Investigation of slosh anomaly in Apollo lunar module propellant gage

Analysis of propellant sloshing in lunar module during Apollo 14 flight and resultant erroneous indication of low level of propellan

Some space shuttle tile/strain-isolator-pad sinusoidal vibration tests

Vibration tests were performed on the tile/strain-isolator-pad system used as thermal protection for the space shuttle orbiter. Experimental data on normal and in-plane vibration response and damping properties are presented. Three test specimens exhibited shear type motion during failures that occurred in the tile near the tile/strain-isolator-pad bond-line. A dynamic instability is described which has large in-plane motion at a frequency one-half that of the nominal driving frequency. Analysis shows that this phenomenon is a parametric response

Modeling, Analysis, and Optimization Issues for Large Space Structures

Topics concerning the modeling, analysis, and optimization of large space structures are discussed including structure-control interaction, structural and structural dynamics modeling, thermal analysis, testing, and design

Remote sensing study of land use and sedimentation in the Ross Barnett Reservoir, Jackson, Mississippi area

This multi-year study is aimed at focusing on the recognition of sediment and other affluents in a selected area of the Ross Barnett Reservoir. The principle objectives are the determination of land use types, effect of land use on erosion, and the correlation of sediment with land use in the area. The I2S multi-band imagery was employed in conjunction with ground truth data for both water and land use studies. The selected test site contains approximately forty square miles including forest, open land, and water in addition to residential and recreational areas

Are the Tails of Percolation Thresholds Gaussians ?

The probability distribution of percolation thresholds in finite lattices were first believed to follow a normal Gaussian behaviour. With increasing computer power and more efficient simulational techniques, this belief turned to a stretched exponential behaviour, instead. Here, based on a further improvement of Monte Carlo data, we show evidences that this question is not yet answered at all.Comment: 7 pages including 3 figure

Cut generation for an employee timetabling problem

Motivated by an industrial application, we study a specific employee timetabling problem. Several investigations are being conducted: a lower bound by Lagrangian relaxation, a heuristic based on a cut generation process and an exact method by Benders decomposition. Experimental results on real and generated instances are reported

Réductions de domaine lagrangiennes pour le problème de minimisation des pénalités d'avance et de retard ponderées sur une machine

Cet article présente de nouvelles règles d\u27élimination pour le problème de minimisation des pénalités d\u27avance et de retard sur une machine, avec ousans dates de disponibilité. Ces règles, basées sur une décomposition lagrangienne, permettent de réduire considérablement les fenêtres d\u27exécution des tâches, et, ainsi, d\u27utiliser efficacement d\u27autres règles d\u27élimination classiques. Les expérimentations montrent que des instances comportant jusqu\u27à 70 tâches sans date de disponiblité, et 40 tâches avec dates de disponibilité, peuvent être résolues optimalement en une heure, en intégrant ces propriétés dans un branch-and-bound

Efficient Monte Carlo algorithm and high-precision results for percolation

We present a new Monte Carlo algorithm for studying site or bond percolation on any lattice. The algorithm allows us to calculate quantities such as the cluster size distribution or spanning probability over the entire range of site or bond occupation probabilities from zero to one in a single run which takes an amount of time scaling linearly with the number of sites on the lattice. We use our algorithm to determine that the percolation transition occurs at occupation probability 0.59274621(13) for site percolation on the square lattice and to provide clear numerical confirmation of the conjectured 4/3-power stretched-exponential tails in the spanning probability functions.Comment: 8 pages, including 3 postscript figures, minor corrections in this version, plus updated figures for the position of the percolation transitio

A fast Monte Carlo algorithm for site or bond percolation

We describe in detail a new and highly efficient algorithm for studying site or bond percolation on any lattice. The algorithm can measure an observable quantity in a percolation system for all values of the site or bond occupation probability from zero to one in an amount of time which scales linearly with the size of the system. We demonstrate our algorithm by using it to investigate a number of issues in percolation theory, including the position of the percolation transition for site percolation on the square lattice, the stretched exponential behavior of spanning probabilities away from the critical point, and the size of the giant component for site percolation on random graphs.Comment: 17 pages, 13 figures. Corrections and some additional material in this version. Accompanying material can be found on the web at http://www.santafe.edu/~mark/percolation

Scale-invariant universal crossing probability in one-dimensional diffusion-limited coalescence

The crossing probability in the time direction is defined for an off-equilibrium reaction-diffusion system as the probability that the system of size L is still active at time t, in the finite-size scaling limit. Exact results are obtained for the diffusion-limited coalescence problem in 1+1 dimensions with periodic and free boundary conditions using empty interval methods. The crossing probability is a scale-invariant universal function of an effective aspect ratio, L^2/Dt, which is the natural scaling variable for this strongly anisotropic system.Comment: 12 pages, 2 figure