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 $\Delta$ 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 $\Delta$ 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 $\Delta$ and disorder gives rise to a $\Delta$ 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, $T_K$, 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 $\Delta$ 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$_c$ of the hybridization the susceptibility exhibits a low-T exponential activation behavior determined by the interplay of the spin gap and $\Delta$.Comment: 4 pages, 5 figure