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Xiangqian Shen,Tong Li,Lei Xu,Faraz Kiarasi,Masoud Babaei,Kamran Asemi Techno-Press 2024 Advances in nano research Vol.16 No.1
In this study, free vibration analysis of FG porous spherical cap reinforced by graphene platelets resting on Winkler-type elastic foundation has been surveyed for the first time. Three different types of porosity patterns are considered for the spherical cap whose two types of porosity patterns in the metal matrix are symmetric and the other one is uniform. Besides, five GPL patterns are assumed for dispersing of GPLs in the metal matrix. Tsai-Halpin and extended rule of the mixture are used to determine the Young modulus and mass density of the shell, respectively. Employing 3D FEM elasticity in conjunction with Hamilton's Principle, the governing motion equations of the structure are obtained and solved. The impact of various parameters including porosity coefficient, various porosity distributions in conjunction with different GPL patterns, the weight fraction of graphene Nano fillers, polar angles and stiffness coefficient of elastic foundation on natural frequencies of FG porous spherical cap reinforced by GPLs have been reported for the first time.
Zhengliang Li,Wenliang Fan,Runyu Liu,Xiangqian Sheng 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.12
Estimation of statistical moments of structural response effectively and accurately is still one of the main topics for analysis of random systems. For the sake of reducing function evaluations to alleviate curse of dimensionality and improve the accuracy in moment estimation, a generalized anisotropic sparse grid integral based on the adaptive high dimensional model representation and appropriate reference variables is proposed. By introducing different transformations, a system with general variables is transformed into the one with appropriate independent reference variables and a generalized anisotropic sparse grid integral will be presented for moment estimation. Then, anisotropic sparse grid collections should be divided into several mutually exclusive sub-collections and the generalized anisotropic sparse grid integral (SGI) can be remodeled in a new form. With this new form, the adaptive high dimensional model representation can be introduced for function evaluations conveniently, which can be regarded as an alternative way to evaluate functions precisely and efficiently without any approximation. Finally, several examples are presented to demonstrate the effectiveness and accuracy of the proposed method.
Linking UT Signals to Properties of Weakly Bonded Composites by Four-point Bending Test
Ting Zhang,Xiangqian Li,Leishan Chen 한국섬유공학회 2022 Fibers and polymers Vol.23 No.3
A new method of producing accurately controlled bond ratios in weakly bonded composites was developed toinvestigate the influence of adhesive porosity on mechanical properties of the bondline. The ultrasonic A-scan was used todetect weak bonds in adhesive joints and the ultrasonic A-scan signals of weak bonds were analyzed to link with adhesiveporosity. As well, relations of adhesive porosities to four-point bending (4PB) were established based on experimental andnumerical results. It was found that the amplitudes of amplitudes of A-scan signals of the adhesive interface areapproximately linear functions of the bond ratios, as well as the adhesive porosities. The shear strength of bondlinesdecreases linearly with the bond ratios. Based on above results, properties of weak bonds could be evaluated by the UT(Ultrasonic Test) signals, which is of great value in engineering application.
Application of Improved BP Neural Network with Correlation Rules in Network Intrusion Detection
Yongfeng Cui,Xiangqian Li Ma,Zhijie Liu 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.4
To detect various network attacks in real time, this paper developed a network intrusion detection system based on artificial neural network. This paper first introduced the recent development of neural network, BP algorithm and structure of a simple perceptron. Then, this paper developed an improved BP neural network algorithm to detect anomaly network traffic with adjusted correlation rules. Finally, the network intrusion system in this paper was tested in a real network situation; the improved BP algorithm neural network with adjusted correlation rules shows a reduction in total error and increment in alarm rate compared to the traditional basic BP algorithm model.
A Novel Speed Estimation Method of Induction Motors Using Real-Time Adaptive Extended Kalman Filter
Zhang, Yanqing,Yin, Zhonggang,Li, Guoyin,Liu, Jing,Tong, Xiangqian The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.1
To improve the performance of sensorless induction motor (IM) drives, a novel speed estimation method based on the real-time adaptive extended Kalman filter (RAEKF) is proposed in this paper. In this algorithm, the fuzzy factor is introduced to tune the measurement covariance matrix online by the degree of mismatch between the actual innovation and the theoretical. Simultaneously, the fuzzy factor can be continuously self-tuned tuned by the fuzzy logic reasoning system based on Takagi-Sugeno (T-S) model. Therefore, the proposed method improves the model adaptability to the actual systems and the environmental variations, and reduces the speed estimation error. Furthermore, a simple exponential function based on the fuzzy theory is used to reduce the computational burden, and the real-time performance of the system is improved. The correctness and the effectiveness of the proposed method are verified by the simulation and experimental results.
Research on the Effect of Health food on Consumer Purchase Intention
Ying-Mei Lee,Zhang Xiangqian,Wen-Tsann Lin,Meng-Hua Li,Hung-Lung Chang 대한산업공학회 2015 대한산업공학회 추계학술대회논문집 Vol.2015 No.11
This study used the structural equation modeling (SEM) of SPSS and AMOS to verify the hypotheses on the correlation between various dimensions, which were all supported. The correlations were significantly positive. The results showed that the effect of consumer health concept on algae product knowledge is significantly positive, where path coefficient is 0.9, indicating that consumers with health concept are more willing to accept new algae product knowledge, thereby affecting their purchase intention on algae product.
Haibing Wen,Jiayuan Li,Jiadong Yang,Peng Wang,Ke-Han Zhang,Lei Yang,Yaopeng Zhao,Xiangqian Tong 한국전자파학회 2024 Journal of Electromagnetic Engineering and Science Vol.24 No.3
To achieve simple and reliable conversion from constant current (CC) charging mode to constant voltage (CV) charging mode in wireless power transfer systems, this paper proposes a hybrid topology equipped with a reconfigurable rectifier. An AC switch is adapted to simul- taneously realize the change from half-bridge rectification to full-bridge rectification and achieve the shift from a topology with capacitors in the series compensated primary and secondary sides to a topology with capacitors in the series compensated primary side and the induc- tor-capacitor-inductor (LCL) compensated secondary side. Notably, communication between the transmitter and receiver sides is not necessary in the proposed method. Furthermore, the zero phase angle characteristic is successfully maintained in both charging modes. The experimental results obtained using the 48 V/0.7 A experimental prototype, which was built to validate the relevant theoretical analy- sis, show that output current/voltage can be achieved in CC/CV charging mode independent of load resistance. Notably, the maximum power transfer efficiency of the system during the charging process reached 95.33%.
Acoustic emission characterization of the fracture process in steel fiber reinforced concrete
Xiong Zhou,Yuyou Yang,Xiangqian Li,Guoqing Zhao 사단법인 한국계산역학회 2016 Computers and Concrete, An International Journal Vol.18 No.4
The correlation between the characteristics of acoustic emission signals and the strength parameters of concretes is investigated by combining the acoustic emission (AE) technique and steel fiber reinforced concrete (SFRC). By means of AE detection system, three kinds of steel fibers of varying content were used as reinforcement in concrete and their influence on the fracture process and the acoustic activity was considered in this paper. Analysis of the AE test results revealed that for different steel fiber contents, the role of steel fiber is different. Concave-convex steel fiber has an inhibitory effect on the control of crack expansion. Bow steel fiber has a better effect on the control of crack propagation when the fiber content is lower. The compressive strength of SFRC decrease when bow steel fiber content rises. Ultra-short can prevent early cracks of concrete.
Lightweight Design of an Electric Tricycle Frame Considering Dynamic Stress in Driving Conditions
Pan Longye,Zhu Xiangqian,Li Yang,Guan Tingcheng 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.4
Since most tricycles are driven on rough roads, a static analysis of the frame with a constant load and a specific boundary condition is insufficient to assess whether the lightweight design satisfies the strength requirements. A flexible multibody dynamics approach is used to assess the dynamic stress of a tricycle frame in five driving conditions to determine the positions where material can be removed. The five driving conditions, including high-speed driving, turning, climbing, braking and driving on a bumpy road, are established according to two national standards. An electric tricycle prototype is modeled using the rigid-flexible coupling method, and experiments are conducted to adjust the center of mass and stiffness of the suspension. The frame stress results obtained from the simulation are in good agreement with the loading test results. Subsequently, the dynamic stress of the frame is analyzed, and a steel plate with a suitable thickness is selected according to the stress distribution and the allowable stress. The modified frame is about 19.1 % lighter, and the maximum stress is only 2.8 % larger than that of the prototype. The results demonstrate that the proposed method is suitable for the lightweight design of one component in a system operating under various working conditions.