Algorithms Algorithms Gerth Stlting Brodal Overview Overview - PowerPoint PPT Presentation

Master Thesis Preparation Algorithms Algorithms Gerth Stølting Brodal

Overview Overview Algo Algorit rithm hms s gr grou oup p at at DAIMI DAIMI • Who? • Where? • Courses • Research Mas Maste ter r th thes esis is in Algor in Algorithms ithms • Types of thesis • Recent thesis topics

Algori Algorithms thms Group Group – Who? Who? Fa Facu cult lty Rese esear arche hers Lars Arge Thomas Mailund Gerth Stølting Brodal Henrik Blunck Ph.d. Ph .d. stud studen ents ts Gudmund Skovbjerg Frandsen Peter Bro Miltersen ~ 10 Maste Master s r stud tuden ents ts Christian Nørgaard Storm Pedersen ~ 20 (Erik Meineche Schmidt) (Sven Skyum)

Algori Algorithms thms Group Group – Where Where ? BioInformatics (Building 090) Pedersen, Mailund Algorithms (Turing 2) Arge, Brodal, Frandsen, Miltersen, Blunck

Algorithms Algori thms Group Group – Courses Courses Introd Intr oduc ucto tory ry • Programming 2 - Frandsen • Algorithms and data structures - Brodal, Schmidt • Machine architecture/Operating systems - Pedersen Advan Adv ance ced • Optimization/Combinatorial search - Miltersen • Computational geometry - Arge, Brodal • I/O algorithms - Arge, Brodal • Advanced data structures - Arge, Brodal • Dynamic algorithms - Frandsen • Randomized algorithms - Frandsen • String algorithms - Pedersen • Algorithms in bioinformatics - Pedersen • Complexity theory - Miltersen • Data compression (loseless/lossy) - Miltersen • Algorithmic game playing - Miltersen

Algorithms Algorithms Group Group – Research Research I/O algorithms Computational geometry Data structures Arge String algorithms Complexity theory Brodal Data compression Frandsen Optimization Miltersen Algebraic algorithms Pedersen BioInformatics Graph algorithms Mailund Dynamic algorithms Randomized algorithms Subset of research interests Solid lines = major interst Algorithmic game theory

Algorithms Algorithms Group Group – Research Research • Theoretical computer science • Tool development – BioInformatics, I/O algorithms • Algorithm engineering – primarily in relation to thesis work • Algorithms and complexity research seminar – www.daimi.au.dk/~gerth/alcom-seminar/

Algori Algorithm thm Research Research – a typica a typical res l result sta ult stateme tement nt Results Cache-Oblivious Data Structures and Algorithms for Undirected Breadth-First Search and Shortest Paths , G. S. Brodal, R. Fagerberg, U. Meyer, N. Zeh. In Proc. 9th Scandinavian Workshop on Algorithm Theory , volume 3111 of Lecture Notes in Computer Science , pages 480-492. Springer Verlag, Berlin, 2004.

Algori Algorithm thm Research Research – an anoth other typical result er typical result Comparisons by Quicksort Element swaps Running time On the Adaptiveness of Quicksort, G. S. Brodal, R. Fagerberg, G. Moruz. In Proc. 7th Workshop on Algorithm Engineering and Experiments , 2005.

Types of Algorithmic Thesis • Solve a concrete problem …using algorithmic techniques • Survey of a research area • Implement a technical paper ...fill in the missing details ...perform experiments • Explain all (missing) details in a technical paper ...how 8 pages become +100 pages • Experimental comparison of several algorithms • The clever idea: Describe a new algorithm

Master Thesis in Algorithms The hesis sis wor ork • Large fraction of time spend on trying to understand technical complicated constructions • Implementations are often an ”existence proof” – most algorithm authors do not implement their algorithms (did they ever think about the missing details?) • Hard to convince friends that it took you a year to understand an 8 page paper...

Hidden work... ! Warning ! Nontrivial construction ahead of you ! Warning ! Need to understand another paper first

Algorith Algorithms Master ms Master Theses Theses Refined Buneman Trees Pedersen Integer Sorting Fagerberg Trade-offs for Internal and External Memory Dictionaries Fagerberg A Survey of Density Keeping Algorithms Fagerberg Shortest Paths in Directed Graphs Fagerberg Approksimative afstande i planare grafer Brodal Vedligeholdelse af sammenhængskomponenter i Frandsen dynamiske grafer Pedersen Maksimale par og suffikstræer Skjulte Markov modeller og genidentifikation Pedersen Towards practical deterministic extractors Miltersen Fagerberg/ Engineering cache-oblivious sorting algorithms Brodal Analyse og håndtering af genekspressionsdata Pedersen Dynamisk Pattern Matching Frandsen Redigeringsafstande imellem niveau-strenge Frandsen Automated Layout of Classified Ads Brodal