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	Provedor de dados AGRIAMBI (2) Autor Lima,José M. de (2) Lopes,Diego (2) Mello,Carlos R. de (2) Ferreira,Daniel F. (1) Oliveira,Geraldo C. de (1) Silva,Antônio M. da (1) Mais... Palavra-chave Bacia efêmera (1) Curva característica (1) Escoamento superficial (1) Irrigação (1) Modelo hidrológico (1) Método CN (1) Umidade do solo (1) Mais... Tipo do documento Info:eu-repo/semantics/article (2) Ano 2005 (1) 2003 (1) País Brazil (2) Idioma Português (2)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 24 Primeira ... 1 2 ... Última Designs and model effects definitions in the initial stage of a plant breeding program PAB Souza,Emanuel Fernando Maia de; Peternelli,Luiz Alexandre; Barbosa,Márcio Henrique Pereira. The objective of this work was to compare the relative efficiency of initial selection and genetic parameter estimation, using augmented blocks design (ABD), augmented blocks twice replicated design (DABD) and group of randomised block design experiments with common treatments (ERBCT), by simulations, considering fixed effect model and mixed model with regular treatment effects as random. For the simulations, eight different conditions (scenarios) were considered. From the 600 simulations in each scenario, the mean percentage selection coincidence, the Pearsons´s correlation estimates between adjusted means for the fixed effects model, and the heritability estimates for the mixed model were evaluated. DABD and ERBCT were very similar in their comparisons... Tipo: Info:eu-repo/semantics/article Palavras-chave: Augmented design; Incomplete block; Selection; Heritability; Sugarcane; Stochastic simulation. Ano: 2006 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2006000300001 Wetterderivate: Ein Instrument im Risikomanagement für die Landwirtschaft? AgEcon Berg, Ernst; Schmitz, Bernhard; Starp, Michael; Trenkel, Hermann. The risks associated with farming activities are likely to increase in the future. It, therefore, appears worthwhile to analyse new risk management instruments. This paper investigates weather derivatives for which a market has already emerged in the USA. Contrary to traditional financial derivatives, their payoff is determined by future weather events, such as temperature or precipitation. Thus, they hedge risks which result from climate. Since they address production risks they are complementary to instruments that hedge price risks, such as future markets. The objective of the paper is to evaluate the economic impacts of weather derivatives and to assess their potential as farm level instruments of risk management. After outlining the main... Tipo: Journal Article Palavras-chave: Weather derivatives; Weather risk; Risk management; Stochastic simulation; Financial Economics; Risk and Uncertainty. Ano: 2005 URL: http://purl.umn.edu/97213 ESTIMATING PRICE VARIABILITY IN AGRICULTURE: IMPLICATIONS FOR DECISION MAKERS AgEcon Ray, Daryll E.; Richardson, James W.; Torre Ugarte, Daniel de la; Tiller, Kelly. Using a stochastic version of the POLYSYS modeling framework, an examination of projected variability in agricultural prices, supply, demand, stocks, and incomes is conducted for corn, wheat, soybeans, and cotton during the 1998-2006 period. Increased planting flexibility introduced in the 1996 farm bill results in projections of significantly higher planted acreage variability compared to recent historical levels. Variability of ending stocks and stock-to-use ratios is projected to be higher for corn and soybeans and lower for wheat and cotton compared to the 1986-96 period. Significantly higher variability is projected for corn prices, with wheat and soybean prices also being more variable. No significant change in cotton price variability is projected. Tipo: Journal Article Palavras-chave: POLYSYS model; Price variability; Stochastic simulation; Crop Production/Industries. Ano: 1998 URL: http://purl.umn.edu/15100 ESTIMATED IMPACT OF NON-PRICE COORDINATION OF FED CATTLE PURCHASES ON MEAT PACKER PROCESSING COSTS AgEcon Anderson, John D.; Trapp, James N.. Stochastic simulation of daily slaughter level was used in conjunction with estimated packing plant cost curves to assess potential reductions in processing costs due to improved vertical coordination between feedlots and packing plants. Results indicate that processing cost reductions of $1 to $5 per head are possible. Tipo: Conference Paper or Presentation Palavras-chave: Fed cattle; Processing cost; Stochastic simulation; Vertical coordination; Agribusiness; Livestock Production/Industries. Ano: 1999 URL: http://purl.umn.edu/21703 Are The Poverty Effects of Trade Policies Invisible? AgEcon Verma, Monika; Valenzuela, Ernesto; Hertel, Thomas W.. With the advent of the WTO’s Doha Development Agenda, as well as the Millennium Development Goals aiming to reduce poverty by 50 percent by 2015, poverty impacts of trade reforms have attracted increasing attention. This has been particularly true of agricultural trade reform due to the importance of food in the diets of the poor, relatively higher protection in agriculture, as well as the heavy concentration of global poverty in rural areas where agriculture is the main source of income. Yet some in this debate have argued that, given the extreme volatility in agricultural commodity markets, the additional price and poverty impacts due to trade liberalization might well be undetectable. This paper formally tests this “invisibility hypothesis” via... Tipo: Conference Paper or Presentation Palavras-chave: Trade policy reform; Agricultural trade; Computable general equilibrium; Developing countries; Poverty headcount; Volatility; Stochastic simulation; Non-parametric hypothesis testing; Financial Economics; Risk and Uncertainty; C68; F17; I32; Q17; R20. Ano: 2010 URL: http://purl.umn.edu/61793 THE IMPACTS OF U.S. COTTON PROGRAMS ON THE WEST AND CENTRAL AFRICAN COUNTRIES COTTON EXPORT EARNINGS AgEcon Fadiga, Mohamadou L.; Mohanty, Samarendu; Pan, Suwen. This study uses a stochastic simulation approach based on a partial equilibrium structural econometric model of the world fiber market to examine the effects of a removal of U.S. cotton programs on the world market. The effects on world cotton prices and African export earnings were analyzed. The results suggest that on average an elimination of U.S. cotton programs would lead to a marginal increase in the world cotton prices thus resulting in minimal gain for cotton exporting countries in Africa. Tipo: Conference Paper or Presentation Palavras-chave: Stochastic simulation; Partial equilibrium model; United States; Africa; Cotton subsidies; Export earnings; Agricultural and Food Policy; Crop Production/Industries; Q11; Q17. Ano: 2004 URL: http://purl.umn.edu/20312 Controlling Ozone and Fine Particulates: Cost Benefit Analysis with Meteorological Variability AgEcon Shih, Jhih-Shyang; Bergin, Michelle S.; Krupnick, Alan J.; Russell, Armistead G.. In this paper, we develop an integrated cost-benefit analysis framework for ozone and fine particulate control, accounting for variability and uncertainty. The framework includes air quality simulation, sensitivity analysis, stochastic multi-objective air quality management, and stochastic cost-benefit analysis. This paper has two major contributions. The first is the development of stochastic source-receptor (S-R) coefficient matrices for ozone and fine particulate matter using an advanced air quality simulation model (URM-1ATM) and an efficient sensitivity algorithm (DDM-3D). The second is a demonstration of this framework for alternative ozone and PM2.5 reduction policies. Alternative objectives of the stochastic air quality management model include... Tipo: Working or Discussion Paper Palavras-chave: Ambient air; Ozone; Particulate matter; Risk management; Public policy; Cost-benefit analysis; Variability and uncertainty; Stochastic simulation; Stochastic multi-objective programming; Decision-making; National Ambient Air Quality Standards; Environmental Economics and Policy; C6; Q2; Q25; Q28. Ano: 2003 URL: http://purl.umn.edu/10735 Investment planning under uncertainty and flexibility: the case of a purchasable sales contract AgEcon Musshoff, Oliver; Hirschauer, Norbert. Investment decisions are not only characterised by irreversibility and uncertainty but also by flexibility with regard to the timing of the investment. This paper describes how stochastic simulation can be successfully integrated into a backward recursive programming approach in the context of flexible investment planning. We apply this hybrid approach to a marketing question from primary production which can be viewed as an investment problem: should grain farmers purchase sales contracts which guarantee fixed product prices over the next 10 years? The model results support the conclusion from dynamic investment theory that it is essential to take simultaneously account of uncertainty and flexibility. Tipo: Journal Article Palavras-chave: Dynamic programming; Flexibility; Investment; Sales contract; Stochastic simulation; Uncertainty; Agricultural Finance; Risk and Uncertainty. Ano: 2008 URL: http://purl.umn.edu/117741 An Economic Analysis of No-Till Rotations and Effects on Carbon Sequestration and Long Term Sustainability of Agriculture AgEcon Janssen, Larry; Harer, Justin. This study summarizes key economic results from 100 different no-till (NT) crop rotations and a conventional (CT) corn-soybean rotation based on agronomic data from Brookings County, South Dakota for 2001 -2008. A 1200 acre model crop farm was constructed to conduct the farm management budget and simulation analyses. Results indicate: (1) the CT rotation had the highest average net returns, (2) Several four-crop no-till rotations were preferred as producer risk aversion increased, and (3) carbon credit payments would need to be $14 to $36 per acre for the top four NT rotations to be as profitable as the CT rotation. Tipo: Conference Paper or Presentation Palavras-chave: No-till crop systems; Stochastic simulation; Carbon Credit Payments; Farm Management; Production Economics; Q12. Ano: 2010 URL: http://purl.umn.edu/61176 Mitigating the impact of El Nino-related drought on smallholder farmers in Central Sulawesi, Indonesia: An interdisciplinary modelling approach combining linear programming with stochastic simulation AgEcon Keil, Alwin; Teufel, Nils; Gunawan, Dodo; Leemhuis, Constanze. Crop production in the tropics is subject to considerable climate variability caused by the El Niño-Southern Oscillation (ENSO) phenomenon. In Southeast Asia, El Niño causes comparatively dry conditions leading to substantial declines of crop yields with severe consequences for the welfare of local farm households. Using a modelling approach that combines regression analysis with linear programming and stochastic simulation, and integrates climatic and hydrologic modelling results, the objective of this paper is to assess the impact of El Niño on agricultural incomes of smallholder farmers in Central Sulawesi, Indonesia, and to identify suitable crop management strategies to mitigate the income depressions. The results contribute to the formulation of... Tipo: Conference Paper or Presentation Palavras-chave: ENSO; Risk management; Linear programming; Stochastic simulation; Indonesia; Farm Management. Ano: 2007 URL: http://purl.umn.edu/7942 Die Berücksichtigung von Unsicherheit und Flexibilität in der Investitionsplanung – dargestellt am Beispiel einer Vertragsinvestition für Roggen AgEcon Musshoff, Oliver; Hirschauer, Norbert. Investment decisions are, as a rule, characterized by uncertainty, irreversibility and flexibility. Simple net present value calculations will not account for these features. In many situations even flexible investment planning with decision trees, which represents the most advanced method of traditional investment appraisal, does not have the capacity to solve practical decision problems adequately. One handicap is a realistic and manageable representation of stochastic variables. It has long been known that stochastic simulation procedures offer a nearly unlimited capacity to represent distributions and stochastic processes. However, a standard simulation will not allow for the consideration of flexibility. The problem is that with a simple forward... Tipo: Journal Article Palavras-chave: Investment; Uncertainty; Flexibility; Stochastic simulation; Dynamic programming; Sales contracts with fixed prices; Farm Management; Research Methods/ Statistical Methods; Risk and Uncertainty. Ano: 2004 URL: http://purl.umn.edu/97437 Comparison of Risk Between Cropping Systems in Eastern Norway AgEcon Lien, Gudbrand D.; Flaten, Ola; Schumann, Keith D.; Richardson, James W.; Korsaeth, Audun; Eltun, Ragnar. The aim of this study was to compare production and policy risk of organic, integrated and conventional cropping systems in Norway. Experimental cropping system data (1991-1999) from eastern Norway were combined with budgeted data. Empirical distributions of total farm income for different cropping systems were estimated with a simulation model that uses a multivariate kernel density function to smooth the limited experimental data. Stochastic efficiency with respect to a function (SERF) was used to rank the cropping systems for farmers with various risk aversion levels. The results show that the organic system had the greatest net farm income variability, but the existing payment system and organic price premiums makes it the most economically viable... Tipo: Conference Paper or Presentation Palavras-chave: Organic; Integrated and conventional crop farming; Stochastic simulation; Multivariate kernel estimator; Risk aversion; Stochastic efficiency with respect to a function; Crop Production/Industries; Risk and Uncertainty; Q12; C44. Ano: 2005 URL: http://purl.umn.edu/24663 A Stochastic Analysis of Proposals for the New US Farm Bill AgEcon Binfield, Julian C.R.; Adams, Gary M.; Westhoff, Patrick C.; Young, Robert E., II. Most of the large scale modeling systems used in the analysis of agricultural policies produce deterministic projections. In reality, however, the agricultural sector is subject to a high degree of uncertainty as a result of fluctuations in exogenous factors such as the weather or macroeconomic variation. A stochastic approach can provide additional information to policy makers regarding the implications of this uncertainty, through the use of stochastically generated projections. This paper also shows how deterministic analysis may result in systematic errors in the projection of some variables. As an applied example, the FAPRI model of the US agricultural sector is simulated stochastically to analyse the impact of proposals for the new US farm bill. Tipo: Conference Paper or Presentation Palavras-chave: Stochastic simulation; US Farm Bill; Policy analysis; Agricultural and Food Policy. Ano: 2002 URL: http://purl.umn.edu/24913 Input-Output Analysis with Public Policy Objectives: A Case Study of the Georgia Cotton Industry AgEcon Flanders, Archie; Smith, Nathan B.; McKissick, John C.. Farm bill legislation directed at agricultural commodities contributes to economies of rural areas. This research quantifies the economic impacts of the Georgia cotton industry for the U.S. economy. A cotton industry model with cotton and peanut acreage is utilized with IMPLAN to estimate impacts. The Georgia cotton industry creates 4% more tax revenues for federal, state, and local governments than it receives in commodity support payments. Stochastic simulation analysis indicates that the Georgia cotton industry is not likely to remain viable without government payments. Tipo: Journal Article Palavras-chave: Economic impact; FSRI; IMPLAN; Industry model; Multivariate empirical distribution; Simetar; Social welfare analysis; Stochastic simulation; Agribusiness; Research and Development/Tech Change/Emerging Technologies. Ano: 2006 URL: http://purl.umn.edu/62279 Including Risk in Economic Feasibility Analyses: The Case of Ethanol Production in Texas AgEcon Richardson, James W.; Herbst, Brian K.; Outlaw, Joe L.; Gill, Robert Chope, II. The widespread use of personal computers and spreadsheet models for feasibility studies makes risk-based Monte Carlo simulation analysis of proposed investments a relatively simple task. Add-in simulation packages for Microsoft® Excel can be used to make spreadsheet models stochastic. Rather than basing investment decisions on point estimates, investors can easily estimate the implied distributions of returns for uncertain investments and calculate the risk of an investment as well as the probability of success. The benefits of using Monte Carlo simulation to analyze a risky investment are demonstrated using an ethanol plant as an example. Tipo: Journal Article Palavras-chave: Economic feasibility analysis; Ethanol feasibility; Risk management; Stochastic simulation; Agribusiness; Research and Development/Tech Change/Emerging Technologies. Ano: 2007 URL: http://purl.umn.edu/62291 Stochastic Optimization: An Application to Sub-Arctic Dairy Farming AgEcon Asheim, Leif Jarle; Richardson, James W.; Schumann, Keith D.; Feldman, Paul A.. The paper demonstrates how a deterministic farm linear programming (LP) model can be made stochastic and simulated using Solver and Simetar© in Excel©. The demonstration is conducted with an LP-model for a dairy farm for a sub arctic region of Norway. The income risks arising from variation in milk and crop yields due to winter damage in leys and pastures have been quantified for farms demonstrating low, medium and high forage yield risk. The estimated distribution of farm profit will be skewed to the left, indicating a downside risk. In the presence of risks, farmers maximize income by producing the milk quota with using surplus forage for meat production. The analysis demonstrated here may assist farmers and farm managers in improving sensitivity... Tipo: Conference Paper or Presentation Palavras-chave: Dairy production; Northern Norway; Stochastic optimization; Stochastic simulation; Yield risks; Livestock Production/Industries. Ano: 2005 URL: http://purl.umn.edu/24253 Protecting Your Turf: First-mover Advantages as a Barrier to Competitor Innovation AgEcon Briggeman, Brian C.; Gunderson, Michael A.; Detre, Joshua D.. Product innovation for a juice company and its associated first-mover advantages are analyzed. Stochastic simulation is used to model market size, price, competitive intensity, and the likelihood of competitor entry. Results of moving first allow the firm to capture market share, realize first-mover advantages in excess of $2 million, and deter competitor innovation. In addition, the proposed model is flexible enough to be applied in other industries. Tipo: Journal Article Palavras-chave: Product innovation; First-mover advantages; Barriers to entry; Stochastic simulation; Uncertainty; Research and Development/Tech Change/Emerging Technologies. Ano: 2006 URL: http://purl.umn.edu/8206 Simulating Multivariate Distributions with Sparse Data: A Kernal Density Smoothing Procedure AgEcon Lien, Gudbrand D.; Hardaker, J. Brian; Richardson, James W.. Often analysts must conduct risk analysis based on a small number of observations. This paper describes and illustrates the use of a kernel density estimation procedure to smooth out irregularities in such a sparse data set for simulating univariate and multivariate probability distributions. Tipo: Conference Paper or Presentation Palavras-chave: Stochastic simulation; Smoothing; Multivariate kernel estimator; Parzen; Research Methods/ Statistical Methods; Q12; C8. Ano: 2006 URL: http://purl.umn.edu/25449 Economic Feasibility of Organic Farms and Risk Management Strategies AgEcon Medina, Felipe; Iglesias, Ana. Organic farmers must face different risks than conventional farmers Due to the special features of management of their productive system, and due to the specific characteristics of their cultivations. This study analyses the specific risks that organic farmers must manage as well as the different strategies that there are developing nowadays. Even if the Spanish farmers rely on the insurance system to manage their risks, today organic farmers do not have specific insurance products to manage them. The methodology and results presented in this study include a risk analysis carried out by evaluating statistical, probabilistic, and stochastic properties of the organic production data. We evaluate and discuss the aspects of our study that relate to other... Tipo: Conference Paper or Presentation Palavras-chave: Risk management; Organic farming; Stochastic simulation; Risk strategies and agricultural insurance; Farm Management; Risk and Uncertainty. Ano: 2008 URL: http://purl.umn.edu/44065 Reform der EU-Milchmarktpolitik bei instabilen Weltmärkten AgEcon Grams, Michael. The article examines the market and welfare effects of the current CAP reform and further policy options on the EU dairy market. The main focus is the influence of unstable world markets and the uncertainty it generates in policy analysis which has been widely neglected. The simulations of a stochastic dairy market model reveal that the considered policy options affect the impact of world market instabilities on the EU dairy market. Thus, not only a changing level of producer price or revenues can be expected, but also a changing degree of instability. Policy making without taking such instability changes into account may lead to undesired effects and, finally, could undermine the realisation of policy objectives. Also, the evaluation of the welfare... Tipo: Journal Article Palavras-chave: CAP; Dairy market; Milk quota system; Partial equilibrium model; Uncertainty; Stochastic simulation; Agricultural and Food Policy; Livestock Production/Industries. Ano: 2005 URL: http://purl.umn.edu/97212 Registros recuperados: 24 Primeira ... 1 2 ... Última

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