Experimental study of digital image processing techniques for LANDSAT data

The author has identified the following significant results. Results are reported for: (1) subscene registration, (2) full scene rectification and registration, (3) resampling techniques, (4) and ground control point (GCP) extraction. Subscenes (354 pixels x 234 lines) were registered to approximately 1/4 pixel accuracy and evaluated by change detection imagery for three cases: (1) bulk data registration, (2) precision correction of a reference subscene using GCP data, and (3) independently precision processed subscenes. Full scene rectification and registration results were evaluated by using a correlation technique to measure registration errors of 0.3 pixel rms thoughout the full scene. Resampling evaluations of nearest neighbor and TRW cubic convolution processed data included change detection imagery and feature classification. Resampled data were also evaluated for an MSS scene containing specular solar reflections

Illuminating spindle convex bodies and minimizing the volume of spherical sets of constant width

A subset of the d-dimensional Euclidean space having nonempty interior is called a spindle convex body if it is the intersection of (finitely or infinitely many) congruent d-dimensional closed balls. The spindle convex body is called a "fat" one, if it contains the centers of its generating balls. The core part of this paper is an extension of Schramm's theorem and its proof on illuminating convex bodies of constant width to the family of "fat" spindle convex bodies.Comment: 17 page

Lewis X antigen mediates adhesion of human breast carcinoma cells to activated endothelium. Possible involvement of the endothelial scavenger receptor C-Type lectin

Lewis x (Lex, CD15), also known as SSEA-1 (stage specific embryonic antigen-1), is a trisaccharide with the structure Galβ(1–4)Fucα(1–3)GlcNAc, which is expressed on glycoconjugates in human polymorphonuclear granulocytes and various tumors such as colon and breast carcinoma. We have investigated the role of Lex in the adhesion of MCF-7 human breast cancer cells and PMN to human umbilical endothelial cells (HUVEC) and the effects of two different anti-Lex mAbs (FC-2.15 and MCS-1) on this adhesion. We also analyzed the cytolysis of Lex+-cells induced by anti-Lex mAbs and complement when cells were adhered to the endothelium, and the effect of these antibodies on HUVEC. The results indicate that MCF-7 cells can bind to HUVEC, and that MCS-1 but not FC-2.15 mAb inhibit this interaction. Both mAbs can efficiently lyse MCF-7 cells bound to HUVEC in the presence of complement without damaging endothelial cells. We also found a Lex-dependent PMN interaction with HUVEC. Although both anti-Lex mAbs lysed PMN in suspension and adhered to HUVEC, PMN aggregation was only induced by mAb FC-2.15. Blotting studies revealed that the endothelial scavenger receptor C-type lectin (SRCL), which binds Lex-trisaccharide, interacts with specific glycoproteins of Mr␣∼␣28 kD and 10 kD from MCF-7 cells. The interaction between Lex+-cancer cells and vascular endothelium is a potential target for cancer treatment.Fil: Elola, Maria Teresa. Fundación Instituto Leloir; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Capurro, Mariana Isabel. University of Toronto; CanadáFil: Barrio, Maria Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para la Investigación, Docencia y Prevención del Cáncer; ArgentinaFil: Coombs, Peter J.. Imperial College London; Reino UnidoFil: Taylor, Maureen E.. Imperial College London; Reino UnidoFil: Drickamer, Kurt. Imperial College London; Reino UnidoFil: Mordoh, Jose. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para la Investigación, Docencia y Prevención del Cáncer; Argentin

Thermodynamics of (3+1)-dimensional black holes with toroidal or higher genus horizons

We examine counterparts of the Reissner-Nordstrom-anti-de Sitter black hole spacetimes in which the two-sphere has been replaced by a surface Sigma of constant negative or zero curvature. When horizons exist, the spacetimes are black holes with an asymptotically locally anti-de Sitter infinity, but the infinity topology differs from that in the asymptotically Minkowski case, and the horizon topology is not S^2. Maximal analytic extensions of the solutions are given. The local Hawking temperature is found. When Sigma is closed, we derive the first law of thermodynamics using a Brown-York type quasilocal energy at a finite boundary, and we identify the entropy as one quarter of the horizon area, independent of the horizon topology. The heat capacities with constant charge and constant electrostatic potential are shown to be positive definite. With the boundary pushed to infinity, we consider thermodynamical ensembles that fix the renormalized temperature and either the charge or the electrostatic potential at infinity. Both ensembles turn out to be thermodynamically stable, and dominated by a unique classical solution.Comment: 25 pages, REVTeX v3.1, contains 5 LaTeX figures. (Typos corrected, references and minor comments added. To be published in Phys. Rev. D.

Complex actions in two-dimensional topology change

We investigate topology change in (1+1) dimensions by analyzing the scalar-curvature action $1/2 \int R dV$ at the points of metric-degeneration that (with minor exceptions) any nontrivial Lorentzian cobordism necessarily possesses. In two dimensions any cobordism can be built up as a combination of only two elementary types, the ``yarmulke'' and the ``trousers.'' For each of these elementary cobordisms, we consider a family of Morse-theory inspired Lorentzian metrics that vanish smoothly at a single point, resulting in a conical-type singularity there. In the yarmulke case, the distinguished point is analogous to a cosmological initial (or final) singularity, with the spacetime as a whole being obtained from one causal region of Misner space by adjoining a single point. In the trousers case, the distinguished point is a ``crotch singularity'' that signals a change in the spacetime topology (this being also the fundamental vertex of string theory, if one makes that interpretation). We regularize the metrics by adding a small imaginary part whose sign is fixed to be positive by the condition that it lead to a convergent scalar field path integral on the regularized spacetime. As the regulator is removed, the scalar density $1/2 \sqrt{-g} R$ approaches a delta-function whose strength is complex: for the yarmulke family the strength is $\beta -2\pi i$, where $\beta$ is the rapidity parameter of the associated Misner space; for the trousers family it is simply $+2\pi i$. This implies that in the path integral over spacetime metrics for Einstein gravity in three or more spacetime dimensions, topology change via a crotch singularity is exponentially suppressed, whereas appearance or disappearance of a universe via a yarmulke singularity is exponentially enhanced.Comment: 34 pages, REVTeX v3.0. (Presentational reorganization; core results unchanged.

Convex hulls of random walks, hyperplane arrangements, and Weyl chambers

We give an explicit formula for the probability that the convex hull of an n-step random walk in Rd does not contain the origin, under the assumption that the distribution of increments of the walk is centrally symmetric and puts no mass on affine hyperplanes. This extends the formula by Sparre Andersen (Skand Aktuarietidskr 32:27–36, 1949) for the probability that such random walk in dimension one stays positive. Our result is distribution-free, that is, the probability does not depend on the distribution of increments. This probabilistic problem is shown to be equivalent to either of the two geometric ones: (1) Find the number of Weyl chambers of type Bn intersected by a generic linear subspace of Rn of codimension d; (2) Find the conic intrinsic volumes of a Weyl chamber of type Bn. We solve the first geometric problem using the theory of hyperplane arrangements. A by-product of our method is a new simple proof of the general formula by Klivans and Swartz (Discrete Comput Geom 46(3):417–426, 2011) relating the coefficients of the characteristic polynomial of a linear hyperplane arrangement to the conic intrinsic volumes of the chambers constituting its complement. We obtain analogous distribution-free results for Weyl chambers of type An−1 (yielding the probability of absorption of the origin by the convex hull of a generic random walk bridge), type Dn, and direct products of Weyl chambers (yielding the absorption probability for the joint convex hull of several random walks or bridges). The simplest case of products of the form B1 ×···× B1 recovers the Wendel formula (Math Scand 11:109–111, 1962) for the probability that the convex hull of an i.i.d. multidimensional sample chosen from a centrally symmetric distribution does not contain the origin. We also give an asymptotic analysis of the obtained absorption probabilities as n → ∞, in both cases of fixed and increasing dimension d

Air Traffic Control System Baseline Methodology Guide

The Air Traffic Control System Baseline Methodology Guide serves as a reference in the design and conduct of baseline studies. Engineering research psychologists are the intended audience for the Methodology Guide, which focuses primarily on techniques for studying the interaction between ATC systems and the controllers who use them. The Methodology Guide provides the following information: (a) descriptions of and references to past baselines that have successfully used the methodology, (b) detailed descriptions of the baseline operational constructs and corresponding objective and subjective measures, (c) a description of the overall baseline methodology, (d) other recommendations and lessons learned regarding the successful conduct of system baselines, and (e) a discussion of the role of system baselines in the ATC system acquisition process

The Password Survival Guide : A User-Friendly Resource for Technical Operations

With security becoming increasingly important, users may be faced with 50 or more passwords. Human memory can store only limited amounts of information and can be overloaded by too many passwords. This guide is intended to help password users cope with the increasing number and complexity of passwords by providing strategies for reducing the memory load without compromising password complexity. We developed this document based on field research with Technical Operations personnel. The material is presented in a graphical cartoon format along with limited text narrative. The goal is to provide a number of easy-to-use strategies in a format that would motivate Technical Operations personnel to read it. The ideas covered are addressed to Technical Operations, but in many cases transcend Technical Operations and apply to passwords in general

Information Organization for a Portal Using A Card-Sorting Technique

The Office of Knowledge Management at the Federal Aviation Administration\u2019s William J. Hughes Technical Center asked researchers from the National Airspace System Human Factors Group to provide human factors input for a new enterprise information portal. The portal would contain a large amount of information. In order for the portal to be successful, the portal needed to provide information so that the users could easily find what they needed. Researchers from the William J. Hughes Technical Center used a simple method called a card sort to organize the information in a way that would reflect the mental model of the users. This document describes the card-sorting methodology. The researchers developed a set of information that potentially could be included in the portal through a combination of items identified by the sponsor as high priority items, information provided on the current employee intranet, and structured interviews with potential portal users. The researchers placed the information items on index cards. Participants representing various types of end users sorted the cards into categories and then named the categories. The researchers grouped similar categories and analyzed the data to determine categories and strength of association between items. The analyses led to the development of a taxonomy for the organization of information items within the portal. This report describes the card-sorting methodology and provides lessons learned on the application of this technique. Although the card-sorting technique alone will not produce an effective information architecture, it is a valuable technique that can lead to a more usable end product

Human Factors Considerations for Passwords and Other User Identification Techniques Part 2: Field Study, Results and Analysis

Within the Federal Aviation Administration (FAA) Air Traffic Organization (ATO), Technical Operations (TO) personnel ensure that the systems that make up the National Airspace System (NAS) function safely and effectively. TO personnel manage and maintain more than 44,000 pieces of NAS equipment and systems at over 6,000 facilities and locations. They work at many types of facilities including the National Operations Control Center (NOCC), Operations Control Centers (OCCs), Air Route Traffic Control Centers (ARTCCs), Terminal Radar Approach Control (TRACON) facilities, Air Traffic Control Towers (ATCTs), and Automated Flight Service Stations (AFSSs). The FAA employs a variety of user-identification techniques including knowledge-based techniques, such as passwords, token-based techniques (such as badge readers) to ensure that facilities, equipment, and personnel are secure. In 2004, the Technical Operations Services organization became increasingly concerned about the number of usernames, passwords, and tokens that TO personnel were being expected to use. The NAS Human Factors Group conducted a field study to examine the human factors implications of user-identification techniques currently employed at field sites to prevent unauthorized access to NAS equipment and information technology systems. In this report, we present findings from the field study and provide recommendations that are specific to the TO users, tasks, and environment. These recommendations seek to improve the human factors of user-identification technologies and policies to improve the productivity, workload, and job satisfaction of TO employees