Error evaluation for difference approximations to ordinary differential equations

Method involves relationships between errors introduced by using finite sampling rates and parameters describing specific numerical method used. Procedurre is used in design and analysi of digital filters and simulators

Threshold behavior of bosonic two-dimensional few-body systems

Bosonic two-dimensional self-bound clusters consisting of $N$ atoms interacting through additive van der Waals potentials become unbound at a critical mass m*(N); m*(N) has been predicted to be independent of the size of the system. Furthermore, it has been predicted that the ground state energy E(N) of the N-atom system varies exponentially as the atomic mass approaches m*. This paper reports accurate numerical many-body calculations that allow these predictions to be tested. We confirm the existence of a universal critical mass m*, and show that the near-threshold behavior can only be described properly if a previously neglected term is included. We comment on the universality of the energy ratio E(N+1)/E(N) near threshold.Comment: 6 pages, 3 figure

The Administrative Law of Regulatory Slop and Strategy

Judicial review of agency behavior is often criticized as either interfering too much with agencies’ domains or doing too little to ensure fidelity to statutory directives and the rule of law. But the Trump administration has produced an unprecedented volume of agency actions that blatantly flout settled administrative-law doctrine. This phenomenon, which we term “regulatory slop,” requires courts to reinforce the norms of administrative law by adhering to established doctrine and paying careful attention to remedial options. In this Article, we document numerous examples of regulatory slop and canvass how the Trump agencies have fared in court thus far. We contend that traditional critiques of judicial review carry little force in such circumstances. Further, regulatory slop should be of concern regardless of one’s political leanings because it threatens the rule of law. Rather than argue for a change to substantive administrative-law doctrine, therefore, we take a close look at courts’ remedial options in such circumstances. We conclude that a strong approach to remedies can send corrective signals to agencies that reinforce both administrative-law values and the rule of law

Sampling errors in closed loop hybrid computer programs

Sampling errors in closed loop hybrid computer program

Peripheral vision horizon display testing in RF-4C aircraft

A test program to assess the capability of the peripheral vision horizon display (PVHD) to provide peripheral attitude cues to the pilot is described. The system was installed in the rear cockpit of a RF-4C aircraft, selected because its poor instrument crosscheck conditions. The PVHD test plan was designed to assess three primary areas: (1) ability of the system to reduce spatial disorientation; (2) ability of the system to aid the pilot in recovering from unusual attitudes; and (3) improvement in pilot performance during instrument landing system (ILS) approaches. Results of preliminary test flights are summarized. The major problem areas concern the distinction of the display itself and the capability of the display to provide pitch motion cues

Errors in hybrid computers

Method is described for reduction of error components in numerical integration, sampling with zero hold order, and execution time delay

Hybrid computer techniques for solving partial differential equations

Techniques overcome equipment limitations that restrict other computer techniques in solving trivial cases. The use of curve fitting by quadratic interpolation greatly reduces required digital storage space

Opacity of hot, highly compressed hydrogen Final report

Ballistic piston compressor used to study opacity of hot highly compressed hydroge

The AFGL absolute gravity program

A brief discussion of the AFGL's (Air Force Geophysics Laboratory) program in absolute gravity is presented. Support of outside work and in-house studies relating to gravity instrumentation are discussed. A description of the current transportable system is included and the latest results are presented. These results show good agreement with measurements at the AFGL site by an Italian system. The accuracy obtained by the transportable apparatus is better than 0.1 microns sq sec 10 microgal and agreement with previous measurements is within the combined uncertainties of the measurements

The Tunisian Fertilizer Distribution System - Structural and Policy Considerations

Crop Production/Industries,