The following technical report is available from
http://aib.informatik.rwth-aachen.de:
Symbolic Evaluation Graphs and Term Rewriting --- A General Methodology
for Analyzing Logic Programs
Jürgen Giesl, Thomas Ströder, Peter Schneider-Kamp, Fabian Emmes, and
Carsten Fuhs
AIB 2012-12
There exist many powerful techniques to analyze termination and
complexity of term rewrite systems (TRSs). Our goal is to use these
techniques for the analysis of other programming languages as well. For
instance, approaches to prove termination of definite logic programs by
a transformation to TRSs have been studied for decades. However, a
challenge is to handle languages with more complex evaluation strategies
(such as Prolog, where predicates like the cut influence the control
flow). In this paper, we present a general methodology for the analysis
of such programs. Here, the logic program is first transformed into a
symbolic evaluation graph which represents all possible evaluations in a
finite way. Afterwards, different analyses can be performed on these
graphs. In particular, one can generate TRSs from such graphs and apply
existing tools for termination or complexity analysis of TRSs to infer
information on the termination or complexity of the original logic program.
The following technical report is available from
http://aib.informatik.rwth-aachen.de:
Quantitative Timed Analysis of Interactive Markov Chains
Dennis Guck, Tingting Han, Joost-Pieter Katoen, and Martin R. Neuhäußer
AIB 2012-09
This paper presents new algorithms and accompanying tool support for
analyzing interactive Markov chains (IMCs), a stochastic timed 1
1/2-player game in which delays are exponentially distributed. IMCs are
compositional and act as semantic model for engineering formalisms such
as AADL and dynamic fault trees. We provide algorithms for determining
the extremal expected time of reaching a set of states, and the long-run
average of time spent in a set of states. The prototypical tool Imca
supports these algorithms as well as the synthesis of ε-optimal
piecewise constant timed policies for timed reachability objectives. Two
case studies show the feasibility and scalability of the algorithms.
The following technical report is available from
http://aib.informatik.rwth-aachen.de:
Hackers in Your Pocket: A Survey of Smartphone Security Across Platforms
André Egners, Björn Marschollek, and Ulrike Meyer
AIB 2012-07
In the past research on smart phone operating system security has been
scattered over blog posts and other non-archival publications. Over the
last 5 years with advent of Android, iOS and Windows Phone 7, an
increasing amount of research has also been published in the academic
sphere on individual security mechanisms of the three platfroms.
However, for a non-expert it is hard to get an overview over this
research area.
In this paper, we close this gap and provide a structured easy to access
overview on the security features and prior research of the three most
popular smartphone platforms: Android, iOS, and Windows Phone 7.
In particular, we discuss and compare how each of these platforms uses
sandboxing and memory protection, provides code signing, protects
service connections, provides application shop security, and handles
permissions.