CEGI - Indexed Articles in Conferences
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ItemTRAVELLING TO WORK OR JUST FOR FUN? EXPLORING DIFFERENCES IN PERCEPTIONS AND ATTITUDES BY TRAVEL MODES( 2010) Gabriela Beirão ; José Sarsfield Cabral
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ItemEvolução do desempenho de lojas de retalho ao longo do tempo utilizando o índice de Malmquist( 2011) Ana Camanho ; Maria Clara VazEste artigo avalia a evolução do desempenho de lojas de base alimentar de um retalhista Europeu. A técnica de Data Envelopment Analysis e o índice de Malmquist são combinados com a técnica de bootstrap para medir as alterações de produtividade entre os anos de 2002 e 2004, e identificar as alterações consideradas estatisticamente significativas. Na avaliação de desempenho ao longo do tempo há que ter em conta dois efeitos: a variação de eficiência técnica de cada loja e a alteração da fronteira da tecnologia. O índice de Malmquist permite captar correctamente estes dois efeitos. A variação da eficiência técnica mede a evolução da capacidade de cada loja em aproximar-se dos melhores níveis observados nas unidades de referência. A alteração da fronteira da tecnologia traduz a evolução verificada nas práticas das melhores lojas, que indicam os melhores níveis de produtividade alcançáveis no período em análise, e o rumo o seguir numa perspectiva de melhoria contínua.
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ItemAssessment of performance and innovation of Portuguese construction companies( 2011) Isabel Horta ; Jorge Moreira da Costa ; Ana Camanho
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ItemNew Integer Programming formulations for the Kidney Exchange Problem( 2012) Ana Viana ; Xenia Klimentova ; Miguel Constantino
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ItemMetodologia de apoio à gestão logística em unidades de saúde.( 2012) Maria Clara Vaz
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ItemMetodologia de apoio à gestão logística em unidades de saúde( 2012) Maria Clara Vaz
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ItemA Compact Formulation for the Kidney Exchange Problem( 2012) Abdur Rais ; Miguel Cosntantino ; Xenia Klimentova ; Ana Viana ; João Pedro Pedroso
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ItemA MODEL BASED ON BIBLIOMETRIC INDICATORS: THE PREDICTIVE POWER( 2013) Elizabeth Sousa Vieira ; José Sarsfield Cabral ; Gomes,JANF
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ItemAssessing contextual mood in public transport: A pilot study( 2013) Costa,PM ; Pitt,J ; Teresa Galvão ; João Falcão CunhaIn recent years, the technological developments in mobile and communication networks have paved the way for smart environments, whose final goal is to provide users with enhanced experiences. The measure of user experience satisfaction, or quality of experience, may be defined as an affective state in response to a service. Thus, an experiment was devised to explore the relationship between users' affective state and their context, for assessing quality of experience in urban public transport services. A pilot study, conducted to evaluate the feasibility and requirements of such an experiment is presented, leading to a large scale field study. © 2013 Authors.
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ItemCircle covering using medial axis( 2013) Pedro Filipe Rocha ; Rui Pedro Rodrigues ; Toledo,FMB ; António Miguel GomesA good representation of a simple polygon, with a desired degree of approximation and complexity, is critical in many applications. This paper presents a method to achieve a complete Circle Covering Representation of a simple polygon, through a topological skeleton, the Medial Axis. The aim is to produce an efficient circle representation of irregular pieces, while considering the approximation error and the resulting complexity, i.e. the number of circles. This will help to address limitations of current approaches to some problems, such as Irregular Placement problems, which will, in turn, provide a positive economic and environmental impact where similar problems arise. © 2013 IFAC.
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ItemPredictive production planning in an integrated pulp and paper mill( 2013) Gonçalo Reis Figueira ; Furlan,M ; Bernardo Almada-LoboDisturbance Management is a major issue in process industries like the pulp and paper (P&P) industry. In this paper, a case study in an integrated P&P mill is examined. Production plans for the whole mill need not only to be optimized concerning company's indicators, but also to be robust so that disturbances can be avoided. We present a simulation-optimization approach that generates plans, correctly weighting their quality (regarding various indicators) and robustness. A discrete-event simulation model replicates the dynamics of implementation and adaptation of production plans in practice. The simulation model gives then feedback to optimization, in order to enhance the analytical model, which is thus able to generate robust plans. © IFAC.
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ItemDISTRIBUTED AGENT BASED SIMULATION FRAMEWORK( 2013) Carlos Bragança Oliveira ; António Carvalho BritoIndustrial companies are faced today with strong competition and fast changing markets. To reduce the risk and evaluate alternatives, simulation is often considered to be an adequate tool. Industrial companies' simulation models must have enough internal detail to be useful but, at the same time, must take into account the external environmental behaviour. Distributed simulation has specific characteristics to allow the integration of these models but its complexity limits its use in industry as stated in the literature. To overcome these difficulties, a framework is proposed, using Agent-based Modelling and Simulation (ABMS) technique and offering communication and synchronization mechanisms, which allow the integration of simulation models in the industrial area. To promote semantic interoperability, a business language is also proposed based on the OASIS Universal Business Language (UBL). To validate the framework a prototype was developed. The experiments made with the prototype shows that a distributed simulation can be more efficient than a single computer simulation as the number of agents increases in the model.
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ItemThe railway blues: Affective interaction for personalised transport experiences( 2013) Costa,PM ; Vasalou,A ; Pitt,J ; Teresa Galvão ; João Falcão CunhaThe convergence of personal devices, pervasive communication networks and remote computing has caused a fundamental shift in the user interaction paradigm. Multiple methods have enabled an implicit loop of interaction that goes beyond the traditional graphical interfaces. Human emotion is one of such dimensions, supporting the development of empathic systems. Thus, quality of user experience, a subjective measure, may be defined as the resulting affective state from an interaction, which can be dynamically assessed. In mobile ubiquitous settings, leveraging this affective interaction for providing personalisation and immersive digital services has the potential to significantly impact user experience. This paper investigates the relationship between user affect and experience in the context of urban public transport. © 2013 ACM.
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ItemHealthcare professionals as customers: A service perspective on Portuguese primary care health information systems( 2013) Jorge Daniel Teixeira ; Lia Patrício ; Nobrega,L ; Constantine,L ; Fisk,RPHealth information systems are becoming ubiquitous throughout healthcare delivery processes. Governments, enticed by the potential for improved patient care and cost reduction, are pushing for more integrated IT systems in healthcare. However, the successful adoption of these systems depends on the value they create as a service for healthcare professionals and how they support their activities. Following a call for more multidisciplinary research in health information systems and increased end-user participation in HIS development, this study presents a service perspective that considers users of health information systems (HIS) as active partners and co-creators of value, instead of passive recipients of the functionalities brought by these IT systems. From a service perspective we frame healthcare professionals as customers of HIS, and analyze how they can better support healthcare provision. We present an in-depth study of primary care professionals experience with the HIS of the Portuguese National Health Service. Experience was systematized using Customer Experience Modeling, a method that takes into account the holistic nature of experience. Results portray and evaluate HIS according to professionals' experience requirements. They also show a fragmented reality where HIS usefulness is being hampered by integration and performance issues. HIS design guidelines are also posited. © 2013 IEEE.
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ItemA Proposal for a Mobile Ticketing Solution for Metropolitan Area of Oporto Public Transport( 2013) Marta Campos Ferreira ; Novoa,MH ; Teresa GalvãoThe use of mobile phones to make payments is already a wide-spreading reality. While some mobile payment solutions achieved a considerable success and are already in use, others failed in the pilot phase. Nevertheless, there is an area where mobile payments have been quite successful: mobile ticketing in public transport. In fact, there are several advantages of mobile ticketing over traditional ticketing systems, such as queue avoidance, ubiquitous and remote access to payment, and the lack of need to carry coins and cash. This paper intends to propose a mobile payment system to be implemented in the Public Transport of Metropolitan Area of Oporto. After defining the payment ticketing model, a prototype was developed and tested by a sample of users. These tests allowed gathering some feedback about the feasibility of the system as well as useful insights about the concept, new in public transport in Portugal. The findings attained so far suggest that users considered the system extremely useful, since it is more convenient than traditional systems, improving the travelling process and experience. It was also clear that users valued the integration of additional and complementary services with mobile payments, such as real-time traffic information, maps and schedules. There are also several barriers to the adoption of such a system elicited by users, such as premium price, complex interfaces and perceived risks, such as security and privacy concerns.
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ItemDynamic multi-interface services: An application to the design of a multimedia service( 2013) Jorge Daniel Teixeira ; Lia Patrício ; Huang,KH ; Nobrega,L ; Constantine,L ; Fisk,RPThe development and widespread market acceptance of recent technological devices, such as smart phones and tablets, poses new challenges and great opportunities for innovative service designs. In fact these devices no longer merely replicate the same functionalities in different contexts, they can also dynamically interact among themselves when in close proximity. Thus, this is a two-fold challenge for service designers, they must handle the additional points of contact between service providers and their customers independently, and also in combinations. In this paper we present the relevant concepts for designing multi-interface services, and also introduce the concept of dynamic service interfaces. We illustrate these dynamic service interfaces by presenting an application to the design of a new multimedia service. This service makes use of dynamic service interfaces to deliver an improved and innovative customer experience. © 2013 IEEE.
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ItemShip damage control action simulation using HLA( 2013) Martins,PT ; Rossetti,RJF ; António Carvalho BritoThis work discusses on the simulation of a ship crew reaction in controlling damage in a single watertight compartment, taking into account ship's hydrostatics and equipment limitation. Three different simulators were built which exchange data using High Level Architecture concepts, implemented with an open source RTI called CERTI and a MatlabHLA Tollbox.
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ItemUrban public transport service co-creation: leveraging passenger's knowledge to enhance travel experience( 2014) António Júlio Nunes ; Teresa Galvão ; João Falcão CunhaMobile devices are increasingly pervasive and are transforming information distribution paradigms. A rapidly growing segment of urban public transport passengers carry mobile computing devices, permanently and on the move. In a context of thinning financial resources, getting customers involved in the actual delivery of a public transport service as real-time information consumers and providers, may be a powerful method to enhance travel experience while reducing operational costs for the service operator. Each and every customer travelling on a public transport network has unique knowledge about the service operation as it unfolds. This paper proposes a framework that aims to unify public transport passengers' collective intelligence through crowdsourcing, using their mobile computing devices and dedicated web services. It strives to intensify win-win relationships between public transport passengers and operators. The structured exchange of information is sustained by a validation mechanism for data reliability, and an incentive mechanism to encourage passenger participation. Passengers benefit from rich real-time data tailored to their profiles, to ease their journeys and improve travel experience, in exchange for their own participation providing and validating information. Operators gain access to rich customer generated data, which in an aggregated format may provide a real-time assessment of customer experience and of local performance across the entire network operation. Operators may be required to reward travellers who become prolific co-creators of the public transport service, but higher customer experience levels, lesser needs for investment in controlling mechanisms, and continuous free monitoring of customer opinions can jointly lead to financial returns. (C) 2013 The Authors. Published by Elsevier Ltd.
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ItemState of the art and future perspectives for smart support services for public transport( 2014) João Falcão Cunha ; Teresa GalvãoThis paper summarizes existing systems and research on information transport services, and proposes a hypothetic scenario for future travellers using public transport. Increased distributed intelligence in pervasive mobile smart devices and in sensor networks in public transport vehicles is enabling a new approach for enhancing the experience of public transport customers. Such environment could be modelled through a distributed multi-agent service system. This paper presents advanced information services already available on such environments, in particular the MOVE-ME smartphone application, and indicates a possible service environment where people's feedback may benefit all transport service stakeholders. Mobile computing and crowdsourcing are key enablers for enhancing user experience in the transport services, and also for enhancing overall public transport services. Better experience leads to increased usage of shared mobility modes, and therefore to more sustainable cities in the future. Concerns about data security, and anonymity of travellers will need to be adequately addressed in the future scenarios presented. © 2014 Springer International Publishing Switzerland.
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ItemRobust Production Planning and Scheduling of a Pulp Digester and a Paper Machine( 2014) Gonçalo Reis Figueira ; Bernardo Almada-LoboDisturbance Management is a major issue in process industries like the pulp and paper (P&P) case and is mostly performed in the execution/control level. That approach is confined to the amendment of plans sent by upper levels and can thus be problematic. This paper moves towards the integration of planning and control, starting from the planning's point of view. The application of Simulation-Optimization (S-O) allows considering uncertainty, but keeping a deterministic tractable optimization model. Indeed, it is the simulation model that incorporates more complex elements such as stochastic variables, as well as integrates (with more or less detail) the execution/control behaviour. In this work, we present a case study of a P&P mill, focusing on the two most critical production resources (the digester and the paper machine). The feedback obtained by simulating their interaction is used to adjust the slacks introduced in the intermediate tank. In this way, we are able to generate plans that are not only optimized concerning company's indicators, but also robust against disturbances.