9 research outputs found
Verification of interlocking systems using statistical model checking
In the railway domain, an interlocking is the system ensuring safe train
traffic inside a station by controlling its active elements such as the signals
or points. Modern interlockings are configured using particular data, called
application data, reflecting the track layout and defining the actions that the
interlocking can take. The safety of the train traffic relies thereby on
application data correctness, errors inside them can cause safety issues such
as derailments or collisions. Given the high level of safety required by such a
system, its verification is a critical concern. In addition to the safety, an
interlocking must also ensure that availability properties, stating that no
train would be stopped forever in a station, are satisfied. Most of the
research dealing with this verification relies on model checking. However, due
to the state space explosion problem, this approach does not scale for large
stations. More recently, a discrete event simulation approach limiting the
verification to a set of likely scenarios, was proposed. The simulation enables
the verification of larger stations, but with no proof that all the interesting
scenarios are covered by the simulation. In this paper, we apply an
intermediate statistical model checking approach, offering both the advantages
of model checking and simulation. Even if exhaustiveness is not obtained,
statistical model checking evaluates with a parametrizable confidence the
reliability and the availability of the entire system.Comment: 12 pages, 3 figures, 2 table
Integration of analysis techniques in security and fault-tolerance
This thesis focuses on the study of integration of formal methodologies in security protocol analysis and fault-tolerance analysis. The research is developed in two different directions: interdisciplinary and intra-disciplinary. In the former, we look for a beneficial interaction between strategies of analysis in security protocols and fault-tolerance; in the latter, we search for connections among different approaches of analysis within the security area. In the following we summarize the main results of the research
Library buildings around the world
"Library Buildings around the World" is a survey based on researches of several years. The objective was to gather library buildings on an international level starting with 1990
Software Tools for Technology Transfer manuscript No. (will be inserted by the editor) Using Symbolic CTL Model Checking to Verify the Railway Stations of Hoorn-Kersenboogerd and Heerhugowaard
Abstract. We examine the application of symbolic CTL model checking to railway interlocking software. We show that the railway interlocking systems examined exhibit the characteristics of robustness and locality, and that these characteristics allow optimizations to the model checking algorithms not possible in the general case. In order to gain a better understanding of robustness and locality, we examine in detail a small railway interlocking