Baroclinically unstable zones in midlatitudes normally produce medium-scale planetary waves that propagate toward the equator where they generate easterlies while transferring westerly momentum poleward, so that the jet lies in higher latitudes than in the corresponding axisymmetric (eddy-free) state. When the baroclinically unstable zone is moved into low latitudes, however, the equatorward si...

An experimental study of simultaneousmultipoint measurements in the flowfield and acoustic field of aMach 1.75 cold-air jet is presented. A series of four optical-deflectometer probes measured turbulent fluctuations in or near the jet flow, and eight microphones recorded the far-field pressure in the direction of peak emission. The correlation methodology involves the coherence between the dela...

the rapidly increasing number of messages on twitter is quite interesting. Through twitter streaming, this paper is capable of delivering tweets for any keywords from clients all around the world or Hashtag in real-time. However, semantic topic extraction and tracking the userinterested news events from messages on twitter can be considered as a challenging task. In this paper focused on detect...

An infrastructure is emerging that supports the delivery of on-line, location-enabled services to mobile users. Such services involve novel database queries, and the database research community is quite active in proposing techniques for the efficient processing of such queries. In parallel to this, the management of data streams has become an active area of research. While most research in mob...

In recent years, the potential of seasonal outlooks for tornadoes has attracted the attention of researchers. Previous studies on this topic have focused mainly on the influence of global circulation patterns [e.g., El Niño– Southern Oscillation (ENSO), North Atlantic Oscillation, or Pacific decadal oscillation] on spring tornadoes. However, these studies have yielded conflicting results of the...

For the past decade, Radio-Frequency Identification (RFID) technology has gained a significant momentum. It has promised to improve the efficiency of supply chain and library management by providing the automatic identification and data capture. It is expected that RFID will replace a barcode system in the near future. However, a large volume of data, resulting from the fast capturing RFID read...

An infrastructure is emerging that supports the delivery of on-line, location-enabled services to mobile users. Such services involve novel database queries, and the database research community is quite active in proposing techniques for the efficient processing of such queries. In parallel to this, the management of data streams has become an active area of research. While most research in mob...

We consider the Euclidean facility location problem with uniform opening cost. In this problem, we are given a set of n points P ⊆ R and an opening cost f ∈ R, and we want to find a set of facilities F ⊆ R that minimizes f · |F |+ ∑ p∈P min q∈F d(p, q) , where d(p, q) is the Euclidean distance between p and q. We obtain two main results: • A (1 + ε)-approximation algorithm with running time O(n...