Li Zhang

Dr. Li Zhang

Department of Computer Science, Royal Holloway, University of London, Surrey TW20 0EX, UK
orcid

Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

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

Representative Publications

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3 September 2020 in IEEE Access
Verified
Journal Article
Open access
HXHailun Xie
Hailun Xie
Li ZhangLi Zhang
Li Zhang
CLChee Peng Lim
Chee Peng Lim
In this research, we propose an enhanced Grey Wolf Optimizer (GWO) for designing the evolving Convolutional Neural Network-Long Short-Term Memory (CNN-LSTM) networks for time series analysis. To overcome the probability of stagnation at local optima and a slow convergence rate of the classical GWO algorithm, the newly proposed variant incorporates four distinctive search mechanisms. They comprise a nonlinear exploration scheme for dynamic search territory adjustment, a chaotic leadership dispatching strategy among the dominant wolves, a rectified spiral local exploitation action, as well as probability distribution-based leader enhancement. The evolving CNN-LSTM models are subsequently devised using the proposed GWO variant, where the network topology and learning hyperparameters are optimized for time series prediction and classification tasks. Evaluated using a number of benchmark problems, the proposed GWO-optimized CNN-LSTM models produce statistically significant results over those from several classical search methods and advanced GWO and Particle Swarm Optimization variants. Comparing with the baseline methods, the CNN-LSTM networks devised by the proposed GWO variant offer better representational capacities to not only capture the vital feature interactions, but also encapsulate the sophisticated dependencies in complex temporal contexts for undertaking time-series tasks.

5 March 2019 in IEEE Access
Verified
Journal Article
Open access
TTTeck Yan Tan
Teck Yan Tan
Li ZhangLi Zhang
Li Zhang
CLChee Peng Lim
Chee Peng Lim
BFBen Fielding
Ben Fielding
YYYonghong Yu
Yonghong Yu
EAEmma Anderson
Emma Anderson
In this research, we propose Particle Swarm Optimization (PSO)-enhanced ensemble deep neural networks and hybrid clustering models for skin lesion segmentation. A PSO variant is proposed, which embeds diverse search actions including Simulated Annealing, Levy flight, helix behaviour, modified PSO and Differential Evolution (DE) operations with spiral search coefficients. These search actions work in a cascade manner to not only equip each individual with different search operations throughout the search process, but also assign distinctive search actions to different particles simultaneously in each single iteration. The proposed PSO variant is used to optimize the learning hyper-parameters of Convolutional Neural Networks (CNNs) and the cluster centroids of classical Fuzzy C-Means (FCM) clustering respectively to overcome performance barriers. Ensemble deep networks and hybrid clustering models are subsequently constructed based on the optimized CNN and hybrid clustering segmenters for lesion segmentation. We evaluate the proposed ensemble models using three skin lesion databases, i.e., PH2, ISIC 2017, and Dermofit Image Library, and a blood cancer data set, i.e. ALL-IDB2. The empirical results indicate that our models outperform other hybrid ensemble clustering models combined with advanced PSO variants, as well as state-of-the-art deep networks in the literature for diverse challenging image segmentation tasks.

4 April 2020 in Applied Bionics and Biomechanics
Verified
Journal Article
Open access
Li ZhangLi Zhang
Li Zhang
GLGeng Liu
Geng Liu
BHBing Han
Bing Han
ZWZhe Wang
Zhe Wang
YYYuzhou Yan
Yuzhou Yan
PWPingping Wei
Pingping Wei
The knee joint, as the main lower limb motor joint, is the most vulnerable and susceptible joint. The knee injuries considerably impact the normal living ability and mental health of patients. Understanding the biomechanics of a normal and diseased knee joint is in urgent need for designing knee assistive devices and optimizing a rehabilitation exercise program. In this paper, we systematically searched electronic databases (from 2000 to November 2019) including ScienceDirect, Web of Science, PubMed, Google Scholar, and IEEE/IET Electronic Library for potentially relevant articles. After duplicates were removed and inclusion criteria applied to the titles, abstracts, and full text, 138 articles remained for review. The selected articles were divided into two groups to be analyzed. Firstly, the real movement of a normal knee joint and the normal knee biomechanics of four kinds of daily motions in the sagittal and coronal planes, which include normal walking, running, stair climbing, and sit-to-stand, were discussed and analyzed. Secondly, an overview of the current knowledge on the movement biomechanical effects of common knee musculoskeletal disorders and knee neurological disorders were provided. Finally, a discussion of the existing problems in the current studies and some recommendation for future research were presented. In general, this review reveals that there is no clear assessment about the biomechanics of normal and diseased knee joints at the current state of the art. The biomechanics properties could be significantly affected by knee musculoskeletal or neurological disorders. Deeper understanding of the biomechanics of the normal and diseased knee joint will still be an urgent need in the future.

3 October 2016 in Neural Computing and Applications
Verified
Journal Article
Open access
PDF file
MAMohammad Alauthman
Mohammad Alauthman
Nauman AslamNauman Aslam
Nauman Aslam
Li ZhangLi Zhang
Li Zhang
RARafe Alasem
Rafe Alasem
MHM. A. Hossain
M. A. Hossain
In recent years, Botnets have been adopted as a popular method to carry and spread many malicious codes on the Internet. These malicious codes pave the way to execute many fraudulent activities including spam mail, distributed denial-of-service attacks and click fraud. While many Botnets are set up using centralized communication architecture, the peer-to-peer (P2P) Botnets can adopt a decentralized architecture using an overlay network for exchanging command and control data making their detection even more difficult. This work presents a method of P2P Bot detection based on an adaptive multilayer feed-forward neural network in cooperation with decision trees. A classification and regression tree is applied as a feature selection technique to select relevant features. With these features, a multilayer feed-forward neural network training model is created using a resilient back-propagation learning algorithm. A comparison of feature set selection based on the decision tree, principal component analysis and the ReliefF algorithm indicated that the neural network model with features selection based on decision tree has a better identification accuracy along with lower rates of false positives. The usefulness of the proposed approach is demonstrated by conducting experiments on real network traffic datasets. In these experiments, an average detection rate of 99.08 % with false positive rate of 0.75 % was observed.

9 October 2015 in Scientific Reports
Verified
Journal Article
Open access
SNSiew Chin Neoh
Siew Chin Neoh
WSWorawut Srisukkham
Worawut Srisukkham
Li ZhangLi Zhang
Li Zhang
Stephen TodrykStephen Todryk
Stephen Todryk
BGBrigit Greystoke
Brigit Greystoke
NANauman Aslam
Nauman Aslam
This research proposes an intelligent decision support system for acute lymphoblastic leukaemia diagnosis from microscopic blood images. A novel clustering algorithm with stimulating discriminant measures (SDM) of both within- and between-cluster scatter variances is proposed to produce robust segmentation of nucleus and cytoplasm of lymphocytes/lymphoblasts. Specifically, the proposed between-cluster evaluation is formulated based on the trade-off of several between-cluster measures of well-known feature extraction methods. The SDM measures are used in conjuction with Genetic Algorithm for clustering nucleus, cytoplasm and background regions. Subsequently, a total of eighty features consisting of shape, texture and colour information of the nucleus and cytoplasm sub-images are extracted. A number of classifiers (multi-layer perceptron, Support Vector Machine (SVM) and Dempster-Shafer ensemble) are employed for lymphocyte/lymphoblast classification. Evaluated with the ALL-IDB2 database, the proposed SDM-based clustering overcomes the shortcomings of Fuzzy C-means which focuses purely on within-cluster scatter variance. It also outperforms Linear Discriminant Analysis and Fuzzy Compactness and Separation for nucleus-cytoplasm separation. The overall system achieves superior recognition rates of 96.72% and 96.67% accuracies using bootstrapping and 10-fold cross validation with Dempster-Shafer and SVM, respectively. The results also compare favourably with those reported in the literature, indicating the usefulness of the proposed SDM-based clustering method.

1 June 2017 in Computer Methods and Programs in Biomedicine
Verified
Journal Article
Closed access
DPDiptangshu Pandit
Diptangshu Pandit
Li ZhangLi Zhang
Li Zhang
CLChengyu Liu
Chengyu Liu
SCSamiran Chattopadhyay
Samiran Chattopadhyay
NANauman Aslam
Nauman Aslam
CLChee Peng Lim
Chee Peng Lim