The single-crystal elastic moduli of alpha-quartz were measured to above 20 GPa in a diamond-anvil cell by Brillouin spectroscopy. The behavior of the elastic moduli indicates that the high-pressure phase transition in quartz is ferroelastic in nature and is driven by softening of C44 through one of the Born stability criteria. The trends in elastic moduli confirm theoretical predictions, but t...

Robust portfolio optimization has been developed to resolve the high sensitivity to inputs of the Markowitz mean-variance model. Although much effort has been put into forming robust portfolios, there have not been many attempts to analyze the characteristics of portfolios formed from robust optimization. We investigate the behavior of robust portfolios by analytically describing how robustness...

By means of high-resolution ultrasonic velocity measurements, as a function of temperature and magnetic field, the nature of the different low temperatures magnetic phase transitions observed for the quasi-one-dimensional compound CsNiCl3 is established. Special attention has been devoted to the field-induced 120 degrees phase transition above the multicritical point in the H-T phase diagram wh...

This paper focuses on a congestion externality in the labor market which is caused by non sequential search. A model is presented in which unemployment is caused by selection delays of the employers It is shown that the individual probability to get a job offer is increasing in the number of applications but that the aggregate hiring rate is decreasing in the average amount of applications per ...

The complete elastic tensor of Fe0.94O (wüstite) has been determined to 10 GPa using acoustic interferometry at GHz frequencies inside a diamond-anvil cell. The soft mode (C44) elastic constant of FeO is reduced by 20% over the experimental pressure range. An unusual discontinuity in the pressure derivatives of C11 and C12 at 4.7+/-0.2 GPa corresponds to the pressure at which the onset of a mag...

The statistical properties of the efficiency estimators based on Data Envelopment Analysis (DEA) are largely unknown. Recent work by Simar et al. and Banker has shown the consistency of the DEA estimators under specific assumptions, and Banker proposes asymptotic tests of whether two subsamples have the same efficiency distribution. There are difficulties arising from bias in small samples and ...

We consider a group of mean-variance investors with mimicking desire such that each investor is willing to penalize deviations of his portfolio composition from compositions of other group members. Penalizing norm constraints are already applied for statistical improvement of Markowitz portfolio procedure in order to cope with estimation risk. We relate these penalties to individuals’ wish of s...

We present a new financial decision making model by using the fuzzy generalized probabilistic weighted averaging (FGPWA) operator. The main advantage of this new approach is that it is able to deal with probabilities (objective information) and weighted averages (subjective information) in the same formulation. Moreover, it is also able to deal with an uncertain environment that can be assessed...

The temperature dependence of the elastic functions of the improper ferroelastic polytype 2 MC-SbsOTI has been investigated in the temperature range from room temperature to well above the structural phase transition at T~=481 K. The stiffnesses c(c*c*), c(a,a), c22 and c(c*a) show a considerable softening up to 20% around Tc whereas c44 remains unaffected by the phase transition. The experimen...

Decision making of agents who are members of a society is analyzed from the point of view of quantum decision theory. This generalizes the approach, developed earlier by the authors for separate individuals, to decision making under the influence of social interactions. The generalized approach not only avoids paradoxes, typical of classical decision making based on utility theory, but also exp...