Some Remarks on the Approximation of Transitional Density in Stochastic Differential Equations

Aijt-Sahalia (2002) introduced a method to estimate transitional probability densities of di®usion processes by means of Hermite expansions with coe±cients determined by means of Taylor series. This note describes a numerical procedure to ¯nd these coe±cients based on the calculation of moments. One advantage of this procedure is that it can be used e®ectively when the mathematical operations required to ¯nd closed-form expressions for these coe±cients are otherwise infeasible.

The way forward : report on the preparatory phase of prefabricated building design and construction methodology: identifying critical issues and recommending the way forward

This is an initial report of the PolyU SD part of the team to study Pre-fabricated Building Design and Construction Methodology and marks the completion of Phase 1. It follows our first notes prepared for the meeting on 2 February that identified some critical issues including future lifestyles, life expectancy of buildings, sustainability, size, flexibility and planning considerations. It is also an expansion of our presentation in Dongguan on 23 February. It is not a comprehensive survey of existing approaches or possible ways forward, but it has homed in on certain specific issues and does give specific examples to make the suggestions concrete. It is recommended that more comprehensive research be done to establish previous work and experience internationally. It is also recommended that more research be done on lifestyles as a preliminary to developing at least three concepts for evaluation before proceeding to the detailed design of one concept for full prototyping and market testing. The goal at this point is not to define a single direction but to suggest several future trajectories for further consideration. By the same token, this report is not intended as an exhaustive description of the considerable base of knowledge and ideas brought by the PolyU team to this exciting task. Before taking on an issue of this magnitude and importance in the definition of Hong Kong's future, one must carry out a thoughtful analysis of the issues at hand and an informed definition of paradigms, directions, goals and methods whereby our energies can be best used in the next steps. This report is the result of this analysis

Brite phase 1 report to industry : innovate – now

Trying to innovate or wanting to? Making a start is the most difficult step on any journey. Whether trying to innovate for the first time, or seeking improvements on current performance, organisations are confronted with a plethora of options. Innovate ― Now! makes action easier by presenting some of the key considerations for improving innovation performance. This guide has been based on the outcomes of a survey and case studies conducted between 2003 and 2005 in the Australian property and construction industry and therefore contains unique and up-to-date information, examples and suggestions tailored specifically to your industry needs.

Variations in MIMO-OFDM channel capacity due to random human movement in an indoor environment

Channel measurements and simulations have been carried out to observe the effects of pedestrian movement on multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) channel capacity. An in-house built MIMO-OFDM packet transmission demonstrator equipped with four transmitters and four receivers has been utilized to perform channel measurements at 5.2 GHz. Variations in the channel capacity dynamic range have been analysed for 1 to 10 pedestrians and different antenna arrays (2 × 2, 3 × 3 and 4 × 4). Results show a predicted 5.5 bits/s/Hz and a measured 1.5 bits/s/Hz increment in the capacity dynamic range with the number of pedestrian and the number of antennas in the transmitter and receiver array.

Relative entropy rate based multiple hidden Markov Model Approximation

This paper proposes a novel relative entropy rate (RER) based approach for multiple HMM (MHMM) approximation of a class of discrete-time uncertain processes. Under different uncertainty assumptions, the model design problem is posed either as a min-max optimisation problem or stochastic minimisation problem on the RER between joint laws describing the state and output processes (rather than the more usual RER between output processes). A suitable filter is proposed for which performance results are established which bound conditional mean estimation performance and show that estimation performance improves as the RER is reduced. These filter consistency and convergence bounds are the first results characterising multiple HMM approximation performance and suggest that joint RER concepts provide a useful model selection criteria. The proposed model design process and MHMM filter are demonstrated on an important image processing dim-target detection problem.

Before the first export decision : internationalisation readiness in the pre-export phase

Although the internationalisation process of the firm has been well researched since the 1970s, the behaviour of firms prior to internationalisation has not received commensurate research attention.This paper argues that a focus on firms’ pre-internationalisation activities will not only offer an additional important perspective to the study of firm internationalisation but it will also address a significant research gap in studies that are theoretically based on the so-called stages models. During the pre-internationalisation phase, a firm is exposed to stimuli factors that may trigger an impulse for foreign market expansion. Decision makers’ perceptions of stimuli, their attitudinal commitment towards internationalisation, the firms’ resources and capabilities, as well as the mediating effect of lateral rigidity comprise a learning process that leads a firm towards readiness to initiate an internationalisation decision. This paper advances the concept of internationalisation readiness and proposes a method for developing an Internationalisation Readiness Index.

A fully Bayesian approach to inference for Coxian phase-type distributions with covariate dependent mean

Phase-type distributions represent the time to absorption for a finite state Markov chain in continuous time, generalising the exponential distribution and providing a flexible and useful modelling tool. We present a new reversible jump Markov chain Monte Carlo scheme for performing a fully Bayesian analysis of the popular Coxian subclass of phase-type models; the convenient Coxian representation involves fewer parameters than a more general phase-type model. The key novelty of our approach is that we model covariate dependence in the mean whilst using the Coxian phase-type model as a very general residual distribution. Such incorporation of covariates into the model has not previously been attempted in the Bayesian literature. A further novelty is that we also propose a reversible jump scheme for investigating structural changes to the model brought about by the introduction of Erlang phases. Our approach addresses more questions of inference than previous Bayesian treatments of this model and is automatic in nature. We analyse an example dataset comprising lengths of hospital stays of a sample of patients collected from two Australian hospitals to produce a model for a patient's expected length of stay which incorporates the effects of several covariates. This leads to interesting conclusions about what contributes to length of hospital stay with implications for hospital planning. We compare our results with an alternative classical analysis of these data.