An Improved Approximation Algorithm for Computing Geometric Shortest Paths

2003 ◽  
pp. 246-257 ◽  
Author(s):  
Lyudmil Aleksandrov ◽  
Anil Maheshwari ◽  
Jörg-Rüdiger Sack
Keyword(s):  
Approximation Algorithm ◽  
Shortest Paths

scholarly journals An Approximation Algorithm for Computing Shortest Paths in Weighted 3-d Domains

2013 ◽  
Vol 50 (1) ◽  
pp. 124-184 ◽  
Author(s):  
Lyudmil Aleksandrov ◽  
Hristo Djidjev ◽  
Anil Maheshwari ◽  
Jörg-Rüdiger Sack
Keyword(s):  
Approximation Algorithm ◽  
Shortest Paths

Performance Evaluation on a Hybrid Algorithm for Computing Constrained Shortest Paths

2015 ◽  
Vol 719-720 ◽  
pp. 784-790
Author(s):  
Xiang Zhu He ◽  
Gang Feng
Keyword(s):  
Approximation Algorithm ◽  
Communication Networks ◽  
Hybrid Algorithm ◽  
Shortest Paths ◽  
Service Provisioning ◽  
Fundamental Issue ◽  
Least Cost Path ◽  
Simulation Results ◽  
Quality Of Service Provisioning

Finding a delay constrained least-cost path in a directed graph is a fundamental issue for quality of service provisioning in communication networks. Recently Feng and Turkay proposed a hybrid algorithm which uses a heuristic approach to boost the average performance of a well known approximation algorithm. In this paper we provide extensive simulation results to show that the hybrid algorithm runs significantly faster than the approximation algorithm, often by one or two orders of magnitude.

scholarly journals Approximation Algorithm for Shortest Path in Large Social Networks

Algorithms ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 36 ◽  
Author(s):  
Dennis Nii Ayeh Mensah ◽  
Hui Gao ◽  
Liang Wei Yang
Keyword(s):  
Approximation Algorithm ◽  
Large Scale ◽  
High Efficiency ◽  
Shortest Paths ◽  
Real Life ◽  
Original Network ◽  
Hierarchical Networks ◽  
Life Data ◽  
Real Life Data ◽  
Large Scale Networks

Proposed algorithms for calculating the shortest paths such as Dijikstra and Flowd-Warshall’s algorithms are limited to small networks due to computational complexity and cost. We propose an efficient and a more accurate approximation algorithm that is applicable to large scale networks. Our algorithm iteratively constructs levels of hierarchical networks by a node condensing procedure to construct hierarchical graphs until threshold. The shortest paths between nodes in the original network are approximated by considering their corresponding shortest paths in the highest hierarchy. Experiments on real life data show that our algorithm records high efficiency and accuracy compared with other algorithms.

Approximate Shortest Paths in Polygons with Violations

2020 ◽  
Vol 30 (01) ◽  
pp. 79-95
Author(s):  
Binayak Dutta ◽  
Sasanka Roy
Keyword(s):  
Approximation Algorithm ◽  
Shortest Path ◽  
Shortest Paths ◽  
Simple Polygon ◽  
Geometric Parameters

We study the shortest [Formula: see text]-violation path problem in a simple polygon. Let [Formula: see text] be a simple polygon in [Formula: see text] with [Formula: see text] vertices and let [Formula: see text] be a pair of points in [Formula: see text]. Let [Formula: see text] represent the interior of [Formula: see text]. Let [Formula: see text] represent the exterior of [Formula: see text]. For an integer [Formula: see text], the shortest [Formula: see text]-violation path problem in [Formula: see text] is the problem of computing the shortest path from [Formula: see text] to [Formula: see text] in [Formula: see text], such that at most [Formula: see text] path segments are allowed to be in [Formula: see text]. The subpaths of a [Formula: see text]-violation path are not allowed to bend in [Formula: see text]. For any [Formula: see text], we present a [Formula: see text] factor approximation algorithm for the problem that runs in [Formula: see text] time. Here [Formula: see text] and [Formula: see text], [Formula: see text], [Formula: see text] are geometric parameters.

eMap: A Web Application for Identifying and Visualizing Electron or Hole Hopping Pathways in Proteins

2019 ◽  
Author(s):  
Ruslan N. Tazhigulov ◽  
James R. Gayvert ◽  
Melissa Wei ◽  
Ksenia B. Bravaya
Keyword(s):  
Web Application ◽  
Shortest Paths ◽  
Coarse Grained ◽  
Decay Parameter ◽  
Electron Hole ◽  
Web Based ◽  
Aromatic Amino Acid Residue ◽  
Pathways Model ◽  
Visualization Tools ◽  
Effective Decay

<p>eMap is a web-based platform for identifying and visualizing electron or hole transfer pathways in proteins based on their crystal structures. The underlying model can be viewed as a coarse-grained version of the Pathways model, where each tunneling step between hopping sites represented by electron transfer active (ETA) moieties is described with one effective decay parameter that describes protein-mediated tunneling. ETA moieties include aromatic amino acid residue side chains and aromatic fragments of cofactors that are automatically detected, and, in addition, electron/hole residing sites that can be specified by the users. The software searches for the shortest paths connecting the user-specified electron/hole source to either all surface-exposed ETA residues or to the user-specified target. The identified pathways are ranked based on their length. The pathways are visualized in 2D as a graph, in which each node represents an ETA site, and in 3D using available protein visualization tools. Here, we present the capability and user interface of eMap 1.0, which is available at https://emap.bu.edu.</p>

An Improved Sequential Polygonal Approximation Algorithm on Skeleton Curves

2009 ◽  
Vol 34 (12) ◽  
pp. 1467-1474
Author(s):  
Zhe LV ◽  
Fu-Li WANG ◽  
Yu-Qing CHANG ◽  
Yang LIU
Keyword(s):  
Approximation Algorithm ◽  
Polygonal Approximation
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