1,204 research outputs found

    A discriminant rule under transformation.

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    We present a new rule for discriminating among continuous populations which are not multivariate normal. The basic idea is to construct the sample maximum likelihood discriminant rule after transforming the data by a suitable multivariate transformation to normalityCross-validation; Multivariate Box-Cox Transformation;

    A discriminant rule under transformation

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    We present a new rule for discriminating among continuous populations which are not multivariate normal. The basic idea is to construct the sample maximum likelihood discriminant rule after transforming the data by a suitable multivariate transformation to normalit

    HLStool: Una herramienta de Síntesis de Alto Nivel para el aprendizaje del estudiante en asignaturas de ATC

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    La utilización de herramientas de Síntesis de Alto Nivel (SAN) es una práctica habitual en las empresas dedicadas al diseño de circuitos. El principal beneficio de estas herramientas se basa en la reducción del “tiempo de lanzamiento al mercado”, ya que permiten evaluar múltiples soluciones en un tiempo reducido. En esta contribución, se propone el uso de una herramienta de síntesis altamente visual y amigable que contenga los algoritmos clásicos para enseñar al alumno las técnicas básicas de SAN, y adicionalmente familiarizarle con el método de trabajo de las compañías de diseño de circuitos. Con esta contribución se propone ofrecer una formación más completa a los futuros graduados que cursen asignaturas del área de la Arquitectura y Tecnología de Computadores.The use of High-Level Synthesis (HLS) tools is a common practice in circuit design companies. The main benefit of these tools consists of diminishing time to market, as they provide multiple solutions to explore in a reduced amount of time. In this paper we propose the use of a highly visual synthesis tool, which implements the classic algorithms to teach students the basic HLS concepts and to get them closer to the companies’ methodology. In this way, Computer Architecture and Technology related subjects will offer a more complete programme to the future graduates.Universidad de Granada: Departamento de Arquitectura y Tecnología de Computadores; Vicerrectorado para la Garantía de la Calidad

    Evaluation of thermal comfort and building form attributes in different semi-outdoor environments in a high-density tropical setting

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    In highly dense tropical cities, a semi-outdoor space (SOS) is frequently used as a social space within tall building forms where people can interact and connect. Thermal comfort in SOSs within tall buildings, however, may vary depending on the type and form attributes that define it. This study classifies 63 SOSs in four tall buildings of Singapore into five types based on literature review: perimeter buffers, sky terraces, horizontal breezeways, breezeway atria and vertical breezeways. Findings suggest that the five SOS types perform differently in terms of thermal comfort (based on PMV*), environmental parameters (air temperature, mean radiant temperature, relative humidity, and air velocity), and building form attributes (height-to-depth ratio, open space ratio, and green plot ratio). Of these five, vertical breezeways and horizontal breezeways are the most thermally comfortable for all activities during a typically warm hour. It is postulated that higher thermal comfort levels in these SOS types are linked to form attributes that enhance air velocity. This study examines the pros and cons of each SOS type in terms of thermal comfort in their role as communal spaces in tall buildings situated within a highly dense tropical city

    Passive cooling design strategies as adaptation measures for lowering the indoor overheating risk in tropical climates

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    Year-round high temperatures and humidity in the Tropics, coupled with poor design decisions and climate change, can cause indoor environments to overheat, affecting health and increasing energy demand and carbon emissions. Passive cooling could help lower the indoor overheating risk. Given the gap in the relative influence of passive cooling design strategies on lowering the indoor overheating risk in tropical locations, this study investigated their impact in two warm tropical cities (i.e., Tegucigalpa and San Pedro Sula), considering both current and future climate scenarios, with a total of 3840 thermal simulations performed. Indoor overheating risk in apartment-type dwellings was assessed using two metrics (i.e., hours of exceedance and the indoor overheating degree), and considering fixed and adaptive thermal comfort limits. Simulation results show that the overheating risk can be significantly lowered in these tropical contexts using solely passive cooling strategies as heat adaptation measures. Multivariate regression models demonstrate that natural ventilation, wall absorptance, the solar heat gain coefficient, and semi-outdoor spaces have the greatest impact in lowering the risk in vertical social housing projects. This study emphasizes the importance of passive cooling and overheating protection design strategies in tropical building codes and building design while considering current and future risk

    Dating archaeological copper using electrochemical impedance spectroscopy. Comparison with voltammetry of microparticles dating

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    [EN] A methodology for dating copper/bronze archaeological objects aged under atmospheric environments using electrochemical impedance spectroscopy (EIS) is described. The method is based on the measurement of resistance associated to the growth of corrosion layers in EIS recorded upon immersion of the pieces in mineral water and applying a bias potential for the reduction of dissolved oxygen. Theoretical expressions for the time variation of such resistance following a potential rate law are presented. Equivalent expressions are derived and applied for estimating the variation of the tenorite/cuprite ratio from their specific voltammetric signals using voltammetry of microparticles data. Calibration curves were constructed from a set of well-documented coins.Financial support from the MEC Projects CTQ2011-28079-CO3-01 and 02 and CTQ2014-53736-C3-2-P which are supported with ERDF funds is gratefully acknowledged.Domenech Carbo, A.; Capelo, S.; Piquero-Cilla, J.; Domenech Carbo, MT.; Barrio, J.; Fuentes, A.; Al Sekhaneh, W. (2016). Dating archaeological copper using electrochemical impedance spectroscopy. Comparison with voltammetry of microparticles dating. Materials and Corrosion. 67(2):120-129. https://doi.org/10.1002/maco.201408048S120129672Friedman, I., & Smith, R. L. (1960). Part I, The Development of the Method. American Antiquity, 25(4), 476-493. doi:10.2307/276634Reich, S., Leitus, G., & Shalev, S. (2003). Measurement of corrosion content of archaeological lead artifacts by their Meissner response in the superconducting state; a new dating method. New Journal of Physics, 5, 99-99. doi:10.1088/1367-2630/5/1/399Scholz, F., Schröder, U., Meyer, S., Brainina, K. Z., Zakhachuk, N. F., Sobolev, N. V., & Kozmenko, O. A. (1995). The electrochemical response of radiation defects of non-conducting materials An electrochemical access to age determinations. Journal of Electroanalytical Chemistry, 385(1), 139-142. doi:10.1016/0022-0728(94)03840-yDoménech-Carbó, A., Labuda, J., & Scholz, F. (2012). Electroanalytical chemistry for the analysis of solids: Characterization and classification (IUPAC Technical Report). Pure and Applied Chemistry, 85(3), 609-631. doi:10.1351/pac-rep-11-11-13Doménech-Carbó, A., Doménech-Carbó, M. T., & Costa, V. (Eds.). (2009). Electrochemical Methods in Archaeometry, Conservation and Restoration. Monographs in Electrochemistry. doi:10.1007/978-3-540-92868-3Doménech-Carbó, A., Doménech-Carbó, M. T., & Peiró-Ronda, M. A. (2011). Dating Archeological Lead Artifacts from Measurement of the Corrosion Content Using the Voltammetry of Microparticles. Analytical Chemistry, 83(14), 5639-5644. doi:10.1021/ac200731qDoménech-Carbó, A., Doménech-Carbó, M. T., Capelo, S., Pasíes, T., & Martínez-Lázaro, I. (2014). Dating Archaeological Copper/Bronze Artifacts by Using the Voltammetry of Microparticles. Angewandte Chemie International Edition, 53(35), 9262-9266. doi:10.1002/anie.201404522Benarie, M., & Lipfert, F. L. (1986). A general corrosion function in terms of atmospheric pollutant concentrations and rain pH. Atmospheric Environment (1967), 20(10), 1947-1958. doi:10.1016/0004-6981(86)90336-7Strandberg, H. (1998). Reactions of copper patina compounds—II. influence of sodium chloride in the presence of some air pollutants. Atmospheric Environment, 32(20), 3521-3526. doi:10.1016/s1352-2310(98)00058-2Cano, E., Lafuente, D., & Bastidas, D. M. (2009). Use of EIS for the evaluation of the protective properties of coatings for metallic cultural heritage: a review. Journal of Solid State Electrochemistry, 14(3), 381-391. doi:10.1007/s10008-009-0902-6Hernandez-Escampa, M., Gonzalez, J., & Uruchurtu-Chavarin, J. (2009). Electrochemical assessment of the restoration and conservation of a heavily corroded archaeological iron artifact. Journal of Applied Electrochemistry, 40(2), 345-356. doi:10.1007/s10800-009-0003-3Angelini, E., Grassini, S., Parvis, M., & Zucchi, F. (2011). An in situ investigation of the corrosion behaviour of a weathering steel work of art. Surface and Interface Analysis, 44(8), 942-946. doi:10.1002/sia.3842Grassini, S., Angelini, E., Parvis, M., Bouchar, M., Dillmann, P., & Neff, D. (2013). An in situ corrosion study of Middle Ages wrought iron bar chains in the Amiens Cathedral. Applied Physics A, 113(4), 971-979. doi:10.1007/s00339-013-7724-1Doménech-Carbó, A., Doménech-Carbó, M. T., Peiró-Ronda, M. A., Martínez-Lázaro, I., & Barrio-Martín, J. (2012). Application of the voltammetry of microparticles for dating archaeological lead using polarization curves and electrochemical impedance spectroscopy. Journal of Solid State Electrochemistry, 16(7), 2349-2356. doi:10.1007/s10008-012-1668-9Degrigny, C., Guibert, G., Ramseyer, S., Rapp, G., & Tarchini, A. (2009). Use of E corr vs time plots for the qualitative analysis of metallic elements from scientific and technical objects: the SPAMT Test Project. Journal of Solid State Electrochemistry, 14(3), 425-435. doi:10.1007/s10008-009-0890-6Souissi, N., Bousselmi, L., Khosrof, S., & Triki, E. (2004). Voltammetric behaviour of an archeaological bronze alloy in aqueous chloride media. Materials and Corrosion, 55(4), 284-292. doi:10.1002/maco.200303719Souissi, N., Triki, E., Bousselmi, L., & Khosrof, S. (2006). Comparaison between archaeological and artificially aged bronze interfaces. Materials and Corrosion, 57(10), 794-799. doi:10.1002/maco.200503974Souissi, N., & Triki, E. (2009). Characterization of ethnographic copper corrosion. Materials and Corrosion, 60(4), 262-268. doi:10.1002/maco.200805068Mata, A. L., Salta, M. M. L., Neto, M. M. M., Mendonça, M. H., & Fonseca, I. T. E. (2010). Characterization of two Roman coins from an archaeological site in Portugal. Materials and Corrosion, 61(3), 205-210. doi:10.1002/maco.200905284Feliu, S., Morcillo, M., & Feliu, S. (1993). The prediction of atmospheric corrosion from meteorological and pollution parameters—II. Long-term forecasts. Corrosion Science, 34(3), 415-422. doi:10.1016/0010-938x(93)90113-uSpence, J. W., Haynie, F. H., Lipfert, F. W., Cramer, S. D., & McDonald, L. G. (1992). Atmospheric Corrosion Model for Galvanized Steel Structures. CORROSION, 48(12), 1009-1019. doi:10.5006/1.3315903Bhattacharjee, S., Roy, N., Dey, A. K., & Banerjee, M. K. (1993). Statistical appraisal of the atmospheric corrosion of mild steel. Corrosion Science, 34(4), 573-581. doi:10.1016/0010-938x(93)90273-jKobus, J. (2000). Long-term atmospheric corrosion monitoring. Materials and Corrosion, 51(2), 104-108. doi:10.1002/(sici)1521-4176(200002)51:23.0.co;2-vBalasubramaniam, R., Laha, T., & Srivastava, A. (2004). Long term corrosion behaviour of copper in soil: A study of archaeological analogues. Materials and Corrosion, 55(3), 194-202. doi:10.1002/maco.200303723Natesan, M., Venkatachari, G., & Palaniswamy, N. (2006). Kinetics of atmospheric corrosion of mild steel, zinc, galvanized iron and aluminium at 10 exposure stations in India. Corrosion Science, 48(11), 3584-3608. doi:10.1016/j.corsci.2006.02.006Doménech, A., Doménech-Carbó, M. T., Pasies, T., & del Carmen Bouzas, M. (2012). Modeling Corrosion of Archaeological Silver-Copper Coins Using the Voltammetry of Immobilized Particles. Electroanalysis, 24(10), 1945-1955. doi:10.1002/elan.201200252Rosas-Camacho, O., Uquidi-Macdonald, M., & Macdonald, D. D. (2009). Deterministic Modeling of the Corrosion of Low-Carbon Steel by Dissolved Carbon Dioxide and the Effect of Acetic Acid. I-Effect of Carbon Dioxide. doi:10.1149/1.3259806Macdonald, D., & Englehardt, G. (2010). The Point Defect Model for Bi-Layer Passive Films. doi:10.1149/1.3496427Sharifi-Asl, S., Taylor, M. L., Lu, Z., Engelhardt, G. R., Kursten, B., & Macdonald, D. D. (2013). Modeling of the electrochemical impedance spectroscopic behavior of passive iron using a genetic algorithm approach. Electrochimica Acta, 102, 161-173. doi:10.1016/j.electacta.2013.03.143Macdonald, D. D. (2011). The history of the Point Defect Model for the passive state: A brief review of film growth aspects. Electrochimica Acta, 56(4), 1761-1772. doi:10.1016/j.electacta.2010.11.005Doménech-Carbó, A., Lastras, M., Rodríguez, F., Cano, E., Piquero-Cilla, J., & Osete-Cortina, L. (2013). Monitoring stabilizing procedures of archaeological iron using electrochemical impedance spectroscopy. Journal of Solid State Electrochemistry, 18(2), 399-409. doi:10.1007/s10008-013-2232-yBlum, D., Leyffer, W., & Holze, R. (1996). Pencil-Leads as new electrodes for abrasive stripping voltammetry. Electroanalysis, 8(3), 296-297. doi:10.1002/elan.1140080317Doménech-Carbó, A., Doménech-Carbó, M. T., & Peiró-Ronda, Mªa. (2011). ‘One-Touch’ Voltammetry of Microparticles for the Identification of Corrosion Products in Archaeological Lead. Electroanalysis, 23(6), 1391-1400. doi:10.1002/elan.201000739Nair, M. T. ., Guerrero, L., Arenas, O. L., & Nair, P. . (1999). Chemically deposited copper oxide thin films: structural, optical and electrical characteristics. Applied Surface Science, 150(1-4), 143-151. doi:10.1016/s0169-4332(99)00239-1Scott, D. A. (1997). Copper compounds in metals and colorants: oxides and hydroxides. Studies in Conservation, 42(2), 93-100. doi:10.1179/sic.1997.42.2.93Doménech, A., Doménech-Carbó, M. T., & Martínez-Lázaro, I. (2010). Layer-by-layer identification of copper alteration products in metallic works of art using the voltammetry of microparticles. Analytica Chimica Acta, 680(1-2), 1-9. doi:10.1016/j.aca.2010.09.002Doménech, A., Doménech-Carbó, M. T., Pasies, T., & Bouzas, M. C. (2011). Application of Modified Tafel Analysis to the Identification of Corrosion Products on Archaeological Metals Using Voltammetry of Microparticles. Electroanalysis, 23(12), 2803-2812. doi:10.1002/elan.201100577Li, W. S., Cai, S. Q., & Luo, J. L. (2004). Chronopotentiometric Responses and Capacitance Behaviors of Passive Film Formed on Iron in Borate Buffer Solution. Journal of The Electrochemical Society, 151(4), B220. doi:10.1149/1.1667521Liu, W., Zhang, H., Qu, Z., Zhang, Y., & Li, J. (2009). Corrosion behavior of the steel used as a huge storage tank in seawater. Journal of Solid State Electrochemistry, 14(6), 965-973. doi:10.1007/s10008-009-0886-2Toledo-Matos, L. A., & Pech-Canul, M. A. (2010). Evolution of an iron passive film in a borate buffer solution (pH 8.4). Journal of Solid State Electrochemistry, 15(9), 1927-1934. doi:10.1007/s10008-010-1213-7Park, J.-J., & Pyun, S.-I. (2003). Analysis of impedance spectra of a pitted Inconel alloy 600 electrode in chloride ion-containing thiosulfate solution at temperatures of 298–573 K. Journal of Solid State Electrochemistry, 7(6), 380-388. doi:10.1007/s10008-002-0346-8Ibrahim, M. A., Pongkao, D., & Yoshimura, M. (2001). The electrochemical behavior and characterization of the anodic oxide film formed on titanium in NaOH solutions. Journal of Solid State Electrochemistry, 6(5), 341-350. doi:10.1007/s100080100229Xia, Z., Nanjo, H., Aizawa, T., Kanakubo, M., Fujimura, M., & Onagawa, J. (2007). Growth process of atomically flat anodic films on titanium under potentiostatical electrochemical treatment in H2SO4 solution. Surface Science, 601(22), 5133-5141. doi:10.1016/j.susc.2007.04.211Acevedo-Peña, P., Vázquez, G., Laverde, D., Pedraza-Rosas, J. E., & González, I. (2009). Influence of structural transformations over the electrochemical behavior of Ti anodic films grown in 0.1 M NaOH. Journal of Solid State Electrochemistry, 14(5), 757-767. doi:10.1007/s10008-009-0838-xFabregat-Santiago, F., Bisquert, J., Garcia-Belmonte, G., Boschloo, G., & Hagfeldt, A. (2005). Influence of electrolyte in transport and recombination in dye-sensitized solar cells studied by impedance spectroscopy. Solar Energy Materials and Solar Cells, 87(1-4), 117-131. doi:10.1016/j.solmat.2004.07.017Rubinstein, I. (1987). Electrochemical Impedance Analysis of Polyaniline Films on Electrodes. Journal of The Electrochemical Society, 134(12), 3078. doi:10.1149/1.2100343Lee, S.-J., & Pyun, S.-I. (2006). Assessment of corrosion resistance of surface-coated galvanized steel by analysis of the AC impedance spectra measured on the salt-spray-tested specimen. Journal of Solid State Electrochemistry, 11(6), 829-839. doi:10.1007/s10008-006-0229-5Doménech, A., Doménech-Carbó, M. T., & Edwards, H. G. M. (2008). Quantitation from Tafel Analysis in Solid-State Voltammetry. Application to the Study of Cobalt and Copper Pigments in Severely Damaged Frescoes. Analytical Chemistry, 80(8), 2704-2716. doi:10.1021/ac7024333Mora, N., Cano, E., Polo, J. L., Puente, J. M., & Bastidas, J. M. (2004). Corrosion protection properties of cerium layers formed on tinplate. Corrosion Science, 46(3), 563-578. doi:10.1016/s0010-938x(03)00171-9Bastidas, J. M., Polo, J. L., Cano, E., Torres, C. L., & Mora, N. (2000). Localised corrosion of highly alloyed stainless steels in an ammonium chloride and diethylamine chloride aqueous solution. Materials and Corrosion, 51(10), 712-718. doi:10.1002/1521-4176(200010)51:103.0.co;2-vXu, J., Huang, W., & McCreery, R. L. (1996). Isotope and surface preparation effects on alkaline dioxygen reduction at carbon electrodes. Journal of Electroanalytical Chemistry, 410(2), 235-242. doi:10.1016/0022-0728(96)04545-7Kuang, F., Zhang, D., Li, Y., Wan, Y., & Hou, B. (2008). Electrochemical impedance spectroscopy analysis for oxygen reduction reaction in 3.5% NaCl solution. Journal of Solid State Electrochemistry, 13(3), 385-390. doi:10.1007/s10008-008-0570-yChen, G., Waraksa, C. C., Cho, H., Macdonald, D. D., & Mallouka, T. E. (2003). EIS Studies of Porous Oxygen Electrodes with Discrete Particles. Journal of The Electrochemical Society, 150(9), E423. doi:10.1149/1.159472

    Sistema de b-learning en Farmacología (I): pilotando

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    Siguiendo el espíritu renovador derivado de la implementación del Espacio Europeo de Educación Superior y utilizando el entorno del Campus Virtual de la UCM (WebCT), se han desarrollado las bases para la implantación de un sistema de b-learning. Los estudiantes de “Farmacología, Farmacia y Terapéutica” de la Licenciatura de Veterinaria podrán consultar, organizado por módulos temáticos, material didáctico para aprender de forma activa los contenidos de esta asignatura troncal. Las herramientas que conforman este sistema presentan diversas finalidades y formatos: formativas (guiones, presentaciones, vídeos, problemas); comunicativas (foro de intercambio de ideas, dudas e iniciativas y avisos); y evaluadoras (autoevaluaciones para los alumnos y encuestas sobre la utilidad de la propia herramienta). La idea es que los estudiantes sean los gestores de su propio aprendizaje. Para ello, cuentan con el apoyo de una herramienta virtual (Aula Virtual de Farmacología), con actividades docentes presenciales (seminarios y tutorías) y con herramientas de evaluación de los conocimientos adquiridos.Following the innovative spirit derived from implementation of the European Higher Education Area and using an online learning environment (Campus Virtual-UCM), the bases for the implantation of a b-learning system have been developed. The students of "Pharmacology, Pharmacy and Therapeutic" of the Veterinary Medicine degree will be able to consult, organized by thematic modules, educational material to learn in an active way the contents of this core subject. The tools that shape this system present diverse purposes and formats: formatives (scripts, presentations, videos, problems); communicatives (forum to exchanging of ideas, doubts or initiatives and notices); assessments (autoevaluations for the pupils and surveys on the usefulness of the own tool). The idea is that students are the managers of their own learning. For it, they have the support of a virtual tool (Virtual Classroom of Pharmacology), face-to-face educational activities (seminars, tutorials) and tools of evaluation of the acquired knowledge

    Sistema de Seguridad Basado en una Plataforma Heterogénea Distribuida

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    Este trabajo presenta el proyecto “Ecosistema Digital de Seguridad”, realizado en la asignatura Sistemas Empotrados Distribuidos, perteneciente a la titulación Máster en Ingeniería Informática de la Universidad Complutense de Madrid. En este trabajo se describe e implementa un sistema de seguridad por medio de una plataforma heterogénea, cuyo objetivo es la verificación de los usuarios autorizados. En concreto, la placa Raspberry Pi se encarga del reconocimiento de la imagen y la contraseña, mientras que la STM32F4 Discovery sirve de interfaz con el usuario, recibiendo la contraseña y enviándosela a la Raspberry a través de la interfaz RS-232.This work presents the project en titled “Digital Security Ecosystem”, carried out as a final project in th e Distributed Embedded Systems subject, which belongs to the Computer Engineering Master, at the Complutense University of Madrid. In this work, a security system is described and implemented through a hetero geneous platform, whose objective consists of the authorized users’ verification. Concretely , the Raspberry Pi board is responsible for identifying the image and the password, while the STM32F4 Discovery board acts as the user interface, receivi ng the password which will be sent to the Raspberry by using the RS-232 interface.Universidad de Granada: Departamento de Arquitectura y Tecnología de Computadores; Vicerrectorado para la Garantía de la Calidad

    Sistema Empotrado Distribuido para el Control de Accesos - RFIDoors

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    Con el paso del tiempo se ha ido ampliando la utilización de sistemas con identificación por radiofrecuencia (RFID) en los distintos ámbitos de la sociedad actual. En este trabajo se presenta la implementación de un sistema empotrado distribuido compuesto por elementos de fácil adquisición y de bajo coste como la Raspberry Pi, los módulos RFID o los sensores de ultrasonidos, cuyo objetivo es controlar y gestionar un sistema de autenticación para la apertura y cierre de puertas. Como complemento, este sistema consta además de un servidor y una aplicación para la parte administrativa y operativa del sistema.Nowadays, the use of the systems with radio frequency identification (RFID) is becoming widespread in different scenarios of society. This paper presents the implementation of a Distributed Embedded System composed of low-cost components such as Raspberry Pi, RFID modules, ultrasound sensors and others, whose objective is to manage an authentication system for the opening and closing of doors. Furthermore, this system incorporates a server and an application for the administrative and operative part of the system.Universidad de Granada: Departamento de Arquitectura y Tecnología de Computadore
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