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—A characteristic of urban sensing is that applications need to compose the operations and fuse information from sensing fabrics extant in the environment, to meet requirements for which the fabrics were not designed a priori. We propose an architecture, WEAVE, that allows tailoring of applications across one or more urban sensing fabrics. Key to the(More)
—Typically, for energy efficiency and scalability purposes , sensor networks have been used in the context of environmental and traffic monitoring applications in which operations at the sensor level are not computationally intensive. But increasingly, sensor network applications require data and compute intensive sensors such video cameras and microphones.(More)
Detection of radioactive materials in an urban environment usually requires large, portal-monitor-style radiation detectors. However, this may not be a practical solution in many transport scenarios. Alternatively, a distributed sensor network (DSN) could complement portal-style detection of radiological materials through the implementation of arrays of low(More)
We present a portable wireless multi-camera network based system that quickly recognizes face of human subjects. The system uses low-power embedded cameras to acquire video frames of subjects in an uncontrolled environment and opportunistically extracts frontal face images in real time. The extracted images may have heavy motion blur, small resolution and(More)
This paper describes Census, a protocol for data aggregation and statistical counting in MANETs. Census operates by circulating a set of tokens in the network using biased random walks such that each node is visited by at least one token. The protocol is structure-free so as to avoid high messaging overhead for maintaining structure in the presence of node(More)
Real-time information about the state (location, speed, direction) of other vehicles in the system is critical for both safety and navigation applications in future intelligent transportation systems. However, reliably obtaining this information over multiple hops in a wireless network while avoiding network congestion in the shared channel poses a(More)
— We present a distributed camera control algorithm that can be used for the monitoring of large regions using a network of PTZ (pan/tilt/zoom) cameras. The proposed strategy would allow for continuous target tracking at a high resolution, while still maintaining coverage over the entire monitored region at the highest possible resolution. Our algorithm(More)
This thesis describes the design, implementation and performance analysis of a transcoder for MPEG– 2 streams. When streaming MPEG video over a heterogeneous network such as Internet, the available bandwidth is not the same at different points of the broadcast chain. Video transcoding is one of the key technologies required to dynamically adapt the bit-rate(More)
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