scholarly journals Near-Optimal Worst-Case Throughput Routing for Two-Dimensional Mesh Networks

2005 ◽  
Author(s):  
Daeho Seo ◽  
A. Ali ◽  
Won-Taek Lim ◽  
N. Rafique ◽  
M. Thottethodi
Keyword(s):  
Mesh Networks ◽  
Two Dimensional ◽  
Worst Case

scholarly journals Near-Optimal Worst-Case Throughput Routing for Two-Dimensional Mesh Networks

2005 ◽  
Vol 33 (2) ◽  
pp. 432-443 ◽  
Author(s):  
Daeho Seo ◽  
Akif Ali ◽  
Won-Taek Lim ◽  
Nauman Rafique ◽  
Mithuna Thottethodi
Keyword(s):  
Mesh Networks ◽  
Two Dimensional ◽  
Worst Case

Robust Flutter Analysis of an Airfoil with Flap Freeplay Uncertainty

2008 ◽  
Vol 33-37 ◽  
pp. 1247-1252 ◽  
Author(s):  
Zhi Chun Yang ◽  
Ying Song Gu
Keyword(s):  
Control Surface ◽  
Two Dimensional ◽  
Advanced Technique ◽  
Worst Case ◽  
Wing Model ◽  
Freeplay Nonlinearity ◽  
Flutter Analysis ◽  
Flutter Boundary ◽  
Nominal Parameter ◽  
Flutter Margin

Modern robust flutter method is an advanced technique for flutter margin estimation. It always gives the worst-case flutter speed with respect to potential modeling errors. Most literatures are focused on linear parameter uncertainty in mass, stiffness and damping parameters, etc. But the uncertainties of some structural nonlinear parameters, the freeplay in control surface for example, have not been taken into account. A robust flutter analysis approach in μ-framework with uncertain nonlinear operator is proposed in this study. Using describing function method the equivalent stiffness formulation is derived for a two dimensional wing model with freeplay nonlinearity in its flap rotating stiffness. The robust flutter margin is calculated for the two dimensional wing with flap freeplay uncertainty and the results are compared with that obtained with nominal parameter values. It is found that by considering the perturbation of freeplay parameter more conservative flutter boundary can be obtained, and the proposed method in μ-framework can be applied in flutter analysis with other types of concentrated nonlinearities.

TWO-DIMENSIONAL RANGE SEARCH BASED ON THE VORONOI DIAGRAM

2005 ◽  
Vol 15 (02) ◽  
pp. 151-166
Author(s):  
TAKESHI KANDA ◽  
KOKICHI SUGIHARA
Keyword(s):  
Voronoi Diagram ◽  
Dimensional Space ◽  
Search Problem ◽  
Two Dimensional ◽  
Worst Case ◽  
Average Case ◽  
Range Search ◽  
Almost All ◽  
Set Of Points ◽  
Dimensional Range

This paper studies the two-dimensional range search problem, and constructs a simple and efficient algorithm based on the Voronoi diagram. In this problem, a set of points and a query range are given, and we want to enumerate all the points which are inside the query range as quickly as possible. In most of the previous researches on this problem, the shape of the query range is restricted to particular ones such as circles, rectangles and triangles, and the improvement on the worst-case performance has been pursued. On the other hand, the algorithm proposed in this paper is designed for a general shape of the query range in the two-dimensional space, and is intended to accomplish a good average-case performance. This performance is actually observed by numerical experiments. In these experiments, we compare the execution time of the proposed algorithm with those of other representative algorithms such as those based on the bucketing technique and the k-d tree. We can observe that our algorithm shows the better performance in almost all the cases.

scholarly journals OceanMesh2D 1.0: MATLAB-based software for two-dimensional unstructured mesh generation in coastal ocean modeling

2019 ◽  
Vol 12 (5) ◽  
pp. 1847-1868 ◽  
Author(s):  
Keith J. Roberts ◽  
William J. Pringle ◽  
Joannes J. Westerink
Keyword(s):  
Ocean Circulation ◽  
Mesh Generation ◽  
Mesh Size ◽  
Unstructured Meshes ◽  
Coastal Ocean ◽  
Ocean Modeling ◽  
Force Balance ◽  
Generation Process ◽  
Two Dimensional ◽  
Worst Case

Abstract. OceanMesh2D is a set of MATLAB functions with preprocessing and post-processing utilities to generate two-dimensional (2-D) unstructured meshes for coastal ocean circulation models. Mesh resolution is controlled according to a variety of feature-driven geometric and topo-bathymetric functions. Mesh generation is achieved through a force balance algorithm to locate vertices and a number of topological improvement strategies aimed at improving the worst-case triangle quality. The placement of vertices along the mesh boundary is adapted automatically according to the mesh size function, eliminating the need for contour simplification algorithms. The software expresses the mesh design and generation process via an objected-oriented framework that facilitates efficient workflows that are flexible and automatic. This paper illustrates the various capabilities of the software and demonstrates its utility in realistic applications by producing high-quality, multiscale, unstructured meshes.

On the functional complexity of a two-dimensional interval search problem

2002 ◽  
Vol 12 (1) ◽  
Author(s):  
E.E. Gasanov ◽  
I.V. Kuznetsova
Keyword(s):  
Search Time ◽  
Search Problem ◽  
Two Dimensional ◽  
Worst Case ◽  
Logarithmic Average ◽  
Functional Complexity

AbstractWe suggest a modification of the Bentley-Maurer algorithm which solves a twodimensional interval search problem. This modification allows us to decrease the initially logarithmic average search time to constant, retaining the logarithmic worst-case search time. This algorithm depends on a parameter whose change results in variation of the needed memory from Ϭ(k

Study of interface reactions between Ti/Al/Ni/Au metallization and AlGaN/GaN heterostructures

Open Physics ◽  
2013 ◽  
Vol 11 (2) ◽  
Author(s):  
Wojciech Macherzyński ◽  
Bogdan Paszkiewicz
Keyword(s):  
Solid State ◽  
Structural Changes ◽  
Electron Gas ◽  
Solid State Reactions ◽  
Two Dimensional ◽  
Dimensional Electron ◽  
Two Dimensional Electron Gas ◽  
Metallic Contact ◽  
Worst Case ◽  
Dimensional Electron Gas

AbstractThe electrical characteristics, and the range of interface metal-semiconductor reactions of Ti/Al/Ni/Au metallization with AlGaN/GaN heterostructures at various annealing temperatures ranging from 715°C to 865°C, have been investigated. The relation between the depth of the interface solid state reaction and the current-voltage (I-V) characteristics of the ohmic contact, have been studied. It was observed, that the transition from nonlinear to linear I-V behaviour occurred after the annealing at 805°C. The structural changes in AlGaN/GaN heterostructures beneath the metallic contact after the thermal treatment, were investigated. After removing the metallization by etching, the atomic force microscope profiles and scanning electron microscope images, were studied to define the depth to which the interfacial solid state reactions between the metallization and the semiconductor structure take place. It was observed, that the changes in the heterostructures, caused by the interface m-s reactions, were observed up to a depth of 180 nm at 865°C. In the worst case, this could result in the complete removal of the two-dimensional electron gas under the metallization of the ohmic contacts. To study the influence of the annealing process parameters on the properties of the two-dimensional electron gas, the van der Pauw Hall mobility measurement was performed.

PERIODIC SORTING ON TWO-DIMENSIONAL MESHES

1992 ◽  
Vol 02 (02n03) ◽  
pp. 213-220 ◽  
Author(s):  
MIROSLAW KUTYLOWSKI ◽  
ROLF WANKA
Keyword(s):  
Upper Bound ◽  
Second Phase ◽  
Two Dimensional ◽  
Worst Case

We consider the following periodic sorting procedure on two-dimensional meshes of processors: Initially, each node contains one number. We proceed in rounds each round consisting of sorting the columns of the grid, and, in the second phase, of sorting the rows according to the snake-like ordering. We exactly characterize the number of rounds necessary to sort on an l × m-grid in the worst case, where l is the number of the rows and m the number of the columns. An upper bound of ⌈ log l⌉ + 1was known before. This bound is tight for the case that m is not a power of 2. Surprisingly, it turns out that far fewer rounds are necessary if m is a power of 2 (and m ≪ l) in this case, exactly min { log m + 1, ⌈ log l⌉ + 1} rounds are needed in the worst case.

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