Xiaojun Zhai

Dr. Xiaojun Zhai

University of Essex
orcid

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

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

Representative Publications

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29 May 2020 in IEEE Systems Journal
Verified
Journal Article
Closed access
HAHaider Ali
Haider Ali
UTUmair Ullah Tariq
Umair Ullah Tariq
MHMubashir Hussain
Mubashir Hussain
LLLu Liu
Lu Liu
JPJohn Panneerselvam
John Panneerselvam
Xiaojun ZhaiXiaojun Zhai
Xiaojun Zhai
Wireless sensor network (WSN) consists of a large number of sensor nodes distributed over a certain target area. The WSN plays a vital role in surveillance, advanced healthcare, and commercialized industrial automation. Enhancing energy-efficiency of the WSN is a prime concern because higher energy consumption restricts the lifetime (LT) of the network. Clustering is a powerful technique widely adopted to increase LT of the network and reduce the transmission energy consumption. In this article (LT) we develop a novel ARSH-FATI-based Cluster Head Selection (ARSH-FATI-CHS) algorithm integrated with a heuristic called novel ranked-based clustering (NRC) to reduce the communication energy consumption of the sensor nodes while efficiently enhancing LT of the network. Unlike other population-based algorithms ARSH-FATI-CHS dynamically switches between exploration and exploitation of the search process during run-time to achieve higher performance trade-off and significantly increase LT of the network. ARSH-FATI-CHS considers the residual energy, communication distance parameters, and workload during cluster heads (CHs) selection. We simulate our proposed ARSH-FATI-CHS and generate various results to determine the performance of the WSN in terms of LT. We compare our results with state-of-the-art particle swarm optimization (PSO) and prove that ARSH-FATI-CHS approach improves the LT of the network by ~ 25%.

21 October 2016 in IEEE Access
Verified
Journal Article
Open access
Xiaojun ZhaiXiaojun Zhai
Xiaojun Zhai
AAAmine Ait Si Ali
Amine Ait Si Ali
Abbes AmiraAbbes Amira
Abbes Amira
Faycal BensaaliFaycal Bensaali
Faycal Bensaali
Systems based on wireless gas sensor networks offer a powerful tool to observe and analyze data in complex environments over long monitoring periods. Since the reliability of sensors is very important in those systems, gas classification is a critical process within the gas safety precautions. A gas classification system has to react fast in order to take essential actions in the case of fault detection. This paper proposes a low latency real-time gas classification service system, which uses a multi-layer perceptron (MLP) artificial neural network to detect and classify the gas sensor data. An accurate MLP is developed to work with the data set obtained from an array of tin oxide (SnO2) gas sensor, based on convex micro hotplates. The overall system acquires the gas sensor data through radio-frequency identification (RFID), and processes the sensor data with the proposed MLP classifier implemented on a system on chip (SoC) platform from Xilinx. Hardware implementation of the classifier is optimized to achieve very low latency for real-time application. The proposed architecture has been implemented on a ZYNQ SoC using fixed-point format and the achieved results have shown that an accuracy of 97.4% has been obtained.

19 September 2018 in IEEE Sensors Journal
Verified
Journal Article
Closed access
HDHamza Djelouat
Hamza Djelouat
Xiaojun ZhaiXiaojun Zhai
Xiaojun Zhai
MDMohamed Al Disi
Mohamed Al Disi
Abbes AmiraAbbes Amira
Abbes Amira
Faycal BensaaliFaycal Bensaali
Faycal Bensaali
The ever-increasing demand for biometric solutions for the internet of thing (IoT)-based connected health applications is mainly driven by the need to tackle fraud issues, along with the imperative to improve patient privacy, safety and personalized medical assistance. However, the advantages offered by the IoT platforms come with the burden of big data and its associated challenges in terms of computing complexity, bandwidth availability and power consumption. This paper proposes a solution to tackle both privacy issues and big data transmission by incorporating the theory of compressive sensing (CS) and a simple, yet, efficient identification mechanism using the electrocardiogram (ECG) signal as a biometric trait. Moreover, the paper presents the hardware implementation of the proposed solution on a system on chip (SoC) platform with an optimized architecture to further reduce hardware resource usage. First, we investigate the feasibility of compressing the ECG data while maintaining a high identification quality. The obtained results show a 98.88% identification rate using only a compression ratio of 30%. Furthermore, the proposed system has been implemented on a Zynq SoC using heterogeneous software/hardware solution, which is able to accelerate the software implementation by a factor of 7.73 with a power consumption of 2.318 W.

19 August 2023 in GeroScience
Verified
Journal Article
Open access
PDF file
YWYucheng Wang
Yucheng Wang
OGOlivia A. Grant
Olivia A. Grant
Xiaojun ZhaiXiaojun Zhai
Xiaojun Zhai
KMKlaus D. Mcdonald-Maier
Klaus D. Mcdonald-Maier
LSLeonardo C. Schalkwyk
Leonardo C. Schalkwyk
DNA methylation (DNAm)-based age clocks have been studied extensively as a biomarker of human ageing and a risk factor for age-related diseases. Despite different tissues having vastly different rates of proliferation, it is still largely unknown whether they age at different rates. It was previously reported that the cerebellum ages slowly; however, this claim was drawn from a single clock using a relatively small sample size and so warrants further investigation. We collected the largest cerebellum DNAm dataset (N = 752) to date. We found the respective epigenetic ages are all severely underestimated by six representative DNAm age clocks, with the underestimation effects more pronounced in the four clocks whose training datasets do not include brain-related tissues. We identified 613 age-associated CpGs in the cerebellum, which accounts for only 14.5% of the number found in the middle temporal gyrus from the same population (N = 404). From the 613 cerebellum age-associated CpGs, we built a highly accurate age prediction model for the cerebellum named CerebellumClockspecific (Pearson correlation=0.941, MAD=3.18 years). Ageing rate comparisons based on the two tissue-specific clocks constructed on the 201 overlapping age-associated CpGs support the cerebellum has younger DNAm age. Nevertheless, we built BrainCortexClock to prove a single DNAm clock is able to unbiasedly estimate DNAm ages of both cerebellum and cerebral cortex, when they are adequately and equally represented in the training dataset. Comparing ageing rates across tissues using DNA methylation multi-tissue clocks is flawed. The large underestimation of age prediction for cerebellums by previous clocks mainly reflects the improper usage of these age clocks. There exist strong and consistent ageing effects on the cerebellar methylome, and we suggest the smaller number of age-associated CpG sites in cerebellum is largely attributed to its extremely low average cell replication rates.

7 February 2019 in Concurrency and Computation: Practice and Experience
Verified
Journal Article
Closed access
PDF file
Xiaojun ZhaiXiaojun Zhai
Xiaojun Zhai
AAAbbes Amira
Abbes Amira
Faycal BensaaliFaycal Bensaali
Faycal Bensaali
AAAlMaha Al‐Shibani
AlMaha Al‐Shibani
AAAsma Al‐Nassr
Asma Al‐Nassr
JAJulien Abinahed
Julien Abinahed

22 November 2018 in IEEE Access
Verified
Journal Article
Open access
HAHaider Ali
Haider Ali
UTUmair Ullah Tariq
Umair Ullah Tariq
YZYongjun Zheng
Yongjun Zheng
Xiaojun ZhaiXiaojun Zhai
Xiaojun Zhai
LLLu Liu
Lu Liu