The market potential of the South African apple industry: Strategies and options

This paper uses one of four possible areas of strategic market research, namely Trademaps , to analyse the South African market potential for deciduous fruit. It isolates the apple industry to illustrate the application of Trademaps. An overview of the export performance within the apple industry is given. Export Trademaps are then utilised to analyse the trade flows and the market potential of South African apples on the world market. The Trademaps generated are based on trade data for the years 1995 to 1999 as reported by nearly 100 trading nations in the COMTRADE database of the United Nations Statistical Division. Possible strategies and options are suggested, given the results of the Trademap analysis. It is concluded that this analysis demonstrates the usefulness of Trademaps as a research tool to provide market information on new and existing markets.Crop Production/Industries,

Modelling fertiliser use in the grain crop and oilseed sectors of South Africa

A Partial Equilibrium (PE) model is developed to model fertiliser use in the grain crop and oilseed sectors to assess the impact of changes in the physical and economic environment on production and fertiliser use. Since the adoption of a policy of trade liberalisation and the shift towards a free market for agricultural products, the actual cropping patterns of grain crops have moved closer to the expected optimum production pattern. It is shown that the total area cultivated will decrease by 2,4 percent. Results show that except for the area under sunflower (that remains unchanged) and yellow maize that increases, the area utilised by other crops will decrease. Fertiliser use is directly correlated with production patterns in the provinces. A comparison of the base-case scenario and optimum solution revealed that the movement from a base to an optimum solution results in a drop in total area cultivated, production and exports. Fertiliser use correspondingly decreases.Crop Production/Industries,

Maximum likelihood estimation of photon number distribution from homodyne statistics

We present a method for reconstructing the photon number distribution from the homodyne statistics based on maximization of the likelihood function derived from the exact statistical description of a homodyne experiment. This method incorporates in a natural way the physical constraints on the reconstructed quantities, and the compensation for the nonunit detection efficiency.Comment: 3 pages REVTeX. Final version, to appear in Phys. Rev. A as a Brief Repor

Group Theoretical Quantum Tomography

The paper is devoted to the mathematical foundation of the quantum tomography using the theory of square-integrable representations of unimodular Lie groups.Comment: 13 pages, no figure, Latex2e. Submitted to J.Math.Phy

Broadband detection of squeezed vacuum: A spectrum of quantum states

We demonstrate the simultaneous quantum state reconstruction of the spectral modes of the light field emitted by a continuous wave degenerate optical parametric amplifier. The scheme is based on broadband measurement of the quantum fluctuations of the electric field quadratures and subsequent Fourier decomposition into spectral intervals. Applying the standard reconstruction algorithms to each bandwidth-limited quantum trajectory, a "spectrum" of density matrices and Wigner functions is obtained. The recorded states show a smooth transition from the squeezed vacuum to a vacuum state. In the time domain we evaluated the first order correlation function of the squeezed output field, showing good agreement with the theory.Comment: 11 pages, 5 figure

The Economic Rationale for Agricultural Regeneration and Rural Infrastructure Investment in South Africa

This paper informs government policy insofar as it relates to the agricultural and rural development sectors and infrastructure investment within these sectors. The paper first quantifies the role of agriculture in the South African economy. This is done within the context of, inter alia, food security, agriculture’s contribution to gross domestic product (GDP), economic linkages and multipliers with respect to the agricultural sector, as well as agriculture’s employment creation and external stabilisation capacity. Investment in the agricultural and rural sectors are then analysed with a view of supporting the argument that agriculture’s role in the economy is sufficiently important to warrant regenerative strategies, including renewed emphasis on agricultural and rural infrastructure investment by South African policy makers. The quantification of the agricultural sector in relation to the total economy and that of agricultural and rural infrastructure investment are investigated against the backdrop of declining government support, increasing production risks due to a variety of exogenous events like climate change, and increasing dynamic trade impacts. In this paper, the authors offer both supporting arguments in terms of current economic policy and recommendations for more decisive policy measures aimed at agricultural regeneration and rural infrastructure investment.

Quantum engineering of squeezed states for quantum communication and metrology

We report the experimental realization of squeezed quantum states of light, tailored for new applications in quantum communication and metrology. Squeezed states in a broad Fourier frequency band down to 1 Hz has been observed for the first time. Nonclassical properties of light in such a low frequency band is required for high efficiency quantum information storage in electromagnetically induced transparency (EIT) media. The states observed also cover the frequency band of ultra-high precision laser interferometers for gravitational wave detection and can be used to reach the regime of quantum non-demolition interferometry. And furthermore, they cover the frequencies of motions of heavily macroscopic objects and might therefore support the attempts to observe entanglement in our macroscopic world.Comment: 12 pages, 3 figure

Measuring quantum optical Hamiltonians

We show how recent state-reconstruction techniques can be used to determine the Hamiltonian of an optical device that evolves the quantum state of radiation. A simple experimental setup is proposed for measuring the Liouvillian of phase-insensitive devices. The feasibility of the method with current technology is demonstrated on the basis of Monte Carlo simulated experiments.Comment: Accepted for publication on Phys. Rev. Lett. 8 eps figures, 4 two-column pages in REVTE

Quantum phase space distributions in thermofield dynamics

It is shown that the the quantum phase space distributions corresponding to a density operator $\rho$ can be expressed, in thermofield dynamics, as overlaps between the state $\mid \rho >$ and "thermal" coherent states. The usefulness of this approach is brought out in the context of a master equation describing a nonlinear oscillator for which exact expressions for the quantum phase distributions for an arbitrary initial condition are derived.Comment: 17 pages, revtex, no figures. number of pages were incorrectly stated as 3 instead of 17. No other correction