An Efficient Algorithm to Compute the Euclidean Distance Spectrum of a General Intersymbol Interference Channel and Its Applications

2004 ◽  
Vol 52 (12) ◽  
pp. 2041-2046 ◽  
Author(s):  
J. Li ◽  
K.R. Narayanan ◽  
C.N. Georghiades
2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Tien-Khoi Phan ◽  
HaRim Jung ◽  
Ung-Mo Kim

Given a set of positive-weighted points and a query rectangler(specified by a client) of given extents, the goal of a maximizing range sum (MaxRS) query is to find the optimal location ofrsuch that the total weights of all the points covered byrare maximized. All existing methods for processing MaxRS queries assume the Euclidean distance metric. In many location-based applications, however, the motion of a client may be constrained by an underlying (spatial) road network; that is, the client cannot move freely in space. This paper addresses the problem of processing MaxRS queries in a road network. We propose the external-memory algorithm that is suited for a large road network database. In addition, in contrast to the existing methods, which retrieve only one optimal location, our proposed algorithm retrieves all the possible optimal locations. Through simulations, we evaluate the performance of the proposed algorithm.


2010 ◽  
Vol 20 (01) ◽  
pp. 43-67
Author(s):  
JINHUI XU ◽  
YANG YANG ◽  
YONGDING ZHU ◽  
NAOKI KATOH

Geometric spanner is a fundamental structure in computational geometry and plays an important role in many geometric networks design applications. In this paper, we consider a generalization of the classical geometric spanner problem (called segment spanner): Given a set S of n disjoint 2-D segments, find a spanning network GS with minimum size so that for any pair of points in S, there exists a path in GS with length no more than t times their Euclidean distance. Based on a number of interesting techniques (such as weakly dominating set, strongly dominating set, interval cover, and imaginary Steiner points), we present an efficient algorithm to construct the segment spanner. Our approach first identifies a set Q of Steiner points in S and then constructs a point spanner for the set of Steiner points. Our algorithm runs in O(|Q| + n2 log n) time and Q is a constant approximation (in terms of its size) of the optimal solution when S has a constant relative separation ratio. The approximation ratio depends on the stretch factor t and the relative separation ratio of S.


1996 ◽  
Vol 27 (7) ◽  
pp. 18-24 ◽  
Author(s):  
Toshihiro Kato ◽  
Tomio Hirata ◽  
Toyofumi Saito ◽  
Kenji Kise

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