In this paper,we consider a class of quadratic maximization problems.For a subclass of the problems,we show that the SDP relaxation approach yields an approximation solution with the worst-case performance ratio at le...In this paper,we consider a class of quadratic maximization problems.For a subclass of the problems,we show that the SDP relaxation approach yields an approximation solution with the worst-case performance ratio at leastα=0.87856….In fact,the estimated worst-case performance ratio is dependent on the data of the problem withαbeing a uniform lower bound.In light of this new bound,we show that the actual worst-case performance ratio of the SDP relaxation approach (with the triangle inequalities added) is at leastα+δ_d if every weight is strictly positive,whereδ_d>0 is a constant depending on the problem dimension and data.展开更多
For every i = 1, 2, we let Li =-?ni+ Vi be a Schr¨odinger operator on Rni in which Vi∈ L1loc(Rni)is a non-negative function on Rni. We obtain some characterizations for functions in the product Hardy space H1L1,...For every i = 1, 2, we let Li =-?ni+ Vi be a Schr¨odinger operator on Rni in which Vi∈ L1loc(Rni)is a non-negative function on Rni. We obtain some characterizations for functions in the product Hardy space H1L1,L2(Rn1 × Rn2) associated to L1 and L2 by using different norms on distinct variables.展开更多
基金This work was supported by the National Natural Science Foundation of China (Grant No.10401038)Startup Grant for Doctoral Research of Beijing University of Technology and Hong Kong RGC Earmarked Grant CUHK4242/04E
文摘In this paper,we consider a class of quadratic maximization problems.For a subclass of the problems,we show that the SDP relaxation approach yields an approximation solution with the worst-case performance ratio at leastα=0.87856….In fact,the estimated worst-case performance ratio is dependent on the data of the problem withαbeing a uniform lower bound.In light of this new bound,we show that the actual worst-case performance ratio of the SDP relaxation approach (with the triangle inequalities added) is at leastα+δ_d if every weight is strictly positive,whereδ_d>0 is a constant depending on the problem dimension and data.
基金supported by National Natural Science Foundation of China (Grant Nos. 11471176 and 11326093)Natural Science Foundation of Shandong Province for Doctor (Grant No. BS2014SF002)
文摘For every i = 1, 2, we let Li =-?ni+ Vi be a Schr¨odinger operator on Rni in which Vi∈ L1loc(Rni)is a non-negative function on Rni. We obtain some characterizations for functions in the product Hardy space H1L1,L2(Rn1 × Rn2) associated to L1 and L2 by using different norms on distinct variables.
