Federico Barber

Learn More
Railway scheduling has been a significant issue in the railway industry. Over the last few years, numerous approaches and tools have been developed to compute railway scheduling. However, robust solutions are necessary to absorb short disruptions. In this paper, we present the robustness problem from the point of view of railway operators and we give some(More)
Railway Scheduling is considered to be a difficult and time-consuming task. This is due to real railway networks can be modelled as Constraint Satisfaction Problems (CSPs), but they require a huge number of variables and constraints. The general CSP is known to be NP-complete; however, distributed models may reduce the exponential complexity by dividing the(More)
Many combinatorial problems can be modelled as Constraint Satisfaction Problems (CSPs). Solving a general CSP is known to be NP-complete, so closure and heuristic search are usually used. However, many problems are inherently distributed and the problem complexity can be reduced by dividing the problem into a set of subproblems. Nevertheless, general(More)
Constraint programming is gaining a great deal of attention because many combinatorial problems especially in areas of planning and scheduling can be expressed in a natural way as a Constraint Satisfaction Problem (CSP). It is well known that a non-binary CSP can be transformed into an equivalent binary CSP using some of the actual techniques. However, when(More)
This work deals with the multi-mode resource-constrained project scheduling problem. In this problem, activities of the project may be executed in more than one operating mode and renewable resource constraints exist. Each activity operation mode has a different duration and requires different amount of renewable resources. The objective function considered(More)
Many problems of theoretical and practical interest can be formulated as Constraint Satisfaction Problems (CSPs). Solving a general CSP is known to be NP-complete; however, distributed models may take advantage of dividing the problem into a set of simpler interconnected sub-problems which can be more easily solved. The purpose of this paper is threefold:(More)
Solving scheduling problems with Constraint Satisfaction Problems (CSP’s) techniques implies a wide space search with a large number of variables, each one of them with a wide interpretation domain. This paper discusses the application of CSP heuristic techniques (based on the concept of slack of activities) for variable and value ordering on a special type(More)
Constraint-based formalisms are a useful and common way to deal with temporal reasoning tasks. Assertions represent temporal constraints between temporal objects, time-points or intervals: Metric temporal constraints between time points permit us to express a minimum and maximum temporal distance between two time points and to define a valid temporal(More)
A container terminal is a facility where cargo containers are transshipped between different transport vehicles. We focus our attention on the transshipment between vessels and land vehicles, in which case the terminal is described as a maritime container terminal. In these container terminals, many combinatorial related problems appear and the solution of(More)
The efficient use of infrastructures is a hard requirement for railway companies. Thus, the scheduling of trains should aim toward optimality, which is an NP-hard problem. The paper presents a friendly and flexible computer-based decision support system for railway timetabling. It implements an efficient method, based on meta-heuristic techniques, which(More)