536 research outputs found
Playing a quantum game with a corrupted source
The quantum advantage arising in a simplified multi-player quantum game, is
found to be a disadvantage when the game's qubit-source is corrupted by a noisy
"demon". Above a critical value of the corruption-rate, or noise-level, the
coherent quantum effects impede the players to such an extent that the optimal
choice of game changes from quantum to classical.Comment: This version will appear in PRA (Rapid Comm.
CORRECTION OF TRANSIENT SOLID-EMBEDDED THERMOCOUPLE DATA WITH APPLICATION TO INVERSE HEAT CONDUCTION
The current research investigates the use of solid-embedded thermocouples for determining accurate transient temperature measurements within a solid medium, with emphasis on measurements intended for use in inverse heat conduction problems. Metal casting experiments have been conducted to collect internal mold temperatures to be used, through inverse conduction methods, to estimate the heat exchange between a casting and mold. Inverse conduction methods require accurate temperature measurements for valid boundary estimates. Therefore, various sources of thermocouple measurement uncertainty are examined and some suggestions for uncertainty reduction are presented. Thermocouple installation induced bias uncertainties in experimental temperature data are dynamically corrected through the development and implementation of an embedded thermocouple correction (ETC) transfer function. Comparisons of experimental data to dynamically adjusted data, as well as the inverse conduction estimates for heat flux from each data set, are presented and discussed
Minority game with arbitrary cutoffs
We study a model of a competing population of N adaptive agents, with similar
capabilities, repeatedly deciding whether to attend a bar with an arbitrary
cutoff L. Decisions are based upon past outcomes. The agents are only told
whether the actual attendance is above or below L. For L-> N/2, the game
reproduces the main features of Challet and Zhang's minority game. As L is
lowered, however, the mean attendances in different runs tend to divide into
two groups. The corresponding standard deviations for these two groups are very
different. This grouping effect results from the dynamical feedback governing
the game's time-evolution, and is not reproduced if the agents are fed a random
history.Comment: 4 pages (Revtex) + 6 separate pdf 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
Crowd-anticrowd theory of the Minority Game
The Minority Game is a simple yet highly non-trivial agent-based model for a
complex adaptive system. Despite its importance, a quantitative explanation of
the game's fluctuations which applies over the entire parameter range of
interest has so far been lacking. We provide such a quantitative description
based on the interplay between crowds of like-minded agents and their
anti-correlated partners (anticrowds).Comment: Shortened version of cond-mat/0003486. Submitted for publicatio
An NMR-based nanostructure switch for quantum logic
We propose a nanostructure switch based on nuclear magnetic resonance (NMR)
which offers reliable quantum gate operation, an essential ingredient for
building a quantum computer. The nuclear resonance is controlled by the magic
number transitions of a few-electron quantum dot in an external magnetic field.Comment: 4 pages, 2 separate PostScript figures. Minor changes included. One
reference adde
Evolutionary minority game with heterogeneous strategy distribution
We present detailed numerical results for a modified form of the so-called
Minority Game, which provides a simplified model of a competitive market. Each
agent has a limited set of strategies, and competes to be in a minority. An
evolutionary rule for strategy modification is included to mimic simple
learning. The results can be understood by considering crowd formation within
the population.Comment: Revtex file + 4 figure
Volatility and Agent Adaptability in a Self-Organizing Market
We present results for the so-called `bar-attendance' model of market
behavior: adaptive agents, each possessing prediction rules chosen
randomly from a pool, attempt to attend a bar whose cut-off is . The global
attendance time-series has a mean near, but not equal to, . The variance, or
`volatility', can show a minimum with increasing adaptability of the individual
agents.Comment: 8 pages, 3 figs. [email protected], [email protected]
Anatomy of extreme events in a complex adaptive system
We provide an analytic, microscopic analysis of extreme events in an adaptive
population comprising competing agents (e.g. species, cells, traders,
data-packets). Such large changes tend to dictate the long-term dynamical
behaviour of many real-world systems in both the natural and social sciences.
Our results reveal a taxonomy of extreme events, and provide a microscopic
understanding as to their build-up and likely duration.Comment: 8 pages, 4 figures. Now with Postscript figure
Influence of external information in the minority game
The influence of a fixed number of agents with the same fixed behavior on the
dynamics of the minority game is studied. Alternatively, the system studied can
be considered the minority game with a change in the comfort threshold away
from half filling. Agents in the frustrated, non ergodic phase tend to
overreact to the information provided by the fixed agents, leading not only to
large fluctuations, but to deviations of the average occupancies from their
optimal values. Agents which discount their impact on the market, or which use
individual strategies reach equilibrium states, which, unlike in the absence of
the external information provided by the fixed agents, do not give the highest
payoff to the collective.Comment: 8 pages, 6 figure
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