Thoughts on the chimera method of simulation of three-dimensional viscous flow

The chimera overset grid is reviewed and discussed relative to other procedures for simulating flow about complex configurations. It is argued that while more refinement of the technique is needed, current schemes are competitive to unstructured grid schemes and should ultimately prove more useful

Economic Growth and Sectoral Change under Resource Reallocation Costs

A general growth model with explicit resource reallocation costs is set up. A new feature is the property of hysteresis (i.e. a continuum of stationary equilibria) in closed-economy growth models. Employing a linear model the hysteresis range and the consequences for the long-run growth rate are determined analytically. The most important conclusions are the following: (1) An economy’s long-run position may depend critically on the initial intersectoral allocation pattern as well as on the efficiency of the resource reallocation sector; (2) if we interpret the resource reallocation sector as a specific part of the education sector, there is a straightforward possibility for the government to reduce the range of hysteresis and hence the dependence on initial conditions; (3) international trade is an important device to overcome the negative consequences of high resource reallocation costs for long-run growth.Sectoral change; economic growth; resource reallocation costs; hysteresis; multiplicity of equilibria

History, Expectations, and Public Policy: Economic Development in Eastern Germany

Motivated by the process of economic development in Eastern Germany since the German reunification we set up a dynamic macroeconomic model of a small open economy where both capital and labor are mobile and there are increasing returns to scale at the aggregate level. The model features multiple equilibria as well as (local and global) indeterminacy. Expectations matter for resulting equilibrium dynamics, implying that economic confidence may be crucial for the process of economic development. Despite its simplicity, the model can replicate major empirical facts and bears a number of non-trivial implications.increasing returns to scale, capital mobility, migration, multiple equilibria, indeterminacy, history vs. expectations, economic policy

On the Insertion Time of Cuckoo Hashing

Cuckoo hashing is an efficient technique for creating large hash tables with high space utilization and guaranteed constant access times. There, each item can be placed in a location given by any one out of k different hash functions. In this paper we investigate further the random walk heuristic for inserting in an online fashion new items into the hash table. Provided that k > 2 and that the number of items in the table is below (but arbitrarily close) to the theoretically achievable load threshold, we show a polylogarithmic bound for the maximum insertion time that holds with high probability.Comment: 27 pages, final version accepted by the SIAM Journal on Computin