12,828 research outputs found
Game theory
Game theory is a section of applied mathematics that studies various
mathematical models of optimal decision making in conflict situations. J.
Von Neumann and O. Monhenshternom in 1944 wrote the work "Theory of
Games and Economic Behavior." From the very beginning of its
development, it was aimed at solving economic problems. Later it began to
be applied in other areas related to the conflict. Theoretical and playing
methods of optimal solutions are widely used in medicine, in economic and
social planning and forecasting, and other matters of science and
technology.Today, the game theory is widely used in various sciences such
as economic, political, computer, social, etc. Game theory attempts to
identify strategic behavior in different situations mathematically in which
success is the subject of the decision-making and depends on the moves of
other players
Pump-Probe Experiments on the Single-Molecule Magnet Fe8 : Measurement of Excited Level Lifetimes
We present magnetization measurements on the single molecule magnet Fe8 in
the presence of pulsed microwave radiation. A pump-probe technique is used with
two microwave pulses with frequencies of 107 GHz and 118 GHz and pulse lengths
of several nanoseconds to study the spin dynamics via time-resolved
magnetization measurements using a Hall probe magnetometer. We find evidence
for short spin-phonon relaxation times of the order of one microsecond. The
temperature dependence of the spin-phonon relaxation time in our experiments is
in good agreement with previously published theoretical results. We also
established the presence of very short energy diffusion times, that act on a
timescale of about 70 ns.Comment: submitted to Phys. Rev. Lett. (01 March 2007
New Record of \u3ci\u3eBrachycercus Maculatus\u3c/i\u3e Berner (Ephemeroptera: Caenidae) From New York and a Key to Larvae of Northeastern Species
Brachycercus maculatus, a member of a rare group of mayflies, is now recorded for the first time from New York State in the upper Hudson River. An illustrated key to the Brachycercus larvae of northeastern North America is provided to spur further study of the genus in the region
Laser velocimetry in highly three-dimensional and vortical flows
The need for experimentally determined 3-D velocity information is crucial to the understanding of highly 3-dimensional and vortical flow fields. In addition to gaining an understanding of the physics of flow fields, a correlation of velocity data is needed for advanced computational modelling. A double pass method for acquiring 3-D flow field information using a 2-D laser velocimeter (LV) is described. The design and implementation of a 3-D LV with expanded capabilities to acquire real-time 3-D flow field information are also described. Finally, the use of such an instrument in a wind tunnel study of a generic fighter configuration is described. The results of the wind tunnel study highlight the complexities of 3-D flow fields, particularly when the vortex behavior is examined over a range of angles of attack
Disproportionation Transition at Critical Interaction Strength: NaCoO
Charge disproportionation (CD) and spin differentiation in NaCoO
are studied using the correlated band theory approach. The simultaneous CD and
gap opening seen previously is followed through a first order charge
disproportionation transition 2Co Co+Co, whose ionic
identities are connected more closely to spin (S=0, S=1/2 respectively) than to
real charge. Disproportionation in the Co orbital is compensated by
opposing charge rearrangement in other 3d orbitals. At the transition large and
opposing discontinuities in the (all-electron) kinetic and potential energies
are slightly more than balanced by a gain in correlation energy. The CD state
is compared to characteristics of the observed charge-ordered insulating phase
in NaCoO, suggesting the Coulomb repulsion value is
concentration-dependent, with 3.5 eV.Comment: 4 pages and 4 embedded figure
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