雷达高度表作为重要的微波遥感器件,由于其全天候、全时段特性,在地形探测等方面备受关注。机载雷达高度表具有较高的机动性,在实际探测中使用广泛。随着探测场景复杂度的提升,对雷达高度表测量精度也有较高的要求。现阶段提升测量精度...雷达高度表作为重要的微波遥感器件,由于其全天候、全时段特性,在地形探测等方面备受关注。机载雷达高度表具有较高的机动性,在实际探测中使用广泛。随着探测场景复杂度的提升,对雷达高度表测量精度也有较高的要求。现阶段提升测量精度的主要方法有对场景进行精准建模、使用参数估计算法。对传统参数估计算法而言,受步长影响,在估计过程中容易陷入局部最优,且随着参数维度的增高,只能求解低维参数的传统算法,难以获得较为精确的估计结果。因此,为了满足现阶段测量精度的需求,需要使用一种高精度参数估计算法。针对雷达高度表传统参数估计算法在面对参数的高维特性时会出现过拟合的情况,提出一种新颖的基于近端算子的哈密顿蒙特卡洛算法(proximal hamiltonian monte carlo,PHMC)。通过面元仿真数据进行测试,并使用了提出的算法与多种传统算法进行比对,证明了所提出算法的参数估计能力优于传统参数估计算法。展开更多
Fibre-reinforced polymer(FRP)has the advantages of high strength,light weight,corrosion resistance and convenient construction and is widely used in repairing and strengthening damaged concrete columns.Most of the exi...Fibre-reinforced polymer(FRP)has the advantages of high strength,light weight,corrosion resistance and convenient construction and is widely used in repairing and strengthening damaged concrete columns.Most of the existing strength models were built by regression analysis of experimental data;however,in this article,a new unified strength model is proposed using the Hoek-Brown failure criterion.To study the strength of FRP-confined damaged and undamaged concrete columns,900 test data were collected from the published literature and a large database that contains the cross-sectional shape of each specimen,the damage type,the damage level and the FRP-confined stiffness was established.A new strength model using the Hoek-Brown failure criterion was established and is suitable for both circular and square columns that are undamaged,load-damaged and fire-damaged.Based on the database,most of the existing strength models from the published literature and the model proposed in this paper were evaluated.The evaluation shows that the proposed model can predict the compressive strength for FRP-confined pre-damaged and undamaged concrete columns with good accuracy.展开更多
文摘雷达高度表作为重要的微波遥感器件,由于其全天候、全时段特性,在地形探测等方面备受关注。机载雷达高度表具有较高的机动性,在实际探测中使用广泛。随着探测场景复杂度的提升,对雷达高度表测量精度也有较高的要求。现阶段提升测量精度的主要方法有对场景进行精准建模、使用参数估计算法。对传统参数估计算法而言,受步长影响,在估计过程中容易陷入局部最优,且随着参数维度的增高,只能求解低维参数的传统算法,难以获得较为精确的估计结果。因此,为了满足现阶段测量精度的需求,需要使用一种高精度参数估计算法。针对雷达高度表传统参数估计算法在面对参数的高维特性时会出现过拟合的情况,提出一种新颖的基于近端算子的哈密顿蒙特卡洛算法(proximal hamiltonian monte carlo,PHMC)。通过面元仿真数据进行测试,并使用了提出的算法与多种传统算法进行比对,证明了所提出算法的参数估计能力优于传统参数估计算法。
基金Project(2017M622540)supported by the China Postdoctoral Science FoundationProject(51808419)supported by the National Natural Science Foundation of China+1 种基金Project(2019CFB217)supported by the National Natural Science Foundation of Hubei Province,ChinaProject(201623)supported by the Science and Technology Project of Wuhan Urban and Rural Construction Committee,China。
文摘Fibre-reinforced polymer(FRP)has the advantages of high strength,light weight,corrosion resistance and convenient construction and is widely used in repairing and strengthening damaged concrete columns.Most of the existing strength models were built by regression analysis of experimental data;however,in this article,a new unified strength model is proposed using the Hoek-Brown failure criterion.To study the strength of FRP-confined damaged and undamaged concrete columns,900 test data were collected from the published literature and a large database that contains the cross-sectional shape of each specimen,the damage type,the damage level and the FRP-confined stiffness was established.A new strength model using the Hoek-Brown failure criterion was established and is suitable for both circular and square columns that are undamaged,load-damaged and fire-damaged.Based on the database,most of the existing strength models from the published literature and the model proposed in this paper were evaluated.The evaluation shows that the proposed model can predict the compressive strength for FRP-confined pre-damaged and undamaged concrete columns with good accuracy.
