Talking quiescence: a rigorous theory that supports parallel composition, action hiding and determinisation

The notion of quiescence - the absence of outputs - is vital in both behavioural modelling and testing theory. Although the need for quiescence was already recognised in the 90s, it has only been treated as a second-class citizen thus far. This paper moves quiescence into the foreground and introduces the notion of quiescent transition systems (QTSs): an extension of regular input-output transition systems (IOTSs) in which quiescence is represented explicitly, via quiescent transitions. Four carefully crafted rules on the use of quiescent transitions ensure that our QTSs naturally capture quiescent behaviour. We present the building blocks for a comprehensive theory on QTSs supporting parallel composition, action hiding and determinisation. In particular, we prove that these operations preserve all the aforementioned rules. Additionally, we provide a way to transform existing IOTSs into QTSs, allowing even IOTSs as input that already contain some quiescent transitions. As an important application, we show how our QTS framework simplifies the fundamental model-based testing theory formalised around ioco.Comment: In Proceedings MBT 2012, arXiv:1202.582

Specification and Testing of E-Commerce Agents Described by Using UIOLTSs

International audienceIn this paper we expand our work in our specification formalism UIOLTSs. We present three implementation relations and provide alternative characterizations of these relations in terms of the tests that the implementation under test successfully passes. In addition, we present the main ideas to obtain an algorithm to derive complete test suites from specifications

Allelopathy And Weed Competition

Currently, only two herbicides, Londax® (bensulfuron) and Taipan® (benzofenap) are available for the effective control of all four major broadleaf weeds infesting NSW rice paddocks. Prolonged and widespread use of these two herbicides in the rice growing regions increases the threat of herbicide resistance. The low likelihood of new herbicides in the foreseeable future increases the impact of herbicide resistance on the Australian rice industry. Allelopathy, chemical interactions between plants, is an alternative control option. Weeds could be controlled by using crops which have been developed to exert their own weed control by releasing chemicals into the soil. These naturally occurring compounds could play a valuable role in an integrated weed management system, potentially reducing the amount of synthetic herbicides required for weed control. In rice, the potential use of allelopathy in weed control has been explored by several researchers worldwide. Funding for work on allelopathic potential was provided by the Rice CRC as they recognised that the Australian weed community is very different and many of the weeds infesting rice paddocks are typically Australian problems not likely to be tackled by international research groups. Twenty-seven rice cultivars were examined in the laboratory for their allelopathic potential against several currently important and potentially important rice weeds in Australia, namely barnyard grass (Echinochloa crus-galli), dirty dora (Cyperus difformis), lance-leaved water plantain (Alisma lanceolatum), starfruit (Damasonium minus), arrowhead (Sagittaria montevidensis) and S. graminea. Weed root growth inhibition ranged from 0.3 % to 93.6 % of the control depending on the cultivar and the weed species being tested. One weed was actually stimulated by Langi. Several rice varieties significantly inhibited root growth of more than one weed. A field trial using starfruit as the test species was conducted to see if those cultivars which inhibited starfruit in the laboratory experiment also inhibited starfruit in the field and to determine whether allelopathy was an important factor in the resulting field performance. Twenty-four cultivars were used in a field trial based at the Yanco Agricultural Institute. Starfruit dry matter was measured as an indicator of weed inhibition. It was found that there was a correlation between laboratory and field results, and that allelopathy was an important contributor to field performance of a rice variety

UPPAAL in practice : quantitative verification of a RapidIO network.

Packet switched networks are widely used for interconnecting distributed computing platforms. RapidIO (Rapid Input/Output) is an industry standard for packet switched networks to interconnect multiple processor boards. Key performance metrics for these platforms include average-case and worst-case packet transfer latencies. We focus on verifying such quantitative properties for a RapidIO based multi-processor platform that executes a motion control application. A performance model is available in the Parallel Object-Oriented Specification Language (POOSL) that allows for simulation based estimation results. It is however required to determine the exact worst-case latency as the application is time-critical. A model checking approach has been proposed in our previous work which transforms the POOSL model into an UPPAAL model. However, such an approach only works for a fairly small system. We extend the transformation approach with various heuristics to reduce the underlying state space, thereby providing an effective approximation approach that scales to industrial problems of a reasonable complexity

Model-Based Testing of GUI-Driven Applications

While thorough testing of reactive systems is essential to ensure device safety, few testing methods center on GUI-driven applications. In this paper we present one approach for the model-based testing of such systems. Using the AHLTA-Mobile case study to demonstrate our approach, we first introduce a high-level method of modeling the expected behavior of GUI-driven applications. We show how to use the NModel tool to generate test cases from this model and present a way to execute these tests within the application, highlighting the challenges of using an API-geared tool in a GUI-based setting. Finally we present the results of our case study

From POOSL to UPPAAL : transformation and quantitative analysis

POOSL (Parallel Object-Oriented Specification Language) is a powerful general purpose system-level modeling language. In research on design space exploration of motion control systems, POOSL has been used to construct models for performance analysis. The considered motion control algorithms are characterized by periodic execution. They are executed by multiple processors, which are interconnected by Rapid Input/Output (RapidIO) packet switches. Packet latencies as worst-case latencies and average-case latencies are essential performance criteria for motion control systems. However, POOSL analysis merely allows for estimation results for these latency metrics since it is primarily based on simulation. Because motion control systems are time-critical and safety-critical, worst-case latencies of packets are strict timing constraints. Therefore exact worst-case latencies are to be determined. Motivated by this requirement we propose to use model checking techniques. In this paper we illustrate how a POOSL model of a (simplified) motion control system can be transformed into an UPPAAL model and we verify its functional behavior and worst-case latencies. Moreover, we show that analysis of average-case latencies can also be accomplished with assistance of the model checking tool UPPAAL

Conformance Verification of Normative Specifications using C-O Diagrams

C-O Diagrams have been introduced as a means to have a visual representation of normative texts and electronic contracts, where it is possible to represent the obligations, permissions and prohibitions of the different signatories, as well as what are the penalties in case of not fulfillment of their obligations and prohibitions. In such diagrams we are also able to represent absolute and relative timing constrains. In this paper we consider a formal semantics for C-O Diagrams based on a network of timed automata and we present several relations to check the consistency of a contract in terms of realizability, to analyze whether an implementation satisfies the requirements defined on its contract, and to compare several implementations using the executed permissions as criteria.Comment: In Proceedings FLACOS 2012, arXiv:1209.169