388 research outputs found
A Survey on IT-Techniques for a Dynamic Emergency Management in Large Infrastructures
This deliverable is a survey on the IT techniques that are relevant to the three use cases of the project EMILI. It describes the state-of-the-art in four complementary IT areas: Data cleansing, supervisory control and data acquisition, wireless sensor networks and complex event processing. Even though the deliverable’s authors have tried to avoid a too technical language and have tried to explain every concept referred to, the deliverable might seem rather technical to readers so far little familiar with the techniques it describes
A support tool for teaching grafcet : engineering students' perceptions
Modeling discrete event systems with sequential behavior
can be a very hard and complex task. Some formalisms are
used in this context, such as: Petri Nets, Statecharts, Finite
automata, Grafcet and others. Among these, Grafcet seems to
be a good choice because it is easy: to learn, to understand and
to use. Teaching Grafcet is then relevant within engineering
courses concerned with Industrial Automation.
A virtual laboratory, e-GRAFCET, developed and first
tested in UTAD University; it is a new, easy-to-use multimedia
e-educational tool to support the self-learning process of
Grafcet. This paper, reports a study of e-GRAFCET use by the
students of University of Minho. A questionnaire was prepared
and students asked to fulfill it in a volunteer basis. The results
were statistically analyzed and the scores compared. The
overall objective is to understand how the tool helps students in
their study, and consequently improve their learning off
Grafcet, independently of their engineering background
Temporal Phase Shifts in SCADA Networks
In Industrial Control Systems (ICS/SCADA), machine to machine data traffic is
highly periodic. Previous work showed that in many cases, it is possible to
create an automata-based model of the traffic between each individual
Programmable Logic Controller (PLC) and the SCADA server, and to use the model
to detect anomalies in the traffic. When testing the validity of previous
models, we noticed that overall, the models have difficulty in dealing with
communication patterns that change over time. In this paper we show that in
many cases the traffic exhibits phases in time, where each phase has a unique
pattern, and the transition between the different phases is rather sharp. We
suggest a method to automatically detect traffic phase shifts, and a new
anomaly detection model that incorporates multiple phases of the traffic.
Furthermore we present a new sampling mechanism for training set assembly,
which enables the model to learn all phases during the training stage with
lower complexity. The model presented has similar accuracy and much less
permissiveness compared to the previous general DFA model. Moreover, the model
can provide the operator with information about the state of the controlled
process at any given time, as seen in the traffic phases.Comment: Full version of CPS-SPC'18 short pape
Evolutionary Computation Applied to Urban Traffic Optimization
At the present time, many sings seem to indicate that we live a global energy and environmental crisis. The scientific community argues that the global warming process is, at least in some degree, a consequence of modern societies unsustainable development. A key area in that situation is the citizens mobility. World economies seem to require fast and efficient transportation infrastructures for a significant fraction of the population. The non-stopping overload process that traffic networks are suffering calls for new solutions. In the vast majority of cases it is not viable to extend that infrastructures due to costs, lack of available space, and environmental impacts. Thus, traffic departments all around the world are very interested in optimizing the existing infrastructures to obtain the very best service they can provide. In the last decade many initiatives have been developed to give the traffic network new management facilities for its better exploitation. They are grouped in the so called Intelligent Transportation Systems. Examples of these approaches are the Advanced Traveler Information Systems (ATIS) and Advanced Traffic Management Systems (ATMS). Most of them provide drivers or traffic engineers the current traffic real/simulated situation or traffic forecasts. They may even suggest actions to improve the traffic flow. To do so, researchers have done a lot of work improving traffic simulations, specially through the development of accurate microscopic simulators. In the last decades the application of that family of simulators was restricted to small test cases due to its high computing requirements. Currently, the availability of cheap faster computers has changed this situation. Some famous microsimulators are MITSIM(Yang, Q., 1997), INTEGRATION (Rakha, H., et al., 1998), AIMSUN2 (Barcelo, J., et al., 1996), TRANSIMS (Nagel, K. & Barrett, C., 1997), etc. They will be briefly explained in the following section. Although traffic research is mainly targeted at obtaining accurate simulations there are few groups focused at the optimization or improvement of traffic in an automatic manner â not dependent on traffic engineers experience and âartâ. O pe n A cc es s D at ab as e w w w .ite ch on lin e. co
Control Behavior Integrity for Distributed Cyber-Physical Systems
Cyber-physical control systems, such as industrial control systems (ICS), are
increasingly targeted by cyberattacks. Such attacks can potentially cause
tremendous damage, affect critical infrastructure or even jeopardize human life
when the system does not behave as intended. Cyberattacks, however, are not new
and decades of security research have developed plenty of solutions to thwart
them. Unfortunately, many of these solutions cannot be easily applied to
safety-critical cyber-physical systems. Further, the attack surface of ICS is
quite different from what can be commonly assumed in classical IT systems.
We present Scadman, a system with the goal to preserve the Control Behavior
Integrity (CBI) of distributed cyber-physical systems. By observing the
system-wide behavior, the correctness of individual controllers in the system
can be verified. This allows Scadman to detect a wide range of attacks against
controllers, like programmable logic controller (PLCs), including malware
attacks, code-reuse and data-only attacks. We implemented and evaluated Scadman
based on a real-world water treatment testbed for research and training on ICS
security. Our results show that we can detect a wide range of
attacks--including attacks that have previously been undetectable by typical
state estimation techniques--while causing no false-positive warning for
nominal threshold values.Comment: 15 pages, 8 figure
PLC Control and Matlab/Simulink Simulations – A Translation Approach
Postprint (published version
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