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In the context of anomalous global climate change and the frequent occurrence of droughts and floods, studying trends in the conversion rate between precipitable water vapor (PWV) and actual precipitation in a certain region can help in analyzing the causes of these natural disasters. This paper examines the variation trend in the conversion rate between PWV and actual precipitation on a monthly scale in Hubei from 1960 to 2020. To estimate historical PWV data, we propose a new method for estimating PWV using water vapor pressure based on the RF algorithm. The new method was evaluated by radiosonde data and improved the accuracy by 1 mm over the traditional method in Hubei. Based on this method, we extrapolate the monthly average PWV in Hubei from 1960 to 2020 and analyze the conversion rate between PWV and precipitation during this period. Our results showed that there was no obvious cyclical pattern in the conversion rate in either the longitude or latitude directions. In Hubei, where the topography varies significantly in the longitude direction, the conversion rate is influenced by topography, with the smallest conversion rate being in the transition zone between the mountainous region of western Hubei and the Jianghan Plain. In the latitudinal direction, the conversion rate decreases with increasing latitude. [ABSTRACT FROM AUTHOR]

The partial errors-in-variables (PEIV) model is a structured form of errors-in-variables (EIV) model reformulated by collecting all the independent random elements of the coefficient matrix. When some reliable inequality constraints are taken into account, the adjustment results of inequality constrained PEIV (ICPEIV) model are probably improved. In this contribution, we first present the optimality conditions for inequality constrained weighted total least squares (ICWTLS) solution in ICPEIV model. Then we modified the existing linear approximation (LA) approach to make it suitable for cross-correlated data. The sequential quadratic programming (SQP) method is proposed based on the optimality conditions. Since the Hessian matrix is difficult to compute in the SQP algorithm and it converges slowly or even not converges when the Hessian matrix is indefinite positive, the damped quasi-Newton (DQN) SQP method is proposed. Finally, three examples are given to show the feasibility and performance of the proposed algorithms. [ABSTRACT FROM AUTHOR]

Through a series of experiments of dynamic deformation and destruction under time series loading on an indoor real model bridge, Ground-based real-aperture radar interferometry (GB-InRAR) discovered that before the structure of the bridge was damaged, its amplitude and acceleration increased with the increase of load; After its structure was damaged or cracked, such dynamic characteristics as natural frequency, damping ratio, stiffness and bearing capacity decreased obviously. Moreover, GB-InRAR dynamic load monitoring of Xiangtan Railway Bridge and Inter-city Railway Bridge. In the process of vehicle dynamic load, such important parameters as bridge deflection, natural frequency and damping ratio conform to the bridge loading procedures and dynamic characteristics. The results show that the GB-InRAR can accurately measure the deflection changes, natural vibration frequency and spectrum characteristics of bridges, and it can be used as effective means of the dynamic characteristics analysis in the safety detection and health evaluation of bridges. [ABSTRACT FROM AUTHOR]