Mathematical programs with equilibrium constraints: automatic reformulation and solution via constrained optimization

Constrained optimization has been extensively used to solve many large scale deterministic problems arising in economics, including, for example, square systems of equations and nonlinear programs. A separate set of models have been generated more recently, using complementarity to model various phenomenon, particularly in general equilibria. The unifying framework of mathematical programs with equilibrium constraints (MPEC) has been postulated for problems that combine facets of optimization and complementarity. This paper briefly reviews some methods available to solve these problems and described a new suite of tools for working with MPEC models. Computational results demonstrating the potential of this tool are given that automatically construct and solve a variety of different nonlinear programming reformulations of MPEC problems.\ud \ud This material is based on research partially supported by the National Science Foundation Grant CCR-9972372, the Air Force Office of Scientific Research Grant F49620-01-1-0040, Microsoft Corporation and the Guggenheim Foundation

A Comparison of a Full Time Grazing and a Partial Storage Feeding System, for Dairy Cows

Partial storage feeding has been adopted by a number of Northern Ireland dairy farmers in recent years. This is due in part to increasing cow numbers, and as such, insufficient pasture close to the milking parlour to permit full time grazing. Partial storage feeding may also have environmental benefits, as well as reducing labour requirements associated with \u27droving\u27 and pasture management. In view of this, a study was undertaken to examine animal performance with either a full-time grazing, or a partial storage feeding regime

Factors Influencing the Adoption of Fodder Production Techniques by Milk Producers in Dhankuta District, Eastern Nepal

Many districts are food-deficient in Nepal. Increased milk consumption could improve human health and nutrition, while milk sales can provide families with a valuable source of income. However, milk production in Nepal is low, mainly because of the poor nutritional status of livestock, which can be attributed in part to a fodder deficit. However there is potential to increase fodder production, and some innovative fodder production techniques have been tried and proven locally. These include planting of fodder trees, fodder grasses and fodder crops. As the level of adoption of these techniques is variable, a survey was undertaken to quantify adoption levels by milk producers in Eastern Nepal, together with factors influencing adoption levels

Dairy Cow Performance Associated with Two Contrasting Silage Feeding Systems

As a result of increasing labour costs, the lack of skilled labour, and the desire of many farmers to reduce their working hours, there is considerable interest in using simple feeding systems for dairy cows. A study was conducted to compare two silage feeding systems that differed in complexity

Photochemical reactions of cyanoacetylene and dicyanoacetylene: Possible processes in Titan's atmosphere

Titan has an atmosphere which is subject to dramatic chemical evolution due mainly to the dramatic effect of the UV flux from the Sun. The energetic solar photons and other particles are converting the methane-nitrogen atmosphere into the unsaturated carbon compounds observed by the Voyager probes. These same solar photons are also converting some of these unsaturated reaction products into the aerosols observed in the atmosphere which obscure the view of the surface of Titan. In particular, the photochemical reactions of cyanoacetylene, dicyanoacetylene, acetylene and ethylene may result in the formation of the higher hydrocarbons and polymers which result in the aerosols observed in Titan's atmosphere. Polymers are the principal reaction products formed by irradiation of cyanoacetylene and dicyanoacetylene. Irradiation of cyanoacetylene with 185 nm of light also yields 1,3,5-tricyanobenzene while irradiation at 254 nm yields 1,2,4-tricyanobenzene and tetracyano cyclooctatetraenes. Photolyses of mixtures of cyanoacetylene and acetylene yields mono- and di- cyanobenzenes. The 1-Cyanocyclobutene is formed from the photochemical addition of cyanoacetylene with ethylene. The photolysis of dicyanoacetylene with acetylene yields 2,3-dicyano-1,3-butadiene and 1,2-dicyanobenzene. Tetracyano cyclooctatetraene products were also observed in the photolysis of mixtures of dicyanoacetylene and acetylene with 254 nm light. The 1,2-Dicyano cyclobutene is obtained from the photolysis dicyanoacetylene and ethylene. Reaction mechanisms will be proposed to explain the observed photoproducts

IPO Underpricing Firm Quality, and Subsequent Reissuance Activity

A signaling argument has recently been developed whereby IPO underpricing is a signal of future firm value. Only higher quality firms can be expected to recover the cost of this signal through subsequent offerings of seasoned equities. This study uses three proxies for firm quality and finds evidence of a positive relationship between these measures of firm quality and reissuance activity. Greater IPO underpricing is also found to be associated with greater levels of future equity selling and higher levels of earnings per share

Too Busy to Mind the Business? Monitoring by Directors with Multiple Board Appointments

We examine the number of external appointments held by corporate directors. Directors who serve larger firms and sit on larger boards are more likely to attract directorships. Consistent with Fama and Jensen (1983), we find that firm performance has a positive effect on the number of appointments held by a director. We find no evidence that multiple directors shirk their responsibilities to serve on board committees. We do not find that multiple directors are associated with a greater likelihood of securities fraud litigation. We conclude that the evidence does not support calls for limits on directorships held by an individual

Too Busy to Mind the Business? Monitoring by Directors with Multiple Board Appointments

We examine the number of external appointments held by corporate directors. Directors who serve larger firms and sit on larger boards are more likely to attract directorships. Consistent with Fama and Jensen (1983), we find that firm performance has a positive effect on the number of appointments held by a director. We find no evidence that multiple directors shirk their responsibilities to serve on board committees. We do not find that multiple directors are associated with a greater likelihood of securities fraud litigation. We conclude that the evidence does not support calls for limits on directorships held by an individual

Results of correlations for transition location on a clean-up glove installed on an F-14 aircraft and design studies for a laminar glove for the X-29 aircraft accounting for spanwise pressure gradient

Results of correlative and design studies for transition location, laminar and turbulent boundary-layer parameters, and wake drag for forward swept and aft swept wings are presented. These studies were performed with the use of an improved integral-type boundary-layer and transition-prediction methods. Theoretical predictions were compared with flight measurements at subsonic and transonic flow conditions for the variable aft swept wing F-14 aircraft for which experimental pressure distributions, transition locations, and turbulent boundary-layer velocity profiles were measured. Flight data were available at three spanwise stations for several values of sweep, freestream unit Reynolds number, Mach numbers, and lift coefficients. Theory/experiment correlations indicate excellent agreement for both transition location and turbulent boundary-layer parameters. The results of parametric studies performed during the design of a laminar glove for the forward swept wing X-29 aircraft are also presented. These studies include the effects of a spanwise pressure gradient on transition location and wake drag for several values of freestream Reynolds numbers at a freestream Mach number of 0.9