A transportation problem formulation for the MAC Airlift Planning problem

The Military Airlift Command (MAC) is responsible for planning the allocation of airlift resources for the movement of cargo and passengers. A heuristic algorithm, the Airlift Planning Algorithm (APA), has recently been developed under subcontract to the Oak Ridge National Laboratory to assist MAC in scheduling airlift resources. In this paper, we present a transportation problem formulation which can be used as a preprocessor to the APA or as an estimator for the APA. This paper examines the robustness and sensitivity of the transportation problem formulation. In particular, the performance of the APA improves by approximately 10% when the transportation problem is used as a preprocessor for two hypothetical problems and improves by up to 50% for derived airlift constrained problems.     

A finite concave minimization algorithm using branch and bound and neighbor generation

In this article we present a new finite algorithm for globally minimizing a concave function over a compact polyhedron. The algorithm combines a branch and bound search with a new process called neighbor generation. It is guaranteed to find an exact, extreme point optimal solution, does not require the objective function to be separable or even analytically defined, requires no nonlinear computations, and requires no determinations of convex envelopes or underestimating functions. Linear programs are solved in the branch and bound search which do not grow in size and differ from one another in only one column of data. Some preliminary computational experience is also presented.     

Plant antitumour agents-XV: Isolation and x-ray crystal structure of a new antileukaemic quassinoid undulatone from Hannoa undulata

The structure of Undulatone, a new antileukaemic quassinoid from Hannoa undulata was determined by spectral means and confirmed by single crystal X-ray analysis of the methanol solvate.     

Nitrone cycloadditions. regiochemistry.

The regiochemistry of nitrone cycloadditions has been reexamined. Certain nitrones afford regioisomeric mixtures of isoxazolidines, with a tendency toward increasing amounts of the 4-substituted regioisomer as the ionization potential of the dipolarophile is increased.