We study the general problem of an agent wishing to minimize the risk of a position at a fixed date. The agent trades in a market with a risky asset, with incomplete information, proportional transaction costs, and possibly constraints on strategies. In particular, this framework includes the problems of hedging contingent claims and maximizing utility from wealth. We obtain a minimization prob...

We have obtained optical spectrophotometry of 11 H II regions in the polar ring of NGC 2685 (the Helix galaxy), and have used these data to study the physical characteristics of the polar-ring H II regions. The H II regions have normal spectra with no suggestion of unusual density, temperature, extinction, or composition. Semi-empirical calculations yield high oxygen abundance estimates (0.8–1....

The effects of interstitial carbon on the electronic and mechanical properties of copper are studied theoretically. Semiempirical methodology, atomistic simulations, and first-principles density functional embedded cluster schemes are combined to extract some understanding of the diffusion process and related degradation of Cu/C composite materials under extremes of temperature and stress. High...

An approximate theoretical formula for the distribution of aerodynamic load over arbitrary thick wings in incompressible flow is developed by combining three-dimensional results from thin-wing theory with two-dimensional results from thick-aerofoil theory. The formula is applied to two wings of identical planform, with 60 degrees trailing-edge sweepback and differing aerofoil thickness, which h...

A semiempirical theory of solid solubility in transition metal alloys is presented. The theory is based on writing the energy of formation of the solid solution as a sum of several contributions: a) a chemical contribution due to electronic redistribution in forming the alloy, b) an elastic contribution arising from the difference in size between solute and solvent atoms and c) a structural con...

matrix analysis of corrosion inhibition phenomena (macip), in which an inhibitor isconsidered as a point in a multi-dimensional virtual efficiency space, was performed on somepyridine derivatives. the needed molecular parameters such as homo and lumo energylevels, charge densities on hetero atom, dipole moment, heat of formation, and total energyvalues were obtained by means of semi-empirical q...