2015
Autores
Sato, AK; Guerra Tsuzuki, MDG; Martins, TD; Gomes, AM;
Publicação
IFAC PAPERSONLINE
Abstract
Irregular nesting is a subgroup of cutting and packing problems in which a set of irregular items must be inserted in a rectangular container with a variable width. It is often found ill industries such as textile, wood and shipbuilding and an efficient solution usually renders an economical and environmental positive impact. Due to the complex geometry of items, the no overlapping rule is hard to guarantee and, therefore, geometric tools are usually employed. In this work, a raster method is proposed to solve the overlap minimization problem, which can be adapted to solve the irregular nesting problem. A map of overlap values is created and is employed to find the minimum overlap placement for each item A multiresolution approach is used to reduce the size of the map and, consequently, accelerate the search process. The results from tests performed using 4 benchmark tests indicates that more compact layouts can be obtained using multiple resolutions. Moreover, the results are competitive when compared to other solutions in the literature. Copyright (C)2015 IFAC.
2015
Autores
Rocha, P; Rodrigues, R; Miguel Gomes, AM; Toledo, FMB; Andretta, M;
Publicação
IFAC PAPERSONLINE
Abstract
This paper presents an approaches. that assists in producing highly compacted Nesting layouts with irregular pieces using free rotations. This approach consists in the selection and compaction of big pieces in a first phase, while in a second phase, places the remaining small pieces between the big pieces, compacting all of them. The effect of several parameters are analyzed, such as minimum length to be achieved in the first phase, attraction of the pieces to the edges of the container, attraction between each pair of pieces, among others. This approach can provide good compaction results, while improving computational cost in some cases, which cart allow to tackle real world problems more effectively mkt efficiently.
2015
Autores
Rocha, P; Rodrigues, R; Miguel Gomes, A; Alves, C;
Publicação
Operations Research and Big Data: IO2015-XVII Congress of Portuguese Association of Operational Research (APDIO)
Abstract
In this paper, we address the irregular strip packing problem (or nesting problem) where irregular shapes have to be placed on strips representing a piece of material whose width is constant and length is virtually unlimited. We explore a constructive heuristic that relies on the use of graphical processing units to accelerate the computation of different geometrical operations. The heuristic relies on static selection processes, which assume that a sequence of pieces to be placed is defined a priori. Here, the emphasis is put on the analysis of the impact of these sequences on the global performance of the solution algorithm. Computational results on benchmark datasets are provided to support this analysis, and guide the selection of the most promising methods to generate these sequences.
2015
Autores
Sousa, C; Soares, A;
Publicação
ON THE MOVE TO MEANINGFUL INTERNET SYSTEMS: OTM 2015 WORKSHOPS
Abstract
Lightweight ontologies are increasingly used by domain experts in a variety of activities. The development of these knowledge representation artefacts carries the challenge of the proper conceptualisation of the considered reality/situation. In particular, the elicitation of conceptual relations is widely acknowledged in the literature as being the most difficult part of the process. This paper proposes a technique to support domain experts in the elicitation of conceptual relations in the development of lightweight ontologies by providing the means to develop and ascertain the consistency of the produced conceptualisation results towards its reusability. Its innovation comes from the development of a reference model for the conceptual relations elicitation.
2015
Autores
Vaz Almeida, M; Soares, AL;
Publicação
Handbook of Research on Effective Project Management through the Integration of Knowledge and Innovation
Abstract
Project-based organizations have characteristics that raise additional barriers to information management, knowledge sharing, and to organizational learning. The main causes of this are inadequate information architectures and governance, poor collaborative culture, and lack of organization-wide information management strategies. This chapter presents a comprehensive basis to understand the information and knowledge-sharing practices in PBO, as well as the methods and tools that information professionals and project managers should have in mind when performing their tasks. For that, literatures are reviewed focusing on the explanation of the processes of knowledge creation and sharing leading to organizational learning. The main conclusion is that a knowledge-sharing strategy in a PBO should include a set of mechanisms that address a customized mix of the codification and personalization dimensions and that strategies for collaborative information management should be used as enablers for embedding knowledge sharing within the organizational practices and culture.
2015
Autores
Messina, D; Barros, AC; Soares, AL;
Publicação
Atas da Conferencia da Associacao Portuguesa de Sistemas de Informacao
Abstract
This thesis aims at contributing with new research at the intersection of the research fields of information management and supply chain risk management. Information is a fundamental element for an effective risk management in supply networks. In spite of this, research on how to use internal and external information for risk management decisions in supply networks is scarce. Therefore, this thesis main goal is to characterize information models used in supply networks and the supply chain risk management process in order to propose an aggregated model of internal and external information for risk management decision support in supply networks. This work is based on the Design Science paradigm, which will be applied through several research methods: systematic literature review to analyse the current state of the art on information management in supply networks; field research to analyse the influence of different information organisation models in the process of supply chain risk management and to develop an information model based (artifact); and action research to implement the artifact for the definition of risk mitigation strategies in aeronautic supply networks.
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