Simulation modelling and visualisation: toolkits for building artificial worlds

Simulations users at all levels make heavy use of compute resources to drive computational simulations for greatly varying applications areas of research using different simulation paradigms. Simulations are implemented in many software forms, ranging from highly standardised and general models that run in proprietary software packages to ad hoc hand-crafted simulations codes for very specific applications. Visualisation of the workings or results of a simulation is another highly valuable capability for simulation developers and practitioners. There are many different software libraries and methods available for creating a visualisation layer for simulations, and it is often a difficult and time-consuming process to assemble a toolkit of these libraries and other resources that best suits a particular simulation model. We present here a break-down of the main simulation paradigms, and discuss differing toolkits and approaches that different researchers have taken to tackle coupled simulation and visualisation in each paradigm

Animating the evolution of software

The use and development of open source software has increased significantly in the last decade. The high frequency of changes and releases across a distributed environment requires good project management tools in order to control the process adequately. However, even with these tools in place, the nature of the development and the fact that developers will often work on many other projects simultaneously, means that the developers are unlikely to have a clear picture of the current state of the project at any time. Furthermore, the poor documentation associated with many projects has a detrimental effect when encouraging new developers to contribute to the software. A typical version control repository contains a mine of information that is not always obvious and not easy to comprehend in its raw form. However, presenting this historical data in a suitable format by using software visualisation techniques allows the evolution of the software over a number of releases to be shown. This allows the changes that have been made to the software to be identified clearly, thus ensuring that the effect of those changes will also be emphasised. This then enables both managers and developers to gain a more detailed view of the current state of the project. The visualisation of evolving software introduces a number of new issues. This thesis investigates some of these issues in detail, and recommends a number of solutions in order to alleviate the problems that may otherwise arise. The solutions are then demonstrated in the definition of two new visualisations. These use historical data contained within version control repositories to show the evolution of the software at a number of levels of granularity. Additionally, animation is used as an integral part of both visualisations - not only to show the evolution by representing the progression of time, but also to highlight the changes that have occurred. Previously, the use of animation within software visualisation has been primarily restricted to small-scale, hand generated visualisations. However, this thesis shows the viability of using animation within software visualisation with automated visualisations on a large scale. In addition, evaluation of the visualisations has shown that they are suitable for showing the changes that have occurred in the software over a period of time, and subsequently how the software has evolved. These visualisations are therefore suitable for use by developers and managers involved with open source software. In addition, they also provide a basis for future research in evolutionary visualisations, software evolution and open source development

Introductory programming: a systematic literature review

As computing becomes a mainstream discipline embedded in the school curriculum and acts as an enabler for an increasing range of academic disciplines in higher education, the literature on introductory programming is growing. Although there have been several reviews that focus on specific aspects of introductory programming, there has been no broad overview of the literature exploring recent trends across the breadth of introductory programming. This paper is the report of an ITiCSE working group that conducted a systematic review in order to gain an overview of the introductory programming literature. Partitioning the literature into papers addressing the student, teaching, the curriculum, and assessment, we explore trends, highlight advances in knowledge over the past 15 years, and indicate possible directions for future research

The State Of Play: A Notional Machine for Learning Programming

Comprehension of programming and programs is known to be a difficult task for many beginning students, with many computing courses showing significant drop out and failure rates. In this paper, we present a new notional machine de- sign and implementation to help with understanding of pro- gramming and its dynamics for beginning learners. The no- tional machine offers an abstraction of the physical machine designed for comprehension and learning purposes. We in- troduce the notional machine and a graphical notation for its representation. We also present Novis, an implementation of a dynamic real-time visualiser of this notional machine, integrated into BlueJ

Algon: a framework for supporting comparison of distributed algorithm performance

Programmers often need to use distributed algorithms to add non-functional behaviour such as mutual exclusion, deadlock detection and termination, to a distributed application. They find the selection and implementation of these algorithms daunting. Consequently, they have no idea which algorithm will be best for their particular application. To address this difficulty the Algon framework provides a set of pre-coded distributed algorithms for programmers to choose from, and provides a special performance display tool to support choice between algorithms. The performance tool is discussed. The developer of a distributed application will be able to observe the performance of each of the available algorithms according to a set of of widely accepted and easily-understandable performance metrics and compare and contrast the behaviour of the algorithms to support an informed choice. The strength of the Algon framework is that it does not require a working knowledge of algorithmic theory or functionality in order for the developer to use the algorithms

Applying inspection to object-oriented software

The benefits of the object-oriented paradigmare widely cited. At the same time, inspection is deemed to be the most cost-effective means of detecting defects in software products. Why then, is there no published experience, let alone quantitative data, on the application of inspection to object-oriented systems? We describe the facilities of the object-oriented paradigm and the issues that these raise when inspecting object-oriented code. Several problems are caused by the disparity between the static code structure and its dynamic runtime behaviour. The large number of small methods in object-oriented systems can also cause problems. We then go on to describe three areas which may help mitigate problems found. Firstly, the use of various programming methods may assist in making object-oriented code easier to inspect. Secondly, improved program documentation can help the inspector understand the code which is under inspection. Finally, tool support can help the inspector to analyse the dynamic behaviour of the code. We conclude that while both the object-oriented paradigm and inspection provide excellent benefits on their own, combining the two may be a difficult exercise, requiring extensive support if it is to be successful

Integrating BIM and Planning Software for Health and Safety Site Induction

Project management software packages have been around for quite a long time to help managers to run construction projects effectively. Building Information Modelling – also known as Object-orientated Modelling technology was used at the beginning in architectural design which has become more widespread in structural and services engineering. The development of BIM modelling has made the tool more users friendly. As a result, BIM became widely used by most practitioners in their specialist areas. For health and safety practitioners within construction project management, This tool has not been fully explored. BIM technology has the potential to be used in safety planning procedures particularly those related to tasks on construction sites. The section of the research presented in this paper intend to explore and review health and safety issues on construction site with the sole intension of using better visualisation software to meet the needs of health and safety site practitioners in understanding such H&S problems. A framework needed for better H&S practice on site that may be used actively by all practitioners will be developed. The intension is to find a way forward in addressing ‘real’ health and safety site issues that may not be easy to be understood by practitioners without the full aid of visualisation. Keywords: Health, Safety, construction site, BIM, 4D Modellin

Runtime visualisation of object-oriented software

Software is a complex and invisible entity, yet one which is core to modem life. The development and maintenance of such software includes one staple task, the need to understand the software at the implementation level. This process of program comprehension is difficult and time consuming. Yet, despite its importance, there remains very limited tool support for program comprehension activities. The results of this research show the role that runtime visualisation can play in aiding the comprehension of object-oriented software by highlighting both its static and dynamic structure. Previous work in this area is discussed, both in terms of the representations used and the methods of extracting runtime information. Building on this previous work, this thesis develops new representations of object-oriented software at runtime, which are then implemented in a proof of concept tool. This tool allowed the representations to be investigated on real software systems. The representations are evaluated against two feature-based evaluation frameworks. The evaluation focuses on generic software visualisation criteria, due to the lack of any specific frameworks for visualising dynamic information. The evaluation also includes lessons learnt in the implementation of a prototype visualisation tool. The object-oriented paradigm continues to grow in popularity and provides advantages to program comprehension activities. However, it also brings a number of new challenges to program comprehension due to the discrepancies between its static definition and its runtime structure. Therefore, techniques that highlight both the static definition and the runtime behaviour of object-oriented systems offer benefits to their comprehension. Software visualisation offers an approach to aid program comprehension activities through providing a means to deal with the size and complexity of the software and its invisible nature. This thesis highlights the generic issues that software visualisation faces, before focusing on how the visualisation of runtime information affects these issues. Many of the issues are compounded by the dynamic nature of the information to be visualised and the explosive growth in the volume of information that this dynamism can bring. Wider results of this research have allowed the proposal of the necessary concepts that should be considered in the design and evaluation of runtime visualisations. Software visualisation at runtime is still a relatively unexplored area and there remains many research challenges within it. This thesis aims to act as a first step to addressing these challenges and aims to promote interest and future development within this area

A virtual environment to support the distributed design of large made-to-order products

An overview of a virtual design environment (virtual platform) developed as part of the European Commission funded VRShips-ROPAX (VRS) project is presented. The main objectives for the development of the virtual platform are described, followed by the discussion of the techniques chosen to address the objectives, and finally a description of a use-case for the platform. Whilst the focus of the VRS virtual platform was to facilitate the design of ROPAX (roll-on passengers and cargo) vessels, the components within the platform are entirely generic and may be applied to the distributed design of any type of vessel, or other complex made-to-order products

An overview of the VRS virtual platform

This paper provides an overview of the development of the virtual platform within the European Commission funded VRShips-ROPAX (VRS) project. This project is a major collaboration of approximately 40 industrial, regulatory, consultancy and academic partners with the objective of producing two novel platforms. A physical platform will be designed and produced representing a scale model of a novel ROPAX vessel with the following criteria: 2000 passengers; 400 cabins; 2000 nautical mile range, and a service speed of 38 knots. The aim of the virtual platform is to demonstrate that vessels may be designed to meet these criteria, which was not previously possible using individual tools and conventional design approaches. To achieve this objective requires the integration of design and simulation tools representing concept, embodiment, detail, production, and operation life-phases into the virtual platform, to enable distributed design activity to be undertaken. The main objectives for the development of the virtual platform are described, followed by the discussion of the techniques chosen to address the objectives, and finally a description of a use-case for the platform. Whilst the focus of the VRS virtual platform was to facilitate the design of ROPAX vessels, the components within the platform are entirely generic and may be applied to the distributed design of any type of vessel, or other complex made-to-order products