Panos K. Chrysanthis

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ACTA is a comprehensive transaction framework that facilitates the formal description of properties of extended transaction models. Specifically, using ACTA, one can specify and reason about (1) the effects of transactions on objects and (2) the interactions between transactions. This article presents ACTA <italic>as a tool for the synthesis of extended(More)
This paper presents TiNA, a scheme for minimizing energy consumption in sensor networks by exploiting end-user tolerance to temporal coherency. TiNA utilizes temporal coherency tolerances to both reduce the amount of information transmitted by individual nodes (communication cost dominates power usage in sensor networks), and to improve quality of data when(More)
In-network aggregation has been proposed as one method for reducing energy consumption in sensor networks. In this paper, we explore two ideas related to further reducing energy consumption in the context of in-network aggregation. The first is by influencing the construction of the routing trees for sensor networks with the goal of reducing the size of(More)
Recently, a number of extensions to the traditional transaction model have been proposed to support new information-intensive applications such as CAD/CAM and software development. However, these extended models capture only a subset of interactions that can be found in such applications, and represent only some of the points within the spectrum of(More)
Location aware services are becoming attractive with the deployment of next generation wireless networks and broadband multimedia wireless networks especially in indoor and campus areas. To provide location aware services, obtaining the position of a user accurately is important. While it is possible to deploy additional infrastructure for this purpose,(More)
ACTA is a comprehensive transaction framework that permits a transaction modeler to specify the e ects of extended transactions on each other and on objects in the database. ACTA allows the speci cation of (1) the interactions between transactions in terms of relationships between signi cant (transaction management) events, such as begin, commit, abort,(More)
Recently, push-based delivery has attracted considerable attention as a means of disseminating information to large client populations in both wired and wireless settings. In this paper, we address the problem of ensuring the consistency and currency of client read-only transactions in the presence of updates. To this end, additional control information is(More)
Recently, broadcasting has attracted considerable attention as a means of disseminating information to large client populations in both wired and wireless settings. In this paper, we exploit versions to increase the concurrency of client transactions in the presence of updates. We consider three alternative mediums for storing versions: (a) the air: older(More)
In-network aggregation has been proposed as one method for reducing energy consumption in networked sensors. In this paper, we explore the idea of influencing the construction of the routing trees for sensor networks with the goal of reducing the size of transmitted data for networks with in-network aggregation involving Group By queries. Toward this, we(More)