| Design, Construction and Testing of a Prototype Holonomic Autonomous Vehicle |
DEC 2007 |
211 pages |
| Authors:
Kirk N. Volland; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
 | United States Department of Defense (DoD) autonomous vehicle efforts have concentrated research in areas that support development of unmanned ground and air battlefield vehicles. Little attention has been paid to applying robotics to automate routine tasks. A robotic solution consisting of a prototype holonomic vehicle is proposed to search for, detect, and remove debris that could cause foreign object damage (FOD) to turbine-engine aircraft operated from ships. Holonomic, or omnidirectional, ... |
|
| Progress Report of the IAU Working Group on Precession and the Ecliptic |
DEC 2006 |
6 pages |
| Authors:
J. L. Hilton; N. Capitaine; J. Chapront; J. M. Ferrandiz; A. Fienga; T. Fukushima; J. Getino; P. Mathews; J-L. Simon; M. Soffel; NAVAL OBSERVATORY WASHINGTON DC
|
| The IAU Working group on Precession and the Ecliptic looked at several solutions for replacing the precession part of the IAU 2000A precession-nutation model, which is not dynamically consistent. These comparisons show that the Capitaine et al. (2003) precession theory, P03, is both dynamically consistent and the solution most compatible with the IAU 2000A nutation model. The two greatest sources of uncertainty in the precession theory are the rate of ... |
|
| A Review of Submarine Out-of-Plane Normal Force and Pitching Moment |
AUG 2004 |
|
| Authors:
M. Mackay; DEFENCE RESEARCH AND DEVELOPMENT ATLANTIC DARTMOUTH (CANADA)
|
 | The normal force and pitching moment experienced by a submarine in a turn, or at an angle of drift, are called out-of-plane because they are loads induced in the vertical plane by a maneuver in the horizontal plane. They arise from the interaction of flow circulation generated by the sail with cross flow on the hull aft of the sail, i.e., the Magnus Effect. Smaller than the corresponding in-plane loads, ... |
|
| Atomistic Modelling of Cross Slip and its Contribution to the Understanding of Texture and Fatigue in Fcc Materials |
18 MAR 2004 |
35 pages |
| Authors:
T. Leffers; O. B. Pederson; RISOE NATIONAL LAB ROSKILDE (DENMARK)
|
| Viewgraphs of presentation on the atomistic modelling of cross slip and its contribution to the understanding of texture and fatigue in fcc materials. |
|
| Development of Artificial Y-Type Hexaferrites |
01 MAY 2003 |
2 pages |
| Authors:
C. Vittoria; NORTHEASTERN UNIV BOSTON MA
|
| We have developed a technique to orient particles of Y-type hexaferrite in which the c-axis of the particles are oriented perpendicular to a plane As such, that plane becomes necessarily the easy plane of magnetization. For microwave device application the easy plane of magnetization is chosen as the plane to deposit a metallic microstrip and related circuit patterns. The technique entails the rotation of an external magnetic field in the ... |
|
| Planar Image Particle Analyzer for Whole Field Spray Applications |
19 JUN 2001 |
4 pages |
| Authors:
Cecil Hess; METROLASER IRVINE CA
|
| The purpose of this work is to develop a whole field measurement technique that is capable of simultaneously sizing multiple transparent droplets on a plane from scattered light features that are independent of laser beam intensity and obscuration. Light scattered by reflection and refraction from droplets immersed in a laser sheet is recorded holographically to yield the smallest possible probe volume and correspondingly largest number density. Last year we reported ... |
|
| The Optical Properties of Aerosols |
MAY 2001 |
4 pages |
| Authors:
F. Borghese; CENTRO SICILIANO PER LE RICERCHE ATMOSFERICHE E DI FISICA DELL'AMBIENTE MESSINA (ITALY)
|
| The topics investigated under the present Contract can be summarized as follows: 1. Analysis by nondestructive means of the degree of cleanliness of a metallic or dielectric surface. 2. Determination of the contribution to the greenhouse effect from the ice crystal that are present in the high atmosphere (namely in cirrus clouds). 3. Discrimination of the shape and backscattering properties of atmospheric ice crystals in the millimeter wave range. The ... |
|
| Combustion Oscillations, Extinction & Control |
MAR 2000 |
23 pages |
| Authors:
J. H. Whitelaw; ICON LTD LONDON (UNITED KINGDOM)
|
| The research has involved experiments with three main flow configurations and the development of a computational method. Most of the experiments were carried out in two sudden-expansion flows, one with a plane geometry which afforded complete optical assess and the other in an axisymmetric arrangement which was closer to engineering practice but with less comprehensive optical access. A combination of optical methods was used to explore ... |
|
| Investigator of Coherence Imaging, Photon Migration, and Short-Pulse Image Processing |
12 JAN 2000 |
10 pages |
| Authors:
Emmett N. Leith; MICHIGAN UNIV ANN ARBOR DEPT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCE
|
| A theoretical investigation was made into the angular correlation that exists between two plane waves propagating through a scattering medium. Comparisons were made with the coherence existing between the angular correlation and the correlation of the exiting waves with a reference wave. Such studies are important to understanding how a wave field can be recovered after propagation through a scattering medium. A new concept, that of spatial filtering time gating, ... |
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| The Optical Properties of Aerosols |
AUG 1998 |
35 pages |
| Authors:
F. Borghese; CENTRO SICILIANO PER LE RICERCHE ATMOSFERICHE E DI FISICA DELL'AMBIENTE MESSINA (ITALY)
|
| The purpose of this paper is to present some results for the full scattering pattern from binary aggregates of identical spheres deposited on a plane surface. The extension of our theory to the case of aggregated spheres is far from trivial because one has to consider the effect of the mutual interaction of the aggregated spheres: in other words, we had to modify our ... |
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| Thermoacoustic Engines in Alternate Geometry Resonators |
12 SEP 97 |
150 pages |
| Authors:
Richard Raspet; Henry E. Bass; Jay A. Lightfoot; JAMIE WHITTEN NATIONAL CENTER FOR PHYSICAL ACOUSTICS UNIVERSITY MS
|
| The purpose of the research reported herein is to branch out from thermoacoustics in the plane wave geometry to study radial wave thermoacoustic engines. Specifically, two possible advantages were sought from radial systems: (1) reduction of harmonic generation due to natural anharmonicity of the resonators and (2) improved engine performance using naturally sloped stacks. Results show that the anharmonicity of the resonator significantly reduces non- linear harmonic generation and that ... |
|
| Apparatus and Method of Concomitant Scenario Topography with the Aid of a Digital Computer. |
27 JAN 1997 |
36 pages |
| Authors:
Peter Fleischer; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| This patent application refers to a system for concomitant scenario topography with the aid of a digital computer such that a two dimensional or three dimensional map is produced and displayed which illustrates the combined effects, particularly geoenvironmental, of multiple, diverse criteria and factors relative to uniquely-referenced, uniform, small areas of a plane surface or the surface of a solid. The topography system employs plural interrelated tables, worksheets and mapping ... |
|
| On Levels in Arrangements of Lines, Segments, Planes, and Triangles |
1997 |
9 pages |
| Authors:
Pankaj K. Agarwal; Boris Aronov; Micha Sharir; DUKE UNIV DURHAM NC DEPT OF COMPUTER SCIENCE
|
| We consider the problem of bounding the complexity of the k-th level in an arrangement of n curves or surfaces, a problem dual to, and extending the well-known k-set problem. (a) We review and simplify some old proofs in new disguise and give new proofs of the bound O(n the square root of k + 1) for the complexity of the k-th level in an arrangement of n lines. (b) ... |
|
| Fundamental Studies of Radial Wave Thermoacoustic Engines |
10 NOV 96 |
20 pages |
| Authors:
W. P. Arnott; NEVADA UNIV SYSTEM RENO ATMOSPHERIC SCIENCES CENTER
|
| Our goal was to evaluate the influence of resonator geometry on thermoacoustic engine performance. Resonator geometry affects thermoacoustic heat transport and acoustic power generation, energy dissipation, and stack volume. Thermoacoustic engines placed in the first radial mode of a cylindrical resonator were studied in detail, and were compared with the more-developed plane wave resonator counterparts. A radial wave prime mover was constructed from use of our numerical model. Experimental results ... |
|
| Range Searching |
08 SEP 96 |
32 pages |
| Authors:
Pankaj K. Agarwal; DUKE UNIV DURHAM NC DEPT OF COMPUTER SCIENCE
|
| Range searching is one of the central problems in computational geometry, because it arises in many applications and a wide variety of geometric problems can be formulated as a range-searching problem. Range counting and range reporting are just two instances of range-searching queries. Typically, the canonical subsets are organized in a tree-like data structure, each of whose node V is associated with a canonical subset A; V stores the weight ... |
|
| Electromagnetic Scattering from Semi-Infinite Planar Arrays |
SEP 96 |
182 pages |
| Authors:
Peter J. Collins; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
|
| A hybrid method of moments(MM) based numerical model for the electromagnetic scattering from large finite by infinite planar slot arrays is developed. The method incorporates the novel concept of a physical basis function (PBF) to dramatically reduce the number of required unknowns. The model can represent a finite number of slot columns with slots oriented along the infinite axis, surrounded by an arbitrary number of coplanar dielectric slabs. Each slot ... |
|
| Fundamental Studies of Radial Wave Thermoacoustic Engines |
SEP 96 |
19 pages |
| Authors:
W. P. Arnott; NEVADA UNIV SYSTEM RENO ATMOSPHERIC SCIENCES CENTER
|
| Our goal was to evaluate the influence of resonator geometry on thermoacoustic engine performance. Resonator geometry affects thermoacoustic heat transport and acoustic power generation, energy dissipation, and stack volume. Thermoacoustic engines placed in the first radial mode of a cylindrical resonator were studied in detail, and were compared with the more-developed plane wave resonator counterparts. A radial wave prime mover was constructed from use of our numerical model. Experimental results ... |
|
| A Probabilistic Analysis of the Power of Arithmetic Filters |
SEP 96 |
31 pages |
| Authors:
Olivier Devillers; Franco Preparata; BROWN UNIV PROVIDENCE RI DEPT OF COMPUTER SCIENCE
|
| The assumption of real-number arithmetic, which is at the basis of conventional geometric algorithms, has been seriously challenged in recent years, since digital computers do not exhibit such capability. A geometric predicate usually consists of evaluating the sign of some algebraic expression. In most cases, rounded computations yield a reliable result, but sometimes rounded arithmetic introduces errors which may invalidate the algorithms. The rounded arithmetic may produce an incorrect result ... |
|
| Proximity Drawings of Outerplanar Graphs (Preliminary Version) |
JUN 96 |
15 pages |
| Authors:
William Lenhart; Giuseppe Liotta; BROWN UNIV PROVIDENCE RI DEPT OF COMPUTER SCIENCE
|
| A proximity drawing of a graph is one in which pairs of adjacent vertices are drawn relatively close together according to some proximity measure while pairs of non-adjacent vertices are drawn relatively far apart. The fundamental question concerning proximity drawability is: Given a graph G and a definition of proximity, is it possible to construct a proximity drawing of G? We consider this question for outerplanar graphs with respect to ... |
|
| Proximity Constraints and Representable Trees |
96 |
30 pages |
| Authors:
Prosenjit Bose; Giuseppe Di Battista; William Lenhart; Giuseppe Liotta; BROWN UNIV PROVIDENCE RI DEPT OF COMPUTER SCIENCE
|
| This paper examines an infinite family of proximity drawings of graphs called open and closed B-drawings, first defined by Kirkpatrick and Radke in the context of computational morphology. Such proximity drawings include as special cases the well-known Gabriel, relative neighborhood and strip drawings. Complete characterizations of those trees that admit open B-drawings for 0 <= B <= 1/(1-cos(2pi/5)) and 1/cos(2pi/5) < B < infinity or closed B-drawings for 0 <= ... |
|
| Low Degree Algorithms for Computing and Checking Gabriel Graphs. (Extended Abstract) |
96 |
13 pages |
| Authors:
Giuseppe Liotta; BROWN UNIV PROVIDENCE RI
|
| In the context of robust computational geometry we focus on the problem of computing and checking Gabriel graphs with algorithms that are not affected by degenaracies and have low arithmetic demand. A simple and practical linear-time algorithm is presented that constructs the Gabriel Graph of a finite point set on the plane from its Delaunay diagram. The degree of the algorithm, i.e. a measure of the arithmetic precision required to ... |
|
| Strong Restricted-Orientation Convexity |
JUN 95 |
|
| Authors:
Eugene Fink; Derick Wood; CARNEGIE-MELLON UNIV PITTSBURGH PA DEPT OF COMPUTER SCIENCE
|
| Strong O-convexity is a generalization of standard convexity, defined with respect to a fixed set O of hyperplanar orientations. We explore the properties of strongly O-convex sets in two and more dimensions and develop a mathematical foundation of strong convexity. We characterize strongly 0-convex polytopes, flats, and halfspaces, establish the strong 0-convexity of the affine hull of a strongly O-convex set, and describe conditions under which two orientation sets yield ... |
|
| Algebraic Functions for Recognition |
JAN 94 |
12 pages |
| Authors:
Amnon Shashua; MASSACHUSETTS INST OF TECH CAMBRIDGE ARTIFICIAL INTELLIGENCE LAB
|
| In the general case, a trilinear relationship between three perspective views is shown to exist. The trilinearity result is shown to be of much practical use in visual recognition by alignment --- yielding a direct method that cuts through the computations of camera transformation, scene structure and epipolar geometry. The proof of the central result may be of further interest as it demonstrates certain regularities across homographies of the plane ... |
|
| Field Emission Current-Voltage Curves as a Diagnostic for Scanning Tunneling Microscope Tips |
01 DEC 91 |
|
| Authors:
J. A. Meyer; S. J. Stranick; J. B. Wang; P. S. Weiss; PENNSYLVANIA STATE UNIV UNIVERSITY PARK DEPT OF CHEMISTRY
|
| The current-voltage (I-V) characteristics of a low temperature ultrahigh vacuum scanning tunneling microscope (STM) tip positioned >100 A from a planar surface have been recorded. We find curvature in the Fowler-Nordheim plots (logl0 I vs. 1 ) due to the tip-plane geometry as has been predicted V2 V theoretically. Additionally, oscillations and sharp -breaks in these I-V curves are observed over a wide voltage range, 50-1000 V. These I-V curves ... |
|
| A Generalized Intact Stability Analysis Procedure for Modular Construction Platforms |
JUN 91 |
68 pages |
| Authors:
T. Huang; NAVAL CIVIL ENGINEERING LAB PORT HUENEME CA
|
| This report presents a generalized numerical procedure for evaluating the responses of a modular construction floating platform subjected to static loads. The theory employed is applicable to watertight pontoon platforms undergoing unlimited rotations. This procedure enables users to investigate platform stability under various deck load configurations. Users are able to design a pontoon platform with prefabricated modules, check the platform for static stability, and modify the platform in a sequence ... |
|
| Reflection of Incident Pressure Waves by Ribbed Panels |
FEB 91 |
|
| Authors:
G. Maidanik; J. Dickey; DAVID TAYLOR RESEARCH CENTER BETHESDA MD
|
| The definitions of the reflection coefficients, in the absence of ribs and due to ribs, of an incident pressure wave on a plane at the surface of a ribbed fluid loaded panel are defined, examined, and computed. The incident pressure wave is described by a plane wave and by a collimated beam. The results of representative computations are displayed. Through these displays, some aspects of the influence on the reflection ... |
|
| Comparison of Sound Pressure in a Wedge-Shaped Ocean as Predicted by an Image Method and a PE Model |
DEC 90 |
|
| Authors:
Jong R. Kim; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| We compare and contrast results of three different models of acoustic propagation in an ocean with a sloping bottom, predicting the pressure field in a wedge-shaped ocean with a pressure release surface and an acoustically fast bottom. On image and two PE (Parabolic Equation) models were selected. The computer model for the image method was written in Basic for use on a PC and in Fortran for use on the ... |
|
| A Model of the Acoustic Interactions Occurring Under Arctic Ice |
22 MAY 90 |
|
| Authors:
Roger R. Ullman Ii; NAVAL ACADEMY ANNAPOLIS MD
|
| Underwater sound interacting with the Arctic ice cover is reflected from the plane surface as well as scattered due to small-scale roughness elements and large pressure-ridge keel structures. Experiments modeled the acoustic ice interactions using burst transmissions from omnidirectional underwater point sources. Floating acrylic plates were employed to represent the Arctic ice due to similarity in impedance characteristics and other physical properties to known ice values. Geometrical properties of the ... |
|
| Optical Spatial Tracking Using Coherent Detection in the Pupil Plane |
19 MAY 89 |
|
| Authors:
Eric A. Swanson; Gary M. Carter; D. J. Bernays; David M. Hodsdon; MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB
|
| Design considerations for a heterodyne spatial tracking system utilizing pupil-plane processing techniques and its advantages over traditional focal-plane processing are described. Noise performance bounds, optimal and suboptimal local oscillator distributions, pull-in performance, and applications other than spatial tracking are discussed. Experimental verification of a one- axis closed-loop tracking system is presented. (rh) |
|
| The h-p Version of the Boundary Element Method with Geometric Mesh on Polygonal Domains |
MAY 89 |
|
| Authors:
I. Babuska; B. Q. Guo; E. P. Stephan; MARYLAND UNIV COLLEGE PARK INST FOR PHYSICAL SCIENCE AND TECHNOLOGY
|
| This paper applies the techniques of the h-p version to the boundary element method for boundary value problems on plane non-smooth domains with piecewisely analytic boundary and data. The exponential rate of convergence of the boundary element Galerkin solution is obtained when a geometric mesh refinement is used near the vertices. (aw) |
|
| Modification of Parabolic Dish Antenna Pattern Using Two Symmetrically Placed Circular Flat Plates |
DEC 87 |
|
| Authors:
Glen C. Thorpe; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
|
| This study aims to formulate a method of predicting the far field pattern of a parabolic dish antenna with two moveable flat plates mounted symmetrically on either side of the feed horn. The approach taken has been to first analyze the radiation pattern of the antenna with the disks at certain heights out from the surface of the dish. To do this the near-field radiation in amplitude and phase was ... |
|
| Electron Tunneling Microscopy |
01 OCT 87 |
|
| Authors:
John D. Baldeschwieler; CALIFORNIA INST OF TECH PASADENA
|
| The high vacuum STM system at Caltech has been applied to study the surface structure of MoS2. The resolution in the plane of the surface is about 1A, while that normal to the surface is better than 0.1A. It is straightforward to distinguish two distinct atomic sites at this surface by tunneling microscopy, both in the conventional constant current variable height mode as well as in the variable current constant ... |
|
| Use of Depletion-Edge-Translation for High Speed Modulation and Switching of Lightwaves |
22 MAY 87 |
|
| Authors:
Larry A. Coldren; J. G. Mendoza-Alvarez; T. C. Huang; T. R. Hausken; K. W. Lee; CALIFORNIA UNIV SANTA BARBARA DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| This report focused on the investigation of the basic properties of novel depletion edge translation (DET) waveguide phase modulators oriented in the plane of the substrate. Devices based upon this concept have now provided record levels of phase shifting efficiency, and theoretical calculations have indicated a significant potential for still further improvements in this area. The in plane geometry maximizes the interaction between applied fields and the propagating wave by ... |
|
| Speckle Image Reconstruction. Appendix 1 |
01 APR 85 |
|
| Authors:
P. A. Strittmatter; E. K. Hege; STEWARD OBSERVATORY TUCSON ARIZ
|
| By adjusting the optical pathlengths of the MMT (Multiple Mirror Telescopes) telescopes, it is possible to make the MMT into a phased array with a 6.86 m baseline. A coherent, phased focus can be achieved with tilted focal planes if the tilt angle is chosen so that the internal phase differences exactly compensate the external phase differences. This amounts to a slight change in configuration such that the beams are ... |
|
| Cyclic Coloration of 3-Polytopes |
85 |
|
| Authors:
Michael D. Plummer; Bjarne Toft; VANDERBILT UNIV NASHVILLE TN
|
| This paper, all graphs will be finite, loopless and will have no parallel lines. Let G be a 2-connected planar graph with =p points. Suppose G has some fixed imbedding Phi: G approaches R-sq in the plane. The pair (G Phi) is often called a plane graph. A cyclic coloration of (G Phi) is an assignment to colors to the points of G such that for any face-bounding cycle F ... |
|
| Analysis of In-Plane and Out-of-Plane Ground Motions Using the Boundary Element Method |
JUL 1984 |
|
| Authors:
M. H. Sadd; J. M. Rice; RHODE ISLAND UNIV KINGSTON DEPT OF MECHANICAL ENGINEERING AND APPLIED MECHANICS
|
| A completed research program is presented which has developed new computational methods to study geomechanics ground motions excited by subsurface sources. Both in-plane (plane strain) and out-of-plane (anti-plane strain) motions are investigated by employing a direct boundary element method within the framework of linear dynamic elasticity theory. The constructed boundary element method uses a time-dependent, half-space Green's function; thereby, eliminating the need to discretize the free surface, allowing the causality ... |
|
| On the Equidecomposability of a Regular Triangle and A Square of Equal Areas |
JAN 1984 |
|
| Authors:
D. W. Crowe; I. J. Schoenberg; WISCONSIN UNIV-MADISON MATHEMATICS RESEARCH CENTER
|
| This paper deals with the subject of the first chapter of the second author's book Mathematical Time Exposures: The equidecomposability of a regular triangle and a square of equal areas. A new solution of the problem is given, which also shows that the solution of the problem as given in the third edition of Hogo Steinhaus 'Mathematical Snapshots', is not correct. (Author) |
|
| The Labeled Discrete Voroni Diagram |
MAY 83 |
|
| Authors:
T. Phillips; T. Matsuyama; MARYLAND UNIV COLLEGE PARK CENTER FOR AUTOMATION RESEARCH
|
| Generalized voronoi diagrams of sets of digital curves are a helpful tool in picture anlaysis. In this paper, an algorithm for computing laberled Voronoi diagrams for digital straight line segments is given. Special emphasis was given to the use of a labeled Euclidean distance transform. This transform is the key feature of the proposed lable propagation process. The proposed parallel algorithm for computing labeled Voronoi diagrams has time complexity 0(max(M,N)) ... |
|
| Spacefilling Curves and Routing Problems in the Plane |
11 FEB 1983 |
|
| Authors:
Loren K. Platzman; John J. Bartholdi III; GEORGIA INST OF TECH ATLANTA PRODUCTION AND DISTRIBUTION RESEARCH CENTER
|
| This paper introduces a novel heuristic to compute a minimal-length tour of N given points in the plane: they are sequenced as they appear along a spacefilling curve. The algorithm consists essentially of sorting: it is easily coded, requires only O (N) memory, and may be implemented to execute in O (N log N) operations at most, or O (N) operations on the average. |
|
| Frequency Domain Optical Storage |
20 DEC 1982 |
|
| Authors:
Gary C. Bjorklund; George Castro; IBM RESEARCH LAB SAN JOSE CA
|
| The phenomenon of photochemical hole burning makes it possible to utilize optical frequency as an additional dimension for the organization of an optical data store. Storage densities of 10 to the 11th power bits/cm squared may ultimately be achieved. The basic principles of photochemical hole burning are reviewed in this paper and recent research results are presented. (Author) |
|
| High-Agility Reflector Support and Drive System. |
23 NOV 1982 |
|
| Authors:
James W. Titus; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| An apparatus for mounting a device defining a mounting plane so as to be selectively rotatable about mutually perpendicular axis with respect to a base member defining a base plane. The first axis is defined by a transverse pin fitted to the gimbal and rotatably secured to the base plane. The mounting plane is tilted about either axis by driving an associated, diagonally opposite pair of support arm members linearly ... |
|
| Visibility Probabilties and Moments of Measures of Visibility on Curves in the Plane for Poisson Shadowing Processes |
15 SEP 1982 |
|
| Authors:
Micha Yadin; S. Zacks; STATE UNIV OF NEW YORK AT BINGHAMTON DEPT OF MATHEMATICAL SCIENCES
|
| The present study generalizes the methodology developed in (10) to determine visibility probabilities of points in the plane, when shadows are cast by a Poisson field of random objects (disks), given a source of light in the origin. Furthermore, a technique is developed for the determination of the moments of a visibility measure on star-shaped curves in the plane. A numerical example is provided to illustrate the method in some ... |
|
| Layouts for the Shuffle-Exchange Graph Based on the Complex Plane Diagram |
JUN 1982 |
|
| Authors:
Frank Thomson Leighton; Margaret Lepley; Gary L. Miller; MASSACHUSETTS INST OF TECH CAMBRIDGE LAB FOR COMPUTER SCIENCE
|
| The shuffle-exchange graph is one of the best structures known for parallel computation. Among other things, a shuffle-exchange computer can be used to compute discrete Fourier transforms, multiply matrices, evaluate polynomials, perform permutations and sort lists. The algorithms needed for these operations are extremely simple and many require no more than logarithmic time and constant space per processor. In this paper, we analyze the algebraic structure of the shuffle-exchange graph ... |
|
| ACOSS Eleven (Active Control of Space Structures). Volume I |
MAY 1982 |
33 pages |
| Authors:
Thomas H. Brooks; Virenda N. Mahajan; Jiguan G. Lin; Glenn J. Kissell; Daniel R. Hegg; CHARLES STARK DRAPER LAB INC CAMBRIDGE MA
|
| The Active Control of Space Structures (ACOSS) Eleven contract includes three distinct areas of endeavor: Simulations Extensions, HALO Optics and ACOSS. This report covers the work performed in each of these areas between May and November 1981. Simulations Extension and HALO Optics are presented in Volume I and ACOSS is presented in Volume II. (Author) |
|
| Ejection of Particles from a Charged Infinite Strip |
01 FEB 1982 |
|
| Authors:
Christopher Sherman; Patricia Bench; AIR FORCE GEOPHYSICS LAB HANSCOM AFB MA
|
| Trajectories of charged particles emitted from an infinite strip at a fixed potential with respect to and embedded in a unipotential ambient plane are calculated. Separation curves that divide emitted particles into those that escape from the emission plane and those that return to it are obtained. Results are compared with trajectories calculated in a previously studied, simpler model. Asymptotic properties are examined. The case of particles emitted from an ... |
|
| Average Case Analysis of an Adjacency Map Searching Technique |
DEC 1981 |
|
| Authors:
Gianfranco Bilardi; ILLINOIS UNIV AT URBANA APPLIED COMPUTATION THEORY GROUP
|
| The adjacency map is a data structure (a tree) used to solve the following problem: given a set of parallel segments in the plane and a point p, find the segments closest to p among those intersected by the straight line through p, perpendicular to the common direction of the segments. The search is performed in the repetitive mode, so that preprocessing is convenient. The problem considered is a particular ... |
|
| A Method for Calculating Three-Dimensional Flow in Bladed Turbomachines by Using Arbitrary Quasi Perpendicular Intersecting Planes |
09 OCT 1981 |
|
| Authors:
Xin Xiaokang; Jiang Jinliang; FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OH
|
|
| Program for Automated Holographic Data Reduction |
AUG 1981 |
|
| Authors:
R. W. Menzel; L. D. Vandergriff; ARNOLD ENGINEERING DEVELOPMENT CENTER ARNOLD AFS TN
|
| An automated program for reducing data from holographic reconstructions of particle fields is described. The instrumentation is based on the optical measurements of the Quantimet-720 Image Analyzing Computer. The focal plane detection of individual images is particularly emphasized by theoretical derivations and by experimental results. (Author) |
|
| On the Pallet Loading Problem |
AUG 1981 |
|
| Authors:
Thom J. Hodgson; FLORIDA UNIV GAINESVILLE DEPT OF INDUSTRIAL AND SYSTEMS ENGINEERING
|
| In this paper the two-dimensional pallet loading problem is considered: that is, the problem of loading a rectangular pallet of size 'L' by 'W', drawing from a set of 'n' rectangular boxes. The objective is to maximize the area covered on the pallet by the boxes loaded. The problem is approached using a combination of Dynamic Programming and heuristics. The structured solutions resulting from the application of the 'dynamic program' ... |
|
| Representations of Intervals and Optimal Error Bounds. |
JUL 1980 |
|
| Authors:
L. B. Rall; WISCONSIN UNIV-MADISON MATHEMATICS RESEARCH CENTER
|
| Calculations with interval arithmetic and interval extensions of real functions are often used to obtain lower and upper bounds for what would be the theoretical results of precise computations on exact data. A more traditional way to represent approximate data and results contained in intervals is by means of a representative point x in the interval and an associated measure of error E. For example, the midpoint of an interval ... |
|
Reports by Keyword(s)
PLANE GEOMETRY
