Kezhi Li

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32ranked-venue papers
6as first author
20since 2021 · last 2026
—ORCID · conflict

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Applied, interdisciplinary, general and emerging computing · 13 · 3 first-author · 9 since 2021Graphics, computer vision, multimedia, augmented reality and games · 7 · 3 first-author · 1 since 2021Artificial intelligence and machine learning · 4 · 3 since 2021Systems, architecture and hardware · 3 · 3 since 2021Computer networks · 3 · 3 since 2021Theory of computation · 1
YearPublicationVenuePosition
2026 Solve-Detect-Verify: Inference-Time Scaling with Flexible Generative Verifier
abstract
Figure 1: The Solve-Detect-Verify (SDV) pipeline transforms linguistic signals into efficiency.Left: On AIME 2024, SDV achieves 83.3% accuracy (vs.63.3% for GenPRM) while using 6x fewer verification tokens by pruning redundant reasoning.Right: The pipeline is powered by FlexiVe , a unified verifier.Unlike process-based verifiers that incur per-step overhead, FlexiVe analyzes traces holistically.It employs a "pragmatic" consensus strategy: parallel "Fast Thinking" checks (∼0.1k tokens) provide an initial semantic intuition, escalating to deliberative "Slow Thinking" (∼4k tokens) only when the model exhibits verbalized uncertainty.
Jianyuan Zhong, Zeju Li, Xiangyu Wen 0001, Kezhi Li, Qiang Xu 0001
ACL (1)5
2026 AC-Refiner: Efficient Arithmetic Circuit Optimization Using Conditional Diffusion Models
Chenhao Xue, Kezhi Li, Zhengyuan Shi, Chen Zhang 0001, Yibo Lin, Lining Zhang, Qiang Xu 0001, Guangyu Sun 0003
ASP-DAC2
2026 Evaluation of trajectory analysis for disease risk assessment: a scoping review
abstract
OBJECTIVES: Increasingly, structured longitudinal electronic health records (EHRs) are being harnessed to predict risk of having present but as yet undetected disease by analyzing "patient trajectories." Trajectory studies explore clinical event associations, characterize disease trajectories, and enhance risk prediction. This scoping review assesses study characteristics and objectives, identifies model types, and appraises model performance and reporting. MATERIALS AND METHODS: We conducted a scoping review, focused on a PubMed and Web of Science search for studies using temporal EHR sequences to identify disease signatures or predict disease presence. RESULTS: We identified 62 studies. Statistical methods, such as testing temporal associations were primarily used for clustering, while deep learning models focused on outcome prediction. Sixty-five percent of studies used secondary care data, with the most common outcomes being disease agnostic (39%) and cardiovascular disease (20%). Forty-eight studies aimed at risk prediction, with 50% comparing trajectory-based models to static baselines. Among 31 studies reporting area under the curve (AUC), temporal models showed moderate performance gains (relative/absolute AUC: median 5.7%/4.2%, range -2.6% to 58.9%/-2.3% to 33.0%). DISCUSSION: Trajectory studies are increasing in volume, but lacking in application to primary care datasets, a diverse set of diseases, external validation, and consideration of clinical applicability. CONCLUSION: While the field's nascency hinders firm conclusions, there are promising results across a range of model types and objectives. Continued research from diverse perspectives will help determine whether this growing field can deliver meaningful clinical benefits.
Freya Pollington, Spiros C. Denaxas, Kezhi Li, Johan Hilge Thygesen, Georgios Lyratzopoulos, Becky White
J. Am. Medical Informatics Assoc.3
2026 Privacy Preserved Blood Glucose Level Cross-Prediction: An Asynchronous Decentralized Federated Learning Approach
abstract
Newly diagnosed Type 1 Diabetes (T1D) patients often struggle to obtain effective Blood Glucose (BG) prediction models due to the lack of sufficient BG data from Continuous Glucose Monitoring (CGM), presenting a significant "cold start" problem in patient care. Utilizing population models to address this challenge is a potential solution, but collecting patient data for training population models in a privacy-conscious manner is challenging, especially given that such data is often stored on personal devices. Considering the privacy protection and addressing the "cold start" problem in diabetes care, we propose "GluADFL", blood Glucose prediction by Asynchronous Decentralized Federated Learning. We compared GluADFL with eight baseline methods using four distinct T1D datasets, comprising 298 participants, which demonstrated its superior performance in accurately predicting BG levels for cross-patient analysis. Furthermore, patients' data might be stored and shared across various communication networks in GluADFL, ranging from highly interconnected (e.g., random, performs the best among others) to more structured topologies (e.g., cluster and ring), suitable for various social networks. The asynchronous training framework supports flexible participation. By adjusting the ratios of inactive participants, we found it remains stable if less than 70% are inactive. Our results confirm that GluADFL offers a practical, privacy-preserved solution for BG prediction in T1D, significantly enhancing the quality of diabetes management.
Chengzhe Piao, Taiyu Zhu, Yu Wang 0115, Stephanie E. Baldeweg, Pantelis Georgiou, Jun Wang 0012, Kezhi Li
IEEE J. Biomed. Health Informatics9
2025 Functional Matching of Logic Subgraphs: Beyond Structural Isomorphism
abstract
Subgraph matching in logic circuits is foundational for numerous Electronic Design Automation (EDA) applications, including datapath optimization, arithmetic verification, and hardware trojan detection. However, existing techniques rely primarily on structural graph isomorphism and thus fail to identify function-related subgraphs when synthesis transformations substantially alter circuit topology. To overcome this critical limitation, we introduce the concept of functional subgraph matching, a novel approach that identifies whether a given logic function is implicitly present within a larger circuit, irrespective of structural variations induced by synthesis or technology mapping. Specifically, we propose a two-stage multi-modal framework: (1) learning robust functional embeddings across AIG and post-mapping netlists for functional subgraph detection, and (2) identifying fuzzy boundaries using a graph segmentation approach. Evaluations on standard benchmarks (ITC99, OpenABCD, ForgeEDA) demonstrate significant performance improvements over existing structural methods, with average 93.8% accuracy in functional subgraph detection and a dice score of 91.3% in fuzzy boundary identification.
Kezhi Li, Zhengyuan Shi, Qiang Xu 0001
NeurIPS2
2025 Enhancement of UFLD by Improving Global Dependencies
abstract
Lane detection is a vital component of autonomous driving technology. It identifies the positions and boundaries of lane lines in images captured by onboard cameras, facilitating key autonomous driving functions and enhancing road safety. Deep learning-based methods dominate lane detection task, with the Ultra Fast Lane Detection (UFLD) model being one of the most well-known recent approaches. Unlike other pixel segmentation-based methods, UFLD distinguishes itself through its row-anchor detection approach, enabling rapid processing speed. However, UFLD encounters challenges related to detection accuracy in various complex scenarios. An analysis of UFLD architecture revealed that insufficient global dependencies limit its performance and generalizability in complex scenarios. To address this limitation, this paper proposed a non-local UFLD model, which strengthens the global dependencies by integrating non-local blocks. Additionally, an auxiliary Lane Intersection over Union (LIoU) loss function is introduced to refine the model’s ability to accurately detect the position and shape of the lane lines. Experimental results on the CULane dataset show that non-local UFLD surpasses original UFLD in detection accuracy across most scenarios while maintaining high detection speed.
Jiye Yang, Kezhi Li, Bijie Yang, Yuanjian Zhang 0001
VTC2025-Fall2
2025 GARNN: An interpretable graph attentive recurrent neural network for predicting blood glucose levels via multivariate time series
abstract
Accurate prediction of future blood glucose (BG) levels can effectively improve BG management for people living with type 1 or 2 diabetes, thereby reducing complications and improving quality of life. The state of the art of BG prediction has been achieved by leveraging advanced deep learning methods to model multimodal data, i.e., sensor data and self-reported event data, organized as multi-variate time series (MTS). However, these methods are mostly regarded as "black boxes" and not entirely trusted by clinicians and patients. In this paper, we propose interpretable graph attentive recurrent neural networks (GARNNs) to model MTS, explaining variable contributions via summarizing variable importance and generating feature maps by graph attention mechanisms instead of post-hoc analysis. We evaluate GARNNs on four datasets, representing diverse clinical scenarios. Upon comparison with fifteen well-established baseline methods, GARNNs not only achieve the best prediction accuracy but also provide high-quality temporal interpretability, in particular for postprandial glucose levels as a result of corresponding meal intake and insulin injection. These findings underline the potential of GARNN as a robust tool for improving diabetes care, bridging the gap between deep learning technology and real-world healthcare solutions.
Chengzhe Piao, Taiyu Zhu, Stephanie E. Baldeweg, Pantelis Georgiou, Jun Wang 0012, Kezhi Li
Neural Networks8
2025 Multi-Horizon Glucose Prediction Across Populations With Deep Domain Generalization
abstract
Real-time continuous glucose monitoring (CGM), augmented with accurate glucose prediction, offers an effective strategy for maintaining blood glucose levels within a therapeutically appropriate range. This is particularly crucial for individuals with type 1 diabetes (T1D) who require long-term self-management. However, with extensive glycemic variability, developing a prediction algorithm applicable across diverse populations remains a significant challenge. Leveraging meta-learning for domain generalization, we propose GPFormer, a Transformer-based zero-shot learning method designed for multi-horizon glucose prediction. We developed GPFormer on the REPLACE-BG dataset, comprising 226 participants with T1D, and proceeded to evaluate its performance using three external clinical datasets with CGM data. These included the OhioT1DM dataset, a publicly available dataset including 12 T1D participants, as well as two proprietary datasets. The first proprietary dataset included 22 participants, while the second contained 45 participants, encompassing a diverse group with T1D, type 2 diabetes, and those without diabetes, including patients admitted to hospitals. These four datasets include both outpatient and inpatient settings, various intervention strategies, and demographic variability, which effectively reflect real-world scenarios of CGM usage. When compared with a group of machine learning baseline methods, GPFormer consistently demonstrated superior performance and achieved the lowest root mean square error for all the evaluated datasets up to a prediction horizon of two hours. These experimental results highlight the effectiveness and generalizability of the proposed model across a variety of populations, demonstrating its substantial potential to enhance glucose management in a wide range of practical clinical settings.
Taiyu Zhu, Ioannis Afentakis, Kezhi Li, Ryan Armiger, Neil Hill, Nick Oliver, Pantelis Georgiou
IEEE J. Biomed. Health Informatics3
2025 Game-Theoretic Incentive Mechanism for Blockchain-Based Federated Learning
abstract
Blockchain-based federated learning (BFL) has gained attention for its potential to establish decentralized trust. While existing research primarily focuses on personalized frameworks for various applications, essential aspects including incentive mechanisms—critical for ensuring stable system operation—remain under-explored. To bridge this gap, we propose a game-theoretic incentive mechanism designed to foster active participation in BFL tasks. Specifically, we model a BFL system comprising a model owner (MO), i.e., task publisher, multiple miners, and training terminals, framing their interactions through two-tier Stackelberg games. In the first-tier game, the MO designs reward strategies to incentivize training terminals to contribute more data, enhancing model accuracy. The second-tier game introduces a multi-leader multi-follower Stackelberg game, enabling miners to set model packaging prices based on competitors' strategies and anticipated user behavior. By deriving the Stackelberg equilibrium, we identify optimal strategies for all participants, leading to an incentive mechanism balancing individual interests with overall performance. Compared to its benchmarks, our incentive mechanism offers 5.8% and 53.4% higher utilities in the two games compared to its alternatives, accelerating convergence and improving accuracy.
Wenzheng Tang, Erwu Liu, Wei Ni 0001, Xinyu Qu, Butian Huang, Kezhi Li, Dusit Niyato, Abbas Jamalipour
IEEE Trans. Mob. Comput.6
2023 Edge-Based Temporal Fusion Transformer for Multi-Horizon Blood Glucose Prediction
abstract
Deep learning models have achieved the state of the art in blood glucose (BG) prediction, which has been shown to improve type 1 diabetes (T1D) management. However, most existing models can only provide single-horizon prediction and face a variety of real-world challenges, such as lacking hardware implementation and interpretability. In this work, we introduce a new deep learning framework, the edge-based temporal fusion Transformer (E-TFT), for multi-horizon BG prediction, and implement the trained model on a customized wristband with a system on a chip (Nordic nRF52832) for edge computing. E-TFT employs a self-attention mechanism to extract long-term temporal dependencies and enables post-hoc explanation for feature selection. On a clinical dataset with 12 T1D subjects, it achieved a mean root mean square error of 19.09 ± 2.47 mg/dL and 32.31 ± 3.79 mg/dL for 30 and 60-minute prediction horizons, respectively, and outperformed all the considered baseline methods, such as N-BEATS and N-HiTS. The proposed model is effective for multi-horizon BG prediction and can be deployed on wearable devices to enhance T1D management in clinical settings.
Taiyu Zhu, Junming Zeng, Kezhi Li, Pantelis Georgiou
ISCAS5
2023 IoMT-Enabled Real-Time Blood Glucose Prediction With Deep Learning and Edge Computing
abstract
Blood glucose (BG) prediction is essential to the success of glycemic control in type 1 diabetes (T1D) management. Empowered by the recent development of the Internet of Medical Things (IoMT), continuous glucose monitoring (CGM) and deep learning technologies have been demonstrated to achieve the state of the art in BG prediction. However, it is challenging to implement such algorithms in actual clinical settings to provide persistent decision support due to the high demand for computational resources, while smartphone-based implementations are limited by short battery life and require users to carry the device. In this work, we propose a new deep learning model using an attention-based evidential recurrent neural network and design an IoMT-enabled wearable device to implement the embedded model, which comprises a low-cost and low-power system on a chip to perform Bluetooth connectivity and edge computing for real-time BG prediction and predictive hypoglycemia detection. In addition, we developed a smartphone app to visualize BG trajectories and predictions, and desktop and cloud platforms to backup data and fine-tune models. The embedded model was evaluated on three clinical data sets including 47 T1D subjects. The proposed model achieved superior performance of root mean square error (RMSE), mean absolute error, and glucose-specific RMSE, and obtained the best accuracy for hypoglycemia detection when compared with a group of machine learning baseline methods. Moreover, we performed hardware-in-the-loop in silico trials with ten virtual T1D adults to test the whole IoMT system with predictive low-glucose management, which significantly reduced hypoglycemia and improved BG control.
Taiyu Zhu, John Daniels, Pau Herrero, Kezhi Li, Pantelis Georgiou
IEEE Internet Things J.5
2023 Offline Deep Reinforcement Learning and Off-Policy Evaluation for Personalized Basal Insulin Control in Type 1 Diabetes
abstract
Recent advancements in hybrid closed-loop systems, also known as the artificial pancreas (AP), have been shown to optimize glucose control and reduce the self-management burdens for people living with type 1 diabetes (T1D). AP systems can adjust the basal infusion rates of insulin pumps, facilitated by real-time communication with continuous glucose monitoring. Deep reinforcement learning (DRL) has introduced new paradigms of basal insulin control algorithms. However, all the existing DRL-based AP controllers require extensive random online interactions between the agent and environment. While this can be validated in T1D simulators, it becomes impractical in real-world clinical settings. To this end, we propose an offline DRL framework that can develop and validate models for basal insulin control entirely offline. It comprises a DRL model based on the twin delayed deep deterministic policy gradient and behavior cloning, as well as off-policy evaluation (OPE) using fitted Q evaluation. We evaluated the proposed framework on an in silico dataset generated by the UVA/Padova T1D simulator, and the OhioT1DM dataset, a real clinical dataset. The performance on the in silico dataset shows that the offline DRL algorithm significantly increased time in range while reducing time below range and time above range for both adult and adolescent groups. Then, we used the OPE to estimate model performance on the clinical dataset, where a notable increase in policy values was observed for each subject. The results demonstrate that the proposed framework is a viable and safe method for improving personalized basal insulin control in T1D.
Taiyu Zhu, Kezhi Li, Pantelis Georgiou
IEEE J. Biomed. Health Informatics2
2023 GluGAN: Generating Personalized Glucose Time Series Using Generative Adversarial Networks
abstract
Time series data generated by continuous glucose monitoring sensors offer unparalleled opportunities for developing data-driven approaches, especially deep learning-based models, in diabetes management. Although these approaches have achieved state-of-the-art performance in various fields such as glucose prediction in type 1 diabetes (T1D), challenges remain in the acquisition of large-scale individual data for personalized modeling due to the elevated cost of clinical trials and data privacy regulations. In this work, we introduce GluGAN, a framework specifically designed for generating personalized glucose time series based on generative adversarial networks (GANs). Employing recurrent neural network (RNN) modules, the proposed framework uses a combination of unsupervised and supervised training to learn temporal dynamics in latent spaces. Aiming to assess the quality of synthetic data, we apply clinical metrics, distance scores, and discriminative and predictive scores computed by post-hoc RNNs in evaluation. Across three clinical datasets with 47 T1D subjects (including one publicly available and two proprietary datasets), GluGAN achieved better performance for all the considered metrics when compared with four baseline GAN models. The performance of data augmentation is evaluated by three machine learning-based glucose predictors. Using the training sets augmented by GluGAN significantly reduced the root mean square error for the predictors over 30 and 60-minute horizons. The results suggest that GluGAN is an effective method in generating high-quality synthetic glucose time series and has the potential to be used for evaluating the effectiveness of automated insulin delivery algorithms and as a digital twin to substitute for pre-clinical trials.
Taiyu Zhu, Kezhi Li, Pau Herrero, Pantelis Georgiou
IEEE J. Biomed. Health Informatics2
2022 3D Compressed Spectrum Mapping With Sampling Locations Optimization in Spectrum-Heterogeneous Environment
abstract
Spectrum mapping has emerged as an important problem in wireless communications, which generates a spectrum map for the spectrum resource analysis and management. Given the constrained transceiver volume and the limited energy consumption, how to effectively reconstruct the spectrum situation by the limited sampling data is a pressing challenge for spectrum mapping. In this paper, by exploiting the sparse nature of spectrum situation, we firstly attempt to solve the three-dimensional (3D) compressed spectrum mapping problem in the way of compressed sensing. Then, we develop a quadrature and right-triangular (QR) pivoting based measurement matrix optimization algorithm. By iteratively selecting new dominant sampling locations, it promotes the recovery accuracy compared to random measurement. After that, we propose a 3D spatial subspace based orthogonal matching pursuit (OMP) algorithm to recover spectrum situation for 3D compressed spectrum mapping. Finally, simulations are presented to show the comparisons in terms of localization, source signal strength recovery, recovery success rate and situation recovery. Results show our proposed 3D spectrum mapping scheme not only effectively reduces the sampling number, but also achieves a high level of spectrum mapping accuracy.
Zheng Wang 0013, Guoru Ding, Kezhi Li, Qihui Wu 0001
IEEE Trans. Wirel. Commun.4
2021 Blood Glucose Prediction in Type 1 Diabetes Using Deep Learning on the Edge
abstract
Real-time blood glucose (BG) prediction can enhance decision support systems for insulin dosing such as bolus calculators and closed-loop systems for insulin delivery. Deep learning has been proven to achieve state-of-the-art performance in BG prediction. However, it is usually seen as a very computationally expensive approach, hence difficult to implement in wearable medical devices such as transmitters in continuous glucose monitoring (CGM) systems. In this work, we introduce a novel deep learning framework to predict BG levels with the edge inference on a microcontroller unit embedded in a low- power system. By using glucose measurements from a CGM sensor and a recurrent neural network that builds on long-short term memory, the personalized models achieves state-of-the-art performance on a clinical data set obtained from 12 subjects with T1D. In particular, the proposed method achieves an average root mean square error of 19.10 ± 2.04 for a 30-minute prediction horizon (PH) and 32.61 ± 3.45 for a 60-minute PH with high clinical accuracy. Notably, the framework has been optimized to achieve a minimum use of hardware resources (34KB FLASH and 1KB SRAM) as well as an execution time of 22 ms for low power operations (8 μW). The presented system has the potential to be implemented in wearable medical devices for diabetes care (CGM and insulin pumps) and to be integrated within an Internet of Things platform.
Taiyu Zhu, Kezhi Li, Junming Zeng, Pau Herrero, Pantelis Georgiou
ISCAS3
2021 On-line quantum state estimation using continuous weak measurement and compressed sensing
Shuang Cong, Yaru Tang, Sajede Harraz, Kezhi Li, Jingbei Yang
Sci. China Inf. Sci.4
2021 Ensemble learning for poor prognosis predictions: A case study on SARS-CoV-2
abstract
OBJECTIVE: Risk prediction models are widely used to inform evidence-based clinical decision making. However, few models developed from single cohorts can perform consistently well at population level where diverse prognoses exist (such as the SARS-CoV-2 [severe acute respiratory syndrome coronavirus 2] pandemic). This study aims at tackling this challenge by synergizing prediction models from the literature using ensemble learning. MATERIALS AND METHODS: In this study, we selected and reimplemented 7 prediction models for COVID-19 (coronavirus disease 2019) that were derived from diverse cohorts and used different implementation techniques. A novel ensemble learning framework was proposed to synergize them for realizing personalized predictions for individual patients. Four diverse international cohorts (2 from the United Kingdom and 2 from China; N = 5394) were used to validate all 8 models on discrimination, calibration, and clinical usefulness. RESULTS: Results showed that individual prediction models could perform well on some cohorts while poorly on others. Conversely, the ensemble model achieved the best performances consistently on all metrics quantifying discrimination, calibration, and clinical usefulness. Performance disparities were observed in cohorts from the 2 countries: all models achieved better performances on the China cohorts. DISCUSSION: When individual models were learned from complementary cohorts, the synergized model had the potential to achieve better performances than any individual model. Results indicate that blood parameters and physiological measurements might have better predictive powers when collected early, which remains to be confirmed by further studies. CONCLUSIONS: Combining a diverse set of individual prediction models, the ensemble method can synergize a robust and well-performing model by choosing the most competent ones for individual patients.
Honghan Wu, Andreas Karwath, Zina M. Ibrahim, Kevin Dhaliwal, Daniel Bean, Victor Roth Cardoso, Kezhi Li, James T. Teo, Amitava Banerjee, Fang Gao-Smith, Tony Whitehouse, Tonny Veenith, Georgios V. Gkoutos, Richard J. B. Dobson, Bruce Guthrie
J. Am. Medical Informatics Assoc.12
2021 An efficient online estimation algorithm with measurement noise for time-varying quantum states
Kun Zhang 0028, Shuang Cong, Kezhi Li
Signal Process.3
2021 Basal Glucose Control in Type 1 Diabetes Using Deep Reinforcement Learning: An In Silico Validation
abstract
People with Type 1 diabetes (T1D) require regular exogenous infusion of insulin to maintain their blood glucose concentration in a therapeutically adequate target range. Although the artificial pancreas and continuous glucose monitoring have been proven to be effective in achieving closed-loop control, significant challenges still remain due to the high complexity of glucose dynamics and limitations in the technology. In this work, we propose a novel deep reinforcement learning model for single-hormone (insulin) and dual-hormone (insulin and glucagon) delivery. In particular, the delivery strategies are developed by double Q-learning with dilated recurrent neural networks. For designing and testing purposes, the FDA-accepted UVA/Padova Type 1 simulator was employed. First, we performed long-term generalized training to obtain a population model. Then, this model was personalized with a small data-set of subject-specific data. In silico results show that the single and dual-hormone delivery strategies achieve good glucose control when compared to a standard basal-bolus therapy with low-glucose insulin suspension. Specifically, in the adult cohort (n = 10), percentage time in target range 70, 180 mg/dL improved from 77.6% to 80.9% with single-hormone control, and to 85.6% with dual-hormone control. In the adolescent cohort (n = 10), percentage time in target range improved from 55.5% to [Formula: see text] with single-hormone control, and to 78.8% with dual-hormone control. In all scenarios, a significant decrease in hypoglycemia was observed. These results show that the use of deep reinforcement learning is a viable approach for closed-loop glucose control in T1D.
Taiyu Zhu, Kezhi Li, Pau Herrero, Pantelis Georgiou
IEEE J. Biomed. Health Informatics2
2021 Deep Learning for Diabetes: A Systematic Review
abstract
Diabetes is a chronic metabolic disorder that affects an estimated 463 million people worldwide. Aiming to improve the treatment of people with diabetes, digital health has been widely adopted in recent years and generated a huge amount of data that could be used for further management of this chronic disease. Taking advantage of this, approaches that use artificial intelligence and specifically deep learning, an emerging type of machine learning, have been widely adopted with promising results. In this paper, we present a comprehensive review of the applications of deep learning within the field of diabetes. We conducted a systematic literature search and identified three main areas that use this approach: diagnosis of diabetes, glucose management, and diagnosis of diabetes-related complications. The search resulted in the selection of 40 original research articles, of which we have summarized the key information about the employed learning models, development process, main outcomes, and baseline methods for performance evaluation. Among the analyzed literature, it is to be noted that various deep learning techniques and frameworks have achieved state-of-the-art performance in many diabetes-related tasks by outperforming conventional machine learning approaches. Meanwhile, we identify some limitations in the current literature, such as a lack of data availability and model interpretability. The rapid developments in deep learning and the increase in available data offer the possibility to meet these challenges in the near future and allow the widespread deployment of this technology in clinical settings.
Taiyu Zhu, Kezhi Li, Pau Herrero, Pantelis Georgiou
IEEE J. Biomed. Health Informatics2
2020 Dynamic Markov Chain Monte Carlo-Based Spectrum Sensing
abstract
In this letter, a random sampling strategy is proposed for the non-cooperative spectrum sensing to improve its performance and efficiency in cognitive radio (CR) networks. The proposed refined Metropolis-Hastings (RMH) algorithm generates the desired channel sequence for fine sensing by sampling from the approximated channel availability distributions in an Markov chain Monte Carlo (MCMC) way. The proposal distribution during the sampling is fully exploited and the convergence of the Markov chain is studied in detail, which theoretically demonstrate the superiorities of the proposed RMH sampling algorithm in both sensing performance and efficiency.
Zheng Wang 0013, Ling Liu 0003, Kezhi Li
IEEE Signal Process. Lett.3
2020 Convolutional Recurrent Neural Networks for Glucose Prediction
abstract
Control of blood glucose is essential for diabetes management. Current digital therapeutic approaches for subjects with type 1 diabetes mellitus such as the artificial pancreas and insulin bolus calculators leverage machine learning techniques for predicting subcutaneous glucose for improved control. Deep learning has recently been applied in healthcare and medical research to achieve state-of-the-art results in a range of tasks including disease diagnosis, and patient state prediction among others. In this paper, we present a deep learning model that is capable of forecasting glucose levels with leading accuracy for simulated patient cases (root-mean-square error (RMSE) = 9.38 ± 0.71 [mg/dL] over a 30-min horizon, RMSE = 18.87 ± 2.25 [mg/dL] over a 60-min horizon) and real patient cases (RMSE = 21.07 ± 2.35 [mg/dL] for 30 min, RMSE = 33.27 ± 4.79% for 60 min). In addition, the model provides competitive performance in providing effective prediction horizon ([Formula: see text]) with minimal time lag both in a simulated patient dataset ([Formula: see text] = 29.0 ± 0.7 for 30 min and [Formula: see text] = 49.8 ± 2.9 for 60 min) and in a real patient dataset ([Formula: see text] = 19.3 ± 3.1 for 30 min and [Formula: see text] = 29.3 ± 9.4 for 60 min). This approach is evaluated on a dataset of ten simulated cases generated from the UVA/Padova simulator and a clinical dataset of ten real cases each containing glucose readings, insulin bolus, and meal (carbohydrate) data. Performance of the recurrent convolutional neural network is benchmarked against four algorithms. The proposed algorithm is implemented on an Android mobile phone, with an execution time of 6 ms on a phone compared to an execution time of 780 ms on a laptop.
Kezhi Li, John Daniels, Pau Herrero, Pantelis Georgiou
IEEE J. Biomed. Health Informatics1
2020 GluNet: A Deep Learning Framework for Accurate Glucose Forecasting
abstract
For people with Type 1 diabetes (T1D), forecasting of blood glucose (BG) can be used to effectively avoid hyperglycemia, hypoglycemia and associated complications. The latest continuous glucose monitoring (CGM) technology allows people to observe glucose in real-time. However, an accurate glucose forecast remains a challenge. In this work, we introduce GluNet, a framework that leverages on a personalized deep neural network to predict the probabilistic distribution of short-term (30-60 minutes) future CGM measurements for subjects with T1D based on their historical data including glucose measurements, meal information, insulin doses, and other factors. It adopts the latest deep learning techniques consisting of four components: data pre-processing, label transform/recover, multi-layers of dilated convolution neural network (CNN), and post-processing. The method is evaluated in-silico for both adult and adolescent subjects. The results show significant improvements over existing methods in the literature through a comprehensive comparison in terms of root mean square error (RMSE) ([Formula: see text] mg/dL) with short time lag ([Formula: see text] minutes) for prediction horizons (PH) = 30 mins (minutes), and RMSE ([Formula: see text] mg/dL) with time lag ([Formula: see text] mins) for PH = 60 mins for virtual adult subjects. In addition, GluNet is also tested on two clinical data sets. Results show that it achieves an RMSE ([Formula: see text] mg/dL) with time lag ([Formula: see text] mins) for PH = 30 mins and an RMSE ([Formula: see text] mg/dL) with time lag ([Formula: see text] mins) for PH = 60 mins. These are the best reported results for glucose forecasting when compared with other methods including the neural network for predicting glucose (NNPG), the support vector regression (SVR), the latent variable with exogenous input (LVX), and the auto regression with exogenous input (ARX) algorithm.
Kezhi Li, Taiyu Zhu, Pau Herrero, Pantelis Georgiou
IEEE J. Biomed. Health Informatics1
2019 An Efficient and Fast Quantum State Estimator With Sparse Disturbance
abstract
A pure or nearly pure quantum state can be described as a low-rank density matrix, which is a positive semidefinite and unit-trace Hermitian. We consider the problem of recovering such a low-rank density matrix contaminated by sparse components, from a small set of linear measurements. This quantum state estimation task can be formulated as a robust principal component analysis (RPCA) problem subject to positive semidefinite and unit-trace Hermitian constraints. We propose an efficient and fast inexact alternating direction method of multipliers (I-ADMM), in which the subproblems are solved inexactly and hence have closed-form solutions. We prove global convergence of the proposed I-ADMM, and the theoretical result provides a guideline for parameter setting. Numerical experiments show that the proposed I-ADMM can recover state density matrices of 5 qubits on a laptop in 0.69 s, with 6 × 10-4accuracy (99.38% fidelity) using 30% compressive sensing measurements, which outperforms existing algorithms.
Shuang Cong, Qing Ling 0001, Kezhi Li
IEEE Trans. Cybern.4
2019 Consensus-Based Cooperative Control for Multi-Platoon Under the Connected Vehicles Environment
abstract
This paper investigates formation control protocols for autonomous vehicular strings with vehicle-to-vehicle (V2V) communication connections. To this end, a four-layer framework is first proposed to illustrate the cooperative mechanism within and across strings. Then, cooperative control protocols are designed based on vehicle role, i.e., leader or follower, in vehicular multi-string. In particular, longitudinal controllers are designed for single string and multiple strings by incorporating inter-vehicle gap and velocity difference of the follower vehicle with respect to the preceding vehicle and the lead vehicle. In addition, lateral controllers are proposed for single string and multiple strings based on the artificial function method. The proposed protocols ensure that follower vehicles asymptotically track the leader within each string, while different vehicular strings can form a desired platoon pattern. The study further analyzes the stability and consensus of the proposed control protocols using the Routh-Hurwitz stable criterion and the Lyapunov technique. Numerical experiments are performed for two cooperative mechanisms-parallel and serial. Results from numerical experiments illustrate the effects of the proposed control protocols on road throughput and demonstrate their effectiveness for position and velocity consensuses.
Yongfu Li 0001, Chuancong Tang, Kezhi Li, Xiaozheng He 0001, Srinivas Peeta
IEEE Trans. Intell. Transp. Syst.3
2018 Robust Visual Tracking Via Adaptive Structure-Enhanced Particle Filter
abstract
An effective representation model plays an important role in the visual tracking, as it relates to how the most meaningful information are recognized and understood in the dictionary space. However, it is difficult to know the structure and the weights of tracking objects in advance. In addition, how to balance the adaption and robustness in tracking algorithms remains a nontrivial problem. In this paper, we propose a robust visual tracker based on adaptive structure-enhanced regularizations, and achieve a sequential Monte Carlo searching via simplified particle filters. Specifically, multiple atomic norms are incorporated in the cost function in the target dictionary space, and their weights are updated adaptively during the detection step between each frame. Sparse and low-rank structures as well as other atomic norms enhance the robustness by capturing various features meanwhile ruling out outliers, and the velocity of moving objects are considered accordingly in the probabilistic distribution of particles. Moreover, the algorithm has been accelerated by adopting prefilters as classifiers for target particles using pixel variances in colours and intensities, which ensures a real-time tracking in practice. On challenging tracking datasets, the proposed approach show advantages in tracking fast-moving objects and favorable performance against other 10 state-of-the-art visual trackers.
Nan Song, Kezhi Li, Wei Chen 0016
ICASSP2
2017 Efficient reconstruction of density matrices for high dimensional quantum state tomography
Kezhi Li, Shuang Cong, Haitao Wang 0004
Signal Process.2
2016 Piecewise sparse signal recovery via piecewise orthogonal matching pursuit
abstract
In this paper, we consider the recovery of piecewise sparse signals from incomplete noisy measurements via a greedy algorithm. Here piecewise sparse means that the signal can be approximated in certain domain with known number of nonzero entries in each piece/segment. This paper makes a two-fold contribution to this problem: 1) formulating a piecewise sparse model in the framework of compressed sensing and providing the theoretical analysis of corresponding sensing matrices; 2) developing a greedy algorithm called piecewise orthogonal matching pursuit (POMP) for the recovery of piecewise sparse signals. Experimental simulations verify the effectiveness of the proposed algorithms.
Kezhi Li, Cristian R. Rojas, Tao Yang 0003, Håkan Hjalmarsson, Karl Henrik Johansson, Shuang Cong
ICASSP1
2016 Alternating strategies with internal ADMM for low-rank matrix reconstruction
Kezhi Li, Martin Sundin, Cristian R. Rojas, Saikat Chatterjee, Magnus Jansson
Signal Process.1
2015 State of the art and prospects of structured sensing matrices in compressed sensing
Kezhi Li, Shuang Cong
Frontiers Comput. Sci.1
2012 Golay meets Hadamard: Golay-paired Hadamard matrices for fast compressed sensing
abstract
This paper introduces Golay-paired Hadamard matrices for fast compressed sensing of sparse signals in the time or spectral domain. These sampling operators feature low-memory requirement, hardware-friendly implementation and fast computation in reconstruction. We show that they require a nearly optimal number of measurements for faithful reconstruction of a sparse signal in the time or frequency domain. Simulation results demonstrate that the proposed sensing matrices offer a reconstruction performance similar to that of fully random matrices.
Lu Gan 0002, Kezhi Li, Cong Ling 0001
ITW2
2011 Deterministic compressed-sensing matrices: Where Toeplitz meets Golay
abstract
Recently, the statistical restricted isometry property (STRIP) has been formulated to analyze the performance of deterministic sampling matrices for compressed sensing. In this paper, a class of deterministic matrices which satisfy STRIP with overwhelming probability are proposed, by taking advantage of concentration inequalities using Stein's method. These matrices, called orthogonal symmetric Toeplitz matrices (OSTM), guarantee successful recovery of all but an exponentially small fraction of K-sparse signals. Such matrices are deterministic, Toeplitz, and easy to generate. We derive the STRIP performance bound by exploiting the specific properties of OSTM, and obtain the near-optimal bound by setting the underlying sign sequence of OSTM as the Golay sequence. Simulation results show that these deterministic sensing matrices can offer reconstruction performance similar to that of random matrices.
Kezhi Li, Cong Ling 0001, Lu Gan 0002
ICASSP1