Modeling and Testing Implementations of Protocols with Complex Messages

This paper presents a new language called APSL for formally describing protocols to facilitate automated testing. Many real world communication protocols exchange messages whose structures are not trivial, e.g. they may consist of multiple and nested fields, some could be optional, and some may have values that depend on other fields. To properly test implementations of such a protocol, it is not sufficient to only explore different orders of sending and receiving messages. We also need to investigate if the implementation indeed produces correctly formatted messages, and if it responds correctly when it receives different variations of every message type. APSL's main contribution is its sublanguage that is expressive enough to describe complex message formats, both text-based and binary. As an example, this paper also presents a case study where APSL is used to model and test a subset of Courier IMAP email server

Characterization and modelling of Langmuir interfaces with finite elasticity

ISSN:1744-683XISSN:1744-684

Does the strain hardening modulus of glassy polymers scale with the flow stress?

Employing a generic coarse-grained bead-spring model, Hoy and Robbins (J Polym Sci Part B: Polym Phys 2006, 44, 3487-3500) reproduced important experimental observations on strain hardening, specifically the generally observed Gaussian strain hardening response and its dependence on network density and temperature. Moreover, their simulation results showed that the strain hardening response at different strain rates collapses to a single curve when scaled to the value of the flow stress, a phenomenon that has not yet been verified experimentally.In the present study the proposed scaling law is experimentally investigated on a variety of polymer glasses: poly(methyl methacrylate), poly(phenylene ether), polycarbonate, polystyrene and poly(ethylene terephthalate)-glycol. For these polymers true stress-strain curves in uniaxial compression were collected over a range of strain rates and temperatures and scaled to the flow stress. It was found that, generally, the curves do not collapse on a mastercurve. In all cases the strain hardening modulus is observed to increase linearly, but not proportionally to the flow stress. The experimental data, therefore, unambiguously demonstrate that the proposed scaling law does not apply within the range of temperature and strain rate covered in this study

Solutions for mitigating cybersecurity risks caused by legacy software in medical devices: A scoping review

Cyberattacks against healthcare institutions threaten patient care. The risk of being targeted by a damaging attack is increased when medical devices are used which rely on unmaintained legacy software that cannot be replaced and may have publicly known vulnerabilities. This review aims to provide insight into solutions presented in the literature that mitigate risks caused by legacy software on medical devices. We performed a scoping review by categorising and analysing the contributions of a selection of articles, taken from a literature set discovered through bidirectional citation searching. We found 18 solutions, each fitting at least one of the categories of intrusion detection and prevention, communication tunnelling or hardware protections. Approaches taken include proxying Bluetooth communication through smartphones, behaviour-specification based anomaly detection and authenticating signals based on physical characteristics. These solutions are applicable to various use-cases, ranging from securing pacemakers to medical sensor networks. Most of the solutions are based on intrusion detection and on tunnelling insecure wireless communications. These technologies have distinct application areas, and the decision which one is most appropriate will depend on the type of medical device.</p