We demonstrate a synchronization-free localization system, called Whistle, for wireless sensor networks. The system is tested in several realistic environments on commercial off-the-shelf(COTS) devices and the mean error is 10~20 centimeters in a 9 x 9 x 4<i>m</i><sup>3</sup> 3D space.
Service processes in SOA are composed dynamically by services from different service providers. At run-time, some services may become faulty and cause a service process to violate its end-to-end quality of service (QoS) constraints. We propose an effective approach for replacing only faulty services and some of their neighboring services to maintain the… (More)
With the increasing stress and unhealthy lifestyles in people's daily life, mental health problems are becoming a global concern. In particular, mood related mental health problems, such as mood disorders, depressions, and elation, are seriously impacting people's quality of life. However, due to the complexity and unstableness of personal mood, assessing… (More)
Service dependency graph (SDG) is an AND/OR graph showing input output dependencies among service operations. As dependencies in an SDG are indirectly expressed by reasoning on data models used by service interface definitions, their re-usability and expressiveness are limited. In this paper, we propose an enhanced version of service dependency graph,… (More)
—Location privacy has been a serious concern for mobile users who use location-based services provided by the third-party provider via mobile networks. Recently, there have been tremendous efforts on developing new anonymity or obfuscation techniques to protect location privacy of mobile users. Though effective in certain scenarios, these existing… (More)
—Delay tolerant networks (DTNs) may lack continuous network connectivity. Routing in DTNs is thus challenging since it must handle network partitioning, long delays, and dynamic topology in such networks. In recent years, social-based approaches , which attempt to exploit social behaviors of DTN nodes to make better routing decision, have drawn tremendous… (More)
—In delay tolerant networks (DTNs), the lack of continuous connectivity, network partitioning, and long delays make design of network protocols very challenging. Previous DTN research mainly focuses on routing and information propagation. However, with large number of wireless devices' participation, how to maintain efficient and dynamic topology of the DTN… (More)
As SOC and Web service technology become more widely used, large amounts of services need to be efficiently and effectively composed to meet complex businesses. In this paper, we proposed an approach to resolve the composition problem over large-scale services. We used an inverted table as index for a quick service discovery, and applied a Service… (More)