8 research outputs found
Membrane form finding by means of functional minimization
This study deals with the methods of architectural design of structures made of textile membranes. We consider the problem of form finding of membranes strained by rigid skeletons and cables installed along the free edges of the membrane. First, we recall the methods used to solve the simple problem of finding form in the case of constant surface tension. Then we propose a method based on the minimization of the total potential energy. The problem is discretized using membrane triangular finite elements. The potential considered is an energy density per unit area of uniform and constant surface tension. The minimization of this potential leads to the minimal surface solution. However the problem is singular with respect to the in-plane displacement. To handle this problem, the potential is enhanced by an elastic energy in order to regularize the numerical scheme and prevent the mesh degeneration. It is also enhanced by the elastic energy due to the cable tensions. The solution is obtained by minimizing the potential energy using the conjugate gradient method
Membrane form finding by means of functional minimization
This study deals with the methods of architectural design of structures made of textile membranes. We consider the problem of form finding of membranes strained by rigid skeletons and cables installed along the free edges of the membrane. First, we recall the methods used to solve the simple problem of finding form in the case of constant surface tension. Then we propose a method based on the minimization of the total potential energy. The problem is discretized using membrane triangular finite elements. The potential considered is an energy density per unit area of uniform and constant surface tension. The minimization of this potential leads to the minimal surface solution. However the problem is singular with respect to the in-plane displacement. To handle this problem, the potential is enhanced by an elastic energy in order to regularize the numerical scheme and prevent the mesh degeneration. It is also enhanced by the elastic energy due to the cable tensions. The solution is obtained by minimizing the potential energy using the conjugate gradient method
Development and application of a multilingual electronic decision-support tool for risk screening non-native terrestrial animals under current and future climate conditions
Electronic decision-support tools are becoming an essential component of government strategies to tackle non-native species invasions. This study describes the development and application of a multilingual electronic decision-support tool for screening terrestrial animals under current and future climate conditions: the Terrestrial Animal Species Invasiveness Screening Kit (TAS-ISK). As an adaptation of the widely employed Aquatic Species Invasiveness Screening Kit (AS-ISK), the TAS-ISK question template inherits from the original Weed Risk Assessment (WRA) and related WRA-type toolkits and complies with the ‘minimum requirements’ for use with the recent European Regulation on invasive alien species of concern. The TAS-ISK consists of 49 basic questions on the species’ biogeographical/historical traits and its biological/ecological interactions, and of 6 additional questions to predict how climate change is likely to influence the risks of introduction, establishment, dispersal and impact of the screened species. Following a description of the main features of this decision-support tool as a turnkey software application and of its graphical user interface with support for 32 languages, sample screenings are provided in different risk assessment areas for one representative species of each of the main taxonomic groups of terrestrial animals supported by the toolkit: mammals, birds, reptiles, amphibians, annelids, insects, molluscs, nematodes, and platyhelminths. The highest-scoring species were the red earthworm Lumbricus rubellus for the Aegean region of Turkey and the New Zealand flatworm Arthurdendyus triangulatus for Croatia. It is anticipated that adoption of this toolkit will mirror that of the worldwide employed AS-ISK, hence allowing to share information and inform decisions for the prevention of entry and/or dispersal of (high-risk) non-native terrestrial animal species – a crucial step to implement early-stage control and eradication measures as part of rapid-response strategies to counteract biological invasions
Development and application of a second-generation multilingual tool for invasion risk screening of non-native terrestrial plants
Speaking their language – development of a multilingual decision-support tool for communicating invasive species risks to decision makers and stakeholders
Environmental changes due to non-native species introductions and translocations are a global concern. Whilst understanding the causes of bioinvasions is important, there is need for decision-support tools that facilitate effective communication of the potential risks of invasive non-native species to stakeholders. Decision-support tools have been developed mostly in English language only, which increases linguistic uncertainty associated with risk assessments undertaken by assessors not of English mother tongue and who need to communicate outcomes to local stakeholders. To reduce language-based uncertainty, the ‘ecology-of-language’ paradigm was applied when developing the Aquatic Species Invasiveness Screening Kit (AS-ISK), a decision-support tool that offers 32 languages in which to carry out screenings and communicate outcomes to stakeholders. Topics discussed include uncertainty related to language-specific issues encountered during the AS-ISK translation and the potential benefits of a multilingual decision-support tool for reducing linguistic uncertainty and enhancing communication between scientists, environmental managers, policy and decision makers
Speaking their language : Development of a multilingual decision-support tool for communicating invasive species risks to decision makers and stakeholders
Environmental changes due to non-native species introductions and translocations are a global concern. Whilst understanding the causes of bioinvasions is important, there is need for decision-support tools that facilitate effective communication of the potential risks of invasive non-native species to stakeholders. Decision-support tools have been developed mostly in English language only, which increases linguistic uncertainty associated with risk assessments undertaken by assessors not of English mother tongue and who need to communicate outcomes to local stakeholders. To reduce language-based uncertainty, the ‘ecology-of-language’ paradigm was applied when developing the Aquatic Species Invasiveness Screening Kit (AS-ISK), a decision-support tool that offers 32 languages in which to carry out screenings and communicate outcomes to stakeholders. Topics discussed include uncertainty related to language-specific issues encountered during the AS-ISK translation and the potential benefits of a multilingual decision-support tool for reducing linguistic uncertainty and enhancing communication between scientists, environmental managers, and policy and decision makers.Published version is available for viewing only. (See "Related URI")「関連URI」より出版社版の閲覧専用ページへリン
A global-scale screening of non-native aquatic organisms to identify potentially invasive species under current and future climate conditions
10.1016/j.scitotenv.2021.147868Science of the Total Environment78814786
A global-scale screening of non-native aquatic organisms to identify potentially invasive species under current and future climate conditions
The threat posed by invasive non-native species worldwide requires a global approach to identify which introduced species are likely to pose an elevated risk of impact to native species and ecosystems. To inform policy, stakeholders and management decisions on global threats to aquatic ecosystems, 195 assessors representing 120 risk assessment areas across all six inhabited continents screened 819 non-native species from 15 groups of aquatic organisms (freshwater, brackish, marine plants and animals) using the Aquatic Species Invasiveness Screening Kit. This multi-lingual decision-support tool for the risk screening of aquatic organisms provides assessors with risk scores for a species under current and future climate change conditions that, following a statistically based calibration, permits the accurate classification of species into high-, medium- and low-risk categories under current and predicted climate conditions. The 1730 screenings undertaken encompassed wide geographical areas (regions, political entities, parts thereof, water bodies, river basins, lake drainage basins, and marine regions), which permitted thresholds to be identified for almost all aquatic organismal groups screened as well as for tropical, temperate and continental climate classes, and for tropical and temperate marine ecoregions. In total, 33 species were identified as posing a ‘very high risk’ of being or becoming invasive, and the scores of several of these species under current climate increased under future climate conditions, primarily due to their wide thermal tolerances. The risk thresholds determined for taxonomic groups and climate zones provide a basis against which area-specific or climate-based calibrated thresholds may be interpreted. In turn, the risk rankings help decision-makers identify which species require an immediate ‘rapid’ management action (e.g. eradication, control) to avoid or mitigate adverse impacts, which require a full risk assessment, and which are to be restricted or banned with regard to importation and/or sale as ornamental or aquarium/fishery enhancement