We study preconditioning techniques used in conjunction with the conjugate gradient method for solving multi-length-scale symmetric positive definite linear systems originating from the quantum Monte Carlo simulation ...We study preconditioning techniques used in conjunction with the conjugate gradient method for solving multi-length-scale symmetric positive definite linear systems originating from the quantum Monte Carlo simulation of electron interaction of correlated materials. Existing preconditioning techniques are not designed to be adaptive to varying numerical properties of the multi-length-scale systems. In this paper, we propose a hybrid incomplete Cholesky （HIC） preconditioner and demonstrate its adaptivity to the multi-length-scale systems. In addition, we propose an extension of the compressed sparse column with row access （CSCR） sparse matrix storage format to efficiently accommodate the data access pattem to compute the HIC preconditioner. We show that for moderately correlated materials, the HIC preconditioner achieves the optimal linear scaling of the simulation. The development of a linear-scaling preconditioner for strongly correlated materials remains an open topic.展开更多
The aim of this study was to develop a new bread formulation from different amounts of acai powder and polydextrose incorporated into wheat flour on bread technological properties. The formulations were developed usin...The aim of this study was to develop a new bread formulation from different amounts of acai powder and polydextrose incorporated into wheat flour on bread technological properties. The formulations were developed using the central composite rotational design and having as dependent variables specific volume, hardness, crumb color and image analysis. Statistical analysis was performed using multiple regression and response surface. The results showed that the inclusion of powdered acai and polydextrose in bread formulations reduces the specific volume and alveoli number and increases the browning and hardness of the bread. However, values of this addition （30 g/100 g） were found that did not promote significant quality reduction and the scanning electron microscopy （SEM） showed minimal damage to the gluten network at this level of incorporation.展开更多
基金supported in part by the US National Science Foundation grant 0611548in part by the US Department of Energy grant DE-FC02-06ER25793
文摘We study preconditioning techniques used in conjunction with the conjugate gradient method for solving multi-length-scale symmetric positive definite linear systems originating from the quantum Monte Carlo simulation of electron interaction of correlated materials. Existing preconditioning techniques are not designed to be adaptive to varying numerical properties of the multi-length-scale systems. In this paper, we propose a hybrid incomplete Cholesky （HIC） preconditioner and demonstrate its adaptivity to the multi-length-scale systems. In addition, we propose an extension of the compressed sparse column with row access （CSCR） sparse matrix storage format to efficiently accommodate the data access pattem to compute the HIC preconditioner. We show that for moderately correlated materials, the HIC preconditioner achieves the optimal linear scaling of the simulation. The development of a linear-scaling preconditioner for strongly correlated materials remains an open topic.
文摘The aim of this study was to develop a new bread formulation from different amounts of acai powder and polydextrose incorporated into wheat flour on bread technological properties. The formulations were developed using the central composite rotational design and having as dependent variables specific volume, hardness, crumb color and image analysis. Statistical analysis was performed using multiple regression and response surface. The results showed that the inclusion of powdered acai and polydextrose in bread formulations reduces the specific volume and alveoli number and increases the browning and hardness of the bread. However, values of this addition （30 g/100 g） were found that did not promote significant quality reduction and the scanning electron microscopy （SEM） showed minimal damage to the gluten network at this level of incorporation.
