Genetic Algorithm for Decentralized PI Controller Tuning of a Multi-Span Web Transport System Based on Overlapping Decomposition

The use of multi-span web transport systems often requires dedicating a particular effort for defining a control system able to protect the integrity of the web. In web handling processes there is a clear need for controlling web velocity and tension. As for any control problem, the best results are achieved when there is a clear understanding of the controlled process. Starting from a new mathematical model called Transfer Matrix Model for a more accurate description of a web transport system, an optimization study for identifying parameters of the PI controllers for a decentralized multiinput and multi-output system (MIMO) has been proposed. The possibility of using PI controllers for each section is attractive considering that an overlapping system decomposition may permit to take into account the mutual interaction of the neighbor sections reaching specified performance objectives. Finally, by using a nonlinear interpolation of the trend of a preliminary database of values obtained through genetic algorithm, a self-tuning strategy is proposed to estimate optimal PI parameters under certain conditions, avoiding the long identification process and making the system flexible and adaptive. Simulations and experimental results validate and illustrate the effectiveness and the simplicity of the proposed method by considering several different set-points.The 2017 Asian Control Conference -ASCC 2017, December 17-20, 2017, Gold Coast Convention Centre, Australi

Implementation and Validation of a Lumped Model for an Experimental Multi-Span Web Transport System

Correct modeling is necessary in order to design a better control system or to identify the plant parameters experimentally. On the web dynamics itself, lumped parameters expressions may be used to designate a web section between two adjacent drive rolls, and there is the necessity of incorporating the property of viscoelasticity to the web. Lumped model of an experimental multi-span web transport system is based on the conservation mass, torque balance and viscoelasticity. A new way for describing this kind of MIMO system has been introduced through a four by four Transfer Matrix which considers mutual interactions between inputs and outputs. Finally, comparing experimental data with Transfer Matrix parametric expressions, it has been possible to identify the system parameters and thus fully validate the effectiveness of the proposed dynamic lumped model.The 2017 Asian Control Conference -ASCC2017, December 17-20, 2017, Gold Coast Convention Centre, Australi

Lysosomal Glycohydrolase Activities in Dendritic Cells: Is It a Function of Hematopoietic Stem Cells Differentiation Process?.

Abstract A key mechanism responsible for processing of peptide-MHC class II complexes in mature Dendritic Cells (DCs) is the generalized activation of lysosomal function. Mechanisms underlie these developmental changes are controversial. Thus, it is unclear whether immature DCs can present self antigens, and which are the checkpoints that regulate antigen presentation in immature and mature DCs. Here we generated in-vitro human DCs from peripheral blood CD34+ hematopoietic stem cells (HSCs), by adding to the medium culture Flt-3, GM-CSF, IL-4, and TNF-a (cytokine cocktail, CC) at 37°C for 14 days, and analysed the lysosomal glycohydrolases production and function. Lysosomal enzymes, b-N-Acetyl-Hexosaminidase, a-Mannosidase, b-Galactosidase and b-Glucoronidase are highly increased in a wide range in DCs (14 days of culture) with respect to the CD34+HSCs. All the glycohydrolases activities measured at 3 and 7 days in-vitro culture, were similar and four times more than CD34+HSCs (day 0) respectively. Interestingly, no activities increase were observed, even when SCF, an early acting cytokine, promoting cellular proliferation, were added to the CC medium, indicating that this phenomenon is independent from the proliferation process. Moreover, LPS treatment, to induce DCs maturation, slightly enhance the specific activities of all enzymes that we tested as respect to the untreated cells. and support the evidence that the lysosomal glycohydrolases activation is up-stream to DCs maturation process. Furthermore, for the first time, this date indicated that lysosomal glycohydrolases are regulated during the stem cell differentiation process. Understanding the key mechanism leading this phenomenon is critical for therapeutic application in immunologic or neoplastic disease.</jats:p