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Signal Processing Commons

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Articles 1 - 4 of 4

Full-Text Articles in Signal Processing

Anonymous Query Processing In Road Networks, Kyriakos Mouratidis, Man Lung Yiu Dec 2010

Anonymous Query Processing In Road Networks, Kyriakos Mouratidis, Man Lung Yiu

Kyriakos MOURATIDIS

The increasing availability of location-aware mobile devices has given rise to a flurry of location-based services (LBSs). Due to the nature of spatial queries, an LBS needs the user position in order to process her requests. On the other hand, revealing exact user locations to a (potentially untrusted) LBS may pinpoint their identities and breach their privacy. To address this issue, spatial anonymity techniques obfuscate user locations, forwarding to the LBS a sufficiently large region instead. Existing methods explicitly target processing in the euclidean space and do not apply when proximity to the users is defined according to network distance …


Continuous Monitoring Of Spatial Queries In Wireless Broadcast Environments, Kyriakos Mouratidis, Spiridon Bakiras, Dimitris Papadias Dec 2010

Continuous Monitoring Of Spatial Queries In Wireless Broadcast Environments, Kyriakos Mouratidis, Spiridon Bakiras, Dimitris Papadias

Kyriakos MOURATIDIS

Wireless data broadcast is a promising technique for information dissemination that leverages the computational capabilities of the mobile devices in order to enhance the scalability of the system. Under this environment, the data are continuously broadcast by the server, interleaved with some indexing information for query processing. Clients may then tune in the broadcast channel and process their queries locally without contacting the server. Previous work on spatial query processing for wireless broadcast systems has only considered snapshot queries over static data. In this paper, we propose an air indexing framework that 1) outperforms the existing (i.e., snapshot) techniques in …


On Iterative Decoding Of Two-Level Superposition Codes For Cooperative Broadcasting Based On Qpsk And 4-Pam Constellations, Robert H. Morelos-Zaragoza Nov 2010

On Iterative Decoding Of Two-Level Superposition Codes For Cooperative Broadcasting Based On Qpsk And 4-Pam Constellations, Robert H. Morelos-Zaragoza

Robert Henry Morelos-Zaragoza

This paper considers iterative decoding of two-level superposition codes used in cooperative broadcasting over wireless networks. The coding scheme consists of two low-density parity-check (LDPC) codes combined using Plotkin’s |u|u+v|-construction and provides two levels of error protection.


A Novel Eight Switches Inverter Topology For Plug-In Hybrid Electric Vehicle, Omar Hegazy, Joeri Van Mierlo Mar 2010

A Novel Eight Switches Inverter Topology For Plug-In Hybrid Electric Vehicle, Omar Hegazy, Joeri Van Mierlo

Dr. Eng. Omar Hegazy

In this paper, a novel inverter topology, Eight Switches Inverter (ESI), is proposed for HEV, especially PHEV system to reduce the number of switches, and to achieve high performance during discharging mode, braking mode and charging mode from grid. Thereby, this topology gives the ability to connect the vehicle with grid at home or at work to charge the Energy Storage System (ESS) easily, especially the battery unit. In addition, the cost and the volume of the power electronics unit (PEU) have reduced. In this research, there are two control strategies have tested to validate the performance of the proposed …