7,103 research outputs found
Automatic Viewpoint Dependent Representation of 3-D Object Based on Extended Boundary Model
No full text
FINITE-ELEMENT BASIS FOR THE EXPANSION OF RADIAL WAVE-FUNCTION IN QUANTUM SCATTERING CALCULATIONS
No full textRadial wavefunctions in quantum scattering calculations are expanded in terms of two shape functions for each finite element. This approach is the R matrix version of Kohn's variational method and also directly applicable to S matrix in the log-derivative version. The linear algebra involved amounts to solving definite banded systems. In this basis set method, R matrix or log-derivative matrix is greatly simplified and the computational effort is linearly proportional to the number of radial basis functions, promising computational efficiencies for large scale calculations. Convergences for test vases are also reasonably rapid
The Landau Equation with the Specular Reflection Boundary Condition
No full textThe existence and stability of the Landau equation (1936) in a general bounded domain with a physical boundary condition is a long-outstanding open problem. This work proves the global stability of the Landau equation with the Coulombic potential in a general smooth bounded domain with the specular reflection boundary condition for initial perturbations of the Maxwellian equilibrium states. The highlight of this work also comes from the low-regularity assumptions made for the initial distribution. This work generalizes the recent global stability result for the Landau equation in a periodic box (Kim et al. in Peking Math J, 2020). Our methods consist of the generalization of the wellposedness theory for the Fokker-Planck equation (Hwang et al. SIAM J Math Anal 50(2):2194-2232, 2018; Hwang et al. Arch Ration Mech Anal 214(1):183-233, 2014) and the extension of the boundary value problem to a whole space problem, as well as the use of a recent extension of De Giorgi-Nash-Moser theory for the kinetic Fokker-Planck equations (Golse et al. Ann Sc Norm Super Pisa Cl Sci 19(1):253-295, 2019) and the Morrey estimates (Bramanti et al. J Math Anal Appl 200(2):332-354, 1996) to further control the velocity derivatives, which ensures the uniqueness. Our methods provide a new understanding of the grazing collisions in the Landau theory for an initial-boundary value problem. © Springer-Verlag GmbH Germany, part of Springer Nature (2020)11Nsciescopu
SC author and illustrator Kate Salley Palmer signing book
No full textPhotograph of SC author and illustrator Kate Salley Palmer signing boo
Dissolved Oxygen Concentration Regulation Using Auto-Tuning PID Controller in Fermentation Process.
No full textADAPTIVE-CONTROL OF DISSOLVED-OXYGEN CONCENTRATION IN A BIOREACTOR
No full textA new adaptive DO (dissolved oxygen) concentration control algorithm considering DO electrode dynamics with response time delay has been developed. A system model with two time-varying parameters was used to relate the DO concentration with two control variables: air flow rate and agitation speed. Parameters of this model were estimated on-line using a regularized constant trace recursive least-squares method. An extended Kalman filter was used to remove the effect of noises from the DO concentration measurements and thus to improve control performance. A discrete one-step ahead control scheme was adopted to determine control actions based on the parameter estimation results. Experimental results showed that the new adaptive DO concentration control algorithm performed better than other algorithms tested, a PID controller and adaptive algorithms without the DO electrode dynamics
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