Erasure-coded storage systems can achieve highly reliable data storage with low storage overhead. However, updating data blocks necessitates updating parity blocks, and updating multiple data blocks incurs heavy I/O and computational overhead, leading to prolonged update times in heterogeneous storage environments. This paper proposes an erasure-coded multi-data block update method for heterogeneous storage environments, named MBUS, to expedite data updates. MBUS blends re-encoding and delta-based updates and considers factors such as intermediate blocks, computational overhead, and I/O overhead across different storage media. It iteratively computes the minimal I/O time for updating each parity block dynamically. Once the computation equation for each parity block is determined, MBUS prioritizes computing common XOR expressions and reuses the results to reduce the number of XOR operations. MBUS caches a certain number of scheduling plans to minimize redundant computations in subsequent updates, thereby reducing computation time. Experimental results replaying real-world traces demonstrate that MBUS reduces update time by 64.43% compared to state-of-the-art techniques.

The power supply system design of a marine data buoy system is a challenge. Due to cost reasons, it is difficult for marine buoys to obtain electricity directly from the power grid. At present, marine buoys use solar energy, wind energy or wave energy to supply power to sensors. Among them, the employment of wave energy and solar energy has broad application prospects due to the complementary power production of these sources. This paper presents a new wave energy conversion (WEC) device for a marine buoy, which is composed of a floating body and a power generation device. In addition, a three-dimensional finite element simulation model of the buoy movement is established, and the simulation is carried out using hydrodynamic software. On the basis of simulation, experiments are carried out on a 50 kg core power generation unit to estimate the power generation performance of the proposed WEC device.