Variations in water exchange through the Kerama Gap （between Okinawa Island and Miyakojima Island） from 1979 to 2003 were estimated with the 0.08° Pacific HYbrid Coordinate Ocean Model （HYCOM）. The model resu...Variations in water exchange through the Kerama Gap （between Okinawa Island and Miyakojima Island） from 1979 to 2003 were estimated with the 0.08° Pacific HYbrid Coordinate Ocean Model （HYCOM）. The model results show that the mean transport through the Kerama Gap （KGT） from the Pacific Ocean to the East China Sea （ECS） was 2.1 Sv, which agrees well with the observed mean KGT （2.0 Sv） for 2009- 2010. Over the time period examined, the monthly KGT varied from -10.9 Sv to 15.8 Sv and had a standard deviation of ＋5.0 Sv. The water mainly enters the ECS via the subsurface layer （300-500 m） along the northeastern slope of the Kerama Gap and mainly flows out of the ECS into the southwest of the Kerama Gap. The seasonal and interannual variations of the KGT and the Kuroshio upstream transport were negatively correlated. The Kuroshio upstream transport was largest in summer and smallest in auamm while the KGT was smallest in summer （1.02 Sv） and largest in spring （2.94 Sv） and autumn （2.44 Sv）. The seasonal and interarmual variations in the Kuroshio downstream （across the PN-line） transport differed significantly from the Kuroshio upstream transport but corresponded well with the KGT and the sum of the transport through the Kerama Gap and the Kuroshio upstream, which indicates that information about variation in the KGT is important for determining variation in the Kuroshio transport along the PN-line.展开更多
In this paper, a class of new biased estimators for linear model is proposed by modifying the singular values of the design matrix so as to directly overcome the difficulties caused by ill_conditioning in the design m...In this paper, a class of new biased estimators for linear model is proposed by modifying the singular values of the design matrix so as to directly overcome the difficulties caused by ill_conditioning in the design matrix. Some important properties of these new estimators are obtained. By appropriate choices of the biased parameters, we construct many useful and important estimators. An application of these new estimators in three_dimensional position adjustment by distance in a spatial coordiate surveys is given. The results show that the proposed biased estimators can effectively overcome ill_conditioning and their numerical stabilities are preferable to ordinary least square estimation.展开更多
We study the set where the so-called Bergman representative coordinates (or Bergman functions) form an immersion. We provide an estimate of the size of a maximal geodesic ball with respect to the Bergman metric contai...We study the set where the so-called Bergman representative coordinates (or Bergman functions) form an immersion. We provide an estimate of the size of a maximal geodesic ball with respect to the Bergman metric contained in this set. By concrete examples we show that these estimates are the best possible.展开更多
基金Supported by the National Natural Science Foundation of China(No.41306020)the National Ocean Subject(No.XDA11020601)+1 种基金the NSFC Shandong Joint Found for Marine Science Research Centers(No.U1406401)the NSFC Innovative Group Grant(No.41421005)
文摘Variations in water exchange through the Kerama Gap （between Okinawa Island and Miyakojima Island） from 1979 to 2003 were estimated with the 0.08° Pacific HYbrid Coordinate Ocean Model （HYCOM）. The model results show that the mean transport through the Kerama Gap （KGT） from the Pacific Ocean to the East China Sea （ECS） was 2.1 Sv, which agrees well with the observed mean KGT （2.0 Sv） for 2009- 2010. Over the time period examined, the monthly KGT varied from -10.9 Sv to 15.8 Sv and had a standard deviation of ＋5.0 Sv. The water mainly enters the ECS via the subsurface layer （300-500 m） along the northeastern slope of the Kerama Gap and mainly flows out of the ECS into the southwest of the Kerama Gap. The seasonal and interannual variations of the KGT and the Kuroshio upstream transport were negatively correlated. The Kuroshio upstream transport was largest in summer and smallest in auamm while the KGT was smallest in summer （1.02 Sv） and largest in spring （2.94 Sv） and autumn （2.44 Sv）. The seasonal and interarmual variations in the Kuroshio downstream （across the PN-line） transport differed significantly from the Kuroshio upstream transport but corresponded well with the KGT and the sum of the transport through the Kerama Gap and the Kuroshio upstream, which indicates that information about variation in the KGT is important for determining variation in the Kuroshio transport along the PN-line.
文摘In this paper, a class of new biased estimators for linear model is proposed by modifying the singular values of the design matrix so as to directly overcome the difficulties caused by ill_conditioning in the design matrix. Some important properties of these new estimators are obtained. By appropriate choices of the biased parameters, we construct many useful and important estimators. An application of these new estimators in three_dimensional position adjustment by distance in a spatial coordiate surveys is given. The results show that the proposed biased estimators can effectively overcome ill_conditioning and their numerical stabilities are preferable to ordinary least square estimation.
文摘We study the set where the so-called Bergman representative coordinates (or Bergman functions) form an immersion. We provide an estimate of the size of a maximal geodesic ball with respect to the Bergman metric contained in this set. By concrete examples we show that these estimates are the best possible.
