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Registros recuperados: 33
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Dynamic Time Warping of Paleomagnetic Secular Variation Data ArchiMer
Hagen, Cedric J; Reilly, Brendan T; Stoner, Joseph S; Creveling, Jessica R.
We present and make publicly available a dynamic programming algorithm to simultaneously align the inclination and declination vector directions of sedimentary paleomagnetic secular variation data.This algorithmgenerates a library of possible alignments through the systematic variation of assumptions about the relative accumulation rate and shared temporal overlap of two or more time-series. The paleomagnetist can then evaluate this library of reproducible and objective alignments using available geologic constraints, statistical methods, and expert knowledge.We apply the algorithm to align previously (visually) correlated medium to high accumulation rate northern North Atlantic Holocene deposits (101– 102 cm/ka) with strong radiocarbon control. The...
Tipo: Text Palavras-chave: Palaeomagnetic secular variation; Palaeomagnetism; Magnetostratigraphy; Dynamic programming; Statistical methods; Atlantic Ocean.
Ano: 2020 URL: https://archimer.ifremer.fr/doc/00601/71322/69749.pdf
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Trade-offs between conflicting animal welfare concerns and cow replacement strategy in out-wintering Scottish suckler herds AgEcon
Vosough Ahmadi, Bouda; Morgan, Colin A.; Stott, Alistair W..
Since decoupling of the CAP, many Scottish suckler cow farms are facing financial difficulties. In response, many farmers are out-wintering extensively managed suckler cows to minimise production costs. These systems are of animal welfare concern. A range of trade-offs between animal welfare indicators and between animal welfare and farm profitability can be identified. A Dynamic Programming (DP) model was developed to study these trade-offs. Two herds were modelled assuming their feeding regimes were either low (LHERD) or high (HHERD). The objective of the DP was to maximise the expected net margin from a current cow and its successors over an infinite time horizon. Preliminary results showed that the rate of voluntary culling was higher in HHERD than in...
Tipo: Working or Discussion Paper Palavras-chave: Livestock Production/Industries; Beef cow; Economics; Dynamic programming; Animal welfare.
Ano: 2009 URL: http://purl.umn.edu/61122
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VALUING AGRICULTURAL MORTGAGE-BACKED SECURITIES AgEcon
Stokes, Jeffrey R.; Brinch, Brian M..
A model to value Federal Agricultural Mortgage Corporation (Farmer Mac) agricultural mortgage-backed securities (AMBS) is developed and numerically solved. The results suggest prepayment penalties currently being used by Farmer Mac reduce yields on AMBS considerably. Even with prepayment penalties, it can be advantageous for profit maximizing mortgagors to optimally prepay or even default on agricultural mortgages. The model is used to quantify prepayment and default risk by valuing the embedded options in the mortgages. Monte Carlo simulation is also used to determine the probability to optimal prepayment given the term structure assumption used to develop the model.
Tipo: Journal Article Palavras-chave: Agricultural mortgage-backed securities; Default; Dynamic programming; Simulation; Prepayment; Agricultural Finance; G13; G21.
Ano: 2001 URL: http://purl.umn.edu/15459
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On the Potential Use of Adaptive Control Methods for Improving Adaptive Natural Resource Management AgEcon
Bond, Craig A..
The paradigm of adaptive natural resource management (AM), in which experiments are used to learn about uncertain aspects of natural systems, is gaining prominence as the preferred technique for administration of large-scale environmental projects. To date, however, tools consistent with economic theory have yet to be used to either evaluate AM strategies or improve decision-making in this framework. Adaptive control (AC) techniques provide such an opportunity. This paper demonstrates the conceptual link between AC methods, the alternative treatment of realized information during a planning horizon, and AM practices; shows how the different assumptions about the treatment of observational information can be represented through alternative dynamic...
Tipo: Working or Discussion Paper Palavras-chave: Adaptive control; Adaptive management; Dynamic programming; Value of experimentation; Value of information; Resource /Energy Economics and Policy.
Ano: 2008 URL: http://purl.umn.edu/108721
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Exploring long-term land improvements under land tenure insecurity AgEcon
Myyra, Sami; Pietola, Kyosti.
This article explores long-term land improvement (lime application) under land tenure insecurity on leased land. The dynamic optimisation problem is solved by a stochastic dynamic programming routine with known parameters for one-period returns and transition equations. The model parameters represent Finnish soil quality and production conditions. The farmer's decision rules are solved for alternative likelihood scenarios over the continuation of the fixed term lease contract. The results suggest that, as the probability for non-renewal of the lease contract increases, farmers quickly decrease investments in irreversible land improvement and, thereafter, yields decline gradually. The estimated decision rules are a part of larger set of farmer's decision...
Tipo: Conference Paper or Presentation Palavras-chave: Dynamic programming; Land tenure; Land improvements; Land Economics/Use.
Ano: 2006 URL: http://purl.umn.edu/31954
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Accounting for agronomic rotations in crop production: A theoretical investigation and an empirical modeling framework AgEcon
Carpentier, Alain; Gohin, Alexandre; Letort, Elodie.
As far as crop acreage choices are concerned, a consensus seems to exist among agricultural scientists and extension agents: crop rotation effects and the related constraints are major determinants of farmers’ crop choices. Crop rotation effects are inherently dynamic. They are generally ignored in multicrop models with land as an allocable input found in the literature since most of these models are developed within a static framework. The aim of this paper is twofold (i) to propose a new approach and tools for investigating dynamic crop acreage choices accounting for crop rotation benefits and constraints and (ii) to illustrate the impacts of crop rotation effects and constraints on farmers’ acreage choices through simulation examples. The models...
Tipo: Conference Paper or Presentation Palavras-chave: Crop rotation; Dynamic programming; Acreage choice; Crop Production/Industries; Land Economics/Use; Q12; D21; D24; D92.
Ano: 2011 URL: http://purl.umn.edu/103431
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Recursive Sustainability: Intertemporal Efficiency and Equity AgEcon
Knapp, Keith C..
PV-optimality in a capital-resource economy can imply decreasing utility over some portion of the time horizon. Various criteria have been proposed to maintain intergenerational equity defined as nondeclining utility, but these have some limitations and problems. This paper proposes a new welfare criteria incorporating present value to maintain efficiency, and an equity function with convex costs on declining utility. This criterion is economically efficient, time-consistent and recursive. An extension of dynamic programming to multiple value functions is developed to solve this problem. Increasing the equity weight increasingly eliminates declining portions of utility time paths. Sustainability implies increasing consumption in the early time periods and...
Tipo: Conference Paper or Presentation Palavras-chave: Growth; Environment; Intergenerational equity; Dynamic programming; Research Methods/ Statistical Methods.
Ano: 2006 URL: http://purl.umn.edu/21472
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The value of market uncertainty in a livestock epidemic AgEcon
Niemi, Jarkko K.; Lehtonen, Heikki.
Introduction of foot and mouth disease (FMD) into country typically initiates eradication procedures which remove animals from the market, and halts the export of livestock products from the infected country. The magnitude of these effects can be highly uncertain. This paper presents a stochastic dynamic programming model which simulates possible market implications of alternative FMD and export scenarios in the Finnish pig sector. It takes into account dynamics and adjustment of the animal stock, price movements and uncertainty related to the duration of the trade ban. Results suggest that losses to pig producers can increase considerably when the risk of prolonged export ban increases. Production adjustments also strengthen. Consumers can gain from a...
Tipo: Conference Paper or Presentation Palavras-chave: Livestock epidemics; Dynamic programming; Demand; Supply; Export; International Relations/Trade; Livestock Production/Industries.
Ano: 2008 URL: http://purl.umn.edu/6158
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DEVELOPING FLEXIBLE ECONOMIC THRESHOLDS FOR PEST MANAGEMENT USING DYNAMIC PROGRAMMING AgEcon
Harper, Jayson K.; Mjelde, James W.; Rister, M. Edward; Way, Michael O.; Drees, Bastiaan M..
The rice stink bug is a major pest of rice in Texas, causing quality related damage. The previous threshold used for assisting in rice stink bug spray decisions lacked flexibility in economic and production decision variables and neglected the dynamics of the pest population. Using stochastic dynamic programming, flexible economic thresholds for the rice stink bug were generated. The new thresholds offer several advantages over the old, static thresholds, including increased net returns, incorporation of pest dynamics, user flexibility, ease of implementation, and a systematic process for updating.
Tipo: Journal Article Palavras-chave: Economic thresholds; Dynamic programming; Pest management; Rice; Crop Production/Industries.
Ano: 1994 URL: http://purl.umn.edu/15411
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Tipping Points and Ambiguity in the Economics of Climate Change AgEcon
Lemoine, Derek M.; Traeger, Christian P..
Replaced with revised version of paper Feb 13, 2012 available at http://purl.umn.edu/120349
Tipo: Report Palavras-chave: Threshold; Climate; Integrated assessment; Regime shift; Ambiguity; Uncertainty; Dynamic programming; Social cost of carbon; Tipping point; Carbon tax; Environmental Economics and Policy; Risk and Uncertainty; Q54; D90; D81.
Ano: 2010 URL: http://purl.umn.edu/98127
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Tipping points and ambiguity in the economics of climate change AgEcon
Lemoine, Derek M.; Traeger, Christian P..
Replaces CUDARE Working Paper no. 1111, with the title; Tipping Points and Ambiguity in the Integrated Assessment of Climate Change, issued 12-26-2010
Tipo: Working Paper Palavras-chave: Tipping point; Threshold; Regime shift; Ambiguity; Climate; Uncertainty; Integrated assessment; Dynamic programming; Social cost of carbon; Carbon tax; Political Economy; Resource /Energy Economics and Policy; Q54; D90; D81.
Ano: 2011 URL: http://purl.umn.edu/120349
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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
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Risk and Aversion in the Integrated Assessment of Climate Change AgEcon
Crost, Benjamin; Traeger, Christian P..
Tipo: Working or Discussion Paper Palavras-chave: Climate change; Uncertainty; Integrated assessment; Risk aversion; Intertemporal substitution; Recursive utility; Dynamic programming; Risk and Uncertainty; Q54; Q00; D90; C63.
Ano: 2010 URL: http://purl.umn.edu/90935
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Insure or Invest in Green Technologies to Protect Against Adverse Weather Events? AgEcon
Pietola, Kyosti; Myyra, Sami; Niemi, Jarkko K.; Van Asseldonk, Marcel A.P.M..
This paper analyses investments in green technologies when insurance is also an option. Green technologies are defined to have the power to increase productivity and decrease volatility of future revenues. The insurance options involve the scale and coverage either in a yield insurance or in an index insurance. The stochastic process is a combination of insurable stationary short-run process and non-stationary long run process. The optimal decision rules are solved numerically by stochastic dynamic programming. The results suggest that the index insurance maintains market based incentives to invest in green technologies whereas a yield insurance substantially decreases investments, as expected. An actuarially fair yield insurance decreases investments at...
Tipo: Working or Discussion Paper Palavras-chave: Investment; Insurance; Uncertainty; Dynamic programming; Green technology; Agribusiness; Agricultural Finance; Financial Economics; Risk and Uncertainty.
Ano: 2011 URL: http://purl.umn.edu/100738
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Optimisation of policy interventions in environmental quota AgEcon
Buysse, Jeroen; Van der Straeten, Bart; Nolte, Stephan; Claeys, Dakerlia; Lauwers, Ludwig H.; Van Huylenbroeck, Guido.
The paper analyses the governance choices in production quota with the Flemish nutrient production rights as a case. A static model of quota trade in the short run shows the inefficiency of discrete non-auctioned trade with fixed transaction costs. This model also shows that an obligation to quota sellers to stop their production stimulates structural change. A dynamic model of trade indicates that the measures taken to prevent speculative behaviour causes inefficiencies and stimulates overuse of quota if the penalties are too low. Finally, the dynamic model indicates that a flat rate reduction on traded quota combined with too low penalties for overuse stimulate the total production.
Tipo: Conference Paper or Presentation Palavras-chave: Production rights; Quota; Dynamic programming; Transaction costs; Agricultural and Food Policy; Farm Management; Land Economics/Use.
Ano: 2010 URL: http://purl.umn.edu/61084
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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
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Using Numerical Dynamic Programming to Compare Passive and Active Learning in the Adaptive Management of Nutrients in Shallow Lakes AgEcon
Bond, Craig A.; Loomis, John B..
This paper illustrates the use of dual/adaptive control methods to compare passive and active adaptive management decisions in the context of an ecosystem with a threshold effect. Using discrete-time dynamic programming techniques, we model optimal phosphorus loadings under both uncertainty about natural loadings and uncertainty regarding the critical level of phosphorus concentrations beyond which nutrient recycling begins. Active management is modeled by including the anticipated value of information (or learning) in the structure of the problem, and thus the agent can perturb the system (experiment), update beliefs, and learn about the uncertain parameter. Using this formulation, we define and value optimal experimentation both ex ante and ex post. Our...
Tipo: Working or Discussion Paper Palavras-chave: Adaptive control; Adaptive management; Dynamic programming; Value of experimentation; Value of information; Nonpoint source pollution; Learning; Decisions under uncertainty; Resource /Energy Economics and Policy.
Ano: 2008 URL: http://purl.umn.edu/108720
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A Dynamic Optimisation Model of Weed Control AgEcon
Cacho, Oscar J.; Jones, Randall E..
It is argued in this paper that static approaches to weed management, where the benefits and costs are only considered within a single season, are inappropriate for assessing the economic benefits of weed control technologies. There are carryover effects from weed management as weeds that escape control in one season may reproduce and replenish weed populations in following seasons. Consequently, it is appropriate to view weed control in the context of a resource management problem where the goal is to determine the optimal inter-temporal level of weed control that maximises economic benefits over some pre-determined period of time. A dynamic optimisation model for weed control is presented. Using the tools of comparative static analysis and Pontryagin's...
Tipo: Working or Discussion Paper Palavras-chave: Weed control; Resource economics; Optimal control; Dynamic programming; Wild oats; Farm Management.
Ano: 2000 URL: http://purl.umn.edu/12902
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MODELLING THE DYNAMICS OF PRODUCTION ADJUSTMENT TO SHORT-TERM MARKET SHOCKS AgEcon
Niemi, Jarkko K.; Lehtonen, Heikki.
Models of agricultural economics typically operate at an annual basis or in a static equilibrium framework where inputs, outputs and their prices may change considerably. Production dynamics, however, imply that models relying on spatial and temporal aggregation do not capture the effects of biological constraints in the short run. This paper examines short and long-term impacts of demand and production cost shocks in the pig sector. The analysis is carried out with a dynamic programming model which takes into account changes in export and domestic demand and market clearing price. It optimizes the supply of piglets on a monthly basis. Econometric techniques are used to estimate demand functions. Short-term negative market shocks can already have...
Tipo: Conference Paper or Presentation Palavras-chave: Pig; Demand; Dynamic programming; Export; Livestock epidemics; Price; Supply; Demand and Price Analysis; Livestock Production/Industries; Production Economics; Risk and Uncertainty.
Ano: 2008 URL: http://purl.umn.edu/6401
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LONG-TERM PLANNING OF A LIVESTOCK-CROP FARM UNDER GOVERNMENT PROGRAMS AgEcon
Kouka, Pierre-Justin; Duffy, Patricia A.; Taylor, C. Robert.
Optimal crop and livestock mix was determined for a representative Alabama farm using a dynamic programming model. Results indicate that decisions concerning livestock production are highly influenced by the amount of cotton base available on the farm. In most cases, increasing cotton base results in less cattle production. The triple base provisions of the 1990 Farm Bill, however, may give some cotton farmers an incentive to produce more stocker cattle during the winter months. Research results also indicate that the availability of farm programs can alter the optimal enterprise mix on a farm with no beginning base in cotton.
Tipo: Journal Article Palavras-chave: Farm programs; Dynamic programming; Livestock; Farm Management.
Ano: 1994 URL: http://purl.umn.edu/15407
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