New england and the space program

Competing for space program business - marketing facto

Vacuum Cerenkov Radiation in Lorentz-Violating Theories Without CPT Violation

In theories with broken Lorentz symmetry, Cerenkov radiation may be possible even in vacuum. We analyze the Cerenkov emissions that are associated with the least constrained Lorentz-violating modifications of the photon sector, calculating the threshold energy, the frequency spectrum, and the shape of the Mach cone. In order to obtain sensible results for the total power emitted, we must make use of information contained within the theory which indicates at what scale new physics must enter.Comment: 9 page

Diapause in the Boll Weevil, Anthonontus grandis Boheman, As Related to Fruiting Activity in the Cotton Plant

Studies in Arkansas show that boll weevil diapause is related to changes in fruiting activity of the cotton plant. Generally, when larval development took place while fruiting levels were increasing or being held at a high level, diapause in resulting adults was low (0-20%). Diapause was approximately 20-50% when larval development coincided with decreasing fruiting levels, and was 50-100% as true cut-out approached. Regrowth cotton generally lowered diapause incidence and as fruiting levels decreased, diapause increased. Therefore, the boll weevil not only responds to short photoperiods that are characteristic during the fall in the temperate zone, but also may respond throughout the season to changes in fruiting activity of the cotton plant

Falling sphere-radar mathematical simulation techniques Final report, 15 Dec. - 15 Aug. 1965

Computer program for describing falling sphere trajectory and conversion of sphere trajectory into simulated radar tracking dat

A computational method to model radar return range in a polygonally based, computer-generated-imagery simulation

Described is a method for modeling a ground-mapping radar system for use in simulations where the terrain is in a polygonal form commonly used with computer generated imagery (CGI). The method employs a unique approach for rapidly rejecting polygons not visible to the radar to facilitate the real-time simulation of the radar return. This rapid rejection of the nonvisible polygons requires the precalculation and storage of a set of parameters that do not vary during the simulation. The calculation of a radar range as a function of the radar forward-looking angle to the CGI terrain is carried out only for the visible polygons. This method was used as part of a simulation for terrain-following helicopter operations on the vertical motion simulator at the NASA Ames Research Center. It proved to be an efficient means for returning real-time simulated radar range data

Self-Selection and Tests for Bias and Risk in Mortgage Lending: Can You Price the Mortgage If You Don't Know the Process?

There is increasing interest in understanding the determinants of mortgage rejection by lenders and default by borrowers. Although many researchers have proposed simple single-equation models of rejection and default, we argue that far more complex econometric specifications are needed. This paper focuses attention on problems of sample selection in the process creating a sample of applicants for conventional mortgages. We illustrate that corrections for sample selection bias may have a substantial effect on estimation results and hence should not be ignored in studies of mortgage rejection or default.

Out-reach in-space technology experiments program: Control of flexible robot manipulators in zero gravity, experiment definition phase

The results obtained show that it is possible to control light-weight robots with flexible links in a manner that produces good response time and does not induce unacceptable link vibrations. However, deflections induced by gravity cause large static position errors with such a control system. For this reason, it is not possible to use this control system for controlling motion in the direction of gravity. The control system does, on the other hand, have potential for use in space. However, in-space experiments will be needed to verify its applicability to robots moving in three dimensions