Search results for "Balanced"

Hits ?▲	Authors	Title	Venue	Year	Link	Author keywords
16	Govind Krishnamurthi, Arun K. Somani	Effect of Failures on Optimal Location Management Algorithms.	FTCS	1999	DBLP DOI BibTeX RDF	database failures, robust load balancing, query delay, call blocking probability, PCS networks
16	Yuan C. Chou, Daniel P. Siewiorek, John Paul Shen	A Realistic Study on Multithreaded Superscalar Processor Design.	Euro-Par	1997	DBLP DOI BibTeX RDF
16	Kaoru Kurosawa, Takashi Satoh	Design of SAC/PC(l) of Order k Boolean Functions and Three Other Cryptographic Criteria.	EUROCRYPT	1997	DBLP DOI BibTeX RDF
16	Teofilo F. Gonzalez	The On-Line d-Dimensional Dictionary Problem.	SODA	1992	DBLP BibTeX RDF
16	Hongzhong Wu	On Tests of Uniform Tree Circuits.	CONPAR	1992	DBLP DOI BibTeX RDF
16	Ricardo A. Baeza-Yates, Gaston H. Gonnet, Nivio Ziviani	Expected Behaviour Analysis of AVL Trees.	SWAT	1990	DBLP DOI BibTeX RDF
16	Andreas Henrich, Hans-Werner Six, Peter Widmayer	Paging Binary Trees with External Balancing.	WG	1989	DBLP DOI BibTeX RDF
14	Hesam Chiniforooshan Esfahani, Eric S. K. Yu, Maria Carmela Annosi	Strategically balanced process adoption.	ICSSP	2011	DBLP DOI BibTeX RDF
14	Cristina Vagnoni, Marino Zennaro	The Analysis and the Representation of Balanced Complex Polytopes in 2D.	Found. Comput. Math.	2009	DBLP DOI BibTeX RDF	Mathematics Subject Classification (2000) 52B12, 52B55, 65Y99
14	Yuri L. Borissov	On the Cusick-Cheon Conjecture About Balanced Boolean Functions in the Cosets of the Binary Reed-Muller Code.	IEEE Trans. Inf. Theory	2009	DBLP DOI BibTeX RDF
14	Yuan Wu 0001, Danny H. K. Tsang	Joint Rate-and-Power Allocation for Multi-channel Spectrum Sharing Networks with Balanced QoS Provisioning and Power Saving.	Mob. Networks Appl.	2009	DBLP DOI BibTeX RDF	multi-channel spectrum sharing, QoS provisioning, non-cooperative game
14	Claude Carlet, Keqin Feng	An Infinite Class of Balanced Vectorial Boolean Functions with Optimum Algebraic Immunity and Good Nonlinearity.	IWCC	2009	DBLP DOI BibTeX RDF
14	Masaaki Kumagai, Takaya Ochiai	Development of a robot balanced on a ball - Application of passive motion to transport -.	ICRA	2009	DBLP DOI BibTeX RDF
14	Jing-Ming Guo, Jia-Jin Tsai	Data Hiding in Halftone Images Using Adaptive Noise-Balanced Error Diffusion and Quality-Noise Look Up Table.	IAS	2009	DBLP DOI BibTeX RDF
14	Vicente García 0001, Ramón Alberto Mollineda, José Salvador Sánchez 0001	Index of Balanced Accuracy: A Performance Measure for Skewed Class Distributions.	IbPRIA	2009	DBLP DOI BibTeX RDF
14	Chi Ho Yeung, K. Y. Michael Wong	Self-organized Balanced Resources in Random Networks with Transportation Bandwidths.	Complex (1)	2009	DBLP DOI BibTeX RDF	Maxwell’s construction, Bethe approximation, resource allocation, message-passing, bandwidth, scale-free networks
14	Duo Li, Sheldon X.-D. Tan, Gengsheng Chen, Xuan Zeng 0001	Statistical analysis of on-chip power grid networks by variational extended truncated balanced realization method.	ASP-DAC	2009	DBLP DOI BibTeX RDF
14	Weihua Gong, Liang Huai Yang, Decai Huang, Lijun Chen 0002	New Balanced Data Allocating and Online Migrating Algorithms in Database Cluster.	APWeb/WAIM	2009	DBLP DOI BibTeX RDF	Heterogeneous database cluster, Over-loaded nodes, Load balancing, Data distribution
14	Jong-Hyuk Lee, SungJin Song, Joon-Min Gil, Kwang-Sik Chung, Taeweon Suh, Heon-Chang Yu	Balanced Scheduling Algorithm Considering Availability in Mobile Grid.	GPC	2009	DBLP DOI BibTeX RDF	scheduling, load balancing, availability, mobile grid
14	Antonio Restivo, Giovanna Rosone	Balanced Words Having Simple Burrows-Wheeler Transform.	Developments in Language Theory	2009	DBLP DOI BibTeX RDF
14	Xiang Zhou	CFI Construction and Balanced Graphs.	FAW	2009	DBLP DOI BibTeX RDF
14	David Rodríguez Rueda, Carlos Cotta, Antonio J. Fernández 0001	Finding Balanced Incomplete Block Designs with Metaheuristics.	EvoCOP	2009	DBLP DOI BibTeX RDF
14	Rabindra Bista, Yong-Ki Kim 0001, Young-Ho Choi, Jae-Woo Chang	A New Energy-Balanced Data Aggregation Scheme in Wireless Sensor Networks.	CSE (2)	2009	DBLP DOI BibTeX RDF
14	K. Renuga, S. S. Tan, Y. Q. Zhu, T. C. Low, Y. H. Wang	Balanced and Efficient Data Placement and Replication Strategy for Distributed Backup Storage Systems.	CSE (1)	2009	DBLP DOI BibTeX RDF
14	Long-Sheng Li, Gwo-Chuan Lee, Li-Keng Kang, Jhu-Shyuan Mei	Construct the Load-Balanced Topology in NEMO.	ICA3PP	2009	DBLP DOI BibTeX RDF	Router Advertisement, MANET, Load Balancing, Network Mobility, Mobile Router
14	Moonseong Kim, Matt W. Mutka	On Relocation of Hopping Sensors for Balanced Migration Distribution of Sensors.	ICCSA (2)	2009	DBLP DOI BibTeX RDF	Hopping Sensors, Wireless Sensor Networks (WSNs), Mobile Sensors, Relocation
14	Hsueh-I Lu, Chia-Chi Yeh	Balanced parentheses strike back.	ACM Trans. Algorithms	2008	DBLP DOI BibTeX RDF	XML document representation, Succinct data structures
14	Khoongming Khoo, Chu-Wee Lim, Guang Gong	Highly nonlinear balanced S-boxes with improved bound on unrestricted and generalized nonlinearity.	Appl. Algebra Eng. Commun. Comput.	2008	DBLP DOI BibTeX RDF	Generalized nonlinearity, Unrestricted nonlinearity, Vectorial Boolean functions, Power functions
14	Jianxing Yin, Jie Yan, Chengmin Wang	Generalized balanced tournament designs and related codes.	Des. Codes Cryptogr.	2008	DBLP DOI BibTeX RDF	AMS Classifications 05B05, 94B25
14	Ngai Wong	Efficient Positive-Real Balanced Truncation of Symmetric Systems Via Cross-Riccati Equations.	IEEE Trans. Comput. Aided Des. Integr. Circuits Syst.	2008	DBLP DOI BibTeX RDF
14	Jie Fang	Ockham Algebras with Balanced Double Pseudocomplementation.	Stud Logica	2008	DBLP DOI BibTeX RDF	double pseudocomplementation, Ockham algebra, Priestely duality, subdirectly irreducible
14	Cunsheng Ding	Optimal Constant Composition Codes From Zero-Difference Balanced Functions.	IEEE Trans. Inf. Theory	2008	DBLP DOI BibTeX RDF
14	Karan Gupta, Prasenjit Sarkar, Lesley Mbogo	MIRAGE: storage provisioning in large data centers using balanced component utilizations.	ACM SIGOPS Oper. Syst. Rev.	2008	DBLP DOI BibTeX RDF	storage optimization, algorithm, data center
14	Sarra Bouallagui, Le Thi Hoai An, Pham Dinh Tao	Design of Highly Nonlinear Balanced Boolean Functions Using an Hybridation of DCA and Simulated Annealing Algorithm.	MCO	2008	DBLP DOI BibTeX RDF	DCA (DC Algorithm), SA, Boolean function, nonlinearity, balance, DC programming
14	Luca Di Gaspero, Andrea Schaerf	Hybrid Local Search Techniques for the Generalized Balanced Academic Curriculum Problem.	Hybrid Metaheuristics	2008	DBLP DOI BibTeX RDF
14	Zongyao Tang, Xuezhi Xing, Fan Jiang 0005	Providing Balanced and Enhanced Transmission for WLANs with Multi-beam Access Point.	CNSR	2008	DBLP DOI BibTeX RDF	multi-beam antenna, WLAN, MAC
14	Rani Rizk, Sébastien Krut, Etienne Dombre	Design of a 3D gravity balanced orthosis for upper limb.	ICRA	2008	DBLP DOI BibTeX RDF
14	Aaron Archer, Shankar Krishnan	Importance Sampling via Load-Balanced Facility Location.	IPCO	2008	DBLP DOI BibTeX RDF
14	Brighten Godfrey	Balls and bins with structure: balanced allocations on hypergraphs.	SODA	2008	DBLP BibTeX RDF
14	Haider Rizvi, Joyce Coleman, Sam Lightstone	Poster session: Simplifying business intelligence with a hybrid appliance: the IBM balanced warehouse.	ICDE Workshops	2008	DBLP DOI BibTeX RDF
14	Masataka Suzuki, Shinya Kitai, Shigeo Hirose	Advanced child unit of "Anchor Climber" using modified internally-balanced magnet.	IROS	2008	DBLP DOI BibTeX RDF
14	Chengjie Wu, Ruixi Yuan, Hongchao Zhou	A Novel Load Balanced and Lifetime Maximization Routing Protocol in Wireless Sensor Networks.	VTC Spring	2008	DBLP DOI BibTeX RDF
14	Pejman Lotfi-Kamran, Masoud Daneshtalab, Caro Lucas, Zainalabedin Navabi	BARP-A Dynamic Routing Protocol for Balanced Distribution of Traffic in NoCs.	DATE	2008	DBLP DOI BibTeX RDF
14	Steven D. Galbraith, Michael Harrison, David J. Mireles Morales	Efficient Hyperelliptic Arithmetic Using Balanced Representation for Divisors.	ANTS	2008	DBLP DOI BibTeX RDF
14	Lee Kee Goh, Bharadwaj Veeravalli	An Energy-Balanced Task Scheduling Heuristic for Heterogeneous Wireless Sensor Networks.	HiPC	2008	DBLP DOI BibTeX RDF	heterogeneous multiprocessor scheduling, wireless sensor network, power management, dynamic voltage scaling, Energy-aware scheduling
14	Changqiao Xu, Gabriel-Miro Muntean, Enda Fallon, Austin Hanley	A Balanced Tree-Based Strategy for Unstructured Media Distribution in P2P Networks.	ICC	2008	DBLP DOI BibTeX RDF
14	Hojoong Kwon, Byeong Gi Lee	A Resource Allocation with Balanced Data Throughput and Power Consumption under QoS Constraint in MIMO Interference Systems: A Noncooperative Game Approach.	ICC	2008	DBLP DOI BibTeX RDF
14	Ranjan Pal	A Lexicographically Optimal Load Balanced Routing Scheme for Wireless Mesh Networks.	ICC	2008	DBLP DOI BibTeX RDF
14	Wei He, Hui Li, Bingrui Wang, Qin-shu Chen, Peng Yi, Binqiang Wang	Load-Balanced Multipath Self-Routing Switching Structure by Concentrators.	ICC	2008	DBLP DOI BibTeX RDF
14	Dong In Kim	Multiple Access Performance of M-ary Orthogonal Balanced UWB Transmitted-Reference Systems.	ICC	2008	DBLP DOI BibTeX RDF
14	Athanasios Christakidis, Nikolaos Efthymiopoulos, Spyros G. Denazis, Odysseas G. Koufopavlou	P2P-InfoReflect: Dynamic Locality-Aware and Multi-balanced Overlay for Network Dependent Applications and Services.	HPCC	2008	DBLP DOI BibTeX RDF
14	Mingui Zhang, Bin Liu 0001, Beichuan Zhang 0001	Load-Balanced IP Fast Failure Recovery.	IPOM	2008	DBLP DOI BibTeX RDF	load balance, Linear Programming, failure recovery, OSPF
14	Konrad J. Kulikowski, Vyas Venkataraman, Zhen Wang 0001, Alexander Taubin, Mark G. Karpovsky	Asynchronous balanced gates tolerant to interconnect variability.	ISCAS	2008	DBLP DOI BibTeX RDF
14	Amita Rani, Mayank Dave	Weighted load balanced routing protocol for MANET.	ICON	2008	DBLP DOI BibTeX RDF
14	Rahul S. Sampath, Santi S. Adavani, Hari Sundar, Ilya Lashuk, George Biros	Dendro: parallel algorithms for multigrid and AMR methods on 2: 1 balanced octrees.	SC	2008	DBLP DOI BibTeX RDF
14	Tsung-Han Lin, Tsung-Hsuan Ho, Yu-Wei Chan, Yeh-Ching Chung	M-Ring: A Distributed, Self-Organized, Load-Balanced Communication Method on Super Peer Network.	ISPAN	2008	DBLP DOI BibTeX RDF	peer-to-peer, DHT, chord, super peer
14	Hongbo Li 0012, Lei Huang	Complex brackets, balanced complex differences, and applications in symbolic geometric computing.	ISSAC	2008	DBLP DOI BibTeX RDF	bracket algebra, complex numbers method, graph theory, theorem proving, geometric algebra
14	Jesse S. A. Bridgewater, P. Oscar Boykin, Vwani P. Roychowdhury	Balanced Overlay Networks (BON): An Overlay Technology for Decentralized Load Balancing.	IEEE Trans. Parallel Distributed Syst.	2007	DBLP DOI BibTeX RDF	load balancing, Distributed computing, randomized algorithms, random walks, random graphs
14	Ngai Wong, Venkataramanan Balakrishnan	Fast Positive-Real Balanced Truncation Via Quadratic Alternating Direction Implicit Iteration.	IEEE Trans. Comput. Aided Des. Integr. Circuits Syst.	2007	DBLP DOI BibTeX RDF
14	Shuicheng Yan, Dong Xu 0001, Xiaoou Tang	Face Verification With Balanced Thresholds.	IEEE Trans. Image Process.	2007	DBLP DOI BibTeX RDF
14	Jun Wang 0063, Di Zheng, Huaimin Wang, Quanyuan Wu	Fuzzy Logic Based Replica Management Infrastructure for Balanced Resource Allocation and Efficient Overload Control of the Complex Service-Oriented Applications.	Analysis and Design of Intelligent Systems using Soft Computing Techniques	2007	DBLP DOI BibTeX RDF	Load Balancing, Middleware, Fuzzy Logic, Adaptive Resource Allocation, WebService
14	XiaoRan Wang, Shigeaki Tagashira, Satoshi Fujita	FDAR: A Load-Balanced Routing Scheme for Mobile Ad-Hoc Networks.	ADHOC-NOW	2007	DBLP DOI BibTeX RDF	routing, Ad-hoc network, load-balancing, metric
14	Ngai Wong	Fast positive-real balanced truncation of symmetric systems using cross Riccati equations.	DATE	2007	DBLP DOI BibTeX RDF
14	Ruay-Shiung Chang, Jih-Sheng Chang, Po-Sheng Lin	Balanced Job Assignment Based on Ant Algorithm for Computing Grids.	APSCC	2007	DBLP DOI BibTeX RDF
14	François Pellegrini	A Parallelisable Multi-level Banded Diffusion Scheme for Computing Balanced Partitions with Smooth Boundaries.	Euro-Par	2007	DBLP DOI BibTeX RDF
14	Amir Khatib Zadeh, Catherine H. Gebotys	Enhanced Current-Balanced Logic (ECBL): An Area Efficient Solution to Secure Smart Cards against Differential Power Attack.	ITNG	2007	DBLP DOI BibTeX RDF
14	Tony Benavides, Justin Treon, Weide Chang	The Apparatus and Enabling of a Code Balanced System.	ITNG	2007	DBLP DOI BibTeX RDF
14	Bruno Courcelle, Mamadou Moustapha Kanté	Graph Operations Characterizing Rank-Width and Balanced Graph Expressions.	WG	2007	DBLP DOI BibTeX RDF
14	Hai Jin 0001, Jie Xu 0006	TRES-CORE: Content-Based Retrieval Based on the Balanced Tree in Peer to Peer Systems.	PaCT	2007	DBLP DOI BibTeX RDF
14	Jorge-Arnulfo Quiané-Ruiz, Philippe Lamarre, Patrick Valduriez	KnBest - A Balanced Request Allocation Method for Distributed Information Systems.	DASFAA	2007	DBLP DOI BibTeX RDF
14	Jun Wang 0063, Yi Ren, Di Zheng, Quanyuan Wu	A Balanced Resource Allocation and Overload Control Infrastructure for the Service Grid Environment.	International Conference on Computational Science (1)	2007	DBLP DOI BibTeX RDF	Service based Grid Applications, Web Service, Load Balancing, Middleware, Adaptive Resource Allocation
14	Ching-Te Chiu, Yu-Hao Hsu, Min-Sheng Kao, Hou-Cheng Tzeng, Ming-Chang Du, Ping-Ling Yang, Ming-Hao Lu, Fanta Chen, Hung-Yu Lin, Jen-Ming Wu, Shuo-Hung Hsu, Yarsun Hsu	A Scalable Load Balanced Birkhoff-von Neumann Symmetric TDM Switch IC for High-Speed Networking Applications.	ISCAS	2007	DBLP DOI BibTeX RDF
14	Shreyas Prasad, André Schumacher, Harri Haanpää, Pekka Orponen	Balanced Multipath Source Routing.	ICOIN	2007	DBLP DOI BibTeX RDF
14	Sushmita Ruj, Bimal K. Roy	Key Predistribution Using Partially Balanced Designs in Wireless Sensor Networks.	ISPA	2007	DBLP DOI BibTeX RDF	PBIBD designs, Resiliency, Combinatorial Design
14	Aleksander Mendyk, Przemyslaw Dorozynski, Renata Jachowicz	Artificial Neural Networks as Modeling Tools in the Identification of Drugs Release Mechanisms from Hydrodynamically-Balanced Systems Formulated with Various Polymers.	IJCNN	2007	DBLP DOI BibTeX RDF
14	Yurong Zeng, Lin Wang 0001, Yonggang Wang	A Novel Model for Evaluating Performance of IT Department based on Balanced Scorecard and Artificial Neural Network Approach.	IITA	2007	DBLP DOI BibTeX RDF
14	Per Austrin	Balanced max 2-sat might not be the hardest.	STOC	2007	DBLP DOI BibTeX RDF	Max 2-Sat, inapproximability, unique games conjecture
14	Arun K. Somani	Capacity Balanced Efficient Protection and Grooming Architecture for Optical Networks - Keynote.	BROADNETS	2007	DBLP DOI BibTeX RDF
14	Edgar Magaña, Masum Hasan, Joan Serrat 0001	BLOMERS: Balanced Load Multi-Constrained Resource Scheduler.	ICNS	2007	DBLP DOI BibTeX RDF
14	Veit Köppen, Henner Graubitz, Hans-Knud Arndt, Hans-Joachim Lenz	A Procedure to Estimate Relations in a Balanced Scorecard.	GfKl	2007	DBLP DOI BibTeX RDF
14	Udi Wieder	Balanced allocations with heterogenous bins.	SPAA	2007	DBLP DOI BibTeX RDF	balls and bins, the multiple choice paradigm
14	Brice Augustin, Timur Friedman, Renata Teixeira	Measuring load-balanced paths in the internet.	Internet Measurement Conference	2007	DBLP DOI BibTeX RDF	load balancing, multipath, path diversity, traceroute
14	Miguel A. Otaduy, Olivier Chassot, Denis Steinemann, Markus H. Gross	Balanced Hierarchies for Collision Detection between Fracturing Objects.	VR	2007	DBLP DOI BibTeX RDF
14	Marlies van Steenbergen, Martin van den Berg, Sjaak Brinkkemper	A Balanced Approach to Developing the Enterprise Architecture Practice.	ICEIS (Selected Papers)	2007	DBLP DOI BibTeX RDF	Architecture Maturity Matrix, Software Process Improvement, Enterprise Architecture, Maturity Models
14	Yaling Yang, Jun Wang 0011, Robin Kravets	Load-balanced routing for mesh networks.	ACM SIGMOBILE Mob. Comput. Commun. Rev.	2006	DBLP DOI BibTeX RDF
14	Cheng-Shang Chang, Duan-Shin Lee, Chi-Yao Yue	Providing guaranteed rate services in the load balanced Birkhoff-von Neumann switches.	IEEE/ACM Trans. Netw.	2006	DBLP DOI BibTeX RDF	Birkhoff-von Neumann switches, guaranteed rate services, multi-stage switches, multicasting flows, variable length packets
14	Dmitry Vasilyev, Michal Rewienski, Jacob K. White 0001	Macromodel Generation for BioMEMS Components Using a Stabilized Balanced Truncation Plus Trajectory Piecewise-Linear Approach.	IEEE Trans. Comput. Aided Des. Integr. Circuits Syst.	2006	DBLP DOI BibTeX RDF
14	Yulong Xing, Chi-Wang Shu	High-Order Well-Balanced Finite Difference WENO Schemes for a Class of Hyperbolic Systems with Source Terms.	J. Sci. Comput.	2006	DBLP DOI BibTeX RDF	Hyperbolic balance laws, source term, elastic wave equation, chemosensitive movement, nozzle flow, conservation laws, shallow water equation, two phase flow, high-order accuracy, WENO scheme
14	Charilaos Efthymiou 0002, Sotiris E. Nikoletseas, José D. P. Rolim	Energy balanced data propagation in wireless sensor networks.	Wirel. Networks	2006	DBLP DOI BibTeX RDF	Wireless sensor networks, Randomized algorithms, Data propagation, Energy balance
14	Josep Díaz, Fabrizio Grandoni 0001, Alberto Marchetti-Spaccamela	Balanced Cut Approximation in Random Geometric Graphs.	ISAAC	2006	DBLP DOI BibTeX RDF
14	Gabriel Pui Cheong Fung, Jeffrey Xu Yu, Haixun Wang, David W. Cheung, Huan Liu 0001	A Balanced Ensemble Approach to Weighting Classifiers for Text Classification.	ICDM	2006	DBLP DOI BibTeX RDF
14	Jae-Min Seol, Seong-Whan Kim	Efficient Collision-Resilient RFID Tag Identification using Balanced Incomplete Block Design Code.	CIT	2006	DBLP DOI BibTeX RDF
14	Tzung-Shi Chen, Hua-Wen Tsai, Chih-Ping Chu	Gathering-Load-Balanced Tree Protocol for Wireless Sensor Networks.	SUTC (2)	2006	DBLP DOI BibTeX RDF
14	Claude Carlet	On Bent and Highly Nonlinear Balanced/Resilient Functions and Their Algebraic Immunities.	AAECC	2006	DBLP DOI BibTeX RDF	Boolean function, stream cipher, resiliency, nonlinearity, algebraic attack, algebraic degree
14	Lan Lan 0005, Ying Yu Tai, Shu Lin 0001, Behshad Memari, Bahram Honary	New Constructions of Quasi-cyclic LDPC Codes Based on Two Classes of Balanced Incomplete Block Designs: For AWGN and Binary Erasure Channels.	AAECC	2006	DBLP DOI BibTeX RDF
14	Chien-Chih Yu, Hsing-I Wang	Analyzing Strategic Gaps of Digital Divide Projects Based on the Balanced Scorecard.	I3E	2006	DBLP DOI BibTeX RDF
14	Tony Lambert, Carlos Castro 0001, Éric Monfroy, Frédéric Saubion	Solving the Balanced Academic Curriculum Problem with an Hybridization of Genetic Algorithm and Constraint Propagation.	ICAISC	2006	DBLP DOI BibTeX RDF	hybrid resolution, genetic algorithms, CSP, constraint propagation
14	Benjamas Tongprasit, Tadashi Shibata	Power-balanced reconfigurable floating-gate-MOS logic circuit for tamper resistant VLSI.	ISCAS	2006	DBLP DOI BibTeX RDF
14	Takafumi Yamaji, Tetsuro Itakura, Rui Ito, Takeshi Ueno, Hidenori Okuni	Balanced 3-phase analog signal processing for radio communications.	ISCAS	2006	DBLP DOI BibTeX RDF
14	Kil-Woong Jang, Byung-Soon Kim	A Balanced Deployment Algorithm for Mobile Sensor Networks.	ICCSA (2)	2006	DBLP DOI BibTeX RDF