Abstract
This paper addresses the problem of interaction design for service provision to customers in a multi-platform environment. It is based on a qualitative and quantitative study of a Portuguese multi-channel retail bank, and shows that, as most of the financial operations are functionally available across the different service platforms, experience requirements become increasingly influential in customers' usage of the different channels. Different financial services generate different interaction needs, and the fit between experience requirements and channel performance in satisfying those needs has a strong impact on customer channel choices. Based on these findings, essential use cases are applied and extended to capture experience requirements for the different financial operations in a technology independent way. With this approach, interaction designers can identify which platforms are best suited to provide the different services available, improving the multi-channel service as a whole. On the other hand, it also enables the identification of areas of interaction experience that need improvement in each platform, if services offered are likely to be effectively used.

Abstract
In this paper, we study the complexity of a data mining algorithm for extracting patterns from user web navigation data that was proposed in previous work.(3) The user web navigation sessions are inferred from log data and modeled as a Markov chain. The chain's higher probability trails correspond to the preferred trails on the web site. The algorithm implements a depth-first search that scans the Markov chain for the high probability trails. We show that the average behaviour of the algorithm is linear time in the number of web pages accessed.

Abstract
This paper presents some lines of thinking related with the establishment of a concrete mathematical basis to measure the ability of enterprises in a supply chain to maintain equilibrium under unexpected variations. It will be argued that flexibility will be the most appropriate term to classify the concept behind such idea and that agility can be understood as a special case of flexibility. Then, a simple theory of flexibility directed to demand variations in the supply chain is deduced and commented, as well as some results achieved by dynamic supply chain simulation presented and discussed.

Abstract
Here we present a computer application planned to be used as an interactive tool for Supply Chain Management Training. Implemented with Visual C++, this application embeds the "Cranfield Blocks Game" (Richard Saw, 2002) network structure, and uses precisely the same demand patterns as the manual version of the game. Anyhow, instead of reducing the play to 12 reorder cycles, as the manual version does, this application extends those patterns throughout the time till any number of reorder cycles, what let the results become more useful and interesting even for didactic purposes. At the same time, the present application substitutes the classroom table by the computer screen, and can be made to run in AUTOPLAY mode, meaning the game can also be played with only one player or even automatically, with no players at all. In a certain way, this comes closer to some kind of Distributed Supply Chain Simulation, apart from the fact each lead time is fixed, as the "Cranfield Blocks Game" states, and the AUTOPLAY stock policy is empirical. As each application communicates with the SERVER using the TCP/IP protocol, the players can be spread by different computers and even placed at different geographic locations if connected to the INTERNET. In the end of this paper, results achieved with an automatic running session and with the involvement of a group of students from the Escola de Gestao do Porto (EGP) will be presented and compared.

Abstract
The main purpose of this paper is to present a preliminary study on the impact of stratospheric ozone on tropospheric ozone levels under specific atmospheric dynamical conditions. It is well accepted that stratospheric ozone can be the source of part of the tropospheric ozone. Previous studies indicate that the mechanism responsible for this ozone intrusion occurs generally in several steps or just in a single step, usually associated with strong upward motion. In the first part of this paper, the methodology used in order to identify particular short-term episodes, potentially associated to the abovementioned phenomenon, is presented. Several episodes have been studied occurring during 14 years of ozone data collection, recorded by the Portuguese ozone network. Then, an analysis of the dynamical atmospheric conditions associated to previously identified episodes have been developed in order to verify the possibility of stratospheric contribution for the observed ozone level in each episode. Two of these episodes show a relatively good relationship between synoptical patterns related to stratospheric intrusions and backward trajectories. For these cases, the possibility of stratospheric origin should not be discarded before further study is developed.

Abstract
In this paper an application of constraint logic programming (CLP) to the resolution of nesting problems is presented. Nesting problems are a special case of the cutting and packing problems, in which the pieces generally have non-convex shapes. Because of their combinatorial optimization nature, nesting problems have traditionally been tackled by heuristics and in the recent past by meta-heuristics. When trying to formulate nesting problems as linear programming models, to achieve global optimal solutions, the difficulty of dealing with the disjunction of constraints arises. On the contrary, CLP deals easily with this type of relationships among constraints. A CLP implementation for the nesting problem is described for convex and non-convex shapes. The concept of nofit polygon is used to deal with the geometric constraints inherent to all cutting and packing problems. Computational results are presented. © 2003 Wiley Periodicals, Inc.