<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>0035-001X</journal-id>
<journal-title><![CDATA[Revista mexicana de física]]></journal-title>
<abbrev-journal-title><![CDATA[Rev. mex. fis.]]></abbrev-journal-title>
<issn>0035-001X</issn>
<publisher>
<publisher-name><![CDATA[Sociedad Mexicana de Física]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0035-001X2006000400010</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Método para la medición de frecuencia usando aproximaciones racionales]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Hernández-Balbuena]]></surname>
<given-names><![CDATA[D.]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Tyrsa]]></surname>
<given-names><![CDATA[V.E.]]></given-names>
</name>
<xref ref-type="aff" rid="A02"/>
</contrib>
</contrib-group>
<aff id="A01">
<institution><![CDATA[,Universidad Autónoma de Baja California Facultad de Ingeniería ]]></institution>
<addr-line><![CDATA[Baja California Mexicali]]></addr-line>
</aff>
<aff id="A02">
<institution><![CDATA[,Universidad Autónoma de Baja California Instituto de Ingeniería ]]></institution>
<addr-line><![CDATA[Baja California Mexicali]]></addr-line>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>08</month>
<year>2006</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>08</month>
<year>2006</year>
</pub-date>
<volume>52</volume>
<numero>4</numero>
<fpage>359</fpage>
<lpage>364</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_arttext&amp;pid=S0035-001X2006000400010&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_abstract&amp;pid=S0035-001X2006000400010&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_pdf&amp;pid=S0035-001X2006000400010&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[Se presenta un método alternativo para la medición de frecuencia de osciladores altamente estables basado en la comparación directa de frecuencias, el uso de aproximaciones racionales y la propiedad arquimediana de los numeros reales. Este método permite, en corto tiempo, obtener niveles de incertidumbre de medición comparables en magnitud a la incertidumbre de frecuencia de un oscilador atómico. Se presentan resultados de simulaciones basadas en el modelo matemático del método propuesto.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[An alternative method for frequency measurement of highly stable oscillators based on the direct comparison of frequencies, the use of rational approximation, and the Archimedean property of the real numbers is presented. This method allows figure out a level of measurement uncertainty comparable in magnitude to the frequency uncertainty of an atomic oscillator in a very short amount of time. Simulation results based on the mathematical model of the proposed method are presented.]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[Medición de frecuencia]]></kwd>
<kwd lng="es"><![CDATA[aproximaciones racionales]]></kwd>
<kwd lng="es"><![CDATA[propiedad arquimediana de los reales]]></kwd>
<kwd lng="en"><![CDATA[Frequency measurement]]></kwd>
<kwd lng="en"><![CDATA[rational approximations]]></kwd>
<kwd lng="en"><![CDATA[archimedean property of the real numbers]]></kwd>
</kwd-group>
</article-meta>
</front><body><![CDATA[ <p align="justify"><font face="verdana" size="4">Investigaci&oacute;n</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="center"><font face="verdana" size="4"><b>M&eacute;todo para la medici&oacute;n de frecuencia usando aproximaciones racionales</b></font></p>     <p align="center"><font face="verdana" size="2">&nbsp;</font></p>     <p align="center"><font face="verdana" size="2"><b>D. Hern&aacute;ndez&#150;Balbuena*, V.E. Tyrsa**</b></font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><i>* Facultad de Ingenier&iacute;a, Universidad Aut&oacute;noma de Baja California, Blvd. Benito Juarez s/n, 21280, Mexicali, Baja California, e&#150;mail: <a href="mailto:dhernan@uabc.mx">dhernan@uabc.mx</a></i></font></p>     <p align="justify"><font face="verdana" size="2"><i>** Instituto de Ingenier&iacute;a, Universidad Aut&oacute;noma de Baja California, Blvd. Benito Juarez s/n, 21280, Mexicali, Baja California, e&#150;mail: <a href="mailto:v_tyrsa@iing.mxl.uabc.mx">v_tyrsa@iing.mxl.uabc.mx</a></i></font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2">Recibido el 11 de mayo de 2006    ]]></body>
<body><![CDATA[<br> Aceptado el 30 de junio de 2006</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><b>Resumen</b></font></p>     <p align="justify"><font face="verdana" size="2">Se presenta un m&eacute;todo alternativo para la medici&oacute;n de frecuencia de osciladores altamente estables basado en la comparaci&oacute;n directa de frecuencias, el uso de aproximaciones racionales y la propiedad arquimediana de los numeros reales. Este m&eacute;todo permite, en corto tiempo, obtener niveles de incertidumbre de medici&oacute;n comparables en magnitud a la incertidumbre de frecuencia de un oscilador at&oacute;mico. Se presentan resultados de simulaciones basadas en el modelo matem&aacute;tico del m&eacute;todo propuesto.</font></p>     <p align="justify"><font face="verdana" size="2"><b>Descriptores: </b>Medici&oacute;n de frecuencia; aproximaciones racionales; propiedad arquimediana de los reales.</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><b>Abstract</b></font></p>     <p align="justify"><font face="verdana" size="2">An alternative method for frequency measurement of highly stable oscillators based on the direct comparison of frequencies, the use of rational approximation, and the Archimedean property of the real numbers is presented. This method allows figure out a level of measurement uncertainty comparable in magnitude to the frequency uncertainty of an atomic oscillator in a very short amount of time. Simulation results based on the mathematical model of the proposed method are presented.</font></p>     <p align="justify"><font face="verdana" size="2"><b>Keywords: </b>Frequency measurement; rational approximations; archimedean property of the real numbers.</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     ]]></body>
<body><![CDATA[<p align="justify"><font face="verdana" size="2">PACS: 06.30.Ft; 06.20&#150;f</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><a href="/pdf/rmf/v52n4/v52n4a10.pdf" target="_blank">DESCARGAR ART&Iacute;CULO EN FORMATO PDF</a></font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><b>Referencias</b></font></p>     <!-- ref --><p align="justify"><font face="verdana" size="2">1. M.A.  Lombardi, <i>The Mecatronics Handbook, </i>(2001) CRC Press LCC.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8318949&pid=S0035-001X200600040001000001&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">2. J.C. Berquist, S.R. Jefferts, D. <i>J. Phys. Today, </i>(2001) 37.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8318950&pid=S0035-001X200600040001000002&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">3. Quartzlock, Frequency, Phase &amp; Phase Noise Measurement System, A7&#150;A&amp; A7&#150;MX Datasheet.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8318951&pid=S0035-001X200600040001000003&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">4. Agilent Technologies, Undertanding Frequency Counter Specificationes, Applications, Note 200&#150;4.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8318952&pid=S0035-001X200600040001000004&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">5. V.E. Tyrsa, <i>Meas. Techs. </i>(Izmer. Tekh. in Russian) <b>18</b> (1975) 357.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8318953&pid=S0035-001X200600040001000005&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">6. V.E. Tyrsa y V.V. Dyunyashev, <i>Meas. Techs. </i>(Izmer. Tekh. in Russian) <b>24</b> (1981). 308.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8318954&pid=S0035-001X200600040001000006&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">7. W. J. Le Veque, <i>Teor&iacute;a elemental de los n&uacute;meros, </i>Centro de Regional de Ayuda Tecnica. Agencia Para el Desarrollo Internacional (Mexico, 1968).</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8318955&pid=S0035-001X200600040001000007&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --> ]]></body><back>
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</article>
