Subjects: Dynamic and Electric Engineering >> Electrical Engineering Subjects: Mathematics >> Control and Optimization. submitted time 2022-08-07
Abstract： In this paper, a study of the day-ahead unit commitment problem with stochastic wind power generation is presented, which considers conditional and correlated wind power forecast errors through a distributionally robust optimization approach. Firstly, to capture the characteristics of random wind power forecast errors, the least absolute shrinkage and selection operator (Lasso) is utilized to develop a robust conditional error estimator, while an unbiased estimator is used to obtain the covariance matrix. The conditional error and the covariance matrix are then used to construct an enhanced ambiguity set. Secondly, we develop an equivalent mixed integer semidefinite programming (MISDP) formulation of the two-stage distributionally robust unit commitment model with a polyhedral support of random variables. Further, to efficiently solve this problem, a novel cutting plane algorithm that makes use of the extremal distributions identified from the second-stage semidefinite programming (SDP) problems is introduced. Finally, numerical case studies show the advantage of the proposed model in capturing the spatiotemporal correlation in wind power generation, as well as the economic efficiency and robustness of dispatch decisions.
Subjects: Medicine, Pharmacy >> Preclinical Medicine submitted time 2018-06-15 Cooperative journals: 《南方医科大学学报》
Abstract： Objective To investigate osteogenic effect of collagen/bioglass composites loaded with a small interfering RNA (siRNA) targeting noggin. Methods The collagen/bioglass composites loaded with the negative control siRNA or noggin siRNA were prepared by freeze-drying method. CCK8 test was used to evaluate the proliferation of MC3T3 cells exposed to the aqueous extracts of collagen/bioglass composites and the siRNA-loaded collagen/bioglass composites. ALP activity assay, quantitative real-time PCR and Alizarin Red staining were used to assess the effect of the 3 composites on mineralization in MC3T3 cells. Results MC3T3 cells cultured for 3 and 5 days in the presence of the extracts of the 3 composites all showed significantly more active proliferation than the blank control cells (P<0.05). Compared with the cells seeded on the scaffold without siRNA, MC3T3 cells seeded on collagen/bioglass scaffold loaded with noggin siRNA showed a significantly higher ALP activity at 14 days after seeding (P<0.05) with significantly increased expression of ALP, Runx2 and BSP mRNAs (P<0.05). Alizarin Red staining showed that the cells seeded on the noggin siRNA-loading collagen/bioglass scaffold contained significantly more mineralized nodules than the other cells (P<0.05). Conclusion The collagen/bioglass composites loaded with noggin siRNA have a good biocompatibility, and the collagen/bioglass composites and noggin siRNA show a synergistic effect in promoting osteogenesis.
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