OBJECTIVE To investigate family members' experiences of involvement in a previous study (conducted August 1995 to June 1997) following their child's diagnosis with Ewing's sarcoma. DESIGN Retrospective survey, conducted between 1 November and 30 November 1997, using a postal questionnaire. PARTICIPANTS Eighty-one of 97 families who had previously completed an in-depth interview as part of a...

Advances in developmental research has made it clear that word learning has a long beginning. Recent work has demonstrated that infants learn words at 6 months of age—that is, before the traditional “first word” milestone in productive language—which is a full year before the usual “naming explosion” in productive vocabulary. Before infants talk, walk, or even point, how can the earliest stage ...

Representation and reasoning about time-dependent information is an active and important research area in Artificial Intelligence and in Computer Science. Vilain and Kautz’s point algebra (see [VK86]) is one of the most influential models used for representing and reasoning with qualitative time information, because the reasoning tasks are solvable in polynomial time in that model, contrary to ...

In this article, we propose a new extension to a Dynamic Programming Algorithm (DPA) approach for Track-beforeDetect challenges. This extension enables the DPA to process time-delayed sensor data directly. Such delay might appear because of delays in communication networks. The extended DPA is identical to the recursive standard DPA in case of all sensor data appear in the timely correct order....

We describe a video tracking application using the dual-tree Polar Matching Algorithm. We develop the dynamical and observation models in a probabilistic setting and study the empirical probability distribution of the Polar Matching output. We model the visible and occluded target statistics using Beta distributions. This is incorporated into a Track-Before-Detect (TBD) solution for the overall...

An algorithm has been developed for the detection of point targets in uncluttered background based on a Bayesian track before detect method. The algorithm has an application in the detection of sea skimming antiship missiles at maximum range, when the missile appears over the horizon. Because of the long range, angular motion of the target will be insignificant, and target motion cannot be used...

The Histogram Probabilistic Multi-Hypothesis Tracker (H-PMHT) algorithm is a parametric track-before-detect method. It locates targets in imagery by fitting a mixture of probability densities. In recent work, an unknown target shape was accommodated through the use of a Wishart prior on the measurement probability density, this version of the algorithm is referred to as H-PMHT-RM. This paper ap...

While there is no consensus about the history of time since the beginning, in this paper I will discuss some possibilities. We have a pretty clear picture of cosmic history from the electroweak phase transition through the time of recombination, a period which includes the QCD phase transition and big bang nucleosynthesis. This paper includes a quantitative discussion of the age of the universe...

Tracking multiple targets in a cluttered environment is a challenging task. Probabilistic multiple hypothesis tracking (PMHT) is an efficient approach for dealing with it. Essentially PMHT is based on expectation-maximization for handling with association conflicts. Linearity in the number of targets and measurements is the main motivation for a further development and extension of this methodo...