GPSense: an algorithmic framework for intelligent sensing at node level in WSN

We proposed a new Genetic Programming algorithm termed GPSense for use in wireless sensor networks (WSN). Existing algorithms for pattern recognition and data mining in WSNs work offline, i.e. they query the WSN nodes, bring data to the base-station and the mining is done at the base-station. This increases the latency of decision making, enhances decision communication costs and generally leads to non-local decisions. It is generally believed that this paradigm is more powerefficient since sensor nodes are significantly constrained in terms of computing power (processor speed, low-power batteries, limited-memory). We believe that a distributed data mining approach can be evolved where small-footprint mining algorithms can be developed to work on the sensor-nodes thereby improving the current state-of-the-art. GPSense is the first of such in-network data mining frameworks and has the following desirable characteristics: It is designed to work as a distributed algorithm that co-ordinates and exchanges genetic material with collaborating nodes. It is aware of the resource constraints at node level with its footprint being consistently smaller than that of the sensor node\u27s processing capabilities. Its localized nature - enables the entire WSN to make decisions at the nodelevel instead of aggregating results from long-running continuous queries to the root node for eventual filtering. In this thesis we describe the GPSense framework and demonstrate its utility based on the results we obtained on a test-bed WSN

Estimated cumulative radiation dose from PET/CT in children with malignancies: a 5-year retrospective review

The increasing use of serial PET/CT scans in the management of pediatric malignancies raises the important consideration of radiation exposure in children. To estimate the cumulative radiation dose from PET/CT studies to children with malignancy and to compare with the data in literature. Two hundred forty-eight clinical PET/CT studies performed on 78 patients (50 boys/28 girls, 1.3 to 18 years old from December 2002 to October 2007) were retrospectively reviewed under IRB approval. The whole-body effective dose (ED) estimates for each child were obtained by estimating the effective dose from each PET/CT exam performed using the ImPACT Patient Dosimetry Calculator for CT and OLINDA for PET. The average number of PET/CT studies was 3.2 per child (range: 1 to 14 studies). The average ED of an individual CT study was 20.3 mSv (range: 2.7 to 54.2), of PET study was 4.6 mSv (range: 0.4 to 7.7) and of PET/CT study was 24.8 mSv (range: 6.2 to 60.7). The average cumulative radiation dose per patient from CT studies was 64.4 mSv (range: 2.7 to 326), from PET studies was 14.5 mSv (range: 2.8 to 73) and from PET/CT studies was 78.9 mSv (range: 6.2 to 399). The radiation exposure from serial PET/CT studies performed in pediatric malignancies was considerable; however, lower doses can be used for both PET and CT studies. The ALARA principle must be applied without sacrificing diagnostic information