Specifications and programs for computer software validation

Three software products developed during the study are reported and include: (1) FORTRAN Automatic Code Evaluation System, (2) the Specification Language System, and (3) the Array Index Validation System

The programmable logic controller : its prehistory, emergence and application

Programmable Logic Controllers (PLCs) are widely used devices controlling industrial machines and processes and many other diverse applications, requiring primarily, combinatorial logic and sequential control. The PLC is a hidden technology, little known by the general public and overlooked in academic historical studies of technology. The research reported in this thesis aims to address this lack of awareness. The thesis explores the development of sequential and combinatorial logic control technologies, the emergence of the PLC, its subsequent development and its industrial applications. Patents and first- hand accounts and experiences from senior industrial engineers in a number of diverse manufacturing industries have been used as the primary research sources since, as a hidden technology, academic historical accounts are sparse. This approach illustrates, through using the PLC as an example, a potential method of studying other, unrelated hidden technologies. The research has revealed the influence of geography, industrial settings and earlier engineering practices on the design, selection and application of PLC control technologies, and comments on the how these influences define specific communities of practice

Implementation exploration of imaging algorithms on FPGAs

This portfolio thesis documents the work carried out as part of the Engineering Doctorate (EngD) programme undertaken at the Institute for System Level Integration. This work was sponsored and aided by Thales Optronics Ltd, a company well versed in developing specialised electro-optical devices. Field programmable gate arrays (FPGAs) are the devices of choice for custom image processing algorithms due to their reconfigurable nature. This also makes them more economical for low volume production runs where non-recoverable engineering costs are a large factor. Asynchronous circuits have had a remarkable surge in development over the last 20 years, to such an extent that they are beginning to displace conventional designs for niche applications. Their unique ability to adapt to environmental and data dependent processing needs have lead them to out-perform synchronous designs in ASIC platforms for certain applications. Abstract The main body of research was separated into three areas of work presented as three technical documents. The first area of research addresses an FPGA implementation of contrast limited adaptive histogram equalisation (CLAHE), an algorithm which provides increased visual performance over conventional methods. From this, a novel implementation strategy was provided along with the key design factors for future use in a commercial context. The second area of research investigates the ability to create asynchronous circuits on FPGA devices. The main motivation for this work was to establish if any of the benefits which had been demonstrated for ASIC devices can be applied to FPGA devices. The investigation surmised the most suitable asynchronous design style for FPGA devices, a design flow to allow asynchronous circuits to function correctly on FPGAs and novel design strategies to implement consistent and repeatable asynchronous components. The result of this work established a route to implement circuits asynchronously in an FPGA. The final area of research focused on a unique conversion tool that allows synchronous circuits to run asynchronously on FPGAs whilst maintaining the same data flow patterns. This research produced an automated tool capable of implementing circuits on an FPGA asynchronously from their synchronous descriptions. This approach allowed the primary motivators of this work to be addressed. The results of this work show timing, resource utilisation and noise spectrum benefits by implementing circuits asynchronously on FPGA devices

Cryptography for Ultra-Low Power Devices

Ubiquitous computing describes the notion that computing devices will be everywhere: clothing, walls and floors of buildings, cars, forests, deserts, etc. Ubiquitous computing is becoming a reality: RFIDs are currently being introduced into the supply chain. Wireless distributed sensor networks (WSN) are already being used to monitor wildlife and to track military targets. Many more applications are being envisioned. For most of these applications some level of security is of utmost importance. Common to WSN and RFIDs are their severely limited power resources, which classify them as ultra-low power devices. Early sensor nodes used simple 8-bit microprocessors to implement basic communication, sensing and computing services. Security was an afterthought. The main power consumer is the RF-transceiver, or radio for short. In the past years specialized hardware for low-data rate and low-power radios has been developed. The new bottleneck are security services which employ computationally intensive cryptographic operations. Customized hardware implementations hold the promise of enabling security for severely power constrained devices. Most research groups are concerned with developing secure wireless communication protocols, others with designing efficient software implementations of cryptographic algorithms. There has not been a comprehensive study on hardware implementations of cryptographic algorithms tailored for ultra-low power applications. The goal of this dissertation is to develop a suite of cryptographic functions for authentication, encryption and integrity that is specifically fashioned to the needs of ultra-low power devices. This dissertation gives an introduction to the specific problems that security engineers face when they try to solve the seemingly contradictory challenge of providing lightweight cryptographic services that can perform on ultra-low power devices and shows an overview of our current work and its future direction