Panayiotis Neophytou

Learn More
— Amazon, Google, and IBM now sell cloud computing services. We consider the setting of a for-profit business selling data stream monitoring/management services and we investigate auction-based mechanisms for admission control of continuous queries. When submitting a query, each user also submits a bid of how much she is willing to pay for that query to(More)
This demo presents AstroShelf, our on-going effort to enable astrophysicists to collaboratively investigate celestial objects using data originating from multiple sky surveys, hosted at different sites. The AstroShelf platform combines database and data stream, workflow and visualization technologies to provide a means for querying and displaying telescope(More)
Traditional workflow enactment systems and workflow design processes view the workflow as a one-time interaction with the various data sources, executing a series of steps once, whenever the workflow results are requested. The fundamental underlying assumption has been that data sources are passive and all interactions are structured along the request/reply(More)
Wireless sensor networks link the physical and digital worlds enabling both surveillance as well as scientific exploration. In both cases, on-line detection of interesting events can be accomplished with continuous queries (CQs) in a Data Stream Management System (DSMS). However, the quality-of-service requirements of detecting these events are different(More)
—Data streams have become pervasive and data production rates are increasing exponentially, driven by advances in technology, for example the proliferation of sensors, smart phones, and their applications. This fact effectuates an unprecedented opportunity to build real-time monitoring and analytics applications, which when used collaboratively and(More)
Traditional workflow enactment systems view a workflow as a one-time interaction with various data sources, executing a series of steps once, whenever the workflow results are requested. The fundamental underlying assumption has been that data sources are passive and all interactions are structured along the request/reply (query) model. Hence, traditional(More)
Complex event detection over data streams has become ubiquitous through the widespread use of sensors, wireless connectivity and the wide variety of end-user mobile devices. Typically, such event detection is carried out by a data stream management server executing continuous queries, previously submitted by the users. In this paper, we consider the(More)
Problem solving using grid computing environments has become very popular amongst research groups in computation-demanding fields. This is due to the ability of Grid technologies and middleware to enable large-scale resource sharing. Application-development in such environments is a challenging process, thus the need for grid enabled development tools is(More)
Net-dbx-G is a tool that utilizes Java and other World Wide Web tools as an interface to Grid services to help Grid application developers debug their MPI programs from anywhere in the Internet. Net-dbx-G is a source level debugger with the full power of gdb (the GNU Debugger), providing the user with full Grid functionality. The portability of the tool is(More)
—Complex event detection over data streams has become ubiquitous through the widespread use of sensors, wireless connectivity and the wide variety of end-user mobile devices. Typically, such event detection is carried out by a data stream management system executing continuous queries (CQs), previously submitted by the users. In this paper, we consider the(More)