WorldWideScience

Sample records for medir radios orbitales

  1. Sub-coulomb transfer method of a nucleon for measure orbital radii; Metodo de transferencia sub-coulombiana de un nucleon para medir radios orbitales

    Energy Technology Data Exchange (ETDEWEB)

    Aguilera R, E.F.; Murillo, G.; Ramirez, J.; Avila, O. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1986-04-15

    The neutron transfer method is revised to measure neutron orbital radii and possible interest systems to apply it are determined. Its were carried out DWBA preliminary calculations for the system {sup 209} Bi(d,t) {sup 208} Bi. (Author)

  2. ORBITALES. A program for the calculation of wave functions with an analytical central potential; ORBITALES. Programa de calculo de Funciones de Onda para una Potencial Central Analitico

    Energy Technology Data Exchange (ETDEWEB)

    Carretero, Yunta; Rodriguez Mayquez, E

    1974-07-01

    In this paper is described the objective, basis, carrying out in FORTRAN language and use of the program ORBITALES. This program calculate atomic wave function in the case of ths analytical central potential (Author) 8 refs.

  3. ORBITALES. A program for the calculation of wave functions with an analytical central potential

    International Nuclear Information System (INIS)

    Yunta Carretero; Rodriguez Mayquez, E.

    1974-01-01

    In this paper is described the objective, basis, carrying out in FORTRAN language and use of the program ORBITALES. This program calculate atomic wave function in the case of ths analytical central potential (Author) 8 refs

  4. La aproximación topológica en el cálculo de orbitales moleculares localizados.

    OpenAIRE

    Paniagua, Juan Carlos

    1983-01-01

    [spa] Es bien sabido que cualquier función de onda que se exprese como determinante de Slater construido a partir de orbitales moleculares doblemente ocupados es invariante frente a transformaciones unitarias de dichos orbitales. Aunque las posibilidades de elección son ilimitadas, en la práctica sólo se utilizan dos tipos de orbitales: los canónicos y los localizados. Los primeros se caracterizan por ser funciones propias de algún hamiltoniano monoelectrónico efectivo y entre sus propieda...

  5. Aproximación topológica en el cálculo de orbitales moleculares localizados, La

    OpenAIRE

    Paniagua Valle, Juan Carlos

    1983-01-01

    Es bien sabido que cualquier función de onda que se exprese como determinante de Slater construido a partir de orbitales moleculares doblemente ocupados es invariante frente a transformaciones unitarias de dichos orbitales.Aunque las posibilidades de elección son ilimitadas, en la práctica sólo se utilizan dos tipos de orbitales: los canónicos y los localizados. Los primeros se caracterizan por ser funciones propias de algún hamiltoniano monoelectrónico efectivo y entre sus propiedades más in...

  6. Neutron orbital radii in {sup 13} C; Radios orbitales neutronicos en {sup 13} C

    Energy Technology Data Exchange (ETDEWEB)

    Aguilera R, E.F.; Murillo, G.; Ramirez, J.J.; Avila, O.L. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1988-01-15

    In this work its were carried out experimental measurements of the reaction {sup 12}C(d,p) {sup 13}C at low energy. Preliminary results of a DWBA analysis of the data are presented, and the possibility of using this reaction to obtain the orbital radius of the transferred neutron is investigated. (Author)

  7. Estudio teórico del CO2. Orbitales de valencia y del ``core''

    Science.gov (United States)

    Olalla Gutiérrez, E.

    Hemos calculado las intensidades de las transiciones E1 a los miembros de las series de Rydberg con origen en los orbitales ``no enlazantes'' del dióxido de carbono, especie de conocida relevancia atmosférica. Se han computado, asimismo, los continuos de fotoionización correspondientes a los distintos canales de ionización, representándolos como densidad espectral de fuerza de oscilador frente a la energía del fotón incidente; mostramos los resultados df/dE para la fotoionización total de esta especie en el intervalo 15-60 eV. Todos los cálculos se han llevado a cabo mediante la formulación Molecular del Método de los Orbitales de Defecto Cuántico, MQDO [1,2]. La calidad de los resultados que presentamos se ha evaluado en base a la comparación con los datos, tanto experimentales como teóricos, disponibles en la bibliografía. El acuerdo encontrado es altamente satisfactorio

  8. Procedimientos para detectar y medir el sesgo entre observadores

    OpenAIRE

    Benavente, Ana; Alto, Manuel; López, Juan José

    2006-01-01

    En este trabajo se realiza un análisis de los distintos métodos para detectar y medir el sesgo entre observadores desde dos perspectivas básicas: el enfoque clásico, fundamentado en índices descriptivos y el enfoque del modelado, fundamentado en modelos loglineales. Se demuestra que estas medidas no son satisfactorias para detectar y medir el sesgo de forma unívoca porque presentan resultados contradictorios y se proponen nuevas alternativas a desarrollar que permitan descomponer correctament...

  9. Extensión del Formalismo de Orbitales de Defecto Cuántico al tratamiento del efecto Stark (SQDO).

    Science.gov (United States)

    Menéndez, J. M.; Martín, I.; Velasco, A. M.

    El estudio experimental de las interacciones de átomos Rydberg altamente excitados con campos eléctricos ha experimentado un creciente interés durante las dos últimas décadas debido, en gran medida, al desarrollo de nuevas técnicas para crear y estudiar átomos Rydberg en el laboratorio. Acompañando a estas nuevas técnicas experimentales, es necesario el desarrollo de modelos teóricos que nos permitan contrastar sus medidas y conocer mejor los fundamentos de los mismos. Desde el punto de vista teórico el conocimiento del desdoblamiento de los niveles energéticos de un átomo en función de la magnitud del campo eléctrico aplicado (lo que se conoce como mapa Stark) es el mejor punto de partida para la descripción del sistema y un prerrequisito fundamental para el cálculo de distintas propiedades atómicas en presencia del campo eléctrico tales como intensidades de transición, umbrales de ionización de campo eléctrico, tiempos de vida, posición y anchura de cruces evitados, etc. En este trabajo presentamos la adaptación del método de orbitales de defecto cuántico [1,2,3] al tratamiento del efecto Stark (SQDO) [4] y su aplicación al cálculo de los desdoblamientos energéticos y fuerzas de oscilador de estados Rydberg en los átomos de Li, Na y K. El propósito de este estudio es, por un lado, desarrollar métodos fiables para la determinación de propiedades atómicas en presencia de campos eléctricos y, por otro, mostrar la fiabilidad de las funciones de onda QDO en la descripción del efecto Stark en sistemas atómicos.

  10. ESCALA ACTDIV PARA MEDIR LA ACTITUD HACIA LA DIVERSIDAD

    Directory of Open Access Journals (Sweden)

    María Julieta Solórzano Salas

    2013-01-01

    Full Text Available El presente artículo expone los resultados de la investigación realizada en el año 2011, cuyo objetivo fue medir las actitudes hacia la diversidad que presenta el estudiantado de primer ingreso de la Escuela de Formación Docente, Universidad de Costa Rica. Se creó una Escala tipo Likert denominada "Escala ACTDIV". La revisión teórica permitió definir que la diversidad se conceptualiza desde la diferencia humana y se presenta en la cotidianidad, en las relaciones que se dan con los otros, quienes a su vez determinan la diferencia. El constructo latente denominado diversidad se explicó a partir de las diferencias humanas existentes en los aspectos personales, culturales y cognitivos, siendo estos últimos los subconstructos. Por otra parte, la Escala ACTDIV midió en el estudiantado de primer ingreso la actitud a la diversidad mediante dos categorías llamadas "Sensibles a la diversidad" en el cual se ubicaron el 86% de las personas consultadas que desean conocer y aprender de las diferencias existentes en las personas y "Mi mundo", con un 14% que valoran de manera egocéntrica y hegemónica la realidad social.

  11. Estudio piloto sobre una tarea para medir la creatividad musical

    Directory of Open Access Journals (Sweden)

    Javier Valverde

    2015-01-01

    Full Text Available La creatividad es un fenómeno complejo que se expresa en los distintos ámbitos de la actuación humana. Un importante impedimento a la hora de valorar la creatividad musical es la experiencia con la que cuenta el alumno en términos de uso de instrumentos musicales y composición. El test propuesto por Wang (1985 trata de salvar ese obstáculo, para ofrecer una herramienta válida para identificar el talento musical temprano. Con el fin de adaptar dicho test, se tomó una muestra de 74 niños que asistían a un Instituto de Educación Secundaria en la Región de Murcia. Se utilizó la primera tarea propuesta por Wang (1985 pero adaptando los criterios para poder medir no sólo fluidez, si no también las variables de flexibilidad, originalidad y elaboración.

  12. Escala ACTDIV para medir la actitud a la diversidad

    Directory of Open Access Journals (Sweden)

    Solórzano Salas, María Julieta

    2013-01-01

    Full Text Available Resumen: El presente artículo expone los resultados de la investigación realizada en el año 2011, cuyo objetivo fue medir las actitudes hacia la diversidad que presenta el estudiantado de primer ingreso de la Escuela de Formación Docente, Universidad de Costa Rica. Se creó una Escala tipo Likert denominada “Escala ACTDIV”. La revisión teórica permitió definir que la diversidad se conceptualiza desde la diferencia humana y se presenta en la cotidianidad, en las relaciones que se dan con los otros, quienes a su vez determinan la diferencia. El constructo latente denominado diversidad se explicó a partir de las diferencias humanas existentes en los aspectos personales, culturales y cognitivos, siendo estos últimos los subconstructos. Por otra parte, la Escala ACTDIV midió en el estudiantado de primer ingreso la actitud a la diversidad mediante dos categorías llamadas “Sensibles a la diversidad” en el cual se ubicaron el 86% de las personas consultadas que desean conocer y aprender de las diferencias existentes en las personas y “Mi mundo”, con un 14% que valoran de manera egocéntrica y hegemónica la realidad social. Abstract: This paper presents the results of the investigation done on the year 2011, which objective was to measure the attitude towards diversity the students had during their first year in the School for Teacher Training (Escuela de Formación Docente in the University of Costa Rica. Therefore, the Liker “ACTDIV Scale” was created. The theoretical revisions defined that diversity is conceptualized from human differences, and it is present every day in the relationships with other people, whom at the same time, determine the difference. The latent construct denominated diversity was explained through existing human differences in the personal, cultural and cognitive aspects, this last one being the sub-construct. Furthermore, the ACTDIV scale measured the attitude towards diversity in first year students

  13. Dispositivo y procedimiento para medir concentración de biomasa, y uso de un elemento electrónico chip para medir dicha concentración de biomasa

    OpenAIRE

    Muñoz, Francesc Xavier; Muñoz Pascual, Francisco Javier; Escudé-Pujol, Roger; Mas Gordi, Jordi; Vigués Frantzen, Núria; Campo García, Francisco Javier del

    2008-01-01

    [ES] La invención relaciona a un dispositivo para medir la concentración de la biomasa de un medio, incluyendo: medio para medir el cambio en la impedancia eléctrica producida por la presencia de biomasa, y control y medio de procesamiento para determinar la concentración de la biomasa del medio dicho para medir el cambio de la impedancia. La invención se caracteriza en que el medio de medición del cambio de la impedancia incluye por lo menos dos electrodos que tienen una configuración adecua...

  14. Radio astronomy

    Energy Technology Data Exchange (ETDEWEB)

    Nagnibeda, V.G.

    1981-01-01

    The history of radio astronomical observations at the Astronomical Observatory of Leningrad State University is reviewed. Various facilities are described, and methods and instruments used are discussed. Some results are summarized for radio observations of the sun, including observations of local sources of solar radio emission, the absolute solar radio flux, and radio emission from filaments and prominences.

  15. METODO OPTICO PARA MEDIR EL COMPORTAMIENTO DE UNA LINEA DE TRANSMISION.

    OpenAIRE

    ASAHI KODAMA, TAKESHI EDUARDO; ASAHI KODAMA, TAKESHI EDUARDO

    1998-01-01

    El objetivo de esta tesis es el de establecer un método de manera de poder medir en forma óptica la corriente y el voltaje que circulan en una línea de transmisión. Para ello, se utilizan los fenómenos de Faraday y Kerr en líneas de transmisión que tienen 57p.

  16. Teresa Zweifel, Medir lo inconmensurable. Los cambios en los procedimientos para relevar la pampa anterior (1796-1895

    Directory of Open Access Journals (Sweden)

    Sandra Szir

    2015-09-01

    Full Text Available Reseña bibliográfica del libro de Teresa Zweifel, Medir lo inconmensurable. Los cambios en los procedimientos para relevar la pampa anterior (1796-1895, Rosario, Prohistoria Ediciones, 2014, 191 pp.

  17. CÓMO ELABORAR ENCUESTAS PARA MEDIR EL USO DE LA INFORMÁTICA

    Directory of Open Access Journals (Sweden)

    Elsa del Carmen Gutiérrez Báez

    2010-07-01

    Full Text Available Cuando hablamos de instrumentos para medir la efectividad del uso de la Informática, nos detenemos en las encuestas como un instrumento poco utilizado en el proceso de aprendizaje. En este material se propone su uso como instrumento fundamental de investigación. Se define, qué es una encuesta, cuántos tipos existen, se muestra cómo se pueden redactar las diferentes preguntas y cómo se tabulan; a partir de ejemplos prácticos aplicados en la Educación Infantil.

  18. Cómo medir la innovación en las organizaciones

    OpenAIRE

    Bermúdez García, Javier Eduardo

    2014-01-01

    En estos días se habla mucho sobre la importancia de la innovación en nuestras organizaciones como fuente generadora de valor, pero existe un vacío relacionado a la forma de medición de la misma. Es por esta razón que el objetivo de la presente investigación, exploratoria y descriptiva, es responder a la siguiente pregunta: ¿Cómo medir la innovación en las organizaciones?

  19. Aplicación móvil para medir campos magnéticos

    OpenAIRE

    Valdecantos Perales, Víctor; González, Manuel Á.

    2015-01-01

    Este proyecto tiene como objetivo medir el campo magnético en cualquier punto de la tierra mediante un dispositivo móvil con sistema operativo Android. Con estas medidas se quieren crear puntos sobre un mapa mundial que reflejen la intensidad y sentido del campo. Estos dispositivos cuentan con un gran número de sensores tales como sensor de proximidad, acelerómetro, temperatura, gravedad, luz... pero este proyecto se van a utilizar sólo dos de esos sensores: el acelerómetro y sensor magnético...

  20. CÓMO ELABORAR ENCUESTAS PARA MEDIR EL USO DE LA INFORMÁTICA

    OpenAIRE

    Elsa del Carmen Gutiérrez Báez

    2010-01-01

    Cuando hablamos de instrumentos para medir la efectividad del uso de la Informática, nos detenemos en las encuestas como un instrumento poco utilizado en el proceso de aprendizaje. En este material se propone su uso como instrumento fundamental de investigación. Se define, qué es una encuesta, cuántos tipos existen, se muestra cómo se pueden redactar las diferentes preguntas y cómo se tabulan; a partir de ejemplos prácticos aplicados en la Educación Infantil.

  1. Método para Medir Indirectamente la Velocidad de Fase en Sensores Surface Acoustic Wave

    Directory of Open Access Journals (Sweden)

    Leonardo Andrés Pérez

    2015-10-01

    Full Text Available El sensor de temperatura Surface Acoustic Wave (SAW ofrece amplias posibilidades para ser utilizado en ambientes hostiles. En teoría, las mediciones del SAW se pueden leer inalámbricamente sin integrar circuitos electrónicos en su estructura, permitiendo funcionalidades en mediciones a muy altas temperaturas. La literatura reporta que las variaciones de temperatura del SAW ocasionan corrimientos en su frecuencia de sincronismo, efecto que se atribuye a la sensibilidad térmica de la velocidad de fase del substrato piezoeléctrico. Caracterizar  apropiadamente el SAW requiere una buena medición de la velocidad de fase. No obstante, medir esta velocidad con respecto a la temperatura no es posible con la instrumentación actual. Este artículo reporta un método indirecto para medir estas variaciones de velocidad a través de  simulaciones basadas en el Modelo de Mason y mediciones de la respuesta en frecuencia de un prototipo SAW. Identificar la velocidad de fase del SAW conlleva a graficar, con aceptable precisión, la curva de funcionamiento del sensor, la cual puede utilizarse posteriormente como curva de calibración.

  2. Escala propuesta para medir la calidad del servicio de los cines

    Directory of Open Access Journals (Sweden)

    Eduardo Torres Moraga1

    2010-04-01

    Full Text Available En la actualidad, existe un alto nivel de competencia entre las diferentes cadenas de cines que se encuentran en Chile. En este escenario, el éxito está determinado en gran parte por los servicios que estas ofrecen a sus clientes. Si bien previamente se han desarrollado escalas para medir la calidad del servicio percibida en diversos sectores, por sus características, es necesario construir una escala específica que pueda ser aplicada a los cines. Los resultados obtenidos por medio de este estudio muestran que la calidad del servicio de los cines percibida por los consumidores es un constructor multidimensional que difiere en gran parte de las escalas estándar propuestas anteriormente, y que además se compone de la confiabilidad, la atención personal, la accesibilidad, los tangibles del cine y los tangibles de la sala de proyección de la película. Estos resultados entregan a los directivos de marketing de los cines una importante herramienta que les permitirá medir y gestionar la calidad del servicio.

  3. Radio stars

    International Nuclear Information System (INIS)

    Hjellming, R.M.

    1976-01-01

    Any discussion of the radio emission from stars should begin by emphasizing certain unique problems. First of all, one must clarify a semantic confusion introduced into radio astronomy in the late 1950's when most new radio sources were described as radio stars. All of these early 'radio stars' were eventually identified with other galactic and extra-galactic objects. The study of true radio stars, where the radio emission is produced in the atmosphere of a star, began only in the 1960's. Most of the work on the subject has, in fact, been carried out in only the last few years. Because the real information about radio stars is quite new, it is not surprising that major aspects of the subject are not at all understood. For this reason this paper is organized mainly around three questions: what is the available observational information; what physical processes seem to be involved; and what working hypotheses look potentially fruitful. (Auth.)

  4. Una propuesta con estudiantes de Bacteriolog?a: ?C?mo abordar el proceso de medir magnitudes experimentalmente?

    OpenAIRE

    Caycedo Lozano, Liliana; Vargas Hern?ndez, Jeannette

    2003-01-01

    Existen conceptos que se emplean cotidianamente, como es el de ?medir?; tal vez, por ello, el sistema educativo tangencialmente delega a dicha cotidianidad la responsabilidad de la pr?ctica y experimentaci?n. Sin embargo, se evidencia que en la educaci?n universitaria dif?cilmente se puede trabajar en la formalizaci?n del concepto ?medir? sin antes haber generado los espacios para experimentar y analizar los procesos de medici?n de algunas magnitudes. Es por ello que se plantea una propuesta ...

  5. Nuevo método para medir un inductor de proteínas recombinantes

    OpenAIRE

    Fernández Castañé, Alfred

    2012-01-01

    El IPTG es un azúcar sintético análogo de la lactosa que se utiliza para la inducción de la producción de proteínas en la bacteria Escherichia coli. En la presente tesis doctoral se ha desarrollado por primera vez un método analítico para medir el IPTG en el medio de cultivo y dentro de las células que ha permitido estudiar el comportamiento de inducción en cultivos de alta densidad celular así como optimizar su dosis para obtener la máxima cantidad de producto.

  6. ¿Cómo medir el impacto del Ciget en el sector empresarial?

    OpenAIRE

    Orelve Machado La Rosa

    2007-01-01

    La razón de ser fundamental del Centro de Información y Gestión Tecnológica lo constituye la aplicación de técnicas de gestión en apoyo a los procesos de innovación tecnológica en el sector empresarial del territorio. El presente trabajo se desarrolla a partir de la necesidad que existe de contar con una herramienta capaz de medir el impacto del accionar en este sector empresarial. Se parte de evaluar aspectos tales como el diseño gerencial, la cultura de la innovación, la generació...

  7. Radio stars

    International Nuclear Information System (INIS)

    Hjellming, R.M.; Gibson, D.M.

    1985-01-01

    Studies of stellar radio emission became an important field of research in the 1970's and have now expanded to become a major area of radio astronomy with the advent of new instruments such as the Very Large Array in New Mexico and transcontinental telescope arrays. This volume contains papers from the workshop on stellar continuum radio astronomy held in Boulder, Colorado, and is the first book on the rapidly expanding field of radio emission from stars and stellar systems. Subjects covered include the observational and theoretical aspects of stellar winds from both hot and cool stars, radio flares from active double star systems and red dwarf stars, bipolar flows from star-forming regions, and the radio emission from X-ray binaries. (orig.)

  8. Propuesta de un modelo para medir activos intangibles en empresas de software a partir de una herramienta multicriterio

    Directory of Open Access Journals (Sweden)

    Patricia González G

    2015-04-01

    Full Text Available El objetivo de este artículo es presentar una propuesta de un modelo para medir y categorizar los activos intangibles en empresas pequeñas de software, a partir de los fundamentos teóricos de una herramienta multicriterio como es el Análisis de Procesos por Jerarquías, de tal modo que esto permita identificar la mejor empresa de software. La metodología consistió en aplicar el modelo propuesto para medir intangibles en tres empresas de software ubicadas en el Parque Tecnológico de la Ciudad de Cali (Colombia, en donde el programa expert choice fue usado para fines de cálculo. De acuerdo con los resultados obtenidos, se concluye que los gerentes podrían tomar decisiones relacionadas con procesos de mejora continua, benchmarking e, incluso, aquellas relacionadas con inversión y gestión.

  9. Propuesta de un modelo para medir activos intangibles en empresas de software a partir de una herramienta multicriterio

    Directory of Open Access Journals (Sweden)

    Patricia González G

    2015-01-01

    Full Text Available El objetivo de este artículo es presentar una propuesta de un modelo para medir y categorizar los activos intangibles en empresas pequeñas de software, a partir de los fundamentos teóricos de una herramienta multicriterio como es el Análisis de Procesos por Jerarquías, de tal modo que esto permita identificar la mejor empresa de software. La metodología consistió en aplicar el modelo propuesto para medir intangibles en tres empresas de software ubicadas en el Parque Tecnológico de la Ciudad de Cali (Colombia, en donde el programa expert choice fue usado para fines de cálculo. De acuerdo con los resultados obtenidos, se concluye que los gerentes podrían tomar decisiones relacionadas con procesos de mejora continua, benchmarking e, incluso, aquellas relacionadas con inversión y gestión.

  10. Solar Radio

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Scientists monitor the structure of the solar corona, the outer most regions of the Sun's atmosphere, using radio waves (100?s of MHz to 10?s of GHz). Variations in...

  11. Radio astronomy

    International Nuclear Information System (INIS)

    Parijskij, Y.N.; Gossachinskij, I.V.; Zuckerman, B.; Khersonsky, V.K.; Pustilnik, S.; Robinson, B.J.

    1976-01-01

    A critical review of major developments and discoveries in the field of radioastronomy during the period 1973-1975 is presented. The report is presented under the following headings:(1) Continuum radiation from the Galaxy; (2) Neutral hydrogen, 21 cm (galactic and extragalactic) and recombination lines; (3) Radioastronomy investigations of interstellar molecules; (4) Extragalactic radio astronomy and (6) Development in radio astronomy instruments. (B.R.H.)

  12. ¿Cómo medir el impacto del Ciget en el sector empresarial?

    Directory of Open Access Journals (Sweden)

    Orelve Machado La Rosa

    2007-06-01

    Full Text Available La razón de ser fundamental del Centro de Información y Gestión Tecnológica lo constituye la aplicación de técnicas de gestión en apoyo a los procesos de innovación tecnológica en el sector empresarial del territorio. El presente trabajo se desarrolla a partir de la necesidad que existe de contar con una herramienta capaz de medir el impacto del accionar en este sector empresarial. Se parte de evaluar aspectos tales como el diseño gerencial, la cultura de la innovación, la generación de nuevos conceptos dentro de la organización, el desarrollo de nuevos productos, el rediseño de los procesos productivos y de comercialización y la gestión del conocimiento y la tecnología alcanzados; a partir de la incidencia del trabajo del CIGET en la organización. La evaluación consiste en cuantificar numéricamente los cambios positivos (en el orden organizacional, gerencial e innovativo provocados en la organización y estandarizarlos para demostrar entonces la calidad de la intervención en el sector o empresa en cuestión. Para facilitar el cálculo de dicha evaluación se diseña una herramienta, la cual basa su cálculo sobre estándares numéricos.

  13. Desarrollo de un instrumento para medir creencias y actitudes hacia la vasectomía

    Directory of Open Access Journals (Sweden)

    R.D. Hernández-Aguilera

    2015-12-01

    Full Text Available La participación del varón en la planificación familiar es relativamente reciente, pues empezó a raíz de la Conferencia Internacional sobre Población y Desarrollo del Cairo en 1994. Existen muchos mitos acerca de la vasectomía que contribuyen a la renuencia de aceptarla, lo que hace indispensable su estudio. La mayor parte de los estudios que hay sobre el tema son cualitativos, y en la literatura revisada se encontraron únicamente 3 cuestionarios: uno mide solo conocimientos, el segundo está dirigido solamente al personal médico, y el tercero mide solo actitudes negativas sin considerar aspectos positivos. El objetivo del presente estudio fue diseñar y validar en México un cuestionario para medir creencias y actitudes hacia la vasectomía dirigido a hombres sin vasectomía y a mujeres. Fue un estudio transversal dividido en 2 etapas. En la primera participaron 405 hombres y mujeres de 35 a 55 años. Se calculó la validez de contenido y la capacidad discriminatoria de los reactivos, se realizó un análisis de componentes principales y se calculó la confiabilidad usando el alfa de Cronbach. Se obtuvieron 4 factores: disminución de la virilidad, beneficios, miedo a la cirugía y percepción negativa. La confiabilidad total fue de 0.85. En la segunda etapa se probó la sensibilidad del instrumento con 248 participantes, encontrando diferencias significativas en los 4 factores al comparar los resultados de acuerdo a la escolaridad. Se presenta un cuestionario con diferentes aplicaciones, que puede ser usado tanto por investigadores como por profesionales en el campo de la salud reproductiva.

  14. Radio astronomy

    CERN Document Server

    Alder, Berni

    1975-01-01

    Methods in Computational Physics, Volume 14: Radio Astronomy is devoted to the role of the digital computer both as a control device and as a calculator in addressing problems related to galactic radio noise. This volume contains four chapters and begins with a technical description of the hardware and the special data-handling problems of using radioheliography, with an emphasis on a selection of observational results obtained with the Culgoora radioheliograph and their significance to solar physics and to astrophysics in general. The subsequent chapter examines interstellar dispersion, i

  15. Aplicación de la metodología Molecular de Orbitales de Defecto Cuántico (MQDO) al cálculo de intensidades vibrónicas y vidas medias de niveles vibracionales

    Science.gov (United States)

    María Velasco Sanz, Ana

    Desde que se formuló, en 1996, la metodología Molecular de Orbitales de Defecto Cuántico (MQDO) [1], se han obtenido datos de calidad relativos a intensidades de bandas electrónicas que implican estados Rydberg para una gran variedad de sistemas moleculares [2]. Animados por los buenos resultados obtenidos, recientemente hemos abordado el estudio de transiciones vibrónicas, es decir aquellas que ocurren entre estados vibracionales que pertenecen a distintos estados Rydberg electrónicos. Como prototipo adecuado para nuestros propósitos hemos elegido la molécula de NO, importante en la química de la atmósfera, y para la cual existen en la bibliografía datos experimentales de calidad suficiente para contrastar la validez de nuestros resultados. En concreto, hemos calculado las fuerzas de oscilador y coeficientes de Einstein para transiciones electrónicas y vibrónicas de las principales bandas del NO, al igual que vidas medias radiativas de niveles vibracionales de dicha molécula. Las propiedades estudiadas son esenciales para la comprensión de los aspectos teóricos de los procesos físicos básicos relativos a la dispersión electrónica en moléculas heteronucleares con capas abiertas. Además, valores fiables de probabilidades de transición moleculares tienen importantes aplicaciones en Astrofísica, en la modelización de procesos fotodinámicos moleculares, etc., al igual que para evaluar más profundamente la validez de nuestra metodología teórica.

  16. Validación del modelo REI para medir la clase social en población adulta

    Directory of Open Access Journals (Sweden)

    Antonio Cabrera de León

    2009-01-01

    mayor riesgo de problemas de salud, con mayor fuerza en las mujeres: sedentarismo (OR = 1,8, obesidad (OR = 4,4, obesidad abdominal (OR = 5,4, síndrome metabólico (OR = 3,4 y diabetes mellitus (OR = 2,0. Conclusiones: REI es un indicador válido, no basado en la ocupación ni en la situación laboral, fácilmente estandarizable, apto para medir cuantitativamente la clase social en estudios que precisen analizar el impacto de la misma como determinante de salud.

  17. Desarrollo de una escala para medir las áreas sensible, racional y moral en estudiantes universitarios

    OpenAIRE

    Álvarez-Izazaga, Marsela Alejandra; Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán (México); Roldán-Amaro, José Antonio; Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán (México); Reidl-Martínez, Lucy María; Universidad Nacional Autónoma de México

    2015-01-01

    El objetivo del estudio fue evaluar la efectividad de la Escala Tridimensional de la Toma de Decisiones en la Vida Cotidiana (ETDVC) para medir las características conductuales en tres áreas: sensible, racional y moral. La muestra estuvo conformada por 646 estudiantes de las carreras de Filosofía, Teología, Ciencias y Artes Plásticas en universidades de la Ciudad de México, de los cuales 261 son mujeres y 385 hombres, la edad promedio fue de 22,5 años. El instrumento final está conformado por...

  18. Entropía de grafos y su uso para medir la inteligibilidad de la ciudad

    Directory of Open Access Journals (Sweden)

    Aguilera Ontiveros, Antonio

    2014-12-01

    Full Text Available Within space cognition studies, Hillier (1996 proposed the concept of intelligibility as a property of space that allows it to be understood by people that either live in or transit through that space. Hillier, in the theory of space syntax, suggests that intelligibility is the correlation between a local variable and a global variable. Basing themselves on the above, Volchenkov and Blanchard (2008 proposed a way to measure intelligibility outside the technical context of the theory of space syntax. This paper returns to theoretical and methodological discussion of Hillier’s work and explains the method proposed by Volchenkov and Blanchard. As an example, the intelligibility of the historic center of the city of San Luis Potosi, Mexico, was measured. It was found that this space has a high intelligibility in the terms of the method proposed by Volchenkov and Blanchard.Dentro de los estudios de cognición del espacio, Hillier (1996 propuso el concepto de inteligibilidad como una propiedad del espacio que permite que éste sea comprendido por las personas que lo transitan y/o habitan. Hillier, dentro de la teoría de la sintaxis del espacio, propone que la inteligibilidad es la correlación entre una variable local y una variable global. Basados en lo anterior, Volchenkov y Blanchard (2008 han propuesto una forma de medir la inteligibilidad fuera del contexto técnico de la teoría de la sintaxis del espacio. Este trabajo recupera la discusión teórica-metodológica del trabajo de Hillier y expone el método de Volchenkov y Blanchard. Como ejemplo del mismo se midió la inteligibilidad del centro histórico de la ciudad de San Luis Potosí, México. Se encontró que dicho espacio tiene una inteligibilidad alta según el método propuesto por Volchenkov y Blanchard. [fr] Dans le cadre des études de la cognition spatiale, Hillier (1996 a proposé le concept d’intelligibilité comme une propriété de l’espace permettant que celui-ci soit

  19. The Radio JOVE Project - Shoestring Radio Astronomy

    Science.gov (United States)

    Thieman, J.; Flagg, R.; Greenman, W.; Higgins, C.; Reyes, F.; Sky, J.

    2010-01-01

    Radio JOVE is an education and outreach project intended to give students and other interested individuals hands-on experience in learning radio astronomy. They can do this through building a radio telescope from a relatively inexpensive kit that includes the parts for a receiver and an antenna as well as software for a computer chart recorder emulator (Radio Skypipe) and other reference materials

  20. Space Telecommunications Radio System STRS Cognitive Radio

    Science.gov (United States)

    Briones, Janette C.; Handler, Louis M.

    2013-01-01

    Radios today are evolving from awareness toward cognition. A software defined radio (SDR) provides the most capability for integrating autonomic decision making ability and allows the incremental evolution toward a cognitive radio. This cognitive radio technology will impact NASA space communications in areas such as spectrum utilization, interoperability, network operations, and radio resource management over a wide range of operating conditions. NASAs cognitive radio will build upon the infrastructure being developed by Space Telecommunication Radio System (STRS) SDR technology. This paper explores the feasibility of inserting cognitive capabilities in the NASA STRS architecture and the interfaces between the cognitive engine and the STRS radio. The STRS architecture defines methods that can inform the cognitive engine about the radio environment so that the cognitive engine can learn autonomously from experience, and take appropriate actions to adapt the radio operating characteristics and optimize performance.

  1. Modelo de gestión del conocimiento para medir la capacidad productiva en grupos de investigación

    Directory of Open Access Journals (Sweden)

    Fredy Eduardo Vásquez Rizo

    2010-01-01

    Full Text Available Las organizaciones actuales manejan y producen numerosos datos e información. Muchos de estos elementos son subutilizados o despreciados al carecer de mecanismos y/o procesos para transformarlos en conocimiento útil. El estudio que se expone se centra en datos e información relacionados con la capacidad productiva de los grupos de investigación de una universidad colombiana (Universidad Autónoma de Occidente- UAO, utilizándolos para la generación de conocimiento valioso, a través de la construcción de un modelo. Este modelo, basado en indicadores, permite medir dicha capacidad productiva y sugerir algunas opciones para potenciar sus posibilidades de éxito en las convocatorias colombianas de reconocimiento y medición de grupos de investigación, establecidas por el Departamento Administrativo de Ciencia, Tecnología e Innovación-Colciencias.

  2. A Braça da Rede, uma Técnica Caiçara de Medir

    Directory of Open Access Journals (Sweden)

    Gilberto Chieus Jr.

    2009-08-01

    Full Text Available Este artigo relata como os caiçaras da cidade de Ubatuba litoral norte paulista medem suas redes de pesca.Mas antes de estar analisando sua técnica de medir estaremos fazendo uma pequena abordagem da cultura caiçara e suas transformações. Em seguida mostraremos alguns momentos históricos da construção do metro. Depois como os caiçaras medem suas redes e o problema ocorrido no Brasil na implantação do sistema métrico decimal e a resistência de determinadas civilizações que se utiliza de outros padrões para realizar suas medidas, ignorando o atual sistema métrico, devidos o seu contexto cultural. Toda esta discussão está enfocada numa perspectiva histórica da Etnomatemática.

  3. Propuesta metodológica para medir la calidad del servicio de consulta externa en medicina general

    Directory of Open Access Journals (Sweden)

    Mauricio Losada Otálora, Ph.d (c

    2011-07-01

    Full Text Available Este artículo ofrece una propuesta metodológica para medir la calidad del servicio de consulta externa con el modelo de la zona de tolerancia. Con una mezcla de entrevistas en profundidad, grupos focales, análisis factorial exploratorio y análisis factorial confirmatorio, se encontró que los usuarios de los servicios de consulta externa evalúan la calidad considerando la conveniencia del servicio, los elementos sustanciales del mismo y los aspectos profesionales/ humanos de quienes los atienden. El artículo incluye una guía para los gerentes sobre cómo aplicar, interpretar y utilizar los resultados de la metodología de evaluación propuesta. Finalmente, se señalan las limitaciones y se sugieren futuras líneas de investigación.

  4. The radio universe

    International Nuclear Information System (INIS)

    Worvill, R.

    1977-01-01

    Elementary description of the development of radioastronomy, radio waves from the sun and planets, the use of radio telescopes and the detection of nebulae, supernova, radio galaxies and quasars is presented. A brief glossary of terms is included. (UK)

  5. Un método no endógeno para medir el gasto electoral en Chile, 2005-2009

    Directory of Open Access Journals (Sweden)

    Sergio Acevedo

    2015-01-01

    Full Text Available El debate sobre el efecto del dinero invertido en campaiias sobre los resultados de las elecciones ha puesto en tela de juicio cuestiones centrales sobre la calidad de la democracia y la efectividad de las e1ecciones como mecanismo de control ciudadano. EI gasto en campana es una variable central a la hora de evaluar su éxito, por lo tanto, la forma en que se mide influye en las conclusiones a las que se llega con respecto a su efecto en los resultados de una elección. En este artículo se utiliza el caso chileno (específicamente, las elecciones de 2005 y 2009 para analizar los dos métodos más com unes de medir el gasto en campana y proponer un tercero que estima de mejor forma sus efectos. Esta contribución metodológica complementa y refIna el conocimiento que ya se poseía sobre la forma en que d gasto afecta los resultados electorales, a la vez que abre una línea de investigación que permite evaluar otros aspectos de la dinámica que relaciona el gasto en campafias con el desempeno electoral. Sugerimos que el camino a seguir se centre en la fiscalización dei gasto efectivo y no en reducir los límites al gasto reportado.

  6. PROPUESTA METODOLÓGICO-ESTADÍSTICA PARA MEDIR LA INTELIGENCIA ORGANIZACIONAL, FUNDAMENTADA EN LA QUINTA DISCIPLINA DE PETER SENGE

    Directory of Open Access Journals (Sweden)

    Ángel Adrianis Gómez Degraves

    2012-07-01

    Full Text Available Esta investigación tuvo por objeto diseñar una propuesta metodológico-estadística para medir la inteligencia organizacional, fundamentada en la quinta disciplina de Peter Senge. Para ello, se desarrolló un proyecto factible con un estadio de investigación exploratoria documental, bajo un diseño bibliográfico, obteniéndose como resultado la definición del constructo Inteligencia Organizacional, la operacionalización del constructo Aprendizaje Organizacional, la elaboración del instrumento escala de investigación y las técnicas estadísticas adecuadas para el análisis estadístico de los datos generados por la escala. La revisión documental proporcionó elementos básicos, teórico-metodológico-estadísticos, en la construcción de una escala de medida de la Inteligencia Organizacional.

  7. Indicadores FOCO* para medir la eficiencia en la utilización del microcrédito

    Directory of Open Access Journals (Sweden)

    Verónica Patricia Rodríguez Vázquez

    2013-12-01

    Full Text Available No obstante que el objetivo fundamental de los microcréditos es el apoyo para creación de fuentes productivas y autoempleo, las diferentes Instituciones Microfinancieras (IMF dan poco o nulo seguimiento a la eficacia de la aplicación de los financiamientos otorgados, siendo su principal preocupación la recuperación del crédito. Este trabajo propone un conjunto de indicadores financieros como una metodología que ayude a medir la eficacia en la utilización del microcrédito y detectar posibles ineficacias en la gestión financiera de la microempresa. Para validar la aplicación del modelo se seleccionó una muestra piloto discrecional de 35 microempresas detectando que mejoraron en su operación financiera en el año 2012 comparado con 2011 y que las microempresas con créditos refaccionarios tuvieron mejores resultados que las microempresas con créditos de habilitación o avío

  8. Validación de una encuesta para medir conocimientos y creencias sobre epilepsia, en los padres de familia

    Directory of Open Access Journals (Sweden)

    Miriam Mendoza

    2012-07-01

    Full Text Available La Epilepsia es una enfermedad crónica que en muchos casos se encuentra ligada a conceptos mágico-religiosos que condicionan rechazo social. Objetivo: Elaborar y validar un cuestionario que permita medir el grado de conocimientos y creencias sobre epilepsia en los padres de familia. Material y métodos: Se realizó un estudio transversal para la construcción de un instrumento válido y confiable. Se determinó la validez cualitativa por medio del análisis de expertos y la validez cuantitativa, (confiabilidad y validez interna, a través del cálculo del KR-20, el índice de correlación intraclase y el índice de discriminación, respectivamente. Resultados: El coeficiente KR- 20 fue de 0,89 y el coeficiente de correlación intraclase 0,986, ambos considerados como valores altos. Además, se obtuvo valores para el índice de discriminación de cada ítem dentro de los límites aceptados. Conclusiones: El instrumento elaborado es válido y confiable.

  9. Desarrollo de una escala para medir la motivación laboral del empleado puertorriqueño

    Directory of Open Access Journals (Sweden)

    José Armando Pérez Santiago

    2005-01-01

    Full Text Available Esta investigación se llevo a cabo con el propósito de desarrollar una escala para medir la motivación laboral del empleado puertorriqueño. Un total de 639 empleados/as participaron en este estudio psicométrico. La mayoría pertenece al género femenino (72%, con un promedio de edad de 36.37 años y una desviación estándar de 9.31. El 69.1% de los participantes informó no ocupar un puesto gerencial o de supervisión. Los resultados reflejaron una solución de cuatro factores como la más apropiada para explicar la variancia en las puntuaciones. Estos factores fueron denominados pareo esfuerzo-recompensa, autonomía en el desempeño de las tareas, reconocimiento por parte de otros y calidad de la relación con los/as compañeros/as de trabajo. Un total de 47 reactivos cumplieron con los criterios de discriminación y cargas factoriales apropiadas en uno de los cuatro factores. El índice de confiabilidad obtenido para la versión de 47 reactivos de la escala fue .93

  10. Impact of cognitive radio on radio astronomy

    NARCIS (Netherlands)

    Bentum, Marinus Jan; Boonstra, A.J.; Baan, W.A.

    2010-01-01

    The introduction of new communication techniques requires an increase in the efficiency of spectrum usage. Cognitive radio is one of the new techniques that fosters spectrum efficiency by using unoccupied frequency spectrum for communications. However, cognitive radio will increase the transmission

  11. La teoría de conjuntos difusos como una opción para medir la pobreza. El caso de México

    Directory of Open Access Journals (Sweden)

    Marco Antonio Morales-Ramos

    2008-01-01

    Full Text Available El principal propósito de este artículo es presentar la teoría de conjuntos difusos como un instrumento confiable y preciso para medir pobreza, que además ofrece ventajas comparativas respecto a los métodos tradicionalmente empleados para esta tarea. Este artículo también muestra que la metodología de conjuntos difusos es compatible con la información censal (información agrupada para calcular índices de pobreza. Se presentan los resultados de medir la pobreza para los niveles estatal, municipal y localidad, y se comparan con resultados oficiales. Esta comparación revela que la teoría difusa resuelve algunos de los problemas metodológicos que enfrentan las líneas de pobreza y los índices de marginación, lo que hace de este instrumento una opción útil no solo para medir, sino también para aplicar y evaluar la política pública encaminada a combatir la pobreza.

  12. Fast Radio Bursts

    Indian Academy of Sciences (India)

    Akshaya Rane

    2017-09-12

    ) which were first discovered a decade ago. Following an introduction to radio transients in general, including pulsars and rotating radio transients, we discuss the discovery of FRBs. We then discuss FRB follow-up ...

  13. La radio digital

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Cortés S.

    2015-01-01

    Full Text Available La radio digital es un producto de la llamada convergencia digital. Las nuevas tecnologías interconectadas permiten la aparición de nuevos modos de audiencia y la implementación de herramientas versátiles. Habla del problema de los estándares, de la radio satelital, la radio digital terrestre, las radios internacionales, la interactividad.

  14. Commercial Radio as Communication.

    Science.gov (United States)

    Rothenbuhler, Eric W.

    1996-01-01

    Compares the day-to-day work routines of commercial radio with the principles of a theoretical communication model. Illuminates peculiarities of the conduct of communication by commercial radio. Discusses the application of theoretical models to the evaluation of practicing institutions. Offers assessments of commercial radio deriving from…

  15. Ham radio for dummies

    CERN Document Server

    Silver, H Ward

    2013-01-01

    An ideal first step for learning about ham radio Beyond operating wirelessly, today's ham radio operators can transmit data and pictures; use the Internet, laser, and microwave transmitters; and travel to places high and low to make contact. This hands-on beginner guide reflects the operational and technical changes to amateur radio over the past decade and provides you with updated licensing requirements and information, changes in digital communication (such as the Internet, social media, and GPS), and how to use e-mail via radio. Addresses the critical use of ham radio for replacing downe

  16. Radiography of Spanish Radio

    Directory of Open Access Journals (Sweden)

    Dra. Emma Rodero Antón

    2007-01-01

    Full Text Available In its eighty years of existence, radio has been always characterized to adapt to the social, cultural and technological transformations. Thus it has been until this moment. Nevertheless, some years ago, the authors and professionals of this medium have been detecting a stagnation that affects to its structure. At a time in continuous technological evolution, radio demands a deep transformation. For that reason, from the conviction of which the future radio, public and commercial, will necessarily have to renew itself, in this paper we establish ten problems and their possible solutions to the radio crisis in order to draw an x-ray of radio in Spain. Radio has future, but it is necessary to work actively by it. That the radio continues being part of sound of our life, it will depend on the work of all: companies, advertisers, professionals, students, investigators and listeners.

  17. La dificultad de medir

    Directory of Open Access Journals (Sweden)

    Samuel Schmidt Nedvedovich

    2012-01-01

    Full Text Available Network analysis has popularized because it has facilitated approaching structural relationships which other methods ignored, however, still some methodological problems remain to be solved in the search of more complex explanations, such as the generation of centrality indexes in which connections with weight and attributes. In this article we indicate some of the problems we found in our centrality analysis of the Mexican network of power and the difficulty to generate an index of power.

  18. Senior radio listeners

    DEFF Research Database (Denmark)

    Blaakilde, Anne Leonora

    Radiobroadcasting and the hardware materialization of radio have during the 20th century changed significantly, which means that senior radio listeners have travelled along with this evolution from large, impressive radio furnitures to DAB and small, wireless, mobile devices, and from grave...... and solemn radio voices to lightharted, laughing and chatting speakers. Senior radio listerners have experienced the development and refinements of technique, content and genres. It is now expected of all media users that they are capable of crossing media, combining, juggling and jumping between various...... media platforms, not the least when listening to radio. The elder generation is no exception from this. Recently, for instance, the Danish public broadcast DR has carried out an exodus of programmes targeted for the senior segment. These programmes are removed from regular FM and sent to DAB receivers...

  19. Análisis de variables e indicadores para medir el e-gobierno publicados en la literatura científica

    Directory of Open Access Journals (Sweden)

    Dayanis Esther Pacheco Redondo

    2017-01-01

    Full Text Available El desarrollo del e-gobierno ha sido promovido como estrategia para mejorar la eficiencia y eficacia de la gestión pública, facilitar la realización de trámites ante las entidades del Estado, ahorrar tiempo y dinero, aumentar la transparencia, acercar al Gobierno a los diferentes actores, así como buscar una mayor participación en la toma de las decisiones. Dada la importancia que el e-gobierno tiene para varios países, incluida Colombia, es importante analizar qué aspectos son considerados, por la comunidad académica y científica, para su medición y seguimiento. En ese sentido, el propósito de este artículo es presentar el resultado del análisis de variables e indicadores propuestos en la literatura científica en el periodo de 2004 a 2014 para medir el gobierno electrónico. Además, se realizó un análisis cien-tométrico para la literatura publicada en 2015 y 2016. Para identificar los documentos por analizar se realizó una revisión sistemática de literatura. Posteriormente, las variables y los indicadores fueron clasificados y analizados. Los resultados obtenidos evidencian el interés en medir aspectos relacionados con los servicios ofertados en el e-gobierno y el uso de estándares para el desarrollo de los portales, así como en medir aspectos relacionados con la caracterización de usuarios. Los resultados obtenidos pueden constituirse en un punto de partida para la construcción de sistemas de medición del e-gobierno.

  20. Confiabilidad de un cuestionario para medir la actividad física y los comportamientos sedentarios en niños desde preescolar hasta cuarto grado de primaria

    OpenAIRE

    Camargo, Diana Marina; Santisteban, Stefany; Paredes, Erika; Flórez, Mary Ann; Bueno, Diego

    2015-01-01

    Introducción. Las recomendaciones internacionales sobre actividad física y tiempo dedicado a comportamientos sedentarios en niños a partir de la edad preescolar, plantean la necesidad de disponer de instrumentos de medición con propiedades psicométricas que permitan evaluar la dinámica a nivel de la población y las intervenciones dirigidas a mejorar su salud. Objetivo. Evaluar la confiabilidad de un cuestionario para medir la actividad física y los comportamientos sedentarios en niños desde p...

  1. Confiabilidad de un cuestionario para medir la actividad física y los comportamientos sedentarios en niños desde preescolar hasta cuarto grado de primaria

    OpenAIRE

    Diana Marina Camargo; Stefany Santisteban; Erika Paredes; Mary Ann Flórez; Diego Alejandro Bueno

    2015-01-01

    Introducción. Las recomendaciones internacionales sobre actividad física y tiempo dedicado a comportamientos sedentarios en niños a partir de la edad preescolar, plantean la necesidad de disponer de instrumentos de medición con propiedades psicométricas que permitan evaluar la dinámica a nivel de la población y las intervenciones dirigidas a mejorar su salud. Objetivo. Evaluar la confiabilidad de un cuestionario para medir la actividad física y los comportamientos sedentarios en niños desd...

  2. IMPLEMENTANDO UNA ECUACIÓN ESTADÍSTICA PARA MEDIR EL COLAPSO EN LA ANTIGUA MESOAMÉRICA (Implementing a Statistical Equation to Measure Collapse in Ancient Mesoamerica

    Directory of Open Access Journals (Sweden)

    Pascual Izquierdo-Egea

    2018-12-01

    Full Text Available Se propone la implementación de una ecuación estadística capaz de medir el riesgo de colapso en las antiguas civilizaciones a partir de su registro funerario, probándola con éxito en la Mesoamérica prehispánica. ENGLISH: This brief communication presents the successful test of a statistical means to measure collapse risk in ancient civilizations with the mortuary record using data from pre-Hispanic Mesoamerica.

  3. Desarrollo de un método experimental para medir la velocidad de evaporación de solventes por cromatografía gaseosa

    OpenAIRE

    Casella, Mónica Laura

    1989-01-01

    Los objetivos del presente trabajo han sido, por un lado, desarrollar una técnica simple y efectiva que permitiera medir la velocidad de evaporación no sólo de solventes puros, sino también seguir el proceso de evaporación de mezclas compuestas por solventes volátiles o solventes volátiles y no volátiles. El estudio realizado con solventes puros apuntaba a desarrollar y estandarizar la técnica, permitiendo además obtener un número apreciable de datos para comparar con los de la lite...

  4. Ionosphere and Radio Communication

    Indian Academy of Sciences (India)

    The upperionosphere is used for radio communication and navigationas it reflects long, medium, as well as short radio waves. Sincesolar radiation is the main cause of the existence of ionosphere,any variation in the radiations can affect the entireradio communication system. This article attempts to brieflyintroduce the ...

  5. Writing for Radio.

    Science.gov (United States)

    Tupper, Marianna S.

    1995-01-01

    Describes a 24-hour commercial radio station simulation class project for eighth-grade language arts. Students wrote their own scripts, chose music and were disc jockeys on their own music and talk shows, and prepared news and traffic reports. Guest speakers from actual commercial radio came in to discuss issues such as advertising, censorship,…

  6. Valuing commercial radio licences

    NARCIS (Netherlands)

    Kerste, M.; Poort, J.; van Eijk, N.

    2015-01-01

    Within the EU regulatory framework, licensees for commercial radio broadcasting may be charged a fee to ensure optimal allocation of scarce resources but not to maximize public revenues. While radio licence renewal occurs in many EU countries, an objective, model-based approach for setting licence

  7. The Radio Jove Project

    Science.gov (United States)

    Thieman, J. R.

    2010-01-01

    The Radio love Project is a hands-on education and outreach project in which students, or any other interested individuals or groups build a radio telescope from a kit, operate the radio telescope, transmit the resulting signals through the internet if desired, analyze the results, and share the results with others through archives or general discussions among the observers. Radio love is intended to provide an introduction to radio astronomy for the observer. The equipment allows the user to observe radio signals from Jupiter, the Sun, the galaxy, and Earth-based radiation both natural and man-made. The project was started through a NASA Director's Discretionary Fund grant more than ten years ago. it has continued to be carried out through the dedicated efforts of a group of mainly volunteers. Dearly 1500 kits have been distributed throughout the world. Participation can also be done without building a kit. Pre-built kits are available. Users can also monitor remote radio telescopes through the internet using free downloadable software available through the radiosky.com website. There have been many stories of prize-winning projects, inspirational results, collaborative efforts, etc. We continue to build the community of observers and are always open to new thoughts about how to inspire the observers to still greater involvement in the science and technology associated with Radio Jove.

  8. Boom Booom Net Radio

    DEFF Research Database (Denmark)

    Grimshaw, Mark Nicholas; Yong, Louisa; Dobie, Ian

    1999-01-01

    of an existing Internet radio station; Boom Booom Net Radio. Whilst necessity dictates some use of technology-related terminology, wherever possible we have endeavoured to keep such jargon to a minimum and to either explain it in the text or to provide further explanation in the appended glossary....

  9. Unlocking radio broadcasts

    DEFF Research Database (Denmark)

    Skov, Mette; Lykke, Marianne

    2012-01-01

    This poster reports the preliminary results of a user study uncovering the information seeking behaviour of humanities scholars dedicated to radio research. The study is part of an interdisciplinary research project on radio culture and auditory resources. The purpose of the study is to inform...... the design of information architecture and interaction design of a research infrastructure that will enable future radio and audio based research. Results from a questionnaire survey on humanities scholars‟ research interest and information needs, preferred access points, and indexing levels are reported....... Finally, a flexible metadata schema is suggested, that includes both general metadata and highly media and research project specific metadata....

  10. Radio y elecciones

    Directory of Open Access Journals (Sweden)

    Alma Rosa Alva de la Selva

    2000-01-01

    Full Text Available En este trabajo se analiza el comportamiento de la radio en México ante la contienda electoral de julio de 2000. Se examina el papel de la radio como espacio para la discusión política, así como el tratamiento informativo que hizo del tema. Asimismo, se analiza la posible repercusión de factores de reciente surgimiento en el panorama radiofónico para un manejo más autónomo de la información política en la radio

  11. Construcción y validación inicial de un instrumento para medir el estilo de vida en pacientes con diabetes mellitus tipo 2

    Directory of Open Access Journals (Sweden)

    López-Carmona Juan Manuel

    2003-01-01

    Full Text Available OBJETIVO: Construir y validar un instrumento específico para medir el estilo de vida en los pacientes con diabetes mellitus tipo 2. MATERIAL Y MÉTODOS: Entre marzo de 2001 y abril de 2002 se hizo un estudio observacional, longitudinal y prospectivo en unidades de medicina familiar de la delegación Estado de México Oriente, del Instituto Mexicano del Seguro Social. Se diseñó un instrumento de autoadministración, denominado instrumento para medir el estilo de vida en diabéticos, el cual fue sometido a revisión por un panel multidisciplinario de expertos para determinar su validez lógica y de contenido. Se aplicó el instrumento en dos días diferentes a 412 sujetos adultos con diabetes mellitus. Fueron depurados los ítems considerando la frecuencia de selección de sus opciones de respuesta, su correlación ítem-total y su carga significativa en los dominios durante el análisis factorial. RESULTADOS: Completaron el estudio 389 (94.7% sujetos. Los coeficientes de correlación intra-clase para la validez lógica y de contenido fueron de 0.91 y 0.95, respectivamente. Después de la depuración de ítems se obtuvo un instrumento conformado por 25 preguntas cerradas, distribuidas en siete dominios: nutrición, actividad física, consumo de tabaco, consumo de alcohol, información sobre diabetes, emociones y adherencia terapéutica. El a de Cronbach para la calificación total fue de 0.81 y el coeficiente de correlación test-retest de 0.84. CONCLUSIONES: El instrumento para medir el estilo de vida en diabéticos es el primer cuestionario específico para sujetos con diabetes mellitus tipo 2 y tiene validez aparente, validez de contenido y buen nivel de consistencia.

  12. Social cognitive radio networks

    CERN Document Server

    Chen, Xu

    2015-01-01

    This brief presents research results on social cognitive radio networks, a transformational and innovative networking paradigm that promotes the nexus between social interactions and cognitive radio networks. Along with a review of the research literature, the text examines the key motivation and challenges of social cognitive radio network design. Three socially inspired distributed spectrum sharing mechanisms are introduced: adaptive channel recommendation mechanism, imitation-based social spectrum sharing mechanism, and evolutionarily stable spectrum access mechanism. The brief concludes with a discussion of future research directions which ascertains that exploiting social interactions for distributed spectrum sharing will advance the state-of-the-art of cognitive radio network design, spur a new line of thinking for future wireless networks, and enable novel wireless service and applications.

  13. NOAA Weather Radio

    Science.gov (United States)

    del tiempo incluido. Si eres quieres ser avisado de las advertencias y relojes de día o de noche, un Weather Radio relojes son independientes o basadas en el Condado (parroquia basados en Luisiana), aunque

  14. The digital sport radio.

    Directory of Open Access Journals (Sweden)

    Hilario José ROMERO BEJARANO

    2014-07-01

    Full Text Available Radio has been immersed in recent years in a phase of technological integration and business of multimedia, as well as diversification of systems and channels for broadcasting. In addition, Internet has been consolidated as the platform of digital radio that more has evolved as a result of its continued expansion. However, the merger radio-Internet must be understood as a new form of communication, and not solely as a new complementary medium. In this context, it is of great interest to analyze that transformations in the way of reception, contents, languages, programs and schedules, has brought with it for the radio that integration. To this end is taken as main reference the sports areas, a key aspect and broadly representative of the current broadcasting landscape.

  15. Music, radio and mediatization

    DEFF Research Database (Denmark)

    Michelsen, Morten; Krogh, Mads

    2016-01-01

    of mediatization where media as such seem to be ascribed agency. Instead, we consider historical accounts of music–radio in order to address the complex nonlinearity of concrete processes of mediatization as they take place in the multiple meetings between a decentred notion of radio and musical life.......Mediatization has become a key concept for understanding the relations between media and other cultural and social fields. Contributing to the discussions related to the concept of mediatization, this article discusses how practices of radio and music(al life) influence each other. We follow Deacon......’s and Stanyer’s advice to supplement the concept of mediatization with ‘a series of additional concepts at lower levels of abstraction’ and suggest, in this respect, the notion of heterogeneous milieus of music–radio. Hereby, we turn away from the all-encompassing perspectives related to the concept...

  16. ITSY Handheld Software Radio

    National Research Council Canada - National Science Library

    Bose, Vanu

    2001-01-01

    .... A handheld software radio platform would enable the construction of devices that could inter-operate with multiple legacy systems, download new waveforms and be used to construct adhoc networks...

  17. Structure in radio galaxies

    International Nuclear Information System (INIS)

    Breugel, W. van.

    1980-01-01

    It is shown that radio jets are a rather common phenomenon in radio galaxies. Jets can be disguised as trails in head-tail sources, bridges in double sources or simply remain undetected because of lack of resolution and sensitivity. It is natural to associate these jets with the channels which had previously been suggested to supply energy to the extended radio lobes. The observations of optical emission suggest that a continuous non-thermal spectrum extending from 10 9 to 10 15 Hz is a common property of jets. Because significant amounts of interstellar matter are also observed in each of the galaxies surveyed it seems that models for jets which involve an interaction with this medium may be most appropriate. New information about the overall structure of extended radio sources has been obtained from the detailed multifrequency study with the WSRT. (Auth.)

  18. Wireless radio a history

    CERN Document Server

    Coe, Lewis

    2006-01-01

    ""Informative...recommended""--Choice; ""interesting...a good read...well worth reading""--Contact Magazine. This history first looks at Marconi's wireless communications system and then explores its many applications, including marine radio, cellular telephones, police and military uses, television and radar. Radio collecting is also discussed, and brief biographies are provided for the major figures in the development and use of the wireless.

  19. ¿Radios ciudadanas?

    OpenAIRE

    López Vigil, José Ignacio

    1998-01-01

    Educativas, sindicales, populares, comunitarias, libres, rebeldes, participativas, alternativas, alterativas, han sido las denominaciones de la radio cuando su proyecto está al servicio de la gente. Palabras apropiadas y nobles -dice elautor-pero devaluadas, a las que ahora se agrega la radio ciudadana, para relievarla como ejercicio depoder y espacio de verdadera participación de la genteenla vida de su nación.

  20. Classics in radio astronomy

    CERN Document Server

    Sullivan, Woodruff Turner

    1982-01-01

    Radio techniques were the nrst to lead astronomy away from the quiescent and limited Universe revealed by traditional observations at optical wave­ lengths. In the earliest days of radio astronomy, a handful of radio physicists and engineers made one startling discovery after another as they opened up the radio sky. With this collection of classic papers and the extensive intro­ ductory material, the reader can experience these exciting discoveries, as well as understand the developing techniques and follow the motivations which prompted the various lines of inquiry. For instance he or she will follow in detail the several attempts to detect radio waves from the sun at the turn of the century; the unravelling by Jansky of a "steady hiss type static"; the incredible story of Reber who built a 9 meter dish in his backyard in 1937 and then mapped the Milky Way; the vital discoveries by Hey and colleagues of radio bursts from the Sun and of a discrete source in the constellation of Cygnus; the development of re...

  1. Solar radio observations and interpretations

    International Nuclear Information System (INIS)

    Rosenberg, H.

    1976-01-01

    The recent solar radio observations related to flares are reviewed for the frequency range of a few kilohertz to several gigahertz. The analysis of the radio data leads to boundary conditions on the acceleration processes which are responsible for the fast particles which cause radio emission. The role and cause of plasma turbulence at the plasma-frequency and at much lower frequencies is discussed in relation to the acceleration processes and the radio emission mechanisms for the various radio bursts. (author)

  2. Tools of radio astronomy

    CERN Document Server

    Wilson, Thomas L; Hüttemeister, Susanne

    2013-01-01

    This 6th edition of “Tools of Radio Astronomy”, the most used introductory text in radio astronomy, has been revised to reflect the current state of this important branch of astronomy. This includes the use of satellites, low radio frequencies, the millimeter/sub-mm universe, the Cosmic Microwave Background and the increased importance of mm/sub-mm dust emission. Several derivations and presentations of technical aspects of radio astronomy and receivers, such as receiver noise, the Hertz dipole and  beam forming have been updated, expanded, re-worked or complemented by alternative derivations. These reflect advances in technology. The wider bandwidths of the Jansky-VLA and long wave arrays such as LOFAR and mm/sub-mm arrays such as ALMA required an expansion of the discussion of interferometers and aperture synthesis. Developments in data reduction algorithms have been included. As a result of the large amount of data collected in the past 20 years, the discussion of solar system radio astronomy, dust em...

  3. Galactic radio astronomy

    CERN Document Server

    Sofue, Yoshiaki

    2017-01-01

    This book is a concise primer on galactic radio astronomy for undergraduate and graduate students, and provides wide coverage of galactic astronomy and astrophysics such as the physics of interstellar matter and the dynamics and structure of the Milky Way Galaxy and galaxies. Radio astronomy and its technological development have led to significant progress in galactic astronomy and contributed to understanding interstellar matter and galactic structures. The book begins with the fundamental physics of radio-wave radiation, i.e., black body radiation, thermal emission, synchrotron radiation, and HI and molecular line emissions. The author then gives overviews of ingredients of galactic physics, including interstellar matter such as the neutral (HI), molecular hydrogen, and ionized gases, as well as magnetic fields in galaxies. In addition, more advanced topics relevant to the Galaxy and galaxies are also contained here: star formation, supernova remnants, the Galactic Center and black holes, galactic dynamics...

  4. Radio structure in quasars

    International Nuclear Information System (INIS)

    Barthel, P.D.

    1984-01-01

    In this thesis, observational attention is given to the extended extragalactic radio sources associated with quasars. The isolated compact radio sources, often identified with quasars, are only included in the discussions. Three aspects of the radio structure in quasars and their cosmic evolution are considered: a study of the parsec scale morphology in quasar cores, in relation to the extended morphologies; an investigation of possible epoch dependent hotspot properties as well as a more detailed investigation of this fine scale structure; a VLA project was carried out to obtain morphological information on scales of 0.5 arcsec on high redshift quasars and to investigate possible epoch dependent morphological properties. MERLIN observations at 0.1 arcsec resolution to supplement the VLA data were initiated. (Auth.)

  5. Radio Emission from Supernovae

    International Nuclear Information System (INIS)

    Weiler, Kurt W.; Panagia, Nino; Sramek, Richard A.; Van Dyk, Schuyler D.; Williams, Christopher L.; Stockdale, Christopher J.; Kelley, Matthew T.

    2009-01-01

    Study of radio supernovae over the past 27 years includes more than three dozen detected objects and more than 150 upper limits. From this work it is possible to identify classes of radio properties, demonstrate conformance to and deviations from existing models, estimate the density and structure of the circumstellar material and, by inference, the evolution of the presupernova stellar wind, and reveal the last stages of stellar evolution before explosion. It is also possible to detect ionized hydrogen along the line of sight, to demonstrate binary properties of the presupernova stellar system, and to detect dumpiness of the circumstellar material.

  6. Radio emission from Jupiter

    International Nuclear Information System (INIS)

    Velusamy, T.

    1976-01-01

    The basic features of the different radio emissions from the planet Jupiter are reviewed. These radio emissions characterized into three types as thermal, decimetric and decametric, are discussed. The coherent emission mechanism for the origin of the decametric bursts and the acceleration mechanism for relativistic electrons in the decimetric radiation have not been properly understood. The emissions are much related to the magnetic field of Jupiter. The system III rotation period for Jupiter has been calculated as 092 55 m 29.74 S. (A.K.)

  7. ¿Radios Comunitarias?

    OpenAIRE

    José Ignacio López Vigil

    2015-01-01

    Varias han sido las denominaciones dadas a la radio cuando su proyecto está al servicio de la gente. Palabras apropiadas pero devaluadas al decir del autor, a las que ahora se suma otras radios ciudadanas. Ciudadana para relievarla como ejercicio de poder y espacio de verdadera participación de la gente en la vida de su nación. Ciudadanos son los que piensan con cabeza propia y pesan en la opinión pública. Presenta una sinopsis de la historia de éstas desde 1974. Señala que la competencia obl...

  8. Spectrum management and radio resource management considering cognitive radio systems

    NARCIS (Netherlands)

    Haartsen, J.C.; Wieweg, Lasse; Huschke, Jörg

    2005-01-01

    International fora and some national administrations define a cognitive radio (CR) as a pioneering radio communication system that would be capable of altering and adapting its transmitter and receiver parameters based on communication and the exchange of information with related detectable radio

  9. Compact radio sources

    International Nuclear Information System (INIS)

    Altschuler, D.R.

    1975-01-01

    Eighty-seven compact radio sources were monitored between 1971 and 1974 with the National Radio Astronomy Observatory interferometer. Both flux density and polarization were measured at intervals of about one month at wavelengths of 3.7 and 11.1 cms. Forty-four sources showed definite variability in their total and/or polarized flux density. The variations in polarization were of a shorter time scale than the corresponding flux density variations. Some of the qualitative features of an expanding source model were observed. The data suggest that some form of injection of relativistic electrons is taking place. The absence of significant depolarization in the variable sources indicates that only a small fraction of the mass of the radio outburst is in the form of non-relativistic plasma. Some of the objects observed belong to the BL-Lacertal class. It is shown that this class is very inhomogeneous in its radio properties. For the violently variable BL-Lacertal type objects the spectrum, flux variations and polarization data strongly suggest that these are very young objects

  10. Valuing commercial radio licences

    NARCIS (Netherlands)

    Kerste, M.; Poort, J.; van Eijk, N.

    2011-01-01

    Within the EU Regulatory Framework, licensees for commercial radio broadcasting may be charged a fee to ensure optimal allocation of scarce resources but not to maximize public revenues. In this paper, it is described how such a fee can be determined for the purpose of licence renewal or extension.

  11. Radio Frequency Identification

    Indian Academy of Sciences (India)

    Radio Frequency Identification (RFID) has been around sinceearly 2000. Its use has currently become commonplace as thecost of RFID tags has rapidly decreased. RFID tags have alsobecome more 'intelligent' with the incorporation of processorsand sensors in them. They are widely used now in manyinnovative ways.

  12. Nanolensed Fast Radio Bursts

    Science.gov (United States)

    Eichler, David

    2017-12-01

    It is suggested that fast radio bursts can probe gravitational lensing by clumpy dark matter objects that range in mass from 10-3 M ⊙-102 M ⊙. They may provide a more sensitive probe than observations of lensings of objects in the Magellanic Clouds, and could find or rule out clumpy dark matter with an extended mass spectrum.

  13. AMATEUR "HAM" RADIO

    Science.gov (United States)

    these cooler months. Did you know your body can cool 25 times faster in water than in air? That water code at 13 or 20 words-per-minute will no longer be required to obtain amateur radio operating be found by contacting the ARRL or using an Internet search engine to search on such topics as "

  14. Radio images of the planets

    International Nuclear Information System (INIS)

    De Pater, I.

    1990-01-01

    Observations at radio wavelengths make possible detailed studies of planetary atmospheres, magnetospheres, and surface layers. The paper addresses the question of what can be learned from interferometric radio images of planets. Results from single-element radio observations are also discussed. Observations of both the terrestrial and the giant planets are considered. 106 refs

  15. The importance of Radio Quiet Zone (RQZ) for radio astronomy

    Science.gov (United States)

    Umar, Roslan; Abidin, Zamri Zainal; Ibrahim, Zainol Abidin

    2013-05-01

    Most of radio observatories are located in isolated areas. Since radio sources from the universe is very weak, astronomer need to avoid radio frequency interference (RFI) from active spectrum users and radio noise produced by human made (telecommunication, mobile phone, microwave user and many more. There are many observatories around the world are surrounded by a Radio Quiet Zone (RQZ), which is it was set up using public or state laws. A Radio Quiet Zone normally consists of two areas: an exclusive area in which totally radio emissions are forbidden, with restrictions for residents and business developments, and a larger (radius up to 100 km above) coordination area where the power of radio transmission limits to threshold levels. Geographical Information System (GIS) can be used as a powerful tool in mapping large areas with varying RQZ profiles. In this paper, we report the initial testing of the usage of this system in order to identify the areas were suitable for Radio Quiet Zone. Among the important parameters used to develop the database for our GIS are population density, information on TV and telecommunication (mobile phones) transmitters, road networks (highway), and contour shielding. We will also use other information gathered from on-site RFI level measurements on selected 'best' areas generated by the GIS. The intention is to find the best site for the purpose of establishing first radio quiet zones for radio telescope in Malaysia.

  16. Introduction to international radio regulations

    Energy Technology Data Exchange (ETDEWEB)

    Radicella, S M [Abdus Salam International Centre for Theoretical Physics, Trieste (Italy)

    2003-12-15

    These lecture notes contain an overview of basic problems of the International Radio Regulations. Access to the existing information infrastructure, and to that of the future Information Society, depends critically on radio, especially in poor, remote and sparsely populated regions with under-developed telecommunication infrastructure. How the spectrum of radio frequencies is regulated has profound impact on the society, its security, prosperity, and culture. The radio regulations represent a very important framework for an adequate use of radio and should be known by all of those working in the field.

  17. Introduction to international radio regulations

    International Nuclear Information System (INIS)

    Radicella, S.M.

    2003-01-01

    These lecture notes contain an overview of basic problems of the International Radio Regulations. Access to the existing information infrastructure, and to that of the future Information Society, depends critically on radio, especially in poor, remote and sparsely populated regions with under-developed telecommunication infrastructure. How the spectrum of radio frequencies is regulated has profound impact on the society, its security, prosperity, and culture. The radio regulations represent a very important framework for an adequate use of radio and should be known by all of those working in the field

  18. Validación de una escala para medir la calidad de vida laboral en hospitales públicos de Tlaxcala

    Directory of Open Access Journals (Sweden)

    Irma Alejandra Hernández-Vicente

    2017-03-01

    Full Text Available Objetivo. Validar un instrumento para medir la calidad de vida laboral en hospitales públicos (CVL-HP de Tlaxcala,México. Material y métodos. El instrumento fue validado en 669 trabajadores de seis hospitales de la Secretaría de Salud de Tlaxcala, México. Se evaluó validez de contenido por consulta a expertos, de constructo mediante análisis factorial, de criterio por comparación con otras escalas y la confiabilidad con Alpha de Cronbach. Resultados. El análisis factorial descubrió cuatro dimensiones: “bienestar individual”,“condiciones y medio ambiente de trabajo”, “organización”y “bienestar logrado a través del trabajo”. La confiabilidad fue de 0.921. Los trabajadores con mejor CVL-HP fueron menores de 50 años, de contrato, con menor antigüedad laboral, personal de jornada acumulada diurna y aquéllos con licenciatura. Conclusiones. La escala CVL-HP mostró ser psicométricamente válida y confiable. Se recomienda probar esta escala en otras instituciones públicas y privadas,y relacionarla con  indicadores de desempeño y gestión de los servicios de salud.

  19. Diseño, construcción y funcionamiento de un prototipo para medir cargas vehiculares en un pavimento flexible

    Directory of Open Access Journals (Sweden)

    Hugo Rondón

    2014-01-01

    Full Text Available El artículo presenta el diseño y la construcción de un prototipo con el cual es posible medir cargas vehiculares en un pavimento flexible, a partir de las vibraciones que dichos vehículos generan cuando se movilizan sobre esta estructura vial. El principio físico es simple: cuando un vehículo circula sobre la superficie de un pavimento, éste genera vibraciones que pueden ser percatadas en zonas adyacentes a la vía en estudio, y las amplitudes de dichas deformaciones pueden dar información sobre la magnitud de la carga rodante. Adicionalmente, se reportan los resultados de un estudio de campo ejecutado con el fin de calibrar una ecuación matemática que simula las señales de vibración obtenidas con el prototipo. De manera general se concluye que el prototipo es capaz de predecir la carga que circula sobre el pavimento a partir de las vibraciones que éstos inducen cuando transitan sobre la capa de rodadura.

  20. Construcción de una escala para medir el perfil motivacional de las matronas hacia los programas de educación maternal

    Directory of Open Access Journals (Sweden)

    Matilde Fernández y Fernández-Arroyo

    Full Text Available Justificación: Describir el perfil motivacional permite investigar el clima de la organización y la calidad de vida profesional percibida. Objetivo: elaborar un instrumento para medir el perfil motivacional de las matronas hacia los programas de educación maternal. Metodología: se estudió una muestra no probabilística de 93 matronas, lo que corresponde al 54,6% de las matronas de atención primaria de Madrid. La escala se compuso de nueve ítems de motivación. Resultados: La escala presentó una fiabilidad de Alfa de Cronbach =0,78, lo que indica una consistencia interna considerable. Del análisis factorial se obtuvo una estructura bifactorial. La consistencia interna de ambas dimensiones es igualmente alta. Esta agrupación resultó coherente con la planteada en la fase de operativización del constructo teórico. Conclusión: La escala diferencia a las matronas en cuanto a sus niveles de motivación hacia los programas de Educación Maternal, por lo que es una herramienta que facilita investigaciones futuras.

  1. Construcción de un instrumento para medir el clima organizacional en función del modelo de los valores en competencia

    Directory of Open Access Journals (Sweden)

    Roberto Hernández Sampieri

    2014-01-01

    Full Text Available El presente estudio estableció como objetivo central analizar en el ámbito laboral mexicano un modelo que contextualizara al clima organizacional y lo vinculara con la cultura organiza - cional. Se eligió al modelo de valores en competencia (MVC de Kim S. Cameron y Robert E. Quinn, por ser tal vez el marco de referencia con mayor evidencia empírica en lo que respecta a la cultura organizacional. El MVC propone una estructura de cuadrantes de valores para las organizaciones: 1 enfoque interno, flexibilidad (organización familiar o clan; 2 enfoque interno, estabilidad y control (organización jerárquica; 3 en - foque externo, flexibilidad (organización adhocrática; y 4 en - foque externo, estabilidad y control (organización de mercado o metas. Asimismo, este modelo sostiene que las organizacio - nes presentan una mezcla de valores de todos los cuadrantes. Los resultados, en términos generales, fundamentaron dicho modelo en una muestra heterogénea de doce organizaciones de la región central de México (1 424 casos. Por otra parte, se construyó una primera versión de un instrumento que pretende medir el clima organizacional en función del MVC, el cual de - mostró capacidad de discriminar entre organizaciones y ser en términos generales válido y confiable.

  2. Índices para medir las desigualdades de salud de carácter social basados en la noción de entropía

    Directory of Open Access Journals (Sweden)

    Jorge Bacallao

    Full Text Available Los índices descritos en la literatura para medir las desigualdades de salud de carácter social tienen facetas positivas pero también algunas insuficiencias, según las circunstancias de su aplicación. El objetivo de este artículo es proponer y demostrar, en los planos teórico y práctico, las ventajas de las mediciones de la desigualdad basadas en la noción de entropía, conocida ampliamente en la física y la teoría de la información. Se definen y exponen las principales propiedades de los índices basados en las nociones de entropía y redundancia. Se ilustra su aplicación en dos conjuntos de datos ficticios y en datos reales, derivados de los indicadores básicos de salud para las Américas, de la Organización Panamericana de la Salud. Los índices basados en la noción de entropía poseen, entre otras, las siguientes propiedades: a no varían con los cambios de escala; b son simétricos; c incorporan la dimensión social, y d son fáciles de interpretar gracias a la condición de equivalencia entre la entropía y un sistema con dos clases.

  3. Radio-capacity of ecosystems

    International Nuclear Information System (INIS)

    Kultakhmedov, Yu.; Kultakhmedova-Vyshnyakova, V.

    1997-01-01

    This paper consider a universal approach to ecosystems of different types, based on representation of their radio-capacity. The concept of ecosystem includes reproduction of components (bio-productivity) and conditions such as maintaining of environment quality. Radio-capacity in the case of radionuclide pollution appears in accumulation and redistribution of radionuclides in the ecosystem. As a result the radionuclides are redistributed and buried in soil or lake bottom sediments. Estimation models for the radio-capacity of water and terrestrial ecosystems are represented. The calculations of the radio-capacity factor of water ecosystems are performed, and the high radio-capacity of a freshwater reservoir (F=0.6-0.8) and extremely high radio-capacity of a reservoir cascade (F c =0.99) is shown material from the Dnieper's cascade reservoirs. The methods of radio-capacity estimation of agroecosystems, wood and marine ecosystems are developed. (authors)

  4. The Concept of 'Radio Music'

    DEFF Research Database (Denmark)

    Fjeldsøe, Michael

    2016-01-01

    , educational and didactic effort which would enlighten all of society. For a while it seemed that radio music was considered a genre of its own. To fulfil its function, radio music had to consider technical limitations as well as the educational level and listening modes of the new mass audience. Public radio......, as discussed by Kurt Weill and Paul Hindemith, was at first greeted with great expectations, but soon a more realistic attitude prevailed. Weill, himself a radio critic as well, composed Der Lindberghflug (1929) as a piece of ‘radio music theatre’, but then changed some of its features in order to turn...... it into a didactical play for amateurs, a so-called Lehrstück. The article will present the concept of ‘radio music’ developed within German Neue Sachlichkeit and discuss the relevance of such a concept for current research in the field of radio and music....

  5. Tools of radio astronomy

    CERN Document Server

    Wilson, Thomas L; Hüttemeister, Susanne

    2009-01-01

    The recent years have seen breathtaking progress in technology, especially in the receiver and digital technologies relevant for radio astronomy, which has at the same time advanced to shorter wavelengths. This is the updated and completely revised 5th edition of the most used introductory text in radio astronomy. It presents a unified treatment of the entire field from centimeter to sub-millimeter wavelengths. Topics covered include instruments, sensitivity considerations, observational methods and interpretations of the data recorded with both single dishes and interferometers. This text is useful to both students and experienced practicing astronomers. Besides making major updates and additions throughout the book, the authors have re-organized a number of chapters to more clearly separate basic theory from rapidly evolving practical aspects. Further, problem sets have been added at the end of each chapter.

  6. Radio telescope control

    CERN Document Server

    Schraml, J

    1972-01-01

    An on-line computer control process developed for the 100-m radio telescope of the Max-Planck-Institut fur Radioastronomie in Bonn is described. The instrument is the largest fully steerable antenna in the world. Its operation started on May 31st 1972. It is controlled by a Ferranti Argus 500 on-line computer. The first part of the paper deals with the process itself, the radio telescope and its operation, and the demands resulting for the control program. The second part briefly describes the computer and its hardware. The final part introduces the architecture of the executive program in general, which has been tailored to meet the demands of the process and the hardware. The communication between the observer and the system, the format of data on magnetic tape and an on-line reduction of position measurements are considered. (0 refs).

  7. Die radio in Afrika

    Directory of Open Access Journals (Sweden)

    S. de Villiers

    1966-03-01

    Full Text Available Omvang van radio-uitsendings in en na Afrika. — Redes vir die versnelde tempo van uitbreiding. — Radio as die geskikste massa-kommunikasiemiddel vir Afrika. — Faktore wat die verspreiding bemoeilik. — Skouspelagtige toename in luistertalle.Toe Plinius, wat in die jaar 79 oorlede is, in sy „Historia Naturalis” verklaar het dat daar altyd iets nuuts uit Afrika afkomstig is, kon hy nouliks voorsien het dat die „iets" negentien eeue later in die lug sou setel wat hierdie reuse-vasteland oorspan — ’n Babelse spraakverwarring en ’n ongekende, verbete woorde-oorlog in die etergolwe, onder meer daarop bereken om die harte en hoofde van derduisendes te verower.

  8. NOAA Weather Radio

    Science.gov (United States)

    cosas afectan la recepción de señas de la radio. Por ejemplo, las extensiones grandes de agua de sal receptor con una antena interior de calidad buena, o conectarlo a una antena externa. Generalmente los Programación Español Listado de estación Explicacion de SAME Coverage Station Listing County Listing

  9. Radio Frequency Interference Mitigation

    Science.gov (United States)

    An, T.; Chen, X.; Mohan, P.; Lao, B. Q.

    2017-09-01

    The observational facilities of radio astronomy keep constant upgrades and developments to achieve better capabilities including increasing the time of the data recording and frequency resolutions, and increasing the receiving and recording bandwidth. However in contrast, only a limited spectrum resource has been allocated to radio astronomy by the International Telecommunication Union, resulting in that the radio observational instrumentations are inevitably exposed to undesirable radio frequency interference (RFI) signals which originate mainly from the terrestrial human activity and are becoming stronger with time. RFIs degrade the quality of data and even lead to invalid data. The impact of RFIs on scientific outcome becomes more and more serious. In this article, the requirement for RFI mitigation is motivated, and the RFI characteristics, mitigation techniques, and strategies are reviewed. The mitigation strategies adopted at some representative observatories, telescopes, and arrays are also introduced. The advantages and shortcomings of the four classes of RFI mitigation strategies are discussed and presented, applicable at the connected causal stages: preventive, pre-detection, pre-correlation, and post-correlation. The proper identification and flagging of RFI is the key to the reduction of data loss and improvement in data quality, and is also the ultimate goal of developing RFI mitigation technique. This can be achieved through a strategy involving a combination of the discussed techniques in stages. The recent advances in the high speed digital signal processing and high performance computing allow for performing RFI excision of the large data volumes generated from large telescopes or arrays in both real time and offline modes, aiding the proposed strategy.

  10. AIDS radio triggers.

    Science.gov (United States)

    Elias, A M

    1991-07-01

    In April 1991, the Ethnic Communities' Council of NSW was granted funding under the Community AIDS Prevention and Education Program through the Department of Community Services and Health, to produce a series of 6x50 second AIDS radio triggers with a 10-second tag line for further information. The triggers are designed to disseminate culturally-sensitive information about HIV/AIDS in English, Italian, Greek, Spanish, Khmer, Turkish, Macedonian, Serbo-Croatian, Arabic, Cantonese, and Vietnamese, with the goal of increasing awareness and decreasing the degree of misinformation about HIV/AIDS among people of non-English-speaking backgrounds through radio and sound. The 6 triggers cover the denial that AIDS exists in the community, beliefs that words and feelings do not protect one from catching HIV, encouraging friends to be compassionate, compassion within the family, AIDS information for a young audience, and the provision of accurate and honest information on HIV/AIDS. The triggers are slated to be completed by the end of July 1991 and will be broadcast on all possible community, ethnic, and commercial radio networks across Australia. They will be available upon request in composite form with an information kit for use by health care professionals and community workers.

  11. Métodos semiempíricos para la evaluación rápida de orbitales frontera en la clasificación de agonistas y antagonistas de la subunidad NR1 de los receptores iGluR-NMDA

    Directory of Open Access Journals (Sweden)

    Juvenal Yosa-Reyes

    2010-12-01

    Full Text Available Los receptores iGluR-NMDAposeen gran interés farmacológico debido a que están implicadosen desordenes neurodegenerativos y neurosiquiátricos inclusoparticipan en procesos como plasticidad sináptica, esencial para la formación de la memoria. La subunidad NR1 de los iGluR-NMDA es fundamental para que éste tipo de receptores se activen apropiadamente, de hecho muchos de los fármacos estudiados paralos desordenes anteriormente mencionados, están dirigidos específicamente a la subunidad NR1. Estudios previos han determinado que el orbital molecular de más baja energía (LUMO, puede ser usado como parámetro para estimar la actividad agonista o antagonista en la subunidad NR1. Objetivo Evaluar el método semiempírico CNDO para el cálculo rápido de la energía LUMO, con la finalidad de crear un modelo sencillo para el diseño in silico de nuevos fármacos. Materiales y métodos. Fueron seleccionadas 168 moléculas entre agonistas y antagonistas de la subunidad NR1. La energía de cada estructura fue optimizada y posteriormente fueron calculadas las energías de los orbitales frontera, el LogP, la energía total, la capacidad de formar puentes de hidrógeno, la energía de unión y el momento dipolar. Resultados. Se demuestra quela energía LUMO es suficiente para discriminar entre moléculas agonistas y antagonistas de esta subunidad y que el método CNDO evalúa estas propiedades de manera rápida y eficiente, Conclusión. El método CNDO permite el cálculo rápido, generando a futuro procedimientos eficaces para la caracterización de fármacos potenciales que actúen sobre este sitio en particular.

  12. Respiración del suelo como herramienta para evaluar calidad de fondos en acuicultura. i. desarrollo de un protocolo estándar para medir dióxido de Carbono

    OpenAIRE

    Krebs Reginatto, Luciano

    2003-01-01

    Respiración del suelo como herramienta para evaluar calidad de fondos en acuicultura. I. Desarrollo de un protocolo estándar para medir dióxido de carbono La calidad de los suelos es determinada principalmente por métodos químicos tales como: contenido de materia orgánica (MO), azufre, elementos minerales, potencial de hidrógeno (pH) y potencial redox, entre otros.

  13. Flexible Adaptation in Cognitive Radios

    CERN Document Server

    Li, Shujun

    2013-01-01

    This book provides an introduction to software-defined radio and cognitive radio, along with methodologies for applying knowledge representation, semantic web, logic reasoning and artificial intelligence to cognitive radio, enabling autonomous adaptation and flexible signaling. Readers from the wireless communications and software-defined radio communities will use this book as a reference to extend software-defined radio to cognitive radio, using the semantic technology described. Readers with a background in semantic web and artificial intelligence will find in this book the application of semantic web and artificial intelligence technologies to wireless communications. For readers in networks and network management, this book presents a new approach to enable interoperability, collaborative optimization and flexible adaptation of network components. Provides a comprehensive ontology covering the core concepts of wireless communications using a formal language; Presents the technical realization of using a ...

  14. The properties of radio ellipticals

    International Nuclear Information System (INIS)

    Sparks, W.B.; Disney, M.J.; Rodgers, A.W.

    1984-01-01

    Optical and additional radio data are presented for the bright galaxies of the Disney and Wall survey (1977 Mon. Not. R. Astron. Soc. 179, 235). These data form the basis of a statistical comparison of the properties of radio elliptical galaxies to radio-quiet ellipticals. The correlations may be explained by the depth of the gravitational potential well in which the galaxy resides governing the circumstances under which an elliptical galaxy rids itself of internally produced gas. (author)

  15. Análisis Factorial Confirmatorio para medir las limitantes percibidas en el pregrado para el desarrollo de actividades de investigación

    Directory of Open Access Journals (Sweden)

    Deneb Elí Magaña Medina

    2017-01-01

    Full Text Available Introducción : El objetivo de este acercamiento fue validar a través de un análisis factorial confirmatorio un modelo de medida para determinar las limitantes percibidas para desarrollar interés por las actividades científica s o tecnológicas en el pregrado . Método : El estudio tuvo un enfoque cuantitativo con un diseño no experimental descriptivo y fue realizado en una Universidad Pública Estatal en el Sureste de México en donde s e seleccionaron 378 estudiantes de pregrado con más del 60% de créditos en su trayectoria escolar y que representaran todas las áreas del conocimiento. Se realizó un análisis factorial exploratorio y confirmatorio para determinar las propiedades psicométricas del instrumento . Resultados : El modelo propuesto corroboró a través del análisis factorial conf i rmatorio los valores de los principales indicadores de ajuste ( X 2 = 98.07, p = .00 1 ; CMIN/DF= 2.62; CFI=.95; GFI= .97, IFI= .95; RMSEA= .06 ; IC 90 [.03 - .09] . Asimismo, los resultados señalan que el 39.85% percibe alguna limitante importante de tipo personal y el 37.9% de conocimiento. Discusión o Conclusión : Los resultados permiten confirmar la sustentabilidad empírica para el modelo propuesto para medir las limitantes percibidas para la formación científica (LFC en estudiantes de pregrado de todas las áreas del conocimiento, pues los datos presentados muestran evidencia de un modelo factorial sustentable , siendo las limitantes personales las que afectan en mayor medida a los estudiantes encuestados.

  16. UNA TECNICA ESTADISTICA PARA MEDIR LA CONFLICTIVIDAD SOCIAL A TRAVES DEL REGISTRO ARQUEOLOGICO (A Statistical Technique to Measure Social Conflict through the Archaeological Record

    Directory of Open Access Journals (Sweden)

    Pascual Izquierdo-Egea

    2015-03-01

    Full Text Available Se presenta aqui una tecnica estadistica para medir la conflictividad social a traves del registro mortuorio. Nace al amparo del metodo de valoracion contextual empleado en el analisis de los ajuares funerarios desde 1993. Se trata de una herramienta fundamental para el desarrollo de la arqueologia de los fenomenos sociales, cuyos relevantes resultados empiricos avalan su trascendencia teorica. Tras proceder a su conceptualizacion en funcion de la desigualdad social y la riqueza relativa, se explican las dos clases de conflictividad social definidas: estructural o estatica y coyuntural o dinamica. Finalmente, se incluyen sus conexiones con la ley demografica de Malthus a traves de sus dos parametros: poblacion y recursos. Todo este entramado teorico se ilustra con algunas aplicaciones referidas a las civilizaciones antiguas, abarcando la protohistoria iberica, la Mesoamerica prehispanica o la Roma altoimperial. ENGLISH: A statistical technique to measure social conflict through the mortuary record is presented here. It is born under the contextual valuation method used in the analysis of grave goods since 1993. This is a fundamental tool for the development of the archaeology of social phenomena, whose relevant empirical results support its theoretical significance. After conveying its conceptualization in terms of social inequality and relative wealth, the two classes of social conflict are explained: static or structural and dynamic or conjunctural. Finally, connections with the Malthusian demographic law through its two parameters—population and resources—are included. The synthesis of these theoretical frameworks is illustrated with applications to ancient civilizations, including Iberian protohistory, prehispanic Mesoamerica, and early imperial Rome.

  17. Desarrollo de un instrumento para medir percepciones sobre el contexto de construccion del conocimiento cientifico de estudiantes universitarios de nuevo ingreso

    Science.gov (United States)

    Garcia-Ramirez, Jaime Antonio

    En esta investigacion, se desarrollo un instrumento que permite medir percepciones relacionadas al contexto de constriccion del conocimiento cientifico. Se examinaron instrumentos existentes y se encontro que el VOSTS (Views on science, technology, and society), instrumento desarrollado empiricamente en Canada por Aikenhead, Ryan y Fleming, podia traducirse y validarse en el contexto cultural puertorriqueno. El instrumento es extenso, consta de 113 reactivos, cada uno con una premisa basica relacionada a la tematica ciencia, tecnologia y sociedad y un numero de alternativas relacionadas a la premisa que oscila entre siete y trece. Se delimito su utilizacion a los quince reactivos identificados por los autores como relacionados a la construccion social del conocimiento cientifico. Metodologicamente, se procedio a utilizar el modelo de adaptacion intercultural, que permite que el instrumento desarrollado satisfaga las dimensiones de equivalencia semantica, de contenido, tecnica, de criterio y conceptual, atemperado asi al instrumento original. Se cumplio con este proposito mediante la traduccion de la version original en ingles al espanol y viceversa. Se utilizaron comites para examinar la traduccion y la retro-traduccion del instrumento. Se realizo una prueba piloto con estudiantes universitarios de nuevo ingreso, utilizando el instrumento traducido para asegurar su intelegibilidad. La confiabilidad del instrumento se determino mediante la intervencion de un panel de expertos quienes clasificaron las distintas posiciones dentro de cada reactivo en: realista, con merito e ingenua; se transformaron estas opciones en valores numericos lo que permitio establecer una escala Likert para cada una. Se suministro el instrumento a una muestra de estudiantes universitarios de nuevo ingreso con caracteristicas similares a las de la poblacion puertorriquena en cuanto a ejecucion en las pruebas de aptitud verbal y matematica del College Board. Los resultados de sus contestaciones

  18. DISEÑO Y VALIDACIÓN DE DOS ESCALAS PARA MEDIR LA ACTITUD HACIA LA ALIMENTACIÓN Y LA ACTIVIDAD FÍSICA DURANTE LA ADOLESCENCIA

    Directory of Open Access Journals (Sweden)

    Marta Lima-Serrano

    2012-01-01

    Full Text Available Fundamentos: Diversos autores proponen la actitud como un mediador en el cambio de comportamiento, por lo que puede predecir la práctica de este. El objetivo del trabajo fue diseñar y validar dos escalas para medir la actitud de los adolescentes hacia la alimentación saludable, y la actitud hacia la actividad física. Métodos: Se realizó el diseño tras una revisión de la literatura. Se procedió a la validación mediante un panel Delphi on-line con 18 expertos/as, un pretest, y una prueba piloto con una muestra de 188 alumnos/as de educación secundaria. Se analizaron la comprensibilidad, la validez de contenido, la adecuación, la fiabilidad mediante la prueba alpha de Cronbach, y la validez de constructo, mediante el análisis factorial exploratorio. Resultados: Las escalas validadas por los expertos/as se consideraron adecuadas en el pretest. En la prueba piloto, la Escala de Actitud hacia la Alimentación de diez ítems, obtuvo un ¿=0,72. La Escala de Actitud hacia la Actividad Física de ocho ítems, tuvo un ¿=0,86. En el análisis factorial mostraron datos a favor de su unidimensionalidad, a todos los ítems obtuvieron pesos r>0,30 en el primer factor sin rotar, b este explicaba una proporción importante de varianza con respecto a los demás, c la varianza total explicada por los factores principales era mayor al 50%. Conclusiones: Las escalas demostraron su validez y fiabilidad y pueden ser utilizadas para valorar la actitud hacia estas áreas de atención prioritarias en adolescentes españoles, y para evaluar este resultado intermedio de intervenciones y programas de salud.

  19. Central radio sources

    International Nuclear Information System (INIS)

    Phinney, E.S.

    1985-01-01

    The compact radio sources in the nuclei of most active galaxies lie closer to their centers of activity than any other region accessible to observation, excepting only the broad emission line region. They provide uniquely strong evidence for bulk motion of matter at relativistic velocities, encouraging the belief that the activity originates in a gravitational potential well whose escape velocity is of the order of the speed of light. The observational facts are reviewed as well as several theoretical pictures of them. Those places where systematic observations could help to distinguish the true theoretical picture from the many competing forgeries are emphasized. 76 references

  20. Radio Frequency Anechoic Chamber Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Supports the design, manufacture, and test of antenna systems. The facility is also used as an electromagnetic compatibility/radio frequency interference...

  1. The Hartebeeshoek Radio Astronomy Observatory

    International Nuclear Information System (INIS)

    Nicolson, G.D.

    1986-01-01

    This article briefly discusses the questions, problems and study fields of the modern astronomer. Radioastronomy has made important contributions to the study of the evolution of stars and has given much information on the birth of stars while at the other extreme, studies of neutron stars and the radio emission from the remnants of supernova explosions have given further insight into the death of individual stars. Radio astronomical studies have learned astronomers much about the structure of the Milky way and some twenty years ago, in a search for new radio galaxies, quasars were discovered. Radioastronomy research in South Africa is carried out at the Hartebeesthoek Radio Astronomy Observatory

  2. Dramatugi Penyiar Radio

    Directory of Open Access Journals (Sweden)

    Hastika Yanti Nora

    2009-07-01

    Full Text Available Dramaturgy is the work of Erving Goffman. He wrote "Presentation of Self in Everyday Life" in '1959. Following the theatrical analogy, Goffman spoke of a front stage and back stage. The front stage is that part of the performance that generally functions in rather fixed and general ways to define the situation for those who observed the performance. The back stage is situation where facts suppressed in the front or various kinds of informal actions may appear. A back stage is usually adjacent to the front stage, but it also cut off from it. Everyone in this world have to run his role in their everyday life. It also a radio announcer. As an actor, they have to be a nice and friendy person when they perform to make air personality, that is  a good  impression, from their audience. But before their perform in the front stage, there so much to do to prepare in the backstage. The front and back stage is radio announcer dramaturgy.

  3. Tuning in to pavement radio

    NARCIS (Netherlands)

    Ellis, S.

    1989-01-01

    This article describes a phenomenon known all over Africa, for which there is no really satisfactory term in English but which is summed up in the French term 'radio trottoir', literally 'pavement radio'. It may be defined as the popular and unofficial discussion of current affairs in Africa,

  4. Wide Field Radio Transient Surveys

    Science.gov (United States)

    Bower, Geoffrey

    2011-04-01

    The time domain of the radio wavelength sky has been only sparsely explored. Nevertheless, serendipitous discovery and results from limited surveys indicate that there is much to be found on timescales from nanoseconds to years and at wavelengths from meters to millimeters. These observations have revealed unexpected phenomena such as rotating radio transients and coherent pulses from brown dwarfs. Additionally, archival studies have revealed an unknown class of radio transients without radio, optical, or high-energy hosts. The new generation of centimeter-wave radio telescopes such as the Allen Telescope Array (ATA) will exploit wide fields of view and flexible digital signal processing to systematically explore radio transient parameter space, as well as lay the scientific and technical foundation for the Square Kilometer Array. Known unknowns that will be the target of future transient surveys include orphan gamma-ray burst afterglows, radio supernovae, tidally-disrupted stars, flare stars, and magnetars. While probing the variable sky, these surveys will also provide unprecedented information on the static radio sky. I will present results from three large ATA surveys (the Fly's Eye survey, the ATA Twenty CM Survey (ATATS), and the Pi GHz Survey (PiGSS)) and several small ATA transient searches. Finally, I will discuss the landscape and opportunities for future instruments at centimeter wavelengths.

  5. CONSTRAINING RADIO EMISSION FROM MAGNETARS

    Energy Technology Data Exchange (ETDEWEB)

    Lazarus, P.; Kaspi, V. M.; Dib, R. [Department of Physics, Rutherford Physics Building, McGill University, 3600 University Street, Montreal, Quebec H3A 2T8 (Canada); Champion, D. J. [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, 53121 Bonn (Germany); Hessels, J. W. T., E-mail: plazar@physics.mcgill.ca [Netherlands Institute for Radio Astronomy (ASTRON), Postbus 2, 7990 AA Dwingeloo (Netherlands)

    2012-01-10

    We report on radio observations of five magnetars and two magnetar candidates carried out at 1950 MHz with the Green Bank Telescope in 2006-2007. The data from these observations were searched for periodic emission and bright single pulses. Also, monitoring observations of magnetar 4U 0142+61 following its 2006 X-ray bursts were obtained. No radio emission was detected for any of our targets. The non-detections allow us to place luminosity upper limits of L{sub 1950} {approx}< 1.60 mJy kpc{sup 2} for periodic emission and L{sub 1950,single} {approx}< 7.6 Jy kpc{sup 2} for single pulse emission. These are the most stringent limits yet for the magnetars observed. The resulting luminosity upper limits together with previous results are discussed, as is the importance of further radio observations of radio-loud and radio-quiet magnetars.

  6. Radio observations of symbiotic stars

    Energy Technology Data Exchange (ETDEWEB)

    Wright, A E [Commonwealth Scientific and Industrial Research Organization, Epping (Australia). Div. of Radiophysics; Allen, D A

    1978-09-01

    A search for 2-cm continuum emission from 91 symbiotic stars has been undertaken using the Parkes radio telescope. Nine sources have been detected, four of which are reported for the first time. The radio spectral indices are mostly about + 0.6; these are interpreted in terms of mass loss. In two stars a portion of the radio spectrum has an index of zero, and for one of these stars (RX Puppis) this is plausibly a manifestation of the cessation of symbiotic activity that occurred about two decades ago. There is an extraordinarily good correlation between the detectability at 2cm and the presence of circumstellar dust, but not between the radio and optical domains. The importance of continued radio monitoring of HM Sagittae over the next few years is stressed.

  7. Radio opaque gloves

    International Nuclear Information System (INIS)

    Whittaker, A.V.; Whittaker, R.E. Jr.; Goldstrom, R.A.; Shipko, F.J.

    1975-01-01

    Radiation shielding garments and accessories, such as radio-opaque gloves for surgeons, shielding against the harmful x-ray radiation in a fluoroscopic zone, are advantageously different from garments for shielding from other medical uses of x-rays. Such garments are provided with zones of differing opacity, whereby desired sensitivity and ''feel'' through the glove material is retained. One feature is the provision of an ''opacity gradient'' across the glove cross section with opacity being relatively low at the fingertip area (lesser shield-thickness), but relatively high at the less nonprehensile hand zones, such as the palm. Glove fabrication techniques for achieving such an opacity gradient are described. (U.S.)

  8. MUSIC RADIO-JOURNALISM

    Directory of Open Access Journals (Sweden)

    Dubovtceva Ludmila I.

    2014-04-01

    Full Text Available The article is based on years of practical experience, the author highlights the main radio genres in which music correspondent, music reviewer, music commentator, and music leading and a disc jockey work. Theoretical principles of their creative activities are analyzed in common journalistic genres, such as interview, reportage, talk show, live broadcast, radiofilm, as well as specialized genres like concert on demand and music competition. Journalist’ speech is seen as a logical element, the incoming with music in art-structural relationships. However, it does not become the predominant sound layer and aims to harmonious correlation or local penetration into music opus. In addition, important links in music journalism are defined the auxiliary "offscreen" editor's job and keeping the original sound archive. The author cites a number of own work examples on the air.

  9. Radio-adaptive response

    International Nuclear Information System (INIS)

    Ikushima, T.

    1992-01-01

    Knowledge about cellular events in mammalian cells exposed to low doses of ionizing radiation is meager. Recent works showed that human lymphocytes become resistant to radiation-induced chromosomal damage after exposure to low doses of ionizing radiation. Experimental evidence for radio-adaptive response (RAR) in cultured mammalian cells was obtained. Exposure to very low doses of gamma-rays or tritium beta-rays make cells less susceptible to the induction of micronuclei and sister chromatid exchanges by subsequent higher doses. Many important characteristics of the novel response suggest that RAR is a stress response resulting in the enhanced repair of chromosomal DNA damage in cell under restricted conditions. Experiments are still in progress in order to elucidate the molecular basis for RAR processes. (author). 13 refs.; 2 figs., 1 tab

  10. Implementing Software Defined Radio

    CERN Document Server

    Grayver, Eugene

    2013-01-01

    Software Defined Radio makes wireless communications easier, more efficient, and more reliable. This book bridges the gap between academic research and practical implementation. When beginning a project, practicing engineers, technical managers, and graduate students can save countless hours by considering the concepts presented in these pages. The author covers the myriad options and trade-offs available when selecting an appropriate hardware architecture. As demonstrated here, the choice between hardware- and software-centric architecture can mean the difference between meeting an aggressive schedule and bogging down in endless design iterations. Because of the author’s experience overseeing dozens of failed and successful developments, he is able to present many real-life examples. Some of the key concepts covered are: Choosing the right architecture for the market – laboratory, military, or commercial Hardware platforms – FPGAs, GPPs, specialized and hybrid devices Standardization efforts to ens...

  11. Radio-adaptive response

    International Nuclear Information System (INIS)

    Ikushima, Takaji

    1991-01-01

    An adaptive response to radiation stress was found in cultured Chinese hamster V79 cells, as a suppressed induction of micronuclei (MNs) and sister chromatid exchanges (SCEs) in the cells conditioned by very low doses. The important characteristics of the novel chromosomal response, called radio-adaptive response (RAR), that have newly emerged in this study are: 1) Low doses of beta-rays from tritiated water (HTO) as well as tritiated thymidine can cause the RAR. 2) Thermal neutrons, a high LET radiation, can not act as tritium beta-rays or gamma-rays. 3) The RAR expression is suppressed by an inhibition of protein synthesis. 4) Several proteins are newly synthesized concurrently with the RAR expression after adapting doses, viewed by two-dimensional electrophoresis of cellular proteins. These results suggest that the RAR is an adaptive chromosomal DNA repair induced by very low doses of low LET radiations under restricted conditions, accompanying the inducible specific gene expression. (author)

  12. A turbulent radio jet

    International Nuclear Information System (INIS)

    Kahn, F.D.

    1983-01-01

    A relativistic plasma flow can explain many of the observations on the one-sided jets, which are associated with radio sources that show superluminal motions in their cores. The pressure from the ambient medium will communicate across the jet in a relatively short distance, typically 30 kpc. The friction between the jet and the external medium then makes the flow go turbulent. As a result the jet dissipates energy and will be brought to rest within a few hundred kpc, if it does not strike an obstacle before. The mean flow in the jet is strongly sheared and stretches the lines of force of any magnetic field frozen into the plasma. The dominant field direction, as seen from the rest frame of the plasma, is therefore parallel to the length of the jet. Polarization measurements have shown that this is in fact the case. (author)

  13. AGONIZAN RADIOS MINERAS

    Directory of Open Access Journals (Sweden)

    Raquel Salinas

    2015-01-01

    Full Text Available Se ofrece un amplio análisis sobre la industria electoral, recordando que un candidato a presidente es "un producto para la venta". Se Desmenuzan las estrategias utilizadas en el plebiscito chileno,las elecciones norteamericanas con el NO a BUSH. El Mercadeo Social es una nueva metodología utilizada en proyectos de desarrollo a nivel de campo por ello se hace un esclarecimiento y clarifica el vínculo con la comunicación. Se agrega temas como: Los modelos de recepción de mensajes cuyos marcos conceptuales y metodologías aún no se han adaptado al potencial de esta línea de trabajo.Se analiza la agonía de las radios mineras en Bolivia en la que 42 años de historia y heroísmo se desmoronan.

  14. Radio-isotopic tracers

    International Nuclear Information System (INIS)

    Wolfangel, R.G.

    1976-01-01

    The invention concerns the dispersions that may be used for preparing radio-isotopic tracers, technetium labelled dispersions, processes for preparing these dispersions and their use as tracers. Technetium 99m sulphur colloids are utilized as scintillation tracers to give a picture of the reticulo-endothelial system, particularly the liver and spleen. A dispersion is provided which only requires the addition of a radioactive nuclide to form a radioactively labelled dispersion that can be injected as a tracer. It is formed of a colloid of tin sulphur dispersed in an aqueous buffer solution. Such a reagent has the advantage of being safe and reliable and is easier to use. The colloid can be prepared more quickly since additions of several different reagents are avoided. There is no need to heat up and no sulphuretted hydrogen, which is a toxic gas, is used [fr

  15. Radio frequency picosecond phototube

    International Nuclear Information System (INIS)

    Margaryan, A.; Carlini, R.; Ent, R.; Grigoryan, N.; Gyunashyan, K.; Hashimoto, O.; Hovater, K.; Ispiryan, M.; Knyazyan, S.; Kross, B.; Majewski, S.; Marikyan, G.; Mkrtchyan, M.; Parlakyan, L.; Popov, V.; Tang, L.; Vardanyan, H.; Yan, C.; Zhamkochyan, S.; Zorn, C.

    2006-01-01

    We propose a photon detector for recording low-level and ultra-fast optical signals, based on radio frequency (RF) analysis of low-energy photoelectrons (PEs). By using currently developed 500 MHz RF deflector, it is possible to scan circularly and detect single PEs, amplified in multi-channel plates (MCPs). The operation of the tube is investigated by means of thermionic electron source. It is demonstrated that the signals generated in the MCP can be processed event by event; by using available nanosecond electronics and that time resolution better than 20 ps can be achieved. Timing characteristics of the Cherenkov detector with RF phototube in a 'head-on' geometry is investigated by means of Monte Carlo simulation

  16. Radio frequency picosecond phototube

    Energy Technology Data Exchange (ETDEWEB)

    Margaryan, A. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia)]. E-mail: mat@mail.yerphi.am; Carlini, R. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Ent, R. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Grigoryan, N. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Gyunashyan, K. [Yerevan State University of Architecture and Construction, Yerevan (Armenia); Hashimoto, O. [Tohoku University, Sendai 98-77 (Japan); Hovater, K. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Ispiryan, M. [University of Houston, 4800 Calhoun Rd, Houston TX 77204 (United States); Knyazyan, S. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Kross, B. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Majewski, S. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Marikyan, G. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Mkrtchyan, M. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Parlakyan, L. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Popov, V. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Tang, L. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Vardanyan, H. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Yan, C. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Zhamkochyan, S. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Zorn, C. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States)

    2006-10-15

    We propose a photon detector for recording low-level and ultra-fast optical signals, based on radio frequency (RF) analysis of low-energy photoelectrons (PEs). By using currently developed 500 MHz RF deflector, it is possible to scan circularly and detect single PEs, amplified in multi-channel plates (MCPs). The operation of the tube is investigated by means of thermionic electron source. It is demonstrated that the signals generated in the MCP can be processed event by event; by using available nanosecond electronics and that time resolution better than 20 ps can be achieved. Timing characteristics of the Cherenkov detector with RF phototube in a 'head-on' geometry is investigated by means of Monte Carlo simulation.

  17. Radio propagation measurement and channel modelling

    CERN Document Server

    Salous, Sana

    2013-01-01

    While there are numerous books describing modern wireless communication systems that contain overviews of radio propagation and radio channel modelling, there are none that contain detailed information on the design, implementation and calibration of radio channel measurement equipment, the planning of experiments and the in depth analysis of measured data. The book would begin with an explanation of the fundamentals of radio wave propagation and progress through a series of topics, including the measurement of radio channel characteristics, radio channel sounders, measurement strategies

  18. Magnetospheric radio sounding

    International Nuclear Information System (INIS)

    Ondoh, Tadanori; Nakamura, Yoshikatsu; Koseki, Teruo; Watanabe, Sigeaki; Murakami, Toshimitsu

    1977-01-01

    Radio sounding of the plasmapause from a geostationary satellite has been investigated to observe time variations of the plasmapause structure and effects of the plasma convection. In the equatorial plane, the plasmapause is located, on the average, at 4 R sub(E) (R sub(E); Earth radius), and the plasma density drops outwards from 10 2 -10 3 /cm 3 to 1-10/cm 3 in the plasmapause width of about 600 km. Plasmagrams showing a relation between the virtual range and sounding frequencies are computed by ray tracing of LF-VLF waves transmitted from a geostationary satellite, using model distributions of the electron density in the vicinity of the plasmapause. The general features of the plasmagrams are similar to the topside ionograms. The plasmagram has no penetration frequency such as f 0 F 2 , but the virtual range of the plasmagram increases rapidly with frequency above 100 kHz, since the distance between a satellite and wave reflection point increases rapidly with increasing the electron density inside the plasmapause. The plasmapause sounder on a geostationary satellite has been designed by taking account of an average propagation distance of 2 x 2.6 R sub(E) between a satellite (6.6 R sub(E)) and the plasmapause (4.0 R sub(E)), background noise, range resolution, power consumption, and receiver S/N of 10 dB. The 13-bit Barker coded pulses of baud length of 0.5 msec should be transmitted in direction parallel to the orbital plane at frequencies for 10 kHz-2MHz in a pulse interval of 0.5 sec. The transmitter peak power of 70 watts and 700 watts are required respectively in geomagnetically quiet and disturbed (strong nonthermal continuum emissions) conditions for a 400 meter cylindrical dipole of 1.2 cm diameter on the geostationary satellite. This technique will open new area of radio sounding in the magnetosphere. (auth.)

  19. A Radio Astronomy Science Education Partnership - GAVRT and Radio JOVE

    Science.gov (United States)

    Higgins, C. A.; Thieman, J. R.; Bunnell, K.; Soholt, G.

    2009-12-01

    The planet Jupiter provides an excellent subject to educate, engage, and inspire students and teachers to learn science. The Goldstone Apple-Valley Radio Telescope (GAVRT) program (http://www.lewiscenter.org/gavrt) and The Radio JOVE project (http://radiojove.gsfc.nasa.gov) each have a long history of allowing students and teachers to interact with scientists and real radio telescopes. The upcoming Juno mission to Jupiter (2011 launch) allows both GAVRT and Radio JOVE to combine efforts and engage with the NASA Juno mission, thus increasing the excitement and learning potential for teachers, students, and the general public. Teachers can attend workshops for training to operate a 34-meter radio telescope and/or build their own simple radio telescope, both of which can be used directly in the classroom. We will overview some classroom activities and highlight some teacher-student experiences. In addition, we will update our efforts on greater Web-based control of the radio telescopes, as well as highlight our upcoming workshops to allow better access for teachers in different parts of the Country.

  20. Una propuesta para medir la calidad de la atención hospitalaria usando información sobre mortalidad A proposal for quality assessment through mortality data

    Directory of Open Access Journals (Sweden)

    Esteban Puentes-Rosas

    2011-01-01

    Full Text Available OBJETIVO. Presentar la Razón Estandarizada de Mortalidad Intrahospitalaria (REMI como alternativa para medir la calidad de atención hospitalaria en México. MATERIAL Y MÉTODOS. Las fuentes de información fueron los registros de egresos hospitalarios del Instituto Mexicano del Seguro Social (IMSS, del Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado (ISSSTE y de la Secretaría de Salud en 2008. Mediante regresión logística se estimó la probabilidad de muerte intrahospitalaria controlando por sexo, edad, días de estancia y diagnóstico. La REMI es el resultado de dividir las muertes observadas entre la suma de las probabilidades estimadas para cada hospital. RESULTADOS. La REMI más baja correspondió a los hospitales del ISSSTE. Por entidad, los servicios con mejores resultados fueron los del ISSSTE en Veracruz, y los que tuvieron peor desempeño fueron los de la SS en Nayarit. CONCLUSIÓN. Los resultados obtenidos sugieren que la REMI puede constituirse como una alternativa adecuada para monitorear el desempeño de los hospitales en términos de la mortalidad observada.OBJECTIVE. To introduce the Hospital Standardized Mortality Ratio (HSMR as an alternative to assess the quality of hospital care in Mexico. MATERIAL AND METHODS. Data-sets of public hospital discharges were used as source of information. The analyses were based in a logistic model to estimate the risk of hospital death adjusting by sex, age, length of stay and main diagnosis. The HSMR is estimated dividing the observed deaths by the addition of the risk for each discharge by hospital. RESULTS. The ISSSTE had the lowest HSMR. At state level, the best figure was obtained by the hospitals of the ISSSTE in Veracruz, while the worst performance corresponds to hospitals of the SS in Nayarit. CONCLUSION. Our results suggest that this indicator can be used as a suitable alternative to evaluate the performance of hospitals in terms of mortality.

  1. Un método rápido y no-destructivo para medir la permeabilidad al aire del hormigón

    Directory of Open Access Journals (Sweden)

    Torrent, R. J.

    1999-06-01

    Full Text Available New device for non-destructive test. It is designed for "in situ" measurement of the impermeability to air of a concrete coating. The system is based on creating a vacuum inside a cell placed on its surface, and to measure how long does it take for the pressure to be back to the atmospheric value. The characteristic aspects of the method are: a cell with an inward chamber and a regulator to keep the pressure in balance inside this central chamber (measurement and in the surrounding chamber (preservation ring. This ensures a single air flow direction towards the central chamber, avoiding any spurious transversal flow. The data of the measurement are processed by a microprocessor that indicates the permeability coefficient value at the end of the test which lasts 2 to 12 minutes. Results on coatings of different quality obtained through this technique are presented, which show an excellent correlation with values obtained on specimens using Cembureau method for permeability to oxigen imperviousness.

    Se presenta un nuevo dispositivo de ensayo no destructivo, diseñado para la medición "in situ " de la permeabilidad al aire del recubrimiento de hormigón. Se basa en crear vacío dentro de una celda colocada sobre la superficie del mismo y en medir la velocidad con que la presión retorna al valor atmosférico. Aspectos característicos del método son: una celda con doble cámara y un regulador que equilibra la presión en la cámara central (de medicióny en la cámara exterior (anillo de guarda. Esto asegura un flujo unidireccional de aire hacia la cámara central, eliminando todo flujo espúreo transversal. Los datos de la medición son procesados por un microprocesador que indica el valor del coeficiente de permeabilidad al finalizar el ensayo, que dura de 2 a 12 minutos. Se presentan resultados obtenidos con esta técnica sobre recubrimientos de distinta calidad, que muestran una excelente correlación con los valores obtenidos

  2. South African Radio League Introduction to Amateur Radio: A study guide for the Radio Amateur Examination

    CSIR Research Space (South Africa)

    Burger, Chris

    2016-01-01

    Full Text Available ) .............................................................................. 15 1.12 The Radio Amateurs’ Examination .......................................................................... 15 1.13 Restrictions on the Use of an Amateur Radio Station .............................................. 16 Chapter 2: Operating... ............................................................................................. 116 14.1 Theory of Operation ............................................................................................... 116 14.2 Turns Ratio...

  3. Radio Astronomy Explorer /RAE/. I - Observations of terrestrial radio noise.

    Science.gov (United States)

    Herman, J. R.; Caruso, J. A.; Stone, R. G.

    1973-01-01

    Radio Astronomy Explorer (RAE) I data are analyzed to establish characteristics of HF terrestrial radio noise at an altitude of about 6000 km. Time and frequency variations in amplitude of the observed noise well above cosmic noise background are explained on the basis of temporal and spatial variations in ionospheric critical frequency coupled with those in noise source distributions. It is shown that terrestrial radio noise regularly breaks through the ionosphere and reaches RAE with magnitudes 15 dB and more above cosmic noise background, on frequencies above the F-layer critical frequency.

  4. Orbital free molecular dynamics; Approche sans orbitale des plasmas denses

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, F

    2007-08-15

    The microscopic properties of hot and dense plasmas stay a field essentially studied thanks to classical theories like the One Component Plasma, models which rely on free parameters, particularly ionization. In order to investigate these systems, we have used, in this PhD work, a semi-classical model, without free parameters, that is based on coupling consistently classical molecular dynamics for the nuclei and orbital free density functional theory for the electrons. The electronic fluid is represented by a free energy entirely determined by the local density. This approximation was validated by a comparison with an ab initio technique, quantum molecular dynamics. This one is identical to the previous except for the description of the free energy that depends on a quantum-independent-particle model. Orbital free molecular dynamics was then used to compute equation of state of boron and iron plasmas in the hot and dense regime. Furthermore, comparisons with classical theories were performed on structural and dynamical properties. Finally, equation of state and transport coefficients mixing laws were studied by direct simulation of a plasma composed of deuterium and copper. (author)

  5. X rays from radio binaries

    International Nuclear Information System (INIS)

    Apparao, K.M.V.

    1977-01-01

    Reference is made to the radio binary systems CC Cas, AR Lac, β Per (Algol), β Lyr, b Per and Cyg X-1. It is stated that a thermal interpretation of the radiation from Algol requires a much larger x-ray flux than the observed value of 3.8 x 10 -11 erg/cm 2 /sec/keV in the 2 to 6 keV energy range. Observations of some non-thermal flares, together with the small size of the radio source in Algol, indicate that the radio emission is non-thermal in nature. The radio emission is interpreted as synchrotron radiation and it is suggested that the observed x-ray emission is due to inverse Compton scattering of the light of the primary star by the radio electrons. The x-ray emission from other radio binaries is also calculated using this model. The energy for the radio electrons can arise from annihilation of magnetic lines connecting the binary stars, twisted by the rotation of the stars. (U.K.)

  6. 75 FR 10439 - Cognitive Radio Technologies and Software Defined Radios

    Science.gov (United States)

    2010-03-08

    ... petition could not through the exercise of due diligence have learned of the facts in question prior to... to a wide variety of radio services, including safety-of-life services--the Commission holds the...

  7. radio frequency based radio frequency based water level monitor

    African Journals Online (AJOL)

    eobe

    ABSTRACT. This paper elucidates a radio frequency (RF) based transmission and reception system used to remotely monitor and .... range the wireless can cover but in this prototype, it ... power supply to the system, the sensed water level is.

  8. Introduction to solar radio astronomy and radio physics

    International Nuclear Information System (INIS)

    Krueger, A.

    1979-01-01

    A systematic summary is presented of the work done during the last thirty years in the field of solar radio astronomy from the standpoint of general solar physics. Instrumental aspects, observations and theory are covered. A brief introduction is given to the matter consisting of the history of solar radio astronomy and some fundamentals of astronomy and solar physics are outlined. Some topics of the instrumental background of solar radio astronomy and the main results of observations are presented. The elements of a theoretical interpretation of solar radio observations are reported and a synthesis of both observation and theory contributing to a general picture of solar and solar-terrestrial physics is outlined. (C.F./Auth)

  9. Introduction to international radio regulations

    Energy Technology Data Exchange (ETDEWEB)

    Struzak, R

    2003-12-15

    These notes introduce the ITU Radio Regulations and related UN and WTO agreements that specify how terrestrial and satellite radio should be used in all countries over the planet. Access to the existing information infrastructure, and to that of the future Information Society, depends critically on these regulations. The paper also discusses few problems related to the use of the radio frequencies and satellite orbits. The notes are extracted from a book under preparation, in which these issues are discussed in more detail. (author)

  10. Introduction to international radio regulations

    International Nuclear Information System (INIS)

    Struzak, R.

    2003-01-01

    These notes introduce the ITU Radio Regulations and related UN and WTO agreements that specify how terrestrial and satellite radio should be used in all countries over the planet. Access to the existing information infrastructure, and to that of the future Information Society, depends critically on these regulations. The paper also discusses few problems related to the use of the radio frequencies and satellite orbits. The notes are extracted from a book under preparation, in which these issues are discussed in more detail. (author)

  11. Magnetogasdynamics of double radio sources

    International Nuclear Information System (INIS)

    Nepveu, M.

    1979-01-01

    The magnetogasdynamical behaviour of plasmoids moving through an ambient gas is investigated numerically with a two-dimensional code, based on the SHASTA scheme. The astrophysical importance of this study lies in the observed extended extragalactic radio sources. It is assumed that plasma clouds with cylinder symmetry are ejected from the nucleus of a galaxy. Their large-scale evolution in the intergalactic medium (IGM) is followed. The gas dynamics of an ejected cloud, the magnetogasdynamics of ejected clouds, the Christiansen-Pacholczyk-Scott picture for radio galaxies and the shear layers in double radio sources are studied. (Auth.)

  12. Shoestring Budget Radio Astronomy (Abstract)

    Science.gov (United States)

    Hoot, J. E.

    2017-12-01

    (Abstract only) The commercial exploitation of microwave frequencies for cellular, WiFi, Bluetooth, HDTV, and satellite digital media transmission has brought down the cost of the components required to build an effective radio telescope to the point where, for the cost of a good eyepiece, you can construct and operate a radio telescope. This paper sets forth a family of designs for 1421 MHz telescopes. It also proposes a method by which operators of such instruments can aggregate and archive data via the Internet. With 90 or so instruments it will be possible to survey the entire radio sky for transients with a 24 hour cadence.

  13. Adaptación y validación de un cuestionario para medir la satisfacción del tratamiento de fisioterapia en atención primaria

    OpenAIRE

    Escatllar González, Marta

    2017-01-01

    Introducción: Analizar la satisfacción de los pacientes con un instrumento de medición, permite conocer la percepción y los resultados de una intervención sanitaria, considerada como un requisito indispensable de los programas de evaluación y mejora de la calidad. Hipótesis: Las pruebas psicométricas de la medición del nuevo cuestionario traducido al español, demostrarán que es un instrumento fiable y válido para medir la satisfacción de los pacientes que reciben tratamiento de fisioterap...

  14. The excess radio background and fast radio transients

    International Nuclear Information System (INIS)

    Kehayias, John; Kephart, Thomas W.; Weiler, Thomas J.

    2015-01-01

    In the last few years ARCADE 2, combined with older experiments, has detected an additional radio background, measured as a temperature and ranging in frequency from 22 MHz to 10 GHz, not accounted for by known radio sources and the cosmic microwave background. One type of source which has not been considered in the radio background is that of fast transients (those with event times much less than the observing time). We present a simple estimate, and a more detailed calculation, for the contribution of radio transients to the diffuse background. As a timely example, we estimate the contribution from the recently-discovered fast radio bursts (FRBs). Although their contribution is likely 6 or 7 orders of magnitude too small (though there are large uncertainties in FRB parameters) to account for the ARCADE 2 excess, our development is general and so can be applied to any fast transient sources, discovered or yet to be discovered. We estimate parameter values necessary for transient sources to noticeably contribute to the radio background

  15. Radio frequency integrated circuit design for cognitive radio systems

    CERN Document Server

    Fahim, Amr

    2015-01-01

    This book fills a disconnect in the literature between Cognitive Radio systems and a detailed account of the circuit implementation and architectures required to implement such systems.  Throughout the book, requirements and constraints imposed by cognitive radio systems are emphasized when discussing the circuit implementation details.  In addition, this book details several novel concepts that advance state-of-the-art cognitive radio systems.  This is a valuable reference for anybody with background in analog and radio frequency (RF) integrated circuit design, needing to learn more about integrated circuits requirements and implementation for cognitive radio systems. ·         Describes in detail cognitive radio systems, as well as the circuit implementation and architectures required to implement them; ·         Serves as an excellent reference to state-of-the-art wideband transceiver design; ·         Emphasizes practical requirements and constraints imposed by cognitive radi...

  16. A radio and optical study of Molonglo radio sources

    Science.gov (United States)

    Ishwara-Chandra, C. H.; Saikia, D. J.; McCarthy, P. J.; van Breugel, W. J. M.

    2001-05-01

    We present multi-wavelength radio observations with the Very Large Array, and narrow- and broad-band optical observations with the 2.5-m telescope at the Las Campanas Observatory, of a well-defined sample of high-luminosity Fanaroff-Riley class II radio galaxies and quasars, selected from the Molonglo Reference Catalogue 1-Jy sample. These observations were carried out as part of a programme to investigate the effects of orientation and environment on some of the observed properties of these sources. We examine the dependence of the Liu-Pooley relationship, which shows that radio lobes with flatter radio spectra are less depolarized, on size, identification and redshift, and show that it is significantly stronger for smaller sources, with the strength of the relationship being similar for both radio galaxies and quasars. In addition to Doppler effects, there appear to be intrinsic differences between the lobes on opposite sides. We discuss the asymmetry in brightness and location of the hotspots, and present estimates of the ages and velocities from matched-resolution observations in the L and C bands. Narrow- and broad-band optical images of some of these sources were made to study their environments and correlate with the symmetry parameters. An extended emission-line region is seen in a quasar, and in four of the objects possible companion galaxies are seen close to the radio axis.

  17. Radio-adaptive response

    International Nuclear Information System (INIS)

    Ikushima, T.

    1992-01-01

    An adaptive response to radiation stress was found as a suppressed induction of chromosomal damage including micronuclei and sister chromatid exchanges in cultured Chinese hamster V79 cells pre-exposed to very low doses of ionizing radiations. The mechanism underlying this novel chromosomal response, called 'radio-adaptive response (RAR)' has been studied progressively. The following results were obtained in recent experiments. 1. Low doses of β-rays from tritiated water (HTO) as well as tritium-thymidine can cause RAR. 2. Thermal neutrons, a high LET radiation, can not act as tritium β-rays or γ-rays. 3. The RAR expression is suppressed not only by the treatment with an inhibitor of protein synthesis but also by RNA synthesis inhibition. 4. Several proteins are newly synthesized concurrently with the RAR expression after the adapting doses, viewed by two-dimensional electrophoresis of cellular proteins. These results suggests that the RAR might be a cellular stress response to a signal produced preferentially by very low doses of low LET radiation under restricted conditions, accompany the inducible specific gene expression. (author)

  18. Beamsteerable GNSS Radio Occultation ASIC

    Data.gov (United States)

    National Aeronautics and Space Administration — We will develop an integrated RF ASIC to enable high quality radio occultation (RO) weather observations using the Global Navigations System Satellite (GNSS)...

  19. Sea Turtle Radio Telemetry Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Radio transmitters attached to sea turtles captured in various fishing gear enabled us to track and measure surfacing time of each turtle. Determining location of...

  20. Zero-Power Radio Device.

    Energy Technology Data Exchange (ETDEWEB)

    Brocato, Robert W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2018-02-01

    This report describes an unpowered radio receiver capable of detecting and responding to weak signals transmit ted from comparatively long distances . This radio receiver offers key advantages over a short range zero - power radio receiver previously described in SAND2004 - 4610, A Zero - Power Radio Receiver . The device described here can be fabricated as an integrated circuit for use in portable wireless devices, as a wake - up circuit, or a s a stand - alone receiver operating in conjunction with identification decoders or other electroni cs. It builds on key sub - components developed at Sandia National Laboratories over many years. It uses surface acoustic wave (SAW) filter technology. It uses custom component design to enable the efficient use of small aperture antennas. This device uses a key component, the pyroelectric demodulator , covered by Sandia owned U.S. Patent 7397301, Pyroelectric Demodulating Detector [1] . This device is also described in Sandia owned U.S. Patent 97266446, Zero Power Receiver [2].

  1. On the evaluation of Web Radio

    OpenAIRE

    Field, A.N.; Hartel, Pieter H.

    2001-01-01

    We develop an evaluation method for Web radio, and perform it to see what we can be learnt about seven prominent Web radio sites. We also evaluate a commercial FM radio station for control purposes. We present a taxonomy of Web radio, and we give our observations and conclusions on this evaluation.

  2. Radio and line transmission 2

    CERN Document Server

    Roddy, Dermot

    2013-01-01

    Radio and Line Transmission, Volume 2 gives a detailed treatment of the subject as well as an introduction to additional advanced subject matter. Organized into 14 chapters, this book begins by explaining the radio wave propagation, signal frequencies, and bandwidth. Subsequent chapters describe the transmission lines and cables; the aerials; tuned and coupled circuits; bipolar transistor amplifiers; field-effect transistors and circuits; thermionic valve amplifiers; LC oscillators; the diode detectors and modulators; and the superheterodyne receiver. Other chapters explore noise and interfere

  3. Historic Radio Astronomy Working Group

    Science.gov (United States)

    2007-06-01

    This special issue of Astronomische Nachrichten contains the proceedings of a session of the Historic Radio Astronomy Working Group of the International Astronomical Union that took place during the 26th General Assembly of the IAU in Prague on 17th August 2006. In addition to the talks presented in Prague some contributions were solicited to give a more complete overview of `The Early History of European Radio Astronomy'.

  4. Radio astronomy on the moon

    International Nuclear Information System (INIS)

    Burns, J.O.; Asbell, J.

    1987-01-01

    The advantages and opportunities for radio astronomy on the moon during the early to mid 21st century are reviewed. In particular, it is argued that the lack of atmosphere, the extremely low seismic activity, the low RF background, and the natural cryogenic environment make the moon (particularly the far side and the poles) a nearly ideal locale for submillimeter/FIR to VLF (below 10 MHz) radio astronomy. 22 references

  5. RADIO NOISE ADVANCES SEXUAL MATURITY

    African Journals Online (AJOL)

    ansistf-lewis

    Mean age at first egg for the radio birds (143 d) was 13 d significantly earlier than controls, but body weight at ... the first 8 h of a 12-h photoperiod with radio noise, to leave only 4 h of light (4L:20D), supported rates of lay ... Age (AFE) and body weight at, and weight of, first egg were recorded for individual birds, and, after a.

  6. RADIO WITHOUT A LISTENER: "MAYAK"

    Directory of Open Access Journals (Sweden)

    Bysko Maxim V.

    2017-12-01

    Full Text Available The singularity of this article is that it is entirely based on a critical analysis of only one live musical radio program on the Mayak radio station and dedicated to the life and work of the famous British composer Andrew Lloyd Webber. In principle, the article can be considered a scientific review of the media product. Based on his analysis, the author comes to the paradoxical conclusion that the presence of a listener becomes unnecessary for modern broadcasting. This is stated by many principles of the conduct of the air, presented in the radio program, where all the information load is placed on the guest in the studio, where there is no preparatory work of the DJs, where their inability to navigate the genres of journalism violates communication norms and colloquial ethics, where an obvious deconstructive approach to the material offered for the listener. In addition, the phenomenon of being the DJs in the radio studio exclusively "for themselves" is emphasized by the sound design of the radio program, which runs counter to the logic of auditory perception (for example, the sequence of jingles, as well as the incompetent selection of musical material, which undoubtedly repels professional radio listeners-musicians.

  7. The development of a scale to measure concepts of schizophrenia: experience among Brazilian psychiatrists Desenvolvimento de escala para medir conceitos de esquizofrenia: experiência entre psiquiatras brasileiros

    Directory of Open Access Journals (Sweden)

    Darci N. Santos

    1998-06-01

    Bleulerian sub-scale limits confidence in the whole scale but on the other hand this questionnaire contributes to the understanding of the controversy over Bleulerian and Schneiderian models for conceptualisation of schizophrenia, the former requiring more inference and therefore being prone to unreliability.INTRODUÇÃO: Foi desenvolvida uma escala para medir aderência ao conceito Bleuleriano e Schneideriano de esquizofrenia entre psiquiatras trabalhando em São Paulo, analisando relações entre variáveis sociodemográficas e de formação sobre o escore obtido. MÉTODOS: Questionário contendo escala visual analógica com dezessete enunciados sobre conceitos Schneideriano e Bleuleriano de esquizofrenia, foi distribuído para 150 psiquiatras. As sub-escalas Bleuleriana e Schneideriana foram avaliadas por metódos psicométricos de consistência interna, estrutura das subescalas e confiabilidade test- reteste. RESULTADOS: Completaram o questionário 117 psiquiatras. A subescala Schneideriana demonstrou melhor consistência interna e melhores coeficientes de correlação intraclasse. Não houve associação negativa entre os escores das subescalas. Discordância com o conceito Bleuleriano predominou entre profissionais treinados na USP. CONCLUSÕES: A baixa confiabilidade da sub-escala Bleuleriana limita a confiabilidade do instrumento como um todo, embora contribua para a discussão dos modelos em questão. Argumenta-se que o modelo Bleuleriano, por exigir maior inferência, torna-se propenso a baixa confiabilidade.

  8. The radio properties of infrared-faint radio sources

    Science.gov (United States)

    Middelberg, E.; Norris, R. P.; Hales, C. A.; Seymour, N.; Johnston-Hollitt, M.; Huynh, M. T.; Lenc, E.; Mao, M. Y.

    2011-02-01

    Context. Infrared-faint radio sources (IFRS) are objects that have flux densities of several mJy at 1.4 GHz, but that are invisible at 3.6 μm when using sensitive Spitzer observations with μJy sensitivities. Their nature is unclear and difficult to investigate since they are only visible in the radio. Aims: High-resolution radio images and comprehensive spectral coverage can yield constraints on the emission mechanisms of IFRS and can give hints to similarities with known objects. Methods: We imaged a sample of 17 IFRS at 4.8 GHz and 8.6 GHz with the Australia Telescope Compact Array to determine the structures on arcsecond scales. We added radio data from other observing projects and from the literature to obtain broad-band radio spectra. Results: We find that the sources in our sample are either resolved out at the higher frequencies or are compact at resolutions of a few arcsec, which implies that they are smaller than a typical galaxy. The spectra of IFRS are remarkably steep, with a median spectral index of -1.4 and a prominent lack of spectral indices larger than -0.7. We also find that, given the IR non-detections, the ratio of 1.4 GHz flux density to 3.6 μm flux density is very high, and this puts them into the same regime as high-redshift radio galaxies. Conclusions: The evidence that IFRS are predominantly high-redshift sources driven by active galactic nuclei (AGN) is strong, even though not all IFRS may be caused by the same phenomenon. Compared to the rare and painstakingly collected high-redshift radio galaxies, IFRS appear to be much more abundant, but less luminous, AGN-driven galaxies at similar cosmological distances.

  9. Information Content in Radio Waves: Student Investigations in Radio Science

    Science.gov (United States)

    Jacobs, K.; Scaduto, T.

    2013-12-01

    We describe an inquiry-based instructional unit on information content in radio waves, created in the summer of 2013 as part of a MIT Haystack Observatory (Westford, MA) NSF Research Experiences for Teachers (RET) program. This topic is current and highly relevant, addressing science and technical aspects from radio astronomy, geodesy, and atmospheric research areas as well as Next Generation Science Standards (NGSS). Projects and activities range from simple classroom demonstrations and group investigations, to long term research projects incorporating data acquisition from both student-built instrumentation as well as online databases. Each of the core lessons is applied to one of the primary research centers at Haystack through an inquiry project that builds on previously developed units through the MIT Haystack RET program. In radio astronomy, students investigate the application of a simple and inexpensive software defined radio chip (RTL-SDR) for use in systems implementing a small and very small radio telescope (SRT and VSRT). Both of these systems allow students to explore fundamental principles of radio waves and interferometry as applied to radio astronomy. In ionospheric research, students track solar storms from the initial coronal mass ejection (using Solar Dynamics Observatory images) to the resulting variability in total electron density concentrations using data from the community standard Madrigal distributed database system maintained by MIT Haystack. Finally, students get to explore very long-baseline interferometry as it is used in geodetic studies by measuring crustal plate displacements over time. Alignment to NextGen standards is provided for each lesson and activity with emphasis on HS-PS4 'Waves and Their Applications in Technologies for Information Transfer'.

  10. Adaptación transcultural de la escala para medir autoeficacia en el uso del condón masculino Cross cultural adaptation of condom uses self-efficacy scale

    Directory of Open Access Journals (Sweden)

    Abdul Hernández Cortina

    2011-09-01

    Full Text Available Objetivo principal: adaptar culturalmente la escala para medir autoeficacia en el uso del condón masculino, determinando su fiabilidad y validez para la investigación en el contexto cubano. Metodología: diseño transversal con metodología exploratoria en una muestra de 38 estudiantes de enfermería entre 17 y 42 años de edad. Resultados: el Alpha Cronbach para la escala total fue de 0,78 y el Índice de Correlación Interclase fue de 0,73. Conclusiones: la escala es confiable y válida para medir el uso del condón masculino en el contexto cubano.Objective: The purpose of this manuscript is to evaluate a Spanish version of the Condom Uses Self Efficacy Scale, and to determine its reliability and validity for use in cross-cultural research among Cuban populations. Methods: A cross- sectional design an exploratory survey methodology was used in 38 nursing students between 17 and 41 years old. Results: The Alpha Coefficient for the total scale was 0,78. The interclass correlation coefficient to measure scale's stability over time was 0,73 (test-retest two weeks. Conclusions: Findings support that Condom Use Self Efficacy Scale is a reliable and valid scale in measuring condom self-efficacy among Cuban persons.

  11. Radio Frequency Interference Site Survey for Thai Radio Telescopes

    Science.gov (United States)

    Jaroenjittichai, P.; Punyawarin, S.; Singwong, D.; Somboonpon, P.; Prasert, N.; Bandudej, K.; Kempet, P.; Leckngam, A.; Poshyachinda, S.; Soonthornthum, B.; Kramer, B.

    2017-09-01

    Radio astronomical observations have increasingly been threaten by the march of today telecommunication and wireless technology. Performance of radio telescopes lies within the fact that astronomical sources are extremely weak. National Astronomy Research Institute of Thailand (NARIT) has initiated a 5-year project, known as the Radio Astronomy Network and Geodesy for Development (RANGD), which includes the establishment of 40-meter and 13-meter radio telescopes. Possible locations have been narrowed down to three candidates, situated in the Northern part of Thailand, where the atmosphere is sufficiently dry and suitable for 22 and 43 GHz observations. The Radio Frequency Interference (RFI) measurements were carried out with a DC spectrum analyzer and directional antennas at 1.5 meter above ground, from 20 MHz to 6 GHz with full azimuth coverage. The data from a 3-minute pointing were recorded for both horizontal and vertical polarizations, in maxhold and average modes. The results, for which we used to make preliminary site selection, show signals from typical broadcast and telecommunication services and aeronautics applications. The signal intensity varies accordingly to the presence of nearby population and topography of the region.

  12. IA-Regional-Radio - Social Network for Radio Recommendation

    Science.gov (United States)

    Dziczkowski, Grzegorz; Bougueroua, Lamine; Wegrzyn-Wolska, Katarzyna

    This chapter describes the functions of a system proposed for the music hit recommendation from social network data base. This system carries out the automatic collection, evaluation and rating of music reviewers and the possibility for listeners to rate musical hits and recommendations deduced from auditor's profiles in the form of regional Internet radio. First, the system searches and retrieves probable music reviews from the Internet. Subsequently, the system carries out an evaluation and rating of those reviews. From this list of music hits, the system directly allows notation from our application. Finally, the system automatically creates the record list diffused each day depending on the region, the year season, the day hours and the age of listeners. Our system uses linguistics and statistic methods for classifying music opinions and data mining techniques for recommendation part needed for recorded list creation. The principal task is the creation of popular intelligent radio adaptive on auditor's age and region - IA-Regional-Radio.

  13. RADIO VARIABILITY IN SEYFERT NUCLEI

    International Nuclear Information System (INIS)

    Mundell, C. G.; Ferruit, P.; Nagar, N.; Wilson, A. S.

    2009-01-01

    Comparison of 8.4 GHz radio images of a sample of eleven, early-type Seyfert galaxies with previous observations reveals possible variation in the nuclear radio flux density in five of them over a seven year period. Four Seyferts (NGC 2110, NGC 3081, MCG -6-30-15, and NGC 5273) show a decline in their 8.4 GHz nuclear flux density between 1992 and 1999, while one (NGC 4117) shows an increase; the flux densities of the remaining six Seyferts (Mrk 607, NGC 1386, Mrk 620, NGC 3516, NGC 4968, and NGC 7465) have remained constant over this period. New images of MCG -5-23-16 are also presented. We find no correlation between radio variability and nuclear radio luminosity or Seyfert nuclear type, although the sample is small and dominated by type 2 Seyferts. Instead, a possible correlation between the presence of nuclear radio variability and the absence of hundred parsec-scale radio emission is seen, with four out of five marginally resolved or unresolved nuclei showing a change in nuclear flux density, while five out of six extended sources show no nuclear variability despite having unresolved nuclear sources. NGC 2110 is the only source in our sample with significant extended radio structure and strong nuclear variability (∼38% decline in nuclear flux density over seven years). The observed nuclear flux variability indicates significant changes are likely to have occurred in the structure of the nucleus on scales smaller than the VLA beam size (i.e., within the central ∼0.''1 (15 pc)), between the two epochs, possibly due to the appearance and fading of new components or shocks in the jet, consistent with previous detection of subparsec-scale nuclear structure in this Seyfert. Our results suggest that all Seyferts may exhibit variation in their nuclear radio flux density at 8.4 GHz, but that variability is more easily recognized in compact sources in which emission from the variable nucleus is not diluted by unresolved, constant flux density radio jet emission

  14. Radio science investigations with Voyager

    International Nuclear Information System (INIS)

    Eshleman, V.R.; Tyler, G.L.; Croft, T.A.

    1977-01-01

    The planned radio science investigations during the Voyager missions to the outer planets involve: (1) the use of the radio links to and from the spacecraft for occultation measurements of planetary and satellite atmospheres and ionospheres, the rings of Saturn, the solar corona, and the general-relativistic time delay for radiowave propagation through the Sun's gravity field; (2) radio link measurements of true or apparent spacecraft motion caused by the gravity fields of the planets, the masses of their larger satellites, and characteristics of the interplanetary medium; and (3) related measurements which could provide results in other areas, including the possible detection of long-wavelength gravitational radiation propagating through the Solar System. The measurements will be used to study: atmospheric and ionospheric structure, constituents, and dynamics; the sizes, radial distribution, total mass, and other characteristics of the particles in the rings of Saturn; interior models for the major planets and the mean density and bulk composition of a number of their satellites; the plasma density and dynamics of the solar corona and interplanetary medium; and certain fundamental questions involving gravitation and relativity. The instrumentation for these experiments is the same ground-based and spacecraft radio systems as will be used for tracking and communicating with the Voyager spacecraft, although several important features of these systems have been provided primarily for the radio science investigations. (Auth.)

  15. Observations of radio sources or 'What happened to radio stars?'

    International Nuclear Information System (INIS)

    Conway, R.G.

    1988-01-01

    A review is given of the early history of the interpretation of the radiation mechanisms following the discovery of the discrete radio sources, both galactic and extragalactic. The conflicting views which prevailed in the early fifties are discussed in some detail: some advocated thermal radiation from stars relatively close by, and others proposed the alternative that synchrotron radiation was responsible for the majority of the radio sources. Attention is drawn to the importance of high-resolution interferometry, whereby the structure of many of the sources could be obtained. Red-shift measurements and spectral distributions also played a part in determining distances and flux strengths at the sources. (U.K.)

  16. Radio Context Awareness and Applications

    Directory of Open Access Journals (Sweden)

    Luca Reggiani

    2013-01-01

    Full Text Available The context refers to “any information that can be used to characterize the situation of an entity, where an entity can be a person, place, or physical object.” Radio context awareness is defined as the ability of detecting and estimating a system state or parameter, either globally or concerning one of its components, in a radio system for enhancing performance at the physical, network, or application layers. In this paper, we review the fundamentals of context awareness and the recent advances in the main radio techniques that increase the context awareness and smartness, posing challenges and renewed opportunities to added-value applications in the context of the next generation of wireless networks.

  17. Modular Software-Defined Radio

    Directory of Open Access Journals (Sweden)

    Rhiemeier Arnd-Ragnar

    2005-01-01

    Full Text Available In view of the technical and commercial boundary conditions for software-defined radio (SDR, it is suggestive to reconsider the concept anew from an unconventional point of view. The organizational principles of signal processing (rather than the signal processing algorithms themselves are the main focus of this work on modular software-defined radio. Modularity and flexibility are just two key characteristics of the SDR environment which extend smoothly into the modeling of hardware and software. In particular, the proposed model of signal processing software includes irregular, connected, directed, acyclic graphs with random node weights and random edges. Several approaches for mapping such software to a given hardware are discussed. Taking into account previous findings as well as new results from system simulations presented here, the paper finally concludes with the utility of pipelining as a general design guideline for modular software-defined radio.

  18. Unseen cosmos the universe in radio

    CERN Document Server

    Graham-Smith, Francis

    2013-01-01

    Radio telescopes have transformed our understanding of the Universe. Pulsars, quasars, Big Bang cosmology: all are discoveries of the new science of radio astronomy. Here, Francis Graham-Smith describes the birth, development, and maturity of radio astronomy, from the first discovery of cosmic radio waves to its present role as a major part of modern astronomy. Radio is part of the electromagnetic spectrum, covering infra-red, visible light, ultraviolet, X-rays, and gamma-rays, and Graham-Smith explains why it is that radio waves give us a unique view of the Universe. Tracing the development o

  19. Reconfigurable radio systems network architectures and standards

    CERN Document Server

    Iacobucci, Maria Stella

    2013-01-01

    This timely book provides a standards-based view of the development, evolution, techniques and potential future scenarios for the deployment of reconfigurable radio systems.  After an introduction to radiomobile and radio systems deployed in the access network, the book describes cognitive radio concepts and capabilities, which are the basis for reconfigurable radio systems.  The self-organizing network features introduced in 3GPP standards are discussed and IEEE 802.22, the first standard based on cognitive radio, is described. Then the ETSI reconfigurable radio systems functional ar

  20. Miniature EVA Software Defined Radio

    Science.gov (United States)

    Pozhidaev, Aleksey

    2012-01-01

    As NASA embarks upon developing the Next-Generation Extra Vehicular Activity (EVA) Radio for deep space exploration, the demands on EVA battery life will substantially increase. The number of modes and frequency bands required will continue to grow in order to enable efficient and complex multi-mode operations including communications, navigation, and tracking applications. Whether conducting astronaut excursions, communicating to soldiers, or first responders responding to emergency hazards, NASA has developed an innovative, affordable, miniaturized, power-efficient software defined radio that offers unprecedented power-efficient flexibility. This lightweight, programmable, S-band, multi-service, frequency- agile EVA software defined radio (SDR) supports data, telemetry, voice, and both standard and high-definition video. Features include a modular design, an easily scalable architecture, and the EVA SDR allows for both stationary and mobile battery powered handheld operations. Currently, the radio is equipped with an S-band RF section. However, its scalable architecture can accommodate multiple RF sections simultaneously to cover multiple frequency bands. The EVA SDR also supports multiple network protocols. It currently implements a Hybrid Mesh Network based on the 802.11s open standard protocol. The radio targets RF channel data rates up to 20 Mbps and can be equipped with a real-time operating system (RTOS) that can be switched off for power-aware applications. The EVA SDR's modular design permits implementation of the same hardware at all Network Nodes concept. This approach assures the portability of the same software into any radio in the system. It also brings several benefits to the entire system including reducing system maintenance, system complexity, and development cost.

  1. Radio-opaque dental compositions

    International Nuclear Information System (INIS)

    Temin, S.C.

    1979-01-01

    Thorium oxide or tantalum oxide, or combinations thereof are used as the x-ray material for radio-opaque filler compositions having particular applicability in dental restorative compositions. The filler compositions contain from about 3% by weight to about 10% by weight, based on the total filler composition, of the x-ray absorbing materials and the remainder being conventional particulate glass or silica, quarts or ceramic filler material. The radio opaque filler compositions are insoluble and non-leachable in alkaline, acidic or neutral aqueous environments, are essentially non-toxic, are either essentially colorless or translucent, and are compatible with acrylic monomers and other polymerizable binder systems

  2. Synthesis imaging in radio astronomy

    International Nuclear Information System (INIS)

    Perley, R.A.; Schwab, F.R.; Bridle, A.H.

    1989-01-01

    Recent advances in techniques and instrumentation for radio synthesis imaging in astronomy are discussed in a collection of review essays. Topics addressed include coherence in radio astronomy, the interferometer in practice, primary antenna elements, cross correlators, calibration and editing, sensitivity, deconvolution, self-calibration, error recognition, and image analysis. Consideration is given to wide-field imaging (bandwidth and time-average smearing, noncoplanar arrays, and mosaicking), high-dynamic-range imaging, spectral-line imaging, VLBI, solar imaging with a synthesis telescope, synthesis imaging of spatially coherent objects, noise in images of very bright sources, synthesis observing strategies, and the design of aperture-synthesis arrays

  3. New discoveries with radio telescopes

    International Nuclear Information System (INIS)

    Schmidt, J.

    1985-01-01

    The author describes in a simple fashion the results obtained by astronomers from ETH Zurich using the broadband 7-m radio telescope in Switzerland to observe the sun over a period of six years. He explains the results in terms of our present understanding of the sun's workings. The astronomers found that a solar eruption is not a single event but consists of tens of thousands of small eruptions or spikes each only 200 km high and producing a burst of radio waves 10-100 times as intense as the background. (T.J.R.A.)

  4. Origin of solar radio waves

    International Nuclear Information System (INIS)

    Olmr, J.

    1977-01-01

    Solar radiowave radiation amounts to about 10 -7 of the total solar radiation. The solar atmosphere emits radiation of different wavelengths from a fraction of nanometer to kilometer waves. The solar radiowaves are of thermal origin and except for neutral hydrogen emission and solid body radio emission their emission always results from free electrons. The radiowave radiation active components were classified in several types, such as noise storms, flashes, flares, continuum, and flashes lasting for several minutes. The respective types are discussed and their origins shown. The mechanisms are described permitting the formation of radio waves of nonthermal origin, i.e., plasma oscillations, gyromagnetic emission, synchrotron and Cherenkov radiations. (J.P.)

  5. Intelligent Cognitive Radio Models for Enhancing Future Radio Astronomy Observations

    Directory of Open Access Journals (Sweden)

    Ayodele Abiola Periola

    2016-01-01

    Full Text Available Radio astronomy organisations desire to optimise the terrestrial radio astronomy observations by mitigating against interference and enhancing angular resolution. Ground telescopes (GTs experience interference from intersatellite links (ISLs. Astronomy source radio signals received by GTs are analysed at the high performance computing (HPC infrastructure. Furthermore, observation limitation conditions prevent GTs from conducting radio astronomy observations all the time, thereby causing low HPC utilisation. This paper proposes mechanisms that protect GTs from ISL interference without permanent prevention of ISL data transmission and enhance angular resolution. The ISL transmits data by taking advantage of similarities in the sequence of observed astronomy sources to increase ISL connection duration. In addition, the paper proposes a mechanism that enhances angular resolution by using reconfigurable earth stations. Furthermore, the paper presents the opportunistic computing scheme (OCS to enhance HPC utilisation. OCS enables the underutilised HPC to be used to train learning algorithms of a cognitive base station. The performances of the three mechanisms are evaluated. Simulations show that the proposed mechanisms protect GTs from ISL interference, enhance angular resolution, and improve HPC utilisation.

  6. Perkembangan dan Problematika Radio Komunitas di Indonesia

    Directory of Open Access Journals (Sweden)

    Masduki .

    2013-12-01

    Full Text Available Abstract: This article is about the development of community radio in Indonesia, it is problems and solutions. Community radio in Indonesia developed as an alternative to both public radio and commercial radio after the fall of Soeharto in 1998. Two important features of community radio are that it provides all community members with equal access to information, enhancing their rights and obligations, access to justice, public accountability and also enables them to participate actively in radio management and production. Both features enhance people’s selfawareness and sense of belonging to a community. The expansion of the progressive, participatory, community ownership, and non-profit model of community radio, has become a third sector of communication beside the commercial or state media. The dynamic development of community radio in Indonesia faced several problems starting from it is definition, implementation of regulation until standards of programmes operation based on the concept of community approach and participation

  7. Interweave Cognitive Radio with Improper Gaussian Signaling

    KAUST Repository

    Hedhly, Wafa; Amin, Osama; Alouini, Mohamed-Slim

    2018-01-01

    Improper Gaussian signaling (IGS) has proven its ability in improving the performance of underlay and overlay cognitive radio paradigms. In this paper, the interweave cognitive radio paradigm is studied when the cognitive user employs IGS

  8. Contribution Towards Practical Cognitive Radios Systems

    KAUST Repository

    Ben Ghorbel, Mahdi

    2013-01-01

    to cognitive radio systems while taking into account practical constraints. Cogni- tive radios requires a capability to detect spectrum holes (spectrum sensing) and a scheduling flexibility to avoid the occupied spectrum and selectively use the empty spectrum

  9. Educational Radio: The Brazilian Experience.

    Science.gov (United States)

    Speyer, Anne Marie

    1983-01-01

    Explains the value of radio for literacy education, gives a synopsis of the development of educational broadcasting in Brazil, and describes the Movement of Basic Education, a program designed to meet the needs of members of rural communities in their daily working lives. (EAO)

  10. Hybrid spread spectrum radio system

    Science.gov (United States)

    Smith, Stephen F [London, TN; Dress, William B [Camas, WA

    2010-02-09

    Systems and methods are described for hybrid spread spectrum radio systems. A method, includes receiving a hybrid spread spectrum signal including: fast frequency hopping demodulating and direct sequence demodulating a direct sequence spread spectrum signal, wherein multiple frequency hops occur within a single data-bit time and each bit is represented by chip transmissions at multiple frequencies.

  11. Radio frequency modulation made easy

    CERN Document Server

    Faruque, Saleh

    2017-01-01

    This book introduces Radio Frequency Modulation to a broad audience. The author blends theory and practice to bring readers up-to-date in key concepts, underlying principles and practical applications of wireless communications. The presentation is designed to be easily accessible, minimizing mathematics and maximizing visuals.

  12. The isotropic radio background revisited

    Energy Technology Data Exchange (ETDEWEB)

    Fornengo, Nicolao; Regis, Marco [Dipartimento di Fisica Teorica, Università di Torino, via P. Giuria 1, I–10125 Torino (Italy); Lineros, Roberto A. [Instituto de Física Corpuscular – CSIC/U. Valencia, Parc Científic, calle Catedrático José Beltrán, 2, E-46980 Paterna (Spain); Taoso, Marco, E-mail: fornengo@to.infn.it, E-mail: rlineros@ific.uv.es, E-mail: regis@to.infn.it, E-mail: taoso@cea.fr [Institut de Physique Théorique, CEA/Saclay, F-91191 Gif-sur-Yvette Cédex (France)

    2014-04-01

    We present an extensive analysis on the determination of the isotropic radio background. We consider six different radio maps, ranging from 22 MHz to 2.3 GHz and covering a large fraction of the sky. The large scale emission is modeled as a linear combination of an isotropic component plus the Galactic synchrotron radiation and thermal bremsstrahlung. Point-like and extended sources are either masked or accounted for by means of a template. We find a robust estimate of the isotropic radio background, with limited scatter among different Galactic models. The level of the isotropic background lies significantly above the contribution obtained by integrating the number counts of observed extragalactic sources. Since the isotropic component dominates at high latitudes, thus making the profile of the total emission flat, a Galactic origin for such excess appears unlikely. We conclude that, unless a systematic offset is present in the maps, and provided that our current understanding of the Galactic synchrotron emission is reasonable, extragalactic sources well below the current experimental threshold seem to account for the majority of the brightness of the extragalactic radio sky.

  13. The isotropic radio background revisited

    International Nuclear Information System (INIS)

    Fornengo, Nicolao; Regis, Marco; Lineros, Roberto A.; Taoso, Marco

    2014-01-01

    We present an extensive analysis on the determination of the isotropic radio background. We consider six different radio maps, ranging from 22 MHz to 2.3 GHz and covering a large fraction of the sky. The large scale emission is modeled as a linear combination of an isotropic component plus the Galactic synchrotron radiation and thermal bremsstrahlung. Point-like and extended sources are either masked or accounted for by means of a template. We find a robust estimate of the isotropic radio background, with limited scatter among different Galactic models. The level of the isotropic background lies significantly above the contribution obtained by integrating the number counts of observed extragalactic sources. Since the isotropic component dominates at high latitudes, thus making the profile of the total emission flat, a Galactic origin for such excess appears unlikely. We conclude that, unless a systematic offset is present in the maps, and provided that our current understanding of the Galactic synchrotron emission is reasonable, extragalactic sources well below the current experimental threshold seem to account for the majority of the brightness of the extragalactic radio sky

  14. Utrecht and Galactic Radio Astronomy

    NARCIS (Netherlands)

    van Woerden, H.

    Important roles in early Dutch Galactic radio astronomy were played by several Utrecht astronomers: Van de Hulst, Minnaert and Houtgast. The poster announcing the conference contained a number of pictures referring to scientific achievements of the Astronomical Institute Utrecht. One of these

  15. A repeating fast radio burst.

    Science.gov (United States)

    Spitler, L G; Scholz, P; Hessels, J W T; Bogdanov, S; Brazier, A; Camilo, F; Chatterjee, S; Cordes, J M; Crawford, F; Deneva, J; Ferdman, R D; Freire, P C C; Kaspi, V M; Lazarus, P; Lynch, R; Madsen, E C; McLaughlin, M A; Patel, C; Ransom, S M; Seymour, A; Stairs, I H; Stappers, B W; van Leeuwen, J; Zhu, W W

    2016-03-10

    Fast radio bursts are millisecond-duration astronomical radio pulses of unknown physical origin that appear to come from extragalactic distances. Previous follow-up observations have failed to find additional bursts at the same dispersion measure (that is, the integrated column density of free electrons between source and telescope) and sky position as the original detections. The apparent non-repeating nature of these bursts has led to the suggestion that they originate in cataclysmic events. Here we report observations of ten additional bursts from the direction of the fast radio burst FRB 121102. These bursts have dispersion measures and sky positions consistent with the original burst. This unambiguously identifies FRB 121102 as repeating and demonstrates that its source survives the energetic events that cause the bursts. Additionally, the bursts from FRB 121102 show a wide range of spectral shapes that appear to be predominantly intrinsic to the source and which vary on timescales of minutes or less. Although there may be multiple physical origins for the population of fast radio bursts, these repeat bursts with high dispersion measure and variable spectra specifically seen from the direction of FRB 121102 support an origin in a young, highly magnetized, extragalactic neutron star.

  16. Quality in radio-immunology

    International Nuclear Information System (INIS)

    Hegesippe, Michel

    1982-01-01

    The author outlines the technique of radio-immunological analysis (RIA) which is now widely used for neo-natal detection of congenital hyperthyroidism. He describes the methods and controls that are called for - as regards the specificity of doses, the sensitivity and reliability of the separation technique - to guarantee the quality of RIA and the validity of its results [fr

  17. Evaluación de dos estrategias de educación nutricional vía radio en Guadalajara, México

    Directory of Open Access Journals (Sweden)

    Carlos Enrique Cabrera-Pivaral

    Full Text Available La modificación de los conocimientos y de las actitudes desde la óptica de la comunicación persuasiva en salud vía radio ha reportado resultados alentadores para los planificadores sanitarios. El objetivo fue medir el efecto de una estrategia educativa en los conocimientos y en las actitudes, utilizando el radio, en dos comunidades marginadas. Es una intervención educativa vía radio en dos comunidades marginadas y socioeconómicamente homogéneas en Guadalajara, Jalisco, México. Se seleccionaron al azar dos comunidades marginadas y se formaron dos grupos de radioescuchas, se midieron los conocimientos y las actitudes sobre contenidos de educación nutricional para la salud mediante un instrumento codificado y estructurado. El primer grupo "A", de 37 sujetos, fue organizado y expuesto a la dinámica del radio foro durante los 4 meses que dura el proyecto. El grupo "B" (n = 33, no organizado, se expuso al proyecto radiofónico según su propia dinámica cultural. La mediana del grupo A para Conocimientos y Actitudes (CA, en la pre medición, fue de 56,8 y, para la pos medición, fue de 74,1 (W: p = -0,05. Para el grupo B, los CA fueron de 53 y 59,2, respectivamente (W: p = -0,05. Así se refuerzan las ventajas del radio foro como estrategia comunicativa en salud en el área de la nutrición humana.

  18. Evaluación de dos estrategias de educación nutricional vía radio en Guadalajara, México

    Directory of Open Access Journals (Sweden)

    Cabrera-Pivaral Carlos Enrique

    2002-01-01

    Full Text Available La modificación de los conocimientos y de las actitudes desde la óptica de la comunicación persuasiva en salud vía radio ha reportado resultados alentadores para los planificadores sanitarios. El objetivo fue medir el efecto de una estrategia educativa en los conocimientos y en las actitudes, utilizando el radio, en dos comunidades marginadas. Es una intervención educativa vía radio en dos comunidades marginadas y socioeconómicamente homogéneas en Guadalajara, Jalisco, México. Se seleccionaron al azar dos comunidades marginadas y se formaron dos grupos de radioescuchas, se midieron los conocimientos y las actitudes sobre contenidos de educación nutricional para la salud mediante un instrumento codificado y estructurado. El primer grupo "A", de 37 sujetos, fue organizado y expuesto a la dinámica del radio foro durante los 4 meses que dura el proyecto. El grupo "B" (n = 33, no organizado, se expuso al proyecto radiofónico según su propia dinámica cultural. La mediana del grupo A para Conocimientos y Actitudes (CA, en la pre medición, fue de 56,8 y, para la pos medición, fue de 74,1 (W: p = -0,05. Para el grupo B, los CA fueron de 53 y 59,2, respectivamente (W: p = -0,05. Así se refuerzan las ventajas del radio foro como estrategia comunicativa en salud en el área de la nutrición humana.

  19. Diseño y validación de un cuestionario para medir la autoestima infantil. La relación entre autoestima, rendimiento académico y las variables sociodemográficas

    OpenAIRE

    Serrano Muñoz, Antonio M.

    2014-01-01

    El objetivo del presente estudio ha sido diseñar y analizar la validez de contenido, comprensión y constructo de un instrumento para medir la autoestima infantil en niños y niñas de tres a siete años de edad. En primer lugar, la validación de contenido se llevó a cabo a través del acuerdo y consenso de nueve expertos mediante la técnica Delphi. La validez de comprensión y constructo quedó determinada en un estudio piloto con 250 escolares. Los datos iniciales recogidos a través del Delphi y d...

  20. Newnes radio and electronics engineer's pocket book

    CERN Document Server

    Moorshead, H W; Perry, J

    1978-01-01

    Newnes Radio and Electronics Engineer's Pocket Book, Fifteenth Edition provides reference of the information relevant in radio and electronics engineering. The book presents tables, illustrations, and diagrams of various data used in radio and electronics engineering. The coverage of the text includes abbreviations and symbols, electrical equations, and code conversions. The text will be useful to engineers, technicians, and other professionals who require a reference about the different aspects of radio and electronics.

  1. IRAS observations of radio-quiet and radio-loud quasars

    Science.gov (United States)

    Neugebauer, G.; Soifer, B. T.; Miley, G.; Habing, H. J.; Young, E.; Low, F. J.; Beichman, C. A.; Clegg, P. E.; Harris, S.; Rowan-Robinson, M.

    1984-01-01

    Observations from 12 to 100 microns are presented of two radio-quiet and three radio-loud quasars. Over this wavelength range, all five have grossly similar continuum energy distributions. The continua of the radio-loud quasars are consistent with synchrotron radiation. There is an indication, however, of excess 100 micron emission in the two radio-quiet quasars.

  2. Propuesta para la medición del impacto de las TIC en la enseñanza universitaria Proposta para medir o impacto das TICs no ensino universitario Proposal for Measuring the Impact of ICT on College Teaching

    Directory of Open Access Journals (Sweden)

    Gloria Patricia Ávila-Fajardo

    2011-04-01

    Full Text Available El objetivo general de este artículo es establecer una metodología apropiada que permita medir el impacto de las TIC en los procesos de enseñanza-aprendizaje en la educación superior (Impactic. El contexto de la investigación se centra en facultades de corte humanístico. La construcción de Impactic se encuentra relacionada con la fundamentación, especialmente en el análisis de los modelos pedagógicos, el proceso de inclusión de las TIC en el contexto educativo y el impacto de la tecnología en el ambiente educativo.Este trabalho desenvolve o objetivo geral de estabelecer uma metodologia adequada para medir o impacto das TICs no ensino-aprendizagem no ensino superior (IMPACTIC. O contexto da pesquisa centra-se em faculdades de tipo humanista. A construção de IMPACTIC fundamenta-se na análise de modelos pedagógicos, o processo de inclusão das TICs no contexto educacional e o impacto da tecnologia no ambiente educacional.The general objective of this article is to define at an appropriate method for measuring the impact of ICT on teaching-learning processes in higher education (IMPACTIC. In terms of its context, the study is centered on faculties in the area of humanities. The construction of IMPACTIC is related to the basics, particularly an analysis of teaching models, processes for incorporating ICT into educational contexts, and the impact of technology on the educational environment.

  3. Division B Commission 40: Radio Astronomy

    NARCIS (Netherlands)

    Chapman, Jessica M.; Giovaninni, Gabriele; Taylor, Russell; Carilli, Christopher; Hills, Richard; Hirabayashi, Hisashi; Jonas, Justin L.; Lazio, Joseph; Morganti, Raffaella; Nan, Rendong; Rubio, Monica; Shastri, Prjaval; Kellermann, Ken; Ekers, Ronald; Ohishi, Masatoshi

    2016-01-01

    IAU Commission 40 for Radio Astronomy (hereafter C40) brought together scientists and engineers who carry out observational and theoretical research in radio astronomy and who develop and operate the ground and space-based radio astronomy facilities and instrumentation. As of June 2015, the

  4. Exploring Community Radio Programming Practices to Inform ...

    African Journals Online (AJOL)

    A collective case study (multi-site) design was used to probe educational programming practices used in community radio. The paper explores how community radio station programming engages listeners in community generated education programmes that are produced through collaborative work with radio listener clubs.

  5. Politics and Radio in the 1924 Campaign.

    Science.gov (United States)

    Berkman, Dave

    1987-01-01

    Discusses the relation between radio broadcasting and politics in the 1924 presidential campaign, focusing on newspaper and magazine coverage. Notes radio's influence on candidate image, the aspect of censorship, and the use of radio during the campaign and after the election. (MM)

  6. The Effect of Solar Radiation on Radio Signal for Radio Astronomy Purposes

    International Nuclear Information System (INIS)

    Nor Hazmin Sabri; Atiq Wahidah Azlan; Roslan Umar; Roslan Umar; Shahirah Syafa Sulan; Zainol Abidin Ibrahim; Wan Zul Adli Wan Mokhtar

    2015-01-01

    Radio astronomy is a subfields of astronomy which is discovers the celestial objects at radio frequencies. Observation in radio astronomy is conducted using single antenna or array of antennas, known as radio telescope. Other than that, radio astronomy also holds an advantage over other alternatives to optical astronomy due to its capability of observing from the ground level. In this study, the effect of solar radiation that contributes the Radio Frequency Interferences (RFI) is reviewed. The low RFI level is required to set up the radio telescope for radio astronomy observation. The effect of solar radiation on radio signal was investigated by determining the RFI pattern using spectrum analyzer. The solar radiation data was obtained from weather station located at KUSZA Observatory, East Coast Environmental Research Institute (ESERI), UniSZA. We can conclude that the solar radiation factor give the minimum significant effect to radio signal. (author)

  7. Radio Astronomy Explorer (RAE) 1 observations of terrestrial radio noise

    Science.gov (United States)

    Herman, J. R.; Caruso, J. A.

    1971-01-01

    Radio Astonomy Explorer (RAE) 1 data are analyzed to establish characteristics of HF terrestrial radio noise at an altitude of about 6000 km. Time and frequency variations in amplitude of the observed noise well above cosmic noise background are explained on the basis of temporal and spatial variations in ionospheric critical frequency coupled with those in noise source distributions. It is shown that terrestrial noise regularly breaks through the ionosphere and reaches RAE with magnitudes 15 or more db higher than cosmic noise background. Maximum terrestrial noise is observed when RAE is over the dark side of the Earth in the neighborhood of equatorial continental land masses where thunderstorms occur most frequently. The observed noise level is 30-40 db lower with RAE over oceans.

  8. Fast Radio Bursts and Radio Transients from Black Hole Batteries

    OpenAIRE

    Mingarelli, Chiara M. F.; Levin, Janna; Lazio, T. Joseph W.

    2015-01-01

    Most black holes (BHs) will absorb a neutron star (NS) companion fully intact without tidal disruption, suggesting the pair will remain dark to telescopes. Even without tidal disruption, electromagnetic (EM) luminosity is generated from the battery phase of the binary when the BH interacts with the NS magnetic field. Originally, the luminosity was expected to be in high-energy X-rays or gamma-rays, however, we conjecture that some of the battery power is emitted in the radio bandwidth. While ...

  9. Radio halo sources in clusters of galaxies

    International Nuclear Information System (INIS)

    Hanisch, R.J.

    1986-01-01

    Radio halo sources remain one of the most enigmatic of all phenomena related to radio emission from galaxies in clusters. The morphology, extent, and spectral structure of these sources are not well known, and the models proposed to explain them suffer from this lack of observational detail. However, recent observations suggest that radio halo sources may be a composite of relic radio galaxies. The validity of this model could be tested using current and planned high resolutions, low-frequency radio telescopes. 31 references

  10. Radio investigations of clusters of galaxies

    International Nuclear Information System (INIS)

    Valentijn, E.A.

    1978-01-01

    This thesis contains a number of papers of the series entitled, A Westerbork Survey of Rich Clusters of Galaxies. The primary aim was to study the radio characteristics of cluster galaxies and especially the question whether their ''radio-activity'' is influenced by their location inside a cluster. It is enquired whether the presence of an intra-cluster medium (ICM), or the typical cluster evolution or cluster dynamical processes can give rise to radio-observable effects on the behaviour of cluster galaxies. 610 MHz WSRT observations of the Coma cluster (and radio observations of the Hercules supercluster) are presented. Extended radio sources in Abell clusters are then described. (Auth.)

  11. Propagation engineering in radio links design

    CERN Document Server

    Ghasemi, Abdollah; Ghasemi, Farshid

    2013-01-01

    Propagation Engineering in Radio Link Design covers the basic principles of radiowaves propagation in a practical manner.  This fundamental understanding enables the readers to design radio links efficiently. This book elaborates on new achievements as well as recently developed propagation models.  This is in addition to a comprehensive overview of fundamentals of propagation in various scenarios. It examines theoretical calculations, approaches and applied procedures needed for radio links design. The authors study and analysis of the main propagation phenomena and its mechanisms based on the recommendations of International Telecommunications Union, (ITU). The book has been organized in 9 chapters and examines the role of antennas and passive reflectors in radio services, propagation mechanisms related to radar, satellite, short distance, broadcasting and trans-horizon radio links, with two chapters devoted to radio noise and main  parameters of radio link design. The book presents some 278 illustration...

  12. Precision Geodesy via Radio Interferometry.

    Science.gov (United States)

    Hinteregger, H F; Shapiro, I I; Robertson, D S; Knight, C A; Ergas, R A; Whitney, A R; Rogers, A E; Moran, J M; Clark, T A; Burke, B F

    1972-10-27

    Very-long-baseline interferometry experiments, involving observations of extragalactic radio sources, were performed in 1969 to determine the vector separations between antenna sites in Massachusetts and West Virginia. The 845.130-kilometer baseline was estimated from two separate experiments. The results agreed with each other to within 2 meters in all three components and with a special geodetic survey to within 2 meters in length; the differences in baseline direction as determined by the survey and by interferometry corresponded to discrepancies of about 5 meters. The experiments also yielded positions for nine extragalactic radio sources, most to within 1 arc second, and allowed the hydrogen maser clocks at the two sites to be synchronized a posteriori with an uncertainty of only a few nanoseconds.

  13. Recent radio studies of SNR

    International Nuclear Information System (INIS)

    Dickel, J.R.

    1983-01-01

    SNR can generally be recognized as extended sources of continuum radio emission with non-thermal spectra located near the galactic plane. The author describes the kinds of observations currently being obtained and what they tell us about the objects. The data include continuum observations which can reach resolutions of about 1 arcsec using aperture synthesis techniques and also spectral line observations of the interstellar matter being encountered by the remnants. (Auth.)

  14. Superconducting Radio-Frequency Cavities

    Science.gov (United States)

    Padamsee, Hasan S.

    2014-10-01

    Superconducting cavities have been operating routinely in a variety of accelerators with a range of demanding applications. With the success of completed projects, niobium cavities have become an enabling technology, offering upgrade paths for existing facilities and pushing frontier accelerators for nuclear physics, high-energy physics, materials science, and the life sciences. With continued progress in basic understanding of radio-frequency superconductivity, the performance of cavities has steadily improved to approach theoretical capabilities.

  15. Identification of southern radio sources

    International Nuclear Information System (INIS)

    Savage, A.; Bolton, J.G.; Wright, A.E.

    1976-01-01

    Identifications are suggested for 36 radio sources from the southern zones of the Parkes 2700 MHz survey, 28 with galaxies, six with confirmed and two with suggested quasi-stellar objects. The identifications were made from the ESO quick blue survey plates, the SRC IIIa-J deep survey plates and the Palomar sky survey prints. Accurate optical positions have also been measured for nine of the objects and for five previously suggested identifications. (author)

  16. LEP Radio Frequency Copper Cavity

    CERN Multimedia

    The pulse of a particle accelerator. 128 of these radio frequency cavities were positioned around CERN's 27-kilometre LEP ring to accelerate electrons and positrons. The acceleration was produced by microwave electric oscillations at 352 MHz. The electrons and positrons were grouped into bunches, like beads on a string, and the copper sphere at the top stored the microwave energy between the passage of individual bunches. This made for valuable energy savings as it reduced the heat generated in the cavity.

  17. Expanding radio astronomy in Africa

    International Nuclear Information System (INIS)

    Gaylard, M J

    2013-01-01

    The Square Kilometre Array (SKA) Organisation announced in May 2012 that its members had agreed on a dual site solution for the SKA [1]. South Africa's bid for hosting the SKA has caused a ramp up of radio astronomy in Africa. To develop technology towards the SKA, the South African SKA Project (SKA SA) built a protoype radio telescope in 2007, followed in 2010 the seven antenna Karoo Array Telescope (KAT-7). Next is the 64 antenna MeerKAT, which will merge into SKA Phase 1 in Africa. As SKA Phase 2 is intended to add a high resolution capability with baselines out to 3000 km, the SKA SA brought in partner countries in Africa to host outstations. South Africa has been working with the partners to build capacity to operate the SKA and to benefit from it. The SA Department of Science and Technology (DST) developed a proposal to establish radio telescopes in the partner countries to provide hands-on learning and a capability for Very Long Baseline Interferometry (VLBI) research. Redundant 30 m class satellite antennas are being incorporated in this project.

  18. Radio outbursts in extragalactic sources

    International Nuclear Information System (INIS)

    Kinzel, W.M.

    1989-01-01

    Three aspects of the flux density variability of extragalactic radio sources were examined: millimeter wavelength short timescale variability, the spectral evolution of outbursts, and whether the outbursts are periodically spaced. Observations of extragalactic radio sources were conducted using the Five College Radio Astronomy Observatory between January and June 1985 at 88.2 GHz and during June and July 1985 at 40.0 GHz. Many of the sources exhibited significant flux density variations during the observing span. In addition, the most rapid variations observed were comparable with those reported in previous works. Two sources, 0355+50 and OJ287, both exhibited outbursts whose rise and fall timescales were less than a month. An anomalous flux density dropout was observed in 3C446 and was interpreted as an occultation event. Data at five frequencies between 2.7 and 89.6 GHz from the Dent-Balonek monitoring program were used to investigate the spectral evolution of eight outbursts. Outburst profile fitting was used to deconvolve the individual outbursts from one another at each frequency. The fit profiles were used to generate multiple epoch spectra to investigate the evolution of the outbursts. A phase residual minimization method was used to examine four sources for periodic behavior

  19. Advances in solar radio astronomy

    Science.gov (United States)

    Kundu, M. R.

    1982-01-01

    The status of the observations and interpretations of the sun's radio emission covering the entire radio spectrum from millimeter wavelengths to hectometer and kilometer wavelengths is reviewed. Emphasis is given to the progress made in solar radio physics as a result of recent advances in plasma and radiation theory. It is noted that the capability now exists of observing the sun with a spatial resolution of approximately a second of arc and a temporal resolution of about a millisecond at centimeter wavelengths and of obtaining fast multifrequency two-dimensional pictures of the sun at meter and decameter wavelengths. A summary is given of the properties of nonflaring active regions at millimeter, centimeter, and meter-decameter wavelengths. The properties of centimeter wave bursts are discussed in connection with the high spatial resolution observations. The observations of the preflare build-up of an active region are reviewed. High spatial resolution observations (a few seconds of arc to approximately 1 arcsec) are discussed, with particular attention given to the one- and two-dimensional maps of centimeter-wavelength burst sources.

  20. Workshop on Radio Recombination Lines

    CERN Document Server

    1980-01-01

    Since their first detection 15 years ago, radio recombination lines from several elements have been observed in a wide variety of objects including HII regions, planetary nebulae, molecular clouds, the diffuse interstellar medium, and recently, other galaxies. The observations span almost the entire range from 0.1 to 100 GHz, and employ both single­ djsh and aperture synthesis techniques. The theory of radio recombination lines has also advanced strongly, to the point where it is perhaps one of the best-understood in astro­ physics. In a parallel development, it has become possible over the last decade to study these same highly-excited atoms in the laboratory; this work provides further confirmation of the theoretical framework. However there has been continuing controversy over the astrophysical interpre­ tation of radio recombination line observations, especially regarding the role of stimulated emission. A workshop was held in Ottawa on 24-25 August, 1979, bringing together many of the active scientist...

  1. Evaluación de dos estrategias de educación nutricional vía radio en Guadalajara, México Evaluation of two strategies for nutritional education using radio programs in Guadalajara, Mexico

    Directory of Open Access Journals (Sweden)

    Carlos Enrique Cabrera-Pivaral

    2002-10-01

    Full Text Available La modificación de los conocimientos y de las actitudes desde la óptica de la comunicación persuasiva en salud vía radio ha reportado resultados alentadores para los planificadores sanitarios. El objetivo fue medir el efecto de una estrategia educativa en los conocimientos y en las actitudes, utilizando el radio, en dos comunidades marginadas. Es una intervención educativa vía radio en dos comunidades marginadas y socioeconómicamente homogéneas en Guadalajara, Jalisco, México. Se seleccionaron al azar dos comunidades marginadas y se formaron dos grupos de radioescuchas, se midieron los conocimientos y las actitudes sobre contenidos de educación nutricional para la salud mediante un instrumento codificado y estructurado. El primer grupo "A", de 37 sujetos, fue organizado y expuesto a la dinámica del radio foro durante los 4 meses que dura el proyecto. El grupo "B" (n = 33, no organizado, se expuso al proyecto radiofónico según su propia dinámica cultural. La mediana del grupo A para Conocimientos y Actitudes (CA, en la pre medición, fue de 56,8 y, para la pos medición, fue de 74,1 (W: p = -0,05. Para el grupo B, los CA fueron de 53 y 59,2, respectivamente (W: p = -0,05. Así se refuerzan las ventajas del radio foro como estrategia comunicativa en salud en el área de la nutrición humana.Modifying knowledge and attitudes through persuasive communication in health via radio has produced encouraging results for public health planners. This study's objective was to measure the effect of an educational strategy on knowledge and attitudes towards nutrition in two marginalized communities in Guadalajara, Mexico. Two communities were randomly selected. In each community a group of individuals was invited to be exposed to radio broadcasts. Using a coded and structured instrument, knowledge and attitudes towards the contents of nutritional education for health were measured before and after the intervention in both groups. Group A (n = 37

  2. Sources of the Radio Background Considered

    Energy Technology Data Exchange (ETDEWEB)

    Singal, J.; /KIPAC, Menlo Park /Stanford U.; Stawarz, L.; /KIPAC, Menlo Park /Stanford U. /Jagiellonian U., Astron. Observ.; Lawrence, A.; /Edinburgh U., Inst. Astron. /KIPAC, Menlo Park /Stanford U.; Petrosian, V.; /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., Appl. Phys. Dept.

    2011-08-22

    We investigate possible origins of the extragalactic radio background reported by the ARCADE 2 collaboration. The surface brightness of the background is several times higher than that which would result from currently observed radio sources. We consider contributions to the background from diffuse synchrotron emission from clusters and the intergalactic medium, previously unrecognized flux from low surface brightness regions of radio sources, and faint point sources below the flux limit of existing surveys. By examining radio source counts available in the literature, we conclude that most of the radio background is produced by radio point sources that dominate at sub {mu}Jy fluxes. We show that a truly diffuse background produced by elections far from galaxies is ruled out because such energetic electrons would overproduce the observed X-ray/{gamma}-ray background through inverse Compton scattering of the other photon fields. Unrecognized flux from low surface brightness regions of extended radio sources, or moderate flux sources missed entirely by radio source count surveys, cannot explain the bulk of the observed background, but may contribute as much as 10%. We consider both radio supernovae and radio quiet quasars as candidate sources for the background, and show that both fail to produce it at the observed level because of insufficient number of objects and total flux, although radio quiet quasars contribute at the level of at least a few percent. We conclude that the most important population for production of the background is likely ordinary starforming galaxies above redshift 1 characterized by an evolving radio far-infrared correlation, which increases toward the radio loud with redshift.

  3. Radio y cultura: una propuesta de radio ciudadana en Internet

    Directory of Open Access Journals (Sweden)

    Mauricio Andrés Álvarez-Moreno

    2015-01-01

    Full Text Available El presente artículo es resultado de la investigación para optar a título de magíster “La Peña Cultural: modelo de radio ciudadana en Internet”, realizada durante los años 2013 y 2014 para la Universidad de Medellín. En ella se realiza una exploración de la radio en Internet como plataforma con herramientas multimediales que podrían afianzar la formación de ciudadanía reflexiva por medio de contenidos de promoción cultural. De la misma manera, identifica, a partir de un rastreo de emisoras en Colombia, cómo esas herramientas –las redes sociales, podcasts, chats, canales de video y nuevas formas comunicativas– permiten la participación activa de los ciudadanos en su producción. Rescatar el uso de tecnologías que facilitan la comunicación, como la radio en Internet, para reconocer y recuperar el valor de la promoción cultural propia de un estado en aras de la formación de una ciudadanía reflexiva, es el acercamiento que se hizo a partir de la etnografía y la investigación aplicada y que ahora se expone en este artículo. Es la forma en que los ciudadanos podrían converger en un medio de comunicación para producir contenidos que fortalezcan su identidad cultural o, si se quiere, su visión de nación. Es la apuesta por establecer una alternativa a los ya tradicionales modelos, una guía para la comunidad interesada en promover una ciudadanía reflexiva del patrimonio cultural. Palabras clave

  4. FAST RADIO BURSTS AND RADIO TRANSIENTS FROM BLACK HOLE BATTERIES

    Energy Technology Data Exchange (ETDEWEB)

    Mingarelli, Chiara M. F. [TAPIR, MC 350-17, California Institute of Technology, Pasadena, CA 91125 (United States); Levin, Janna [Institute for Strings, Cosmology and Astroparticle Physics (ISCAP), Columbia University, New York, NY 10027 (United States); Lazio, T. Joseph W. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2015-12-01

    Most black holes (BHs) will absorb a neutron star (NS) companion fully intact without tidal disruption, suggesting the pair will remain dark to telescopes. Even without tidal disruption, electromagnetic (EM) luminosity is generated from the battery phase of the binary when the BH interacts with the NS magnetic field. Originally, the luminosity was expected to be in high-energy X-rays or gamma-rays, however, we conjecture that some of the battery power is emitted in the radio bandwidth. While the luminosity and timescale are suggestive of fast radio bursts (FRBs; millisecond-scale radio transients) NS–BH coalescence rates are too low to make these a primary FRB source. Instead, we propose that the transients form a FRB sub-population, distinguishable by a double peak with a precursor. The rapid ramp-up in luminosity manifests as a precursor to the burst which is 20%–80% as luminous given 0.5 ms timing resolution. The main burst arises from the peak luminosity before the merger. The post-merger burst follows from the NS magnetic field migration to the BH, causing a shock. NS–BH pairs are especially desirable for ground-based gravitational wave (GW) observatories since the pair might not otherwise be detected, with EM counterparts greatly augmenting the scientific leverage beyond the GW signal. The EM signal’s ability to break degeneracies in the parameters encoded in the GW and probe the NS magnetic field strength is quite valuable, yielding insights into open problems in NS magnetic field decay.

  5. FAST RADIO BURSTS AND RADIO TRANSIENTS FROM BLACK HOLE BATTERIES

    International Nuclear Information System (INIS)

    Mingarelli, Chiara M. F.; Levin, Janna; Lazio, T. Joseph W.

    2015-01-01

    Most black holes (BHs) will absorb a neutron star (NS) companion fully intact without tidal disruption, suggesting the pair will remain dark to telescopes. Even without tidal disruption, electromagnetic (EM) luminosity is generated from the battery phase of the binary when the BH interacts with the NS magnetic field. Originally, the luminosity was expected to be in high-energy X-rays or gamma-rays, however, we conjecture that some of the battery power is emitted in the radio bandwidth. While the luminosity and timescale are suggestive of fast radio bursts (FRBs; millisecond-scale radio transients) NS–BH coalescence rates are too low to make these a primary FRB source. Instead, we propose that the transients form a FRB sub-population, distinguishable by a double peak with a precursor. The rapid ramp-up in luminosity manifests as a precursor to the burst which is 20%–80% as luminous given 0.5 ms timing resolution. The main burst arises from the peak luminosity before the merger. The post-merger burst follows from the NS magnetic field migration to the BH, causing a shock. NS–BH pairs are especially desirable for ground-based gravitational wave (GW) observatories since the pair might not otherwise be detected, with EM counterparts greatly augmenting the scientific leverage beyond the GW signal. The EM signal’s ability to break degeneracies in the parameters encoded in the GW and probe the NS magnetic field strength is quite valuable, yielding insights into open problems in NS magnetic field decay

  6. An overview and guide: planning instructional radio.

    Science.gov (United States)

    Imhoof, M

    1984-03-01

    Successful instructional radio projects require both comprehensive and complex planning. The instructional radio planning team needs to have knowledge and capabilities in several technical, social, and educational areas. Among other skills, the team must understand radio, curriculum design, the subject matter being taught, research and evaluation, and the environment in which the project operates. Once a basic approach to educational planning has been selected and broad educational goals set, radio may be selected as a cost effective means of achieving some of the goals. Assuming radio is a wise choice, there are still several factors which must be analyzed by a team member who is a radio specialist. The most obvious consideration is the inventory and evaluation of the facilities: studios; broadcast, recording, and transmission equipment; classroom radios; and so on. Capabilities of broadcast personnel are another consideration. Initial radio lessons need to teach the learners how to listen to the radio if they have no previous experience with institutional radio broadcasts. A captive, inschool audience ready to listen to radio instructions requires a different use of the medium than a noncaptive audience. With the noncaptive audience, the educational broadcaster must compete with entertaining choices from other media and popular activities and pastimes of the community. The most complex knowledge and analysis required in planning instructional radio concerns the relationship of the content to the medium. Environmental factors are important in planning educational programs. The physical environment may present several constraints on the learning experience and the use of radio. The most obvious is the effect of climate and terrain on the quality of radio reception. The physical environment is easily studied through experience in the target area, but this knowledge plays a significant role in designing effective learning materials for specific learners. Social

  7. The collective radio properties of symbiotic stars

    International Nuclear Information System (INIS)

    Seaquist, E.R.; Taylor, A.R.

    1990-01-01

    Radio measurements of symbiotic stars are reported which extend the search for radio emission and provide multifrequency and multiepoch measurements of previously detected stars. The results show no evidence that there are time variations in excess of about 30 percent over a period of several years in the detected stars. The radio flux densities are correlated with brightness in the IR, especially at the longer IR wavelengths where dust emission dominates. It is confirmed that symbiotics with the latest red giant spectral types are the most luminous radio emitters. The D-types are the most radio-luminous. Virtually all detected stars with measurements at more than one frequency exhibit a positive spectral index, consistent with optically thick thermal bremsstrahlung. The binary separation for a number of radio-emitting symbiotics is estimated, and it is found that the distribution of inferred binary separations is dramatically different for IR D-types than for S-types. 37 refs

  8. The Impact of Radio Interference on Future Radio Telescopes

    Science.gov (United States)

    Mitchell, Daniel A.; Robertson, Gordon J.; Sault, Robert J.

    While future radio telescopes will require technological advances from the communications industry interference from sources such as satellites and mobile phones is a serious concern. In addition to the fact that the level of interference is growing constantly the increased capabilities of next generation instruments make them more prone to harmful interference. These facilities must have mechanisms to allow operation in a crowded spectrum. In this report some of the factors which may limit the effectiveness of these mechanisms are investigated. Radio astronomy is unique among other observing wavelengths in that the radiation can be fully sampled at a rate which completely specifies the electromagnetic environment. Knowledge of phases and antennae gain factors affords one the opportunity to attempt to mitigate interference from the astronomical data. At present several interference mitigation techniques have been demonstrated to be extremely effective. However the observational scales of the new facilities will push the techniques to their limits. Processes such as signal decorrelation varying antenna gain and instabilities in the primary beam will have a serious effect on some of the algorithms. In addition the sheer volume of data produced will render some techniques computationally and financially impossible.

  9. Radio emission in peculiar galaxies

    Science.gov (United States)

    Demellorabaca, Dulia F.; Abraham, Zulema

    1990-01-01

    During the last decades a number of surveys of peculiar galaxies have been carried out and accurate positions become available. Since peculiarities are a possible evidence of radio emission (Wright, 1974; Sulentic, 1976; Stocke et al., 1978), the authors selected a sample of 24 peculiar galaxies with optical jet-like features or extensions in different optical catalogues, mainly the Catalogue of Southern Peculiar Galaxies and Associations (Arp and Madore, 1987) and the ESO/Uppsala Survey of the ESO(B) Atlas (Lauberts, 1982) for observation at the radio continuum frequency of 22 GHz. The sample is listed in a table. Sol (1987) studied this sample and concluded that the majority of the jet-like features seem to admit an explanation in terms of interactive galaxies with bridges and/or tails due to tidal effects. Only in a few cases do the jets seem to be possibly linked to some nuclear activity of the host galaxy. The observations were made with the 13.7m-radome enclosed Itapetinga Radiotelescope (HPBW of 4.3 arcmin), in Brazil. The receiver was a 1 GHz d.s.b. super-heterodine mixer operated in total-power mode, with a system temperature of approximately 800 K. The observational technique consisted in scans in right ascention, centralized in the optical position of the galaxy. The amplitude of one scan was 43 arcmin, and its duration time was 20 seconds. The integration time was at least 2 hours (12 ten-minute observations) and the sensibility limit adopted was an antenna temperature greater than 3 times the r.m.s. error of the baseline determination. Virgo A was used as the calibrator source. Three galaxies were detected for the first time as radio sources and four other known galaxies at low frequencies had their flux densities measured at 22 GHz. The results for these sources are presented.

  10. Coping with Radio Frequency Interference

    Science.gov (United States)

    Lewis, B. M.

    2009-01-01

    The radio spectrum is a finite resource, on which humanity makes many demands. And pressure on it is ever increasing with the development of new technology and ideas for radio services. After all, we all benefit from wifi and cell phones. Radio astronomers have a small percentage of the spectrum allocated to them at octave intervals in the metre-centimetre bands, and at important frequencies, such as that of the 21cm line of HI. Signals from other services, as well as from our own poorly-engineered equipment, sometimes contaminate our bands: these signals constitute RFI. These may totally obliterate the astronomical signal, or, in the case of CLOUDSAT, may be capable of completely destroying a receiver, which introduces us to the new possibility of 'destructive interference'. A geo-stationary satellite can block access to a piece of sky from one site. Good equipment design eliminates self-inflicted interference, while physical separation often provides adequate practical mitigation at many frequencies. However, new observatories end up being located in the West Australian desert or Antarctica. In future they may be on the back side of the Moon. But there is no Earth-bound protection via physical separation against satellite signals. Some mitigation can be achieved by frequent data dumps and the excision of RFI, or by real-time detection and blanking of the receiver, or by more sophisticated algoriths. Astronomers of necessity aim to achieve mitigation via coordination, at the local level, and by participating in spectrum management at the national and international levels. This involves them spending a lot of time in Geneva at the International Telegraphic Union protecting their access to spectrum, and access to clean spectrum from the L3 point and the far side of the Moon.

  11. 47 CFR 95.201 - (R/C Rule 1) What is the Radio Control (R/C) Radio Service?

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false (R/C Rule 1) What is the Radio Control (R/C...) SAFETY AND SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES Radio Control (R/C) Radio Service General Provisions § 95.201 (R/C Rule 1) What is the Radio Control (R/C) Radio Service? The R/C Service is a private...

  12. A Fast Radio Burst Host Galaxy

    OpenAIRE

    Keane, E. F.; Johnston, S.; Bhandari, S.; Barr, E.; Bhat, N. D. R.; Burgay, M.; Caleb, M.; Flynn, C.; Jameson, A.; Kramer, M.; Petroff, E.; Possenti, A.; van Straten, W.; Bailes, M.; Burke-Spolaor, S.

    2016-01-01

    In recent years, millisecond duration radio signals originating from distant galaxies appear to have been discovered in the so-called Fast Radio Bursts. These signals are dispersed according to a precise physical law and this dispersion is a key observable quantity which, in tandem with a redshift measurement, can be used for fundamental physical investigations. While every fast radio burst has a dispersion measurement, none before now have had a redshift measurement, due to the difficulty in...

  13. Flattening and radio emission among elliptical galaxies

    International Nuclear Information System (INIS)

    Disney, M.J.; Sparks, W.B.; Wall, J.V.

    1984-01-01

    In a sample of 132 bright elliptical galaxies it is shown that there is a strong correlation between radio activity and flattening in the sense that radio ellipticals are both apparently and inherently rounder than the average elliptical. Both extended and compact sources are subject to the same correlation. No galaxies with axial ratios below 0.65 are found to be radio emitters. (author)

  14. Radio cobalt in French rivers

    International Nuclear Information System (INIS)

    Lambrechts, A.; Baudin-Jaulent, Y.

    1996-01-01

    The isotopes 58 and 60 of cobalt present in liquid wastes from nuclear plants or from fuel reprocessing plant of Marcoule are fixed in the different compartments of French rivers. The activity levels of radio-cobalt vary according to the sampled compartments nature (bryophyta > immersed plants > sediment > fish). Elsewhere, laboratory experimentations show that the contamination of fish occurs essentially from the water way rather than from food. Cobalt is mainly fixed by kidneys; muscles is no more than 30 % of the total fish activity. (author)

  15. Signal processing for cognitive radios

    CERN Document Server

    Jayaweera, Sudharman K

    2014-01-01

    This book covers power electronics, in depth, by presenting the basic principles and application details, and it can be used both as a textbook and reference book.  Introduces the specific type of CR that has gained the most research attention in recent years: the CR for Dynamic Spectrum Access (DSA). Provides signal processing solutions to each task by relating the tasks to materials covered in Part II. Specialized chapters then discuss specific signal processing algorithms required for DSA and DSS cognitive radios  

  16. The polarization of radio galaxies

    International Nuclear Information System (INIS)

    Jaegers, W.J.

    1986-01-01

    In this thesis radio observations at 0.6 GHz together with matched (convolved) observations at 1.4 GHz of 30 radiosources are described and interpreted. Sources of great interest which are individually discussed are the complex nearby source 3C66B, the source 4C73.48, the narrow edge-darkened double source 3C130 (together with two newly observed narrow-edge-darkened doubles), the galaxies 3C129 and 3C390.3 and the giant quasar 4C34.47. (Auth.)

  17. La radio universitaria se mueve

    OpenAIRE

    Gloria Rodríguez Garay

    2015-01-01

    El reto que plantea la radiodifusión universitaria en México con el intercambio productivo como sistema y procedimiento para optimizar el medio, hace necesaria la concienciación y participación activa de la comunidad universitaria; estudiantil, docente y administrativa, con el fin de valorar la producción radiofónica como elemento fundamental para el desarrollo académico de las mismas instituciones y su vinculación permanente con la sociedad. La radio universitaria cumple funciones de informa...

  18. Identification of southern radio sources

    International Nuclear Information System (INIS)

    Savage, A.; Bolton, J.G.; Wright, A.E.

    1977-01-01

    Identifications are suggested for 53 radio sources from the southern zones of the Parkes 2700-MHz survey, 32 with galaxies, 11 with suggested QSOs and 10 with confirmed QSOs. The identifications were made from the ESO quick blue survey plates, the SRC IIIa-J deep survey plates and the Palomar Sky Survey prints. Accurate optical positions have been measured for four of the new identifications and for two previously suggested identifications. A further nine previously suggested QSO identifications have also been confirmed by two-colour photography or spectroscopy. (author)

  19. HF radio systems and circuits

    CERN Document Server

    Sabin, William

    1998-01-01

    A comprehensive reference for the design of high frequency communications systems and equipment. This revised edition is loaded with practical data, much of which cannot be found in other reference books. Its approach to the subject follows the needs of an engineer from system definition and performance requirements down to the individual circuit elements that make up radio transmitters and receivers. The accompanying disk contains updated software on filters, matching networks and receiver analysis. SciTech Publishing also provides many other products related to Communication Systems Design.

  20. Radio Propagation into Modern Buildings

    DEFF Research Database (Denmark)

    Rodriguez Larrad, Ignacio; Nguyen, Huan Cong; Jørgensen, Niels T.K.

    2014-01-01

    Energy-efficient buildings are gaining momentum in order to comply with the new energy regulations. Especially in northern cold countries, thick reinforced walls and energy-efficient windows composed of several layers of glass plus metal coating are becoming the de facto elements in modern building...... constructions. These materials are used in favor of achieving a proper level of thermal isolation, but it has been noticed that they can impact heavily on radio signal propagation. This paper presents a measurement-based analysis of the outdoor-to-indoor attenuation experienced in several modern constructions...

  1. Identification of southern radio sources

    International Nuclear Information System (INIS)

    Savage, A.

    1976-01-01

    Identifications are suggested for 32 radio sources from the southern zones of the Parkes 2700 MHz survey, 18 with galaxies, one with a confirmed and 12 with possible quasistellar objects, and one with a supernova remnant in the Large Magellanic Cloud. The identifications were made from the ESO IIa-O quick blue survey plates, the SRC IIIa-J deep survey plates and the Palomar sky survey prints. Accurate optical positions have also been measured for 10 of the objects and for five previously suggested QSOs. (author)

  2. Meteor trajectory estimation from radio meteor observations

    Science.gov (United States)

    Kákona, J.

    2016-01-01

    Radio meteor observation techniques are generally accepted as meteor counting methods useful mainly for meteor flux detection. Due to the technical progress in radio engineering and electronics a construction of a radio meteor detection network with software defined receivers has become possible. These receivers could be precisely time synchronized and could obtain data which provide us with more information than just the meteor count. We present a technique which is able to compute a meteor trajectory from the data recorded by multiple radio stations.

  3. The other radios: Alternative scenario in Peru

    Directory of Open Access Journals (Sweden)

    Carlos Rivadeneyra-Olcese

    2009-10-01

    Full Text Available Peruvian radio shows a huge diversity in direct proportion to its multiculturality, the same which shows a process full of different influences of social actor which have produced a complex and extremely rich scenario, that is also filled with opportunities and challenges. Beyond the great capital commercial radio are the other radios, small companies, provincial, from church or the mayor or small business owners sons of folkloric melomania, different actors with a passion to establish a new media. The multiple motivations produce a scenario with many types of radio that we wishes to start knowing.

  4. Radio emission of the sun and planets

    CERN Document Server

    Zheleznyakov, V V

    1970-01-01

    International Series of Monographs in Natural Philosophy, Volume 25: Radio Emission of the Sun and Planets presents the origin of the radio emission of the planets. This book examines the outstanding triumphs achieved by radio astronomy of the solar system. Comprised of 10 chapters, this volume begins with an overview of the physical conditions in the upper layers of the Sun, the Moon, and the planets. This text then examines the three characteristics of radio emission, namely, the frequency spectrum, the polarization, and the angular spectrum. Other chapters consider the measurements of the i

  5. Radio systems engineering a tutorial approach

    CERN Document Server

    Santos, Héctor J De Los; Ponte, Juan

    2015-01-01

    This book is intended for readers who already have knowledge of devices and circuits for radio-frequency (RF) and microwave communication and are ready to study the systems engineering-level aspects of modern radio communications systems. The authors provide a general overview of radio systems with their components, focusing on the analog parts of the system and their non-idealities. Based on the physical functionality of the various building blocks of a modern radio system, block parameters are derived, which allows the examination of their influence on the overall system performance. The dis

  6. Computing angle of arrival of radio signals

    Science.gov (United States)

    Borchardt, John J.; Steele, David K.

    2017-11-07

    Various technologies pertaining to computing angle of arrival of radio signals are described. A system that is configured for computing the angle of arrival of a radio signal includes a cylindrical sheath wrapped around a cylindrical object, where the cylindrical sheath acts as a ground plane. The system further includes a plurality of antennas that are positioned about an exterior surface of the cylindrical sheath, and receivers respectively coupled to the antennas. The receivers output measurements pertaining to the radio signal. A processing circuit receives the measurements and computes the angle of arrival of the radio signal based upon the measurements.

  7. Millisecond radio pulsars in globular clusters

    Science.gov (United States)

    Verbunt, Frank; Lewin, Walter H. G.; Van Paradijs, Jan

    1989-01-01

    It is shown that the number of millisecond radio pulsars, in globular clusters, should be larger than 100, applying the standard scenario that all the pulsars descend from low-mass X-ray binaries. Moreover, most of the pulsars are located in a small number of clusters. The prediction that Teran 5 and Liller 1 contain at least about a dozen millisecond radio pulsars each is made. The observations of millisecond radio pulsars in globular clusters to date, in particular the discovery of two millisecond radio pulsars in 47 Tuc, are in agreement with the standard scenario, in which the neutron star is spun up during the mass transfer phase.

  8. The Origin of Powerful Radio Sources

    Science.gov (United States)

    Wilson, A. S.; Colbert, E. J. M.

    1995-05-01

    Radio-loud active galaxies are associated with elliptical or elliptical-like galaxies, many of which appear to be the result of a recent merger. In contrast, radio-quiet active galaxies prefer spiral hosts. Despite the very large difference in radio luminosities between the two classes, their continua and line spectra from infrared through X-ray frequencies are very similar. In this paper, we describe recent developments of our model (Ap. J. 438, 62 1995) in which the radio-loud phenomenon is the result of a merger of two galaxies, with each galaxy nucleus containing a slowly (or non-) rotating supermassive black hole. It is envisaged that the two black holes eventually coalesce. For the small fraction of mergers in which the two holes are both massive and of comparable mass, a rapidly-spinning, high-mass hole results. The spin energy of a rapidly rotating 10(8-9) solar mass hole suffices to provide the ~ 10(60) ergs in relativistic particles and magnetic fields in the most energetic radio sources. Luminous radio-quiet active galaxies contain high-mass, slowly-rotating holes, with the infrared through X-ray emission of both classes being fuelled by accretion as commonly assumed. We discuss constraints on the model from the luminosity functions of radio-loud and radio-quiet galaxies and from the known cosmological evolution of the radio source population; this evolution is assumed to reflect higher galaxy merger rates in the past.

  9. 47 CFR 2.815 - External radio frequency power amplifiers.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false External radio frequency power amplifiers. 2... AND RADIO TREATY MATTERS; GENERAL RULES AND REGULATIONS Marketing of Radio-frequency Devices § 2.815 External radio frequency power amplifiers. (a) As used in this part, an external radio frequency power...

  10. Mean and Extreme Radio Properties of Quasars and the Origin of Radio Emission

    Science.gov (United States)

    Richards, Gordon T.; Kratzer, R.

    2014-01-01

    We explore the evolution of the fraction of radio loud quasars and the mean radio properties of quasars. Although any quasar has only a ~10% chance of being radio loud and the average quasar has a radio luminosity of ~4x10^30 ergs/s/Hz, these properties are strong functions of not only luminosity, redshift, black hole mass, and accretion rate, but also the strength of the accretion disk wind (as characterized by CIV emission line properties). Quasars with higher optical luminosity and/or lower redshift have a higher than average probability of being radio loud, but their median radio luminosity (relative to optical) is much lower than average. We find that, while radio properties of quasars generally cannot be predicted from their optical properties, objects where one expects a strong radiation line driven wind (based on emission line features) have virtually no chance of being radio loud. The redder quasars are in the optical, the more radio flux (relative to optical) they have; this trend holds even for quasars that are not expected to be significantly dust reddened/extincted in the optical. Finally, we consider the radio properties of quasars in the framework of models which describe the radio loud extrema as being due to particularly high spin resulting from second generation mergers and in the context of star formation at lower levels of radio flux. This work was supported by NSF AAG grant 1108798.

  11. Construcción de una Escala Para Medir Creencias Legitimadoras de Violencia en la Población Infantil Elaboration of a Children's Scale That Measures Beliefs Which Legitimize Violence

    Directory of Open Access Journals (Sweden)

    Susan Galdames

    2007-05-01

    Full Text Available Este artículo presenta la construcción y validación preliminar de una escala diseñada para niños y niñas, cuyo objetivo es medir creencias que legitiman la violencia en las relaciones interpersonales. El proceso incluyó su aplicación a 608 niños de 12 colegios de Coquimbo y a 20 niños víctimas de violencia. El instrumento muestra adecuados niveles de confiabilidad y evidencia un constructo multidimensional, compuesto por distintas formas de legitimación de la violencia. Los resultados permiten vincular estas creencias a contextos relaciónales violentos y sugieren su asociación con las variables: cultura escolar y socialización de género. El instrumento se plantea como una herramienta para el estudio de los mecanismos que obstaculizan la erradicación de la violencia en nuestras comunidades.This article presents the development of a scale, designed for children, which measures beliefs that legitimate interpersonal violence. The scale shows adequate reliability and shows evidence of a multidimensional construct, constituted by different ways to legitimize violence. Results suggest an association of this beliefs system with violent relational contexts, school culture and gender socialization. The scale is proposed as a tool for investigation of underlying mechanisms that perpetuate violence in our communities.

  12. The detectability of radio emission from exoplanets

    Science.gov (United States)

    Lynch, C. R.; Murphy, Tara; Lenc, E.; Kaplan, D. L.

    2018-05-01

    Like the magnetised planets in our Solar System, magnetised exoplanets should emit strongly at radio wavelengths. Radio emission directly traces the planetary magnetic fields and radio detections can place constraints on the physical parameters of these features. Large comparative studies of predicted radio emission characteristics for the known population of exoplanets help to identify what physical parameters could be key for producing bright, observable radio emission. Since the last comparative study, many thousands of exoplanets have been discovered. We report new estimates for the radio flux densities and maximum emission frequencies for the current population of known exoplanets orbiting pre-main sequence and main-sequence stars with spectral types F-M. The set of exoplanets predicted to produce observable radio emission are Hot Jupiters orbiting young stars. The youth of these system predicts strong stellar magnetic fields and/or dense winds, which are key for producing bright, observable radio emission. We use a new all-sky circular polarisation Murchison Widefield Array survey to place sensitive limits on 200 MHz emission from exoplanets, with 3σ values ranging from 4.0 - 45.0 mJy. Using a targeted Giant Metre Wave Radio Telescope observing campaign, we also report a 3σ upper limit of 4.5 mJy on the radio emission from V830 Tau b, the first Hot Jupiter to be discovered orbiting a pre-main sequence star. Our limit is the first to be reported for the low-frequency radio emission from this source.

  13. SURVEY PERILAKU MENDENGARKAN RADIO DI JAKARTA

    Directory of Open Access Journals (Sweden)

    Siti Dewi Sri Ratna Sari

    2016-05-01

    Full Text Available This research is to find out the profile of radio broadcasting’s content in Jakarta and to look for measured data as the parameter to assess radio broadcasting programs and the radio listeners profile in DKI Jakarta. The research methodology is survey with 1000 respondents as the sample with 2.24% margin of error and 95% credibility level. The sampling method used is Multistage Random Sampling from 5 out of 6 DKI Jakarta Province areas, except Thousand Islands Regency. Data collection technique used is face to face personal interview by giving gift to the respondents. Research result describes the profile of radio listeners is middle class productive age working men and women whose prime reason listening to radio is music as their pastime. Respondents are categorized as medium listeners with 1.87 hour as their average of listening to radio. Nevertheless, the prime time is covering the whole day both while they are listening at home and while they are mobile. Research found that respondents are already satisfied by the radio programs in Jakarta. The competition of radio stations in Jakarta based on their listeners is Gen FM at the top with 44.6%, followed by Bens Radio, Elshinta, I-Radio, Prambors, CBB, and so on. An interesting finding is that radio’s function to deliver social communication is fulfilled by placing religious speech and information as the second and the third most preferable programs with 9.8% and 8.0% below music program.   Penelitian ini bertujuan untuk mengetahui profil isi siaran radio yang selama ini bersiaran di Jakarta sekaligus mencari data terukur sebagai parameter untuk melakukan penilaian terhadap program isi siaran radio, termasuk pola mendengarkan radio pendengar radio seperti durasi dan tempat di provinsi DKI Jakarta. Metode penelitian berupa survei dengan sampel yang diambil sebanyak 1000 responden, margin of error 2.24% dan tingkat kepercayaan 95%. Metode pengambilan sampel dalam penelitian ini adalah dengan

  14. The Giant Radio Array for Neutrino Detection

    DEFF Research Database (Denmark)

    Martineau-Huynh, Olivier; Bustamante, Mauricio; Carvalho, Washington

    2017-01-01

    The Giant Radio Array for Neutrino Detection (GRAND) is a planned array of ~200 000 radio antennas deployed over ~200 000 km2 in a mountainous site. It aims primarly at detecting high-energy neutrinos via the observation of extensive air showers induced by the decay in the atmosphere of taus...

  15. Orbiting low frequency array for radio astronomy

    NARCIS (Netherlands)

    Rajan, Rai Thilak; Rajan, Raj; Engelen, Steven; Bentum, Marinus Jan; Verhoeven, Chris

    2011-01-01

    Recently new and interesting science drivers have emerged for very low frequency radio astronomy from 0.3 MHz to 30 MHz. However Earth bound radio observations at these wavelengths are severely hampered by ionospheric distortions, man made interference, solar flares and even complete reflection

  16. 50 CFR 300.37 - Radio monitoring.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Radio monitoring. 300.37 Section 300.37 Wildlife and Fisheries INTERNATIONAL FISHING AND RELATED ACTIVITIES INTERNATIONAL FISHERIES REGULATIONS South Pacific Tuna Fisheries § 300.37 Radio monitoring. The international distress frequency, 2.182 mHz...

  17. Radio frequency system for nuclear fusion

    International Nuclear Information System (INIS)

    Kozeki, Shoichiro; Sagawa, Norimoto; Takizawa, Teruhiro

    1987-01-01

    The importance of radio frequency waves has been increasing in the area of nuclear fusion since they are indispensable for heating of plasma, etc. This report outlines radio frequency techniques used for nuclear fusion and describes the development of radio frequency systems (radio frequency plasma heating system and current drive system). Presently, in-depth studies are underway at various research institutes to achieve plasma heating by injection of radio frequency electric power. Three ranges of frequencies, ICRF (ion cyclotron range of frequency), LHRF (lower hybrid range of frequency) and ECRF (electron cyclotron range of frequency), are considered promissing for radio frequency heating. Candidate waves for plasma current driving include ECW (electron cyclotron wave), LHW (lower hybrid wave), MSW (magnetic sound wave), ICW (ion cyclotron wave) with minority component, and FW (fast wave). FW is the greatest in terms of current drive efficiency. In general, a radio frequency system for nuclear fusion consists of a radio frequency power source, transmission/matching circuit component and plasma connection component. (Nogami, K.)

  18. Basic radio interferometry for future lunar missions

    NARCIS (Netherlands)

    Aminaei, Amin; Klein Wolt, Marc; Chen, Linjie; Bronzwaer, Thomas; Pourshaghaghi, Hamid Reza; Bentum, Marinus Jan; Falcke, Heino

    2014-01-01

    In light of presently considered lunar missions, we investigate the feasibility of the basic radio interferometry (RIF) for lunar missions. We discuss the deployment of two-element radio interferometer on the Moon surface. With the first antenna element is envisaged to be placed on the lunar lander,

  19. 14 CFR 99.9 - Radio requirements.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Radio requirements. 99.9 Section 99.9 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.9 Radio requirements. (a) A...

  20. 78 FR 23150 - Commercial Radio Operators

    Science.gov (United States)

    2013-04-18

    ...'s privatized ship radio inspection program. * * * * * 0 3. Section 0.131 is amended by revising... this chapter), and the Commission's privatized ship radio inspection program (part 80 of this chapter... inspection to ships in accordance with applicable provisions of the Communications Act, the Safety Convention...

  1. 47 CFR 32.2231 - Radio systems.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Radio systems. 32.2231 Section 32.2231 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES UNIFORM SYSTEM OF ACCOUNTS FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.2231 Radio systems. (a...

  2. Adaptive OFDM System Design For Cognitive Radio

    NARCIS (Netherlands)

    Zhang, Q.; Kokkeler, Andre B.J.; Smit, Gerardus Johannes Maria

    2006-01-01

    Recently, Cognitive Radio has been proposed as a promising technology to improve spectrum utilization. A highly flexible OFDM system is considered to be a good candidate for the Cognitive Radio baseband processing where individual carriers can be switched off for frequencies occupied by a licensed

  3. Ionospheric Caustics in Solar Radio Observations

    Science.gov (United States)

    Koval, A.; Chen, Y.; Stanislavsky, A.

    2016-12-01

    The Earth ionosphere possesses by natural focusing and defocusing effects on radio waves due to presence of variable ionospheric irregularities which could act like convergent and divergent lenses on incident radiation. In particular, the focusing of emission from the Sun was firstly detected on the Nançay Decameter Array dynamic spectra in the 1980s. On time-frequency spectrograms the intensity variations form specific structures different from well-known solar radio bursts and clearly distinguishing on a background of solar radiation. Such structures have been identified as ionospheric caustics (ICs) and considered to be the result of radio waves refraction on medium scale travelling ionospheric disturbances (MSTIDs). Although nowadays the ICs are registered by different radio observatories due to augmentation of low-frequency radio telescopes, the most recent papers devoted to ICs in solar radio records date back to the 1980s. In this study, we revisit the ICs issue with some new results by conducting a statistical analysis of occurrence rate of ICs in solar dynamic spectra in meter-decameter wavelength range for long continuous period (15 years). The seasonal variations in ICs appearance have been found for the first time. Besides, we report the possible solar cycle dependence of ICs emergence. The radio waves propagation in the ionosphere comprising MSTIDs will be considered. The present research renews the subject of ICs in the low-frequency solar radio astronomy after about 35-year letup.

  4. Mars' radio spectrum and the flying dust.

    NARCIS (Netherlands)

    Roos-Serote, M.; Stam, D.M.; Fender, R.P.

    2004-01-01

    Mars' radio spectrum at centimeter wavelengths is produced by thermal radiation from the surface and sub-surface. Observations at 2.8 cm made in the 1975 and 1978 show variations of its radio brightness as a function of longitude on the planet (Doherty et al. , ApJ 233, 1979). In addition, an

  5. Physical processes in extragalactic radio sources

    NARCIS (Netherlands)

    Carilli, CL; Perley, R; Harris, DE; Barthel, PD

    This paper summarizes extensive observational studies of the closest ultraluminous radio galaxy Cygnus A. These data are used to test jet theory for powering the double-lobed radio emitting structures. Issues addressed include: (i) jet stability, confinement, composition, and velocity, (ii) the

  6. Radio monitoring problems, methods, and equipment

    CERN Document Server

    Rembovsky, Anatoly; Kozmin, Vladimir; Smolskiy, Sergey

    2009-01-01

    Offers a unified approach to fundamental aspects of Automated Radio Monitoring (ARM). This book discusses the development, modeling, design, and manufacture of ARM systems. It provides classification and descriptions of modern high-efficient hardware-software ARM equipment, including the equipment for detection and radio direction-finding.

  7. A Radio-Controlled Car Challenge

    Science.gov (United States)

    Roman, Harry T.

    2010-01-01

    Watching a radio-controlled car zip along a sidewalk or street has become a common sight. Within this toy are the basic ingredients of a mobile robot, used by industry for a variety of important and potentially dangerous tasks. In this challenge, students consider modifying an of-the-shelf, radio-controlled car, adapting it for a robotic task.

  8. Radio Interoperability: There Is More to It Than Hardware

    National Research Council Canada - National Science Library

    Hutchins, Susan G; Timmons, Ronald P

    2007-01-01

    Radio Interoperability: The Problem *Superfluous radio transmissions contribute to auditory overload of first responders -Obscure development of an accurate operational picture for all involved -Radio spectrum is a limited commodity once...

  9. VHF spectrum monitoring using Meraka cognitive radio platform

    CSIR Research Space (South Africa)

    Aderonmu, AI

    2012-11-01

    Full Text Available discuss the Meraka Cognitive Radio Platform (MCRP) developed using the second version of the Universal Serial Radio Peripheral (USRP2) hardware and the GNU Radio software. We also discussed how the spectrum monitoring system is being implemented...

  10. Cognitive Radio RF: Overview and Challenges

    Directory of Open Access Journals (Sweden)

    Van Tam Nguyen

    2012-01-01

    Full Text Available Cognitive radio system (CRS is a radio system which is aware of its operational and geographical environment, established policies, and its internal state. It is able to dynamically and autonomously adapt its operational parameters and protocols and to learn from its previous experience. Based on software-defined radio (SDR, CRS provides additional flexibility and offers improved efficiency to overall spectrum use. CRS is a disruptive technology targeting very high spectral efficiency. This paper presents an overview and challenges of CRS with focus on radio frequency (RF section. We summarize the status of the related regulation and standardization activities which are very important for the success of any emerging technology. We point out some key research challenges, especially implementation challenges of cognitive radio (CR. A particular focus is on RF front-end, transceiver, and analog-to-digital and digital-to-analog interfaces which are still a key bottleneck in CRS development.

  11. Optical spectra and radio properties of quasars

    International Nuclear Information System (INIS)

    Wills, B.J.

    1982-01-01

    Using high quality spectrophotometric scans obtained at the McDonald Observatory, and data from the literature the author shows that, for quasars, the relative strength of optical Fe II emission (the broad blended feature lambda4570) may be roughly inversely proportional to line widths (full width at half maximum, FWHM). A similar relation between the relative intensity of the UV Fe II blend between 2300 and 2600 A (the lambda2500 feature) and the widths of Mg II and Hβ is shown. She distinguishes between compact and extended radio sources and includes radio quiet quasars, Seyfert 1 galaxies and BLRG's. The quasars associated with extended radio sources have the broadest emission lines and the weakest Fe II, falling close to the region occupied by BLRG's which also have extended radio structure. Those quasars with strong Fe II and compact radio structure are most similar to the Seyfert 1 galaxies. (Auth.)

  12. The crisis of the radio producing

    Directory of Open Access Journals (Sweden)

    Dr. Raúl Garcés

    2007-09-01

    Full Text Available In a media world highly influenced by new technologies revolution and the increasing impact of television, speeches on radio are frequently polarized: in one side, some scholars argue radio belongs to the past and it is no longer able of attracting younger audiences. In the other, lay those who predict long life to radio as a source of alternative and communitarian communication experiences. The author reviews the arguments that sustain both perspectives and emphasizes the need of renovating radio producing with audacious and creative formulas. At the same time, he discusses some of the challenges Cuban radio has ahead to attract new audiences, when television and printed press are recovering from the economic crack the Island suffered after Eastern European socialism disappeared.

  13. The statistics of radio emission from quasars

    International Nuclear Information System (INIS)

    Peacock, J.A.; Miller, L.; Longair, M.S.; Edinburgh Univ.

    1986-01-01

    The radio properties of quasars have traditionally been discussed in terms of the radio-to-optical flux-density ratio R, implying a correlation between emission in these wavebands. It is here shown that, for bright quasars, this apparent correlation is largely due to an abrupt change in the radio properties of the quasar population near absolute magnitude Msub(B)=-24. It is suggested that this change in due to the existence of two classes of quasar with differing host galaxies: a proportion of quasars brighter than Msub(B)approx.=-24 lie in elliptical galaxies and thus generate powerful radio sources, while elliptical galaxies with weaker nuclear quasar components are classified as N-galaxies rather than quasars; quasars fainter than Msub(B)approx.=-24 lie in spiral galaxies and thus are high-luminosity analogues of radio-quiet Seyfert galaxies. (author)

  14. Hybrid cognitive engine for radio systems adaptation

    KAUST Repository

    Alqerm, Ismail

    2017-07-20

    Network efficiency and proper utilization of its resources are essential requirements to operate wireless networks in an optimal fashion. Cognitive radio aims to fulfill these requirements by exploiting artificial intelligence techniques to create an entity called cognitive engine. Cognitive engine exploits awareness about the surrounding radio environment to optimize the use of radio resources and adapt relevant transmission parameters. In this paper, we propose a hybrid cognitive engine that employs Case Based Reasoning (CBR) and Decision Trees (DTs) to perform radio adaptation in multi-carriers wireless networks. The engine complexity is reduced by employing DTs to improve the indexing methodology used in CBR cases retrieval. The performance of our hybrid engine is validated using software defined radios implementation and simulation in multi-carrier environment. The system throughput, signal to noise and interference ratio, and packet error rate are obtained and compared with other schemes in different scenarios.

  15. Radio Frequency Interference: The Study of Rain Effect on Radio Signal Attenuation

    International Nuclear Information System (INIS)

    Roslan Umar; Roslan Umar; Shahirah Syafa Sulan; Atiq Wahidah Azlan; Zainol Abidin Ibrahim

    2015-01-01

    The intensity of radio waves received by radio telescopes is always not subject to human control. In the millimetre band, the propagation of the electromagnetic waves is severely affected by rain rate, dust particle size and drop size in the terms of attenuation, noise and depolarization. At the frequency above 10 GHz, the absorption and scattering by rain cause a reduction in the transmitted signal amplitude which will lead to the reducing of the availability, reliability and performance on the communications link. In this study, the rain effect on radio signal has been investigated. Spectrum analyzer and weather stations were used to obtain the RFI level and rain rate data respectively. The radio frequency interference (RFI) pattern due to rain factor was determined. This will benefit radio astronomer in managing sites for radio observation for radio astronomy purposes. (author)

  16. Planck early results. XV. Spectral energy distributions and radio continuum spectra of northern extragalactic radio sources

    DEFF Research Database (Denmark)

    Aatrokoski, J.; Lähteenmäki, A.; Lavonen, N.

    2011-01-01

    Spectral energy distributions (SEDs) and radio continuum spectra are presented for a northern sample of 104 extragalactic radio sources, based on the Planck Early Release Compact Source Catalogue (ERCSC) and simultaneous multifrequency data. The nine Planck frequencies, from 30 to 857 GHz......, are complemented by a set of simultaneous observations ranging from radio to gamma-rays. This is the first extensive frequency coverage in the radio and millimetre domains for an essentially complete sample of extragalactic radio sources, and it shows how the individual shocks, each in their own phase...... of development, shape the radio spectra as they move in the relativistic jet. The SEDs presented in this paper were fitted with second and third degree polynomials to estimate the frequencies of the synchrotron and inverse Compton (IC) peaks, and the spectral indices of low and high frequency radio data...

  17. Program on Resorbable Radio Devices

    Science.gov (United States)

    2014-05-05

    water   electrolysis  to give out gas ‐. Gas pushes  water  out of the weak point of the  water   tank, e.g., a pre‐made hole with/without covering with  a thin...are capable of complete dissolution in water . The views, opinions and/or findings contained in this report are those of the author(s) and should not...device designs for radio enabled electronics that are capable of complete dissolution in water . (a) Papers published in peer-reviewed journals (N/A

  18. VLSI Technology for Cognitive Radio

    Science.gov (United States)

    VIJAYALAKSHMI, B.; SIDDAIAH, P.

    2017-08-01

    One of the most challenging tasks of cognitive radio is the efficiency in the spectrum sensing scheme to overcome the spectrum scarcity problem. The popular and widely used spectrum sensing technique is the energy detection scheme as it is very simple and doesn’t require any previous information related to the signal. We propose one such approach which is an optimised spectrum sensing scheme with reduced filter structure. The optimisation is done in terms of area and power performance of the spectrum. The simulations of the VLSI structure of the optimised flexible spectrum is done using verilog coding by using the XILINX ISE software. Our method produces performance with 13% reduction in area and 66% reduction in power consumption in comparison to the flexible spectrum sensing scheme. All the results are tabulated and comparisons are made. A new scheme for optimised and effective spectrum sensing opens up with our model.

  19. Radio Frequency Energy Harvesting Sources

    Directory of Open Access Journals (Sweden)

    Action NECHIBVUTE

    2017-12-01

    Full Text Available This radio frequency (RF energy harvesting is an emerging technology and research area that promises to produce energy to run low-power wireless devices. The great interest that has recently been paid to RF harvesting is predominantly driven by the great progress in both wireless communication systems and broadcasting technologies that have availed a lot of freely propagating ambient RF energy. The principle aim of an RF energy harvesting system is to convert the received ambient RF energy into usable DC power. This paper presents a state of the art concise review of RF energy harvesting sources for low power applications, and also discusses open research questions and future research directions on ambient RF energy harvesting.

  20. Integral luminosities of radio pulsars

    Science.gov (United States)

    Malov, I.; Malov, O.

    The integral radio luminosities L for 311 normal pulsars and for 27 ones with the rotation period Pfalls for fast ones. The mean values of K are -3.73 and -4.85 for normal and fast pulsars, respectively. There are no changes of L with the kinematic age T = z/V, where z is the pulsar height over the Galactic plane and V = 300 km/s is its mean velocity. The correlation between L and the rate of the rotation energy losses E is detected for both pulsar groups under consideration. It is shown that L= A E^(1/3) for the whole sample. The total number of pulsars in the Galaxy and their birth rate are in agreement with data on the rate of supernova explosions.

  1. Can Radio Telescopes Find Axions?

    Science.gov (United States)

    Kohler, Susanna

    2017-08-01

    axions. Now scientists Katharine Kelley and Peter Quinn at ICRAR, University of Western Australia, have explored how we might use next-generation radio telescopes to search for photons that were created by axions interacting with the magnetic fields of our galaxy.Hope for Next-Gen TelescopesPotential axion coupling strengths vs. mass (click for a closer look). The axion mass is thought to lie between a eV and a meV; two theoretical models are shown with dashed lines. The plot shows the sensitivity of the upcoming SKA and its precursors, ASKAP and MEERKAT. [KelleyQuinn 2017]By using a simple galactic halo model and reasonable assumptions for the central galactic magnetic field even taking into account the time dependence of the field Kelley and Quinn estimate the radio-frequency power density that we would observe at Earth from axions being converted to photons within the Milky Ways magnetic field.The authors then compare this signature to the detection capabilities of upcoming radio telescope arrays. They show that the upcoming Square Kilometer Array and its precursors should have the capability to detect signs of axions across large parts of parameter space.Kelley and Quinn conclude that theres good cause for optimism about future radio telescopes ability to detect axions. And if we did succeed in making a detection, it would be a triumph for both particle physics and astrophysics, finally providing an explanation for the universes dark matter.CitationKatharine Kelley and P. J. Quinn 2017 ApJL 845 L4. doi:10.3847/2041-8213/aa808d

  2. Grote Reber, Radio Astronomy Pioneer, Dies

    Science.gov (United States)

    2002-12-01

    Grote Reber, one of the earliest pioneers of radio astronomy, died in Tasmania on December 20, just two days shy of his 91st birthday. Reber was the first person to build a radio telescope dedicated to astronomy, opening up a whole new "window" on the Universe that eventually produced such landmark discoveries as quasars, pulsars and the remnant "afterglow" of the Big Bang. His self- financed experiments laid the foundation for today's advanced radio-astronomy facilities. Grote Reber Grote Reber NRAO/AUI photo "Radio astronomy has changed profoundly our understanding of the Universe and has earned the Nobel Prize for several major contributions. All radio astronomers who have followed him owe Grote Reber a deep debt for his pioneering work," said Dr. Fred Lo, director of the National Radio Astronomy Observatory (NRAO). "Reber was the first to systematically study the sky by observing something other than visible light. This gave astronomy a whole new view of the Universe. The continuing importance of new ways of looking at the Universe is emphasized by this year's Nobel Prizes in physics, which recognized scientists who pioneered X-ray and neutrino observations," Lo added. Reber was a radio engineer and avid amateur "ham" radio operator in Wheaton, Illinois, in the 1930s when he read about Karl Jansky's 1932 discovery of natural radio emissions coming from outer space. As an amateur operator, Reber had won awards and communicated with other amateurs around the world, and later wrote that he had concluded "there were no more worlds to conquer" in radio. Learning of Jansky's discovery gave Reber a whole new challenge that he attacked with vigor. Analyzing the problem as an engineer, Reber concluded that what he needed was a parabolic-dish antenna, something quite uncommon in the 1930s. In 1937, using his own funds, he constructed a 31.4-foot-diameter dish antenna in his back yard. The strange contraption attracted curious attention from his neighbors and became

  3. Radio Flares from Gamma-ray Bursts

    Science.gov (United States)

    Kopač, D.; Mundell, C. G.; Kobayashi, S.; Virgili, F. J.; Harrison, R.; Japelj, J.; Guidorzi, C.; Melandri, A.; Gomboc, A.

    2015-06-01

    We present predictions of centimeter and millimeter radio emission from reverse shocks (RSs) in the early afterglows of gamma-ray bursts (GRBs) with the goal of determining their detectability with current and future radio facilities. Using a range of GRB properties, such as peak optical brightness and time, isotropic equivalent gamma-ray energy, and redshift, we simulate radio light curves in a framework generalized for any circumburst medium structure and including a parameterization of the shell thickness regime that is more realistic than the simple assumption of thick- or thin-shell approximations. Building on earlier work by Mundell et al. and Melandri et al. in which the typical frequency of the RS was suggested to lie at radio rather than optical wavelengths at early times, we show that the brightest and most distinct RS radio signatures are detectable up to 0.1-1 day after the burst, emphasizing the need for rapid radio follow-up. Detection is easier for bursts with later optical peaks, high isotropic energies, lower circumburst medium densities, and at observing frequencies that are less prone to synchrotron self-absorption effects—typically above a few GHz. Given recent detections of polarized prompt gamma-ray and optical RS emission, we suggest that detection of polarized radio/millimeter emission will unambiguously confirm the presence of low-frequency RSs at early time.

  4. RADIO FLARES FROM GAMMA-RAY BURSTS

    International Nuclear Information System (INIS)

    Kopač, D.; Mundell, C. G.; Kobayashi, S.; Virgili, F. J.; Harrison, R.; Japelj, J.; Gomboc, A.; Guidorzi, C.; Melandri, A.

    2015-01-01

    We present predictions of centimeter and millimeter radio emission from reverse shocks (RSs) in the early afterglows of gamma-ray bursts (GRBs) with the goal of determining their detectability with current and future radio facilities. Using a range of GRB properties, such as peak optical brightness and time, isotropic equivalent gamma-ray energy, and redshift, we simulate radio light curves in a framework generalized for any circumburst medium structure and including a parameterization of the shell thickness regime that is more realistic than the simple assumption of thick- or thin-shell approximations. Building on earlier work by Mundell et al. and Melandri et al. in which the typical frequency of the RS was suggested to lie at radio rather than optical wavelengths at early times, we show that the brightest and most distinct RS radio signatures are detectable up to 0.1–1 day after the burst, emphasizing the need for rapid radio follow-up. Detection is easier for bursts with later optical peaks, high isotropic energies, lower circumburst medium densities, and at observing frequencies that are less prone to synchrotron self-absorption effects—typically above a few GHz. Given recent detections of polarized prompt gamma-ray and optical RS emission, we suggest that detection of polarized radio/millimeter emission will unambiguously confirm the presence of low-frequency RSs at early time

  5. Amateur Planetary Radio Data Archived for Science and Education: Radio Jove

    Science.gov (United States)

    Thieman, J.; Cecconi, B.; Sky, J.; Garcia, L. N.; King, T. A.; Higgins, C. A.; Fung, S. F.

    2015-12-01

    The Radio Jove Project is a hands-on educational activity in which students, teachers, and the general public build simple radio telescopes, usually from a kit, to observe single frequency decameter wavelength radio emissions from Jupiter, the Sun, the galaxy, and the Earth usually with simple dipole antennas. Some of the amateur observers have upgraded their receivers to spectrographs and their antennas have become more sophisticated as well. The data records compare favorably to more sophisticated professional radio telescopes such as the Long Wavelength Array (LWA) and the Nancay Decametric Array. Since these data are often carefully calibrated and recorded around the clock in widely scattered locations they represent a valuable database useful not only to amateur radio astronomers but to the professional science community as well. Some interesting phenomena have been noted in the data that are of interest to the professionals familiar with such records. The continuous monitoring of radio emissions from Jupiter could serve as useful "ground truth" data during the coming Juno mission's radio observations of Jupiter. Radio Jove has long maintained an archive for thousands of Radio Jove observations, but the database was intended for use by the Radio Jove participants only. Now, increased scientific interest in the use of these data has resulted in several proposals to translate the data into a science community data format standard and store the data in professional archives. Progress is being made in translating Radio Jove data to the Common Data Format (CDF) and also in generating new observations in that format as well. Metadata describing the Radio Jove data would follow the Space Physics Archive Search and Extract (SPASE) standard. The proposed archive to be used for long term preservation would be the Planetary Data System (PDS). Data sharing would be achieved through the PDS and the Paris Astronomical Data Centre (PADC) and the Virtual Wave Observatory (VWO

  6. Extended radio sources in the cluster environment

    International Nuclear Information System (INIS)

    Burns, J.O. Jr.

    1979-01-01

    Extended radio galaxies that lie in rich and poor clusters were studied. A sample of 3CR and 4C radio sources that spatially coincide with poor Zwicky clusters of galaxies was observed to obtain accurate positions and flux densities. Then interferometer observations at a resolution of approx. = 10 arcsec were performed on the sample. The resulting maps were used to determine the nature of the extended source structure, to make secure optical identifications, and to eliminate possible background sources. The results suggest that the environments around both classical double and head-tail radio sources are similar in rich and poor clusters. The majority of the poor cluster sources exhibit some signs of morphological distortion (i.e., head-tails) indicative of dynamic interaction with a relatively dense intracluster medium. A large fraction (60 to 100%) of all radio sources appear to be members of clusters of galaxies if one includes both poor and rich cluster sources. Detailed total intensity and polarization observations for a more restricted sample of two classical double sources and nine head-tail galaxies were also performed. The purpose was to examine the spatial distributions of spectral index and polarization. Thin streams of radio emission appear to connect the nuclear radio-point components to the more extended structures in the head-tail galaxies. It is suggested that a non-relativistic plasma beam can explain both the appearance of the thin streams and larger-scale structure as well as the energy needed to generate the observed radio emission. The rich and poor radio cluster samples are combined to investigate the relationship between source morphology and the scale sizes of clustering. There is some indication that a large fraction of radio sources, including those in these samples, are in superclusters of galaxies

  7. Diseño y validación de una escala para medir la percepción sobre el trabajo en el primer nivel de atención en estudiantes de medicina de Latinoamérica

    Directory of Open Access Journals (Sweden)

    Percy Mayta-Tristán

    Full Text Available Objetivos. Diseñar y validar una escala para evaluar la percepción sobre el primer nivel de atención (PNA en estudiantes de medicina latinoamericanos. Materiales y métodos. Se realizó un estudio multicéntrico, observacional, en dos fases: i Se diseñó un cuestionario autoaplicado referente a la percepción sobre la labor del médico en el PNA, y ii Se aplicó el cuestionario en estudiantes de medicina de 18 universidades de ocho países hispanohablantes latinoamericanos. Se desarrolló un análisis factorial exploratorio (AFE por medio de un análisis de componentes principales con rotación ortogonal varimax. Se evaluó la adecuación y el ajuste de la muestra. La extracción de factores fue hecha en base a los criterios de Kaiser, la pendiente de Catell y la varianza explicada (>5%. La consistencia interna fue medida con el alfa de Cronbach. Resultados. Se incluyeron 423 estudiantes, el 53,4% pertenecían a universidades peruanas. Tras el AFE el cuestionario quedo constituido por 11 ítems, los cuales se distribuyen en tres dominios que, en su conjunto, explican el 55,47% de la varianza total. i Percepciones sobre el médico que trabaja en PNA, ii Percepciones sobre el trabajo asistencial en PNA y iii Percepciones sobre las consecuencias económicas de trabajar en PNA. Conclusiones. La escala presenta tres dominios y constituye un instrumento que puede ser usado para medir las percepciones sobre el trabajo médico en el primer nivel de atención en estudiantes de medicina latinoamericanos de habla hispana.

  8. Mobile radio channel as a complex medium

    DEFF Research Database (Denmark)

    Matic, Dusan; Prasad, Ramjee; Kalluri, Dikshitulu K.

    2001-01-01

    physical phenomena, their implications on the transmitted signal, and how the radio channels are modelled. Special attention is given to the small-scale effects, such as multipath, and Rayleigh and Rice distributions of received signal, as these dominate in the case of indoor communication systems.......Optical fibres have almost unlimited capacity, but can not the address the users desire for mobility and ubiquitous access. The synergy of these two worlds can be seen in the direction of the Radio-over-Fibre. This paper presents to the reader an introduction for the mobile radio channel - basic...

  9. Particle reacceleration and apparent radio source structure

    International Nuclear Information System (INIS)

    Eilek, J.A.

    1982-01-01

    The radio galaxy model which uses magnetohydrodynamic turbulence generated by surface instabilities to reaccelerate the radiating electrons has striking consequences for apparent source structure. Strong wave damping in the plasma results in a narrow turbulent edge. Particles accelerated in this edge must diffuse across field lines into the radio source; this predicts strong limb brightening in some cases. The structure of this edge and diffusion into the source are described. The relevance of this model to jets, radio tails, and standard double sources is discussed

  10. New radio observations of NGC1275

    International Nuclear Information System (INIS)

    Pedlar, A.; Perley, R.; Crane, P.; Harrison, B.; Davies, R.D.

    1986-01-01

    VLA maps are presented for NGC1275 at 20 cm, with resolutions ranging from 1 to 40 arcsec. Over the central 30 arcsec there is evidence for collimated ejection at position angle -160 deg. Outside this region the radio structure bends rapidly by approximately 90 deg before merging into the 10-arcmin radio halo. It is suggested that models of pressure-driven accretion flows should take into account the presence of the relativistic gas which is responsible for the radio halo. 14 references

  11. Blazars with arcminute-scale radio halos

    International Nuclear Information System (INIS)

    Ulvestad, J.S.; Antonucci, R.R.J.; Space Telescope Science Institute, Baltimore, MD)

    1986-01-01

    About 10-arcsec resolution 20-cm wavelength maps are presented for three nearby BL Lac objects: Mkn 180, whose halo has a linear size of 85 kpc, 2155-304, with a halo about 375 kpc across, and 1727 + 502, whose one-sided diffuse emission extends to a distance of about 145 kpc from its radio core. Little evidence is found for strong radio variability in the cores of the three blazars; these and other results obtained are consistent with the assertion that the three objects should be classified as normal low luminosity double radio galaxies with optically dull nuclei, if seen from other directions. 20 references

  12. Cognitive Radio MAC Protocol for WLAN

    DEFF Research Database (Denmark)

    Zhang, Qi; Fitzek, Frank H.P.; Iversen, Villy Bæk

    2008-01-01

    hole; moreover, it designs dual inband sensing scheme to detect primary user appearance. Additionally, C-CSMA/CA has the advantage to effectively solve the cognitive radio self-coexistence issues in the overlapping CR BSSs scenario. It also realizes station-based dynamic resource selection......To solve the performance degradation issue in current WLAN caused by the crowded unlicensed spectrum, we propose a cognitive radio (CR) media access protocol, C-CSMA/CA. The basic idea is that with cognitive radio techniques the WLAN devices can not only access the legacy WLAN unlicensed spectrum...

  13. Radio Imaging of Envelopes of Evolved Stars

    Science.gov (United States)

    Cotton, Bill

    2018-04-01

    This talk will cover imaging of stellar envelopes using radio VLBI techniques; special attention will be paid to the technical differences between radio and optical/IR interferomery. Radio heterodyne receivers allow a straightforward way to derive spectral cubes and full polarization observations. Milliarcsecond resolution of very bright, i.e. non thermal, emission of molecular masers in the envelopes of evolved stars can be achieved using VLBI techniques with baselines of thousands of km. Emission from SiO, H2O and OH masers are commonly seen at increasing distance from the photosphere. The very narrow maser lines allow accurate measurements of the velocity field within the emitting region.

  14. New radio meteor detecting and logging software

    Science.gov (United States)

    Kaufmann, Wolfgang

    2017-08-01

    A new piece of software ``Meteor Logger'' for the radio observation of meteors is described. It analyses an incoming audio stream in the frequency domain to detect a radio meteor signal on the basis of its signature, instead of applying an amplitude threshold. For that reason the distribution of the three frequencies with the highest spectral power are considered over the time (3f method). An auto notch algorithm is developed to prevent the radio meteor signal detection from being jammed by a present interference line. The results of an exemplary logging session are discussed.

  15. Radio continuum, far infrared and star formation

    International Nuclear Information System (INIS)

    Wielebinski, R.; Wunderlich, E.; Klein, U.; Hummel, E.

    1987-01-01

    A very tight correlation was found between the radio emission and the far infrared emission from galaxies. This has been found for various samples of galaxies and is explained in terms of recent star formation. The tight correlation would imply that the total radio emission is a good tracer of star formation. The correlation between the radio power at 5 GHz and the far infrared luminosity is shown. The galaxies are of various morphological types and were selected from the various IRAS circulars, hence the sample is an infrared selected sample. The far infrared luminosities were corrected for the dust temperature. This is significant because it decreases the dispersion in the correlation

  16. NAC/NINE Program Building Radio Jove's and Brining Radio Astronomy to the Community

    Science.gov (United States)

    Ramona Gallego, Angelina; Paul Gueye, Al Amin Kabir,

    2018-01-01

    During the course of the 8-week program, (NINE, National and International Non-Traditional Exchange Program), the summer was spent in Socorro, New Mexico, working on building a Radio Jove, and making observations with the Radio Jove as well as working on learning project management practices in order to take the CAPM PMI Exam. The NINE built the Radio Jove’s at the same time and in doing so learned to replicate it to teach it to others. The final portion of the program that was worked on was to create a NINE hub and do outreach with the community teaching them about radio astronomy and teaching students how to build their own Radio Jove’s and make observations. An important aspect of the summer program was to bring back the knowledge received about radio astronomy and teach it to high school students with the help of the institution each NINE participants came from.

  17. Aliphatic Nucleophilic Radio-fluorination

    International Nuclear Information System (INIS)

    Roeda, D.; Dolle, F.

    2010-01-01

    In this review we are looking at some aspects of nucleophilic aliphatic radio-fluorination, notably the labelled fluoride source, design aspects, the leaving group and the solvent. It should be clear that there is more to this branch of radiolabelling than one would suspect from the frequently used standard tosylate replacement with kryptofix/[ 18 F]fluoride in acetonitrile or DMSO. Competitive elimination can be a serious problem that can affect both yield and purification. De-protection of sensitive groups after radiolabelling and its possible side reactions can complicate purification. The right choice of leaving group and protecting groups may be crucial. Newer developments such as the use of tertiary alcohols or ionic liquids as solvents, long-chain poly-fluorinated sulphonate leaving groups facilitating fluorous solid phase extraction, or immobilisation of the precursor on a solid phase support may help to solve these problems, for example the longstanding problems with [ 18 F]FLT, whereas older concepts such as certain cyclic reactive entities for ring opening or even an abandoned reagent as [ 18 F]DAST should not be forgotten. (authors)

  18. Nganyi Community Resource Centre: Community radio station ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2016-05-04

    May 4, 2016 ... To mark World Meteorological Day on March 23, 2015, the Kenya Meteorological Services (KMS) launched a resource centre and radio station in western Kenya to disseminate weather and climate information.

  19. Mean field games for cognitive radio networks

    KAUST Repository

    Tembine, Hamidou; Tempone, Raul; Vilanova, Pedro

    2012-01-01

    In this paper we study mobility effect and power saving in cognitive radio networks using mean field games. We consider two types of users: primary and secondary users. When active, each secondary transmitter-receiver uses carrier sensing

  20. Fabrication of superconducting niobium radio frequency structures

    International Nuclear Information System (INIS)

    Kirchgessner, J.; Amato, J.; Brawley, J.

    1983-01-01

    During the last several years a variety of superconducting radio frequency structures have been designed, fabricated and tested. The diverse structures and fabrication techniques are described. This paper is a description of the authors' experiences in this field

  1. Solar energetic particles and radio burst emission

    Directory of Open Access Journals (Sweden)

    Miteva Rositsa

    2017-01-01

    Full Text Available We present a statistical study on the observed solar radio burst emission associated with the origin of in situ detected solar energetic particles. Several proton event catalogs in the period 1996–2016 are used. At the time of appearance of the particle origin (flare and coronal mass ejection we identified radio burst signatures of types II, III and IV by inspecting dynamic radio spectral plots. The information from observatory reports is also accounted for during the analysis. The occurrence of solar radio burst signatures is evaluated within selected wavelength ranges during the solar cycle 23 and the ongoing 24. Finally, we present the burst occurrence trends with respect to the intensity of the proton events and the location of their solar origin.

  2. Ionosphere and its Influence on Radio Communications

    Indian Academy of Sciences (India)

    Italian radio pioneer G Marconi succeeded in transmitting. 'wireless' signals over a distance of about 2000 miles across the. Atlantic Ocean. Physicists had .... indirectly, to the ionizing power of the solar radiation. As this radiation penetrates the ...

  3. Rural Radio in Bolivia: A Case Study.

    Science.gov (United States)

    Gwyn, Robert J.

    1983-01-01

    Examines the programing and audiences of two small rural commercial radio stations in the Jordan and Punata provinces. Shows how these stations have interacted with the local culture and how they offer significant potential for development. (PD)

  4. Radio transmission system for industrial area

    International Nuclear Information System (INIS)

    Iliescu, M.; Culcer, M.; Curuia, M.; Anghel, N.M.; Stefanescu, I.

    2003-01-01

    The paper deals with a data transmission system operating in a large, noisy industrial area. The radio transmission system permits data and commands communication between the local units of collecting data and a central monitoring and/or command station ( dispatch). The communication support are radio waves in the range 450 MHz. The transducers are of transmitter type, with 4-20 mA output signal, providing information about environmental and/or work parameters. Data are primarily acquisitioned in a data logger with microcontroller, then transmitted via a FSK radio modem and a radio station to the dispatch. Data logger can also be connected in a network. The dispatch personal computer receives and processes data and transmits commands. The system functioning is supervised by a communication software in MCS - 51 assembler and an application software in Visual C ++ . (author)

  5. Information Management: Military Affiliate Radio System (MARS)

    National Research Council Canada - National Science Library

    1986-01-01

    .... It describes a program sponsored by the Department of Defense and supported by the Department of the Army in which military installations, military units, clubs, and volunteer licensed amateur radio...

  6. Software Defined Multiband EVA Radio, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this research is to propose a reliable, lightweight, programmable, multi-band, multi-mode, miniaturized frequency-agile EVA software defined radio...

  7. Reconfigurable, Cognitive Software Defined Radio, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — IAI is actively developing Software Defined Radio platforms that can adaptively switch between different modes of operation by modifying both transmit waveforms and...

  8. Software Defined Multiband EVA Radio, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of Phase 2 is to build a reliable, lightweight, programmable, multi-mode, miniaturized EVA Software Defined Radio (SDR) that supports data telemetry,...

  9. Distortion mitigation in cognitive radio receivers

    NARCIS (Netherlands)

    Mahrof, D.H.

    2015-01-01

    The exponential increase of wireless communication increasingly leads to spectrum congestion. Attempts are being made to increase RF spectrum utilization efficiency by introducing Cognitive Radio (CR) concept. A CR tries to intelligently solve the congestion problem via Dynamic Spectrum Access

  10. mathematical models for estimating radio channels utilization

    African Journals Online (AJOL)

    2017-08-08

    Aug 8, 2017 ... Mathematical models for radio channels utilization assessment by real-time flows transfer in ... data transmission networks application having dynamic topology ..... Journal of Applied Mathematics and Statistics, 56(2): 85–90.

  11. Hybrid cognitive engine for radio systems adaptation

    KAUST Repository

    Alqerm, Ismail; Shihada, Basem

    2017-01-01

    of our hybrid engine is validated using software defined radios implementation and simulation in multi-carrier environment. The system throughput, signal to noise and interference ratio, and packet error rate are obtained and compared with other schemes

  12. Reconfigurable, Cognitive Software Defined Radio, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Intelligent Automation Inc, (IAI) is currently developing a software defined radio (SDR) platform that can adaptively switch between different modes of operation for...

  13. 49 CFR 220.23 - Publication of radio information.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Publication of radio information. 220.23 Section... § 220.23 Publication of radio information. Each railroad shall designate where radio base stations are.... The publication shall indicate the periods during which base and wayside radio stations are...

  14. Community Radio in Political Theory and Development Practice

    African Journals Online (AJOL)

    zeleza

    These structural and conceptual elements provide community radio the ... characteristic problems of development projects based on its theoretical and structural .... and to fix basic radio equipment is a standard practice of community radio stations. ... community radio stations and participatory media organizations, but also ...

  15. 47 CFR 2.107 - Radio astronomy station notification.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Radio astronomy station notification. 2.107....107 Radio astronomy station notification. (a) Pursuant to No. 1492 of Article 13 and Section F of Appendix 3 to the international Radio Regulations (Geneva, 1982), operators of radio astronomy stations...

  16. Survival and reproduction of radio-marked adult spotted owls.

    Science.gov (United States)

    C.C. Foster; E.D. Forsman; E.C. Meslow; G.S. Miller; J.A. Reid; F.F. Wagner; A.B. Carey; J.B. Lint

    1992-01-01

    We compared survival, reproduction, and body mass of radio-marked and non radio-marked spotted owls (Strix occidentalis) to determine if backpack radios influenced reproduction or survival. In most study areas and years, there were no differences (P > 0.05) in survival of males and females or in survival of radio-marked versus banded owls. There...

  17. Communicating Science for Impact: Radio for Reaching Farmers ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Radio to share results The project will translate research results into simple radio campaign messages targeting small-scale farmers. Researchers will test ... The project will assess the effect of radio campaigns in influencing adoption decisions among listeners. Farm Radio ... Agent(e) responsable du CRDI. crmadm CRM ...

  18. 47 CFR 20.9 - Commercial mobile radio service.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Commercial mobile radio service. 20.9 Section... COMMERCIAL MOBILE RADIO SERVICES § 20.9 Commercial mobile radio service. (a) The following mobile services shall be treated as common carriage services and regulated as commercial mobile radio services...

  19. Sending the right message : forty years of BBC Radio News

    NARCIS (Netherlands)

    Luscombe-Serlie, J.C.

    2012-01-01

    Radio is, compared to television and newspapers, an under-researched area in media studies. This research has looked at BBC Radio News in the period 1966-2008; it is a case study into the views of 43 (former) writers of the BBC Radio Newsroom and BBC Radio One. Interviews were conducted with

  20. Paradigms of modern radio-biology

    International Nuclear Information System (INIS)

    Grodzins'kij, D.M.

    2005-01-01

    The basic paradigms of modern radio-biology are considered as models of pictures of essence of radio-biology problems and methods of their decision. It is marked on absolute heuristics of these ascending conceptual assertions and their assistance to subsequent development of experimental science. That has the concrete display in the decision of actual tasks of protection of people from action of ionizing radiation

  1. First Colombian Solar Radio Interferometer: current stage

    Science.gov (United States)

    Guevara Gómez, J. C.; Martínez Oliveros, J. C.; Calvo-Mozo, B.

    2017-10-01

    Solar radio astronomy is a fast developing research field in Colombia. Here, we present the scientific goals, specifications and current state of the First Colombian Solar Radio Interferometer consisting of two log-periodic antennas covering a frequency bandwidth op to 800 MHz. We describe the importance and benefits of its development to the radioastronomy in Latin America and its impact on the scientific community and general public.

  2. Designing for cooperation at a Radio Station

    DEFF Research Database (Denmark)

    Kensing, F.; Simonsen, Jesper; Bødker, Keld

    1997-01-01

    We address computer support for work and its coordination in one of the radio channels of the Danish Broadcasting Corporation. Based upon ethnographically inspired analysis and participatory design techniques, we propose design solutions now implemented or under implementation. We focus on cooper......We address computer support for work and its coordination in one of the radio channels of the Danish Broadcasting Corporation. Based upon ethnographically inspired analysis and participatory design techniques, we propose design solutions now implemented or under implementation. We focus...

  3. Big Data Challenges for Large Radio Arrays

    Science.gov (United States)

    Jones, Dayton L.; Wagstaff, Kiri; Thompson, David; D'Addario, Larry; Navarro, Robert; Mattmann, Chris; Majid, Walid; Lazio, Joseph; Preston, Robert; Rebbapragada, Umaa

    2012-01-01

    Future large radio astronomy arrays, particularly the Square Kilometre Array (SKA), will be able to generate data at rates far higher than can be analyzed or stored affordably with current practices. This is, by definition, a "big data" problem, and requires an end-to-end solution if future radio arrays are to reach their full scientific potential. Similar data processing, transport, storage, and management challenges face next-generation facilities in many other fields.

  4. Mengusung Masyarakat Madani Melalui Radio Komunitas

    Directory of Open Access Journals (Sweden)

    Dede Lilis Chaerowati

    2013-12-01

    Full Text Available This article is about the phenomenon of community radio in Pantura Area, West Java. Radio communities maganed by, for and about the community are rapidly developing among the farmers and fishermen, including in Pantura Area, West Java. The focus of the study is the formation of civil society by standing firmly on communicative actions of Jürgen Habermas. By using qualitative method with case study design, a finding would be produced that community radios implement participatory paradigm and manage community cohesion. We will discuss in details on: (1 initiators of the establishment of community radio, (2 forms of community participation, (3 the financing source of community radio, and (4 the construction of civil society through community radio. This article also covers about how the people see the world of life, that there is social transformation through emancipatordialogs, which then produce community’s selfconsciousness  as individuals and community members in demanding a domination-free communication process. This reality creates the origination of civil society.

  5. Radio-flaring Ultracool Dwarf Population Synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Route, Matthew, E-mail: mroute@purdue.edu [Department of Astronomy and Astrophysics, the Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States)

    2017-08-10

    Over a dozen ultracool dwarfs (UCDs), low-mass objects of spectral types ≥M7, are known to be sources of radio flares. These typically several-minutes-long radio bursts can be up to 100% circularly polarized and have high brightness temperatures, consistent with coherent emission via the electron cyclotron maser operating in approximately kilogauss magnetic fields. Recently, the statistical properties of the bulk physical parameters that describe these UCDs have become described adequately enough to permit synthesis of the population of radio-flaring objects. For the first time, I construct a Monte Carlo simulator to model the population of these radio-flaring UCDs. This simulator is powered by Intel Secure Key (ISK), a new processor technology that uses a local entropy source to improve random number generation that has heretofore been used to improve cryptography. The results from this simulator indicate that only ∼5% of radio-flaring UCDs within the local interstellar neighborhood (<25 pc away) have been discovered. I discuss a number of scenarios that may explain this radio-flaring fraction and suggest that the observed behavior is likely a result of several factors. The performance of ISK as compared to other pseudorandom number generators is also evaluated, and its potential utility for other astrophysical codes is briefly described.

  6. Radio Source Morphology: 'nature or nuture'?

    Science.gov (United States)

    Banfield, Julie; Emonts, Bjorn; O'Sullivan, Shane

    2012-10-01

    Radio sources, emanating from supermassive black-holes in the centres of active galaxies, display a large variety of morphological properties. It is a long-standing debate to what extent the differences between various types of radio sources are due to intrinsic properties of the central engine (`nature') or due to the properties of the interstellar medium that surrounds the central engine and host galaxy (`nurture'). Settling this `nature vs. nurture' debate for nearby radio galaxies, which can be studied in great detail, is vital for understanding the properties and evolution of radio galaxies throughout the Universe. We propose to observe the radio galaxy NGC 612 where previous observations have detected the presence of a large-scale HI bridge between the host galaxy and a nearby galaxy NGC 619. We request a total of 13 hrs in the 750m array-configuration to determine whether or not the 100 kpc-scale radio source morphology is directly related to the intergalactic distribution of neutral hydrogen gas.

  7. Radio-quiet Gamma-ray Pulsars

    Directory of Open Access Journals (Sweden)

    Lupin Chun-Che Lin

    2016-09-01

    Full Text Available A radio-quiet γ-ray pulsar is a neutron star that has significant γ-ray pulsation but without observed radio emission or only limited emission detected by high sensitivity radio surveys. The launch of the Fermi spacecraft in 2008 opened a new epoch to study the population of these pulsars. In the 2nd Fermi Large Area Telescope catalog of γ-ray pulsars, there are 35 (30 % of the 117 pulsars in the catalog known samples classified as radio-quiet γ-ray pulsars with radio flux density (S1400 of less than 30 μJy. Accompanying the observations obtained in various wavelengths, astronomers not only have the opportunity to study the emitting nature of radio-quiet γ-ray pulsars but also have proposed different models to explain their radiation mechanism. This article will review the history of the discovery, the emission properties, and the previous efforts to study pulsars in this population. Some particular cases known as Geminga-like pulsars (e.g., PSR J0633+1746, PSR J0007+7303, PSR J2021+4026, and so on are also to specified discuss their common and specific features.

  8. Radio peptide imaging and therapy

    International Nuclear Information System (INIS)

    Buscombe, Jonh

    1997-01-01

    Full text. The concept of the magic bullet retains its attraction to us. If only we could take a drug or radioisotope and inject this intravenously and then will attach to the target cancer. This may allow imaging if labelled with a radio pharmaceutical or possibly even effective therapy. Initially work was started using antibodies of mouse origin. These have shown some utility in targeting tumors but there are problems in that these are essentially non-human proteins, often derived from mice. This leads to the formation of antibodies against that antibody so that repeat administrations lead to reduced efficacy and possibly may carry a risk anaphylaxis for the patient. Two different methods have evolved to deal with this situation. Either make antibodies more human or use smaller fragments, so that they are less likely to cause allergic reactions. The second method is to try and use a synthetic peptide. This will contain a series of amino acids which recognize a certain cell receptor. For example the somatostatin analogue Octreotide is an 8 amino acid peptide which has the same biological actions as natural somatostatin but an increased plasma half life. To this is added a linker a good example being DTPA and then radioisotope for example In-111. There we can have the complex In-111-DTPA-Octreotide which can be used to image somatostatin receptors in vivo. The main advantage over antibodies is that the cost production is less and many different variation of peptides for a particular receptor can be manufactured and assessed to find which is the optimal agent tumour imaging at a fraction of the cost of antibody production. There are two main approaches. Firstly to take a natural peptide hormone such as insulin or VIP and label by a simple method such as iodination with I-123. A group in Vienna have done it and shown good uptake of I-123 Insulin in primary hepatomas and of I-123 VIP in pancreatic cancers. Many natural peptide hormones however have a short plasma half

  9. Plasma Diagnostics of the Interstellar Medium with Radio Astronomy

    OpenAIRE

    Haverkorn, Marijke; Spangler, Steven R.

    2013-01-01

    We discuss the degree to which radio propagation measurements diagnose conditions in the ionized gas of the interstellar medium (ISM). The "signal generators" of the radio waves of interest are extragalactic radio sources (quasars and radio galaxies), as well as Galactic sources, primarily pulsars. The polarized synchrotron radiation of the Galactic non-thermal radiation also serves to probe the ISM, including space between the emitting regions and the solar system. Radio propagation measurem...

  10. Construcción de una escala para medir el perfil motivacional de las matronas hacia los programas de educación maternal Scale building to measure midwives motivational profile towards maternal education programmes

    Directory of Open Access Journals (Sweden)

    Matilde Fernández y Fernández-Arroyo

    2009-06-01

    Full Text Available Justificación: Describir el perfil motivacional permite investigar el clima de la organización y la calidad de vida profesional percibida. Objetivo: elaborar un instrumento para medir el perfil motivacional de las matronas hacia los programas de educación maternal. Metodología: se estudió una muestra no probabilística de 93 matronas, lo que corresponde al 54,6% de las matronas de atención primaria de Madrid. La escala se compuso de nueve ítems de motivación. Resultados: La escala presentó una fiabilidad de Alfa de Cronbach =0,78, lo que indica una consistencia interna considerable. Del análisis factorial se obtuvo una estructura bifactorial. La consistencia interna de ambas dimensiones es igualmente alta. Esta agrupación resultó coherente con la planteada en la fase de operativización del constructo teórico. Conclusión: La escala diferencia a las matronas en cuanto a sus niveles de motivación hacia los programas de Educación Maternal, por lo que es una herramienta que facilita investigaciones futuras.Rationale: Midwives motivational profile description allows researching organization climate and quality of life perceived. Objectives: Developing an instrument to measure midwives motivational profile towards Maternal Education Programmes. Methodology: A non-probability sample of 93 midwives, which corresponds to 54.6% of midwives primary care in Madrid, has been studied. The scale is composed of nine items of motivation. Results: The scale presented a reliability of Cronbach Alpha = 0.78, indicating a substantial internal consistency. From factorial analysis was obtained a bifactorial structurere. Internal consistency of both dimensions was equally high. This grouping was consistent with the raised stage in the calculation of the theoretical construct. Conclusion: The scale differentiates midwives on their levels of motivation towards Maternal Education Programmes, so it is a tool that facilitates future research.

  11. Propuesta de una escala para medir la calidad del servicio de los centros de atención secundaria de salud Proposal of a scale to measure the quality of service in secondary healthcare centers

    Directory of Open Access Journals (Sweden)

    Eduardo Torres Moraga

    2008-08-01

    Full Text Available El Ministerio de Salud en Chile se ha planteado como uno de sus principales objetivos, proveer servicios acorde a las expectativas de la población. Para lograrlo, se requiere necesariamente, conocer cuál es la calidad del servicio ofrecida por los centros de salud. En Chile, los centros de atención secundaria, no han desarrollado escalas de calidad del servicio que tengan un buen grado de validez, fiabilidad y dimensionalidad. Este artículo, propone una escala que cumpla estas condiciones, para medir de manera óptima la calidad del servicio que los Centros de Atención Secundaria ofrecen a sus pacientes. Para lograr este objetivo, se aplicó una encuesta estructurada y posteriormente se realizó un exhaustivo análisis psicométrico de los datos, a través de una serie de análisis exploratorios y confirmatorios que incluyó ecuaciones estructurales. Este estudio permitió construir y proponer una escala fiable, válida y con buen grado de dimensionalidad, compuesta por cinco subescalas claramente relacionadas e integradas en un único constructo. Estas son: confiabilidad, empatía, capacidad de respuesta, accesibilidad y tangibles.Chile's Ministry of Health has made it one of its main objectives to provide services that meet the expectations of the population. To achieve this, it is necessary to know what the quality of service offered by healthcare centers is like. In Chile, secondary healthcare centers have not developed quality of service scales that have a good level of validity, dependability, and dimensionality. This article proposes a scale that fulfills these conditions so as to measure in an optimal way the quality of service that secondary healthcare centers offer their patients. To achieve this objective, a structured survey was applied, followed by an exhaustive psychometric analysis of the facts through exploratory and confirmatory analysis that included structural equations. This study allowed for the construction and

  12. Diseño y validación de la escala CapPsi para medir capital psicológico (Design and Validation of the Cappsi Scale to Measure Psychological Capital

    Directory of Open Access Journals (Sweden)

    Alicia Omar

    2014-12-01

    Full Text Available RESUMEN: El objetivo del presente estudio fue el desarrollo y validación de una escala para medir capital psicológico en adultos. Los ítems iniciales se elaboraron sobre la base de la revisión bibliográfica, entrevistas con empleados y consultas con especialistas. Inicialmente se efectuó una prueba piloto que permitió realizar ajustes conceptuales y semánticos de los ítems. La escala fue administrada a 382 empleados, conjuntamente con las medidas de desempeño laboral, comportamientos organizacionales contraproducentes y satisfacción general. Asimismo, se estudió la validez factorial exploratoria y confirmatoria; además de la confiabilidad como consistencia interna a través del coeficiente alpha de Cronbach. Los resultados mostraron la existencia de cuatro factores con satisfactorios niveles de validez y confiabilidad, los que fueron rotulados como: Esperanza (α = .87, Optimismo (α = .91, Resiliencia (α = .84 y Autoeficacia (α = .79. La escala cumple con los criterios psicométricos exigidos y puede ser empleada como herramienta de diagnóstico y gestión organizacional. ABSTRACT: The objective of this study was the development and validation of a scale to measure psychological capital in adults.The initial items were developed on the basis of the bibliographical review, interviews with employees and consultations with specialists. Initially a pilot test was carried out which allowed conceptual and semantic adjustments of the items. The scale was administered to 382 employees, together with the measures of job performance, organizational self-defeating behaviors and overall satisfaction. Also, it is studied the exploratory and confirmatory factorial validity; in addition to the re liability and internal consistency through Cronbach’s alpha coefficient. The results showed the existence of four factors with satisfactory levels of validity and reliability, which were labeled as: Hope (α = .87, Optimism (α = .91, Resilience (

  13. Índices para medir las desigualdades de salud de carácter social basados en la noción de entropía Indices based on the notion of entropy for measuring social inequalities in health

    Directory of Open Access Journals (Sweden)

    Jorge Bacallao

    2002-12-01

    Full Text Available Los índices descritos en la literatura para medir las desigualdades de salud de carácter social tienen facetas positivas pero también algunas insuficiencias, según las circunstancias de su aplicación. El objetivo de este artículo es proponer y demostrar, en los planos teórico y práctico, las ventajas de las mediciones de la desigualdad basadas en la noción de entropía, conocida ampliamente en la física y la teoría de la información. Se definen y exponen las principales propiedades de los índices basados en las nociones de entropía y redundancia. Se ilustra su aplicación en dos conjuntos de datos ficticios y en datos reales, derivados de los indicadores básicos de salud para las Américas, de la Organización Panamericana de la Salud. Los índices basados en la noción de entropía poseen, entre otras, las siguientes propiedades: a no varían con los cambios de escala; b son simétricos; c incorporan la dimensión social, y d son fáciles de interpretar gracias a la condición de equivalencia entre la entropía y un sistema con dos clases.As described in the scientific literature, indices used to measure social inequalities in health have positive features, but they also have shortcomings, depending on how they are applied. The objective of this article is to put forward and to demonstrate, in both theoretical and practical terms, the advantages of measurements of inequality based on the notion of entropy, which is well known in physics and in information theory. The article defines and presents the main properties of indices based on the notions of entropy and redundancy. The application of the indices is illustrated with two fictitious data sets and also with real data derived from basic health indicators for the Americas, from the Pan American Health Organization. Indices based on the notion of entropy have properties that include: a not varying with scale changes, b being symmetrical, c incorporating a socioeconomic dimension

  14. VLA radio observations of AR Scorpii

    Science.gov (United States)

    Stanway, E. R.; Marsh, T. R.; Chote, P.; Gänsicke, B. T.; Steeghs, D.; Wheatley, P. J.

    2018-03-01

    Aims: AR Scorpii is unique amongst known white dwarf binaries in showing powerful pulsations extending to radio frequencies. Here we aim to investigate the multi-frequency radio emission of AR Sco in detail, in order to constrain its origin and emission mechanisms. Methods: We present interferometric radio frequency imaging of AR Sco at 1.5, 5 and 9 GHz, analysing the total flux and polarization behaviour of this source at high time resolution (10, 3 and 3 s), across a full 3.6 h orbital period in each band. Results: We find strong modulation of the radio flux on the orbital period and the orbital sideband of the white dwarf's spin period (also known as the "beat" period). This indicates that, like the optical flux, the radio flux arises predominantly from on or near the inner surface of the M-dwarf companion star. The beat-phase pulsations of AR Sco decrease in strength with decreasing frequency. They are strongest at 9 GHz and at an orbital phase 0.5. Unlike the optical emission from this source, radio emission from AR Sco shows weak linear polarization but very strong circular polarization, reaching 30% at an orbital phase 0.8. We infer the probable existence of a non-relativistic cyclotron emission component, which dominates at low radio frequencies. Given the required magnetic fields, this also likely arises from on or near the M-dwarf. A table of the flux time series is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/611/A66

  15. Curved Radio Spectra of Weak Cluster Shocks

    Science.gov (United States)

    Kang, Hyesung; Ryu, Dongsu

    2015-08-01

    In order to understand certain observed features of arc-like giant radio relics such as the rareness, uniform surface brightness, and curved integrated spectra, we explore a diffusive shock acceleration (DSA) model for radio relics in which a spherical shock impinges on a magnetized cloud containing fossil relativistic electrons. Toward this end, we perform DSA simulations of spherical shocks with the parameters relevant for the Sausage radio relic in cluster CIZA J2242.8+5301, and calculate the ensuing radio synchrotron emission from re-accelerated electrons. Three types of fossil electron populations are considered: a delta-function like population with the shock injection momentum, a power-law distribution, and a power law with an exponential cutoff. The surface brightness profile of the radio-emitting postshock region and the volume-integrated radio spectrum are calculated and compared with observations. We find that the observed width of the Sausage relic can be explained reasonably well by shocks with speed {u}{{s}}˜ 3× {10}3 {km} {{{s}}}-1 and sonic Mach number {M}{{s}}˜ 3. These shocks produce curved radio spectra that steepen gradually over (0.1-10){ν }{br} with a break frequency {ν }{br}˜ 1 GHz if the duration of electron acceleration is ˜60-80 Myr. However, the abrupt increase in the spectral index above ˜1.5 GHz observed in the Sausage relic seems to indicate that additional physical processes, other than radiative losses, operate for electrons with {γ }{{e}}≳ {10}4.

  16. Perancangan Radio Streaming Edukasi (Studi Kasus Balai Pengembangan Media Radio YOGYAKARTA)

    OpenAIRE

    Nurwulan, Ayu Isni; Paputungan, Irving Vitra

    2009-01-01

    Pendidikan berkualitas sudah sewajarnya bisa dinikmati secara merata oleh semua orang. Mediapembelajaran secara audio yang selama ini disampaikan masih memiliki banyak keterbatasan, terutama padalingkup wilayah penyampaian. Dalam makalah ini, sebuah media pendidikan berbasis audio dengan cara laindiusulkan. Media tersebut bernama radio streaming. Pembuatan radio streaming memerlukan banyak analisissehingga perancangannya tepat. Hasil analisis dan perancangan yang disampaikan dalam makalah ini...

  17. La radio en África. Una radio para el desarrollo

    Directory of Open Access Journals (Sweden)

    Jean-Paul Lafrance

    2015-01-01

    Full Text Available La radio de tipo comunitario, tal como la conocemos en Norteamérica y Europa (no-comercial, no-estatal y particípatíva, no existe en Africa. Sin embargo, la situación histórica y el contexto socio-político particulares de Africa han precedido la instauración de una radio que, dentro del marco del presente estudio, nos ha resultado interesante. Se trata de la radio educativa rural. Aunque enmarcada dentro del molde estatal de regímenes que en su mayoría son dictaduras, la radio rural africana, al igual que las radios de tipo comunitario, utiliza la radio con otros fines además de los convencionales. En este caso, la radio es un instrumento al servicio del desarrollo, por no decir al servicio del campesino, en una relación con éste último que probablemente dejará cada vez más de ser uni-direccional. La experiencia africana nos proporcionará en esta perspectiva nuevos elementos de reflexión en lo que respecta al rol de la radio dentro de la comunidad y sobre las condiciones incluso del éxito o no-éxito de la participación popular.

  18. Planck Early Results. XV. Spectral Energy Distributions and Radio Continuum Spectra of Northern Extragalactic Radio Sources

    Science.gov (United States)

    Aatrokoski, J.; Ade, P. A. R.; Aghanim, N.; Aller, H. D.; Aller, M. F.; Angelakis, E.; Amaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; hide

    2011-01-01

    Spectral energy distributions (SEDs) and radio continuum spectra are presented for a northern sample of 104 extragalactic radio sources. based on the Planck Early Release Compact Source Catalogue (ERCSC) and simultaneous multi frequency data. The nine Planck frequencies, from 30 to 857 GHz, are complemented by a set of simultaneous observations ranging from radio to gamma-rays. This is the first extensive frequency coverage in the radio and millimetre domains for an essentially complete sample of extragalactic radio sources, and it shows how the individual shocks, each in their own phase of development, shape the radio spectra as they move in the relativistic jet. The SEDs presented in this paper were fitted with second and third degree polynomials to estimate the frequencies of the synchrotron and inverse Compton (IC) peaks, and the spectral indices of low and high frequency radio data, including the Planck ERCSC data, were calculated. SED modelling methods are discussed, with an emphasis on proper. physical modelling of the synchrotron bump using multiple components. Planck ERCSC data also suggest that the original accelerated electron energy spectrum could be much harder than commonly thought, with power-law index around 1.5 instead of the canonical 2.5. The implications of this are discussed for the acceleration mechanisms effective in blazar shock. Furthermore in many cases the Planck data indicate that gamma-ray emission must originate in the same shocks that produce the radio emission.

  19. Transistor Radio Receivers; Radio and Television Service, Intermediate: 9785.04.

    Science.gov (United States)

    Dade County Public Schools, Miami, FL.

    The course outlined is one of the required courses in the Radio and Television Service Curriculum. Mastery of the skills in Basic Radio Circuits and Vacuum Tube AM Troubleshooting (9785.03) is a prerequisite. Eight blocks of instruction are divided into several units each. The instruction blocks are: orientation, fundamentals of transistor…

  20. New radio model in the fourth screen: radiovision, the radio that you can watch

    Directory of Open Access Journals (Sweden)

    Sandra CAVIA FRAILE

    2016-12-01

    Full Text Available The traditional radio is not strange to the social revolution that Internet and new technologies are raising. In recent years, the fourth screen has led the emergence of new models of radio, including Radiovision. The «radio that you can watch» intends to change and innovate the radio broadcasting media to offer a product that meets the multimedia requirements of users. However, currently, the Radiovisión is still at an early stage and it has many aspects that it should improve and care, as the contents and the staging. It is a big chance for the radio that poses challenges and opportunities both for journalism and journalists.

  1. Interferometry and synthesis in radio astronomy

    CERN Document Server

    Thompson, A Richard; Swenson Jr , George W

    2017-01-01

    This book is open access under a CC BY-NC 4.0 license. The third edition of this indispensable book in radio interferometry provides extensive updates to the second edition, including results and technical advances from the past decade; discussion of arrays that now span the full range of the radio part of the electromagnetic spectrum observable from the ground, 10 MHz to 1 THz; an analysis of factors that affect array speed; and an expanded discussion of digital signal-processing techniques and of scintillation phenomena and the effects of atmospheric water vapor on image distortion, among many other topics. With its comprehensiveness and detailed exposition of all aspects of the theory and practice of radio interferometry and synthesis imaging, this book has established itself as a standard reference in the field. It begins with an overview of the basic principles of radio astronomy, a short history of the development of radio interferometry, and an elementary discussion of the operation of an interferomete...

  2. Radio Astronomy on and Around the Moon

    Science.gov (United States)

    Falcke, Heino; Klein Wolt, Mark; Ping, Jinsong; Chen, Linjie

    2018-06-01

    The exploration of remote places on other planets has now become a major goal in current space flight scenarios. On the other hand, astronomers have always sought the most remote and isolated sites to place their observatories and to make their most precise and most breath taking discoveries. Especially for radio astronomy, lunar exploration offers a complete new window to the universe. The polar region and the far-side of the moon are acknowledged as unique locations for a low-frequency radio telescope providing scientific data at wavelengths that cannot be obtained from the Earth nor from single satellites. Scientific areas to be covered range from radio surveys, to solar-system studies, exo-planet detection, and astroparticle physics. The key science area, however, is the detection and measurement of cosmological 21 cm hydrogen emission from the still unexplored dark ages of the universe. Developing a lunar radio facility can happen in steps and may involve small satellites, rover-based radio antennas, of free- flying constellations around the moon. A first such step could be the Netherlands-Chinese Long Wavelength Explorer (NCLE), which is supposed to be launched in 2018 as part of the ChangE’4 mission to the moon-earth L2 point.

  3. The Beginnings of Australian Radio Astronomy

    Science.gov (United States)

    Sullivan, Woodruff T.

    The early stages of Australian radio astronomy, especially the first decade after World War II, are described in detail. These include the transition of the CSIRO Radiophysics Laboratory, under the leadership of Joseph Pawsey and Taffy Bowen, from a wartime laboratory in 1945 to, by 1950, the largest and one of the two most important radio astronomy groups in the world (with the Cavendish Laboratory at Cambridge University). The initial solar investigations are described, including discovery of the hot corona and development of the sea-cliff interferometer. During this same period painstaking `radio star' observations by John Bolton and colleagues led to the first suggested optical identifications of Taurus-A (the Crab Nebula), Centaurus-A (NGC 5128), and Virgo-A (M87). The factors that led to the extraordinary early success of the Radiophysics Laboratory are analyzed in detail, followed by discussion of how the situation changed significantly in the second decade of 1955-1965. Finally, the development of major Australian instruments, from the Parkes Radio Telescope (1961) to the Australia Telescope (1988), is briefly presented. This chapter is a direct reprint of the following research paper: Sullivan, W., 2005. The beginnings of Australian radio astronomy. Journal of Astronomical History and Heritage, 8, 11-32.

  4. Latest results of the Tunka Radio Extension

    Directory of Open Access Journals (Sweden)

    Kostunin D.

    2017-01-01

    Full Text Available The Tunka Radio Extension (Tunka-Rex is an antenna array consisting of 63 antennas at the location of the TAIGA facility (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy in Eastern Siberia, nearby Lake Baikal. Tunka-Rex is triggered by the air-Cherenkov array Tunka-133 during clear and moonless winter nights and by the scintillator array Tunka-Grande during the remaining time. Tunka-Rex measures the radio emission from the same air-showers as Tunka-133 and Tunka-Grande, but with a higher threshold of about 100 PeV. During the first stages of its operation, Tunka-Rex has proven, that sparse radio arrays can measure air-showers with an energy resolution of better than 15% and the depth of the shower maximum with a resolution of better than 40 g/cm2. To improve and interpret our measurements as well as to study systematic uncertainties due to interaction models, we perform radio simulations with CORSIKA and CoREAS. In this overview we present the setup of Tunka-Rex, discuss the achieved results and the prospects of mass-composition studies with radio arrays.

  5. Mobile radio alternative systems study traffic model

    Science.gov (United States)

    Tucker, W. T.; Anderson, R. E.

    1983-06-01

    The markets for mobile radio services in non-urban areas of the United States are examined for the years 1985-2000. Three market categories are identified. New Services are defined as those for which there are different expressed ideas but which are not now met by any application of available technology. The complete fulfillment of the needs requires nationwide radio access to vehicles without knowledge of vehicle location, wideband data transmission from remote sites, one- and two way exchange of short data and control messages between vehicles and dispatch or control centers, and automatic vehicle location (surveillance). The commercial and public services market of interest to the study is drawn from existing users of mobile radio in non-urban areas who are dissatisfied with the geographical range or coverage of their systems. The mobile radio telephone market comprises potential users who require access to the public switched telephone network in areas that are not likely to be served by the traditional growth patterns of terrestrial mobile telephone services. Conservative, likely, and optimistic estimates of the markets are presented in terms of numbers of vehicles that will be served and the radio traffic they will generate.

  6. Radio on the Other Side of Time

    Directory of Open Access Journals (Sweden)

    Alicia TAPIA LÓPEZ

    2016-06-01

    Full Text Available On October 30, 1938, Orson Welles aired the radio drama The War of the Worlds on the CBS Radio network, adapting the science-fiction novel by the British writer H. G. Wells. During the broadcast, listeners became stricken with panic, believing that the Earth was actually being invaded by giant snake-like Martians launching rays of fire down on humans. Welles was a groundbreaking figure whose trickery exploited the technological novelty of the radio to its fullest, adapting classic texts in ways that exploited the opportunities afforded by this new medium. Over the years, this radio classic has been adapted a number of times, though none has seized on the technological advances of our times. Drawing on the most salient innovations seen in Internet radio, this article creates an imaginary scenario that replicates Orson Welles’s work in the present day, when the Internet has become a channel for broadcasting and hyperlinks have brought different media together. The text is an exploration of the other side of time, where transmedia storytelling facilitates the exchange of stories among consumers, and broadcast programming is no longer linear.

  7. Innovations to enrich science communication through radio

    Directory of Open Access Journals (Sweden)

    Thakar Bhaumik

    2004-12-01

    Full Text Available The Radio is an instrument of communication that has percolated to all the strata of the diverse Indian society. Its position has been consolidated through history as a regular companion and a source of information and entertainment. Its affordability, accessibility and non-reliance on costly resources have ensured its presence in almost all the households. It has become indispensable from kitchens, family rooms and even workspaces. It is one of the few or rather the only medium of communication after the print media wherein information dissemination still is primary and entertainment a secondary requirement, especially the rural areas. The role of radio in rural India is one that demands prominence and hence has been used as a primary resource for various projects on science communication. A majority of the science radio serial listeners are from the rural areas. The radio therefore is an ideal medium for reaching out to the masses. The radio even with its popularity and huge following is lacking in certain aspects that make science communication complete. Manthan Educational Programme Society developed concepts to make these efforts more effective by ensuring higher involvement and interest in these programs.

  8. Russian Speech in Radio: Norm and Deviation

    Directory of Open Access Journals (Sweden)

    Igor V. Nefedov

    2017-06-01

    Full Text Available National radio, like television, is called upon to bring to the masses not only relevant information, but also a high culture of language. There were always serious demands to oral public speech from the point of view of the correctness and uniformity of the pronunciation. However, today the analysis of the language practice of broadcasting often indicates a discrepancy between the use of linguistic resources in existing literary norms. The author of the article from the end of December 2016 to early April 2017 listened and analyzed from the point of view of language correctness the majority of programs on the radio Komsomolskaya Pravda (KP. In general, recognizing the good speech qualification of the workers of this radio, as well as their «guests» (political scientists, lawyers, historians, etc., one can not but note the presence of a significant number of errors in their speech. The material presented in the article allows us to conclude that at present, broadcasting is losing its position in the field of speech culture. Neglect of the rules of the Russian language on the radio «Komsomolskaya Pravda» negatively affects the image of the Russian language, which is formed in the minds of listeners. The language of radio should strive to become a standard of cleanliness and high culture for the population, since it has the enormous power of mass impact and supports the unity of the cultural and linguistic space.

  9. Radio emission from embryonic superluminous supernova remnants

    Science.gov (United States)

    Omand, Conor M. B.; Kashiyama, Kazumi; Murase, Kohta

    2018-02-01

    It has been widely argued that Type-I superluminous supernovae (SLSNe-I) are driven by powerful central engines with a long-lasting energy injection after the core-collapse of massive progenitors. One of the popular hypotheses is that the hidden engines are fast-rotating pulsars with a magnetic field of B ˜ 1013-1015 G. Murase, Kashiyama & Mészáros proposed that quasi-steady radio/submm emission from non-thermal electron-positron pairs in nascent pulsar wind nebulae can be used as a relevant counterpart of such pulsar-driven supernovae (SNe). In this work, focusing on the nascent SLSN-I remnants, we examine constraints that can be placed by radio emission. We show that the Atacama Large Millimeter/submillimetre Array can detect the radio nebula from SNe at DL ˜ 1 Gpc in a few years after the explosion, while the Jansky Very Large Array can also detect the counterpart in a few decades. The proposed radio follow-up observation could solve the parameter degeneracy in the pulsar-driven SN model for optical/UV light curves, and could also give us clues to young neutron star scenarios for SLSNe-I and fast radio bursts.

  10. Validez y fiabilidad de un sensor basado en acelerometr??a y de un transductor lineal de posici??n para medir la velocidad de ejecuci??n en el ejercicio de press de banca = Validity and reliability of an accelerometry based sensor and a linear position transducer to measure the speed in the bench press exercise.

    OpenAIRE

    Albal?? G??mez, Borja

    2017-01-01

    La fuerza y su correcta dosificaci??n y control son factores determinantes para el rendimiento deportivo. El entrenamiento de fuerza basado en la velocidad de ejecuci??n presenta importantes ventajas respecto a los m??todos tradicionales de programaci??n. Para la aplicaci??n de este m??todo se requieren dispositivos capaces de medir la velocidad de ejecuci??n en los ejercicios de fuerza. El prop??sito de este estudio fue evaluar la validez y fiabilidad de un transductor lineal y de un disposi...

  11. Sounds energetic: the radio producer's energy minibook

    Energy Technology Data Exchange (ETDEWEB)

    1980-12-01

    The Minibook will be expanded into the final Radio Producer's Energy Sourcebook. Radio producers and broadcasters are asked to contribute ideas for presenting energy knowledge to the public and to be included in the Sourcebook. Chapter One presents a case study suggesting programming and promotion ideas and sample scripts for a radio campaign that revolves around no-cost or low-cost steps listeners can take to increase their home energy efficiency and save money. A variety of other energy topics and suggestions on ways to approach them are addressed in Chapter Two. Chapter Three contains energy directories for Baltimore, Philadelphia, Pittsburg, and Washington, DC. The directories will be expanded in the Sourcebook and will consist of a selection of local public and private sector energy-related organizations and list local experts and organizations and the best Federal, state, and local government programs that can provide consumers and citizens groups with information, technical assistance, and financial support. (MCW)

  12. Advertising Radio Discourse – Lexical Analysis

    Directory of Open Access Journals (Sweden)

    Dumitrascu Elena

    2017-01-01

    Full Text Available Radio advertising, although it seems to be the "poor relative" on the advertising market, is avery interesting topic of study, because it uses language to a very large extent. In a relatively shorttime, a maximum of information is transmitted that causes emotions and raises the interest of asmany people as possible for a product or brand, all wrapped up in a coherent text of 60 to 100words . In radio advertising, the text is the one that has priority, being the star because themessage is based on the text. For this reason, radio discourse may be a research object of interestto linguists, and this has led us to pay close attention to it.

  13. Reconfigurable, Cognitive Software-Defined Radio

    Science.gov (United States)

    Bhat, Arvind

    2015-01-01

    Software-defined radio (SDR) technology allows radios to be reconfigured to perform different communication functions without using multiple radios to accomplish each task. Intelligent Automation, Inc., has developed SDR platforms that switch adaptively between different operation modes. The innovation works by modifying both transmit waveforms and receiver signal processing tasks. In Phase I of the project, the company developed SDR cognitive capabilities, including adaptive modulation and coding (AMC), automatic modulation recognition (AMR), and spectrum sensing. In Phase II, these capabilities were integrated into SDR platforms. The reconfigurable transceiver design employs high-speed field-programmable gate arrays, enabling multimode operation and scalable architecture. Designs are based on commercial off-the-shelf (COTS) components and are modular in nature, making it easier to upgrade individual components rather than redesigning the entire SDR platform as technology advances.

  14. Indoor Positioning with Radio Location Fingerprinting

    DEFF Research Database (Denmark)

    Kjærgaard, Mikkel Baun

    . A promising indoor positioning technique is radio-based location ngerprinting, having the major advantage of exploiting already existing radio infrastructures, like IEEE 802.11 or GSM, which avoids extra deployment costs and eort. The research goal of this thesis is to address the limitations of current...... indoor location ngerprinting systems. In particular the aim is to advance location ngerprinting techniques for the challenges of handling heterogeneous clients, scalability to many clients, and interference between communication and positioning. The wireless clients used for location ngerprinting...... are heterogeneous even when only considering clients for the same technology. The heterogeneity is due to dierent radios, antennas, and rmwares causing measurements for location ngerprinting not to be directly comparable among clients. Heterogeneity is a challenge for location ngerprinting because it severely...

  15. FM Radio and Youth: Listeners or Users?

    Directory of Open Access Journals (Sweden)

    Marina Mučalo

    2014-06-01

    Full Text Available A survey conducted in the spring of 2013, says that Zagreb’s high school students are not regular listeners to FM radio programs. The dominant media is the Internet, which is used a few hours a day, mostly for Facebook. Despite the expressed need for music, the linear and passive nature of FM radio, does not correspond to the individual requirements of young and networked users. The Internet is the most popular daily source for music, with ability to download, while smartphones are becoming devices for storage and playback. However, this survey has shown that students are interested in web radio sites. Changes in media preferences and habits caused by the Internet show us the importance of information literacy, as a basic skill for participation in a networked society.

  16. Cryoconite. An exotic radio-ecological delicacy

    International Nuclear Information System (INIS)

    Tieber, A.; Wilflinger, T.; Lettner, H.; Hubmer, A.K.; Bossew, P.; Sattler, B.

    2009-01-01

    Five years of research on the radio-ecology of cryconite, a sediment of mineral and organic compounds found on glacier surfaces and within glacier ice, has led to amazing insights into the properties of an environmental medium which has been neglegted almost completely previously. It has turned out that a surprising radio-ecological diversity exists on and within glaciers, apart from their quality as thrieving biotopes, also not known for long. This presentation summarizes results from different research projects related to high-Alpine radio-ecology: radionuclide inventories and spatial distributions of cryoconite, hypotheses about their origin and formation, their cycling on and within glaciers, and their role in glacier melting due to global warming. (orig.)

  17. Gamma-Ray Bursts: A Radio Perspective

    Directory of Open Access Journals (Sweden)

    Poonam Chandra

    2016-01-01

    Full Text Available Gamma-ray bursts (GRBs are extremely energetic events at cosmological distances. They provide unique laboratory to investigate fundamental physical processes under extreme conditions. Due to extreme luminosities, GRBs are detectable at very high redshifts and potential tracers of cosmic star formation rate at early epoch. While the launch of Swift and Fermi has increased our understanding of GRBs tremendously, many new questions have opened up. Radio observations of GRBs uniquely probe the energetics and environments of the explosion. However, currently only 30% of the bursts are detected in radio bands. Radio observations with upcoming sensitive telescopes will potentially increase the sample size significantly and allow one to follow the individual bursts for a much longer duration and be able to answer some of the important issues related to true calorimetry, reverse shock emission, and environments around the massive stars exploding as GRBs in the early Universe.

  18. Radio continuum observations of NML Cygni

    International Nuclear Information System (INIS)

    Gregory, P.C.; Seaquist, E.R.

    1976-01-01

    An attempt to detect thermal radio emission from a compact circumstellar cloud about the infrared star NML Cyg has been carried out at three frequencies, 2.7, 8.1, and 10.5 GHz. Although positive results were obtained with single-dish observations at 10.5 GHz, the radio emission is not from a circumstellar cloud about NML Cyg. Instead it is postulated that the emission is from an H ii region with an angular extent of approx.2'. The red print of the Sky Survey shows a faint nebulosity of comparable angular size overlapping the star's position, lending support to this interpretation. The interferometer observations at 2.7 and 8.1 GHz provide an upper limit on the radio emission from any compact circumstellar cloud about NML Cyg of 2.8 mJy, which is well below the flux density expected for the absorbing cloud postulated by Davies et al. (1972)

  19. Biodiversity Loss in the Orion Radio Zoo?

    Science.gov (United States)

    Henney, W. J.; García-Díaz, Ma. T.; Kurtz, S. E.

    2001-03-01

    We re-examine radio observations of compact sources in the core of the Orion nebula and find that 70% of the sources correspond to known proplyds. For all of these sources, including many that have been previously classified as variable and non-thermal, the radio flux between 1.5 and 86 Ghz is fully accounted for by thermal free-free emission from the photoevaporation flow. We therefore suggest that many of the proposed Orion FOXES are in fact EIDERS, and that their apparent variability reflects observational difficulties in detecting the lower surface-brightness portions of the proplyds. The PIGs turn out to be extinct in Orion, and the hybrid creatures that we dub PANTHERS (Proplyds Associated with Non-THErmal Radio Sources) remain elusive.

  20. Are the infrared-faint radio sources pulsars?

    Science.gov (United States)

    Cameron, A. D.; Keith, M.; Hobbs, G.; Norris, R. P.; Mao, M. Y.; Middelberg, E.

    2011-07-01

    Infrared-faint radio sources (IFRS) are objects which are strong at radio wavelengths but undetected in sensitive Spitzer observations at infrared wavelengths. Their nature is uncertain and most have not yet been associated with any known astrophysical object. One possibility is that they are radio pulsars. To test this hypothesis we undertook observations of 16 of these sources with the Parkes Radio Telescope. Our results limit the radio emission to a pulsed flux density of less than 0.21 mJy (assuming a 50 per cent duty cycle). This is well below the flux density of the IFRS. We therefore conclude that these IFRS are not radio pulsars.

  1. Real-Time Measurements for Adaptive and Cognitive Radio Systems

    Directory of Open Access Journals (Sweden)

    Hüseyin Arslan

    2009-01-01

    Full Text Available Adaptive and cognitive radios (CR have been becoming popular for optimizing mobile radio system transmission and reception. One of the most important elements of the adaptive radio and CR concepts is the ability to measure, sense, learn about, and be aware of parameters related to the radio channel characteristics, availability of spectrum and power, interference and noise temperature, operational environment of radio, user requirements and applications, available networks and infrastructures, local policies, other operating restrictions, and so on. This paper discusses some of the important measurement parameters for enabling adaptive radio and CR systems along with their relationships and impacts on the performance including relevant challenges.

  2. More of the Same - On Spotify Radio

    Directory of Open Access Journals (Sweden)

    Pelle Snickars

    2017-10-01

    Full Text Available Spotify Radio allows users to find new music within Spotify's vast back-catalogue, offering a potential infinite avenue of discovery. Nevertheless, the radio service has also been disliked and accused of playing the same artists over and over. We decided to set up an experiment with the purpose to explore the possible limitations found within 'infinite archives' of music streaming services. Our hypothesis was that Spotify Radio appears to consist of an infinite series of songs. It claims to be personalised and never-ending, yet music seems to be delivered in limited loop patterns. What would such loop patterns look like? Are Spotify Radio's music loops finite or infinite? How many tracks (or steps does a normal loop consist of? To answer these research questions, at Umeå University's digital humanities hub, Humlab, we set up an intervention using 160 bot listeners. Our bots were all Spotify Free users. They literally had no track record and were programmed to listen to different Swedish music from the 1970s. All bots were to document all subsequent tracks played in the radio loop and (interact within the Spotify Web client as an obedient bot listener, a liker, a disliker, and a skipper. The article describes different research strategies when dealing with proprietary data. Foremost, however, it empirically recounts the radio looping interventions set up at Humlab. Essentially, the article suggests a set of methodologies for performing humanist inquiry on big data and black-boxed media services that increasingly provide key delivery mechanisms for cultural materials. Spotify serves as a case in point, yet principally any other platform or service could be studied in similar ways. Using bots as research informants can be deployed within a range of different digital scholarship, so this article appeals not only to media or software studies scholars, but also to digitally inclined cultural studies such as the digital humanities.

  3. Giant Metrewave Radio Telescope Observations of Head–Tail Radio Galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Sebastian, Biny; Lal, Dharam V.; Rao, A. Pramesh, E-mail: biny@ncra.tifr.res.in [National Center for Radio Astrophysics—Tata Institute of Fundamental Research Post Box 3, Ganeshkhind P.O., Pune 41007 (India)

    2017-10-01

    We present results from a study of seven large known head–tail radio galaxies based on observations using the Giant Metrewave Radio Telescope at 240 and 610 MHz. These observations are used to study the radio morphologies and distribution of the spectral indices across the sources. The overall morphology of the radio tails of these sources is suggestive of random motions of the optical host around the cluster potential. The presence of multiple bends and wiggles in several head–tail sources is possibly due to the precessing radio jets. We find steepening of the spectral index along the radio tails. The prevailing equipartition magnetic field also decreases along the radio tails of these sources. These steepening trends are attributed to the synchrotron aging of plasma toward the ends of the tails. The dynamical ages of these sample sources have been estimated to be ∼10{sup 8} yr, which is a factor of six more than the age estimates from the radiative losses due to synchrotron cooling.

  4. Radio universitaria: trabajo en red como imperativo

    Directory of Open Access Journals (Sweden)

    Tiziana Cavallo

    2014-01-01

    Full Text Available Trabajo en red es un concepto clave en la radio universitaria, tanto desde el punto de vista individual como del colectivo. A través de dos estudios de caso, enfocados en la radio universitaria de Italia y de Colombia, este artículo muestra cómo el trabajo en red ha sido decisivo para el fortalecimiento de su función, la ampliación de su impacto, la conformación de su identidad y el crecimiento de su visibilidad en las sociedades en las cuales desarrollan su labor.

  5. Radio resource allocation and dynamic spectrum access

    CERN Document Server

    Benmammar , Badr

    2013-01-01

    We are currently witnessing an increase in telecommunications norms and standards given the recent advances in this field. The increasing number of normalized standards paves the way for an increase in the range of services available for each consumer. Moreover, the majority of available radio frequencies have already been allocated. This explains the emergence of cognitive radio (CR) - the sharing of the spectrum between a primary user and a secondary user.In this book, we will present the state of the art of the different techniques for spectrum access using cooperation and competit

  6. On making radio contact with extraterrestrial civilizations

    International Nuclear Information System (INIS)

    Bates, D.R.

    1978-01-01

    The problem of attempting to make radio contact with other technological civilizations is examined. It is argued that there are few (perhaps indeed no) omnidirectional radio beacons in the Galaxy primarily because any such beacon, to be effective, would have to be designed for a call-response time of at least some 10 4 years, which is much too long to be likely to be acceptable to governments. A consequence is that any search program by us would have little chance of detecting incoming signals. (Auth.)

  7. Baseline-dependent averaging in radio interferometry

    Science.gov (United States)

    Wijnholds, S. J.; Willis, A. G.; Salvini, S.

    2018-05-01

    This paper presents a detailed analysis of the applicability and benefits of baseline-dependent averaging (BDA) in modern radio interferometers and in particular the Square Kilometre Array. We demonstrate that BDA does not affect the information content of the data other than a well-defined decorrelation loss for which closed form expressions are readily available. We verify these theoretical findings using simulations. We therefore conclude that BDA can be used reliably in modern radio interferometry allowing a reduction of visibility data volume (and hence processing costs for handling visibility data) by more than 80 per cent.

  8. Optical images of quasars and radio galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Hutchings, J.B.; Johnson, I.; Pyke, R.

    1988-04-01

    Matched contour plots and gray-scale diagrams are presented for 54 radio quasars or radio galaxies of redshift 0.1-0.6, observed with the Canada-France-Hawaii Telescope. All except four were recorded on the RCA1 CCD chip; four were summed from several photographic exposures behind an image tube. All except nine of the objects form the principal data base used by Hutchings (1987). Detailed comments are given on all objects, and some further measures of the objects and their companions. 12 references.

  9. Optical images of quasars and radio galaxies

    International Nuclear Information System (INIS)

    Hutchings, J.B.; Johnson, I.; Pyke, R.

    1988-01-01

    Matched contour plots and gray-scale diagrams are presented for 54 radio quasars or radio galaxies of redshift 0.1-0.6, observed with the Canada-France-Hawaii Telescope. All except four were recorded on the RCA1 CCD chip; four were summed from several photographic exposures behind an image tube. All except nine of the objects form the principal data base used by Hutchings (1987). Detailed comments are given on all objects, and some further measures of the objects and their companions. 12 references

  10. Optical images of quasars and radio galaxies

    Science.gov (United States)

    Hutchings, J. B.; Johnson, I.; Pyke, R.

    1988-04-01

    Matched contour plots and gray-scale diagrams are presented for 54 radio quasars or radio galaxies of redshift 0.1-0.6, observed with the Canada-France-Hawaii Telescope. All except four were recorded on the RCA1 CCD chip; four were summed from several photographic exposures behind an image tube. All except nine of the objects form the principal data base used by Hutchings (1987). Detailed comments are given on all objects, and some further measures of the objects and their companions.

  11. Radio images of the interplanetary turbulent plasma

    International Nuclear Information System (INIS)

    Vlasov, V.I.

    1979-01-01

    The results of the interplanetary scintillation daily observations of approximately 140 radio sources are given. The observations were carried out at the radiotelescope VLPA FIAN during 24 days in October-November 1975 and 6 days in April 1976. The maps (radio images) of interplanetary turbulent plasma are presented. The analysis of the maps reveals the presence of large-scale irregularities in the interplanetary plasma. The variability in large-scale structure of the interplanetary plasma is due mainly to transport of matter from the Sun. A comparison of the scintillation with the geomagnetic activity index detected the presence of a straight connection between them

  12. Radio Observations of Gamma-ray Novae

    Science.gov (United States)

    Linford, Justin D.; Chomiuk, L.; Ribeiro, V.; project, E.-Nova

    2014-01-01

    Recent detection of gamma-ray emission from classical novae by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope surprised many in the astronomical community. We present results from radio observations, obtained using the Karl G. Jansky Very Large Array (VLA), of three gamma-ray novae: Mon2012, Sco2012, and Del2013. Radio observations allow for the calculation of ejecta masses, place limits on the distances, and provide information about the gamma-ray emission mechanism for these sources.

  13. HF Radio Astronomy from a Small Satellite

    Science.gov (United States)

    2016-06-15

    SSC16-XI-03 HF Radio Astronomy from a Small Satellite Frank C. Robey1, Mary Knapp2, Alan J. Fenn1, Mark Silver1, Kerry Johnson1 Frank J. Lind3...frequency end of the electromagnetic spectrum (below 15 MHz) is one of the least explored windows in observational astronomy . Observations at these...pdf. [Accessed: 17-Oct-2015]. 3. G. Hallinan, “The Owens Valley LWA,” in Exascale Radio Astronomy , 2014, vol. 2. 4. C. J. Lonsdale, R. J. Cappallo

  14. Solar system radio astronomy at low frequencies

    International Nuclear Information System (INIS)

    Desch, M.D.

    1987-01-01

    The planetary radio-astronomy observations obtained with the two Voyager spacecraft since their launch in 1977 are briefly characterized and illustrated with graphs, diagrams, and sample spectra. Topics addressed include the spacecraft designs and trajectories, the wavelength coverage of the radio instruments, the Io-controlled LF emission of Jupiter, the solar-wind effect on the Saturn kilometric radiation, the Saturn electrostatic discharges, and the use of the clocklike feature of the Uranus emission to measure the planet's rotation period. 23 references

  15. Radio propagation through the turbulent interstellar plasma

    International Nuclear Information System (INIS)

    Rickett, B.J.

    1990-01-01

    The current understanding of interstellar scattering is reviewed, and its impact on radio astronomy is examined. The features of interstellar plasma turbulence are also discussed. It is concluded that methods involving the investigation of the flux variability of pulsars and extragalactic sources and the VLBI visibility curves constitute new techniques for probing the ISM. However, scattering causes a seeing limitation in radio observations. It is now clear that variation due to RISS (refractive interstellar scintillations) is likely to be important for several classes of variable sources, especially low-frequency variables and centimeter-wave flickering. 168 refs

  16. Reflection jets and collimation of radio sources

    International Nuclear Information System (INIS)

    Pacholczyk, A.G.

    1983-01-01

    A discussion of the hydrodynamics of jets formed by discrete portions of materials ejected from the parent galaxy through a channel, and reflected back to it as a result of an encounter with the material accumulated at the end of the channel, is the basis of the present descriptive hypothesis for a class of jets in extended radio sources. The model encompasses the view of extended radio sources as the multiple ejection of plasmoids through a channel, as well as the formation of retrojets through the interaction of a plasmon with the dense relic material at the end of a channel, and the collimation of plasmon material in channels. 14 references

  17. Electronic analogue simulator of radio cardiograms

    International Nuclear Information System (INIS)

    Roux, G.; Lansiart, A.; Vernejoul, P. de; Kellershohn, C.

    1967-01-01

    The various parameters of the heart pump and of the blood circulation can be determined by radio-cardio-graphical techniques. The curves thus obtained can be more easily used in radiocardiography if the electronic analogue simulator described here is employed. The experimental and simulated radio-cardiograms are made to coincide by varying the electrical parameters of the simulator. Using simple charts it is possible to obtain directly the actual original physiological parameters from these electrical parameters. Some examples are given showing the excellent accuracy obtained in the determination of ejection indices by the simulator. (authors) [fr

  18. RADIO SOURCE FEEDBACK IN GALAXY EVOLUTION

    International Nuclear Information System (INIS)

    Shabala, Stanislav; Alexander, Paul

    2009-01-01

    We present a galaxy evolution model which incorporates a physically motivated implementation of active galactic nucleus feedback. Intermittent jets inflate cocoons of radio plasma which then expand supersonically, shock heating the ambient gas. The model reproduces observed star formation histories to the highest redshifts for which reliable data exist, as well as the observed galaxy color bimodality. Intermittent radio source feedback also naturally provides a way of keeping the black hole and spheroid growth in step. We find possible evidence for a top-heavy initial mass function for z > 2, consistent with observations of element abundances, and submillimeter and Lyman break galaxy counts.

  19. Surveys of radio sources at 5 GHz

    International Nuclear Information System (INIS)

    Pauliny-Toth, I.I.K.

    1977-01-01

    A number of surveys have been carried out at a frequency of 5 GHz at the National Radio Astronomy Observatory (NRAO) and at the Max-Planck-Institut fuer Radioastronomy (MPIFR) with the aim of determining the number-flux density relation for the sources detected and also of obtaining their radio spectra and optical identifications. The surveys fall into two categories: first, the strong source (S) surveys which are intended in due course to cover the whole northern sky and to be complete above a flux density of about 0.6 Jy; second, surveys of limited areas of sky down to lower levels of the flux density. (Auth.)

  20. ARTIP: Automated Radio Telescope Image Processing Pipeline

    Science.gov (United States)

    Sharma, Ravi; Gyanchandani, Dolly; Kulkarni, Sarang; Gupta, Neeraj; Pathak, Vineet; Pande, Arti; Joshi, Unmesh

    2018-02-01

    The Automated Radio Telescope Image Processing Pipeline (ARTIP) automates the entire process of flagging, calibrating, and imaging for radio-interferometric data. ARTIP starts with raw data, i.e. a measurement set and goes through multiple stages, such as flux calibration, bandpass calibration, phase calibration, and imaging to generate continuum and spectral line images. Each stage can also be run independently. The pipeline provides continuous feedback to the user through various messages, charts and logs. It is written using standard python libraries and the CASA package. The pipeline can deal with datasets with multiple spectral windows and also multiple target sources which may have arbitrary combinations of flux/bandpass/phase calibrators.

  1. Radio Frequency Fragment Separator at NSCL

    International Nuclear Information System (INIS)

    Bazin, D.; Andreev, V.; Becerril, A.; Doleans, M.; Mantica, P.F.; Ottarson, J.; Schatz, H.; Stoker, J.B.; Vincent, J.

    2009-01-01

    A new device has been designed and built at NSCL which provides additional filtering of radioactive beams produced via projectile fragmentation. The Radio Frequency Fragment Separator (RFFS) uses the time micro structure of the beams accelerated by the cyclotrons to deflect particles according to their time-of-flight, in effect producing a phase filtering. The transverse RF (Radio Frequency) electric field of the RFFS has superior filtering performance compared to other electrostatic devices, such as Wien filters. Such filtering is critical for radioactive beams produced on the neutron-deficient side of the valley of stability, where strong contamination occurs at intermediate energies from 50 to 200 MeV/u.

  2. Radio-frequency integrated-circuit engineering

    CERN Document Server

    Nguyen, Cam

    2015-01-01

    Radio-Frequency Integrated-Circuit Engineering addresses the theory, analysis and design of passive and active RFIC's using Si-based CMOS and Bi-CMOS technologies, and other non-silicon based technologies. The materials covered are self-contained and presented in such detail that allows readers with only undergraduate electrical engineering knowledge in EM, RF, and circuits to understand and design RFICs. Organized into sixteen chapters, blending analog and microwave engineering, Radio-Frequency Integrated-Circuit Engineering emphasizes the microwave engineering approach for RFICs. Provide

  3. Ecuador: La experiencia de Radio Latacunga

    Directory of Open Access Journals (Sweden)

    David Silva

    2015-01-01

    Full Text Available En Latacunga - Ecuador es entrevistada Lucelly Villa, de la comunidad Hijas de San Pablo, "Hermanas Paulinas", ella es directora de la Radio y presidenta de la CORAPE (Coordinadora de Radios Populares y Educativas de Ecuador. En la entrevista comenta la experiencia de las emisoras en las zonas campesinas de la provincia cuya población indígena campesina esta geográficamente dispersa en la provincia de Cotopaxi. Habla de las dificultades y logros en once años de labor, informa de cómo funcionan las cabinas y la programación.

  4. Mean and extreme radio properties of quasars and the origin of radio emission

    Energy Technology Data Exchange (ETDEWEB)

    Kratzer, Rachael M.; Richards, Gordon T. [Department of Physics, Drexel University, Philadelphia, PA (United States)

    2015-02-01

    We investigate the evolution of both the radio-loud fraction (RLF) and (using stacking analysis) the mean radio loudness of quasars. We consider how these properties evolve as a function of redshift and luminosity, black hole (BH) mass and accretion rate, and parameters related to the dominance of a wind in the broad emission-line region. We match the FIRST source catalog to samples of luminous quasars (both spectroscopic and photometric), primarily from the Sloan Digital Sky Survey. After accounting for catastrophic errors in BH mass estimates at high redshift, we find that both the RLF and the mean radio luminosity increase for increasing BH mass and decreasing accretion rate. Similarly, both the RLF and mean radio loudness increase for quasars that are argued to have weaker radiation line driven wind components of the broad emission-line region. In agreement with past work, we find that the RLF increases with increasing optical/UV luminosity and decreasing redshift, while the mean radio loudness evolves in the exact opposite manner. This difference in behavior between the mean radio loudness and the RLF in L−z may indicate selection effects that bias our understanding of the evolution of the RLF; deeper surveys in the optical and radio are needed to resolve this discrepancy. Finally, we argue that radio-loud (RL) and radio-quiet (RQ) quasars may be parallel sequences, but where only RQ quasars at one extreme of the distribution are likely to become RL, possibly through slight differences in spin and/or merger history.

  5. THE RADIO PROPERTIES OF RADIO-LOUD NARROW-LINE SEYFERT 1 GALAXIES ON PARSEC SCALES

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Minfeng; Chen, Yongjun; Shen, Zhiqiang [Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030 (China); Komossa, S.; Zensus, J. A. [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Yuan, Weimin [Key Lab for Space Astronomy and Technology, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Wajima, Kiyoaki [Korea Astronomy and Space Science Institute, 776 Daedeokdae-ro, Yuseong, Daejeon 305-348 (Korea, Republic of); Zhou, Hongyan, E-mail: gumf@shao.ac.cn [Polar Research Institute of China, 451 Jinqiao Road, Shanghai 200136 (China)

    2015-11-15

    We present the detection of the compact radio structures of 14 radio-loud narrow-line Seyfert 1 (NLS1) galaxies from Very Long Baseline Array (VLBA) observations at 5 GHz performed in 2013. While 50% of the sources of our sample show a compact core only, the remaining 50% exhibit a core-jet structure. The measured brightness temperatures of the cores range from 10{sup 8.4} to 10{sup 11.4} K with a median value of 10{sup 10.1} K, indicating that the radio emission is from non-thermal jets, and that, likely, most sources are not strongly beamed, thus implying a low jet speed in these radio-loud NLS1 galaxies. In combination with archival data taken at multiple frequencies, we find that seven sources show flat or even inverted radio spectra, while steep spectra are revealed in the remaining seven objects. Although all of these sources are very radio-loud with R > 100, their jet properties are diverse in terms of their milliarcsecond (mas) scale (parsec scale) morphology and their overall radio spectral shape. The evidence for slow jet speeds (i.e., less relativistic jets), in combination with the low kinetic/radio power, may offer an explanation for the compact VLBA radio structure in most sources. The mildly relativistic jets in these high accretion rate systems are consistent with a scenario where jets are accelerated from the hot corona above the disk by the magnetic field and the radiation force of the accretion disk. Alternatively, a low jet bulk velocity can be explained by low spin in the Blandford–Znajek mechanism.

  6. A Radio-Frequency-over-Fiber link for large-array radio astronomy applications

    International Nuclear Information System (INIS)

    Mena, J; Bandura, K; Cliche, J-F; Dobbs, M; Gilbert, A; Tang, Q Y

    2013-01-01

    A prototype 425-850 MHz Radio-Frequency-over-Fiber (RFoF) link for the Canadian Hydrogen Intensity Mapping Experiment (CHIME) is presented. The design is based on a directly modulated Fabry-Perot (FP) laser, operating at ambient temperature, and a single-mode fiber. The dynamic performance, gain stability, and phase stability of the RFoF link are characterized. Tests on a two-element interferometer built at the Dominion Radio Astrophysical Observatory for CHIME prototyping demonstrate that RFoF can be successfully used as a cost-effective solution for analog signal transport on the CHIME telescope and other large-array radio astronomy applications

  7. The radio spectral energy distribution of infrared-faint radio sources

    Science.gov (United States)

    Herzog, A.; Norris, R. P.; Middelberg, E.; Seymour, N.; Spitler, L. R.; Emonts, B. H. C.; Franzen, T. M. O.; Hunstead, R.; Intema, H. T.; Marvil, J.; Parker, Q. A.; Sirothia, S. K.; Hurley-Walker, N.; Bell, M.; Bernardi, G.; Bowman, J. D.; Briggs, F.; Cappallo, R. J.; Callingham, J. R.; Deshpande, A. A.; Dwarakanath, K. S.; For, B.-Q.; Greenhill, L. J.; Hancock, P.; Hazelton, B. J.; Hindson, L.; Johnston-Hollitt, M.; Kapińska, A. D.; Kaplan, D. L.; Lenc, E.; Lonsdale, C. J.; McKinley, B.; McWhirter, S. R.; Mitchell, D. A.; Morales, M. F.; Morgan, E.; Morgan, J.; Oberoi, D.; Offringa, A.; Ord, S. M.; Prabu, T.; Procopio, P.; Udaya Shankar, N.; Srivani, K. S.; Staveley-Smith, L.; Subrahmanyan, R.; Tingay, S. J.; Wayth, R. B.; Webster, R. L.; Williams, A.; Williams, C. L.; Wu, C.; Zheng, Q.; Bannister, K. W.; Chippendale, A. P.; Harvey-Smith, L.; Heywood, I.; Indermuehle, B.; Popping, A.; Sault, R. J.; Whiting, M. T.

    2016-10-01

    Context. Infrared-faint radio sources (IFRS) are a class of radio-loud (RL) active galactic nuclei (AGN) at high redshifts (z ≥ 1.7) that are characterised by their relative infrared faintness, resulting in enormous radio-to-infrared flux density ratios of up to several thousand. Aims: Because of their optical and infrared faintness, it is very challenging to study IFRS at these wavelengths. However, IFRS are relatively bright in the radio regime with 1.4 GHz flux densities of a few to a few tens of mJy. Therefore, the radio regime is the most promising wavelength regime in which to constrain their nature. We aim to test the hypothesis that IFRS are young AGN, particularly GHz peaked-spectrum (GPS) and compact steep-spectrum (CSS) sources that have a low frequency turnover. Methods: We use the rich radio data set available for the Australia Telescope Large Area Survey fields, covering the frequency range between 150 MHz and 34 GHz with up to 19 wavebands from different telescopes, and build radio spectral energy distributions (SEDs) for 34 IFRS. We then study the radio properties of this class of object with respect to turnover, spectral index, and behaviour towards higher frequencies. We also present the highest-frequency radio observations of an IFRS, observed with the Plateau de Bure Interferometer at 105 GHz, and model the multi-wavelength and radio-far-infrared SED of this source. Results: We find IFRS usually follow single power laws down to observed frequencies of around 150 MHz. Mostly, the radio SEDs are steep (α IFRS show statistically significantly steeper radio SEDs than the broader RL AGN population. Our analysis reveals that the fractions of GPS and CSS sources in the population of IFRS are consistent with the fractions in the broader RL AGN population. We find that at least % of IFRS contain young AGN, although the fraction might be significantly higher as suggested by the steep SEDs and the compact morphology of IFRS. The detailed multi

  8. Affirmation of triggered Jovian radio emissions and their attribution to corotating radio lasers

    Science.gov (United States)

    Calvert, W.

    1985-01-01

    It is argued that the original statistical evidence for the existence of triggered radio emissions and corotating radio lasers on Jupiter remains valid notwithstanding the critique of Desch and Kaiser (1985). The Voyager radio spectrograms used to identify the triggered emissions are analyzed and the results are discussed. It is shown that the critique by Desch and Kaiser is unjustified because it is not based on the original event criteria, i.e., the correlation between the occurrence of Jovian auroral kilometric radiation and fast-drift type III solar bursts in the same frequency.

  9. Desenvolvimento de uma escala para medir o potencial empreendedor utilizando a Teoria da Resposta ao Item (TRI Development of a scale to measure the entrepreneurial potential using the Item Response Theory (IRT

    Directory of Open Access Journals (Sweden)

    Luciano Ricardo Rath Alves

    2011-01-01

    Full Text Available Diversas variáveis estão relacionadas ao desenvolvimento da atividade empreendedora, verifica-se, entre elas, a importância do agente empreendedor. Dos estudos que contribuem para o seu entendimento, este segue a linha que defende que o empreendedor tem características e traços de personalidade singulares em relação à população, os quais são propícios ao sucesso do empreendedorismo. O objetivo deste trabalho é desenvolver uma escala para medir o potencial empreendedor utilizando a Teoria da Resposta ao Item. Foi utilizado o modelo logístico de dois parâmetros da TRI. As estimativas dos parâmetros foram obtidas a partir da amostra com 764 pessoas que responderam a um instrumento composto por 103 itens. A curva de informação e do erro padrão do teste e a interpretação qualitativa de níveis da escala permitiram determinar o intervalo mais apropriado para utilização do instrumento. Os resultados mostraram que a escala é mais adequada para avaliar indivíduos com baixo até moderadamente alto potencial empreendedor. Por isso, sugere-se que novos itens sejam incorporados ao instrumento para mensurar e interpretar níveis ainda mais elevados. A Teoria da Resposta ao Item permite que novos itens sejam calibrados a fim de mensurar os empreendedores com alto potencial empreendedor, aproveitando os dados já obtidos.Several variables are related to the development of entrepreneurial activities. An important one among them is the entrepreneurial agent. This study is one of many that contribute to the understanding of the entrepreneurial agent. In its line of thought, it upholds the idea that the entrepreneur has characteristics and personality traits that stand out from the general population and that are favorable to the success of the entrepreneurship. This study aims at developing a measurement scale for entrepreneurial potential using the Item Response Theory. The items were generated by Santos (2008 based on a theoretical model

  10. Desarrollo y validación de un cuestionario para medir la reputación de los hospitales Development and validation of a questionnaire to measure hospitals´ social reputation

    Directory of Open Access Journals (Sweden)

    Isabel María Navarro

    2012-10-01

    Full Text Available Objetivo: Diseñar y validar un cuestionario (MeFío para medir la reputación social de un hospital desde el punto de vista de los ciudadanos y de los pacientes. Material y método: Revisión de la literatura para acotar los límites del concepto de reputación social de un hospital. Se realizaron cuatro grupos nominales con la participación de 47 directivos y profesionales y de 32 posibles clientes para establecer factores a priori del cuestionario MeFío. Se elaboraron ítems reactivos y se realizó una prueba piloto de comprensión. Se seleccionó una muestra aleatoria de 385 sujetos y se analizaron los efectos suelo y techo, la consistencia interna, la fiabilidad y la validez de constructo y de criterio. Resultados: Se obtuvieron 343 cuestionarios válidos (tasa de respuesta del 89%. MeFío cuenta con 21 ítems agrupados en cinco factores. En todos los casos los valores de correlación ítem-total fueron superiores a 0,30, las cargas factoriales superiores a 0,5, el rango de varianza explicada entre el 66,2% y el 80,4%, y el valor alfa de Cronbach entre 0,7 y 0,88. Los índices de fiabilidad compuesta fueron mayores de 0,7. La estrategia de modelos rivales mostró un mejor ajuste del modelo con dos factores de segundo orden. En el análisis de validez convergente-discriminante, todas las cargas estandarizadas fueron superiores a 0,6. Los factores explicaron un 50% de la variabilidad de la satisfacción con las atenciones sanitarias (F = 66,5; p Objective: To design and validate a questionnaire (MeFio to measure the social reputation of a hospital from patients´ and citizens´ perspective. Material and methods: We performed a literature review to define the concept of a hospital's social reputation. Four nominal groups were conducted to set up the a priori factors of the MeFio questionnaire. These groups consisted of 47 managers and health professionals and 32 potential customers. Reactive items were identified and a pilot test was

  11. Aspects of HF radio propagation

    Directory of Open Access Journals (Sweden)

    Stephane Saillant

    2009-06-01

    Full Text Available

    radio systems. From the point of view Working Group 2 of the COST 296 Action, interest lies with effects associated

    with propagation via the ionosphere of signals within the HF band. Several aspects are covered in this paper:

    a The directions of arrival and times of flight of signals received over a path oriented along the trough have

    been examined and several types of propagation effects identified. Of particular note, combining the HF observations

    with satellite measurements has identified the presence of irregularities within the floor of the trough that

    result in propagation displaced from the great circle direction. An understanding of the propagation effects that

    result in deviations of the signal path from the great circle direction are of particular relevance to the operation

    of HF radiolocation systems.

    b Inclusion of the results from the above mentioned measurements into a propagation model of the northerly

    ionosphere (i.e. those regions of the ionosphere located poleward of, and including, the mid-latitude trough

    and the use of this model to predict the coverage expected from transmitters where the signals impinge on the

    northerly ionosphere

  12. Particularites radio-cliniques et bacteriologique de la tuberculose ...

    African Journals Online (AJOL)

    Particularites radio-cliniques et bacteriologique de la tuberculose pulmonaire chez les patients infectees par le vih au centre hospitalier Sylvanus Olympio de Lome. Radio-clinical and bacteriologial peculiarities of the pulmonary tuberculosis in hiv infe.

  13. Protocols for Impulse Radio UWB Ad Hoc Networks

    NARCIS (Netherlands)

    Shi, N.

    2010-01-01

    Ultra Wideband (UWB) technology offers an unprecedented opportunity to further accelerate the evolution of wireless communication and expand the application landscape by enabling outstanding capabilities. UWB radio is fundamentally different from most radio technologies, e.g., Bluetooth, WLAN, etc.

  14. Adaptive Decision-Making Scheme for Cognitive Radio Networks

    KAUST Repository

    Alqerm, Ismail; Shihada, Basem

    2014-01-01

    Radio resource management becomes an important aspect of the current wireless networks because of spectrum scarcity and applications heterogeneity. Cognitive radio is a potential candidate for resource management because of its capability to satisfy

  15. Goldstone-Apple Valley Radio Telescope System Theory of Operation

    Science.gov (United States)

    Stephan, George R.

    1997-01-01

    The purpose of this learning module is to enable learners to describe how the Goldstone-Apple Valley Radio Telescope (GAVRT) system functions in support of Apple Valley Science and Technology Center's (AVSTC) client schools' radio astronomy activities.

  16. The Importance of Site Selection for Radio Astronomy

    International Nuclear Information System (INIS)

    Umar, Roslan; Abidin, Zamri Zainal; Ibrahim, Zainol Abidin

    2014-01-01

    Radio sources are very weak since this object travel very far from outer space. Radio astronomy studies are limited due to radio frequency interference (RFI) that is made by man. If the harassment is not stopped, it will provide critical problems in their radio astronomy scientists research. The purpose of this study is to provide RFI map Peninsular Malaysia with a minimum mapping techniques RFI interference. RFI mapping technique using GIS is proposed as a tool in mapping techniques. Decision-making process for the selection requires gathering information from a variety of parameters. These factors affecting the selection process are also taken account. In this study, various factors or parameters involved such as availability of telecommunications transmission (including radio and television), rainfall, water line and human activity. This study will benefit radio astronomy research especially in the RFI profile in Malaysia. Keywords: Radio Astronomy, Radio Frequency Interference (RFI), RFI mapping technique : GIS

  17. Wideband Autonomous Cognitive Radios for Networked Satellites Communications, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Wideband Autonomous Cognitive Radios (WACRs) are advanced radios that have the ability to sense state of the RF spectrum and the network and self-optimize its...

  18. Online Cloud Offloading Using Heterogeneous Enhanced Remote Radio Heads

    KAUST Repository

    Shnaiwer, Yousef N.; Sorour, Sameh; Sadeghi, Parastoo; Al-Naffouri, Tareq Y.

    2018-01-01

    This paper studies the cloud offloading gains of using heterogeneous enhanced remote radio heads (eRRHs) and dual-interface clients in fog radio access networks (F-RANs). First, the cloud offloading problem is formulated as a collection

  19. Distributed opportunistic spectrum sharing in cognitive radio networks

    KAUST Repository

    Hawa, Mohammed; Alammouri, Ahmad; Alhiary, Ala; Alhamad, Nidal

    2016-01-01

    In cases where the licensed radio spectrum is underutilized, cognitive radio technology enables cognitive devices to sense and then dynamically access this scarce resource making the most out of it. In this work, we introduce a simple and intuitive

  20. A generalized and parameterized interference model for cognitive radio networks

    KAUST Repository

    Mahmood, Nurul Huda; Yilmaz, Ferkan; Alouini, Mohamed-Slim

    2011-01-01

    For meaningful co-existence of cognitive radios with primary system, it is imperative that the cognitive radio system is aware of how much interference it generates at the primary receivers. This can be done through statistical modeling

  1. The Official Radio and Television Institute in Spain

    Science.gov (United States)

    Ruiz, Anibal Arias

    1976-01-01

    A description of the Official School of Radio and Television which is designed to train university graduates in the fields of journalism, the sciences of cinema, radio and television, and advertising. (JY)

  2. Reconfigurable Ultra-Low Power Miniaturized EVA Radio, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — EVA radio is an important integral part of lunar missions and beyond. To minimize power consumption and mass of an EVA radio, innovative solutions are needed for the...

  3. Software defined radios from smart(er) to cognitive

    CERN Document Server

    Pollin, Sofie; Van der Perre, Liesbet

    2011-01-01

    Software Defined Radios presents a systematic approach to dealing with the complexity of wireless systems with varying standards. The text aims to enable smart operation of radios with impressive efficiency gains, without hampering the quality of service.

  4. En kvantitativ metode til analyse af radio

    Directory of Open Access Journals (Sweden)

    Christine Lejre

    2014-06-01

    Full Text Available I den danske såvel som den internationale radiolitteratur er bud på metoder til analyse af radiomediet sparsomme. Det skyldes formentlig, at radiomediet er svært at analysere, fordi det er et medie, der ikke er visualiseret i form af billeder eller understøttet af printet tekst. Denne artikel har til formål at beskrive en ny kvantitativ metode til analyse af radio, der tager særligt hensyn til radiomediets modalitet – lyd struktureret som et lineært forløb i tid. Metoden understøtter dermed både radiomediet som et medie i tid og som et blindt medie. Metoden er udviklet i forbindelse med en komparativ analyse af kulturprogrammer på P1 og Radio24syv lavet for Danmarks Radio. Artiklen peger på, at metoden er velegnet til analyse af ikke kun radio, men også andre medieplatforme samt forskellige journalistiske stofområder.

  5. Radio Ranging Techniques to test Relativistic Gravitation

    OpenAIRE

    Cowsik, R.

    1999-01-01

    It is suggested that modern techniques of radio ranging when applied to study the motion of the Moon, can improve the accuracy of tests of relativistic gravitation obtained with currently operating laser ranging techniques. Other auxillary information relevant to the Solar system would also emerge from such a study.

  6. Inhomogeneities and the Modeling of Radio Supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Björnsson, C.-I.; Keshavarzi, S. T., E-mail: bjornsson@astro.su.se [Department of Astronomy, AlbaNova University Center, Stockholm University, SE–106 91 Stockholm (Sweden)

    2017-05-20

    Observations of radio supernovae (SNe) often exhibit characteristics not readily accounted for by a homogeneous, spherically symmetric synchrotron model; e.g., flat-topped spectra/light curves. It is shown that many of these deviations from the standard model can be attributed to an inhomogeneous source structure. When inhomogeneities are present, the deduced radius of the source and, hence, the shock velocity, is sensitive to the details of the modeling. As the inhomogeneities are likely to result from the same mechanism that amplify the magnetic field, a comparison between observations and the detailed numerical simulations now under way may prove mutually beneficial. It is argued that the radio emission in Type Ib/c SNe has a small volume filling factor and comes from a narrow region associated with the forward shock, while the radio emission region in SN 1993J (Type IIb) is determined by the extent of the Rayleigh–Taylor instability emanating from the contact discontinuity. Attention is also drawn to the similarities between radio SNe and the structural properties of SN remnants.

  7. Powerful Radio Burst Indicates New Astronomical Phenomenon

    Science.gov (United States)

    2007-09-01

    Astronomers studying archival data from an Australian radio telescope have discovered a powerful, short-lived burst of radio waves that they say indicates an entirely new type of astronomical phenomenon. Region of Strong Radio Burst Visible-light (negative greyscale) and radio (contours) image of Small Magellanic Cloud and area where burst originated. CREDIT: Lorimer et al., NRAO/AUI/NSF Click on image for high-resolution file ( 114 KB) "This burst appears to have originated from the distant Universe and may have been produced by an exotic event such as the collision of two neutron stars or the death throes of an evaporating black hole," said Duncan Lorimer, Assistant Professor of Physics at West Virginia University (WVU) and the National Radio Astronomy Observatory (NRAO). The research team led by Lorimer consists of Matthew Bailes of Swinburne University in Australia, Maura McLaughlin of WVU and NRAO, David Narkevic of WVU, and Fronefield Crawford of Franklin and Marshall College in Lancaster, Pennsylvania. The astronomers announced their findings in the September 27 issue of the online journal Science Express. The startling discovery came as WVU undergraduate student David Narkevic re-analyzed data from observations of the Small Magellanic Cloud made by the 210-foot Parkes radio telescope in Australia. The data came from a survey of the Magellanic Clouds that included 480 hours of observations. "This survey had sought to discover new pulsars, and the data already had been searched for the type of pulsating signals they produce," Lorimer said. "We re-examined the data, looking for bursts that, unlike the usual ones from pulsars, are not periodic," he added. The survey had covered the Magellanic Clouds, a pair of small galaxies in orbit around our own Milky Way Galaxy. Some 200,000 light-years from Earth, the Magellanic Clouds are prominent features in the Southern sky. Ironically, the new discovery is not part of these galaxies, but rather is much more distant

  8. Radio frequency channel coding made easy

    CERN Document Server

    Faruque, Saleh

    2016-01-01

    This book introduces Radio Frequency Channel Coding to a broad audience. The author blends theory and practice to bring readers up-to-date in key concepts, underlying principles and practical applications of wireless communications. The presentation is designed to be easily accessible, minimizing mathematics and maximizing visuals.

  9. 78 FR 32165 - Commercial Radio Operators; Correction

    Science.gov (United States)

    2013-05-29

    ...) Grants emergency exemption requests, extensions or waivers of inspection to ships in accordance with..., marking and lighting of antenna structures (part 17 of this chapter), and the Commission's privatized ship radio inspection program (part 80 of this chapter). * * * * * (s)(1) Extends the Communications Act...

  10. Radio transients from newborn black holes

    Science.gov (United States)

    Kashiyama, Kazumi; Hotokezaka, Kenta; Murase, Kohta

    2018-05-01

    We consider radio emission from a newborn black hole (BH), which is accompanied by a mini-disk with a mass of ≲ M⊙. Such a disk can be formed from an outer edge of the progenitor's envelope, especially for metal-poor massive stars and/or massive stars in close binaries. The disk accretion rate is typically super-Eddington and an ultrafast outflow with a velocity of ˜0.1-0.3 c will be launched into the circumstellar medium. The outflow forms a collisionless shock, and electrons are accelerated and emit synchrotron emission in radio bands with a flux of ˜ 10^{26-30} erg s^{-1} Hz^{-1} days to decades after the BH formation. The model predicts not only a fast UV/optical transient but also quasi-simultaneous inverse-Compton X-ray emission ˜ a few days after the BH formation, and the discovery of the radio counterpart with coordinated searches will enable us to identify this type of transients. The occurrence rate can be 0.1 - 10 % of the core-collapse supernova rate, which makes them a promising target of dedicated radio observations such as the Jansky VLA Sky Survey.

  11. Reflectivity level of radio anechoic chambers

    DEFF Research Database (Denmark)

    Appel-Hansen, Jørgen

    1973-01-01

    A comparison between the antenna-pattern comparison technique and the free-space voltage standing-wave ratio technique for evaluating the reflectivity level of radio anechoic chambers is presented. Based on an analysis of the two techniques, it is pointed out which parameters influence the measured...

  12. Hartebeesthoek Radio Astronomy Observatory (HartRAO)

    Science.gov (United States)

    Nickola, Marisa; Gaylard, Mike; Quick, Jonathan; Combrinck, Ludwig

    2013-01-01

    HartRAO provides the only fiducial geodetic site in Africa, and it participates in global networks for VLBI, GNSS, SLR, and DORIS. This report provides an overview of geodetic VLBI activities at HartRAO during 2012, including the conversion of a 15-m alt-az radio telescope to an operational geodetic VLBI antenna.

  13. Measuring Ethical Sensitivity to Radio Messages.

    Science.gov (United States)

    Potter, Robert F.

    A study examined whether ethical sensitivity can be measured in response to radio programming. The study was interested in the extent to which a person feels a program is unethical in either its substance or its presentation. Subjects, 17 undergraduates in telecommunications at a large midwestern university, received course credit for their…

  14. A comparative study of cognitive radio platforms

    CSIR Research Space (South Africa)

    Masonta, MT

    2012-10-01

    Full Text Available -life deployments of CR systems, the research community is now focusing on the development of CR platforms. With different software defined radio (SDR) packages and hardware available, it is confusing to decide which one to build or use. The objective of this paper...

  15. Radio requestable passive SAW water content sensor

    NARCIS (Netherlands)

    Reindl, L.; Ruppel, C.C.W.; Kirmayr, A.; Stockhausen, N.; Hilhorst, M.A.; Balendonk, J.

    2001-01-01

    A new passive sensor for remote measurement of water content in sandy soil was designed, using a surface acoustic wave (SAW) reflective delay line. Information from this sensor can be obtained by an interrogation device via a radio link operating in the European 434-MHz industrial-scientific-medical

  16. The Acceptability of Speech with Radio Interference

    DEFF Research Database (Denmark)

    Baykaner, K.; Hummersone, H.; Mason, R.

    2014-01-01

    A listening test was conducted to investigate the acceptability of audio-on-audio interference for radio programs featuring speech as the target. Twenty-one subjects, including naïve and expert listeners, were presented with 200 randomly assigned pairs of stimuli and asked to report, for each trial...

  17. Extragalactic dispersion measures of fast radio bursts

    International Nuclear Information System (INIS)

    Xu, Jun; Han, J. L.

    2015-01-01

    Fast radio bursts show large dispersion measures, much larger than the Galactic dispersion measure foreground. Therefore, they evidently have an extragalactic origin. We investigate possible contributions to the dispersion measure from host galaxies. We simulate the spatial distribution of fast radio bursts and calculate the dispersion measures along the sightlines from fast radio bursts to the edge of host galaxies by using the scaled NE2001 model for thermal electron density distributions. We find that contributions to the dispersion measure of fast radio bursts from the host galaxy follow a skew Gaussian distribution. The peak and the width at half maximum of the dispersion measure distribution increase with the inclination angle of a spiral galaxy, to large values when the inclination angle is over 70°. The largest dispersion measure produced by an edge-on spiral galaxy can reach a few thousand pc cm −3 , while the dispersion measures from dwarf galaxies and elliptical galaxies have a maximum of only a few tens of pc cm −3 . Notice, however, that additional dispersion measures of tens to hundreds of pc cm −3 can be produced by high density clumps in host galaxies. Simulations that include dispersion measure contributions from the Large Magellanic Cloud and the Andromeda Galaxy are shown as examples to demonstrate how to extract the dispersion measure from the intergalactic medium. (paper)

  18. Spectrum access games for cognitive radio networks

    CSIR Research Space (South Africa)

    Masonta, MT

    2010-09-01

    Full Text Available received a wide acceptance in next generation and intelligent wireless communication systems. In this paper the authors make use of game theory approach to model and analyze cognitive radio networks in order to allow dynamic spectrum access in broadband...

  19. Radio broadcasting for sustainable development in southern ...

    African Journals Online (AJOL)

    Patrick O. Waeber and Yvonne Orengo

    2008-12-01

    Dec 1, 2008 ... ABSTRACT. The Millennium Development Goals have been written into the Madagascar Road Map (2007 - 2012) in order to improve the Malagasy social, economic and environmental situation. The Andrew Lees Trust Radio Broadcasting Project in southern. Madagascar has been set up to alleviate ...

  20. Magnetized environs of a repeating radio burst

    Science.gov (United States)

    Metzger, Brian D.

    2018-03-01

    One of the astrophysical sources that gives rise to the mysterious transients known as fast radio bursts is embedded in a highly magnetized environment, such as the vicinity of an accreting massive black hole or the birth nebula of a highly magnetized neutron star.

  1. Solar Radio Bursts and Space Weather

    Science.gov (United States)

    Gopalswamy, Natchimuthuk,

    2012-01-01

    Radio bursts from the Sun are produced by electron accelerated to relativistic energies by physical processes on the Sun such as solar flares and coronal mass ejections (CMEs). The radio bursts are thus good indicators of solar eruptions. Three types of nonthermal radio bursts are generally associated with CMEs. Type III bursts due to accelerated electrons propagating along open magnetic field lines. The electrons are thought to be accelerated at the reconnection region beneath the erupting CME, although there is another view that the electrons may be accelerated at the CME-driven shock. Type II bursts are due to electrons accelerated at the shock front. Type II bursts are also excellent indicators of solar energetic particle (SEP) events because the same shock is supposed accelerate electrons and ions. There is a hierarchical relationship between the wavelength range of type /I bursts and the CME kinetic energy. Finally, Type IV bursts are due to electrons trapped in moving or stationary structures. The low frequency stationary type IV bursts are observed occasionally in association with very fast CMEs. These bursts originate from flare loops behind the erupting CME and hence indicate tall loops. This paper presents a summary of radio bursts and their relation to CMEs and how they can be useful for space weather predictions.

  2. Giant pulses of pulsar radio emission

    OpenAIRE

    Kuzmin, A. D.

    2007-01-01

    Review report of giant pulses of pulsar radio emission, based on our detections of four new pulsars with giant pulses, and the comparative analysis of the previously known pulsars with giant pulses, including the Crab pulsar and millisecond pulsar PSR B1937+21.

  3. Energy-Aware Cognitive Radio Systems

    KAUST Repository

    Bedeer, Ebrahim

    2016-01-15

    The concept of energy-aware communications has spurred the interest of the research community in the most recent years due to various environmental and economical reasons. It becomes indispensable for wireless communication systems to shift their resource allocation problems from optimizing traditional metrics, such as throughput and latency, to an environmental-friendly energy metric. Although cognitive radio systems introduce spectrum efficient usage techniques, they employ new complex technologies for spectrum sensing and sharing that consume extra energy to compensate for overhead and feedback costs. Considering an adequate energy efficiency metric—that takes into account the transmit power consumption, circuitry power, and signaling overhead—is of momentous importance such that optimal resource allocations in cognitive radio systems reduce the energy consumption. A literature survey of recent energy-efficient based resource allocations schemes is presented for cognitive radio systems. The energy efficiency performances of these schemes are analyzed and evaluated under power budget, co-channel and adjacent-channel interferences, channel estimation errors, quality-of-service, and/or fairness constraints. Finally, the opportunities and challenges of energy-aware design for cognitive radio systems are discussed.

  4. The Spectrum Landscape: Prospects for Terrestrial Radio Astronomy

    Science.gov (United States)

    Liszt, Harvey Steven

    2018-01-01

    Radio astronomers work within broad constraints imposed by commercial and other non-astronomical uses of the radio spectrum, somewhat modified to accommodate astronomy’s particular needs through the provision of radio quiet zones, radio frequency allocations, coordination agreements and other devices of spectrum management. As radio astronomers increase the instantaneous bandwidth, frequency coverage and sensitivity of their instruments, these external constraints, and not the limitations of their own instruments, will increasingly be the greatest obstacles to radio astronomy’s ability to observe the cosmos from the surface of the Earth. Therefore, prospects for future radio astronomy operations are contingent on situational awareness and planning for the impact of non-astronomical uses of the radio frequency spectrum. New radio astronomy instruments will have to incorporate adaptive reactions to external developments, and radio astronomers should be encouraged to think in untraditional ways. Increased attention to spectrum management is one of these. In this talk I’ll recap some recent developments such as the proliferation of 76 – 81 GHz car radar and orbiting earth-mapping radars, either of which can burn out a radio astronomy receiver. I’ll summarize present trends for non-astronomical radio spectrum use that will be coming to fruition in the next decade or so, categorized into terrestrial fixed and mobile, airborne and space-borne uses, sub-divided by waveband from the cm to the sub-mm. I’ll discuss how they will impact terrestrial radio astronomy and the various ways in which radio astronomy should be prepared to react. Protective developments must occur both within radio astronomy’s own domain – designing, siting and constructing its instruments and mitigating unavoidable RFI – and facing outward toward the community of other spectrum users. Engagement with spectrum management is no panacea but it is an important means, and perhaps the only

  5. The Dynamic Radio Sky: An Opportunity for Discovery

    Science.gov (United States)

    2010-01-01

    giant pulses from the Crab pulsar , a small number of dedicated radio transient surveys, and the serendipitous discovery of transient radio sources...used in the discovery of over 1800 radio pulsars . In 2003, the Parkes Multibeam Survey had covered the entire Galactic plane visible from Parkes... pulsars , and confirmed the neutron star nature of these sources, dubbed Rotating Radio Transients (RRATs). Since the discovery of the original 11 RRATs

  6. DIFFERENCES BETWEEN RADIO-LOUD AND RADIO-QUIET γ -RAY PULSARS AS REVEALED BY FERMI

    Energy Technology Data Exchange (ETDEWEB)

    Hui, C. Y.; Lee, Jongsu [Department of Astronomy and Space Science, Chungnam National University, Daejeon (Korea, Republic of); Takata, J. [Institute of Particle physics and Astronomy, Huazhong University of Science and Technology (China); Ng, C. W.; Cheng, K. S., E-mail: cyhui@cnu.ac.kr, E-mail: takata@hust.edu.cn [Department of Physics, University of Hong Kong, Pokfulam Road (Hong Kong)

    2017-01-10

    By comparing the properties of non-recycled radio-loud γ -ray pulsars and radio-quiet γ -ray pulsars, we have searched for the differences between these two populations. We found that the γ -ray spectral curvature of radio-quiet pulsars can be larger than that of radio-loud pulsars. Based on the full sample of non-recycled γ -ray pulsars, their distributions of the magnetic field strength at the light cylinder are also found to be different. We note that this might result from an observational bias. By reexamining the previously reported difference of γ -ray-to-X-ray flux ratios, we found that the significance can be hampered by their statistical uncertainties. In the context of the outer gap model, we discuss the expected properties of these two populations and compare with the possible differences that are identified in our analysis.

  7. A COTS RF Optical Software Defined Radio for the Integrated Radio and Optical Communications Test Bed

    Science.gov (United States)

    Nappier, Jennifer M.; Zeleznikar, Daniel J.; Wroblewski, Adam C.; Tokars, Roger P.; Schoenholz, Bryan L.; Lantz, Nicholas C.

    2016-01-01

    The Integrated Radio and Optical Communications (iROC) project at the National Aeronautics and Space Administration (NASA) is investigating the merits of a hybrid radio frequency (RF) and optical communication system for deep space missions. In an effort to demonstrate the feasibility and advantages of a hybrid RFOptical software defined radio (SDR), a laboratory prototype was assembled from primarily commercial-off-the-shelf (COTS) hardware components. This COTS platform has been used to demonstrate simultaneous transmission of the radio and optical communications waveforms through to the physical layer (telescope and antenna). This paper details the hardware and software used in the platform and various measures of its performance. A laboratory optical receiver platform has also been assembled in order to demonstrate hybrid free space links in combination with the transmitter.

  8. Comparison of VLBI radio core and X-ray flux densities of extragalactic radio sources

    International Nuclear Information System (INIS)

    Bloom, S.D.; Marscher, A.P.

    1990-01-01

    The Einstein Observatory revealed that most quasars, selected in a variety of ways, are strong x-ray emitters. Radio bright quasars are statistically more luminous in the x-ray than their radio-quiet counterparts. It was also found that the 90 GHz to soft x-ray spectral index has a very small dispersion for sources selected by their strong millimeter emission. This implies a close relationship between compact radio flux density and x-ray emission. Strong correlations have been found between the arcsecond scale flux densities and soft x-ray fluxes. It is suggested that the correlation can be explained if the soft x-rays were produced by the synchrotron self-Compton (SSC) process within the compact radio emitting region. (author)

  9. HOW DOES RADIO AGN FEEDBACK FEED BACK?

    International Nuclear Information System (INIS)

    De Young, David S.

    2010-01-01

    The possible role of radio active galactic nucleus (AGN) 'feedback' in conventional hierarchical cosmological models has become widely discussed. This paper examines some of the details of how such feedback might work. A basic requirement is the conversion of radio AGN outflow energy into heating of the circumgalactic medium in a time comparable to the relevant cooling times. First, the class of radio AGN relevant to this process is identified as FR-I radio sources. Second, it is argued via comparisons with experimental data that these AGN outflows are strongly decelerated and become fully turbulent sonic or subsonic flows due to their interaction with the surrounding medium. Using this, a three-dimensional time-dependent calculation of the evolution of such turbulent magnetohydrodynamic flows is made to determine the time scale required for conversion of the turbulent energy into heat. This calculation, when coupled with observational data, suggests that the onset of heating can occur ∼10 8 yr after the fully turbulent flow is established, and this time is less than or comparable to the local cooling times in the interstellar or circumgalactic medium for many of these objects. The location of where heat deposition occurs remains uncertain, but estimates of outflow speeds suggest that heating may occur many tens of kpc from the center of the parent galaxy. Recent observations suggest that such radio AGN outflows may become dispersed on much larger scales than previously thought, thus possibly satisfying the requirement that heating occurs over a large fraction of the volume occupied by the circumgalactic gas.

  10. Optimization of the radio lanthanides separation device

    International Nuclear Information System (INIS)

    Vera T, A. L.

    2009-01-01

    At present, cancer is a major cause of mortality in our country, therefore, its prevention, diagnosis and treatment are vital to health systems. The cancer treatment and other diseases, from monoclonal antibodies, peptides, or amino macro aggregates marked with beta particle emitting radionuclides, is a highly promising field. The radioactive lanthanides: Pm, Tb, Ho, and Lu are beta emitters, which possess nuclear and chemical properties, which have shown their feasibility as radioisotopes of radiotherapeutic use. However, these radioisotopes are not available commercially in this connection, the Research Laboratory of Radioactive Materials of the National Institute of Nuclear Research, has developed the methodology of production of these radioisotopes and based on this work is designed, constructed and installed the radio lanthanides separation device for the radioisotopes production routinely. This device is part of the cell, , which has and auxiliary air service, an extraction system and is protected with a 10 cm of lead shielding. The radio lanthanides separation device is manual and easy to handle. The main function of this equipment is the radio lanthanides separation from extractive chromatography through packed columns with a commercial resin (Ln SPS) and coated on the top and bottom by fiberglass. The radio lanthanides separation device comprises a main carrousel where the separation columns and elution containers are mounted. It also has a system of open irradiation vials, carrier samples for columns and glassware. This paper presents a detailed description of the radio lanthanides separation device and its management, which allows the radioisotopes production Pm, Tb, Ho, and Lu from the separation of its parents Nd, Dy, Gd, and Yb respectively. (Author)

  11. INTERSTELLAR SCINTILLATION AND THE RADIO COUNTERPART OF THE FAST RADIO BURST FRB 150418

    Energy Technology Data Exchange (ETDEWEB)

    Akiyama, Kazunori [Massachusetts Institute of Technology, Haystack Observatory, Route 40, Westford, MA 01886 (United States); Johnson, Michael D., E-mail: kazu@haystack.mit.edu [Harvard Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2016-06-10

    Keane et al. have recently reported the discovery of a new fast radio burst (FRB), FRB 150418, with a promising radio counterpart at 5.5 and 7.5 GHz—a rapidly decaying source, falling from 200–300 μ Jy to 100 μ Jy on timescales of ∼6 days. This transient source may be associated with an elliptical galaxy at redshift z = 0.492, providing the first firm spectroscopic redshift for an FRB and the ability to estimate the density of baryons in the intergalactic medium via the combination of known redshift and radio dispersion of the FRB. An alternative explanation, first suggested by Williams and Berger, is that the identified counterpart may instead be a compact active galactic nucleus (AGN). The putative counterpart’s variation may then instead be extrinsic, caused by refractive scintillation in the ionized interstellar medium of the Milky Way, which would invalidate the association with FRB 150418. We examine this latter explanation in detail and show that the reported observations are consistent with scintillating radio emission from the core of a radio-loud AGN having a brightness temperature T {sub b} ≳ 10{sup 9} K. Using numerical simulations of the expected scattering for the line of sight to FRB 150418, we provide example images and light curves of such an AGN at 5.5 and 7.5 GHz. These results can be compared with continued radio monitoring to conclusively determine the importance of scintillation for the observed radio variability, and they show that scintillation is a critical consideration for continued searches for FRB counterparts at radio wavelengths.

  12. The statistics of low frequency radio interference at the Murchison Radio-astronomy Observatory

    OpenAIRE

    Sokolowski, Marcin; Wayth, Randall B.; Lewis, Morgan

    2016-01-01

    We characterize the low frequency radio-frequency interference (RFI) environment at the Murchison Radio-astronomy Observatory (MRO), the location selected for the low-frequency component of the Square Kilometre Array. Data were collected from the BIGHORNS instrument, located at the MRO, which records a contiguous bandwidth between 70 and 300 MHz, between November 2014 to March 2015 inclusive. The data were processed to identify RFI, and we describe a series of statistics in both the time and ...

  13. INTERSTELLAR SCINTILLATION AND THE RADIO COUNTERPART OF THE FAST RADIO BURST FRB 150418

    International Nuclear Information System (INIS)

    Akiyama, Kazunori; Johnson, Michael D.

    2016-01-01

    Keane et al. have recently reported the discovery of a new fast radio burst (FRB), FRB 150418, with a promising radio counterpart at 5.5 and 7.5 GHz—a rapidly decaying source, falling from 200–300 μ Jy to 100 μ Jy on timescales of ∼6 days. This transient source may be associated with an elliptical galaxy at redshift z = 0.492, providing the first firm spectroscopic redshift for an FRB and the ability to estimate the density of baryons in the intergalactic medium via the combination of known redshift and radio dispersion of the FRB. An alternative explanation, first suggested by Williams and Berger, is that the identified counterpart may instead be a compact active galactic nucleus (AGN). The putative counterpart’s variation may then instead be extrinsic, caused by refractive scintillation in the ionized interstellar medium of the Milky Way, which would invalidate the association with FRB 150418. We examine this latter explanation in detail and show that the reported observations are consistent with scintillating radio emission from the core of a radio-loud AGN having a brightness temperature T _b ≳ 10"9 K. Using numerical simulations of the expected scattering for the line of sight to FRB 150418, we provide example images and light curves of such an AGN at 5.5 and 7.5 GHz. These results can be compared with continued radio monitoring to conclusively determine the importance of scintillation for the observed radio variability, and they show that scintillation is a critical consideration for continued searches for FRB counterparts at radio wavelengths.

  14. 77 FR 61535 - Private Land Mobile Radio Rules

    Science.gov (United States)

    2012-10-10

    ... technology that we believe can provide valuable benefits to land mobile radio users. III. Summary of..., GPS equipment, pagers, cellular phones, mobile communications equipment, and radio and television...-114] Private Land Mobile Radio Rules AGENCY: Federal Communications Commission. ACTION: Final rule...

  15. 75 FR 76294 - Radio Broadcasting Services; Fairbanks, AK

    Science.gov (United States)

    2010-12-08

    ... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 73 [DA 10-2211; MB Docket No. 10-81; RM-11600] Radio Broadcasting Services; Fairbanks, AK AGENCY: Federal Communications Commission. ACTION: Final rule. SUMMARY... Subjects in 47 CFR Part 73 Radio, Radio broadcasting. 0 For the reasons discussed in the preamble, the...

  16. Predicting radio fluxes of extrasolar planets (Griessmeier+, 2007)

    NARCIS (Netherlands)

    Griessmeier, J.M.; Zarka, P.; Spreeuw, H.

    2007-01-01

    Expected radio emission from presently known exoplanets. For each of the currently known exoplanets, we list its estimated magnetic moment, maximum radio emission frequency, plasma frequency in the ambient stellar wind, and radio fluxes according to three different models. (1 data file).

  17. Division X, XII / Commission 40, 41 / Working Group Radio Astronomy

    NARCIS (Netherlands)

    Kellermann, Kenneth; Orchiston, Wayne; Davies, Rod; Gurvits, Leonid; Ishiguro, Masato; Lequeux, James; Swarup, Govind; Wall, Jasper; Wielebinski, Richard; van Woerden, Hugo

    The IAU Working Group on Historical Radio Astronomy (WGHRA) was formed at the 2003 General Assembly of the IAU as a Joint Working Group of Commissions 40 (Radio Astronomy) and 41 (History of Astronomy), in order to: a) assemble a master list of surviving historically-significant radio telescopes and

  18. The Miners' Radio Stations in Bolivia: A Culture of Resistance.

    Science.gov (United States)

    O'Connor, Alan

    1990-01-01

    Examines local community radio stations in rural regions of Bolivia. Finds that active miners' radio has flourished as an entertainment and political medium and that, through their radio stations, miners' organizations have played an important role in shaping the political position of the Bolivian union movement. (KEH)

  19. Radio imaging of core-dominated high redshift quasars

    DEFF Research Database (Denmark)

    Barthel, Peter D.; Vestergaard, Marianne; Lonsdale, Colin J.

    1999-01-01

    VLA imaging at kiloparsec-scale resolution of sixteen core-dominated radio-loud QSOs is presented. Many objects appear to display variable radio emission and their radio morphologies are significantly smaller than those of steep-spectrum quasars, consistent with these objects being observed...

  20. 47 CFR 80.289 - Requirements for radio direction finder.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Requirements for radio direction finder. 80.289... Requirements for radio direction finder. (a) The radio direction finding apparatus must: (1) Be capable of...) Possess a sensitivity, sufficient to permit the taking of bearings on a signal having a field strength of...

  1. Mathematical models for estimating radio channels utilization when ...

    African Journals Online (AJOL)

    Definition of the radio channel utilization indicator is given. Mathematical models for radio channels utilization assessment by real-time flows transfer in the wireless self-organized network are presented. Estimated experiments results according to the average radio channel utilization productivity with and without buffering of ...

  2. 47 CFR 0.485 - Commercial radio operator examinations.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Commercial radio operator examinations. 0.485....485 Commercial radio operator examinations. Generally, written and telegraphy examinations for commercial radio operator licenses shall be conducted at locations and times specified by commercial operator...

  3. Effectiveness of radio in dissemination of agricultural information to ...

    African Journals Online (AJOL)

    The three objectives of the study were; (1) to identify the agricultural technologies /recommendations which rural farmers used with the help of radio; (2) to assess the frequency by rural farmers' access radio in getting extension information; and (3) to assess the frequency by which the rural farmer listening to some radio ...

  4. Unification of Radio Galaxies and their Accretion Jet Properties ...

    Indian Academy of Sciences (India)

    Abstract. We investigate the relation between black hole mass, Mbh, and jet power, Qjet, for a sample of BL Lacs and radio quasars. We find that BL Lacs are separated from radio quasars by the FR I/II dividing line in Mbh–Qjet plane, which strongly supports the unification scheme of FR. I/BL Lac and FR II/radio quasar.

  5. Radio search for pulsed emission from X-ray pulsars

    Energy Technology Data Exchange (ETDEWEB)

    delli Santi, F S; Delpino, F [Bologna Univ. (Italy). Ist. di Astronomia; Inzani, P; Sironi, G [Consiglio Nazionale delle Ricerche, Milan (Italy). Lab. di Fisica Cosmica e Tecnologie Relative; Mandolesi, N; Morigi, G [Consiglio Nazionale delle Ricerche, Bologna (Italy). Lab. TESRE

    1981-05-01

    An experiment has been performed at 325 MHz, with a 10 m tracking dish, for the search of pulsed radio emission associated with X-ray pulsars. No evidence of radio pulses has been found in the four sources investigated, although the radio pulsar PSR 0329 + 54, used a testing object, has been detected successfully.

  6. How To Tell Your Literacy Stories through Radio.

    Science.gov (United States)

    Martini, Michael A.

    This paper offers advice to educators on how to tell their literacy stories through the medium of radio. It suggests educators examine their story idea closely and decide if radio is the best medium. It also suggests that educators should become familiar with the radio stations in the local market and get to know the personnel at the particular…

  7. Remote Sensing of the Heliospheric Solar Wind using Radio ...

    Indian Academy of Sciences (India)

    tribpo

    Astr. (2000) 21, 439–444. Remote Sensing of the Heliospheric Solar Wind using Radio. Astronomy Methods and Numerical Simulations. S. Ananthakrishnan, National Center for Radio Astrophysics, Tata Institute of. Fundamental Research, Pune, India. Abstract. The ground-based radio astronomy method of interplanetary.

  8. ON THE ORIGIN OF FANAROFF-RILEY CLASSIFICATION OF RADIO GALAXIES: DECELERATION OF SUPERSONIC RADIO LOBES

    International Nuclear Information System (INIS)

    Kawakatu, Nozomu; Kino, Motoki; Nagai, Hiroshi

    2009-01-01

    We argue that the origin of 'FRI/FRII dichotomy' - the division between Fanaroff-Riley class I (FRI) with subsonic lobes and class II (FRII) radio sources with supersonic lobes is sharp in the radio-optical luminosity plane (Owen-White diagram) - can be explained by the deceleration of advancing radio lobes. The deceleration is caused by the growth of the effective cross-sectional area of radio lobes. We derive the condition in which an initially supersonic lobe turns into a subsonic lobe, combining the ram pressure equilibrium between the hot spots and the ambient medium with the relation between 'the hot spot radius' and 'the linear size of radio sources' obtained from the radio observations. We find that the dividing line between the supersonic lobes and subsonic ones is determined by the ratio of the jet power L j to the number density of the ambient matter at the core radius of the host galaxy n-bar a . It is also found that the maximal ratio of (L j ,n-bar a ) exists and its value resides in (L j ,n-bar a ) max ∼10 44-47 er s -1 cm 3 , taking into account considerable uncertainties. This suggests that the maximal value (L j ,n-bar a ) max separates between FRIs and FRIIs.

  9. Analiza efikasnosti funkcionalnih radio-komunikacionih centara / The efficiency analysis of functional radio communication centers

    Directory of Open Access Journals (Sweden)

    Saša M. Devetak

    2008-10-01

    Full Text Available U radu je prikazan jedan pristup u analizi efikasnosti radio-komunikacionih centara funkcionalnog telekomunikacionog sistema, kao što je vojni sistem veza. Radio-komunikacioni centar modelovan je kao sistem masovnog opsluživanja. Opisana su stanja sistema i parametri i izveden izraz za određivanje verovatnoće opsluživanja radio-komunikacionog centra, kao kriterijuma za ocenu efikasnosti. Predstavljen je, takođe, model, odnosno izrazi za kvantitativnu analizu efikasnosti radio- komunikacionih centara u uslovima elektronskih dejstava. / One approach in the analysis of efficiency of radio communication centers of functional telecommunication systems (for example Military Systems has been shown in this article. A radio communication centre has been presented as a model of mass service systems. The system states and its parameters have been described as well as the resulting formula for determining service probability as a criterion for efficiency evaluation. A model and the formulae for quantitative analysis of efficiency in electronic warfare have been presented as well.

  10. Spectral Energy Distribution and Radio Halo of NGC 253 at Low Radio Frequencies

    Energy Technology Data Exchange (ETDEWEB)

    Kapińska, A. D.; Staveley-Smith, L.; Meurer, G. R.; For, B.-Q. [International Centre for Radio Astronomy Research (ICRAR), University of Western Australia, 35 Stirling Hwy, WA 6009 (Australia); Crocker, R. [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia); Bhandari, S.; Callingham, J. R.; Gaensler, B. M.; Hancock, P. J.; Lenc, E. [ARC Centre of Excellence for All-Sky Astrophysics (CAASTRO), Sydney NSW (Australia); Hurley-Walker, N.; Seymour, N. [International Centre for Radio Astronomy Research (ICRAR), Curtin University, Bentley, WA 6102 (Australia); Offringa, A. R. [Netherlands Institute for Radio Astronomy (ASTRON), P.O. Box 2, 7990 AA Dwingeloo (Netherlands); Hanish, D. J. [Spitzer Science Center, California Institute of Technology, MC 220-6, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Ekers, R. D.; Bell, M. E. [CSIRO Astronomy and Space Science (CASS), P.O. Box 76, Epping, NSW 1710 (Australia); Dwarakanath, K. S. [Raman Research Institute, Bangalore 560080 (India); Hindson, L. [Centre of Astrophysics Research, University of Hertfordshire, College Lane, Hatfield AL10 9AB (United Kingdom); Johnston-Hollitt, M. [School of Chemical and Physical Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6140 (New Zealand); McKinley, B., E-mail: anna.kapinska@uwa.edu.au [School of Physics, The University of Melbourne, Parkville, VIC 3010 (Australia); and others

    2017-03-20

    We present new radio continuum observations of NGC 253 from the Murchison Widefield Array at frequencies between 76 and 227 MHz. We model the broadband radio spectral energy distribution for the total flux density of NGC 253 between 76 MHz and 11 GHz. The spectrum is best described as a sum of a central starburst and extended emission. The central component, corresponding to the inner 500 pc of the starburst region of the galaxy, is best modeled as an internally free–free absorbed synchrotron plasma, with a turnover frequency around 230 MHz. The extended emission component of the spectrum of NGC 253 is best described as a synchrotron emission flattening at low radio frequencies. We find that 34% of the extended emission (outside the central starburst region) at 1 GHz becomes partially absorbed at low radio frequencies. Most of this flattening occurs in the western region of the southeast halo, and may be indicative of synchrotron self-absorption of shock-reaccelerated electrons or an intrinsic low-energy cutoff of the electron distribution. Furthermore, we detect the large-scale synchrotron radio halo of NGC 253 in our radio images. At 154–231 MHz the halo displays the well known X-shaped/horn-like structure, and extends out to ∼8 kpc in the z -direction (from the major axis).

  11. Radio morphing - towards a full parametrisation of the radio signal from air showers

    Science.gov (United States)

    Zilles, A.; Charrier, D.; Kotera, K.; Le Coz, S.; Martineau-Huynh, O.; Medina, C.; Niess, V.; Tueros, M.; de Vries, K.

    2017-12-01

    Over the last decades, radio detection of air showers has been established as a detection technique for ultra-high-energy cosmic-rays impinging on the Earth's atmosphere with energies far beyond LHC energies. Today’s second-generation of digital radio-detection experiments, as e.g. AERA or LOFAR, are becoming competitive in comparison to already standard techniques e.g. fluorescence light detection. Thanks to a detailed understanding of the physics of the radio emission in extensive air showers, simulations of the radio signal are already successfully tested and applied in the reconstruction of cosmic rays. However the limits of the computational power resources are easily reached when it comes to computing electric fields at the numerous positions requested by large or dense antenna arrays. In the case of mountainous areas as e.g. for the GRAND array, where 3D shower simulations are necessary, the problem arises with even stronger acuity. Therefore we developed a full parametrisation of the emitted radio signal on the basis of generic shower simulations which will reduce the simulation time by orders of magnitudes. In this talk we will present this concept after a short introduction to the concept of the radio detection of air-shower induced by cosmic rays.

  12. The difference between radio-loud and radio-quiet active galaxies

    Science.gov (United States)

    Wilson, A. S.; Colbert, E. J. M.

    1995-01-01

    The recent development of unified theories of active galactic nuclei (AGNs) has indicated that there are two physically distinct classes of these objects--radio-loud and radio-quiet. Despite differences, the (probable) thermal emissions from the AGNs (continua and lines from X-ray to infrared wavelengths) are quite similar to the two classes of object. We argue that this last result suggests that the black hole masses and mass accretion rates in the two classes are not greatly different, and that the difference between the classes is associated with the spin of the black hole. We assume that the normal process of accretion through a disk does not lead to rapidly spinning holes and propose that galaxies (e.g., spirals) which have not suffered a recent major merger event contain nonrotating or only slowly rotating black holes. When two such galaxies merge, the two black holes are known to form a binary and we assume that they eventually coalesce. The ratio of the number of radio-loud to radio-quiet AGNs at a given thermal (e.g., optical) luminosity is determined by the galaxy merger rate. Comparisons between the predicted and observed radio luminosity functions constrain the efficiencies with which jet power is extracted from the spinning hole and radio emission is produced by the jet.

  13. Radio and the Church – a Historical Glance

    Directory of Open Access Journals (Sweden)

    Carl-Mario Sultana

    2014-09-01

    Full Text Available Radio is a very powerful mass communication medium. In radio broadcasting, one can hear the echo of Christ’s words to his apostles in the missionary discourse: “You received without charge, give without charge...What you hear in whispers, proclaim from the house tops” (Mt 10,8b.27. Although the Church uses radio as a means to transmit the Good News of salvation, and we as human beings receive radio transmissions as a part of our daily life, we barely stop to think and reflect upon the underlying aspects of radio as a means of communication. In this paper, the Author endeavours to give a historical overview of what makes radio an important medium for evangelisation according to four key documents of the Church, while also studying the underlying theological positions found in these documents. These documents enable us to study radio as a broadcasting medium, highlighting the possible reactions of the Church to radio and how the Church changed its stance on radio over the years. The reason for focussing specifically on radio is for two particular reasons: from the very beginning, the Church has considered radio as a means for evangelising the masses. Notwithstanding this, what is going to be discussing in the paper can be equally applied to Television as a mass communication medium. Secondly, the Church took an active role in radio broadcasting by asking Guglielmo Marconi himself to construct the Vatican Radio in 1931. The documents of the Church also offer us a theology of radio as a mass communication medium, with unity, progress and evangelisation being the fundamental aspects. Church documents posit that not everything should be broadcasted over radio but only messages which bring about peace and unity.

  14. Cross-Correlations in Quasar Radio Emission

    Science.gov (United States)

    Nefedyev, Yuri; Panischev, Oleg; Demin, Sergey

    The main factors forming the complex evolution of the accretive astrophysical systems are nonlinearity, intermittency, nonstationarity and also collective phenomena. To discover the dynamic processes in these objects and to detain understanding their properties we need to use all the applicable analyzing methods. Here we use the Flicker-Noise Spectroscopy (FNS) as a phenomenological approach to analyzing and parameterizing the auto- and cross-correlations in time series of astrophysical objects dynamics. As an example we consider the quasar flux radio spectral density at frequencies 2.7 GHz and 8.1 GHz. Data have been observed by Dr. N. Tanizuka (Laboratory for Complex Systems Analysis, Osaka Prefecture University) in a period of 1979 to 1988 (3 309 days). According to mental habits quasar is a very energetic and distant active galactic nucleus containing a supermassive black hole by size 10-10,000 times the Schwarzschild radius. The quasar is powered by an accretion disc around the black hole. The accretion disc material layers, moving around the black hole, are under the influence of gravitational and frictional forces. It results in raising the high temperature and arising the resonant and collective phenomena reflected in quasar emission dynamics. Radio emission dynamics of the quasar 0215p015 is characterized by three quasi-periodic processes, which are prevalent in considering dynamics. By contrast the 1641p399's emission dynamics have not any distinguish processes. It means the presence of high intermittency in accretive modes. The second difference moment allows comparing the degree of manifesting of resonant and chaotic components in initial time series of the quasar radio emission. The comparative analysis shows the dominating of chaotic part of 1641p399's dynamics whereas the radio emission of 0215p015 has the predominance of resonant component. Analyzing the collective features of the quasar radio emission intensity demonstrates the significant

  15. Radio Access Sharing Strategies for Multiple Operators in Cellular Networks

    DEFF Research Database (Denmark)

    Popovska Avramova, Andrijana; Iversen, Villy Bæk

    2015-01-01

    deployments (required for coverage enhancement), increased base station utilization, and reduced overall power consumption. Today, network sharing in the radio access part is passive and limited to cell sites. With the introduction of Cloud Radio Access Network and Software Defined Networking adoption...... to the radio access network, the possibility for sharing baseband processing and radio spectrum becomes an important aspect of network sharing. This paper investigates strategies for active sharing of radio access among multiple operators, and analyses the individual benefits depending on the sharing degree...

  16. FeltRadio: Sensing and Making Sense of Wireless Traffic

    DEFF Research Database (Denmark)

    Gronvall, Erik; Fritsch, Jonas; Vallgårda, Anna

    2016-01-01

    Radio waves surround us but still they remain largely undetected by our senses. Unless we use specifically tuned hardware, such as FM radios, cell phones or WiFi modems, human beings cannot perceive wirelessly transmitted data. This paper presents FeltRadio, a portable and wireless technology...... that makes it possible to turn radio signals into visual and tactile stimuli as a form of sensorial augmentation. FeltRadio explores and makes us reflect upon what it would be like if we could sense, and feel, wireless traffic such as WiFi or Bluetooth. We present the technological design behind Felt...

  17. Analysis and Modeling of Jovian Radio Emissions Observed by Galileo

    Science.gov (United States)

    Menietti, J. D.

    2003-01-01

    Our studies of Jovian radio emission have resulted in the publication of five papers in refereed journals, with three additional papers in progress. The topics of these papers include the study of narrow-band kilometric radio emission; the apparent control of radio emission by Callisto; quasi-periodic radio emission; hectometric attenuation lanes and their relationship to Io volcanic activity; and modeling of HOM attenuation lanes using ray tracing. A further study of the control of radio emission by Jovian satellites is currently in progress. Abstracts of each of these papers are contained in the Appendix. A list of the publication titles are also included.

  18. Two-way radios and scanners for dummies

    CERN Document Server

    Silver, H Ward

    2013-01-01

    Discover a fun new hobby with helpful possibilities Get directions, talk to folks overseas, or find out whether the fish are biting Want to check out the morning news in London, help out in emergencies, or tune in to the big race? Two-way radios open up a world of possibilities - literally. This handy guide tells you about the equipment you need, fills you in on radio etiquette, shows you how to stay legal, and gives you lots of cool ideas for family-friendly radio activities. Discover how to * Use the right radio lingo * Choose and operate different types of radios * Get a license if you n

  19. A Comparison of Radioisotope Methods for River Flow Measurement; Comparaison de methodes radioisotopiques de mesure du debit des cours d'eau; Sravnenie radioizotopnykh metodov izmereniya rechnykh stokov; Comparacion de los metodos radioisotopicos para medir el caudal de los rios

    Energy Technology Data Exchange (ETDEWEB)

    Clayton, C. G.; Smith, D. B. [Wantage Research Laboratory Atomic Energy Research Establishment Wantage, Berks (United Kingdom)

    1963-08-15

    del lecho del rio. Desde este punto de vista, el tritio posee excelentes propiedades, puesto que no es absorbido, pero es dificil de medir y no es posible seguir directamente su desplazamiento en el rio. Otros indicadores resultan mas convenientes, pero pueden sufrir adsorcion. Los autores han estudiado los grados de adsorcion del {sup 24}Na, {sup 82}Br y {sup 32}P en forma de NaHC0{sub 3}, NH{sub 4}Br y NaH{sub 2}PO{sub 3} respectivamente, que introdujeron en un mismo punto del rio junto con agua tritiada (HTO), para comparar despues las mediciones realizadas en varios lugares situados aguas abajo. Se ha visto que el EP, para el que se esperaban grandes perdidas por quimisorcion, no sirve para medir el caudal de rios cuando se emplea sin portador, aunque el error disminuye notablemente cuando se trabaj a con portador. En el caso del {sup 24}Na y del {sup 32}Br, no se observa adsorcion a distancias mucho mayores que la requerida para que la mezcla lateral sea satisfactoria si bien a una distancia de 660 m en el rio de corriente mas lenta se observo que parte del {sup 24}Na habia desaparecido. Los autores formulan algunas observaciones sobre el grado de dispersion lateral y longitudinal que tienen importancia para la aplicacion de tecnicas radioisotopicas en general a la medicion del caudal de rios. Llegan a la conclusion de que los tres metodos pueden dar resultados satisfactorios. En definitiva, los autores dan preferencia al metodo de muestreo continuo, ya que permite alcanzar una mayor precision para un consumo minimo de indicador. (author) [Russian] Metody razbavleniya, nepreryvnogo otbora prob i polnogo scheta primenyayutsya pri sravnitel'nom izuchenii radioindikatornykh metodov izmereniya stokov v rekakh Ajbehrton Bruk v Gluchestershire i Usvej Bern i Alvin Rivers - v Nortamberlehnde. EHto - tri reki s razlichnymi geologicheskimi kharakteristikami i skorostyami stokov, izmenyayushchikhsya v diagyuzone ot 2,5 l/sek do 3 m{sup 3}/sek. Pri ispol'zovanii lyubykh

  20. Radio-embolization for hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Raoul, J.L.; Edeline, J.; Pracht, M.; Boucher, E.; Rolland, Y.; Garin, E.

    2011-01-01

    Hepatocellular carcinoma is now a major public health concern. In intermediate stages (one third of hepatocellular carcinoma patients), chemo-embolization is the standard of care despite a poor tolerance and a moderate efficacy. Moreover, despite recent improvements, this technique seems in a dead end. Radio-embolization could be an excellent tool for such patients. Currently 131 I-Lipiodol, 188 Re-Lipiodol, 90 Y-glass or resin microspheres are available. More recent and promising data come from microspheres, but phase II and III studies are needed before drawing any conclusion. In the future, the combination of radio-embolization with systemic chemotherapy or targeted agents (particularly anti-angiogenic drugs) seems very promising. (authors)

  1. Remote radio control of insect flight

    Directory of Open Access Journals (Sweden)

    Hirotaka Sato

    2009-10-01

    Full Text Available We demonstrated the remote control of insects in free flight via an implantable radio-equipped miniature neural stimulating system. The pronotum mounted system consisted of neural stimulators, muscular stimulators, a radio transceiver-equipped microcontroller and a microbattery. Flight initiation, cessation and elevation control were accomplished through neural stimulus of the brain which elicited, suppressed or modulated wing oscillation. Turns were triggered through the direct muscular stimulus of either of the basalar muscles. We characterized the response times, success rates, and free-flight trajectories elicited by our neural control systems in remotely-controlled beetles. We believe this type of technology will open the door to in-flight perturbation and recording of insect flight responses.

  2. Remote radio control of insect flight.

    Science.gov (United States)

    Sato, Hirotaka; Berry, Christopher W; Peeri, Yoav; Baghoomian, Emen; Casey, Brendan E; Lavella, Gabriel; Vandenbrooks, John M; Harrison, Jon F; Maharbiz, Michel M

    2009-01-01

    We demonstrated the remote control of insects in free flight via an implantable radio-equipped miniature neural stimulating system. The pronotum mounted system consisted of neural stimulators, muscular stimulators, a radio transceiver-equipped microcontroller and a microbattery. Flight initiation, cessation and elevation control were accomplished through neural stimulus of the brain which elicited, suppressed or modulated wing oscillation. Turns were triggered through the direct muscular stimulus of either of the basalar muscles. We characterized the response times, success rates, and free-flight trajectories elicited by our neural control systems in remotely controlled beetles. We believe this type of technology will open the door to in-flight perturbation and recording of insect flight responses.

  3. Survey on Cloud Radio Access Network

    Directory of Open Access Journals (Sweden)

    Reeta Chhatani

    2016-01-01

    Full Text Available The existing wireless network will face the challenge of data tsunami in the near future. Densification of network will deal huge data traffic but will increase the interferences and network cost. At the same time, the existing wireless network is underutilized due to dynamic traffic. To deal with this adverse scenario, a change in the current network architecture is required. Based on virtualization, Cloud Radio Access Network (CRAN was proposed for wireless network. In CRAN the functionality of base station will be distributed into base band unit (BBU and remote radio heads (RRH which will achieve benefits of centralization. This paper presents a survey on CRAN centring on optimized resource allocation, energy efficiency and throughput maximization under fronthaul capacity. The existing solution and future opportunities in CRAN are also summarized.

  4. Evolutionary tracks of extended radio sources

    International Nuclear Information System (INIS)

    Baldwin, J.E.

    1982-01-01

    We know almost nothing about the evolutionary tracks of extragalactic radio sources but those tracks are, however, strongly constrained by the distribution of sources in the radio luminosity, P, overall physical size, D, diagram. The P-D diagram for the 3CR 166 source sample of Jenkins et al. (1977) is presented with later additions. Most of the sources are identified and have known redshifts. Because of doubts about the completeness of the sample in this region, the author has made searches in the 6C 151MHz survey for sources with specific surface brightnesses. The numbers found to a limiting flux density of 1-2 Jy suggest that there is no serious underestimate of the numbers in 166 source sample. (Auth.)

  5. Rapid variability of extragalactic radio sources

    Energy Technology Data Exchange (ETDEWEB)

    Quirrenbach, A.; Witzel, A.; Krichbaum, T.; Hummel, C.A.; Alberdi, A.; Schalinski, C.

    1989-02-02

    Since its discovery more than 20 years ago, variability of extragalactic radio sources on timescales of weeks to years has been the subject of many investigations. We have examined the variability of these sources on timescales of hours at wavelengths of 6 and 11 cm using the 100-m telescope of the Max-Planck-Institut fuer Radioastronomie and report the results for two sources. The quasar QSO0917 + 62 showed variations with amplitudes of up to 23% in /similar to/ 24 hours, which were correlated at the two wavelengths; in the BL Lac object 0716 + 71 we found variations with amplitudes of 7-11%. We discuss intrinsic effects, gravitational lensing and scattering in the interstellar medium as possible explanations for rapid radio variability.

  6. High Capacity Radio over Fiber Transmission Links

    DEFF Research Database (Denmark)

    Caballero Jambrina, Antonio

    . This achievement has satisfied the requirements on transmission robustness and high capacity of next generation hybrid optical fibre-wireless networks. One important contribution of this thesis is the novel concept of photonic downconversion with free-running pulsed laser source for phase modulated Radio-over-Fiber......This thesis expands the state-of-the-art on the detection of high speed wireless signals using optics. Signal detection at speeds over 1 Gbps at carrier Radio Frequency (RF) ranging from 5 GHz to 100 GHz have been achieved by applying novel concepts on optical digital coherent receivers......-wave frequencies at carrier frequencies exceeding 60 GHz, using photonic baseband technologies. For signal generation, high spectral-efficient optical modulation technologies are used together with optical heterodyning. In the detection side, the mm-wave signal is modulated in the optical domain and received using...

  7. Radio wave propagation and parabolic equation modeling

    CERN Document Server

    Apaydin, Gokhan

    2018-01-01

    A thorough understanding of electromagnetic wave propagation is fundamental to the development of sophisticated communication and detection technologies. The powerful numerical methods described in this book represent a major step forward in our ability to accurately model electromagnetic wave propagation in order to establish and maintain reliable communication links, to detect targets in radar systems, and to maintain robust mobile phone and broadcasting networks. The first new book on guided wave propagation modeling and simulation to appear in nearly two decades, Radio Wave Propagation and Parabolic Equation Modeling addresses the fundamentals of electromagnetic wave propagation generally, with a specific focus on radio wave propagation through various media. The authors explore an array of new applications, and detail various v rtual electromagnetic tools for solving several frequent electromagnetic propagation problems. All of the methods described are presented within the context of real-world scenari...

  8. Collective radio-emission from plasmas

    International Nuclear Information System (INIS)

    Papadopoulos, K.; Freund, H.P.

    1979-01-01

    Collective radiation processes operating in laboratory and space plasmas are reviewed with an emphasis towards astrophysical applications. Particular stress is placed on the physics involved in the various processes rather than in the detailed derivation of the formulas. Radiation processes from stable non-thermal, weakly turbulent and strongly turbulent magnetized and unmagnetized plasmas are discussed. The general theoretical ideas involved in amplification processes such as stimulated scattering are presented along with their application to free electron and plasma lasers. Direct radio-emission of electromagnetic waves by linear instabilities driven by beams or velocity anisotropies are shown to be of relevance in space applications. Finally, as an example of the computational state of the art pertaining to plasma radiation, a study of the type III solar radio bursts is presented. (orig.)

  9. Radio-analysis. Definitions and techniques

    International Nuclear Information System (INIS)

    Bourrel, F.; Courriere, Ph.

    2003-01-01

    This paper presents the different steps of the radio-labelling of a molecule for two purposes: the radio-immuno-analysis and the auto-radiography: 1 - definitions, radiations and radioprotection: activity of a radioactive source; half-life; radioactivity (alpha-, beta- and gamma radioactivity, internal conversion); radioprotection (irradiation, contamination); 2 - radionuclides used in medical biology and obtention of labelled molecules: gamma emitters ( 125 I, 57 Co); beta emitters; obtention of labelled molecules (general principles, high specific activity and choice of the tracer, molecule to be labelled); main labelling techniques (iodation, tritium); purification of the labelled compound (dialysis, gel-filtering or molecular exclusion chromatography, high performance liquid chromatography); quality estimation of the labelled compound (labelling efficiency calculation, immuno-reactivity conservation, stability and preservation). (J.S.)

  10. Radio techniques for probing the terrestrial ionosphere.

    Science.gov (United States)

    Hunsucker, R. D.

    The subject of the book is a description of the basic principles of operation, plus the capabilities and limitations of all generic radio techniques employed to investigate the terrestrial ionosphere. The purpose of this book is to present to the reader a balanced treatment of each technique so they can understand how to interpret ionospheric data and decide which techniques are most effective for studying specific phenomena. The first two chapters outline the basic theory underlying the techniques, and each following chapter discusses a separate technique. This monograph is entirely devoted to techniques in aeronomy and space physics. The approach is unique in its presentation of the principles, capabilities and limitations of the most important presently used radio techniques. Typical examples of data are shown for the various techniques, and a brief historical account of the technique development is presented. An extended annotated bibliography of the salient papers in the field is included.

  11. Reflection jets and collimation of radio sources

    International Nuclear Information System (INIS)

    Pacholczyk, A.G.

    1983-01-01

    The author proposes a description of only a certain class of jets in extended radio sources by discussing hydrodynamics of jets formed by discrete portions of material ejected from the parent galaxy through a channel and reflected back into it as a result of an encounter with the material accumulated at the end of the channel. The picture presented here combines some older ideas with recent ones. The older ideas consist of modeling of extended radio sources in terms of multiple ejection of plasmons through a channel ploughed by the first few plasmons in the ambient medium with a resupply of energy in plasmons through the conversion of bulk kinetic energy into relativistic electron energy through instability driven turbulence. The recent ideas concern the formation of retro-jets as the result of interaction of a plasmon with the dense relic material at the end of a channel and the collimation of plasmon material in channels. (Auth.)

  12. Graphene radio frequency receiver integrated circuit.

    Science.gov (United States)

    Han, Shu-Jen; Garcia, Alberto Valdes; Oida, Satoshi; Jenkins, Keith A; Haensch, Wilfried

    2014-01-01

    Graphene has attracted much interest as a future channel material in radio frequency electronics because of its superior electrical properties. Fabrication of a graphene integrated circuit without significantly degrading transistor performance has proven to be challenging, posing one of the major bottlenecks to compete with existing technologies. Here we present a fabrication method fully preserving graphene transistor quality, demonstrated with the implementation of a high-performance three-stage graphene integrated circuit. The circuit operates as a radio frequency receiver performing signal amplification, filtering and downconversion mixing. All circuit components are integrated into 0.6 mm(2) area and fabricated on 200 mm silicon wafers, showing the unprecedented graphene circuit complexity and silicon complementary metal-oxide-semiconductor process compatibility. The demonstrated circuit performance allow us to use graphene integrated circuit to perform practical wireless communication functions, receiving and restoring digital text transmitted on a 4.3-GHz carrier signal.

  13. Rapid variability of extragalactic radio sources

    International Nuclear Information System (INIS)

    Quirrenbach, A.; Witzel, A.; Krichbaum, T.; Hummel, C.A.; Alberdi, A.; Schalinski, C.

    1989-01-01

    Since its discovery more than 20 years ago, variability of extragalactic radio sources on timescales of weeks to years has been the subject of many investigations. We have examined the variability of these sources on timescales of hours at wavelengths of 6 and 11 cm using the 100-m telescope of the Max-Planck-Institut fuer Radioastronomie and report the results for two sources. The quasar QSO0917 + 62 showed variations with amplitudes of up to 23% in ∼ 24 hours, which were correlated at the two wavelengths; in the BL Lac object 0716 + 71 we found variations with amplitudes of 7-11%. We discuss intrinsic effects, gravitational lensing and scattering in the interstellar medium as possible explanations for rapid radio variability. (author)

  14. EUV and radio spectrum of coronal holes

    Energy Technology Data Exchange (ETDEWEB)

    Chiuderi Drago, F [Osservatorio Astrofisico di Arcetri, Florence (Italy)

    1980-03-01

    From the intensity of 19 EUV lines whose formation temperature anti T ranges from 3 x 10/sup 4/ to 1.4 x 10/sup 6/, two different models of the transition region and corona for the cell-centre and the network are derived. It is shown that both these models give radio brightness temperatures systematically higher than the observed ones. An agreement with radio data can be found only with lines formed at low temperature (anti T < 8.5 x 10/sup 5/) by decreasing the coronal temperature and the emission measure. The possibility of resolving the discrepancy by using different ion abundances has also been investigated with negative results.

  15. Radio Propagation in Open-pit Mines

    DEFF Research Database (Denmark)

    Portela Lopes de Almeida, Erika; Caldwell, George; Rodriguez Larrad, Ignacio

    2017-01-01

    In this paper we present the results of an extensive measurement campaign performed at two large iron ore mining centers in Brazil at the 2.6 GHz band. Although several studies focusing on radio propagation in underground mines have been published, measurement data and careful analyses for open......-pit mines are still scarce. Our results aim at filling this gap in the literature. The research is motivated by the ongoing mine automation initiatives, where connectivity becomes critical. This paper presents the first set of results comprising measurements under a gamut of propagation conditions. A second...... paper detailing sub-GHz propagation is also in preparation. The results indicate that conventional wisdom is wrong, in other words, radio-frequency (RF) propagation in surface mines can be far more elaborate than plain free-space line-of-sight conditions. Additionally, the old mining adage “no two mines...

  16. Stellar populations in distant radio galaxies

    International Nuclear Information System (INIS)

    Lilly, S.J.; Longair, M.S.

    1984-01-01

    A homogeneous data set of infrared observations of 83 3CR galaxies with redshifts 0< z<1.6, selected from a statistically complete sample of 90 radio sources, is used to study the colours and magnitudes of these galaxies as a function of their redshifts. New infrared observations are presented for 66 radio galaxies, in addition to new optical results obtained from a re-analysis of existing CCD images. It is shown that the infrared colours do not deviate from the predicted relations with redshift for a standard giant elliptical galaxy spectrum. The optical to infrared colours, however, show substantial deviations at high redshift. No galaxies have been found that are significantly redder than a passively evolving galaxy, and there is a significant scatter of colours bluewards from this model. The excess of ultraviolet light responsible for these colours is not concentrated at the nucleus, and is interpreted as resulting from bursts of star formation, throughout the galaxy. (author)

  17. Morphology and power of radio sources

    International Nuclear Information System (INIS)

    Scheuer, P.A.G.

    1982-01-01

    The author discusses two points: 1. Observations suggest that the hot-spots move about either because the beam precesses or more discontinuously, as in sources like 3C351 that have multiple hot-spots. The natural interpretation is that the hot-spot at the end of the beam slides over the inner surface of a 'cavity' filled with very hot dilute ex-hot-spot material, extending the cavity at various places at different times. 2. Most of the radio emission of most really powerful radio sources comes from their hot spots. Contrariwise, straightforward equipartition calculations on models lead to at least as much emission from the 'cavity' as from the hot-spots. (Auth.)

  18. Radio Science from an Optical Communications Signal

    Science.gov (United States)

    Moision, Bruce; Asmar, Sami; Oudrhiri, Kamal

    2013-01-01

    NASA is currently developing the capability to deploy deep space optical communications links. This creates the opportunity to utilize the optical link to obtain range, doppler, and signal intensity estimates. These may, in turn, be used to complement or extend the capabilities of current radio science. In this paper we illustrate the achievable precision in estimating range, doppler, and received signal intensity of an non-coherent optical link (the current state-of-the-art for a deep-space link). We provide a joint estimation algorithm with performance close to the bound. We draw comparisons to estimates based on a coherent radio frequency signal, illustrating that large gains in either precision or observation time are possible with an optical link.

  19. Interweave Cognitive Radio with Improper Gaussian Signaling

    KAUST Repository

    Hedhly, Wafa

    2018-01-15

    Improper Gaussian signaling (IGS) has proven its ability in improving the performance of underlay and overlay cognitive radio paradigms. In this paper, the interweave cognitive radio paradigm is studied when the cognitive user employs IGS. The instantaneous achievable rate performance of both the primary and secondary users are analyzed for specific secondary user sensing and detection capabilities. Next, the IGS scheme is optimized to maximize the achievable rate secondary user while satisfying a target minimum rate requirement for the primary user. Proper Gaussian signaling (PGS) scheme design is also derived to be used as benchmark of the IGS scheme design. Finally, different numerical results are introduced to show the gain reaped from adopting IGS over PGS under different system parameters. The main advantage of employing IGS is observed at low sensing and detection capabilities of the SU, lower PU direct link and higher SU interference on the PU side.

  20. Radio frequency-assisted fast superconducting switch

    Science.gov (United States)

    Solovyov, Vyacheslav; Li, Qiang

    2017-12-05

    A radio frequency-assisted fast superconducting switch is described. A superconductor is closely coupled to a radio frequency (RF) coil. To turn the switch "off," i.e., to induce a transition to the normal, resistive state in the superconductor, a voltage burst is applied to the RF coil. This voltage burst is sufficient to induce a current in the coupled superconductor. The combination of the induced current with any other direct current flowing through the superconductor is sufficient to exceed the critical current of the superconductor at the operating temperature, inducing a transition to the normal, resistive state. A by-pass MOSFET may be configured in parallel with the superconductor to act as a current shunt, allowing the voltage across the superconductor to drop below a certain value, at which time the superconductor undergoes a transition to the superconducting state and the switch is reset.

  1. Explaining fast radio bursts through Dicke's superradiance

    Science.gov (United States)

    Houde, Martin; Mathews, Abhilash; Rajabi, Fereshteh

    2018-03-01

    Fast radio bursts (FRBs), characterized by strong bursts of radiation intensity at radio wavelengths lasting on the order of a millisecond, have yet to be firmly associated with a family, or families, of astronomical sources. It follows that despite the large number of proposed models, no well-defined physical process has been identified to explain this phenomenon. In this paper, we demonstrate how Dicke's superradiance, for which evidence has recently been found in the interstellar medium, can account for the characteristics associated with FRBs. Our analysis and modelling of previously detected FRBs suggest they could originate from regions in many ways similar to those known to harbour masers or megamasers, and result from the coherent radiation emanating from populations of molecules associated with large-scale entangled quantum mechanical states. We estimate this entanglement to involve as many as ˜1030 to ˜1032 molecules over distances spanning 100-1000 au.

  2. Radio protective effects of some medicinal plants

    International Nuclear Information System (INIS)

    Barupal, G.K.

    2012-01-01

    Many plants are known to have beneficial therapeutic effects as noted in the traditional Indian system of medicine, Ayurveda and used since time immemorial for curing diseases. Even today, nearly 70% of the world's population is dependent on plants for handling their health related problems and plants have been utilized successfully for the treatment of free radical-mediated diseases in human such as Rheumatoid arthritis, Atherosclerosis, Cancer, Alzheimer's disease, Parkinson's disease, aging and several other conditions including inflammatory diseases. Plant extracts eliciting radio protective efficacy contain a plethora of compounds including antioxidants, immunostimulants, cell proliferation stimulators, anti-inflammatory and antimicrobial agent, some of which may act in isolation as well as in combination with other constituents from the same plants. Glycyrrhiza glabra, Allium sepa, Allium sativum, Aloe arborescens, Amaranthus paniculatus, Curcuma longa, Moringa olefera and Syzygium cumini are some important radio protective plants. Alium sativum has been reported to possess antioxidant antimicrobial, antitumor, antimutagenic and anti-inflammatory properties. Aloe arborescens acts as a cell proliferate, healer and allergy reducer. Amaranthus paniculatus is used for purifying blood and treating scrofulous sores. Curcuma longa is widely used in antitumor and antibacterial activities. Leaf extract of Moringa oleifera is significantly used in nervous debility and healing of wound. Chlorella is well known nutrient dense superfood that contains 60% protein, 18 amino acids (including all the essential amino acids), more than 20 vitamins and minerals. Chlorell has been used to treat cancer and also protect the body from the effects of cancer radiation treatment due to its chlorophyll in abundance level. However they have little attention for their radio protective as well as antioxidant. There is an urgent need to develop newer, more efficient and reliable bioassays

  3. A model for superliminal radio sources

    International Nuclear Information System (INIS)

    Milgrom, M.; Bahcall, J.N.

    1977-01-01

    A geometrical model for superluminal radio sources is described. Six predictions that can be tested by observations are summarized. The results are in agreement with all the available observations. In this model, the Hubble constant is the only numerical parameter that is important in interpreting the observed rates of change of angular separations for small redshifts. The available observations imply that H 0 is less than 55 km/s/Mpc if the model is correct. (author)

  4. Concurrent bandits and cognitive radio networks

    OpenAIRE

    Avner, Orly; Mannor, Shie

    2014-01-01

    We consider the problem of multiple users targeting the arms of a single multi-armed stochastic bandit. The motivation for this problem comes from cognitive radio networks, where selfish users need to coexist without any side communication between them, implicit cooperation or common control. Even the number of users may be unknown and can vary as users join or leave the network. We propose an algorithm that combines an $\\epsilon$-greedy learning rule with a collision avoidance mechanism. We ...

  5. REVIEW OF IMPROVEMENTS IN RADIO FREQUENCY PHOTONICS

    Science.gov (United States)

    2017-09-01

    AFRL-RY-WP-TR-2017-0156 REVIEW OF IMPROVEMENTS IN RADIO FREQUENCY PHOTONICS Preetpaul S. Devgan RF/EO Subsystems Branch Aerospace Components...Center (DTIC) (http://www.dtic.mil). AFRL-RY-WP-TR-2017-0156 HAS BEEN REVIEWED AND IS APPROVED FOR PUBLICATION IN ACCORDANCE WITH ASSIGNED DISTRIBUTION...public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions

  6. Review of Radio Frequency Photonics Basics

    Science.gov (United States)

    2017-09-06

    AFRL-RY-WP-TR-2017-0157 REVIEW OF RADIO FREQUENCY PHOTONICS BASICS Preetpaul S. Devgan RF/EO Subsystems Branch Aerospace Components & Subsystems...Center (DTIC) (http://www.dtic.mil). AFRL-RY-WP-TR-2017-0157 HAS BEEN REVIEWED AND IS APPROVED FOR PUBLICATION IN ACCORDANCE WITH ASSIGNED...including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing

  7. From radio signals to cosmic rays

    International Nuclear Information System (INIS)

    Riviere, C.

    2009-12-01

    Radio detection of high energy cosmic rays is currently being reinvested, both on the experimental and theoretical sides. The question is to know whether radio-detection is a competitive technique compared or in addition to usual detection techniques; in order to increase statistics at the highest energies (around 10 20 eV - where particle astronomy should be possible) or to characterize precisely the cosmic rays at lower energies (some 10 18 eV). During this work, we tried to progress towards the answer, using radio emission models, experimental data analysis and preparing the next generation of detectors. On the theoretical side, geo-synchrotron emission of the particles of the showers has been computed analytically using a simplified shower model as well as using the Monte Carlo simulation AIRES to have a realistic shower development. Various dependencies of the electric field have been extracted, among which a proportionality of the field with the -v → * B → vector under certain conditions. Experimentally, the analysis of CODALEMA data enabled to characterise more precisely the electric field produced by air showers, in particular the topology of the field at ground level, the energy dependency and the coherence with a -v → * B → proportionality. These results are summarised in an overall parametrization of the electric field. More data are probably required in order to give a definitive statement on the interest of the radio-detection technique. The CODALEMA parametrization has finally been used to extrapolate CODALEMA's results to a future larger array, extrapolation applied in particular to the AERA detector of the Pierre Auger Observatory. (author)

  8. SPITZER OBSERVATIONS OF HOTSPOTS IN RADIO LOBES

    International Nuclear Information System (INIS)

    Werner, Michael W.; Murphy, David W.; Livingston, John H.; Gorjian, Varoujan; Jones, Dayton L.; Meier, David L.; Lawrence, Charles R.

    2012-01-01

    We have carried out a systematic search with Spitzer Warm Mission and archival data for infrared emission from the hotspots in radio lobes that have been described by Hardcastle et al. These hotspots have been detected with both radio and X-ray observations, but an observation at an intermediate frequency in the infrared can be critical to distinguish between competing models for particle acceleration and radiation processes in these objects. Between the archival and warm mission data, we report detections of 18 hotspots; the archival data generally include detections at all four IRAC bands, the Warm Mission data only at 3.6 μm. Using a theoretical formalism adopted from Godfrey et al., we fit both archival and warm mission spectral energy distributions (SEDs)—including radio, X-ray, and optical data from Hardcastle as well as the Spitzer data—with a synchrotron self-Compton (SSC) model, in which the X-rays are produced by Compton scattering of the radio frequency photons by the energetic electrons which radiate them. With one exception, an SSC model requires that the magnetic field be less or much less than the equipartition value which minimizes total energy and has comparable amounts of energy in the magnetic field and in the energetic particles. This conclusion agrees with those of comparable recent studies of hotspots, and with the analysis presented by Hardcastle et al. We also show that the infrared data rule out the simplest synchrotron-only models for the SEDs. We briefly discuss the implications of these results and of alternate interpretations of the data.

  9. Millijansky radio variability in SDSS stripe 82

    Energy Technology Data Exchange (ETDEWEB)

    Hodge, J. A.; Becker, R. H. [University of California, 1 Shields Avenue, Davis, CA 95616 (United States); White, R. L. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Richards, G. T., E-mail: hodge@mpia.de [Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States)

    2013-06-01

    We report on a blind survey for extragalactic radio variability that was carried out by comparing two epochs of data from the Faint Images of the Radio Sky at Twenty centimeters survey with a third epoch from a new 1.4 GHz survey of SDSS Stripe 82. The three epochs are spaced seven years apart and have an overlapping area of 60 deg{sup 2}. We uncover 89 variable sources down to the millijansky level, 75 of which are newly identified, and we find no evidence for transient phenomena. This new sample of variable sources allows us to infer an upper limit to the mean characteristic timescale of active galactic nucleus radio variability of 14 yr. We find that only 1% of extragalactic sources have fractional variability f {sub var} > 3, while 44% of Galactic sources vary by this much. The variable sample contains a larger fraction of quasars than a comparable non-variable control sample, though the majority of the variable sources appear to be extended galaxies in the optical. This implies that either quasars are not the dominant contributor to the variability of the sample, or that the deep optical data allow us to detect the host galaxies of some low-z quasars. We use the new, higher resolution data to report on the morphology of the variable sources. Finally, we show that the fraction of sources that are variable remains constant or increases at low flux densities. This may imply that next generation radio surveys with telescopes like Australian Square Kilometer Array Pathfinder and MeerKAT will see a constant or even increasing fraction of variable sources down into the sub-millijansky regime.

  10. Chautauqua notebook: appropriate technology on radio

    Energy Technology Data Exchange (ETDEWEB)

    Renz, B.

    1981-01-01

    Experiences in establishing and maintaining a regional call-in information-exchange radio show (Chautauqua) on energy conservation, appropriate technology, renewable energy sources, and self-reliance are discussed. Information is presented on: appropriate technology; the Chautauquaa concept; topics discussed; research performed; guests; interviewing tips; types of listeners; program features; where to find help; promotion and publicity; the technical and engineering aspects; the budget and funding; and station policies. (MCW)

  11. Innovations to enrich science communication through radio

    OpenAIRE

    Thakar Bhaumik; Kothari Abhay

    2004-01-01

    The Radio is an instrument of communication that has percolated to all the strata of the diverse Indian society. Its position has been consolidated through history as a regular companion and a source of information and entertainment. Its affordability, accessibility and non-reliance on costly resources have ensured its presence in almost all the households. It has become indispensable from kitchens, family rooms and even workspaces. It is one of the few or rather the only medium of communicat...

  12. Passive radio frequency peak power multiplier

    Science.gov (United States)

    Farkas, Zoltan D.; Wilson, Perry B.

    1977-01-01

    Peak power multiplication of a radio frequency source by simultaneous charging of two high-Q resonant microwave cavities by applying the source output through a directional coupler to the cavities and then reversing the phase of the source power to the coupler, thereby permitting the power in the cavities to simultaneously discharge through the coupler to the load in combination with power from the source to apply a peak power to the load that is a multiplication of the source peak power.

  13. Cognitive Radio Networks for Tactical Wireless Communications

    Science.gov (United States)

    2014-12-01

    exists. Instead, security is an evolving process, as we have seen in the context of WLANs and 2G / 3G networks. New system vulnerabilities continue to...in the network configuration and radio parameters take place due to mobility of platforms, and variation in other users of the RF environment. CRNs...dynamic spectrum access experimentally, and it represents the largest military Mobile Ad hoc Network (MANET) as of today. The WNaN demonstrator has been

  14. STUDY ON ROLE OF RADIO FOR RURAL EDUCATION IN PAKISTAN

    Directory of Open Access Journals (Sweden)

    Nabi Bux JUMANI

    2009-10-01

    Full Text Available Radio is a mean not only for information and entertainment but also for education. Radio is being used for educational purposes all over the world. In Pakistan it is also a medium of communication. Pakistan broadcasting corporation has started broadcasting educational programs of Allama Iqbal Open University. There is no denying the fact that educational broadcasting in Pakistan is being run successfully. The rural population of the country is getting benefit from the educational programmes of the radio.The main aim of the study was to examine the effectiveness of educational radio and its various strategies being applied for rural education. The study was delimited the radio listeners, radio producers/comperes and social workers/opinion leaders. The masters list of listeners was obtained from Radio Station, Hyderabad. The second sample was radio producers/comperes whereas the third sample was social workers/opinion leaders. The tool used in this study was questionnaires. It was found that the majority of the listeners possessed radio sets and was getting benefit from the educational programmes of radio. The programmes were informative and motivating. The strategies of radio for rural education were appreciable because these infused mobility, widened horizon of rural people and focused attention on the goals and problems of rural people. It could be used to enhance literacy (through distance and non-formal education.the producers/comperes were found keenly interested in their job. It was revealed that priority was given to education and rural development programmes of radio. Programmes needed detail and summary at the end. Furthermore language was not easy. Mobile radio station was needed for rural educational programme to cater to the needs of far flung areas. School broadcast (distance and non-formal teaching was the need of the day. Social workers/opinion leaders opined that there was need of developing self reliance. Radio provides guidance

  15. Data multiplexing in radio interferometric calibration

    Science.gov (United States)

    Yatawatta, Sarod; Diblen, Faruk; Spreeuw, Hanno; Koopmans, L. V. E.

    2018-03-01

    New and upcoming radio interferometers will produce unprecedented amount of data that demand extremely powerful computers for processing. This is a limiting factor due to the large computational power and energy costs involved. Such limitations restrict several key data processing steps in radio interferometry. One such step is calibration where systematic errors in the data are determined and corrected. Accurate calibration is an essential component in reaching many scientific goals in radio astronomy and the use of consensus optimization that exploits the continuity of systematic errors across frequency significantly improves calibration accuracy. In order to reach full consensus, data at all frequencies need to be calibrated simultaneously. In the SKA regime, this can become intractable if the available compute agents do not have the resources to process data from all frequency channels simultaneously. In this paper, we propose a multiplexing scheme that is based on the alternating direction method of multipliers with cyclic updates. With this scheme, it is possible to simultaneously calibrate the full data set using far fewer compute agents than the number of frequencies at which data are available. We give simulation results to show the feasibility of the proposed multiplexing scheme in simultaneously calibrating a full data set when a limited number of compute agents are available.

  16. Radio Observations of Elongated Pulsar Wind Nebulae

    Science.gov (United States)

    Ng, Stephen C.-Y.

    2015-08-01

    The majority of pulsars' rotational energy is carried away by relativistic winds, which are energetic particles accelerated in the magnetosphere. The confinement of the winds by the ambient medium result in synchrotron bubbles with broad-band emission, which are commonly referred to as pulsar wind nebulae (PWNe). Due to long synchrotron cooling time, a radio PWN reflects the integrated history of the system, complementing information obtained from the X-ray and higher energy bands. In addition, radio polarization measurements can offer a powerful probe of the PWN magnetic field structure. Altogether these can reveal the physical conditions and evolutionary history of a system.I report on preliminary results from high-resolution radio observations of PWNe associated with G327.1-1.1, PSRs J1015-5719, B1509-58, and J1549-4848 taken with the Australia Telescope Compact Array (ATCA). Their magnetic field structure and multiwavelength comparison with other observations are discussed.This work is supported by a ECS grant of the Hong Kong Government under HKU 709713P. The Australia Telescope is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO.

  17. At the Dawn of Radio Communications

    Directory of Open Access Journals (Sweden)

    V. P. Samokhin

    2017-01-01

    Full Text Available A brief review of the history of radio communications, which were used before the advent of humanity tubes, in the context of the essays in the series "At the root of media", published in the "History of Technical Progress" section of the supplement to our journal "Science and Education". The review covers the main stages of the development of spark radio-telegraph systems, the creation of the first powerful arc and electric machine generators of non-stopping oscillations of the carrier frequency for radiotelephony and the detection features. The first experiments of Mahlon Loomis, scientific and technical achievements of James Maxwell, Henry Hertz, Eduard Branly, Alexander Popov, Oliver Lodge, Jagadish Bosch, Karl Brown, Lee de Forest, Louis Austin, Herman Simon, William Duddel, Valdemar Paulsen, Ernst Alexander, Valentin Vologdin, Semyon Eisenstein and other creators of the nascent radio engineering. Particular attention is paid to the intersections of their work with the work of Thomas Edison, Nikola Tesla, Guglielmo Marconi, Reginald Fessenden and other heroes of our essays.

  18. JPL Space Telecommunications Radio System Operating Environment

    Science.gov (United States)

    Lux, James P.; Lang, Minh; Peters, Kenneth J.; Taylor, Gregory H.; Duncan, Courtney B.; Orozco, David S.; Stern, Ryan A.; Ahten, Earl R.; Girard, Mike

    2013-01-01

    A flight-qualified implementation of a Software Defined Radio (SDR) Operating Environment for the JPL-SDR built for the CoNNeCT Project has been developed. It is compliant with the NASA Space Telecommunications Radio System (STRS) Architecture Standard, and provides the software infrastructure for STRS compliant waveform applications. This software provides a standards-compliant abstracted view of the JPL-SDR hardware platform. It uses industry standard POSIX interfaces for most functions, as well as exposing the STRS API (Application Programming In terface) required by the standard. This software includes a standardized interface for IP components instantiated within a Xilinx FPGA (Field Programmable Gate Array). The software provides a standardized abstracted interface to platform resources such as data converters, file system, etc., which can be used by STRS standards conformant waveform applications. It provides a generic SDR operating environment with a much smaller resource footprint than similar products such as SCA (Software Communications Architecture) compliant implementations, or the DoD Joint Tactical Radio Systems (JTRS).

  19. Radio Emissions from Magnetopause Reconnection Events

    Science.gov (United States)

    Fung, S. F.; Kunze, J.

    2017-12-01

    A new terrestrial radio emission has recently been identified and attributed to a source connected to the magnetopause magnetic reconnection process [Fung et al., 2013]. Known as the terrestrial myriametric radio burst (TMRB), the new emission was observed by both the IMAGE and Geotail spacecraft during a period of northward interplanetary magnetic field (IMF Bz >0) as a temporal and isolated burst of emission with perhaps well-defined or directed emission cones. Spectral and spin-modulation analyses showed that both the intensity and source direction of the emission are sensitive to the variability of the IMF. The strong control of the emission by the IMF suggests that the emission is connected to the magnetopause reconnection process. A number of potential TMRB events have now been identified by surveying all the dynamic spectrogram data obtained by the IMAGE, Geotail, Cluster, and Wind spacecraft in 5/2000-12/2005. This paper will present our analyses of how the spectral signatures and beaming characteristics of the emissions might depend on the IMF orientations, and thus their likelihood of being TMRBs. Special emphasis will be on events associated with northward and southward IMF in order to determine if TMRBs might be generally produced from magnetopause reconnection processes. Fung, S. F., K. Hashimoto, H. Kojima, S. A. Boardsen, L. N. Garcia, H. Matsumoto, J. L. Green, and B. W. Reinisch (2013), Terrestrial myriametric radio burst observed by IMAGE and Geotail satellites, J. Geophys. Res. Space Physics, 118, doi:10.1002/jgra.50149.

  20. Radio-science performance analysis software

    Science.gov (United States)

    Morabito, D. D.; Asmar, S. W.

    1995-02-01

    The Radio Science Systems Group (RSSG) provides various support functions for several flight project radio-science teams. Among these support functions are uplink and sequence planning, real-time operations monitoring and support, data validation, archiving and distribution functions, and data processing and analysis. This article describes the support functions that encompass radio-science data performance analysis. The primary tool used by the RSSG to fulfill this support function is the STBLTY program set. STBLTY is used to reconstruct observable frequencies and calculate model frequencies, frequency residuals, frequency stability in terms of Allan deviation, reconstructed phase, frequency and phase power spectral density, and frequency drift rates. In the case of one-way data, using an ultrastable oscillator (USO) as a frequency reference, the program set computes the spacecraft transmitted frequency and maintains a database containing the in-flight history of the USO measurements. The program set also produces graphical displays. Some examples and discussions on operating the program set on Galileo and Ulysses data will be presented.