A logical approach for behavioural composition of scenario-based models

As modern systems become more complex, design approaches model different aspects of the system separately. When considering (intra and inter) system interactions, it is usual to model individual scenarios using UML’s sequence diagrams. Given a set of scenarios we then need to check whether these are consistent and can be combined for a better understanding of the overall behaviour. This paper addresses this by presenting a novel formal technique for composing behavioural models at the metamodel level through exact metamodel restriction (EMR). In our approach a sequence diagram can be completely described by a set of logical constraints at the metamodel level. When composing sequence diagrams we take the union of the sets of logical constraints for each diagram and additional behavioural constraints that describe the matching composition glue. A formal semantics for composition in accordance with the glue guides our model transformation to Alloy. Alloy’s fully automated constraint solver gives us the solution. Our technique has been implemented as an Eclipse plugin SD2Alloy.Postprin

Combining behavioural types with security analysis

Today's software systems are highly distributed and interconnected, and they increasingly rely on communication to achieve their goals; due to their societal importance, security and trustworthiness are crucial aspects for the correctness of these systems. Behavioural types, which extend data types by describing also the structured behaviour of programs, are a widely studied approach to the enforcement of correctness properties in communicating systems. This paper offers a unified overview of proposals based on behavioural types which are aimed at the analysis of security properties

Ontology-based modelling of architectural styles

The conceptual modelling of software architectures is of central importance for the quality of a software system. A rich modelling language is required to integrate the different aspects of architecture modelling, such as architectural styles, structural and behavioural modelling, into a coherent framework. Architectural styles are often neglected in software architectures. We propose an ontological approach for architectural style modelling based on description logic as an abstract, meta-level modelling instrument. We introduce a framework for style definition and style combination. The application of the ontological framework in the form of an integration into existing architectural description notations is illustrated

Key research themes on travel behavior, lifestyle, and sustainable urban mobility

The concept of lifestyle adds a behavioral component to travel models that used to be dominated by engineering and econometric traditions. This article presents an overview of how lifestyle is defined and measured in transport studies, and how travel behavior is influenced by lifestyles. Lifestyles are often used pragmatically rather than theoretically in the behavior studies. Nevertheless, some important theoretical contributions have been made, especially in sociology by scholars such as Weber, Bourdieu, Ganzeboom, and Schulze who agree on the communicative character of lifestyles: individuals express their social position through specific patterns of behavior, consumption, and leisure. These behavioral patterns are shaped by underlying opinions and orientations, including beliefs, interests, and attitudes. Thus, travel behavior is not simply determined by price, speed, and comfort but is also related to attitudes, status, and preferences. Because lifestyle has many different dimensions, a variety of measurement approaches exists. Nevertheless, most studies suggest that travel behavior is conditioned by specific lifestyles. How lifestyles themselves can be modified to promote more sustainable patterns of transport has not received much attention to date. This article argues that lifestyles need to be considered as dynamic rather than as static and given, and that future research could delve more deeply into this area

Ontology-based patterns for the integration of business processes and enterprise application architectures

Increasingly, enterprises are using Service-Oriented Architecture (SOA) as an approach to Enterprise Application Integration (EAI). SOA has the potential to bridge the gap between business and technology and to improve the reuse of existing applications and the interoperability with new ones. In addition to service architecture descriptions, architecture abstractions like patterns and styles capture design knowledge and allow the reuse of successfully applied designs, thus improving the quality of software. Knowledge gained from integration projects can be captured to build a repository of semantically enriched, experience-based solutions. Business patterns identify the interaction and structure between users, business processes, and data. Specific integration and composition patterns at a more technical level address enterprise application integration and capture reliable architecture solutions. We use an ontology-based approach to capture architecture and process patterns. Ontology techniques for pattern definition, extension and composition are developed and their applicability in business process-driven application integration is demonstrated

A monitoring approach for runtime service discovery

Effective runtime service discovery requires identification of services based on different service characteristics such as structural, behavioural, quality, and contextual characteristics. However, current service registries guarantee services described in terms of structural and sometimes quality characteristics and, therefore, it is not always possible to assume that services in them will have all the characteristics required for effective service discovery. In this paper, we describe a monitor-based runtime service discovery framework called MoRSeD. The framework supports service discovery in both push and pull modes of query execution. The push mode of query execution is performed in parallel to the execution of a service-based system, in a proactive way. Both types of queries are specified in a query language called SerDiQueL that allows the representation of structural, behavioral, quality, and contextual conditions of services to be identified. The framework uses a monitor component to verify if behavioral and contextual conditions in the queries can be satisfied by services, based on translations of these conditions into properties represented in event calculus, and verification of the satisfiability of these properties against services. The monitor is also used to support identification that services participating in a service-based system are unavailable, and identification of changes in the behavioral and contextual characteristics of the services. A prototype implementation of the framework has been developed. The framework has been evaluated in terms of comparison of its performance when using and when not using the monitor component

Behavioural equivalences for timed systems

Timed transition systems are behavioural models that include an explicit treatment of time flow and are used to formalise the semantics of several foundational process calculi and automata. Despite their relevance, a general mathematical characterisation of timed transition systems and their behavioural theory is still missing. We introduce the first uniform framework for timed behavioural models that encompasses known behavioural equivalences such as timed bisimulations, timed language equivalences as well as their weak and time-abstract counterparts. All these notions of equivalences are naturally organised by their discriminating power in a spectrum. We prove that this result does not depend on the type of the systems under scrutiny: it holds for any generalisation of timed transition system. We instantiate our framework to timed transition systems and their quantitative extensions such as timed probabilistic systems

Activity-based model development to support transport planning in the Stockholm region

The environment in which transportation analysis and infrastructure planning take place has changed dramatically during the last years. The focus is now, to a considerable extent, on how to transform the transportation system in a direction that could be sustainable in the long run, rather than on planning for infrastructure investment to meet new demand. At the same time information technology penetrates all sectors of the society. This will change how the transportation system will be used by travellers and conveyers, both directly, through new products and services, and, indirectly, through a spatial reorganisation of many activities that govern the transport demand. In such a situation it must be questioned whether the analytical tools that may have functioned reasonably well in the past, also are appropriate, or possible to adapt, to be useful for the issues we will face in the future. A survey is made of ideas for model development for travel analysis with an emphasis on activity based models based on an international literature review. The study treats tools for the whole chain from location decisions to network effects. The main focus is on such development that is of interest for a medium-sized city like Stockholm. It stresses demands that might be raised on modelling tools with a background in the planning issues that can expected to be central within the next ten-year period. Different ideas for model development, and existing models that could be considered for implementation, are evaluated with respect to their usefulness for planning, need for resources, demand for competence and data, and obstacles of implementation. Finally, we are suggesting some specific model development that should be tested in Stockholm, including a pilot study concerning the implementation of an activity-based model.

Cyber-Virtual Systems: Simulation, Validation & Visualization

We describe our ongoing work and view on simulation, validation and visualization of cyber-physical systems in industrial automation during development, operation and maintenance. System models may represent an existing physical part - for example an existing robot installation - and a software simulated part - for example a possible future extension. We call such systems cyber-virtual systems. In this paper, we present the existing VITELab infrastructure for visualization tasks in industrial automation. The new methodology for simulation and validation motivated in this paper integrates this infrastructure. We are targeting scenarios, where industrial sites which may be in remote locations are modeled and visualized from different sites anywhere in the world. Complementing the visualization work, here, we are also concentrating on software modeling challenges related to cyber-virtual systems and simulation, testing, validation and verification techniques for them. Software models of industrial sites require behavioural models of the components of the industrial sites such as models for tools, robots, workpieces and other machinery as well as communication and sensor facilities. Furthermore, collaboration between sites is an important goal of our work.Comment: Preprint, 9th International Conference on Evaluation of Novel Approaches to Software Engineering (ENASE 2014