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Publications

2007

Improving the quality of collaboration requirements for information management through social networks analysis

Authors
Pereira, CS; Soares, AL;

Publication
INTERNATIONAL JOURNAL OF INFORMATION MANAGEMENT

Abstract
The right choice of the method of organizational analysis to use is a key factor ill the process of requirements analysis and specification of an information system. Although a high number of approaches of organizational analysis exist, the choice of the most appropriate option for each concrete case will influence the quality of the results obtained in the analysis of requirements and consequent specification. This paper presents a new way for organizational analysis to improve the quality of the requirements of systems that support information management and where collaboration is an important aspect. This is achieved through the application of the social network analysis approach, applied to refine, classify and prioritize the requirements for collaboration and information management in an organization. The paper begins by analysing shortly content management systems and wiki systems as IT platforms for collaboration and information management. After having described the method, a practical case of application of SNetCol method to an R&D institution is presented. The paper finishes by presenting the results of the evaluation of the two particular technological options considered for satisfying the specified requirements are described.

2007

Iterative reordering of rules for building ensembles without relearning

Authors
Azevedo, PJ; Jorge, AM;

Publication
DISCOVERY SCIENCE, PROCEEDINGS

Abstract
We study a new method for improving the classification accuracy of a model composed of classification association rules (CAR). The method consists in reordering the original set of rules according to the error rates obtained on a set of training examples. This is done iteratively, starting from the original set of rules. After obtaining N models these are used as an ensemble for classifying new cases. The net effect of this approach is that the original rule model is clearly improved. This improvement is due to the ensembling of the obtained models, which are, individually, slightly better than the original one. This ensembling approach has the advantage of running a single learning process, since the models in the ensemble are obtained by self replicating the original one.

2007

An open source IEC 61131-3 integrated development environment

Authors
Tisserant, E; Bessard, L; de Sousa, M;

Publication
2007 5TH IEEE INTERNATIONAL CONFERENCE ON INDUSTRIAL INFORMATICS, VOLS 1-3

Abstract
The IEC 61131-3 standard defines a common framework for programming PLCs (Programmable Logic Controllers), which includes the complete definition of four programming languages and a state machine definition language. Industrial PLC vendors are slowly offering support for this standard, however small inconsistencies remain between their implementations, transferring programs between vendors is almost impossible due to different rile formats, and licenses are generally too expensive to allow students do install these commercial solutions on their own computers. To this end, the authors have developed an Integrated Development Environment (IDE) for the IEC 61131-3 framework, which is being offered to the general public under the GNU Public License (GPL). The IDE consists of a Graphical User Interface (GUI) and a backend compiler. Using the GUI the user may develop programs in any of the four programming languages, as well as the state machine definition language. The backend compiler is used to convert these programs into equivalent C++ programs which may later be compiled and executed on various platforms.

2007

An overview on learning from data streams - Preface

Authors
Gama, J; Rodrigues, P; Aguilar Ruiz, J;

Publication
NEW GENERATION COMPUTING

Abstract

2007

How has the Portuguese innovation capability evolved? Estimating a time series of the stock of technological knowledge (1960–2001)

Authors
Teixeira, AAC;

Publication
Portuguese Journal of Social Science

Abstract
The importance of promoting innovation has been elevated up to a status of official standard since the Lisbon European Summit in 2000. Here research and development (R&D) has been singled out as an essential element of the foundation on which innovation could be built. R&D has been a growing area of investigation namely at level of firms micro studies aimed at uncovering firms’ innovation capability. At the macro level, the relevance of R&D for countries’ innovation capability has been, in a dynamic perspective, more often presumed rather than effectively tested. This latter limitation is, to a large extent, explained by the paucity of aggregated continuous time series on innovation indicators specifically those based on R&D expenditures. This paper aims at filling this gap by providing an estimate of the Portuguese innovation capability over the two last four decades based on the accumulated R&D efforts. Such indicator, albeit preliminary, will desirably endorse new investigation on the Portuguese catching-up process and, in this way, might inform present and future public programs related to R&D policies in particular and innovation policies in general.

2007

Heuristics for the single machine scheduling problem with early and quadratic tardy penalties

Authors
Valente, JMS;

Publication
EUROPEAN JOURNAL OF INDUSTRIAL ENGINEERING

Abstract
This paper considers the single machine scheduling problem with linear earliness and quadratic tardiness costs, and no machine idle time. Several dispatching heuristics are proposed, and their performance is analysed on a wide range of instances. The heuristics include simple scheduling rules, as well as a procedure that takes advantage of the strengths of these rules, Linear early/quadratic tardy dispatching rules are also considered, as well as a greedy-type procedure. Extensive experiments are performed to determine appropriate values for the parameters required by some of the heuristics. The computational tests show that the best results are given by the linear early/quadratic tardy dispatching rule. This procedure is also quite efficient, and can quickly solve even very large instances. [Received 15 December 2006; Revised 20 July 2007; Accepted 24 July 2007]

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