به نام خدا
Title: Bluetooth Positioning using RSSI and Triangulation Methods
Authors: Yapeng Wang, Xu Yang Yutian Zhao
Abstract: Location based services are the hottest applications on mobile devices nowadays and the growth is continuing. Indoor wireless positioning is the key technology to enable location based services to work well indoors, where GPS normally could not work. Bluetooth has been widely used in mobile devices like phone, PAD etc. therefore Bluetooth based indoor positioning has great market potential. Radio Signal Strength (RSS) is a key parameter for wireless positioning. New Bluetooth standard (since version 2.1) enables RSS to be discovered without time consuming pre-connection. In this research, general wireless positioning technologies are firstly analysed. Then RSS based Bluetooth positioning using the new feature is studied. The mathematical model is established to analyse the relation between RSS and the distance between two Bluetooth devices. Three distance-based algorithms are used for Bluetooth positioning: Least Square Estimation, Three-border and Centroid Method. Comparison results are analysed and the ways to improve the positioning accuracy are discussed.
Publish Year: 2013
Published in: CCNC - IEEE
Number of Pages: 6
موضوع: بلوتوث
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حامی دانش بومی ایرانیان
به نام خدا
Title: Electron repulsion integrals for self-energy calculations
Authors: Y Pavlyukh , J Berakdar
Abstract: A fast algorithm for the calculation of the electron repulsion integrals in an atomic basis is a prerequisite of any ab initio quantum chemistry method. Unlike the case of a self-consistent field (SCF) approach, correlated methods often require a full or partial integral transformation to the molecular basis. The run- time of such an algorithm scales unfavorably as O(N ? where N ? is the number of the basis function, and additionally poses high requirements on the computer memory. The problem is aggravated in the case of large highly symmetric molecules which can only be modeled by fully taking the symmetry into account (as was recently demonstrated by us in J. Chem. Phys. 135 (2011) 201103). Wedescribe here the algorithm for the calculation of the electron repulsion integrals, the transformation and their use in the correlated Green s function approach for systems with icosahedral symmetry.
Publish Year: 2013
Published in: Computer Physics Communications - Science Direct
Number of Pages: 9
موضوع: فیزیک
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حامی دانش بومی ایرانیان