Search

Supporting the execution of service-oriented applications over ubiquitous networks specifically calls for a service-oriented middleware (SOM), which effectively enables ubiquitous networking while benefiting from the diversity and richness of the networking infrastructure. However, developing ubiquitous applications that exploit the specific features offered by a SOM might be a time-consuming task, which demands a deep knowledge spanning from the application domain concepts down to the underlying middleware technicalities. In this paper, first we present the model-driven development process underpinning ubiSOAP, a SOM for the ubiquitous networking domain. Then, based on the domain concepts defined by the conceptual model of ubiSOAP, its architecture and its technicalities, we propose a domain-specific environment, called ubiDSE, that aids the development of applications that exploits the ubiSOAP features, from design to implementation. ubiDSE allows developers to focus on the main behavior of the modeled systems, rather than on complex details inherent to ubiquitous environments. As part of ubiDSE, specific tools are provided to automatically generate skeleton code for service-oriented applications to be executed on ubiSOAP-enabled devices, hence facilitating the exploitation of ubiSOAP by developers.

CAEX is one of the most promising standards when it comes to data exchange between engineering tools in the production system automation domain. This is also reflected by the current emergence of AutomationML, which uses CAEX as its core representation data format. Having such standards at hand, the question arises how to deal with the evolution of such standards as is currently happening with the transition from CAEX 2.15 to CAEX 3.0. In this paper, we take a language engineering point of view to the evolution of engineering data formats. In particular, we present how CAEX can be formulated in a model-based framework, which allows to reason about evolution of the data format as well as its impact on the data stored in such evolving formats. By this, not only the migration process of existing data to the new format version is possible, but also a more theoretical investigation on information preservation is possible. We demonstrate the approach by the concrete case of the upcoming CAEX evolution.

In this paper, we report on our experience with the application of validated models to assess performance, reliability, and adaptability of a complex mission critical system that is being developed to dynamically monitor and control the position of an oil-drilling platform. We present real-time modeling results that show that all tasks are schedulable. We performed stochastic analysis of the distribution of task execution time as a function of the number of system interfaces. We report on the variability of task execution times for the expected system configurations. In addition, we have executed a system library for an important task inside the performance model simulator. We report on the measured algorithm convergence as a function of the number of vessel thrusters. We have also studied the system architecture adaptability by comparing the documented system architecture and the implemented source code. We report on the adaptability findings and the recommendations we were able to provide to the system's architect. Finally, we have developed models of hardware and software reliability. We report on hardware and software reliability results based on the evaluation of the system architecture.

System models are essential in planning, designing, realizing, and maintaining production systems. AutomationML (AML) is an emerging standard to represent and exchange heterogeneous artifacts throughout the complete system life cycle and is more and more used as a modeling language. AML is designed as a flexible, prototype-based language able to represent the full spectrum of different artifacts. It may be utilized to build reusable libraries containing prototypical elements to build up production systems by using clones. However, libraries have to evolve over time, e.g., to reflect bug fixes, new features or refactorings, and so system models have to co-evolve to reflect the changes in the libraries. To tackle this co-evolution challenge, we specify in this paper the relationship between library elements, i.e., prototypes, and system elements, i.e., clones, by establishing a formal model for prototype-based modeling languages. Based on this formalization, we introduce several levels of consistency rigor one may want to achieve when modeling with prototype-based languages. These levels are also the main input to reason about the impact of library changes on the concrete system models for which we provide semi-automated co-evolution propagation strategies. We apply the established theory to the concrete AML case and present concrete tool support for evolving AML models based on Eclipse which demonstrates that consistency between system models and libraries may be maintained semi-automatically.

In industrial production systems engineering projects, the work of software managers depends on engineering artifacts coming from multiple disciplines. In particular, it is important to software managers to assess the project risk from the status and evolution of various heterogenous distributed engineering artifacts. Thus, software risk management is most often an error prone and cumbersome task in such projects. To tackle this challenge, we introduce a model-based foundation for risk assessment in multi-disciplinary systems engineering projects. In particular, we build on the recent modeling support for the Automation ML (AML) standard which enables representing data coming from different engineering disciplines as models and employ a linking language to reason on a set of distributed engineering artifacts and their relationships. Based on this pillars, we propose in this paper a dedicated metric suite and measurement support for AML as an important ingredient for efficient risk assessment of heterogenous and distributed engineering data. We evaluate the feasibility of the proposed approach by providing tool support on top of the Eclipse Modeling Framework (EMF) and demonstrate its application with a showcase based on a real-world case study.

Wireless Sensor Networks (WSN) are nowadays applied to a wide set of domains (e.g., security, health). WSN are networks of spatially distributed, radio-communicating, battery-powered, autonomous sensor nodes. WSN are characterized by scarcity of resources, hence an application running on them should carefully manage its resources. The most critical resource in WSN is the nodes’ battery.

The growing request for high-quality applications for wireless sensor network (wsn) demands model-driven approaches that facilitate the design and the early validation of extra-functional properties by combining design and analysis models. for this purpose, uml and several analysis-specific languages can be chosen and weaved through translational approaches. however, the complexity brought by the underlying technological spaces may hinder the adoption of uml-based approaches in the wsn domain. the recently introduced foundational uml (fuml) standard provides a formal semantics to a strict uml subset, enabling the execution of uml models.

For developing software systems it is crucial to consider non-functional properties already in an early development stage to guarantee that the system will satisfy its non-functional requirements. Following the model-based engineering paradigm facilitates an early analysis of non-functional properties of the system being developed based on the elaborated design models. Although UML is widely used in model-based engineering, it is not suitable for model-based analysis directly due to its lack of formal semantics. Thus, current model-based analysis approaches transform UML models into formal languages dedicated for analyses purpose, which may introduce accidental complexity of implementing the required model transformations.The recently introduced fUML standard provides a formal semantics of a subset of UML enabling the execution of UML models. In this paper, we show how fUML can be utilized for analyzing UML models directly without having to transform them. We present a reusable framework for performing model-based analyses leveraging execution traces of UML models and integrating UML profiles heretofore unsupported by fUML. A case study in the performance analysis domain is used to illustrate the benefits of our framework.

Wireless Sensor Networks are becoming one of the most successful choices for the development and deployment of a wide range of applications, from intelligent homes to environment monitoring. In response to the growing demand for fast development of WSN applications, we extend an existing UML-based approach for the design and code generation of Agilla applications with functional simulation and timing analysis capabilities through executable UML models. The proposed approach makes use of both a UML profile and an executable model library for Agilla. Execution times, annotated on Agilla instructions and patterns in the library, are given as additional input parameters during the model execution to carry out a timing analysis of the simulated Agilla applications. Modeling and simulation activities rely on MagicDraw© and Cameo Simulation Toolkit©. A running case study is provided to show the approach and the supporting tools at work.

Context is an application-specific set of heterogeneous data that a context-aware system should be capable to sense to accordingly adapt its behavior. Context evolution may affect the qualities of the functionalities provided by context-aware systems, in terms of variations of its non-functional properties. In this paper we propose a distributed tool that is capable to monitor, retrieve and arrange heterogeneous data from any IP-enabled device in a set of state-based awareness manager models. The latter are meant to model the context evolution and to be integrated in model-driven approaches to evaluate the impact of the evolution of context on the quality of the provisioned services.

Cognitive behavioral systems would definitely benefit from a supporting technology able to automatically recognize the context where humans operate, their gestures and even facial expressions. Such capability poses challenges for many researchers in various fields because the ultimate goal is to transfer to machines the human capability of representing and reasoning on the environment and its elements. The automation can be achieved through a supporting infrastructure able to capture a huge amount of information from the environment, much more than humans do, and sending it to a processing unit able to build a representation of the context that would catch all elements necessary to interpret the specific environment. The goal of this paper is to present the VISION infrastructure and how it can support cognitive systems. Indeed, VISION is a software/hardware infrastructure that overcomes the limitations of current technology for Wireless Sensor Networks (WSNs) providing broadband wireless links for 3D video streaming with very high reliability, obtained by an innovative reconfigurable context and resource aware middleware for WSNs. We show VISION at work on the communicative impaired children scenario.

In this chapter, we describe the most important network protocols supporting modern applications in mobile cellular networks, wireless sensor networks (WSN) and mobile ad hoc networks (MANETs). We first focus on the handover procedure in mobile cellular networks and the network failures due this procedure. The current solutions to enable seamless handover in the existing networks technologies are presented. We then present, in the context of WSN, a framework for model-based design and performance analysis of WSN software applications. WSN are often used for applications with strict non-functional requirements. They, thus, require solid modelling approaches for non-functional attributes of WSN software applications. We finally discuss approaches and cross-layer protocols addressing the problems of security, wireless communications, and network topology changes in MANETs before presenting a framework which aims to study both the benefits of increased awareness between software layers on the same node (inter-layer awareness) and between the same layer over different nodes (intra-layer awareness), and the combination of new/existing protocols designed with a cross-layer criterion.

In this paper, we report on our experience with the application of validated models to assess performance, reliability, and adaptability of a complex mission critical system that is being developed to dynamically monitor and control the position of an oil-drilling platform. We present real-time modeling results that show that all tasks are schedulable. We performed stochastic analysis of the distribution of tasks execution time as a function of the number of system interfaces. We report on the variability of task execution times for the expected system configurations. In addition, we have executed a system library for an important task inside the performance model simulator. We report on the measured algorithm convergence as a function of the number of vessel thrusters. We have also studied the system architecture adaptability by comparing the documented system architecture and the implemented source code. We report on the adaptability findings and the recommendations we were able to provide to the system's architect. Finally, we have developed models of hardware and software reliability. We report on hardware reliability results based on the evaluation of the system architecture. As a topic for future work, we report on an approach that we recommend be applied to evaluate the system under study software reliability.

Context-awareness is becoming a first class attribute of software systems. In fact, applications for mobile devices need to be aware of their context in order to adapt their structure and behavior and offer the best quality of service even in case the (software and hardware) resources are limited. Although performance is a key non-functional property for such applications, existing approaches for performance modeling and analysis fail to capture the characteristics related to the context, thus resulting not suited for this domain. In this paper we introduce a framework for modeling and analyzing the performance of context-aware mobile software systems. The framework allows to model: the software architecture, the context management, the adaptable behaviors and the performance parameters. Such models can then be transformed into performance models for analysis purposes. We tailor an integrated environment for modeling these elements in UML, and we show how to use it for performance analysis purposes. The modeling environment description and the performance analysis are driven by an example in the eHealth domain.

Software services in the near ubiquitous future will need to cope with variability, as they are deployed on an increasingly large diversity of computing platforms, operate in different execution environments, and communicate through Beyond 3G (B3G) networks. Heterogeneity of the underlying communication and computing infrastructure, physical mobility of platform devices, and continuously evolving requirements claim for services to be adaptable according to the context changes without degrading their quality. Supporting the development and execution of software services in this setting raises numerous challenges that involve languages, methods and tools. However these challenges taken in isolation are not new in the service domain. Integrated solutions to these challenges are the main targets of the IST PLASTIC project. In this paper we introduce the PLASTIC development process model for self-adapting context-aware services, in which we propose model-based solutions to address the main issues of this domain in a comprehensive way. We instantiate the process model by providing methodologies to generate Quality of Service models and adaptable code from UML service models. All these methodologies are supported by an integrated framework which is based on an UML profile that we have defined for the PLASTIC domain.

In this paper, we report on our experience with the application of validated models to assess performance, reliability, and adaptability of a complex mission critical system that is being developed to dynamically monitor and control the position of an oil-drilling platform. We present real-time modeling results that show that all tasks are schedulable. We performed stochastic analysis of the distribution of tasks execution time as a function of the number of system interfaces. We report on the variability of task execution times for the expected system configurations. In addition, we have executed a system library for an important task inside the performance model simulator. We report on the measured algorithm convergence as a function of the number of vessel thrusters. We have also studied the system architecture adaptability by comparing the documented system architecture and the implemented source code. We report on the adaptability findings and the recommendations we were able to provide to the system's architect. Finally, we have developed models of hardware and software reliability. We report on hardware reliability results based on the evaluation of the system architecture. As a topic for future work, we report on an approach that we recommend be applied to evaluate the system under study software reliability.