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| Registros recuperados: 172 | |
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| Kahuda, Daniel; Vach, Marek; Cerba, Otakar; Krivanek, Zbynek; Jezek, Jan; Charvat, Karel; Vohnout, Premysl; Dvorak, V.. |
| NASYP is an online Geoportal tool being developed in cooperation with state and regional authorities to improve insufficient practices based on implementation of Directive nr. 2003/105/ES on the control of major-accident hazards involving dangerous substances. The tool is applicable for managing the permits, reporting and regular monitoring issues. Furthermore, it’s applicable for a risk assessment and a rapid management of disasters in the initial phase. There’re simple modeling tools included to simulate early stages of the contamination caused by disasters occurred to be used for decision making and effective use of emergency services. In this manner, there’re low atmospheric and surface water pollutions taken into account. For the study area, Liberec... |
| Tipo: Journal Article |
Palavras-chave: Spatial data; Geoportal; Risk management; Modelling; Research and Development/Tech Change/Emerging Technologies; Research Methods/ Statistical Methods; Risk and Uncertainty; GA; IN. |
| Ano: 2011 |
URL: http://purl.umn.edu/116384 |
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| Priour, Daniel. |
| Trawls energy efficiency is greatly affected by the drag, as well as by the swept area regarding pelagic trawls and by the swept width for bottom ones. The drag results in an increase of the energy consumption and the sweeping influences the catch. In order to reduce the drag per swept area (or width) a numerical tool dedicated to the automatic optimisation of the trawl design has been developed. Based on a finite element method model for flexible netting structures, the tool modifies step by step a reference design. For each step the best-modified design, in terms of drag per swept area (or width), is kept. Such a methodology was used in two cases: which show a 43% increase in energy efficiency regarding the pelagic trawl case and 27% for the bottom trawl... |
| Tipo: Text |
Palavras-chave: Swept width; Swept area; Drag; Fuel consumption; Optimisation; Modelling; Trawl; Fishing gears. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6583.pdf |
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| Stott, Alistair W.. |
| Endemic disease of animals is an economic problem as it deprives humans of scarce resources that might otherwise satisfy human wants. Optimisation methods identify the strategies that minimise this economic problem. Given the potentially vast extent of the deprivation, not only in terms of lost wealth but also in terms of animal welfare, human health and environmental damage, this subject offers great benefits to decision-makers from the individual farm to the global level. This paper uses examples to illustrate the basic economic principles concerned. It shows how these principles may be extended to deal with current limitations in theory and practice. Lack of data is a common problem that may be dealt with by using computer simulation, theoretical... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Economics; Decision analysis; Optimisation; Modelling; Endemic disease; Knowledge transfer; Health Economics and Policy. |
| Ano: 2006 |
URL: http://purl.umn.edu/46000 |
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| Perez Dominguez, Ignacio; Holm-Muller, Karin. |
| In light of international discussions on a possible opt-in of the agricultural sector to the current European emission trading system for greenhouse gases, the objective of this article is to present a feasible implementation strategy for a market of emission permits in European agriculture and to simulate its economic effects within the regionalised agricultural sector model CAPRI. With this purpose, we compare the effects of a 15% reduction of greenhouse gas emissions from European agriculture with and without a trading scheme. Our findings suggest that if significant emission abatement is to be achieved in the agricultural sector, efficiency gains from expanding the current emission trading scheme to this sector can be appreciable. An additional finding... |
| Tipo: Journal Article |
Palavras-chave: Climate gas emissions; Emission trading; Abatement costs; Agricultural policy; Modelling; Agricultural and Food Policy. |
| Ano: 2007 |
URL: http://purl.umn.edu/96766 |
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| Institut de Recherche pour le Développement, Paris (France); Fall, Massal. |
| Français - Les traits essentiels de la côte sénégalaise, repères historiques de la pêche, communautés de pêcheurs, caractéristiques des flottes et modes d’accès à la ressource et d’interaction sont analysés. Les caractéristiques, tendances décroissantes de l’abondance,niveaux d’exploitation, mesures d’aménagement, relations interspécifiques, changements potentiels et sources de variation des stocks démersaux côtiers sont précisés. Les notions de tactiques et stratégies de pêche sont passées en revue, conceptualisées puis étudiées.Le modèle «Dynamique Conjointe Exploitation Ressource» utilisé repose sur la définition de 4 typologies. L’utilisation de méthodes de classification et de connaissances d’experts conduit à considérer 32 stocks, 31 strates, 82... |
| Tipo: Theses and Dissertations |
Palavras-chave: Fisheries; Demersal fisheries; Modelling; Stocks; Ecosystems; Community fishing; Inland waters; Marine water; Hydrologic cycle; Fishermen; Fishing fleet; Shrimp fisheries; Capture fisheries; Fisheries management; Trawling; Artisanal fishing; Fishing licenses. |
| Ano: 2009 |
URL: http://hdl.handle.net/1834/5004 |
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| Perruche, Coralie; Riviere, Pascal; Pondaven, Philippe; Carton, Xavier. |
| This paper aims at studying analytically the functioning of a very simple ecosystem model with two phytoplankton species. First, using the dynamical system theory, we determine its nonlinear equilibria, their stability and characteristic timescales with a focus on phytoplankton competition. Particular attention is paid to the model sensitivity to parameter change. Then, the influence of vertical mixing and sinking of detritus on the vertically-distributed ecosystem model is investigated. The analytical results reveal a high diversity of ecosystem structures with fixed points and limit cycles that are mainly sensitive to variations of light intensity and total amount of nitrogen matter. The sensitivity to other parameters such as remineralisation, growth... |
| Tipo: Text |
Palavras-chave: Water mixing; Dynamical system; Phytoplankton; Competition; Ecosystem; Modelling. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/2009/publication-7334.pdf |
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| Witzke, Heinz Peter; Britz, Wolfgang. |
| In the context of a long run agricultural outlook on behalf of the European Environmental Agency a new methodology has been developed to systematically integrate external forecasts into a quite detailed agricultural sector model. External forecasts usually provide estimates for the exogenous variables in modelling work and frequently they are also used for comparisons and potential reassessment of empirical specifications. The innovative characteristic of this study is that expert forecasts have been used to specify parameter changes expressing structural change affecting behavioural functions. The outlook was therefore set up as a simultaneous estimation and forecasting effort which permitted to integrate various, usually contradictory expert forecasts... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Agricultural outlook; Forecasting; Modelling; Expert information; Agricultural and Food Policy; C15; C53; Q11; Q19; Q21. |
| Ano: 2005 |
URL: http://purl.umn.edu/24666 |
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| Peters,Jan; Wieme,Vanessa; Boeckx,Pascal; Samson,Roeland; Godoy,Roberto; Oyarzún,Carlos; Verhoest,Niko. |
| Ecohydrology investigates how hydrological processes affect plant growth and vice versa. As these mutual interactions are important in many ecosystems, ecohydrology has wide applicability. An important aspect of ecohydrological research is the assessment and prediction of the occurrence of plant species or vegetation types in relation to hydrological or hydrogeochemical habitat conditions. Several models have been developed (e.g. DEMNAT, ICHORS, ITORS, ITORS-VL). All of these models are data driven. Consequently a monitoring network has to be installed, possibly in addition to existing databases. These networks are ecosystem specific but the most widely monitored variables are: water table depth, electric conductivity of groundwater, soil moisture content... |
| Tipo: Journal article |
Palavras-chave: Ecohydrology; Modelling; Vegetation; Hydrology; Decision support systems. |
| Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-66432005000200007 |
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| Pereira,André Belmont; Villa Nova,Nilson Augusto; Ramos,Valdir Josué; Pereira,Antonio Roberto. |
| There is currently a great deal of interest in estimating crop productivity as a function of climatic elements by means of different crop weather models. An agrometeorological model is presented based on carbon dioxide assimilation maximum rates for C3 plants, fraction of photosynthetically active radiation, air temperature, photoperiod duration, and crop parameters under tropical climate conditions. Such crop parameters include leaf area and harvest indexes, dry matter content of potato tubers, and crop cycles to estimate potato potential yields. Field data from observed productivity obtained with the cultivar Itararé (IAC-5986), grown under adequate soil water supply conditions at four different regions in the State of São Paulo (Itararé, Piracicaba,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Modelling; Solanum tuberosum L.; Climatic elements; Crop indexes; Yield. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052008000200008 |
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| Sultan, Nabil; Voisset, Michel; Marsset, Bruno; Marsset, Tania; Cauquil, E; Colliat, J. |
| The study area, offshore Nigeria, is located in one of the compressional zones within the Niger Delta, which is characterized by imbricate thrust structures. Although the low mean slope angle (around 2°), bathymetry data from the study area have shown the existence of several submarine landslides which coincide with known subsurface faulted compressive features. In this paper, we have focused on a submarine slide occurring in water depths ranging between 1690 and 1750 m. Headwall scars, internal architecture and associated deposits have been characterized using a combination of 3D seismic data, near-bottom echosounder seismic profiles, Kullenberg cores and in-situ geotechnical measurements. The slide shows horseshoe shaped headwall scars and depositional... |
| Tipo: Text |
Palavras-chave: Slope stability; Piezometer; Penetrometer; Niger Delta; Modelling; Compressional structures. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2408.pdf |
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| Nkakini, Silas Ovua; Douglas, I. E.. |
| In this study, a comparative evaluation of tractive force models for disc harrowing, at different tillage speeds was carried out in order to determine optimal tillage speeds. The predictive models were developed using dimensional analysis. The tillage operation in a loamy sand soil, at tillage speeds of 1.94 m s-1, 2.22 m s-1 and 2.5 m s-1 respectively was conducted, using trace tractor techniques. Parameters such as drawbar pull, rolling resistance, wheel slip, moisture content, cone index, wheel numeric, contact pressure, speed, width of harrow, depth of harrow, and tractive force were measured. The developed mathematical models describing the tractors tyre-soil interactions parameters were evaluated using sensitivity analysis of the measured... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Predictive; Tractive force; Disc harrowing; Tillage; Loamy; Sand; Soil; Modelling; Sensitivity measurement; Soil moisture.. |
| Ano: 2013 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/2374 |
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| Evans, Matthew R.; Bithell, Mike; Cornell, Stephen J.; Dall, Sasha R. X.; Diaz, Sandra; Emmott, Stephen; Ernande, Bruno; Grimm, Volker; Hodgson, David J.; Lewis, Simon L.; Mace, Georgina M.; Morecroft, Michael; Moustakas, Aristides; Murphy, Eugene; Newbold, Tim; Norris, K. J.; Petchey, Owen; Smith, Matthew; Travis, Justin M. J.; Benton, Tim G.. |
| Human societies, and their well-being, depend to a significant extent on the state of the ecosystems that surround them. These ecosystems are changing rapidly usually in response to anthropogenic changes in the environment. To determine the likely impact of environmental change on ecosystems and the best ways to manage them, it would be desirable to be able to predict their future states. We present a proposal to develop the paradigm of predictive systems ecology, explicitly to understand and predict the properties and behaviour of ecological systems. We discuss the necessary and desirable features of predictive systems ecology models. There are places where predictive systems ecology is already being practised and we summarize a range of terrestrial and... |
| Tipo: Text |
Palavras-chave: Modelling; Systems ecology; Climate change; Ecosystem assessment. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00177/28816/27291.pdf |
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| Registros recuperados: 172 | |
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