Background: ADHD is one of the most common psychiatric disorders in children and adolescents. Altered functional connectivity has been associated with ADHD symptoms. This study aimed to investigate abnormal changes in the functional connectivity of resting-state brain networks (RSNs) among adolescent patients with different subtypes of ADHD. Methods: The data were obtained from the ADHD-200 Global Competition, including fMRI data from 88 ADHD patients (56 patients of ADHD-Combined, ADHD-C and 32 patients of ADHD-Inattentive, ADHD-I) and 67 typically developing controls (TD-C). Group ICA was utilized to research aberrant brain functional connectivity within the different subtypes of ADHD. Results: In comparison with the TD-C group, the ADHD-C group showed clusters of decreased functional connectivity in the left inferior occipital gyrus (p = 0.0041) and right superior occipital gyrus (p = 0.0011) of the dorsal attention network (DAN), supplementary motor area (p = 0.0036) of the executive control network (ECN), left supramarginal gyrus (p = 0.0081) of the salience network (SN), middle temporal gyrus (p = 0.0041), and superior medial frontal gyrus (p = 0.0055) of the default mode network (DMN), while the ADHD-I group showed decreased functional connectivity in the right superior parietal gyrus (p = 0.0017) of the DAN and left middle temporal gyrus (p = 0.0105) of the DMN. In comparison with the ADHD-I group, the ADHD-C group showed decreased functional connectivity in the superior temporal gyrus (p = 0.0062) of the AN, inferior temporal gyrus (p = 0.0016) of the DAN, and the dorsolateral superior frontal gyrus (p = 0.0082) of the DMN. All the clusters surviving at p < 0.05 (AlphaSim correction). Conclusion: The results suggested that decreased functional connectivity within the DMN and DAN was responsible, at least in part, for the symptom of inattention in ADHD-I patients. Similarly, we believed that the impaired functional connectivity within networks may contribute to the manifestations of ADHD-C patients, including inattention, hyperactivity/impulsivity, and unconscious movements.

For battery equivalent circuit model parameter identification, the fractional-order modeling and the bionic algorithm are two excellent techniques. The former can describe the impedance characteristics of batteries accurately, while the latter has natural advantages in solving some nonlinear problems. However, the high computational cost limits their application. In this article, a parameter-identification method for a battery fractional-order model based on the coevolutionary particle swarm optimization (CPSO) is proposed. In this algorithm, a large number of optimization calculations are dispersed between the adjacent sampling times in the form of evolutionary steps by CPSO, so the algorithm can run in real time with the sampling process. In addition, the simplified fractional approximation further reduces the computational cost. By conducting tests under various algorithm conditions, we evaluate the main factors affecting the algorithm performance in detail. Our results show that compared with the integer-order model, the fractional-order model can track the optimal value more effectively in a wider optimization space, CPSO can track the time-varying battery parameters in real time by continuous evolution, and computational costs can be effectively reduced by using a fixed-order fractional-order model and appropriately compressing the length of the historical data required for fractional-order computation.

The wireless power transfer (WPT) system is widely applied in the underwater environment. A multitransmitter multireceiver WPT system is proposed in this article for the application of the submerged buoy, and numbers of beacons can be charged at the same time to send more data. Both series and parallel connection structures of several coils are analyzed in detail. In order to increase the system efficiency at ultracapacitors charging process, a maximum efficiency tracking with a primary current controller and an optimal resistance controller is studied and designed. All mentioned above analyses are verified in a three-receiver WPT system prototype. When ultracapacitors are charged from 10 to 25 V, the system efficiency is achieved at almost 70.5%, and the charging voltage of all three receivers can be stabled.

The power supply of underwater devices can be realized by the non-electrical contact wireless power transfer (WPT) technology. The diversity and flexibility of devices carried by the remote operated vehicle (ROV) can be increased by the WPT which can achieve convenient and safe device switching. Power independent regulation is a key for the underwater wireless power connector (UWPC) with multi-load, and a superimposed dual-frequency modulation (SDFM) method is proposed in this article to achieve the load power independent regulation. The equal-area rule is first applied to SDFM, which can use one inverter to generate SDFM current at the transmitter. The theory of decoupled power transfer is analyzed in detail for the SDFM UWPC with dual-load. All above analyses are verified in a dual-load UWPC system prototype. The experimental results show that the SDFM current is generated using one inverter, and the load power can be independently regulated by adjusting the output voltage of the inverter. Furthermore, the load power is still independent and controllable under the conditions of load switching and mutual inductances changing. The dual-load UWPC system power can reach 50 W and DC-DC efficiency is about 68.73 %.

This paper proposes a wireless power transfer (WPT) system with quasi-uniform magnetic coupling to satisfy the Unmanned Aerial Vehicle (UAV) lightweight constant current (CC) charging without secondary feedback control. The traditional wired charging for UAVs is less automated and not portable. WPT as a new way of energy supply has shown great potential for charging UAVs with safety and automation. However, some actual challenges still exist due to the UAV's special structure and lightweight requirements. Accordingly, a coupler with a lightweight receiving coil and double transmitting coils to satisfy the CC wireless charge of the UAV without communication and control is proposed in this paper. The power transfer and CC charging theory analysis are carried out, and the structure of the coupler is designed. A simulation model and a prototype are built, as well as the simulation and experimental results are given to verify the performance of the proposed UAV CC charging system. In the experiment, 23.8 Wh of power is charged to the UAV's lithium battery pack with CC in two hours. This paper provides a reference to the design of the UAV wireless charging stations.

This paper proposes a multiple transmitting array wireless power transfer (MTA-WPT) system with constant output power charging for consumer electronics, such as tablets and mobile phones. Compared to conventional WPT systems, this proposed system can achieve constant output power by controlling the current phase shift of the transmitting (Tx) coils when the receive (Rx) coil is located at different positions and directions. The detailed circuit topology of the proposed system is modeled and analyzed to obtain the correspondence between the current phase shift and load output power. Furthermore, the excitation current distribution strategies for a system of three and four Tx coils at optimized efficiency are theoretically analyzed. The simulation demonstrates that the proposed system can achieve constant output power with modulating the phase shift at various Rx sites. Finally, an experimental prototype with four Tx coils is designed and carried out to prove the effectiveness of the phase shift modulation method and current distribution strategy. Besides, the superiority of the proposed MTA-WPT system is verified by comparison with other methodologies. The experimental results show that the output power of Rx at different positions is kept at roughly 41W with the transmission efficiency over 80% by the Tx current phase shift modulation.