Claudia Roncancio

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Transaction support is crucial in mobile data management. Specific characteristics of mobile environments (e.g. variable bandwidth, disconnections, limited resources on mobile hosts) make traditional transaction management techniques no longer appropriate. Several models for mobile transactions have been proposed but it is difficult to have an overview of(More)
In Web-based searching systems that access distributed information providers, efficient query processing requires an advanced caching mechanism to reduce the query response time. The keyword-based querying is often the only way to retrieve data from Web providers, and therefore standard page-based and tuple-based caching mechanisms turn out to be improper(More)
Smart sensors are already being used in various application domains such as medical, environmental, urban, domestic and industrial. These applications mostly need data from sensors of different types (temperature, pressure, location, camera, etc.) that may be managed by different software, e.g., proprietary software from manufacturers. Heterogeneous(More)
This paper presents a novel research direction in the field of sensor data management. It concerns transactional support in heterogeneous large scale sensor systems. Besides well-known continuous queries on sensor data, system management queries should be supported in these systems. Indeed, with increasing capacity and diversity of sensors, new applications(More)
Tiny devices, smart objects, home gateways, sensor networks, have become an integral part of our everyday life and of our socio-economic ecosystem. However their large number, their distribution and their volatility andheterogeneity make their management fiendishly complex. Traditional management systems, that are mainly ad-hoc or centralized, reach their(More)
Mobile environments are characterized by high variability (e.g. variable bandwidth, disconnections, different communication prices) as well as by limited mobile host resources. Such characteristics lead to high rates of transaction failures and variable execution costs. To raise the success rate of transactions and to have a minimal control on resources(More)
PURPOSE To investigate the incidence of translocations induced by iodine-131 therapy in thyrotoxicosis patients 1 year after the administration of the radiolabelled compound. MATERIALS AND METHODS Tricolour FISH with whole-chromosome-specific probes for chromosomes 2, 4 and 8 was used for scoring translocations. From the genomic translocation frequencies,(More)
This paper uses the BEAST benchmark to present the first comprehensive performance study of object-oriented active database management systems (ADBMS). BEAST stresses the performance-critical components of active systems: event detection, event composition, rule retrieval, and rule firing. Method invocation events and transactional events are taken into(More)
Querying streams of data from the sensors or other devices requires several operators. One of the most important operators is called Windowing. Creating windows consists in grouping of tuples from data streams at a specific rate according to a certain pattern. A large variety of window patterns exist and reflect different data management semantics that are(More)