Student Project Topics
Below is a list of topics for students who would like to work with
me. For foreigner students (ie non Australian), it is very
difficult for me to find fundings here in Australia. However,
there are often many fundings in your countries. Send me an email
in all cases.
Complexity of a diagnosis question
The problem of diagnosis is understanding what happens in a system
given observations on its behaviour. In the model-based approach, it
is often understood as computing all possible behaviours of the
system. However, the diagnosis is often much more concrete and serves
a real application. Some diagnosis questions are simpler to answer
than other questions. In this project, we propose to investigate the
complexity of answering particular questions given particular
representations of the diagnosis.
Evaluation of the diagnosis cost
Diagnosis is the problem of understanding what happens in a system
given observations of its behaviour. It is a prerequisite to find
failures and perform repairs. Finding an accurate diagnosis is
theoretically exponentially hard in the number of components of the
system. In practice, the real cost highly depends on the system
features. Some systems generate so many and so useful observations
that the diagnosis is obvious; some systems require complex cross
checkings to determine accurately what happened.
Being able to predict the cost is very important because we need to
make sure that the diagnosis can be performed on time, and approximate
techniques sometimes have to be used. This project proposes to find a
method to empirically estimate this cost from the system model.
Possible parameters include: the number of components, the number of
states in the components, the ratio observable events/unobservable
events, the tree-width of the system, etc.
Pre-processing in diagnosis by SAT
Diagnosis is the problem of understanding what happens in a system
given observations of its behaviour. It is a prerequisite to find
failures and perform repairs. A technique recently proposed for the
diagnosis of DES is the use of Propositional Satisfiability (SAT),
which is one of the most famous Computer Science problems.
The purpose of this project is to study how simple pre-processing
actions impact on the runtime to solve the diagnosis. Typical
techniques include local diagnosis which consists in performing a
local non SAT-based diagnosis reasoning before running the SAT
approach.
Automatic learning and accuracy of chronicles
Diagnosis is the problem of understanding what happens in a system
given observations of its behaviour. It is a prerequisite to find
failures and perform repairs. A popular method is the use of
chronicles, patterns of temporary-constrained events. Each chronicle
is associated with a particular type of behaviour (normal, failure,
etc.), and the recognition of the chronicle implies the recognition of
the associated behaviour.
A problem of the chronicle is that they are usually generated by hand
by an expert. This implies many possible mistakes, from the simple
typo to the default or the incompleteness in the expert knowledge.
This project proposes to automatically learn chronicles from the
system model (description of the system behaviour). It also includes
the testing of the correctness of a set of chronicles.
Specialising SAT solvers for the diagnosis
Diagnosis is the problem of understanding what happens in a system
given observations of its behaviour. It is a prerequisite to find
failures and perform repairs. A technique recently proposed for the
diagnosis of DES is the use of Propositional Satisfiability (SAT).
SAT is one of the most famous Computer Science problems as it defines
the NP-Complete complexity class and remains a hot research topic.
The aim of this project is to study the SAT heuristics that make the
diagnosis problem easier to solve. It will suit particularly students
who like to hack as SAT solvers are programs with no more than 1,000
lines but where any slight modification has a huge impact on the
runtime.
Probabilistic reasonning on discrete event systems
Discrete-event system (DES) is a way to model many real-world systems
ranging from network (electricity or water distribution,
telecommunication), to satellites, cars, robots, etc. Because systems
have systems with size exponential in the number of components,
decentralised models are required.
To make any reasoning on the model practical, probabilistic
information is often required. This project aims at studying how to
model probabilistic DES and how to perform diagnosis reasoning on it
(ie. determining what happened when incomplete observations are given
from the model). The project will suit a student with a strong
mathematical background.
Symbolic approach of diagnosis
Diagnosis is the problem of understanding what happens in a system
given observations of its behaviour. It is a prerequisite to find
failures and perform repairs.
Symbolic tools have proven very useful for reasoning about systems.
Rather than enumerating possibilities, the symbolic approach describes
them in a synthetic form such as: (the door is opened and the light
is on) or (the radio is broken). The aim of this project is to
explore the use of symbolic tools to solve diagnosis-related problems.
These problems include (but are not limited to):
- distributed diagnosis with symbolic tools,
- diagnosability with symbolic tools, and
- diagnosis with sd-DNNF (a particular family of symbolic
representation)
Useful Games
People tend to spend more and more time on games. When they do so,
they often have to solve problems, and they get rewards when
these problems are solved. Now, there exist very difficult problems
that cannot be solved by computers because they require tastes or
general knowledge. Rather than asking the computer to solve it, it is
possible to ask a human to do it, as long as it is transformed into a
game.
The purpose of this project is to identify a problem that is hard for
a computer to solve, and to find a way to encode it into a game.
Alban Grastien
Last modified: Mon Sep 28 16:58:44 EST 2009