Though completely integrable Camassa-Holm (CH) equation and Degasperis-Procesi (DP) equation are cast in the same peakon family, they possess the secondand third-order Lax operators, respectively. From the viewpoint of algebro-geometrical study, this difference lies in hyper-elliptic and non-hyper-elliptic curves. The non-hyper-elliptic curves lead to great difficulty in the construction of alg...

In a recent paper (Reid et al., 2009) we introduced a method to calculate optimal hierarchies in the visual network that utilizes continuous, rather than discrete, hierarchical levels, and permits a range of acceptable values rather than attempting to fit fixed hierarchical distances. There, to obtain a hierarchy, the sum of deviations from the constraints that define the hierarchy was minimize...

The central conjecture of parameterized complexity states that FPT 6= W[1], and is generally regarded as the parameterized counterpart to P 6= NP. We revisit the issue of the plausibility of FPT 6= W[1], focusing on two aspects: the difficulty of proving the conjecture (assuming it holds), and how the relation between the two classes might differ from the one between P and NP. Regarding the fir...

Visual language specification has been investigated for more than two decades now and many different formalisms for specifying and parsing visual languages have been invented. However, there has been little attempt to develop a systematic and comprehensive hierarchy of visual languages based on their formal properties. Given the importance of the Chomsky hierarchy for the theory of textual lang...

Exhibiting inferential capabilities is one of the major goals of many modern Natural Language Processing systems. However, if attempts have been made to define what textual inferences are, few seek to classify inference phenomena by difficulty. In this paper we propose a hierarchical taxonomy for inferences, relatively to their hardness, and with corpus annotation and system design and evaluati...

A common measure of activity limitations for both children and adults with neuromuscular disorders was developed using the Rasch model. A self-reported questionnaire containing daily activities was submitted to 245 adult patients and to the parents of 124 affected children from the two major Belgian communities. They were asked to provide their perceived difficulty in performing daily activitie...

Infant sleep is a major source of distress in many families. The purpose of this study was to assess infant sleep and parental sleep-related cognitions about infant sleep in clinical and control samples. The clinical sample consisted of 48 infants referred to a sleep clinic because of night-wakings problems. The control sample included 48 infants with no parental complaints about sleep difficul...

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...