Abstract
This paper studies periodic gaits of multi-legged robot locomotion systems based on dynamic models. The purpose is to determine the system performance during walking and the best set of locomotion variables. For that objective the prescribed motion of the robot is completely characterized in terms of several locomotion variables such as gait, duty factor, body height, step length, stroke pitch, foot clearance, legs link lengths, foot-hip offset, body and legs mass and cycle time. In this perspective, we formulate four performance measures of the walking robot namely, the locomobility of the foot, the mean absolute power, the mean power dispersion and the mean power lost in the joint actuators per walking distance. A set of model-based experiments reveals the influence of the locomotion variables in the proposed indices.

Abstract
We report the use of the electric arc technique to apodise Fibre Bragg Gratings (FBG). Electric arc discharges applied at the ends of the grating produce a smoothing of the refractive index modulation profile which reduces the side lobes at longer wavelengths. Using this technique, a FBG was apodised with a side lobe reduction of 17 dB.

Abstract
Recently, a framework was proposed intended to support the development of replicated and distributed Ravenscar applications. This framework provides a transparent abstraction for application replication, allowing applications to be developed without considering replication and distribution issues. However, it is also necessary to assess if the Ravenscar profile is expressive enough for the implementation of this complex middleware. Therefore, this paper presents some conclusions that were drawn on the implementation of a prototype of the framework.

Abstract
Dependability has become an essential parameter on system design. The fulfillment of the system function, either in mission oriented or in continuous operation, requires knowledge about all possible failure modes. If a fault occurrence causes a mis-operation it should be approached a design for a dependable system. Some issues should be performed both at system design and development stages, in order to build a robust system, by evaluating correctly failure conditions and guaranteeing the fulfillment of the system function. The main one is the validation process as well as it conditions the modelling methods associated to and the techniques to be adopted. This paper presents an approach for analysis of validation techniques for electronic systems. The analysis points out two directions, verification techniques needed to support the design at different phases and fault forecasting techniques to assess systems behavior for modelling faults activation and occurrence.

Abstract
The coordination and control problems arising in team composition and tasking of autonomous underwater vehicles are discussed in the framework of dynamic optimization. Team composition and tasking are specified in terms of sets and relations among the elements of these sets. Results from dynamic optimization and non-smooth analysis are used to show that these coordination and control problems can be phrased in terms of concepts such as invariance, solvability, monotonicity, and switchings among value functions.

Abstract
In this paper, first order necessary conditions of optimality for control problems with pathwise state constraints are provided. These conditions axe able to avoid the degeneracy phenomenon which affects standard versions of the maximum principle. A common. feature of the endpoint degeneracy phenomena described in the literature is identified and it is shown that similar phenomena might occur other than at the endpoints of the trajectory. A strengthened form of the maximum principle is established under suitable constraint qualifications, in which the (measure) multiplier associated with the pathwise state constraint is not involved in the nontriviality condition. Copyright (C) 2001 IFAC.