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    33 <H2>2014/15 BSc Projects</H2>
       
    34 <H4>Supervisor: Christian Urban</H4> 
       
    35 <H4>Email: christian dot urban at kcl dot ac dot uk,  Office: Strand Building S1.27</H4>
       
    36 <H4>If you are interested in a project, please send me an email and we can discuss details. Please include
       
    37 a short description about your programming skills and Computer Science background in your first email. 
       
    38 I will also need your King's username in order to book the project for you. Thanks.</H4> 
       
    39 
       
    40 <H4>Note that besides being a lecturer at the theoretical end of Computer Science, I am also a passionate
       
    41     <A HREF="http://en.wikipedia.org/wiki/Hacker_(programmer_subculture)">hacker</A> &hellip;
       
    42     defined as &ldquo;a person who enjoys exploring the details of programmable systems and 
       
    43     stretching their capabilities, as opposed to most users, who prefer to learn only the minimum 
       
    44     necessary.&rdquo; I am always happy to supervise like-minded students.</H4>  
       
    45 
       
    46 <ul class="striped">
       
    47 <li> <H4>[CU1] Regular Expression Matching and Partial Derivatives</H4>
       
    48 
       
    49   <p>
       
    50   <B>Description:</b>  
       
    51   <A HREF="http://en.wikipedia.org/wiki/Regular_expression">Regular expressions</A> 
       
    52   are extremely useful for many text-processing tasks such as finding patterns in texts,
       
    53   lexing programs, syntax highlighting and so on. Given that regular expressions were
       
    54   introduced in 1950 by <A HREF="http://en.wikipedia.org/wiki/Stephen_Cole_Kleene">Stephen Kleene</A>,
       
    55   you might think regular expressions have since been studied and implemented to death. But you would definitely be
       
    56   mistaken: in fact they are still an active research area. For example
       
    57   <A HREF="http://www.home.hs-karlsruhe.de/~suma0002/publications/ppdp12-part-deriv-sub-match.pdf">this paper</A> 
       
    58   about regular expression matching and partial derivatives was presented last summer at the international 
       
    59   PPDP'12 conference. They even work on a followup paper that has not yet been presented at any
       
    60   conference. The task in this project is to implement their results.</p>
       
    61 
       
    62   <p>The background for this project is that some regular expressions are 
       
    63   &ldquo;<A HREF="http://en.wikipedia.org/wiki/ReDoS#Examples">evil</A>&rdquo;
       
    64   and can &ldquo;stab you in the back&rdquo; according to
       
    65   this <A HREF="http://tech.blog.cueup.com/regular-expressions-will-stab-you-in-the-back">blog post</A>.
       
    66   For example, if you use in <A HREF="http://www.python.org">Python</A> or 
       
    67   in <A HREF="http://www.ruby-lang.org/en/">Ruby</A> (probably also other mainstream programming languages) the 
       
    68   innocently looking regular expression <code>a?{28}a{28}</code> and match it, say, against the string 
       
    69   <code>aaaaaaaaaaaaaaaaaaaaaaaaaaaa</code> (that is 28 <code>a</code>s), you will soon notice that your CPU usage goes to 100%. In fact,
       
    70   Python and Ruby need approximately 30 seconds of hard work for matching this string. You can try it for yourself:
       
    71   <A HREF="http://www.dcs.kcl.ac.uk/staff/urbanc/cgi-bin/repos.cgi/afl-material/raw-file/tip/progs/re.py">re.py</A> (Python version) and 
       
    72   <A HREF="http://www.dcs.kcl.ac.uk/staff/urbanc/cgi-bin/repos.cgi/afl-material/raw-file/tip/progs/re.rb">re.rb</A> 
       
    73   (Ruby version). You can imagine an attacker
       
    74   mounting a nice <A HREF="http://en.wikipedia.org/wiki/Denial-of-service_attack">DoS attack</A> against 
       
    75   your program if it contains such an &ldquo;evil&rdquo; regular expression. Actually 
       
    76   <A HREF="http://www.scala-lang.org/">Scala</A> (and also Java) are almost immune from such
       
    77   attacks as they can deal with strings of up to 4,300 <code>a</code>s in less than a second. But if you scale
       
    78   the regular expression and string further to, say, 4,600 <code>a</code>s, then you get a <code>StackOverflowError</code> 
       
    79   potentially crashing your program.
       
    80   </p>
       
    81 
       
    82   <p>
       
    83   On a rainy afternoon, I implemented 
       
    84   <A HREF="http://www.dcs.kcl.ac.uk/staff/urbanc/cgi-bin/repos.cgi/afl-material/raw-file/tip/progs/re3.scala">this</A> 
       
    85   regular expression matcher in Scala. It is not as fast as the official one in Scala, but
       
    86   it can match up to 11,000 <code>a</code>s in less than 5 seconds  without raising any exception
       
    87   (remember Python and Ruby both need nearly 30 seconds to process 28(!) <code>a</code>s, and Scala's
       
    88   official matcher maxes out at 4,600 <code>a</code>s). My matcher is approximately
       
    89   85 lines of code and based on the concept of 
       
    90   <A HREF="http://lambda-the-ultimate.org/node/2293">derivatives of regular expressions</A>.
       
    91   These derivatives were introduced in 1964 by <A HREF="http://en.wikipedia.org/wiki/Janusz_Brzozowski_(computer_scientist)">
       
    92   Janusz Brzozowski</A>, but according to this 
       
    93   <A HREF="http://www.cl.cam.ac.uk/~so294/documents/jfp09.pdf">paper</A> had been lost in the &ldquo;sands of time&rdquo;.
       
    94   The advantage of derivatives is that they side-step completely the usual 
       
    95   <A HREF="http://hackingoff.com/compilers/regular-expression-to-nfa-dfa">translations</A> of regular expressions
       
    96   into NFAs or DFAs, which can introduce the exponential behaviour exhibited by the regular
       
    97   expression matchers in Python and Ruby.
       
    98   </p>
       
    99 
       
   100   <p>
       
   101   Now the authors from the 
       
   102   <A HREF="http://www.home.hs-karlsruhe.de/~suma0002/publications/ppdp12-part-deriv-sub-match.pdf">PPDP'12-paper</A> mentioned 
       
   103   above claim they are even faster than me and can deal with even more features of regular expressions
       
   104   (for example subexpression matching, which my rainy-afternoon matcher cannot). I am sure they thought
       
   105   about the problem much longer than a single afternoon. The task 
       
   106   in this project is to find out how good they actually are by implementing the results from their paper. 
       
   107   Their approach is based on the concept of partial derivatives introduced in 1994 by
       
   108   <A HREF="http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.56.2509&rep=rep1&type=pdf">Valentin Antimirov</A>.
       
   109   I used them once myself in a <A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/Publications/rexp.pdf">paper</A> 
       
   110   in order to prove the <A HREF="http://en.wikipedia.org/wiki/Myhill–Nerode_theorem">Myhill-Nerode theorem</A>.
       
   111   So I know they are worth their money. Still, it would be interesting to actually compare their results
       
   112   with my simple rainy-afternoon matcher and potentially &ldquo;blow away&rdquo; the regular expression matchers 
       
   113   in Python and Ruby (and possibly in Scala too).
       
   114   </p>
       
   115 
       
   116   <p>
       
   117   <B>Literature:</B> 
       
   118   The place to start with this project is obviously this
       
   119   <A HREF="http://www.home.hs-karlsruhe.de/~suma0002/publications/ppdp12-part-deriv-sub-match.pdf">paper</A>.
       
   120   Traditional methods for regular expression matching are explained
       
   121   in the Wikipedia articles 
       
   122   <A HREF="http://en.wikipedia.org/wiki/DFA_minimization">here</A> and 
       
   123   <A HREF="http://en.wikipedia.org/wiki/Powerset_construction">here</A>.
       
   124   The authoritative <A HREF="http://infolab.stanford.edu/~ullman/ialc.html">book</A>
       
   125   on automata and regular expressions is by John Hopcroft and Jeffrey Ullmann (available in the library). 
       
   126   There is also an online course about this topic by Ullman at 
       
   127   <A HREF="https://www.coursera.org/course/automata">Coursera</A>, though IMHO not 
       
   128   done with love. 
       
   129   Finally, there are millions of other pointers about regular expression
       
   130   matching on the Web. I found the chapter on Lexing in this
       
   131   <A HREF="http://www.diku.dk/~torbenm/Basics/">online book</A> very helpful.
       
   132   Test cases for &ldquo;<A HREF="http://en.wikipedia.org/wiki/ReDoS#Examples">evil</A>&rdquo;
       
   133   regular expressions can be obtained from <A HREF="http://en.wikipedia.org/wiki/ReDoS#Examples">here</A>.
       
   134   </p>
       
   135 
       
   136   <p>
       
   137   <B>Skills:</B> 
       
   138   This is a project for a student with an interest in theory and some
       
   139   reasonable programming skills. The project can be easily implemented
       
   140   in functional languages like
       
   141   <A HREF="http://www.scala-lang.org/">Scala</A>,
       
   142   F#, 
       
   143   <A HREF="http://en.wikipedia.org/wiki/Standard_ML">ML</A>,  
       
   144   <A HREF="http://haskell.org/haskellwiki/Haskell">Haskell</A>, etc. Python and other non-functional languages
       
   145   can be also used, but seem much less convenient.
       
   146   </p>
       
   147   
       
   148 <li> <H4>[CU2] A Compiler for a Programming Language</H4>
       
   149 
       
   150   <p>
       
   151   <b>Description:</b> 
       
   152   Compilers translate high-level programs that humans can read and write into
       
   153   efficient machine code that can be run on a CPU or virtual machine.
       
   154   A compiler for a simple functional language generating X86 code is described
       
   155   <A HREF="https://github.com/chameco/Shade">here</A>.
       
   156   I recently implemented a very simple compiler for an even simpler functional
       
   157   programming language following this 
       
   158   <A HREF="http://www.cs.princeton.edu/~dpw/papers/tal-toplas.pdf">paper</A> 
       
   159   (also described <A HREF="http://www.cs.princeton.edu/~dpw/papers/tal-tr.pdf">here</A>).
       
   160   My code, written in <A HREF="http://www.scala-lang.org/">Scala</A>, of this compiler is 
       
   161   <A HREF="http://www.dcs.kcl.ac.uk/staff/urbanc/compiler.scala">here</A>.
       
   162   The compiler can deal with simple programs involving natural numbers, such
       
   163   as Fibonacci numbers or factorial (but it can be easily extended - that is not the point).
       
   164   </p>
       
   165 
       
   166   <p>
       
   167   While the hard work has been done (understanding the two papers above),
       
   168   my compiler only produces some idealised machine code. For example I
       
   169   assume there are infinitely many registers. The goal of this
       
   170   project is to generate machine code that is more realistic and can
       
   171   run on a CPU, like X86, or run on a virtual machine, say the JVM. 
       
   172   This gives probably a speedup of thousand times in comparison to
       
   173   my naive machine code and virtual machine. The project
       
   174   requires to dig into the literature about real CPUs and generating 
       
   175   real machine code. 
       
   176   </p>
       
   177   <p>
       
   178   An alternative is to not generate machine code, but build a compiler that compiles to
       
   179   <A HREF="http://www.w3schools.com/js/">JavaScript</A>. This is the language that is supported by most
       
   180   browsers and therefore is a favourite
       
   181   vehicle for Web-programming. Some call it <B>the</B> scripting language of the Web.
       
   182   Unfortunately, JavaScript is probably one of the worst
       
   183   languages to program in (being designed and released in a hurry). <B>But</B> it can be used as a convenient target
       
   184   for translating programs from other languages. In particular there are two
       
   185   very optimised subsets of JavaScript that can be used for this purpose:
       
   186   one is <A HREF="http://asmjs.org">asm.js</A> and the other is
       
   187   <A HREF="https://github.com/kripken/emscripten/wiki">emscripten</A>.
       
   188   There is a <A HREF="https://github.com/kripken/emscripten/wiki/Tutorial">tutorial</A> for emscripten
       
   189   and an impressive <A HREF="http://www.unrealengine.com/html5/">demo</A> which runs the
       
   190   <A HREF="http://en.wikipedia.org/wiki/Unreal_Engine">Unreal Engine 3</A>
       
   191   in a browser with spectacular speed. This was achieved by compiling the
       
   192   C-code of the Unreal Engine to the LLVM intermediate language and then translating the LLVM
       
   193   code to JavaScript.
       
   194   </p>
       
   195 
       
   196   <p>
       
   197   <B>Literature:</B>
       
   198   There is a lot of literature about compilers 
       
   199   (for example <A HREF="http://www.cs.princeton.edu/~appel/papers/cwc.html">this book</A> -
       
   200   I can lend you my copy for the duration of the project, or this
       
   201   <A HREF="http://www.diku.dk/~torbenm/Basics/">online book</A>). A very good overview article
       
   202   about implementing compilers by 
       
   203   <A HREF="http://tratt.net/laurie/">Laurie Tratt</A> is 
       
   204   <A HREF="http://tratt.net/laurie/tech_articles/articles/how_difficult_is_it_to_write_a_compiler">here</A>.
       
   205   An online book about the Art of Assembly Language is
       
   206   <A HREF="http://flint.cs.yale.edu/cs422/doc/art-of-asm/pdf/">here</A>.
       
   207   An introduction into x86 machine code is <A HREF="http://ianseyler.github.com/easy_x86-64/">here</A>.
       
   208   Intel's official manual for the x86 instruction is 
       
   209   <A HREF="http://download.intel.com/design/intarch/manuals/24319101.pdf">here</A>. 
       
   210   A simple assembler for the JVM is described <A HREF="http://jasmin.sourceforge.net">here</A>.
       
   211   An interesting twist of this project is to not generate code for a CPU, but
       
   212   for the intermediate language of the <A HREF="http://llvm.org">LLVM</A> compiler
       
   213   (also described <A HREF="https://wiki.aalto.fi/display/t1065450/LLVM+IR">here</A> and
       
   214   <A HREF="http://llvm.org/docs/LangRef.html">here</A>). If you want to see
       
   215   what machine code looks like you can compile your C-program using gcc -S.
       
   216   </p>
       
   217   <p>
       
   218   If JavaScript is chosen as a target instead, then there are plenty of <A HREF="http://www.w3schools.com/js/">tutorials</A> on the Web.
       
   219   <A HREF="http://jsbooks.revolunet.com">Here</A> is a list of free books on JavaScript.
       
   220   A project from which you can draw inspiration is this
       
   221   <A HREF="http://jlongster.com/2012/01/04/outlet-my-lisp-to-javascript-experiment.html">List-to-JavaScript</A>
       
   222   translator. <A HREF="https://bitbucket.org/ktg/parenjs/overview">Here</A> is another such project.
       
   223   And <A HREF="https://github.com/viclib/liscript">another</A> in less than 100 lines of code.
       
   224   <A HREF="http://en.wikipedia.org/wiki/CoffeeScript">Coffeescript</A> is a similar project
       
   225   except that it is already quite <A HREF="http://coffeescript.org">mature</A>. And finally not to
       
   226   forget <A HREF="http://www.typescriptlang.org">TypeScript</A> developed by Microsoft. The main
       
   227   difference between these projects and this one is that they translate into relatively high-level
       
   228   JavaScript code; none of them use the much lower levels <A HREF="http://asmjs.org">asm.js</A> and 
       
   229   <A HREF="https://github.com/kripken/emscripten/wiki">emscripten</A>.
       
   230   </p>
       
   231   <p>
       
   232   <B>Skills:</B> 
       
   233   This is a project for a student with a deep interest in programming languages and
       
   234   compilers. Since my compiler is implemented in <A HREF="http://www.scala-lang.org/">Scala</A>,
       
   235   it would make sense to continue this project in this language. I can be
       
   236   of help with questions and books about <A HREF="http://www.scala-lang.org/">Scala</A>.
       
   237   But if Scala is a problem, my code can also be translated quickly into any other functional
       
   238   language. 
       
   239   </p>
       
   240 
       
   241   <p>
       
   242   <B>PS:</B> Compiler projects, like this [CU2] and [CU3], consistently received high marks in the past.
       
   243   I suprvised four so far and none of them received a mark below 70% - one even was awarded a prize.
       
   244   </p>
       
   245 
       
   246 <li> <H4>[CU3] Language Translator into JavaScript</H4>
       
   247 
       
   248   <p>
       
   249   <b>Description:</b> 
       
   250   <A HREF="http://www.w3schools.com/js/">JavaScript</A> is a language that is supported by most
       
   251   browsers and therefore is a favourite
       
   252   vehicle for Web-programming. Some call it <B>the</B> scripting language of the Web.
       
   253   Unfortunately, JavaScript is probably one of the worst
       
   254   languages to program in (being designed and released in a hurry). <B>But</B> it can be used as a convenient target
       
   255   for translating programs from other languages. In particular there are two
       
   256   very optimised subsets of JavaScript that can be used for this purpose:
       
   257   one is <A HREF="http://asmjs.org">asm.js</A> and the other is
       
   258   <A HREF="https://github.com/kripken/emscripten/wiki">emscripten</A>.
       
   259   There is a <A HREF="https://github.com/kripken/emscripten/wiki/Tutorial">tutorial</A> for emscripten
       
   260   and an impressive <A HREF="http://www.unrealengine.com/html5/">demo</A> which runs the
       
   261   <A HREF="http://en.wikipedia.org/wiki/Unreal_Engine">Unreal Engine 3</A>
       
   262   in a browser with spectacular speed. This was achieved by compiling the
       
   263   C-code of the Unreal Engine to the LLVM intermediate language and then translating the LLVM
       
   264   code to JavaScript.
       
   265   </p>
       
   266 
       
   267   <p>
       
   268   <B>Skills:</B> 
       
   269   This project is about exploring these two subsets of JavaScript and implement a translator
       
   270   of a small language into them.  This is similar to the project [CU2] above and requires
       
   271   similar skills. In addition it would be good to have already some familiarity with JavaScript.
       
   272   There are plenty of <A HREF="http://www.w3schools.com/js/">tutorials</A> on the Web.
       
   273   <A HREF="http://jsbooks.revolunet.com">Here</A> is a list of free books on JavaScript.
       
   274   This is a project for a student who wants to get more familiar with JavaScript and Web-programming.
       
   275   A project from which you can draw inspiration is this
       
   276   <A HREF="http://jlongster.com/2012/01/04/outlet-my-lisp-to-javascript-experiment.html">List-to-JavaScript</A>
       
   277   translator. <A HREF="https://bitbucket.org/ktg/parenjs/overview">Here</A> is another such project.
       
   278   And <A HREF="https://github.com/viclib/liscript">another</A> in less than 100 lines of code.
       
   279   <A HREF="http://en.wikipedia.org/wiki/CoffeeScript">Coffeescript</A> is a similar project
       
   280   except that it is already quite <A HREF="http://coffeescript.org">mature</A>. And finally not to
       
   281   forget <A HREF="http://www.typescriptlang.org">TypeScript</A> developed by Microsoft. The main
       
   282   difference between these projects and this one is that they translate into relatively high-level
       
   283   JavaScript code; none of them use the much lower levels <A HREF="http://asmjs.org">asm.js</A> and 
       
   284   <A HREF="https://github.com/kripken/emscripten/wiki">emscripten</A>.
       
   285 </p>
       
   286 
       
   287 <li> <H4>[CU4] Slide-Making in the Web-Age</H4>
       
   288 
       
   289   <p>
       
   290   The standard technology for writing scientific papers in Computer Science  is to use
       
   291   <A HREF="http://en.wikipedia.org/wiki/LaTeX">LaTeX</A>, a document preparation
       
   292   system originally implemented by <A HREF="http://en.wikipedia.org/wiki/Donald_Knuth">Donald Knuth</A>
       
   293   and <A HREF="http://en.wikipedia.org/wiki/Leslie_Lamport">Leslie Lamport</A>.
       
   294   LaTeX produces very pleasantly looking documents, can deal nicely with mathematical
       
   295   formulas and is very flexible. If you are interested, <A HREF="http://openwetware.org/wiki/Word_vs._LaTeX">here</A>
       
   296   is a side-by-side comparison between Word and LaTeX (which LaTeX &ldquo;wins&rdquo; with 18 out of 21 points).
       
   297   Computer scientists not only use LaTeX for documents,
       
   298   but also for slides (really, nobody who wants to be cool uses Keynote or Powerpoint).
       
   299   </p>
       
   300 
       
   301   <p>
       
   302   Although used widely, LaTeX seems nowadays a bit dated for producing
       
   303   slides. Unlike documents, which are typically &ldquo;static&rdquo; and published in a book or journal,
       
   304   slides often contain changing contents that might first only be partially visible and
       
   305   only later be revealed as the &ldquo;story&rdquo; of a talk or lecture demands.
       
   306   Also slides often contain animated algorithms where each state in the
       
   307   calculation is best explained by highlighting the changing data.
       
   308   </p>
       
   309 
       
   310   <p>
       
   311   It seems HTML and JavaScript are much better suited for generating
       
   312   such animated slides. This <A HREF="http://www.impressivewebs.com/html-slidedeck-toolkits/">page</A>
       
   313   links to 22 slide-generating programs using this combination of technologies. 
       
   314   <A HREF="http://www.impressivewebs.com/html-slidedeck-toolkits/">Here</A> are even more such
       
   315   projects. However, the problem with all of these project is that they depend heavily on the users being
       
   316   able to write JavaScript, CCS or HTML...not something one would like to depend on given that
       
   317   &ldquo;normal&rdquo; users likely only have a LaTeX background. The aim of this project is to invent a
       
   318   very simple language that is inspired by LaTeX and then generate from code written in this language
       
   319   slides that can be displayed in a web-browser.
       
   320   </p>
       
   321 
       
   322  <p>
       
   323  This sounds complicated, but there is already some help available:
       
   324  <A HREF="http://www.mathjax.org">Mathjax</A> is a JavaScript library that can
       
   325  be used to display mathematical text, for example
       
   326 
       
   327  <blockquote>
       
   328  <p>When \(a \ne 0\), there are two solutions to \(ax^2 + bx + c = 0\) and they are
       
   329  \(x = {-b \pm \sqrt{b^2-4ac} \over 2a}\).</p>
       
   330  </blockquote>
       
   331 
       
   332  by writing code in the familiar LaTeX-way. This can be reused. There are also plenty of JavaScript
       
   333  libraries for graphical animations (for example
       
   334  <A HREF="http://raphaeljs.com">Raphael</A>,
       
   335  <A HREF="http://svgjs.com">SVG.JS</A>,
       
   336  <A HREF="http://bonsaijs.org">Bonsaijs</A>,
       
   337  <A HREF="http://jsxgraph.uni-bayreuth.de/wp/">JSXGraph</A>). The inspiration for how the user should be able to write
       
   338  slides could come from the LaTeX packages <A HREF="http://en.wikipedia.org/wiki/Beamer_(LaTeX)">Beamer</A>
       
   339  and <A HREF="http://en.wikipedia.org/wiki/PGF/TikZ">PGF/TikZ</A>.
       
   340  </p>
       
   341 
       
   342   <p>
       
   343   <B>Skills:</B> 
       
   344   This is a project requires good knowledge of JavaScript. You need to be able to
       
   345   parse a language and translate it to a suitable part of JavaScript using
       
   346   appropriate libraries. Tutorials for JavaScript are <A HREF="http://www.w3schools.com/js/">here</A>.
       
   347   A parser generator for JavaScript is <A HREF="http://pegjs.majda.cz">here</A>. There are probably also
       
   348   others.
       
   349   </p>
       
   350 
       
   351 <li> <H4>[CU5] An Online Student Voting System</H4>
       
   352 
       
   353   <p>
       
   354   <B>Description:</B>
       
   355   One of the more annoying aspects of giving a lecture is to ask a question
       
   356   to the students and no matter how easy the question is to not 
       
   357   receive any answer. Recently, the online course system 
       
   358   <A HREF="http://www.udacity.com">Udacity</A> made an art out of
       
   359   asking questions during lectures (see for example the
       
   360   <A HREF="http://www.udacity.com/overview/Course/cs253/CourseRev/apr2012">Web Application Engineering</A> 
       
   361   course CS253).
       
   362   The lecturer there gives multiple-choice questions as part of the lecture and the students need to 
       
   363   click on the appropriate answer. This works very well in the online world. 
       
   364   For  &ldquo;real-world&rdquo; lectures, the department has some 
       
   365   <A HREF="http://en.wikipedia.org/wiki/Audience_response">clickers</A>
       
   366   (these are little devices which form a part of an audience response systems). However, 
       
   367   they are a logistic nightmare for the lecturer: they need to be distributed 
       
   368   during the lecture and collected at the end. Nowadays, where students
       
   369   come with their own laptop or smartphone to lectures, this can
       
   370   be improved.
       
   371   </p>
       
   372 
       
   373   <p>
       
   374   The task of this project is to implement an online student
       
   375   polling system. The lecturer should be able to prepare 
       
   376   questions beforehand (encoded as some web-form) and be able to 
       
   377   show them during the lecture. The students
       
   378   can give their answers by clicking on the corresponding webpage.
       
   379   The lecturer can then collect the responses online and evaluate them 
       
   380   immediately. Such a system is sometimes called
       
   381   <A HREF="http://en.wikipedia.org/wiki/Audience_response#Smartphone_.2F_HTTP_voting">HTML voting</A>. 
       
   382   There are a number of commercial
       
   383   solutions for this problem, but they are not easy to use (in addition
       
   384   to being ridiculously expensive). A good student can easily improve upon
       
   385   what they provide. 
       
   386   </p>
       
   387 
       
   388   <p>
       
   389   The problem of student polling is not as hard as 
       
   390   <A HREF="http://en.wikipedia.org/wiki/Electronic_voting">electronic voting</A>, 
       
   391   which essentially is still an unsolved problem in Computer Science. The
       
   392   students only need to be prevented from answering question more than once thus skewing
       
   393   any statistics. Unlike electronic voting, no audit trail needs to be kept
       
   394   for student polling. Restricting the number of answers can probably be solved 
       
   395   by setting appropriate cookies on the students
       
   396   computers or smart phones.
       
   397   </p>
       
   398 
       
   399   <p>
       
   400   <B>Literature:</B> 
       
   401   The project requires fluency in a web-programming language (for example 
       
   402   <A HREF="http://en.wikipedia.org/wiki/JavaScript">Javascript</A>,
       
   403   <A HREF="http://en.wikipedia.org/wiki/Go_(programming_language)">Go</A>, 
       
   404   <A HREF="http://www.scala-lang.org/">Scala</A>). However JavaScript with
       
   405   the <A HREF="http://nodejs.org">Node.js</A> extension seems to be best suited for the job.
       
   406   <A HREF="http://www.nodebeginner.org">Here</A> is a tutorial on Node.js for beginners.
       
   407   For web-programming the 
       
   408   <A HREF="http://www.udacity.com/overview/Course/cs253/CourseRev/apr2012">Web Application Engineering</A>
       
   409   course at <A HREF="http://www.udacity.com">Udacity</A> is a good starting point 
       
   410   to be aware of the issues involved. This course uses <A HREF="http://www.python.org">Python</A>.
       
   411   To evaluate the answers from the students, Google's 
       
   412   <A HREF="https://developers.google.com/chart/image/docs/making_charts">Chart Tools</A>
       
   413   might be useful, which is also described in this 
       
   414   <A HREF="http://www.youtube.com/watch?v=NZtgT4jgnE8">youtube</A> video.
       
   415   </p>
       
   416 
       
   417   <p>
       
   418   <B>Skills:</B> 
       
   419   In order to provide convenience for the lecturer, this project needs very good web-programming skills. A 
       
   420   <A HREF="http://en.wikipedia.org/wiki/Hacker_(programmer_subculture)">hacker mentality</A>
       
   421   (see above) is probably very beneficial: web-programming is an area that only emerged recently and
       
   422   many tools still lack maturity. You probably have to experiment a lot with several different
       
   423   languages and tools.
       
   424   </p>
       
   425 
       
   426 <li> <H4>[CU6] An Infrastructure for Displaying and Animating Code in a Web-Browser</H4>
       
   427   
       
   428 <p>
       
   429   <B>Description:</B>
       
   430   The project aim is to implement an infrastructure for displaying and
       
   431   animating code in a web-browser. The infrastructure should be agnostic
       
   432   with respect to the programming language, but should be configurable.
       
   433   I envisage something smaller than the projects 
       
   434   <A HREF="http://www.pythontutor.com">here</A> (for Python),
       
   435   <A HREF="http://ideone.com">here</A> (for Java),
       
   436   <A HREF="http://codepad.org">here</A> (for multiple languages),
       
   437   <A HREF="http://www.w3schools.com/html/tryit.asp?filename=tryhtml_intro">here</A> (for HTML)
       
   438   <A HREF="http://repl.it/languages/JavaScript">here</A> (for JavaScript),
       
   439   and <A HREF="http://www.scala-tour.com/#/welcome">here</A> (for Scala).
       
   440   </p>
       
   441 
       
   442   <p>
       
   443   The tasks in this project are being able (1) to lex and parse languages and (2) to write an interpreter.
       
   444   The goal is to implement this as much as possible in a language-agnostic fashion.
       
   445   </p>
       
   446 
       
   447   <p>
       
   448   <B>Skills:</B> 
       
   449   Good skill in lexing and language parsing, as well as being fluent with web programming (for
       
   450   example JavaScript).
       
   451   </p>
       
   452 
       
   453 
       
   454 <li> <H4>[CU7] Implementation of a Distributed Clock-Synchronisation Algorithm developed at NASA</H4>
       
   455   
       
   456   <p>
       
   457   <B>Description:</B>
       
   458   There are many algorithms for synchronising clocks. This
       
   459   <A HREF="http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20120000054_2011025573.pdf">paper</A> 
       
   460   describes a new algorithm for clocks that communicate by exchanging
       
   461   messages and thereby reach a state in which (within some bound) all clocks are synchronised.
       
   462   A slightly longer and more detailed paper about the algorithm is 
       
   463   <A HREF="http://hdl.handle.net/2060/20110020812">here</A>.
       
   464   The point of this project is to implement this algorithm and simulate networks of clocks.
       
   465   </p>
       
   466 
       
   467   <p>
       
   468   <B>Literature:</B> 
       
   469   There is a wide range of literature on clock synchronisation algorithms. 
       
   470   Some pointers are given in this
       
   471   <A HREF="http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20120000054_2011025573.pdf">paper</A>,
       
   472   which describes the algorithm to be implemented in this project. Pointers
       
   473   are given also <A HREF="http://en.wikipedia.org/wiki/Clock_synchronization">here</A>.
       
   474   </p>
       
   475 
       
   476   <p>
       
   477   <B>Skills:</B> 
       
   478   In order to implement a simulation of a network of clocks, you need to tackle
       
   479   concurrency. You can do this for example in the programming language
       
   480   <A HREF="http://www.scala-lang.org/">Scala</A> with the help of the 
       
   481   <A HREF="http://akka.io">Akka</a> library. This library enables you to send messages
       
   482   between different <I>actors</I>. <A HREF="http://www.scala-lang.org/node/242">Here</A> 
       
   483   are some examples that explain how to implement exchanging messages between actors. 
       
   484   </p>
       
   485 
       
   486 
       
   487 
       
   488 
       
   489 <li> <H4>[CU8] Raspberry Pi's and Arduinos</H4>
       
   490 
       
   491   <p>
       
   492   <B>Description:</B>
       
   493   This project is for true hackers! <A HREF="http://en.wikipedia.org/wiki/Raspberry_Pi">Raspberry Pi's</A>
       
   494   are small Linux computers the size of a credit-card and only cost &pound;34 (see picture left below). They were introduced
       
   495   in 2012 and people went crazy...well some of them. There is a
       
   496   <A HREF="https://plus.google.com/communities/113390432655174294208?hl=en">Google+</A> community about Raspberry Pi's that has more
       
   497   than 150k of followers. It is hard to keep up with what people do with these small computers. The possibilities
       
   498   seem to be limitless. The main resource for Raspberry Pi's is <A HREF="http://www.raspberrypi.org">here</A>.
       
   499   There are <A HREF="http://www.themagpi.com">magazines</A> dedicated to them and tons of
       
   500   <A HREF="http://www.raspberrypi.org/phpBB3/viewforum.php?f=39">books</A> (not to mention
       
   501   floods of <A HREF="https://www.google.co.uk/search?q=raspberry+pi">online</A> material).
       
   502   Google just released a
       
   503   <A HREF="http://googlecreativelab.github.io/coder/">framework</A>
       
   504   for web-programming and for turning Raspberry Pi's into webservers.
       
   505   </p>
       
   506 
       
   507   <p>
       
   508   <A HREF="http://en.wikipedia.org/wiki/Arduino">Arduinos</A> are slightly older (from 2005) but still very cool (see picture right below). They
       
   509   are small single-board micro-controllers that can talk to various external gadgets (sensors, motors, etc). Since Arduinos
       
   510   are open-software and open-hardware there are many clones and add-on boards. Like for the Raspberry Pi, there
       
   511   is a lot of material <A HREF="https://www.google.co.uk/search?q=arduino">available</A> about Arduinos.
       
   512   The main reference is <A HREF="http://www.arduino.cc">here</A>. Like the Raspberry Pi's, the good thing about
       
   513   Arduinos is that they can be powered with simple AA-batteries.
       
   514   </p>
       
   515 
       
   516   <p>
       
   517   I have two such Raspberry Pi's including wifi-connectors and two <A HREF="http://www.raspberrypi.org/camera">cameras<A>.
       
   518   I also have two <A HREF="http://www.freaklabs.org/index.php/Blog/Store/Introducing-the-Freakduino-Chibi-An-Arduino-based-Board-For-Wireless-Sensor-Networking.html">Freakduino Boards</A> that are Arduinos extended with wireless communication. I can lend them to responsible
       
   519   students for one or two projects. However, the aim is to first come up with an idea for a project. Popular projects are
       
   520   automated temperature sensors, network servers, robots, web-cams (<A HREF="http://www.secretbatcave.co.uk/electronics/shard-rain-cam/">here</A>
       
   521   is a <A HREF="http://www.raspberrypi.org/archives/3547">web-cam</A> directed at the Shard that can
       
   522   <A HREF="http://www.secretbatcave.co.uk/software/shard-rain-cam-quantifying-cloudy/">tell</A>
       
   523   you whether it is raining or cloudy). There are plenty more ideas listed
       
   524   <A HREF="http://www.raspberrypi.org/phpBB3/viewforum.php?f=15">here</A> for Raspberry Pi's and
       
   525   <A HREF="http://playground.arduino.cc/projects/ideas">here</A> for Arduinos.
       
   526   </p>
       
   527 
       
   528   <p>
       
   529   There are essentially two kinds of projects: One is purely software-based. Software projects for Raspberry Pi's are often
       
   530   written in <A HREF="http://www.python.org">Python</A>, but since these are Linux-capable computers any other
       
   531   language would do as well. You can also write your own operating system as done
       
   532   <A HREF="http://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/">here</A>. For example the students
       
   533   <A HREF="http://www.recantha.co.uk/blog/?p=4918">here</A> developed their own bare-metal OS and then implemented
       
   534   a chess-program on top of it (have a look at their very impressive
       
   535   <A HREF="http://www.youtube.com/watch?v=-03bouPsfEQ&feature=player_embedded">youtube</A> video).
       
   536   The other kind of project is a combination of hardware and software; usually attaching some sensors
       
   537   or motors to the Raspberry Pi or Arduino. This might require some soldering or what is called
       
   538   a <A HREF="http://en.wikipedia.org/wiki/Breadboard">bread-board</A>. But be careful before choosing a project
       
   539   involving new hardware: these devices
       
   540   can be destroyed (if &ldquo;Vin connected to GND&rdquo; or &ldquo;drawing more than 30mA from a GPIO&rdquo;
       
   541   does not make sense to you, you should probably stay away from such a project). 
       
   542   </p>
       
   543 
       
   544   <p>
       
   545   <center>
       
   546   <img style="-webkit-user-select: none; cursor: -webkit-zoom-in;
       
   547   "src="http://upload.wikimedia.org/wikipedia/commons/3/3d/RaspberryPi.jpg" width="313" height="209">
       
   548 
       
   549   <img style="-webkit-user-select: none; cursor: -webkit-zoom-in;
       
   550   "src="http://upload.wikimedia.org/wikipedia/commons/3/38/Arduino_Uno_-_R3.jpg" width="240" height="209">
       
   551   </center>
       
   552   </p>
       
   553 
       
   554   <p>
       
   555   <B>Skills:</B> 
       
   556   Well, you must be a hacker; happy to make things. Your desk might look like this:
       
   557   <center>
       
   558   <img style="-webkit-user-select: none; cursor: -webkit-zoom-in;
       
   559   "src="http://www.inf.kcl.ac.uk/staff/urbanc/rpi-photo.jpg" width="209" height="313">
       
   560   </center>
       
   561   </p>
       
   562 
       
   563 <li> <H4>[CU9] Proving the Correctness of Programs</H4>
       
   564 
       
   565  <p>
       
   566  I am one of the main developers of the interactive theorem prover
       
   567  <A HREF="http://isabelle.in.tum.de">Isabelle</A>. This theorem prover
       
   568  has been used to establish the correctness of some quite large
       
   569  programs (for example an <A HREF="http://ertos.nicta.com.au/research/l4.verified/">operating system</A>).
       
   570  Together with colleagues from Nanjing, I used this theorem prover to establish the correctness of a
       
   571  scheduling algorithm, called
       
   572  <A HREF="http://en.wikipedia.org/wiki/Priority_inheritance">Priority Inheritance</A>,
       
   573  for real time operating systems. This scheduling algorithm is part of the operating
       
   574  system that drives, for example, the 
       
   575  <A HREF="http://en.wikipedia.org/wiki/Mars_Exploration_Rover">Mars rovers</A>.
       
   576  Actually, the very first Mars rover mission in 1997 did not have this
       
   577  algorithm switched on and it almost caused a catastrophic mission failure (see
       
   578  this youtube video <A HREF="http://www.youtube.com/watch?v=lyx7kARrGeM">here</A>
       
   579  for an explanation what happened).
       
   580  We were able to prove the correctness of this algorithm, but were also able to
       
   581  establish the correctness of some optimisations in this
       
   582  <A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/Publications/pip.pdf">paper</A>.
       
   583  </p>
       
   584 
       
   585  <p>On a much smaller scale, there are a few small programs and underlying algorithms where it
       
   586  is not really understood whether they always compute a correct result (for example the
       
   587  regular expression matcher by Sulzmann and Lu in project [CU1]). The aim of this
       
   588  project is to completely specify an algorithm in Isabelle and then prove it correct (that is,
       
   589  it always computes the correct result).
       
   590 </p>
       
   591 
       
   592   <p>
       
   593   <B>Skills:</B> 
       
   594   This project is for a very good student with a knack for theoretical things and formal reasoning.
       
   595   </p>
       
   596 
       
   597 <li> <H4>Earlier Projects</H4>
       
   598 
       
   599  I am also open to project suggestions from you. You might find some inspiration from my earlier projects:
       
   600  <A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/bsc-projects-12.html">BSc 2012/13</A>, 
       
   601  <A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/msc-projects-12.html">MSc 2012/13</A>, 
       
   602  <A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/bsc-projects-13.html">BSc 2013/14</A> 
       
   603 </ul>
       
   604 </TD>
       
   605 </TR>
       
   606 </TABLE>
       
   607 
       
   608 <P>
       
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