where ri,Ki,αi ∈ C(R,R+), αi > Ki, i = 1,2, τi,σi ∈ C(R,R+), i = 1,2, ri, Ki, αi, τi, σi(i = 1,2) are functions of period ω > 0. Since the study on periodic solutions of a population model is of great interest in mathematical biology [5] and many authors [1, 7] have argued that the discrete-time models governed by difference equations are more appropriate than the continuous ones when the popul...

We give a brief, elementary and analytic proof of the theorem of Hubbard and Masur [HM] (see also [K], [G]) that every class of measured foliations on a compact Riemann surface R of genus g can be uniquely represented by the vertical measured foliation of a holomorphic quadratic differential on R. The theorem of Thurston [Th] that the space of classes of projective measured foliations is a 6g −...

We argue that it is imperative that modelers select the right, and potentially differing levels of abstraction for different components of their computational models, as too global or too specific components will hinder scientific progress. We describe ACT-R, from the perspective that is a useful modeling architecture to support this process, and provide two examples in which mixing different l...

A system that provides translation from speech to sign language (TESSA) is described. TESSA has been developed to assist a Post Office clerk (who has no knowledge of sign language) in making a transaction with a customer using sign language. The system uses a set of about 370 pre-defined phrases which have been prestored and can be signed by a specially-developed avatar. The clerk is unable to ...

MOTIVATION The proportion of non-differentially expressed genes (pi(0)) is an important quantity in microarray data analysis. Although many statistical methods have been proposed for its estimation, it is still necessary to develop more efficient methods. METHODS Our approach for improving pi(0) estimation is to modify an existing simple method by introducing artificial censoring to P-values....

We investigate the model checking problem for branching time logics and Basic Parallel Processes. We show that the problem is undecidable for the logic 8L(O; F; U) (equivalent to CTL) in the usual interleaving semantics, but decidable in a standard partial order interpretation.

Physical processes are computations only when we use them to externalize thought. Computation is the performance of one or more fixed processes within a contingent environment. We reformulate the Church-Turing thesis so that it applies to programs rather than to computability. When suitably formulated agent-based computing in an open, multi-scalar environment represents the current consensus vi...

Spoken language recognition meets with difficulties when an unknown word is encountered. In addition to the new word being unrecognisable, its presence impacts on recognition performance on the surrounding words. The possibility is explored here of using a back-off statistical recogniser to allow recognition of out-of-vocabulary words in a grammar-based speech recognition system. This study sho...

This work combines grammars and statistical language models for speech recognition together in the same sentence. The grammars are compiled into bigrams with word indices, which serve to distinguish different syntactic positions of the same word. For both the grammatical and statistical parts there is one common interface for obtaining a language model score for bior trigrams. With only a small...

We present a Bayesian model selection analysis of WMAP3 data using our code CosmoNest. We focus on the density perturbation spectral index nS and the tensor-to-scalar ratio r, which define the plane of slow-roll inflationary models. We find that while the Bayesian evidence supports the conclusion that nS 6= 1, the data are not yet powerful enough to do so at a strong or decisive level. If tenso...