Experimental Object-Oriented Modelling

This thesis examines object-oriented modelling in experimental system development. Object-oriented modelling aims at representing concepts and phenomena of a problem domain in terms of classes and objects. Experimental system development seeks active experimentation in a system development project through, e.g., technical prototyping and active user involvement. We introduce and examine "experimental object-oriented modelling" as the intersection of these practices

A Safety Analysis via Minimal Path Sets Detection for Object-Oriented Models

A new method is developed that integrates safety analysis with multi-domain object-oriented modelling. This is the contribution aimed by this paper. First, it recaps the basics of object-oriented modelling. Then, a model of a safety relevant aircraft system, a stabiliser trim system, is established using component models from generic libraries that are supplemented with failure behaviour. Next, a generic method is developed that automatically detects the minimal path sets of a technical system based on the corresponding object-oriented model, thus performing a safety analysis. Techniques from graph theory are adopted for computational efficiency and feasibility of the method. The minimal path sets detection method is exemplified by means of the established realistic system model

Object-oriented modelling with unified modelling language 2.0 for simple software application based on agile methodology

Unified modelling language (UML) 2.0 introduced in 2002 has been developing and influencing object-oriented software engineering and has become a standard and reference for information system analysis and design modelling. There are many concepts and theories to model the information system or software application with UML 2.0, which can make ambiguities and inconsistencies for a novice to learn to how to model the system with UML especially with UML 2.0. This article will discuss how to model the simple software application by using some of the diagrams of UML 2.0 and not by using the whole diagrams as suggested by agile methodology. Agile methodology is considered as convenient for novices because it can deliver the information technology environment to the end-user quickly and adaptively with minimal documentation. It also has the ability to deliver best performance software application according to the customer's needs. Agile methodology will make simple model with simple documentation, simple team and simple tools.Comment: 15 pages, 30 figure

Automating Dynamic Decoupling in Object-Oriented Modelling and Simulation Tools

Abstract This manuscript presents a technique that allows Equationbased Object-Oriented Modelling Tools (EOOMT) to exploit Dynamic Decoupling (DD) for partitioning a complex model into "weakly coupled" submodels. This enhances simulation efficiency, and is naturally keen to parallel integration or co-simulation. After giving an overview of the problem and of related work, we propose a method to automate DD by means of a novel structural analysis of the system -called "cycle analysis" -and of a mixed-mode integration method. Also, some considerations are exposed on how the presented technique can be integrated in EOOMT, considering as representative example a Modelica translator. Simulation tests demonstrate the technique, and the realised implementation is released as free software

A unified model of the electrical power network

Traditionally, the different infrastructure layers, technologies and management activities associated with the design, control and protection operation of the Electrical Power Systems have been supported by numerous independent models of the real world network. As a result of increasing competition in this sector, however, the integration of technologies in the network and the coordination of complex management processes have become of vital importance for all electrical power companies. The aim of the research outlined in this paper is to develop a single network model which will unify the generation, transmission and distribution infrastructure layers and the various alternative implementation technologies. This 'unified model' approach can support ,for example, network fault, reliability and performance analysis. This paper introduces the basic network structures, describes an object-oriented modelling approach and outlines possible applications of the unified model

A software modelling exercise using FCA

This paper describes an exercise in object-oriented modelling where Formal Concept Analysis is applied to a formal specification case study using Object-Z. In particular, the informal description from the case study is treated as a set of use-cases from which candidate classes and objects are derived. The resulting class structure is contrasted with the existing Object-Z design and the two approaches are discussed

Object-oriented modelling of thermal building behaviour

Zur Entwicklung und Planung energiesparender Gebäude, zum Entwurf geeigneter Regelungsalgorithmen benötigt man detailliertes Wissen über das thermische und energetische Verhalten eines Gebäudes, das in Wechselwirkung mit seiner Umgebung und seinen Bewohnern steht. Dies leistet ein mathematisches Modell. Die Beschreibung großer, komplexer technischer Systeme führt zu hoch komplexen, umfangreichen mathematischen Modellen, die - zur Simulation implementiert - große Softwaresysteme ergeben. Es liegt daher nahe, Konzepte der Informatik auch in der mathematischen Modellbildung zu nutzen. Neben der Dekomposition in Teilsysteme, den Strukturierungskonzepten zur Beherrschung der Komplexität ist hier ein aktueller Forschungsgegenstand der Informatik von besonderem Interesse. Es handelt sich um die Nutzung der Wiederverwendung als methodisches Element des Softwareentwicklungsprozesses großer Systeme. Es wurde eine Modellbibliothek zur Simulation thermischen Gebäudeverhaltens in Modelica erstellt. Sie untergliedert sich in die Abschnitte Gebäude-, Thermohydraulik-, Umgebungs- und Algorithmenbibliothek. Die objektorientiert implementierten, nicht berechnungskausalen Modellkomponenten sind hierarchisch strukturiert. Ihre Implementierung orientiert sich am intuitiven physikalischen Verständnis des zu beschreibenden technischen Prozesses. So aggregiert ein Gebäude einzelne Räume, Fenster, Wände und diese wiederum einzelne Wandschichten.For the development and construction of energy-saving buildings, their HVAC system, for the design of adequate control algorithms detailed knowledge about its thermal and energetic behaviour is needed. The external influences of the outdoor climate, user behaviour and internal loads have to be taken into account. An adequate mathematical description of the processes requires a wide spectrum of mathematical models from different physical and engineering disciplines. Explicit usage of reuse as design-method enhances the quality and efficiency of mathematical model development. Crucial for the reusability of the model components is besides the development of an adequate library structure the usage of modern concepts like object-oriented and non causal mathematical modelling. According to these principles an interdisciplinary model library for simulation of thermal building behaviour has been developed in Modelica. The model library is divided into four sublibraries (building, weather, heating, controller). Building models have been validated in exemplary configurations with the building simulation system TRNSYS