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Xian Zhong,Ling Yu 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.82 No.6
Structural damage identification (SDI) methods have been proposed to monitor the safety of structures. However, the traditional SDI methods using modal parameters, such as natural frequencies and mode shapes, are not sensitive enough to structural damage. To tackle this problem, this paper proposes a new SDI method based on transmissibility assurance criterion (TAC) and weighted Schatten-p norm regularization. Firstly, the transmissibility function (TF) has been proved a useful damage index, which can effectively detect structural damage under unknown excitations. Inspired by the modal assurance criterion (MAC), TF and MAC are combined to construct a new damage index, so called as TAC, which is introduced into the objective function together with modal parameters. In addition, the weighted Schatten-p norm regularization method is adopted to improve the ill-posedness of the SDI inverse problem. To evaluate the effectiveness of the proposed method, some numerical simulations and experimental studies in laboratory are carried out. The results show that the proposed method has a high SDI accuracy, especially for weak damages of structures, it can precisely achieve damage locations and quantifications with a good robustness.
Fair Power Control Using Game Theory with Pricing Scheme in Cognitive Radio Networks
Xianzhong Xie,Helin Yang,Athanasios V. Vasilakos,Lu He 한국통신학회 2014 Journal of communications and networks Vol.16 No.2
This paper proposes a payment-based power controlscheme using non-cooperative game with a novel pricing functionin cognitive radio networks (CRNs). The proposed algorithm considersthe fairness of power control among second users (SUs)where the value of per SU’ signal to noise ratio (SINR) or distancebetween SU and SU station is used as reference for punishmentprice setting. Due to the effect of uncertainty fading environment,the system is unable to get the link gain coefficient tocontrol SUs’ transmission power accurately, so the quality of service(QoS) requirements of SUs may not be guaranteed, and theexistence of Nash equilibrium (NE) is not ensured. Therefore, analternative iterative scheme with sliding model is presented for thenon-cooperative power control game algorithm. Simulation resultsshow that the pricing policy using SUs’ SINR as price punishmentreference can improve total throughput, ensure fairness and reducetotal transmission power in CRNs.
Flexural behavior of steel storage rack base-plate upright connections with concentric anchor bolts
Xianzhong Zhao,Zhaoqi Huang,Yue Wang,Ken S. Sivakumaran 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.33 No.3
Steel storage racks are slender structures whose overall behavior and the capacity depend largely on the flexural behavior of the base-plate to upright connections and on the behavior of beam-to-column connections. The base-plate upright connection assembly details, anchor bolt position in particular, associated with the high-rise steel storage racks differ from those of normal height steel storage racks. Since flexural behavior of high-rise rack base connection is hitherto unavailable, this investigation experimentally establishes the flexural behavior of base-plate upright connections of high-rise steel storage racks. This investigation used an enhanced test setup and considered nine groups of three identical tests to investigate the influence of factors such as axial load, base plate thickness, anchor bolt size, bracket length, and upright thickness. The test observations show that the base-plate assembly may significantly influence the overall behavior of such connections. A rigid plate analytical model and an elastic plate analytical model for the overall rotations stiffness of base-plate upright connections with concentric anchor bolts were constructed, and were found to give better predictions of the initial stiffness of such connections. Analytical model based parametric studies highlight and quantify the interplay of components and provide a means for efficient maximization of overall rotational stiffness of concentrically anchor bolted high-rise rack base-plate upright connections.
Joint Optimization of Mobile Charging and Data Gathering for Wireless Rechargeable Sensor Networks
( Xianzhong Tian ),( Jiacun He ),( Yuzhe Chen ),( Yanjun Li ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.7
Recent advances in radio frequency (RF) power transfer provide a promising technology to power sensor nodes. Adoption of mobile chargers to replenish the nodes’ energy has recently attracted a lot of attention and the mobility assisted energy replenishment provides predictable and sustained power service. In this paper, we study the joint optimization of mobile charging and data gathering in sensor networks. A wireless multi-functional vehicle (WMV) is employed and periodically moves along specified trajectories, charge the sensors and gather the sensed data via one-hop communication. The objective of this paper is to maximize the uplink throughput by optimally allocating the time for the downlink wireless energy transfer by the WMV and the uplink transmissions of different sensors. We consider two scenarios where the WMV moves in a straight line and around a circle. By time discretization, the optimization problem is formulated as a 0-1 programming problem. We obtain the upper and lower bounds of the problem by converting the original 0-1 programming problem into a linear programming problem and then obtain the optimal solution by using branch and bound algorithm. We further prove that the network throughput is independent of the WMV’s velocity under certain conditions. Performance of our proposed algorithm is evaluated through extensive simulations. The results validate the correctness of our proposed theorems and demonstrate that our algorithm outperforms two baseline algorithms in achieved throughput under different settings.
Xianzhong Wang,Li Chen,Ning Li,Yu Xia,Ye-Ping Xiong 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.4
Based on precise transfer matrix method (PTMM), the analytical model of the double-walled steel cylindrical shell was setup by taking into account of the annular plate and interlayer water. Under the linear sweep frequency excitation or the fi xed frequency excitation, an experimental model of the double-walled steel cylindrical shell has been designed, which is performed to gain the natural frequencies, forced vibration in air and water, underwater acoustic radiation. The analytical model was established to calculate natural frequencies, vibration acceleration level and sound pressure level and compare with the relevant experimental results. The compared results show that analytical results coincide with the experimental value and prove that the analytical model established by PTMM is reliable and credible. Meanwhile, the forced vibration behaviour of measuring positions at inner and outer shells was investigated both theoretically and experimentally. Eff ects of diff erent types of external excitations on the vibration and sound radiation of the double-walled cylindrical shell are discussed. As to acoustic radiation, the acoustic excitation plays a leading role in the low-frequency range. The force excitation is a major contributor in middle-high frequency range conversely.
Ultra-low cycle fatigue tests of Class 1 H-shaped steel beams under cyclic pure bending
Xianzhong Zhao,Yafeng Tian,Liang-Jiu Jia,Tao Zhang 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.26 No.4
This paper presents experimental and numerical study on buckling behaviors and hysteretic performance of Class 1 H-shaped steel beam subjected to cyclic pure bending within the scope of ultra-low cycle fatigue (ULCF). A loading device was designed to achieve the pure bending loading condition and 4 H-shaped specimens with a small width-to-thickness ratio were tested under 4 different loading histories. The emphasis of this work is on the impacts induced by local buckling and subsequent ductile fracture. The experimental and numerical results indicate that the specimen failure is mainly induced by elasto-plastic local buckling, and is closely correlated with the plastic straining history. Compared with monotonic loading, the elasto-plastic local buckling can occur at a much smaller displacement amplitude due to a number of preceding plastic reversals with relative small strain amplitudes, which is mainly correlated with decreasing tangent modulus of the material under cyclic straining. Ductile fracture is found to be a secondary factor leading to deterioration of the load-carrying capacity. In addition, a new ULCF life evaluation method is proposed for the specimens using the concept of energy decomposition, where the cumulative plastic energy is classified into two categories as isotropic hardening and kinematic hardening correlated. A linear correlation between the two energies is found and formulated, which compares well with the experimental results.
Vibro-acoustic modelling of immersed cylindrical shells with variable thickness
Wang, Xianzhong,Lin, Hongzhou,Zhu, Yue,Wu, Weiguo The Society of Naval Architects of Korea 2020 International Journal of Naval Architecture and Oc Vol.12 No.1
Based on the Precise Transfer Matrix Method (PTMM), the dynamic model is constructed to observe the vibration behaviour of cylindrical shells with variable thickness by solving a set of first-order differential equations. The free vibration of stiffened cylindrical shells with variable thickness can be obtained to compare with the exact solution and FEM results. The reliability of the present method of free vibration is well proved. Furthermore, the effect of thickness on the vibration responses of the cylindrical shell is also discussed. The acoustic response of immersed cylindrical shells is analyzed by a Pluralized Wave Superposition Method (PWSM). The sound pressure coefficient can be gained by collocating points along the meridian line to satisfy the Neumann boundary condition. The mode convergence analysis of the cylindrical shell is carried out to guarantee calculation precision. Also, the reliability of the present method on sound radiation is verified by comparing with experimental results and numerical results.
Vibro-acoustic modelling of immersed cylindrical shells with variable thickness
Wang, Xianzhong,Lin, Hongzhou,Zhu, Yue,Wu, Weiguo The Society of Naval Architects of Korea 2020 International Journal of Naval Architecture and Oc Vol.12 No.-
Based on the Precise Transfer Matrix Method (PTMM), the dynamic model is constructed to observe the vibration behaviour of cylindrical shells with variable thickness by solving a set of first-order differential equations. The free vibration of stiffened cylindrical shells with variable thickness can be obtained to compare with the exact solution and FEM results. The reliability of the present method of free vibration is well proved. Furthermore, the effect of thickness on the vibration responses of the cylindrical shell is also discussed. The acoustic response of immersed cylindrical shells is analyzed by a Pluralized Wave Superposition Method (PWSM). The sound pressure coefficient can be gained by collocating points along the meridian line to satisfy the Neumann boundary condition. The mode convergence analysis of the cylindrical shell is carried out to guarantee calculation precision. Also, the reliability of the present method on sound radiation is verified by comparing with experimental results and numerical results.
Fair Power Control Using Game Theory with Pricing Scheme in Cognitive Radio Networks
Xie, Xianzhong,Yang, Helin,Vasilakos, Athanasios V.,He, Lu The Korea Institute of Information and Commucation 2014 Journal of communications and networks Vol.16 No.2
This paper proposes a payment-based power control scheme using non-cooperative game with a novel pricing function in cognitive radio networks (CRNs). The proposed algorithm considers the fairness of power control among second users (SUs) where the value of per SU' signal to noise ratio (SINR) or distance between SU and SU station is used as reference for punishment price setting. Due to the effect of uncertainty fading environment, the system is unable to get the link gain coefficient to control SUs' transmission power accurately, so the quality of service (QoS) requirements of SUs may not be guaranteed, and the existence of Nash equilibrium (NE) is not ensured. Therefore, an alternative iterative scheme with sliding model is presented for the non-cooperative power control game algorithm. Simulation results show that the pricing policy using SUs' SINR as price punishment reference can improve total throughput, ensure fairness and reduce total transmission power in CRNs.
Joint Beamforming and Precoding in TD-SCDMA Downlink System
Wanhong Ba,Xianzhong Xie 대한전자공학회 2008 ITC-CSCC :International Technical Conference on Ci Vol.2008 No.7
In this paper, beamforming and precoding is combined to improve the performance of TD-SCDMA downlink based on MIMO (Multiple-Input-Multiple-Output). We deduced beamforming vector and precoding matrix combined beamforming and precoding. And then, we compared beamforming scheme based signal-to-interference-plus-noise ratio (SINR) and based signal-to-leakage-plus-noise ratio (SLNR) in TD-SCDMA Downlink System. The performance of scheme with precoding based on SINR and SLNR outperform than the scheme without precoding. As the user number or the number of receive antenna increase, the beamforming scheme with precoding outperform the traditional beamforming still, and the beamforming precoding based on SLNR is superior gradually to the beamforming precoding based on SINR.