Transmission cost allocation using cooperative game theory: a comparative study

In this paper is presented a Game Theory based methodology to allocate transmission costs, considering cooperation and competition between producers. As original contribution, it finds the degree of participation on the additional costs according to the demand behavior. A comparative study was carried out between the obtained results using Nucleolus balance and Shapley Value, with other techniques such as Averages Allocation method and the Generalized Generation Distribution Factors method (GGDF). As example, a six nodes network was used for the simulations. The results demonstrate the ability to find adequate solutions on open access environment to the networks.

Effect of peel and seed removal on the nutritional value and antioxidant activity of tomato (Lycopersicon esculentum L.) fruits

The effect of peel and seed removal, two commonly practiced procedures either at home or by the processing industry, on the physicochemical properties, bioactive compounds contents and antioxidant capacity of tomato fruits of four typical Portuguese cultivars (cereja, chucha, rama and redondo) were appraised. Both procedures caused significant nutritional and antioxidant activity losses in fruits of every cultivar. In general, peeling was more detrimental, since it caused a higher decrease in lycopene, bcarotene, ascorbic acid and phenolics contents (averages of 71%, 50%, 14%, and 32%, respectively) and significantly lowered the antioxidant capacity of the fruits (8% and 10%, using DPPH. and b-carotene linoleate model assays, correspondingly). Although seeds removal favored the increase of both color and sweetness, some bioactive compounds (11% of carotenoids and 24% of phenolics) as well as antioxidant capacity (5%) were loss. The studied cultivars were differently influenced by these procedures. The fruits most affected by peeling were those from redondo cultivar (-66% lycopene, -44% b-carotene, -26% ascorbic acid and -38% phenolics). Seeds removal, in turn, was more injurious for cereja tomatoes (-10% lycopene, -38% b-carotene, -25% ascorbic acid and -63% phenolics). Comparatively with the remaining ones, the rama fruits were less affected by the trimming procedures.

Desenvolvimento de um modelo para a gestão de stocks no grupo Nors

Hoje em dia, um dos grandes objetivos das empresas é conseguirem uma gestão eficiente. Em particular, empresas que lidam com grandes volumes de stocks têm a necessidade de otimizar as quantidades dos seus produtos armazenados, com o objetivo, de entre outros, reduzir os seus custos associados. O trabalho documentado descreve um novo modelo, desenvolvido para a gestão de encomendas de uma empresa líder em soluções de transporte. A eficiência do modelo foi alcançada com a utilização de vários métodos matemáticos de previsão. Salientam-se os métodos de Croston, Teunter e de Syntetos e Boylan adequados para artigos com procuras intermitentes e a utilização de métodos mais tradicionais, tais como médias móveis ou alisamento exponencial. Os conceitos de lead time, stock de segurança, ponto de encomenda e quantidade económica a encomendar foram explorados e serviram de suporte ao modelo desenvolvido. O stock de segurança recebeu especial atenção. Foi estabelecida uma nova fórmula de cálculo em conformidade com as necessidades reais da empresa. A eficiência do modelo foi testada com o acompanhamento da evolução do stock real. Para além de uma redução significativa do valor dos stocks armazenados, a viabilidade do modelo é reflectida pelo nível de serviço alcançado.