In this paper we show that every real-time system speciied in a certain subset of Duration Calculus 24] can be decomposed into an untimed system communicating with suitable timers. Both asynchronous and synchronous communication are considered.

The spin dynamics in Ni is studied by an exact diagonalization method on the ultrafast time scale. It is shown that the femtosecond relaxation of the magneto-optical response results from exchange interaction and spin-orbit coupling. Each of the two mechanisms affects the relaxation process differently. We find that the intrinsic spin dynamics occurs during about 10 fs while extrinsic effects s...

We present a complete axiomatisation of the operator of projection onto state in the Duration Calculus (DC ) relative to validity in DC without extending constructs. Projection onto state was introduced and studied extensively in our earlier works. We first establish the completeness of a system of axioms and proof rules for the operator relative to validity in the extension of DC by neighbourh...

Among the possible approaches for expressing real-time problems with the B method, two are dominant : the use of the usual B mechanisms to define temporal constraints on one hand, and extending B through another formalism more adapted to the real-time context. We define here a possible temporal semantic for B, by using a temporal logic (the duration calculus), and we illustrate how this extensi...

Suprasegmental information, while generally thought to play an important role in speech recognition by human listeners, has shown little promise in previous attempts to integrate into ASR systems. This paper outlines an approach that will successfully exploit suprasegmental information by modeling duration within the context of N-gram language modeling. Results show that up to half of the varia...

This paper addresses the problem of state duration modeling in combination with spectral subtraction and Rasta filtering to cancel both additive and convolutional noise in a text-dependent speaker verification task. The results presented in this paper suggest that temporal constraints can lead to reductions of 30 and 14% in the error rates at SNR equal to 0 and 6dB, respectively, without noise ...

Explicit duration modeling has been shown to increase the eeectiveness of hidden Markov models in automatic speech recognition. Ferguson found the optimum parameters of the duration model for the case where duration is assumed to be distributed according to a non-parametric probability mass function. Levinson determined the best gamma density to model duration. In this paper, duration is assume...

This paper aims to investigate the effects of motion duration on the structural seismic demands, seeking potential correlations between motion durations and structural responses at several seismic intensity levels. Three seismic intensity levels with 100years, 475years, and 2475years earthquake return periods (RPs) are first considered for correlation computations. Spectrally matched ground mot...

The HMM-based Text-to-Speech System can produce high quality synthetic speech with flexible modeling of spectral and prosodic parameters. However, the prosodic features, like F0 and duration trajectories, generated by HMM-based speech synthesis are often excessively smoothed and lack prosodic variance. In HMM-based TTS durations are typically modeled statistically using state duration probabili...

BACKGROUND We examine the effect of heat waves on mortality, over and above what would be predicted on the basis of temperature alone. METHODS Present modeling approaches may not fully capture extra effects relating to heat wave duration, possibly because the mechanisms of action and the population at risk are different under more extreme conditions. Modeling such extra effects can be achieve...