Semantic segmentation of building facades from 3D mesh data is essential for scene understanding but often relies on costly fine-grained annotations.In response to this issue, a semi-supervised learning approach was proposed, introducing a semi-supervised semantic segmentation method based on contrastive learning SS_CC(semi-supervised semantic segmentation based on contrastive learning and consistency regularization)to segment building facades in 3D mesh data.In the SS_CC method, the enhanced contrastive learning module exploited the class separability between positive and negative samples to more effectively utilize class-specific feature information.Additionally, the proposed feature-space consistency regularization loss improved the discriminative capability of the extracted building facade features by leveraging global feature representations.Experimental results show that the proposed SS_CC method outperforms some mainstream methods in F1 score and mIoU, and has relatively better segmentation performance on building walls and windows.

To investigate the generation mechanism and variation patterns of the ship corrosion electric field under navigation conditions, the galvanic corrosion cathode of the ship propeller was equated to a rotating disk, and an equivalent model of the corrosion electric field of the rotating disk under turbulent medium conditions was established.Combining the boundary layer theory in fluid mechanics and electrochemical corrosion related theories, the boundary layer flow state and corrosion current density on the surface of a disk under laminar and turbulent medium flow conditions were calculated, and differentiation treatment on the disk was performed.The multiple point charge superposition method was used to calculate the corrosion electric field of a rotating disk under the control of oxygen mass transfer in a flowing medium.The variation law of corrosion electric field on rotating disks at different speeds was studied and experimentally verified.The results indicate that as the rotational speed of the disk increases, the corrosion electric field gradually increases.When the flow state of the medium on the surface of the disk gradually transitions from laminar to turbulent, the corrosion electric field modulus increases significantly.

In order to improve the sensitivity of time-frequency system integrity monitoring, a time-frequency system integrity monitoring method based on robust Kalman filter was proposed.In this method, a robust Kalman filter model was constructed using the historical measurement data of time difference, the time difference prediction bias and the frequency bias were estimated in real time, and the consistency detection was carried out separately, so that the integrity monitoring was realized.The model and method were verified through measured data and simulation analysis, and the results show that:this method can effectively detect and identify single faults of phase jump and frequency jump, and alarm the user;in a single fault scenario, compared with the traditional integrity monitoring method, the detection sensitivity is increased by about 25.0%;in a multi-fault scenario, the method can effectively detect faults, but there is a problem of insufficient fault identification, and the detection sensitivity is reduced by about 26.2% compared to a single fault, but it is still better than the traditional method.

To investigate the process fluctuation influence on SRAM（static random-access memory）single event upset in sub-20 nm FinFET（fin field-effect transistor）process，a high precision three dimensional technology computer-aid design model based on commercial process fluctuations was established，then simulated to find the FinFET SRAM single event upset threshold under different process corners.The simulation results show that the FinFET SRAM upset threshold has less variation induced by process corner fluctuation.Meanwhile，the sensitive positions of SRAM are on the N-complementary metal oxide semiconductor.Then，to understand the the impact of specific process parameter fluctuations on the single event upset threshold，the process fluctuation factor impact on single event upset was discussed，including fin width，fin height，the oxide thickness and the work function fluctuation.The simulation results show that the first two factors did not affect the upset threshold，while the latter two factors caused slight fluctuations in the upset threshold.Significant reduction in the impact of process fluctuations on FinFET SRAM single event upset threshold is firstly found，which is of great significance for the development of highly consistent radiation hardened aerospace integrated circuits.

For high-order continuous linear multi-agent systems, a minimum-energy formation design method with sampled-data communication was proposed.Based on local neighboring information of multi-agent systems at sampling time, a time-varying formation cooperative control protocol with global control energy consumption being considered was presented.By the state-space decomposition method, the time-varying formation problem of multi-agent systems was transformed into the stability problem of decomposed non-consensus subsystems.A formation feasible condition was constructed, and sufficient conditions for the design of time-varying formation under minimum-energy constraints were obtained by the generalized eigenvalue approach, which ensured that the time-varying formation of multi-agent systems could be realized under minimum-energy constraints.Theoretical results were verified by a numerical simulation, and simulation results show that the formation control method with minimum-energy constraints can effectively reduce the global control energy consumption of time-varying formation of multi-agent systems with sampled-data communication.

The PHM index is directly affected the design of PHM and the availability of equipment.In response to the shortage of theoretical and implementable methods, a graded demonstration method was introduced, outlining a progression from comprehensive efficiency indicators to PHM comprehensive indicators and then to PHM capability indicators.The availability was selected as the comprehensive efficiency indicator, and the health evaluation rate was defined as the PHM comprehensive indicator.The relationship between availability and health evaluation rate was derived.The optimal health evaluation rate was obtained by maximizing the availability.It was deduced that the health evaluation rate was equal to the product of fault coverage and evaluation accuracy, where depend on the number of sensors and the accuracy of diagnostic/prognostic methods, respectively.This conclusion can guide PHM design.The effectiveness and practicality of this method were verified by cases.

In view of the contradiction between the need of the electromagnetic sled for real-time accurate position and speed information and the limitation or high cost of traditional position and speed measurement methods, a new measurement system based on vernier caliper structure was proposed and designed.The principle of high precision positioning and the corresponding position analysis method was expounded, and the position prediction algorithm and Kalman filter algorithm were designed to improve the accuracy and real-time performance.The hardware circuit and software program were designed to realize the function, and a synchronous belt guide rail experimental platform was built to verify the designed system.The test results show that the system can achieve millimeter-level positioning accuracy, and performs well in terms of real-time capability, accuracy and engineering application.The positioning and speed measurement system was applied to the electromagnetic levitation propulsion platform.