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Publications

Publications by CESE

2005

Multi-perspective challenges on collaborative networks business environments

Authors
Chituc, CM; Azevedo, AL;

Publication
Collaborative Networks and Their Breeding Environments

Abstract
New forms of collaboration emerged as response to transformations of the business environment and the rapid information and communication technologies developments. In this context, collaborative networks rise as a powerful mechanism to achieve strategic objectives in a time response, quality and cost effective manner. The aim of this paper is to present the most relevant challenges concerning collaborative networks paradigm analysis, and to advance a multi-perspective approach on collaborative networks (technological, semantic, social and business perspective), emphasizing the importance of the business view that allows collaborative networks to be regarded as combinations of inter- and intra-enterprise business processes. Balance Scorecard is seen as a powerful tool which can guarantee the strategic and business goal alignment within the network.

2005

Towards a self-forming business networking environment

Authors
Chituc, CM; Azevedo, AL;

Publication
ICEIS 2005 - Proceedings of the 7th International Conference on Enterprise Information Systems

Abstract
The rapid evolution of the markets and the changing client's demands determined enterprises to adapt their business from traditional business practices to e-business, and new forms of collaboration (such as supply chain enterprises, extended enterprises or virtual enterprises) were created. Technologies such as Peer-to-Peer, Web services, intelligent agents, Workflow become core technologies supporting enterprise integration, streamlining transactions while supporting process coordination and consistency. The aim of this paper is to concisely present some relevant business integration reference models, frameworks, standards and technologies, and to propose an approach towards the development of a conceptual framework for a self-forming business networking environment based on Plug-and-Do Business paradigm.

2005

Learning, planning, and the life cycle of workflow management

Authors
Ferreira, DR; Ferreira, HM;

Publication
Ninth IEEE International EDOC Enterprise Computing Conference, Proceedings

Abstract
This paper describes an approach towards workflow management based on the combination of learning and planning. Assuming that processes cannot be fully described at build-time, the approach makes use of learning techniques, namely Inductive Logic Programming (ILP), in order to discover workflow activities as planning operators. These operators will be subsequently fed to a partial-order planner in order to find the process model as a planning solution. The continuous interplay between learning, planning and execution aims at arriving at a feasible plan by successive refinement of the operators. The approach is illustrated in two simple scenarios. The paper concludes by relating the proposed approach with previous developments in this area.

2005

Sewage outfall plume dispersion observations with an Autonomous Underwater Vehicle

Authors
Ramos, P; Cunha, SR; Neves, MV; Pereira, FL; Quintaneiro, I;

Publication
WATER SCIENCE AND TECHNOLOGY

Abstract
This work represents one of the first successful applications of Autonomous Underwater Vehicles (AUVs) for interdisciplinary coastal research. A monitoring mission to study the shape and estimate the initial dilution of the S. Jacinto sewage outfall plume using an AUV was performed on July 2002. An efficient sampling strategy enabling greater improvements in spatial and temporal range of detection demonstrated that the sewage effluent plume can be clearly traced using naturally occurring tracers in the wastewater. The outfall plume was found at the surface highly influenced by the weak stratification and low currents. Dilution varying with distance downstream was estimated from the plume rise over the outfall diffuser until a nearly constant value of 130:1, 60 m from the diffuser, indicating the near field end. Our results demonstrate that AUVs can provide high-quality measurements of physical properties of effluent plumes in a very effective manner and valuable considerations about the initial mixing processes under real oceanic conditions can be further investigated.

2005

Metaheuristics applied to mixed and simultaneous extensions of vehicle routing problems with backhauls

Authors
Crispim, J; Brandao, J;

Publication
JOURNAL OF THE OPERATIONAL RESEARCH SOCIETY

Abstract
Metaheuristics are a class of approximate methods designed to solve hard combinatorial optimization problems arising within various different areas. The importance of metaheuristics results from their ability to continue the search beyond a local optimum so that near-optimal or optimal solutions are efficiently found. In order to solve the backhauling problem associated with mixed and simultaneous delivery and pick-ups, this paper presents a hybrid algorithm which is comprised of the two metaheuristics of tabu search and variable neighbourhood descent. The primary challenge associated with backhauling consists of creating routes in which vehicles are not only required to deliver goods, but also to perform pick-ups at customer locations. The problems associated with these two categories of problems, however, have received little attention in the literature to date. A set of examples taken from the literature with Euclidean cost matrices are presented. Finally, some numerical results are illustrated to show the effectiveness of the proposed approach.

2005

A new input-output control order release mechanism: How workload control improves manufacturing operations in a job shop

Authors
Moreira, MR; Alves, R;

Publication
Modelling and Simulation 2005

Abstract
Make-to-order companies, such as job shops, have been extensively studied. Some of those studies emphasise the importance of the workload control in order to improve manufacturing operations. In this paper a multiple decision-making scheme, with the purpose of planning and controlling operations and getting better delivery and workload related performance measures, as well as one order release decision rule are proposed. The decision-making scheme includes four main decisions: (i) accept or reject an in-coming order; (ii) define the order's due date; (iii) release the accepted jobs; and (iv) dispatch the jobs at the station level. Extensive simulation experiments were performed to compare the proposed rule with the benchmark mechanisms, as well as with rules presented in previous studies. They led to the conclusion that considering the four decisions simultaneously can improve the job shop measures of performance, and that the proposed release rule is the best in almost all instances.

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