Xiaohua Zhang

Prof. Xiaohua Zhang


Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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16 September 2023 in Horticulturae
Verified
Journal Article
Open access
PDF file
XZXiaohua Zhang
Xiaohua Zhang
HLHaolin Li
Haolin Li
SSSihai Sun
Sihai Sun
WZWenfeng Zhang
Wenfeng Zhang
FSFuxi Shi
Fuxi Shi
QLQin Liu
Qin Liu
Automaticidentification and prevention of leaf diseases and insect pests on fruit crops represent a key trend in the development of smart agriculture. In order to address the limitations of existing models with low identification rates of apple leaf diseases and insect pests, a novel identification model based on an improved ResNet-50 architecture was proposed, which incorporated the coordinate attention (CA) module and weight-adaptive multi-scale feature fusion (WAMFF) to enhance the ResNet-50’s image feature extraction capabilities. Transfer learning and online data enhancement are employed to boost the model’s generalization ability. The proposed model achieved a top-1 accuracy rate of 98.32% on the basis of AppleLeaf9 datasets, which is 4.58% higher than the value from the original model, and the improved model can effectively improve the localization of lesion features. Furthermore, compared with mainstream deep networks, such as AlexNet, VGG16, DenseNet, MNASNet, and GoogLeNet on the same dataset, the top-1 accuracy rate increased by 7.3%, 3.19%, 4.98%, 6.04% and 3.87%, respectively. The experimental results demonstrate that the improved model is effective in improving the identification accuracy of apple leaf diseases and insect pests and enhancing the model’s effective feature extraction capabilities.

20 July 2023 in IEEE Transactions on Circuits and Systems II: Express Briefs
Verified
Journal Article
Closed access
Liping ChenLiping Chen
Liping Chen
MXMin Xue
Min Xue
António LopesAntónio Lopes
António Lopes
RWRanchao Wu
Ranchao Wu
XZXiaohua Zhang
Xiaohua Zhang
YangQuan ChenYangQuan Chen
YangQuan Chen
The synchronization of fractional-order (FO) chaotic systems has received much attention in recent years. However, most research was focused on FO commensurate systems. In this brief, the synchronization of incommensurate fractional-order (IFO) chaotic systems is addressed. By employing the linear feedback control method, a new sufficient condition is proposed to ensure the synchronization of IFO chaotic systems. Compared with other approaches reported in the literature, the new method depends just on the system’s parameters, is easier to implement in engineering practice, applies to systems with FO in the interval (0,2), and is still valid for synchronizing IFO chaotic systems of irrational order. The effectiveness of the theoretical findings is illustrated by numerical simulations using two IFO chaotic systems.

9 February 2023 in Micromachines
Verified
Journal Article
Open access
PDF file
XZXiaohua Zhang
Xiaohua Zhang
HLHaolin Li
Haolin Li
WZWenfeng Zhang
Wenfeng Zhang
António LopesAntónio Lopes
António Lopes
XWXiaobo Wu
Xiaobo Wu
Liping ChenLiping Chen
Liping Chen
With the aim of increasing the model accuracy of lithium-ion batteries (LIBs), this paper presents a complex-order beetle swarm optimization (CBSO) method, which employs complex-order (CO) operator concepts and mutation into the traditional beetle swarm optimization (BSO). Firstly, a fractional-order equivalent circuit model of LIBs is established based on electrochemical impedance spectroscopy (EIS). Secondly, the CBSO is used for model parameters’ identification, and the model accuracy is verified by simulation experiments. The root-mean-square error (RMSE) and maximum absolute error (MAE) optimization metrics show that the model accuracy with CBSO is superior when compared with the fractional-order BSO.

1 January 2019 in Mathematical Problems in Engineering
Verified
Journal Article
Open access
PDF file
XZXiaohua Zhang
Xiaohua Zhang
JGJunli Gao
Junli Gao
WZWenfeng Zhang
Wenfeng Zhang
TZTao Zeng
Tao Zeng
LYLiping Ye
Liping Ye
This paper presents the disturbance observers‐based distributed formation control for multiple quadrotor aircrafts with external disturbances and uncertain parameters using multi‐agent theory and finite‐time control method. Firstly, the finite‐time disturbance observers are proposed to handle the external disturbances on the position‐loop. Similarly, when there are both the uncertain parameters and external disturbances on the attitude‐loop, the finite‐time disturbance observers are designed to estimate the total lump disturbances. By skillfully using homogeneous system theory, Lyapunov theory, and multi‐agent theory, the distributed formation control algorithms are developed. Finally, through simulations, the efficiency of the proposed method (including the convergence rate and disturbance rejection) is verified.

27 February 2022 in Shock and Vibration
Verified
Journal Article
Open access
PDF file
RMRuijun Ma
Ruijun Ma
THTaymaz Homayouni
Taymaz Homayouni
Arash ToudeshkiArash Toudeshki
Arash Toudeshki
REReza Ehsani
Reza Ehsani
XZXiaohua Zhang
Xiaohua Zhang
Trunk shakers are the most widely used mechanical harvesting machines for harvesting nut trees, including pistachio in California. Improvement of these machines requires a better understanding of the shaking dynamics of the existing trunk shakers during harvest. In this study, the effects of four different shaking patterns on three sizes of pistachio trees of different ages, shapes, and sizes were investigated under field conditions. The vibration acceleration of the real pistachio tree was measured using a wireless network of 3-axis accelerometers installed on the shaker head and different parts of the trees during the shaking harvest. Changes in acceleration and the effect of tree morphology on the magnitude of acceleration in each pattern are presented and discussed. A new location index λ, which is based on the distance of the sensor from the shaking point and diameter of the branch at each sensor location, is introduced. This study focused on mathematical modeling of the variation and distribution of the acceleration throughout the tree canopy. The sensor location index, relative force ratio (RFR), and relative kinetic energy ratio (RKER) were defined to better understand the energy damping in each part of the tree. The results showed that the relationship between the acceleration peaks and the sensor location index could be expressed by a third-degree polynomial function with an acceptable coefficient of determination. Under different shaking patterns, similar changes in the RFR of the tree at different locations and for different trees were observed. This finding indicates that the vibration force is significantly damped as the distance from the shaker clamps increases. However, the RKER values at the same shaking pattern result in different effects at different points on the branches according to tree morphology.

16 November 2020 in Frontiers in Neurorobotics
Verified
Journal Article
Open access
PDF file
JGJunli Gao
Junli Gao
HCHuajun Chen
Huajun Chen
XZXiaohua Zhang
Xiaohua Zhang
JGJing Guo
Jing Guo
WLWenyu Liang
Wenyu Liang
Microexpression is usually characterized by short duration and small action range, and the existing general expression recognition algorithms do not work well for microexpression. As a feature extraction method, non-negative matrix factorization can decompose the original data into different components, which has been successfully applied to facial recognition. In this paper, local non-negative matrix factorization is explored to decompose microexpression into some facial muscle actions, and extract features for recognition based on apex frame. However, the existing microexpression datasets fall short of samples to train a classifier with good generalization. The macro-to-micro algorithm based on singular value decomposition can augment the number of microexpressions, but it cannot meet non-negative properties of feature vectors. To address these problems, we propose an improved macro-to-micro algorithm to augment microexpression samples by manipulating the macroexpression data based on local non-negative matrix factorization. Finally, several experiments are conducted to verify the effectiveness of the proposed scheme, which results show that it has a higher recognition accuracy for microexpression compared with the related algorithms based on CK+/CASME2/SAMM datasets.