An interaction form is an abstract model of interaction based on a description of power distribution among agents over alternatives. A solution known as the settlement set is defined at any preference profile. Necessary and sufficient conditions for stability, that is the existence of settlements, are established. A Stability Index that plays a role similar to that of the Nakamura Number is def...

This paper studies the problem of designing output feedback controllers for enlarging the stability region of continuous stirred microbial bioreactors, in the presence of biomass decay. A specific application is in anaerobic digestion, where the stability region can be very small if the operating steady state is selected to maximize the methane production rate. A proportional output feedback co...

Nine Aspergillus and three of Trichoderma strains were grown on wheat bran (WB) medium under solid state fermentation (SSF) for amylase production. Aspergillus oryzae LS1 produced the highest level of the enzyme. The thermal stability profile of its crude enzyme revealed the half-life time of more than 2 h at 50 and 60ºC. The enzyme production was affected by strain type, incubation periods, le...

Several types of production systems have been studied and researched in the past using either simulation and\or optimization methods. In this paper we describe the design and development of a simulation assisted predictivereactive system for scheduling and rescheduling a typical flexible production system configuration. Aspects like the combined use of simulation and optimization to solve compl...

Global supply chains are complex dynamical systems. Due to nonlinear dependencies between production locations, already a perturbation at one location can change the dynamic behavior of the whole supply chain. As a consequence the supply of customers in time may be at risk. In this paper we present an approach to supply chain design that maximizes the robustness of a supply chain in regard to p...

We study a 2-sided labor market with a set of heterogeneous firms and workers in an environment where jobs are secured by regulation. Without job security Kelso and Crawford have shown that stable outcomes and efficiency prevail when all workers are (weak) gross substitutes to each firm, in the sense that increases in other workers’ salaries can never cause a firm to withdraw an offer from a wo...

Fungi form the genus Monascus are a promising source for natural color additives. However, before effectively applying Monascus to foods, it is important to select strains which produce large amounts of biopigments but little or no citrinin, a mycotoxin usually also produced by these fungi. Also, color stability of these pigments should be properly investigated. In order to compare Monascus str...

The traditional production planning model based upon the famous linear programming formulation has been well known in the literature. The consideration of uncertainty in manufacturing systems supposes a great advance. Models for production planning which do not recognize the uncertainty can be expected to generate inferior planning decisions as compared to models that explicitly account the unc...

Being protein function a conformation-dependent issue, avoiding aggregation during production is a major challenge in biotechnological processes, what is often successfully addressed by convenient upstream, midstream or downstream approaches. Even when obtained in soluble forms, proteins tend to aggregate, especially if stored and manipulated at high concentrations, as is the case of protein dr...