AnO(n logn) plane-sweep algorithm forL 1 andL ∞ Delaunay triangulations

Algorithmica ◽  
1991 ◽  
Vol 6 (1-6) ◽  
pp. 207-221 ◽  
Author(s):  
Gary M. Shute ◽  
Linda L. Deneen ◽  
Clark D. Thomborson
2021 ◽  
Author(s):  
Panagiotis Bouros ◽  
Nikos Mamoulis ◽  
Dimitrios Tsitsigkos ◽  
Manolis Terrovitis

AbstractThe interval join is a popular operation in temporal, spatial, and uncertain databases. The majority of interval join algorithms assume that input data reside on disk and so, their focus is to minimize the I/O accesses. Recently, an in-memory approach based on plane sweep (PS) for modern hardware was proposed which greatly outperforms previous work. However, this approach relies on a complex data structure and its parallelization has not been adequately studied. In this article, we investigate in-memory interval joins in two directions. First, we explore the applicability of a largely ignored forward scan (FS)-based plane sweep algorithm, for single-threaded join evaluation. We propose four optimizations for FS that greatly reduce its cost, making it competitive or even faster than the state-of-the-art. Second, we study in depth the parallel computation of interval joins. We design a non-partitioning-based approach that determines independent tasks of the join algorithm to run in parallel. Then, we address the drawbacks of the previously proposed hash-based partitioning and suggest a domain-based partitioning approach that does not produce duplicate results. Within our approach, we propose a novel breakdown of the partition-joins into mini-joins to be scheduled in the available CPU threads and propose an adaptive domain partitioning, aiming at load balancing. We also investigate how the partitioning phase can benefit from modern parallel hardware. Our thorough experimental analysis demonstrates the advantage of our novel partitioning-based approach for parallel computation.


2017 ◽  
pp. 1594-1597
Author(s):  
Jordan Wood ◽  
Sangho Kim
Keyword(s):  

2011 ◽  
Vol 219-220 ◽  
pp. 223-227
Author(s):  
Xi Juan Guo ◽  
Lei Chang ◽  
Yan Li Gao

The overlay algorithm is an important branch in computational geometry field, it is an important process for computing exact Minkowski sum of two convex polyhedrons. By improving the existing plane sweep algorithm, the overlay algorithm for simple subdivision of arbitrary polygon in plane is given. The algorithm can be used to overlay arbitrary polygon after subdivision into simple polygon in the plane. It has lower time complexity than the existing overlay algorithm. The whole algorithm consists of three steps: line segment intersection, reconstructing topology and constructing the DCEL for overlay graph. The results show that the algorithm can compute the overlay of two planar subdivisions in linear time.


2017 ◽  
Vol 10 (11) ◽  
pp. 1346-1357 ◽  
Author(s):  
Panagiotis Bouros ◽  
Nikos Mamoulis
Keyword(s):  

2008 ◽  
pp. 876-878
Author(s):  
Jordan Wood ◽  
Sangho Kim
Keyword(s):  

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