Efficient computation of aerodynamic influence coefficients for aeroelastic analysis on a transputer network

Aeroelastic analysis is multi-disciplinary and computationally expensive. Hence, it can greatly benefit from parallel processing. As part of an effort to develop an aeroelastic capability on a distributed memory transputer network, a parallel algorithm for the computation of aerodynamic influence coefficients is implemented on a network of 32 transputers. The aerodynamic influence coefficients are calculated using a 3-D unsteady aerodynamic model and a parallel discretization. Efficiencies up to 85 percent were demonstrated using 32 processors. The effect of subtask ordering, problem size, and network topology are presented. A comparison to results on a shared memory computer indicates that higher speedup is achieved on the distributed memory system

Distributed Finite Element Analysis Using a Transputer Network

The principal objective of this research effort was to demonstrate the extraordinarily cost effective acceleration of finite element structural analysis problems using a transputer-based parallel processing network. This objective was accomplished in the form of a commercially viable parallel processing workstation. The workstation is a desktop size, low-maintenance computing unit capable of supercomputer performance yet costs two orders of magnitude less. To achieve the principal research objective, a transputer based structural analysis workstation termed XPFEM was implemented with linear static structural analysis capabilities resembling commercially available NASTRAN. Finite element model files, generated using the on-line preprocessing module or external preprocessing packages, are downloaded to a network of 32 transputers for accelerated solution. The system currently executes at about one third Cray X-MP24 speed but additional acceleration appears likely. For the NASA selected demonstration problem of a Space Shuttle main engine turbine blade model with about 1500 nodes and 4500 independent degrees of freedom, the Cray X-MP24 required 23.9 seconds to obtain a solution while the transputer network, operated from an IBM PC-AT compatible host computer, required 71.7 seconds. Consequently, the $80,000 transputer network demonstrated a cost-performance ratio about 60 times better than the$15,000,000 Cray X-MP24 system

Network control for a multi-user transputer-based system.

A dissertation submitted to the Faculty of Engineering, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science in EngineeringThe MC2/64 system is a configureable multi-user transputer- based system which was designed using a modular approach. The MC2/64 consists of MC2 Clusters which are connected using a modified Clos network. The MC2 Clusters were designed and realised as completely configurable modules using and extending an algorithm based on Eulerian cycles through a requested graph. This dissertation discusses the configuration algorithm and the extensions made to the algorithm for the MC2 Clusters. The total MC2/64 system is not completely configurable as a MC2 Cluster releases only a limited number of links for inter-cluster connections. This dissertation analyses the configurability of MC2/64, but also presents algorithms which enhance the usability of the system from the user's point of view. The design and the implementation of the network control software are also submitted as topics in this dissertation. The network control software must allow multiple users to use the system, but without them influencing each other's transputer domains. This dissertation therefore seeks to give an overview of network control problems and the solutions implemented in current MC2/64 systems. The results of the research done for this dissertation will hopefully aid in the design of future MC2 systems which will provide South Africa with much needed, low cost, high performance computing power.Andrew Chakane 201

A transputer based implementation of a quick look processor for an airborne SAR system

Includes bibliographical references.The purpose of this thesis is to describe the development of a transputer based real-time Synthetic Aperture Radar (SAR) processor called the Quick Look Processor (QLP). The QLP is required to produce medium resolution, real-time images at a wavelength of 2.5m for the airborne South African SAR (SASAR) system which is under development at the University of Cape Town (UCT). The required azimuth resolution for the QLP is 30m and system is required to process 2048 range bins at a rate of 39 range lines per second. The algorithm used was developed at UCT, and works on the principle of dividing up the synthetic aperture into subapertures with appropriate phase corrections. This method is used in order to reduce computational loading (for real-time processing), but at the same time achieve medium resolution processing. One of the fundamental issues concerning this algorithm is its efficiency as the required azimuth resolution is increased. The system is designed around a host PC and a network of nine transputers. The host PC communicates with the other SASAR subsystems via an Ethernet network. It is responsible for displaying and saving the SAR image, receiving and displaying geocoding information and configuring the transputer network. The transputer network is responsible for processing the SAR data. The network is connected in a pipeline configuration with a master transputer controlling the other eight slave transputers. Each slave transputer concurrently processes a section of the swath width. This method allows for easy scalability

Effective interprocess communication (IPC) in a real-time transputer network

The thesis describes the design and implementation of an interprocess communication (IPC) mechanism within a real-time distributed operating system kernel (RT-DOS) which is designed for a transputer-based network. The requirements of real-time operating systems are examined and existing design and implementation strategies are described. Particular attention is paid to one of the object-oriented techniques although it is concluded that these techniques are not feasible for the chosen implementation platform. Studies of a number of existing operating systems are reported. The choices for various aspects of operating system design and their influence on the IPC mechanism to be used are elucidated. The actual design choices are related to the real-time requirements and the implementation that has been adopted is described. [Continues.

Parallelisation of algorithms

Most numerical software involves performing an extremely large volume of algebraic computations. This is both costly and time consuming in respect of computer resources and, for large problems, often super-computer power is required in order for results to be obtained in a reasonable amount of time. One method whereby both the cost and time can be reduced is to use the principle "Many hands make light work", or rather, allow several computers to operate simultaneously on the code, working towards a common goal, and hopefully obtaining the required results in a fraction of the time and cost normally used. This can be achieved through the modification of the costly, time consuming code, breaking it up into separate individual code segments which may be executed concurrently on different processors. This is termed parallelisation of code. This document describes communication between sequential processes, protocols, message routing and parallelisation of algorithms. In particular, it deals with these aspects with reference to the Transputer as developed by INMOS and includes two parallelisation examples, namely parallelisation of code to study airflow and of code to determine far field patterns of antennas. This document also reports on the practical experiences with programming in parallel

A file server for the DistriX prototype : a multitransputer UNIX system

Bibliography: pages 90-94.The DISTRIX operating system is a multiprocessor distributed operating system based on UNIX. It consists of a number of satellite processors connected to central servers. The system is derived from the MINIX operating system, compatible with UNIX Version 7. A remote procedure call interface is used in conjunction with a system wide, end-to-end communication protocol that connects satellite processors to the central servers. A cached file server provides access to all files and devices at the UNIX system call level. The design of the file server is discussed in depth and the performance evaluated. Additional information is given about the software and hardware used during the development of the project. The MINIX operating system has proved to be a good choice as the software base, but certain features have proved to be poorer. The Inmos transputer emerges as a processor with many useful features that eased the implementation

DistriX : an implementation of UNIX on transputers

Bibliography: pages 104-110.Two technologies, distributed operating systems and UNIX are very relevant in computing today. Many distributed systems have been produced and many are under development. To a large extent, distributed systems are considered to be the only way to solve the computing needs of the future. UNIX, on the other hand, is becoming widely recognized as the industry standard for operating systems. The transputer, unlike. UNIX and distributed systems is a relatively new innovation. The transputer is a concurrent processing machine based on mathematical principles. Increasingly, the transputer is being used to solve a wide range of problems of a parallel nature. This thesis combines these three aspects in creating a distributed implementation of UNIX on a network of transputers. The design is based on the satellite model. In this model a central controlling processor is surrounded by worker processors, called satellites, in a master/ slave relationship