Vladimir Zadorozhny

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Abstract. The rapid growth of the Internet and support for interoperability protocols has increased the number of Web accessible sources, WebSources. Current wrapper mediator architectures need to be extended with a wrapper cost model (WCM) for WebSources that can estimate the response time (delays) to access sources as well as other relevant statistics.(More)
Public health programs — especially vaccination programs — have led to dramatic declines in the incidence of contagious diseases in the United States over the past century.1-3 However, some contagious diseases are now on the rise despite the availability of vaccines. Pertussis vaccines have been available since the 1920s, but the worst pertussis epidemic(More)
Rich, interactive eLearning tools receive a lot of attention nowadays from both practitioners and researchers. However, broader dissemination of these tools is hindered by the technical difficulties of their integration into existing platforms. This article explores the technical and conceptual problems of using several interactive educational tools in the(More)
Database-like query processing over a network of sensors has become an attractive paradigm for building sensor applications. A sensor query is characterized by data streams among participating sensor nodes with possible in-node data filtering or aggregation, and can be described as a tree-like data delivery pattern. The data delivery pattern can also be(More)
There are performance deficiencies that hamper the deployment of Wireless Sensor Networks (WSNs) in critical monitoring applications. Such applications are characterized by considerable network load generated as a result of sensing some characteristics of the monitored system. Excessive packet collisions lead to packet losses and retransmissions, resulting(More)
In this paper, we introduce novel probabilistic transmission protocols for data intensive wireless sensor networks. The protocols combine a randomized transmission scheme with scheduling based on heuristics to alleviate network performance degradation due to excessive collisions and retransmissions. In particular, by utilizing local information about sensor(More)
Despite the growing popularity of user modeling servers, little attention has been paid to optimizing and evaluating the performance of these servers. We argue that implementation issues and their influence on server performance should become the central focus of the user modeling community, since there is a sharply increasing real-life load on user(More)
Queries in sensor networks are expected to produce results in a timely manner and for long periods, as needed. This implies that sensor queries need to be optimized with respect to both response time and energy consumption. With these requirements in mind, we develop novel cross-layer optimization techniques that utilize information about how the medium(More)
We introduce a novel strategy for data processing in Wireless Sensor Networks (WSNs) in the case of emergency fire evacuation with stringent delay constraints. Such networks should perform distributed emergency assessment, continuous emergency monitoring, and dynamic selection of optimal evacuation strategies. The obvious complexity of these tasks restricts(More)
We propose a novel data delivery strategy, called Whirlpool, for efficient SHM using Wireless Sensor Networks. Whirlpool implements a rotating interrogation of a monitoring structure and provides collision-aware scheduling of the monitoring queries. The Whirlpool strategy can be tuned for the required Quality of Data (QoD). We apply Whirlpool to examine the(More)