Data-driven initialization of deep learning solvers for Hamilton-Jacobi-Bellman PDEs

A deep learning approach for the approximation of the Hamilton-Jacobi-Bellman partial differential equation (HJB PDE) associated to the Nonlinear Quadratic Regulator (NLQR) problem. A state-dependent Riccati equation control law is first used to generate a gradient-augmented synthetic dataset for supervised learning. The resulting model becomes a warm start for the minimization of a loss function based on the residual of the HJB PDE. The combination of supervised learning and residual minimization avoids spurious solutions and mitigate the data inefficiency of a supervised learning-only approach. Numerical tests validate the different advantages of the proposed methodology

Thermal simulation of a supermarket cold zone with integrated assessment of human thermal comfort

This work seeks to analyze the thermal comfort of the occupants in a large building of Commerce and Services, integrating measures of assessment and energy efficiency promotion. The building is still in the construction phase and at its conclusion, will correspond to a supermarket located in the Central region of Portugal. For the evaluation of thermal comfort, Fanger’s methodology was used, where the Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD) were calculated based on a detailed analysis of the environmental variables. These are essential to obtain, namely, mean air velocity, mean radiant temperature, mean air temperature and relative humidity. The other crucial variables are the metabolic rate and the thermal clothing resistance. The simulations necessary for the thermal comfort assessment were performed in ANSYS Fluent, in order to minimize the energy consumption in the cold thermal zone of the building, the sales area with frozen and chilled food, by means of reducing the inflow of air, without compromising thermal Comfort. The final results showed that the reduction of the amount of air to be inflated did not compromise the thermal comfort of the occupants. The Computational Fluid Dynamics (CFD) methodology allowed the creation of comfort maps, albeit for a single zone due to computational limitations. According to the results, the most comfortable zone was located right below the air insufflation with the summer being a more comfortable season. In winter, the main problem detected was the cold located near the floor.The authors would like to express their gratitude for the support given by FCT within the R&D Units Project Scope UIDB/00319/2020 (ALGORITMI) and R&D Units Project Scope UIDP/04077/2020 (MEtRICs)

Abstract 104: The Use of Nitrated apolipoprotein A1 (NT-ApoA1) to Predict Mortality in Patients with Known or Suspected Coronary Artery Disease

Background: Studies have suggested that nitrated apolipoprotein A1 (NT-apoA1) levels may be associated with coronary artery disease (CAD). We therefore hypothesized that NT-apoA1 might be associated with the prediction of all-cause mortality in CAD patients. Methods: Using an ELISA, we measured plasma NT-apoA1 levels in 236 patients with known or suspected coronary artery disease (CAD) undergoing coronary angiography. The patients were then followed prospectively for the development of all-cause mortality for up to 7 years. Results: Lower NT-apoA1 levels were associated with worse renal function, lower HDL levels, higher triglyceride levels and lower ejection fraction. There was positive correlation between NT-apoA1 and HDL cholesterol levels (correlation coefficient 0.366; p &lt;0.0001). After adjustment for a variety of baseline clinical, angiographic and laboratory parameters, log plasma NT-ApoA1 levels were an independent predictor of all-cause mortality [HR, 0.279; 95% CI, 0.084-0.922; p=0.036]. Furthermore, all-cause mortality was lower in patients whose plasma NT-ApoA1 levels were greater than or equal to the median value of the cohort compared to those whose levels were lower than median value (25.88% vs 8.82%; p = 0.001 by log-rank test). Conclusions: Higher NT-apoA1 levels are significantly associated with lower all-cause mortality in CAD patients, which may relate to HDL cholesterol function. Further studies are warranted to investigate this paradoxical finding. </jats:p