Predicting the Corn Basis in the Texas Triangle Area

Shifting patterns of corn use as a result of the ethanol boom may be causing basis levels to change across the United States, creating the need for methods to predict basis levels in dynamic conditions. This study develops a new and straightforward economic model of basis forecasting that outperforms the simple three-year average method suggested in much of the literature. We use monthly data of the corn basis in the Texas Triangle Area from February 1997 to July 2008. The results show the new model based on economic fundamentals performs better than basis estimates using a three-year moving average.basis, corn, grain marketing, Texas Triangle Area, Agribusiness, Marketing,

Predicting the Corn Basis in the Texas Triangle Area

This study develops a new and straightforward economic model of basis forecasting that outperforms the simple three-year average method suggested in much of the literature. We use monthly data of the corn basis in the Texas Triangle Area from February 1997 to July 2008. The results and the graphs indicate that the new model based on economic fundamentals performs better than basis estimates using a three-year moving average.Hedging, basis, corn, Agribusiness, Agricultural Finance, Financial Economics, Marketing, Risk and Uncertainty,

All-optical signal processing using semiconductor optical amplifiers for next generation optical networks

This thesis details an experimental and simulation investigation of some novel all-optical signal processing techniques for future optical communication networks. These all-optical techniques include modulation format conversion, phase discrimination and clock recovery. The methods detailed in this thesis use the nonlinearities associated with semiconductor optical amplifiers (SOA) to manipulate signals in the optical domain. Chapter 1 provides an introduction into the work detailed in this thesis, discusses the increased demand for capacity in today’s optical fibre networks and finally explains why all-optical signal processing may be of interest for future optical networks. Chapter 2 discusses the relevant background information required to fully understand the all-optical techniques demonstrated in this thesis. Chapter 3 details some pump-probe measurement techniques used to calculate the gain and phase recovery times of a long SOA. A remarkably fast gain recovery is observed and the wavelength dependent nature of this recovery is investigated. Chapter 4 discusses the experimental demonstration of an all-optical modulation conversion technique which can convert on-off- keyed data into either duobinary or alternative mark inversion. In Chapter 5 a novel phase sensitive frequency conversion scheme capable of extracting the two orthogonal components of a quadrature phase modulated signal into two separate frequencies is demonstrated. Chapter 6 investigates a novel all-optical clock recovery technique for phase modulated optical orthogonal frequency division multiplexing superchannels and finally Chapter 7 provides a brief conclusion

High-bandwidth generation of duobinary and alternate-mark-inversion modulation formats using SOA-based signal processing

We report on the novel all-optical generation of duobinary (DB) and alternate-mark-inversion (AMI) modulation formats at 42.6 Gb/s from an input on-off keyed signal. The modulation converter consists of two semiconductor optical amplifier (SOA)-based Mach-Zehnder interferometer gates. A detailed SOA model numerically confirms the operational principles and experimental data shows successful AMI and DB conversion at 42.6 Gb/s. We also predict that the operational bandwidth can be extended beyond 40 Gb/s by utilizing a new pattern-effect suppression scheme, and demonstrate dramatic reductions in patterning up to 160 Gb/s. We show an increasing trade-off between pattern-effect reduction and mean output power with increasing bitrate

All-optical modulation converter for on-off keying to duobinary and alternate-mark inversion at 42.6 Gbps

Advanced modulation formats have become increasingly important as telecoms engineers strive for improved tolerance to both linear and nonlinear fibre-based transmission impairments. Two important modulation schemes are Duobinary (DB) and Alternate-mark inversion (AMI) [1] where transmission enhancement results from auxiliary phase modulation. As advanced modulation formats displace Return-to-zero On-Off Keying (RZ-OOK), inter-modulation converters will become increasingly important. If the modulation conversion can be performed at high bitrates with a small number of operations per bit, then all-optical techniques may offer lower energy consumption compared to optical-electronic-optical approaches. In this paper we experimentally demonstrate an all-optical system incorporating a pair of hybrid-integrated semiconductor optical amplifier (SOA)-based Mach-Zehnder interferometer (MZI) gates which translate RZ-OOK to RZ-DB or RZ-AMI at 42.6 Gbps. This scheme includes a wavelength conversion to arbitrary output wavelength and has potential for high-level photonic integration, scalability to higher bitrates, and should exhibit regenerative properties [2]

A systematic review on the clustering and co-occurrence of multiple risk behaviours.

BACKGROUND: Risk behaviours, such as smoking and physical inactivity account for up to two-thirds of all cardiovascular deaths, and are associated with substantial increased mortality in many conditions including cancer and diabetes. As risk behaviours are thought to co-occur in individuals we conducted a systematic review of studies addressing clustering or co-occurrence of risk behaviours and their predictors. As the main aim of the review was to inform public health policy in England we limited inclusion to studies conducted in the UK. METHODS: Key databases were searched from 1990 to 2016. We included UK based cross-sectional and longitudinal studies that investigated risk behaviours such as smoking, physical inactivity, unhealthy diet. High heterogeneity precluded meta-analyses. RESULTS: Thirty-seven studies were included in the review (32 cross-sectional and five longitudinal). Most studies investigated unhealthy diet, physical inactivity, alcohol misuse, and smoking. In general adult populations, there was relatively strong evidence of clustering between alcohol misuse and smoking; and unhealthy diet and smoking. For young adults, there was evidence of clustering between sexual risk behaviour and smoking, sexual risk behaviour and illicit drug use, and sexual risk behaviour and alcohol misuse. The strongest associations with co-occurrence and clustering of multiple risk behaviours were occupation (up to 4-fold increased odds in lower SES groups) and education (up to 5-fold increased odds in those with no qualifications). CONCLUSIONS: Among general adult populations, alcohol misuse and smoking was the most commonly identified risk behaviour cluster. Among young adults, there was consistent evidence of clustering found between sexual risk behaviour and substance misuse. Socio-economic status was the strongest predictor of engaging in multiple risk behaviours. This suggests the potential for interventions targeting multiple risk behaviours either sequentially or concurrently particularly where there is evidence of clustering. In addition, there is potential for intervening at the social or environmental level due to the strong association with socio-economic status

Power spectrum for the small-scale Universe

The first objects to arise in a cold dark matter universe present a daunting challenge for models of structure formation. In the ultra small-scale limit, CDM structures form nearly simultaneously across a wide range of scales. Hierarchical clustering no longer provides a guiding principle for theoretical analyses and the computation time required to carry out credible simulations becomes prohibitively high. To gain insight into this problem, we perform high-resolution (N=720^3 - 1584^3) simulations of an Einstein-de Sitter cosmology where the initial power spectrum is P(k) propto k^n, with -2.5 < n < -1. Self-similar scaling is established for n=-1 and n=-2 more convincingly than in previous, lower-resolution simulations and for the first time, self-similar scaling is established for an n=-2.25 simulation. However, finite box-size effects induce departures from self-similar scaling in our n=-2.5 simulation. We compare our results with the predictions for the power spectrum from (one-loop) perturbation theory and demonstrate that the renormalization group approach suggested by McDonald improves perturbation theory's ability to predict the power spectrum in the quasilinear regime. In the nonlinear regime, our power spectra differ significantly from the widely used fitting formulae of Peacock & Dodds and Smith et al. and a new fitting formula is presented. Implications of our results for the stable clustering hypothesis vs. halo model debate are discussed. Our power spectra are inconsistent with predictions of the stable clustering hypothesis in the high-k limit and lend credence to the halo model. Nevertheless, the fitting formula advocated in this paper is purely empirical and not derived from a specific formulation of the halo model.Comment: 30 pages including 10 figures; accepted for publication in MNRA