Data perturbation is a method of reference control in statistical database. Data modification and data exchange are two methods of data perturbation. Data modification replaces the original data with the sample data sequence after deciding probability distribution function of the original data and generating sample data sequence. Data swapping interchanges attribute values of records. While the algorithm of the former is complex, this paper presents a new method in which the sample sequence generation is skipped. We simply sort the original data, divide them into different groups and exchange attribute values of the same group. Experiments show that the proposed method can effectively simplify the former method and guarantee the safety of the statistical data at the same time.

To solve the problem how to prevent the marine environment monitoring feature data from leaking when an emergency occurs, a destruction of data used in marine environment monitoring buoy system is researched. The architecture design of the system is introduced; a data overwrite algorithm based on the data secret level of the marine work is proposed; through data overwrite technology and the high-pressure circuit to achieve the safe destruction of data elements in marine environmental monitoring. The study shows the data destruction system can trigger data destruction procedures in real time, it can solve data security issues for marine environmental monitoring buoy in the out of control situation, and the destroyed data is unrecoverable, thus preventing data loss and leakage.

Faced up with the fact that the buoy used in marine environmental monitoring did not install the self-destruction mechanism, and combined with the current development of the data destruction technology, data self-destruction technology for buoy was researched. The study shows that when the buoy system is out of control, it can select the two different data self-destruction methods by analyze different degree of threat which buoy system suffered. So it can destruct the marine environmental factor data in a fast and effective way, and make the data be unrecovered, thereby prevent data leaks, ensure data security.

The performance of absorbing boundary conditions in SWASH is examined. The method to determine the sponge layer region in each processor when calculating with multiple processors is improved. An exponential decay function is employed to the momentum equations in the sponge layer region. The numerical tests show that the proposed damping coefficients work efficiently on reducing the wave energy of reflective waves in the sponge layer.

To implement the objective of steady operation of the marine observation buoy system on the sea throughout the year,based on energy balance between supply and demand, this paper presents the mathematical model of solar energy power supply system derived from double batteries switching technology. The batteries are divided into main batteries and auxiliary batteries. The main batteries are used regularly and the auxiliary batteries are used in periodic rainy weather. The main advantage of this model is that the capacity of auxiliary batteries can be dynamic calculated based on the numbers of maximum continuous rainy days and minimum intervals between rainy days. The batteries capacity is sufficient but not redundant. This design project has been tested on marine buoy and the accuracy of the model is splendid for most engineering projects.