Neurally Implementable Semantic Networks

We propose general principles for semantic networks allowing them to be implemented as dynamical neural networks. Major features of our scheme include: (a) the interpretation that each node in a network stands for a bound integration of the meanings of all nodes and external events the node links with; (b) the systematic use of nodes that stand for categories or types, with separate nodes for instances of these types; (c) an implementation of relationships that does not use intrinsically typed links between nodes.Comment: 32 pages, 12 figure

Inter-temporal differences in the income elasticity of demand for lottery tickets

We estimate annual income elasticities of demand for lottery tickets using roughly twenty years of county-level data for three states. We find that the income elasticity of demand (and thus the tax burden) for lottery tickets has changed over time. We argue that these changes are due to changes in a state's lottery game portfolio and the growth in consumer income. Trends in the income elasticity of demand for instant and online lottery games appear to be different. Our results question the long-term growth potential of lottery revenue and have policy implications for state governments and those concerned about regressivity.Gambling industry ; Income

Why did income growth vary across states during the Great Depression?

State per capita incomes became more disperse during the contraction phase of the Great Depression, and less disperse during the recovery phase. We investigate the effects of spatial dependence, industrial composition, bank failures and fiscal policies on state income growth during each phase. We find that industrial composition and spatial interdependencies contributed to negative state income growth during the contraction, whereas New Deal spending contributed to positive state income growth during the recovery phase. We find no evidence that differences in bank failure rates or state government expenditures contributed to variation in state income growth rates.Depressions

Income and lottery sales: transfers trump income from work and wealth

Previous studies have examined the effect of income on lottery ticket expenditures using an aggregate measure of income, usually personal income. Reasons exist, however, for believing that lottery expenditures do not respond equally to all sources of income. This paper examines the propensity to purchase lottery tickets from separate types of income, namely income from earnings, transfer payments, and wealth. Using county-level data for five states, we find evidence that lottery expenditures respond differently to changes in each income type, and that ticket purchases are most strongly influenced by changes in transfer payments. Several policy implications follow from our results.Income ; Gambling industry

Socioeconomic impact of photovoltaic power at Schuchuli, Arizona

The social and economic impact of photovoltaic power on a small, remote native American village is studied. Village history, group life, energy use in general, and the use of photovoltaic-powered appliances are discussed. No significant impacts due to the photovoltaic power system were observed

Laboratory experiments on the generation of internal tidal beams over steep slopes

We designed a simple laboratory experiment to study internal tides generation. We consider a steep continental shelf, for which the internal tide is shown to be emitted from the critical point, which is clearly amphidromic. We also discuss the dependence of the width of the emitted beam on the local curvature of topography and on viscosity. Finally we derive the form of the resulting internal tidal beam by drawing an analogy with an oscillating cylinder in a static fluid

Hamiltonian formalism and the Garrett-Munk spectrum of internal waves in the ocean

Wave turbulence formalism for long internal waves in a stratified fluid is developed, based on a natural Hamiltonian description. A kinetic equation appropriate for the description of spectral energy transfer is derived, and its self-similar stationary solution corresponding to a direct cascade of energy toward the short scales is found. This solution is very close to the high wavenumber limit of the Garrett-Munk spectrum of long internal waves in the ocean. In fact, a small modification of the Garrett-Munk formalism includes a spectrum consistent with the one predicted by wave turbulence.Comment: 4 pages latex fil