Monetary policy rules：Forward-looking and backward-looking in an overlapping generations model

In the framework of an overlapping generations model, forward-looking monetary policy roles and backward-looking monetary policy rules were investigated. It is shown that the monetary steady state is more likely to be indeterminate under an active forwardlooking rule than under the corresponding backward-looking rule. It is also shown that backward-looking roles can render the monetary steady state unstable.

Study on Spectral Overlap Model for Energy Transfer between J-Multiplets in Rare Earth-Doped Crystals

Based on the experimental data of KY 3F 10∶Tm 3+ reported by Diaf, K ushida′s spectral overlap model (SOM) of energy transfer between J-multipl ets was studied. Firstly, with the help of the Inokuti-Hirayama and Yokota-Tan imoto models, the luminescence decay curve of 3H 4 of Tm 3+ ion was fitted, and the fitted values of corresponding interaction parameters C D A of energy transfer and C DD of energy migration were obtained. Seco ndly, by compared with Kushida′s SOM in which the relevant Judd-Ofelt approxim ative transition rates are known, the average overlap integrals of S DD and S DA were obtained. For S DD, how to treat the contributi on of the electronic-dipole (ED) crystal field transition forbidden by C 4v site symmetry in the calculation of S DD was discussed. For S DA we suggested that, by including the contribution of the phonon sideba nds in the analysis of oscillator strength of transition, Kushida′s SOM of ED- ED resonant energy transfer rate can be extended to non-resonant phonon-assist ed D-A energy transfer. The strengths and widths of phonon sidebands in this ex ample were discussed, and the results were reasonably good.

A Model for the Sounding Rocket Measurement on an Ionospheric E-F Valley at the Hainan Low Latitude Station

To understand the physics of an ionospheric E-F valley, a new overlapping three- Chapman-layer model is developed to interpret the sounding rocket measurement in the morn- ing （sunrise） on May 7, 2011 at the Hainan low latitude ionospheric observation station （19.5°N, 109.1°E）. From our model, the valley width, depth and height are 43.0 km, 62.9% and 121.0 km, re- spectively. From the sounding rocket observation, the valley width, depth and height are 42.2 km, 47.0% and 123.5 km, respectively. The model results are well consistent with the sounding rocket observation. The observed E-F valley at Hainan station is very wide and deep, and rapid deel- opment of the photochemical process in the ionosphere should be the underlying reason.

Observations on Samuelson’s Dictum

The stock market in the form of the S&P 500 is estimated to be inefficient in 13%to 30%of the time since 1963.This is contrary to the theory of efficient capital markets,but in accordance with Samuelson’s Dictum,which posits that the stock market is micro efficient,but macro inefficient.I develop a new model to measure potential inefficiency at macro level.Inefficiency in price(P)is driven by earnings(EPS)and/or valuation(P/E).At the peak of the TMT-bubble in 1999/2000,both factors were in play,while only earnings assumptions were inefficient before the Great Financial Crisis in 2008/09.The model developed show expected results in terms of relative efficiency for Developed vs.Emerging Markets and for Dow Jones vs.Nasdaq.Parts of academia seems to accept a different definition of market efficiency at micro level compared to macro level.At macro level,a standard“price vs.fair value”definition seems to be generally accepted,while at micro level,a relative“price vs.price”definition seems to be broadly used.The latter way of thinking has historically contributed to price bubbles.Numerous examples of stock prices that deviate significantly from their fair value in days,weeks and months and doubtful methods for measuring efficiency at micro level cast doubt about the micro efficiency claim part of Samuelson’s Dictum.

Method for fitting crystal field parameters and the energy level fitting for Yb^(3+) in crystal Sc_2O_3

A method to compute the numerical derivative of eigenvalues of parameterized crystal field Hamiltonian matrix is given, based on the numerical derivatives the general iteration methods such as Levenberg-Marquardt, Newton method, and so on, can be used to solve crystal field parameters by fitting to experimental energy levels. With the numerical eigenvalue derivative, a detailed iteration algorithm to compute crystal field parameters by fitting experimental energy levels has also been described. This method is used to compute the crystal parameters of Yb^3＋ in Sc2O3 crystal, which is prepared by a co-precipitation method and whose structure was refined by Rietveld method. By fitting on the parameters of a simple overlap model of crystal field, the results show that the new method can fit the crystal field energy splitting with fast convergence and good stability.

Analysis and direct calculation of the energy migration interaction parameter in high concentration Nd^(3+) doped YAG laser crystal

The energy migration interaction parameter CDD in high concentration Nd3＋ doped YAG laser crystal was estimated using the Yokota-Tanimoto（Y-T） model and the spectral overlap model（SOM） of Kushida, respectively.Firstly, the experimental luminescence decay curves of 4F3/2 state of Nd3＋ ions in YAG laser crystal at room temperature for 2.0at.% and 3.0at.% Nd3＋ concentrations reported by Mao were fitted successfully using the Y-T model, and the parameter CDD was obtained to be 1.50×10-39 cm6/s.Secondly, the parameter CDD was directly calculated using the spectral overlap model（SOM） of Kushida;CDD was calculated to be 2.73×10-39 cm6/s.By comparing the energy migration interaction parameter CDD with the energy transfer interaction parameter CDA（1.794×10-40 cm6/s）, it was concluded that the energy migration rate between Nd3＋ ions in YAG laser crystal was about 11 times larger than the energy transfer rate, and that energy migration played a very important role in high concentration Nd3＋-doped YAG laser crystal.

Competitive Equilibrium in an Overlapping Generations Model with Production Loans

The paper shows that there do exist two kinds of steady states equilibria in the overlapping generations models with consumption and production loans, similar to the pure exchange economies examined by Gale （1973）. Furthermore, the local stability properties of these two （kinds of） steady states are also investigated： In the classical case, the golden-rule steady state is stable and the balanced steady state is saddle-point stable; however, in the Samuelson case, the golden-rule steady state is saddle-point stable and the balanced steady state is stable.

Investigation and statistical modeling of InAs-based double gate tunnel FETs for RF performance enhancement

In this paper,RF performance analysis of In As-based double gate（DG）tunnel field effect transistors（TFETs）is investigated in both qualitative and quantitative fashion.This investigation is carried out by varying the geometrical and doping parameters of TFETs to extract various RF parameters,unity gain cut-off frequency（f_t）,maximum oscillation frequency（f_（max））,intrinsic gain and admittance（Y）parameters.An asymmetric gate oxide is introduced in the gate-drain overlap and compared with that of DG TFETs.Higher ON-current（ION）of about 0.2 mA and less leakage current（IOFF）of 29 f A is achieved for DG TFET with gate-drain overlap.Due to increase in transconductance（g_m）,higher ft and intrinsic gain is attained for DG TFET with gate-drain overlap.Higher f_（max） of 985 GHz is obtained for drain doping of 5×10^（17）cm^（-3） because of the reduced gate-drain capacitance（C_（gd））with DG TFET with gate-drain overlap.In terms of Y-parameters,gate oxide thickness variation offers better performance due to the reduced values of Cgd.A second order numerical polynomial model is generated for all the RF responses as a function of geometrical and doping parameters.The simulation results are compared with this numerical model where the predicted values match with the simulated values.

Longevity,Fertility,and the Real Exchange Rate

We build a simple overlapping generation model to investigate the effect of life expectancy on the real exchange rate where fertility is chosen endogenously.The model reveals that,although the overall effect of life expectancy on the real exchange rate is not certain,longer life expectancy tends to cause the real exchange rate to depreciate by reducing fertility.Fertility thus serves as a mediator in the effect of life expectancy on the real exchange rate.Evidence from 148 economies(1980-2018)shows a statistically significant and robust negative relationship between life expectancy and the real exchange rate.It is estimated that a I year increase in life expectancy is associated with a 1.5 percent depreciation in the real exchange rate.The evidence also confirms the mediated effect of fertility.The mediated effect that fertility exerts accounts for 30 percent to 50 percent of the total effect,depending on the real exchange rate index used.