Proposed gravity-gradient dynamics experiments using the RAE-1 spacecraft

Gravity gradient dynamics experiments using Radio Astronomy Explorer Satellite in earth orbi

Hysteresis and the European Unemployment Problem

European unemployment has been steadily increasing for the last 15 years and is expected to remain very high for many years to come. In this paper, we argue that this fact implies that shocks have much more persistent effects on unemployment than standard theories can possibly explain. We develop a theory which can explain such persistence, and which is based on the distinction between insiders and outsiders in wage bargaining. We argue that if wages are largely set by bargaining between insiders and firms, shocks which affect actual unemployment tend also to affect equilibrium unemployment. We then confront the theory to both the detailed facts of the European situation as well as to earlier periods of high persistent unemployment such as the Great Depression in the US.

Single-cycle THz pulses with amplitudes exceeding 1 MV/cm generated by optical rectification in LiNbO3

Using the tilted-pulse-intensity-front scheme, we generate single-cycle terahertz (THz) pulses by optical rectification of femtosecond laser pulses in LiNbO3. In the THz generation setup, the condition that the image of the grating coincides with the tilted-optical-pulse front is fulfilled to obtain optimal THz beam characteristics and pump-to-THz conversion efficiency. The designed focusing geometry enables tight focus of the collimated THz beam with a spot size close to the diffraction limit, and the maximum THz electric field of 1.2 MV/cm is obtained

Fiscal Increasing Returns, Hysteresis, Real Wages and Unemployment

European unemployment is widely regarded as a problem of excessive real wages. This view as it is usually expressed carries the disturbing implication that there is a sharp conflict between the interests of those currently employed and the unemployed because it suggests that increases in employment will require reductions in the real wages of those currently employed. The first part of this paper shows that increases in employment in Europe are likely to be associated with rising real take-home pay for workers because of fiscal increasing returns. Increases in employment and output will make possible reductions in taxes sufficiently large to offset any effects of diminishing returns to labor. The second part of the paper considers alternative explanations for the failure of nominal wages to adjust so as to restore full employment and their implications for the efficacy of fiscal policies. It concludes that under a variety of plausible conditions tax cuts would succeed in stimulating employment.

Hysteresis in Unemployment

The recent European experience of high persistent unemployment has led to the development of theories of unemployment hysteresis embodying the idea that the equilibrium unemployment rate depends on the history of the actual unemployment rate. This paper summarizes two directions of research on hysteresis that appear especially promising. Membership theories are based on the distinction between insiders and outsiders and explore the idea that wage setting is largely determined by firms' incumbent workers rather than by the unemployed. Duration theories explore the idea that the long term unemployed exert much less downwards pressure on wages than do the short term unemployed.

Perspectives on High World Real Interest Rates

macroeconomics, international, interest rates

Finite element computation of a viscous compressible free shear flow governed by the time dependent Navier-Stokes equations

A finite element algorithm for solution of fluid flow problems characterized by the two-dimensional compressible Navier-Stokes equations was developed. The program is intended for viscous compressible high speed flow; hence, primitive variables are utilized. The physical solution was approximated by trial functions which at a fixed time are piecewise cubic on triangular elements. The Galerkin technique was employed to determine the finite-element model equations. A leapfrog time integration is used for marching asymptotically from initial to steady state, with iterated integrals evaluated by numerical quadratures. The nonsymmetric linear systems of equations governing time transition from step-to-step are solved using a rather economical block iterative triangular decomposition scheme. The concept was applied to the numerical computation of a free shear flow. Numerical results of the finite-element method are in excellent agreement with those obtained from a finite difference solution of the same problem