UCS2007 -- RFID Privacy Using Spatially Distributed Shared Secrets -- Context Adapted Certificate Using Morph Template Signature for Pervasive Environments -- Handling Spatio-temporal Sensor Data in Global Geographical Context with SENSORD -- Context Awareness by Case-Based Reasoning in a Music Recommendation System -- Developing Intelligent Smart Home by Utilizing Community Computing -- Instant Learning Sound Sensor: Flexible Real-World Event Recognition System for Ubiquitous Computing -- D-FLER – A Distributed Fuzzy Logic Engine for Rule-Based Wireless Sensor Networks -- Secure and Reliable Data Aggregation for Wireless Sensor Networks -- The iNAV Indoor Navigation System -- C-ANIS – A Contextual, Automatic and Dynamic Service-Oriented Integration Framework -- Using Auction Based Group Formation for Collaborative Networking in Ubicomp -- A Software Architecture for Virtual Device Composition and Its Applications -- Ubiquitous Communication Services Based on Effective Knowledge Deployment -- Detection of User Mode Shift in Home -- Discriminative Temporal Smoothing for Activity Recognition from Wearable Sensors -- Activity Recognition Based on Intra and Extra Manipulation of Everyday Objects -- Towards an Activity-Aware Wearable Computing Platform Based on an Egocentric Interaction Model -- mCube – Towards a Versatile Gesture Input Device for Ubiquitous Computing Environments -- uPackage – A Package to Enable Do-It-Yourself Style Ubiquitous Services with Daily Objects -- DroPicks – A Tool for Collaborative Content Sharing Exploiting Everyday Artefacts -- Place Recognition Using Multiple Wearable Cameras -- Compact Data Format for Advertising and Discovery in Ubiquitous Networks -- A Media Access Protocol for Proactive Discovery in Ubiquitous Wireless Networks -- Mobility Helps Data Delivery in Disruption Tolerant Networks.

This book constitutes the refereed proceedings of the 4th International Symposium on Ubiquitous Computing Systems, UCS 2007, held in Tokyo, Japan, in November 2007. The 16 revised full papers and 8 revised short papers presented were carefully reviewed and selected from 96 submissions. The papers are organized in topical sections on security and privacy, context awareness, sensing systems and sensor network, middleware, modeling and social aspects, smart devices, and network.