Yu Liu - RankMe

121 papers A* 1A 4B 10C 14Misc 1Journal 31Unranked 60

Year	Rank	Type	Title / Venue / Authors
2026	J	`jnl`	M IEEE Trans. Computational Imaging Junjie Li, Jiawei Wang, Miyu Li, Yu Liu, Yumei Wang, Haitao Xu
2025	J	`jnl`	Collaborative Integration of Vehicle and Roadside Infrastructure Sensor for Temporal Dependency-Aware Task Offloading in the Internet of Vehicles. Int. J. Intell. Syst. Kaiyue Luo, Yumei Wang, Yu Liu, Konglin Zhu
2025	J	`jnl`	DUSTNet: An Unsupervised and Noise-Resistant Network for Martian Dust Storm Change Detection. IEEE Geosci. Remote. Sens. Lett. Miyu Li, Junjie Li, Yumei Wang, Yu Liu, Haitao Xu
2025	J	`jnl`	Efficient Outsourced Decryption System with Attribute-Based Encryption for Blockchain-Based Digital Asset Transactions. Symmetry Rui Jin, Yuxuan Pan, Junjie Li, Yu Liu, Daquan Yang, Mengmeng Zhou, Konglin Zhu
2025	J	`jnl`	MARSWIN: A Cross-Shot Swin Transformer Network for Super-Resolution on Mars MoRIC Image. IEEE J. Sel. Top. Appl. Earth Obs. Remote. Sens. Junjie Li, Weikun Lv, Linhui Wei, Yu Liu, Yumei Wang, Zhi Liu, Zhi Zeng
2025	J	`jnl`	Space Ground Collaborative SFC Flow Scheduling Strategy in Satellite-Terrestrial Integrated Network-Enabled Internet of Vehicles Rescuing Based on Computation-Space-Time Graph. Int. J. Intell. Syst. Yingjie Deng, Yu Liu, Yumei Wang, Konglin Zhu, Peng Wu, Lu Cao, Wen Sun, Jingwen Xu
2024	J	`jnl`	Blockchain-Based Digital Asset Circulation: A Survey and Future Challenges. Symmetry Konglin Zhu, Fengjuan Wu, Fei Wang, Tingda Shen, Hao Wu, Bowei Xue, Yu Liu
2024	B	`conf`	Collaborative Offloading with Temporal Tolerance in Cybertwin-enabled 6G. PIMRC Kaiyue Luo, Yumei Wang, Yu Liu
2024	J	`jnl`	Data-Sharing System with Attribute-Based Encryption in Blockchain and Privacy Computing. Symmetry Hao Wu, Yu Liu, Konglin Zhu, Lin Zhang
2024	J	`jnl`	JUST360: Optimizing 360-Degree Video Streaming Systems With Joint Utility. IEEE Trans. Broadcast. Zhijun Li, Yumei Wang, Yu Liu, Junjie Li, Ping Zhu
2024	—	`conf`	Open-Domain Question Answering over Tables with Large Language Models. ICIC (12) Xinyi Liang, Rui Hu, Yu Liu, Konglin Zhu
2024	J	`jnl`	Synergistic Temporal-Spatial User-Aware Viewport Prediction for Optimal Adaptive 360-Degree Video Streaming. IEEE Trans. Broadcast. Yumei Wang, Junjie Li, Zhijun Li, Simou Shang, Yu Liu
2024	—	`conf`	Towards Efficient Traffic Engineering via Distributed Optimization in Large-Scale LEO Constellation. ICC Workshops Linhui Wei, Tien Thanh Le, Yusheng Ji, Mingqian Wang, Yu Liu, Yumei Wang, John C. S. Lui
2024	C	`conf`	Unsupervised Denoising with Implicit Noise Mapping for Single Martian Multispectral Image. IGARSS Junjie Li, Weikun Lv, Jiawei Wang, Yumei Wang, Yu Liu
2023	—	`conf`	Data Sharing System Based on Blockchain to Enhance The Visible of Meta Data Information in Privacy Computing. HPCC/DSS/SmartCity/DependSys Hao Wu, Sen Wang, Genghua Dong, Mengmeng Zhou, Yu Liu, Lin Zhang
2023	—	`conf`	Design and Implementation of Access Control for Pension Data : A Smart Contract Approach. IC-NIDC Rui Hu, Xinyi Liang, Sen Wang, Yu Liu, Jin Dong
2023	B	`conf`	Economic Routing for Immersive Media in Satellite-Terrestrial Integrated Network. GLOBECOM Linhui Wei, Mingqian Wang, Yu Liu, Yumei Wang
2023	J	`jnl`	Energy Efficient Maximal Throughput Resource Scheduling Strategy in Satellite Networks. IEEE Wirel. Commun. Lett. Jiacheng Shuai, Yu Liu, Yumei Wang
2023	B	`conf`	FEAMNet: Light Field Depth Estimation Network Based On Feature Extraction and Attention Mechanism. IJCNN Yunming Liu, Yuxuan Pan, Kaiyue Luo, Yu Liu, Lin Zhang
2023	J	`jnl`	LiTrix: A Lightweight Live Light Field Video Scheme for Metaverse Stereoscopic Applications. IEEE Internet Things Mag. Yuxuan Pan, Yu Liu, Lin Zhang
2023	J	`jnl`	MarsNet: Automated Rock Segmentation With Transformers for Tianwen-1 Mission. IEEE Geosci. Remote. Sens. Lett. Weikun Lv, Linhui Wei, Dian Zheng, Yu Liu, Yumei Wang
2023	A*	`conf`	Meta360: Exploring User-Specific and Robust Viewport Prediction in360-Degree Videos through Bi-Directional LSTM and Meta-Adaptation. ISMAR Junjie Li, Yumei Wang, Yu Liu
2023	B	`conf`	Orbit-Grid-Based Dynamic Routing for Software Defined Mega-Constellation Network. GLOBECOM Mingqian Wang, Linhui Wei, Yumei Wang, Yu Liu
2023	J	`jnl`	Rover Attitude and Camera Parameter: Rock Measurements on Mars Surface Based on Rover Attitude and Camera Parameter for Tianwen-1 Mission. Remote. Sens. Dian Zheng, Linhui Wei, Weikun Lv, Yu Liu, Yumei Wang
2022	—	`conf`	DPNet: Depth and Pose Net for Novel View Synthesis via Depth Map Estimation. ChinaCom Ge Zhu, Yu Liu, Yumei Wang
2022	J	`jnl`	Energy-Efficient Controller Placement in Software-Defined Satellite-Terrestrial Integrated Network. Remote. Sens. Linhui Wei, Chen Chang, Yu Liu, Yumei Wang
2022	J	`jnl`	Generating High-Quality Panorama by View Synthesis Based on Optical Flow Estimation. Sensors Wenxin Zhang, Yumei Wang, Yu Liu
2022	B	`conf`	Geometry-guided compact compression for light field image using graph convolutional networks. NOSSDAV Yu Liu, Linhui Wei, Heming Zhao, Jingming Shan, Yumei Wang
2022	—	`conf`	MOFN: Multi-Offset-Flow-Based Network for Video Restoration and Enhancement. ICME Workshops Yiru Chen, Yumei Wang, Yu Liu
2022	J	`jnl`	MetaMars: 3DoF+ Roaming With Panoramic Stitching for Tianwen-1 Mission. IEEE Geosci. Remote. Sens. Lett. Dian Zheng, Linhui Wei, Yu Liu, Yumei Wang
2022	C	`conf`	Refine-PU: A Graph Convolutional Point Cloud Upsampling Network using Spatial Refinement. VCIP Yilin Liu, Yumei Wang, Yu Liu
2022	C	`conf`	Rule Placement and Switch Migration-based Scheme for Controller Load Balancing in SDN. ISCC Gengbiao Yue, Yumei Wang, Yu Liu
2022	C	`conf`	SAD360: Spherical Viewport-Aware Dynamic Tiling for 360-Degree Video Streaming. VCIP Zhijun Li, Yumei Wang, Yu Liu
2022	—	`conf`	Superpixel-Based Optimization for Point Cloud Reconstruction from Light Field. ICME Workshops Heming Zhao, Yu Liu, Linhui Wei, Yumei Wang
2021	A	`conf`	4DLFVD: A 4D Light Field Video Dataset. MMSys Xinjue Hu, Chenchen Wang, Yuxuan Pan, Yunming Liu, Yumei Wang, Yu Liu, Lin Zhang, Shervin Shirmohammadi
2021	B	`conf`	A Multipath Routing Approach for Tile-based Virtual Reality Video Streaming Based on SDN. COMPSAC Fanyuan Zou, Yumei Wang, Yu Liu
2021	—	`conf`	A Tunable Routing Algorithm for Integerated Terrestrial-Satellite Networks Based on the Space-Time Graph. IC-NIDC Yingjie Deng, Yu Liu
2021	—	`conf`	Failure-Based Multi-Controller Placement in Software Defined Satellite Networking. ICC Workshops Chen Chang, Yu Liu, Yumei Wang
2021	—	`conf`	Gbk360: A Game Among Tiles In 360 Video Based On Kalman Filter. ICME Workshops Simou Shang, Yumei Wang, Yu Liu
2021	—	`conf`	Object Detection in Omnidirectional Images Based on Spherical CNN. IC-NIDC Xingxing Li, Yu Liu, Yumei Wang
2021	—	`conf`	SDN-Based QoE Evaluation Methods for HTTP Adaptive Video Streaming. IC-NIDC Mingqian Wang, Yumei Wang, Yu Liu
2021	C	`conf`	SPCNet: A Panoramic image depth estimation method based on spherical convolution. VCIP Si He, Yu Liu, Yumei Wang
2021	—	`conf`	Time-Scalable Low-Latency Video Bitrate Adaptation. ICME Workshops Heng Jiang, Yu Liu, Yumei Wang
2020	J	`jnl`	An Adaptive Two-Layer Light Field Compression Scheme Using GNN-Based Reconstruction. ACM Trans. Multim. Comput. Commun. Appl. Xinjue Hu, Jingming Shan, Yu Liu, Lin Zhang, Shervin Shirmohammadi
2020	B	`conf`	QFR: A QoE-driven Fine-grained Routing Scheme for Virtual Reality Video Streaming over SDN. WCNC Xiaoyu Liu, Yumei Wang, Yu Liu
2020	J	`jnl`	Tensor-Based Light Field Compressed Sensing and Epipolar Plane Images Reconstruction via Deep Learning. IEEE Access Linhui Wei, Yumei Wang, Yu Liu
2019	—	`conf`	A Flexible Viewport-Adaptive Processing Mechanism for Real-Time VR Video Transmission. ICME Workshops Anyue Xu, Xinyu Chen, Yu Liu, Yumei Wang
2019	A	`conf`	Adaptive two-layer light field compression scheme based on sparse reconstruction. MMSys Xinjue Hu, Jingming Shan, Yu Liu, Lin Zhang
2019	—	`conf`	DBS: Delay Based Hierarchical Downlink Scheduling for Real-Time Stream in Cellular Networks. ChinaCom (1) Wenjin Fan, Yu Liu, Yumei Wang
2019	C	`conf`	Light Field Images Compression Based on Graph Convolution Networks. VCIP Jingming Shan, Yu Liu, Yumei Wang
2019	C	`conf`	Light Field Reconstruction Based on Compressed Sensing via Deep Learning. VCIP Linhui Wei, Yu Liu, Yumei Wang
2019	J	`jnl`	Mobile Edge Assisted Live Streaming System for Omnidirectional Video. Mob. Inf. Syst. Xinjue Hu, Wei Quan, Tao Guo, Yu Liu, Lin Zhang
2019	—	`conf`	VAS360: QoE-Driven Viewport Adaptive Streaming for 360 Video. ICME Workshops Yuxiang Hu, Yu Liu, Yumei Wang
2018	—	`conf`	Application Identification for Virtual Reality Video with Feature Analysis and Machine Learning Technique. ChinaCom Xiaoyu Liu, Xinyu Chen, Yumei Wang, Yu Liu
2018	J	`jnl`	Distributed and Adaptive Analog Coding for Video Broadcast in Wireless Cooperative System. Wirel. Pers. Commun. Yumei Wang, Mengyao Sun, Yu Liu
2018	J	`jnl`	Power profiling of multimedia sensor node with name-based segment streaming. Multim. Tools Appl. Adolph Seema, Tejas Shah, Lukas Schwoebel, Yu Liu, Martin Reisslein
2018	—	`conf`	Quality of Experience Prediction of HTTP Video Streaming in Mobile Network with Random Forest. ChinaCom Yue Yu, Yu Liu, Yumei Wang
2017	J	`jnl`	Bus-Ads: Bus Trajectory-Based Advertisement Distribution in VANETs Using Coalition Formation Games. IEEE Syst. J. Lin Zhang, Shucong Jia, Zishan Liu, Yumei Wang, Yu Liu
2017	B	`conf`	SCAST: Wireless Video Multicast Scheme Based on Segmentation and Softcast. WCNC YuanYuan Li, Zhexin Li, Yu Liu, Yumei Wang
2017	B	`conf`	The improved-iterative support detection algorithm for pulse-position-modulation ADC architecture. PIMRC Mengyue Liu, Yu Liu, Yumei Wang
2016	—	`conf`	A new popularity prediction model based on lifetime forecast of online videos. IC-NIDC Benle Su, Yumei Wang, Yu Liu
2016	—	`conf`	Adaptive scalable wireless video coding based on unequal protection and quadtree partition. IC-NIDC Mengyang Lv, Yu Liu, Yumei Wang
2016	—	`conf`	Cooperative video coding scheme with fountain code on the concentration on data size. IC-NIDC Hao Yu, Yumei Wang, Yu Liu
2016	—	`conf`	Cost optimization based network deployment strategies for future dense networks. WPMC Di Wu, Xinyu Gu, Jun Gu, Weichen Liao, Lin Zhang, Yu Liu
2016	J	`jnl`	Hybrid digital-analog video transmission in wireless multicast and multiple-input multiple-output system. J. Electronic Imaging Yu Liu, Xiaocheng Lin, Nianfei Fan, Lin Zhang
2016	—	`conf`	SIA: Segment importance based rate adaptation for Dynamic Adaptive Streaming over HTTP. IC-NIDC Yi Zheng, Yumei Wang, Yu Liu
2016	C	`conf`	Scalable wireless video broadcast based on unequal protection. VCIP Mengyang Lv, Yu Liu, Yumei Wang
2016	—	`conf`	The improved-sparsity adaptive matching pursuit algorithm for pulse-position-modulation ADC architecture. WPMC Mengyue Liu, Huiyang Peng, Lei Chen, Yu Liu, Yumei Wang
2016	—	`conf`	Unequal block for low bandwidth adaption in wireless video broadcast. IC-NIDC Zhexin Li, Yu Liu, Yumei Wang
2016	C	`conf`	Visual information exploited hybrid digital-analog scheme for wireless video multicast. VCIP YuanYuan Li, Yu Liu, Yumei Wang, Zhexin Li
2015	—	`conf`	Adaptive analog coding for video broadcast in wireless cooperative system. ICT Mengyao Sun, Yumei Wang, Xiaocheng Lin, Yu Liu
2015	—	`conf`	Analog channel coding for wireless image/video SoftCast by data division. ICT Xiaocheng Lin, Yu Liu, Mengyao Sun
2015	A	`conf`	Distributed cooperative video coding for wireless video broadcast system. ICME Mengyao Sun, Yumei Wang, Hao Yu, Yu Liu
2015	J	`jnl`	Mobility and QoS oriented 802.11p MAC scheme for vehicle-to-infrastructure communications. Telecommun. Syst. Lin Zhang, Yu Liu, Zi Wang, Jinjie Guo, Yiding Huo
2015	B	`conf`	Scalable video SoftCast using magnitude shift. WCNC Xiaocheng Lin, Yu Liu, Lin Zhang
2015	—	`conf`	Signal recognition and parameter estimation of BPSK-LFM combined modulation. ICDIP Chao Long, Lin Zhang, Yu Liu
2014	—	`conf`	A Novel Layered DVC Structure for Wireless Surveillance System. ICIMCS Mengyao Sun, Yumei Wang, Hui Yin, Yu Liu
2014	J	`jnl`	A Scalable CSMA and Self-Organizing TDMA MAC for IEEE 802.11 p/1609.x in VANETs. Wirel. Pers. Commun. Lin Zhang, Zishan Liu, Rui Zou, Jinjie Guo, Yu Liu
2014	—	`conf`	A Scalable Mobile Video Broadcast Scheme Using 3D Wavelet Transform. VTC Fall Quan Wang, Xiaocheng Lin, Yu Liu, Lin Zhang, Xiaofei Wu
2014	—	`conf`	A channel adaptive video broadcast scheme based on analog coding and delivery. WPMC Guanhong Lai, Yu Liu, Quan Wang, Lin Zhang
2014	—	`conf`	A scalable framework for mobile video broadcast using MCTF and 2D-DWT. WPMC Quan Wang, Xiaocheng Lin, Yu Liu, Lin Zhang, Xiaofei Wu
2014	—	`conf`	Distributed Realcast: A Channel-Adaptive Video Broadcast Delivery Scheme. VTC Fall Guanhong Lai, Yu Liu, Lin Zhang
2014	J	`jnl`	Events localisation and estimation in wireless sensor networks using compressed sensing. Int. J. Ad Hoc Ubiquitous Comput. Yu Liu, Guanhong Lai, Qing Li, Xuqi Zhu, Lin Zhang
2014	C	`conf`	Fusion side information based on feature and motion extraction for distributed multiview video coding. VCIP Hui Yin, Mengyao Sun, Yumei Wang, Yu Liu
2014	—	`conf`	Hybrid digital-analog video multicast scheme based on H.264/AVC and SoftCast. WPMC Nianfei Fan, Yu Liu, Quan Wang, Lin Zhang
2014	—	`conf`	Hybrid digital-analog video transmission based on H.264/AVC and ParCast in MIMO-OFDM WLANs. ICT Nianfei Fan, Yu Liu, Lin Zhang
2013	—	`conf`	Abnormal event detection and localization in wireless sensor network using compressed sensing. ICCT Quan Wang, Yu Liu, Lin Zhang, Xiaofei Wu
2013	—	`conf`	Collision-based Radio frequency identification using compressive sensing. ICCT Guanhong Lai, Yu Liu, Xiaocheng Lin, Lin Zhang
2013	—	`conf`	Combination of analog network coding and compressed sensing in clustered chain-type topology. ICCT Nianfei Fan, Yu Liu, Lin Zhang
2013	—	`conf`	Load balancing performance of dynamic SCell measurement period relaxing in LTE-A. CCNC Xiaoyu Duan, Haotian Zhang, Wenyu Li, Yu Liu, Lin Zhang
2013	—	`conf`	Load balancing performance of dynamic SCell measurement period relaxing in LTE-A. CCNC Xiaoyu Duan, Haotian Zhang, Wenyu Li, Yu Liu, Lin Zhang
2013	—	`conf`	Scalable Distributed Video Coding Using Compressed Sensing in Wavelet Domain. VTC Fall Nianfei Fan, Xuqi Zhu, Yu Liu, Lin Zhang
2012	—	`conf`	A Dynamic Hysteresis-Adjusting Algorithm in LTE Self-Organization Networks. VTC Spring Wenyu Li, Xiaoyu Duan, Shucong Jia, Lin Zhang, Yu Liu, Jiaru Lin
2012	—	`conf`	A Dynamic MaxPRB-Adjusting Scheduling Scheme Based on SINR Dispersion Degree in LTE System. VTC Spring Wenyu Li, Chao Zhang, Li Jin, Zhongfang Wang, Lin Zhang, Yu Liu
2012	—	`conf`	A dynamic Priority update Granularity adjustment algorithm based on user density and service delay requirement in LTE downlink scheduling. IC-NIDC Wenyu Li, Li Jin, Zhongfang Wang, Lin Zhang, Yu Liu
2012	—	`conf`	A dynamic channel switching mechanism based on vehicle density. WPMC Yiding Huo, Jinjie Guo, Rui Zou, Hongtao Zhang, Yu Liu, Lin Zhang
2012	—	`conf`	An adaptive and reliable MAC mechanism for IEEE 1609.4 and 802.11p VANETs. WPMC Jinjie Guo, Yiding Huo, Chang Hu, Tianning Liang, Yu Liu, Lin Zhang
2012	Misc	`conf`	An improved LDPC decoding scheme with reverse bit order mode for distributed video codec. CISS Bin Li, Yumei Wang, Yu Liu, Lin Zhang
2012	J	`jnl`	Campus View: An Innovative Location and Context-Aware Video Sharing Application on Smart Phone. Wirel. Pers. Commun. Lin Zhang, Yu Liu, Xin Zhan, Xiaomin Yang, Xiaoqiang Chi, Shizhen Zhao
2012	J	`jnl`	Distributed Compressed Video Sensing in Camera Sensor Networks. Int. J. Distributed Sens. Networks Yu Liu, Xuqi Zhu, Lin Zhang, Sung Ho Cho
2012	J	`jnl`	Expanding Window Compressed Sensing for Non-Uniform Compressible Signals. Sensors Yu Liu, Xuqi Zhu, Lin Zhang, Sung Ho Cho
2012	—	`conf`	Information sharing service in VANETs with enhanced two-tier P2P communications. WPMC Jinjie Guo, Chang Hu, Yiding Huo, Yu Liu, Lin Zhang
2012	—	`conf`	Noise-resilient distributed compressed video sensing using side-information-based belief propagation. IC-NIDC Yu Liu, Xuqi Zhu, Lin Zhang
2012	—	`conf`	Performance Evaluation and Analysis on Group Mobility of Mobile Relay for LTE Advanced System. VTC Fall Wenyu Li, Chao Zhang, Xiaoyu Duan, Shucong Jia, Yu Liu, Lin Zhang
2011	—	`conf`	A Lightly-loaded cell initiated Load Balancing in LTE self-optimizing networks. CHINACOM Mengru Zhang, Wenyu Li, Shucong Jia, Lin Zhang, Yu Liu
2011	—	`conf`	An Adaptive Modulation Selection Scheme Based on Error Estimating Coding. MSN Qing Li, Bin Li, Yu Liu, Lin Zhang
2011	—	`conf`	An LDPC-based improved decoding scheme for distributed video codec. ICT Bin Li, Yumei Wang, Qing Huang, Yu Liu
2011	—	`conf`	An improved method for side information generation and correlation parameter estimation for distributed video coding. GLOBECOM Workshops Bin Li, Yumei Wang, Yu Liu, Lin Zhang
2011	C	`conf`	An unequally protected Distributed Compressed Video Sensing algorithm. VCIP Bin Li, Xuqi Zhu, Yu Liu, Lin Zhang
2011	—	`conf`	Compressed sensing of correlated signals using belief propagation. ICT Xuqi Zhu, Yu Liu, Bin Li, Xun Wang, Wenbo Zhang, Lin Zhang
2011	A	`conf`	Distributed compressive video sensing based on smoothed ℓ ICME Cong Ma, Yu Liu, Lin Zhang, Xuqi Zhu
2011	—	`conf`	Fusion side information based on spatio-temporal correlation in distributed multi-view video coding. CHINACOM Qing Huang, Bin Li, Yumei Wang, Lin Zhang, Yu Liu
2011	—	`conf`	Mobility and QoS oriented 802.11p MAC scheme for vehicle-to-infrastructure communications. CHINACOM Zi Wang, Teng Jiang, Lin Zhang, Yu Liu
2011	—	`conf`	Multiple event detection in wireless sensor networks using compressed sensing. ICT Yu Liu, Xuqi Zhu, Cong Ma, Lin Zhang
2009	J	`jnl`	Distributed Joint Source-Channel Coding in Wireless Sensor Networks. Sensors Xuqi Zhu, Yu Liu, Lin Zhang
2008	—	`conf`	A fast and reliable decoding scheme with prior-hash bits in distributed video coding. Mobility Conference Song Xu, Bo Zhang, Lin Zhang, Yu Liu
2008	—	`conf`	Unequal error protection in distributed source coding for wireless sensor networks. Mobility Conference Guodong Xue, Bo Zhang, Yu Liu, Lin Zhang
2007	C	`conf`	An Energy Efficiency Scheme Using Local SNR for Clustered Wireless Sensor Networks. MobiQuitous Qianyu Ye, Yu Liu, Lin Zhang, Chan-Hyun Youn
2007	—	`conf`	Target tracking by proportion of distance in wireless sensor networks. Mobility Conference Qianyu Ye, Yu Liu, Lin Zhang, Chan-Hyun Youn
2006	C	`conf`	Information-Driven Sensor Selection Algorithm for Kalman Filtering in Sensor Networks. UIC Yu Liu, Yumei Wang, Lin Zhang, Chan-Hyun Youn
2006	C	`conf`	Information-Driven Task Routing for Network Management in Wireless Sensor Networks. APNOMS Yu Liu, Yumei Wang, Lin Zhang, Chan-Hyun Youn