambos Mouratidis, Nicolas Mayer, Eric Dubois, Patrick Heymans

Abstract: The need to consider security from the early stages of the development process of information systems has been argued by academics and industrialists alike, and security risk management has been recognised as one of the most prominent techniques for eliciting security requirements. However, although existing security modelling languages provide some means to model security aspects, they do not contain concrete constructs to address vulnerable system assets, their risks, and risk treatments. Furthermore, security languages do not provide a crosscutting viewpoint relating all three - assets, risks and risk treatments - together. This is problematic since, for a security analyst, it is difficult to detect what the potential security flaws could be, and how they need to be fixed. In this paper, we extend the Secure Tropos language, an agentand goal-oriented security modelling language to support modelling of security risks. Based on previous work, where we had observed some inadequacies of this language to model security risks, this paper suggests improvements of Secure Tropos semantics and syntax. On the syntax level we extend the concrete and abstract syntax of the language, so that it covers the security risk management domain. On the semantic level, we illustrate how language constructs need to be improved to address the three different levels of security risk management. The suggested improvements are illustrated with the aid of a running example, called eSAP, from the healthcare domain.

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DOI: 10.3217/jucs-018-02-0143

Authors: David Lizcano, Fernando Alonso, Javier Soriano, Genoveva López

Abstract: End-user development (EUD) is much hyped, and its impact has outstripped even the most optimistic forecasts. Even so, the vision of end users programming their own solutions has not yet materialized. This will continue to be so unless we in both industry and the research community set ourselves the ambitious challenge of devising end to end an end-user application development model for developing a new age of EUD tools. We have embarked on this venture, and this paper presents the main insights and outcomes of our research and development efforts as part of a number of successful EU research projects. Our proposal not only aims to reshape software engineering to meet the needs of EUD but also to refashion its components as solution building blocks instead of programs and software developments. This way, end users will really be empowered to build solutions based on artefacts akin to their expertise and understanding of ideal solutions.

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DOI: 10.3217/jucs-017-14-1913

Authors: Márcio Gonçalves, Cleidson R. B. De Souza, Victor González

Abstract: Different aspects defining the nature of software engineering work have been analyzed by empirical studies conducted in the last 30 years. However, in recent years, many changes have occurred in the context of software development that impact the way people collaborate, communicate with each other, manage the development process and search for information to create solutions and solve problems. For instance, the generalized adoption of asynchronous and synchronous communication technologies as well as the adoption of quality models to evaluate the work being conducted are some aspects that define modern software development scenarios. Despite this new context, much of the research in the collaborative aspects of software design is based on research that does not reflect these new work environments. Thus, a more up-to-date understanding of the nature of software engineering work with regards to collaboration, information seeking and communication is necessary. The goal of this paper is to present findings of an observational study to understand those aspects. We found that our informants spend 45% of their time collaborating with their colleagues; information seeking consumes 31,90% of developers' time; and low usage of software process tools is observed (9,35%). Our results also indicate a low usage of e-mail as a communication tool (∼1% of the total time spent on collaborative activities), and software developers, of their total time on communication efforts, spending 15% of it looking for information, that helps them to be aware of their colleagues' work, share knowledge, and manage dependencies between their activities. Our results can be used to inform the design of collaborative software development tools as well as to improve team management practices.

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DOI: 10.3217/jucs-017-13-1863

Authors: Kun Ma, Bo Yang, Ajith Abraham

Abstract: With the help of model transformation, it is possible to generate target models from source models. A possible way to face iterative development process with frequent modifications is to use not only a single transformation but also frequent model synchronization. In this paper, we propose a relational approach to model transformation using Query/View/Transformations (QVT) Relations language that also provides model synchronization mechanism based on the version of the models. The proposed framework uses a Platform-Independent Business Model (PIM-BM) and a Platform-Specific Business Component Model (PSM-BC) via the extension of the UML metamodel and MOF at different levels of abstraction, which sufficiently describe both the structural and behavioral properties of generic Web applications. Also we present the typical model mapping rules between PIM-BMs and PSM-BCs using QVT Relations. Finally the model synchronization based on the version of models is provided for the above model transformation approach.

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DOI: 10.3217/jucs-017-13-1800

Authors: M. Cambronero, Valentín Valero, Enrique Martínez

Abstract: In this paper we show how UML 2.0 sequence diagrams can be used for the design of Web service choreographies with time constraints and how these sequence diagrams can be extended with frames for the description of Web service choreographies. We then show how the diagrams can be translated into WS-CDL documents. This translation is of interest, since non-XML experts can find it difficult to implement a composite web service by WS-CDL, i.e. XML code. Graphic models, such as UML sequence diagrams, are a popular and well-studied framework for a compact representation of interoperation among participants in a distributed system and can be used as a starting document for the design of a composite Web service, from which the corresponding WS-CDL document can be derived.

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DOI: 10.3217/jucs-017-09-1329

Authors: Mark Johnson, Dai Griffiths, Mi Wang

Abstract: The concept of social role is a fundamental underpinning of the design and implementation of a wide range of learning technologies. However, the roles that are designed into technologies often ill-fit the real roles of teachers, learners and other stakeholders in educational institutions. This can exacerbate problems in adoption as stakeholders do not recognise the roles described for them in the technology. In this paper, Positioning Theory is used to explore the relationship between role, social context and communication drawing on specific examples of IMS Learning Design, Virtual Learning Environments, and Personal Learning Environments. With insights gained from this analysis, recommendations are made for theoretical focus on understanding the particulars of practice and identification of specific technical issues of interoperability rather than designing technologies based on idealisations of the roles of stakeholders within institutions.

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DOI: 10.3217/jucs-017-08-1135

Authors: Yue-Shan Chang, Chao-Tung Yang, Yu-Cheng Luo

Abstract: Retrieving information or discovering knowledge from a well organized data center in general is requested to be familiar with its schema, structure, and architecture, which against the inherent concept and characteristics of cloud environment. An effective approach to retrieve desired information or to extract useful knowledge is an important issue in the emerging information/knowledge cloud. In this paper, we propose an ontology-based agent generation framework for information retrieval in a flexible, transparent, and easy way on cloud environment. While user submitting a flat-text based request for retrieving information on a cloud environment, the request will be automatically deduced by a Reasoning Agent (RA) based on predefined ontology and reasoning rule, and then be translated to a Mobile Information Retrieving Agent Description File (MIRADF) that is formatted in a proposed Mobile Agent Description Language (MADF). A generating agent, named MIRA-GA, is also implemented to generate a MIRA according to the MIRADF. We also design and implement a prototype to integrate these agents and show an interesting example to demonstrate the feasibility of the architecture.

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DOI: 10.3217/jucs-017-05-0807

Authors: Paula Fernandes, Cláudia Maria Lima Werner, Eldanae Teixeira

Abstract: Feature modeling is an approach to represent commonalities and variabilities among products of a product line. Context-aware applications use context information to provide relevant services and information for their users. One of the challenges to build a context-aware product line is to develop mechanisms to incorporate context information and adaptation knowledge in a feature model. This paper presents UbiFEX, an approach to support feature analysis for context-aware software product lines, which incorporates a modeling notation and a mechanism to verify the consistency of product configuration regarding context variations. Moreover, an experimental study was performed as a preliminary evaluation, and a prototype was developed to enable the application of the proposed approach.

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DOI: 10.3217/jucs-017-05-0777

Authors: Javier Cubo, Carlos Canal, Ernesto Pimentel

Abstract: Using pre-existing software components (COTS) to develop software systems requires the composition and adaptation of the component interfaces to solve mismatch problems. These mismatches may appear at different interoperability levels (signature, behavioural, quality of service and semantic). In this article, we define an approach which supports composition and adaptation of software components based on model transformation by taking into account the four levels. Signature and behavioural levels are addressed by means of transition systems. Context-awareness and semanticbased techniques are used to tackle quality of service and semantic, respectively, but also both consider the signature level. We have implemented and validated our proposal for the design and application of realistic and complex systems. Here, we illustrate the need to support the variability of the adaptation process in a context-aware pervasive system through a real-world case study, where software components are implemented using Windows Workflow Foundation (WF). We apply our model transformation process to extract transition systems (CA-STS specifications) from WF components. These CA-STSs are used to tackle the composition and adaptation. Then, we generate a CASTS adaptor specification, which is transformed into its corresponding WF adaptor component with the purpose of interacting with all the WF components of the system, thereby avoiding mismatch problems.

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DOI: 10.3217/jucs-017-05-0742

Authors: Fréderic Loiret, Romain Rouvoy, Lionel Seinturier, Daniel Romero, Kévin Sénéchal, Aleš Plšek

Abstract: Software components are used in various application domains, and many component models and frameworks have been proposed to fulfill domain-specific requirements. The general trend followed by these approaches is to provide ad-hoc models and tools for capturing these requirements and for implementing their support within dedicated runtime platforms, limited to features of the targeted domain. The challenge is then to propose more flexible solutions, where components reuse is domain agnostic. In this article, we present a framework supporting compositional construction and development of applications that must meet various extra-functional/domain-specific requirements. The key points of our contribution are: i) We target development of component-oriented applications where extra-functional requirements are expressed as annotations on the units of composition in the application architecture. ii) These annotations are implemented as open and extensible component-based containers, achieving full separation of functional and extra-functional concerns. iii) Finally, the full machinery is implemented using the Aspect-Oriented Programming paradigm. We validate our approach with two case studies: the first is related to real-time and embedded applications, while the

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DOI: 10.3217/jucs-017-05-0684

Authors: Rohit Gheyi, Tiago Massoni, Paulo Borba

Abstract: A feature model (FM) defines the valid combinations of features, whose combinations correspond to a program in a Software Product Line (SPL). FMs may evolve, for instance, during refactoring activities. Developers may use a catalog of refactorings as support. However, the catalog is incomplete in principle. Additionally, it is non-trivial to propose correct refactorings. To our knowledge, no previous analysis technique for FMs is used for checking properties of general FM refactorings (a transformation that can be applied to a number of FMs) containing a representative number of features. We propose an efficient encoding of FMs in the Alloy formal specification language. Based on this encoding, we show how the Alloy Analyzer tool, which performs analysis on Alloy models, can be used to automatically check whether encoded general and specific FM refactorings are correct. Our approach can analyze general transformations automatically to a significant scale in a few seconds. In order to evaluate the analysis performance of our encoding, we evaluated in automatically generated FMs ranging from 500 to 2,000 features. Furthermore, we analyze the soundness of general transformations.

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DOI: 10.3217/jucs-017-02-0183

Authors: Valeria Herskovic, Sergio Ochoa, José Pino, Andrés Neyem

Abstract: Advances in mobile technologies are opening new possibilities to support collaborative activities through mobile devices. Unfortunately, mobile collaborative systems have been difficult to conceive, design and implement. These difficulties are caused in part by their unclear requirements and developers’ lack of experience with this type of systems. However, several requirements involved in the collaborative back-end of these products are recurrent and should be considered in every development. This paper introduces a characterization of mobile collaboration and a framework that specifies a list of general requirements to be considered during the conception and design of a system in order to increase its probability of success. This framework was used in the development of two mobile collaborative systems, providing developers with a base of back-end requirements to aid system design and implementation. The systems were positively evaluated by their users.

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DOI: 10.3217/jucs-016-19-2862

Authors: Mark Melia, Claus Pahl

Abstract: Authoring of Adaptive Educational Hypermedia is a complex activity requiring the combination of a range of design and validation techniques. We demonstrate how Adaptive Educational Hypermedia can be transformed into CAVIAr courseware validation models allowing for its validation. The model-based representation and analysis of different concerns and model-based mappings and transformations are key contributors to this integrated solution. We illustrate the benefits of Model Driven Engineering methodologies that allow for interoperability between CAVIAr and a well known Adaptive Educational Hypermedia framework. By allowing for the validation of Adaptive Educational Hypermedia, the course creator limits the risk of pedagogical problems in migrating to Adaptive Educational Hypermedia from static courseware.

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DOI: 10.3217/jucs-016-17-2475

Authors: José Aguilar, Irene Garrigós, Jose-Norberto Mazón, Juan Trujillo

Abstract: Web designers usually ignore how to model real user expectations and goals, mainly due to the large and heterogeneous audience of the Web. This fact leads to websites which are difficult to comprehend by visitors and complex to maintain by designers. In order to ameliorate this scenario, an approach for using the i* modeling framework in Web engineering has been developed in this paper. Furthermore, due to the fact that most of the existing Web engineering approaches do not consider how to derive conceptual models of the Web application from requirements analysis we also propose the use of MDA (Model Driven Architecture) in Web engineering for: (i) the definition of the requirements of a Web application in a Computational Independent Model (CIM), (ii) the description of Platform Independent Models (PIMs), and (iii) the definition of a set of QVT (Query/View/Transformation) transformations for the derivation of PIMs from requirements specification (CIM), thus to enable the automatic generation of Web applications. Finally, we include a sample of our approach in order to show its applicability and we describe a prototype tool as a proof of concept of our research.

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DOI: 10.3217/jucs-016-17-2435

Authors: Wuliang Sun, Eunjee Song, Paul Grabow, Devon Simmonds

Abstract: There is a need for more rigorous analysis techniques that developers can use for verifying the critical properties in UML models. The UML-based Specification Environment (USE) tool supports verification of invariants, preconditions, and postconditions specified in the Object Constraint Language (OCL). Due to its animation and analysis power, it is useful when checking critical non-functional properties such as security policies. However, the USE requires one to specify a model using its own textual language and does not allow one to import any model specification files created by other UML modeling tools. Hence, you would create a model with OCL constraints using a modeling tool such as the IBM Rational Software Architect (RSA) and then use the USE for the model verification. This approach, however, requires a manual transformation between two different specification formats, which diminishes advantage of using tools for model-level verification. In this paper, we describe our own implementation of a specification transformation engine based on the Model-Driven Architecture (MDA) framework. Our approach currently supports automatic tool-level transformations to USE from UML modeling tools built on the Eclipse-based Modeling Framework (EMF).

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DOI: 10.3217/jucs-016-17-2374

Authors: Edson A. Oliveira Junior, Itana M. S. Gimenes, José Carlos Maldonado

Abstract: This paper presents SMarty, a variability management approach for UMLbased software product lines (PL). SMarty is supported by a UML profile, the SMartyProfile, and a process for managing variabilities, the SMartyProcess. SMartyProfile aims at representing variabilities, variation points, and variants in UML models by applying a set of stereotypes. SMartyProcess consists of a set of activities that is systematically executed to trace, identify, and control variabilities in a PL based on SMarty. It also identifies variability implementation mechanisms and analyzes specific product configurations. In addition, a more comprehensive application of SMarty is presented using SEI's Arcade Game Maker PL. An evaluation of SMarty and related work are discussed.

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DOI: 10.3217/jucs-016-17-2353

Authors: Giovanni Giachetti, Manuela Albert, Beatriz Marín, Oscar Pastor

Abstract: In a model-driven development context, the definition (or selection) of an appropriate modeling language is a crucial task. OMG, in the model-driven architecture specification, recommends the use of UML for model-driven developments. However, the lack of semantic precision in UML has led to different model-driven approaches proposing their own domain-specific modeling languages in order to introduce their modeling needs. This paper focuses on customizing the UML association in order to facilitate its application in model-driven development environments. To do this, a well-defined process is defined to integrate the abstract syntax of a domain-specific modeling language that supports a precise semantics for the association construct in UML by means of the automatic generation of a UML profile. Finally, a brief example shows how the results obtained by the application of the proposed process can generate software products through a real model compilation tool.

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DOI: 10.3217/jucs-016-17-2313

Authors: Miguel Laguna, José Marqués

Abstract: Software product lines have become a successful but challenging approach to software reuse. Some of the problems that hinder the adoption of this development paradigm are the conceptual gap between the variability and design models, as well as the complexity of the traceability management between them. Most current development methods use UML stereotypes or modify UML to face variability and traceability issues. Commercial tools focus mainly on code management, at a fine-grained level. However, the use of specialized techniques and tools represent additional barriers for the widespread introduction of product lines in software companies. In this paper, we propose an alternative based on the UML package merge mechanisms to reflect the structure of the variability models in product line package architecture, thus making the traceability of the configuration decisions straightforward. This package architecture and the configuration of the concrete products are automatically generated (using Model Driven Engineering techniques) from the variability models. As an additional advantage, the package merge mechanism can be directly implemented at code level using partial classes (present in languages such as C#). To support the proposal, we have developed a tool incorporated into MS Visual Studio. This tool permits the product line variability to be modeled and the required transformations to be automated, including the final compilation of concrete products. A case study of a successful experience is described in the article as an example of applying these techniques and tools. The proposed approach, a combination of UML techniques and conventional IDE tools, can make the development of product lines easier for an organization as it removes the need for specialized tools and personnel.

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DOI: 10.3217/jucs-016-15-2111

Authors: Ricardo Tesoriero, José A. Gallud Lázaro, María Lozano, Victor Penichet

Abstract: In order to develop context-aware applications for ubiquitous computing environments we have defined an MDA approach that defines three layers of models. The first layer captures the conceptual characteristics of the application. This layer defines three complementary points of view of the system that are used to build the task, space and social views of the system. The second layer defines the software characteristics of the application. It is composed by three new complementary points of view of the system that are used to build the referential space, the information flow and the entity context views of the system. Finally, the third layer defines the deployment environment of the system according to the views generated by the second layer.

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DOI: 10.3217/jucs-016-15-2038

Authors: Marino Linaje, Juan Preciado, Fernando Sánchez-Figueroa

Abstract: Model-Driven Development concepts are exhibiting as a good engineering solution for the design of ubiquitous applications with multi-device user interfaces and other context-aware capacities. The Web has become an ideal platform for the deployment of such applications and therefore traditional Web development techniques are rapidly adopting Model-Driven principles to cope with the adaptation issues imposed by context-awareness and multichannel solutions. This discipline is being known as Model Driven Web Engineering. However, at the same time that the use of the Web and the number of people with mobile devices is growing, users are demanding more and better user experiences through the user interface. Web vendors answered introducing Rich Internet Applications that take advantage of the single-page paradigm and expand traditional Web features, providing richer content types, richer controls, richer temporal behaviors, richer interactivity and richer communications. While many recent devices support some type of RIA technology, RIAs extended features are showing some limitations of Model Driven Web Engineering methodologies to cope with multi-device context-awareness at the presentation level. This paper presents the combination of two different methodologies, WebML and RUX-Method, both using MDD principles, to obtain multi-device context-aware Rich Internet Applications using a Model-Driven approach. While WebML provides context-awareness at the data and business logic levels, RUX-Method deals with the presentation issues introduced by Rich Internet Applications.

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DOI: 10.3217/jucs-016-12-1612

Authors: Luis Guerrero, Sergio Ochoa, Hector Horta

Abstract: There are many examples of augmented objects in the literature. Augmented objects should provide intelligence to the ambient where they are located and also they must require a low cognitive effort to be used. Few works have been reported providing guidelines to conceive and design these components. Therefore, developers have to use improvised ad hoc software processes to support the development of augmented objects. In order to help dealing with this situation, this article presents a software process to develop these components. The proposed process was named Augmented Objects Development Process (AODeP) and it is based on the authors’ previous experiences and software engineering best practices. The article also reports two case studies in which AODeP was used to guide the development of augmented objects in specific problems. The obtained results are encouraging.

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DOI: 10.3217/jucs-016-12-1592

Authors: Lidia Fuentes, Nadia Gámez

Abstract: Developing Ambient Intelligence applications is a very complex task since it implies dealing with low-level software and hardware resources. The use of a middleware platform may alleviate this task by providing a set of high-level and platform-independent services to these kinds of applications. Nevertheless, the tendency is that the middleware deployed in each device has a flat and homogeneous architecture, although these devices and the requirements of intelligence environments are heterogeneous. This implies the middleware software deployed in each device normally contains more functionality than strictly required, leading to waste resources so scarce in lightweight devices. But the configuration and deployment of a minimal middleware customized to a target platform is a complex task, due to the diversity of hardware and software present in devices and the variable requirements of ambient intelligence applications. In order to solve these shortcomings, we propose to customize the piece of software related to the middleware platform by using a Software Product Line engineering approach. This paper presents an innovative configuration process for a software product line for ambient intelligence middleware where a minimal set of high-level parameters needs to be specified. So, the software engineers for this kind of systems can automatically obtain customized middleware by simply specifying this high-level information.

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DOI: 10.3217/jucs-016-12-1521

Authors: Diego López-De-Ipiña, Ignacio Díaz-De-Sarralde, Javier Garcia-Zubia

Abstract: Although RFID is mainly used to identify objects whose data can then be accessed over the network, passive HF RFID tags do have significant data storage capacity (up to 4K), which can be utilised to store data rather than only IDs. This work explores the potential of storing, accessing and exploiting information on tags both, theoretically, by studying how much data can actually be stored in HF RFID tags, and practically, by describing an NFC-supported platform adopting the data-on-tag approach to improve data management in a care centre. Such platform illustrates two key aspects for AAL: a) RFID tags can serve as temporary repositories of care events whenever a continuous data link is not desirable and b) interactions between RFID wristbands worn by residents and care staff's NFC mobiles can improve care data management and keep relatives up-to-date with elderly people's evolution, through a Web 2.0 social service.

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DOI: 10.3217/jucs-016-09-1234

Authors: Andres Ortega, Jose M. Alcaraz Calero, Juan Botía, Gregorio Pérez, Felix J. Garcia Clemente

Abstract: Ontology rule editing, testing, debugging and validation are still handcrafted and painful tasks. Nowadays, there is a lack of tools that take these tasks into consideration in order to ease the work of the developer. This paper is devoted to explain how we have come to a new tool, ORE (Ontology Rule Editor), which significantly eases these tasks. It rests on a Semantic Web framework together with reasoning engines, which operate with semantic representations. Its design maintains a loosely coupling from the framework and from rule engines. Collaborative functionalities have been tackled in order to enable a real integration of the rule authoring across different tools and/or users. A practical validation of the approach by instantiating our tool with Jena and Pellet reasoning engines is presented here. In order to demonstrate its use, the tool is applied to the task of rule-based management in a ubiquitous computing scenario.

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DOI: 10.3217/jucs-016-03-0424

Authors: Brian Henderson-Sellers, Jolita Ralyté

Abstract: The situational method engineering (SME) literature is surveyed and a synoptic evaluation presented in the context of formalizing and regularizing the conceptual framework and underpinning theory. Metamodels proposed for use in SME are evaluated as well as high-level process models for method construction. Method fragments and method chunks are then described formally followed by their identification and creation (from existing methods, from scratch or from past usage). Method creation is then analyzed in terms of various processes for constructing a full methodology from the method fragments/chunks. In particular, we contrast the use of the "map" technique and of the "deontic matrix" technique. The survey is concluded with an evaluation of some ideas on method tailoring and the emerging research on quality evaluation applied to SME.

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DOI: 10.3217/jucs-015-17-3273

Authors: Louis-Marie Traonouez, Didier Lime, Olivier Roux

Abstract: At the border between control and verification, parametric verification can be used to synthesize constraints on the parameters to ensure that a system verifies given specifications. In this paper we propose a new framework for the parametric verification of time Petri nets with stopwatches. We first introduce a parametric extension of time Petri nets with inhibitor arcs (ITPNs) with temporal parameters and we define a symbolic representation of the parametric state-space based on the classical state-class graph method. Then, we propose semi-algorithms for the parametric modelchecking of a subset of parametric TCTL formulae on ITPNs. These results have been implemented in the tool Romeo and we illustrate them in a case-study based on a scheduling problem.

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DOI: 10.3217/jucs-015-17-3231

Authors: Achraf Telmoudi, Lotfi Nabli, Radhi Hiri

Abstract: In this article a new Control-Supervisory architecture of Flexible Manufacturing Systems (FMS) is presented. We are interested particularly in construction and modelling of FMS robust control of flow-shop type to time constraints. Other than the control of production system, the goal is to observe and interpreted the robustness of resources and of manufacturing system. The P-time Petri Nets which is used for modeling of the time constraints. A methodology of construction of a robust control system generating the margins of passive and active robustness is elaborated. The redundancy of the robustness of the elementary parameters between passive and active leads us to define the ways ensuring the total robus tness of the system. To do so, a set of definitions lemmas and theorems are developed and affirmed by examples of applications.

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DOI: 10.3217/jucs-015-11-2166

Authors: Ronan Barrett, Claus Pahl

Abstract: Distributed systems are being constructed by composing a number of discrete com-ponents. This practice is particularly prevalent within the Web service domain in the form of service process orchestration and choreography. Often, enterprise systems are built from manyexisting discrete applications such as legacy applications exposed using Web service interfaces. There are a number of architectural configurations or distribution patterns, which express how acomposed system is to be deployed in a distributed environment. However, the amount of code required to realise these distribution patterns is considerable. In this paper, we propose a distri-bution pattern-driven approach to service composition and architecting. We develop, based on a catalog of patterns, a UML-compliant framework, which takes existing Web service interfacesas its input and generates executable Web service compositions based on a distribution pattern chosen by the software architect.

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DOI: 10.3217/jucs-015-11-2142

Authors: Ricardo Perrone, Raimundo Macedo, George Lima, Veronica Lima

Abstract: In recent years, many component-based real-time systems have been proposed as a solution to modular and easily maintainable distributed real-time systems. This paper proposes a methodology for estimating probability distributions of execution times in the context of such systems, where no access to component internal code is assumed. In order to evaluate the proposed methodology, experiments were conducted with components, and related compositions, implemented over CIAO and ARCOS. CIAO is a known real-time component-based middleware and ARCOS is a software framework devoted to the construction of real-time control and supervision applications, also developed over CIAO. The collected experimental data show that the proposed approach is indeed a good approximation for component execution time probability distributions.

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DOI: 10.3217/jucs-015-09-1970

Authors: Po-Huan Chiu, Chi-Chun Lo, Kuo-Ming Chao

Abstract: Object-oriented programming (OOP) is a mainstream paradigm for engineering design software tool development. An emerging requirement is the introduction of semantics to achieve heterogeneous information sharing, but many challenges exist. Examples include using object methods to manipulate an RDF data, automatically converting data into RDF format, and supporting various programming languages. In addition, limitations to description capabilities for relationships among object-oriented classes exceed those of RDF, thus hindering direct mapping between object-oriented and Semantic Web classes. Our proposed semantic object framework (SOF) combines object-oriented design and Semantic Web features. SOF utilizes embedded comments in source code to describe semantic relationships between classes and attributes. We use a mobile phone design case study to illustrate how the proposed system operates.

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DOI: 10.3217/jucs-014-21-3608

Authors: Mikai Yang, Greg Michaelson, Rob Pooley

Abstract: The abstract syntax and static semantics of UML, the widely-used generalpurpose graphical modeling language, have been standardized in a four-layer metamodeling framework. However UML's dynamic semantics, such as UML Precise Action Semantics and the behaviors like activities, interactions and state machines, are only standardized in a natural language-English. It is commonly argued that such informal description inevitably involves ambiguities and lacks rigorousness, precluding the early simulation and reasoning about a UML system design. Here we select Action Semantics (AS) as the vehicle to formalize UML. AS is a mature semantics description framework which has advantages of intelligibility, modularity and practicability. In our approach, we formalize UML indirectly by formalizing its textual correspondent-an extended Action Language, which plays a key role as the interface between UML and its action semantics.

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DOI: 10.3217/jucs-014-21-3573

Authors: Rohit Gheyi, Tiago Massoni, Paulo Borba

Abstract: Software Product Lines (SPL) may be adopted by either bootstrapping existing software products into a SPL, or extending an existing SPL to encompass an additional software product. Program refactorings are usually applied for carrying out those tasks. The notion of SPL refactoring is an extension of the traditional definition of refactoring; it involves not only program refactorings, but also Feature Model (FM) refactorings, in order to improve configurability. However, FM refactorings are hard to define, due to the incompleteness of the refactoring catalogs developed as of today. In this paper, we propose a complete, sound catalog of algebraic laws, making up special FM refactorings that preserve configurability. This catalog is also defined as minimal, as one law cannot be derived from another one in the same catalog. In addition, a theory for FMs is presented, in the context of a theorem prover.

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DOI: 10.3217/jucs-014-20-3358

Authors: Timothy Moore

Abstract: Presentation types are used in the CLIM interface library to tag graphical output with a type and establish an input type context in which the user may use the keyboard to type input, accepted by a parser associated with that presentation type, or click on the graphical representation of an object that has an appropriate presentation type. Presentation types are defined using a syntax reminiscent of the deftype syntax of Common Lisp; the input and output actions of the types, as well as aspects of their inheritance, are implemented using a system of generic functions and methods directly based on CLOS. The presentation type system is different enough from the Common Lisp type system that its types, generic functions and methods do not map directly to those of Common Lisp. We describe the presentation type implemention in McCLIM which uses the CLOS Metaobject Protocol to implement presentation type inheritance, method dispatch and method combination without implementing an entire parallel object system next to CLOS. Our implementation supports all types of method combination in the presentation methods, including user-defined method combination.

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DOI: 10.3217/jucs-014-20-3333

Authors: António Leitão

Abstract: UCL-GLORP is a Common Lisp implementation and extension of GLORP (Generic Lightweight Object-Relational Persistence), an Object-Relational Mapper for the Smalltalk language. UCL-GLORP is now a mature framework that largely extends GLORP and that takes advantage of some of Common Lisp unique features. This paper illustrates UCL-GLORP and discusses some of the challenges that we faced in order to find suitable replacements, in Common Lisp, for some of the more esoteric features of Smalltalk that were explored by GLORP.

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DOI: 10.3217/jucs-014-19-3188

Authors: Maik Wurdel, Daniel Sinnig, Peter Forbrig

Abstract: A precise model of the behavioral dynamics is a necessary precondition for the development of collaborative environments. In this paper we present a specification framework for collaborative environments. In particular we highlight the interplay of task specifications and domain models. The framework consists of two components: A formal specification language (called CTML) and the tool CTML Editor and Simulator. CTML has a precisely defined syntax and semantics and is designed to model actors, roles, collaborative tasks and their dependency and impact on the domain. The CTML Editor and Simulator is an Eclipse IDE for the interactive creation and simulation of CTML specifications.

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DOI: 10.3217/jucs-014-19-3142

Authors: William Giraldo, Ana Molina, Cesar Collazos, Manuel Ortega Cantero, Miguel Redondo

Abstract: This paper describes the taxonomy for designing interactive groupware systems. The taxonomy defines the objectives, methods and principles for classifying models and facilitates their integration. In particular, we show the integration process of models in two notations such as CIAN, which considers collaboration and human-computer interaction issues, and UML, which allows specifying the functionality of groupware systems. The proposed integration process is based on a software tool, called CIAT, developed to put our proposal into practice.

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DOI: 10.3217/jucs-014-19-3127

Authors: Tomàs Pallejà, Edgar Rubión, Mercè Teixido, Marcel Tresanchez, Alicia Fernández del Viso, Carlos Rebate, Jordi Palacin

Abstract: The following paper introduces the work conducted to create a relative virtual mouse based on the interpretation of head movements and face gesture through a low cost camera and the optical flow of the images. This virtual device is designed specifically as an alternative non-contact pointer for people with mobility impairments in the upper extremities and reduced head control. The proposed virtual device was compared with a conventional mouse, a touchpad and a digital joystick. Validation results show performances close to a digital joystick but far away from a conventional mouse.

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DOI: 10.3217/jucs-014-14-2343

Authors: Botond Virginas, Marian Ursu, Edward Tsang, Gilbert Owusu, Chris Voudouris

Abstract: This paper considers the problem of resource allocation in the service industries approached from an agent-based perspective. Agent technologies seem to be well suited to this domain by providing a distributed environment, are network centric, semi-autonomous and collaborative and can communicate with each other to achieve better optimisation with little human intervention. The paper describes the context of this solution, a general power model and several pathways with corresponding example implementations with results and discussion The novelty of the solution resides in the fact that it is a natural and versatile formulation that combines an agent-based model with various artificial intelligence and operations research techniques such as rule-based expressions of allocation strategies and multi-criteria optimisation expressions of allocation objectives.

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DOI: 10.3217/jucs-014-13-2182

Authors: Javier Cámara, Gwen Salaün, Carlos Canal

Abstract: Reuse of software entities such as components or Web services raise composition issues since, most of the time, they present mismatches in their interfaces. These mismatches may appear at different interoperability levels: signature, behaviour, quality of service and semantics. The behavioural level is crucial and behavioural mismatches must all be corrected, although this is a difficult task. So far, most adaptation approaches which deal with behavioural mismatches work on a fixed description of components where all ports involved in their interfaces are known at design-time. Here, we focus on systems in which composition is affected by run-time behaviour of the system. This is the case in pervasive systems where a client interacts with a specific service by using new communication channels dynamically created. These are of special interest to allow private interaction between several entities. In this article, we define a behavioural model inspired by the ss-calculus to specify behavioural interfaces of components. Our model is particularly suitable for creating new channels dynamically, also taking concurrent behaviours into account. The dynamic nature of the systems we are dealing with obliges to apply adaptation at run-time, avoiding at the same time the costly generation of full descriptions of adaptors. The main contribution of this article is an adaptation engine that allows the dynamic creation of channels and applies at run-time a composition specification built at designtime. All the underlying formal foundations of our proposal have been implemented in a prototype tool that has been applied to system designs. Aspect-Oriented Programming has been studied as well, as a way to implement our engine for further application to real software components.

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DOI: 10.3217/jucs-014-13-2158

Authors: Enrico Oliva, Antonio Natali, Alessandro Ricci, Mirko Viroli

Abstract: This paper describes a Java-based framework for developing componentbased software systems supporting adaptation with logic laws and considering component interactions as a first-class aspect. On the one side, the framework makes it possible to specify the logic of interaction at the component-level, in terms of input and output interfaces, the events generated and observed by a component, and related information about the management of the control flow. On the other side, it is possible to specify the logic of interaction at the inter-component level, providing a modelling and linguistic support for designing and (dynamically) programming the glue among the components, enabling general forms of adaptation, observation and construction of the interaction space. As a result, the framework supports the adaptation of components at different levels: from interoperability among heterogeneous and unknown components, to the support for dynamic introduction, removal and update of components, to general coordination patterns, such as workflow. The framework uses first-order logic as the reference computational model for describing and defining the logic of interaction: the modalities adopted by components to interact, the adaptation laws gluing the components and the interaction events occurring in the system are expressed as facts and rules. They compose the (evolving) logic theories describing and defining the interaction at the system level, and can be observed and controlled at runtime to allow dynamic re-configurability.

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DOI: 10.3217/jucs-014-12-2007

Authors: Martin Ouimet, Kristina Lundqvist

Abstract: In this paper, we present the Timed Abstract State Machine (TASM) language, which is a language for the specification of embedded real-time systems. In the engineering of embedded real-time systems, the correctness of the system is defined in terms of three aspects - function, time, and resource consumption. The goal of the TASM language and its associated toolset is to provide a basis for specification-based real-time system engineering where these three aspects can be specified and analyzed. The TASM language is built on top of Abstract State Machines (ASM) by including facilities for compact and legible specification of non-functional behavior, namely time and resource consumption. The TASM language provides a notation which is well-suited to the specification needs of embedded real-time systems. We begin the presentation of the language with a historical survey on the use of ASM in specifying real-time systems. The core difference between the TASM language and ASM is that steps are inherently durative instead of being instantaneous and steps consume resources. These concepts capture the reality of physical systems in a flexible abstract model. We present the syntax and semantics of the language and illustrate the concepts using an extended version of the production cell case study.

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DOI: 10.3217/jucs-014-09-1463

Authors: Rafael Duque, Jesús Gallardo, Crescencio Bravo, Antonio Mendes

Abstract: Most of the current academic and professional work requires collaboration between the members of a working group. Groupware tools play a prevailing role in supporting this collaborative work, often from different locations and at the same time. The research field of CSCW (Computer-Supported Cooperative Work) studies how to design effective groupware tools. To increase their potential, groupware systems must be flexible and have the capacity to adapt themselves to multiple tasks and situations. In order to provide answers to these challenges, in this article we propose the use of meta-models and XML-based languages to specify the most important characteristics of a groupware modeling system, such as the application domain, the requirements of the tasks to be carried out, how communication takes place and the regulation of the shared workspace. These models and techniques have been used to develop a specific groupware system called SPACE-DESIGN (SPecification and Automatic Construction of collaborative Environments of DESIGN), a CSCW tool with support for synchronous distributed collaborative work that adapts and re-configures itself as a result of processing the domain specification, the task, the communication and the system working norms.

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DOI: 10.3217/jucs-014-09-1447

Authors: Montserrat Sendín, Víctor López-Jaquero, Cesar Collazos

Abstract: The advent of new advances in mobile computing has changed the manner we do our daily work, even enabling us to perform collaborative activities. However, current groupware approaches do not offer an integrating and efficient solution that jointly tackles the flexibility and heterogeneity inherent to mobility as well as the awareness aspects intrinsic to collaborative environments. Issues related to the diversity of contexts of use are collected under the term plasticity. A great amount of tools have emerged offering a solution to some of these issues, although always focused on individual scenarios. We are working on reusing and specializing some already existing plasticity tools to the groupware design. The aim is to offer the benefits from plasticity and awareness jointly, trying to reach a real collaboration and a deeper understanding of multi-environment groupware scenarios. In particular, this paper presents a conceptual framework aimed at being a reference for the generation of plastic User Interfaces for collaborative environments in a systematic and comprehensive way. Starting from a previous conceptual framework for individual environments, inspired on the model-based approach, we introduce specific components and considerations related to groupware.

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DOI: 10.3217/jucs-014-09-1435

Authors: Ana Molina, Miguel Redondo, Manuel Ortega Cantero, H. Hoppe

Abstract: The design of the groupware systems is a progressively extended task, which is difficult to tackle. There are not proposals to support the joint modeling of collaborative and interactive issues of this kind of systems, that is, proposals that allow designing the presentation layer of these applications. In order to solve this lack we propose a methodological approach, based on a set of notations of both a graphical and a textual nature.

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DOI: 10.3217/jucs-014-08-1314

Authors: Marcelo Alves, Paulo Pires, Flávia Delicato, Maria Luiza M. Campos

Abstract: Nowadays, the complexity of software applications has brought new challenges to developers, having to deal with a large number of computational requirements. Among these requirements, those known as crosscutting concerns transpass components boundaries, leading to maintainability and comprehension problems. This paper presents CrossMDA, a framework that encompasses a transformation process to integrate crosscutting concerns in model-oriented systems. It uses the concepts of horizontal separation of concerns from AOP to create independent business and aspect models, integrating those models through MDA transformations (vertical separation of concerns). CrossMDA comprises a development process, a set of services and support tools. The main advantages of this approach are to raise the abstraction level of aspect modeling, to promote the reuse of crosscutting concerns modeled as PIM elements, besides automating the process of mapping the relationship of crosscutting concerns and business models through the process of MDA transformations.

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DOI: 10.3217/jucs-014-08-1182

Authors: George Edwards, Chiyoung Seo, Nenad Medvidovic

Abstract: Abstract: Prediction of the quality attributes of software architectures requires technologies that enable the application of analyt ic theories to component mode ls. However, available analytic techniques generally opera te on formal models specified in notations that cannot flexibly and intuitively capture the architectures of large- scale distributed system s. The construction of model interpreters that transform architectural m odels into analysis mode ls has proved to be a complex and difficult task. This paper (1) de scribes a methodology for performing automated analysis of architectural models that simplifies the development of model interpreters and enables effective reuse of interpreter logic, an d (2) demonstrates how a framework that utilizes the methodology can be designed, implemented, utilized, and evaluated.

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DOI: 10.3217/jucs-013-13-2002

Authors: Lorenzo Capra, Walter Cazzola

Abstract: Nowadays, software evolution is a very hot topic. It is particularly complex when it regards critical and nonstopping systems. Usually, these situations are tackled by hard-coding all the foreseeable evolutions in the application design and code. Neglecting the obvious difficulties in pursuing this approach, we also get the application code and design polluted with details that do not regard the current system functionality, and that hamper design analysis, code reuse and application maintenance in general. Petri Nets (PN), as a formalism for modeling and designing distributed/concurrent software systems, are not exempt from this issue. The goal of this work is to propose a PN based reflective framework that lets everyone model a system able to evolve, keeping separated functional aspects from evolutionary ones and applying evolution to the model only if necessary. Such an approach tries to keep system's model as simple as possible, preserving (and exploiting) ability of formally verifying system properties typical of PN, granting at the same time adaptability.

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DOI: 10.3217/jucs-013-13-1972

Authors: Shunsuke Sasaki, Tasuku Nishihara, Daisuke Ando, Masahiro Fujita

Abstract: System Dependence Graph (SDG) is a graph representation which shows dependencies among statements / expressions in a design. In this paper, we propose a new HW/SW co-design methodology based on SDG. In our method, any combination of C / C++ / SpecC descriptions is acceptable as input designs so that design functions can be specified flexibly. First, the input descriptions are analyzed and verified with static but partially dynamic program checking methods by traversing SDG. With those methods, large descriptions can be processed. Next, those designs are divided into HW and SW parts. In this step, SDGs are fully utilized to insert parallelism into the designs, and it enables flexible HW/SW partitioning. The HW parts are further optimized and then converted into RTL descriptions by existing behavioral synthesis tools. Finally, the generated RTL descriptions together with the SW parts are compared to the original descriptions in order to make sure that they are logically equivalent. Also, designerspecified properties may be model checked with these final design descriptions. Such formal verifications can be realized by translating those descriptions into Finite State Machine (FSM) type representations and existing formal verifiers. We show two case studies with practical examples to demonstrate the usefulness of our approach.

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DOI: 10.3217/jucs-013-09-1213

Authors: Juan Dodero, Salvador Sánchez-Alonso, Dirk Frosch-Wilke

Abstract: Competence development programmes are collections of units of learning and learning activities used to increase the overall effective performance of a learner within a certain task. The definition of a competence development programme is fairly complex and subject to variability, depending on the available learning units and components. Some instructional engineering approaches have been successfully used to create courseware by the combination of existing learning resources within a systematic and iterative method. In this work, a generative, model-driven engineering approach is used to create and adapt competence development programmes from families of available learning components, such as units of learning, learning designs, and learning services. The process begins from the statement of the learning goals as feature models, and carries out a number of transformations from the analysis model down to learning designs and implementation components. However, shared definitions for competence-related terms and computational semantics are essential in this effort. In this paper, ontologies are proposed as a means to that end. In particular, the transformations between models are defined with the help of a general competence ontology.

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DOI: 10.3217/jucs-013-02-0224

Authors: Iwan Tabakow

Abstract: This paper describes a method of using Petri net P-invariants in system diagnosis. To model this process a net oriented fault classification is presented. Hence, the considered discrete event system is modelled by a live, bounded, and reversible place-transition Petri net. The notions of D-partition of the set of places P of a given place-transition net N and net k-distinguishability are first introduced. Next these two notions are extended to the set of all vertices, i.e. places and transitions of N. So the problem of fault identification of the vertices of N is transformed as a problem of fault identification of the places of a new net N´ called a net simulator of N. Any transition in N´ is assumed to be fault-free. Then the corresponding net place invariants are computed. The system k-distinguishability measure is obtained in a unique way from the place-invariant matrix. For a large value of k, the system model is extended by using some set of additional places called test points and at the same time preserving the original net properties. To obtain a 1-distinguishable net the notion of a marked graph component is used. It is shown a sufficient condition for 1-distinguishability of an arbitrary place-transition net and a corresponding algorithm is presented. Next two different diagnosis test strategies are discussed, i.e. combinational and sequential fault diagnosis. Corresponding (single) place and transition fault models are introduced. The complexity of the proposed method depends on the effectivity of the existing algorithms for computation of the P-cover, i.e. the set of P-invariants covering N. The proposed approach can be extended for higher level Petri nets, e.g such as coloured nets or also to design self-diagnosable circuit realisations of Boolean interpreted Petri nets. Several examples are given.

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DOI: 10.3217/jucs-012-12-1741

Authors: Pascal Poizat, Jean-Claude Royer

Abstract: Component Based Software Engineering has now emerged as a discipline for system development. After years of battle between component platforms, the need for means to abstract away from specific implementation details is now recognized. This paves the way for model driven approaches (such as the OMG MDA) but also for the more older Architectural Description Language (ADL) paradigm. In this paper we present Korrigan, a true ADL (in the [MT00] sense), which provides interesting features: fully formal behaviours and data types, expressive component gluing mechanisms through the use of temporal logic, yet ensuring the specification readability thanks to graphical notations.

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DOI: 10.3217/jucs-012-09-1104

Authors: Attila Adamkó

Abstract: Recently a growing demand has arisen for methods for the development of small- and medium scale Web Information Systems (WIS). Web applications are being built in a rapidly changing environment where requirements are usually unstable. Short-time design and implementation are needed in response to the new technologies. Our work focuses rather on the design and construction of Web applications, than management. Flexibility is a major requirement in such applications, and also in a database-backed environment for the structure and presentation of the sites. We propose a systematic design method for Web applications which takes into account the data-oriented aspects of the application. The method is based on a UML profile adapted to the problem domain by means of stereotypes as well as a strategy for generating code templates from such models. We provide a method to derive the navigation model from the structural model of a Web application. We will also show guidelines for the development of the Data Layer of data-oriented Web application. Moreover, why to divide the business logic layer into two parts: the pure application logic for managing the workflow of the application and the storage logic responsible for the data structures. Rapid development is enabled by providing roundtrip engineering capabilities with support for automatic code generation. We will show the role of XML: why to use XML to support both the reuse of content and context-dependent delivery. An advantage of the proposed methodology is that several steps can be performed is a semi-automatic way providing rapid development and prototyping.

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DOI: 10.3217/jucs-012-04-0450

Authors: Fernando Ciriaco, Taufik Abrão, Paul Jean E. Jeszensky

Abstract: This work analyses two heuristic algorithms based on the genetic evolution theory applied to direct sequence code division multiple access (DS/CDMA) com­ munication systems. For different phases of an evolutionary algorithm new biological processes are analyzed, specially adapted to the multiuser detection (MuD) problem in multipath fading channels. Monte Carlo simulation results show that the detection based on evolutionary heuristic algorithms is a viable option when compared with the optimum solution (ML ­ maximum likelihood), even for hostile channel conditions and severe system operation. Additionally, a comparative table is presented considering the relation between bit error rate (BER) and complexity as the main analyzed figure of merit. Each algorithm complexity is determined and compared with others based on the required number of computational operations to reach de optimum performance and also the spent computational time.

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DOI: 10.3217/jucs-012-03-0297

Authors: Diego De Ipiña, Juan Vázquez, Daniel García, Javier Fernández, Iván García, David Sainz, Aitor Almeida

Abstract: An interesting new application domain for handheld devices may be represented by Ambient Intelligence (AmI), where they can be used as intermediaries between us and our surrounding environment. Thus, the devices, which always accompany us, will behave as electronic butlers who assist us in our daily tasks, by interacting with the smart objects (everyday objects augmented with computational services) in our whereabouts. In order to achieve such goal, this paper proposes an AmI-enabling framework providing two main functions: a) facilitate the development and deployment of smart objects and b) transform mobile devices into universal remote controllers of those smart objects.

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DOI: 10.3217/jucs-012-03-0236

Authors: Lidia Fuentes, Daniel Jiménez, Mónica Pinto

Abstract: In recent times, interest in Ambient Intelligence (or AmI) has increased considerably. One of the main challenges in the development of these systems is to improve their modularization in order to achieve a high degree of reusability, adaptability and extensibility. This will help us to deal with the heterogeneity and evolution of the environments in which AmI devices exit. An example would be to easily adapt existing applications when new communication technologies appear. Current approaches apply component technologies to achieve these goals, but more should be done. Our research focuses on applying aspect technologies to components in order to improve AmI application modularization. We present the benefits of aspect technologies with regard to reusability and adaptability, by showing the limitations of PCOM, a component-based AmI middleware platform. We will show a study comparing DAOPAmI, our own component and aspect-based AmI middleware platform and PCOM.

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DOI: 10.3217/jucs-011-10-1613

Authors: Alexandre Bergel, Stéphane Ducasse, Oscar Nierstrasz

Abstract: Each object­oriented programming language proposes various grouping mechanisms to bundle interacting classes (i.e., packages, modules, selector namespaces, etc). To understand this diversity and to compare the different approaches, a common foundation is needed. In this paper we present a simple module calculus consisting of a small set of operators over environments and modules. Using these operators, we are then able to specify a set of module combinators that capture the semantics of Java packages, C# namespaces, Ruby modules, selector namespaces, gbeta classes, classboxes, MZScheme units, and MixJuice modules. We develop a simple taxonomy of module systems, and show how particular combinations of module operators help us to draw sharp distinctions between classes of module systems that share similar characteristics.

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DOI: 10.3217/jucs-011-10-1580

Authors: A. Cruz, Luís Barbosa, José Oliveira

Abstract: This paper addresses objectification, a formal specification technique which inspects the potential for object-orientation of a declarative model and brings the 'implicit objects' explicit. Criteria for such objectification are formalized and implemented in a runnable prototype tool which embeds Vdm-sl into Vdm++. The paper also includes a quick presentation of a (coinductive) calculus of such generated objects, framed as generalised Moore machines.

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DOI: 10.3217/jucs-011-06-1054

Authors: Marjan Sirjani, Ali Movaghar, Amin Shali, Frank De Boer

Abstract: Actor-based modeling, with encapsulated active objects which communicate asynchronously, is generally recognized to be well-suited for representing concurrent and distributed systems. In this paper we discuss the actor-based language Rebeca which is based on a formal operational interpretation of the actor model. Its Java-like syntax and object-based style of modeling makes it easy to use for software engineers, and its independent objects as units of concurrency leads to natural abstraction techniques necessary for model checking. We present a front-end tool for translating Rebeca to the languages of existing model checkers in order to model check Rebeca models. Automated modular verification and abstraction techniques are supported by the tool.

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DOI: 10.3217/jucs-010-11-1540

Authors: W. Yeung

Abstract: The B Abstract Machine Notation (AMN) and the notation of Communicating Sequential Processes (CSP) have previously been applied to formalise the UML class and state diagrams, respectively. This paper discusses their integrated use in checking the consistency between the two kinds of UML diagrams based on some recent results of research in integrated formal methods. Through a small information system example, the paper illustrates a clear-cut separation of concerns in employing the two formal methods. Of particular interest is the treatment of recursive calls within a single class of objects.

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DOI: 10.3217/jucs-010-10-1408

Authors: Mark Denford, Andrew Solomon, John Leaney, Tim Neill

Abstract: The design of large, complex computer based systems, based on their architecture, will benefit from a formal system that is intuitive, scalable and accessible to practitioners. The work herein is based in graphs which are an efficient and intuitive way of encoding structure, the essence of architecture. A model of system architectures and architectural abstraction is proposed, using poset labelled graphs and their transformations. The poset labelled graph formalism closely models several important aspects of architectures, namely topology, type and levels of abstraction. The technical merits of the formalism are discussed in terms of the ability to express and use domain knowledge to ensure sensible refinements. An abstraction / refinement calculus is introduced and illustrated with a detailed usage scenario. The paper concludes with an evaluation of the formalism in terms of its rigour, expressiveness, simplicity and practicality.

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DOI: 10.3217/jucs-010-10-1383

Authors: Tivadar Szemethy, Gabor Karsai

Abstract: The model-based approach to the development of embedded systems relies on the use of explicit models in the design process. If these models faithfully represent the components of the system with respect to their properties as well as their interactions, then they can be used to predict the dynamic behavior of the system under construction. In this paper we argue for modeling the execution platform that facilitates the component interactions, and show how models of the application and the knowledge of the platform can be used to translate system configurations into another abstract formalism (timed automata, in our case) that allows system verification through model checking.

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DOI: 10.3217/jucs-010-10-1357

Authors: Matthew Emerson, Janos Sztipanovits, Ted Bapty

Abstract: The Meta Object Facility (MOF) forms one of the core standards of the Object Management Group's Model Driven Architecture. It has several use-cases, including as a repository service for storing abstract models used in distributed object-oriented software development, a development environment for generating CORBA IDL, and a metamodeling language for the rapid specification, construction, and management of domain-specific technology-neutral modeling languages. This paper will focus on the use of MOF as a metamodeling language and describe our latest work on changing the MIC metamodeling environment from UML/OCL to MOF. We have implemented a functional graphical metamodeling environment based on the MOF v1.4 standard using GME and GReAT. This implementation serves as a testament to the power of formally well-defined metamodeling and metamodel-based model transformation approaches. Furthermore, our work gave us an opportunity to evaluate sevaral important features of MOF v1.4 as a metamodeling language:Completeness of MOF v1.4 for defining the abstract syntax for complex (multiple aspect) DSML-sThe Package concept for composing and reusing metamodelsFacilities for modeling the mapping between the abstract and concrete syntax of DSML-s

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DOI: 10.3217/jucs-010-07-0859

Authors: Brian Westphal, Frederick C. Harris Jr., Sergiu Dascalu

Abstract: This paper presents an overview of the Redwood programming environment and details one of its key features, snippets. Through snippets, developers can both make use of a variety of predefined programming constructs and build their own reusable program components. Language-independent, snippets are descriptions of program parts that can be as simple as an assignment statement or as complex as a sophisticated optimization algorithm. In Redwood, snippets also provide support for a distinguishing facility of visual environments: direct manipulation via drag-and-drop. An example of working with snippets, including snippet definition, visualization, customization, and mapping to code is also presented in the paper.

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