title: Flexible refinement

authors: Reeves, Steve

abstract: To help make refinement more usable in practice we introduce a general, flexible model of refinement. This is defined in terms of what contexts an entity can appear in, and what observations can be made of it in those contexts.
 Our general model is expressed in terms of an operational semantics, and by exploiting the well-known isomorphism between state-based relational semantics and event-based labelled transition semantics we were able to take particular models from both the state- and event-based literature, reflect on them and gradually evolve our general model. We are also able to view our general model both as a testing semantics and as a logical theory with refinement as implication. 
Our general model can used as a bridge between different particular special models and using this bridge we compare the definition of determinism found in different special models. We do this because the reduction of nondeterminism underpins many definitions of refinement found in a variety of special models. To our surprise we find that the definition of determinism commonly used in the process algebra literature to be at odds with determinism as defined in other special models. In order to rectify this situation we return to the intuitions expressed by Milner in CCS and by formalising these intuitions we are able to define determinism in process algebra in such a way that it no longer at odds with the definitions we have taken from other special models. Using our abstract definition of determinism we are able to construct a new model, interactive branching programs, that is an implementable subset of process algebra. Later in the chapter we show explicitly how five special models, taken from the literature, are instances of our general model. This is done simply by fixing the sets of contexts and observations involved. Next we define vertical refinement on our general model. Vertical refinement can be seen both as a generalisation of what, in the literature, has been called action refinement or non-atomic refinement. Alternatively, by viewing a layer as a logical theory, vertical refinement is a theory morphism, formalised as a Galois connection.
By constructing a vertical refinement between broadcast processes and interactive branching programs we can see how interactive branching programs can be implemented on a platform providing broadcast communication. But we have been unable to extend this theory morphism to implement all of process algebra using broadcast communication. Upon investigation we show the problem arises with the examples that caused the problem with the definition of determinism on process algebra. Finally we illustrate the usefulness of our flexible general model by formally developing a single entity that contains events that use handshake communication and events that use broadcast communication.

text: Flexible refinement To help make refinement more usable in practice we introduce a general, flexible model of refinement. This is defined in terms of what contexts an entity can appear in, and what observations can be made of it in those contexts.
 Our general model is expressed in terms of an operational semantics, and by exploiting the well-known isomorphism between state-based relational semantics and event-based labelled transition semantics we were able to take particular models from both the state- and event-based literature, reflect on them and gradually evolve our general model. We are also able to view our general model both as a testing semantics and as a logical theory with refinement as implication. 
Our general model can used as a bridge between different particular special models and using this bridge we compare the definition of determinism found in different special models. We do this because the reduction of nondeterminism underpins many definitions of refinement found in a variety of special models. To our surprise we find that the definition of determinism commonly used in the process algebra literature to be at odds with determinism as defined in other special models. In order to rectify this situation we return to the intuitions expressed by Milner in CCS and by formalising these intuitions we are able to define determinism in process algebra in such a way that it no longer at odds with the definitions we have taken from other special models. Using our abstract definition of determinism we are able to construct a new model, interactive branching programs, that is an implementable subset of process algebra. Later in the chapter we show explicitly how five special models, taken from the literature, are instances of our general model. This is done simply by fixing the sets of contexts and observations involved. Next we define vertical refinement on our general model. Vertical refinement can be seen both as a generalisation of what, in the literature, has been called action refinement or non-atomic refinement. Alternatively, by viewing a layer as a logical theory, vertical refinement is a theory morphism, formalised as a Galois connection.
By constructing a vertical refinement between broadcast processes and interactive branching programs we can see how interactive branching programs can be implemented on a platform providing broadcast communication. But we have been unable to extend this theory morphism to implement all of process algebra using broadcast communication. Upon investigation we show the problem arises with the examples that caused the problem with the definition of determinism on process algebra. Finally we illustrate the usefulness of our flexible general model by formally developing a single entity that contains events that use handshake communication and events that use broadcast communication.

year: 2007-05-07

title: Like a jungle sometimes: how leaves survive in the rainforest understory

authors: Onoda, Yusuke

subjects: allocation

abstract: Article provides new insights into how leaves resist the rigours of life in the rainforest understory, seeking explanations of durability at multiple levels, and confirming the utility of a new way of standardizing toughness measurements. Their paper relates leaf structural and material properties, as well as chemical composition, to seedling leaf lifespan, herbivory and survival of 24 rainforest tree species in a common garden experiment in gap and understory environments.

text: Like a jungle sometimes: how leaves survive in the rainforest understory Article provides new insights into how leaves resist the rigours of life in the rainforest understory, seeking explanations of durability at multiple levels, and confirming the utility of a new way of standardizing toughness measurements. Their paper relates leaf structural and material properties, as well as chemical composition, to seedling leaf lifespan, herbivory and survival of 24 rainforest tree species in a common garden experiment in gap and understory environments.

year: 2012

title: Work-family enrichment, collectivism, and workplace cultural outcomes: A study of New Zealand Māori

authors: Brougham, David M.

subjects: work-family enrichment

abstract: Although the work-family enrichment literature is well established, it lacks an indigenous focus. The present study explored workplace cultural attitudes amongst 172 Māori employees. Work-family enrichment was significantly related to workplace-cultural-wellbeing, while family-work enrichment was significantly related to workplace-cultural-satisfaction. Collectivism was tested as a potential moderator. The interaction effects show that respondents with low levels of family-work enrichment and high collectivism benefited most, reporting the highest levels of workplace-cultural-wellbeing. Furthermore, respondents with high collectivism reported significantly higher workplace-culturalsatisfaction, irrespective of enrichment. Overall, the benefits of work and family can enhance cultural outcomes in the workplace.

text: Work-family enrichment, collectivism, and workplace cultural outcomes: A study of New Zealand Māori Although the work-family enrichment literature is well established, it lacks an indigenous focus. The present study explored workplace cultural attitudes amongst 172 Māori employees. Work-family enrichment was significantly related to workplace-cultural-wellbeing, while family-work enrichment was significantly related to workplace-cultural-satisfaction. Collectivism was tested as a potential moderator. The interaction effects show that respondents with low levels of family-work enrichment and high collectivism benefited most, reporting the highest levels of workplace-cultural-wellbeing. Furthermore, respondents with high collectivism reported significantly higher workplace-culturalsatisfaction, irrespective of enrichment. Overall, the benefits of work and family can enhance cultural outcomes in the workplace.

year: 2015