Interplay of simple stochastic games as models for the economy

summary:Using the interplay among three simple exchange games, one may give a satisfactory representation of a conservative economic system where total wealth and number of agents do not change in time. With these games it is possible to investigate the emergence of statistical equilibrium in a simple pure-exchange environment. The exchange dynamics is composed of three mechanisms: a decentralized interaction, which mimics the pair-wise exchange of wealth between two economic agents, a failure mechanism, which takes into account occasional failures of agents and includes wealth redistribution favoring righer agents, and a centralized mechanism, which describes the result of a redistributive effort. According to the interplay between these three mechanisms, their relative strength, as well as the details of redistribution, different outcomes are possible

Low-traffic limit and first-passage times for a simple model of the continuous double auction

We consider a simplified model of the continuous double auction where prices are integers varying from 1 to N with limit orders and market orders, but quantity per order limited to a single share. For this model, the order process is equivalent to two M∕M∕1 queues. We study the behaviour of the auction in the low-traffic limit where limit orders are immediately matched by market orders. In this limit, the distribution of prices can be computed exactly and gives a reasonable approximation of the price distribution when the ratio between the rate of order arrivals and the rate of order executions is below 1∕2. This is further confirmed by the analysis of the first-passage time in 1 or N

Osetljivost kukuruza, suncokreta i ječma na rezidualno delovanje klomazona u zemljištu

Sensitivity of maize, sunflower and barley to clomazone residues in loamy soil was assessed in the study using bioassay. Clomazone was applied at a series of concentrations from 0.12 to 12 mg a.i./kg of soil. After 14 days, morphological (shoot height, fresh and dry weight) and physiological (content of carotenoids, chlorophyll a and chlorophyll b) parameters were measured. The results showed that morphological parameters are not valid indicators of clomazone sensitivity. Based on the results showing inhibition of the physiological parameters, I50 values were calculated and used to estimate the difference in sensitivity between the species tested. Sunflower was the most sensitive species, while the difference in sensitivity between maize and barley was not significant. Nomenclature: clomazone (2-(2-chlorbenzyl)-4,4-dimethyl-1,2-oxazolidin-3-one), maize (Zea mays L.), sunflower (Helianthus annuus L.), barley (Hordeum vulgare L.).U radu je ispitivana osetljivost kukuruza, suncokreta i ječma na rezidualno delovanje klomazona u zemljištu tipa ilovače, metodom biotesta. Klomazon je primenjen u seriji koncentracija 0,12-12 mg a.s./kg zemljišta. Nakon 14 dana rasta biljaka mereni su morfološki (visina, sveža i suva masa izdanka) i fiziološki parametri (sadržaj karotenoida, hlorofila a i hlorofila b). Konstatovano je da morfološki parametri nisu pouzdano merilo osetljivosti na klomazon. Prema ostvarenim procentima inhibicije za merene fiziološke parametre izračunate su vrednosti I50, a na osnovu njih utvrđene su razlike u osetljivosti ispitivanih biljnih vrsta. Najosetljiviji je bio suncokret, dok se kukuruz i ječam nisu međusobno značajno razlikovali

Ergodic transition in a simple model of the continuous double auction

We study a phenomenological model for the continuous double auction, whose aggregate order process is equivalent to two independent M/M/1 queues. The continuous double auction defines a continuous-time random walk for trade prices. The conditions for ergodicity of the auction are derived and, as a consequence, three possible regimes in the behavior of prices and logarithmic returns are observed. In the ergodic regime, prices are unstable and one can observe a heteroskedastic behavior in the logarithmic returns. On the contrary, non-ergodicity triggers stability of prices, even if two different regimes can be seen

Interplay of simple stochastic games as models for the economy

summary:Using the interplay among three simple exchange games, one may give a satisfactory representation of a conservative economic system where total wealth and number of agents do not change in time. With these games it is possible to investigate the emergence of statistical equilibrium in a simple pure-exchange environment. The exchange dynamics is composed of three mechanisms: a decentralized interaction, which mimics the pair-wise exchange of wealth between two economic agents, a failure mechanism, which takes into account occasional failures of agents and includes wealth redistribution favoring righer agents, and a centralized mechanism, which describes the result of a redistributive effort. According to the interplay between these three mechanisms, their relative strength, as well as the details of redistribution, different outcomes are possible

A machine learning Automated Recommendation Tool for synthetic biology.

Synthetic biology allows us to bioengineer cells to synthesize novel valuable molecules such as renewable biofuels or anticancer drugs. However, traditional synthetic biology approaches involve ad-hoc engineering practices, which lead to long development times. Here, we present the Automated Recommendation Tool (ART), a tool that leverages machine learning and probabilistic modeling techniques to guide synthetic biology in a systematic fashion, without the need for a full mechanistic understanding of the biological system. Using sampling-based optimization, ART provides a set of recommended strains to be built in the next engineering cycle, alongside probabilistic predictions of their production levels. We demonstrate the capabilities of ART on simulated data sets, as well as experimental data from real metabolic engineering projects producing renewable biofuels, hoppy flavored beer without hops, fatty acids, and tryptophan. Finally, we discuss the limitations of this approach, and the practical consequences of the underlying assumptions failing

Mean values and error bars.

<p>Mean values and error bars of the standard deviation (a), kurtosis (b) of log-returns and the first-lag autocorrelation of absolute log-returns (c) as functions of the parameter , estimated from 1000 Monte Carlo simulations.</p

Time series of prices and log-returns.

<p>Time series of prices and log-returns in a system of prices, length of interval for placing orders , with initial price and number of simulated events . (a) ergodic case (); (b) non-ergodic case for () and (c) non-ergodic case for ().</p