Testing the induced innovation hypothesis in South African agriculture (an error correction approach)

The authors investigate whether factor prices matter in agricultural production and in the selection of production technology. Each stage of the analysis corroborates the inducement hypothesis, which implies that factor prices do matter in agricultural production and in the selection of production technology. The empirical results also suggest that observed rates and biases of technological change are influenced by average farm size, by spending on research and extension, and by favorable tax and interest-rate policies. In South Africa, the authors contend, more attention should be focused on the technological needs of small-scale farmers. The lobbying power of the large commercial farmers, combined with policies followed under apartheid, must have influenced the allocation of research and development funds between labor- and land-saving technical change. This will have distorted the technological bias toward labor saving technical change, which is hardly appropriate for a labor-surplus economy in which small farmers in the former homelands face a chronic scarcity of land. These results show that factor prices do matter in agricultural production and the selection of production technology. And there seems to be merit to the World Bank's usual policy prescription - structural adjustment and market liberalization - for economies in which prices are controlled and distorted. They investigate the role of factor prices by applying cointegration techniques to a model of induced innovation based on the two-stage constant elasticity of substitution production function. This approach results in direct tests of the inducement hypothesis, which are applied to data for South African agriculture for the period 1947-92. They check the time series properties of the variables, establish cointegration, and construct an error correction model (ECM) that allows factor substitution to be separated from technological change. Finally, they subject the ECM formulation to tests of causality, which show that the factor price ratios induce the factor saving biases of technological change.Economic Theory&Research,Environmental Economics&Policies,Agricultural Knowledge&Information Systems,Scientific Research&Science Parks,Markets and Market Access,Environmental Economics&Policies,Economic Theory&Research,Agricultural Knowledge&Information Systems,Scientific Research&Science Parks,Science Education

Functional/thermal verification and validation of an S-band radio for the nanosatellites

© 2018 COSPAR An S-band radio designed with commercial-grade components for the nanosatellites is functionally and thermally characterized for quiet transmission. The QPSK modulation impairments are minor over −20 °C to +50 °C at 24, 26, 28 and 30 dBm RF levels. The channel response is linear in error vector magnitude, frequency, phase, amplitude and IQ errors. On the average, the stability of amplifier bias and nonlinearity gives −22 dBc maximum upper/lower adjacent channel power and 1.27 MHz occupied channel bandwidth. The acceptable level test results provide good confidence toward robust space-to-earth transmission in variable solar weather at low earth orbital altitudes

Integrable Subsectors from Holography

We consider operators in ${\cal N}=4$ super Yang-Mills theory dual to closed string states propagating on a class of LLM geometries. The LLM geometries we consider are specified by a boundary condition that is a set of black rings on the LLM plane. When projected to the LLM plane, the closed strings are polygons with all corners lying on the outer edge of a single ring. The large $N$ limit of correlators of these operators receives contributions from non-planar diagrams even for the leading large $N$ dynamics. Our interest in these fluctuations is because a previous weak coupling analysis argues that the net effect of summing the huge set of non-planar diagrams, is a simple rescaling of the 't Hooft coupling. We carry out some nontrivial checks of this proposal. Using the $su(2|2)^2$ symmetry we determine the two magnon $S$-matrix and demonstrate that it agrees, up to two loops, with a weak coupling computation performed in the CFT. We also compute the first finite size corrections to both the magnon and the dyonic magnon by constructing solutions to the Nambu-Goto action that carry finite angular momentum. These finite size computations constitute a strong coupling confirmation of the proposal.Comment: v2 matches published versio

Ion Beams for Space Applications

This chapter uses an active space mission as well as current and ongoing research work to showcase the role of ion beams in the advancement of space science and technology. It uses the mission objectives of the ZACUBE-2 space mission developed at the Cape Peninsula University of Technology in Cape Town, South Africa, to predict the space environment it will encounter when in orbit. These predictions are then used to show how ion beam parameters for single event effect testing are selected, and how trade-offs are made to achieve a cost effective use of beam time. An experiment is detailed, showcasing the role of ion beams in the investigation of the shielding capabilities of coatings obtained from the pulsed laser ablation of W2B5/B4C for solar panel applications in space. The results of this experiment show that indeed this is a potential shield capable of reducing solar panel degradation due to low energy protons. By using ZACUBE-2 and coatings made from W2B5/B4C, this chapter takes a practical and current approach to demonstrate the central role played by ion beams in advancing space technology. More importantly, it eases the conversation between the satellite and the ion beam communities