Search results for "HMMs"

Hits ?▲	Authors	Title	Venue	Year	Link	Author keywords
26	Yeon Gu Kang, Phill-Kyu Rhee	Head Gesture Recognition Using Feature Interpolation.	KES (1)	2006	DBLP DOI BibTeX RDF
26	Cornie Scheffer, Herman A. Engelbrecht, P. Stephan Heyns	A comparative evaluation of neural networks and hidden Markov models for monitoring turning tool wear.	Neural Comput. Appl.	2005	DBLP DOI BibTeX RDF	Tool wear, Neural networks, Hidden Markov models, Condition monitoring
26	Alexander Schliep, Ivan G. Costa, Christine Steinhoff, Alexander Schönhuth	Analyzing Gene Expression Time-Courses.	IEEE ACM Trans. Comput. Biol. Bioinform.	2005	DBLP DOI BibTeX RDF	partially supervised learning, time-course analysis, hidden Markov models, Mixture modeling, gene expression
26	Yuji Kawada, Yasubumi Sakakibara	Discriminative Discovery of Transcription Factor Binding Sites from Location Data.	CSB	2005	DBLP DOI BibTeX RDF
26	Min Song 0001, Il-Yeol Song, Xiaohua Hu 0001, Robert B. Allen	Integrating Text Chunking with Mixture Hidden Markov Models for Effective Biomedical Information Extraction.	International Conference on Computational Science (2)	2005	DBLP DOI BibTeX RDF
26	Fu-ren Lin, Lu-Shih Hsieh, Shung-mei Pan	Learning Clinical Pathway Patterns by Hidden Markov Model.	HICSS	2005	DBLP DOI BibTeX RDF
26	Say Wei Foo, Yong Lian 0001, Liang Dong	Recognition of visual speech elements using adaptively boosted hidden Markov models.	IEEE Trans. Circuits Syst. Video Technol.	2004	DBLP DOI BibTeX RDF
26	Kyoung-Jae Won, Adam Prügel-Bennett, Anders Krogh	The Block Hidden Markov Model for Biological Sequence Analysis.	KES	2004	DBLP DOI BibTeX RDF
26	Fabien Cardinaux, Conrad Sanderson, Samy Bengio	Face Verification Using Adapted Generative Models.	FGR	2004	DBLP DOI BibTeX RDF
26	D. Srikrishna Satish, C. Chandra Sekhar	Kernel Based Clustering for Multiclass Data.	ICONIP	2004	DBLP DOI BibTeX RDF
26	Masashi Inoue, Naonori Ueda	Exploitation of Unlabeled Sequences in Hidden Markov Models.	IEEE Trans. Pattern Anal. Mach. Intell.	2003	DBLP DOI BibTeX RDF	extended Baum-Welch algorithm, hidden Markov models, Unlabeled data, sequential data
26	Stéphane Perrin, Masatoshi Ishikawa	Quantized Features for Gesture Recognition Using High Speed Vision Camera.	SIBGRAPI	2003	DBLP DOI BibTeX RDF
26	Yagiz Yasaroglu, A. Aydin Alatan	Summarizing Video: Content, Features, and HMM Topologies.	VLBV	2003	DBLP DOI BibTeX RDF
26	Owen Lamont, Graham Mann	A Unified Stochastic Architecture for Spoken Dialogue Systems.	Australian Conference on Artificial Intelligence	2003	DBLP DOI BibTeX RDF	AI architectures, Language understanding/generation, Machine learning
26	Alexander Ypma, Tom Heskes	Automatic Categorization of Web Pages and User Clustering with Mixtures of Hidden Markov Models.	WEBKDD	2002	DBLP DOI BibTeX RDF	automatic categorization, data mining, clustering, hidden Markov models, user profiling, mixture models, Web usage mining, navigation patterns
26	Georgios Sigletos, Georgios Paliouras, Vangelis Karkaletsis	Role Identification from Free Text Using Hidden Markov Models.	SETN	2002	DBLP DOI BibTeX RDF
26	Mitsuru Nakai, Naoto Akira, Hiroshi Shimodaira, Shigeki Sagayama	Substroke Approach to HMM-Based On-line Kanji Handwriting Recognition.	ICDAR	2001	DBLP DOI BibTeX RDF
26	Thierry Artières, J.-M. Marchand, Patrick Gallinari, Bernadette Dorizzi	Multi-Modal Segmental Models for On-Line Handwriting Recognition.	ICPR	2000	DBLP DOI BibTeX RDF
26	T. Wessels, Christian W. Omlin	Refining Hidden Markov Models with Recurrent Neural Networks.	IJCNN (2)	2000	DBLP DOI BibTeX RDF
26	Jindrich Matousek, Josef Psutka, Zbynek Tychtl	Statistical Approach to the Automatic Synthesis of Czech Speech.	TSD	1999	DBLP DOI BibTeX RDF
26	Patrick Gallinari	Predictive Models for Sequence Modelling, Application to Speech and Character Recognition.	Summer School on Neural Networks	1997	DBLP DOI BibTeX RDF
26	Walid G. Aref, Daniel Barbará, Padmavathi Vallabhaneni	The Handwritten Trie: Indexing Electronic Ink.	SIGMOD Conference	1995	DBLP DOI BibTeX RDF
25	Adrià Giménez, Alfons Juan	Bernoulli HMMs at Subword Level for Handwritten Word Recognition.	IbPRIA	2009	DBLP DOI BibTeX RDF	Subword, Bernoulli, HMM, Handwritten word recognition
25	Kyogu Lee, Malcolm Slaney	Acoustic Chord Transcription and Key Extraction From Audio Using Key-Dependent HMMs Trained on Synthesized Audio.	IEEE Trans. Speech Audio Process.	2008	DBLP DOI BibTeX RDF
25	Mihai Gurban, Jean-Philippe Thiran, Thomas Drugman, Thierry Dutoit	Dynamic modality weighting for multi-stream hmms inaudio-visual speech recognition.	ICMI	2008	DBLP DOI BibTeX RDF	multi-stream hmm, stream reliability, multimodal fusion, audio-visual speech recognition
25	Juan Manuel Pascual-Gaspar, Valentín Cardeñoso-Payo	Automatic Online Signature Verification Using HMMs with User-Dependent Structure.	ICB	2007	DBLP DOI BibTeX RDF
25	Erika Vilches, Ivan A. Escobar, Edgar E. Vallejo, Charles E. Taylor	Targeting Input Data for Acoustic Bird Species Recognition Using Data Mining and HMMs.	ICDM Workshops	2007	DBLP DOI BibTeX RDF
25	Yongzhao Zhan, Gengtao Zhou	Facial Expression Recognition Based on Hybrid Features and Fusing Discrete HMMs.	HCI (14)	2007	DBLP DOI BibTeX RDF	hybrid feature extraction, pattern recognition, active appearance model, facial expression recognition, Gabor wavelet transformation
25	Yen-Shou Lai, Hung-Hsu Tsai, Pao-Ta Yu, Jenq-Muh Hsu	A Multimedia Learning System Using HMMs to Improve Phonemic Awareness for English Pronunciation.	MUE	2007	DBLP DOI BibTeX RDF
25	Dong Zhang 0001, Daniel Gatica-Perez, Samy Bengio, Iain McCowan	Modeling individual and group actions in meetings with layered HMMs.	IEEE Trans. Multim.	2006	DBLP DOI BibTeX RDF
25	Jun Du, Peng Liu 0001, Frank K. Soong, Jian-Lai Zhou, Ren-Hua Wang	Noisy Speech Recognition Performance of Discriminative HMMs.	ISCSLP	2006	DBLP DOI BibTeX RDF	Minimum Divergence, Minimum Word Error, Noise Robustness, Discriminative Training
25	Jinyoung Song, Daijin Kim 0001	Simultaneous Gesture Segmentation and Recognition based on Forward Spotting Accumulative HMMs.	ICPR (1)	2006	DBLP DOI BibTeX RDF
25	Mark Barnard, Jean-Marc Odobez	Sports Event Recognition Using Layered HMMS.	ICME	2005	DBLP DOI BibTeX RDF
25	Yuta Okabe, Suguru Saito, Masayuki Nakajima 0001	Paintbrush rendering of lines using HMMs.	GRAPHITE	2005	DBLP DOI BibTeX RDF	learning, HMM, stroke, footprint
25	Tracy L. Westeyn, Kristin Vadas, Xuehai Bian, Thad Starner, Gregory D. Abowd	Recognizing Mimicked Autistic Self-Stimulatory Behaviors Using HMMs.	ISWC	2005	DBLP DOI BibTeX RDF
25	Sajid M. Siddiqi, Andrew W. Moore 0001	Fast inference and learning in large-state-space HMMs.	ICML	2005	DBLP DOI BibTeX RDF
25	Ye Du, Huiqiang Wang, Yonggang Pang	HMMs for Anomaly Intrusion Detection.	CIS	2004	DBLP DOI BibTeX RDF
25	Hang-Bong Kang	Affective content detection using HMMs.	ACM Multimedia	2003	DBLP DOI BibTeX RDF	emotional event, hidden Markov models, content analysis
25	Hiroshi Shimodaira, Takashi Sudo, Mitsuru Nakai, Shigeki Sagayama	On-line Overlaid-Handwriting Recognition Based on Substroke HMMs.	ICDAR	2003	DBLP DOI BibTeX RDF
25	Satoshi Nakamura 0001, Ken'ichi Kumatani, Satoshi Tamura	Multi-Modal Temporal Asynchronicity Modeling by Product HMMs for Robust.	ICMI	2002	DBLP DOI BibTeX RDF
25	Hiromitsu Nishimura, Masayoshi Tsutsumi, Minoru Maruyama, Hidetoshi Miyao, Yasuaki Nakano	Off-line Hand-written Character Recognition Using Integrated 1D HMMs Based on Feature Extraction Filters.	ICDAR	2001	DBLP DOI BibTeX RDF
21	Anne-Laure Bianne-Bernard, Farès Menasri, Ramy Al-Hajj Mohamad, Chafic Mokbel, Christopher Kermorvant, Laurence Likforman-Sulem	Dynamic and Contextual Information in HMM Modeling for Handwritten Word Recognition.	IEEE Trans. Pattern Anal. Mach. Intell.	2011	DBLP DOI BibTeX RDF	Latin and Arabic handwriting recognition, context-dependent HMMs, neural-network combination
21	Eric Nichols, Dan Morris 0001, Sumit Basu	Data-driven exploration of musical chord sequences.	IUI	2009	DBLP DOI BibTeX RDF	hmms, clustering, creativity, music, genre, chords, transition matrix, pca
21	Sarah Favre, Alfred Dielmann, Alessandro Vinciarelli	Automatic role recognition in multiparty recordings using social networks and probabilistic sequential models.	ACM Multimedia	2009	DBLP DOI BibTeX RDF	HMMS, role recognition, social network analysis, statistical language models
21	Nelson Neto 0001, Patrick Silva, Aldebaro Klautau, André Gustavo Adami	Spoltech and OGI-22 Baseline Systems for Speech Recognition in Brazilian Portuguese.	PROPOR	2008	DBLP DOI BibTeX RDF	Brazilian Portuguese, pronunciation dictionary, HMMs, Speech recognition
21	Tao Wang 0003, Jianguo Li, Wei Hu 0002, Xiaofeng Tong, Yimin Zhang 0002, Carole Dulong	Event Detection Models Using 2d-BN and CRFs.	MMM (2)	2007	DBLP DOI BibTeX RDF	Semantic event detection, Three-level framework, Soccer highlights detection, 2d-BNs, SVM, HMMs, CRFs
21	R. Bharat Rao, Sathyakama Sandilya, Radu Stefan Niculescu, Colin Germond, Harsha Rao	Clinical and financial outcomes analysis with existing hospital patient records.	KDD	2003	DBLP DOI BibTeX RDF	Bayes Nets, data mining, HMMs, temporal reasoning
21	Premkumar Natarajan, Issam Bazzi, Zhidong Lu, John Makhoul, Richard M. Schwartz	Robust OCR of Degraded Documents.	ICDAR	1999	DBLP DOI BibTeX RDF	degraded documents, adaptation, HMMs, OCR
17	Srilatha Attaluri, Scott McGhee, Mark Stamp 0001	Profile hidden Markov models and metamorphic virus detection.	J. Comput. Virol.	2009	DBLP DOI BibTeX RDF
17	Naoki Tadokoro, Tetsuo Kosaka, Masaharu Katoh, Masaki Kohda	Improvement of Speaker Vector-Based Speaker Verification.	IAS	2009	DBLP DOI BibTeX RDF
17	Pei-Chann Chang, Jui-Chien Hsieh, Jyun-Jie Lin, Yen-Hung Chou, Chen-Hao Liu	A Hybrid System with Hidden Markov Models and Gaussian Mixture Models for Myocardial Infarction Classification with 12-Lead ECGs.	HPCC	2009	DBLP DOI BibTeX RDF
17	Stavros Petridis, Hatice Gunes, Sebastian Kaltwang, Maja Pantic	Static vs. dynamic modeling of human nonverbal behavior from multiple cues and modalities.	ICMI	2009	DBLP DOI BibTeX RDF	frame-based representation, multicue and multimodal fusion, static classification, window-based representation, dynamic classification
17	Yu Tsao 0001, Jinyu Li 0001, Chin-Hui Lee, Satoshi Nakamura 0001	Soft margin estimation on improving environment structures for ensemble speaker and speaking environment modeling.	IUCS	2009	DBLP DOI BibTeX RDF	ESSEM, SME, model adaptation, noise robustness, ASR
17	Balakrishnan Varadarajan, Carol E. Reiley, Henry Lin 0001, Sanjeev Khudanpur, Gregory D. Hager	Data-Derived Models for Segmentation with Application to Surgical Assessment and Training.	MICCAI (1)	2009	DBLP DOI BibTeX RDF
17	German Florez-Larrahondo, Walker Haddock	Aspect oriented programming with hidden markov models to verify design use cases.	AOSD	2009	DBLP DOI BibTeX RDF	aspect-oriented programming, stochastic models, runtime verification, acm proceedings
17	Naresh P. Cuntoor, B. Yegnanarayana 0001, Rama Chellappa	Activity Modeling Using Event Probability Sequences.	IEEE Trans. Image Process.	2008	DBLP DOI BibTeX RDF
17	Ugo Galassi, Attilio Giordana, Lorenza Saitta	Structured Hidden Markov Models: A General Tool for Modeling Agent Behaviors.	Soft Computing Applications in Business	2008	DBLP DOI BibTeX RDF	Hidden Markov Model, User authentication, Keystroking dynamics
17	Georgios Th. Papadopoulos, Vasileios Mezaris, Ioannis Kompatsiaris, Michael G. Strintzis	Estimation and representation of accumulated motion characteristics for semantic event detection.	ICIP	2008	DBLP DOI BibTeX RDF
17	Dongheui Lee, Dana Kulic, Yoshihiko Nakamura	Missing motion data recovery using factorial hidden Markov models.	ICRA	2008	DBLP DOI BibTeX RDF
17	Yong-Joo Chung 0001	Using Kullback-Leibler Distance in Determining the Classes for the Heart Sound Signal Classification.	IDEAL	2008	DBLP DOI BibTeX RDF
17	Bengt J. Borgstrom, Abeer Alwan	An efficient approximation of the forward-backward algorithm to deal with packet loss, with applications to remote speech recognition.	ICASSP	2008	DBLP DOI BibTeX RDF
17	Yun-Hsuan Sung, Constantinos Boulis, Daniel Jurafsky	Maximum conditional likelihood linear regression and maximum a posteriori for hidden conditional random fields speaker adaptation.	ICASSP	2008	DBLP DOI BibTeX RDF
17	Yoshihiko Nankaku, Kazuhiro Nakamura, Heiga Zen, Keiichi Tokuda	Acoustic modeling with contextual additive structure for HMM-based speech recognition.	ICASSP	2008	DBLP DOI BibTeX RDF
17	Satoshi Asakawa, Nobuaki Minematsu, Keikichi Hirose	Multi-stream parameterization for structural speech recognition.	ICASSP	2008	DBLP DOI BibTeX RDF
17	Junxia Gu, Xiaoqing Ding, Shengjin Wang, Youshou Wu	Full body tracking-based human action recognition.	ICPR	2008	DBLP DOI BibTeX RDF
17	Rohit Prasad, Shirin Saleem, Matin Kamali, Ralf Meermeier, Premkumar Natarajan	Improvements in hidden Markov model based Arabic OCR.	ICPR	2008	DBLP DOI BibTeX RDF
17	Zhi Zeng, Xin Li, Xiaohong Ma, Qiang Ji	Adaptive context recognition based on audio signal.	ICPR	2008	DBLP DOI BibTeX RDF
17	Hogyeong Jeong, Amit Gupta, Rod D. Roscoe, John Wagster, Gautam Biswas, Daniel L. Schwartz 0001	Using Hidden Markov Models to Characterize Student Behaviors in Learning-by-Teaching Environments.	Intelligent Tutoring Systems	2008	DBLP DOI BibTeX RDF	Learning by Teaching environments, hidden Markov modeling, Behavior Analysis, Metacognition
17	François Brémond, Guido Pusiol	Commentary Paper on "Learning and Classification of Trajectories in Dynamic Scenes: A General Framework for Live Video Analysis".	AVSS	2008	DBLP DOI BibTeX RDF
17	Heiner Markert, Zöhre Kara Kayikci, Günther Palm	Sentence Understanding and Learning of New Words with Large-Scale Neural Networks.	ANNPR	2008	DBLP DOI BibTeX RDF	Hidden Markov Models, Speech Recognition, Associative Memories, Hebbian Learning, Language Understanding
17	Georgios Th. Papadopoulos, Vasileios Mezaris, Ioannis Kompatsiaris, Michael G. Strintzis	Accumulated motion energy fields estimation and representation for semantic event detection.	CIVR	2008	DBLP DOI BibTeX RDF	accumulated motion fields, hidden Markov Models, event detection, motion representation
17	Duong Van Hieu, Supot Nitsuwat	Image Preprocessing and Trajectory Feature Extraction based on Hidden Markov Models for Sign Language Recognition.	SNPD	2008	DBLP DOI BibTeX RDF	feature extraction, Hidden Markov Model, sign language recognition, image preprocessing
17	Long Qin, Yi-Jian Wu, Zhen-Hua Ling, Ren-Hua Wang	Model Adaptation for HMM-Based Speech Synthesis under Minimum Generation Error Criterion.	ISM	2008	DBLP DOI BibTeX RDF
17	Jong-Hun Kim, Chang-Woo Song, Kyung-Yong Chung, Un-Gu Kang, Kee-Wook Rim, Jung-Hyun Lee	Context Model Based CF Using HMM for Improved Recommendation.	PAKM	2008	DBLP DOI BibTeX RDF	Ubiquitous Computing, Recommendation System, Collaborative Filtering
17	Li Xie, Valery A. Ugrinovskii, Ian R. Petersen	A Posteriori Probability Distances Between Finite-Alphabet Hidden Markov Models.	IEEE Trans. Inf. Theory	2007	DBLP DOI BibTeX RDF
17	Wei Han, Kwok-Wai Hon, Cheong-Fat Chan, Oliver Chiu-sing Choy, Kong-Pang Pun	A Speech Recognition IC Using Hidden Markov Models with Continuous Observation Densities.	J. VLSI Signal Process.	2007	DBLP DOI BibTeX RDF	HMM, speech recognition, Viterbi algorithm, Gaussian mixtures
17	Kyungsuk Pyun, Johan Lim, Chee Sun Won, Robert M. Gray	Image Segmentation Using Hidden Markov Gauss Mixture Models.	IEEE Trans. Image Process.	2007	DBLP DOI BibTeX RDF
17	Yan Han, Johan de Veth, Lou Boves	Trajectory Clustering for Solving the Trajectory Folding Problem in Automatic Speech Recognition.	IEEE Trans. Speech Audio Process.	2007	DBLP DOI BibTeX RDF
17	Bertrand Mesot, David Barber	Switching Linear Dynamical Systems for Noise Robust Speech Recognition.	IEEE Trans. Speech Audio Process.	2007	DBLP DOI BibTeX RDF
17	Xiaodong Cui, Yifan Gong 0001	A Study of Variable-Parameter Gaussian Mixture Hidden Markov Modeling for Noisy Speech Recognition.	IEEE Trans. Speech Audio Process.	2007	DBLP DOI BibTeX RDF
17	Erik McDermott, Timothy J. Hazen, Jonathan Le Roux, Atsushi Nakamura, Shigeru Katagiri	Discriminative Training for Large-Vocabulary Speech Recognition Using Minimum Classification Error.	IEEE Trans. Speech Audio Process.	2007	DBLP DOI BibTeX RDF
17	Dana Kulic, Wataru Takano, Yoshihiko Nakamura	Representability of human motions by factorial hidden Markov models.	IROS	2007	DBLP DOI BibTeX RDF
17	Timothy F. Oliver, Leow Yuan Yeow, Bertil Schmidt	High Performance Database Searching with HMMer on FPGAs.	IPDPS	2007	DBLP DOI BibTeX RDF
17	Evan Tan, Jing Chen	Vehicular traffic density estimation via statistical methods with automated state learning.	AVSS	2007	DBLP DOI BibTeX RDF
17	R. Anitha 0003, C. Chandra Sekhar	Acoustic Modeling Using Continuous Density Hidden Markov Models in the Mercer Kernel Feature Space.	ISNN (1)	2007	DBLP DOI BibTeX RDF
17	Hua Chen, Zhi Geng, Jinzhu Jia	Hidden Markov Models with Multiple Observers.	ICIC (2)	2007	DBLP DOI BibTeX RDF	Multiple observers, Hidden Markov models, Identifiability
17	Dong Zhang 0001, Samy Bengio	Exploring Contextual Information in a Layered Framework for Group Action Recognition.	ICME	2007	DBLP DOI BibTeX RDF
17	Johannes Wagner 0001, Thurid Vogt, Elisabeth André	A Systematic Comparison of Different HMM Designs for Emotion Recognition from Acted and Spontaneous Speech.	ACII	2007	DBLP DOI BibTeX RDF
17	Kai Sun, Junqing Yu	Video Affective Content Representation and Recognition Using Video Affective Tree and Hidden Markov Models.	ACII	2007	DBLP DOI BibTeX RDF
17	Dong Yu 0001, Li Deng 0001	Large-Margin Discriminative Training of Hidden Markov Models for Speech Recognition.	ICSC	2007	DBLP DOI BibTeX RDF
17	Sheng-De Wang, Zheng Yi Huang	Layered Peer to Peer Streaming Using Hidden Markov Models.	EUC Workshops	2007	DBLP DOI BibTeX RDF	Peer to Peer, HMM, Streaming
17	Zöhre Kara Kayikci, Heiner Markert, Günther Palm	Neural Associative Memories and Hidden Markov Models for Speech Recognition.	IJCNN	2007	DBLP DOI BibTeX RDF
17	Tony Jebara, Yingbo Song, Kapil Thadani	Spectral Clustering and Embedding with Hidden Markov Models.	ECML	2007	DBLP DOI BibTeX RDF
17	Xin Xu, Yongqiang Sun, Zunguo Huang	Defending DDoS Attacks Using Hidden Markov Models and Cooperative Reinforcement Learning.	PAISI	2007	DBLP DOI BibTeX RDF
17	Weidong Zhang, Feng Chen 0007, Wenli Xu, Zisheng Cao	Decomposition in Hidden Markov Models for Activity Recognition.	MCAM	2007	DBLP DOI BibTeX RDF
17	Tong-Hua Su, Tianwen Zhang, De-Jun Guan, Hu-Jie Huang	Gabor-Based Recognizer for Chinese Handwriting from Segmentation-Free Strategy.	CAIP	2007	DBLP DOI BibTeX RDF	Chinese handwriting recognition, HMM, Gabor filter
17	Wesley Nunes Gonçalves, Jonathan de Andrade Silva, Bruno Brandoli Machado, Hemerson Pistori, Albert Schiaveto de Souza	Hidden Markov Models Applied to Snakes Behavior Identification.	PSIVT	2007	DBLP DOI BibTeX RDF	Animals Behavior Recognition, Hidden Markov Models, Snakes
17	Tong-Hua Su, Tianwen Zhang, Hu-Jie Huang, Yu Zhou	HMM-Based Recognizer with Segmentation-free Strategy for Unconstrained Chinese Handwritten Text.	ICDAR	2007	DBLP DOI BibTeX RDF
17	Haiying Tu, Jefferey Allanach, Satnam Singh, Krishna R. Pattipati, Peter Willett 0001	Information Integration via Hierarchical and Hybrid Bayesian Networks.	IEEE Trans. Syst. Man Cybern. Part A	2006	DBLP DOI BibTeX RDF
17	Fabien Cardinaux, Conrad Sanderson, Samy Bengio	User authentication via adapted statistical models of face images.	IEEE Trans. Signal Process.	2006	DBLP DOI BibTeX RDF