Search results for "kNN"

Hits ?▲	Authors	Title	Venue	Year	Link
13	Weijun Tan, Hongwei Guo, Rushuai Liu	A Fast Partial Video Copy Detection Using KNN and Global Feature Database.	WACV	2022	DBLP DOI BibTeX RDF
13	Archita Negi, Farshid Hajati	Analysis of Variants of KNN for Disease Risk Prediction.	AINA (3)	2022	DBLP DOI BibTeX RDF
13	Kengo Nakata, Youyang Ng, Daisuke Miyashita, Asuka Maki, Yu-Chieh Lin 0002, Jun Deguchi	Revisiting a kNN-Based Image Classification System with High-Capacity Storage.	ECCV (37)	2022	DBLP DOI BibTeX RDF
13	Rosalyn R. Porle, Suzanih Embok	Speech-Based Number Recognition Using KNN and SVM.	IICAIET	2022	DBLP DOI BibTeX RDF
13	Jonathan Jakob, André Artelt, Martina Hasenjäger, Barbara Hammer	SAM-kNN Regressor for Online Learning in Water Distribution Networks.	ICANN (3)	2022	DBLP DOI BibTeX RDF
13	Nova D. Doyog, Chinsu Lin	Effects of KNN Neighbor's Density and Distance on Forest-Stand-Level AGB Estimation.	IGARSS	2022	DBLP DOI BibTeX RDF
13	Suomi Kobayashi, Shohei Matsugu, Hiroaki Shiokawa	Tree-Based Graph Indexing for Fast kNN Queries.	iiWAS	2022	DBLP DOI BibTeX RDF
13	Chi-Yueh Hsu, Chun-Ming Kuo, Ruo-Wei Hung, Jong-Shin Chen	Research on KNN-Based GNSS Coordinate Classification for Epidemic Management.	ICS	2022	DBLP DOI BibTeX RDF
13	Yixuan Wei, Yifei Wanyan, Keer Cao, Yuning Zhang, Yixuan Li	Research on Intelligent Prediction and Big Data Analysis of Aesthetic Medicine based on KNN Model.	ICCSIE	2022	DBLP DOI BibTeX RDF
13	Florian Lalande, Kenji Doya	Numerical Data Imputation: Choose kNN over Deep Learning.	SISAP	2022	DBLP DOI BibTeX RDF
13	Sayed Waleed Qayyumi, Laurence A. F. Park, Oliver Obst	Active Learning for kNN Using Instance Impact.	AI	2022	DBLP DOI BibTeX RDF
13	Heping Peng, Zhong Xu, Wenxiong Mo, Yong Wang, Qingdan Huang	Survey on kNN.	CAIBDA	2022	DBLP BibTeX RDF
13	Yunhua Zhou, Peiju Liu, Xipeng Qiu	KNN-Contrastive Learning for Out-of-Domain Intent Classification.	ACL (1)	2022	DBLP DOI BibTeX RDF
13	Saeed Zeraatkar, Fatemeh Afsari	Interval-valued fuzzy and intuitionistic fuzzy-KNN for imbalanced data classification.	Expert Syst. Appl.	2021	DBLP DOI BibTeX RDF
13	Guancen Lin, Aijing Lin, Jianing Cao	Multidimensional KNN algorithm based on EEMD and complexity measures in financial time series forecasting.	Expert Syst. Appl.	2021	DBLP DOI BibTeX RDF
13	Amin Shokrzade, Mohsen Ramezani, Fardin Akhlaghian Tab, Mahmud Abdulla Mohammad	A novel extreme learning machine based kNN classification method for dealing with big data.	Expert Syst. Appl.	2021	DBLP DOI BibTeX RDF
13	Yunwen Zhu, Wenjun Zhang, Meixian Zhang, Ke Zhang, Yonghua Zhu	Image emotion distribution learning based on enhanced fuzzy KNN algorithm with sparse learning.	J. Intell. Fuzzy Syst.	2021	DBLP DOI BibTeX RDF
13	Shilong Wu	Simulation of classroom student behavior recognition based on PSO-kNN algorithm and emotional image processing.	J. Intell. Fuzzy Syst.	2021	DBLP DOI BibTeX RDF
13	Siyu Zhu, Chongnan He, Mingjuan Song, Linna Li	Two-parameter KNN algorithm and its application in recognition of brand rice.	J. Intell. Fuzzy Syst.	2021	DBLP DOI BibTeX RDF
13	Soni Lanka Karri, Liyanage C. De Silva, Daphne Teck Ching Lai, Shiaw Yin Yong	Classification and Prediction of Driving Behaviour at a Traffic Intersection Using SVM and KNN.	SN Comput. Sci.	2021	DBLP DOI BibTeX RDF
13	Pablo Aparicio-Ruiz, Elena Barbadilla-Martín, José Guadix, Pablo Cortés 0001	KNN and adaptive comfort applied in decision making for HVAC systems.	Ann. Oper. Res.	2021	DBLP DOI BibTeX RDF
13	Luefeng Chen, Min Li, Wanjuan Su, Min Wu 0002, Kaoru Hirota, Witold Pedrycz	Adaptive Feature Selection-Based AdaBoost-KNN With Direct Optimization for Dynamic Emotion Recognition in Human-Robot Interaction.	IEEE Trans. Emerg. Top. Comput. Intell.	2021	DBLP DOI BibTeX RDF
13	Wendong Li, Chi Zhang, Fugee Tsung, Yajun Mei	Nonparametric monitoring of multivariate data via KNN learning.	Int. J. Prod. Res.	2021	DBLP DOI BibTeX RDF
13	Yupeng Hu, Chong Yang, Peng Zhan, Jia Zhao, Yujun Li, Xueqing Li	Efficient continuous KNN join processing for real-time recommendation.	Pers. Ubiquitous Comput.	2021	DBLP DOI BibTeX RDF
13	Diego Lopez-Bernal, David Balderas Silva, Pedro Ponce, Arturo Molina 0001	Education 4.0: Teaching the Basics of KNN, LDA and Simple Perceptron Algorithms for Binary Classification Problems.	Future Internet	2021	DBLP DOI BibTeX RDF
13	Nan Luo, Hongquan Yu, Zhenfeng Huo, Jinhui Liu, Quan Wang 0006, Ying Xu, Yun Gao	KVGCN: A KNN Searching and VLAD Combined Graph Convolutional Network for Point Cloud Segmentation.	Remote. Sens.	2021	DBLP DOI BibTeX RDF
13	Shi Ying, Bingming Wang, Lu Wang 0014, Qingshan Li, Yishi Zhao, Jianga Shang, Hao Huang 0001, Guoli Cheng, Zhe Yang, Jiangyi Geng	An Improved KNN-Based Efficient Log Anomaly Detection Method with Automatically Labeled Samples.	ACM Trans. Knowl. Discov. Data	2021	DBLP DOI BibTeX RDF
13	Hemant Choubey, Alpana Pandey	A combination of statistical parameters for the detection of epilepsy and EEG classification using ANN and KNN classifier.	Signal Image Video Process.	2021	DBLP DOI BibTeX RDF
13	Lingli Li, Jie Xu, Yu Li, Jingwen Cai	HCTree+: A workload-guided index for approximate kNN search.	Inf. Sci.	2021	DBLP DOI BibTeX RDF
13	Rui Zhang, Tao Du 0002, Shouning Qu, Hongwei Sun	Adaptive density-based clustering algorithm with shared KNN conflict game.	Inf. Sci.	2021	DBLP DOI BibTeX RDF
13	Kyoungok Kim	Normalized class coherence change-based kNN for classification of imbalanced data.	Pattern Recognit.	2021	DBLP DOI BibTeX RDF
13	Redha Taguelmimt, Rachid Beghdad	DS-kNN: An Intrusion Detection System Based on a Distance Sum-Based K-Nearest Neighbors.	Int. J. Inf. Secur. Priv.	2021	DBLP DOI BibTeX RDF
13	Nguyen Gia Bach, Le Huy Hoang, Tran Hoang Hai	Improvement of K-nearest Neighbors (KNN) Algorithm for Network Intrusion Detection Using Shannon-Entropy.	J. Commun.	2021	DBLP DOI BibTeX RDF
13	Jeong-Hun Kim, Jong-Hyeok Choi, Young-Ho Park 0002, Carson Kai-Sang Leung, Aziz Nasridinov	KNN-SC: Novel Spectral Clustering Algorithm Using k-Nearest Neighbors.	IEEE Access	2021	DBLP DOI BibTeX RDF
13	Chuanzhen Li, Minqiao Liu, Juanjuan Cai, Yang Yu, Hui Wang 0070	Topic Detection and Tracking Based on Windowed DBSCAN and Parallel KNN.	IEEE Access	2021	DBLP DOI BibTeX RDF
13	Omar Kherif, Youcef Benmahamed, Madjid Teguar, Ahmed Boubakeur, Sherif S. M. Ghoneim	Accuracy Improvement of Power Transformer Faults Diagnostic Using KNN Classifier With Decision Tree Principle.	IEEE Access	2021	DBLP DOI BibTeX RDF
13	Mohd Nadhir Ab Wahab, Amril Nazir, Anthony Tan Zhen Ren, Mohd Halim Mohd Noor, Muhammad Firdaus Akbar, Ahmad Sufril Azlan Mohamed	Efficientnet-Lite and Hybrid CNN-KNN Implementation for Facial Expression Recognition on Raspberry Pi.	IEEE Access	2021	DBLP DOI BibTeX RDF
13	Dai-Duong Nguyen, Minh Thuy Le 0001	Enhanced Indoor Localization Based BLE Using Gaussian Process Regression and Improved Weighted kNN.	IEEE Access	2021	DBLP DOI BibTeX RDF
13	Yang Ma, Xujun Zhao	POD: A Parallel Outlier Detection Algorithm Using Weighted kNN.	IEEE Access	2021	DBLP DOI BibTeX RDF
13	Poonam Chaudhari, Himanshu Agarwal, Vikrant Bhateja	Data augmentation for cancer classification in oncogenomics: an improved KNN based approach.	Evol. Intell.	2021	DBLP DOI BibTeX RDF
13	Mohammed Erritali, Badr Hssina, Abdelkader Grota	Building Recommendation Systems Using the Algorithms KNN and SVD.	Int. J. Recent Contributions Eng. Sci. IT	2021	DBLP DOI BibTeX RDF
13	Nan Luo, Yifeng Wang, Yun Gao, Yumin Tian, Quan Wang 0006, Chuan Jing	kNN-based feature learning network for semantic segmentation of point cloud data.	Pattern Recognit. Lett.	2021	DBLP DOI BibTeX RDF
13	Wiem Abbes, Dorra Sellami, Stella Marc-Zwecker, Cecilia Zanni-Merk	Fuzzy decision ontology for melanoma diagnosis using KNN classifier.	Multim. Tools Appl.	2021	DBLP DOI BibTeX RDF
13	Shuli Cheng, Lie-Jun Wang, Gao Huang, Anyu Du	A privacy-preserving image retrieval scheme based secure kNN, DNA coding and deep hashing.	Multim. Tools Appl.	2021	DBLP DOI BibTeX RDF
13	Arunit Maity, P. Prakasam 0001, Sarthak Bhargava	Machine learning based KNN classifier: towards robust, efficient DTMF tone detection for a Noisy environment.	Multim. Tools Appl.	2021	DBLP DOI BibTeX RDF
13	Shan Zhong, Zongming Bao, Shengrong Gong, Kaijian Xia	Person Reidentification Based on Pose-Invariant Feature and B-KNN Reranking.	IEEE Trans. Comput. Soc. Syst.	2021	DBLP DOI BibTeX RDF
13	Benjamin Ghansah, Ben-Bright Benuwa, Augustine Monney	A Discriminative Locality-Sensitive Dictionary Learning With Kernel Weighted KNN Classification for Video Semantic Concepts Analysis.	Int. J. Intell. Inf. Technol.	2021	DBLP DOI BibTeX RDF
13	Liliya A. Demidova	Two-Stage Hybrid Data Classifiers Based on SVM and kNN Algorithms.	Symmetry	2021	DBLP DOI BibTeX RDF
13	Angelo Coluccia, Alessio Fascista, Giuseppe Ricci	A KNN-Based Radar Detector for Coherent Targets in Non-Gaussian Noise.	IEEE Signal Process. Lett.	2021	DBLP DOI BibTeX RDF
13	Mohamed A. Mahfouz, Amin A. Shoukry, Mohamed A. Ismail	EKNN: Ensemble classifier incorporating connectivity and density into kNN with application to cancer diagnosis.	Artif. Intell. Medicine	2021	DBLP DOI BibTeX RDF
13	Oleksandra Levchenko, Boyan Kolev, Djamel Edine Yagoubi, Reza Akbarinia, Florent Masseglia, Themis Palpanas, Dennis E. Shasha, Patrick Valduriez	BestNeighbor: efficient evaluation of kNN queries on large time series databases.	Knowl. Inf. Syst.	2021	DBLP DOI BibTeX RDF
13	Federico Magliani, Andrea Prati 0001	LSH kNN graph for diffusion on image retrieval.	Inf. Retr. J.	2021	DBLP DOI BibTeX RDF
13	Michael Gowanlock	Hybrid KNN-join: Parallel nearest neighbor searches exploiting CPU and GPU architectural features.	J. Parallel Distributed Comput.	2021	DBLP DOI BibTeX RDF
13	Fayssal Bendaoud	Adaptive Knn-based algorithm for network selection in next-generation networks.	J. High Speed Networks	2021	DBLP DOI BibTeX RDF
13	Yewang Chen, Lida Zhou, Songwen Pei, Zhiwen Yu 0002, Yi Chen 0007, Xin Liu 0011, Jixiang Du, Naixue Xiong	KNN-BLOCK DBSCAN: Fast Clustering for Large-Scale Data.	IEEE Trans. Syst. Man Cybern. Syst.	2021	DBLP DOI BibTeX RDF
13	Muhammad Tanveer 0001, A. Sharma, Ponnuthurai N. Suganthan	Least squares KNN-based weighted multiclass twin SVM.	Neurocomputing	2021	DBLP DOI BibTeX RDF
13	Jasmir Jasmir, Siti Nurmaini, Bambang Tutuko	Fine-Grained Algorithm for Improving KNN Computational Performance on Clinical Trials Text Classification.	Big Data Cogn. Comput.	2021	DBLP DOI BibTeX RDF
13	Angela Fan, Claire Gardent, Chloé Braud, Antoine Bordes	Augmenting Transformers with KNN-Based Composite Memory for Dialog.	Trans. Assoc. Comput. Linguistics	2021	DBLP DOI BibTeX RDF
13	Hao Fan, Kaijun Wu, Hamid Parvin, Akram Beigi, Kim-Hung Pho	A Hybrid Recommender System Using KNN and Clustering.	Int. J. Inf. Technol. Decis. Mak.	2021	DBLP DOI BibTeX RDF
13	Hamoud Younes, Ali Ibrahim, Mostafa Rizk, Maurizio Valle	An Efficient Selection-Based kNN Architecture for Smart Embedded Hardware Accelerators.	IEEE Open J. Circuits Syst.	2021	DBLP DOI BibTeX RDF
13	Bruno Henrique Meyer, Aurora Trinidad Ramirez Pozo, Wagner M. Nunan Zola	Improving Barnes-Hut t-SNE Algorithm in Modern GPU Architectures with Random Forest KNN and Simulated Wide-Warp.	ACM J. Emerg. Technol. Comput. Syst.	2021	DBLP DOI BibTeX RDF
13	Durmus Özkan Sahin, Sedat Akleylek, Erdal Kiliç	On the Effect of k Values and Distance Metrics in KNN Algorithm for Android Malware Detection.	Adv. Data Sci. Adapt. Anal.	2021	DBLP DOI BibTeX RDF
13	Dan He, Sibo Wang 0001, Xiaofang Zhou 0001, Reynold Cheng	GLAD: A Grid and Labeling Framework with Scheduling for Conflict-Aware kNN Queries.	IEEE Trans. Knowl. Data Eng.	2021	DBLP DOI BibTeX RDF
13	Shohei Tsuruoka, Daichi Amagata, Shunya Nishio, Takahiro Hara	Distributed Spatial-Keyword kNN Monitoring for Location-aware Pub/Sub.	CoRR	2021	DBLP BibTeX RDF
13	Hamid Bekamiri, Daniel S. Hain, Roman Jurowetzki	Hybrid Model for Patent Classification using Augmented SBERT and KNN.	CoRR	2021	DBLP BibTeX RDF
13	Rashmi Bakshi	Feature Extraction and Prediction for Hand Hygiene Gestures with KNN Algorithm.	CoRR	2021	DBLP BibTeX RDF
13	Ning Yu, Timothy Haskins	KNN, An Underestimated Model for Regional Rainfall Forecasting.	CoRR	2021	DBLP BibTeX RDF
13	Stefan Klikovits, Paolo Arcaini	KNN-Averaging for Noisy Multi-objective Optimisation.	CoRR	2021	DBLP BibTeX RDF
13	Weijun Tan, Hongwei Guo, Rushuai Liu	A Fast Partial Video Copy Detection Using KNN and Global Feature Database.	CoRR	2021	DBLP BibTeX RDF
13	Tim Sziburis, Markus Nowak, Davide Brunelli	KNN Learning Techniques for Proportional Myocontrol in Prosthetics.	CoRR	2021	DBLP BibTeX RDF
13	Srikantaiah K. C, Salony Mewara, Sneha Goyal, Subhiksha S	A Friend Recommendation System using Semantic Based KNN Algorithm.	CoRR	2021	DBLP BibTeX RDF
13	Xulong Zhang 0001, Jiale Qian, Yi Yu 0001, Yifu Sun, Wei Li 0012	Singer Identification Using Deep Timbre Feature Learning with KNN-Net.	CoRR	2021	DBLP BibTeX RDF
13	Songnian Zhang, Suprio Ray, Rongxing Lu, Yandong Zheng	Spatial Interpolation-based Learned Index for Range and kNN Queries.	CoRR	2021	DBLP BibTeX RDF
13	Aryan Naim, Joseph Bowkett, Sisir Karumanchi, Peyman Tavallali, Brett Kennedy	Deterministic Iteratively Built KD-Tree with KNN Search for Exact Applications.	CoRR	2021	DBLP BibTeX RDF
13	Shichao Zhang 0001, Jiaye Li	Z Distance Function for KNN Classification.	CoRR	2021	DBLP BibTeX RDF
13	Alexander Marx, Jonas Fischer	Estimating Mutual Information via Geodesic kNN.	CoRR	2021	DBLP BibTeX RDF
13	Itzik Mizrahi, Shai Avidan	kNet: A Deep kNN Network To Handle Label Noise.	CoRR	2021	DBLP BibTeX RDF
13	Pramod Vadiraja, Christoph Peter Balada	Leveraging Reinforcement Learning for evaluating Robustness of KNN Search Algorithms.	CoRR	2021	DBLP BibTeX RDF
13	Micheal Olaolu Arowolo, Marion Olubunmi Adebiyi, Ayodele Ariyo Adebiyi, Oludayo O. Olugbara	Optimized hybrid investigative based dimensionality reduction methods for malaria vector using KNN classifier.	J. Big Data	2021	DBLP DOI BibTeX RDF
13	Baligh Al-Helali, Qi Chen 0002, Bing Xue 0001, Mengjie Zhang 0001	A new imputation method based on genetic programming and weighted KNN for symbolic regression with incomplete data.	Soft Comput.	2021	DBLP DOI BibTeX RDF
13	Dongdong Zhao 0001, Xiaoyi Hu, Shengwu Xiong, Jing Tian, Jianwen Xiang, Jing Zhou, Huanhuan Li 0002	k-means clustering and kNN classification based on negative databases.	Appl. Soft Comput.	2021	DBLP DOI BibTeX RDF
13	José García 0002, Carlos Maureira	A KNN quantum cuckoo search algorithm applied to the multidimensional knapsack problem.	Appl. Soft Comput.	2021	DBLP DOI BibTeX RDF
13	Mohammadreza Tabatabaei, Roohollah Kimiaefar, Alireza Hajian, Alireza Akbari	Robust outlier detection in geo-spatial data based on LOLIMOT and KNN search.	Earth Sci. Informatics	2021	DBLP DOI BibTeX RDF
13	Xiaoyan Zhu 0003, Chenzhen Ying, Jiayin Wang, Jiaxuan Li, Xin Lai 0003, Guangtao Wang	Ensemble of ML-KNN for classification algorithm recommendation.	Knowl. Based Syst.	2021	DBLP DOI BibTeX RDF
13	Xiaobo Qi, Husheng Guo, Wenjian Wang	A reliable KNN filling approach for incomplete interval-valued data.	Eng. Appl. Artif. Intell.	2021	DBLP DOI BibTeX RDF
13	Uzair Aslam Bhatti, Linwang Yuan, Zhaoyuan Yu, Saqib Ali Nawaz, Anum Mehmood, Mughair Aslam Bhatti, Qurat ul Ain, Mir Muhammad Nizamani, Zeeshan, Sheng-Jun Xiao	Predictive Data Modeling Using sp-kNN for Risk Factor Evaluation in Urban Demographical Healthcare Data.	J. Medical Imaging Health Informatics	2021	DBLP DOI BibTeX RDF
13	Martin Schäler, Christine Tex, Veit Köppen, David Broneske, Gunter Saake	Towards multi-purpose main-memory storage structures: Exploiting sub-space distance equalities in totally ordered data sets for exact knn queries.	Inf. Syst.	2021	DBLP DOI BibTeX RDF
13	Andreas Tjärnberg, Omar Mahmood, Christopher A. Jackson, Giuseppe-Antonio Saldi, Kyunghyun Cho, Lionel A. Christiaen, Richard A. Bonneau	Optimal tuning of weighted kNN- and diffusion-based methods for denoising single cell genomics data.	PLoS Comput. Biol.	2021	DBLP DOI BibTeX RDF
13	Maheshwari Venkatasen, Sandeep Kumar Mathivanan 0001, Prasanna Mani, Prabhu Jayagopal, Thanapal Pandi, Manivannan Sorakaya Somanathan, Upendra Babu K., D. Elangovan	Effectiveness of Contact Tracing Using KNN for COVID-19.	J. Mobile Multimedia	2021	DBLP DOI BibTeX RDF
13	Selim Bahadir, Elvan Ceyhan	On the Number of Weakly Connected Subdigraphs in Random kNN Digraphs.	Discret. Comput. Geom.	2021	DBLP DOI BibTeX RDF
13	Mei Sun, Yan Zhang, Rongpu Chen, Yulian Wen, Peiyao Nie	Hedging strategy for commodity futures based on SVM-KNN.	Int. J. Reason. based Intell. Syst.	2021	DBLP DOI BibTeX RDF
13	Haiyan Wang 0012, Peidi Xu, Jinghua Zhao	Improved KNN Algorithm Based on Preprocessing of Center in Smart Cities.	Complex.	2021	DBLP DOI BibTeX RDF
13	Jue Gao, Ya Gu	Feature matching for multi-beam sonar image sequence using KD-Tree and KNN search.	Int. J. Comput. Appl. Technol.	2021	DBLP DOI BibTeX RDF
13	Johannes Jakob, Michael Guthe	Optimizing LBVH-Construction and Hierarchy-Traversal to accelerate kNN Queries on Point Clouds using the GPU.	Comput. Graph. Forum	2021	DBLP DOI BibTeX RDF
13	Qin Liu 0001, Zhengzheng Hao, Yu Peng, Hongbo Jiang 0001, Jie Wu 0001, Tao Peng 0011, Guojun Wang 0001, Shaobo Zhang 0001	SecVKQ: Secure and verifiable kNN queries in sensor-cloud systems.	J. Syst. Archit.	2021	DBLP DOI BibTeX RDF
13	Jie Gui, Yuan Cao 0005, Heng Qi, Keqiu Li, Jieping Ye, Chao Liu 0008, Xiaowei Xu 0005	Fast kNN Search in Weighted Hamming Space With Multiple Tables.	IEEE Trans. Image Process.	2021	DBLP DOI BibTeX RDF
13	Angelo Coluccia, Alessio Fascista, Giuseppe Ricci	Synthetic training set for KNN detection in non-Gaussian noise.		2021	DOI RDF
13	Yevhen Chychkarov, Anastasiia Serhiienko, Iryna Syrmamiikh, Anatolii Kargin	Handwritten Digits Recognition Using SVM, KNN, RF and Deep Learning Neural Networks.	CMIS	2021	DBLP BibTeX RDF
13	Jie Tang 0003, Jiehui Zhang, Zhixin Zeng, Shaoshan Liu	A KNN Query Method for Autonomous Driving Sensor Data.	NPC	2021	DBLP DOI BibTeX RDF
13	Jinfei Liu, Li Xiong 0001, Qiuchen Zhang, Jian Pei, Jun Luo 0007	Eclipse: Generalizing kNN and Skyline.	ICDE	2021	DBLP DOI BibTeX RDF