This volume contains the proceedings of UIC 2009, the 6th International C- ference on Ubiquitous Intelligence and Computing: Building Smart Worlds in Real and Cyber Spaces. The UIC 2009 conference was technically co-sponsored by the IEEE and the IEEE Computer Society Technical Committee on Scalable Computing. The conference was also sponsored by the Australian Centre of - cellence in Information and Communication Technologies (NICTA). UIC 2009 was accompanied by six workshops on a variety of research challenges within the area of ubiquitous intelligence and computing. The conference was held in Brisbane, Australia, July 7¿9, 2009. The event was the sixth meeting of this conference series. USW 2005 (First International Workshop on Ubiquitous Smart World), held in March 2005 in Taiwan, was the ?rst event in the series. This event was followed by UISW 2005 (Second International Symposium on Ubiquitous Intelligence and Smart Worlds) held in December 2005 in Japan. Since 2006, the conference has been held annually under the name UIC (International Conference on Ubiquitous Intelligence and Computing). UIC 2006 was held in September 2006 in Wuhan andThreeGorges,China,followedbyUIC2007heldinJuly2007inHongKong, and UIC 2008 held in June 2008 in Oslo, Norway. Ubiquitous sensors,computers, networksand informationare paving the way towardasmartworldinwhichcomputationalintelligenceisdistributedthrou- out the physical environment to provide reliable and relevant services to people.

Keynote Speeches.- Distributed Computing in Opportunistic Environments.- Web of Things as a Framework for Ubiquitous Intelligence and Computing.- Context Awareness.- Inferring Human Interactions in Meetings: A Multimodal Approach.- Gesture Recognition with a 3-D Accelerometer.- Context-Aware Activity Recognition through a Combination of Ontological and Statistical Reasoning.- Context-Aware Path Planning in Ubiquitous Network.- Middleware and Services.- An Efficient Approach to Situation-Aware Service Discovery in Pervasive Service Computing Environments.- Printing in Ubiquitous Computing Environments.- The Å Publish/Subscribe Framework.- Mining and Visualizing Mobile Social Network Based on Bayesian Probabilistic Model.- Routing and Sensor Networks.- SMSR: A Scalable Multipath Source Routing Protocol for Wireless Sensor Networks.- A Framework to Calibrate a MEMS Sensor Network.- Application Domain Driven Data Visualisation Framework for Wireless Sensor Networks.- Hybrid Bluetooth Scatternet Routing.- Ubiquitous Networks and Devices.- Self-estimation of Neighborhood Density for Mobile Wireless Nodes.- MeshVision: An Adaptive Wireless Mesh Network Video Surveillance System.- SDEC: A P2P Semantic Distance Embedding Based on Virtual Coordinate System.- Dynamic Integration of Zigbee Devices into Residential Gateways for Ubiquitous Home Services.- Location-Based Services.- Fine-Grained Evaluation of Local Positioning Systems for Specific Target Applications.- Indoor Positioning System Using Beacon Devices for Practical Pedestrian Navigation on Mobile Phone.- NavTag: An Inter-Working Framework Based on Tags for Symbolic Location Coordinates for Smart Spaces.- Mobile Web 2.0-Oriented Five Senses Multimedia Technology with LBS-Based Intelligent Agent.- Security andPrivacy.- Conflicting-Set-Based Wormhole Attack Resistant Localization in Wireless Sensor Networks.- Novel and Efficient Identity-Based Authenticated Key Agreement Protocols from Weil Pairings.- Implicit User Re-authentication for Mobile Devices.- Lattice Based Privacy Negotiation Rule Generation for Context-Aware Service.- Ubiquitous Intelligence.- Using RFID to Overcome Inventory Control Challenges: A Proof of Concept.- Anticipative Wrap-Around Inquiry Method towards Efficient RFID Tag Identification.- A Probabilistic Semantic Based Mixture Collaborative Filtering.