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Prize-collecting arc routing problems are arc routing problems where, in addition to the cost function, there is a profit function on the edges that must only be taken into account the first time that an edge is traversed. This work presents the clustered prize-collecting arc routing problem where there are clusters of arcs and it is required that all or none of the edges of a cluster be serviced. The paper studies properties and dominance conditions used for formulating the problem as a linear integer program. An exact algorithm for finding an optimal solution to the problem is also proposed. At the root node of the enumeration tree, the algorithm generates upper and lower bounds obtained from solving an iterative linear programming-based algorithm in which violated cuts are generated when possible. A simple heuristic that generates feasible solutions provides lower bounds at each iteration. The numerical results from a series of computational experiments with various types of instances illustrate the good behavior of the algorithm. Over 75% of the instances were solved at the root node, and the remaining instances were solved with a small additional computational effort.

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Abstract. Two decades ago, people used computers as an information resource for many fields.These fields include library information, climatic information, medicine, transportation schedules, banking, and other areas. The use of international networks at that time enabled people to communicate globally in a rapid and accurate fashion not only to experts, but to the public also. In regions such as South and Central America, however, the uses of information resources were not as widespread as they were in developed countries. Indeed, estimates showed that Latin America contained two percent of the world's informatics equipment. At that time, computers appeared in commercial and governmental agencies as well as universities that used global networks such as the internet, BITNET, FidoNet, and other similar networks.In the mid-1980s, of course, the world wide web was only a dream and the individual use of computers was almost non-existent. The emergence of web-based technology in the 1990s caused a worldwide transformation in the use of computers and their applications, particularly in Latin America. Their natural associations with Spain and Portugal and their strong desire to be at the forefront of informatics changes, Latin American countries developed a new resurgence -a small renaissance -thrusting many of these countries into a modern technical society with accelerated growth and educational promise.This panel attempts to emphasize the progress of computing in representative Spanishspeaking countries and to celebrate the computing achievements made there. The distinguished panelists will bring forward ways in which computing had emerged and the way the computing evolution affected computing education in the regions. The summaries of their dialogue follow.