Showing papers by "Antonios Armaou published in 2019"

Pairing Moving Horizon Estimation and Model Predictive Control via Carleman Approximation for Output Feedback Control

Abstract: An output feedback control structure is proposed for processes in the presense of disturbance and incomplete state information. It combines moving horizon estimation (MHE) and model predictive control (MPC), where Carleman approximation is employed to reduce the nonlinear process plant model and then pair and streamline the computations between the two components. After Carleman approximation, the CMHE/CMPC pair reduces the dynamic optimization problem using analytical expressions for the cost functionals and constraints. CMHE provided state estimates become the initial conditions for CMHE to decide the optimal control signals. With these signals continuously updated in the process model used in CMHE, the state estimates accuracy increases. Analytical gradient vectors and Hessian matrices are supplied to the CMHE/CMPC pair to further reduce computation expenses. We present case studies on a nonlinear CSTR system to show the improvement in computational efficiency with the proposed CMHE/CMPC pair.

Gene Regulatory Network Construction and Key Gene Recognition of Diabetic Nephropathy

Abstract: Diabetic nephropathy (DN) is a diabetic complication that seriously endangers human health. Its pathogenesis involves a variety of factors. The purpose of this paper is to determine key genes in the disease progression that will be potential therapeutic targets of DN. Based on gene expression profiles and the databases of interactions of proteins-proteins, transcription factors-genes, transcription factors-miRNAs and miRNAs-genes, the differentially expressed genes of DN were screened. The regulatory network of DN differential genes was established and key genes of DN were identified using the entity grammar system. According to the regulatory interaction between genes, key genes were defined as the ones that could regulate the state of other genes from abnormal towards normal expression. Identified key genes include BMP2 (bone morphogenetic protein 2), VEGFA (vascular endothelial growth factor A), F3 (coagulation factor III/tissue factor), EGR2 (early growth response protein 2), CDS1 (CDP- diacylglycerol synthase 1) and PLCE1 (phospholipase C epsilon 1). These findings provide clues for the successful drug development of DN.

110th Anniversary: Generalized Singular Value Decomposition Reduced-Order Observers for Linear Time-Invariant Systems with Noisy Measurements

Abstract: The use of observers for improvement of output feedback process control is important for achieving accuracy and processing efficiency, especially for large multivariate process systems. Reduced-ord...