Paul Lansky

The Importance of Being Digital

En la busqueda de aportes al desarrollo sostenible desde la construccion y tomando como referencia la aceptacion y aplicacion practica de los pavimentos con neumaticos reciclados, se realiza una investigacion cuantitativa con el objetivo de establecer las propiedades mecanicas de un concreto a los 28 dias, sustituyendo parcialmente el agregado fino en porcentajes de 5%, 10% y 15% en volumen, por neumatico triturado reciclado sin ningun tratamiento previo. Como aspectos positivos, los resultados muestran una reduccion en el peso unitario y un aumento en la resistencia a la traccion indirecta; sin embargo, se ve afectada la manejabilidad, la resistencia a la compresion, la resistencia a la flexion y se incrementa la absorcion inicial. De igual manera, en del desarrollo de la investigacion, fue analizado visualmente el comportamiento del neumatico dentro de la mezcla, observando una distribucion heterogenea y una adherencia parcial con la matriz.Marine algal seaweed species are often regarded as an underutilized bioresource many have been used as a source of food, industrial raw materials, and in therapeutic and botanical applications for centuries. Seaweeds are best known for the natural polysaccharides. Moreover, seaweed and seaweed-derived products have been widely used as a key ingredient in many pharmaceutical preparations like tablets, as rate retardant in sustained and extended release dosage forms, as stabilizer in liquid orals, cosmetics, implants and as bioplastic in packaging industry. This article provides a comprehensive review of various seaweed species and seaweed products with an emphasis on the use of this renewable bioresource in pharmaceutical industry and medical field.During the Chilean earthquakes of May, 1960, a number of tall, slender structures survived the ground shaking whereas more stable appearing structures were severely damaged. An analysis is made of the rocking motion of structures of inverted pendulum type. It is shown that there is a scale effect which makes tall slender structures more stable against overturning than might have been expected, and, therefore, the survival of such structures during earthquakes is not surprising.La necesidad de preparar al sector de tecnologias de la informacion y las comunicaciones de Colombia para hacer frente a los desafios que trae consigo el desarrollo de la convergencia tecnologica, institucional y de mercados, implicaba plantear un nuevo equilibrio entre la promocion del desarrollo competitivo del sector y el cumplimiento de los fines sociales de mayor cobertura y acceso de los ciudadanos, empresas e instituciones publicas a las TIC, derivados de la naturaleza de servicio publico que ostentan las telecomunicaciones. En consecuencia, el Gobierno colombiano trabajo desde mediados de 2006, con una permanente retroalimentacion intragubernamental y sectorial, en una revision del marco normativo del sector de comunicaciones con el fin de actualizarlo a la dinamica institucional y de mercado, prepararlo para anticipar los rapidos cambios tecnologicos y fortalecer el enfoque de la politica publica orientada a promover la masificacion de las TIC en todos los ambitos sociales, geograficos y economicos.De destacar como avances importantes de este nuevo marco legislativo esta contar con la Habilitacion General para que los proveedores de redes y servicios de telecomunicaciones puedan operar; la unificacion de la contraprestacion periodica a favor del Fondo de Tecnologias de la Informacion y las Comunicaciones; la introduccion del principio de Neutralidad Tecnologica mediante el cual el Estado garantiza la libre adopcion de tecnologias en la provision de redes y servicios; la creacion de la Agencia Nacional del Espectro como ente tecnico especializado; el fortalecimiento y claridad de la capacidad de intervencion del Estado en el sector; la precision del alcance del regimen de proteccion a los usuarios de los servicios de comunicaciones; la unificacion y actualizacion de las normas de radiodifusion sonora; y, la eliminacion del caracter domiciliario de los servicios publicos de comunicaciones.

Fanfares for the Common Tone

It is an intriguing aspect of music that as musical ideas become familiar and even self-evident, they can become more interesting and suggestive. Perhaps this is because we tend to value and use ideas for their ability to expand our sense of music rather than merely to explain and satisfy, and in doing so we consequently invest such ideas with even greater richness and musical palpability. What musical familiarity breeds can, in fact, be extremel fascinating. Consider, for example, Milton Babbitts theorem of pitch-class invariance under transposition:

EIN: A Signal Processing Scratchpad

Computer systems designed for music synthesis usually encapsulate signal-processing algorithms as macros or functions, and thus provide a modular interface which facilitates the development of complex structures. This is the thinking behind Mathews’ original concept of the ‘‘unit generator’’ (Mathews 1969) and most subsequent software synthesis languages use this approach. While it has proven to be an effective method it has not generally provided a means by which the users of these systems, often more musically prepared than wise in the ways of digital signal processing, can gain an intuitive understanding of the mechanisms used to modify and create digital signals. Indeed, there is little conceptual difference between patching a signal through a bank of two-pole resonating filters/unit generators and tweaking the sliders on a graphic equalizer. EIN is an attempt to provide an interface in which the user has direct control over every add, multiply and store applied to each sample, and can gain a more direct understanding of the machinery of digital signal processing. While its main use has been instructional, it also provides a way to experiment with digital filters and design more complex instruments and algorithms. It is, in effect, a kind of low-level circuit design kit for signal processing. EIN Syntax EIN provides the routine machinery for calling the user’s code, executing it, writing the resulting output sound samples to a file, playing the file, and displaying and analyzing it in the time and frequency domains. The user provides a script in a language that is a superset of C. The EIN system then compiles it and provides a wrapper that calls the script for each time sample from t = 0 up to the specifiednumber of samples, nsamps; computes the next output sample y (for the mono case), or the variables left and right (for the stereo case); and writes the output samples to an output sound file,formated for the sampling rate of sr samples/sec. The int variables t and nsamps, and the float variables y, left, right, and sr, are reserved by EIN, and should not be used for other purposes. The mono/stereo option, and the values of sr and nsamps are selected with radio buttons on the interface. The remaining reserved names are described in Appendix 3. As an example, here is a one-line EIN script that produces a sine wave at 440 Hz:

The Music of Claudio Spies

Claudio Spies was born in Chile in 1925; he has lived in the United States since 1942 and became an American citizen in 1966. Raised by parents of German-Jewish origin he speaks fluent English, Spanish, German, Italian and French, and has made great compositional use of these linguistic skills. He has set texts in all these languages but French, and has also set texts in Latin. Half of his output, in fact, consists of vocal music, and is marked by careful attention to prosody and the characteristic rhythms and syntax of the language being set.