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40Ar/39Ar geochronology at the Instituto de Geociências, USP: instrumentation, analytical procedures, and calibration Anais da ABC (AABC)
VASCONCELOS,PAULO M.; ONOE,ARTUR T.; KAWASHITA,KOJI; SOARES,ADALBERTO J.; TEIXEIRA,WILSON.
Laser heating 40Ar/39Ar geochronology provides high analytical precision and accuracy, mum-scale spatial resolution, and statistically significant data sets for the study of geological and planetary processes. A newly commissioned 40Ar/39Ar laboratory at CPGeo/USP, São Paulo, Brazil, equips the Brazilian scientific community with a new powerful tool applicable to the study of geological and cosmochemical processes. Detailed information about laboratory layout, environmental conditions, and instrumentation provides the necessary parameters for the evaluation of the CPGeo/USP 40Ar/39Ar suitability to a diverse range of applications. Details about analytical procedures, including mineral separation, irradiation at the IPEN/CNEN reactor at USP, and mass...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Geochronology; 40Ar/39Ar method; Irradiation; Calibration.
Ano: 2002 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652002000200008
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A BAYESIAN ALTERNATIVE TO GENERALIZED CROSS ENTROPY SOLUTIONS FOR UNDERDETERMINED ECONOMETRIC MODELS AgEcon
Heckelei, Thomas; Mittelhammer, Ronald C.; Jansson, Torbjorn.
This paper presents a Bayesian alternative to Generalized Maximum Entropy (GME) and Generalized Cross Entropy (GCE) methods for deriving solutions to econometric models represented by underdetermined systems of equations. For certain types of econometric model specifications, the Bayesian approach provides fully equivalent results to GME-GCE techniques. However, in its general form, the proposed Bayesian methodology allows a more direct and straightforwardly interpretable formulation of available prior information and can reduce significantly the computational effort involved in finding solutions. The technique can be adapted to provide solutions in situations characterized by either informative or uninformative prior information.
Tipo: Working or Discussion Paper Palavras-chave: Underdetermined Equation Systems; Maximum Entropy; Bayesian Priors; Structural Estimation; Calibration; Research Methods/ Statistical Methods; C11; C13; C51.
Ano: 2008 URL: http://purl.umn.edu/56973
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A framework to quantify uncertainties of seafloor backscatter from swath mapping echosounders ArchiMer
Malik, Mashkoor; Lurton, Xavier; Mayer, Larry.
Multibeam echosounders (MBES) have become a widely used acoustic remote sensing tool to map and study the seafloor, providing co-located bathymetry and seafloor backscatter. Although the uncertainty associated with MBES-derived bathymetric data has been studied extensively, the question of backscatter uncertainty has been addressed only minimally and hinders the quantitative use of MBES seafloor backscatter. This paper explores approaches to identifying uncertainty sources associated with MBES-derived backscatter measurements. The major sources of uncertainty are catalogued and the magnitudes of their relative contributions to the backscatter uncertainty budget are evaluated. These major uncertainty sources include seafloor insonified area (1–3 dB),...
Tipo: Text Palavras-chave: Multibeam echosounder; Calibration; Incidence angle.
Ano: 2018 URL: https://archimer.ifremer.fr/doc/00429/54018/57435.pdf
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A PROGRAMAÇÃO MATEMÁTICA POSITIVA COMO INSTRUMENTO DE CALIBRAÇÃO E PRESCRIÇÃO DOS MODELOS DE OFERTA AGRÍCOLA AgEcon
Fragoso, Rui Manuel de Sousa; Carvalho, Maria Leonor da Silva; Henriques, Pedro Damiao de Sousa.
Neste artigo avalia-se a capacidade de calibração e de prescrição de resultados de um modelo de oferta agrícola da Região Alentejo. A capacidade de calibração é analisada para o regime de preços e de ajudas agrícolas em vigor no ano 2000, comparando os resultados de diferentes formas de especificação da função dos custos variáveis totais do modelo de programação matemática positiva com os resultados do modelo tradicional de programação linear e com os dados estatísticos observados. Depois de calibrado, o modelo de programação matemática positiva foi utilizado na prescrição dos resultados relativos ao cenário de preços e ajudas em vigor no ano de 2004. Concluiu-se que a programação matemática positiva para além de ser um eficaz instrumento de calibração dos...
Tipo: Conference Paper or Presentation Palavras-chave: Programação matemática positiva; Oferta agrícola; Calibração; Prescrição; Positive mathematical programming; Agricultural supply; Calibration; Prescription; Agribusiness.
Ano: 2008 URL: http://purl.umn.edu/108610
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ABSOLUTE CALIBRATION OF THE ERS-2 SCATTEROMETER IN GYRO-LESS MODE USING TRANSPONDERS Gayana
Manise,Nicolas; Neyt,Xavier; Acheroy,Marc.
The scatterometer on-board ERS-2, earth-observation satellite developed by the European Space Agency, is an active real aperture radar instrument designed to measure the backscatter coefficient 0 from the earth. Its main utility is to measure physical parameters such as wind speeds and directions over the sea surface. Due to malfunctions of the on-board gyroscopes and even though a new attitude and orbit control system is used, the yaw-orientation of the spacecraft still exhibits random variations from the nominal attitude. This unpredictable attitude requires re-developing the calibration chain of the scatterometer instrument. Distributed targets, such as the rain forest, are used to perform a relative calibration while transponders situated at known...
Tipo: Journal article Palavras-chave: Scatterometer; Calibration; Transponder.
Ano: 2004 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382004000300011
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Aggregation and Calibration of Agricultural Sector Models Through Crop Mix Restrictions and Marginal Profit Adjustments AgEcon
Wiborg, Torben; McCarl, Bruce A.; Rasmussen, Svend; Schneider, Uwe A..
All agricultural sector models must deal with aggregation and calibration somehow. The aggregation problem involves treating a group of producers as if they all responded in the same way as a single representative unit. The calibration problem concerns making a model reproduce as closely as possible an empirically observed set of decision maker actions. This paper shows how both calibration and aggregation are addressed through crop mix restrictions combined with marginal profit adjust-ments.
Tipo: Conference Paper or Presentation Palavras-chave: Mathematical programming; Aggregation; Calibration; Crop mix; Marginal cost; Agricultural sector model; Agribusiness; C6; C61; Q1; Q11; Q17; Q18; R12; R13; R14.
Ano: 2005 URL: http://purl.umn.edu/24567
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An Unstructured Numerical Model to Study Wind-Driven Circulation Patterns in a Managed Coastal Mediterranean Wetland: The Vaccares Lagoon System ArchiMer
Boutron, Olivier; Bertrand, Olivier; Fiandrino, Annie; Hoehener, Patrick; Sandoz, Alain; Cherain, Yves; Coulet, Eric; Chauvelon, Philippe.
The spatiotemporal structure of wind-driven circulation patterns and associated water exchanges can drive important bio-hydrodynamic interactions in shallow lagoons. The Vaccares lagoon system is a complex shallow hydrosystem located in the central part of the Rhone Delta (France). It is internationally recognized as part of a biosphere reserve within the framework of UNESCO's Man and Biosphere Programme, and as a RAMSAR site. Due to its frequent occurrence in this area, and considering the shallowness of the Vaccares lagoon system, wind is assumed to play a major role in the hydrodynamic and biological processes. In this study, a hydrodynamic model was developed to investigate the structure of wind-driven circulations in the Vaccares lagoon system, to...
Tipo: Text Palavras-chave: Coastal lagoon; Mathematical model; Hydrodynamics; Calibration; Validation; Wind-driven circulation.
Ano: 2015 URL: http://archimer.ifremer.fr/doc/00303/41382/40558.pdf
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An Updated Geophysical Model for AMSR-E and SSMIS Brightness Temperature Simulations over Oceans ArchiMer
Zabolotskikh, Elizaveta; Mitnik, Leonid; Chapron, Bertrand.
In this study, we considered the geophysical model for microwave brightness temperature (BT) simulation for the Atmosphere-Ocean System under non-precipitating conditions. The model is presented as a combination of atmospheric absorption and ocean emission models. We validated this model for two satellite instruments-for Advanced Microwave Sounding Radiometer-Earth Observing System (AMSR-E) onboard Aqua satellite and for Special Sensor Microwave Imager/Sounder (SSMIS) onboard F16 satellite of Defense Meteorological Satellite Program (DMSP) series. We compared simulated BT values with satellite BT measurements for different combinations of various water vapor and oxygen absorption models and wind induced ocean emission models. A dataset of clear sky...
Tipo: Text Palavras-chave: Calibration; Geophysical model; Numerical simulation; SSMIS; AMSR-E; Satellite passive microwave.
Ano: 2014 URL: http://archimer.ifremer.fr/doc/00190/30101/28628.pdf
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Aplicação de cartas controle para avaliar resultados na verificação de balanças. Repositório Alice
SOUZA, D. R. C. de; MARIN, S. A.; FERRACINI, V. L.; TURUTA, T. B.; OLIVARES, I. B..
Resumo: A carta controle é um tipo de gráfico que pode ser utilizado para monitorar e controlar diversos tipos de análises. Na verificação de balanças o objetivo é monitorar, por meio de gráfico, se não ocorreu nenhum desvio significativo dos valores de massa obtidos no intervalo da calibração, além das tendencias de resultados para tomada de ações preventivas, garantindo a rastreabilidade e confiabilidade dos resultados analíticos. A elaboração, implementação e uso de cartas controle na verificação intermediária de balança analítica no Laboratório de Resíduos e Contaminantes na Embrapa Meio Ambiente, utilizando o programa Microsoft Excel, permite o controle estatístico das características da balança de modo que não se modifique até a próxima calibração,...
Tipo: Artigo em anais de congresso (ALICE) Palavras-chave: Cartas controle; Verificação de balança; Calibração; Calibration.
Ano: 2014 URL: http://www.alice.cnptia.embrapa.br/handle/doc/1007624
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Backscatter calibration of high-frequency multibeam echosounder using a reference single-beam system, on natural seafloor ArchiMer
Eleftherakis, Dimitrios; Berger, Laurent; Le Bouffant, Naig; Pacault, Anne; Augustin, Jean-marie; Lurton, Xavier.
The calibration of multibeam echosounders for backscatter measurements can be conducted efficiently and accurately using data from surveys over a reference natural area, implying appropriate measurements of the local absolute values of backscatter. Such a shallow area (20-m mean depth) has been defined and qualified in the Bay of Brest (France), and chosen as a reference area for multibeam systems operating at 200 and 300 kHz. The absolute reflectivity over the area was measured using a calibrated single-beam fishery echosounder (Simrad EK60) tilted at incidence angles varying between 0° and 60° with a step of 3°. This reference backscatter level is then compared to the average backscatter values obtained by a multibeam echosounder (here a Kongsberg EM...
Tipo: Text Palavras-chave: Calibration; Seafloor backscatter; Multibeam echosounder; Single-beam echosounder.
Ano: 2018 URL: https://archimer.ifremer.fr/doc/00429/54016/57434.pdf
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BANANA CULTIVAR TRIALS FOR FRUIT PRODUCTION, ORNAMENTAL-LANDSCAPE USE, AND ORNAMENTAL-NURSERY PRODUCTION IN SOUTH GEORGIA AgEcon
Fonsah, Esendugue Greg; Krewer, Gerard; Rieger, Mark.
North America is the largest net importer of bananas on a regional basis. The United States is still the world’'s number- one importer and consumer of bananas. U.S. companies spend approximately $1.1 billion each year on banana imports, purchasing 31.1% of total world imports (Fonsah 2002; FAO 2001). Bananas and plantains together have been rated the fourth most important crop in the world in terms of food value and food security. This research is aimed at determining the feasibility and suitability of Annual Cropping Production (ACP) for a niche market under Georgia weather conditions and, determining which cultivars have the greatest potential for ornamental-landscape use and ornamental-nursery production. Phenological and pomological sampling and data...
Tipo: Journal Article Palavras-chave: Banana; Cultivars; Input application; Fertility; Field operations; Production; Marketing; Quality; Landscape; Green industry; Finger length; Calibration; Pseudo-stem; Crop Production/Industries.
Ano: 2004 URL: http://purl.umn.edu/27149
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Benefit Transfer as Preference Calibration AgEcon
Smith, V. Kerry; van Houtven, George; Pattanayak, Subhrendu K..
This paper proposes and illustrates the use of a new approach to benefit transfer for the non-market valuation of environmental resources. It treats transfer as an identification problem that requires assessing whether available benefit estimates permit the parameters of a preference function to be identified. The transfer method proposed uses these identifying restrictions to calibrate preference parameters and bases the benefit estimates on that preference function. The approach is illustrated using travel cost, hedonic and contingent valuation estimates, as well as combinations of estimates. It has three potential advantages over conventional practice: (1) it allows multiple, potentially overlapping estimates of the benefits of an improvement in...
Tipo: Working or Discussion Paper Palavras-chave: Benefit transfer; Calibration; Non-market valuation; Environmental Economics and Policy; D61; Q20; H40.
Ano: 1999 URL: http://purl.umn.edu/10607
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Calibração de pulverizadores terrestres e algumas informações sobre equipamentos para aplicações de defensivos no algodoeiro. Infoteca-e
BELTRÃO, N. E. de M.; ARAUJO, J. D. de..
Cuidados, manutencao e principais componentes dos pulverizadores; Calibracao de pulverizadores; Pulverizadores especiais, modernos, munidos de bicos centrífugos ou de bico incorporado "Boozle" eletrodinamico.
Tipo: Circular Técnica (INFOTECA-E) Palavras-chave: Calibracao; Pulverizadores; Equipamentos; Algodao; Gossypium hirsutum; Calibration; Pulverization; Equipment.
Ano: 1987 URL: http://www.infoteca.cnptia.embrapa.br/handle/doc/262768
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Calibração do medidor de clorofila Minolta SPAD-502 para uso na cultura do milho. Infoteca-e
ZOTARELLI, L.; CARDOSO, E. G.; PICCININ, J. L.; URQUIAGA, S.; BODDEY, R. M.; TORRES, E.; ALVES, B. J. R..
2002
Tipo: Comunicado Técnico (INFOTECA-E) Palavras-chave: Milho; Clorofila; Pigmento; Calibração; Medição; Fotossíntese; Maize; Pigments; Calibration; Photosynthesis.
Ano: 2002 URL: http://www.infoteca.cnptia.embrapa.br/handle/doc/624249
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Calibrating Online Survey Sample for Economic Impact Analysis AgEcon
Devkota, Nirmala; Paudel, Krishna P.; Fannin, James Matthew; Hall, Larry M.; Caffey, Rex H..
Online surveys have emerged as low-cost data collection approach in empirical researches; however, the validity of data remains questionable. Therefore, we employed a stochastic frontier estimation method to calibrate online recreational expenditure. Study results suggested the presence of inefficiency on online surveys. Analysis was extended to estimate economic impact of nature based recreation on a local economy.
Tipo: Conference Paper or Presentation Palavras-chave: Calibration; Online survey; Onsite survey; Stochastic frontier approach; Research Methods/ Statistical Methods; Resource /Energy Economics and Policy.
Ano: 2007 URL: http://purl.umn.edu/34997
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Calibration and Validation of SWAT for the Upper Maquoketa River Watershed AgEcon
Kanwar, Ramesh S.; Reungsang, Pipat; Jha, Manoj K.; Gassman, Philip W.; Ahmad, Khalil; Saleh, Ali.
A validation study has been performed using the Soil and Water Assessment Tool (SWAT) model with data collected for the Upper Maquoketa River Watershed (UMRW), which drains over 16,000 ha in northeast Iowa. This validation assessment builds on a previous study with nested modeling for the UMRW that required both the Agricultural Policy EXtender (APEX) model and SWAT. In the nested modeling approach, edge-of-field flows and pollutant load estimates were generated for manure application fields with APEX and were then subsequently routed to the watershed outlet in SWAT, along with flows and pollutant loadings estimated for the rest of the watershed routed to the watershed outlet. In the current study, the entire UMRW cropland area was simulated in SWAT, which...
Tipo: Working or Discussion Paper Palavras-chave: Calibration; Modeling; Nitrate; SWAT; Validation; Water quality; Resource /Energy Economics and Policy.
Ano: 2005 URL: http://purl.umn.edu/18440
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Can Calibration Reconcile Stated and Observed Preferences? AgEcon
Norwood, F. Bailey.
Hypothetical bias is a pervasive problem in stated-preference experiments. Recent research has developed two empirically successful calibrations to remove hypothetical bias, though the calibrations have not been tested using the same data or in a conjoint analysis. This study compares the two calibrations in a conjoint analysis involving donations to a public good. Results find the calibrations are biased predictors of true donations but that calibrated and uncalibrated models together provide upper and lower bounds to true donations.
Tipo: Journal Article Palavras-chave: Calibration; Experimental economics; Forecasting; Hypothetical bias; Public goods; Stated preference; Voluntary contributions; Research Methods/ Statistical Methods; Q51; H41.
Ano: 2005 URL: http://purl.umn.edu/43735
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Comparison of clumped isotope signatures of dolomite cements to fluid inclusion thermometry in the temperature range of 73 to 176 °C ArchiMer
Came, Rosemarie E.; Azmy, Karem; Tripati, Aradhna; Olanipekun, Babatunde-john.
Widespread application of the novel clumped isotope paleothermometer (Δ47) using dolomite samples from shallow crustal settings has been hindered by a lack of adequate constraints on clumped isotope systematics in dolomites that formed at temperatures greater than 50 °C. Consequently, many high-temperature applications involving diagenetic dolomites have required an assumption that the relationship between temperature and Δ47 in diagenetic dolomite resembles the theoretical temperature dependence for calcite. Here we present Δ47 results from dolomite cements for which precipitation temperatures were determined independently using fluid inclusion microthermometry. We compare a rock-based “calibration” for samples from the temperature range of ∼73 to 176 °C...
Tipo: Text Palavras-chave: Clumped isotopes; Dolomite; Calibration.
Ano: 2017 URL: http://archimer.ifremer.fr/doc/00357/46791/46657.pdf
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Control of the repeatability of high frequency multibeam echosounder backscatter by using natural reference areas ArchiMer
Roche, Marc; Degrendele, Koen; Vrignaud, Christophe; Loyer, Sophie; Le Bas, Tim; Augustin, Jean-marie; Lurton, Xavier.
The increased use of backscatter measurements in time series for environmental monitoring necessitates the comparability of individual results. With the current lack of pre-calibrated multibeam echosounder systems for absolute backscatter measurement, a pragmatic solution is the use of natural reference areas for ensuring regular assessment of the backscatter measurement repeatability. This method mainly relies on the assumption of a sufficiently stable reference area regarding its backscatter signature. The aptitude of a natural area to provide a stable and uniform backscatter response must be carefully considered and demonstrated by a sufficiently long time-series of measurements. Furthermore, this approach requires a strict control of the acquisition...
Tipo: Text Palavras-chave: Multibeam echosounder; Seafloor backscatter; Repeatability; Calibration; Reference area; Monitoring.
Ano: 2018 URL: http://archimer.ifremer.fr/doc/00422/53384/54234.pdf
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Development of deficit irrigation for maize crop under drip irrigation in samaru-nigeria CIGR Journal
Ezekiel, Oiganji.
In the past, outcome of any water management strategy could only be known after field experiment, in recent times, means of evaluating the implications of irrigation schedules without field experiment is fast gaining grounds with the use of models.  This research work present a scenarios studies for different developed irrigation scheduling options for a drip irrigated maize crop at the Institute for Agricultural Research (IAR) irrigation farm Samaru-Nigeria during 2013 and 2014 cropping season using a computer-based model.  Aqua Crop was calibrated and validated with data obtained from the field, it was further used to generate scenario of different irrigation scheduling outcome. Grain and biomass yields, harvest index, seasonal evapotranspiration and...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Agricultural Engineering/ soil and water conservation engineering Aqua Crop model; Calibration; Validation; Irrigation schedulling; Water productivity.
Ano: 2017 URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/3752
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