Search results for "Niching"

Hits ?▲	Authors	Title	Venue	Year	Link	Author keywords
192	Minqiang Li, Dan Lin 0002, Jisong Kou	An investigation on niching multiple species based on population replacement strategies for multimodal functions optimization.	Soft Comput.	2010	DBLP DOI BibTeX RDF	Population replacement, Niching strategy, Crowding with nearest neighbors replacement, Species conserving technique, Hierarchical fair competition, Clearing procedure, Species conservation, Genetic algorithms, Multimodal functions optimization
137	Ofer M. Shir, Thomas Bäck	Niching with derandomized evolution strategies in artificial and real-world landscapes.	Nat. Comput.	2009	DBLP DOI BibTeX RDF	Derandomized evolution strategies, CMA, Quantum control, Niching, Laser pulse shaping
137	Ofer M. Shir, Thomas Bäck	Performance analysis of niching algorithms based on derandomized-ES variants.	GECCO	2007	DBLP DOI BibTeX RDF	MPR analysis, derandomized evolution strategies, niching
115	Stefan Bird, Xiaodong Li 0001	Adaptively choosing niching parameters in a PSO.	GECCO	2006	DBLP DOI BibTeX RDF	multimodal function optimisation, evolutionary computation, particle swarms
102	Ofer M. Shir, Michael Emmerich, Thomas Bäck	Self-Adaptive Niching CMA-ES with Mahalanobis Metric.	IEEE Congress on Evolutionary Computation	2007	DBLP DOI BibTeX RDF
102	Ofer M. Shir, Thomas Bäck	Dynamic niching in evolution strategies with covariance matrix adaptation.	Congress on Evolutionary Computation	2005	DBLP DOI BibTeX RDF
102	Jianjun Hu, Erik D. Goodman	Robust and Efficient Genetic Algorithms with Hierarchical Niching and a Sustainable Evolutionary Computation Model.	GECCO (1)	2004	DBLP DOI BibTeX RDF
95	Minqiang Li, Jisong Kou	Crowding with nearest neighbors replacement for multiple species niching and building blocks preservation in binary multimodal functions optimization.	J. Heuristics	2008	DBLP DOI BibTeX RDF	Nearest neighbors replacement, Binary multimodal functions optimization, Genetic algorithms, Niching, Crowding, Steady-state genetic algorithms
82	Weiguo Sheng, Allan Tucker, Xiaohui Liu 0001	A niching genetic k-means algorithm and its applications to gene expression data.	Soft Comput.	2010	DBLP DOI BibTeX RDF	Niching methods, Genetic algorithms, Clustering, K-means, Gene expression
82	Ofer M. Shir, Thomas Bäck	Niching in evolution strategies.	GECCO	2005	DBLP DOI BibTeX RDF	multiple optima search, niching methods, evolution strategies
76	Hirotaka Moriguchi, Shinichi Honiden	Sustaining behavioral diversity in NEAT.	GECCO	2010	DBLP DOI BibTeX RDF	behavioral diversity, neuroevolution, niching, premature convergence, neat
76	Gulshan Singh, Kalyanmoy Deb	Comparison of multi-modal optimization algorithms based on evolutionary algorithms.	GECCO	2006	DBLP DOI BibTeX RDF	clearing, restricted tournament selection, species conserving GA, sharing, niching, crowding
74	Rui Li 0001, Jeroen Eggermont, Ofer M. Shir, Michael T. M. Emmerich, Thomas Bäck, Jouke Dijkstra, Johan H. C. Reiber	Mixed-Integer Evolution Strategies with Dynamic Niching.	PPSN	2008	DBLP DOI BibTeX RDF
74	Ofer M. Shir, Christian Siedschlag, Thomas Bäck, Marc J. J. Vrakking	Niching in Evolution Strategies and Its Application to Laser Pulse Shaping.	Artificial Evolution	2005	DBLP DOI BibTeX RDF
74	Kumara Sastry, Hussein A. Abbass, David E. Goldberg	Sub-structural Niching in Non-stationary Environments.	Australian Conference on Artificial Intelligence	2004	DBLP DOI BibTeX RDF
74	Robert E. Smith 0001, Claudio Bonacina	Mating Restriction and Niching Pressure: Results from Agents and Implications for General EC.	GECCO	2003	DBLP DOI BibTeX RDF
68	Mike Preuss	Niching the CMA-ES via nearest-better clustering.	GECCO (Companion)	2010	DBLP DOI BibTeX RDF	benchmarking, black-box optimization, niching
68	Weiguo Sheng, Xiaohui Liu, Michael C. Fairhurst	A Niching Memetic Algorithm for Simultaneous Clustering and Feature Selection.	IEEE Trans. Knowl. Data Eng.	2008	DBLP DOI BibTeX RDF	niching method, genetic algorithm, Clustering, feature selection, local search, memetic algorithm
68	Cédric Auliac, Florence d'Alché-Buc, Vincent Frouin	Learning Transcriptional Regulatory Networks with Evolutionary Algorithms Enhanced with Niching.	WILF	2007	DBLP DOI BibTeX RDF	evolutionary algorithms, gene regulatory network, niching
68	Mohand Boughanem, Lynda Tamine	A Study on Using Genetic Niching for Query Optimisation in Document Retrieval.	ECIR	2002	DBLP DOI BibTeX RDF	multiple query evaluation, genetic algorithm, Information retrieval, niching
60	Oliver Kramer 0001, Holger Danielsiek	DBSCAN-based multi-objective niching to approximate equivalent pareto-subsets.	GECCO	2010	DBLP DOI BibTeX RDF	hybrid evolutionary multiobjective algorithm, local search, memetic algorithms, hybrid metaheuristics
60	Johannes W. Kruisselbrink, Alexander Aleman, Michael T. M. Emmerich, Adriaan P. IJzerman, Andreas Bender 0002, Thomas Bäck, Eelke van der Horst	Enhancing search space diversity in multi-objective evolutionary drug molecule design using niching.	GECCO	2009	DBLP DOI BibTeX RDF	evolutionary algorithms, drug design, molecules
60	Lin Hao, Maoguo Gong, Yifei Sun, Jin Pan	Niching Clonal Selection Algorithm for Multimodal Function Optimization.	ICNC (1)	2006	DBLP DOI BibTeX RDF
60	Weiguo Sheng, Stephen Swift, Leishi Zhang, Xiaohui Liu	A weighted sum validity function for clustering with a hybrid niching genetic algorithm.	IEEE Trans. Syst. Man Cybern. Part B	2005	DBLP DOI BibTeX RDF
60	Minqiang Li, Jisong Kou	A Novel Type of Niching Methods Based on Steady-State Genetic Algorithm.	ICNC (3)	2005	DBLP DOI BibTeX RDF
60	Andrew R. McIntyre, Malcolm I. Heywood	On Multi-class Classification by Way of Niching.	GECCO (2)	2004	DBLP DOI BibTeX RDF
60	Felix Streichert, Gunnar Stein, Holger Ulmer, Andreas Zell	A Clustering Based Niching Method for Evolutionary Algorithms.	GECCO	2003	DBLP DOI BibTeX RDF
54	Lúcia V. R. Arruda, M. C. S. Swiech, Myriam Regattieri Delgado, Flávio Neves Jr.	PID control of MIMO process based on rank niching genetic algorithm.	Appl. Intell.	2008	DBLP DOI BibTeX RDF	Multiple-input multiple-output (MIMO) process, Genetic Algorithm, Multiobjective Optimization, Pareto optimality, PID control, Niching
47	Yishen Lin, Hong Peng, Jia Wei	A Niching Gene Expression Programming Algorithm Based on Parallel Model.	APPT	2007	DBLP DOI BibTeX RDF
47	Changyin Sun, Hua Liang, Linfeng Li, Derong Liu 0001	Clustering with a Weighted Sum Validity Function Using a Niching PSO Algorithm.	ICNSC	2007	DBLP DOI BibTeX RDF
47	Daniel Angus	Niching for Population-Based Ant Colony Optimization.	e-Science	2006	DBLP DOI BibTeX RDF
47	Ofer M. Shir, Thomas Bäck	Niche Radius Adaptation in the CMA-ES Niching Algorithm.	PPSN	2006	DBLP DOI BibTeX RDF
47	Jun Zhang 0032, Jing-Ru Zhang, Kang Li	A Sequential Niching Technique for Particle Swarm Optimization.	ICIC (1)	2005	DBLP DOI BibTeX RDF
47	Parveen Kalra, P. B. Mahapatra, D. K. Aggarwal	On the comparison of niching strategies for finding solution of multimodal robot inverse kinematics functions.	SMC (6)	2004	DBLP DOI BibTeX RDF
47	Rajeev Kumar, Peter I. Rockett	Effective Evolutionary Multimodal Optimization by Multiobjective Reformulation Without Explicit Niching/Sharing.	AACC	2004	DBLP DOI BibTeX RDF
47	Marco Cioffi, Alessandro Formisano, Raffaele Martone	Distributed Niching Concept for Electromagnetic Shape Optimization by Genetic Algorithm.	PARELEC	2000	DBLP DOI BibTeX RDF
41	Jeffrey Horn	Optimal Nesting of Species for Exact Cover: Many against Many.	PPSN	2008	DBLP DOI BibTeX RDF
41	Vincent van der Goes, Ofer M. Shir, Thomas Bäck	Niche Radius Adaptation with Asymmetric Sharing.	PPSN	2008	DBLP DOI BibTeX RDF
41	Xiaodong Li 0001	A multimodal particle swarm optimizer based on fitness Euclidean-distance ratio.	GECCO	2007	DBLP DOI BibTeX RDF	evolutionary computation, particle swarm optimization, swarm intelligence
41	Yishen Lin, Hong Peng	Niche Gene Expression Programming Based on Clustering Model.	IITA	2007	DBLP DOI BibTeX RDF
41	Rafal Drezewski	A Co-evolutionary Multi-agent System for Multi-modal Function Optimization.	International Conference on Computational Science	2004	DBLP DOI BibTeX RDF
40	Kumara Sastry, Hussein A. Abbass, David E. Goldberg, D. D. Johnson	Sub-structural niching in estimation of distribution algorithms.	GECCO	2005	DBLP DOI BibTeX RDF	fitness estimation, genetic algorithms, multimodal, probabilistic models, estimation of distribution algorithms, building blocks, niching, multiobjective, eCGA, fitness approximation
38	Xiaodong Li 0001	Niching Without Niching Parameters: Particle Swarm Optimization Using a Ring Topology.	IEEE Trans. Evol. Comput.	2010	DBLP DOI BibTeX RDF
38	Xiaodong Li 0001	Erratum to "Niching Without Niching Parameters: Particle Swarm Optimization Using a Ring Topology" [Feb 10 150-169].	IEEE Trans. Evol. Comput.	2010	DBLP DOI BibTeX RDF
35	Cláudio F. Lima, Carlos M. Fernandes 0001, Fernando G. Lobo	Investigating restricted tournament replacement in ECGA for non-stationary environments.	GECCO	2008	DBLP DOI BibTeX RDF	restricted tournament replacement, genetic algorithms, estimation of distribution algorithms, niching, diversity preservation, non-stationary environments
35	Jeffrey Horn	Optimal nesting of species for exact cover of resources: two against many.	GECCO	2007	DBLP DOI BibTeX RDF	exact cover, shape nesting, species, genetic algorithm, evolutionary computation, tiling, coevolution, niches, niching
35	Jeffrey Horn	Shape nesting by coevolving species.	GECCO	2005	DBLP DOI BibTeX RDF	cooperative-competitive evolution, shape nesting, genetic algorithm, evolutionary computation, coevolution, resource sharing, niching, cooperative coevolution, speciation, fitness sharing
35	Mike Preuss, Lutz Schönemann, Michael Emmerich	Counteracting genetic drift and disruptive recombination in (µ, +lambda)-EA on multimodal fitness landscapes.	GECCO	2005	DBLP DOI BibTeX RDF	markov simulation, clustering, evolution strategies, niching, multimodal optimization, genetic drift
35	Michael Sanders, Richard Lobb, Patricia Riddle	Evolving controllers for virtual creature locomotion.	GRAPHITE	2003	DBLP DOI BibTeX RDF	evolutionary algorithms, niching, mass-spring systems, locomotion controllers, virtual creatures
33	José Luis Ávila-Jiménez, Eva Lucrecia Gibaja Galindo, Amelia Zafra, Sebastián Ventura	A Niching Algorithm to Learn Discriminant Functions with Multi-Label Patterns.	IDEAL	2009	DBLP DOI BibTeX RDF
33	Jose Joaquin Aguilera, Manuel Chica, María José del Jesus, Francisco Herrera	Niching Genetic Feature Selection Algorithms Applied to the Design of Fuzzy Rule-based Classification Systems.	FUZZ-IEEE	2007	DBLP DOI BibTeX RDF
33	Isabella Schoeman, Andries P. Engelbrecht	Niching for Dynamic Environments Using Particle Swarm Optimization.	SEAL	2006	DBLP DOI BibTeX RDF
33	Peter Lichodzijewski, Malcolm I. Heywood, Nur Zincir-Heywood	CasGP: building cascaded hierarchical models using niching.	Congress on Evolutionary Computation	2005	DBLP DOI BibTeX RDF
33	Weiguo Sheng, Allan Tucker, Xiaohui Liu 0001	Clustering with Niching Genetic K-means Algorithm.	GECCO (2)	2004	DBLP DOI BibTeX RDF
33	Felix Streichert, Gunnar Stein, Holger Ulmer, Andreas Zell	A Clustering Based Niching EA for Multimodal Search Spaces.	Artificial Evolution	2003	DBLP DOI BibTeX RDF
33	Alexis Bienvenüe, Marc Joannides, Jean Bérard, Éric Fontenas, Olivier François	Niching in Monte Carlo Filtering Algorithms.	Artificial Evolution	2001	DBLP DOI BibTeX RDF
33	Akira Imada, Keijiro Araki	Can a Niching Method Locate Multiple Attractors Embedded in the Hopfield Network?	SEAL	1998	DBLP DOI BibTeX RDF
33	Márk Jelasity	UEGO, an Abstract Niching Technique for Global Optimization.	PPSN	1998	DBLP DOI BibTeX RDF
33	Shigeru Obayashi, Shinichi Takahashi, Yukihiro Takeguchi	Niching and Elitist Models for MOGAs.	PPSN	1998	DBLP DOI BibTeX RDF
33	Alasdair Turner, David Corne, Graeme Ritchie, Peter Ross	Obtaining Multiple Distinct Solutions with Genetic Algorithm Niching Methods.	PPSN	1996	DBLP DOI BibTeX RDF
28	Rafal Drezewski, Marek Kisiel-Dorohinicki	Maintaining Diversity in Agent-Based Evolutionary Computation.	International Conference on Computational Science (3)	2006	DBLP DOI BibTeX RDF
28	Nasreddine Hallam, Peter Blanchfield, Graham Kendall	Handling diversity in evolutionary multiobjective optimization.	Congress on Evolutionary Computation	2005	DBLP DOI BibTeX RDF
28	Grazziela Patrocinio Figueredo, Luís Alfredo V. de Carvalho, Helio J. C. Barbosa	Coevolutionary Genetic Algorithms to Simulate the Immune System's Gene Libraries Evolution.	ICNC (2)	2005	DBLP DOI BibTeX RDF
28	Rajeev Kumar, Peter I. Rockett	Evolutionary Multimodal Optimization Revisited.	GECCO	2003	DBLP DOI BibTeX RDF
28	Martin Pelikan, David E. Goldberg	Genetic Algorithms, Clustering, and the Breaking of Symmetry.	PPSN	2000	DBLP DOI BibTeX RDF
28	Claudio De Stefano, Antonio Della Cioppa, Angelo Marcelli	Handwritten Numeral Recognition by means of Evolutionary Algorithms.	ICDAR	1999	DBLP DOI BibTeX RDF
28	Jeffrey Horn, David E. Goldberg	A Timing Analysis of Convergence to Fitness Sharing Equilibrium.	PPSN	1998	DBLP DOI BibTeX RDF
28	Susanne Beiersdörfer, Jens B. Schmitt, Markus Sauer, Andreas Schulz, Stefan Siebert 0003, Jürgen Hesser, Reinhard Männer, Jürgen Wolfrum	Finding the Conformation of Organic Molecules with Genetic Algorithms.	PPSN	1996	DBLP DOI BibTeX RDF
21	Hamid Reza Hassanzadeh, Modjtaba Rouhani	A Multi-objective Gravitational Search Algorithm.	CICSyN	2010	DBLP DOI BibTeX RDF	Multi-objective Particle Swarm Optimization (MOPSO), Multi-objective Gravitational Search Algorithm (MOGSA), Indirect Niching, Pareto Optimality
21	Severino F. Galán, Ole J. Mengshoel	Generalized crowding for genetic algorithms.	GECCO	2010	DBLP DOI BibTeX RDF	deterministic crowding, probabilistic crowding, genetic algorithms, bayesian networks, experiments, niching, markov chain analysis
21	Martin V. Butz, David E. Goldberg, Pier Luca Lanzi, Kumara Sastry	Problem solution sustenance in XCS: Markov chain analysis of niche support distributions and the impact on computational complexity.	Genet. Program. Evolvable Mach.	2007	DBLP DOI BibTeX RDF	Solution sustenance, Learning classifier systems, XCS, Mutation, LCS, Niching, Markov chain analysis
21	Shin Ando	Heuristic speciation for evolving neural network ensemble.	GECCO	2007	DBLP DOI BibTeX RDF	neural network, pattern recognition, evolutionary design, niching
21	Kumara Sastry, D. D. Johnson, Alexis L. Thompson, David E. Goldberg, Todd J. Martínez, Jeff Leiding, Jane Owens	Multiobjective genetic algorithms for multiscaling excited state direct dynamics in photochemistry.	GECCO	2006	DBLP DOI BibTeX RDF	multiobjective genetic algorithms, non-domination, photochemistry, semiempirical methods, niching, population sizing, NSGA-II, convergence time, multiscale modeling
21	Shin Ando, Shigenobu Kobayashi	Fitness-based neighbor selection for multimodal function optimization.	GECCO	2005	DBLP DOI BibTeX RDF	genetic algorithm, niching, multimodal optimization
21	Emily M. Zechman, S. Ranji Ranjithan	Multipopulation cooperative coevolutionary programming (MCCP) to enhance design innovation.	GECCO	2005	DBLP DOI BibTeX RDF	lymphoma cancer classification, genetic programming, evolutionary programming, niching
19	Jine Cao, Pinlu Cao, Chengda Wen, Hongyu Cao, Shanshan Yao, Qilei Yin	Multi-objective niching quantum genetic algorithm-based optimization method for pneumatic hammer structure.	Expert Syst. Appl.	2024	DBLP DOI BibTeX RDF
19	Yuhan Wu, Xiyu Meng, Junru Zhang, Yang He, Joseph A. Romo, Yabo Dong, Dongming Lu	Effective LSTMs with seasonal-trend decomposition and adaptive learning and niching-based backtracking search algorithm for time series forecasting.	Expert Syst. Appl.	2024	DBLP DOI BibTeX RDF
19	Yu Sun, Yuqing Chang, Shengxiang Yang, Fuli Wang	Dynamic niching particle swarm optimization with an external archive-guided mechanism for multimodal multi-objective optimization.	Inf. Sci.	2024	DBLP DOI BibTeX RDF
19	Shuijia Li, Wenyin Gong, Qiong Gu, Zuowen Liao	Adaptive dual niching-based differential evolution with resource reallocation for nonlinear equation systems.	Neural Comput. Appl.	2023	DBLP DOI BibTeX RDF
19	Yu Sun, Shen Zhang	A decomposition and dynamic niching distance-based dual elite subpopulation evolutionary algorithm for multimodal multiobjective optimization.	Expert Syst. Appl.	2023	DBLP DOI BibTeX RDF
19	Peng Wang 0102, Bing Xue 0001, Jing J. Liang, Mengjie Zhang 0001	Differential Evolution-Based Feature Selection: A Niching-Based Multiobjective Approach.	IEEE Trans. Evol. Comput.	2023	DBLP DOI BibTeX RDF
19	Shi-Jie Jian, Sun-Yuan Hsieh	A Niching Regression Adaptive Memetic Algorithm for Multimodal Optimization of the Euclidean Traveling Salesman Problem.	IEEE Trans. Evol. Comput.	2023	DBLP DOI BibTeX RDF
19	Zuowen Liao, Xianyan Mi, Qishuo Pang, Yu Sun	History archive assisted niching differential evolution with variable neighborhood for multimodal optimization.	Swarm Evol. Comput.	2023	DBLP DOI BibTeX RDF
19	Tao Ma, Hong Zhao, Xiangqian Li, Fang Yang, Chunsheng Liu, Jing Liu	A coarse- and fine-grained niching-based differential evolution for multimodal optimization problems and its application in multirobot task allocation.	Swarm Evol. Comput.	2023	DBLP DOI BibTeX RDF
19	Libin Hong 0001, Xinmeng Yu, Ben Wang, John R. Woodward, Ender Özcan	An improved ensemble particle swarm optimizer using niching behavior and covariance matrix adapted retreat phase.	Swarm Evol. Comput.	2023	DBLP DOI BibTeX RDF
19	Jing J. Liang, Leiyu Zhang, Kunjie Yu, Boyang Qu, Fuxing Shang, Kangjia Qiao	Interactive niching-based two-stage evolutionary algorithm for constrained multiobjective optimization.	Swarm Evol. Comput.	2023	DBLP DOI BibTeX RDF
19	Luis A. Márquez-Vega, Jesús Guillermo Falcón-Cardona, Edgar Covantes Osuna	On the adaptation of reference sets using niching and pair-potential energy functions for multi-objective optimization.	Swarm Evol. Comput.	2023	DBLP DOI BibTeX RDF
19	Shuai Wang 0009, Xiaojun Tan	Finding robust influential seeds from networked systems against structural failures using a niching memetic algorithm.	Appl. Soft Comput.	2023	DBLP DOI BibTeX RDF
19	Xiangqian Li, Hong Zhao, Jing Liu	Minimum spanning tree niching-based differential evolution with knowledge-driven update strategy for multimodal optimization problems.	Appl. Soft Comput.	2023	DBLP DOI BibTeX RDF
19	Rui Wang, Kuangrong Hao, Biao Huang 0001, Xiuli Zhu	Adaptive niching particle swarm optimization with local search for multimodal optimization.	Appl. Soft Comput.	2023	DBLP DOI BibTeX RDF
19	Yucheng Zhuang, Yikun Huang, Wenyu Liu 0004	Integrating Sensor Ontologies with Niching Multi-Objective Particle Swarm Optimization Algorithm.	Sensors	2023	DBLP DOI BibTeX RDF
19	Hao Yan, Lu Zhang, Xiaoyu Wang, Qingping Liu, Mengjun Gu, Weiguo Sheng	Differential Evolution with Clustering-based Niching and Adaptive Mutation for Global Optimization.	CEC	2023	DBLP DOI BibTeX RDF
19	Yanxia Sun, Zenghui Wang, Yves Matanga	Nonlinear system identification using a semi concurrent sequential niching framework.	CSAI	2023	DBLP DOI BibTeX RDF
19	Anjali de Silva, Gang Chen 0002, Hui Ma 0001, Seyed Mohammad Nekooei	Leiden Fitness-Based Genetic Algorithm with Niching for Community Detection in Large Social Networks.	PRICAI (2)	2023	DBLP DOI BibTeX RDF
19	Rong Wan, Wei-Neng Chen, Xuan-Li Shi, Ming-Can Geng	Genetic Algorithm with Dynamic Fitness Sharing Niching Method for Multimodal Opinion Maximization Problem.	SMC	2023	DBLP DOI BibTeX RDF
19	Hayden Andersen, Andrew Lensen, Will N. Browne, Yi Mei 0001	Producing Diverse Rashomon Sets of Counterfactual Explanations with Niching Particle Swarm Optimization Algorithms.	GECCO	2023	DBLP DOI BibTeX RDF
19	Arthur Holtrup Bianchini, Brenda Silva Machado, Jônata Tyska Carvalho	The Effectiveness of Niching on OpenAI-Evolution Strategies in the Evolution of Robotic Behavior.	GECCO Companion	2023	DBLP DOI BibTeX RDF
19	Jing-Ting Huang, Tsung-Che Chiang	Promising Area Exploration Based on Hybrid Niching: A Metaheuristic Search Framework for Multimodal Optimization.	IEEM	2023	DBLP DOI BibTeX RDF
19	Xingsi Xue, Hai Zhu 0001	Matching Knowledge Graphs with Compact Niching Evolutionary Algorithm.	Expert Syst. Appl.	2022	DBLP DOI BibTeX RDF
19	Shuo-Peng Gong, Mohammad Khishe, Mokhtar Mohammadi	Niching chimp optimization for constraint multimodal engineering optimization problems.	Expert Syst. Appl.	2022	DBLP DOI BibTeX RDF