We introduce the automatic recording constraint (ARC) that can be used to model and solve scheduling problems where tasks may not overlap in time and the tasks linearly exhaust some resource. Since achieving generalized arc-consistency for the ARC is NP-hard, we develop a filtering algorithm that achieves approximated consistency only. Numerical results show the benefits of the new constraint o...

In this paper we introduce three greedy algorithms for the traveling salesman problem. These algorithms are unique in that they use arc tolerances, rather than arc weights, to decide whether or not to include an arc in a solution. We report extensive computational experiments on benchmark instances that clearly demonstrate that our tolerance-based algorithms outperform their weight-based counte...

This paper introduces the write-once/read-many XMLtape/ARC storage approach for Digital Objects and their constituent datastreams. The approach combines two interconnected file-based storage mechanisms that are made accessible in a protocol-based manner. First, XMLbased representations of multiple Digital Objects are concatenated into a single file named an XMLtape. An XMLtape is a valid XML fi...

An approach for modelling thermo-mechanical responses in a 3D arc welding process is developed using the Smoothed Particle Hydrodynamics (SPH) method. It is demonstrated for a simple arc welding configuration by using full three-dimensional elastoplastic analysis. The flow pattern of the filler material and the resulting plastic strain distribution are analysed. The effect of welding speed on t...

This paper describes the algorithms, heuristics and general strategies used by the two solvers which have been elaborated from the Abscon platform and submitted to the second CSP solver competition. Both solvers maintain generalized arc consistency during search, explore the search space using a conflict-directed variable ordering heuristic, integrate nogood recording from restarts and exploit ...

The need to improve plasma spraying processes has motivated the development of computational models capable of describing the arc dynamics inside plasma torches. Although progress has been made in the development of such models, the realistic simulation of the arc reattachment process, a central part of the arc dynamics inside plasma torches, is still an unsolved problem. This study presents a ...

In this paper we present a novel approach to solving Constraint Satisfaction Problems whose constraint graphs are highly clustered and the graph of clusters is close to being acyclic. Such graphs are encountered in many real world application domains such as configuration, diagnosis, model-based reasoning and scheduling. We present a class of variable ordering heuristics that exploit the cluste...

Multi-agent systems have become increasingly mature, but their appearance does not make the traditional OO approach obsolete. On the contrary, OO methodologies can benefit from the principles and tools designed for agent systems. The Agent/Rule/Class (ARC) framework is proposed as an approach that builds agents upon traditional OO system components and makes use of business rules to dictate age...

Abstract Many terrestrial silicate reservoirs display a characteristic depletion in Nb, which has been explained some studies by the presence of on Earth with superchondritic Nb/Ta. As one classical example, K-rich lavas from Sunda rear-arc, Indonesia, have invoked to tap such high-Nb/Ta reservoir. To elucidate petrogenetic processes active beneath Java rear-arc and causes for Nb/Ta these lavas...