How Much Do Starting Values Really Matter? An Empirical Comparison of Genetic Algorithm and Traditional Approaches

This research evaluates the impact of using different starting conditions in estimating meat demand systems. Results suggest that as the econometric task becomes increasingly nonlinear, specification of starting conditions becomes increasingly important. This work demonstrates implications of failing to use the best available starting value conditions and how these implications vary with the complexity of the underlying econometric model of interest. Furthermore, this piece proposes a universal approach to be used by all applied econometric practioners to developing appropriate starting values for use in subsequent model estimation.Demand and Price Analysis,

Can the world feed itself? Some insights from growth theory

This paper develops a two-sector growth model incorporating the essential distinguishing features of agriculture, including the reliance of production on a natural resource base as well as on industrially produced inputs, the low income elasticity of demand for food and the life-sustaining function of food consumption. In this framework, the ability of an economy to supply an adequate supply of food to a growing population can be related to the existence of a steady state. This property is used to define a simple analytical criterion upon which to assess the long-term food situation of a closed economy. This sustainability condition relates all the dynamic parameters of the economy: rates of technological change in the two sectors, rate of population growth and rate of land degradation. The condition is used to highlight the technological characteristics in agriculture conducive to sustainability and to assess empirically the food situation of a number of countries. Although no global food crisis appears to be looming ahead, the data suggest that sub-Saharan Africa is likely to increase its food dependence in the future.Food Security and Poverty,

Antisymmetric tensor contribution to the muon g-2

We investigate the Kalb-Ramond antisymmetric tensor field as solution to the muon $g-2$ problem. In particular we calculate the lowest-order Kalb-Ramond contribution to the muon anomalous magnetic moment and find that we can fit the new experimental value for the anomaly by adjusting the coupling without affecting the electron anomalous magnetic moment results.Comment: 7 pages, 1 figur

GROWTH PATTERN, SUSTAINABILITY AND TRADE IN A LAND CONSTRAINED ECONOMY

This paper develops a two-sector model of growth where agriculture is considered explicitly. Key features of the model include: the reliance of agricultural production on a fixed but degrading resource base, the use by the farm sector of industrially produced inputs and differing rates of technological progress in the two sectors. On the demand side, the low income elasticity for food as well as the life-sustaining function of food consumption are recognized. In this simplified framework, the sustainability of growth can be related to the existence of a steady state reflecting the ability of the economy to feed its population. This property is used to identify the characteristics within and outside of agriculture conducive to the sustainability of a land-constrained economy. The empirical application identifies sub-Saharan Africa as the region of the world facing the most important challenges in terms of sustainability. The second part of the paper makes use of the transitional properties of the model to analyse the relationship between agricultural productivity and growth performance. For a closed economy, the model unambiguously supports the view that high agricultural productivity is conducive to fast growth and industrialization. Once the country is allowed to trade, however, the relationship becomes more complex, but a numerical experiment illustrates how trade liberalization can accelerate the growth of a country poorly endowed in agricultural resources.sustainability, agriculture and growth, dynamic general equilibrium model, International Development, O41, O13, F11,

Communications and tracking expert systems study

The original objectives of the study consisted of five broad areas of investigation: criteria and issues for explanation of communication and tracking system anomaly detection, isolation, and recovery; data storage simplification issues for fault detection expert systems; data selection procedures for decision tree pruning and optimization to enhance the abstraction of pertinent information for clear explanation; criteria for establishing levels of explanation suited to needs; and analysis of expert system interaction and modularization. Progress was made in all areas, but to a lesser extent in the criteria for establishing levels of explanation suited to needs. Among the types of expert systems studied were those related to anomaly or fault detection, isolation, and recovery

Economic growth and distribution of income: A growth model to fit Ghanaian data

Income distribution, economic growth, Development strategies,

Surf zone currents and influence on surfability

Surfing headlands are shallow and exposed coastal features that provide a specific form of breaking wave allowing a board-rider to ride on the unbroken wave face. The seabed shape and refraction of the waves in relation to depth contours provide the greatest influence on the quality of the surf break. The large scale and orientation of the Raglan headland allows only the low frequency swells to refract around the headland to create seven different surfing breaks. Each represents a compartmentalization of the shoreline along the headland. This creates variability in wave and current characteristics depending on the orientation and bathymetry at different locations. This provides not only potential access points through the surf-zone (ie: smaller currents), but greater surfability in a range of conditions that is not possible on small scale headlands. Headlands with surfing waves can be classified as mis-aligned sections of the coast, where the higher oblique angle of the breaking surf generates strong wave-driven currents. These currents are far greater than that found on coastlines in equilibrium with the dominant swell direction, where comparatively insignificant longshore drift is found. The strength and direction of wave-driven currents in the surf zone can influence the surfability of a break. At a surfing headland strong currents flowing downdrift along the shoreline make it difficult for a paddling surfer to get to the "take-off" location of the break, or maintain position in the line-up. In comparison currents flowing updrift along headlands makes getting "out the back" relatively easy, although surfers can be taken out to sea past the "take-off" point by a fast flowing current. Field experiments at Raglan, on the west coast of New Zealand have been conducted to measure current speed and direction during a large swell event. Observations of surfers attempting to paddle through the breaking-wave zone, confirms the strength of the wave-driven currents with surfers being swept rapidly down the headland. Results from the experiments at Raglan, have shown strong currents in the inshore breaking wave zone with burst-averaged velocities attaining 0.8 ms-1, and maximum bed orbital velocities of up to 2.0 ms-1. Interestingly, further offshore the currents have been found to flow in a re-circulating gyre back up the headland. Comparisons are made from observations of waves and currents found at other surfing headlands around the world. The effect that strong currents may have on the surfability of artificial surfing reefs needs to be considered in the design process, if the surfing amenity is to be maximised for large surf conditions