Graphical Programming of Simulation Models in an Object-Oriented Environment

Graphical programming has been used in conjunction with conventional simulation languages via block diagrams or activity networks. Its beneficial effects on programming and modeling in simulation have been accepted by everyone involved in these languages. However, none of these conventional techniques is truely interactive. Given the level of the current hardware and software technology, it is possible to design a very good graphical programming system which supports an interactive incremental programming style in specifications of simulation models. The benefit of such a visual system would go beyond the modeling phase of a simulation study and it might as well be realized in understanding the behavior of complex problems, in being a communication and training medium for the user and developers, and finally in presenting the simulation results. In this study, the graphical programming methodology has been investigated from the perspective of object-oriented simulation. The truely interactive and graphical orientation of some of the object-oriented languages (e.g., Smalltalk-80) has opened up new avenues of research in this very important topic. Today, the nature of this type of research will be not whether it can be done but how the known techniques should be combined to yield the highest benefit

Object oriented studies into artificial space debris

A prototype simulation is being developed under contract to the Royal Aerospace Establishment (RAE), Farnborough, England, to assist in the discrimination of artificial space objects/debris. The methodology undertaken has been to link Object Oriented programming, intelligent knowledge based system (IKBS) techniques and advanced computer technology with numeric analysis to provide a graphical, symbolic simulation. The objective is to provide an additional layer of understanding on top of conventional classification methods. Use is being made of object and rule based knowledge representation, multiple reasoning, truth maintenance and uncertainty. Software tools being used include Knowledge Engineering Environment (KEE) and SymTactics for knowledge representation. Hooks are being developed within the SymTactics framework to incorporate mathematical models describing orbital motion and fragmentation. Penetration and structural analysis can also be incorporated. SymTactics is an Object Oriented discrete event simulation tool built as a domain specific extension to the KEE environment. The tool provides facilities for building, debugging and monitoring dynamic (military) simulations

Modeling and Verification in Structured Integrated Circuit Design

Traditional design tools based on geometric representations do not provide an adequate base from which to construct and verify silicon implementations of complex systems. More comprehensive structural, physical and behavioural descriptions must be developed from appropriate representations. This thesis proposes models which may be used to construct unified and consistent descriptions of the structural, physical and behavoural attributes of a design. It also discusses a method of capturing these descriptions using a textual representation embedded in an object oriented programming language. A range of subsytems have been implemented within a design environment tailored to the proposed models of the design activitiy. In addition to the typical graphical feedback and mask making oriented output a comprehensibe list of verificaiton procedures has been integrated into the system. These include dimensional design rule checking, electrical calculations, connectivity verification and simulation at a number of levels of abstraction

Modelling and simulation framework for reactive transport of organic contaminants in bed-sediments using a pure java object - oriented paradigm

Numerical modelling and simulation of organic contaminant reactive transport in the environment is being increasingly relied upon for a wide range of tasks associated with risk-based decision-making, such as prediction of contaminant profiles, optimisation of remediation methods, and monitoring of changes resulting from an implemented remediation scheme. The lack of integration of multiple mechanistic models to a single modelling framework, however, has prevented the field of reactive transport modelling in bed-sediments from developing a cohesive understanding of contaminant fate and behaviour in the aquatic sediment environment. This paper will investigate the problems involved in the model integration process, discuss modelling and software development approaches, and present preliminary results from use of CORETRANS, a predictive modelling framework that simulates 1-dimensional organic contaminant reaction and transport in bed-sediments

A Programming Environment Evaluation Methodology for Object-Oriented Systems

The object-oriented design strategy as both a problem decomposition and system development paradigm has made impressive inroads into the various areas of the computing sciences. Substantial development productivity improvements have been demonstrated in areas ranging from artificial intelligence to user interface design. However, there has been very little progress in the formal characterization of these productivity improvements and in the identification of the underlying cognitive mechanisms. The development and validation of models and metrics of this sort require large amounts of systematically-gathered structural and productivity data. There has, however, been a notable lack of systematically-gathered information on these development environments. A large part of this problem is attributable to the lack of a systematic programming environment evaluation methodology that is appropriate to the evaluation of object-oriented systems

A Development Environment for Visual Physics Analysis

The Visual Physics Analysis (VISPA) project integrates different aspects of physics analyses into a graphical development environment. It addresses the typical development cycle of (re-)designing, executing and verifying an analysis. The project provides an extendable plug-in mechanism and includes plug-ins for designing the analysis flow, for running the analysis on batch systems, and for browsing the data content. The corresponding plug-ins are based on an object-oriented toolkit for modular data analysis. We introduce the main concepts of the project, describe the technical realization and demonstrate the functionality in example applications

Strategic Directions in Object-Oriented Programming

This paper has provided an overview of the field of object-oriented programming. After presenting a historical perspective and some major achievements in the field, four research directions were introduced: technologies integration, software components, distributed programming, and new paradigms. In general there is a need to continue research in traditional areas:\ud (1) as computer systems become more and more complex, there is a need to further develop the work on architecture and design; \ud (2) to support the development of complex systems, there is a need for better languages, environments, and tools; \ud (3) foundations in the form of the conceptual framework and other theories must be extended to enhance the means for modeling and formal analysis, as well as for understanding future computer systems

A methodology for the efficient computer representation of dynamic power systems : application to wind parks

This contribution presents a methodology to efficiently obtain the numerical and computer solution of dynamic power systems with high penetration of wind turbines. Due to the excessive computational load required to solve the abc models that represent the behavior of the wind turbines, a parallel processing scheme is proposed to enhance the solution of the overall system. Case studies are presented which demonstrate the effectiveness and applications of the proposed methodology