11 resultados para Re-negotiation
em Instituto Politécnico do Porto, Portugal
Resumo:
Congestion management of transmission power systems has achieve high relevance in competitive environments, which require an adequate approach both in technical and economic terms. This paper proposes a new methodology for congestion management and transmission tariff determination in deregulated electricity markets. The congestion management methodology is based on a reformulated optimal power flow, whose main goal is to obtain a feasible solution for the re-dispatch minimizing the changes in the transactions resulting from market operation. The proposed transmission tariffs consider the physical impact caused by each market agents in the transmission network. The final tariff considers existing system costs and also costs due to the initial congestion situation and losses. This paper includes a case study for the 118 bus IEEE test case.
Resumo:
The increase of distributed generation (DG) has brought about new challenges in electrical networks electricity markets and in DG units operation and management. Several approaches are being developed to manage the emerging potential of DG, such as Virtual Power Players (VPPs), which aggregate DG plants; and Smart Grids, an approach that views generation and associated loads as a subsystem. This paper presents a multi-level negotiation mechanism for Smart Grids optimal operation and negotiation in the electricity markets, considering the advantages of VPPs’ management. The proposed methodology is implemented and tested in MASCEM – a multiagent electricity market simulator, developed to allow deep studies of the interactions between the players that take part in the electricity market negotiations.
Resumo:
A multilevel negotiation mechanism for operating smart grids and negotiating in electricity markets considers the advantages of virtual power player management.
Resumo:
Glass fibre-reinforced plastics (GFRP), nowadays commonly used in the construction, transportation and automobile sectors, have been considered inherently difficult to recycle due to both the cross-linked nature of thermoset resins, which cannot be remoulded, and the complex composition of the composite itself, which includes glass fibres, polymer matrix and different types of inorganic fillers. Hence, to date, most of the thermoset based GFRP waste is being incinerated or landfilled leading to negative environmental impacts and additional costs to producers and suppliers. With an increasing awareness of environmental matters and the subsequent desire to save resources, recycling would convert an expensive waste disposal into a profitable reusable material. In this study, the effect of the incorporation of mechanically recycled GFRP pultrusion wastes on flexural and compressive behaviour of polyester polymer mortars (PM) was assessed. For this purpose, different contents of GFRP recyclates (0%, 4%, 8% and 12%, w/w), with distinct size grades (coarse fibrous mixture and fine powdered mixture), were incorporated into polyester PM as sand aggregates and filler replacements. The effect of the incorporation of a silane coupling agent was also assessed. Experimental results revealed that GFRP waste filled polymer mortars show improved mechanical behaviour over unmodified polyester based mortars, thus indicating the feasibility of GFRP waste reuse as raw material in concrete-polymer composites.
Resumo:
Media content personalisation is a major challenge involving viewers as well as media content producer and distributor businesses. The goal is to provide viewers with media items aligned with their interests. Producers and distributors engage in item negotiations to establish the corresponding service level agreements (SLA). In order to address automated partner lookup and item SLA negotiation, this paper proposes the MultiMedia Brokerage (MMB) platform, which is a multiagent system that negotiates SLA regarding media items on behalf of media content producer and distributor businesses. The MMB platform is structured in four service layers: interface, agreement management, business modelling and market. In this context, there are: (i) brokerage SLA (bSLA), which are established between individual businesses and the platform regarding the provision of brokerage services; and (ii) item SLA (iSLA), which are established between producer and distributor businesses about the provision of media items. In particular, this paper describes the negotiation, establishment and enforcement of bSLA and iSLA, which occurs at the agreement and negotiation layers, respectively. The platform adopts a pay-per-use business model where the bSLA define the general conditions that apply to the related iSLA. To illustrate this process, we present a case study describing the negotiation of a bSLA instance and several related iSLA instances. The latter correspond to the negotiation of the Electronic Program Guide (EPG) for a specific end viewer.
Resumo:
Electricity Markets are not only a new reality but an evolving one as the involved players and rules change at a relatively high rate. Multi-agent simulation combined with Artificial Intelligence techniques may result in very helpful sophisticated tools. This paper presents a new methodology for the management of coalitions in electricity markets. This approach is tested using the multi-agent market simulator MASCEM (Multi-Agent Simulator of Competitive Electricity Markets), taking advantage of its ability to provide the means to model and simulate Virtual Power Players (VPP). VPPs are represented as coalitions of agents, with the capability of negotiating both in the market and internally, with their members in order to combine and manage their individual specific characteristics and goals, with the strategy and objectives of the VPP itself. A case study using real data from the Iberian Electricity Market is performed to validate and illustrate the proposed approach.
Resumo:
Este artigo procura evidenciar o empreendedorismo enquanto mecanismo de resposta à (re)inserção social, entendido enquanto necessidade ou oportunidade. Para além da apresentação do empreendedorsimo enquanto opção individual, destaca-se o papel que as universidades e institutos politécnicos devem assumir no desenvolvimento do espírito empreendedor no cluster dos recém-licenciados.
Resumo:
O presente documento reflete o percurso do desenho e do desenvolvimento de um projeto de Educação e Intervenção Social num Lar de idosos. Com base numa metodologia de Investigação-Ação Participativa, que privilegia os discursos, perceções e vivências dos atores sociais que integram esta realidade, procurou-se identificar os problemas e as necessidades. O conhecimento coconstruído com os idosos e profissionais da instituição permitiram a conceção e desenvolvimento do projeto “Envelhecer: ser e estar” que assentou, essencialmente, nas necessidades de (re) ativar e fortalecer as relações interpessoais, fomentar momentos de partilha, convívio, diálogo, discussão, negociação e participação, bem como, na urgência de envolver as pessoas na organização e ocupação do seu tempo livre promovendo a participação, o convívio e o lazer entre os idosos. Sendo um projeto das pessoas e com as pessoas, foram pensadas e planeadas ações e atividades que dessem resposta aos objetivos a que o projeto se propunha na tentativa de transformar e mudar os problemas e necessidades identificados pelos participantes. O projeto possibilitou, desta forma, iniciar um processo que permitiu fortalecer as relações entre os idosos, bem como envolvê-los na organização e participação das atividades do seu tempo livre, resultando num processo de transformação pessoal, grupal e institucional de permanente e contínua construção
Resumo:
O presente relatório reflete um projeto de investigação no âmbito do Mestrado em Educação e Intervenção Social, que assume como metodologia a Investigação Ação-Participativa, e que é desenvolvido e construído com um grupo de pessoas desempregadas. Assim, e contando com os participantes como co-construtores de todo o processo, foi necessário elaborar uma análise e caracterização da realidade da qual surgiram alguns problemas. É com base neles que o projeto começa a ser delineado, tendo por base a educação não-formal de adultos, e recorrendo a ações e atividades para se alcançarem os objetivos definidos e, desta forma, ser possível compreender qual o impacto que ele teve na vida dos participantes. Denominado por “Deixem que eu me (Re)Encontre”, este projeto de investigação pretendeu proporcionar momentos de desenvolvimento da autoestima, de redescoberta de capacidades e competências, e de criação de uma rede de suporte afetivo, estimulando nos participantes a apropriação de um poder de intervenção, gerador de mudança nas suas vidas, que há muito se tinha perdido.
Resumo:
Glass fibre-reinforced plastics (GFRP), nowadays commonly used in the construction, transportation and automobile sectors, have been considered inherently difficult to recycle due to both the cross-linked nature of thermoset resins, which cannot be remoulded, and the complex composition of the composite itself, which includes glass fibres, polymer matrix and different types of inorganic fillers. Hence, to date, most of the thermoset based GFRP waste is being incinerated or landfilled leading to negative environmental impacts and additional costs to producers and suppliers. With an increasing awareness of environmental matters and the subsequent desire to save resources, recycling would convert an expensive waste disposal into a profitable reusable material. In this study, the effect of the incorporation of mechanically recycled GFRP pultrusion wastes on flexural and compressive behaviour of polyester polymer mortars (PM) was assessed. For this purpose, different contents of GFRP recyclates (0%, 4%, 8% and 12%, w/w), with distinct size grades (coarse fibrous mixture and fine powdered mixture), were incorporated into polyester PM as sand aggregates and filler replacements. The effect of the incorporation of a silane coupling agent was also assessed. Experimental results revealed that GFRP waste filled polymer mortars show improved mechanical behaviour over unmodified polyester based mortars, thus indicating the feasibility of GFRP waste reuse as raw material in concrete-polymer composites.
Resumo:
Recent Advances in Mechanics and Materials in Design