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Automatic differentiation of computer programs in a parallel computing environment
(Computational Mechanics, 1997)
This paper gives an introduction to a number of methods collectively known as Automatic Differentiation (AD). AD is the systematic application of the rules of calculus to computer programs yielding, as output, programs ...
Binding bit patterns to real world entities
(University of Hertfordshire, 1997)
Public key cryptography is often used to verify the integrity of a piece of data, or more generally to ensure that operations which modify the data have been requested and carried out by principles who are authorized to ...
Why isn't trust transitive?
(1997)
One of the great strengths of public-key cryptography is its potential to allow the localization of trust. This potential is greatest when cryptography is present to guarantee data integrity rather than secrecy, and where ...
Giving reverse differentiation a helping hand
(1997)
Reverse automatic differentiation provides a very low bound on the operations count for calculating a gradient of a scalar function in n dimensions but suffers from a high storage requirement. In this paper we will show ...
An introduction to the Hatfield superscalar architecture
(University of Hertfordshire, 1996)
If a high-performance superscalar processor is to realise its full potential, the complier must re-order or schedule the object code at compile time. This scheduling creates groups of adjacent instructions that are independent ...
Sharing storage using dirty vectors
(Society for Industrial and Applied Mathematics (SIAM Press), 1996)
Consider a computation F with n inputs (independent variables) and m outputs (dependent variables) and suppose that we wish to evaluate the Jacobian of F. Automatic differentiation commonly performs this evaluation by ...
Geometric approach to Fletcher's ideal penalty function
(1995)
In this note, we derive a geometric formulation of an ideal penalty function for equality constrained problems. This differentiable penalty function requires no parameter estimation or adjustment, has numerical conditioning ...
Hades - towards the design of an asynchronous superscalar processor
(University of Hertfordshire, 1995)
Hades is a processor architecture aimed at single and multiple-instruction-issue asynchronous implementations. This paper uses a baseline version of Hades to illustrate some of the difficulties encountered in asynchronous ...
Roles and rights
(University of Hertfordshire, 1995)
In this paper we describe and discuss a protection model designed by Coulouris and Dollimore to protect objects which are shared by different principals participating in a co-operative task. We then show that the ...
Is your computing environment secure? Security problems with interrupt handling mechanisms
(University of Hertfordshire, 1995)
In an open distributed system, resources must be shared among various users. Security is one of the major issues in designing such a system. When a computer system is connected to a network, it is very important to ensure ...