Mixed population Minority Game with generalized strategies

We present a quantitative theory, based on crowd effects, for the market volatility in a Minority Game played by a mixed population. Below a critical concentration of generalized strategy players, we find that the volatility in the crowded regime remains above the random coin-toss value regardless of the "temperature" controlling strategy use. Our theory yields good agreement with numerical simulations.Comment: Revtex file + 3 figure

Enhanced winnings in a mixed-ability population playing a minority game

We study a mixed population of adaptive agents with small and large memories, competing in a minority game. If the agents are sufficiently adaptive, we find that the average winnings per agent can exceed that obtainable in the corresponding pure populations. In contrast to the pure population, the average success rate of the large-memory agents can be greater than 50 percent. The present results are not reproduced if the agents are fed a random history, thereby demonstrating the importance of memory in this system.Comment: 9 pages Latex + 2 figure

Generalized strategies in the Minority Game

We show analytically how the fluctuations (i.e. standard deviation) in the Minority Game (MG) can be made to decrease below the random coin-toss limit if the agents use more general behavioral strategies. This suppression of the standard deviation results from a cancellation between the actions of a crowd, in which agents act collectively and make the same decision, and an anticrowd in which agents act collectively by making the opposite decision to the crowd.Comment: Revised manuscript: a few minor typos corrected. Results unaffecte

Effect of inorganic or organic copper fed without or with added sulfur and molybdenum on the performance, indicators of copper status, and hepatic mRNA in dairy cows

The effect of inorganic (INORG) or organic (ORG) Cu, fed without (−) or with (+) additional S and Mo on Cu status and performance was examined using 56 early lactation dairy cows in a 2 × 2 factorial study design. Supplementary Cu was added as either CuSO4 or BioplexCu (Alltech Inc., Nicholasville, KY) to provide an additional 10 mg of Cu/kg of dry matter (DM), with S added at 1.5 g/kg of DM and Mo at 6.8 mg/kg of DM to reduce Cu bioavailability. The basal ration was composed of corn and grass silages (2:1 respectively, DM basis) and straight feeds. Cows commenced the study at wk 7 of lactation and remained on treatment for 16 wk. An interaction existed between Cu source and added S and Mo on DM intake, with cows offered INORG− Cu having an increased intake compared with those offered INORG+ or ORG− Cu. Milk yield averaged 35.4 kg/d, and was 5% higher with milk fat content 6% lower in cows fed INORG compared with ORG Cu, but milk fat yield, energy-corrected milk yield, and milk protein content did not differ between treatments. A trend existed for cows to have a higher body weight gain when offered ORG compared with INORG Cu. Cows fed diets containing INORG Cu had a higher milk concentration of C17:0 and C18:3n-3 compared with those fed diets containing ORG Cu. Cows fed added S and Mo had a lower milk concentration of C17:0 and C18:0 compared with those that were not supplemented. No effect was observed of dietary treatment on plasma Cu concentration, which averaged 13.1 µmol/L, except during wk 12 when cows receiving added S and Mo had a lower concentration. No effect was observed of Cu source on mean plasma Mo concentrations, but during wk 16 cows offered INORG Cu had a higher concentration than those offered ORG Cu. Hepatic Cu levels decreased by approximately 0.9 mg/kg of DM per day when fed additional S and Mo, but no effect of Cu source was observed. A trend existed for hepatic ATPase, Cu++ transporting, beta polypeptide (ATP7B) to be upregulated in cows when fed S and Mo along with ORG but not INORG Cu. In conclusion, the inclusion of an ORG compared with an INORG source of Cu reduced milk yield but increased milk fat concentration and body weight gain, with no effect on energy-corrected milk yield. Little effect was observed of dietary Cu supply on plasma mineral concentration, liver mRNA abundance, or milk fatty acid profile, whereas the addition of S and Mo reduced hepatic Cu concentrations

Theory of Networked Minority Games based on Strategy Pattern Dynamics

We formulate a theory of agent-based models in which agents compete to be in a winning group. The agents may be part of a network or not, and the winning group may be a minority group or not. The novel feature of the present formalism is its focus on the dynamical pattern of strategy rankings, and its careful treatment of the strategy ties which arise during the system's temporal evolution. We apply it to the Minority Game (MG) with connected populations. Expressions for the mean success rate among the agents and for the mean success rate for agents with $k$ neighbors are derived. We also use the theory to estimate the value of connectivity $p$ above which the Binary-Agent-Resource system with high resource level goes into the high-connectivity state.Comment: 24 pages, 3 figures, submitted to PR

A feasibility, randomised controlled trial of a complex breathlessness intervention in idiopathic pulmonary fibrosis (BREEZE-IPF): study protocol

Introduction Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive lung disease that causes breathlessness and cough that worsen over time, limiting daily activities and negatively impacting quality of life. Although treatments are now available that slow the rate of lung function decline, trials of these treatments have failed to show improvement in symptoms or quality of life. There is an immediate unmet need for evidenced-based interventions that improve patients' symptom burden and make a difference to everyday living. This study aims to assess the feasibility of conducting a definitive randomised controlled trial of a holistic, complex breathlessness intervention in people with IPF. Methods and analysis The trial is a two-centre, randomised controlled feasibility trial of a complex breathlessness intervention compared with usual care in patients with IPF. 50 participants will be recruited from secondary care IPF clinics and randomised 1:1 to either start the intervention within 1 week of randomisation (fast-track group) or to receive usual care for 8 weeks before receiving the intervention (wait-list group). Participants will remain in the study for a total of 16 weeks. Outcome measures will be feasibility outcomes, including recruitment, retention, acceptability and fidelity of the intervention. Clinical outcomes will be measured to inform outcome selection and sample size calculation for a definitive trial. Ethics and dissemination Yorkshire and The Humber – Bradford Leeds Research Ethics Committee approved the study protocol (REC 18/YH/0147). Results of the main trial and all secondary end-points will be submitted for publication in a peer-reviewed journal

Confining strings in SU(N) gauge theories

We calculate the string tensions of $k$-strings in SU($N$) gauge theories in both 3 and 4 dimensions. In D=3+1, we find that the ratio of the $k=2$ string tension to the $k = 1$ fundamental string tension is consistent, at the $2 \sigma$ level, with both the M(-theory)QCD-inspired conjecture and with `Casimir scaling'. In D=2+1 we see a definite deviation from the MQCD formula, as well as a much smaller but still significant deviation from Casimir scaling. We find that in both D=2+1 and D=3+1 the high temperature spatial $k$-string tensions also satisfy approximate Casimir scaling. We point out that approximate Casimir scaling arises naturally if the cross-section of the flux tube is nearly independent of the flux carried, and that this will occur in an effective dual superconducting description, if we are in the deep-London limit. We estimate, numerically, the intrinsic width of $k$-strings in D=2+1 and indeed find little variation with $k$. In addition to the stable $k$-strings we investigate some ofthe unstable strings, finding in D=2+1 that they satisfy (approximate) Casimir scaling. We also investigate the basic assumption that confining flux tubes are described by an effective string theory at large distances. We estimate the coefficient of the universal L\"uscher correction from periodic strings that are longer than 1 fermi, and find $c_L=0.98(4)$ in D=3+1 and $c_L=0.558(19)$ in D=2+1. These values are within $2 \sigma$ of the simple bosonic string values and are inconsistent with other simple effective string theories.Comment: 57 pages, 11 figures. Errors on fits reduced by altering the analysis to a standard one. Conclusions unchanged; note addedchanged. Some typos correcte

Minority games, evolving capitals and replicator dynamics

We discuss a simple version of the Minority Game (MG) in which agents hold only one strategy each, but in which their capitals evolve dynamically according to their success and in which the total trading volume varies in time accordingly. This feature is known to be crucial for MGs to reproduce stylised facts of real market data. The stationary states and phase diagram of the model can be computed, and we show that the ergodicity breaking phase transition common for MGs, and marked by a divergence of the integrated response is present also in this simplified model. An analogous majority game turns out to be relatively void of interesting features, and the total capital is found to diverge in time. Introducing a restraining force leads to a model akin to replicator dynamics of evolutionary game theory, and we demonstrate that here a different type of phase transition is observed. Finally we briefly discuss the relation of this model with one strategy per player to more sophisticated Minority Games with dynamical capitals and several trading strategies per agent.Comment: 19 pages, 7 figure

Agents Play Mix-game

In mix-game which is an extension of minority game, there are two groups of agents; group1 plays the majority game, but the group2 plays the minority game. This paper studies the change of the average winnings of agents and volatilities vs. the change of mixture of agents in mix-game model. It finds that the correlations between the average winnings of agents and the mean of local volatilities are different with different combinations of agent memory length when the proportion of agents in group 1 increases. This study result suggests that memory length of agents in group1 be smaller than that of agent in group2 when mix-game model is used to simulate the financial markets.Comment: 8 pages, 6 figures, 3 table