Why the determinacy condition is a weak criterion in rational expectations models

This paper disputes what Blanchard and Kahn have reported as the solution of linear rational expectation(RE) systems many years ago. Their method leads to traditional determinacy condition which is used very much nowadays. In this paper we have a new look to the mathematical procedure of this solution method and the main problem in their solution will be shown. We introduce a new methodology for modeling the systems with expectation, while in future this way of modeling can be used to replace traditional RE models.Rational expectation; Determinacy condition; Stability; Uniqueness; Predictive control

Designing a Mechanically Robust Thermoelectric Module for High Temperature Application

We report a numerical study on the impacts of variations in the geometry, boundary conditions, and the coefficient of thermal expansion of the materials on the maximum shearing stress in thermoelectric power generator module (TEM) for high temperature applications. The maximum shearing stress in the TEM is evaluated for different designs focusing on their dependency on the fill factor. Although predictions by the previously developed analytical modeling are in partial agreement with numerical results, simplifying assumptions for the analytical model can limit the range of validity. Our numerical analysis shows that reduction of the fill factor alone under all the circumstances will not reduce the maximum shear stress. Imposing mechanical constraints at the boundaries, increasing the number of legs (6 × 6 in the analysis), and engineering the coefficient of thermal expansion are some of the key parameters controlling the maximum shearing stress and its changes with the fill factor

Study of Phonon Modes in Germanium Nanowires

The observation of pure phonon confinement effect in germanium nanowires is limited due to the illumination sensitivity of Raman spectra. In this paper we measured Raman spectra for different size germanium nanowires with different excitation laser powers and wavelengths. By eliminating the local heating effect, the phonon confinement effect for small size nanowires was clearly identified. We have also fitted the Raman feature changes to estimate the size distribution of nanowires for the first time.Comment: 11 pages,15 figure