Richard Overill - Academia.edu (original) (raw)

Uploads

Papers by Richard Overill

The UK’s Active Cyber Defence (ACD) programme has been a key aspect of the work of the National C... more The UK’s Active Cyber Defence (ACD) programme has been a key aspect of the work of the National Cyber Security Centre (NCSC) in improving public-sector cybersecurity since late 2016. According to the NCSC, it has, through a range of ACD measures, objectively reduced the threat of cybercrime to government agencies and service users. On the basis of this success, NCSC has begun to promote ACD as a means of countering low-level cybercriminality and its effects on individuals, businesses, charities and other organisations beyond the public sector. It aims thereby to deliver on the core aspirations of the National Cyber Security Strategy 2016-2021, specifically its commitment to defending UK assets and interests in cyberspace. This report explores the implications of scaling up ACD to the national level and expanding it beyond the public sector.

In Part I infinitesimal self-consistent field Hartree-Fock perturbation theory is applied to the ... more In Part I infinitesimal self-consistent field Hartree-Fock perturbation theory is applied to the calculation of the Fermi contact, electron orbital and spin-dipolar contributions to indirect nuclear spin-spin coupling constants in some small closed-shell molecules from ab initio LCAO-MO SCF wavefunctions. The dependence of the calculated values upon the size of Gaussian basis set employed and upon variations in molecular geometry is examined. The circumstances under which the method may be expected to yield results sufficiently reliable for most chemical purposes are indicated. In Part II the ab initio Unrestricted Hartree-Fock method with single spin annihilation is used in the LCAO-MO approximation with minimal Gaussian basis sets of atomic SCF orbitals to evaluate the isotropic and anisotropic electron-nuclear hyperfine coupling constants in some small doublet state free radicals of current experimental interest. This approach is applied to the identification of new radical species and to the elucidation of their molecular structures. In addition, the method is used to check the experimental assignments of hyperfine coupling constants deduced from ESR spectra and to investigate the reliability of Coulson's equation for the estimation of bond angles in triatomic ABA radicals

2016 SAI Computing Conference (SAI), 2016

If citing, it is advised that you check and use the publisher's definitive version for pagination... more If citing, it is advised that you check and use the publisher's definitive version for pagination, volume/issue, and date of publication details. And where the final published version is provided on the Research Portal, if citing you are again advised to check the publisher's website for any subsequent corrections.

Angewandte Chemie International Edition, 2003

It is our great pleasure to welcome you to the 9th Annual International Workshop on Digital Foren... more It is our great pleasure to welcome you to the 9th Annual International Workshop on Digital Forensics (WSDF) which takes place at the Salzburg University of Applied Sciences (Salzburg, Austria) from 31 August-2 September 2016. Digital forensics is a rapidly evolving field primarily focused on the extraction, preservation and analysis of digital evidence obtained from electronic devices in a manner that is legally acceptable. Research into new methodologies tools and techniques within this domain is necessitated by an everincreasing dependency on tightly interconnected, complex and pervasive computer systems and networks. The ubiquitous nature of our digital lifestyle presents many avenues for the potential misuse of electronic devices in crimes that directly involve, or are facilitated by, these technologies. The aim of digital forensics is to produce outputs that can help investigators ascertain the overall state of a system. This includes any events that have occurred within the system and entities that have interacted with that system.

Exposure of trimethylamine borane to Co γ-rays at 77 K gave, initially, a four-line E.S.R. spectr... more Exposure of trimethylamine borane to Co γ-rays at 77 K gave, initially, a four-line E.S.R. spectrum assigned to the radical anion, Me3[Ndot]-BH3 , having a large (58 G) hyperfine coupling to boron. Theoretical calculations suggest that the radical resembles a perturbed BH3 in which the normally planar unit still has considerable pyramidal character.After annealing above 77 K this species was

The Royal Society of Chemistry eBooks, Nov 1, 1986

The Design of Information Security Management Systems for Small-to-Medium Size Enterprises Elizab... more The Design of Information Security Management Systems for Small-to-Medium Size Enterprises Elizabeth Coles-Kemp and Richard Overill King's College London, Strand, London, UK elizabeth. coles-kemp@ kcl. ac. uk richard. overill@ kcl. ac. uk Abstract: Information ...

Molecular Physics, Feb 1, 1978

An initio SCF perturbation theory in the formulation of Ditchfield and Snyder has been applied to... more An initio SCF perturbation theory in the formulation of Ditchfield and Snyder has been applied to the calculation of the N.M.R. spin-spin coupling constants in CH4, NH3, H2O and HF using large gaussian basis sets, and including all second-order contributions (Fermi contact, orbital and dipolar). In accordance with most other work, the first-order term in the orbital contribution has been neglected, however. The sensitivity of the coupling constants to variations in the basis set has been studied, and the reliability of the method is discussed in the light of these results. It is shown that the Fermi contact contribution provides the largest component of the calculated coupling constants, with the dipolar term being generally negligible. However, the orbital contribution is found to be non-negligible, particularly in the case of the directly bonded couplings in HF and H2O, and is shown to be the primary reason, at the level of calculation adopted, for variations in the HH geminal couplings in the series CH4, NH3 and H2O. We have shown how convergence of the iterative procedure for the computation of the first-order wavefunction may be assured by the use of 'damp factors' and 'level shifters'.

Chemischer Informationsdienst, Jul 23, 1974

International Journal of Bifurcation and Chaos, Aug 1, 1994

The well-known solution of the Feigenbaum-Cvitanović equation can be extended to the complex plan... more The well-known solution of the Feigenbaum-Cvitanović equation can be extended to the complex plane. The resulting analytic function has many interesting properties. Graphical representations of the function are presented, illustrating the complex fractal nature of the extended function.