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Registros recuperados: 108 | |
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Sohngen, Brent; Sedjo, Roger A.. |
In this paper, we compare and contrast two types of timber models that have been used for public policy analysis. These models have been variously used to predict price, inventory and market welfare impacts under different exogenous forces that impact timber markets. The framework and theory for each model type is presented and discussed. We then thoroughly test the two model types across six potential exogenous shocks to timber markets, ranging from instantaneous demand shocks to gradual supply adjustments. Our comparison indicates that these models predict potentially important differences in timber market behavior. These differences are important to consider for those who do public policy analysis. |
Tipo: Working or Discussion Paper |
Palavras-chave: Timber markets; Models; Dynamic adjustment; Optimization; Resource /Energy Economics and Policy; C62; Q21; Q23. |
Ano: 1996 |
URL: http://purl.umn.edu/10467 |
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Kogan,Marcelo; Metz,Alejandra; Ortega,Rodrigo. |
The objective of this work was to investigate glyphosate adsorption by soils and its relationship with unoccupied binding sites for phosphate adsorption. Soil samples of three Chilean soils series - Valdivia (Andisol), Clarillo (Inceptisol) and Chicureo (Vertisol) - were incubated with different herbicide concentrations. Glyphosate remaining in solution was determined by adjusting a HPLC method with a UV detector. Experimental maximum adsorption capacity were 15,000, 14,300 and 4,700 mg g¹ for Valdivia, Clarillo, and Chicureo soils, respectively. Linear, Freundlich, and Langmuir models were used to describe glyphosate adsorption. Isotherms describing glyphosate adsorption differed among soils. Maximum adjusted adsorption capacity with the Langmuir model... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Herbicide; Dosage effects; Models. |
Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2003000400010 |
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Gilabert,Horacio; Paci,Carlos. |
Volume-ratio and total volume models for Eucalyptus nitens and E. globulus grown in southern Chile were ftted independently. The validation process considered the bias and the total error in the volume estimates, as well as the age classes close to thinning and harvesting operations. Volume estimates from the system of functions (volume and ratio) were compared to the volume estimates from a taper function (Bruce model) to estimate the volume at different top stem diameters. The results indicated that general (as opposed to local) logarithmic functions performed better in their estimation of the total volume for both species, while a unique polynomial model was the best model for the ratio estimates for both Eucalyptus species. The system of functions... |
Tipo: Journal article |
Palavras-chave: Eucalyptus; Models; Timber products estimates; Volume-ratio functions. |
Ano: 2010 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-16202010000100001 |
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Resende,Mariana; Cirillo,Marcelo Â.; Borém,Flávio M.. |
ABSTRACT Numerous factors are related to the individual sensory perception of consumers, which makes it impossible to adapt a model that explains their behavior. In this context and given the scarcity of statistical indexes that evaluate preferences for specialty coffees, new statistical methods should be studied. To this end, our study aimed to create an index that measures the acceptance of specialty coffees. The index was built considering the fit of regression models as a function of principal component scores. Validation was done by significance tests, whose probabilities were obtained by bootstrapping, considering the main measures used in diagnosing outliers as weights, with application to real data from different consumer groups. The coffee... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Models; Quality; Bootstrap; Acaia; Bourbon. |
Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000500624 |
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Feki-Sahnoun, W.. |
Le long des côtes du golfe de Gabès, les données collectées dans le cadre du Réseau de Surveillance du Phytoplancton et des Phycotoxines (REPHY), constituent une base pertinente pour examiner la structure et la dynamique des communautés phytoplanctoniques à grandes échelles temporelle (1997-2007) et géographique (l’ensemble de littoral du golfe). S’appuyant sur les données du REPHY, l’objectif de cette étude était de décrire les principales formes de variabilité des communautés phytoplanctoniques observées sur nos côtes. Les schémas de la variabilité des populations phytoplanctoniques ont été examinés à différentes échelles temporelles et géographiques à l’aide de méthodes statistiques multivariées. Dans un premier temps, l’analyse de la dynamique des... |
Tipo: Theses and Dissertations |
Palavras-chave: Phytoplankton; Temporal variations; Geographical distribution; Statistical analysis; Models. |
Ano: 2013 |
URL: http://hdl.handle.net/1834/5444 |
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Vazquez-rodriguez, Marcos; Touratier, Franck; Lo Monaco, Claire; Waugh, D. W.; Padin, X. A.; Bellerby, R. G. J.; Goyet, Catherine; Metzl, Nicolas; Rios, Aida F.; Perez, Fiz F.. |
Five of the most recent observational methods to estimate anthropogenic CO2 (C-ant) are applied to a high-quality dataset from five representative sections of the Atlantic Ocean extending from the Arctic to the Antarctic. Between latitudes 60 degrees N-40 degrees S all methods give similar spatial distributions and magnitude of C-ant. However, discrepancies are found in some regions, in particular in the Southern Ocean and Nordic Seas. The differences in the Southern Ocean have a significant impact on the anthropogenic carbon inventories. The calculated total inventories of C-ant for the Atlantic referred to 1994 vary from 48 to 67 Pg (10(15) g) of carbon, with an average of 54 +/- 8 Pg C, which is higher than previous estimates. These results, both the... |
Tipo: Text |
Palavras-chave: Deep equatorial atlantic; Northern indian-ocean; Water mass ages; CO2; Sea; Transport; Increase; Tracers; Models. |
Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/00202/31313/29724.pdf |
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Vazquez-rodriguez, M.; Touratier, F.; Lo Monaco, C.; Waugh, D. W.; Padin, X. A.; Bellerby, R. G. J.; Goyet, C.; Metzl, N.; Rios, A.f.; Perez, F.f.. |
Five of the most recent observational methods to estimate anthropogenic CO2 (Cant) are applied to a high-quality dataset from five representative sections of the Atlantic Ocean extending from the Arctic to the Antarctic. Between latitudes 60° N–40° S all methods give similar spatial distributions and magnitude of Cant. Conversely, large discrepancies are found in the Southern Ocean and Nordic Seas. The differences in the Southern Ocean have a significant impact on the anthropogenic carbon inventories. The calculated total inventories of Cant for the Atlantic referred to 1994 range from 48 to 67 Pg (1015 g) of carbon, with an average of 54±8 Pg C, which is higher than previous estimates. These results, both the detailed Cant distributions and extrapolated... |
Tipo: Text |
Palavras-chave: Deep equatorial atlantic; Northern indian-ocean; Water mass ages; CO2; Sea; Transport; Increase; Tracers; Models. |
Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00293/40430/38984.pdf |
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MEIRA, C. A. A.; RODRIGUES, L. H. A.. |
A ferrugem do cafeeiro é a principal doença da cultura do café. O conhecimento dos fatores que condicionam as epidemias de ferrugem e a sua previsão são importantes. Uma instância do processo de descoberta de conhecimento em bases de dados foi realizada para avaliar a aplicação de árvores de decisão na análise e no alerta da ferrugem. As classes do atributo meta foram definidas por intervalos da taxa de progresso da doença. Dados meteorológicos, a carga pendente de frutos e o espaçamento entre plantas serviram de atributos preditivos. As árvores de decisão obtidas auxiliaram na compreensão de quais variáveis, e como as interações dessas variáveis, conduziram a ferrugem no campo. O modelo de alerta para lavouras com alta carga pendente de frutos apresentou... |
Tipo: Folhetos |
Palavras-chave: Mineração de dados; Inteligência artificial; Modelagem; Coffee; Plant disease; Café; Doença de Planta; Models. |
Ano: 2009 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/662782 |
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Bertelsmeier, Marcus; Kleinhanss, Werner; Offermann, Frank. |
The FAL model group combines several market, regional and farm models for comprehensive policy impact assessments. Since 1996, policy impact analyses have been provided at the request of the German Agricultural Ministry with respect to the design of direct payments, the Agenda 2000, the Mid-term Review, the Enlargement of the EU as well as several other policy measures. This article gives an overview of the models available as part of the model group, specifically describes the design of the representative farm group model, and provides results with respect to the impacts of the Midterm Review. The paper ends with a discussion of the experiences gained in model based policy consulting and the implications for future developments. |
Tipo: Journal Article |
Palavras-chave: Policy assessment; Models; Agricultural policy; Midterm review; Policy impact analysis; Agricultural and Food Policy. |
Ano: 2003 |
URL: http://purl.umn.edu/98358 |
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Registros recuperados: 108 | |
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