The Self-insurance Role of International Reserves and the 2008-2010 Crisis

There is no standard rule for the definition of an “optimal level” of international reserves and several assumptions underlie the rationale behind holding reserves. There are various theoretical approaches, but no standard for the evaluation of the performance of “optimal level” models, and their parameters are difficult to estimate. The literature suggests that the benefits of holding reserves are high, but the accumulation of reserves is a costly strategy. In fact, in a world of high liquidity and free capital flow, establishing an adequate level of international reserves is still a puzzle. The strategy of accumulating international reserves is evaluated here using data from the 2008-2010 crisis and it is shown that countries with higher international reserve levels had less adjustment costs between 2008 and 2010. The cost-benefit relationship of holding reserves in the 2008-2010 crisis is also discussed based on a sample with 71 countries.

Braneworld solutions for F(R) models with non-constant curvature

This work deal with braneworld scenarios with generalized gravity. We investigate models where the potential of the scalar field is polynomial or nonpolynomial. We obtain exact and approximated solutions for the scalar field, warp factor and energy density, in the complex scenario with no restriction on the scalar curvature. In particular, we describe the case where the brane may split, engendering internal structure, with the splitting caused by the same parameter that controls deviation from standard gravity.Comment: 9 pages, 7 figures; new versio

Pressure measurements on a rectangular wing with a NACA0012 airfoil during conventional flutter

The Structural Dynamics Division at NASA LaRC has started a wind tunnel activity referred to as the Benchmark Models Program. The primary objective of the program is to acquire measured dynamic instability and corresponding pressure data that will be useful for developing and evaluating aeroelastic type CFD codes currently in use or under development. The program is a multi-year activity that will involve testing of several different models to investigate various aeroelastic phenomena. The first model consisted of a rigid semispan wing having a rectangular planform and a NACA 0012 airfoil shape which was mounted on a flexible two degree-of-freedom mount system. Two wind-tunnel tests were conducted with the first model. Several dynamic instability boundaries were investigated such as a conventional flutter boundary, a transonic plunge instability region near Mach = 0.90, and stall flutter. In addition, wing surface unsteady pressure data were acquired along two model chords located at the 60 to 95-percent span stations during these instabilities. At this time, only the pressure data for the conventional flutter boundary is presented. The conventional flutter boundary and the wing surface unsteady pressure measurements obtained at the conventional flutter boundary test conditions in pressure coefficient form are presented. Wing surface steady pressure measurements obtained with the model mount system rigidized are also presented. These steady pressure data were acquired at essentially the same dynamic pressure at which conventional flutter had been encountered with the mount system flexible