3,109 research outputs found
Elliptic flow from event-by-event hydrodynamics
We present an event-by-event hydrodynamical framework which takes into
account the initial density fluctuations arising from a Monte Carlo Glauber
model. The elliptic flow is calculated with the event plane method and a
one-to-one comparison with the measured event plane is made. Both the
centrality- and -dependence of the are remarkably well reproduced.
We also find that the participant plane is a quite good approximation for the
event plane.Comment: 4 pages, 3 figures. Talk given at Quark Matter 2011, 22-28 May 2011,
Annecy, Franc
MODELLING THE DYNAMICS OF PRODUCTION ADJUSTMENT TO SHORT-TERM MARKET SHOCKS
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 significant income effects to agricultural producers. We simulated effects of pig meat export bans of different degrees due to livestock epidemics. Full closure of export markets for six months cost pig sector €21 million.pig, demand, dynamic programming, export, livestock epidemics, price, supply, Demand and Price Analysis, Livestock Production/Industries, Production Economics, Risk and Uncertainty,
Price volatility and return on pig fattening under different price- quantity contract regimes
The goal of this study is to estimate how different price or quantity fixing contracts affect the value of pig space unit in pig fattening. The value of pig space unit is estimated with a stochastic dynamic programming algorithm. The model maximises the value of pig space unit by using four decision variables. The input-output ratios are endogenous and the option to suspend production temporarily is taken into account in the model. The results suggests that the smooth functioning of markets in Finland can be promoted by ensuring that price changes are transmitted smoothly between input and output markets, and that producers are compensated for giving up the option to suspend production temporarily in the event if unfavourable market situation. Instead of fixing only the price of output, the contract should aim at reducing the risk associated with gross margin.Demand and Price Analysis, Livestock Production/Industries,
Designing coordination contracts to support efficient flow-scheduling in pork chain
Risk management and efficient, well coordinated, flow-scheduling have an increasingly important role in the competitive pork production networks. Changes in input and output prices have resulted in distortions in the Finnish pig markets during the last years. The goal of this study is to estimate how different price or quantity-fixing contracts affect the values of pig and sow space unit under price risk. The values are estimated with two stochastic dynamic programming models. The results suggest that a contract which is able to control both the pattern of changes in piglet prices and the option to suspend production temporarily has a value and it can help to improve the competitiveness of the pig sector. However, it is feasible to have incentives towards the contract commitment when market situation upon accepting the commitment is favourable.vo
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