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Now showing items 11-20 of 41
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
Key-spoofing attacks on nested signature blocks
(1995)
For a given signature block and any other data, there exists a key which produces the same signature block. The threat that this poses to schemes which use nested signature blocks as pointers to other tokens is identified, ...
Positive fixed points of lattices under semigroups of positive linear operators
(1995)
Let Z be a Banach lattice endowed with positive cone C and an order-continuous norm ||.||. Let G be a semigroup of positive linear endomorphisms of Z...