OBJECT-BASED CLASSIFICATION OF EARTHQUAKE DAMAGE FROM HIGH-RESOLUTION OPTICAL IMAGERY USING MACHINE LEARNING

Object-based approaches to the segmentation and supervised classification of remotely-sensed images yield more promising results compared to traditional pixel-based approaches. However, the development of an object-based approach presents challenges in terms of algorithm selection and parameter tuning. Subjective methods and trial and error are often used, but time consuming and yield less than optimal results. Objective methods are warranted, especially for rapid deployment in time sensitive applications such as earthquake induced damage assessment. Our research takes a systematic approach to evaluating object-based image segmentation and machine learning algorithms for the classification of earthquake damage in remotely-sensed imagery using Trimble’s eCognition software. We tested a variety of algorithms and parameters on post-event aerial imagery of the 2011 earthquake in Christchurch, New Zealand. Parameters and methods are adjusted and results compared against manually selected test cases representing different classifications used. In doing so, we can evaluate the effectiveness of the segmentation and classification of buildings, earthquake damage, vegetation, vehicles and paved areas, and compare different levels of multi-step image segmentations. Specific methods and parameters explored include classification hierarchies, object selection strategies, and multilevel segmentation strategies. This systematic approach to object-based image classification is used to develop a classifier that is then compared against current pixel-based classification methods for post-event imagery of earthquake damage. Our results show a measurable improvement against established pixel-based methods as well as object-based methods for classifying earthquake damage in high resolution, post-event imagery

OEDIPUS: Onium Evolution, Dipole Interaction and Perturbative Unitarisation Simulation

A Monte Carlo simulation program is presented which can be used to determine the small-$x$ evolution of a heavy onium using Mueller's colour dipole formulation, giving the full distribution of dipoles in rapidity and impact parameter. Routines are also provided which calculate onium-onium scattering amplitudes between individual pairs of onium configurations, making it possible to establish the contribution of multiple pomeron exchange terms to onium-onium scattering (the unitarisation corrections).Comment: 21 pages LaTeX2e. Postscript available from http://www.hep.phy.cam.ac.uk/theory/papers and program available from ftp://axpf.hep.phy.cam.ac.uk/pub/theory/oedipus.tar.g

Characterization of dimensional changes of cement pastes and mortars in fresh state applying an interferometric technique

The effect produced by the incorporation of additives in Portland cement based materials over dimensional changes occurring during the setting process was evaluated employing a fiber optic Fizeau interferometric sensor. The sensor system employed a broadband light source (SLED) centered at 1550 nm, whose spectral emission was modulated by the interferometer formed between the material surface and the end of the optical fiber used to illuminate the sample. An optical spectrum analyzer was used to monitor the variation of the modulated spectrum, while the mentioned process took place. The expansion or contraction experienced by materials with different compositions was observed and quantified. Results obtained point out the accuracy and the potential of the technique.Fil: Mesa Yandy, Angelica Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigaciones Opticas (i); Argentina. Universidad Nacional de La Plata. Facultad de Ingenieria; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Duchowicz, Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigaciones Opticas (i); Argentina. Universidad Austral. Facultad de Ingeniería; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Russo, Nelida Araceli. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Investigaciones Opticas (i); Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Zerbino, Raul Luis. Universidad Nacional de La Plata. Facultad de Ingenieria; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentin

PACOMAR 91/92 - Fahrtbericht SONNE 76 [SO76], 20. Dezember 1991 bis 25. Januar 1992

Das PACOMAR Projekt (PAcific COntinental MARgins) ist ein gemeinsames Vorhaben von deutschen und costaricanischen Forschungseinrichtungen. Es wird hauptsächlich unterstützt vom Bundesministerium für Forschung und Technologie (BMFT) in Form von Zuwendungen an das GEOMAR-Forschungszentrum für marine Geowissenschaften, an das Geologisch-Paläontologische Institut (GPI) der Christian-Aibrechts-Universität zu Kiel sowie an die Bundesanstalt für Geowissenschaften und Rohstoffe (BGR) in Hannover. Auf Seiten Costa Ricas wird das Projekt durch Kooperation mit der costaricanischen Elektrizitätsgesellschaft (ICE), dem Geologischen Institut an der Universität Costa Rica und der costaricanischen Erdölgesellschaft (RECOPE) unterstützt. Dieses Vorhaben befaßt sich mit der Untersuchung von katastrophalen Naturereignissen, wie Erdbeben oder durch sie erzeugte Flutwellen (Tsunamis), und grundlegenden vulkanischen Prozessen. In diesem Fahrtbericht sind die ersten Ergebnisse der Forschungsfahrt S0-76 mit dem F/S Sonne vom 20. Dezember 1991 bis zum 25. Januar 1992 zusammengefaßt. Diese Ergebnisse sowie anschließende Laboruntersuchungen und Auswertungen an Land bilden die Grundlage für die Pla-nungen und Vorbereitungen einer zweiten Fahrt mit dem gleichen Forschungsschiff, S0-81, im August und September 1992

Low cost infrared and near infrared sensors for UAVs

Thermal remote sensing has a wide range of applications, though the extent of its use is inhibited by cost. Robotic and computer components are now widely available to consumers on a scale that makes thermal data a readily accessible resource. In this project, thermal imagery collected via a lightweight remote sensing Unmanned Aerial Vehicle (UAV) was used to create a surface temperature map for the purpose of providing wildland firefighting crews with a cost-effective and time-saving resource. The UAV system proved to be flexible, allowing for customized sensor packages to be designed that could include visible or infrared cameras, GPS, temperature sensors, and rangefinders, in addition to many data management options. Altogether, such a UAV system could be used to rapidly collect thermal and aerial data, with a geographic accuracy of less than one meter

Time evolution of relativistic d + Au and Au + Au collisions

The evolution of charged-particle production in collisions of heavy ions at relativistic energies is investigated as function of centrality in a nonequilibrium-statistical framework. Precise agreement with recent d + Au and Au + Au data at sqrt(s_NN) = 200 GeV is found in a Relativistic Diffusion Model with three sources for particle production. Only the midrapidity source comes very close to local equilibrium, whereas the analyses of the overall pseudorapidity distributions show that the systems remain far from statistical equilibrium.Comment: 16 pages, 5 figures, 1 tabl

Equation of state and initial temperature of quark gluon plasma at RHIC

In gold-gold collisions of the Relativistic Heavy Ion Collider (RHIC) a perfect fluid of quarks, sometimes called the strongly interacting quark gluon plasma (sQGP) is created for an extremely short time. The time evolution of this fluid can be described by hydrodynamical models. After expansion and cooling, the freeze-out happens and hadrons are created. Their distribution reveals information about the final state of the fluid. To investigate the time evolution one needs to analyze penetrating probes, such as direct photon observables. Transverse momentum distributions of low energy direct photons were mesured in 2010 by PHENIX, while azimuthal asymmetry in 2011. These measurements can be compared to hydrodynamics to determine the equation of state and the initial temperature of sQGP. In this paper we analyze an 1+3 dimensional solution of relativistic hydrodynamics. We calculate momentum distribution, azimuthal asymmetry and momentum correlations of direct photons. Based on earlier fits to hadronic spectra, we compare photon calculations to measurements to determine the equation of state and the initial temperature of sQGP. We find that the initial temperature in the center of the fireball is 507+-12 MeV, while for the sound speed we get a speed of sound of 0.36+-0.02. We also estimate a systematic error of these results. We find that the measured azimuthal asymmetry is also not incompatible with this model, and predict a photon source that is significantly larger in the out direction than in the side direction.Comment: 12 pages, 4 figures. This work was supported by the OTKA grant NK-73143 and NK-101438 and M. Csanad's Bolyai scholarshi

Quantum geometry of 2d gravity coupled to unitary matter

We show that there exists a divergent correlation length in 2d quantum gravity for the matter fields close to the critical point provided one uses the invariant geodesic distance as the measure of distance. The corresponding reparameterization invariant two-point functions satisfy all scaling relations known from the ordinary theory of critical phenomena and the KPZ exponents are determined by the power-like fall off of these two-point functions. The only difference compared to flat space is the appearance of a dynamically generated fractal dimension d_h in the scaling relations. We analyze numerically the fractal properties of space-time for Ising and three-states Potts model coupled to 2d dimensional quantum gravity using finite size scaling as well as small distance scaling of invariant correlation functions. Our data are consistent with d_h=4, but we cannot rule out completely the conjecture d_H = -2\alpha_1/\alpha_{-1}, where \alpha_{-n} is the gravitational dressing exponent of a spin-less primary field of conformal weight (n+1,n+1). We compute the moments and the loop-length distribution function and show that the fractal properties associated with these observables are identical, with good accuracy, to the pure gravity case.Comment: LaTeX2e, 38 pages, 13 figures, 32 eps files, added one referenc

The quantum space-time of c=-2 gravity

We study the fractal structure of space-time of two-dimensional quantum gravity coupled to c=-2 conformal matter by means of computer simulations. We find that the intrinsic Hausdorff dimension d_H = 3.58 +/- 0.04. This result supports the conjecture d_H = -2 \alpha_1/\alpha_{-1}, where \alpha_n is the gravitational dressing exponent of a spinless primary field of conformal weight (n+1,n+1), and it disfavours the alternative prediction d_H = 2/|\gamma|. On the other hand ~ r^{2n} for n>1 with good accuracy, i.e. the boundary length l has an anomalous dimension relative to the area of the surface.Comment: 46 pages, 16 figures, 32 eps files, using psfig.sty and epsf.st

High Energy Hadron-Nucleus Cross Sections and Their Extrapolation to Cosmic Ray Energies

Old models of the scattering of composite systems based on the Glauber model of multiple diffraction are applied to hadron-nucleus scattering. We obtain an excellent fit with only two free parameters to the highest energy hadron-nucleus data available. Because of the quality of the fit and the simplicity of the model it is argued that it should continue to be reliable up to the highest cosmic ray energies. Logarithmic extrapolations of proton-proton and proton-antiproton data are used to calculate the proton-air cross sections at very high energy. Finally, it is observed that if the exponential behavior of the proton-antiproton diffraction peak continues into the few TeV energy range it will violate partial wave unitarity. We propose a simple modification that will guarantee unitarity throughout the cosmic ray energy region.Comment: 8 pages, 9 postscript figures. This manuscript replaces a partial manuscript incorrectly submitte