Tracking in a space variant active vision system

Without the ability to foveate on and maintain foveation, active vision for applications such as surveillance, object recognition and object tracking are difficult to build. Although foveation in cartesian coordinates is being actively pursued by many, multi-resolution high accuracy foveation in log polar space has not been given much attention. This paper addresses the use of foveation to track a single object as well as multiple objects for a simulated space variant active vision system. Complex logarithmic mapping is chosen firstly because it provides high resolution and wide angle viewing. Secondly, the spatially variant structure of log polar space leads to an object increasing in size as it moves towards the fovea. This is important as we know which object is closer to the fovea at any instant in time.<br /

On the relation between nuclear and nucleon Structure Functions and their moments

Calculations of nuclear Structure Functions (SF) F_k^A(x,Q^2) routinely exploit a generalized convolution, involving the SF for nucleons F_k^N and the linking SF f^{PN,A} of a fictitious nucleus, composed of point-particles, with the latter usually expressed in terms of hadronic degrees of freedom. For finite Q^2 the approach seemed to be lacking a solid justification and the same is the case for recently proposed, effective nuclear parton distribution functions (pdf), which exactly reproduce the above-mentioned hadronically computed F_k^A. Many years ago Jaffe and West proved the above convolution in the Plane Wave Impulse Approximation (PWIA) for the nuclear components in the convolution. In the present note we extend the above proof to include classes of nuclear Final State Interactions (FSI). One and the same function appears to relate parton distribution functions (pdf) in nuclei and nucleons, and SF for nuclear targets and for nucleons. That relation is the previously conjectured one,with an entirely different interpretation of f^{PN,A}. We conclude with an extensive analysis of moments of nuclear SF based on the generalized convolution. Characteristics of those moments are shown to be quite similar to the same for a nucleon. We conclude that the above evidences asymptotic freedom of a nucleon in a medium and not of a composite nucleus.Comment: 18 pages, 9 figure

Detection limits for close eclipsing and transiting sub-stellar and planetary companions to white dwarfs in the WASP survey

We used photometric data from the WASP (Wide-Angle Search for Planets) survey to explore the possibility of detecting eclipses and transit signals of brown dwarfs, gas giants and terrestrial companions in close orbit around white dwarfs. We performed extensive Monte Carlo simulations and we found that for Gaussian random noise WASP is sensitive to companions as small as the Moon orbiting a $V\sim$12 white dwarf. For fainter stars WASP is sensitive to increasingly larger bodies. Our sensitivity drops in the presence of co-variant noise structure in the data, nevertheless Earth-size bodies remain readily detectable in relatively low S/N data. We searched for eclipses and transit signals in a sample of 194 white dwarfs in the WASP archive however, no evidence for companions was found. We used our results to place tentative upper limits to the frequency of such systems. While we can only place weak limits on the likely frequency of Earth-sized or smaller companions; brown dwarfs and gas giants (radius$\simeq$ R$_{jup}$) with periods $\leq$0.2 days must certainly be rare ($<10\%$). More stringent constraints requires significantly larger white dwarf samples, higher observing cadence and continuous coverage. The short duration of eclipses and transits of white dwarfs compared to the cadence of WASP observations appears to be one of the main factors limiting the detection rate in a survey optimised for planetary transits of main sequence stars.Comment: 8 pages, 3 figure

The Australian Incident Monitoring Study in Intensive Care: AIMS-ICU. The development and evaluation of an incident reporting system in intensive care

Publisher's copy made available with the permission of the publisher © 1996 Australian Society of AnaesthetistsIntensive care units are complex, dynamic patient management environments. Incidents and accidents can be caused by human error, by problems inherent in complex systems, or by a combination of these. Study objectives were to develop and evaluate an incident reporting system. A report form was designed eliciting a description of the incident, contextual information and contributing factors. Staff group sessions using open-ended questions, observations in the workplace and a review of earlier narratives were used to develop the report form. Three intensive care units participated in a two-month evaluation study. Feedback questionnaires were used to assess staff attitudes and understanding, project design and organization. These demonstrated a positive attitude and good understanding by more than 90% participants. Errors in communication, technique, problem recognition and charting were the predisposing factors most commonly chosen in the 128 incidents reported. It was concluded that incident monitoring may be a suitable technique for improving patient safety in intensive care.U. Beckman, L.F. West, G.J. Groombridge, I. Baldwin, G.K. Hart, D.G. Clayton, R.K. Webb, W.B. Runcima

Tortuous ways to the extraction of neutron observables from inclusive lepton scattering

We analyze new JLAB data for inclusive electron scattering on various targets. Computed and measured total inclusive cross sections in the range $0.3\lesssim x\lesssim 0.95$ show on a logarithmic scale reasonable agreement for all targets. However, closer inspection of the Quasi-Elastic components bares serious discrepancies. EMC ratios which may contain less systematic errors fare the same. The above observations for the new data do not enable the extraction of the magnetic form factor (FF) $G_M^n$ and the Structure Function (SFs) $F_2^n$ of the neutron, although the application of exactly the same analysis to older data had been successful. We add to the above analysis older CLAS collaboration on $F_2^D$. Removing some scattered points, it appears possible to obtain the above mentioned neutron information. We compare our results with others from alternative sources. Particular attention is paid to the A=3 iso-doublet. Present data exist only for $^3$He, but the available input and charge symmetry also enable computations for $^3$H. Their average is the computed iso-scalar part and is compared with the empirical modification of $^3$He towards a fictitious A=3 iso-singlet.Comment: 27 pages, 30 figure