title: Using behavioural specifications to support model-checking

authors: Liu, Bowen

subjects: Formal methods,Cucumber,Behavioural Speficication

abstract: Safety-critical interactive systems provide many beneﬁts for human daily life, but erroneous safety-critical interactive systems can lead to serious consequences to the users. Thus building these systems requires that we ensure a high level of correctness. Formal models can be used to ensure that safetycritical systems are developed correctly. However, when models of the systems are being built, there is no guarantee that the modelled system fully satisﬁes the user requirements. If the systems are not what business stakeholders truly desire, new errors can be made. Behaviour-Driven-Development is often applied to ensure the requirements of thesystemareproperlyunderstoodandmaintainedbyusingBehaviouralSpeciﬁcations. These speciﬁcations use natural language, and so, are well suited for expressing user requirements. They can be used as the basis for test generation but do not provide the guarantees of correctness that formal methods can provide. In this work, we develop an approach that takes advantage of the expressivity of behaviour speciﬁcations and combines it with the use of formal methods. We use Behavioural Speciﬁcations to create First-Order-Logic predicates of the requirements. These predicates can be used with formal methods, either to support the creation of the formal models or to ensure the user requirements and speciﬁcations are consistent.

text: Using behavioural specifications to support model-checking Safety-critical interactive systems provide many beneﬁts for human daily life, but erroneous safety-critical interactive systems can lead to serious consequences to the users. Thus building these systems requires that we ensure a high level of correctness. Formal models can be used to ensure that safetycritical systems are developed correctly. However, when models of the systems are being built, there is no guarantee that the modelled system fully satisﬁes the user requirements. If the systems are not what business stakeholders truly desire, new errors can be made. Behaviour-Driven-Development is often applied to ensure the requirements of thesystemareproperlyunderstoodandmaintainedbyusingBehaviouralSpeciﬁcations. These speciﬁcations use natural language, and so, are well suited for expressing user requirements. They can be used as the basis for test generation but do not provide the guarantees of correctness that formal methods can provide. In this work, we develop an approach that takes advantage of the expressivity of behaviour speciﬁcations and combines it with the use of formal methods. We use Behavioural Speciﬁcations to create First-Order-Logic predicates of the requirements. These predicates can be used with formal methods, either to support the creation of the formal models or to ensure the user requirements and speciﬁcations are consistent.

year: 2019

title: The effectiveness of delineation treatments

authors: Charlton, Samuel G.

subjects: delineation

abstract: A literature review undertaken for Transit NZ has found that delineation has a significant effect on driver behaviour with, for example, shoulder rumble strips reducing run-off-theroad crashes by between 22% and 80% (average of 32% for all crashes and 44% for fatal run-of-the-road crashes). The concern that enhancing roadway delineation may sometimes be accompanied by an unwanted increase in drivers’ speeds (known as behavioural adaptation) is not borne out by the research and appears to be a phenomenon associated with a few restricted situations (e.g. where a centre line is added to an otherwise unmarked road).
The preponderance of the evidence supports the conclusion that profiled edge lines and centre lines provide drivers with positive guidance and produce significant reductions in crashes as a result of improving drivers’ lateral position. Further, unlike other safety measures that show decreased effectiveness over time due to a novelty effect, profiled lane delineation continues to work regardless of driver familiarity. There is no published research to suggest that profiled edge lines will decrease the effectiveness of a profiled centre line or will result in an increase in crash rates or an increase in the severity of crashes. However it has also been noted that local conditions have a major influence on the level of benefits that can be achieved through improved delineation.

text: The effectiveness of delineation treatments A literature review undertaken for Transit NZ has found that delineation has a significant effect on driver behaviour with, for example, shoulder rumble strips reducing run-off-theroad crashes by between 22% and 80% (average of 32% for all crashes and 44% for fatal run-of-the-road crashes). The concern that enhancing roadway delineation may sometimes be accompanied by an unwanted increase in drivers’ speeds (known as behavioural adaptation) is not borne out by the research and appears to be a phenomenon associated with a few restricted situations (e.g. where a centre line is added to an otherwise unmarked road).
The preponderance of the evidence supports the conclusion that profiled edge lines and centre lines provide drivers with positive guidance and produce significant reductions in crashes as a result of improving drivers’ lateral position. Further, unlike other safety measures that show decreased effectiveness over time due to a novelty effect, profiled lane delineation continues to work regardless of driver familiarity. There is no published research to suggest that profiled edge lines will decrease the effectiveness of a profiled centre line or will result in an increase in crash rates or an increase in the severity of crashes. However it has also been noted that local conditions have a major influence on the level of benefits that can be achieved through improved delineation.

year: 2005

title: Commentary on 'Family obligations in Micronesian cultures: implications for educators'

authors: Bishop, Russell

subjects: education

abstract: The paper makes some interesting observations about the need for educators to understand the cultural positionings of Micronesian students and by implication challenges readers to extend these understandings to other migrant and minoritised student groups. I would like to take up this challenge and illustrate how useful it is to theorise from a relational discourse when seeking solutions to what many educators are suggesting as the greatest problem we face in contemporary education, i.e. the seemingly immutable and growing educational disparities that accompany the increasing diversity of our student bodies in association with the continuing dominance of monocultural and deficit explanations by teachers about the causes of the disparities. This problem negatively affects indigenous students and students of colour along with migrant students and the paper rightly points to the need for solutions.

text: Commentary on 'Family obligations in Micronesian cultures: implications for educators' The paper makes some interesting observations about the need for educators to understand the cultural positionings of Micronesian students and by implication challenges readers to extend these understandings to other migrant and minoritised student groups. I would like to take up this challenge and illustrate how useful it is to theorise from a relational discourse when seeking solutions to what many educators are suggesting as the greatest problem we face in contemporary education, i.e. the seemingly immutable and growing educational disparities that accompany the increasing diversity of our student bodies in association with the continuing dominance of monocultural and deficit explanations by teachers about the causes of the disparities. This problem negatively affects indigenous students and students of colour along with migrant students and the paper rightly points to the need for solutions.

year: 2010