27 research outputs found
IPCC reasons for concern regarding climate change risks
The reasons for concern framework communicates scientific understanding about risks in relation to varying levels of climate change. The framework, now a cornerstone of the IPCC assessments, aggregates global risks into five categories as a function of global mean temperature change. We review the framework's conceptual basis and the risk judgments made in the most recent IPCC report, confirming those judgments in most cases in the light of more recent literature and identifying their limitations. We point to extensions of the framework that offer complementary climate change metrics to global mean temperature change and better account for possible changes in social and ecological system vulnerability. Further research should systematically evaluate risks under alternative scenarios of future climatic and societal conditions
Editorial
Editorial for Special issue: Quality software - the 4th International Conference on Quality Softwarelink_to_subscribed_fulltex
Architecting product diversification - Formalizing variability dependencies in software product family engineering
In a software product family context, software architects design architectures that support product diversification in both space (multiple contexts) and time (changing contexts). Product diversification is based on the concept of variability: a single architecture and a set of components support a family of products. Software product families need to support increasing amounts of variability, leading to a situation where variability dependencies become of primary concern. This paper presents (1) a formalization of variability dependencies and (2) a case study in designing a program monitor and exception handler The case study uses the formalization to describe variability dependencies in constraint specification language style and shows that architectural robustness is related to the type of variability dependencies
Recolonisation of new habitats by meiobenthic organisms in the deep Arctic Ocean: an experimental approach
Commercial exploitation and abrupt changes of the natural conditions may have
severe impacts on the Arctic deep-sea ecosystem. The present recolonisation
experiment mimicked a situation after a catastrophic disturbance (e.g. by turbidites
caused by destabilized continental slopes after methane hydrate decomposition) and
investigated if the recolonisation of a deep-sea habitat by meiobenthic organisms is
fostered by variations innutrition and/or sediment structure. Two "Sediment Tray Free
Vehicles" were deployed for one year in summer 2003 at 2500 m water depth in the
Arctic deep-sea in the eastern Fram Strait. The recolonisation trays were filled with
different artificial and natural sediment types (glass beads, sand, sediment mixture,
pure deep-sea sediment) and were enriched with various types of food (algae, yeast,
fish). After one year, meiobenthos abundances and various sediment related
environmental parameters were investigated. Foraminifera were generally the most
successful group: they dominated all treatments and accounted for about 87% of the
total meiobenthos. Colonizing meiobenthos specimens were generally smaller
compared to those in the surrounding deep-sea sediment, suggesting an active
recolonisation by juveniles. Although experimental treatments with fine-grained, algaeenriched
sediment showed abundances closest to natural conditions, the results
suggest that food availability was the main determining factor for a successful
recolonisation by meiobenthos and the structure of recolonised sediments was shown
to have a subordinate influence
A novel QoS model and computation framework in web service selection
With the rapid development of e-commerce over Internet, web services have attracted much attention in recent years. Nowadays, enterprises are able to outsource their internal business processes as services and make them accessible via
the Web. Then they can dynamically combine individual services to provide new value-added services. With the increasing number of web services having equivalent functionality, the binding procedure is driven by some non-functional, Quality of Service (QoS) criteria, such as the money cost, response time, reputation, reliability
or a trade-off between them. Thus, an important problem is, given QoS constraints,
how to aggregate and leverage individual service’s QoS information to derive the
optimal QoS of the composite service. In this paper, we propose a novel QoS model
for performing flexible service selection. The key idea of the model is to relax
users’ QoS constraints and try to find the most possible services satisfying users’
QoS requirements. Based on the proposed QoS framework, we develop various
algorithms for making service selection on individual and composite services. We
also introduce a top-k ranking strategy to reflect a user’s personalized requirements.
Experimental evaluation shows the proposed QoS model is efficient and practical