Moustafa A. Hammad

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We present the demonstration of the design of "STEAM", Purdue Boiler Makers' stream database system that allows for the processing of continuous and snap-shot queries over data streams. Specifically, the demonstration focuses on the query processing engine, "Nile". Nile extends the query processor engine of an object-relational database management system,(More)
The tremendous increase in the use of cellular phones, GPS-like devices, and RFIDs results in highly dynamic environments where objects as well as queries are continuously moving. In this paper, we present a continuous query processor designed specifically for highly dynamic environments (e.g., location-aware environments). We implemented the proposed(More)
The widespread use of sensor networks presents revolutionary opportunities for life and environmental science applications. Many of these applications involve continuous queries that require the tracking, monitoring, and correlation of multi-sensor data that represent moving objects. We propose to answer these queries using a multi-way stream window join(More)
Two research efforts have been conducted to realize sliding-window queries in data stream management systems, namely, query revaluation and incremental evaluation. In the query reevaluation method, two consecutive windows are processed independently of each other. On the other hand, in the incremental evaluation method, the query answer for a window is(More)
EmcT!Jing dala stnm.m processing systems rely on windowing /0 enable em-lhe-fly processing oj continuous queries Dvcr unbounded streams. A~' a resuU, swe1ll.1 recent efforL<; have developed window-aware implemcrltations of Query operators such as joins Gnd ag,qregates. 'This focus em individual operators, however, ignores the larger issuc of how to(More)
Many data stream sources are prone to periods of spikes in volume as well as periods of delays and silence. Because peak load during a spike can be orders of magnitude higher than a typical load, fully provisioning data stream monitoring system with all needed resources is generally difficult to achieve. Furthermore, data stream sources are subject to(More)
data types Storage engine Query processor SQL Language Continuous time-based Sliding Window Queries Continuous Predicate-based Window Queries Moving Queries Stream data types Stream of Moving Objects/Queries Stream_Scan Operator W-Expire Operator Negative Tuples INSIDE Operator kNN Operator WINDOW window_clause kNN knn_clause PLACE NILE INSIDE inside_clause
Many applications require storing data in Wireless Sensor Networks (WSNs). For example, in environmental monitoring applications. WSN may archive sensor data for retrieval at periodic intervals. In contrast to conventional network data storage, storing data in WSNs is challenging because of the limited power, memory, and communication bandwidth of WSNs.(More)
A novel approach for modeling access control in video databases is presented. The proposed access control mechanism uses both the semantics and the structural composition of video data. The unit of authorization, a video element, can either be a sequence of video frames or a video object that appears as part of a frame, e.g., the face of an anonymous person(More)
In this paper we study the problem of providing ordered execution of time-based sliding window queries over input streams of sensor data with inherent delays. We present three approaches to achieve the ordered execution. The first approach enforces ordered processing at the input side of the query execution plan. In the second approach we utilize the(More)