In view of the lack of hierarchical and systematic resource recommendation caused by rich online learning resources and many learning platforms, an attention-based ADCF online learning resource recommendation model is proposed by introducing the attention mechanism into a deep collaborative DCF model. Experimental results show that the proposed ADCF model enables an accurate recommendation of online learning resources, reaching 0.626 and 0.339 on the HR and NDCG metrics, respectively, compared to the DCF models before improved, up by 1.31% and 1.25%, and the proposed ADCF models by 1.79%, 2.17%, and 2.32%, respectively, compared to the IUNeu and NeuCF models.

A distribution network in supply chain management increases product reachability and handling density across different warehouses and customers. Relays in the distribution network prevent congestion, supply stagnancy, and delayed deliveries. Protecting the relay functions and streamlining them are tedious due to the varying vehicle and goods densities. This article introduces a populous relay management scheme (PRMS) for multi-access in delivery networks to address the problem above. The proposed scheme relies on vehicle and goods movement frequency for improving the relay utilization without congestion. These features are analyzed for the stagnancy and dispatch priority in maximizing the goods delivery. The conventional back propagation network is employed for identifying stagnancy and relay population (congestion) for distributed delivery assignments. The back propagation process identifies the prioritized tasks for preventing delivery delays and reducing congestion through priority segregation. This enhances the least to large-good migration with controlled delay and rapid migration, reducing congestion.

The IPT system has been studied for underwater applications such as autonomous underwater vehicles (AUVs) and subsea sensors. However, it rarely comparatively shows the performance of the IPT system in air, freshwater, and seawater. Based on the fore‐mentioned research background, this paper presents a survey of the properties of the IPT system in different mediums. Here, a 100 W power‐level experimental IPT prototype is built and tested. The resonant frequency is set at 300 kHz with a gap range from 10 to 190 mm. The comparison is focused on the efficiency, mutual inductance, coupling coefficient, coil resistance, and quality factor of the IPT system. The IPT system is placed in air, freshwater, and seawater with the same settings. What's more, the magnetic fields of coupling coils in air, freshwater, and seawater are presented in this paper. This paper could be acted as a reference to optimize the IPT system and facilitate future IPT research for underwater applications by analysing the performance of the IPT system in different mediums. The 3D Ansys Maxwell simulation of the IPT system is also given here to study the magnetic fields.

Underwater wireless power transfer (UWPT) system has attracted widespread attention. It has been used for power delivery for underwater equipment in the marine environment with high safety and convenience. However, the material of metal plates and the shape which will affect the high frequency alternating electromagnetic fields and the high frequency alternating electric fields for the inductive wireless power transfer (IPT) system and the capacitive wireless power transfer (CPT) system. This paper presents the effects of the hull of the autonomous underwater vehicle (AUV) on the underwater wireless power transfer system including the underwater capacitive wireless power transfer (UCWPT) system and underwater inductive wireless power transfer (UIWPT) system. The features of underwater wireless power transfer systems have been carefully studied with simulation and experimental work. The experimental water tank has been constructed with the 35‰ salinity water. The hull of AUVs has been respectively simulated and built with rectangle metal plates and curved metal plates. The original experimental data and phenomenon have been presented in this paper. The different performance of the UCWPT system and UIWPT system is provided and discussed in this paper. The comparison work with the related paper has been analyzed. This paper could be acted as the reference for designing the underwater wireless power transfer system for AUVs.INDEX TERMS Underwater wireless power transfer (UWPT), capacitive, material, shape, autonomous underwater vehicles (AUVs)