Decision-Making and Statistical Standards

NASA speech on use of statistical methods in governmental decision makin

Education in the Space Age

University role in space programs - need for educatio

A preliminary analysis of a three impulse technique for transearth injection from highly inclined orbits

Preliminary analysis of three impulse technique for transearth injection from highly inclined orbit

Study of the effects of atmospheric turbulence on laser communications systems, volume 1 Interim report

High altitude aircraft test for visible laser communication and analysis of errors in optical communications experiment due to flight path inaccuracie

Address by James E. Webb at the University of Delaware Commencement, Jun. 9, 1963

Motivation for space exploration - international leadership as the representative of capitalis

Stiffened plating under combined in-plane and lateral loading

Imperial Users onl

Self-Avoiding Modes of Motion in a Deterministic Lorentz Lattice Gas

We study the motion of a particle on the two-dimensional honeycomb lattice, whose sites are occupied by either flipping rotators or flipping mirrors, which scatter the particle according to a deterministic rule. For both types of scatterers we find a new type of motion that has not been observed in a Lorentz Lattice gas, where the particle's trajectory is a self-avoiding walk between returns to its initial position. We show that this behavior is a consequence of the deterministic scattering rule and the particular class of initial scatterer configurations we consider. Since self-avoiding walks are one of the main tools used to model the growth of crystals and polymers, the particle's motion in this class of systems is potentially important for the study of these processes.Comment: 32 pages, 18 figure

JT8D and JT9D jet engine performance improvement program. Task 1: Feasibility analysis

JT8D and JT9D component performance improvement concepts which have a high probability of incorporation into production engines were identified and ranked. An evaluation method based on airline payback period was developed for the purpose of identifying the most promising concepts. The method used available test data and analytical models along with conceptual/preliminary designs to predict the performance improvements, weight, installation characteristics, cost for new production and retrofit, maintenance cost, and qualitative characteristics of candidate concepts. These results were used to arrive at the concept payback period, which is the time required for an airline to recover the investment cost of concept implementation