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-<TITLE>Christian Urban</TITLE>
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-<H2>2011/12 MSc Individual Projects</H2>
-<H4>Supervisor: Christian Urban</H4>
-<H4>Email: christian dot urban at kcl dot ac dot uk, Office: Strand Building S6.30</H4>
-<H4>If you are interested in a project, please send me an email and we can discuss details. Please include
-a short description about your programming skills and computer science background in your first email.
-I will also need your King's username in order to book the project for you. Thanks.</H4>
-
-<ul class="striped">
-<li> <H4>[CU1] Implementing a SAT-Solver in a Functional Programming Language</H4>
-
- <p><B>Description:</b>
- SAT-solver search for satisfying assignments of boolean formulas. Although this
- is a computationally hard problem (<A HREF="http://en.wikipedia.org/wiki/NP-complete">NP-complete</A>),
- modern SAT-solvers routinely solve boolean formulas with 100,000 and more variables.
- Application areas of SAT-solver are manifold: they range from hardware verification to
- Sudoku solvers (see <a href="http://anytime.cs.umass.edu/aimath06/proceedings/P34.pdf">here</a>).
- Every 2 years there is a competition of the best SAT-solvers in the world.</p>
-
- <p>
- Most SAT-solvers are written in C. The aim of this project is to design and implement
- a SAT-solver in a functional programming language (preferably
- <A HREF="http://en.wikipedia.org/wiki/Standard_ML">ML</A>, but
- <A HREF="http://haskell.org/haskellwiki/Haskell">Haskell</A>,
- <A HREF="http://www.scala-lang.org/">Scala</A>,
- <A HREF="http://caml.inria.fr/">OCaml</A>, ... are also OK). Starting point is
- the open source SAT-solver MiniSat (available <A HREF="http://minisat.se/Main.html">here</A>).
- The long-term hope is that your implementation becomes part of the interactive theorem prover
- <A HREF="http://www.cl.cam.ac.uk/research/hvg/isabelle/">Isabelle</A>. For this
- the SAT-solver needs to be implemented in ML.</p>
-
- <p>
- <B>Tasks:</B> Understand MiniSat, design and code a SAT-solver in ML,
- empirical evaluation and tuning of your code.</p>
-
- <p>
- <B>Literature:</B> A good starting point for reading about SAT-solving is the handbook
- article <A HREF="http://www.cs.cornell.edu/gomes/papers/SATSolvers-KR-Handbook.pdf">here</A>.
- MiniSat is explained <A HREF="http://minisat.se/downloads/MiniSat.pdf">here</A> and
- <A HREF="http://minisat.se/Papers.html">here</A>. The standard reference for ML is
- <A HREF="http://www.cl.cam.ac.uk/~lp15/MLbook/">here</A> (I can lend you my copy
- of this book for the duration of the project). The best free implementation of ML is
- <A HREF="http://www.polyml.org/">PolyML</A>.
- </p>
-
-<li> <H4>[CU2] A Compiler for System F</H4>
-
- <p><b>Description:</b>
- <A HREF="http://en.wikipedia.org/wiki/System_F">System F</A> is a mini programming language,
- which is often used to study the theory behind programming languages, but is also used as
- a core-language of functional programming languages (for example
- <A HREF="http://haskell.org/haskellwiki/Haskell">Haskell</A>). The language is small
- enough to implement in a reasonable amount of time a compiler to an
- idealised assembly language (preferably
- <A HREF="http://en.wikipedia.org/wiki/Typed_assembly_language">TAL</A>) or an abstract machine.
- This has been explained in full detail in a PhD-thesis by Louis-Julien Guillemette
- (available in English <A HREF="https://papyrus.bib.umontreal.ca/jspui/bitstream/1866/3454/6/Guillemette_Louis-Julien_2009_these.pdf">here</A>). He used <A HREF="http://haskell.org/haskellwiki/Haskell">Haskell</A>
- as his implementation language. Other choices are possible.
- </p>
-
- <p>
- <b>Tasks:</b>
- Read the relevant literature and implement the various components of a compiler
- (parser, intermediate languages, simulator for the idealised assembly language).
- This project is for a good student with an interest in programming languages,
- who can also translate abstract ideas into code. If it is too difficult, the project can
- be easily scaled down to the
- <A HREF="http://en.wikipedia.org/wiki/Simply_typed_lambda_calculus">simply-typed
- lambda calculus</A> (which is simpler than
- System F) or to cover only some components of the compiler.
- </p>
-
- <p>
- <B>Literature:</B>
- The <A HREF="https://papyrus.bib.umontreal.ca/jspui/bitstream/1866/3454/6/Guillemette_Louis-Julien_2009_these.pdf">PhD-thesis</A> by Louis-Julien Guillemette is required reading. A shorter
- paper about this subject is available <A HREF="http://www.iro.umontreal.ca/~monnier/icfp08.pdf">here</A>.
- A good starting point for TAL is <A HREF="http://www.cs.cornell.edu/talc/papers/tal-tr.pdf">here</A>.
- There is a lot of literature about compilers
- (for example <A HREF="http://www.cs.princeton.edu/~appel/papers/cwc.html">this book</A> -
- I can lend you my copy for the duration of the project). A very good overview article
- about implementing compilers by
- <A HREF="http://tratt.net/laurie/">Laurie Tratt</A> is
- <A HREF="http://tratt.net/laurie/tech_articles/articles/how_difficult_is_it_to_write_a_compiler">here</A>.
- </p>
-
- <li> <H4>[CU3] Sorting Suffixes</H4>
-
- <p><b>Description:</b> Given a string, take all its suffixes, and sort them.
- This is often called <A HREF="http://en.wikipedia.org/wiki/Suffix_array">suffix
- array sorting</A>. It sound simple, but there are some difficulties.
- The naive algorithm would generate all suffix strings and sort them
- using a standard sorting algorithm, for example
- <A HREF="http://en.wikipedia.org/wiki/Quicksort">quicksort</A>.
- The problem is that
- this algorithm is not optimal for suffix sorting: it does not take into account that you sort
- suffixes and it also takes a quadratic amount of space. This is a
- huge problem if you have to sort strings of several Megabytes or even Gigabytes,
- as happens often in biotech and DNA data mining. Suffix sorting is also a crucial operation for the
- <A HREF="http://en.wikipedia.org/wiki/Burrows-Wheeler_transform">Burrows-Wheeler transform</A>
- on which the data compression algorithm of the popular
- <A HREF="http://en.wikipedia.org/wiki/Bzip2">bzip2</A>
- program is based.
- </p>
-
- <p>
- There are more efficient algorithms for suffix sorting, for example
- <A HREF="http://books.google.co.uk/books?id=Pn1sHToYf9oC&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false">here</A> and
- <A HREF="http://ls11-www.cs.uni-dortmund.de/people/rahmann/teaching/ss2008/AlgorithmenAufSequenzen/09-walk-bwt.pdf">here</A>.
- However the most space efficient algorithm for suffix sorting
- (<A HREF="http://www.cs.rutgers.edu/~muthu/fm072.pdf">here</A>)
- is horrendously complicated. Your task would be to understand it, and then implement it.
- </p>
-
- <p>
- <B>Tasks:</B>
- Start by reading the literature about suffix sorting. Then work through the
- 12-page <A HREF="http://www.cs.rutgers.edu/~muthu/fm072.pdf">paper</A>
- explaining the horrendously complicated algorithm and implement it.
- Time permitting the work can include an implementation of the Burrows-Wheeler
- data compression. This project is for a good student, who likes to study in-depth
- algorithms. The project can be carried out in almost all programming languages,
- including C, Java, Scala, ML, Haskell and so on.
- </p>
-
- <p>
- <B>Literature:</B> A good starting point for reading about suffix sorting is the
- <A HREF="http://books.google.co.uk/books?id=Pn1sHToYf9oC&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false">book</A> by Crochemore.
- Another good introduction is
- <A HREF="http://people.unipmn.it/manzini/papers/esa02.pdf">here</A>,
- which gives also good pointers for why efficient suffix sorting
- is practically relevant.
- Two simple algorithms are described
- <A HREF="http://ls11-www.cs.uni-dortmund.de/people/rahmann/teaching/ss2008/AlgorithmenAufSequenzen/09-walk-bwt.pdf">here</A>. The main literature is the 12-page
- <A HREF="http://www.cs.rutgers.edu/~muthu/fm072.pdf">article</A> about in-place
- suffix sorting. The Burrows-Wheeler data compression is described
- <A HREF="http://www.hpl.hp.com/techreports/Compaq-DEC/SRC-RR-124.pdf">here</A>.
- </p>
-
-<li> <H4>[CU4] Simplification with Equivalence Relations in the Isabelle Theorem Prover</H4>
- <p>
- <B>Description:</B>
- In this project you have to extend the simplifier of the
- <A HREF="http://isabelle.in.tum.de/">Isabelle theorem prover</A>.
- The simplifier is an important reasoning tool of this theorem prover: it
- replaces a term by another term that can be proved to be equal to it. However,
- currently the simplifier only rewrites terms according to equalities.
- Assuming ≈ is an equivalence relation, the simplifier should also be able
- to rewrite terms according to ≈. Since equivalence relations occur
- frequently in automated reasoning, this extension would make the simplifier
- more powerful and useful. The hope is that your code can go into the
- code base of Isabelle.
- </p>
-
- <p>
- <B>Tasks:</B>
- Read the <A HREF="http://www.springerlink.com/content/x7041m1807738832/">paper</A>
- about rewriting with equivalence relations. Get familiar with parts of the
- implementation of Isabelle (I will be of much help as I can). Implement
- the extension. This project is suitable for a student with a bit of math background.
- It requires knowledge of the functional programming language ML, which
- however can be learned quickly provided you have already written code
- in another functional programming language.
- </p>
-
- <p>
- <B>Literature:</B> A good starting point for reading about rewriting modulo equivalences
- is the paper <A HREF="http://www.springerlink.com/content/x7041m1807738832/">here</A>,
- which uses the ACL2 theorem prover. The implementation of the Isabelle theorem
- prover is described in much detail in this
- <A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/Cookbook/">programming tutorial</A>.
- The standard reference for ML is
- <A HREF="http://www.cl.cam.ac.uk/~lp15/MLbook/">here</A> (I can lend you my copy
- of this book for the duration of the project).
- </p>
-
-
-<li><h4>[CU5] Lexing and Parsing with Derivatives</h4>
-
- <p>
- <B>Description:</B>
- Lexing and parsing are usually done using automated tools, like
- <A HREF="http://en.wikipedia.org/wiki/Lex_programming_tool">lex</A> and
- <A HREF="http://en.wikipedia.org/wiki/Yacc">yacc</A>. The problem
- with them is that they "work when they work", but if they do not, then they are
- <A HREF="http://en.wikipedia.org/wiki/Black_box">black boxes</A>
- which are difficult to debug and change. They are really quite
- clumsy to the point that Might and Darais wrote a paper titled
- "<A HREF="http://arxiv.org/pdf/1010.5023v1">Yacc is dead</A>".</p>
-
- <p>
- There is a simple algorithm for regular expression matching (that is lexing).
- This algorithm was introduced by
- <A HREF="http://en.wikipedia.org/wiki/Janusz_Brzozowski_(computer_scientist)">Brzozowski</A>
- in 1964. It is based on the notion of derivatives of regular expressions and
- has proved <A HREF="http://www.cl.cam.ac.uk/~so294/documents/jfp09.pdf">useful</A>
- for practical lexing. Last year the notion of derivatives was extended by
- <A HREF="http://matt.might.net/papers/might2011derivatives.pdf">Might et al</A>
- to <A HREF="http://en.wikipedia.org/wiki/Context-free_grammar">context free grammars</A>
- and parsing.
- </p>
-
- <p>
- <B>Tasks:</B> Get familiar with the two algorithms and implement them. Regular
- expression matching is relatively simple; parsing with derivatives is the
- harder part. Therefore you should empirically evaluate this part and
- tune your implementation. The project can be carried out in almost all programming
- languages, including C, Java, Scala, ML, Haskell and so on.
- </p>
-
- <p>
- <B>Literature:</B> This
- <A HREF="http://www.cl.cam.ac.uk/~so294/documents/jfp09.pdf">paper</A>
- gives a modern introduction to derivative based lexing. Derivative-based
- parsing is explained <A HREF="http://arxiv.org/pdf/1010.5023v1">here</A>
- and <A HREF="http://matt.might.net/papers/might2011derivatives.pdf">here</A>.
- A proposal for derivative PEG-parsing is
- <A HREF="http://fmota.eu/2011/01/07/PEG-derivatives.html">here</a>. The mailing
- list about PEGs is <A HREF="https://lists.csail.mit.edu/pipermail/peg/">here</A>.
- </p>
-
-<li> <H4>[CU6] Equivalence Checking of Regular Expressions using the Method by Antimirov and Mosses</H4>
-
- <p>
- <B>Description:</B>
- Solving the problem of deciding equivalence of regular expressions can be used
- to decide a number of problems in automated reasoning. Therefore one likes to
- have a method for equivalence checking that is as fast as possible. There have
- been a number of algorithms proposed in the past, but one based on a method
- by Antimirov and Mosses seems relatively simple and easy to implement.
- </p>
-
- <p>
- <B>Tasks:</B>
- The task is to implement the algorithm by Antimirov and Mosses and compare it to
- other methods. Hopefully the algorithm can be tuned to be faster than other
- methods. The project can be carried out in almost all programming languages, but
- as usual functional programming languages such Scala, ML, Haskell have an edge
- for this kind of problems.
- </p>
-
- <p>
- <B>Literature:</B>
- Central to this project are the papers <A HREF="http://www.dcc.fc.up.pt/~nam/publica/ijcs08.pdf">here</A>
- and <A HREF="http://www.dcc.fc.up.pt/~nam/publica/51480046.pdf">here</A>.
- Other methods have been described, for example,
- <A HREF="http://www4.informatik.tu-muenchen.de/~krauss/papers/rexp.pdf">here</A>.
- A relatively complicated method, based on automata, is described
- <A HREF="http://sardes.inrialpes.fr/~braibant/atbr/">here</A>.
- </p>
-
-<li> <H4>[CU7] Game-Playing Engine for Five-In-A-Row on a Large Board</H4>
-
- <p>
- <B>Literature:</b>
- There is a web-page with various pointers to computer players
- <A HREF="http://webdocs.cs.ualberta.ca/~games/">here</A>. There are
- also some good books about computer players, for example:
- <table cellspacing="10">
- <tr><td><i>Artificial Intelligence: A Modern Approach</i> by S. Russel and P. Norvig, Prentice Hall, 2003
- (a standard textbook about search strategies).
- </td></tr>
- <tr><td><i>Principles of Artificial Intelligence</i> by N. J. Nilsson, Springer Verlag, 1980
- (a standard textbook about search strategies).
- </td></tr>
-
- <tr><td><i>Computer Game-Playing: Theory and Practice</i> by M. Bramer, Ellis Horwood Ltd, 1983
- (considers techniques used for programming a variety of games: Chess, Go, Scrabble, Billiards,
- Othello, etc; includes theoretical issues about game searching).
- </td></tr>
- <tr><td><i>Chips Challenging Champions: Games, Computers and Artificial Intelligence</i> by
- J. Schaeffer and H.J. van den Herik, North Holland, 2002.
- </td></tr>
- <tr><td>
- <i>Artificial Intelligence for Games</i> by I. Millington and J. Funge, Morgan Kaufmann, 2009.
- </td></tr>
- <tr><td>
- <i>Computer Gamesmanship: The Complete Guide to Creating and Structuring Intelligent Games Programs</i>
- by D.N.L. Levy, Simon and Schuster, 1983.
- </td></tr>
- </table>
- </p>
-
-<li><h4>[CU8] Webserver for a Revision Control System</h4>
-
- <p>
- Modern revision control systems are
- <A HREF="http://mercurial.selenic.com/">mercurial</A> and
- <A HREF="http://git-scm.com/">git</A>.
- </p>
-
- <p>
- <b>Task:</b> Build a webserver for a revision control system
- that allows user management.
- </p>
-
-</ul>
-</TD>
-</TR>
-</TABLE>
-
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--- a/travelling.html Wed May 04 12:04:16 2016 +0100
+++ b/travelling.html Thu May 05 09:40:48 2016 +0100
@@ -306,9 +306,7 @@
(Krakow, 2 - 5 May)
<LI> Talk at the Natural Deduction meeting in Rio de Janeiro (30 June - 7 July,
slides [<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/Slides/slides-rio.ps.gz">ps.gz</A>])
-<LI> Summer School
-<A HREF="http://www4.informatik.tu-muenchen.de/div/summerschool/">Marktoberdorf</A>
-(24 July - 5 August)
+<LI> Summer School Marktoberdorf (24 July - 5 August)
</ul>
<H5>2000</H5>
@@ -359,8 +357,7 @@
<A HREF="http://orchid.inf.tu-dresden.de/gk-spezifikation/index.html">
Graduate College</A> Meeting held by the University in Dresden
(Reinhartsdorf/Sächsische Schweiz, 17 - 21 February)
-<LI> <A HREF="http://www4.informatik.tu-muenchen.de/div/summerschool/">Summer School
- Marktoberdorf on Computational Logic</A> (29 July - 10 August)
+<LI> Summer School Marktoberdorf on Computational Logic (29 July - 10 August)
<LI> Problems and Advances in the Semantics of Linear Logic
(Utrecht, the Netherlands, 28 - 29 November)
</ul>