20 research outputs found

    Localidad y globalización en la dinámica migratoria hacia los Estados Unidos desde áreas urbano - marginales y rurales: el caso de los municipios de El Progreso y El Negrito en el departamento de Yoro, Honduras

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    ESTE INFORME SE ENFOCA EN EL FENÓMENO MIGRATORIO HACIA LOS Estados Unidos desde los municipios de El Progreso y El Negrito, en el departamento hondureño de Yoro. Destaca las tendencias y consecuencias principales de dicho fenómeno, los sectores de población a los cuales afecta y las características significativas del contexto social, económico y político en el que éste se produce. Se exploran algunos datos relevantes contenidos en la base de datos –en proceso de construcción– del Equipo de Reflexión, Investigación y Comunicación de la Compañía de Jesús en Honduras (ERIC-SJ)

    Design of an Ultra-wideband Radio Frequency Identification System with Chipless Transponders

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    The state-of-the-art commercially available radio-frequency identification (RFID) transponders are usually composed of an antenna and an application specific integrated circuit chip, which still makes them very costly compared to the well-established barcode technology. Therefore, a novel low-cost RFID system solution based on passive chipless RFID transponders manufactured using conductive strips on flexible substrates is proposed in this work. The chipless RFID transponders follow a specific structure design, which aim is to modify the shape of the impinged electromagnetic wave to embed anidentification code in it and then backscatter the encoded signal to the reader. This dissertation comprises a multidisciplinary research encompassing the design of low-cost chipless RFID transponders with a novel frequency coding technique, unlike usually disregarded in literature, this approach considers the communication channel effects and assigns a unique frequency response to each transponder. Hence, the identification codes are different enough, to reduce the detection error and improve their automatic recognition by the reader while working under normal conditions. The chipless RFID transponders are manufactured using different materials and state-of-the-art mass production fabrication processes, like printed electronics. Moreover, two different reader front-ends working in the ultra-wideband (UWB) frequency range are used to interrogate the chipless RFID transponders. The first one is built using high-performance off-theshelf components following the stepped frequency modulation (SFM) radar principle, and the second one is a commercially available impulse radio (IR) radar. Finally, the two readers are programmed with algorithms based on the conventional minimum distance and maximum likelihood detection techniques, considering the whole transponder radio frequency (RF) response, instead of following the commonly used approach of focusing on specific parts of the spectrum to detect dips or peaks. The programmed readers automatically identify when a chipless RFID transponder is placed within their interrogation zones and proceed to the successful recognition of its embedded identification code. Accomplishing in this way, two novel fully automatic SFM- and IRRFID readers for chipless transponders. The SFM-RFID system is capable to successfully decode up to eight different chipless RFID transponders placed sequentially at a maximum reading range of 36 cm. The IR-RFID system up to four sequentially and two simultaneously placed different chipless RFID transponders within a 50 cm range.:Acknowledgments Abstract Kurzfassung Table of Contents Index of Figures Index of Tables Index of Abbreviations Index of Symbols 1 Introduction 1.1 Motivation 1.2 Scope of Application 1.3 Objectives and Structure Fundamentals of the RFID Technology 2.1 Automatic Identification Systems Background 2.1.1 Barcode Technology 2.1.2 Optical Character Recognition 2.1.3 Biometric Procedures 2.1.4 Smart Cards 2.1.5 RFID Systems 2.2 RFID System Principle 2.2.1 RFID Features 2.3 RFID with Chipless Transponders 2.3.1 Time Domain Encoding 2.3.2 Frequency Domain Encoding 2.4 Summary Manufacturing Technologies 3.1 Organic and Printed Electronics 3.1.1 Substrates 3.1.2 Organic Inks 3.1.3 Screen Printing 3.1.4 Flexography 3.2 The Printing Process 3.3 A Fabrication Alternative with Aluminum or Copper Strips 3.4 Fabrication Technologies for Chipless RFID Transponders 3.5 Summary UWB Chipless RFID Transponder Design 4.1 Scattering Theory 4.1.1 Radar Cross-Section Definition 4.1.2 Radar Absorbing Material’s Principle 4.1.3 Dielectric Multilayers Wave Matrix Analysis 4.1.4 Frequency Selective Surfaces 4.2 Double-Dipoles UWB Chipless RFID Transponder 4.2.1 An Infinite Double-Dipole Array 4.2.2 Double-Dipoles UWB Chipless Transponder Design 4.2.3 Prototype Fabrication 4.3 UWB Chipless RFID Transponder with Concentric Circles 4.3.1 Concentric Circles UWB Chipless Transponder 4.3.2 Concentric Rings UWB Chipless RFID Transponder 4.4 Concentric Octagons UWB Chipless Transponders 4.4.1 Concentric Octagons UWB Chipless Transponder Design 1 4.4.2 Concentric Octagons UWB Chipless Transponder Design 2 4.5 Summary 5. RFID Readers for Chipless Transponders 5.1 Background 5.1.1 The Radar Range Equation 5.1.2 Range Resolution 5.1.3 Frequency Band Selection 5.2 Frequency Domain Reader Test System 5.2.1 Stepped Frequency Waveforms 5.2.2 Reader Architecture 5.2.3 Test System Results 5.3 Time Domain Reader 5.3.1 Novelda Radar 5.3.2 Test System Results 5.4 Summary Detection of UWB Chipless RFID Transponders 6.1 Background 6.2 The Communication Channel 6.2.1 AWGN Channel Modeling and Detection 6.2.2 Free-Space Path Loss Modeling and Normalization 6.3 Detection and Decoding of Chipless RFID Transponders 6.3.1 Minimum Distance Detector 6.3.2 Maximum Likelihood Detector 6.3.3 Correlator Detector 6.3.4 Test Results 6.4 Simultaneous Detection of Multiple UWB Chipless Transponders 6.5 Summary System Implementation 7.1 SFM-UWB RFID System with CR-Chipless Transponders 7.2 IR-UWB RFID System with COD1-Chipless Transponders 7.3 Summary Conclusion and Outlook References Publications Appendix A RCS Calculation Measurement Setups Appendix B Resistance and Skin Depth Calculation Appendix C List of Videos Test Videos Consortium Videos Curriculum Vita

    DINÁMICA DEL USO DE LA TIERRA Y LA VARIABILIDAD CLIMÁTICA EN LA SUBCUENCA DEL RÍO PANAJACHEL, CUENCA DEL LAGO DE ATITLÁN, SOLOLÁ

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    El presente estudio partió de la interrogante ¿Cuál es la dinámica del uso de la tierra con la variabilidad climática y cómo se manifiesta con la erosión hídrica? Para ello se realizó revisión bibliográfica, aplicación de la Ecuación Universal de Perdida de Suelos Revisada, Sistemas de Información Geográfica, metodología Conversion of Land use and its Effects CLUE, ortofotos, sobreposición de mapas y software R-Climdex. Los resultados obtenidos evidenciaron que existe aumento significativo en la transformación de bosque a usos como agricultura y urbanización. La tendencia de la precipitación es normal de manera general, observándose una disminución en la precipitación promedio anual de 1,235 mm anual en los últimos 7 años. La erosión hídrica del año 2018, es muy alta con pérdidas mayores a 200 Ton/ha/año en la subcuenca. Dinámica que se mantiene para los escenarios del 2030 y 2040. Por lo tanto; la dinámica del uso de la tierra es variable y está relacionada con la variabilidad climática a través de la precipitación al evidenciar que hay incremento de erosión hídrica

    INFLUENCIA DE LA OSCILACIÓN MADDEN-JULIAN EN LA LLUVIA DE LA REGIÓN SUR DE GUATEMALA DURANTE EL PERIODO DE 1980 – 2015

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    Se reportan evidencias de la presencia de la Oscilación Madden-Julian OMJ en la región sur de Guatemala, que se cuantifica en términos de intensidades diarias de precipitación. Mediante el análisis de filtros de paso bajo, espectro de ondas ecuatoriales, espectro de trasformada wavelet, análisis de radiación de onda larga y simple, acumulado de lluvia relacionada con las fases de la OMJ, se demuestra que hay cierta influencia que principalmente se detecta en las fases 1 y 8 para aportes de precipitación y fase 3 y 4 con inhibición de precipitación, en la región sur de Guatemala. Se estima que existen aportes mínimos a nivel anual que alcanzan 0.48 % de la precipitación anual en la región de boca costa y del 1.12 % en la región de costa sur. Además, se evidencia mayor cambio porcentual en los análisis de acumulados mensuales, los cuales tienen variaciones hasta un 8 % de los milímetros mensuales

    Representations of Utopian Urbanism and the Feminist Geopolitics of ‘New City’ Development

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    Increasingly over the past few years the building of new cities “from scratch” has become a key strategy to promote development across much of the Global South. While several projects are currently under construction, many others exist primarily as proposals awaiting adequate investment or government action. This paper builds on previous literature that considers representations of such projects – promotional materials, digitally-produced video simulations, and master plans – as key components in the production of imagined urban futures. Through an exploration of the proposed Zone for Economic Development and Employment (ZEDE) in Honduras, this article demonstrates a feminist geopolitical approach focused on how such representations of utopian urbanism circulate through the local communities slated for new city development. I examine how representations of future urban spaces and future urban governance regimes become appropriated by local residents in organizing opposition or otherwise making sense of the proposed project’s potential impact on their lives.12 month embargo; published online: 30 Dec 2018This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

    Honduras. El estado fragmentado (1839-1876)

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    INTRODUCCION Las cuatro décadas comprendidas entre la disolución de la Federación centroamericana y el inicio del proceso de reforma liberal en 1876, etapa que es identificada por algunos autores como la época de la “restauración conservadora”, puede también considerarse como un período de aguda lucha entre las fuerzas favorables a la centralización y el fortalecimiento estatal, y aquellas que resistían propugnando la autonomía regional. La lealtad hacia el Estado por parte de algunas comunid..

    Identidad, Estado e integración nacional: el caso de Honduras

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    Se tratará sobre la estrecha relación entre identidad, integración y Estado nacional, y cómo las fortalezas y debilidades de cada uno incide recíprocamente sobre el otro debido a la correspondencia estructural que en el curso de la historia se ha creado entre ellos. Se centra en especial en América Central, y en el caso de Honduras

    Design of an Ultra-wideband Radio Frequency Identification System with Chipless Transponders

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    The state-of-the-art commercially available radio-frequency identification (RFID) transponders are usually composed of an antenna and an application specific integrated circuit chip, which still makes them very costly compared to the well-established barcode technology. Therefore, a novel low-cost RFID system solution based on passive chipless RFID transponders manufactured using conductive strips on flexible substrates is proposed in this work. The chipless RFID transponders follow a specific structure design, which aim is to modify the shape of the impinged electromagnetic wave to embed anidentification code in it and then backscatter the encoded signal to the reader. This dissertation comprises a multidisciplinary research encompassing the design of low-cost chipless RFID transponders with a novel frequency coding technique, unlike usually disregarded in literature, this approach considers the communication channel effects and assigns a unique frequency response to each transponder. Hence, the identification codes are different enough, to reduce the detection error and improve their automatic recognition by the reader while working under normal conditions. The chipless RFID transponders are manufactured using different materials and state-of-the-art mass production fabrication processes, like printed electronics. Moreover, two different reader front-ends working in the ultra-wideband (UWB) frequency range are used to interrogate the chipless RFID transponders. The first one is built using high-performance off-theshelf components following the stepped frequency modulation (SFM) radar principle, and the second one is a commercially available impulse radio (IR) radar. Finally, the two readers are programmed with algorithms based on the conventional minimum distance and maximum likelihood detection techniques, considering the whole transponder radio frequency (RF) response, instead of following the commonly used approach of focusing on specific parts of the spectrum to detect dips or peaks. The programmed readers automatically identify when a chipless RFID transponder is placed within their interrogation zones and proceed to the successful recognition of its embedded identification code. Accomplishing in this way, two novel fully automatic SFM- and IRRFID readers for chipless transponders. The SFM-RFID system is capable to successfully decode up to eight different chipless RFID transponders placed sequentially at a maximum reading range of 36 cm. The IR-RFID system up to four sequentially and two simultaneously placed different chipless RFID transponders within a 50 cm range.:Acknowledgments Abstract Kurzfassung Table of Contents Index of Figures Index of Tables Index of Abbreviations Index of Symbols 1 Introduction 1.1 Motivation 1.2 Scope of Application 1.3 Objectives and Structure Fundamentals of the RFID Technology 2.1 Automatic Identification Systems Background 2.1.1 Barcode Technology 2.1.2 Optical Character Recognition 2.1.3 Biometric Procedures 2.1.4 Smart Cards 2.1.5 RFID Systems 2.2 RFID System Principle 2.2.1 RFID Features 2.3 RFID with Chipless Transponders 2.3.1 Time Domain Encoding 2.3.2 Frequency Domain Encoding 2.4 Summary Manufacturing Technologies 3.1 Organic and Printed Electronics 3.1.1 Substrates 3.1.2 Organic Inks 3.1.3 Screen Printing 3.1.4 Flexography 3.2 The Printing Process 3.3 A Fabrication Alternative with Aluminum or Copper Strips 3.4 Fabrication Technologies for Chipless RFID Transponders 3.5 Summary UWB Chipless RFID Transponder Design 4.1 Scattering Theory 4.1.1 Radar Cross-Section Definition 4.1.2 Radar Absorbing Material’s Principle 4.1.3 Dielectric Multilayers Wave Matrix Analysis 4.1.4 Frequency Selective Surfaces 4.2 Double-Dipoles UWB Chipless RFID Transponder 4.2.1 An Infinite Double-Dipole Array 4.2.2 Double-Dipoles UWB Chipless Transponder Design 4.2.3 Prototype Fabrication 4.3 UWB Chipless RFID Transponder with Concentric Circles 4.3.1 Concentric Circles UWB Chipless Transponder 4.3.2 Concentric Rings UWB Chipless RFID Transponder 4.4 Concentric Octagons UWB Chipless Transponders 4.4.1 Concentric Octagons UWB Chipless Transponder Design 1 4.4.2 Concentric Octagons UWB Chipless Transponder Design 2 4.5 Summary 5. RFID Readers for Chipless Transponders 5.1 Background 5.1.1 The Radar Range Equation 5.1.2 Range Resolution 5.1.3 Frequency Band Selection 5.2 Frequency Domain Reader Test System 5.2.1 Stepped Frequency Waveforms 5.2.2 Reader Architecture 5.2.3 Test System Results 5.3 Time Domain Reader 5.3.1 Novelda Radar 5.3.2 Test System Results 5.4 Summary Detection of UWB Chipless RFID Transponders 6.1 Background 6.2 The Communication Channel 6.2.1 AWGN Channel Modeling and Detection 6.2.2 Free-Space Path Loss Modeling and Normalization 6.3 Detection and Decoding of Chipless RFID Transponders 6.3.1 Minimum Distance Detector 6.3.2 Maximum Likelihood Detector 6.3.3 Correlator Detector 6.3.4 Test Results 6.4 Simultaneous Detection of Multiple UWB Chipless Transponders 6.5 Summary System Implementation 7.1 SFM-UWB RFID System with CR-Chipless Transponders 7.2 IR-UWB RFID System with COD1-Chipless Transponders 7.3 Summary Conclusion and Outlook References Publications Appendix A RCS Calculation Measurement Setups Appendix B Resistance and Skin Depth Calculation Appendix C List of Videos Test Videos Consortium Videos Curriculum Vita
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