11,875 research outputs found

    Entry, Exit, and Structural Change in Pennsylvania's Dairy Sector

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    Data on the number of Pennsylvania dairy farms by size category are analyzed in a Markov chain setting to determine factors affecting entry, exit, expansion, and contraction within the sector. Milk prices, milk price volatility, land prices, policy, and cow productivity all impact structural change in Pennsylvania's dairy sector. Stochastic simulation analysis suggests that the number of dairy farms in Pennsylvania will likely fall by only 2.0 percent to 2.5 percent annually over the next 20 years, indicating that dairy farming in Pennsylvania is likely to be a significant enterprise for the state in the foreseeable future.dairy, maximum entropy, farm size, Markov chain, simulation, Farm Management, Industrial Organization,

    A DERIVATIVE SECURITY APPROACH TO SETTING CROP REVENUE COVERAGE INSURANCE PREMIUMS

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    The nature of indemnities and reliance on futures price averaging during two distinct time intervals throughout the production year imply Crop Revenue Coverage (CRC) insurance behaves like an exotic put option. Treating this type of insurance as a derivative security, an analytical model is developed and an algorithm for solving the model to place a lower bound on insurance premiums is presented. Monte Carlo simulation, taking into account the path-dependent nature of an Asian-type option, is then used to determine lower-bound estimates for insurance premiums on corn gross revenue under specified price and yield distributions.Risk and Uncertainty,

    Multispectral scanner optical system

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    An optical system for use in a multispectral scanner of the type used in video imaging devices is disclosed. Electromagnetic radiation reflected by a rotating scan mirror is focused by a concave primary telescope mirror and collimated by a second concave mirror. The collimated beam is split by a dichroic filter which transmits radiant energy in the infrared spectrum and reflects visible and near infrared energy. The long wavelength beam is filtered and focused on an infrared detector positioned in a cryogenic environment. The short wavelength beam is dispersed by a pair of prisms, then projected on an array of detectors also mounted in a cryogenic environment and oriented at an angle relative to the optical path of the dispersed short wavelength beam

    Radicals of 0-regular algebras

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    We consider a generalisation of the Kurosh--Amitsur radical theory for rings (and more generally multi-operator groups) which applies to 0-regular varieties in which all operations preserve 0. We obtain results for subvarieties, quasivarieties and element-wise equationally defined classes. A number of examples of radical and semisimple classes in particular varieties are given, including hoops, loops and similar structures. In the first section, we introduce 0-normal varieties (0-regular varieties in which all operations preserve 0), and show that a key isomorphism theorem holds in a 0-normal variety if it is subtractive, a property more general than congruence permutability. We then define our notion of a radical class in the second section. A number of basic results and characterisations of radical and semisimple classes are then obtained, largely based on the more general categorical framework of L. M\'arki, R. Mlitz and R. Wiegandt as in [13]. We consider the subtractive case separately. In the third section, we obtain results concerning subvarieties and quasivarieties based on the results of the previous section, and also generalise to subtractive varieties some results for multi-operator group radicals defined by simple equational rules. Several examples of radical and semisimple classes are given for a range of fairly natural 0-normal varieties of algebras, most of which are subtractive

    VALUING AGRICULTURAL MORTGAGE-BACKED SECURITIES

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    A model to value Federal Agricultural Mortgage Corporation (Farmer Mac) agricultural mortgage-backed securities (AMBS) is developed and numerically solved. The results suggest prepayment penalties currently being used by Farmer Mac reduce yields on AMBS considerably. Even with prepayment penalties, it can be advantageous for profit maximizing mortgagors to optimally prepay or even default on agricultural mortgages. The model is used to quantify prepayment and default risk by valuing the embedded options in the mortgages. Monte Carlo simulation is also used to determine the probability to optimal prepayment given the term structure assumption used to develop the model.agricultural mortgage-backed securities, default, dynamic programming, simulation, prepayment, Agricultural Finance, G13, G21,

    The development of an unconventional food regeneration process: Quantifying the nutritional components of a model methylotrophic yeast

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    A hybrid chemical/biological approach to unconventional food regeneration is discussed. Carbon dioxide and water, the major wastes of human metabolism would be converted to methanol by one of several physiochemical processes available (thermal, photocatalytic, etc.). Methanol is then used to supply carbon and energy for the culture of microorganisms which in turn produce biological useful basic food stuffs for human nutrition. Our work has focused on increasing the carbohydrate levels of a candidate methylotrophic yeast to more nearly coincide with human nutritional requirements. Yeasts were chosen due to their high carbohydrate levels compared to bacteria and their present familiarity in the human diet. The initial candidate yeast studied was a thermotolerant strain of Hansenula polymor pha, DL-1. The quantitative results that permit an evaluation of the overall efficiency in hybrid chemical/biological food production schemes are discussed. A preliminary evaluation of the overall efficiency of such schemes is also discussed

    Multifactorial analysis of human blood cell responses to clinical total body irradiation

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    Multiple regression analysis techniques are used to study the effects of therapeutic radiation exposure, number of fractions, and time on such quantal responses as tumor control and skin injury. The potential of these methods for the analysis of human blood cell responses is demonstrated and estimates are given of the effects of total amount of exposure and time of protraction in determining the minimum white blood cell concentration observed after exposure of patients from four disease groups

    Dosimetry for radiobiological studies of the human hematopoietic system

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    A system for estimating individual bone marrow doses in therapeutic radiation exposures of leukemia patients was studied. These measurements are used to make dose response correlations and to study the effect of dose protraction on peripheral blood cell levels. Three irradiators designed to produce a uniform field of high energy gamma radiation for total body exposures of large animals and man are also used for radiobiological studies

    Interrelationships between tracking performance measures, control dynamics, and the effects of incentives

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    Interrelationships between tracking performance measures, control dynamics, and effects of incentive

    Pre-apprenticeship training for young people: Estimating the marginal and average treatment effects

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    This paper evaluates traineeships, a voluntary programme of work placement and preparation that aims to help young unemployed people in England compete for jobs and apprenticeships. Applying the method of local instrumental variables to administrative data, we estimate the marginal treatment effects on apprenticeship take-up and employment. The heterogeneous impacts are then aggregated to form an estimate of the average impact of treatment for all participants. The results suggest that, among younger trainees, participation increases the probability of becoming an apprentice and that this holds across the distribution of unobserved heterogeneity. For older trainees, we find no significant effect on the probability of becoming an apprenticeship on average but some evidence of a negative effect among those more resistant to participating. We find no effects on employment for either age group
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