304 research outputs found
Incremental Consistency Checking in Delta-oriented UML-Models for Automation Systems
Automation systems exist in many variants and may evolve over time in order
to deal with different environment contexts or to fulfill changing customer
requirements. This induces an increased complexity during design-time as well
as tedious maintenance efforts. We already proposed a multi-perspective
modeling approach to improve the development of such systems. It operates on
different levels of abstraction by using well-known UML-models with activity,
composite structure and state chart models. Each perspective was enriched with
delta modeling to manage variability and evolution. As an extension, we now
focus on the development of an efficient consistency checking method at several
levels to ensure valid variants of the automation system. Consistency checking
must be provided for each perspective in isolation, in-between the perspectives
as well as after the application of a delta.Comment: In Proceedings FMSPLE 2016, arXiv:1603.0857
Detecting and Explaining Conflicts in Attributed Feature Models
Product configuration systems are often based on a variability model. The
development of a variability model is a time consuming and error-prone process.
Considering the ongoing development of products, the variability model has to
be adapted frequently. These changes often lead to mistakes, such that some
products cannot be derived from the model anymore, that undesired products are
derivable or that there are contradictions in the variability model. In this
paper, we propose an approach to discover and to explain contradictions in
attributed feature models efficiently in order to assist the developer with the
correction of mistakes. We use extended feature models with attributes and
arithmetic constraints, translate them into a constraint satisfaction problem
and explore those for contradictions. When a contradiction is found, the
constraints are searched for a set of contradicting relations by the
QuickXplain algorithm.Comment: In Proceedings FMSPLE 2015, arXiv:1504.0301
Secure mobile multiagent systems in virtual marketplaces : a case study on comparison shopping
The growth of the Internet has deeply influenced our daily lives as well as our commercial structures. Agents and multiagent systems will play a major role in the further development of Internet-based applications like virtual marketplaces. However, there is an increasing awareness of the security problems involved. These systems will not be successful until their problems are solved. This report examines comparison shopping, a virtual marketplace scenario and an application domain for a mobile multiagent system, with respect to its security issues. The interests of the participants in the scenario, merchants and clients, are investigated. Potential security threats are identified and security objectives counteracting those threats are established. These objectives are refined into building blocks a secure multiagent system should provide. The building blocks are transformed into features of agents and executing platforms. Originating from this analysis, solutions for the actual implementation of these building blocks are suggested. It is pointed out under which assumptions it is possible to achieve the security goals, if at all
Using Abstraction in Modular Verification of Synchronous Adaptive Systems
Self-adaptive embedded systems autonomously adapt to
changing environment conditions to improve their functionality and to
increase their dependability by downgrading functionality in case of fail-
ures. However, adaptation behaviour of embedded systems significantly
complicates system design and poses new challenges for guaranteeing
system correctness, in particular vital in the automotive domain. Formal
verification as applied in safety-critical applications must therefore be
able to address not only temporal and functional properties, but also
dynamic adaptation according to external and internal stimuli.
In this paper, we introduce a formal semantic-based framework to model,
specify and verify the functional and the adaptation behaviour of syn-
chronous adaptive systems. The modelling separates functional and adap-
tive behaviour to reduce the design complexity and to enable modular
reasoning about both aspects independently as well as in combination.
By an example, we show how to use this framework in order to verify
properties of synchronous adaptive systems. Modular reasoning in com-
bination with abstraction mechanisms makes automatic model checking
efficiently applicable
SOTIF-Compliant Scenario Generation Using Semi-Concrete Scenarios and Parameter Sampling
Scenario-based testing is considered state-of-the-art to verify and validate
Advanced Driver Assistance Systems or Automated Driving Systems. Due to the
official launch of the SOTIF-standard (ISO 21448), scenario-based testing
becomes more and more relevant for releasing those Highly Automated Driving
Systems. However, an essential missing detail prevent the practical application
of the SOTIF-standard: How to practically generate scenarios for scenario-based
testing? In this paper, we perform a Systematic Literature Review to identify
techniques that generate scenarios complying with requirements of the
SOTIF-standard. We classify existing scenario generation techniques and
evaluate the characteristics of generated scenarios wrt. SOTIF requirements. We
investigate which details of the real-world are covered by generated scenarios,
whether scenarios are specific for a system under test or generic, and whether
scenarios are designed to minimize the set of unknown and hazardous scenarios.
We conclude that scenarios generated with existing techniques do not comply
with requirements implied by the SOTIF-standard; hence, we propose directions
for future research.Comment: accepted at IEEE ITSC 202
QbC: Quantum Correctness by Construction
Thanks to the rapid progress and growing complexity of quantum algorithms,
correctness of quantum programs has become a major concern. Pioneering research
over the past years has proposed various approaches to formally verify quantum
programs using proof systems such as quantum Hoare logic. All these prior
approaches are post-hoc: one first implements a complete program and only then
verifies its correctness. In this work, we propose Quantum Correctness by
Construction (QbC): an approach to constructing quantum programs from their
specification in a way that ensures correctness. We use pre- and postconditions
to specify program properties, and propose a set of refinement rules to
construct correct programs in a quantum while language. We validate QbC by
constructing quantum programs for two idiomatic problems, teleportation and
search, from their specification. We find that the approach naturally suggests
how to derive program details, highlighting key design choices along the way.
As such, we believe that QbC can play an important role in supporting the
design and taxonomization of quantum algorithms and software.Comment: 33 page
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