New mode switching algorithm for the JPL 70-meter antenna servo controller

The design of control mode switching algorithms and logic for JPL's 70 m antenna servo controller are described. The old control mode switching logic was reviewed and perturbation problems were identified. Design approaches for mode switching are presented and the final design is described. Simulations used to compare old and new mode switching algorithms and logic show that the new mode switching techniques will significantly reduce perturbation problems

A new linear quadratic optimal controller for the 34-meter high efficiency antenna position loop

The design of a new position loop controller for the 34-meter High Efficiency Deep Space antennas using linear quadratic (LQ) optimal control techniques is discussed. The LQ optimal control theory is reviewed, and model development and verification are discussed. Families of optimal gain vectors are generated by varying weight parameters. Performance specifications were used to select a final gain vector. Estimator dynamics were selected and the corresponding gain vectors were computed. Final estimator selection was based on position, commanded rate, and estimator error responses

Analysing correlated noise on the surface code using adaptive decoding algorithms

Laboratory hardware is rapidly progressing towards a state where quantum error-correcting codes can be realised. As such, we must learn how to deal with the complex nature of the noise that may occur in real physical systems. Single qubit Pauli errors are commonly used to study the behaviour of error-correcting codes, but in general we might expect the environment to introduce correlated errors to a system. Given some knowledge of structures that errors commonly take, it may be possible to adapt the error-correction procedure to compensate for this noise, but performing full state tomography on a physical system to analyse this structure quickly becomes impossible as the size increases beyond a few qubits. Here we develop and test new methods to analyse blue a particular class of spatially correlated errors by making use of parametrised families of decoding algorithms. We demonstrate our method numerically using a diffusive noise model. We show that information can be learnt about the parameters of the noise model, and additionally that the logical error rates can be improved. We conclude by discussing how our method could be utilised in a practical setting blue and propose extensions of our work to study more general error models.Comment: 19 pages, 8 figures, comments welcome; v2 - minor typos corrected some references added; v3 - accepted to Quantu

Axisymmetric two-phase perfect gas performance program

Computer program calculates the inviscid axisymmetric nozzle expansion of propellant systems having both gaseous and condensed exhaust products. The program uses velocity and thermal lags and will perform calculations for contoured and conical nozzles

CAPITALIZATION OF FARMLAND PRESERVATION PROGRAMS INTO FARMLAND PRICES

This paper examines whether permanent farmland preservation programs are capitalized into farmland prices. We consider the landowner's decision to voluntarily participate and correct for sample selection bias in our estimation of sales prices. Initial results suggest development restrictions resulting from participation in these programs are fully capitalized into farmland prices.Demand and Price Analysis, Land Economics/Use,

Application of optimal control theory to the design of the NASA/JPL 70-meter antenna servos

The application of Linear Quadratic Gaussian (LQG) techniques to the design of the 70-m axis servos is described. Linear quadratic optimal control and Kalman filter theory are reviewed, and model development and verification are discussed. Families of optimal controller and Kalman filter gain vectors were generated by varying weight parameters. Performance specifications were used to select final gain vectors

Financial innovation, strategic real options and endogenous competition : theory and an application to Internet banking

Innovations in financial services continuously influence the scope of financial intermediation and the nature of competition between intermediaries. This paper examines the optimal exercise of strategic real options to invest in such an innovation, Internet banking technology, within a two-stage game, parameterized by the distribution of bank size and uncertainty over the profitability of investment, and empirically tests the results on a novel data set. Unlike traditional options, in which the distribution of the future value of the underlying asset is exogenous and the timing of exercise affects only the return to the option holder, the timing of the exercise of real options in a strategic context allows the option holder to manipulate the distribution of returns to all players. The value of the strategic investment option in our model, as a consequence, depends on both expected future profits as well as the variance of those profits. Expected profits to an entrant depend, in equilibrium, on its size, as measured by existing market share (concentration) or total assets, relative to its rivals. Conditional on the degree of uncertainty, larger banks should, as a consequence, exercise their options earlier than smaller banks, for purely strategic advantages, and act as market leaders in the provision of Internet banking services. Like ordinary options, however, the value of the strategic investment option to both large and small banks increases in uncertainty, implying that early exercise will be more likely the more information is available about potential demand. We test these hypotheses on investment in Internet banking services with data from a sample of 1,618 commercial banks in the tenth Federal Reserve District during 1999. Evidence indicates that relative bank size, as measured by either market share or asset size, positively influences the likelihood of entry into Internet banking, and trend-adjusted variation in income per person (a proxy for uncertainty of demand) negatively influences the likelihood of entry into Internet banking. In addition, market concentration of a bank's competitive rivals has a negative relationship with the likelihood of entering the market for Internet banking services. These relations are evident in both bivariate analysis and in multivariate logit regression analysis.Competition ; Internet ; Internet banking

Protecting Rural Amenities Through Farmland Preservation Programs

We investigate what farmland preservation programs reveal about the importance of protecting different rural amenities. An extensive content analysis of the enabling legislation of various farmland protection programs suggests wide variation exists in the protection of amenities. An analysis of 27 individual Purchase of Development Rights (PDR) programs' selection criteria suggests these programs favor preserving amenities that are jointly provided by cropland and livestock operations. These PDR selection criteria also reveal unique preferences regarding the spatial patterns of preserved agricultural lands. Variation in relative weights given to protecting most parcel characteristics in PDR programs is not easily explained by factors that characterize areas experiencing farmland losses.Land Economics/Use,

Participation in Conservation Programs by Targeted Farmers: Beginning, Limited-Resource, and Socially Disadvantaged Operators' Enrollment Trends

Beginning, limited-resource, and socially disadvantaged farmers make up as much as 40 percent of all U.S. farms. Some Federal conservation programs contain provisions that encourage participation by such “targeted” farmers and the 2008 Farm Act furthered these efforts. This report compares the natural resource characteristics, resource issues, and conservation treatment costs on farms operated by targeted farmers with those of other participants in the largest U.S. working-lands and land retirement conservation programs. Some evidence shows that targeted farmers tend to operate more environmentally sensitive land than other farmers, have different conservation priorities, and receive different levels of payments. Data limitations preclude a definitive analysis of whether efforts to improve participation by targeted farmers hinders or enhances the conservation programs’ ability to deliver environmental benefits cost effectively. But the different conservation priorities among types of farmers suggest that if a significantly larger proportion of targeted farmers participates in these programs, the programs’ economic and environmental outcomes could change.Conservation programs, Environmental Quality Incentives Program (EQIP), Conservation Reserve Program (CRP), Wetlands Reserve Program (WRP), beginning farmers, limited-resource producers, socially disadvantaged farmers and ranchers, Environmental Economics and Policy, Farm Management, Financial Economics, Food Consumption/Nutrition/Food Safety, Food Security and Poverty, Land Economics/Use, Production Economics, Research and Development/Tech Change/Emerging Technologies,

THE EFFECT OF A FOREST CONSERVATION REGULATION ON THE VALUE OF SUBDIVISIONS IN MARYLAND

Profit-maximizing land developers are hypothesized to configure subdivisions to minimize the effects of a conservation regulation on developed land values, subject to their expectations about the demand for developed building lots. This hypothesis allows development of a hedonic price model that takes account of production adjustments. The model is applied to the Maryland Forest Conservation Act, which requires developers to retain or plant trees on part of the developed land. Being exempt from the Act allows developers to gain more for the subdivisions they develop: the cost to regulated developers is about six percent of the per-acre price of developed land. The Act has significantly lowered per-acre developed land values in subdivisions with a mixture of townhouses and single-family dwellings. Costs of the Act are reduced by provisions that allow developers to plant trees offsite or to pay fees in lieu of planting.Resource /Energy Economics and Policy,