A system for monitoring a physical change of a marine structure includes a complex optical measuring instrument configured to detect a behavior and structural change of the marine structure by using at least one optical sensor by means of optical fiber Bragg grating.

A system for monitoring a physical change of a marine structure includes a complex optical measuring instrument configured to detect a behavior and structural change of the marine structure by using at least one optical sensor by means of optical fiber Bragg grating.

The present disclosure relates to the technical field of condition monitoring on offshore engineering structures, in particular to a method and system for predicting equivalent scour depths of an offshore engineering structure. The method includes: acquiring vibration accelerations at different wave measuring points above a water surface of the offshore engineering structure and extracting first-order frequencies and first-order displacement vectors thereof at different wave measuring points; respectively establishing equivalent constraint finite element models based on different fixed constraint positions below a mud surface; analyzing the models to obtain first-order frequencies of the models and first-order shape vectors at all the wave measuring points for compiling a finite element model database; and matching the first-order frequencies and the first-order displacement vectors of the offshore engineering structure with the finite element model database respectively, and obtaining predicted values of the equivalent scour depths via calculation based on a matching result.

The present disclosure relates to the technical field of condition monitoring on offshore engineering structures, in particular to a method and system for predicting equivalent scour depths of an offshore engineering structure. The method includes: acquiring vibration accelerations at different wave measuring points above a water surface of the offshore engineering structure and extracting first-order frequencies and first-order displacement vectors thereof at different wave measuring points; respectively establishing equivalent constraint finite element models based on different fixed constraint positions below a mud surface; analyzing the models to obtain first-order frequencies of the models and first-order shape vectors at all the wave measuring points for compiling a finite element model database; and matching the first-order frequencies and the first-order displacement vectors of the offshore engineering structure with the finite element model database respectively, and obtaining predicted values of the equivalent scour depths via calculation based on a matching result.

A method and device for imputing missing values in dual-directional automatic identification system (AIS) data based on deep learning are provided. The method includes constructing a deep-dual-directional chained imputation (DDDCI) model including a forward model and a backward model and predicting a missing value at a prediction time point t, which is to be imputed for AIS data, by using a forward prediction value predicted through learning by the forward model and a backward prediction value predicted through learning by the backward model.

A method and device for imputing missing values in dual-directional automatic identification system (AIS) data based on deep learning are provided. The method includes constructing a deep-dual-directional chained imputation (DDDCI) model including a forward model and a backward model and predicting a missing value at a prediction time point t, which is to be imputed for AIS data, by using a forward prediction value predicted through learning by the forward model and a backward prediction value predicted through learning by the backward model.

A design method for a passive simulator of full-space echo characteristics of an underwater vehicle includes: obtaining a target strength color map of the divided grid of the vehicle surface, and conducting a color interpolation on the divided grid, so as to obtain the distribution cloud map of the bright spot area contributed by the target strength of the underwater vehicle surface; dividing the scale model of the underwater vehicle into the bow, the midship and the stern, and retaining a contribution area to form the partial model of the bow, the midship and the stern; designing the partial simulator of each partial model, and determining the linear array of each partial simulator to form the underwater vehicle simulator; according to the time domain echo of the simulated underwater target, placing the bow, midship and stern simulator structures, and conducting the overall simulator design of the underwater target.

A design method for a passive simulator of full-space echo characteristics of an underwater vehicle includes: obtaining a target strength color map of the divided grid of the vehicle surface, and conducting a color interpolation on the divided grid, so as to obtain the distribution cloud map of the bright spot area contributed by the target strength of the underwater vehicle surface; dividing the scale model of the underwater vehicle into the bow, the midship and the stern, and retaining a contribution area to form the partial model of the bow, the midship and the stern; designing the partial simulator of each partial model, and determining the linear array of each partial simulator to form the underwater vehicle simulator; according to the time domain echo of the simulated underwater target, placing the bow, midship and stern simulator structures, and conducting the overall simulator design of the underwater target.