subproject 3 large scale optimization participants cti, cuni, mpii, rwth, tu wroclaw, ucy, upb...

Subproject 3

Large Scale Optimization

Participants

CTI, CUNI, MPII, RWTH, TU Wroclaw, UCY, UPB

presented by Burkhard Monien (UPB)

Burkhard Monien (UPB)

Large Scale OptimizationSubproject 3

Goals of SP3 „Large Scale Optimization“

Long term new approximation theory, methodological framework and software

implementations for large-scale optimization problems.Short term Identification of key problems, initial modellings, approximation

algorithms for large-scale optimization problems.

Approximation theory

Algorithms

Implementations

Documentation

Large-scale wired networks, network problems, wireless networks

Introduction



Structure of SP3 „Large Scale Optimization“

WP 3.1Approximation Techniques forLarge-Scale Optimization

WP 3.2Optimization Methods

for Large-Scale Communication and

Transportation Networks and the Web

WP 3.3Foundations

Of WirelessNetworks

WP 3.4A Compendium of Large-Scale Optimization Problems

Introduction



Publications

Total??? conference / journal papers, ??? reports under submission

Last 12 Month??? conference / journal papers, ??? reports under submission

Introduction



Deliverables due at month 24

D3.1.3: Establishment of Basic Methodological Framework of Nonlinear Optimization Approaches for Large-Scale Optimization Problems

D3.2.2: Initial Modeling of Selected Problems for Communication/Transportation Networks

D3.3.3: Assessment of Developed Algorithmic Techniques

D3.4.3: Initial Experimental Studies of Selected Problems

Introduction



External Memory (Meyer & Ajwani, MPII)

x

• main memory size << problem size• external memory = D disks• data is transferred in blocks of size B• up to D · B data per I/O operation• Goal: minimize number of I/O operations

scan(x) = O( x / (D · B) )sort(x) = O( x / (D · B) · logM/B (x/B) )



Breadth First Search (BFS)



External BFS — Motivation

Solving real world optimization problem often boils down to structured graph traversal

Crawling, analyzing the WWW Generalizations: Shortest Paths, A* Route planning using small navigation devices with

flash memory cards State space exploration



External BFS — Experimental Study

A computational study of three BFS-algorithms from the literature

D. Ajwani, R. Dementiev, U. Meyer, SODA'05 (DELIS-TR-0276)

Internal-memory algorithm

Munagala, Ranade SODA'99

Mehlhorn, Meyer ESA'02



The End

Thank you!

subproject 3 large scale optimization participants cti, cuni, mpii, rwth, tu wroclaw, ucy, upb...

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