Parametric search and locating supply centers in trees

2005 ◽  
pp. 299-319 ◽  
Author(s):  
Greg N. Frederickson
Keyword(s):  
Parametric Search

scholarly journals Computing the Yolk in Spatial Voting Games without Computing Median Lines

2019 ◽  
Vol 33 ◽  
pp. 2012-2019
Author(s):  
Joachim Gudmundsson ◽  
Sampson Wong
Keyword(s):  
Upper Bound ◽  
Linear Time ◽  
Search Technique ◽  
Important Concept ◽  
Uncovered Set ◽  
Spatial Voting ◽  
Voting Games ◽  
Parametric Search ◽  
Linear Time Algorithms

The yolk is an important concept in spatial voting games: the yolk center generalises the equilibrium and the yolk radius bounds the uncovered set. We present near-linear time algorithms for computing the yolk in the plane. To the best of our knowledge our algorithm is the first that does not precompute median lines, and hence is able to break the best known upper bound of O(n4/3) on the number of limiting median lines. We avoid this requirement by carefully applying Megiddo’s parametric search technique, which is a powerful framework that could lead to faster algorithms for other spatial voting problems.

scholarly journals Parametric search made practical

2004 ◽  
Vol 28 (2-3) ◽  
pp. 75-88 ◽  
Author(s):  
René van Oostrum ◽  
Remco C. Veltkamp
Keyword(s):  
Parametric Search

scholarly journals Ray Shooting and Parametric Search

1993 ◽  
Vol 22 (4) ◽  
pp. 794-806 ◽  
Author(s):  
Pankaj K. Agarwal ◽  
Jiří Matoušek
Keyword(s):  
Ray Shooting ◽  
Parametric Search

Melt Compounding Based Rotational Foam Molding Technology for Manufacture of Polypropylene Foams

2002 ◽  
Vol 21 (2) ◽  
pp. 101-120 ◽  
Author(s):  
Remon Pop-Iliev ◽  
Chul B. Park
Keyword(s):  
Raw Materials ◽  
Single Layer ◽  
Flow Rates ◽  
Melt Compounding ◽  
Processing Strategies ◽  
Single Piece ◽  
Wide Range ◽  
Parametric Search ◽  
Twin Screw ◽  
Material Preparation

This paper is intended to provide an engineering understanding of the technological potentials for processing polypropylene (PP) foams in rotational foam molding. A process proposal, based on the melt compounding material-preparation approach, capable of producing completely foamed, single-layer, single-piece PP products in rotational foam molding, is disclosed in detail. It comprises dispersing a chemical blowing agent (CBA) in the PP matrix using a twin-screw compounder, pelletizing the obtained expandable composition, and then producing foams in an uninterrupted rotational foam molding cycle by using the pre-compounded foamable pellets. Several PP grades were deliberately selected to cover a wide range of melt flow rates (MFR), starting from 5.5 up to 35 dg/min. After the raw materials participating in the study were characterized using thermal analysis instrumentation, different foamable compositions were formulated in order to prepare both 3-fold and 6-fold foamable pellets from each PP grade. The optimal foam processing strategies were identified via a systematic experimental parametric search. Foams with the best cell morphologies were obtained out of the high melt strength PP grades. In addition, the experimental results revealed that the cell morphology of the processed PP foams is not as good as that of respective PE foams. However, the cell morphologies of the PP foams processed by using the melt compounding-based approach demonstrated significant improvements in comparison with those processed by using the dry blending-based approach.

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