49,049 research outputs found
Knowledge-based acquisition of tradeoff preferences of negotiating agents
A wide range of algorithms have been developed for various types of automated egotiation. In developing such algorithms the main focus has been on their efficiency and their effectiveness. However, this is only part of the picture. Agents typically negotiate on behalf of their owners and for this to be effective the agent must be able to adequately represent the owners' preferences. However, the process by which such knowledge is acquired is typically left unspecified. To remove this shortcoming, we present a case study indicating how the knowledge for a particular negotiation algorithm can be acquired. More precisely, according to the analysis on the automated negotiation model, we identified that user trade-off preferences play a fundamental role in negotiation in general. This topic has been addressed little in the research area of user preference elicitation for general decision making problems as well. In a previous paper, we proposed an exhaustive method to acquire user trade-off preferences. In this paper, we developed another method to remove the limitation of the high user workload of the exhaustive method. Although we cannot say that it can exactly capture user trade-off preferences, it models the main commonalities of trade-off relations and re users' individualities as well
Tuning the magnetism of ordered and disordered strongly-correlated electron nanoclusters
Recently, there has been a resurgence of intense experimental and theoretical
interest on the Kondo physics of nanoscopic and mesoscopic systems due to the
possibility of making experiments in extremely small samples. We have carried
out exact diagonalization calculations to study the effect of energy spacing
in the conduction band states, hybridization, number of electrons, and
disorder on the ground-state and thermal properties of strongly-correlated
electron nanoclusters. For the ordered systems, the calculations reveal for the
first time that tunes the interplay between the {\it local} Kondo and
{\it non local} RKKY interactions, giving rise to a "Doniach phase diagram" for
the nanocluster with regions of prevailing Kondo or RKKY correlations. The
interplay of and disorder gives rise to a versus
concentration T=0 phase diagram very rich in structure. The parity of the total
number of electrons alters the competition between the Kondo and RKKY
correlations. The local Kondo temperatures, , and RKKY interactions depend
strongly on the local environment and are overall {\it enhanced} by disorder,
in contrast to the hypothesis of ``Kondo disorder'' single-impurity models.
This interplay may be relevant to experimental realizations of small rings or
quantum dots with tunable magnetic properties.Comment: 10 pages, 13 figures, to appear in Physics of Spin in Solids:
Materials, Methods, and Applications, (2004
The Massive Schwinger Model in a Fast Moving Frame
We present a non-perturbative study of the massive Schwinger model. We use a
Hamiltonian approach, based on a momentum lattice corresponding to a fast
moving reference frame, and equal time quantization.Comment: contribution to Lattice'98 including: 2 style files
(espcrc2.sty,psfig.sty) + text file (LaTeX) + 3 figures (ps) + complete
paper(ps
The perfect spin injection in silicene FS/NS junction
We theoretically investigate the spin injection from a ferromagnetic silicene
to a normal silicene (FS/NS), where the magnetization in the FS is assumed from
the magnetic proximity effect. Based on a silicene lattice model, we
demonstrated that the pure spin injection could be obtained by tuning the Fermi
energy of two spin species, where one is in the spin orbit coupling gap and the
other one is outside the gap. Moreover, the valley polarity of the spin species
can be controlled by a perpendicular electric field in the FS region. Our
findings may shed light on making silicene-based spin and valley devices in the
spintronics and valleytronics field.Comment: 6 pages, 3 figure
Inverted U-Shaped relationship between central venous pressure and intra-abdominal pressure in the early phase of severe acute pancreatitis: A retrospective study
published_or_final_versio
Tunable "Doniach Phase Diagram" for strongly-correlated nanoclusters
Exact diagonalization calculations reveal that the energy spacing in
the conduction band tunes the interplay between the {\it local} Kondo and {\it
non local} RKKY interactions, giving rise to a "Doniach phase diagram" for a
nanocluster with regions of prevailing Kondo or RKKY correlations. The parity
of the total number of electrons alters the competition between the Kondo and
RKKY correlations. This interplay may be relevant to experimental realizations
of small rings or quantum dots with tunable magnetic properties. Below a
critical value V of the hybridization the susceptibility exhibits a low-T
exponential activation behavior determined by the interplay of the spin gap and
.Comment: 4 pages, 5 figure
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