Abstract
Good design and implementation are necessary but not sufficient pre-requisites for successfully reusing object-oriented frameworks. Although not always recognized, good documentation is crucial for effective framework reuse, and often hard, costly, and tiresome, coming with many issues, especially when we are not aware of the key problems and respective ways of addressing them. Based on existing literature, case studies and lessons learned, the authors have been mining proven solutions to recurrent problems of documenting object-oriented frameworks, and writing them in pattern form, as patterns are a very effective way of communicating expertise and best practices. This paper presents a small set of patterns addressing problems related to the framework documentation itself, here seen as an autonomous and tangible product independent of the process used to create it. The patterns aim at helping non-experts on cost-effectively documenting object-oriented frameworks. In concrete, these patterns provide guidance on choosing the kinds of documents to produce, how to relate them, and which contents to include. Although the focus is more on the documents themselves, rather than on the process and tools to produce them, some guidelines are also presented in the paper to help on applying the patterns to a specific framework. © 2011 Springer-Verlag Berlin Heidelberg.

Abstract
This paper describes the embedding of ClassSheet models in spreadsheet systems. ClassSheet models are well-known and describe the business logic of spreadsheet data. We embed this domain specific model representation on the (general purpose) spreadsheet system. By defining such an embedding, we provide end users a model-driven engineering spreadsheet developing environment. End users can interact with both the model and the spreadsheet data in the same environment. Moreover, we use advanced techniques to evolve spreadsheets and models and to have them synchronized. In this paper we present our work on extending a widely used spreadsheet system with such a model-driven spreadsheet engineering environment.

Abstract
Human pressure is pushing many of our natural resources to their limits in various regions of the world. Optimize their use is an urgent need. The management of agro-industry has been aware of that need, seeking to improve the productivity and reduce waste throughout the production process, as well by increasing the distribution efficiency of their products. Information and Communication Technologies (ICT) can support the control/management of the process inputs and outputs in various activities. This article attempts to describe a complete mushroom production chain. The information system developed by the agro-industry company studied allows to acquire, in real-time, the information about what is being produced (quantity and type of mushroom), which products are to be delivered to the different clients and which should be the planning for the next few days. © 2011 AISTI.

Abstract
The class of subspace system identification algorithms is used here to derive new identification algorithms for 2-D causal, recursive, and separable-in-denominator (CRSD) state space systems in the Roesser form. The algorithms take a known deterministic input-output pair of 2-D signals and compute the system order (n) and system parameter matrices {A, B, C, D}. Since the CRSD model can be treated as two 1-D systems, the proposed algorithms first separate the vertical component from the state and output equations and then formulate a set of 1-D horizontal subspace equations. The solution to the horizontal subproblem contains all the information necessary to compute (n) and {A, B, C, D}. Four algorithms are presented for the identification of CRSD models directly from input-output data: an intersection algorithm, (N4SID), (MOESP), and (CCA). The intersection algorithm is distinguished from the rest in that it computes the state sequences, as well as the system parameters, whereas N4SID, MOESP, and CCA differ primarily in the way they compute the system parameter matrices {A1, C1}. The advantage of the intersection algorithm is that the identified model is in balanced coordinates, thus ideally suited for 2-D model reduction. However, it is computationally more expensive than the other algorithms. A comparison of all algorithms is presented.

Abstract
Although much of mathematics is algorithmic in nature, the skills needed to formulate and solve algorithmic problems do not form an integral part of mathematics education. In particular, logic, which is central to algorithm development, is rarely taught explicitly at pre-university level, under the justification that it is implicit in mathematics and therefore does not need to be taught as an independent topic. This paper argues in the opposite direction, describing a one-week workshop done at the University of Minho, in Portugal, whose goal was to introduce to high-school students calculational principles and techniques of algorithmic problem solving supported by calculational logic. The workshop resorted to recreational problems to convey the principles and to software tools, the Alloy Analyzer and Netlogo, to animate models.

Abstract
Although roles have been around for a long time they have not yet reached mainstream programming languages. The variety of existing role models may be a limiting factor. We believe that for roles to be widely accepted they must enhance code reuse. An outcome would be a library of roles. We present and discuss what we feel are the characteristics that a role model must have to enable reusable and playerindependent roles. In this paper we present our role model and JavaStage, a role language that extends Java, with examples of reusable roles. Finally, we present our steps towards the building of a role library, by presenting the roles developed from the analysis of the GoF Design Patterns. The results obtained, we developed roles for 10 of the 23 GoF patterns, are promising. © Copyright 2011 Carnegie Mellon University.