Mahmoud Attia Sakr

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This paper presents a novel approach to express and evaluate the complex class of queries in moving object databases called spatiotemporal pattern queries (STP queries). That is, one can specify temporal order constraints on the fulfillment of several predicates. This is in contrast to a standard spatiotemporal query that is composed of a single predicate.(More)
In previous work, we have proposed a tool for <i>Spatiotemporal Pattern Query</i>. It matches individual moving object trajectories against a given movement pattern. For example, it can be used to find the situations of <i>Missed Approach</i> in ATC data (Air Traffic Control systems, used for tracking the movement of aircrafts), where the landing of the(More)
The availability of devices that can be used to track moving objects has increased dramatically leading to a great growth in movement data from almost every application domain. Therefore, there has been an increasing interest in proposing new methodologies for indexing, classifying, clustering, querying and measuring similarity between moving objects' data.(More)
In this paper, we demonstrate our results of designing and implementing spatiotemporal pattern queries. That is, one can specify temporal order constraints on the fulfillment of predicates on moving objects. Compared with other approaches, our approach is not restricted in terms of the types of moving object or the sets of predicates. Our work covers the(More)
This article reports the optical properties such as absorption profile, molar absorptivity, fluorescence profile and photo-physical parameters such as dipole moment, oscillator strength, fluorescence quantum yields, fluorescence lifetimes, laser performance and finally photostability of 2,5-Bis(5-tert-butyl-benzoxazol-2-yl)thiophene(More)
Mobile devices leave a huge number of digital traces that are collected as trajectories, describing the movement of its users or a path followed by any moving object in geographical space over some period of time. However, those mobile devices provide just raw trajectories (x, y, t), ignoring information about their related contextual data, these additional(More)