1,267 research outputs found
Modelling and analyzing adaptive self-assembling strategies with Maude
Building adaptive systems with predictable emergent behavior is a challenging task and it is becoming a critical need. The research community has accepted the challenge by introducing approaches of various nature: from software architectures, to programming paradigms, to analysis techniques. We recently proposed a conceptual framework for adaptation centered around the role of control data. In this paper we show that it can be naturally realized in a reflective logical language like Maude by using the Reflective Russian Dolls model. Moreover, we exploit this model to specify and analyse a prominent example of adaptive system: robot swarms equipped with obstacle-avoidance self-assembly strategies. The analysis exploits the statistical model checker PVesta
Proceedings of the 11th Overture Workshop
The 11th Overture Workshop was held in Aarhus, Denmark on Wed/Thu 28â29th Au- gust 2013. It was the 11th workshop in the current series focusing on the Vienna De- velopment Method (VDM) and particularly its community-based tools development project, Overture (http://www.overturetool.org/), and related projects such as COMPASS(http://www.compass-research.eu/) and DESTECS (http://www.destecs.org). Invited talks were given by Yves Ledru and Joe Kiniry. The workshop attracted 25 participants representing 10 nationalities. The goal of the workshop was to provide a forum to present new ideas, to identify and encourage new collaborative research, and to foster current strands of work towards publication in the mainstream conferences and journals. The Overture initiative held its first workshop at FMâ05. Workshops were held subsequently at FMâ06, FMâ08 and FMâ09, FMâ11, FMâ12 and in between
Timed Actors and Their Formal Verification
In this paper we review the actor-based language, Timed Rebeca, with a focus
on its formal semantics and formal verification techniques. Timed Rebeca can be
used to model systems consisting of encapsulated components which communicate
by asynchronous message passing. Messages are put in the message buffer of the
receiver actor and can be seen as events. Components react to these
messages/events and execute the corresponding message/event handler. Real-time
features, like computation delay, network delay and periodic behavior, can be
modeled in the language. We explain how both Floating-Time Transition System
(FTTS) and common Timed Transition System (TTS) can be used as the semantics of
such models and the basis for model checking. We use FTTS when we are
interested in event-based properties, and it helps in state space reduction.
For checking the properties based on the value of variables at certain point in
time, we use the TTS semantics. The model checking toolset supports
schedulability analysis, deadlock and queue-overflow check, and assertion based
verification of Timed Rebeca models. TCTL model checking based on TTS is also
possible but is not integrated in the tool.Comment: In Proceedings EXPRESS/SOS2023, arXiv:2309.0578
The Impact of Petri Nets on System-of-Systems Engineering
The successful engineering of a large-scale system-of-systems project towards deterministic behaviour depends on integrating autonomous components using international communications standards in accordance with dynamic requirements. To-date, their engineering has been unsuccessful: no combination of top-down and bottom-up engineering perspectives is adopted, and information exchange protocol and interfaces between components are not being precisely specified. Various approaches such as modelling, and architecture frameworks make positive contributions to system-of-systems specification but their successful implementation is still a problem.
One of the most popular modelling notations available for specifying systems, UML, is intuitive and graphical but also ambiguous and imprecise. Supplying a range of diagrams to represent a system under development, UML lacks simulation and exhaustive verification capability. This shortfall in UML has received little attention in the context of system-of-systems and there are two major research issues:
1. Where the dynamic, behavioural diagrams of UML can and cannot be used to model and analyse system-of-systems
2. Determining how Petri nets can be used to improve the specification and analysis of the dynamic model of a system-of-systems specified using UML
This thesis presents the strengths and weaknesses of Petri nets in relation to the specification of system-of-systems and shows how Petri net models can be used instead of conventional UML Activity Diagrams. The model of the system-of-systems can then be analysed and verified using Petri net theory. The Petri net formalism of behaviour is demonstrated using two case studies from the military domain. The first case study uses Petri nets to specify and analyse a close air support mission. This case study concludes by indicating the strengths, weaknesses, and shortfalls of the proposed formalism in system-of-systems specification. The second case study considers specification of a military exchange network parameters problem and the results are compared with the strengths and weaknesses identified in the first case study.
Finally, the results of the research are formulated in the form of a Petri net enhancement to UML (mapping existing activity diagram elements to Petri net elements) to meet the needs of system-of-systems specification, verification and validation
Development of a GIS-based decision support tool for environmental impact assessment and due-diligence analyses of planned agricultural floating solar systems
Text in EnglishIn recent years, there have been tremendous advances in information technology, robotics, communication technology, nanotechnology, and artificial intelligence, resulting in the merging of physical, digital, and biological worlds that have come to be known as the "fourth industrial revolutionâ. In this context, the present study engages such technology in the green economy and to tackle the techno-economic environmental impact assessments challenges associated with floating solar system applications in the agricultural sector of South Africa. In response, this exploratory study aimed to examine the development of a Geographical Information System (GIS)-based support platform for Environmental Impact Assessment (EIA) and due-diligence analyses for future planned agricultural floating solar systems, especially with the goal to address the vast differences between the environmental impacts for land-based and water-based photovoltaic energy systems.
A research gap was identified in the planning processes for implementing floating solar
systems in South Africaâs agricultural sector. This inspired the development of a novel GIS-based modelling tool to assist with floating solar system type energy infrastructure planning in the renewable energy discourse. In this context, there are significant challenges and future research avenues for technical and environmental performance modelling in the new sustainable energy transformation. The present dissertation and geographical research ventured into the conceptualisation, designing and development of a software GIS-based decision support tool to assist environmental impact practitioners, project owners and landscape architects to perform environmental scoping and environmental due-diligence analysis for planned floating solar systems in the local agricultural sector. In terms of the aims and objectives of the research, this project aims at the design and development of a dedicated GIS toolset to determine the environmental feasibility around the use of floating solar systems in agricultural applications in South Africa. In this context, the research objectives of this study included the use of computational modelling and simulation techniques to theoretically determine the energy yield predictions and computing environmental impacts/offsets for future planned agricultural floating solar systems in South
Africa. The toolset succeeded in determining these aspects in applications where floating
solar systems would substitute Eskom grid power. The study succeeded in developing a
digital GIS-based computer simulation model for floating solar systems capable of (a) predicting the anticipated energy yield, (b) calculating the environmental offsets achieved by substituting coal-fired generation by floating solar panels, (c) determining the environmental impact and land-use preservation benefits of any floating solar system, and (d) relating these metrics to water-energy-land-food (WELF) nexus parameters suitable for user project viability analysis and decision support. The research project has demonstrated how the proposed GIS toolset supports the body of geographical knowledge in the fields of Energy and Environmental Geography. The new toolset, called EIAcloudGIS, was developed to assist in solving challenges around
energy and environmental sustainability analysis when planning new floating solar installations on farms in South Africa. Experiments conducted during the research showed how the geographical study in general, and the toolset in particular, succeeded in solving a real-world problem. Through the formulation and development of GIS-based computer simulation models embedded into GIS layers, this new tool practically supports the National Environmental Management Act (NEMA Act No. 107 of 1998), and in particular, associated EIA processes. The tool also simplifies and semi-automates certain aspects of environmental impact analysis processes for newly envisioned and planned floating solar installations in South Africa.GeographyM.Sc. (Geography
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