Clustering via kernel decomposition

Spectral clustering methods were proposed recently which rely on the eigenvalue decomposition of an affinity matrix. In this letter, the affinity matrix is created from the elements of a nonparametric density estimator and then decomposed to obtain posterior probabilities of class membership. Hyperparameters are selected using standard cross-validation methods

Keystroke dynamics in the pre-touchscreen era

Biometric authentication seeks to measure an individual’s unique physiological attributes for the purpose of identity verification. Conventionally, this task has been realized via analyses of fingerprints or signature iris patterns. However, whilst such methods effectively offer a superior security protocol compared with password-based approaches for example, their substantial infrastructure costs, and intrusive nature, make them undesirable and indeed impractical for many scenarios. An alternative approach seeks to develop similarly robust screening protocols through analysis of typing patterns, formally known as keystroke dynamics. Here, keystroke analysis methodologies can utilize multiple variables, and a range of mathematical techniques, in order to extract individuals’ typing signatures. Such variables may include measurement of the period between key presses, and/or releases, or even key-strike pressures. Statistical methods, neural networks, and fuzzy logic have often formed the basis for quantitative analysis on the data gathered, typically from conventional computer keyboards. Extension to more recent technologies such as numerical keypads and touch-screen devices is in its infancy, but obviously important as such devices grow in popularity. Here, we review the state of knowledge pertaining to authentication via conventional keyboards with a view toward indicating how this platform of knowledge can be exploited and extended into the newly emergent type-based technological contexts

Infrared studies of supernova remnants with the IRAS

A comparative study of the infrared and X-ray fluxes and morphologies of supernova remnants (SNR) can yield valuable information on their evolution and on their interaction with the smbient interstellar medium (ISM)

The behavioural impact of a visually represented virtual assistant in a selfservice checkout context

Our research investigated whether the presence of an interface agent - or virtual assistant (VA) - in a self-service checkout context has behavioural effects on the transaction process during particular tasks. While many participants claimed to have not noticed a VA within the self-service interface, behaviour was still affected, i.e. fewer people made errors with the VA present than in the voice-only and control conditions. The results are explained as reflective of an unconscious observation of non-verbal cues exhibited by the VA. The results are discussed in relation to possible behavioural outcomes of VA presence.</p

Linking recorded data with emotive and adaptive computing in an eHealth environment

Telecare, and particularly lifestyle monitoring, currently relies on the ability to detect and respond to changes in individual behaviour using data derived from sensors around the home. This means that a significant aspect of behaviour, that of an individuals emotional state, is not accounted for in reaching a conclusion as to the form of response required. The linked concepts of emotive and adaptive computing offer an opportunity to include information about emotional state and the paper considers how current developments in this area have the potential to be integrated within telecare and other areas of eHealth. In doing so, it looks at the development of and current state of the art of both emotive and adaptive computing, including its conceptual background, and places them into an overall eHealth context for application and development

X-ray spectra of supernova remnants

X-ray spectra were obtained from fields in three supernova remnants with the solid state spectrometer of the HEAO 2 satellite. These spectra, which contain lines from K-shell transitions of several abundant elements with atomic numbers between 10 and 22, were compared with various models, including some of spectra that would be produced by adiabatic phase remnants when the time-dependence of the ionization is considered

Investigating phishing awareness using virtual agents and eye movements

Phishing emails typically attempt to persuade recipients to reveal private or confidential information (e.g., passwords or bank details). Interaction with such emails places individuals at risk of financial loss and identity theft. We present an ongoing study using eye tracking metrics and varying interface components to assess users' ability to spot simulated phishing attempts. Findings seek to establish how users interact with email inbox interfaces and will inform future design of usable security tools.</p

Is the remnant of SN1006 crab-like?

The solid state spectrometer on the Einstein Observatory and the GSFC cosmic X-ray spectrometer on OSO-8 observed the X-ray spectrum of SN1006. The data can be well-represented by a power-law model with alpha = 1.2, similar to the spectrum of the Crab nebula. This is in contrast to the radio and X-ray maps of SN1006 which show a shell structure more typical of SNR with thermal X-ray emission. The X-ray spectrum is suggestive of nonthermal synchrotron emission, raising the possibility that the remnant of SN1006 contains a source of relativistic electrons