2020
Authors
Bahramara, S; Sheikhahmadi, P; Mazza, A; Chicco, G; Shafie Khah, M; Catalao, JPS;
Publication
IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS
Abstract
One of the emergent prospects for active distribution networks (DN) is to establish new roles to the distribution company (DISCO). The DISCO can act as an aggregator of the resources existing in the DN, also when parts of the network are structured and managed as microgrids (MGs). The new roles of the DISCO may open the participation of the DISCO as a player trading energy in the wholesale markets, as well as in local energy markets. In this paper, the decision making aspects involving the DISCO are addressed by proposing a bilevel optimization approach in which the DISCO problem is modeled as the upper-level problem and the MGs problems and day-ahead wholesale market clearing process are modeled as the lower-level problems. To include the uncertainty of renewable energy sources, a risk-based two-stage stochastic problem is formulated, in which the DISCO's risk aversion is modeled by using the conditional value at risk. The resulting nonlinear bilevel model is transformed into a linear single-level one by applying the Karush-Kuhn-Tucker conditions and the duality theory. The effectiveness of the model is shown in the application to the IEEE 33-bus DN connected to the IEEE RTS 24-bus power system.
2020
Authors
Poinhos, R; Oliveira, BMPM; Sorokina, A; Franchini, B; Afonso, C; de Almeida, MDV;
Publication
PROCEEDINGS OF THE NUTRITION SOCIETY
Abstract
2020
Authors
Oliveira, B; Ramos, AG; De Sousa, JP;
Publication
Transportation Research Procedia
Abstract
Urban freight transport is an important enabling factor for economic growth and social activities in cities but despite its benefits, it also generates important negative externalities including traffic congestion, pollution, noise and overall less safety. Moreover, increased limitations on urban freight transport, including access constraints, limited kerbside and private parking spaces for loading/unloading, and the often prohibitive costs of installing logistics infrastructures in city centres, have further constrained urban freight transport. To address these issues, several city logistics solutions have been proposed, such as two-tier distribution systems and distribution systems based on mobile depots. In this paper, we focus on two-tier urban freight distribution systems based on mobile depots, where little or no physical infrastructure is considered and where storage is not permitted at transfer locations. In these types of systems, coordination and synchronisation between vehicles are essential, and the main objective is to have vehicles at the transfer locations in a need-to-be basis as a way of minimising the negative externalities. We review and analyse 13 cases found in the scientific literature, trial reports and online resources, and propose a classification of these systems based on the level of mobility and accessibility of transportation modes operating at the first-tier. Furthermore, we characterise the main components and operational features of the different systems, including the existence of multi-trips, the types of transport modes used at both tiers, transported loads and the organisation of the transfer sites (satellites). This work aims to contribute for a clearer characterisation of two-tier urban distribution systems based on mobile depots, to later support the development of the most adequate mathematical models and solution methods to be applied to each variant of this type of systems. © 2020 The Authors. Published by Elsevier B.V.
2020
Authors
Silva, CD; Sousa, PSA; Moreira, MRA; Amaro, GM;
Publication
INTERNATIONAL JOURNAL OF INFORMATION SYSTEMS AND SUPPLY CHAIN MANAGEMENT
Abstract
Firms recognize that an assertive SCM could lead to an important competitive advantage in the business world. The purpose of this study is to capture the effect of supply chain management practices in the performance of firms, through a meta-analysis. It aims at highlighting which SCM practices that have a superior effect and their positive or negative impact on performance. Partnership with suppliers, process driven events, employee involvement, and customer satisfaction are the SCM practices that proved to have a positive impact in firm performance, according to the meta-analysis results. The findings from the research can help managers deciding on in which SCM practices concentrate their effort. It also allows making comparisons among different regions in terms of practices with a positive effect and how SCM practices evolves since first insights to now and if it changes throughout time. Concerning supply chain theories, this research sustains the hypotheses that SCM practices impact on some firm performance measures.
2020
Authors
Aguiar Castro, JD; Landeira, C; da Silva, JR; Ribeiro, C;
Publication
Int. J. Digit. Curation
Abstract
2020
Authors
Magalhães, C; Martins, A; Santos, AD;
Publication
Zooplankton Ecology
Abstract
The access to the final selection minute is only available to applicants.
Please check the confirmation e-mail of your application to obtain the access code.