Leveraging legacy codes to distributed problem solving environments: A web service approach

This paper describes techniques used to leverage high performance legacy codes as CORBA components to a distributed problem solving environment. It first briefly introduces the software architecture adopted by the environment. Then it presents a CORBA oriented wrapper generator (COWG) which can be used to automatically wrap high performance legacy codes as CORBA components. Two legacy codes have been wrapped with COWG. One is an MPI-based molecular dynamic simulation (MDS) code, the other is a finite element based computational fluid dynamics (CFD) code for simulating incompressible Navier-Stokes flows. Performance comparisons between runs of the MDS CORBA component and the original MDS legacy code on a cluster of workstations and on a parallel computer are also presented. Wrapped as CORBA components, these legacy codes can be reused in a distributed computing environment. The first case shows that high performance can be maintained with the wrapped MDS component. The second case shows that a Web user can submit a task to the wrapped CFD component through a Web page without knowing the exact implementation of the component. In this way, a user’s desktop computing environment can be extended to a high performance computing environment using a cluster of workstations or a parallel computer

Experiences modelling and using object-oriented telecommunication service frameworks in SDL

This paper describes experiences in using SDL and its associated tools to create telecommunication services by producing and specialising object-oriented frameworks. The chosen approach recognises the need for the rapid creation of validated telecommunication services. It introduces two stages to service creation. Firstly a software expert produces a service framework, and secondly a telecommunications ‘business consultant' specialises the framework by means of graphical tools to rapidly produce services. Here the focus is given to the underlying technology required. In particular, the advantages and disadvantages of SDL and tools for this purpose are highlighted

Experiences in Integrated Multi-Domain Service Management

Increased competition, complex service provision chains and integrated service offerings require effective techniques for the rapid integration of telecommunications services and management systems over multiple organisational domains. This paper presents some of the results of practical development work in this area, detailing the technologies and standards used, the architectural approach taken and the application of this approach to specific services. This work covers the integration of multimedia services, broadband networks, service management and network management, though the detailed examples given focus specifically on the integration of services and service management

Location independent distributed model for on-line load flow monitoring for multi–area power systems

The main objective of this paper is to construct a location transparent distributed environment through which the on-line load flow of multi-area power systems can be monitored and controlled. A single-server/multi-client architecture has been proposed which enables that the neighboring powered system clients can access the remote relay control server at any time, with their respective data. The location transparency is the key feature of Common Object Request Broker Architecture (CORBA). Location transparency of the proposed model is the ability to access and invoke operations on the CORBA server object without needing to know where the power system object resides. Developed distributed model also provides language transparency that facilitates the implementation of the power system logic in any programming language. A CORBA based distributed model has been developed in such a way that for every specific period of time, the remote relay control server obtains the system data simultaneously from the neighboring relays which are the clients registered with it and the server send back the response to the respective clients. The relay control server creates a new thread of control for every client request and hence complete distributed environment has been exploited