Abstract
Programming contests should be capable of being appealing to both the contestants and the general public. We feel that the use of graphical user interfaces and computer graphics could help achieve this goal, providing new ways of viewing the task. We describe experiments we made with games (Tic-Tac-Toe, Snake and Ataxx, an Othello-like game), which were made available to students with graphical components, and discuss the results. We also present a simple graphic library where simple drawings can be made and show how it can be used in a programming contest environment. We then conclude by revisiting some past IOI problems, suggesting ways to enhance them with graphical components.

Abstract
This paper describes a fully complete autonomous hybrid robot system, named YAM (Yet Another Mouse), that is able to navigate through an unknown maze environment. YAM effectively tackles the problem of how to represent the environment using its sensor data to produce probability maps of the walls and beacons. Besides that, it is capable of computing long-term path plans using an adapted breadth-first search algorithm. It also shows how it is possible to model the actual motors behavior as a reactive task, using artificially created virtual short-term goals. We give real contest results, showing how YAM behaved on the "CiberRato" robotics competition.

Abstract
The computational efficiency of linear ?-calculi with iterators is evaluated using closed reduction strategies. The interaction between linearity and closed reduction and the computational power of linear systems with and without closed reduction is analyzed. A linear version of Gödel's System T with closed reductions is defined to analyze the computational power of linear systems. Closed reduction strategies in the ?-calculus restrict the reduction rules since closed reduction strategies can take place when certain terms are closed and do not contain free variables. Closed reduction strategies impose strong constraints on the application of reduction rules. Closed reduction strategies can simulate call-by-name and call-by-value evaluations in the ?-calculus. Linear ?-calculus with iterators can be efficiently analyzed by relaxing the constraints on the construction of iterator terms.

Abstract
System L is a linear A-calculus with numbers and an iterator, which, although imposing linearity restrictions on terms, has all the computational power of Godel's System T. System C owes its power to two features: the use of a closed reduction strategy (which permits the construction of an iterator on an open function, but only iterates the function after it becomes closed), and the use of a liberal typing rule for iterators based on iterative types. In this paper, we study these new types, and show how they relate to intersection types. We also give a sound and complete type reconstruction algorithm for System L.

Abstract
With the recent trend of analysing the process of computation through the linear logic looking glass, it is well understood that the ability to copy and erase data is essential in order to obtain a Turing-complete computation model. However, erasing and copying don't need to be explicitly included in Turing-complete computation models: in this paper we show that the class of partial recursive functions that are syntactically linear (that is, partial recursive functions where no argument is erased or copied) is Turing-complete.

Abstract
Underwater acoustic networks can be quite effective to establish communication links between autonomous underwater vehicles (AUVs) and other vehicles or control units, enabling complex vehicle applications and control scenarios. A communications and control framework to support the use of underwater acoustic networks and sample application scenarios are described for single and multi-AUV operation.