Computational Methods for Complex Stochastic Systems: A Review of Some Alternatives to MCMC.

We consider analysis of complex stochastic models based upon partial information. MCMC and reversible jump MCMC are often the methods of choice for such problems, but in some situations they can be difficult to implement; and suffer from problems such as poor mixing, and the difficulty of diagnosing convergence. Here we review three alternatives to MCMC methods: importance sampling, the forward-backward algorithm, and sequential Monte Carlo (SMC). We discuss how to design good proposal densities for importance sampling, show some of the range of models for which the forward-backward algorithm can be applied, and show how resampling ideas from SMC can be used to improve the efficiency of the other two methods. We demonstrate these methods on a range of examples, including estimating the transition density of a diffusion and of a discrete-state continuous-time Markov chain; inferring structure in population genetics; and segmenting genetic divergence data

Prototyping Object-Oriented Specifications

CoopnBuilder is an integrated development environment (IDE) for Concurrent Object Oriented Petri Nets (COOPN). It comes with a complete set of tools enabling the user to view, edit, check, simulate and generate code from CO-OPN specifications. The Code Generation tool allows the user to develop applications in an open way: the produced code can be integrated in larger projects or use existing libraries. The code generation will be emphasized in this paper, and we will focus on ease-of-use and extensibility. CoopnBuilder is an open-source Java program and can be downloaded from http://cui.unige.ch/smv</a

Aerial service robotics: The AIRobots perspective

This paper presents the main vision and research activities of the ongoing European project AIRobots (Innovative Aerial Service Robot for Remote Inspection by Contact, www.airobots.eu). The goal of AIRobots is to develop a new generation of aerial service robots capable of supporting human beings in all those activities that require the ability to interact actively and safely with environments not constrained on ground but, indeed, airborne. Besides presenting the main ideas and the research activities within the three-year project, the paper shows the first technological outcomes obtained during the first year and a half of activity