519 research outputs found
Identifying Alterability States of a Single Track Railway Line Control System
In the context of automation and deployment of computer based control systems, a specific application on French railway line is proposed on low traffic single track railway lines. The issue of updates requires thorough consideration. In the case of low traffic single track railway lines, handling the removal of a shunting track, which role is to allow trains to circulate in both directions of a same line, the issue of timing the update to the control system is particularly critical. Indeed, a wrongly timed update could lead to a deadlock, while one or more trains are expected to travel while respecting safety constraints on the blocked infrastructure. This paper studies the application of works from the field of dynamic software updating, specifically the works of Panzica La Manna et al. [12]. Using their results on a graph based model of a single track rail line, it identifies alterability states that ensure safety constraints are respected at all times without causing deadlocks. These results are then used to discuss the pertinence of using concepts from dynamic software updating in the context of railway systems
In Pursuit of Aviation Cybersecurity: Experiences and Lessons From a Competitive Approach
The passive and independent localization of aircraft has been the subject of much cyberphysical security research. We designed a multistage open competition focusing on the offline batch localization problem using opportunistic data sources. We discuss setup, results, and lessons learned
A Framework for Automated Correctness Checking of Biochemical Protocol Realizations on Digital Microfluidic Biochips
Recent advances in digital microfluidic (DMF) technologies offer a promising
platform for a wide variety of biochemical applications, such as DNA analysis,
automated drug discovery, and toxicity monitoring. For on-chip implementation
of complex bioassays, automated synthesis tools have been developed to meet the
design challenges. Currently, the synthesis tools pass through a number of
complex design steps to realize a given biochemical protocol on a target DMF
architecture. Thus, design errors can arise during the synthesis steps. Before
deploying a DMF biochip on a safety critical system, it is necessary to ensure
that the desired biochemical protocol has been correctly implemented, i.e., the
synthesized output (actuation sequences for the biochip) is free from any
design or realization errors. We propose a symbolic constraint-based analysis
framework for checking the correctness of a synthesized biochemical protocol
with respect to the original design specification. The verification scheme
based on this framework can detect several post-synthesis fluidic violations
and realization errors in 2D-array based or pin-constrained biochips as well as
in cyberphysical systems. It further generates diagnostic feedback for error
localization. We present experimental results on the polymerase chain reaction
(PCR) and in-vitro multiplexed bioassays to demonstrate the proposed
verification approach
FlexiChain 2.0: NodeChain Assisting Integrated Decentralized Vault for Effective Data Authentication and Device Integrity in Complex Cyber-Physical Systems
Distributed Ledger Technology (DLT) has been introduced using the most common
consensus algorithm either for an electronic cash system or a decentralized
programmable assets platform which provides general services. Most established
reliable networks are unsuitable for all applications such as smart cities
applications, and, in particular, Internet of Things (IoT) and Cyber Physical
Systems (CPS) applications. The purpose of this paper is to provide a suitable
DLT for IoT and CPS that could satisfy their requirements. The proposed work
has been designed based on the requirements of Cyber Physical Systems.
FlexiChain is proposed as a layer zero network that could be formed from
independent blockchains. Also, NodeChain has been introduced to be a
distributed (Unique ID) UID aggregation vault to secure all nodes' UIDs.
Moreover, NodeChain is proposed to serve mainly FlexiChain for all node
security requirements. NodeChain targets the security and integrity of each
node. Also, the linked UIDs create a chain of narration that keeps track not
merely for assets but also for who authenticated the assets. The security
results present a higher resistance against four types of attacks. Furthermore,
the strength of the network is presented from the early stages compared to
blockchain and central authority. FlexiChain technology has been introduced to
be a layer zero network for all CPS decentralized applications taking into
accounts their requirements. FlexiChain relies on lightweight processing
mechanisms and creates other methods to increase security
Special Issue on Recent Advances in Petri Nets, Automata, and Discrete-Event Hybrid Systems
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