\input zb-basic \input zb-ioport \iteman{io-port 05878003} \itemau{Gil, Joon-Min; Paek, Kwang-Jin; Song, Ui-Sung} \itemti{VSAM: virtual sensor agent-oriented middleware for distributed and heterogeneous WSNs.} \itemso{Kim, Tai-hoon (ed.) et al., Grid and distributed computing, control and automation. International conferences, GDC and CA 2010, held as Part of the future generation information technology conference, FGIT 2010, Jeju Island, Korea, December 13--15, 2010. Proceedings. Berlin: Springer (ISBN 978-3-642-17624-1/pbk; 978-3-642-17625-8/ebook). Communications in Computer and Information Science 121, 155-166 (2011).} \itemab Summary: Since the emergence of WSNs (Wireless Sensor Networks), various middleware architectures have been proposed to achieve a suitable abstraction from the distribution and management tasks of sensor devices. This allows users to focus on application development. In the near future, WSNs will be more pervasive, common, and distributed. Programming on WSNs requires a novel programming paradigm and middleware, especially in distributed and heterogeneous WSNs. We propose Virtual Sensor Agent-Oriented Middleware (VSAM), a middleware system for distributed and heterogeneous WSNs, which provides data dissemination protocol-independent Application Programming Interface (API) and an integrated platform for sensor applications. VSAM makes it possible to integrate WSNs with traditional networks. \itemrv{~} \itemcc{} \itemut{virtual sensor network; middleware; agent system; lifetime; energy efficiency; QoS} \itemli{doi:10.1007/978-3-642-17625-8\_16} \end