Devang Negandhi

In the wake of the torpedo attacks and disappearance of North Korean shark-class submarine from the sonar as well as massive oil spills in Gulf of Mexico that is difficult to track, we recognize the mounting need for a high resolution, in-situ underwater monitoring technology. One of the well studied technologies for underwater temperature and current monitoring is Ocean Acoustic Tomography. The traditional use of the technology is to construct low resolution temperature and current map of… Show more

In the wake of the torpedo attacks and disappearance of North Korean shark-class submarine from the sonar as well as massive oil spills in Gulf of Mexico that is difficult to track, we recognize the mounting need for a high resolution, in-situ underwater monitoring technology. One of the well studied technologies for underwater temperature and current monitoring is Ocean Acoustic Tomography. The traditional use of the technology is to construct low resolution temperature and current map of large bodies of water for various studies in global changes in ecology and climate. We have taken the key concepts behind the technology and applied it to distributed underwater acoustic sensor network to enable marina scale underwater acoustic tomography. Since the area of interest is significantly smaller, we find that precision of time measurement and synchronization within the network has to be very high in order to produce meaning temperature map. On the other hand, the reduced scale introduces a new opportunity to utilize the technology to sense even the slightest temperature changes underwater with proportionally smaller delays. In this paper, we present our prototype wireless underwater acoustic sensor nodes and the experimental results that indicates temperature resolution below tenth of a degree Celsius. We also present our micro-tomography simulation system that is used to analyze the feasibility and the requirement for the wireless underwater acoustic sensor network for building marina scale underwater acoustic tomography.
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In this paper, we present an adaptive tutoring system for students of multiple
domains with a web-based interface for flexibility. The displayed media is adapted
according to the student’s capability and aptitude by evaluating the student according to
historical data and quizzes. The media is divided into dynamic frames and content of
each frame is displayed adaptively. A weighted approach is used to evaluate the student
capability and frames are generated based on a beta… Show more

In this paper, we present an adaptive tutoring system for students of multiple
domains with a web-based interface for flexibility. The displayed media is adapted
according to the student’s capability and aptitude by evaluating the student according to
historical data and quizzes. The media is divided into dynamic frames and content of
each frame is displayed adaptively. A weighted approach is used to evaluate the student
capability and frames are generated based on a beta distribution. Initial evaluation of the
system based on a paper simulation showed encouraging results. Show less