title: Search Techniques for the Web of Things: A Taxonomy and Survey.
abstract: The Web of Things aims to make physical world objects and their data accessible through standard Web technologies to enable intelligent applications and sophisticated data analytics. Due to the amount and heterogeneity of the data, it is challenging to perform data analysis directly; especially when the data is captured from a large number of distributed sources. However, the size and scope of the data can be reduced and narrowed down with search techniques, so that only the most relevant and useful data items are selected according to the application requirements. Search is fundamental to the Web of Things while challenging by nature in this context, e.g., mobility of the objects, opportunistic presence and sensing, continuous data streams with changing spatial and temporal properties, efficient indexing for historical and real time data. The research community has developed numerous techniques and methods to tackle these problems as reported by a large body of literature in the last few years. A comprehensive investigation of the current and past studies is necessary to gain a clear view of the research landscape and to identify promising future directions. This survey reviews the state-of-the-art search methods for the Web of Things, which are classified according to three different viewpoints: basic principles, data/knowledge representation, and contents being searched. Experiences and lessons learned from the existing work and some EU research projects related to Web of Things are discussed, and an outlook to the future research is presented.
authors.affiliation: Institute for Communication Systems (ICS), University of Surrey, Guildford GU2 7XH, UK. yuchao.zhou@surrey.ac.uk.
authors.forename: Yuchao
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Institute for Communication Systems (ICS), University of Surrey, Guildford GU2 7XH, UK. s.de@surrey.ac.uk.
authors.forename: Suparna
authors.initials: S
authors.lastname: De
authors.affiliation: Department of Computer Science and Software Engineering, Xi'an Jiaotong-Liverpool University, Ren'ai Road Dushu Lake Higher Education Town SIP, Suzhou 215123, China. Wei.Wang03@xjtlu.edu.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Institute for Communication Systems (ICS), University of Surrey, Guildford GU2 7XH, UK. k.moessner@surrey.ac.uk.
authors.forename: Klaus
authors.initials: K
authors.lastname: Moessner
keywords: Internet of Things; Web of Things; entities; linked data; observation and measurement data; search; sensors; streaming data