Various processes are often classified as both deterministic and random or chaotic. The main difficulty in analysing the randomness of such processes is the apparent tension between the notions of randomness and determinism: what type of randomness could exist in a deterministic process? Ergodic theory seems to offer a particularly promising theoretical tool for tackling this problem by positin...

BACKGROUND Invariant item ordering (IIO) is defined as the extent to which items have the same ordering (in terms of item difficulty/severity - i.e. demonstrating whether items are difficult [rare] or less difficult [common]) for each respondent who completes a scale. IIO is therefore crucial for establishing a scale hierarchy that is replicable across samples, but no research has demonstrated ...

BACKGROUND Social, emotional and behavioural development in early to middle childhood impact upon many outcomes in future life and are influenced by home, neighbourhood and school environments. We used linked data to investigate differences between areas in Glasgow City in level of difficulties in pre-school age children, after consideration of demographics, including area-level deprivation. ...

In the present study, linkages were examined between parental behaviors (maternal practices) at bedtime, emotional availability of mothering at bedtime, and infant sleep quality in a cross-sectional sample of families with infants between 1 and 24 months of age. Observations of maternal behaviors and maternal emotional availability were conducted independently by 2 sets of trained observers who...

The associations between self-reported rewards and difficulties of caregiving and burden were examined in a sample of 200 informal caregivers to older post-rehabilitation patients. Sixteen percent (16%) of caregivers reported that caregiving was physically difficult only, 15% reported emotional difficulties only, 11% reported social difficulties only, 17% reported multiple difficulties, and 40%...

One would hope, therefore, that it would be possible to calculate reliably in perturbation theory. If that were the end of the story, things would be simple. The only difficulty, which makes quarkonium very interesting, is that there is another natural small scale in the problem, the relative velocity of the heavy quarks, v. For charmonium v c ∼ 1/4, while for bottomonium v 2 b ∼ 1/10. Since we...

One of the promising approaches to analyzing taskoriented dialogues has involved modeling the plans of the speakers in the task domain. In general, these models work well as long as the topic follows the task structure closely, but they have difficulty in accounting for clarification subdialogues and topic change. We have developed a model based on a hierarchy of plans and metaplans that accoun...

Hierarchical task decomposition is a method used in many agent systems to organize agent knowledge. This work shows how the combination of a hierarchy and persistent assertions of knowledge can lead to difficulty in maintaining logical consistency in asserted knowledge. We explore the problematic consequences of persistent assumptions in the reasoning process and introduce novel potential solut...

We study the stability of the gauge hierarchy in hidden-sector supergravity theories. We show that a destabilizing tadpole can appear if a theory has a gaugeand global-symmetry singlet with renormalizable couplings to the visible fields. We also find a quadratically divergent two-loop contribution to the supersymmetric effective potential. This term illustrates the difficulty of using the “LHC ...

Considering the difficulty in evaluating pipeline safety permafrost region, disaster evaluation index system region is analyzed and established. A comprehensive weight determination method based on improved fuzzy analytic hierarchy process, entropy Lagrange algorithm proposed, a model of Taking China-Russia crude oil as an example, proposed used to determine carry out evaluation. The rationalit...