Yanfeng Li

ORCID

Publication Activity (10 Years)

Years Active: 2003-2024
Publications (10 Years): 101

Top Venues

IEEE Access

Reliab. Eng. Syst. Saf.

Multim. Tools Appl.

Biomed. Signal Process. Control.

Publications

Yanfeng Li, Hui Xie
Base on the Cancer Genome Atlas prognostic for grade II and III glioma. CVDL (2024)
Xian Zhang, Yanfeng Li, Hanyue Zhang
Forest nighttime image enhancement based on improved SCI light estimation and reflection optimization. IET Image Process. 18 (4) (2024)
Zhao Peng, Yanfeng Li, Jie Zhang
Joint optimization of train timetable and passing facility: A capacity allocation strategy. Expert Syst. Appl. 252 (2024)
Yanfeng Li, Jincheng Bian, Rencheng Song
Video-based deception detection using wrapper-based feature selection. CIVEMSA (2024)
Xu Yao, Houjin Chen, Yanfeng Li, Jia Sun, Jiayu Wei
Lightweight image super-resolution based on stepwise feedback mechanism and multi-feature maps fusion. Multim. Syst. 30 (1) (2024)
Haoze Chen, Zhijie Zhang, Wuliang Yin, Guangyu Zhou, Luxiang Wang, Yanfeng Li, Chenyang Zhao, Chao Wang
Shape characterization and depth recognition of metal cracks based on laser infrared thermography and machine learning. Expert Syst. Appl. 238 (Part E) (2024)
Pan Pan, Houjin Chen, Yanfeng Li, Jiaxin Li, Zhanyi Cheng, Shu Wang
Dual teacher model for semi-supervised ABUS tumor segmentation. Biomed. Signal Process. Control. 87 (Part A) (2024)
Pan Gao, Miao Lu, Jinghua Xu, Hongming Zhang, Yanfeng Li, Jin Hu
IPECM Platform: An open-source software for greenhouse environment regulation using machine learning and optimization algorithm. Comput. Electron. Agric. 217 (2024)
Yajing Li, Zhijian Wang, Feng Li, Yanfeng Li, Xiaohong Zhang, Hui Shi, Lei Dong, Weibo Ren
An ensembled remaining useful life prediction method with data fusion and stage division. Reliab. Eng. Syst. Saf. 242 (2024)
Xiaoling Li, Houjin Chen, Yanfeng Li, Yahui Peng
Multi-focus image fusion via adaptive fractional differential and guided filtering. Multim. Tools Appl. 83 (11) (2024)
Wanru Peng, Houjin Chen, Yanfeng Li, Jia Sun
MCFR: multi-confidence contrastive learning with feature refined for unsupervised person re-identification. Vis. Comput. 40 (3) (2024)
Ke Li, Ming Tan, Dexun Xiao, Tiantian Yu, Yanfeng Li, Ji Li
Research on Road Extraction From High-Resolution Remote Sensing Images Based on Improved UNet++. IEEE Access 12 (2024)
Yunzhi Qian, Yanfeng Li, Jing Wang, Shaochen Wang, Rongkun Wang, Fan Meng, Chao Wang
The Graphical Programming Software for the High-Throughput Liquid Handling Workstation. ICISE (2023)
Jia Sun, Yanfeng Li, Houjin Chen, Yahui Peng, Jinlei Zhu
Visible-infrared person re-identification model based on feature consistency and modal indistinguishability. Mach. Vis. Appl. 34 (1) (2023)
Ting Xiang, Yanfeng Li, Wai Yuen Szeto
The daily routing and scheduling problem of home health care: based on costs and participants' preference satisfaction. Int. Trans. Oper. Res. 30 (1) (2023)
Jie Zhang, Yanfeng Li
Collaborative vehicle-drone distribution network optimization for perishable products in the epidemic situation. Comput. Oper. Res. 149 (2023)
Yanfeng Li
Motion Planning for Dynamic Scenario Vehicles in Autonomous-Driving Simulations. IEEE Access 11 (2023)
Yulun Zhang, Kai Zhang, Zheng Chen, Yawei Li, Radu Timofte, Junpei Zhang, Kexin Zhang, Rui Peng, Yanbiao Ma, Licheng Jia, Huaibo Huang, Xiaoqiang Zhou, Yuang Ai, Ran He, Yajun Qiu, Qiang Zhu, Pengfei Li, Qianhui Li, Shuyuan Zhu, Dafeng Zhang, Jia Li, Fan Wang, Chunmiao Li, TaeHyung Kim, Jungkeong Kil, Eon Kim, Yeonseung Yu, Beomyeol Lee, Subin Lee, Seokjae Lim, Somi Chae, Heungjun Choi, Zhi-Kai Huang, YiChung Chen, Yuan-Chun Chiang, Hao-Hsiang Yang, Wei-Ting Chen, Hua-En Chang, I-Hsiang Chen, Chia-Hsuan Hsieh, Sy-Yen Kuo, Ui-Jin Choi, Marcos V. Conde, Sunder Ali Khowaja, Jiseok Yoon, Ik Hyun Lee, Garas Gendy, Nabil Sabor, Jingchao Hou, Guanghui He, Zhao Zhang, Baiang Li, Huan Zheng, Suiyi Zhao, Yangcheng Gao, Yanyan Wei, Jiahuan Ren, Jiayu Wei, Yanfeng Li, Jia Sun, Zhanyi Cheng, Zhiyuan Li, Xu Yao, Xinyi Wang, Danxu Li, Xuan Cui, Jun Cao, Cheng Li, Jianbin Zheng, Anjali Sarvaiya, Kalpesh Prajapati, Ratnadeep Patra, Pragnesh Barik, Chaitanya Rathod, Kishor P. Upla, Kiran B. Raja, Raghavendra Ramachandra, Christoph Busch
NTIRE 2023 Challenge on Image Super-Resolution (×4): Methods and Results. CVPR Workshops (2023)
Ting Xiang, Yanfeng Li, Wai Yuen Szeto
Multi-period scheduling problem of combination of home health care and outpatient services: based on Chinese family doctor contract services. Comput. Ind. Eng. 182 (2023)
Yanfeng Li, Xiaodi Zhu, Jia Sun, Houjin Chen, Zhiyuan Li
Unsupervised person re-identification based on high-quality pseudo labels. Appl. Intell. 53 (12) (2023)
Li Yuan, Xinyi Liu, Jiannan Yu, Yanfeng Li
A full-set tooth segmentation model based on improved PointNet++. Vis. Intell. 1 (1) (2023)
Yanfeng Li, Hongliang Zhang, Xiao Jing, Aiguang Zhao
An Improved Modulation Method for Parallel Three-Level Rectifiers With Circulating Current Mitigation. IEEE Access 11 (2023)
Pei Zhou, Houjin Chen, Yanfeng Li, Yahui Peng
Tumor Segmentation in Weakly Paired Anatomical and Functional MRI images with Multimodal Information Fusion. ICBIP (2023)
Yanfeng Li, Xijiong Xie
Deep multi-view fuzzy k-means with weight allocation and entropy regularization. Appl. Intell. 53 (24) (2023)
Yuntian Ta, Yanfeng Li, Wenan Cai, Qianqian Zhang, Zhijian Wang, Lei Dong, Wenhua Du
Adaptive staged remaining useful life prediction method based on multi-sensor and multi-feature fusion. Reliab. Eng. Syst. Saf. 231 (2023)
Han Wang, Ke Chen, Yanfeng Li
Automatic Detection Method for Black Smoke Vehicles Considering Motion Shadows. Sensors 23 (19) (2023)
Xijiong Xie, Yanfeng Li, Shiliang Sun
Deep multi-view multiclass twin support vector machines. Inf. Fusion 91 (2023)
Ningning Yang, Zhijian Wang, Wenan Cai, Yanfeng Li
Data Regeneration Based on Multiple Degradation Processes for Remaining Useful Life Estimation. Reliab. Eng. Syst. Saf. 229 (2023)
Xinyi Liu, Li Yuan, Chunyu Jiang, JiannanYu, Yanfeng Li
Human Identification Using Tooth Based on PointNet++. CCBR (2023)
Linlin Zhang, Yanfeng Li, Houjin Chen, Wen Wu, Kuan Chen, Shaokang Wang
Anchor-free YOLOv3 for mass detection in mammogram. Expert Syst. Appl. 191 (2022)
Zhiqiang Zeng, Rui Zhang, Wenan Cai, Yanfeng Li
Application of Local Histogram Clipping Equalization Image Enhancement in Bearing Fault Diagnosis. IEEE Access 10 (2022)
Jia Sun, Yanfeng Li, Houjin Chen, Xiaodi Zhu, Yahui Peng, Yanfeng Peng
Inter-cluster and intra-cluster joint optimization for unsupervised cross-domain person re-identification. Knowl. Based Syst. 251 (2022)
Jiaxin Li, Houjin Chen, Yanfeng Li, Yahui Peng, Jia Sun, Pan Pan
Cross-modality synthesis aiding lung tumor segmentation on multi-modal MRI images. Biomed. Signal Process. Control. 76 (2022)
Chen Wang, Liang Peng, Zeng-Guang Hou, Yanfeng Li, Ying Tan, Honglin Hao
A Hierarchical Architecture for Multisymptom Assessment of Early Parkinson's Disease via Wearable Sensors. IEEE Trans. Cogn. Dev. Syst. 14 (4) (2022)
Yanfeng Li, Man Xu, Ming Fang
Cloud Classification Method Based on Convolutional Encoder and Multimodal Feature Fusion. SOLI (2022)
Zhijian Wang, Jie Cui, Wenan Cai, Yanfeng Li
Partial Transfer Learning of Multidiscriminator Deep Weighted Adversarial Network in Cross-Machine Fault Diagnosis. IEEE Trans. Instrum. Meas. 71 (2022)
Xinxin He, Zhijian Wang, Yanfeng Li, Svetlana Khazhina, Wenhua Du, Junyuan Wang, Wenzhao Wang
Joint decision-making of parallel machine scheduling restricted in job-machine release time and preventive maintenance with remaining useful life constraints. Reliab. Eng. Syst. Saf. 222 (2022)
Yan Shi, Zhenzhou Lu, Hong-Zhong Huang, Yu Liu, Yanfeng Li, Enrico Zio, Yicheng Zhou
A new preventive maintenance strategy optimization model considering lifecycle safety. Reliab. Eng. Syst. Saf. 221 (2022)
Rui Zhang, Zhiqiang Zeng, Yanfeng Li, Jiahao Liu, Zhijian Wang
Research on Remaining Useful Life Prediction Method of Rolling Bearing Based on Digital Twin. Entropy 24 (11) (2022)
Xiaoling Li, Houjin Chen, Yanfeng Li, Yahui Peng
MAFusion: Multiscale Attention Network for Infrared and Visible Image Fusion. IEEE Trans. Instrum. Meas. 71 (2022)
Yue Zhou, Houjin Chen, Yanfeng Li, Xuyang Cao, Shu Wang, Dinggang Shen
Cross-Model Attention-Guided Tumor Segmentation for 3D Automated Breast Ultrasound (ABUS) Images. IEEE J. Biomed. Health Informatics 26 (1) (2022)
Xuyang Cao, Houjin Chen, Yanfeng Li, Yahui Peng, Yue Zhou, Lin Cheng, Tianming Liu, Dinggang Shen
Auto-DenseUNet: Searchable neural network architecture for mass segmentation in 3D automated breast ultrasound. Medical Image Anal. 82 (2022)
Zhanyi Cheng, Yanfeng Li, Houjin Chen, Zilu Zhang, Pan Pan, Lin Cheng
DSGMFFN: Deepest semantically guided multi-scale feature fusion network for automated lesion segmentation in ABUS images. Comput. Methods Programs Biomed. 221 (2022)
Naxin Cai, Houjin Chen, Yanfeng Li, Yahui Peng, Jiaxin Li
Adaptive Weighting Landmark-Based Group-Wise Registration on Lung DCE-MRI Images. IEEE Trans. Medical Imaging 40 (2) (2021)
Yanfeng Li, Zhijian Wang, Tiansheng Zhao, Yuan Zhao
Novel Adaptive Sparse-Spike Deconvolution Bearing Fault Detection Method Based on Curvelet Transform. IEEE Access 9 (2021)
Zhenyu Zhang, Huirong Zhang, Lixin Zhou, Yanfeng Li
Analyzing the Coevolution of Mobile Application Diffusion and Social Network: A Multi-Agent Model. Entropy 23 (5) (2021)
Yanfeng Li, Zhijian Wang, Tiansheng Zhao, Wanqing Song
An Improved Multi-Ridge Extraction Method Based on Differential Synchro-Squeezing Wavelet Transform. IEEE Access 9 (2021)
Jingwei Wu, Meng Liu, Xueqian Zhang, Yanfeng Li, Huabin Wang, Jiaguang Han
Terahertz Plasmon-Induced Transparency Effect in Parallel Plate Waveguide. IEEE Access 9 (2021)
Jia Sun, Yanfeng Li, Houjin Chen, Yahui Peng, Xiaodi Zhu, Jinlei Zhu
Visible-infrared cross-modality person re-identification based on whole-individual training. Neurocomputing 440 (2021)
Yanfeng Li, Bin Zhang, Jia Sun, Houjin Chen, Xiaodi Zhu, Jinlei Zhu
Person re-identification based on activation guided identity and attribute classification model. Multim. Tools Appl. 80 (10) (2021)
Yanfeng Li, Zhijian Wang, Tiansheng Zhao, Song Wanqing
Research on a Pattern Recognition Method of Cyclic GMM-FCM Based on Joint Time-Domain Features. IEEE Access 9 (2021)
Haoze Chen, Zhijie Zhang, Chenyang Zhao, Jiaqi Liu, Wuliang Yin, Yanfeng Li, Fengxiang Wang, Chao Li, Zhenyu Lin
Depth Classification of Defects Based on Neural Architecture Search. IEEE Access 9 (2021)
Xuyang Cao, Houjin Chen, Yanfeng Li, Yahui Peng, Shu Wang, Lin Cheng
Uncertainty Aware Temporal-Ensembling Model for Semi-Supervised ABUS Mass Segmentation. IEEE Trans. Medical Imaging 40 (1) (2021)
Jia Sun, Yanfeng Li, Houjin Chen, Bin Zhang, Jinlei Zhu
MEMF: Multi-level-attention embedding and multi-layer-feature fusion model for person re-identification. Pattern Recognit. 116 (2021)
Jia Sun, Yanfeng Li, Houjin Chen, Yahui Peng, Jinlei Zhu
Unsupervised Cross Domain Person Re-Identification by Multi-Loss Optimization Learning. IEEE Trans. Image Process. 30 (2021)
Zhengming Zhang, Ran Zuo, Rui Guo, Yanfeng Li, Ti Zhou, Han Xue, Cuixia Ma, Hongan Wang
Multi-scale visualization based on sketch interaction for massive surveillance video data. Pers. Ubiquitous Comput. 25 (6) (2021)
Xiaodi Zhu, Yanfeng Li, Jia Sun, Houjin Chen, Jinlei Zhu
Unsupervised domain adaptive person re-identification via camera penalty learning. Multim. Tools Appl. 80 (10) (2021)
Linlin Zhang, Yanfeng Li, Wen Wu, Houjin Chen, Yahui Peng
Salient detection network for lung nodule detection in 3D Thoracic MRI Images. Biomed. Signal Process. Control. 66 (2021)
Zilu Zhang, Yanfeng Li, Wen Wu, Houjin Chen, Lin Cheng, Shu Wang
Tumor detection using deep learning method in automated breast ultrasound. Biomed. Signal Process. Control. 68 (2021)
Xuyang Cao, Houjin Chen, Yanfeng Li, Yahui Peng, Shu Wang, Lin Cheng
Dilated densely connected U-Net with uncertainty focus loss for 3D ABUS mass segmentation. Comput. Methods Programs Biomed. 209 (2021)
Yue Zhou, Houjin Chen, Yanfeng Li, Shu Wang, Lin Cheng, Jupeng Li
3D multi-view tumor detection in automated whole breast ultrasound using deep convolutional neural network. Expert Syst. Appl. 168 (2021)
Yue Zhou, Houjin Chen, Yanfeng Li, Qin Liu, Xuanang Xu, Shu Wang, Pew-Thian Yap, Dinggang Shen
Multi-task learning for segmentation and classification of tumors in 3D automated breast ultrasound images. Medical Image Anal. 70 (2021)
Jiaxin Li, Houjin Chen, Yanfeng Li, Yahui Peng, Naxin Cai, Xuyang Cao
AMRSegNet: adaptive modality recalibration network for lung tumor segmentation on multi-modal MR images. Multim. Tools Appl. 80 (25) (2021)
Xiaodi Zhu, Yanfeng Li, Jia Sun, Houjin Chen, Jinlei Zhu
Learning with noisy labels method for unsupervised domain adaptive person re-identification. Neurocomputing 452 (2021)
Sen Liu, Yanan Hu, Xiao Zhang, Yanfeng Li, Ling Liu
Blockchain Service Provider Selection Based on an Integrated BWM-Entropy-TOPSIS Method Under an Intuitionistic Fuzzy Environment. IEEE Access 8 (2020)
Yanfeng Li, Linlin Zhang, Houjin Chen, Lin Cheng
Mass detection in mammograms by bilateral analysis using convolution neural network. Comput. Methods Programs Biomed. 195 (2020)
Jia Sun, Yanfeng Li, Houjin Chen, Jupeng Li, Feng Li
Pedestrian Detection Based on Depth Information. ICMLC (2020)
Xinhui Wang, Houjin Chen, Qi Wan, Yanfeng Li, Naxin Cai, Xinchun Li, Yahui Peng
Motion correction and noise removing in lung diffusion-weighted MRI using low-rank decomposition. Medical Biol. Eng. Comput. 58 (9) (2020)
Yanfeng Li, Zhennan Han, Zhijian Wang
Research on a Signal Separation Method Based on Vold-Kalman Filter of Improved Adaptive Instantaneous Frequency Estimation. IEEE Access 8 (2020)
Xuyang Cao, Houjin Chen, Yanfeng Li, Yahui Peng, Yue Zhou, Lin Cheng
Boundary Loss with Non-Euclidean Distance Constraint for ABUS Mass Segmentation. CISP-BMEI (2020)
Bin Zhang, Yanfeng Li, Houjin Chen, Jia Sun
Improving Person Re-identification by Mask Guiding and Part Pooling. ICMLC (2020)
Cuiru Yu, Houjin Chen, Yanfeng Li, Yahui Peng, Jupeng Li, Fan Yang
Breast cancer classification in pathological images based on hybrid features. Multim. Tools Appl. 78 (15) (2019)
Zhijie Zhang, Yanfeng Li, Hang Chen, Chenyang Zhao, Wuliang Yin
Improved Method of Excitation Signal in Transient Temperature Calibration System Based on Laser. I2MTC (2019)
Jiaxin Li, Houjin Chen, Yanfeng Li, Yahui Peng
A Novel Network Based on Densely Connected Fully Convolutional Networks for Segmentation of Lung Tumors on Multi-Modal MR Images. AIAM (2019)
Cuiru Yu, Houjin Chen, Yanfeng Li, Yahui Peng, Jupeng Li, Fan Yang
Correction to: Breast cancer classification in pathological images based on hybrid features. Multim. Tools Appl. 78 (15) (2019)
Yanfeng Li, Xiangdong Gao, Yanxi Zhang, Deyong You, Congyi Wang, Yaowu Song, Nanfeng Zhang
Detection model of invisible weld defects using magneto-optical imaging induced by rotating magnetic field. CASE (2019)
Naxin Cai, Houjin Chen, Yanfeng Li, Yahui Peng, Jupeng Li, Xinchun Li
Reducing non-realistic deformations in registration using precise and reliable landmark correspondences. Comput. Biol. Medicine 115 (2019)
Yanfeng Li, Linlin Zhang, Houjin Chen, Na Yang
Lung Nodule Detection With Deep Learning in 3D Thoracic MR Images. IEEE Access 7 (2019)
Naxin Cai, Houjin Chen, Yanfeng Li, Yahui Peng
Intrusion Detection and Tracking at Railway Crossing. AIAM (2019)
Linlin Zhang, Yanfeng Li, Houjin Chen, Lin Cheng
Mammographic Mass Detection by Bilateral Analysis Based on Convolution Neural Network. ICIP (2019)
Yu Cheng, Yanfeng Li, Qiankun Liu, Yuan Yao, Venkata Sai Vijay Kumar Pedapudi, Xiaotian Fan, Chi Su, Shengmei Shen
A Graph Based Unsupervised Feature Aggregation for Face Recognition. ICCV Workshops (2019)
Dou Quan, Xuefeng Liang, Shuang Wang, Shaowei Wei, Yanfeng Li, Ning Huyan, Licheng Jiao
AFD-Net: Aggregated Feature Difference Learning for Cross-Spectral Image Patch Matching. ICCV (2019)
Guoxun Xu, Yanfeng Li, Wai Yuen Szeto, Jun Li
A cash transportation vehicle routing problem with combinations of different cash denominations. Int. Trans. Oper. Res. 26 (6) (2019)
Shuang Wang, Yanfeng Li, Xuefeng Liang, Dou Quan, Bowu Yang, Shaowei Wei, Licheng Jiao
Better and Faster: Exponential Loss for Image Patch Matching. ICCV (2019)
Wenchao Lv, Houjin Chen, Yahui Peng, Yanfeng Li, Jupeng Li
An atlas-based multimodal registration method for 2D images with discrepancy structures. Medical Biol. Eng. Comput. 56 (11) (2018)
Yanfeng Li, Haicheng Liu, Ruizhi Yang
A delayed diffusive predator-prey system with predator cannibalism. Comput. Math. Appl. 75 (4) (2018)
Zhijian Pan, Miao Li, Jian Yao, Hong Lu, Zuochang Ye, Yanfeng Li, Yan Wang
Low-cost high-accuracy variation characterization for nanoscale IC technologies via novel learning-based techniques. DATE (2018)
Zhijie Zhang, Yanfeng Li
A dynamic calibration system of thermocouple sensor ased on high temperature furnace. I2MTC (2018)
Yanfeng Li, Houjin Chen, Linlin Zhang, Lin Cheng
Mammographic mass detection based on convolution neural network. ICPR (2018)
Lili Bai, Zhennan Han, Yanfeng Li, Shaohui Ning
A Hybrid De-Noising Algorithm for the Gear Transmission System Based on CEEMDAN-PE-TFPF. Entropy 20 (5) (2018)
Yanfeng Li, Houjin Chen, Xue-Ye Wei, Yahui Peng, Lin Cheng
Mass classification in mammograms based on two-concentric masks and discriminating texton. Pattern Recognit. 60 (2016)
Yan Huang, Ti Zhou, Yanfeng Li, Yan Zhang, CuiXia Ma
Interactive Animation Editing Based on Sketch Interaction. Monterey Workshop (2016)
Weiwen Peng, Yanfeng Li, Yuanjian Yang, Jinhua Mi, Hong-Zhong Huang
Leveraging Degradation Testing and Condition Monitoring for Field Reliability Analysis With Time-Varying Operating Missions. IEEE Trans. Reliab. 64 (4) (2015)
Shuli Geng, Dang Liu, Yanfeng Li, Huiying Zhuo, Woogeun Rhee, Zhihua Wang
A 13.3 mW 500 Mb/s IR-UWB Transceiver With Link Margin Enhancement Technique for Meter-Range Communications. IEEE J. Solid State Circuits 50 (3) (2015)
Yanfeng Li, Houjin Chen, Gustavo Kunde Rohde, Chang Yao, Lin Cheng
Texton analysis for mass classification in mammograms. Pattern Recognit. Lett. 52 (2015)
Jian-Ping Yang, Hong-Zhong Huang, Yu Liu, Yanfeng Li
Quantification Classification Algorithm of Multiple Sources of Evidence. Int. J. Inf. Technol. Decis. Mak. 14 (5) (2015)
Yu Liu, Ming Jian Zuo, Yanfeng Li, Hong-Zhong Huang
Dynamic Reliability Assessment for Multi-State Systems Utilizing System-Level Inspection Data. IEEE Trans. Reliab. 64 (4) (2015)
Yonghe Lu, Wenqiu Liu, Yanfeng Li
A Feature Selection Based on Relevance and Redundancy. J. Comput. 10 (4) (2015)
Yanfeng Li, Houjin Chen, Yongyi Yang, Lin Cheng, Lin Cao
A bilateral analysis scheme for false positive reduction in mammogram mass detection. Comput. Biol. Medicine 57 (2015)
Yanfeng Li, Yutao Liu, Woogeun Rhee, Zhihua Wang
A high-PSRR ADPLL with self-regulated GRO TDC and DCO-dedicated voltage regulator. VLSI-DAT (2015)

Yanfeng Li.css-eqlu8i{font-size:small;padding-left:4px;}

Publication Activity (10 Years)

Top Topics

Top Venues

Yanfeng Li