Browsing by Author "Aguirre, P."
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- ItemAutomated building characterization for seismic risk assessment using street-level imagery and deep learning(2021) Aravena Pelizari, P.; Geiß, C.; Aguirre, P.; Santa María, H.; Merino Peña, Y.; Taubenböck, H.Accurate seismic risk modeling requires knowledge of key structural characteristics of buildings. However, to date, the collection of such data is highly expensive in terms of labor, time and money and thus prohibitive for a spatially continuous large-area monitoring. This study quantitatively evaluates the potential of an automated and thus more efficient collection of vulnerability-related structural building characteristics based on Deep Convolutional Neural Networks (DCNNs) and street-level imagery such as provided by Google Street View. The proposed approach involves a tailored hierarchical categorization workflow to structure the highly heterogeneous street-level imagery in an application-oriented fashion. Thereupon, we use state-of-the-art DCNNs to explore the automated inference of Seismic Building Structural Types. These reflect the main-load bearing structure of a building, and thus its resistance to seismic forces. Additionally, we assess the independent retrieval of two key building structural parameters, i.e., the material of the lateral-load-resisting system and building height to investigate the applicability for a more generic structural characterization of buildings. Experimental results obtained for the earthquake-prone Chilean capital Santiago show accuracies beyond kappa = 0.81 for all addressed classification tasks. This underlines the potential of the proposed methodology for an efficient in-situ data collection on large spatial scales with the purpose of risk assessments related to earthquakes, but also other natural hazards (e.g., tsunamis, or floods).
- ItemEarthquake response sensitivity of complex infrastructure networks(2020) Llera Martin, Juan Carlos de la; Monsalve, Mauricio; Ferrario, Elisa; Allen, E.; Chamorro, A.; Castro, S.; Alberto, Yolanda; Arróspide, Felipe; Poulos, Alan; Candia, G.; Aguirre, P.Resilience of complex infrastructure networks is critical in achieving earthquake resilience in urban environments. Perhaps due to their modeling complexity, very few research studies have addressed sensitivity of the network response to a severe earthquake hazard field. This research aims to characterize earthquake response sensitivity as a function of different topological parameters of 5 critical complex networks in central Chile, covering the electric, transportation, and drinking water networks. Central Chile was selected because it amounts for almost 50% of the country’s population. What is also particular about this setting, is that the seismic characteristics of the region lead to extended (essentially) N-S strike fault ruptures, which run along the subduction margin defined by the E-W convergence between the South American and Pacific Ocean plates at an unusual rate of about 68 mm/year, thus involving in the strong-motion hazard field geographic scales in the hundreds of kilometers. It is concluded that node and link topological structures differ considerably between these complex systems, which are characterized by several different well-known centrality parameters and other interesting indices and network-class discriminators. Secondly, a component criticality analysis under an earthquake hazard field is also presented just in terms of connectivity/service loss, which enables, at least, a rough identification of the robustness of each network as nodes and links are removed. Results from these topological analyses are useful to identify which components are essential in generating larger earthquake resilience. This is the first time such results are obtained for central Chile using very detailed models of these complex networks
- ItemErratum: "The Globular Cluster NGC 5286. II. Variable Stars" (2010, AJ, 139, 357)(2010) Zorotovic, M.; Catelan, Márcio; Smith, H. A.; Pritzl, B. J.; Aguirre, P.; Angulo, R. E.; Aravena, M.; Assef, R. J.; Contreras, C.; Cortés, C.; De Martini, G.; Escobar, M. E.; González, D.; Jofré, P.; Lacerna, I.; Navarro, C.; Palma, O.; Prieto, G. E.; Recabarren, E.; Triviño, J.; Vidal, E.The Fourier decomposition program used in our paper contained a small error that affected the calculation of the temperatures as well as the V - I colors inferred for the RRab stars. The temperatures that appear in Table 6 in the published article are slightly overestimated, and the V - I colors underestimated. A corrected version of Table 6 is presented below....
- ItemFree radicals derived from gamma-radiolysis of water and AAPH thermolysis mediate oxidative crosslinking of eGFP involving Tyr-Tyr and Tyr-Cys bonds : the fluorescence of the protein is conserved only towards peroxyl radicals(2020) Zamora Jofré, Renato Andrés; Fuentes Lemus, Eduardo Felipe; Barrias, P.; Herrera-Morande, A.; Mura, F.; Guixe, V.; Castro-Fernandez, V.; Rojas, T.; López Alarcón, Camilo Ignacio; Aguirre, P.; Rivas-Aravena, A.; Aspee, A.
- ItemReactivity of 2,6-diethyl-4,8-dimethyl-1,5-dioxo-s-hydrindacene towards radical, anionic and cationic germylation(2004) El Kadib, A.; Castel, A.; Delpech, F.; Rivière, Pierre; Rivière-Baudet, M.; Gornitzka, H.; Aguirre, P.; Manríquez M., Juan Manuel; Chávez Madariaga, Ivonne; Abril Milan, Diana Rosa
- ItemThe Atacama Cosmology Telescope (ACT): Beam Profiles and First SZ Cluster Maps(2010) Hincks, A. D.; Acquaviva, V.; Ade, P. A. R.; Aguirre, P.; Amiri, M.; Appel, J. W.; Barrientos, L. F.; Battistelli, E. S.; Bond, J. R.; Brown, B.; Burger, B.; Chervenak, J.; Das, S.; Devlin, M. J.; Dicker, S. R.; Doriese, W. B.; Dunkley, J.; Dünner, R.; Essinger-Hileman, T.; Fisher, R. P.; Fowler, J. W.; Hajian, A.; Halpern, M.; Hasselfield, M.; Hernández-Monteagudo, C.; Hilton, G. C.; Hilton, M.; Hlozek, R.; Huffenberger, K. M.; Hughes, D. H.; Hughes, J. P.; Infante, L.; Irwin, K. D.; Jimenez, R.; Juin, J. B.; Kaul, M.; Klein, J.; Kosowsky, A.; Lau, J. M.; Limon, M.; Lin, Y. -T.; Lupton, R. H.; Marriage, T. A.; Marsden, D.; Martocci, K.; Mauskopf, P.; Menanteau, F.; Moodley, K.; Moseley, H.; Netterfield, C. B.; Niemack, M. D.; Nolta, M. R.; Page, L. A.; Parker, L.; Partridge, B.; Quintana, H.; Reid, B.; Sehgal, N.; Sievers, J.; Spergel, D. N.; Staggs, S. T.; Stryzak, O.; Swetz, D. S.; Switzer, E. R.; Thornton, R.; Trac, H.; Tucker, C.; Verde, L.; Warne, R.; Wilson, G.; Wollack, E.; Zhao, Y.The Atacama Cosmology Telescope (ACT) is currently observing the cosmic microwave background with arcminute resolution at 148 GHz, 218 GHz, and 277 GHz. In this paper, we present ACT's first results. Data have been analyzed using a maximum-likelihood map-making method which uses B-splines to model and remove the atmospheric signal. It has been used to make high-precision beam maps from which we determine the experiment's window functions. This beam information directly impacts all subsequent analyses of the data. We also used the method to map a sample of galaxy clusters via the Sunyaev-Zel'dovich (SZ) effect and show five clusters previously detected with X-ray or SZ observations. We provide integrated Compton-y measurements for each cluster. Of particular interest is our detection of the z = 0.44 component of A3128 and our current non-detection of the low-redshift part, providing strong evidence that the further cluster is more massive as suggested by X-ray measurements. This is a compelling example of the redshift-independent mass selection of the SZ effect.
- ItemThe Atacama Cosmology Telescope: A Measurement of the 600 < ell < 8000 Cosmic Microwave Background Power Spectrum at 148 GHz(2010) Fowler, J. W.; Acquaviva, V.; Ade, P. A. R.; Aguirre, P.; Amiri, M.; Appel, J. W.; Barrientos, L. F.; Battistelli, E. S.; Bond, J. R.; Brown, B.; Burger, B.; Chervenak, J.; Das, S.; Devlin, M. J.; Dicker, S. R.; Doriese, W. B.; Dunkley, J.; Dünner, R.; Essinger-Hileman, T.; Fisher, R. P.; Hajian, A.; Halpern, M.; Hasselfield, M.; Hernández-Monteagudo, C.; Hilton, G. C.; Hilton, M.; Hincks, A. D.; Hlozek, R.; Huffenberger, K. M.; Hughes, D. H.; Hughes, J. P.; Infante, L.; Irwin, K. D.; Jimenez, R.; Juin, J. B.; Kaul, M.; Klein, J.; Kosowsky, A.; Lau, J. M.; Limon, M.; Lin, Y. -T.; Lupton, R. H.; Marriage, T. A.; Marsden, D.; Martocci, K.; Mauskopf, P.; Menanteau, F.; Moodley, K.; Moseley, H.; Netterfield, C. B.; Niemack, M. D.; Nolta, M. R.; Page, L. A.; Parker, L.; Partridge, B.; Quintana, H.; Reid, B.; Sehgal, N.; Sievers, J.; Spergel, D. N.; Staggs, S. T.; Swetz, D. S.; Switzer, E. R.; Thornton, R.; Trac, H.; Tucker, C.; Verde, L.; Warne, R.; Wilson, G.; Wollack, E.; Zhao, Y.We present a measurement of the angular power spectrum of the cosmic microwave background (CMB) radiation observed at 148 GHz. The measurement uses maps with 1'.4 angular resolution made with data from the Atacama Cosmology Telescope (ACT). The observations cover 228 deg(2) of the southern sky, in a 4 degrees.2 wide strip centered on declination 53 degrees south. The CMB at arcminute angular scales is particularly sensitive to the Silk damping scale, to the Sunyaev-Zel'dovich (SZ) effect from galaxy clusters, and to emission by radio sources and dusty galaxies. After masking the 108 brightest point sources in our maps, we estimate the power spectrum between 600 < l < 8000 using the adaptive multi-taper method to minimize spectral leakage and maximize use of the full data set. Our absolute calibration is based on observations of Uranus. To verify the calibration and test the fidelity of our map at large angular scales, we cross-correlate the ACT map to the WMAP map and recover the WMAP power spectrum from 250 < l < 1150. The power beyond the Silk damping tail of the CMB (l similar to 5000) is consistent with models of the emission from point sources. We quantify the contribution of SZ clusters to the power spectrum by fitting to a model normalized to sigma(8) = 0.8. We constrain the model's amplitude A(SZ) < 1.63 (95% CL). If interpreted as a measurement of sigma(8), this implies sigma(SZ)(8) < 0.86 (95% CL) given our SZ model. A fit of ACT and WMAP five-year data jointly to a six-parameter Lambda CDM model plus point sources and the SZ effect is consistent with these results.