Fault Tolerant Time Optimization of Switched Systems with Application to Multi-agent Flight Control

Yuhang Xu,Hao Yang,Bin Jiang 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.2

This paper considers the problem of determining optimal switching time for the switched system inthe presence of switching faults, which may result in the deviation of the prescribed switching time from normal. A passive fault-tolerant scheme, which relies on the min-max strategy containing gradient descent algorithm, isproposed to guarantee that the faulty switched system has the minimal upper bound of the cost function. In thecase that the switching faults take place regularly, an active fault-tolerant scheme is further developed which candecrease the minimal upper bound of the cost function, and thus reduce the conservativeness of the passive one. These two new schemes are applied to resolve the route conflict among multi-airplanes in multi-agent flight controlto illustrate their efficiency and applicability.

PMN-PT Single Crystal for Endoscopic Ultrasound 2D Array Application

Yuhang Zhu,Huageng Liang,Benpeng Zhu,Dan Zhou,Xiaofei Yang 대한금속·재료학회 2017 ELECTRONIC MATERIALS LETTERS Vol.13 No.2

Based on lead magnesium niobate-lead titanate single crystal, a 24 × 24row-column addressing endoscopic two-dimensional array has beensuccessfully fabricated using novel flanged electrodes and “semi-kerf”technologies. Each row/column array element was measured to have anelectromechanical coupling coefficient of 0.81, a center frequency of5MHz, and a fractional bandwidth of approximately 88% at −6 dB. Ofparticular significance was that the lead magnesium niobate-lead titanateelement exhibits much higher sensitivity compared with lead zirconatetitanate-based 2D arrays with similar operational frequency and elementarea. According to the Field II simulated results, although the obtainedbeamwidth at −6 dB was a little inferior to that of the fully sampled 24 × 24two-dimensional array, it is believed that the beamwidth can be improved byappropriately increasing the element number. These results demonstratedthat the lead magnesium niobate-lead titanate single-crystal 2D array is apromising candidate for real-time three-dimensional endoscopic ultrasoundimaging.

A nondestructive method for controlling wind loads and wind-induced responses of wooden pagoda

Yuhang LI,Yang Deng,Ai-Qun Li 한국풍공학회 2022 Wind and Structures, An International Journal (WAS Vol.34 No.6

High-rise wooden pagodas generate large displacement responses under wind action. It is necessary and wise to reduce the wind loads and wind-induced responses on the architectural heritage using artificial plants, which do not damage ancient architecture and increase greenery. This study calculates and analyzes the wind loads and wind-induced responses on the Yingxian Wooden Pagoda, in China, using artificial plants via the finite element analysis (FEA). A three-dimensional windloading field was simulated using a wind tunnel test. Wind loads and wind-induced responses, including the displacement and acceleration of the pagoda with and without artificial plants, were analyzed. In addition, three types of tree arrangements were discussed and analyzed using the score method. The results revealed that artificial plants can effectively control wind loads and wind-induced displacements, but the wind-induced accelerations are enlarged to some extent during the process. The height of the tree significantly affected the shelter effects of the structure. The distance of trees from the pagoda and arrangement width of the tree had less influence on shelter effects. This study extends the understanding of the nondestructive method based on artificial plants, for controlling the wind base loads and structural responses of wooden pagodas and preserving architectural heritage via FEA.

1.5kW LLC Resonant Converter with improved interleaved winding structure and core structure

Yuhang Xu,Xu Yang,Jiwen Wei,Suchen Dong,Wenjie Chen,Kangping Wang 전력전자학회 2023 ICPE(ISPE)논문집 Vol.2023 No.-

In recent years, the power supply of the data center is increasing day by day. The new power supply architecture uses 48V bus to supply power to the subsequent VRM, so as to reduce I2R loss. Because of its soft switching characteristics, LLC resonant converter can meet the requirements of high power density and high efficiency, and is used in isolated DC-DC converter. In this paper, a magnetic integrated transformer is proposed to reduce winding loss and core loss. The windings and magnetic cores are optimized in local detail. A 1500W module was made in the experiment, achieving 97.8% peak efficiency and 97.6% efficiency at full load.

The Balanced Method of Magnetic Torque Under Wind Load for HVDC Inspection Robot

Xianjin Xu,Yuhang Yang,Haoda Chen,Lanlan Liu,Yu Yan 한국자기학회 2021 Journal of Magnetics Vol.26 No.1

Hierarchical carbon layer coated NiCoP nanoparticles embedded on nitrogen-doped carbon nanotubes for high-performance supercapacitors

Fuyao Huang,Yuhang Jia,Shaopei Yang,Yuhong Long,Yuman Dong,Pengcheng Du 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.128 No.-

Transition metal phosphides (TMPs) have been widely recognized as an ideal choice for supercapacitors(SCs) due to exceptional pseudocapacitance performance. Otherwise, reasonable structural design ofTMPs can overcome the defects of low rate performance and poor cycle life. Furthermore, the incorporationof carbon materials can enhance electronic conductivity, thereby enabling rapid electron transmission. Herein, we present a novel hierarchical carbon layer coated NiCoP nanoparticles embedded onnitrogen-doped carbon nanotubes (NiCoP/NCNTs), synthesized through a calcination/phosphorizationprocess. By incorporating a carbon layer to anchor nanoscale NiCoP, an increased number of active sitesand improved structural stability are achieved. Furthermore, the presence of NCNTs enhances the electronicconductivity. These combined features result in impressive performance, with NiCoP/NCNTsexhibiting an impressive specific capacitance of 1628.4 F/g at 1 A/g, and good rate capability of 78.5 %up to 50 A/g. Moreover, it also exhibits outstanding cycling stability, maintaining a capacitance retentionof 71.4% after 10 000 cycles. Moreover, the asymmetric SCs based on NiCoP/NCNTs and AC deliver a highenergy density of 45.46 Wh/kg, and exhibit excellent cycling stability of 92.5% after 5000 cycles. Theseresults highlight the potential of NiCoP/NCNTs as a novel battery-type electrode material for energystoragedevices.

Redox-active 2D porous organic polymers for high-performance supercapacitor

Daping Hu,Yuhang Jia,Shaopei Yang,Fuyao Huang,Yuman Dong,Pengcheng Du 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.123 No.-

Porous organic polymers (POPs) have been received considerable attention due to their advantages oflarge surface areas, good stability and functionalities, which are considered an ideal electrode materialfor the energy storage device that has been developed and applied in lithium batteries, zinc ion batteriesand supercapacitors. Here we describe the synthesis of four kinds of redox-active 2D POPs via solvothermalSchiff base condensation using aniline oligomers with different chain lengths as building units thatexhibit reversible electrochemical processes. Among them, the Tp-AT-POP based on 1,3,5-triformylphloroglucinol (Tp) and aniline trimer (AT) deliver high electrochemical performance mainlycontributed by redox units exhibiting high specific capacitance up to 348.3 F/g at a current density of0.5 A/g and possessing excellent cycling stability of 71% after 5000 cycles. In addition, the Tp-AT-POPis developed to assemble a symmetric supercapacitor with specific capacitances of 167 F/g at 0.3 A/gand good cycling stability. This work provides an efficient strategy for developing the redox-active 2DPOPs with aniline oligomer structure for the next-generation advanced high-performance energy storagedevice.

TGMatting: Automatic Image Matting Based on Trimap Generation

Jianming Wang,Xiao Jiang,Yuhang Zhang,Jiting Yin,Zizhong Yang Korean Institute of Information Scientists and Eng 2024 Journal of Computing Science and Engineering Vol.18 No.2

Design of Integer Chaotic Key Generator for Wireless Sensor Network

Juan Wang,Taiheng Yang,Yuhang Li,Qun Ding 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.11

In the block encryption algorithm of wireless sensor network, the chaotic map is used as a key generator conform to the application requirements of security and efficiency. Due to the one-dimensional discrete chaotic map would appear the degradation of dynamic characteristics after integer quantization, the cascaded and disturbed integer chaotic key generator were constructed in view of the ideas of cascade and disturbance. The performances of dynamic characteristics and statistical randomness were simulated and analyzed for the cascaded and disturbed integer chaotic sequences, and the disturbed integer chaotic sequence whose disturbance position for 1-8 bits was proved to be more excellent, and it can not only meet the encryption requirements of wireless sensor network, but also reduce the computing power and hardware resources overhead of the processor.

Cu nanoplates with ‘‘clean surface”: Synthesis and their enhanced biosensors performance

Xinmei Liu,Chunyang Yang,Wenlong Yang,Jiaqi Lin,Xue Zhou,Yuhang Li 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.108 No.-

In this study, we demonstrated a one-pot synthesis of Cu nanoplates (Cu NPs) with high purity and ‘‘cleansurface”. Different from surfactant-assisted method, we tailored the architecture by controlling the ripeningtime of Cu seeds. Citrate is introduced as a structure-directing agent. Since the ‘‘clean surface” providemore available active sites, the as-prepared Cu NPs show a superior performance when utilized in thenon-enzymatic biosensors. In the detection of nitrite, the sensor constructed by Cu NPs exhibited a superiorsensitivity (303.1 ± 10.18 mAmM1cm2), and the detection range is 5.0 mM. On the contrary, sensitivityfor the Cu NPs by surfactant-assisted method is negligible. As applied in the glucose sensors,detection range by Cu NPs could reach 36.0 mM. And the sensitivity under ambient condition (298 K)is 561.93 ± 3.72 mAmM1cm2, which is ca. 2.11-folds higher than that for Cu NPs by surfactantassistedmethod. In the detection of H2O2, detection range is 10.0 mM, and the enhancement factor fordetection range is up to 2.0-folds. The superior performance can also be extended to the catalysis forthe reduction of 4-nitro-phenol. Since no additional noble metals was applied, this strategy would openup a new avenue for utilizing non-noble metals.