2016
Authors
Demissie, MG; Phithakkitnukoon, S; Sukhvibul, T; Antunes, F; Gomes, R; Bento, C;
Publication
IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS
Abstract
A rise in population, along with urbanization, has been causing an increase in demand for urban transportation services in the sub-Saharan Africa countries. In these countries, mobility of people is mainly ensured by bus services and a large-scale informal public transport service, which is known as paratransit (e.g., car rapides in Senegal, Tro Tros in Ghana, taxis in Uganda and Ethiopia, and Matatus in Kenya). Transport demand estimation is a challenging task, particularly in developing countries, mainly due to its expensive and time-consuming data collection requirements. Without accurate demand estimation, it is difficult for transport operators to provide their services and make other important decisions. In this paper, we present a methodology to estimate passenger demand for public transport services using cell phone data. Significant origins and destinations of inhabitants are extracted and used to build origin-destination matrices that resemble travel demand. Based on the inferred travel demand, we are able to reasonably suggest strategic locations for public transport services such as paratransit and taxi stands, as well as new transit routes. The outcome of this study can be useful for the development of policies that can potentially help fulfill the mobility needs of city inhabitants.
2016
Authors
Lourenco, EJ; Pereira, JP; Barbosa, R; Baptista, AJ;
Publication
23RD CIRP CONFERENCE ON LIFE CYCLE ENGINEERING
Abstract
Multi-layer Stream Mapping (MSM) comprehends a new framework for the performance assessment of complex systems. The MSM was developed for multi-domain analysis in an original manner to assess if resources, process and other domains are used to their full potential. The costs related with misuses/inefficiency situations are also quantified and integrated in a simplified manner. A real case study applying the MSM method is validated through application to a Medium Density Fibreboard (MDF) finishing line. For this study all the resources and materials consumed in each unit process where considered. The overall efficiency was assessed and improvements actions were evaluated. (C) 2016 The Authors. Published by Elsevier B.V.
2016
Authors
Baptista, AJ; Lourenco, EJ; Pereira, JP; Cunha, F; Silva, EJ; Pecas, P;
Publication
23RD CIRP CONFERENCE ON LIFE CYCLE ENGINEERING
Abstract
Assessing eco-efficiency performance of a production system is of great importance, since such assessment enables one to make an informed decision concerning economic and environmental performance of elementary systems within industrial productions systems. The framework presented in this paper is based on the eco-efficiency principles and four cornerstones i) Data inventory, ii) Environmental performance evaluation, iii) Environmental impact assessment and iv) Cost models/Value data. The Eco-Efficiency Integrated Methodology for Production Systems (ecoPROSYS) approach relies on the use of a systematized and organized set of indicators easy to understand/analyse promoting continuous improvement and a more efficient use of resources and energy. The goal is to assess eco-efficiency performance in order to support decision and enable the maximization of product/processes value creation and minimization of environmental burdens. The methodology was applied to a Medium Density Fibreboard (MDF) finishing line. The results of the study intend to validate the applicability of ecoPROSYS. The case study showed that the cutting and the feeding table have superior eco-efficiency performance while packing and sanding have lower eco-efficiency performance. The presented framework is a powerful tool that can be used to identify and quantify key variables, assess alternative scenarios, evaluate environmental aspects, environmental influence and assess unit processes and overall eco-efficiency performance. (C) 2016 The Authors. Published by Elsevier
2016
Authors
Leite, M; Baptista, AJ; Ribeiro, AMR;
Publication
International Journal of Product Development
Abstract
The aim of this research paper is to formulate a road map for implementation of lean techniques within SMEs product development (PD) teams, identifying barriers to change and explaining possible drivers for successful implementation. The research methodology necessary to develop the road map - the IPID cycle - is a combination of different approaches. It combines a literature review, an initial quantitative study with questionnaires, informal interviews and direct observation of companies' practices of five different manufacturing companies organised in a consortium. Like any other case study methodology, it suffers from generalisation issues, but we expect that the proposed road map is applicable whenever managers need to introduce changes inside their PD teams. Also, we found that a consortium arrangement can be highly positive to the implementation of the proposed road map. Finally, we found that the application of the road map to SMEs PD teams is somewhat different from big companies' implementations and discuss the observed particularities of these findings. Copyright © 2016 Inderscience Enterprises Ltd.
2016
Authors
Coutinho, CP; Baptista, AJ; Rodrigues, JD;
Publication
ENGINEERING STRUCTURES
Abstract
Similitude theory is a branch of engineering science concerned with establishing the necessary and sufficient conditions of similarity among phenomena, and has been applied to different fields such as structural engineering, vibration and impact problems. Testing of sub-scale models is still nowadays a valuable design tool, helping engineers to accurately predict the behavior of oversized prototypes through scaling laws applied to the obtained experimental results. In this manuscript it has been reviewed the developments in the methodologies used to create reduced scale models as a design tool, including those based in the use of: dimensional analysis, differential equations and energetic methods. Besides, given their importance, some major areas of research were reviewed apart: impacted structures, rapid prototyping of scale models and size effects. At last, some topics on which additional efforts can be undertaken are highlighted.
2015
Authors
Rodrigues, AM; Ferreira, JS;
Publication
OPERATIONAL RESEARCH: IO 2013 - XVI CONGRESS OF APDIO
Abstract
Collecting and transporting solid waste is a constant problem for municipalities and populations in general. Waste management should take into account the preservation of the environment and the reduction of costs. The goal with this paper is to address a real-life solid waste problem. The case reveals some general and specific characteristics which are not rare, but are not widely addressed in the literature. Furthermore, new methods and models to deal with sectorization and routing are introduced, which can be extended to other applications. Sectorization and routing are tackled following a two-phase approach. In the first phase, a new method is described for sectorization based on electromagnetism and Coulomb's Law. The second phase addresses the routing problems in each sector. The paper addresses not only territorial division, but also the frequency with which waste is collected, which is a critical issue in these types of applications. Special characteristics related to the number and type of deposition points were also a motivation for this work. A new model for a Mixed Capacitated Arc Routing Problem with Limited Multi-Landfills is proposed and tested in real instances. The computational results achieved confirm the effectiveness of the entire approach.
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