Sabiia Seb
PortuguêsEspañolEnglish
Embrapa
        Busca avançada

Botão Atualizar


Botão Atualizar

Ordenar por: RelevânciaAutorTítuloAnoImprime registros no formato resumido
Registros recuperados: 15
Primeira ... 1 ... Última
Imagem não selecionada

Imprime registro no formato completo
A REPRESENTATIVE FARM APPROACH TO OUTREACH WITH BEGINNING FARMERS AND RANCHERS AgEcon
Zimmel, Peter; Wilcox, Lori.
Tipo: Journal Article Palavras-chave: Beginning Farmers and Ranchers; Representative Farm; Whole Farm Analysis; Risk Management; Online Decision Support; Stochastic; Baseline; Farm Management; Teaching/Communication/Extension/Profession; Q12; Q14; D81.
Ano: 2011 URL: http://purl.umn.edu/109477
Imagem não selecionada

Imprime registro no formato completo
A stochastic viability approach to ecosystem-based fisheries management ArchiMer
Doyen, Luc; Thebaud, Olivier; Bene, Christopher; Martinet, V.; Gourguet, S.; Bertignac, Michel; Fifas, Spyros; Blanchard, Fabian.
Academia and management agencies show a growing interest for ecosystem-based fishery management (EBFM). However, the way to operationalize this approach remains challenging. The present paper illustrates how the concepts of stochastic co-viability, which accounts for dynamic complexities, uncertainties, risk and sustainability constraints, can be useful for the implementation of EBFM. In the present case, this concept is used to identify fishing strategies that satisfy both ecological conservation and economic sustainability in a multi-species, multi-fleet context. Economic Viability Analysis (EVA) and the broader Co-Viability Analysis (CVA), are proposed to expand the usual Population Viability Analysis (PVA) and precautionary approach. An illustration is...
Tipo: Text Palavras-chave: Ecosystem based fisheries management; Viability; Stochastic; Nephrops; Hake.
Ano: 2012 URL: http://archimer.ifremer.fr/doc/00074/18571/16153.pdf
Imagem não selecionada

Imprime registro no formato completo
Biological control of invasive plant species: stochastic economic analysis AgEcon
Chalak-Haghighi, Morteza; Ruijs, Arjan; van Ierland, Ekko C..
We analysed to what extent the stochastic effects of two biological control agents (i.e. weevils and mycoherbicides) affect the optimal choice of Californian thistle control. A stochastic, dynamic optimisation model was set up to analyse strategies that maximise the expected net present values. We analysed the cost-effective strategies to control the thistle for deterministic and stochastic cases. Results show that the stochasticity of the efficacy of weevils does not affect the optimal strategy. Compared to the deterministic case, however, mycoherbicides will be introduced at a higher level of weed density if we take the stochastic effect of mycoherbicides into account.
Tipo: Conference Paper or Presentation Palavras-chave: Stochastic; Optimisation; Biological control; Californian thistle; Economics..
Ano: 2009 URL: http://purl.umn.edu/48153
Imagem não selecionada

Imprime registro no formato completo
Calculating Cost Savings Per Acre When Harvest Days are Stochastic AgEcon
Farrell, Matthew; Ibendahl, Gregory A..
New cotton harvesters have been introduced that have higher performance rate as well as eliminate extra labor and accompanying equipment. The new machines build partial modules on board the harvester. Higher field efficiency (performance rate) lets a farmers harvest his cotton in a shorter period. Precipitation causes cotton losses in both quality and quantity of the cotton. This paper seeks to measure cost per acre when harvest days are stochastic by using historic precipitation data. Cost per acre will include the cost of losses from a loss function from precipitation. Cost per acre will be adjusted for conventional versus new technology by quantifying the losses that contribute to extra costs of extended harvesting.
Tipo: Conference Paper or Presentation Palavras-chave: Cotton; Harvester; Fieldwork days; Stochastic; Cost per acre; Agribusiness; Farm Management.
Ano: 2010 URL: http://purl.umn.edu/56507
Imagem não selecionada

Imprime registro no formato completo
Economics of controlling a spreading environmental weed AgEcon
Chalak-Haghighi, Morteza; Pannell, David J..
Weeds can cause significant problems to natural ecosystems. Although there have been numerous studies on the economics of weed control, relatively few of these studies have focused on natural ecosystems. This paper addresses this gap in the literature by assessing the cost-effectiveness of a comprehensive range of control strategies for blackberry (Rubus anglocandicans) in natural environments in Australia. We developed a stochastic dynamic simulation model and a deterministic dynamic optimisation model. The stochastic model calculates the expected net present value (NPV) of a range of control strategies, including any combination of treatment options. The optimisation model identifies the treatment combination that maximises NPV. Both models represent the...
Tipo: Conference Paper or Presentation Palavras-chave: Environment; Economics; Weed; Stochastic; Optimisation; Management; Environmental Economics and Policy.
Ano: 2010 URL: http://purl.umn.edu/58886
Imagem não selecionada

Imprime registro no formato completo
Economics of controlling a spreading environmental weed AgEcon
Chalak, Morteza; Pannell, David J..
Weeds can cause significant problems to natural ecosystems. Although there have been numerous studies on the economics of weed control, relatively few of these studies have focused on natural ecosystems. This paper addresses this gap in the literature by assessing the cost-effectiveness of a comprehensive range of control strategies for blackberry (Rubus anglocandicans) in natural environments in Australia. We developed a stochastic dynamic simulation model and a deterministic dynamic optimisation model. The stochastic model calculates the expected net present value (NPV) of a range of control strategies, including any combination of treatment options. The optimisation model identifies the treatment combination that maximises NPV. Both models represent the...
Tipo: Working or Discussion Paper Palavras-chave: Environment; Economics; Weed; Stochastic; Optimisation; Management; Environmental Economics and Policy.
Ano: 2011 URL: http://purl.umn.edu/108416
Imagem não selecionada

Imprime registro no formato completo
Economics of controlling invasive species: a stochastic optimisation model for a spatial-dynamic process AgEcon
Chalak, Morteza; Pannell, David J.; Polyakov, Maksym.
Invasive species are significant threats to biodiversity, natural ecosystems and agriculture leading to large worldwide economic and environmental damage. Spread and control of invasive species are stochastic processes with important spatial dimensions. Most economic studies of invasive species control ignore spatial and stochastic aspects. This paper covers this gap in the previous studies by analysing a spatially explicit dynamic process of controlling invasive species in a stochastic setting. We show how stochasticity, spatial location of infestation and control can influence the spread, control efficiency and optimal control strategies. The main aim of this paper is to analyse the relationship between economic parameters and stochastic spatial...
Tipo: Conference Paper or Presentation Palavras-chave: Spatial; Dynamics; Invasive; Economics; Stochastic; Optimisation; Environmental Economics and Policy.
Ano: 2011 URL: http://purl.umn.edu/103325
Imagem não selecionada

Imprime registro no formato completo
International Rice Baseline with Deterministic and Stochastic Projections, 2012-2021 AgEcon
Wailes, Eric J.; Chavez, Eddie C..
This publication contains recent baseline projections from the Arkansas Global Rice Economics Program (AGREP) for U.S. and international rice economies. These projections serve as a baseline for evaluating and comparing alternative macroeconomic, policy, weather, and technological scenarios. They are intended for use by government agencies and officials, farmers, consumers, agribusinesses and others who conduct medium-range and long-term planning. The AGREP baseline projections are grounded in a series of assumptions about the general economy, agricultural policies, weather, and technological change. It is generally assumed that current agricultural policies will be continued in the United States and other countries reported in this study. The AGREP World...
Tipo: Technical Report Palavras-chave: International rice; Baseline; Policy; Deterministic; Stochastic; Arkansas Global Rice Model; Demand and Price Analysis; Land Economics/Use; C02; F01; F14; F17; Q17; Q18; R11.
Ano: 2012 URL: http://purl.umn.edu/123203
Imagem não selecionada

Imprime registro no formato completo
Measuring the Stochastic Monetary Benefits of Multiple Inlet Irrigation in Arkansas Rice Production AgEcon
Watkins, K. Bradley; Hristovska, Tatjana; Anders, Merle M..
Irrigation fuel costs represent a significant portion of rice production expenses. Multiple inlet (MI) irrigation represents a water saving alternative to conventional flood irrigation. This study uses simulation to calculate the range of monetary benefits to MI in rice production. Water savings from MI relative to conventional flood irrigation along with rice yields, rice prices, and prices for key production inputs (diesel and fertilizer) are simulated, and stochastic rice net returns above variable and fixed expenses are calculated for different pump lifts with and without MI. Monetary benefits to MI are measured as the difference in net returns with and without MI. The results indicate MI monetary benefits depend greatly on pump lift and the presence...
Tipo: Presentation Palavras-chave: Cost; Cumulative distribution functions; Multiple inlet irrigation; Net return; Rice; Stochastic; Farm Management.
Ano: 2012 URL: http://purl.umn.edu/119655
Imagem não selecionada

Imprime registro no formato completo
Optimal control of a stochastic biological invasion AgEcon
Chalak, Morteza; Pannell, David J..
Although there have been numerous studies on the economics of weed control, relatively few of these studies have focused on natural ecosystems. The aims of this papers are: A) to identify the combination of control options that is optimal for blackberry (Rubus anglocandicans) in Australian natural ecosystems, B) to assess whether an integrated control strategy is superior to chemical-only strategies, C) to evaluate the economic net benefits of specific biologically oriented control methods (a rust and grazing by goats), D) to determine how changes in model parameters affect the optimal control strategy. To address these aims, a stochastic dynamic simulation model and a stochastic dynamic programming model are developed. The results indicate that, while an...
Tipo: Presentation Palavras-chave: Environment; Economics; Weed; Stochastic; Optimisation; Management; Environmental Economics and Policy.
Ano: 2012 URL: http://purl.umn.edu/124373
Imagem não selecionada

Imprime registro no formato completo
Simulated Analysis of Drought's Impact on Different Cow-Calf Production Systems AgEcon
Stockton, Matthew C.; Wilson, Roger K..
Five representative firm level stochastic simulation models were constructed using historical production cost, cattle prices, weather information and scientifically collected production data from the Gundmendson Sandhills Laboratory operated by University of Nebraska. The five hundred iterative results indicate inclusion of crop residual grazing as a viable drought mitigation tool.
Tipo: Conference Paper or Presentation Palavras-chave: Drought Mitigation; Firm Level; Residual Grazing; Simulation; Stochastic; Livestock Production/Industries.
Ano: 2007 URL: http://purl.umn.edu/34981
Imagem não selecionada

Imprime registro no formato completo
THE QUEUING THEORETIC APPROACH TO GROUNDWATER MANAGEMENT AgEcon
Batabyal, Amitrajeet A..
In this paper I propose and develop a new framework for modeling groundwater management issues. Specifically, I apply the methods of queuing theory—for the first time, to the best of my knowledge—to model a groundwater management problem from a long-run perspective. I characterize two simple management regimes as two different kinds of queues and then show how to pose a manager's decision problem as an optimization problem using queuing theoretic techniques. I solve for certain fundamental quantities, such as the expected system size, and then discuss the economic meaning and relevance of the queuing concepts being used. I close by discussing possible extensions to my basic models. Published in Ecological Modelling 85 (2-3, 1996):219-27.
Tipo: Working or Discussion Paper Palavras-chave: Groundwater; Management; Stochastic; Queuing; Theory; Resource /Energy Economics and Policy.
Ano: 1995 URL: http://purl.umn.edu/28349
Imagem não selecionada

Imprime registro no formato completo
VALUE OF SOCIAL CAPITAL TO MID-SIZED NORTHERN PLAINS FARMS AgEcon
Gustafson, Cole R..
As farms increase in size, operators often face the difficult decision of remaining loyal to local merchants or obtaining volume discounts from more distant input suppliers. When farmers bypass local merchants and buy inputs in volume from a wholesaler, they often realize a price discount but forego many services including credit forebearance. In essence, when farmers buy locally, they pay higher prices, which decreases profits and increases financial risk, but generates social capital which can be drawn upon during periods of economic adversity later in the form of credit forebearance. A theoretical model of farm financial risk evaluates borrower behavior in light of cash flow constraints, volume discounts, and social capital. Monte-carlo simulation...
Tipo: Working or Discussion Paper Palavras-chave: Social; Capital; Financial risk; Simulation; Stochastic; Farm Management; Institutional and Behavioral Economics.
Ano: 2004 URL: http://purl.umn.edu/23677
Imagem não selecionada

Imprime registro no formato completo
VALUE OF SOCIAL CAPITAL TO MID-SIZED NORTHERN PLAINS FARMS AgEcon
Gustafson, Cole R..
As farms increase in size, operators face the decision of remaining loyal to local merchants or obtaining volume discounts from distant input suppliers. When farmers bypass local merchants and buy inputs in volume, they often realize price discounts but forego many services including credit forebearance. When farmers buy locally, they pay higher prices, which decreases profits and increases financial risk, but generates social capital which can be drawn upon during periods of economic adversity. A theoretical model of farm financial risk evaluates borrower behavior in light of cash flow constraints, volume discounts, and social capital. Results delineate financial risks involved and value of social capital.
Tipo: Conference Paper or Presentation Palavras-chave: Capital; Financial risk; Simulation; Social; Stochastic; Agricultural Finance.
Ano: 2005 URL: http://purl.umn.edu/19169
Imagem não selecionada

Imprime registro no formato completo
蓮霧農場技術效率之分析 Taiwan Agricultural Research Institute
楊世華; 陳唐平; 潘德芳; Shi-Hua Yang; Tarng-Ping Chen; Te-Fang Pan.
[[abstract]]本研究的目的係利用最大概似半常態隨機性生產邊界函數,衡量47個蓮霧農場的技術效率值,並探討農場間技術效率差異的因素。研究結果發現:Translog隨機性生產邊界函數較 Cobb-Douglas 函數適合於蓮霧生產型態。依Trandlog函數之估計結果,蓮霧農場之生產彈性平均值,以勞動投入之0.5852為最大,資本費之0.5072次之,種植面積之0.0565為最小。其規模報酬值為1.1489,表示蓮霧農場之生產具有規模報酬遞增之特性。因λ值(組合誤差比例)為1.06,顯示在蓮霧農場間的生產誤差,人為的技術效率誤差稍大。整體而言,蓮霧生產之技術效率平均值為0.8715,顯示其技術效率距離完全技術效率之邊界尚差12.85%,表示個別農場之技術效率尚有提升之空間。在技術效率之影響因素方面,發現農場主教育水準較高、每株蓮霧產量較多、蓮霧銷售價格較高及每一勞動管理面積較大,有助於蓮霧生產技術效率的提升;是以要提高蓮霧農場的技術效率,農場主宜多參加相關講習訓練,吸收新知及新技術,加強種植技術、管理能力及生產因素之使用組合,有效利用人力資源,使蓮霧品質提高,並做好產品分級包裝及品牌行銷等工作。
Palavras-chave: 蓮霧 技術效率 隨機性 邊界生產函數 Translog函數 Wax apples; Technical efficiency; Stochastic; Frontier production function; Translog function [[classification]]12.
Ano: 2000
Registros recuperados: 15
Primeira ... 1 ... Última
 

Empresa Brasileira de Pesquisa Agropecuária - Embrapa
Todos os direitos reservados, conforme Lei n° 9.610
Política de Privacidade
Área restrita

Embrapa
Parque Estação Biológica - PqEB s/n°
Brasília, DF - Brasil - CEP 70770-901
Fone: (61) 3448-4433 - Fax: (61) 3448-4890 / 3448-4891 SAC: https://www.embrapa.br/fale-conosco

Valid HTML 4.01 Transitional