A Numerical Method for Shape-From-Shading From A Single Image

This report describes research done at the Artificial Intelligence Laboratory of the Massachusetts Institute of Technology. Support for the laboratory's artificial intelligence research is provided in part by the Advanced Research Projects Agency of the Department of Defense under Office of Naval Research contract N00014-75-C-0643. Thesis Supervisor: Berthold K. P. Horn Title: Associate Professor of Electrical Engineering and Computer ScienceThe shape of an object can be determined from the shading in a single image by solving a first-order, non-linear partial differential equation. The method of characteristics can be used to do this, but it suffers from a number of theoretical difficulties and implementation problems. This thesis presents an iterative relaxation algorithm for solving this equation on a grid of points. Here, repeated local computations eventually lead to a global solution. The algorithm solves for the surface orientation at each point by employing an iterative relaxation scheme. The constraint of surface smoothness is achieved while simultaneously satisfying the constraints imposed by the equation of image illumination. The algorithm has the distinct advantage of being capable of handling any reflectance function whether analytically or empirically specified. Included are brief overviews of some of the more important shape-from-shading algorithms in existence and a list of potential applications of this iterative approach to several image domains including scanning electron microscopy, remote sensing of topography and industrial inspection.MIT Artificial Intelligence Laboratory Department of Defense Advanced Research Projects Agenc

ON THE INTERACTION OF SUBLIMATING GAS WITH COMETARY BODIES

Sublimation of volatiles is a defining process of comet nuclei, and profoundly affects their dynamics, structure, and appearance. Central to understanding the processes by which comets formed and subsequently evolved is a careful computation of this sublimation pressure as a function of heliocentric distance. Unlike previous efforts, I develop a thermodynamic method to numerically compute the sublimation pressure of any species from limited knowledge of its physical properties. I then describe a novel cometary disruption mechanism in which this sublimation pressure induces differential stresses within the body of the nucleus that exceed its material strength, resulting in structural failure and breakup of the nucleus. I show that this mechanism is consistent with the behavior of Comet ISON (C/2012 S1), and use it to estimate the cohesive strength of ISON’s nucleus, a first for a Long-Period Comet

Directory of research projects, 1991. Planetary geology and geophysics program

Information is provided about currently funded scientific research within the Planetary Geology and Geophysics Program. The directory consists of the proposal summary sheet from each proposal funded by the program during fiscal year 1991. Information is provided on the research topic, principal investigator, institution, summary of research objectives, past accomplishments, and proposed investigators

IAU Symposium 160

Some of the topics considered include: Search Programs, Populations of Small Bodies, Dynamics, Physical Observations and Modeling, Observations from Space, Origin and Evolution, and Data Bases.Sponsored by International Astronomical Union.Organized by Osservatorio Astronomico di Torino and the Lunar and Planetary Institute.With the contribution of Regione Piemonte, Provincia di Novara, A.P.T. Lago Maggiore, Consiglio Nazionale delle Ricerche, European Space Agency, Alenia Spazio S.p.A.; with the participation of Banca Popolare di Novara, Camera di Commercio di Novara, Martini & Rossi IVLAS S.p.A.PARTIAL CONTENTS: SMACS: Small Missions to Asteroids and Comets. A Fast, Low Cost Approach to the Space Reconnaissance of Near-Earth Objects / M.J.S. Belton--Stochasticity of Comet P/GE-Wang / D. Benest and R. Gonczi--Chips Off of 4 Vesta: A Newly Confirmed Asteroid Family and Link to Basaltic Achondrite Meteorites / R.P. Binzel--Asteroid 243 IDA as a Member of the Koronis Family: Predictions and Implications for the Galileo Encounter / R.P. Binzel and S.M. Slivan--Photoelectric Observations of 4179 Toutatis / C. Blanco and D. Riccioli--Observations of OH in P/Swift-TuttIe and in Several Recent Weak Comets with the Nancay Radio Telescope / D. Bockehie-Morvan, G. Bourgois, P. Colom, J. Crovisier, E. Gerard, and L. Jorda--The Origin of the 3.2-3.6 Micron Emission Features in Comets: Gas or Dust / D. Bockelee-Morvan, T.Y. Brooke, and J. Crovisier--Observations of Sub-millimeter Lines of CH30H, HCN and H2CO in Comet P/Swift-Tuttle with the James Clerk Maxwell Telescope / D. Bockelee-Morvan, R. Padman, J.K. Davies, and J. Crovisier--Astrometric Measurements of Minor Planets in 1991-1992 / G. Bocsa and M. Birlan--Concerted Elemental Analyses- PIXE and TOF-SIMS- of Interplanetary Dust Particles / J. Bohsung, E.K. Jessberger, and T. Stephan--Dynamical Effects of Asymmetric Nongravitational Forces on Long-Period Comets / A. Bolalto, G. Carballo, and J.A. Fenuindez--Images of Comet Swift-Tuttle 1992t in the Light of H20+ and CO+ Ions, and Dust / T. Bonev, K. Jockers, and G.P. Chernova--Two Components in Meteor Spectra / J. Borovicka

Spacelab Science Results Study

Beginning with OSTA-1 in November 1981 and ending with Neurolab in March 1998, a total of 36 Shuttle missions carried various Spacelab components such as the Spacelab module, pallet, instrument pointing system, or mission peculiar experiment support structure. The experiments carried out during these flights included astrophysics, solar physics, plasma physics, atmospheric science, Earth observations, and a wide range of microgravity experiments in life sciences, biotechnology, materials science, and fluid physics which includes combustion and critical point phenomena. In all, some 764 experiments were conducted by investigators from the U.S., Europe, and Japan. The purpose of this Spacelab Science Results Study is to document the contributions made in each of the major research areas by giving a brief synopsis of the more significant experiments and an extensive list of the publications that were produced. We have also endeavored to show how these results impacted the existing body of knowledge, where they have spawned new fields, and if appropriate, where the knowledge they produced has been applied

The Compton Observatory Science Workshop

The Compton Observatory Science Workshop was held in Annapolis, Maryland on September 23-25, 1991. The primary purpose of the workshop was to provide a forum for the exchange of ideas and information among scientists with interests in various areas of high energy astrophysics, with emphasis on the scientific capabilities of the Compton Observatory. Early scientific results, as well as reports on in-flight instrument performance and calibrations are presented. Guest investigator data products, analysis techniques, and associated software were discussed. Scientific topics covered included active galaxies, cosmic gamma ray bursts, solar physics, pulsars, novae, supernovae, galactic binary sources, and diffuse galactic and extragalactic emission

Generalized averaged Gaussian quadrature and applications

A simple numerical method for constructing the optimal generalized averaged Gaussian quadrature formulas will be presented. These formulas exist in many cases in which real positive GaussKronrod formulas do not exist, and can be used as an adequate alternative in order to estimate the error of a Gaussian rule. We also investigate the conditions under which the optimal averaged Gaussian quadrature formulas and their truncated variants are internal

MS FT-2-2 7 Orthogonal polynomials and quadrature: Theory, computation, and applications

Quadrature rules find many applications in science and engineering. Their analysis is a classical area of applied mathematics and continues to attract considerable attention. This seminar brings together speakers with expertise in a large variety of quadrature rules. It is the aim of the seminar to provide an overview of recent developments in the analysis of quadrature rules. The computation of error estimates and novel applications also are described