Yujie Qian

University of Science and Technology of China | USTC · Department of Automation

Formation path planning of autonomous underwater vehicles (AUVs) entails establishing optimal collision-free routes over challenging underwater terrain while maintaining state coherence to preserve an intended formation, and path planning techniques have been the subject of significant study over the last decade, with swarm intelligence algorithms...

The noise of multi-rotor unmanned aerial vehicles (UAVs) mainly comes from high-speed rotating propellers and brushless direct current motors. With extensive research on the generation mechanism and suppression methods of propeller noise, fruitful results have been achieved on the noise reduction of propellers. Therefore, the noise radiated by UAV...

The coming 6G communication technology introduces the possibility of practice underwater Internet of Things (UIoT) applications with high-speed and reliable underwater communications. Among them, the cooperative coverage path planning (CPP) with autonomous underwater vehicles (AUVs) is a promising approach for enabling deep ocean exploration. The c...

Multi-rotor Unmanned Aerial Vehicles (UAVs) are developing rapidly recently in usage and popularity in civil applications. However, although the great benefits UAVs have brought, their noise pollution is one of the concerns with their proliferation. The two main noise sources of a UAV are the motors and propellers. And the propellers are often assu...

Experimental studies were conducted at a hemi-anechoic chamber to investigate the effectiveness of trailing-edge (TE) serration designs for reducing aerodynamic noise of a propeller. The propeller noise was measured under different speeds in both the vertical and horizontal directions. The thrust force produced by the propeller was also measured at...

Underwater acoustic sensor networks (UASNs) have been proposed as a promising way in supporting the underwater internet of things (UIoT) applications. However, to guarantee and improve quality of service (QoS), they are still facing great challenges especially when it comes to enabling reliable data communication for the UIoT applications and meanw...

Escorting a moving object in a subsea environment with cooperative autonomous underwater vehicles (AUVs) is a typical subject in Underwater Internet of Things (UIoT) applications. It involves two issues that should be studied. First, a mobile task assignment method is required to lead the AUVs to the escorting positions; then, a formation control s...

This study explored the "Training and development impact on employee's performance: a case study of government colleges". The main aim of the study was to find out the government colleges training and development programs in Hyderabad, Pakistan.110 samples were used through primary data collection from senior-staff of colleges. Self administered qu...

This work aims to investigate the acoustic characteristics of a piezoelectric micro-perforated panel (MPP) absorber, which is made of a perforated polyvinylidene fluoride (PVDF) film with a backed airgap of 2 cm, as a combination of an active component and passive absorber. In addition to its inherent passive dissipation, as the PVDF-MPP was driven...

Recently, the development of three-dimensional interference-aware data transmission methods has attracted the attention of scholars due to the increased interest in exploiting and studying the underwater acoustic sensor networks (UASNs). In this paper, an interference aware data transmission protocol based on cellular clustering architecture is pro...

When studying the radiation noise of underwater vehicle, it is more realistic to simulate the underwater vehicle by using the volume source shell structure model. However, in the process of using COMSOL to simulate the radiation noise of the underwater vehicle shell structure, the far field calculation cannot be realized with the software because t...

With the advantages of light weight, thin thickness and environment friendly, the micro-perforated panel (MPP) has been widely studied for noise reduction. Maa’s model pointed out that the MPP could obtain higher sound absorption over broader frequency band when the perforations were reduced to less than 100 μm. However, it is challenging to manufa...

With the progress and development of the Internet of Underwater Things, underwater wireless sensor networks (UWSNs) have been showed as a promising technology to monitor and explore the oceans. Different from terrestrial WSNs, UWSNs adopts acoustic signals instead of radio frequencies for wireless communication. However, marine mammals’ frequencies...

The nonlinear effect at high sound intensity not only degrades the absorption performance of a micro-perforated panel (MPP) absorber, but also makes its performance prediction and structure design become difficult and unreliable due to the absence of accurate nonlinear impedance models. Hence, it is desirable to develop a linear MPP absorber. Based...

Micro-perforated panel (MPP) absorbers are simple to construct, can be used in a variety of applications, show good absorption properties and allow relatively accurate prediction and design under linear conditions. However, when the sound intensity is high, the sound pressure level (SPL) under which the MPP is effective is limited due to the nonlin...

Flexible micro-perforated panel has unique advantages in noise reduction due to its good flexibility compared with traditional rigid micro-perforated panel. In this paper, flexible micro-perforated panel was prepared by computer numerical control (CNC) milling machine. Three kinds of plastics including polyvinylchloride (PVC), polyethylene terephth...

Micro-perforated panel (MPP) absorber has been widely used in noise control and is regarded as a promising alternative to the traditional porous materials. However, the absorption bandwidth of single MPP absorbers is always insufficient to compete with the porous materials. In this paper, aiming at obtaining high absorption over broad frequency ban...

Increased co-channel interference (CCI) in wireless local area networks (WLANs) is bringing serious resource constraints to today's high-density wireless environments. CCI in IEEE 802.11-based networks is inevitable due to the nature of the carrier sensing mechanism however can be reduced by resource optimization approaches. That means the CCI anal...

The high-speed area array CCD (Charge Coupled Devices) signal acquisition system based on FPGA and USB3.0 interface is introduced in this paper. The hardware components of the system, the firmware of the USB interface control chip and an interface module in FPGA to fit the GPIF II are discussed. A PC application is also developed based on MFC with...

Micro-perforated panel (MPP) absorber has been studied and developed for decades and is becoming more and more popular in an environment protective society. Although the traditional MPPs are rigid, the research results in recent years have indicated that flexible MPPs with ultra-micro perforations of diameter less than 100 mu m (ultra-MPPs) may hav...

Super-aligned carbon nanotube (SACNT) arrays are grown on the surface of micro perforated panel (MPP) in the hope of improving the acoustic performance of MPP absorbers by virtue of their unique properties. Scanning electron microscopy reveals that SACNT arrays did not block the perforations of MPPs or changed the perforation diameter due to their...

Micro-perforated panel (MPP) absorbers, well known as a basis for the next generation of sound absorbing materials, are now being widely used in noise control engineering. In order to design the structural parameters of MPP absorbers according to the actual demand, a straightforward method to predict the absorption performance of such absorbers is...

Fabrication process of ultra micro-perforated panels (ultra-MPPs) with perforations of diameter below 100 um based on MEMS technology is expatiated in this paper. As a promising alternative to the conventional porous absorbing materials, MPP absorber is now being widely used in noise control engineering. Theory reveals that the maximum sound absorp...

Micro-perforated panel (MPP) absorber with multi-size holes is a new type of broad band sound absorber which is thin, durable, clean and environmentally friendly. These advantages make it especially suitable for applications in the narrow space. However, so far it has not been widely used partially because of its design complexity. The absorption p...

Micro-perforated panel (MPP) absorber has been widely used in noise reduction and is regarded as a promising alternative to the traditional porous materials. However, the absorption bandwidth of a single MPP is always insufficient to compete with the porous materials. Thus its practical application such as interior finish of room walls which has st...

The superconducting energy gap of the high-Tc superconductor YBa2Cu3O9-delta(Tc=90 K) has been measured by the far-infrared technique in the frequency range 30-150 cm-1 and the temperature range 4.2-200 K. The frequency-dependent reflectances of two different samples show a common feature near omegac~=125 cm-1 where the reflectance curves drop rapi...